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gerrit-public.fairphone.software / platform / art / 18c12bb637d67f17abf6dc1e345a2ac7482cd057 / . / runtime / class_linker.cc
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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "class_linker.h"
#include <algorithm>
#include <deque>
#include <iostream>
#include <memory>
#include <queue>
#include <string>
#include <tuple>
#include <unistd.h>
#include <unordered_map>
#include <utility>
#include <vector>
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/arena_allocator.h"
#include "base/casts.h"
#include "base/logging.h"
#include "base/scoped_arena_containers.h"
#include "base/scoped_flock.h"
#include "base/stl_util.h"
#include "base/time_utils.h"
#include "base/unix_file/fd_file.h"
#include "base/value_object.h"
#include "class_linker-inl.h"
#include "class_table-inl.h"
#include "compiler_callbacks.h"
#include "debugger.h"
#include "dex_file-inl.h"
#include "entrypoints/entrypoint_utils.h"
#include "entrypoints/runtime_asm_entrypoints.h"
#include "gc_root-inl.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/accounting/heap_bitmap.h"
#include "gc/heap.h"
#include "gc/space/image_space.h"
#include "handle_scope-inl.h"
#include "intern_table.h"
#include "interpreter/interpreter.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "leb128.h"
#include "linear_alloc.h"
#include "mirror/class.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/field.h"
#include "mirror/iftable-inl.h"
#include "mirror/method.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/proxy.h"
#include "mirror/reference-inl.h"
#include "mirror/stack_trace_element.h"
#include "mirror/string-inl.h"
#include "native/dalvik_system_DexFile.h"
#include "oat.h"
#include "oat_file.h"
#include "oat_file-inl.h"
#include "oat_file_assistant.h"
#include "oat_file_manager.h"
#include "object_lock.h"
#include "os.h"
#include "runtime.h"
#include "ScopedLocalRef.h"
#include "scoped_thread_state_change.h"
#include "thread-inl.h"
#include "trace.h"
#include "utils.h"
#include "utils/dex_cache_arrays_layout-inl.h"
#include "verifier/method_verifier.h"
#include "well_known_classes.h"
namespace art {
static constexpr bool kSanityCheckObjects = kIsDebugBuild;
static void ThrowNoClassDefFoundError(const char* fmt, ...)
__attribute__((__format__(__printf__, 1, 2)))
SHARED_REQUIRES(Locks::mutator_lock_);
static void ThrowNoClassDefFoundError(const char* fmt, ...) {
va_list args;
va_start(args, fmt);
Thread* self = Thread::Current();
self->ThrowNewExceptionV("Ljava/lang/NoClassDefFoundError;", fmt, args);
va_end(args);
}
static bool HasInitWithString(Thread* self, ClassLinker* class_linker, const char* descriptor)
SHARED_REQUIRES(Locks::mutator_lock_) {
ArtMethod* method = self->GetCurrentMethod(nullptr);
StackHandleScope<1> hs(self);
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(method != nullptr ?
method->GetDeclaringClass()->GetClassLoader() : nullptr));
mirror::Class* exception_class = class_linker->FindClass(self, descriptor, class_loader);
if (exception_class == nullptr) {
// No exc class ~ no <init>-with-string.
CHECK(self->IsExceptionPending());
self->ClearException();
return false;
}
ArtMethod* exception_init_method = exception_class->FindDeclaredDirectMethod(
"<init>", "(Ljava/lang/String;)V", class_linker->GetImagePointerSize());
return exception_init_method != nullptr;
}
// Helper for ThrowEarlierClassFailure. Throws the stored error.
static void HandleEarlierVerifyError(Thread* self, ClassLinker* class_linker, mirror::Class* c)
SHARED_REQUIRES(Locks::mutator_lock_) {
mirror::Object* obj = c->GetVerifyError();
DCHECK(obj != nullptr);
self->AssertNoPendingException();
if (obj->IsClass()) {
// Previous error has been stored as class. Create a new exception of that type.
// It's possible the exception doesn't have a <init>(String).
std::string temp;
const char* descriptor = obj->AsClass()->GetDescriptor(&temp);
if (HasInitWithString(self, class_linker, descriptor)) {
self->ThrowNewException(descriptor, PrettyDescriptor(c).c_str());
} else {
self->ThrowNewException(descriptor, nullptr);
}
} else {
// Previous error has been stored as an instance. Just rethrow.
mirror::Class* throwable_class =
self->DecodeJObject(WellKnownClasses::java_lang_Throwable)->AsClass();
mirror::Class* error_class = obj->GetClass();
CHECK(throwable_class->IsAssignableFrom(error_class));
self->SetException(obj->AsThrowable());
}
self->AssertPendingException();
}
void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c, bool wrap_in_no_class_def) {
// The class failed to initialize on a previous attempt, so we want to throw
// a NoClassDefFoundError (v2 2.17.5). The exception to this rule is if we
// failed in verification, in which case v2 5.4.1 says we need to re-throw
// the previous error.
Runtime* const runtime = Runtime::Current();
if (!runtime->IsAotCompiler()) { // Give info if this occurs at runtime.
std::string extra;
if (c->GetVerifyError() != nullptr) {
mirror::Class* descr_from = c->GetVerifyError()->IsClass()
? c->GetVerifyError()->AsClass()
: c->GetVerifyError()->GetClass();
extra = PrettyDescriptor(descr_from);
}
LOG(INFO) << "Rejecting re-init on previously-failed class " << PrettyClass(c) << ": " << extra;
}
CHECK(c->IsErroneous()) << PrettyClass(c) << " " << c->GetStatus();
Thread* self = Thread::Current();
if (runtime->IsAotCompiler()) {
// At compile time, accurate errors and NCDFE are disabled to speed compilation.
mirror::Throwable* pre_allocated = runtime->GetPreAllocatedNoClassDefFoundError();
self->SetException(pre_allocated);
} else {
if (c->GetVerifyError() != nullptr) {
// Rethrow stored error.
HandleEarlierVerifyError(self, this, c);
}
if (c->GetVerifyError() == nullptr || wrap_in_no_class_def) {
// If there isn't a recorded earlier error, or this is a repeat throw from initialization,
// the top-level exception must be a NoClassDefFoundError. The potentially already pending
// exception will be a cause.
self->ThrowNewWrappedException("Ljava/lang/NoClassDefFoundError;",
PrettyDescriptor(c).c_str());
}
}
}
static void VlogClassInitializationFailure(Handle<mirror::Class> klass)
SHARED_REQUIRES(Locks::mutator_lock_) {
if (VLOG_IS_ON(class_linker)) {
std::string temp;
LOG(INFO) << "Failed to initialize class " << klass->GetDescriptor(&temp) << " from "
<< klass->GetLocation() << "\n" << Thread::Current()->GetException()->Dump();
}
}
static void WrapExceptionInInitializer(Handle<mirror::Class> klass)
SHARED_REQUIRES(Locks::mutator_lock_) {
Thread* self = Thread::Current();
JNIEnv* env = self->GetJniEnv();
ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred());
CHECK(cause.get() != nullptr);
env->ExceptionClear();
bool is_error = env->IsInstanceOf(cause.get(), WellKnownClasses::java_lang_Error);
env->Throw(cause.get());
// We only wrap non-Error exceptions; an Error can just be used as-is.
if (!is_error) {
self->ThrowNewWrappedException("Ljava/lang/ExceptionInInitializerError;", nullptr);
}
VlogClassInitializationFailure(klass);
}
// Gap between two fields in object layout.
struct FieldGap {
uint32_t start_offset; // The offset from the start of the object.
uint32_t size; // The gap size of 1, 2, or 4 bytes.
};
struct FieldGapsComparator {
explicit FieldGapsComparator() {
}
bool operator() (const FieldGap& lhs, const FieldGap& rhs)
NO_THREAD_SAFETY_ANALYSIS {
// Sort by gap size, largest first. Secondary sort by starting offset.
// Note that the priority queue returns the largest element, so operator()
// should return true if lhs is less than rhs.
return lhs.size < rhs.size || (lhs.size == rhs.size && lhs.start_offset > rhs.start_offset);
}
};
typedef std::priority_queue<FieldGap, std::vector<FieldGap>, FieldGapsComparator> FieldGaps;
// Adds largest aligned gaps to queue of gaps.
static void AddFieldGap(uint32_t gap_start, uint32_t gap_end, FieldGaps* gaps) {
DCHECK(gaps != nullptr);
uint32_t current_offset = gap_start;
while (current_offset != gap_end) {
size_t remaining = gap_end - current_offset;
if (remaining >= sizeof(uint32_t) && IsAligned<4>(current_offset)) {
gaps->push(FieldGap {current_offset, sizeof(uint32_t)});
current_offset += sizeof(uint32_t);
} else if (remaining >= sizeof(uint16_t) && IsAligned<2>(current_offset)) {
gaps->push(FieldGap {current_offset, sizeof(uint16_t)});
current_offset += sizeof(uint16_t);
} else {
gaps->push(FieldGap {current_offset, sizeof(uint8_t)});
current_offset += sizeof(uint8_t);
}
DCHECK_LE(current_offset, gap_end) << "Overran gap";
}
}
// Shuffle fields forward, making use of gaps whenever possible.
template<int n>
static void ShuffleForward(size_t* current_field_idx,
MemberOffset* field_offset,
std::deque<ArtField*>* grouped_and_sorted_fields,
FieldGaps* gaps)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(current_field_idx != nullptr);
DCHECK(grouped_and_sorted_fields != nullptr);
DCHECK(gaps != nullptr);
DCHECK(field_offset != nullptr);
DCHECK(IsPowerOfTwo(n));
while (!grouped_and_sorted_fields->empty()) {
ArtField* field = grouped_and_sorted_fields->front();
Primitive::Type type = field->GetTypeAsPrimitiveType();
if (Primitive::ComponentSize(type) < n) {
break;
}
if (!IsAligned<n>(field_offset->Uint32Value())) {
MemberOffset old_offset = *field_offset;
*field_offset = MemberOffset(RoundUp(field_offset->Uint32Value(), n));
AddFieldGap(old_offset.Uint32Value(), field_offset->Uint32Value(), gaps);
}
CHECK(type != Primitive::kPrimNot) << PrettyField(field); // should be primitive types
grouped_and_sorted_fields->pop_front();
if (!gaps->empty() && gaps->top().size >= n) {
FieldGap gap = gaps->top();
gaps->pop();
DCHECK_ALIGNED(gap.start_offset, n);
field->SetOffset(MemberOffset(gap.start_offset));
if (gap.size > n) {
AddFieldGap(gap.start_offset + n, gap.start_offset + gap.size, gaps);
}
} else {
DCHECK_ALIGNED(field_offset->Uint32Value(), n);
field->SetOffset(*field_offset);
*field_offset = MemberOffset(field_offset->Uint32Value() + n);
}
++(*current_field_idx);
}
}
ClassLinker::ClassLinker(InternTable* intern_table)
// dex_lock_ is recursive as it may be used in stack dumping.
: dex_lock_("ClassLinker dex lock", kDefaultMutexLevel),
dex_cache_boot_image_class_lookup_required_(false),
failed_dex_cache_class_lookups_(0),
class_roots_(nullptr),
array_iftable_(nullptr),
find_array_class_cache_next_victim_(0),
init_done_(false),
log_new_class_table_roots_(false),
intern_table_(intern_table),
quick_resolution_trampoline_(nullptr),
quick_imt_conflict_trampoline_(nullptr),
quick_generic_jni_trampoline_(nullptr),
quick_to_interpreter_bridge_trampoline_(nullptr),
image_pointer_size_(sizeof(void*)) {
CHECK(intern_table_ != nullptr);
static_assert(kFindArrayCacheSize == arraysize(find_array_class_cache_),
"Array cache size wrong.");
std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr));
}
bool ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path,
std::string* error_msg) {
VLOG(startup) << "ClassLinker::Init";
Thread* const self = Thread::Current();
Runtime* const runtime = Runtime::Current();
gc::Heap* const heap = runtime->GetHeap();
CHECK(!heap->HasImageSpace()) << "Runtime has image. We should use it.";
CHECK(!init_done_);
// Use the pointer size from the runtime since we are probably creating the image.
image_pointer_size_ = InstructionSetPointerSize(runtime->GetInstructionSet());
// java_lang_Class comes first, it's needed for AllocClass
// The GC can't handle an object with a null class since we can't get the size of this object.
heap->IncrementDisableMovingGC(self);
StackHandleScope<64> hs(self); // 64 is picked arbitrarily.
auto class_class_size = mirror::Class::ClassClassSize(image_pointer_size_);
Handle<mirror::Class> java_lang_Class(hs.NewHandle(down_cast<mirror::Class*>(
heap->AllocNonMovableObject<true>(self, nullptr, class_class_size, VoidFunctor()))));
CHECK(java_lang_Class.Get() != nullptr);
mirror::Class::SetClassClass(java_lang_Class.Get());
java_lang_Class->SetClass(java_lang_Class.Get());
if (kUseBakerOrBrooksReadBarrier) {
java_lang_Class->AssertReadBarrierPointer();
}
java_lang_Class->SetClassSize(class_class_size);
java_lang_Class->SetPrimitiveType(Primitive::kPrimNot);
heap->DecrementDisableMovingGC(self);
// AllocClass(mirror::Class*) can now be used
// Class[] is used for reflection support.
auto class_array_class_size = mirror::ObjectArray<mirror::Class>::ClassSize(image_pointer_size_);
Handle<mirror::Class> class_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), class_array_class_size)));
class_array_class->SetComponentType(java_lang_Class.Get());
// java_lang_Object comes next so that object_array_class can be created.
Handle<mirror::Class> java_lang_Object(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::Object::ClassSize(image_pointer_size_))));
CHECK(java_lang_Object.Get() != nullptr);
// backfill Object as the super class of Class.
java_lang_Class->SetSuperClass(java_lang_Object.Get());
mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self);
java_lang_Object->SetObjectSize(sizeof(mirror::Object));
// Allocate in non-movable so that it's possible to check if a JNI weak global ref has been
// cleared without triggering the read barrier and unintentionally mark the sentinel alive.
runtime->SetSentinel(heap->AllocNonMovableObject<true>(self,
java_lang_Object.Get(),
java_lang_Object->GetObjectSize(),
VoidFunctor()));
// Object[] next to hold class roots.
Handle<mirror::Class> object_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(),
mirror::ObjectArray<mirror::Object>::ClassSize(image_pointer_size_))));
object_array_class->SetComponentType(java_lang_Object.Get());
// Setup the char (primitive) class to be used for char[].
Handle<mirror::Class> char_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(),
mirror::Class::PrimitiveClassSize(image_pointer_size_))));
// The primitive char class won't be initialized by
// InitializePrimitiveClass until line 459, but strings (and
// internal char arrays) will be allocated before that and the
// component size, which is computed from the primitive type, needs
// to be set here.
char_class->SetPrimitiveType(Primitive::kPrimChar);
// Setup the char[] class to be used for String.
Handle<mirror::Class> char_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
char_array_class->SetComponentType(char_class.Get());
mirror::CharArray::SetArrayClass(char_array_class.Get());
// Setup String.
Handle<mirror::Class> java_lang_String(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::String::ClassSize(image_pointer_size_))));
java_lang_String->SetStringClass();
mirror::String::SetClass(java_lang_String.Get());
mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusResolved, self);
// Setup java.lang.ref.Reference.
Handle<mirror::Class> java_lang_ref_Reference(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::Reference::ClassSize(image_pointer_size_))));
mirror::Reference::SetClass(java_lang_ref_Reference.Get());
java_lang_ref_Reference->SetObjectSize(mirror::Reference::InstanceSize());
mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusResolved, self);
// Create storage for root classes, save away our work so far (requires descriptors).
class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(
mirror::ObjectArray<mirror::Class>::Alloc(self, object_array_class.Get(),
kClassRootsMax));
CHECK(!class_roots_.IsNull());
SetClassRoot(kJavaLangClass, java_lang_Class.Get());
SetClassRoot(kJavaLangObject, java_lang_Object.Get());
SetClassRoot(kClassArrayClass, class_array_class.Get());
SetClassRoot(kObjectArrayClass, object_array_class.Get());
SetClassRoot(kCharArrayClass, char_array_class.Get());
SetClassRoot(kJavaLangString, java_lang_String.Get());
SetClassRoot(kJavaLangRefReference, java_lang_ref_Reference.Get());
// Setup the primitive type classes.
SetClassRoot(kPrimitiveBoolean, CreatePrimitiveClass(self, Primitive::kPrimBoolean));
SetClassRoot(kPrimitiveByte, CreatePrimitiveClass(self, Primitive::kPrimByte));
SetClassRoot(kPrimitiveShort, CreatePrimitiveClass(self, Primitive::kPrimShort));
SetClassRoot(kPrimitiveInt, CreatePrimitiveClass(self, Primitive::kPrimInt));
SetClassRoot(kPrimitiveLong, CreatePrimitiveClass(self, Primitive::kPrimLong));
SetClassRoot(kPrimitiveFloat, CreatePrimitiveClass(self, Primitive::kPrimFloat));
SetClassRoot(kPrimitiveDouble, CreatePrimitiveClass(self, Primitive::kPrimDouble));
SetClassRoot(kPrimitiveVoid, CreatePrimitiveClass(self, Primitive::kPrimVoid));
// Create array interface entries to populate once we can load system classes.
array_iftable_ = GcRoot<mirror::IfTable>(AllocIfTable(self, 2));
// Create int array type for AllocDexCache (done in AppendToBootClassPath).
Handle<mirror::Class> int_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
int_array_class->SetComponentType(GetClassRoot(kPrimitiveInt));
mirror::IntArray::SetArrayClass(int_array_class.Get());
SetClassRoot(kIntArrayClass, int_array_class.Get());
// Create long array type for AllocDexCache (done in AppendToBootClassPath).
Handle<mirror::Class> long_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
long_array_class->SetComponentType(GetClassRoot(kPrimitiveLong));
mirror::LongArray::SetArrayClass(long_array_class.Get());
SetClassRoot(kLongArrayClass, long_array_class.Get());
// now that these are registered, we can use AllocClass() and AllocObjectArray
// Set up DexCache. This cannot be done later since AppendToBootClassPath calls AllocDexCache.
Handle<mirror::Class> java_lang_DexCache(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::DexCache::ClassSize(image_pointer_size_))));
SetClassRoot(kJavaLangDexCache, java_lang_DexCache.Get());
java_lang_DexCache->SetDexCacheClass();
java_lang_DexCache->SetObjectSize(mirror::DexCache::InstanceSize());
mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusResolved, self);
// Set up array classes for string, field, method
Handle<mirror::Class> object_array_string(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(),
mirror::ObjectArray<mirror::String>::ClassSize(image_pointer_size_))));
object_array_string->SetComponentType(java_lang_String.Get());
SetClassRoot(kJavaLangStringArrayClass, object_array_string.Get());
// Create runtime resolution and imt conflict methods.
runtime->SetResolutionMethod(runtime->CreateResolutionMethod());
runtime->SetImtConflictMethod(runtime->CreateImtConflictMethod());
runtime->SetImtUnimplementedMethod(runtime->CreateImtConflictMethod());
// Setup boot_class_path_ and register class_path now that we can use AllocObjectArray to create
// DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses
// these roots.
if (boot_class_path.empty()) {
*error_msg = "Boot classpath is empty.";
return false;
}
for (auto& dex_file : boot_class_path) {
if (dex_file.get() == nullptr) {
*error_msg = "Null dex file.";
return false;
}
AppendToBootClassPath(self, *dex_file);
opened_dex_files_.push_back(std::move(dex_file));
}
// now we can use FindSystemClass
// run char class through InitializePrimitiveClass to finish init
InitializePrimitiveClass(char_class.Get(), Primitive::kPrimChar);
SetClassRoot(kPrimitiveChar, char_class.Get()); // needs descriptor
// Set up GenericJNI entrypoint. That is mainly a hack for common_compiler_test.h so that
// we do not need friend classes or a publicly exposed setter.
quick_generic_jni_trampoline_ = GetQuickGenericJniStub();
if (!runtime->IsAotCompiler()) {
// We need to set up the generic trampolines since we don't have an image.
quick_resolution_trampoline_ = GetQuickResolutionStub();
quick_imt_conflict_trampoline_ = GetQuickImtConflictStub();
quick_to_interpreter_bridge_trampoline_ = GetQuickToInterpreterBridge();
}
// Object, String and DexCache need to be rerun through FindSystemClass to finish init
mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusNotReady, self);
CHECK_EQ(java_lang_Object.Get(), FindSystemClass(self, "Ljava/lang/Object;"));
CHECK_EQ(java_lang_Object->GetObjectSize(), mirror::Object::InstanceSize());
mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusNotReady, self);
mirror::Class* String_class = FindSystemClass(self, "Ljava/lang/String;");
if (java_lang_String.Get() != String_class) {
std::ostringstream os1, os2;
java_lang_String->DumpClass(os1, mirror::Class::kDumpClassFullDetail);
String_class->DumpClass(os2, mirror::Class::kDumpClassFullDetail);
LOG(FATAL) << os1.str() << "\n\n" << os2.str();
}
mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusNotReady, self);
CHECK_EQ(java_lang_DexCache.Get(), FindSystemClass(self, "Ljava/lang/DexCache;"));
CHECK_EQ(java_lang_DexCache->GetObjectSize(), mirror::DexCache::InstanceSize());
// Setup the primitive array type classes - can't be done until Object has a vtable.
SetClassRoot(kBooleanArrayClass, FindSystemClass(self, "[Z"));
mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass));
SetClassRoot(kByteArrayClass, FindSystemClass(self, "[B"));
mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass));
CHECK_EQ(char_array_class.Get(), FindSystemClass(self, "[C"));
SetClassRoot(kShortArrayClass, FindSystemClass(self, "[S"));
mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass));
CHECK_EQ(int_array_class.Get(), FindSystemClass(self, "[I"));
CHECK_EQ(long_array_class.Get(), FindSystemClass(self, "[J"));
SetClassRoot(kFloatArrayClass, FindSystemClass(self, "[F"));
mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass));
SetClassRoot(kDoubleArrayClass, FindSystemClass(self, "[D"));
mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass));
CHECK_EQ(class_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Class;"));
CHECK_EQ(object_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Object;"));
// Setup the single, global copy of "iftable".
auto java_lang_Cloneable = hs.NewHandle(FindSystemClass(self, "Ljava/lang/Cloneable;"));
CHECK(java_lang_Cloneable.Get() != nullptr);
auto java_io_Serializable = hs.NewHandle(FindSystemClass(self, "Ljava/io/Serializable;"));
CHECK(java_io_Serializable.Get() != nullptr);
// We assume that Cloneable/Serializable don't have superinterfaces -- normally we'd have to
// crawl up and explicitly list all of the supers as well.
array_iftable_.Read()->SetInterface(0, java_lang_Cloneable.Get());
array_iftable_.Read()->SetInterface(1, java_io_Serializable.Get());
// Sanity check Class[] and Object[]'s interfaces. GetDirectInterface may cause thread
// suspension.
CHECK_EQ(java_lang_Cloneable.Get(),
mirror::Class::GetDirectInterface(self, class_array_class, 0));
CHECK_EQ(java_io_Serializable.Get(),
mirror::Class::GetDirectInterface(self, class_array_class, 1));
CHECK_EQ(java_lang_Cloneable.Get(),
mirror::Class::GetDirectInterface(self, object_array_class, 0));
CHECK_EQ(java_io_Serializable.Get(),
mirror::Class::GetDirectInterface(self, object_array_class, 1));
// Run Class, ArtField, and ArtMethod through FindSystemClass. This initializes their
// dex_cache_ fields and register them in class_table_.
CHECK_EQ(java_lang_Class.Get(), FindSystemClass(self, "Ljava/lang/Class;"));
CHECK_EQ(object_array_string.Get(),
FindSystemClass(self, GetClassRootDescriptor(kJavaLangStringArrayClass)));
// End of special init trickery, subsequent classes may be loaded via FindSystemClass.
// Create java.lang.reflect.Proxy root.
SetClassRoot(kJavaLangReflectProxy, FindSystemClass(self, "Ljava/lang/reflect/Proxy;"));
// Create java.lang.reflect.Field.class root.
auto* class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectField, class_root);
mirror::Field::SetClass(class_root);
// Create java.lang.reflect.Field array root.
class_root = FindSystemClass(self, "[Ljava/lang/reflect/Field;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectFieldArrayClass, class_root);
mirror::Field::SetArrayClass(class_root);
// Create java.lang.reflect.Constructor.class root and array root.
class_root = FindSystemClass(self, "Ljava/lang/reflect/Constructor;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectConstructor, class_root);
mirror::Constructor::SetClass(class_root);
class_root = FindSystemClass(self, "[Ljava/lang/reflect/Constructor;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectConstructorArrayClass, class_root);
mirror::Constructor::SetArrayClass(class_root);
// Create java.lang.reflect.Method.class root and array root.
class_root = FindSystemClass(self, "Ljava/lang/reflect/Method;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectMethod, class_root);
mirror::Method::SetClass(class_root);
class_root = FindSystemClass(self, "[Ljava/lang/reflect/Method;");
CHECK(class_root != nullptr);
SetClassRoot(kJavaLangReflectMethodArrayClass, class_root);
mirror::Method::SetArrayClass(class_root);
// java.lang.ref classes need to be specially flagged, but otherwise are normal classes
// finish initializing Reference class
mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusNotReady, self);
CHECK_EQ(java_lang_ref_Reference.Get(), FindSystemClass(self, "Ljava/lang/ref/Reference;"));
CHECK_EQ(java_lang_ref_Reference->GetObjectSize(), mirror::Reference::InstanceSize());
CHECK_EQ(java_lang_ref_Reference->GetClassSize(),
mirror::Reference::ClassSize(image_pointer_size_));
class_root = FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;");
CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal);
class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagFinalizerReference);
class_root = FindSystemClass(self, "Ljava/lang/ref/PhantomReference;");
CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal);
class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagPhantomReference);
class_root = FindSystemClass(self, "Ljava/lang/ref/SoftReference;");
CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal);
class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagSoftReference);
class_root = FindSystemClass(self, "Ljava/lang/ref/WeakReference;");
CHECK_EQ(class_root->GetClassFlags(), mirror::kClassFlagNormal);
class_root->SetClassFlags(class_root->GetClassFlags() | mirror::kClassFlagWeakReference);
// Setup the ClassLoader, verifying the object_size_.
class_root = FindSystemClass(self, "Ljava/lang/ClassLoader;");
class_root->SetClassLoaderClass();
CHECK_EQ(class_root->GetObjectSize(), mirror::ClassLoader::InstanceSize());
SetClassRoot(kJavaLangClassLoader, class_root);
// Set up java.lang.Throwable, java.lang.ClassNotFoundException, and
// java.lang.StackTraceElement as a convenience.
SetClassRoot(kJavaLangThrowable, FindSystemClass(self, "Ljava/lang/Throwable;"));
mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable));
SetClassRoot(kJavaLangClassNotFoundException,
FindSystemClass(self, "Ljava/lang/ClassNotFoundException;"));
SetClassRoot(kJavaLangStackTraceElement, FindSystemClass(self, "Ljava/lang/StackTraceElement;"));
SetClassRoot(kJavaLangStackTraceElementArrayClass,
FindSystemClass(self, "[Ljava/lang/StackTraceElement;"));
mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement));
// Ensure void type is resolved in the core's dex cache so java.lang.Void is correctly
// initialized.
{
const DexFile& dex_file = java_lang_Object->GetDexFile();
const DexFile::TypeId* void_type_id = dex_file.FindTypeId("V");
CHECK(void_type_id != nullptr);
uint16_t void_type_idx = dex_file.GetIndexForTypeId(*void_type_id);
// Now we resolve void type so the dex cache contains it. We use java.lang.Object class
// as referrer so the used dex cache is core's one.
mirror::Class* resolved_type = ResolveType(dex_file, void_type_idx, java_lang_Object.Get());
CHECK_EQ(resolved_type, GetClassRoot(kPrimitiveVoid));
self->AssertNoPendingException();
}
FinishInit(self);
VLOG(startup) << "ClassLinker::InitFromCompiler exiting";
return true;
}
void ClassLinker::FinishInit(Thread* self) {
VLOG(startup) << "ClassLinker::FinishInit entering";
// Let the heap know some key offsets into java.lang.ref instances
// Note: we hard code the field indexes here rather than using FindInstanceField
// as the types of the field can't be resolved prior to the runtime being
// fully initialized
mirror::Class* java_lang_ref_Reference = GetClassRoot(kJavaLangRefReference);
mirror::Class* java_lang_ref_FinalizerReference =
FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;");
ArtField* pendingNext = java_lang_ref_Reference->GetInstanceField(0);
CHECK_STREQ(pendingNext->GetName(), "pendingNext");
CHECK_STREQ(pendingNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;");
ArtField* queue = java_lang_ref_Reference->GetInstanceField(1);
CHECK_STREQ(queue->GetName(), "queue");
CHECK_STREQ(queue->GetTypeDescriptor(), "Ljava/lang/ref/ReferenceQueue;");
ArtField* queueNext = java_lang_ref_Reference->GetInstanceField(2);
CHECK_STREQ(queueNext->GetName(), "queueNext");
CHECK_STREQ(queueNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;");
ArtField* referent = java_lang_ref_Reference->GetInstanceField(3);
CHECK_STREQ(referent->GetName(), "referent");
CHECK_STREQ(referent->GetTypeDescriptor(), "Ljava/lang/Object;");
ArtField* zombie = java_lang_ref_FinalizerReference->GetInstanceField(2);
CHECK_STREQ(zombie->GetName(), "zombie");
CHECK_STREQ(zombie->GetTypeDescriptor(), "Ljava/lang/Object;");
// ensure all class_roots_ are initialized
for (size_t i = 0; i < kClassRootsMax; i++) {
ClassRoot class_root = static_cast<ClassRoot>(i);
mirror::Class* klass = GetClassRoot(class_root);
CHECK(klass != nullptr);
DCHECK(klass->IsArrayClass() || klass->IsPrimitive() || klass->GetDexCache() != nullptr);
// note SetClassRoot does additional validation.
// if possible add new checks there to catch errors early
}
CHECK(!array_iftable_.IsNull());
// disable the slow paths in FindClass and CreatePrimitiveClass now
// that Object, Class, and Object[] are setup
init_done_ = true;
VLOG(startup) << "ClassLinker::FinishInit exiting";
}
void ClassLinker::RunRootClinits() {
Thread* self = Thread::Current();
for (size_t i = 0; i < ClassLinker::kClassRootsMax; ++i) {
mirror::Class* c = GetClassRoot(ClassRoot(i));
if (!c->IsArrayClass() && !c->IsPrimitive()) {
StackHandleScope<1> hs(self);
Handle<mirror::Class> h_class(hs.NewHandle(GetClassRoot(ClassRoot(i))));
EnsureInitialized(self, h_class, true, true);
self->AssertNoPendingException();
}
}
}
static void SanityCheckArtMethod(ArtMethod* m,
mirror::Class* expected_class,
gc::space::ImageSpace* space)
SHARED_REQUIRES(Locks::mutator_lock_) {
if (m->IsRuntimeMethod()) {
CHECK(m->GetDeclaringClass() == nullptr) << PrettyMethod(m);
} else if (m->IsMiranda()) {
CHECK(m->GetDeclaringClass() != nullptr) << PrettyMethod(m);
} else if (expected_class != nullptr) {
CHECK_EQ(m->GetDeclaringClassUnchecked(), expected_class) << PrettyMethod(m);
}
if (space != nullptr) {
auto& header = space->GetImageHeader();
auto& methods = header.GetMethodsSection();
auto offset = reinterpret_cast<uint8_t*>(m) - space->Begin();
CHECK(methods.Contains(offset)) << m << " not in " << methods;
}
}
static void SanityCheckArtMethodPointerArray(mirror::PointerArray* arr,
mirror::Class* expected_class,
size_t pointer_size,
gc::space::ImageSpace* space)
SHARED_REQUIRES(Locks::mutator_lock_) {
CHECK(arr != nullptr);
for (int32_t j = 0; j < arr->GetLength(); ++j) {
auto* method = arr->GetElementPtrSize<ArtMethod*>(j, pointer_size);
// expected_class == null means we are a dex cache.
if (expected_class != nullptr) {
CHECK(method != nullptr);
}
if (method != nullptr) {
SanityCheckArtMethod(method, expected_class, space);
}
}
}
static void SanityCheckArtMethodPointerArray(
ArtMethod** arr,
size_t size,
size_t pointer_size,
gc::space::ImageSpace* space) SHARED_REQUIRES(Locks::mutator_lock_) {
CHECK_EQ(arr != nullptr, size != 0u);
if (arr != nullptr) {
auto offset = reinterpret_cast<uint8_t*>(arr) - space->Begin();
CHECK(space->GetImageHeader().GetImageSection(
ImageHeader::kSectionDexCacheArrays).Contains(offset));
}
for (size_t j = 0; j < size; ++j) {
ArtMethod* method = mirror::DexCache::GetElementPtrSize(arr, j, pointer_size);
// expected_class == null means we are a dex cache.
if (method != nullptr) {
SanityCheckArtMethod(method, nullptr, space);
}
}
}
static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_UNUSED)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(obj != nullptr);
CHECK(obj->GetClass() != nullptr) << "Null class in object " << obj;
CHECK(obj->GetClass()->GetClass() != nullptr) << "Null class class " << obj;
if (obj->IsClass()) {
auto klass = obj->AsClass();
for (ArtField& field : klass->GetIFields()) {
CHECK_EQ(field.GetDeclaringClass(), klass);
}
for (ArtField& field : klass->GetSFields()) {
CHECK_EQ(field.GetDeclaringClass(), klass);
}
auto* runtime = Runtime::Current();
auto* image_space = runtime->GetHeap()->GetBootImageSpace();
auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize();
for (auto& m : klass->GetDirectMethods(pointer_size)) {
SanityCheckArtMethod(&m, klass, image_space);
}
for (auto& m : klass->GetVirtualMethods(pointer_size)) {
SanityCheckArtMethod(&m, klass, image_space);
}
auto* vtable = klass->GetVTable();
if (vtable != nullptr) {
SanityCheckArtMethodPointerArray(vtable, nullptr, pointer_size, image_space);
}
if (klass->ShouldHaveEmbeddedImtAndVTable()) {
for (size_t i = 0; i < mirror::Class::kImtSize; ++i) {
SanityCheckArtMethod(klass->GetEmbeddedImTableEntry(i, pointer_size), nullptr, image_space);
}
for (int32_t i = 0; i < klass->GetEmbeddedVTableLength(); ++i) {
SanityCheckArtMethod(klass->GetEmbeddedVTableEntry(i, pointer_size), nullptr, image_space);
}
}
auto* iftable = klass->GetIfTable();
if (iftable != nullptr) {
for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) {
if (iftable->GetMethodArrayCount(i) > 0) {
SanityCheckArtMethodPointerArray(iftable->GetMethodArray(i), nullptr, pointer_size,
image_space);
}
}
}
}
}
// Set image methods' entry point to interpreter.
class SetInterpreterEntrypointArtMethodVisitor : public ArtMethodVisitor {
public:
explicit SetInterpreterEntrypointArtMethodVisitor(size_t image_pointer_size)
: image_pointer_size_(image_pointer_size) {}
void Visit(ArtMethod* method) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
if (kIsDebugBuild && !method->IsRuntimeMethod()) {
CHECK(method->GetDeclaringClass() != nullptr);
}
if (!method->IsNative() && !method->IsRuntimeMethod() && !method->IsResolutionMethod()) {
method->SetEntryPointFromQuickCompiledCodePtrSize(GetQuickToInterpreterBridge(),
image_pointer_size_);
}
}
private:
const size_t image_pointer_size_;
DISALLOW_COPY_AND_ASSIGN(SetInterpreterEntrypointArtMethodVisitor);
};
bool ClassLinker::InitFromImage(std::string* error_msg) {
VLOG(startup) << "ClassLinker::InitFromImage entering";
CHECK(!init_done_);
Runtime* const runtime = Runtime::Current();
Thread* const self = Thread::Current();
gc::Heap* const heap = runtime->GetHeap();
gc::space::ImageSpace* const space = heap->GetBootImageSpace();
CHECK(space != nullptr);
image_pointer_size_ = space->GetImageHeader().GetPointerSize();
dex_cache_boot_image_class_lookup_required_ = true;
const OatFile* oat_file = runtime->GetOatFileManager().RegisterImageOatFile(space);
DCHECK(oat_file != nullptr);
CHECK_EQ(oat_file->GetOatHeader().GetImageFileLocationOatChecksum(), 0U);
CHECK_EQ(oat_file->GetOatHeader().GetImageFileLocationOatDataBegin(), 0U);
const char* image_file_location = oat_file->GetOatHeader().
GetStoreValueByKey(OatHeader::kImageLocationKey);
CHECK(image_file_location == nullptr || *image_file_location == 0);
quick_resolution_trampoline_ = oat_file->GetOatHeader().GetQuickResolutionTrampoline();
quick_imt_conflict_trampoline_ = oat_file->GetOatHeader().GetQuickImtConflictTrampoline();
quick_generic_jni_trampoline_ = oat_file->GetOatHeader().GetQuickGenericJniTrampoline();
quick_to_interpreter_bridge_trampoline_ = oat_file->GetOatHeader().GetQuickToInterpreterBridge();
StackHandleScope<2> hs(self);
mirror::Object* dex_caches_object = space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches);
Handle<mirror::ObjectArray<mirror::DexCache>> dex_caches(
hs.NewHandle(dex_caches_object->AsObjectArray<mirror::DexCache>()));
Handle<mirror::ObjectArray<mirror::Class>> class_roots(hs.NewHandle(
space->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)->
AsObjectArray<mirror::Class>()));
class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get());
// Special case of setting up the String class early so that we can test arbitrary objects
// as being Strings or not
mirror::String::SetClass(GetClassRoot(kJavaLangString));
mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject);
java_lang_Object->SetObjectSize(sizeof(mirror::Object));
// Allocate in non-movable so that it's possible to check if a JNI weak global ref has been
// cleared without triggering the read barrier and unintentionally mark the sentinel alive.
runtime->SetSentinel(heap->AllocNonMovableObject<true>(self,
java_lang_Object,
java_lang_Object->GetObjectSize(),
VoidFunctor()));
if (oat_file->GetOatHeader().GetDexFileCount() !=
static_cast<uint32_t>(dex_caches->GetLength())) {
*error_msg = "Dex cache count and dex file count mismatch while trying to initialize from "
"image";
return false;
}
for (int32_t i = 0; i < dex_caches->GetLength(); i++) {
StackHandleScope<1> hs2(self);
Handle<mirror::DexCache> dex_cache(hs2.NewHandle(dex_caches->Get(i)));
const std::string& dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8());
const OatFile::OatDexFile* oat_dex_file = oat_file->GetOatDexFile(dex_file_location.c_str(),
nullptr);
if (oat_dex_file == nullptr) {
*error_msg = StringPrintf("Failed finding oat dex file for %s %s",
oat_file->GetLocation().c_str(),
dex_file_location.c_str());
return false;
}
std::string inner_error_msg;
std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&inner_error_msg);
if (dex_file == nullptr) {
*error_msg = StringPrintf("Failed to open dex file %s from within oat file %s error '%s'",
dex_file_location.c_str(),
oat_file->GetLocation().c_str(),
inner_error_msg.c_str());
return false;
}
if (kSanityCheckObjects) {
SanityCheckArtMethodPointerArray(dex_cache->GetResolvedMethods(),
dex_cache->NumResolvedMethods(),
image_pointer_size_,
space);
}
if (dex_file->GetLocationChecksum() != oat_dex_file->GetDexFileLocationChecksum()) {
*error_msg = StringPrintf("Checksums do not match for %s: %x vs %x",
dex_file_location.c_str(),
dex_file->GetLocationChecksum(),
oat_dex_file->GetDexFileLocationChecksum());
return false;
}
AppendToBootClassPath(*dex_file.get(), dex_cache);
opened_dex_files_.push_back(std::move(dex_file));
}
if (!ValidPointerSize(image_pointer_size_)) {
*error_msg = StringPrintf("Invalid image pointer size: %zu", image_pointer_size_);
return false;
}
// Set classes on AbstractMethod early so that IsMethod tests can be performed during the live
// bitmap walk.
if (!runtime->IsAotCompiler()) {
// Only the Aot compiler supports having an image with a different pointer size than the
// runtime. This happens on the host for compile 32 bit tests since we use a 64 bit libart
// compiler. We may also use 32 bit dex2oat on a system with 64 bit apps.
if (image_pointer_size_ != sizeof(void*)) {
*error_msg = StringPrintf("Runtime must use current image pointer size: %zu vs %zu",
image_pointer_size_ ,
sizeof(void*));
return false;
}
}
if (kSanityCheckObjects) {
for (int32_t i = 0; i < dex_caches->GetLength(); i++) {
auto* dex_cache = dex_caches->Get(i);
for (size_t j = 0; j < dex_cache->NumResolvedFields(); ++j) {
auto* field = dex_cache->GetResolvedField(j, image_pointer_size_);
if (field != nullptr) {
CHECK(field->GetDeclaringClass()->GetClass() != nullptr);
}
}
}
heap->VisitObjects(SanityCheckObjectsCallback, nullptr);
}
// Set entry point to interpreter if in InterpretOnly mode.
if (!runtime->IsAotCompiler() && runtime->GetInstrumentation()->InterpretOnly()) {
const ImageHeader& header = space->GetImageHeader();
const ImageSection& methods = header.GetMethodsSection();
SetInterpreterEntrypointArtMethodVisitor visitor(image_pointer_size_);
methods.VisitPackedArtMethods(&visitor, space->Begin(), image_pointer_size_);
}
// reinit class_roots_
mirror::Class::SetClassClass(class_roots->Get(kJavaLangClass));
class_roots_ = GcRoot<mirror::ObjectArray<mirror::Class>>(class_roots.Get());
// reinit array_iftable_ from any array class instance, they should be ==
array_iftable_ = GcRoot<mirror::IfTable>(GetClassRoot(kObjectArrayClass)->GetIfTable());
DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable());
// String class root was set above
mirror::Field::SetClass(GetClassRoot(kJavaLangReflectField));
mirror::Field::SetArrayClass(GetClassRoot(kJavaLangReflectFieldArrayClass));
mirror::Constructor::SetClass(GetClassRoot(kJavaLangReflectConstructor));
mirror::Constructor::SetArrayClass(GetClassRoot(kJavaLangReflectConstructorArrayClass));
mirror::Method::SetClass(GetClassRoot(kJavaLangReflectMethod));
mirror::Method::SetArrayClass(GetClassRoot(kJavaLangReflectMethodArrayClass));
mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference));
mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass));
mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass));
mirror::CharArray::SetArrayClass(GetClassRoot(kCharArrayClass));
mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass));
mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass));
mirror::IntArray::SetArrayClass(GetClassRoot(kIntArrayClass));
mirror::LongArray::SetArrayClass(GetClassRoot(kLongArrayClass));
mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass));
mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable));
mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement));
const ImageHeader& header = space->GetImageHeader();
const ImageSection& section = header.GetImageSection(ImageHeader::kSectionClassTable);
if (section.Size() > 0u) {
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
ClassTable* const class_table = InsertClassTableForClassLoader(nullptr);
class_table->ReadFromMemory(space->Begin() + section.Offset());
dex_cache_boot_image_class_lookup_required_ = false;
}
FinishInit(self);
VLOG(startup) << "ClassLinker::InitFromImage exiting";
return true;
}
bool ClassLinker::ClassInClassTable(mirror::Class* klass) {
ClassTable* const class_table = ClassTableForClassLoader(klass->GetClassLoader());
return class_table != nullptr && class_table->Contains(klass);
}
void ClassLinker::VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags) {
// Acquire tracing_enabled before locking class linker lock to prevent lock order violation. Since
// enabling tracing requires the mutator lock, there are no race conditions here.
const bool tracing_enabled = Trace::IsTracingEnabled();
Thread* const self = Thread::Current();
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor(
visitor, RootInfo(kRootStickyClass));
if ((flags & kVisitRootFlagAllRoots) != 0) {
// Argument for how root visiting deals with ArtField and ArtMethod roots.
// There is 3 GC cases to handle:
// Non moving concurrent:
// This case is easy to handle since the reference members of ArtMethod and ArtFields are held
// live by the class and class roots.
//
// Moving non-concurrent:
// This case needs to call visit VisitNativeRoots in case the classes or dex cache arrays move.
// To prevent missing roots, this case needs to ensure that there is no
// suspend points between the point which we allocate ArtMethod arrays and place them in a
// class which is in the class table.
//
// Moving concurrent:
// Need to make sure to not copy ArtMethods without doing read barriers since the roots are
// marked concurrently and we don't hold the classlinker_classes_lock_ when we do the copy.
boot_class_table_.VisitRoots(buffered_visitor);
// If tracing is enabled, then mark all the class loaders to prevent unloading.
if (tracing_enabled) {
for (const ClassLoaderData& data : class_loaders_) {
GcRoot<mirror::Object> root(GcRoot<mirror::Object>(self->DecodeJObject(data.weak_root)));
root.VisitRoot(visitor, RootInfo(kRootVMInternal));
}
}
} else if ((flags & kVisitRootFlagNewRoots) != 0) {
for (auto& root : new_class_roots_) {
mirror::Class* old_ref = root.Read<kWithoutReadBarrier>();
root.VisitRoot(visitor, RootInfo(kRootStickyClass));
mirror::Class* new_ref = root.Read<kWithoutReadBarrier>();
// Concurrent moving GC marked new roots through the to-space invariant.
CHECK_EQ(new_ref, old_ref);
}
}
buffered_visitor.Flush(); // Flush before clearing new_class_roots_.
if ((flags & kVisitRootFlagClearRootLog) != 0) {
new_class_roots_.clear();
}
if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) {
log_new_class_table_roots_ = true;
} else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) {
log_new_class_table_roots_ = false;
}
// We deliberately ignore the class roots in the image since we
// handle image roots by using the MS/CMS rescanning of dirty cards.
}
// Keep in sync with InitCallback. Anything we visit, we need to
// reinit references to when reinitializing a ClassLinker from a
// mapped image.
void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) {
class_roots_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
VisitClassRoots(visitor, flags);
array_iftable_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
// Instead of visiting the find_array_class_cache_ drop it so that it doesn't prevent class
// unloading if we are marking roots.
DropFindArrayClassCache();
}
class VisitClassLoaderClassesVisitor : public ClassLoaderVisitor {
public:
explicit VisitClassLoaderClassesVisitor(ClassVisitor* visitor)
: visitor_(visitor),
done_(false) {}
void Visit(mirror::ClassLoader* class_loader)
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE {
ClassTable* const class_table = class_loader->GetClassTable();
if (!done_ && class_table != nullptr && !class_table->Visit(visitor_)) {
// If the visitor ClassTable returns false it means that we don't need to continue.
done_ = true;
}
}
private:
ClassVisitor* const visitor_;
// If done is true then we don't need to do any more visiting.
bool done_;
};
void ClassLinker::VisitClassesInternal(ClassVisitor* visitor) {
if (boot_class_table_.Visit(visitor)) {
VisitClassLoaderClassesVisitor loader_visitor(visitor);
VisitClassLoaders(&loader_visitor);
}
}
void ClassLinker::VisitClasses(ClassVisitor* visitor) {
if (dex_cache_boot_image_class_lookup_required_) {
AddBootImageClassesToClassTable();
}
Thread* const self = Thread::Current();
ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
// Not safe to have thread suspension when we are holding a lock.
if (self != nullptr) {
ScopedAssertNoThreadSuspension nts(self, __FUNCTION__);
VisitClassesInternal(visitor);
} else {
VisitClassesInternal(visitor);
}
}
class GetClassesInToVector : public ClassVisitor {
public:
bool Visit(mirror::Class* klass) OVERRIDE {
classes_.push_back(klass);
return true;
}
std::vector<mirror::Class*> classes_;
};
class GetClassInToObjectArray : public ClassVisitor {
public:
explicit GetClassInToObjectArray(mirror::ObjectArray<mirror::Class>* arr)
: arr_(arr), index_(0) {}
bool Visit(mirror::Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
++index_;
if (index_ <= arr_->GetLength()) {
arr_->Set(index_ - 1, klass);
return true;
}
return false;
}
bool Succeeded() const SHARED_REQUIRES(Locks::mutator_lock_) {
return index_ <= arr_->GetLength();
}
private:
mirror::ObjectArray<mirror::Class>* const arr_;
int32_t index_;
};
void ClassLinker::VisitClassesWithoutClassesLock(ClassVisitor* visitor) {
// TODO: it may be possible to avoid secondary storage if we iterate over dex caches. The problem
// is avoiding duplicates.
if (!kMovingClasses) {
GetClassesInToVector accumulator;
VisitClasses(&accumulator);
for (mirror::Class* klass : accumulator.classes_) {
if (!visitor->Visit(klass)) {
return;
}
}
} else {
Thread* const self = Thread::Current();
StackHandleScope<1> hs(self);
auto classes = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr);
// We size the array assuming classes won't be added to the class table during the visit.
// If this assumption fails we iterate again.
while (true) {
size_t class_table_size;
{
ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
// Add 100 in case new classes get loaded when we are filling in the object array.
class_table_size = NumZygoteClasses() + NumNonZygoteClasses() + 100;
}
mirror::Class* class_type = mirror::Class::GetJavaLangClass();
mirror::Class* array_of_class = FindArrayClass(self, &class_type);
classes.Assign(
mirror::ObjectArray<mirror::Class>::Alloc(self, array_of_class, class_table_size));
CHECK(classes.Get() != nullptr); // OOME.
GetClassInToObjectArray accumulator(classes.Get());
VisitClasses(&accumulator);
if (accumulator.Succeeded()) {
break;
}
}
for (int32_t i = 0; i < classes->GetLength(); ++i) {
// If the class table shrank during creation of the clases array we expect null elements. If
// the class table grew then the loop repeats. If classes are created after the loop has
// finished then we don't visit.
mirror::Class* klass = classes->Get(i);
if (klass != nullptr && !visitor->Visit(klass)) {
return;
}
}
}
}
ClassLinker::~ClassLinker() {
mirror::Class::ResetClass();
mirror::Constructor::ResetClass();
mirror::Field::ResetClass();
mirror::Method::ResetClass();
mirror::Reference::ResetClass();
mirror::StackTraceElement::ResetClass();
mirror::String::ResetClass();
mirror::Throwable::ResetClass();
mirror::BooleanArray::ResetArrayClass();
mirror::ByteArray::ResetArrayClass();
mirror::CharArray::ResetArrayClass();
mirror::Constructor::ResetArrayClass();
mirror::DoubleArray::ResetArrayClass();
mirror::Field::ResetArrayClass();
mirror::FloatArray::ResetArrayClass();
mirror::Method::ResetArrayClass();
mirror::IntArray::ResetArrayClass();
mirror::LongArray::ResetArrayClass();
mirror::ShortArray::ResetArrayClass();
Thread* const self = Thread::Current();
for (const ClassLoaderData& data : class_loaders_) {
DeleteClassLoader(self, data);
}
class_loaders_.clear();
}
void ClassLinker::DeleteClassLoader(Thread* self, const ClassLoaderData& data) {
Runtime* const runtime = Runtime::Current();
JavaVMExt* const vm = runtime->GetJavaVM();
vm->DeleteWeakGlobalRef(self, data.weak_root);
if (runtime->GetJit() != nullptr) {
jit::JitCodeCache* code_cache = runtime->GetJit()->GetCodeCache();
if (code_cache != nullptr) {
code_cache->RemoveMethodsIn(self, *data.allocator);
}
}
delete data.allocator;
delete data.class_table;
}
mirror::PointerArray* ClassLinker::AllocPointerArray(Thread* self, size_t length) {
return down_cast<mirror::PointerArray*>(image_pointer_size_ == 8u ?
static_cast<mirror::Array*>(mirror::LongArray::Alloc(self, length)) :
static_cast<mirror::Array*>(mirror::IntArray::Alloc(self, length)));
}
mirror::DexCache* ClassLinker::AllocDexCache(Thread* self,
const DexFile& dex_file,
LinearAlloc* linear_alloc) {
StackHandleScope<6> hs(self);
auto dex_cache(hs.NewHandle(down_cast<mirror::DexCache*>(
GetClassRoot(kJavaLangDexCache)->AllocObject(self))));
if (dex_cache.Get() == nullptr) {
self->AssertPendingOOMException();
return nullptr;
}
auto location(hs.NewHandle(intern_table_->InternStrong(dex_file.GetLocation().c_str())));
if (location.Get() == nullptr) {
self->AssertPendingOOMException();
return nullptr;
}
DexCacheArraysLayout layout(image_pointer_size_, &dex_file);
uint8_t* raw_arrays = nullptr;
if (dex_file.GetOatDexFile() != nullptr &&
dex_file.GetOatDexFile()->GetDexCacheArrays() != nullptr) {
raw_arrays = dex_file.GetOatDexFile()->GetDexCacheArrays();
} else if (dex_file.NumStringIds() != 0u || dex_file.NumTypeIds() != 0u ||
dex_file.NumMethodIds() != 0u || dex_file.NumFieldIds() != 0u) {
// NOTE: We "leak" the raw_arrays because we never destroy the dex cache.
DCHECK(image_pointer_size_ == 4u || image_pointer_size_ == 8u);
// Zero-initialized.
raw_arrays = reinterpret_cast<uint8_t*>(linear_alloc->Alloc(self, layout.Size()));
}
GcRoot<mirror::String>* strings = (dex_file.NumStringIds() == 0u) ? nullptr :
reinterpret_cast<GcRoot<mirror::String>*>(raw_arrays + layout.StringsOffset());
GcRoot<mirror::Class>* types = (dex_file.NumTypeIds() == 0u) ? nullptr :
reinterpret_cast<GcRoot<mirror::Class>*>(raw_arrays + layout.TypesOffset());
ArtMethod** methods = (dex_file.NumMethodIds() == 0u) ? nullptr :
reinterpret_cast<ArtMethod**>(raw_arrays + layout.MethodsOffset());
ArtField** fields = (dex_file.NumFieldIds() == 0u) ? nullptr :
reinterpret_cast<ArtField**>(raw_arrays + layout.FieldsOffset());
dex_cache->Init(&dex_file,
location.Get(),
strings,
dex_file.NumStringIds(),
types,
dex_file.NumTypeIds(),
methods,
dex_file.NumMethodIds(),
fields,
dex_file.NumFieldIds(),
image_pointer_size_);
return dex_cache.Get();
}
mirror::Class* ClassLinker::AllocClass(Thread* self, mirror::Class* java_lang_Class,
uint32_t class_size) {
DCHECK_GE(class_size, sizeof(mirror::Class));
gc::Heap* heap = Runtime::Current()->GetHeap();
mirror::Class::InitializeClassVisitor visitor(class_size);
mirror::Object* k = kMovingClasses ?
heap->AllocObject<true>(self, java_lang_Class, class_size, visitor) :
heap->AllocNonMovableObject<true>(self, java_lang_Class, class_size, visitor);
if (UNLIKELY(k == nullptr)) {
self->AssertPendingOOMException();
return nullptr;
}
return k->AsClass();
}
mirror::Class* ClassLinker::AllocClass(Thread* self, uint32_t class_size) {
return AllocClass(self, GetClassRoot(kJavaLangClass), class_size);
}
mirror::ObjectArray<mirror::StackTraceElement>* ClassLinker::AllocStackTraceElementArray(
Thread* self,
size_t length) {
return mirror::ObjectArray<mirror::StackTraceElement>::Alloc(
self, GetClassRoot(kJavaLangStackTraceElementArrayClass), length);
}
mirror::Class* ClassLinker::EnsureResolved(Thread* self,
const char* descriptor,
mirror::Class* klass) {
DCHECK(klass != nullptr);
// For temporary classes we must wait for them to be retired.
if (init_done_ && klass->IsTemp()) {
CHECK(!klass->IsResolved());
if (klass->IsErroneous()) {
ThrowEarlierClassFailure(klass);
return nullptr;
}
StackHandleScope<1> hs(self);
Handle<mirror::Class> h_class(hs.NewHandle(klass));
ObjectLock<mirror::Class> lock(self, h_class);
// Loop and wait for the resolving thread to retire this class.
while (!h_class->IsRetired() && !h_class->IsErroneous()) {
lock.WaitIgnoringInterrupts();
}
if (h_class->IsErroneous()) {
ThrowEarlierClassFailure(h_class.Get());
return nullptr;
}
CHECK(h_class->IsRetired());
// Get the updated class from class table.
klass = LookupClass(self, descriptor, ComputeModifiedUtf8Hash(descriptor),
h_class.Get()->GetClassLoader());
}
// Wait for the class if it has not already been linked.
if (!klass->IsResolved() && !klass->IsErroneous()) {
StackHandleScope<1> hs(self);
HandleWrapper<mirror::Class> h_class(hs.NewHandleWrapper(&klass));
ObjectLock<mirror::Class> lock(self, h_class);
// Check for circular dependencies between classes.
if (!h_class->IsResolved() && h_class->GetClinitThreadId() == self->GetTid()) {
ThrowClassCircularityError(h_class.Get());
mirror::Class::SetStatus(h_class, mirror::Class::kStatusError, self);
return nullptr;
}
// Wait for the pending initialization to complete.
while (!h_class->IsResolved() && !h_class->IsErroneous()) {
lock.WaitIgnoringInterrupts();
}
}
if (klass->IsErroneous()) {
ThrowEarlierClassFailure(klass);
return nullptr;
}
// Return the loaded class. No exceptions should be pending.
CHECK(klass->IsResolved()) << PrettyClass(klass);
self->AssertNoPendingException();
return klass;
}
typedef std::pair<const DexFile*, const DexFile::ClassDef*> ClassPathEntry;
// Search a collection of DexFiles for a descriptor
ClassPathEntry FindInClassPath(const char* descriptor,
size_t hash, const std::vector<const DexFile*>& class_path) {
for (const DexFile* dex_file : class_path) {
const DexFile::ClassDef* dex_class_def = dex_file->FindClassDef(descriptor, hash);
if (dex_class_def != nullptr) {
return ClassPathEntry(dex_file, dex_class_def);
}
}
return ClassPathEntry(nullptr, nullptr);
}
static bool IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa,
mirror::ClassLoader* class_loader)
SHARED_REQUIRES(Locks::mutator_lock_) {
return class_loader == nullptr ||
class_loader->GetClass() ==
soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader);
}
bool ClassLinker::FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa,
Thread* self,
const char* descriptor,
size_t hash,
Handle<mirror::ClassLoader> class_loader,
mirror::Class** result) {
// Termination case: boot class-loader.
if (IsBootClassLoader(soa, class_loader.Get())) {
// The boot class loader, search the boot class path.
ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_);
if (pair.second != nullptr) {
mirror::Class* klass = LookupClass(self, descriptor, hash, nullptr);
if (klass != nullptr) {
*result = EnsureResolved(self, descriptor, klass);
} else {
*result = DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(),
*pair.first, *pair.second);
}
if (*result == nullptr) {
CHECK(self->IsExceptionPending()) << descriptor;
self->ClearException();
}
} else {
*result = nullptr;
}
return true;
}
// Unsupported class-loader?
if (class_loader->GetClass() !=
soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader)) {
*result = nullptr;
return false;
}
// Handles as RegisterDexFile may allocate dex caches (and cause thread suspension).
StackHandleScope<4> hs(self);
Handle<mirror::ClassLoader> h_parent(hs.NewHandle(class_loader->GetParent()));
bool recursive_result = FindClassInPathClassLoader(soa, self, descriptor, hash, h_parent, result);
if (!recursive_result) {
// Something wrong up the chain.
return false;
}
if (*result != nullptr) {
// Found the class up the chain.
return true;
}
// Handle this step.
// Handle as if this is the child PathClassLoader.
// The class loader is a PathClassLoader which inherits from BaseDexClassLoader.
// We need to get the DexPathList and loop through it.
ArtField* const cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie);
ArtField* const dex_file_field =
soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile);
mirror::Object* dex_path_list =
soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList)->
GetObject(class_loader.Get());
if (dex_path_list != nullptr && dex_file_field != nullptr && cookie_field != nullptr) {
// DexPathList has an array dexElements of Elements[] which each contain a dex file.
mirror::Object* dex_elements_obj =
soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements)->
GetObject(dex_path_list);
// Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look
// at the mCookie which is a DexFile vector.
if (dex_elements_obj != nullptr) {
Handle<mirror::ObjectArray<mirror::Object>> dex_elements =
hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>());
for (int32_t i = 0; i < dex_elements->GetLength(); ++i) {
mirror::Object* element = dex_elements->GetWithoutChecks(i);
if (element == nullptr) {
// Should never happen, fall back to java code to throw a NPE.
break;
}
mirror::Object* dex_file = dex_file_field->GetObject(element);
if (dex_file != nullptr) {
mirror::LongArray* long_array = cookie_field->GetObject(dex_file)->AsLongArray();
if (long_array == nullptr) {
// This should never happen so log a warning.
LOG(WARNING) << "Null DexFile::mCookie for " << descriptor;
break;
}
int32_t long_array_size = long_array->GetLength();
// First element is the oat file.
for (int32_t j = kDexFileIndexStart; j < long_array_size; ++j) {
const DexFile* cp_dex_file = reinterpret_cast<const DexFile*>(static_cast<uintptr_t>(
long_array->GetWithoutChecks(j)));
const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash);
if (dex_class_def != nullptr) {
mirror::Class* klass = DefineClass(self,
descriptor,
hash,
class_loader,
*cp_dex_file,
*dex_class_def);
if (klass == nullptr) {
CHECK(self->IsExceptionPending()) << descriptor;
self->ClearException();
// TODO: Is it really right to break here, and not check the other dex files?
return true;
}
*result = klass;
return true;
}
}
}
}
}
self->AssertNoPendingException();
}
// Result is still null from the parent call, no need to set it again...
return true;
}
mirror::Class* ClassLinker::FindClass(Thread* self,
const char* descriptor,
Handle<mirror::ClassLoader> class_loader) {
DCHECK_NE(*descriptor, '\0') << "descriptor is empty string";
DCHECK(self != nullptr);
self->AssertNoPendingException();
if (descriptor[1] == '\0') {
// only the descriptors of primitive types should be 1 character long, also avoid class lookup
// for primitive classes that aren't backed by dex files.
return FindPrimitiveClass(descriptor[0]);
}
const size_t hash = ComputeModifiedUtf8Hash(descriptor);
// Find the class in the loaded classes table.
mirror::Class* klass = LookupClass(self, descriptor, hash, class_loader.Get());
if (klass != nullptr) {
return EnsureResolved(self, descriptor, klass);
}
// Class is not yet loaded.
if (descriptor[0] == '[') {
return CreateArrayClass(self, descriptor, hash, class_loader);
} else if (class_loader.Get() == nullptr) {
// The boot class loader, search the boot class path.
ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_);
if (pair.second != nullptr) {
return DefineClass(self, descriptor, hash, NullHandle<mirror::ClassLoader>(), *pair.first,
*pair.second);
} else {
// The boot class loader is searched ahead of the application class loader, failures are
// expected and will be wrapped in a ClassNotFoundException. Use the pre-allocated error to
// trigger the chaining with a proper stack trace.
mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError();
self->SetException(pre_allocated);
return nullptr;
}
} else {
ScopedObjectAccessUnchecked soa(self);
mirror::Class* cp_klass;
if (FindClassInPathClassLoader(soa, self, descriptor, hash, class_loader, &cp_klass)) {
// The chain was understood. So the value in cp_klass is either the class we were looking
// for, or not found.
if (cp_klass != nullptr) {
return cp_klass;
}
// TODO: We handle the boot classpath loader in FindClassInPathClassLoader. Try to unify this
// and the branch above. TODO: throw the right exception here.
// We'll let the Java-side rediscover all this and throw the exception with the right stack
// trace.
}
if (Runtime::Current()->IsAotCompiler()) {
// Oops, compile-time, can't run actual class-loader code.
mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError();
self->SetException(pre_allocated);
return nullptr;
}
ScopedLocalRef<jobject> class_loader_object(soa.Env(),
soa.AddLocalReference<jobject>(class_loader.Get()));
std::string class_name_string(DescriptorToDot(descriptor));
ScopedLocalRef<jobject> result(soa.Env(), nullptr);
{
ScopedThreadStateChange tsc(self, kNative);
ScopedLocalRef<jobject> class_name_object(soa.Env(),
soa.Env()->NewStringUTF(class_name_string.c_str()));
if (class_name_object.get() == nullptr) {
DCHECK(self->IsExceptionPending()); // OOME.
return nullptr;
}
CHECK(class_loader_object.get() != nullptr);
result.reset(soa.Env()->CallObjectMethod(class_loader_object.get(),
WellKnownClasses::java_lang_ClassLoader_loadClass,
class_name_object.get()));
}
if (self->IsExceptionPending()) {
// If the ClassLoader threw, pass that exception up.
return nullptr;
} else if (result.get() == nullptr) {
// broken loader - throw NPE to be compatible with Dalvik
ThrowNullPointerException(StringPrintf("ClassLoader.loadClass returned null for %s",
class_name_string.c_str()).c_str());
return nullptr;
} else {
// success, return mirror::Class*
return soa.Decode<mirror::Class*>(result.get());
}
}
UNREACHABLE();
}
mirror::Class* ClassLinker::DefineClass(Thread* self,
const char* descriptor,
size_t hash,
Handle<mirror::ClassLoader> class_loader,
const DexFile& dex_file,
const DexFile::ClassDef& dex_class_def) {
StackHandleScope<3> hs(self);
auto klass = hs.NewHandle<mirror::Class>(nullptr);
// Load the class from the dex file.
if (UNLIKELY(!init_done_)) {
// finish up init of hand crafted class_roots_
if (strcmp(descriptor, "Ljava/lang/Object;") == 0) {
klass.Assign(GetClassRoot(kJavaLangObject));
} else if (strcmp(descriptor, "Ljava/lang/Class;") == 0) {
klass.Assign(GetClassRoot(kJavaLangClass));
} else if (strcmp(descriptor, "Ljava/lang/String;") == 0) {
klass.Assign(GetClassRoot(kJavaLangString));
} else if (strcmp(descriptor, "Ljava/lang/ref/Reference;") == 0) {
klass.Assign(GetClassRoot(kJavaLangRefReference));
} else if (strcmp(descriptor, "Ljava/lang/DexCache;") == 0) {
klass.Assign(GetClassRoot(kJavaLangDexCache));
}
}
if (klass.Get() == nullptr) {
// Allocate a class with the status of not ready.
// Interface object should get the right size here. Regular class will
// figure out the right size later and be replaced with one of the right
// size when the class becomes resolved.
klass.Assign(AllocClass(self, SizeOfClassWithoutEmbeddedTables(dex_file, dex_class_def)));
}
if (UNLIKELY(klass.Get() == nullptr)) {
self->AssertPendingOOMException();
return nullptr;
}
mirror::DexCache* dex_cache = RegisterDexFile(
dex_file,
GetOrCreateAllocatorForClassLoader(class_loader.Get()));
if (dex_cache == nullptr) {
self->AssertPendingOOMException();
return nullptr;
}
klass->SetDexCache(dex_cache);
SetupClass(dex_file, dex_class_def, klass, class_loader.Get());
// Mark the string class by setting its access flag.
if (UNLIKELY(!init_done_)) {
if (strcmp(descriptor, "Ljava/lang/String;") == 0) {
klass->SetStringClass();
}
}
ObjectLock<mirror::Class> lock(self, klass);
klass->SetClinitThreadId(self->GetTid());
// Add the newly loaded class to the loaded classes table.
mirror::Class* existing = InsertClass(descriptor, klass.Get(), hash);
if (existing != nullptr) {
// We failed to insert because we raced with another thread. Calling EnsureResolved may cause
// this thread to block.
return EnsureResolved(self, descriptor, existing);
}
// Load the fields and other things after we are inserted in the table. This is so that we don't
// end up allocating unfree-able linear alloc resources and then lose the race condition. The
// other reason is that the field roots are only visited from the class table. So we need to be
// inserted before we allocate / fill in these fields.
LoadClass(self, dex_file, dex_class_def, klass);
if (self->IsExceptionPending()) {
// An exception occured during load, set status to erroneous while holding klass' lock in case
// notification is necessary.
if (!klass->IsErroneous()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
}
return nullptr;
}
// Finish loading (if necessary) by finding parents
CHECK(!klass->IsLoaded());
if (!LoadSuperAndInterfaces(klass, dex_file)) {
// Loading failed.
if (!klass->IsErroneous()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
}
return nullptr;
}
CHECK(klass->IsLoaded());
// Link the class (if necessary)
CHECK(!klass->IsResolved());
// TODO: Use fast jobjects?
auto interfaces = hs.NewHandle<mirror::ObjectArray<mirror::Class>>(nullptr);
MutableHandle<mirror::Class> h_new_class = hs.NewHandle<mirror::Class>(nullptr);
if (!LinkClass(self, descriptor, klass, interfaces, &h_new_class)) {
// Linking failed.
if (!klass->IsErroneous()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
}
return nullptr;
}
self->AssertNoPendingException();
CHECK(h_new_class.Get() != nullptr) << descriptor;
CHECK(h_new_class->IsResolved()) << descriptor;
// Instrumentation may have updated entrypoints for all methods of all
// classes. However it could not update methods of this class while we
// were loading it. Now the class is resolved, we can update entrypoints
// as required by instrumentation.
if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) {
// We must be in the kRunnable state to prevent instrumentation from
// suspending all threads to update entrypoints while we are doing it
// for this class.
DCHECK_EQ(self->GetState(), kRunnable);
Runtime::Current()->GetInstrumentation()->InstallStubsForClass(h_new_class.Get());
}
/*
* We send CLASS_PREPARE events to the debugger from here. The
* definition of "preparation" is creating the static fields for a
* class and initializing them to the standard default values, but not
* executing any code (that comes later, during "initialization").
*
* We did the static preparation in LinkClass.
*
* The class has been prepared and resolved but possibly not yet verified
* at this point.
*/
Dbg::PostClassPrepare(h_new_class.Get());
return h_new_class.Get();
}
uint32_t ClassLinker::SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file,
const DexFile::ClassDef& dex_class_def) {
const uint8_t* class_data = dex_file.GetClassData(dex_class_def);
size_t num_ref = 0;
size_t num_8 = 0;
size_t num_16 = 0;
size_t num_32 = 0;
size_t num_64 = 0;
if (class_data != nullptr) {
for (ClassDataItemIterator it(dex_file, class_data); it.HasNextStaticField(); it.Next()) {
const DexFile::FieldId& field_id = dex_file.GetFieldId(it.GetMemberIndex());
const char* descriptor = dex_file.GetFieldTypeDescriptor(field_id);
char c = descriptor[0];
switch (c) {
case 'L':
case '[':
num_ref++;
break;
case 'J':
case 'D':
num_64++;
break;
case 'I':
case 'F':
num_32++;
break;
case 'S':
case 'C':
num_16++;
break;
case 'B':
case 'Z':
num_8++;
break;
default:
LOG(FATAL) << "Unknown descriptor: " << c;
UNREACHABLE();
}
}
}
return mirror::Class::ComputeClassSize(false,
0,
num_8,
num_16,
num_32,
num_64,
num_ref,
image_pointer_size_);
}
OatFile::OatClass ClassLinker::FindOatClass(const DexFile& dex_file,
uint16_t class_def_idx,
bool* found) {
DCHECK_NE(class_def_idx, DexFile::kDexNoIndex16);
const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile();
if (oat_dex_file == nullptr) {
*found = false;
return OatFile::OatClass::Invalid();
}
*found = true;
return oat_dex_file->GetOatClass(class_def_idx);
}
static uint32_t GetOatMethodIndexFromMethodIndex(const DexFile& dex_file,
uint16_t class_def_idx,
uint32_t method_idx) {
const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_idx);
const uint8_t* class_data = dex_file.GetClassData(class_def);
CHECK(class_data != nullptr);
ClassDataItemIterator it(dex_file, class_data);
// Skip fields
while (it.HasNextStaticField()) {
it.Next();
}
while (it.HasNextInstanceField()) {
it.Next();
}
// Process methods
size_t class_def_method_index = 0;
while (it.HasNextDirectMethod()) {
if (it.GetMemberIndex() == method_idx) {
return class_def_method_index;
}
class_def_method_index++;
it.Next();
}
while (it.HasNextVirtualMethod()) {
if (it.GetMemberIndex() == method_idx) {
return class_def_method_index;
}
class_def_method_index++;
it.Next();
}
DCHECK(!it.HasNext());
LOG(FATAL) << "Failed to find method index " << method_idx << " in " << dex_file.GetLocation();
UNREACHABLE();
}
const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* found) {
// Although we overwrite the trampoline of non-static methods, we may get here via the resolution
// method for direct methods (or virtual methods made direct).
mirror::Class* declaring_class = method->GetDeclaringClass();
size_t oat_method_index;
if (method->IsStatic() || method->IsDirect()) {
// Simple case where the oat method index was stashed at load time.
oat_method_index = method->GetMethodIndex();
} else {
// We're invoking a virtual method directly (thanks to sharpening), compute the oat_method_index
// by search for its position in the declared virtual methods.
oat_method_index = declaring_class->NumDirectMethods();
size_t end = declaring_class->NumVirtualMethods();
bool found_virtual = false;
for (size_t i = 0; i < end; i++) {
// Check method index instead of identity in case of duplicate method definitions.
if (method->GetDexMethodIndex() ==
declaring_class->GetVirtualMethod(i, image_pointer_size_)->GetDexMethodIndex()) {
found_virtual = true;
break;
}
oat_method_index++;
}
CHECK(found_virtual) << "Didn't find oat method index for virtual method: "
<< PrettyMethod(method);
}
DCHECK_EQ(oat_method_index,
GetOatMethodIndexFromMethodIndex(*declaring_class->GetDexCache()->GetDexFile(),
method->GetDeclaringClass()->GetDexClassDefIndex(),
method->GetDexMethodIndex()));
OatFile::OatClass oat_class = FindOatClass(*declaring_class->GetDexCache()->GetDexFile(),
declaring_class->GetDexClassDefIndex(),
found);
if (!(*found)) {
return OatFile::OatMethod::Invalid();
}
return oat_class.GetOatMethod(oat_method_index);
}
// Special case to get oat code without overwriting a trampoline.
const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) {
CHECK(method->IsInvokable()) << PrettyMethod(method);
if (method->IsProxyMethod()) {
return GetQuickProxyInvokeHandler();
}
bool found;
OatFile::OatMethod oat_method = FindOatMethodFor(method, &found);
if (found) {
auto* code = oat_method.GetQuickCode();
if (code != nullptr) {
return code;
}
}
if (method->IsNative()) {
// No code and native? Use generic trampoline.
return GetQuickGenericJniStub();
}
return GetQuickToInterpreterBridge();
}
const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) {
if (method->IsNative() || !method->IsInvokable() || method->IsProxyMethod()) {
return nullptr;
}
bool found;
OatFile::OatMethod oat_method = FindOatMethodFor(method, &found);
if (found) {
return oat_method.GetQuickCode();
}
return nullptr;
}
const void* ClassLinker::GetQuickOatCodeFor(const DexFile& dex_file,
uint16_t class_def_idx,
uint32_t method_idx) {
bool found;
OatFile::OatClass oat_class = FindOatClass(dex_file, class_def_idx, &found);
if (!found) {
return nullptr;
}
uint32_t oat_method_idx = GetOatMethodIndexFromMethodIndex(dex_file, class_def_idx, method_idx);
return oat_class.GetOatMethod(oat_method_idx).GetQuickCode();
}
// Returns true if the method must run with interpreter, false otherwise.
static bool NeedsInterpreter(ArtMethod* method, const void* quick_code)
SHARED_REQUIRES(Locks::mutator_lock_) {
if (quick_code == nullptr) {
// No code: need interpreter.
// May return true for native code, in the case of generic JNI
// DCHECK(!method->IsNative());
return true;
}
// If interpreter mode is enabled, every method (except native and proxy) must
// be run with interpreter.
return Runtime::Current()->GetInstrumentation()->InterpretOnly() &&
!method->IsNative() && !method->IsProxyMethod();
}
void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) {
DCHECK(klass->IsInitialized()) << PrettyDescriptor(klass);
if (klass->NumDirectMethods() == 0) {
return; // No direct methods => no static methods.
}
Runtime* runtime = Runtime::Current();
if (!runtime->IsStarted()) {
if (runtime->IsAotCompiler() || runtime->GetHeap()->HasImageSpace()) {
return; // OAT file unavailable.
}
}
const DexFile& dex_file = klass->GetDexFile();
const DexFile::ClassDef* dex_class_def = klass->GetClassDef();
CHECK(dex_class_def != nullptr);
const uint8_t* class_data = dex_file.GetClassData(*dex_class_def);
// There should always be class data if there were direct methods.
CHECK(class_data != nullptr) << PrettyDescriptor(klass);
ClassDataItemIterator it(dex_file, class_data);
// Skip fields
while (it.HasNextStaticField()) {
it.Next();
}
while (it.HasNextInstanceField()) {
it.Next();
}
bool has_oat_class;
OatFile::OatClass oat_class = FindOatClass(dex_file,
klass->GetDexClassDefIndex(),
&has_oat_class);
// Link the code of methods skipped by LinkCode.
for (size_t method_index = 0; it.HasNextDirectMethod(); ++method_index, it.Next()) {
ArtMethod* method = klass->GetDirectMethod(method_index, image_pointer_size_);
if (!method->IsStatic()) {
// Only update static methods.
continue;
}
const void* quick_code = nullptr;
if (has_oat_class) {
OatFile::OatMethod oat_method = oat_class.GetOatMethod(method_index);
quick_code = oat_method.GetQuickCode();
}
const bool enter_interpreter = NeedsInterpreter(method, quick_code);
if (enter_interpreter) {
// Use interpreter entry point.
// Check whether the method is native, in which case it's generic JNI.
if (quick_code == nullptr && method->IsNative()) {
quick_code = GetQuickGenericJniStub();
} else {
quick_code = GetQuickToInterpreterBridge();
}
}
runtime->GetInstrumentation()->UpdateMethodsCode(method, quick_code);
}
// Ignore virtual methods on the iterator.
}
void ClassLinker::EnsureThrowsInvocationError(ArtMethod* method) {
DCHECK(method != nullptr);
DCHECK(!method->IsInvokable());
method->SetEntryPointFromQuickCompiledCodePtrSize(quick_to_interpreter_bridge_trampoline_,
image_pointer_size_);
}
void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class,
uint32_t class_def_method_index) {
Runtime* const runtime = Runtime::Current();
if (runtime->IsAotCompiler()) {
// The following code only applies to a non-compiler runtime.
return;
}
// Method shouldn't have already been linked.
DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr);
if (oat_class != nullptr) {
// Every kind of method should at least get an invoke stub from the oat_method.
// non-abstract methods also get their code pointers.
const OatFile::OatMethod oat_method = oat_class->GetOatMethod(class_def_method_index);
oat_method.LinkMethod(method);
}
// Install entry point from interpreter.
bool enter_interpreter = NeedsInterpreter(method, method->GetEntryPointFromQuickCompiledCode());
if (!method->IsInvokable()) {
EnsureThrowsInvocationError(method);
return;
}
if (method->IsStatic() && !method->IsConstructor()) {
// For static methods excluding the class initializer, install the trampoline.
// It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines
// after initializing class (see ClassLinker::InitializeClass method).
method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub());
} else if (enter_interpreter) {
if (!method->IsNative()) {
// Set entry point from compiled code if there's no code or in interpreter only mode.
method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge());
} else {
method->SetEntryPointFromQuickCompiledCode(GetQuickGenericJniStub());
}
}
if (method->IsNative()) {
// Unregistering restores the dlsym lookup stub.
method->UnregisterNative();
if (enter_interpreter) {
// We have a native method here without code. Then it should have either the generic JNI
// trampoline as entrypoint (non-static), or the resolution trampoline (static).
// TODO: this doesn't handle all the cases where trampolines may be installed.
const void* entry_point = method->GetEntryPointFromQuickCompiledCode();
DCHECK(IsQuickGenericJniStub(entry_point) || IsQuickResolutionStub(entry_point));
}
}
}
void ClassLinker::SetupClass(const DexFile& dex_file,
const DexFile::ClassDef& dex_class_def,
Handle<mirror::Class> klass,
mirror::ClassLoader* class_loader) {
CHECK(klass.Get() != nullptr);
CHECK(klass->GetDexCache() != nullptr);
CHECK_EQ(mirror::Class::kStatusNotReady, klass->GetStatus());
const char* descriptor = dex_file.GetClassDescriptor(dex_class_def);
CHECK(descriptor != nullptr);
klass->SetClass(GetClassRoot(kJavaLangClass));
uint32_t access_flags = dex_class_def.GetJavaAccessFlags();
CHECK_EQ(access_flags & ~kAccJavaFlagsMask, 0U);
klass->SetAccessFlags(access_flags);
klass->SetClassLoader(class_loader);
DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot);
mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, nullptr);
klass->SetDexClassDefIndex(dex_file.GetIndexForClassDef(dex_class_def));
klass->SetDexTypeIndex(dex_class_def.class_idx_);
CHECK(klass->GetDexCacheStrings() != nullptr);
}
void ClassLinker::LoadClass(Thread* self,
const DexFile& dex_file,
const DexFile::ClassDef& dex_class_def,
Handle<mirror::Class> klass) {
const uint8_t* class_data = dex_file.GetClassData(dex_class_def);
if (class_data == nullptr) {
return; // no fields or methods - for example a marker interface
}
bool has_oat_class = false;
if (Runtime::Current()->IsStarted() && !Runtime::Current()->IsAotCompiler()) {
OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(),
&has_oat_class);
if (has_oat_class) {
LoadClassMembers(self, dex_file, class_data, klass, &oat_class);
}
}
if (!has_oat_class) {
LoadClassMembers(self, dex_file, class_data, klass, nullptr);
}
}
LengthPrefixedArray<ArtField>* ClassLinker::AllocArtFieldArray(Thread* self,
LinearAlloc* allocator,
size_t length) {
if (length == 0) {
return nullptr;
}
// If the ArtField alignment changes, review all uses of LengthPrefixedArray<ArtField>.
static_assert(alignof(ArtField) == 4, "ArtField alignment is expected to be 4.");
size_t storage_size = LengthPrefixedArray<ArtField>::ComputeSize(length);
void* array_storage = allocator->Alloc(self, storage_size);
auto* ret = new(array_storage) LengthPrefixedArray<ArtField>(length);
CHECK(ret != nullptr);
std::uninitialized_fill_n(&ret->At(0), length, ArtField());
return ret;
}
LengthPrefixedArray<ArtMethod>* ClassLinker::AllocArtMethodArray(Thread* self,
LinearAlloc* allocator,
size_t length) {
if (length == 0) {
return nullptr;
}
const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_);
const size_t method_size = ArtMethod::Size(image_pointer_size_);
const size_t storage_size =
LengthPrefixedArray<ArtMethod>::ComputeSize(length, method_size, method_alignment);
void* array_storage = allocator->Alloc(self, storage_size);
auto* ret = new (array_storage) LengthPrefixedArray<ArtMethod>(length);
CHECK(ret != nullptr);
for (size_t i = 0; i < length; ++i) {
new(reinterpret_cast<void*>(&ret->At(i, method_size, method_alignment))) ArtMethod;
}
return ret;
}
LinearAlloc* ClassLinker::GetAllocatorForClassLoader(mirror::ClassLoader* class_loader) {
if (class_loader == nullptr) {
return Runtime::Current()->GetLinearAlloc();
}
LinearAlloc* allocator = class_loader->GetAllocator();
DCHECK(allocator != nullptr);
return allocator;
}
LinearAlloc* ClassLinker::GetOrCreateAllocatorForClassLoader(mirror::ClassLoader* class_loader) {
if (class_loader == nullptr) {
return Runtime::Current()->GetLinearAlloc();
}
WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
LinearAlloc* allocator = class_loader->GetAllocator();
if (allocator == nullptr) {
allocator = Runtime::Current()->CreateLinearAlloc();
class_loader->SetAllocator(allocator);
}
return allocator;
}
void ClassLinker::LoadClassMembers(Thread* self,
const DexFile& dex_file,
const uint8_t* class_data,
Handle<mirror::Class> klass,
const OatFile::OatClass* oat_class) {
{
// Note: We cannot have thread suspension until the field and method arrays are setup or else
// Class::VisitFieldRoots may miss some fields or methods.
ScopedAssertNoThreadSuspension nts(self, __FUNCTION__);
// Load static fields.
// We allow duplicate definitions of the same field in a class_data_item
// but ignore the repeated indexes here, b/21868015.
LinearAlloc* const allocator = GetAllocatorForClassLoader(klass->GetClassLoader());
ClassDataItemIterator it(dex_file, class_data);
LengthPrefixedArray<ArtField>* sfields = AllocArtFieldArray(self,
allocator,
it.NumStaticFields());
size_t num_sfields = 0;
uint32_t last_field_idx = 0u;
for (; it.HasNextStaticField(); it.Next()) {
uint32_t field_idx = it.GetMemberIndex();
DCHECK_GE(field_idx, last_field_idx); // Ordering enforced by DexFileVerifier.
if (num_sfields == 0 || LIKELY(field_idx > last_field_idx)) {
DCHECK_LT(num_sfields, it.NumStaticFields());
LoadField(it, klass, &sfields->At(num_sfields));
++num_sfields;
last_field_idx = field_idx;
}
}
// Load instance fields.
LengthPrefixedArray<ArtField>* ifields = AllocArtFieldArray(self,
allocator,
it.NumInstanceFields());
size_t num_ifields = 0u;
last_field_idx = 0u;
for (; it.HasNextInstanceField(); it.Next()) {
uint32_t field_idx = it.GetMemberIndex();
DCHECK_GE(field_idx, last_field_idx); // Ordering enforced by DexFileVerifier.
if (num_ifields == 0 || LIKELY(field_idx > last_field_idx)) {
DCHECK_LT(num_ifields, it.NumInstanceFields());
LoadField(it, klass, &ifields->At(num_ifields));
++num_ifields;
last_field_idx = field_idx;
}
}
if (UNLIKELY(num_sfields != it.NumStaticFields()) ||
UNLIKELY(num_ifields != it.NumInstanceFields())) {
LOG(WARNING) << "Duplicate fields in class " << PrettyDescriptor(klass.Get())
<< " (unique static fields: " << num_sfields << "/" << it.NumStaticFields()
<< ", unique instance fields: " << num_ifields << "/" << it.NumInstanceFields() << ")";
// NOTE: Not shrinking the over-allocated sfields/ifields, just setting size.
if (sfields != nullptr) {
sfields->SetSize(num_sfields);
}
if (ifields != nullptr) {
ifields->SetSize(num_ifields);
}
}
// Set the field arrays.
klass->SetSFieldsPtr(sfields);
DCHECK_EQ(klass->NumStaticFields(), num_sfields);
klass->SetIFieldsPtr(ifields);
DCHECK_EQ(klass->NumInstanceFields(), num_ifields);
// Load methods.
klass->SetDirectMethodsPtr(AllocArtMethodArray(self, allocator, it.NumDirectMethods()));
klass->SetVirtualMethodsPtr(AllocArtMethodArray(self, allocator, it.NumVirtualMethods()));
size_t class_def_method_index = 0;
uint32_t last_dex_method_index = DexFile::kDexNoIndex;
size_t last_class_def_method_index = 0;
for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) {
ArtMethod* method = klass->GetDirectMethodUnchecked(i, image_pointer_size_);
LoadMethod(self, dex_file, it, klass, method);
LinkCode(method, oat_class, class_def_method_index);
uint32_t it_method_index = it.GetMemberIndex();
if (last_dex_method_index == it_method_index) {
// duplicate case
method->SetMethodIndex(last_class_def_method_index);
} else {
method->SetMethodIndex(class_def_method_index);
last_dex_method_index = it_method_index;
last_class_def_method_index = class_def_method_index;
}
class_def_method_index++;
}
for (size_t i = 0; it.HasNextVirtualMethod(); i++, it.Next()) {
ArtMethod* method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_);
LoadMethod(self, dex_file, it, klass, method);
DCHECK_EQ(class_def_method_index, it.NumDirectMethods() + i);
LinkCode(method, oat_class, class_def_method_index);
class_def_method_index++;
}
DCHECK(!it.HasNext());
}
// Ensure that the card is marked so that remembered sets pick up native roots.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(klass.Get());
self->AllowThreadSuspension();
}
void ClassLinker::LoadField(const ClassDataItemIterator& it,
Handle<mirror::Class> klass,
ArtField* dst) {
const uint32_t field_idx = it.GetMemberIndex();
dst->SetDexFieldIndex(field_idx);
dst->SetDeclaringClass(klass.Get());
dst->SetAccessFlags(it.GetFieldAccessFlags());
}
void ClassLinker::LoadMethod(Thread* self,
const DexFile& dex_file,
const ClassDataItemIterator& it,
Handle<mirror::Class> klass,
ArtMethod* dst) {
uint32_t dex_method_idx = it.GetMemberIndex();
const DexFile::MethodId& method_id = dex_file.GetMethodId(dex_method_idx);
const char* method_name = dex_file.StringDataByIdx(method_id.name_idx_);
ScopedAssertNoThreadSuspension ants(self, "LoadMethod");
dst->SetDexMethodIndex(dex_method_idx);
dst->SetDeclaringClass(klass.Get());
dst->SetCodeItemOffset(it.GetMethodCodeItemOffset());
dst->SetDexCacheResolvedMethods(klass->GetDexCache()->GetResolvedMethods(), image_pointer_size_);
dst->SetDexCacheResolvedTypes(klass->GetDexCache()->GetResolvedTypes(), image_pointer_size_);
uint32_t access_flags = it.GetMethodAccessFlags();
if (UNLIKELY(strcmp("finalize", method_name) == 0)) {
// Set finalizable flag on declaring class.
if (strcmp("V", dex_file.GetShorty(method_id.proto_idx_)) == 0) {
// Void return type.
if (klass->GetClassLoader() != nullptr) { // All non-boot finalizer methods are flagged.
klass->SetFinalizable();
} else {
std::string temp;
const char* klass_descriptor = klass->GetDescriptor(&temp);
// The Enum class declares a "final" finalize() method to prevent subclasses from
// introducing a finalizer. We don't want to set the finalizable flag for Enum or its
// subclasses, so we exclude it here.
// We also want to avoid setting the flag on Object, where we know that finalize() is
// empty.
if (strcmp(klass_descriptor, "Ljava/lang/Object;") != 0 &&
strcmp(klass_descriptor, "Ljava/lang/Enum;") != 0) {
klass->SetFinalizable();
}
}
}
} else if (method_name[0] == '<') {
// Fix broken access flags for initializers. Bug 11157540.
bool is_init = (strcmp("<init>", method_name) == 0);
bool is_clinit = !is_init && (strcmp("<clinit>", method_name) == 0);
if (UNLIKELY(!is_init && !is_clinit)) {
LOG(WARNING) << "Unexpected '<' at start of method name " << method_name;
} else {
if (UNLIKELY((access_flags & kAccConstructor) == 0)) {
LOG(WARNING) << method_name << " didn't have expected constructor access flag in class "
<< PrettyDescriptor(klass.Get()) << " in dex file " << dex_file.GetLocation();
access_flags |= kAccConstructor;
}
}
}
dst->SetAccessFlags(access_flags);
}
void ClassLinker::AppendToBootClassPath(Thread* self, const DexFile& dex_file) {
StackHandleScope<1> hs(self);
Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(
self,
dex_file,
Runtime::Current()->GetLinearAlloc())));
CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for "
<< dex_file.GetLocation();
AppendToBootClassPath(dex_file, dex_cache);
}
void ClassLinker::AppendToBootClassPath(const DexFile& dex_file,
Handle<mirror::DexCache> dex_cache) {
CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation();
boot_class_path_.push_back(&dex_file);
RegisterDexFile(dex_file, dex_cache);
}
void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file,
Handle<mirror::DexCache> dex_cache) {
Thread* const self = Thread::Current();
dex_lock_.AssertExclusiveHeld(self);
CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation();
CHECK(dex_cache->GetLocation()->Equals(dex_file.GetLocation()))
<< dex_cache->GetLocation()->ToModifiedUtf8() << " " << dex_file.GetLocation();
// Clean up pass to remove null dex caches.
// Null dex caches can occur due to class unloading and we are lazily removing null entries.
JavaVMExt* const vm = self->GetJniEnv()->vm;
for (auto it = dex_caches_.begin(); it != dex_caches_.end(); ) {
DexCacheData data = *it;
if (self->IsJWeakCleared(data.weak_root)) {
vm->DeleteWeakGlobalRef(self, data.weak_root);
it = dex_caches_.erase(it);
} else {
++it;
}
}
jweak dex_cache_jweak = vm->AddWeakGlobalRef(self, dex_cache.Get());
dex_cache->SetDexFile(&dex_file);
DexCacheData data;
data.weak_root = dex_cache_jweak;
data.dex_file = dex_cache->GetDexFile();
data.resolved_types = dex_cache->GetResolvedTypes();
dex_caches_.push_back(data);
}
mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc) {
Thread* self = Thread::Current();
{
ReaderMutexLock mu(self, dex_lock_);
mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true);
if (dex_cache != nullptr) {
return dex_cache;
}
}
// Don't alloc while holding the lock, since allocation may need to
// suspend all threads and another thread may need the dex_lock_ to
// get to a suspend point.
StackHandleScope<1> hs(self);
Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(AllocDexCache(self, dex_file, linear_alloc)));
WriterMutexLock mu(self, dex_lock_);
mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true);
if (dex_cache != nullptr) {
return dex_cache;
}
if (h_dex_cache.Get() == nullptr) {
self->AssertPendingOOMException();
return nullptr;
}
RegisterDexFileLocked(dex_file, h_dex_cache);
return h_dex_cache.Get();
}
void ClassLinker::RegisterDexFile(const DexFile& dex_file,
Handle<mirror::DexCache> dex_cache) {
WriterMutexLock mu(Thread::Current(), dex_lock_);
RegisterDexFileLocked(dex_file, dex_cache);
}
mirror::DexCache* ClassLinker::FindDexCache(Thread* self,
const DexFile& dex_file,
bool allow_failure) {
ReaderMutexLock mu(self, dex_lock_);
return FindDexCacheLocked(self, dex_file, allow_failure);
}
mirror::DexCache* ClassLinker::FindDexCacheLocked(Thread* self,
const DexFile& dex_file,
bool allow_failure) {
// Search assuming unique-ness of dex file.
for (const DexCacheData& data : dex_caches_) {
// Avoid decoding (and read barriers) other unrelated dex caches.
if (data.dex_file == &dex_file) {
mirror::DexCache* dex_cache =
down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
if (dex_cache != nullptr) {
return dex_cache;
} else {
break;
}
}
}
if (allow_failure) {
return nullptr;
}
std::string location(dex_file.GetLocation());
// Failure, dump diagnostic and abort.
for (const DexCacheData& data : dex_caches_) {
mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
if (dex_cache != nullptr) {
LOG(ERROR) << "Registered dex file " << dex_cache->GetDexFile()->GetLocation();
}
}
LOG(FATAL) << "Failed to find DexCache for DexFile " << location;
UNREACHABLE();
}
void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) {
Thread* const self = Thread::Current();
ReaderMutexLock mu(self, dex_lock_);
for (const DexCacheData& data : dex_caches_) {
if (!self->IsJWeakCleared(data.weak_root)) {
mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(
self->DecodeJObject(data.weak_root));
if (dex_cache != nullptr) {
dex_cache->Fixup(resolution_method, image_pointer_size_);
}
}
}
}
mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) {
mirror::Class* klass = AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_));
if (UNLIKELY(klass == nullptr)) {
self->AssertPendingOOMException();
return nullptr;
}
return InitializePrimitiveClass(klass, type);
}
mirror::Class* ClassLinker::InitializePrimitiveClass(mirror::Class* primitive_class,
Primitive::Type type) {
CHECK(primitive_class != nullptr);
// Must hold lock on object when initializing.
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Class> h_class(hs.NewHandle(primitive_class));
ObjectLock<mirror::Class> lock(self, h_class);
h_class->SetAccessFlags(kAccPublic | kAccFinal | kAccAbstract);
h_class->SetPrimitiveType(type);
mirror::Class::SetStatus(h_class, mirror::Class::kStatusInitialized, self);
const char* descriptor = Primitive::Descriptor(type);
mirror::Class* existing = InsertClass(descriptor, h_class.Get(),
ComputeModifiedUtf8Hash(descriptor));
CHECK(existing == nullptr) << "InitPrimitiveClass(" << type << ") failed";
return h_class.Get();
}
// Create an array class (i.e. the class object for the array, not the
// array itself). "descriptor" looks like "[C" or "[[[[B" or
// "[Ljava/lang/String;".
//
// If "descriptor" refers to an array of primitives, look up the
// primitive type's internally-generated class object.
//
// "class_loader" is the class loader of the class that's referring to
// us. It's used to ensure that we're looking for the element type in
// the right context. It does NOT become the class loader for the
// array class; that always comes from the base element class.
//
// Returns null with an exception raised on failure.
mirror::Class* ClassLinker::CreateArrayClass(Thread* self, const char* descriptor, size_t hash,
Handle<mirror::ClassLoader> class_loader) {
// Identify the underlying component type
CHECK_EQ('[', descriptor[0]);
StackHandleScope<2> hs(self);
MutableHandle<mirror::Class> component_type(hs.NewHandle(FindClass(self, descriptor + 1,
class_loader)));
if (component_type.Get() == nullptr) {
DCHECK(self->IsExceptionPending());
// We need to accept erroneous classes as component types.
const size_t component_hash = ComputeModifiedUtf8Hash(descriptor + 1);
component_type.Assign(LookupClass(self, descriptor + 1, component_hash, class_loader.Get()));
if (component_type.Get() == nullptr) {
DCHECK(self->IsExceptionPending());
return nullptr;
} else {
self->ClearException();
}
}
if (UNLIKELY(component_type->IsPrimitiveVoid())) {
ThrowNoClassDefFoundError("Attempt to create array of void primitive type");
return nullptr;
}
// See if the component type is already loaded. Array classes are
// always associated with the class loader of their underlying
// element type -- an array of Strings goes with the loader for
// java/lang/String -- so we need to look for it there. (The
// caller should have checked for the existence of the class
// before calling here, but they did so with *their* class loader,
// not the component type's loader.)
//
// If we find it, the caller adds "loader" to the class' initiating
// loader list, which should prevent us from going through this again.
//
// This call is unnecessary if "loader" and "component_type->GetClassLoader()"
// are the same, because our caller (FindClass) just did the
// lookup. (Even if we get this wrong we still have correct behavior,
// because we effectively do this lookup again when we add the new
// class to the hash table --- necessary because of possible races with
// other threads.)
if (class_loader.Get() != component_type->GetClassLoader()) {
mirror::Class* new_class = LookupClass(self, descriptor, hash, component_type->GetClassLoader());
if (new_class != nullptr) {
return new_class;
}
}
// Fill out the fields in the Class.
//
// It is possible to execute some methods against arrays, because
// all arrays are subclasses of java_lang_Object_, so we need to set
// up a vtable. We can just point at the one in java_lang_Object_.
//
// Array classes are simple enough that we don't need to do a full
// link step.
auto new_class = hs.NewHandle<mirror::Class>(nullptr);
if (UNLIKELY(!init_done_)) {
// Classes that were hand created, ie not by FindSystemClass
if (strcmp(descriptor, "[Ljava/lang/Class;") == 0) {
new_class.Assign(GetClassRoot(kClassArrayClass));
} else if (strcmp(descriptor, "[Ljava/lang/Object;") == 0) {
new_class.Assign(GetClassRoot(kObjectArrayClass));
} else if (strcmp(descriptor, GetClassRootDescriptor(kJavaLangStringArrayClass)) == 0) {
new_class.Assign(GetClassRoot(kJavaLangStringArrayClass));
} else if (strcmp(descriptor, "[C") == 0) {
new_class.Assign(GetClassRoot(kCharArrayClass));
} else if (strcmp(descriptor, "[I") == 0) {
new_class.Assign(GetClassRoot(kIntArrayClass));
} else if (strcmp(descriptor, "[J") == 0) {
new_class.Assign(GetClassRoot(kLongArrayClass));
}
}
if (new_class.Get() == nullptr) {
new_class.Assign(AllocClass(self, mirror::Array::ClassSize(image_pointer_size_)));
if (new_class.Get() == nullptr) {
self->AssertPendingOOMException();
return nullptr;
}
new_class->SetComponentType(component_type.Get());
}
ObjectLock<mirror::Class> lock(self, new_class); // Must hold lock on object when initializing.
DCHECK(new_class->GetComponentType() != nullptr);
mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject);
new_class->SetSuperClass(java_lang_Object);
new_class->SetVTable(java_lang_Object->GetVTable());
new_class->SetPrimitiveType(Primitive::kPrimNot);
new_class->SetClassLoader(component_type->GetClassLoader());
if (component_type->IsPrimitive()) {
new_class->SetClassFlags(mirror::kClassFlagNoReferenceFields);
} else {
new_class->SetClassFlags(mirror::kClassFlagObjectArray);
}
mirror::Class::SetStatus(new_class, mirror::Class::kStatusLoaded, self);
{
ArtMethod* imt[mirror::Class::kImtSize];
std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod());
new_class->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_);
}
mirror::Class::SetStatus(new_class, mirror::Class::kStatusInitialized, self);
// don't need to set new_class->SetObjectSize(..)
// because Object::SizeOf delegates to Array::SizeOf
// All arrays have java/lang/Cloneable and java/io/Serializable as
// interfaces. We need to set that up here, so that stuff like
// "instanceof" works right.
//
// Note: The GC could run during the call to FindSystemClass,
// so we need to make sure the class object is GC-valid while we're in
// there. Do this by clearing the interface list so the GC will just
// think that the entries are null.
// Use the single, global copies of "interfaces" and "iftable"
// (remember not to free them for arrays).
{
mirror::IfTable* array_iftable = array_iftable_.Read();
CHECK(array_iftable != nullptr);
new_class->SetIfTable(array_iftable);
}
// Inherit access flags from the component type.
int access_flags = new_class->GetComponentType()->GetAccessFlags();
// Lose any implementation detail flags; in particular, arrays aren't finalizable.
access_flags &= kAccJavaFlagsMask;
// Arrays can't be used as a superclass or interface, so we want to add "abstract final"
// and remove "interface".
access_flags |= kAccAbstract | kAccFinal;
access_flags &= ~kAccInterface;
new_class->SetAccessFlags(access_flags);
mirror::Class* existing = InsertClass(descriptor, new_class.Get(), hash);
if (existing == nullptr) {
return new_class.Get();
}
// Another thread must have loaded the class after we
// started but before we finished. Abandon what we've
// done.
//
// (Yes, this happens.)
return existing;
}
mirror::Class* ClassLinker::FindPrimitiveClass(char type) {
switch (type) {
case 'B':
return GetClassRoot(kPrimitiveByte);
case 'C':
return GetClassRoot(kPrimitiveChar);
case 'D':
return GetClassRoot(kPrimitiveDouble);
case 'F':
return GetClassRoot(kPrimitiveFloat);
case 'I':
return GetClassRoot(kPrimitiveInt);
case 'J':
return GetClassRoot(kPrimitiveLong);
case 'S':
return GetClassRoot(kPrimitiveShort);
case 'Z':
return GetClassRoot(kPrimitiveBoolean);
case 'V':
return GetClassRoot(kPrimitiveVoid);
default:
break;
}
std::string printable_type(PrintableChar(type));
ThrowNoClassDefFoundError("Not a primitive type: %s", printable_type.c_str());
return nullptr;
}
mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* klass, size_t hash) {
if (VLOG_IS_ON(class_linker)) {
mirror::DexCache* dex_cache = klass->GetDexCache();
std::string source;
if (dex_cache != nullptr) {
source += " from ";
source += dex_cache->GetLocation()->ToModifiedUtf8();
}
LOG(INFO) << "Loaded class " << descriptor << source;
}
WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
mirror::ClassLoader* const class_loader = klass->GetClassLoader();
ClassTable* const class_table = InsertClassTableForClassLoader(class_loader);
mirror::Class* existing = class_table->Lookup(descriptor, hash);
if (existing != nullptr) {
return existing;
}
if (kIsDebugBuild &&
!klass->IsTemp() &&
class_loader == nullptr &&
dex_cache_boot_image_class_lookup_required_) {
// Check a class loaded with the system class loader matches one in the image if the class
// is in the image.
existing = LookupClassFromBootImage(descriptor);
if (existing != nullptr) {
CHECK_EQ(klass, existing);
}
}
VerifyObject(klass);
class_table->InsertWithHash(klass, hash);
if (class_loader != nullptr) {
// This is necessary because we need to have the card dirtied for remembered sets.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader);
}
if (log_new_class_table_roots_) {
new_class_roots_.push_back(GcRoot<mirror::Class>(klass));
}
return nullptr;
}
void ClassLinker::UpdateClassVirtualMethods(mirror::Class* klass,
LengthPrefixedArray<ArtMethod>* new_methods) {
klass->SetVirtualMethodsPtr(new_methods);
// Need to mark the card so that the remembered sets and mod union tables get updated.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(klass);
}
bool ClassLinker::RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader) {
WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
ClassTable* const class_table = ClassTableForClassLoader(class_loader);
return class_table != nullptr && class_table->Remove(descriptor);
}
mirror::Class* ClassLinker::LookupClass(Thread* self,
const char* descriptor,
size_t hash,
mirror::ClassLoader* class_loader) {
{
ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
ClassTable* const class_table = ClassTableForClassLoader(class_loader);
if (class_table != nullptr) {
mirror::Class* result = class_table->Lookup(descriptor, hash);
if (result != nullptr) {
return result;
}
}
}
if (class_loader != nullptr || !dex_cache_boot_image_class_lookup_required_) {
return nullptr;
}
// Lookup failed but need to search dex_caches_.
mirror::Class* result = LookupClassFromBootImage(descriptor);
if (result != nullptr) {
result = InsertClass(descriptor, result, hash);
} else {
// Searching the image dex files/caches failed, we don't want to get into this situation
// often as map searches are faster, so after kMaxFailedDexCacheLookups move all image
// classes into the class table.
constexpr uint32_t kMaxFailedDexCacheLookups = 1000;
if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) {
AddBootImageClassesToClassTable();
}
}
return result;
}
static mirror::ObjectArray<mirror::DexCache>* GetImageDexCaches(gc::space::ImageSpace* image_space)
SHARED_REQUIRES(Locks::mutator_lock_) {
CHECK(image_space != nullptr);
mirror::Object* root = image_space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches);
DCHECK(root != nullptr);
return root->AsObjectArray<mirror::DexCache>();
}
void ClassLinker::AddBootImageClassesToClassTable() {
if (dex_cache_boot_image_class_lookup_required_) {
AddImageClassesToClassTable(Runtime::Current()->GetHeap()->GetBootImageSpace(),
/*class_loader*/nullptr);
dex_cache_boot_image_class_lookup_required_ = false;
}
}
void ClassLinker::AddImageClassesToClassTable(gc::space::ImageSpace* image_space,
mirror::ClassLoader* class_loader) {
Thread* self = Thread::Current();
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table");
ClassTable* const class_table = InsertClassTableForClassLoader(class_loader);
mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(image_space);
std::string temp;
for (int32_t i = 0; i < dex_caches->GetLength(); i++) {
mirror::DexCache* dex_cache = dex_caches->Get(i);
GcRoot<mirror::Class>* types = dex_cache->GetResolvedTypes();
for (int32_t j = 0, num_types = dex_cache->NumResolvedTypes(); j < num_types; j++) {
mirror::Class* klass = types[j].Read();
if (klass != nullptr) {
DCHECK_EQ(klass->GetClassLoader(), class_loader);
const char* descriptor = klass->GetDescriptor(&temp);
size_t hash = ComputeModifiedUtf8Hash(descriptor);
mirror::Class* existing = class_table->Lookup(descriptor, hash);
if (existing != nullptr) {
CHECK_EQ(existing, klass) << PrettyClassAndClassLoader(existing) << " != "
<< PrettyClassAndClassLoader(klass);
} else {
class_table->Insert(klass);
if (log_new_class_table_roots_) {
new_class_roots_.push_back(GcRoot<mirror::Class>(klass));
}
}
}
}
}
}
class MoveClassTableToPreZygoteVisitor : public ClassLoaderVisitor {
public:
explicit MoveClassTableToPreZygoteVisitor() {}
void Visit(mirror::ClassLoader* class_loader)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_) OVERRIDE {
ClassTable* const class_table = class_loader->GetClassTable();
if (class_table != nullptr) {
class_table->FreezeSnapshot();
}
}
};
void ClassLinker::MoveClassTableToPreZygote() {
WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
boot_class_table_.FreezeSnapshot();
MoveClassTableToPreZygoteVisitor visitor;
VisitClassLoaders(&visitor);
}
mirror::Class* ClassLinker::LookupClassFromBootImage(const char* descriptor) {
ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup");
mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(
Runtime::Current()->GetHeap()->GetBootImageSpace());
for (int32_t i = 0; i < dex_caches->GetLength(); ++i) {
mirror::DexCache* dex_cache = dex_caches->Get(i);
const DexFile* dex_file = dex_cache->GetDexFile();
// Try binary searching the type index by descriptor.
const DexFile::TypeId* type_id = dex_file->FindTypeId(descriptor);
if (type_id != nullptr) {
uint16_t type_idx = dex_file->GetIndexForTypeId(*type_id);
mirror::Class* klass = dex_cache->GetResolvedType(type_idx);
if (klass != nullptr) {
return klass;
}
}
}
return nullptr;
}
// Look up classes by hash and descriptor and put all matching ones in the result array.
class LookupClassesVisitor : public ClassLoaderVisitor {
public:
LookupClassesVisitor(const char* descriptor, size_t hash, std::vector<mirror::Class*>* result)
: descriptor_(descriptor),
hash_(hash),
result_(result) {}
void Visit(mirror::ClassLoader* class_loader)
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE {
ClassTable* const class_table = class_loader->GetClassTable();
mirror::Class* klass = class_table->Lookup(descriptor_, hash_);
if (klass != nullptr) {
result_->push_back(klass);
}
}
private:
const char* const descriptor_;
const size_t hash_;
std::vector<mirror::Class*>* const result_;
};
void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Class*>& result) {
result.clear();
if (dex_cache_boot_image_class_lookup_required_) {
AddBootImageClassesToClassTable();
}
Thread* const self = Thread::Current();
ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
const size_t hash = ComputeModifiedUtf8Hash(descriptor);
mirror::Class* klass = boot_class_table_.Lookup(descriptor, hash);
if (klass != nullptr) {
result.push_back(klass);
}
LookupClassesVisitor visitor(descriptor, hash, &result);
VisitClassLoaders(&visitor);
}
bool ClassLinker::AttemptSupertypeVerification(Thread* self,
Handle<mirror::Class> klass,
Handle<mirror::Class> supertype) {
DCHECK(self != nullptr);
DCHECK(klass.Get() != nullptr);
DCHECK(supertype.Get() != nullptr);
StackHandleScope<1> hs(self);
// Acquire lock to prevent races on verifying the super class.
ObjectLock<mirror::Class> super_lock(self, supertype);
if (!supertype->IsVerified() && !supertype->IsErroneous()) {
VerifyClass(self, supertype);
}
if (supertype->IsCompileTimeVerified()) {
// Either we are verified or we soft failed and need to retry at runtime.
return true;
}
// If we got this far then we have a hard failure.
std::string error_msg =
StringPrintf("Rejecting class %s that attempts to sub-type erroneous class %s",
PrettyDescriptor(klass.Get()).c_str(),
PrettyDescriptor(supertype.Get()).c_str());
LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8();
Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException()));
if (cause.Get() != nullptr) {
// Set during VerifyClass call (if at all).
self->ClearException();
}
// Change into a verify error.
ThrowVerifyError(klass.Get(), "%s", error_msg.c_str());
if (cause.Get() != nullptr) {
self->GetException()->SetCause(cause.Get());
}
ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex());
if (Runtime::Current()->IsAotCompiler()) {
Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref);
}
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) {
// TODO: assert that the monitor on the Class is held
ObjectLock<mirror::Class> lock(self, klass);
// Don't attempt to re-verify if already sufficiently verified.
if (klass->IsVerified()) {
EnsurePreverifiedMethods(klass);
return;
}
if (klass->IsCompileTimeVerified() && Runtime::Current()->IsAotCompiler()) {
return;
}
// The class might already be erroneous, for example at compile time if we attempted to verify
// this class as a parent to another.
if (klass->IsErroneous()) {
ThrowEarlierClassFailure(klass.Get());
return;
}
if (klass->GetStatus() == mirror::Class::kStatusResolved) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifying, self);
} else {
CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime)
<< PrettyClass(klass.Get());
CHECK(!Runtime::Current()->IsAotCompiler());
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifyingAtRuntime, self);
}
// Skip verification if we are forcing a soft fail.
// This has to be before the normal verification enabled check,
// since technically verification is disabled in this mode.
if (UNLIKELY(Runtime::Current()->IsVerificationSoftFail())) {
// Force verification to be a 'soft failure'.
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self);
// As this is a fake verified status, make sure the methods are _not_ marked preverified
// later.
klass->SetPreverified();
return;
}
// Skip verification if disabled.
if (!Runtime::Current()->IsVerificationEnabled()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self);
EnsurePreverifiedMethods(klass);
return;
}
// Verify super class.
StackHandleScope<2> hs(self);
MutableHandle<mirror::Class> supertype(hs.NewHandle(klass->GetSuperClass()));
// If we have a superclass and we get a hard verification failure we can return immediately.
if (supertype.Get() != nullptr && !AttemptSupertypeVerification(self, klass, supertype)) {
CHECK(self->IsExceptionPending()) << "Verification error should be pending.";
return;
}
// Verify all default super-interfaces.
//
// (1) Don't bother if the superclass has already had a soft verification failure.
//
// (2) Interfaces shouldn't bother to do this recursive verification because they cannot cause
// recursive initialization by themselves. This is because when an interface is initialized
// directly it must not initialize its superinterfaces. We are allowed to verify regardless
// but choose not to for an optimization. If the interfaces is being verified due to a class
// initialization (which would need all the default interfaces to be verified) the class code
// will trigger the recursive verification anyway.
if ((supertype.Get() == nullptr || supertype->IsVerified()) // See (1)
&& !klass->IsInterface()) { // See (2)
int32_t iftable_count = klass->GetIfTableCount();
MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr));
// Loop through all interfaces this class has defined. It doesn't matter the order.
for (int32_t i = 0; i < iftable_count; i++) {
iface.Assign(klass->GetIfTable()->GetInterface(i));
DCHECK(iface.Get() != nullptr);
// We only care if we have default interfaces and can skip if we are already verified...
if (LIKELY(!iface->HasDefaultMethods() || iface->IsVerified())) {
continue;
} else if (UNLIKELY(!AttemptSupertypeVerification(self, klass, iface))) {
// We had a hard failure while verifying this interface. Just return immediately.
CHECK(self->IsExceptionPending()) << "Verification error should be pending.";
return;
} else if (UNLIKELY(!iface->IsVerified())) {
// We softly failed to verify the iface. Stop checking and clean up.
// Put the iface into the supertype handle so we know what caused us to fail.
supertype.Assign(iface.Get());
break;
}
}
}
// At this point if verification failed, then supertype is the "first" supertype that failed
// verification (without a specific order). If verification succeeded, then supertype is either
// null or the original superclass of klass and is verified.
DCHECK(supertype.Get() == nullptr ||
supertype.Get() == klass->GetSuperClass() ||
!supertype->IsVerified());
// Try to use verification information from the oat file, otherwise do runtime verification.
const DexFile& dex_file = *klass->GetDexCache()->GetDexFile();
mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady);
bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status);
// If the oat file says the class had an error, re-run the verifier. That way we will get a
// precise error message. To ensure a rerun, test:
// oat_file_class_status == mirror::Class::kStatusError => !preverified
DCHECK(!(oat_file_class_status == mirror::Class::kStatusError) || !preverified);
verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure;
std::string error_msg;
if (!preverified) {
Runtime* runtime = Runtime::Current();
verifier_failure = verifier::MethodVerifier::VerifyClass(self,
klass.Get(),
runtime->GetCompilerCallbacks(),
runtime->IsAotCompiler(),
runtime->IsAotCompiler(),
&error_msg);
}
if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) {
if (!preverified && verifier_failure != verifier::MethodVerifier::kNoFailure) {
VLOG(class_linker) << "Soft verification failure in class " << PrettyDescriptor(klass.Get())
<< " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8()
<< " because: " << error_msg;
}
self->AssertNoPendingException();
// Make sure all classes referenced by catch blocks are resolved.
ResolveClassExceptionHandlerTypes(dex_file, klass);
if (verifier_failure == verifier::MethodVerifier::kNoFailure) {
// Even though there were no verifier failures we need to respect whether the super-class and
// super-default-interfaces were verified or requiring runtime reverification.
if (supertype.Get() == nullptr || supertype->IsVerified()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self);
} else {
CHECK_EQ(supertype->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime);
mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self);
// Pretend a soft failure occurred so that we don't consider the class verified below.
verifier_failure = verifier::MethodVerifier::kSoftFailure;
}
} else {
CHECK_EQ(verifier_failure, verifier::MethodVerifier::kSoftFailure);
// Soft failures at compile time should be retried at runtime. Soft
// failures at runtime will be handled by slow paths in the generated
// code. Set status accordingly.
if (Runtime::Current()->IsAotCompiler()) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self);
} else {
mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self);
// As this is a fake verified status, make sure the methods are _not_ marked preverified
// later.
klass->SetPreverified();
}
}
} else {
VLOG(verifier) << "Verification failed on class " << PrettyDescriptor(klass.Get())
<< " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8()
<< " because: " << error_msg;
self->AssertNoPendingException();
ThrowVerifyError(klass.Get(), "%s", error_msg.c_str());
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
}
if (preverified || verifier_failure == verifier::MethodVerifier::kNoFailure) {
// Class is verified so we don't need to do any access check on its methods.
// Let the interpreter know it by setting the kAccPreverified flag onto each
// method.
// Note: we're going here during compilation and at runtime. When we set the
// kAccPreverified flag when compiling image classes, the flag is recorded
// in the image and is set when loading the image.
EnsurePreverifiedMethods(klass);
}
}
void ClassLinker::EnsurePreverifiedMethods(Handle<mirror::Class> klass) {
if (!klass->IsPreverified()) {
klass->SetPreverifiedFlagOnAllMethods(image_pointer_size_);
klass->SetPreverified();
}
}
bool ClassLinker::VerifyClassUsingOatFile(const DexFile& dex_file,
mirror::Class* klass,
mirror::Class::Status& oat_file_class_status) {
// If we're compiling, we can only verify the class using the oat file if
// we are not compiling the image or if the class we're verifying is not part of
// the app. In other words, we will only check for preverification of bootclasspath
// classes.
if (Runtime::Current()->IsAotCompiler()) {
// Are we compiling the bootclasspath?
if (Runtime::Current()->GetCompilerCallbacks()->IsBootImage()) {
return false;
}
// We are compiling an app (not the image).
// Is this an app class? (I.e. not a bootclasspath class)
if (klass->GetClassLoader() != nullptr) {
return false;
}
}
const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile();
// In case we run without an image there won't be a backing oat file.
if (oat_dex_file == nullptr) {
return false;
}
// We may be running with a preopted oat file but without image. In this case,
// we don't skip verification of preverified classes to ensure we initialize
// dex caches with all types resolved during verification.
// We need to trust image classes, as these might be coming out of a pre-opted, quickened boot
// image (that we just failed loading), and the verifier can't be run on quickened opcodes when
// the runtime isn't started. On the other hand, app classes can be re-verified even if they are
// already pre-opted, as then the runtime is started.
if (!Runtime::Current()->IsAotCompiler() &&
!Runtime::Current()->GetHeap()->HasImageSpace() &&
klass->GetClassLoader() != nullptr) {
return false;
}
uint16_t class_def_index = klass->GetDexClassDefIndex();
oat_file_class_status = oat_dex_file->GetOatClass(class_def_index).GetStatus();
if (oat_file_class_status == mirror::Class::kStatusVerified ||
oat_file_class_status == mirror::Class::kStatusInitialized) {
return true;
}
if (oat_file_class_status == mirror::Class::kStatusRetryVerificationAtRuntime) {
// Compile time verification failed with a soft error. Compile time verification can fail
// because we have incomplete type information. Consider the following:
// class ... {
// Foo x;
// .... () {
// if (...) {
// v1 gets assigned a type of resolved class Foo
// } else {
// v1 gets assigned a type of unresolved class Bar
// }
// iput x = v1
// } }
// when we merge v1 following the if-the-else it results in Conflict
// (see verifier::RegType::Merge) as we can't know the type of Bar and we could possibly be
// allowing an unsafe assignment to the field x in the iput (javac may have compiled this as
// it knew Bar was a sub-class of Foo, but for us this may have been moved into a separate apk
// at compile time).
return false;
}
if (oat_file_class_status == mirror::Class::kStatusError) {
// Compile time verification failed with a hard error. This is caused by invalid instructions
// in the class. These errors are unrecoverable.
return false;
}
if (oat_file_class_status == mirror::Class::kStatusNotReady) {
// Status is uninitialized if we couldn't determine the status at compile time, for example,
// not loading the class.
// TODO: when the verifier doesn't rely on Class-es failing to resolve/load the type hierarchy
// isn't a problem and this case shouldn't occur
return false;
}
std::string temp;
LOG(FATAL) << "Unexpected class status: " << oat_file_class_status
<< " " << dex_file.GetLocation() << " " << PrettyClass(klass) << " "
<< klass->GetDescriptor(&temp);
UNREACHABLE();
}
void ClassLinker::ResolveClassExceptionHandlerTypes(const DexFile& dex_file,
Handle<mirror::Class> klass) {
for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
ResolveMethodExceptionHandlerTypes(dex_file, klass->GetDirectMethod(i, image_pointer_size_));
}
for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
ResolveMethodExceptionHandlerTypes(dex_file, klass->GetVirtualMethod(i, image_pointer_size_));
}
}
void ClassLinker::ResolveMethodExceptionHandlerTypes(const DexFile& dex_file,
ArtMethod* method) {
// similar to DexVerifier::ScanTryCatchBlocks and dex2oat's ResolveExceptionsForMethod.
const DexFile::CodeItem* code_item = dex_file.GetCodeItem(method->GetCodeItemOffset());
if (code_item == nullptr) {
return; // native or abstract method
}
if (code_item->tries_size_ == 0) {
return; // nothing to process
}
const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*code_item, 0);
uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
for (uint32_t idx = 0; idx < handlers_size; idx++) {
CatchHandlerIterator iterator(handlers_ptr);
for (; iterator.HasNext(); iterator.Next()) {
// Ensure exception types are resolved so that they don't need resolution to be delivered,
// unresolved exception types will be ignored by exception delivery
if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) {
mirror::Class* exception_type = ResolveType(iterator.GetHandlerTypeIndex(), method);
if (exception_type == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
Thread::Current()->ClearException();
}
}
}
handlers_ptr = iterator.EndDataPointer();
}
}
mirror::Class* ClassLinker::CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa,
jstring name,
jobjectArray interfaces,
jobject loader,
jobjectArray methods,
jobjectArray throws) {
Thread* self = soa.Self();
StackHandleScope<10> hs(self);
MutableHandle<mirror::Class> klass(hs.NewHandle(
AllocClass(self, GetClassRoot(kJavaLangClass), sizeof(mirror::Class))));
if (klass.Get() == nullptr) {
CHECK(self->IsExceptionPending()); // OOME.
return nullptr;
}
DCHECK(klass->GetClass() != nullptr);
klass->SetObjectSize(sizeof(mirror::Proxy));
// Set the class access flags incl. preverified, so we do not try to set the flag on the methods.
klass->SetAccessFlags(kAccClassIsProxy | kAccPublic | kAccFinal | kAccPreverified);
klass->SetClassLoader(soa.Decode<mirror::ClassLoader*>(loader));
DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot);
klass->SetName(soa.Decode<mirror::String*>(name));
klass->SetDexCache(GetClassRoot(kJavaLangReflectProxy)->GetDexCache());
mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, self);
std::string descriptor(GetDescriptorForProxy(klass.Get()));
const size_t hash = ComputeModifiedUtf8Hash(descriptor.c_str());
// Needs to be before we insert the class so that the allocator field is set.
LinearAlloc* const allocator = GetOrCreateAllocatorForClassLoader(klass->GetClassLoader());
// Insert the class before loading the fields as the field roots
// (ArtField::declaring_class_) are only visited from the class
// table. There can't be any suspend points between inserting the
// class and setting the field arrays below.
mirror::Class* existing = InsertClass(descriptor.c_str(), klass.Get(), hash);
CHECK(existing == nullptr);
// Instance fields are inherited, but we add a couple of static fields...
const size_t num_fields = 2;
LengthPrefixedArray<ArtField>* sfields = AllocArtFieldArray(self, allocator, num_fields);
klass->SetSFieldsPtr(sfields);
// 1. Create a static field 'interfaces' that holds the _declared_ interfaces implemented by
// our proxy, so Class.getInterfaces doesn't return the flattened set.
ArtField& interfaces_sfield = sfields->At(0);
interfaces_sfield.SetDexFieldIndex(0);
interfaces_sfield.SetDeclaringClass(klass.Get());
interfaces_sfield.SetAccessFlags(kAccStatic | kAccPublic | kAccFinal);
// 2. Create a static field 'throws' that holds exceptions thrown by our methods.
ArtField& throws_sfield = sfields->At(1);
throws_sfield.SetDexFieldIndex(1);
throws_sfield.SetDeclaringClass(klass.Get());
throws_sfield.SetAccessFlags(kAccStatic | kAccPublic | kAccFinal);
// Proxies have 1 direct method, the constructor
LengthPrefixedArray<ArtMethod>* directs = AllocArtMethodArray(self, allocator, 1);
// Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we
// want to throw OOM in the future.
if (UNLIKELY(directs == nullptr)) {
self->AssertPendingOOMException();
return nullptr;
}
klass->SetDirectMethodsPtr(directs);
CreateProxyConstructor(klass, klass->GetDirectMethodUnchecked(0, image_pointer_size_));
// Create virtual method using specified prototypes.
auto h_methods = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Method>*>(methods));
DCHECK_EQ(h_methods->GetClass(), mirror::Method::ArrayClass())
<< PrettyClass(h_methods->GetClass());
const size_t num_virtual_methods = h_methods->GetLength();
auto* virtuals = AllocArtMethodArray(self, allocator, num_virtual_methods);
// Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we
// want to throw OOM in the future.
if (UNLIKELY(virtuals == nullptr)) {
self->AssertPendingOOMException();
return nullptr;
}
klass->SetVirtualMethodsPtr(virtuals);
for (size_t i = 0; i < num_virtual_methods; ++i) {
auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_);
auto* prototype = h_methods->Get(i)->GetArtMethod();
CreateProxyMethod(klass, prototype, virtual_method);
DCHECK(virtual_method->GetDeclaringClass() != nullptr);
DCHECK(prototype->GetDeclaringClass() != nullptr);
}
// The super class is java.lang.reflect.Proxy
klass->SetSuperClass(GetClassRoot(kJavaLangReflectProxy));
// Now effectively in the loaded state.
mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, self);
self->AssertNoPendingException();
MutableHandle<mirror::Class> new_class = hs.NewHandle<mirror::Class>(nullptr);
{
// Must hold lock on object when resolved.
ObjectLock<mirror::Class> resolution_lock(self, klass);
// Link the fields and virtual methods, creating vtable and iftables.
// The new class will replace the old one in the class table.
Handle<mirror::ObjectArray<mirror::Class>> h_interfaces(
hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces)));
if (!LinkClass(self, descriptor.c_str(), klass, h_interfaces, &new_class)) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return nullptr;
}
}
CHECK(klass->IsRetired());
CHECK_NE(klass.Get(), new_class.Get());
klass.Assign(new_class.Get());
CHECK_EQ(interfaces_sfield.GetDeclaringClass(), klass.Get());
interfaces_sfield.SetObject<false>(klass.Get(),
soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces));
CHECK_EQ(throws_sfield.GetDeclaringClass(), klass.Get());
throws_sfield.SetObject<false>(
klass.Get(), soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class> >*>(throws));
{
// Lock on klass is released. Lock new class object.
ObjectLock<mirror::Class> initialization_lock(self, klass);
mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self);
}
// sanity checks
if (kIsDebugBuild) {
CHECK(klass->GetIFieldsPtr() == nullptr);
CheckProxyConstructor(klass->GetDirectMethod(0, image_pointer_size_));
for (size_t i = 0; i < num_virtual_methods; ++i) {
auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_);
auto* prototype = h_methods->Get(i++)->GetArtMethod();
CheckProxyMethod(virtual_method, prototype);
}
StackHandleScope<1> hs2(self);
Handle<mirror::String> decoded_name = hs2.NewHandle(soa.Decode<mirror::String*>(name));
std::string interfaces_field_name(StringPrintf("java.lang.Class[] %s.interfaces",
decoded_name->ToModifiedUtf8().c_str()));
CHECK_EQ(PrettyField(klass->GetStaticField(0)), interfaces_field_name);
std::string throws_field_name(StringPrintf("java.lang.Class[][] %s.throws",
decoded_name->ToModifiedUtf8().c_str()));
CHECK_EQ(PrettyField(klass->GetStaticField(1)), throws_field_name);
CHECK_EQ(klass.Get()->GetInterfaces(),
soa.Decode<mirror::ObjectArray<mirror::Class>*>(interfaces));
CHECK_EQ(klass.Get()->GetThrows(),
soa.Decode<mirror::ObjectArray<mirror::ObjectArray<mirror::Class>>*>(throws));
}
return klass.Get();
}
std::string ClassLinker::GetDescriptorForProxy(mirror::Class* proxy_class) {
DCHECK(proxy_class->IsProxyClass());
mirror::String* name = proxy_class->GetName();
DCHECK(name != nullptr);
return DotToDescriptor(name->ToModifiedUtf8().c_str());
}
ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, ArtMethod* proxy_method) {
DCHECK(proxy_class->IsProxyClass());
DCHECK(proxy_method->IsProxyMethod());
{
Thread* const self = Thread::Current();
ReaderMutexLock mu(self, dex_lock_);
// Locate the dex cache of the original interface/Object
for (const DexCacheData& data : dex_caches_) {
if (!self->IsJWeakCleared(data.weak_root) &&
proxy_method->HasSameDexCacheResolvedTypes(data.resolved_types,
image_pointer_size_)) {
mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(
self->DecodeJObject(data.weak_root));
if (dex_cache != nullptr) {
ArtMethod* resolved_method = dex_cache->GetResolvedMethod(
proxy_method->GetDexMethodIndex(), image_pointer_size_);
CHECK(resolved_method != nullptr);
return resolved_method;
}
}
}
}
LOG(FATAL) << "Didn't find dex cache for " << PrettyClass(proxy_class) << " "
<< PrettyMethod(proxy_method);
UNREACHABLE();
}
void ClassLinker::CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out) {
// Create constructor for Proxy that must initialize the method.
CHECK_EQ(GetClassRoot(kJavaLangReflectProxy)->NumDirectMethods(), 16u);
ArtMethod* proxy_constructor = GetClassRoot(kJavaLangReflectProxy)->GetDirectMethodUnchecked(
2, image_pointer_size_);
// Ensure constructor is in dex cache so that we can use the dex cache to look up the overridden
// constructor method.
GetClassRoot(kJavaLangReflectProxy)->GetDexCache()->SetResolvedMethod(
proxy_constructor->GetDexMethodIndex(), proxy_constructor, image_pointer_size_);
// Clone the existing constructor of Proxy (our constructor would just invoke it so steal its
// code_ too)
DCHECK(out != nullptr);
out->CopyFrom(proxy_constructor, image_pointer_size_);
// Make this constructor public and fix the class to be our Proxy version
out->SetAccessFlags((out->GetAccessFlags() & ~kAccProtected) | kAccPublic);
out->SetDeclaringClass(klass.Get());
}
void ClassLinker::CheckProxyConstructor(ArtMethod* constructor) const {
CHECK(constructor->IsConstructor());
auto* np = constructor->GetInterfaceMethodIfProxy(image_pointer_size_);
CHECK_STREQ(np->GetName(), "<init>");
CHECK_STREQ(np->GetSignature().ToString().c_str(), "(Ljava/lang/reflect/InvocationHandler;)V");
DCHECK(constructor->IsPublic());
}
void ClassLinker::CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype,
ArtMethod* out) {
// Ensure prototype is in dex cache so that we can use the dex cache to look up the overridden
// prototype method
auto* dex_cache = prototype->GetDeclaringClass()->GetDexCache();
// Avoid dirtying the dex cache unless we need to.
if (dex_cache->GetResolvedMethod(prototype->GetDexMethodIndex(), image_pointer_size_) !=
prototype) {
dex_cache->SetResolvedMethod(
prototype->GetDexMethodIndex(), prototype, image_pointer_size_);
}
// We steal everything from the prototype (such as DexCache, invoke stub, etc.) then specialize
// as necessary
DCHECK(out != nullptr);
out->CopyFrom(prototype, image_pointer_size_);
// Set class to be the concrete proxy class and clear the abstract flag, modify exceptions to
// the intersection of throw exceptions as defined in Proxy
out->SetDeclaringClass(klass.Get());
out->SetAccessFlags((out->GetAccessFlags() & ~kAccAbstract) | kAccFinal);
// At runtime the method looks like a reference and argument saving method, clone the code
// related parameters from this method.
out->SetEntryPointFromQuickCompiledCode(GetQuickProxyInvokeHandler());
}
void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const {
// Basic sanity
CHECK(!prototype->IsFinal());
CHECK(method->IsFinal());
CHECK(method->IsInvokable());
// The proxy method doesn't have its own dex cache or dex file and so it steals those of its
// interface prototype. The exception to this are Constructors and the Class of the Proxy itself.
CHECK(prototype->HasSameDexCacheResolvedMethods(method, image_pointer_size_));
CHECK(prototype->HasSameDexCacheResolvedTypes(method, image_pointer_size_));
auto* np = method->GetInterfaceMethodIfProxy(image_pointer_size_);
CHECK_EQ(prototype->GetDeclaringClass()->GetDexCache(), np->GetDexCache());
CHECK_EQ(prototype->GetDexMethodIndex(), method->GetDexMethodIndex());
CHECK_STREQ(np->GetName(), prototype->GetName());
CHECK_STREQ(np->GetShorty(), prototype->GetShorty());
// More complex sanity - via dex cache
CHECK_EQ(np->GetReturnType(true /* resolve */, image_pointer_size_),
prototype->GetReturnType(true /* resolve */, image_pointer_size_));
}
bool ClassLinker::CanWeInitializeClass(mirror::Class* klass, bool can_init_statics,
bool can_init_parents) {
if (can_init_statics && can_init_parents) {
return true;
}
if (!can_init_statics) {
// Check if there's a class initializer.
ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_);
if (clinit != nullptr) {
return false;
}
// Check if there are encoded static values needing initialization.
if (klass->NumStaticFields() != 0) {
const DexFile::ClassDef* dex_class_def = klass->GetClassDef();
DCHECK(dex_class_def != nullptr);
if (dex_class_def->static_values_off_ != 0) {
return false;
}
}
// If we are a class we need to initialize all interfaces with default methods when we are
// initialized. Check all of them.
if (!klass->IsInterface()) {
size_t num_interfaces = klass->GetIfTableCount();
for (size_t i = 0; i < num_interfaces; i++) {
mirror::Class* iface = klass->GetIfTable()->GetInterface(i);
if (iface->HasDefaultMethods() &&
!CanWeInitializeClass(iface, can_init_statics, can_init_parents)) {
return false;
}
}
}
}
if (klass->IsInterface() || !klass->HasSuperClass()) {
return true;
}
mirror::Class* super_class = klass->GetSuperClass();
if (!can_init_parents && !super_class->IsInitialized()) {
return false;
}
return CanWeInitializeClass(super_class, can_init_statics, can_init_parents);
}
bool ClassLinker::InitializeClass(Thread* self, Handle<mirror::Class> klass,
bool can_init_statics, bool can_init_parents) {
// see JLS 3rd edition, 12.4.2 "Detailed Initialization Procedure" for the locking protocol
// Are we already initialized and therefore done?
// Note: we differ from the JLS here as we don't do this under the lock, this is benign as
// an initialized class will never change its state.
if (klass->IsInitialized()) {
return true;
}
// Fast fail if initialization requires a full runtime. Not part of the JLS.
if (!CanWeInitializeClass(klass.Get(), can_init_statics, can_init_parents)) {
return false;
}
self->AllowThreadSuspension();
uint64_t t0;
{
ObjectLock<mirror::Class> lock(self, klass);
// Re-check under the lock in case another thread initialized ahead of us.
if (klass->IsInitialized()) {
return true;
}
// Was the class already found to be erroneous? Done under the lock to match the JLS.
if (klass->IsErroneous()) {
ThrowEarlierClassFailure(klass.Get(), true);
VlogClassInitializationFailure(klass);
return false;
}
CHECK(klass->IsResolved()) << PrettyClass(klass.Get()) << ": state=" << klass->GetStatus();
if (!klass->IsVerified()) {
VerifyClass(self, klass);
if (!klass->IsVerified()) {
// We failed to verify, expect either the klass to be erroneous or verification failed at
// compile time.
if (klass->IsErroneous()) {
CHECK(self->IsExceptionPending());
VlogClassInitializationFailure(klass);
} else {
CHECK(Runtime::Current()->IsAotCompiler());
CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime);
}
return false;
} else {
self->AssertNoPendingException();
}
}
// If the class is kStatusInitializing, either this thread is
// initializing higher up the stack or another thread has beat us
// to initializing and we need to wait. Either way, this
// invocation of InitializeClass will not be responsible for
// running <clinit> and will return.
if (klass->GetStatus() == mirror::Class::kStatusInitializing) {
// Could have got an exception during verification.
if (self->IsExceptionPending()) {
VlogClassInitializationFailure(klass);
return false;
}
// We caught somebody else in the act; was it us?
if (klass->GetClinitThreadId() == self->GetTid()) {
// Yes. That's fine. Return so we can continue initializing.
return true;
}
// No. That's fine. Wait for another thread to finish initializing.
return WaitForInitializeClass(klass, self, lock);
}
if (!ValidateSuperClassDescriptors(klass)) {
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
self->AllowThreadSuspension();
CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusVerified) << PrettyClass(klass.Get());
// From here out other threads may observe that we're initializing and so changes of state
// require the a notification.
klass->SetClinitThreadId(self->GetTid());
mirror::Class::SetStatus(klass, mirror::Class::kStatusInitializing, self);
t0 = NanoTime();
}
// Initialize super classes, must be done while initializing for the JLS.
if (!klass->IsInterface() && klass->HasSuperClass()) {
mirror::Class* super_class = klass->GetSuperClass();
if (!super_class->IsInitialized()) {
CHECK(!super_class->IsInterface());
CHECK(can_init_parents);
StackHandleScope<1> hs(self);
Handle<mirror::Class> handle_scope_super(hs.NewHandle(super_class));
bool super_initialized = InitializeClass(self, handle_scope_super, can_init_statics, true);
if (!super_initialized) {
// The super class was verified ahead of entering initializing, we should only be here if
// the super class became erroneous due to initialization.
CHECK(handle_scope_super->IsErroneous() && self->IsExceptionPending())
<< "Super class initialization failed for "
<< PrettyDescriptor(handle_scope_super.Get())
<< " that has unexpected status " << handle_scope_super->GetStatus()
<< "\nPending exception:\n"
<< (self->GetException() != nullptr ? self->GetException()->Dump() : "");
ObjectLock<mirror::Class> lock(self, klass);
// Initialization failed because the super-class is erroneous.
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
}
}
if (!klass->IsInterface()) {
// Initialize interfaces with default methods for the JLS.
size_t num_direct_interfaces = klass->NumDirectInterfaces();
// Only setup the (expensive) handle scope if we actually need to.
if (UNLIKELY(num_direct_interfaces > 0)) {
StackHandleScope<1> hs_iface(self);
MutableHandle<mirror::Class> handle_scope_iface(hs_iface.NewHandle<mirror::Class>(nullptr));
for (size_t i = 0; i < num_direct_interfaces; i++) {
handle_scope_iface.Assign(mirror::Class::GetDirectInterface(self, klass, i));
CHECK(handle_scope_iface.Get() != nullptr);
CHECK(handle_scope_iface->IsInterface());
if (handle_scope_iface->HasBeenRecursivelyInitialized()) {
// We have already done this for this interface. Skip it.
continue;
}
// We cannot just call initialize class directly because we need to ensure that ALL
// interfaces with default methods are initialized. Non-default interface initialization
// will not affect other non-default super-interfaces.
bool iface_initialized = InitializeDefaultInterfaceRecursive(self,
handle_scope_iface,
can_init_statics,
can_init_parents);
if (!iface_initialized) {
ObjectLock<mirror::Class> lock(self, klass);
// Initialization failed because one of our interfaces with default methods is erroneous.
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
}
}
}
const size_t num_static_fields = klass->NumStaticFields();
if (num_static_fields > 0) {
const DexFile::ClassDef* dex_class_def = klass->GetClassDef();
CHECK(dex_class_def != nullptr);
const DexFile& dex_file = klass->GetDexFile();
StackHandleScope<3> hs(self);
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(klass->GetClassLoader()));
Handle<mirror::DexCache> dex_cache(hs.NewHandle(klass->GetDexCache()));
// Eagerly fill in static fields so that the we don't have to do as many expensive
// Class::FindStaticField in ResolveField.
for (size_t i = 0; i < num_static_fields; ++i) {
ArtField* field = klass->GetStaticField(i);
const uint32_t field_idx = field->GetDexFieldIndex();
ArtField* resolved_field = dex_cache->GetResolvedField(field_idx, image_pointer_size_);
if (resolved_field == nullptr) {
dex_cache->SetResolvedField(field_idx, field, image_pointer_size_);
} else {
DCHECK_EQ(field, resolved_field);
}
}
EncodedStaticFieldValueIterator value_it(dex_file, &dex_cache, &class_loader,
this, *dex_class_def);
const uint8_t* class_data = dex_file.GetClassData(*dex_class_def);
ClassDataItemIterator field_it(dex_file, class_data);
if (value_it.HasNext()) {
DCHECK(field_it.HasNextStaticField());
CHECK(can_init_statics);
for ( ; value_it.HasNext(); value_it.Next(), field_it.Next()) {
ArtField* field = ResolveField(
dex_file, field_it.GetMemberIndex(), dex_cache, class_loader, true);
if (Runtime::Current()->IsActiveTransaction()) {
value_it.ReadValueToField<true>(field);
} else {
value_it.ReadValueToField<false>(field);
}
DCHECK(!value_it.HasNext() || field_it.HasNextStaticField());
}
}
}
ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_);
if (clinit != nullptr) {
CHECK(can_init_statics);
JValue result;
clinit->Invoke(self, nullptr, 0, &result, "V");
}
self->AllowThreadSuspension();
uint64_t t1 = NanoTime();
bool success = true;
{
ObjectLock<mirror::Class> lock(self, klass);
if (self->IsExceptionPending()) {
WrapExceptionInInitializer(klass);
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
success = false;
} else if (Runtime::Current()->IsTransactionAborted()) {
// The exception thrown when the transaction aborted has been caught and cleared
// so we need to throw it again now.
VLOG(compiler) << "Return from class initializer of " << PrettyDescriptor(klass.Get())
<< " without exception while transaction was aborted: re-throw it now.";
Runtime::Current()->ThrowTransactionAbortError(self);
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
success = false;
} else {
RuntimeStats* global_stats = Runtime::Current()->GetStats();
RuntimeStats* thread_stats = self->GetStats();
++global_stats->class_init_count;
++thread_stats->class_init_count;
global_stats->class_init_time_ns += (t1 - t0);
thread_stats->class_init_time_ns += (t1 - t0);
// Set the class as initialized except if failed to initialize static fields.
mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self);
if (VLOG_IS_ON(class_linker)) {
std::string temp;
LOG(INFO) << "Initialized class " << klass->GetDescriptor(&temp) << " from " <<
klass->GetLocation();
}
// Opportunistically set static method trampolines to their destination.
FixupStaticTrampolines(klass.Get());
}
}
return success;
}
// We recursively run down the tree of interfaces. We need to do this in the order they are declared
// and perform the initialization only on those interfaces that contain default methods.
bool ClassLinker::InitializeDefaultInterfaceRecursive(Thread* self,
Handle<mirror::Class> iface,
bool can_init_statics,
bool can_init_parents) {
CHECK(iface->IsInterface());
size_t num_direct_ifaces = iface->NumDirectInterfaces();
// Only create the (expensive) handle scope if we need it.
if (UNLIKELY(num_direct_ifaces > 0)) {
StackHandleScope<1> hs(self);
MutableHandle<mirror::Class> handle_super_iface(hs.NewHandle<mirror::Class>(nullptr));
// First we initialize all of iface's super-interfaces recursively.
for (size_t i = 0; i < num_direct_ifaces; i++) {
mirror::Class* super_iface = mirror::Class::GetDirectInterface(self, iface, i);
if (!super_iface->HasBeenRecursivelyInitialized()) {
// Recursive step
handle_super_iface.Assign(super_iface);
if (!InitializeDefaultInterfaceRecursive(self,
handle_super_iface,
can_init_statics,
can_init_parents)) {
return false;
}
}
}
}
bool result = true;
// Then we initialize 'iface' if it has default methods. We do not need to (and in fact must not)
// initialize if we don't have default methods.
if (iface->HasDefaultMethods()) {
result = EnsureInitialized(self, iface, can_init_statics, can_init_parents);
}
// Mark that this interface has undergone recursive default interface initialization so we know we
// can skip it on any later class initializations. We do this even if we are not a default
// interface since we can still avoid the traversal. This is purely a performance optimization.
if (result) {
// TODO This should be done in a better way
ObjectLock<mirror::Class> lock(self, iface);
iface->SetRecursivelyInitialized();
}
return result;
}
bool ClassLinker::WaitForInitializeClass(Handle<mirror::Class> klass,
Thread* self,
ObjectLock<mirror::Class>& lock)
SHARED_REQUIRES(Locks::mutator_lock_) {
while (true) {
self->AssertNoPendingException();
CHECK(!klass->IsInitialized());
lock.WaitIgnoringInterrupts();
// When we wake up, repeat the test for init-in-progress. If
// there's an exception pending (only possible if
// we were not using WaitIgnoringInterrupts), bail out.
if (self->IsExceptionPending()) {
WrapExceptionInInitializer(klass);
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
// Spurious wakeup? Go back to waiting.
if (klass->GetStatus() == mirror::Class::kStatusInitializing) {
continue;
}
if (klass->GetStatus() == mirror::Class::kStatusVerified &&
Runtime::Current()->IsAotCompiler()) {
// Compile time initialization failed.
return false;
}
if (klass->IsErroneous()) {
// The caller wants an exception, but it was thrown in a
// different thread. Synthesize one here.
ThrowNoClassDefFoundError("<clinit> failed for class %s; see exception in other thread",
PrettyDescriptor(klass.Get()).c_str());
VlogClassInitializationFailure(klass);
return false;
}
if (klass->IsInitialized()) {
return true;
}
LOG(FATAL) << "Unexpected class status. " << PrettyClass(klass.Get()) << " is "
<< klass->GetStatus();
}
UNREACHABLE();
}
static void ThrowSignatureCheckResolveReturnTypeException(Handle<mirror::Class> klass,
Handle<mirror::Class> super_klass,
ArtMethod* method,
ArtMethod* m)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(Thread::Current()->IsExceptionPending());
DCHECK(!m->IsProxyMethod());
const DexFile* dex_file = m->GetDexFile();
const DexFile::MethodId& method_id = dex_file->GetMethodId(m->GetDexMethodIndex());
const DexFile::ProtoId& proto_id = dex_file->GetMethodPrototype(method_id);
uint16_t return_type_idx = proto_id.return_type_idx_;
std::string return_type = PrettyType(return_type_idx, *dex_file);
std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader());
ThrowWrappedLinkageError(klass.Get(),
"While checking class %s method %s signature against %s %s: "
"Failed to resolve return type %s with %s",
PrettyDescriptor(klass.Get()).c_str(),
PrettyMethod(method).c_str(),
super_klass->IsInterface() ? "interface" : "superclass",
PrettyDescriptor(super_klass.Get()).c_str(),
return_type.c_str(), class_loader.c_str());
}
static void ThrowSignatureCheckResolveArgException(Handle<mirror::Class> klass,
Handle<mirror::Class> super_klass,
ArtMethod* method,
ArtMethod* m,
uint32_t index,
uint32_t arg_type_idx)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(Thread::Current()->IsExceptionPending());
DCHECK(!m->IsProxyMethod());
const DexFile* dex_file = m->GetDexFile();
std::string arg_type = PrettyType(arg_type_idx, *dex_file);
std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader());
ThrowWrappedLinkageError(klass.Get(),
"While checking class %s method %s signature against %s %s: "
"Failed to resolve arg %u type %s with %s",
PrettyDescriptor(klass.Get()).c_str(),
PrettyMethod(method).c_str(),
super_klass->IsInterface() ? "interface" : "superclass",
PrettyDescriptor(super_klass.Get()).c_str(),
index, arg_type.c_str(), class_loader.c_str());
}
static void ThrowSignatureMismatch(Handle<mirror::Class> klass,
Handle<mirror::Class> super_klass,
ArtMethod* method,
const std::string& error_msg)
SHARED_REQUIRES(Locks::mutator_lock_) {
ThrowLinkageError(klass.Get(),
"Class %s method %s resolves differently in %s %s: %s",
PrettyDescriptor(klass.Get()).c_str(),
PrettyMethod(method).c_str(),
super_klass->IsInterface() ? "interface" : "superclass",
PrettyDescriptor(super_klass.Get()).c_str(),
error_msg.c_str());
}
static bool HasSameSignatureWithDifferentClassLoaders(Thread* self,
size_t pointer_size,
Handle<mirror::Class> klass,
Handle<mirror::Class> super_klass,
ArtMethod* method1,
ArtMethod* method2)
SHARED_REQUIRES(Locks::mutator_lock_) {
{
StackHandleScope<1> hs(self);
Handle<mirror::Class> return_type(hs.NewHandle(method1->GetReturnType(true /* resolve */,
pointer_size)));
if (UNLIKELY(return_type.Get() == nullptr)) {
ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method1);
return false;
}
mirror::Class* other_return_type = method2->GetReturnType(true /* resolve */,
pointer_size);
if (UNLIKELY(other_return_type == nullptr)) {
ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method2);
return false;
}
if (UNLIKELY(other_return_type != return_type.Get())) {
ThrowSignatureMismatch(klass, super_klass, method1,
StringPrintf("Return types mismatch: %s(%p) vs %s(%p)",
PrettyClassAndClassLoader(return_type.Get()).c_str(),
return_type.Get(),
PrettyClassAndClassLoader(other_return_type).c_str(),
other_return_type));
return false;
}
}
const DexFile::TypeList* types1 = method1->GetParameterTypeList();
const DexFile::TypeList* types2 = method2->GetParameterTypeList();
if (types1 == nullptr) {
if (types2 != nullptr && types2->Size() != 0) {
ThrowSignatureMismatch(klass, super_klass, method1,
StringPrintf("Type list mismatch with %s",
PrettyMethod(method2, true).c_str()));
return false;
}
return true;
} else if (UNLIKELY(types2 == nullptr)) {
if (types1->Size() != 0) {
ThrowSignatureMismatch(klass, super_klass, method1,
StringPrintf("Type list mismatch with %s",
PrettyMethod(method2, true).c_str()));
return false;
}
return true;
}
uint32_t num_types = types1->Size();
if (UNLIKELY(num_types != types2->Size())) {
ThrowSignatureMismatch(klass, super_klass, method1,
StringPrintf("Type list mismatch with %s",
PrettyMethod(method2, true).c_str()));
return false;
}
for (uint32_t i = 0; i < num_types; ++i) {
StackHandleScope<1> hs(self);
uint32_t param_type_idx = types1->GetTypeItem(i).type_idx_;
Handle<mirror::Class> param_type(hs.NewHandle(
method1->GetClassFromTypeIndex(param_type_idx, true /* resolve */, pointer_size)));
if (UNLIKELY(param_type.Get() == nullptr)) {
ThrowSignatureCheckResolveArgException(klass, super_klass, method1,
method1, i, param_type_idx);
return false;
}
uint32_t other_param_type_idx = types2->GetTypeItem(i).type_idx_;
mirror::Class* other_param_type =
method2->GetClassFromTypeIndex(other_param_type_idx, true /* resolve */, pointer_size);
if (UNLIKELY(other_param_type == nullptr)) {
ThrowSignatureCheckResolveArgException(klass, super_klass, method1,
method2, i, other_param_type_idx);
return false;
}
if (UNLIKELY(param_type.Get() != other_param_type)) {
ThrowSignatureMismatch(klass, super_klass, method1,
StringPrintf("Parameter %u type mismatch: %s(%p) vs %s(%p)",
i,
PrettyClassAndClassLoader(param_type.Get()).c_str(),
param_type.Get(),
PrettyClassAndClassLoader(other_param_type).c_str(),
other_param_type));
return false;
}
}
return true;
}
bool ClassLinker::ValidateSuperClassDescriptors(Handle<mirror::Class> klass) {
if (klass->IsInterface()) {
return true;
}
// Begin with the methods local to the superclass.
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
MutableHandle<mirror::Class> super_klass(hs.NewHandle<mirror::Class>(nullptr));
if (klass->HasSuperClass() &&
klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) {
super_klass.Assign(klass->GetSuperClass());
for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) {
auto* m = klass->GetVTableEntry(i, image_pointer_size_);
auto* super_m = klass->GetSuperClass()->GetVTableEntry(i, image_pointer_size_);
if (m != super_m) {
if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, image_pointer_size_,
klass, super_klass,
m, super_m))) {
self->AssertPendingException();
return false;
}
}
}
}
for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) {
super_klass.Assign(klass->GetIfTable()->GetInterface(i));
if (klass->GetClassLoader() != super_klass->GetClassLoader()) {
uint32_t num_methods = super_klass->NumVirtualMethods();
for (uint32_t j = 0; j < num_methods; ++j) {
auto* m = klass->GetIfTable()->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>(
j, image_pointer_size_);
auto* super_m = super_klass->GetVirtualMethod(j, image_pointer_size_);
if (m != super_m) {
if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, image_pointer_size_,
klass, super_klass,
m, super_m))) {
self->AssertPendingException();
return false;
}
}
}
}
}
return true;
}
bool ClassLinker::EnsureInitialized(Thread* self, Handle<mirror::Class> c, bool can_init_fields,
bool can_init_parents) {
DCHECK(c.Get() != nullptr);
if (c->IsInitialized()) {
EnsurePreverifiedMethods(c);
return true;
}
const bool success = InitializeClass(self, c, can_init_fields, can_init_parents);
if (!success) {
if (can_init_fields && can_init_parents) {
CHECK(self->IsExceptionPending()) << PrettyClass(c.Get());
}
} else {
self->AssertNoPendingException();
}
return success;
}
void ClassLinker::FixupTemporaryDeclaringClass(mirror::Class* temp_class,
mirror::Class* new_class) {
DCHECK_EQ(temp_class->NumInstanceFields(), 0u);
for (ArtField& field : new_class->GetIFields()) {
if (field.GetDeclaringClass() == temp_class) {
field.SetDeclaringClass(new_class);
}
}
DCHECK_EQ(temp_class->NumStaticFields(), 0u);
for (ArtField& field : new_class->GetSFields()) {
if (field.GetDeclaringClass() == temp_class) {
field.SetDeclaringClass(new_class);
}
}
DCHECK_EQ(temp_class->NumDirectMethods(), 0u);
for (auto& method : new_class->GetDirectMethods(image_pointer_size_)) {
if (method.GetDeclaringClass() == temp_class) {
method.SetDeclaringClass(new_class);
}
}
DCHECK_EQ(temp_class->NumVirtualMethods(), 0u);
for (auto& method : new_class->GetVirtualMethods(image_pointer_size_)) {
if (method.GetDeclaringClass() == temp_class) {
method.SetDeclaringClass(new_class);
}
}
// Make sure the remembered set and mod-union tables know that we updated some of the native
// roots.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(new_class);
}
ClassTable* ClassLinker::InsertClassTableForClassLoader(mirror::ClassLoader* class_loader) {
if (class_loader == nullptr) {
return &boot_class_table_;
}
ClassTable* class_table = class_loader->GetClassTable();
if (class_table == nullptr) {
class_table = new ClassTable;
Thread* const self = Thread::Current();
ClassLoaderData data;
data.weak_root = self->GetJniEnv()->vm->AddWeakGlobalRef(self, class_loader);
data.class_table = class_table;
// Don't already have a class table, add it to the class loader.
CHECK(class_loader->GetClassTable() == nullptr);
class_loader->SetClassTable(data.class_table);
// Should have been set when we registered the dex file.
data.allocator = class_loader->GetAllocator();
CHECK(data.allocator != nullptr);
class_loaders_.push_back(data);
}
return class_table;
}
ClassTable* ClassLinker::ClassTableForClassLoader(mirror::ClassLoader* class_loader) {
return class_loader == nullptr ? &boot_class_table_ : class_loader->GetClassTable();
}
bool ClassLinker::LinkClass(Thread* self,
const char* descriptor,
Handle<mirror::Class> klass,
Handle<mirror::ObjectArray<mirror::Class>> interfaces,
MutableHandle<mirror::Class>* h_new_class_out) {
CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus());
if (!LinkSuperClass(klass)) {
return false;
}
ArtMethod* imt[mirror::Class::kImtSize];
std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod());
if (!LinkMethods(self, klass, interfaces, imt)) {
return false;
}
if (!LinkInstanceFields(self, klass)) {
return false;
}
size_t class_size;
if (!LinkStaticFields(self, klass, &class_size)) {
return false;
}
CreateReferenceInstanceOffsets(klass);
CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus());
if (!klass->IsTemp() || (!init_done_ && klass->GetClassSize() == class_size)) {
// We don't need to retire this class as it has no embedded tables or it was created the
// correct size during class linker initialization.
CHECK_EQ(klass->GetClassSize(), class_size) << PrettyDescriptor(klass.Get());
if (klass->ShouldHaveEmbeddedImtAndVTable()) {
klass->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_);
}
// This will notify waiters on klass that saw the not yet resolved
// class in the class_table_ during EnsureResolved.
mirror::Class::SetStatus(klass, mirror::Class::kStatusResolved, self);
h_new_class_out->Assign(klass.Get());
} else {
CHECK(!klass->IsResolved());
// Retire the temporary class and create the correctly sized resolved class.
StackHandleScope<1> hs(self);
auto h_new_class = hs.NewHandle(klass->CopyOf(self, class_size, imt, image_pointer_size_));
// Set arrays to null since we don't want to have multiple classes with the same ArtField or
// ArtMethod array pointers. If this occurs, it causes bugs in remembered sets since the GC
// may not see any references to the target space and clean the card for a class if another
// class had the same array pointer.
klass->SetDirectMethodsPtrUnchecked(nullptr);
klass->SetVirtualMethodsPtr(nullptr);
klass->SetSFieldsPtrUnchecked(nullptr);
klass->SetIFieldsPtrUnchecked(nullptr);
if (UNLIKELY(h_new_class.Get() == nullptr)) {
self->AssertPendingOOMException();
mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self);
return false;
}
CHECK_EQ(h_new_class->GetClassSize(), class_size);
ObjectLock<mirror::Class> lock(self, h_new_class);
FixupTemporaryDeclaringClass(klass.Get(), h_new_class.Get());
{
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
mirror::ClassLoader* const class_loader = h_new_class.Get()->GetClassLoader();
ClassTable* const table = InsertClassTableForClassLoader(class_loader);
mirror::Class* existing = table->UpdateClass(descriptor, h_new_class.Get(),
ComputeModifiedUtf8Hash(descriptor));
if (class_loader != nullptr) {
// We updated the class in the class table, perform the write barrier so that the GC knows
// about the change.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader);
}
CHECK_EQ(existing, klass.Get());
if (kIsDebugBuild && class_loader == nullptr && dex_cache_boot_image_class_lookup_required_) {
// Check a class loaded with the system class loader matches one in the image if the class
// is in the image.
mirror::Class* const image_class = LookupClassFromBootImage(descriptor);
if (image_class != nullptr) {
CHECK_EQ(klass.Get(), existing) << descriptor;
}
}
if (log_new_class_table_roots_) {
new_class_roots_.push_back(GcRoot<mirror::Class>(h_new_class.Get()));
}
}
// This will notify waiters on temp class that saw the not yet resolved class in the
// class_table_ during EnsureResolved.
mirror::Class::SetStatus(klass, mirror::Class::kStatusRetired, self);
CHECK_EQ(h_new_class->GetStatus(), mirror::Class::kStatusResolving);
// This will notify waiters on new_class that saw the not yet resolved
// class in the class_table_ during EnsureResolved.
mirror::Class::SetStatus(h_new_class, mirror::Class::kStatusResolved, self);
// Return the new class.
h_new_class_out->Assign(h_new_class.Get());
}
return true;
}
static void CountMethodsAndFields(ClassDataItemIterator& dex_data,
size_t* virtual_methods,
size_t* direct_methods,
size_t* static_fields,
size_t* instance_fields) {
*virtual_methods = *direct_methods = *static_fields = *instance_fields = 0;
while (dex_data.HasNextStaticField()) {
dex_data.Next();
(*static_fields)++;
}
while (dex_data.HasNextInstanceField()) {
dex_data.Next();
(*instance_fields)++;
}
while (dex_data.HasNextDirectMethod()) {
(*direct_methods)++;
dex_data.Next();
}
while (dex_data.HasNextVirtualMethod()) {
(*virtual_methods)++;
dex_data.Next();
}
DCHECK(!dex_data.HasNext());
}
static void DumpClass(std::ostream& os,
const DexFile& dex_file, const DexFile::ClassDef& dex_class_def,
const char* suffix) {
ClassDataItemIterator dex_data(dex_file, dex_file.GetClassData(dex_class_def));
os << dex_file.GetClassDescriptor(dex_class_def) << suffix << ":\n";
os << " Static fields:\n";
while (dex_data.HasNextStaticField()) {
const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex());
os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n";
dex_data.Next();
}
os << " Instance fields:\n";
while (dex_data.HasNextInstanceField()) {
const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex());
os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n";
dex_data.Next();
}
os << " Direct methods:\n";
while (dex_data.HasNextDirectMethod()) {
const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex());
os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n";
dex_data.Next();
}
os << " Virtual methods:\n";
while (dex_data.HasNextVirtualMethod()) {
const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex());
os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n";
dex_data.Next();
}
}
static std::string DumpClasses(const DexFile& dex_file1,
const DexFile::ClassDef& dex_class_def1,
const DexFile& dex_file2,
const DexFile::ClassDef& dex_class_def2) {
std::ostringstream os;
DumpClass(os, dex_file1, dex_class_def1, " (Compile time)");
DumpClass(os, dex_file2, dex_class_def2, " (Runtime)");
return os.str();
}
// Very simple structural check on whether the classes match. Only compares the number of
// methods and fields.
static bool SimpleStructuralCheck(const DexFile& dex_file1,
const DexFile::ClassDef& dex_class_def1,
const DexFile& dex_file2,
const DexFile::ClassDef& dex_class_def2,
std::string* error_msg) {
ClassDataItemIterator dex_data1(dex_file1, dex_file1.GetClassData(dex_class_def1));
ClassDataItemIterator dex_data2(dex_file2, dex_file2.GetClassData(dex_class_def2));
// Counters for current dex file.
size_t dex_virtual_methods1, dex_direct_methods1, dex_static_fields1, dex_instance_fields1;
CountMethodsAndFields(dex_data1,
&dex_virtual_methods1,
&dex_direct_methods1,
&dex_static_fields1,
&dex_instance_fields1);
// Counters for compile-time dex file.
size_t dex_virtual_methods2, dex_direct_methods2, dex_static_fields2, dex_instance_fields2;
CountMethodsAndFields(dex_data2,
&dex_virtual_methods2,
&dex_direct_methods2,
&dex_static_fields2,
&dex_instance_fields2);
if (dex_virtual_methods1 != dex_virtual_methods2) {
std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2);
*error_msg = StringPrintf("Virtual method count off: %zu vs %zu\n%s",
dex_virtual_methods1,
dex_virtual_methods2,
class_dump.c_str());
return false;
}
if (dex_direct_methods1 != dex_direct_methods2) {
std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2);
*error_msg = StringPrintf("Direct method count off: %zu vs %zu\n%s",
dex_direct_methods1,
dex_direct_methods2,
class_dump.c_str());
return false;
}
if (dex_static_fields1 != dex_static_fields2) {
std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2);
*error_msg = StringPrintf("Static field count off: %zu vs %zu\n%s",
dex_static_fields1,
dex_static_fields2,
class_dump.c_str());
return false;
}
if (dex_instance_fields1 != dex_instance_fields2) {
std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2);
*error_msg = StringPrintf("Instance field count off: %zu vs %zu\n%s",
dex_instance_fields1,
dex_instance_fields2,
class_dump.c_str());
return false;
}
return true;
}
// Checks whether a the super-class changed from what we had at compile-time. This would
// invalidate quickening.
static bool CheckSuperClassChange(Handle<mirror::Class> klass,
const DexFile& dex_file,
const DexFile::ClassDef& class_def,
mirror::Class* super_class)
SHARED_REQUIRES(Locks::mutator_lock_) {
// Check for unexpected changes in the superclass.
// Quick check 1) is the super_class class-loader the boot class loader? This always has
// precedence.
if (super_class->GetClassLoader() != nullptr &&
// Quick check 2) different dex cache? Breaks can only occur for different dex files,
// which is implied by different dex cache.
klass->GetDexCache() != super_class->GetDexCache()) {
// Now comes the expensive part: things can be broken if (a) the klass' dex file has a
// definition for the super-class, and (b) the files are in separate oat files. The oat files
// are referenced from the dex file, so do (b) first. Only relevant if we have oat files.
const OatDexFile* class_oat_dex_file = dex_file.GetOatDexFile();
const OatFile* class_oat_file = nullptr;
if (class_oat_dex_file != nullptr) {
class_oat_file = class_oat_dex_file->GetOatFile();
}
if (class_oat_file != nullptr) {
const OatDexFile* loaded_super_oat_dex_file = super_class->GetDexFile().GetOatDexFile();
const OatFile* loaded_super_oat_file = nullptr;
if (loaded_super_oat_dex_file != nullptr) {
loaded_super_oat_file = loaded_super_oat_dex_file->GetOatFile();
}
if (loaded_super_oat_file != nullptr && class_oat_file != loaded_super_oat_file) {
// Now check (a).
const DexFile::ClassDef* super_class_def = dex_file.FindClassDef(class_def.superclass_idx_);
if (super_class_def != nullptr) {
// Uh-oh, we found something. Do our check.
std::string error_msg;
if (!SimpleStructuralCheck(dex_file, *super_class_def,
super_class->GetDexFile(), *super_class->GetClassDef(),
&error_msg)) {
// Print a warning to the log. This exception might be caught, e.g., as common in test
// drivers. When the class is later tried to be used, we re-throw a new instance, as we
// only save the type of the exception.
LOG(WARNING) << "Incompatible structural change detected: " <<
StringPrintf(
"Structural change of %s is hazardous (%s at compile time, %s at runtime): %s",
PrettyType(super_class_def->class_idx_, dex_file).c_str(),
class_oat_file->GetLocation().c_str(),
loaded_super_oat_file->GetLocation().c_str(),
error_msg.c_str());
ThrowIncompatibleClassChangeError(klass.Get(),
"Structural change of %s is hazardous (%s at compile time, %s at runtime): %s",
PrettyType(super_class_def->class_idx_, dex_file).c_str(),
class_oat_file->GetLocation().c_str(),
loaded_super_oat_file->GetLocation().c_str(),
error_msg.c_str());
return false;
}
}
}
}
}
return true;
}
bool ClassLinker::LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file) {
CHECK_EQ(mirror::Class::kStatusIdx, klass->GetStatus());
const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex());
uint16_t super_class_idx = class_def.superclass_idx_;
if (super_class_idx != DexFile::kDexNoIndex16) {
mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get());
if (super_class == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
return false;
}
// Verify
if (!klass->CanAccess(super_class)) {
ThrowIllegalAccessError(klass.Get(), "Class %s extended by class %s is inaccessible",
PrettyDescriptor(super_class).c_str(),
PrettyDescriptor(klass.Get()).c_str());
return false;
}
CHECK(super_class->IsResolved());
klass->SetSuperClass(super_class);
if (!CheckSuperClassChange(klass, dex_file, class_def, super_class)) {
DCHECK(Thread::Current()->IsExceptionPending());
return false;
}
}
const DexFile::TypeList* interfaces = dex_file.GetInterfacesList(class_def);
if (interfaces != nullptr) {
for (size_t i = 0; i < interfaces->Size(); i++) {
uint16_t idx = interfaces->GetTypeItem(i).type_idx_;
mirror::Class* interface = ResolveType(dex_file, idx, klass.Get());
if (interface == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
return false;
}
// Verify
if (!klass->CanAccess(interface)) {
// TODO: the RI seemed to ignore this in my testing.
ThrowIllegalAccessError(klass.Get(),
"Interface %s implemented by class %s is inaccessible",
PrettyDescriptor(interface).c_str(),
PrettyDescriptor(klass.Get()).c_str());
return false;
}
}
}
// Mark the class as loaded.
mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, nullptr);
return true;
}
bool ClassLinker::LinkSuperClass(Handle<mirror::Class> klass) {
CHECK(!klass->IsPrimitive());
mirror::Class* super = klass->GetSuperClass();
if (klass.Get() == GetClassRoot(kJavaLangObject)) {
if (super != nullptr) {
ThrowClassFormatError(klass.Get(), "java.lang.Object must not have a superclass");
return false;
}
return true;
}
if (super == nullptr) {
ThrowLinkageError(klass.Get(), "No superclass defined for class %s",
PrettyDescriptor(klass.Get()).c_str());
return false;
}
// Verify
if (super->IsFinal() || super->IsInterface()) {
ThrowIncompatibleClassChangeError(klass.Get(),
"Superclass %s of %s is %s",
PrettyDescriptor(super).c_str(),
PrettyDescriptor(klass.Get()).c_str(),
super->IsFinal() ? "declared final" : "an interface");
return false;
}
if (!klass->CanAccess(super)) {
ThrowIllegalAccessError(klass.Get(), "Superclass %s is inaccessible to class %s",
PrettyDescriptor(super).c_str(),
PrettyDescriptor(klass.Get()).c_str());
return false;
}
// Inherit kAccClassIsFinalizable from the superclass in case this
// class doesn't override finalize.
if (super->IsFinalizable()) {
klass->SetFinalizable();
}
// Inherit class loader flag form super class.
if (super->IsClassLoaderClass()) {
klass->SetClassLoaderClass();
}
// Inherit reference flags (if any) from the superclass.
uint32_t reference_flags = (super->GetClassFlags() & mirror::kClassFlagReference);
if (reference_flags != 0) {
CHECK_EQ(klass->GetClassFlags(), 0u);
klass->SetClassFlags(klass->GetClassFlags() | reference_flags);
}
// Disallow custom direct subclasses of java.lang.ref.Reference.
if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) {
ThrowLinkageError(klass.Get(),
"Class %s attempts to subclass java.lang.ref.Reference, which is not allowed",
PrettyDescriptor(klass.Get()).c_str());
return false;
}
if (kIsDebugBuild) {
// Ensure super classes are fully resolved prior to resolving fields..
while (super != nullptr) {
CHECK(super->IsResolved());
super = super->GetSuperClass();
}
}
return true;
}
// Populate the class vtable and itable. Compute return type indices.
bool ClassLinker::LinkMethods(Thread* self,
Handle<mirror::Class> klass,
Handle<mirror::ObjectArray<mirror::Class>> interfaces,
ArtMethod** out_imt) {
self->AllowThreadSuspension();
// A map from vtable indexes to the method they need to be updated to point to. Used because we
// need to have default methods be in the virtuals array of each class but we don't set that up
// until LinkInterfaceMethods.
std::unordered_map<size_t, ClassLinker::MethodTranslation> default_translations;
// Link virtual methods then interface methods.
// We set up the interface lookup table first because we need it to determine if we need to update
// any vtable entries with new default method implementations.
return SetupInterfaceLookupTable(self, klass, interfaces)
&& LinkVirtualMethods(self, klass, /*out*/ &default_translations)
&& LinkInterfaceMethods(self, klass, default_translations, out_imt);
}
// Comparator for name and signature of a method, used in finding overriding methods. Implementation
// avoids the use of handles, if it didn't then rather than compare dex files we could compare dex
// caches in the implementation below.
class MethodNameAndSignatureComparator FINAL : public ValueObject {
public:
explicit MethodNameAndSignatureComparator(ArtMethod* method)
SHARED_REQUIRES(Locks::mutator_lock_) :
dex_file_(method->GetDexFile()), mid_(&dex_file_->GetMethodId(method->GetDexMethodIndex())),
name_(nullptr), name_len_(0) {
DCHECK(!method->IsProxyMethod()) << PrettyMethod(method);
}
const char* GetName() {
if (name_ == nullptr) {
name_ = dex_file_->StringDataAndUtf16LengthByIdx(mid_->name_idx_, &name_len_);
}
return name_;
}
bool HasSameNameAndSignature(ArtMethod* other)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(!other->IsProxyMethod()) << PrettyMethod(other);
const DexFile* other_dex_file = other->GetDexFile();
const DexFile::MethodId& other_mid = other_dex_file->GetMethodId(other->GetDexMethodIndex());
if (dex_file_ == other_dex_file) {
return mid_->name_idx_ == other_mid.name_idx_ && mid_->proto_idx_ == other_mid.proto_idx_;
}
GetName(); // Only used to make sure its calculated.
uint32_t other_name_len;
const char* other_name = other_dex_file->StringDataAndUtf16LengthByIdx(other_mid.name_idx_,
&other_name_len);
if (name_len_ != other_name_len || strcmp(name_, other_name) != 0) {
return false;
}
return dex_file_->GetMethodSignature(*mid_) == other_dex_file->GetMethodSignature(other_mid);
}
private:
// Dex file for the method to compare against.
const DexFile* const dex_file_;
// MethodId for the method to compare against.
const DexFile::MethodId* const mid_;
// Lazily computed name from the dex file's strings.
const char* name_;
// Lazily computed name length.
uint32_t name_len_;
};
class LinkVirtualHashTable {
public:
LinkVirtualHashTable(Handle<mirror::Class> klass,
size_t hash_size,
uint32_t* hash_table,
size_t image_pointer_size)
: klass_(klass),
hash_size_(hash_size),
hash_table_(hash_table),
image_pointer_size_(image_pointer_size) {
std::fill(hash_table_, hash_table_ + hash_size_, invalid_index_);
}
void Add(uint32_t virtual_method_index) SHARED_REQUIRES(Locks::mutator_lock_) {
ArtMethod* local_method = klass_->GetVirtualMethodDuringLinking(
virtual_method_index, image_pointer_size_);
const char* name = local_method->GetInterfaceMethodIfProxy(image_pointer_size_)->GetName();
uint32_t hash = ComputeModifiedUtf8Hash(name);
uint32_t index = hash % hash_size_;
// Linear probe until we have an empty slot.
while (hash_table_[index] != invalid_index_) {
if (++index == hash_size_) {
index = 0;
}
}
hash_table_[index] = virtual_method_index;
}
uint32_t FindAndRemove(MethodNameAndSignatureComparator* comparator)
SHARED_REQUIRES(Locks::mutator_lock_) {
const char* name = comparator->GetName();
uint32_t hash = ComputeModifiedUtf8Hash(name);
size_t index = hash % hash_size_;
while (true) {
const uint32_t value = hash_table_[index];
// Since linear probe makes continuous blocks, hitting an invalid index means we are done
// the block and can safely assume not found.
if (value == invalid_index_) {
break;
}
if (value != removed_index_) { // This signifies not already overriden.
ArtMethod* virtual_method =
klass_->GetVirtualMethodDuringLinking(value, image_pointer_size_);
if (comparator->HasSameNameAndSignature(
virtual_method->GetInterfaceMethodIfProxy(image_pointer_size_))) {
hash_table_[index] = removed_index_;
return value;
}
}
if (++index == hash_size_) {
index = 0;
}
}
return GetNotFoundIndex();
}
static uint32_t GetNotFoundIndex() {
return invalid_index_;
}
private:
static const uint32_t invalid_index_;
static const uint32_t removed_index_;
Handle<mirror::Class> klass_;
const size_t hash_size_;
uint32_t* const hash_table_;
const size_t image_pointer_size_;
};
const uint32_t LinkVirtualHashTable::invalid_index_ = std::numeric_limits<uint32_t>::max();
const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits<uint32_t>::max() - 1;
bool ClassLinker::LinkVirtualMethods(
Thread* self,
Handle<mirror::Class> klass,
/*out*/std::unordered_map<size_t, ClassLinker::MethodTranslation>* default_translations) {
const size_t num_virtual_methods = klass->NumVirtualMethods();
if (klass->IsInterface()) {
// No vtable.
if (!IsUint<16>(num_virtual_methods)) {
ThrowClassFormatError(klass.Get(), "Too many methods on interface: %zu", num_virtual_methods);
return false;
}
bool has_defaults = false;
// TODO May need to replace this with real VTable for invoke_super
// Assign each method an IMT index and set the default flag.
for (size_t i = 0; i < num_virtual_methods; ++i) {
ArtMethod* m = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_);
m->SetMethodIndex(i);
if (!m->IsAbstract()) {
m->SetAccessFlags(m->GetAccessFlags() | kAccDefault);
has_defaults = true;
}
}
// Mark that we have default methods so that we won't need to scan the virtual_methods_ array
// during initialization. This is a performance optimization. We could simply traverse the
// virtual_methods_ array again during initialization.
if (has_defaults) {
klass->SetHasDefaultMethods();
}
return true;
} else if (klass->HasSuperClass()) {
const size_t super_vtable_length = klass->GetSuperClass()->GetVTableLength();
const size_t max_count = num_virtual_methods + super_vtable_length;
StackHandleScope<2> hs(self);
Handle<mirror::Class> super_class(hs.NewHandle(klass->GetSuperClass()));
MutableHandle<mirror::PointerArray> vtable;
if (super_class->ShouldHaveEmbeddedImtAndVTable()) {
vtable = hs.NewHandle(AllocPointerArray(self, max_count));
if (UNLIKELY(vtable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
for (size_t i = 0; i < super_vtable_length; i++) {
vtable->SetElementPtrSize(
i, super_class->GetEmbeddedVTableEntry(i, image_pointer_size_), image_pointer_size_);
}
// We might need to change vtable if we have new virtual methods or new interfaces (since that
// might give us new default methods). If no new interfaces then we can skip the rest since
// the class cannot override any of the super-class's methods. This is required for
// correctness since without it we might not update overridden default method vtable entries
// correctly.
if (num_virtual_methods == 0 && super_class->GetIfTableCount() == klass->GetIfTableCount()) {
klass->SetVTable(vtable.Get());
return true;
}
} else {
DCHECK(super_class->IsAbstract() && !super_class->IsArrayClass());
auto* super_vtable = super_class->GetVTable();
CHECK(super_vtable != nullptr) << PrettyClass(super_class.Get());
// We might need to change vtable if we have new virtual methods or new interfaces (since that
// might give us new default methods). See comment above.
if (num_virtual_methods == 0 && super_class->GetIfTableCount() == klass->GetIfTableCount()) {
klass->SetVTable(super_vtable);
return true;
}
vtable = hs.NewHandle(down_cast<mirror::PointerArray*>(
super_vtable->CopyOf(self, max_count)));
if (UNLIKELY(vtable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
}
// How the algorithm works:
// 1. Populate hash table by adding num_virtual_methods from klass. The values in the hash
// table are: invalid_index for unused slots, index super_vtable_length + i for a virtual
// method which has not been matched to a vtable method, and j if the virtual method at the
// index overrode the super virtual method at index j.
// 2. Loop through super virtual methods, if they overwrite, update hash table to j
// (j < super_vtable_length) to avoid redundant checks. (TODO maybe use this info for reducing
// the need for the initial vtable which we later shrink back down).
// 3. Add non overridden methods to the end of the vtable.
static constexpr size_t kMaxStackHash = 250;
// + 1 so that even if we only have new default methods we will still be able to use this hash
// table (i.e. it will never have 0 size).
const size_t hash_table_size = num_virtual_methods * 3 + 1;
uint32_t* hash_table_ptr;
std::unique_ptr<uint32_t[]> hash_heap_storage;
if (hash_table_size <= kMaxStackHash) {
hash_table_ptr = reinterpret_cast<uint32_t*>(
alloca(hash_table_size * sizeof(*hash_table_ptr)));
} else {
hash_heap_storage.reset(new uint32_t[hash_table_size]);
hash_table_ptr = hash_heap_storage.get();
}
LinkVirtualHashTable hash_table(klass, hash_table_size, hash_table_ptr, image_pointer_size_);
// Add virtual methods to the hash table.
for (size_t i = 0; i < num_virtual_methods; ++i) {
DCHECK(klass->GetVirtualMethodDuringLinking(
i, image_pointer_size_)->GetDeclaringClass() != nullptr);
hash_table.Add(i);
}
// Loop through each super vtable method and see if they are overridden by a method we added to
// the hash table.
for (size_t j = 0; j < super_vtable_length; ++j) {
// Search the hash table to see if we are overridden by any method.
ArtMethod* super_method = vtable->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_);
MethodNameAndSignatureComparator super_method_name_comparator(
super_method->GetInterfaceMethodIfProxy(image_pointer_size_));
uint32_t hash_index = hash_table.FindAndRemove(&super_method_name_comparator);
if (hash_index != hash_table.GetNotFoundIndex()) {
ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(
hash_index, image_pointer_size_);
if (klass->CanAccessMember(super_method->GetDeclaringClass(),
super_method->GetAccessFlags())) {
if (super_method->IsFinal()) {
ThrowLinkageError(klass.Get(), "Method %s overrides final method in class %s",
PrettyMethod(virtual_method).c_str(),
super_method->GetDeclaringClassDescriptor());
return false;
}
vtable->SetElementPtrSize(j, virtual_method, image_pointer_size_);
virtual_method->SetMethodIndex(j);
} else {
LOG(WARNING) << "Before Android 4.1, method " << PrettyMethod(virtual_method)
<< " would have incorrectly overridden the package-private method in "
<< PrettyDescriptor(super_method->GetDeclaringClassDescriptor());
}
} else if (super_method->IsOverridableByDefaultMethod()) {
// We didn't directly override this method but we might through default methods...
// Check for default method update.
ArtMethod* default_method = nullptr;
switch (FindDefaultMethodImplementation(self,
super_method,
klass,
/*out*/&default_method)) {
case DefaultMethodSearchResult::kDefaultConflict: {
// A conflict was found looking for default methods. Note this (assuming it wasn't
// pre-existing) in the translations map.
if (UNLIKELY(!super_method->IsDefaultConflicting())) {
// Don't generate another conflict method to reduce memory use as an optimization.
default_translations->insert(
{j, ClassLinker::MethodTranslation::CreateConflictingMethod()});
}
break;
}
case DefaultMethodSearchResult::kAbstractFound: {
// No conflict but method is abstract.
// We note that this vtable entry must be made abstract.
if (UNLIKELY(!super_method->IsAbstract())) {
default_translations->insert(
{j, ClassLinker::MethodTranslation::CreateAbstractMethod()});
}
break;
}
case DefaultMethodSearchResult::kDefaultFound: {
if (UNLIKELY(super_method->IsDefaultConflicting() ||
default_method->GetDeclaringClass() != super_method->GetDeclaringClass())) {
// Found a default method implementation that is new.
// TODO Refactor this add default methods to virtuals here and not in
// LinkInterfaceMethods maybe.
// The problem is default methods might override previously present
// default-method or miranda-method vtable entries from the superclass.
// Unfortunately we need these to be entries in this class's virtuals. We do not
// give these entries there until LinkInterfaceMethods so we pass this map around
// to let it know which vtable entries need to be updated.
// Make a note that vtable entry j must be updated, store what it needs to be updated
// to. We will allocate a virtual method slot in LinkInterfaceMethods and fix it up
// then.
default_translations->insert(
{j, ClassLinker::MethodTranslation::CreateTranslatedMethod(default_method)});
VLOG(class_linker) << "Method " << PrettyMethod(super_method)
<< " overridden by default " << PrettyMethod(default_method)
<< " in " << PrettyClass(klass.Get());
}
break;
}
}
}
}
size_t actual_count = super_vtable_length;
// Add the non-overridden methods at the end.
for (size_t i = 0; i < num_virtual_methods; ++i) {
ArtMethod* local_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_);
size_t method_idx = local_method->GetMethodIndexDuringLinking();
if (method_idx < super_vtable_length &&
local_method == vtable->GetElementPtrSize<ArtMethod*>(method_idx, image_pointer_size_)) {
continue;
}
vtable->SetElementPtrSize(actual_count, local_method, image_pointer_size_);
local_method->SetMethodIndex(actual_count);
++actual_count;
}
if (!IsUint<16>(actual_count)) {
ThrowClassFormatError(klass.Get(), "Too many methods defined on class: %zd", actual_count);
return false;
}
// Shrink vtable if possible
CHECK_LE(actual_count, max_count);
if (actual_count < max_count) {
vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, actual_count)));
if (UNLIKELY(vtable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
}
klass->SetVTable(vtable.Get());
} else {
CHECK_EQ(klass.Get(), GetClassRoot(kJavaLangObject));
if (!IsUint<16>(num_virtual_methods)) {
ThrowClassFormatError(klass.Get(), "Too many methods: %d",
static_cast<int>(num_virtual_methods));
return false;
}
auto* vtable = AllocPointerArray(self, num_virtual_methods);
if (UNLIKELY(vtable == nullptr)) {
self->AssertPendingOOMException();
return false;
}
for (size_t i = 0; i < num_virtual_methods; ++i) {
ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_);
vtable->SetElementPtrSize(i, virtual_method, image_pointer_size_);
virtual_method->SetMethodIndex(i & 0xFFFF);
}
klass->SetVTable(vtable);
}
return true;
}
// Determine if the given iface has any subinterface in the given list that declares the method
// specified by 'target'.
//
// Arguments
// - self: The thread we are running on
// - target: A comparator that will match any method that overrides the method we are checking for
// - iftable: The iftable we are searching for an overriding method on.
// - ifstart: The index of the interface we are checking to see if anything overrides
// - iface: The interface we are checking to see if anything overrides.
// - image_pointer_size:
// The image pointer size.
//
// Returns
// - True: There is some method that matches the target comparator defined in an interface that
// is a subtype of iface.
// - False: There is no method that matches the target comparator in any interface that is a subtype
// of iface.
static bool ContainsOverridingMethodOf(Thread* self,
MethodNameAndSignatureComparator& target,
Handle<mirror::IfTable> iftable,
size_t ifstart,
Handle<mirror::Class> iface,
size_t image_pointer_size)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(self != nullptr);
DCHECK(iface.Get() != nullptr);
DCHECK(iftable.Get() != nullptr);
DCHECK_GE(ifstart, 0u);
DCHECK_LT(ifstart, iftable->Count());
DCHECK_EQ(iface.Get(), iftable->GetInterface(ifstart));
DCHECK(iface->IsInterface());
size_t iftable_count = iftable->Count();
StackHandleScope<1> hs(self);
MutableHandle<mirror::Class> current_iface(hs.NewHandle<mirror::Class>(nullptr));
for (size_t k = ifstart + 1; k < iftable_count; k++) {
// Skip ifstart since our current interface obviously cannot override itself.
current_iface.Assign(iftable->GetInterface(k));
size_t num_instance_methods = current_iface->NumVirtualMethods();
// Iterate through every method on this interface. The order does not matter so we go forwards.
for (size_t m = 0; m < num_instance_methods; m++) {
ArtMethod* current_method = current_iface->GetVirtualMethodUnchecked(m, image_pointer_size);
if (UNLIKELY(target.HasSameNameAndSignature(
current_method->GetInterfaceMethodIfProxy(image_pointer_size)))) {
// Check if the i'th interface is a subtype of this one.
if (iface->IsAssignableFrom(current_iface.Get())) {
return true;
}
break;
}
}
}
return false;
}
// Find the default method implementation for 'interface_method' in 'klass'. Stores it into
// out_default_method and returns kDefaultFound on success. If no default method was found return
// kAbstractFound and store nullptr into out_default_method. If an error occurs (such as a
// default_method conflict) it will return kDefaultConflict.
ClassLinker::DefaultMethodSearchResult ClassLinker::FindDefaultMethodImplementation(
Thread* self,
ArtMethod* target_method,
Handle<mirror::Class> klass,
/*out*/ArtMethod** out_default_method) const {
DCHECK(self != nullptr);
DCHECK(target_method != nullptr);
DCHECK(out_default_method != nullptr);
*out_default_method = nullptr;
// We organize the interface table so that, for interface I any subinterfaces J follow it in the
// table. This lets us walk the table backwards when searching for default methods. The first one
// we encounter is the best candidate since it is the most specific. Once we have found it we keep
// track of it and then continue checking all other interfaces, since we need to throw an error if
// we encounter conflicting default method implementations (one is not a subtype of the other).
//
// The order of unrelated interfaces does not matter and is not defined.
size_t iftable_count = klass->GetIfTableCount();
if (iftable_count == 0) {
// No interfaces. We have already reset out to null so just return kAbstractFound.
return DefaultMethodSearchResult::kAbstractFound;
}
StackHandleScope<3> hs(self);
MutableHandle<mirror::Class> chosen_iface(hs.NewHandle<mirror::Class>(nullptr));
MutableHandle<mirror::IfTable> iftable(hs.NewHandle(klass->GetIfTable()));
MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr));
MethodNameAndSignatureComparator target_name_comparator(
target_method->GetInterfaceMethodIfProxy(image_pointer_size_));
// Iterates over the klass's iftable in reverse
for (size_t k = iftable_count; k != 0; ) {
--k;
DCHECK_LT(k, iftable->Count());
iface.Assign(iftable->GetInterface(k));
size_t num_instance_methods = iface->NumVirtualMethods();
// Iterate through every method on this interface. The order does not matter so we go forwards.
for (size_t m = 0; m < num_instance_methods; m++) {
ArtMethod* current_method = iface->GetVirtualMethodUnchecked(m, image_pointer_size_);
// Skip abstract methods and methods with different names.
if (current_method->IsAbstract() ||
!target_name_comparator.HasSameNameAndSignature(
current_method->GetInterfaceMethodIfProxy(image_pointer_size_))) {
continue;
}
// The verifier should have caught the non-public method.
DCHECK(current_method->IsPublic()) << "Interface method is not public!";
if (UNLIKELY(chosen_iface.Get() != nullptr)) {
// We have multiple default impls of the same method. This is a potential default conflict.
// We need to check if this possibly conflicting method is either a superclass of the chosen
// default implementation or is overridden by a non-default interface method. In either case
// there is no conflict.
if (!iface->IsAssignableFrom(chosen_iface.Get()) &&
!ContainsOverridingMethodOf(self,
target_name_comparator,
iftable,
k,
iface,
image_pointer_size_)) {
LOG(WARNING) << "Conflicting default method implementations found: "
<< PrettyMethod(current_method) << " and "
<< PrettyMethod(*out_default_method) << " in class "
<< PrettyClass(klass.Get()) << " conflict.";
*out_default_method = nullptr;
return DefaultMethodSearchResult::kDefaultConflict;
} else {
break; // Continue checking at the next interface.
}
} else {
// chosen_iface == null
if (!ContainsOverridingMethodOf(self,
target_name_comparator,
iftable,
k,
iface,
image_pointer_size_)) {
// Don't set this as the chosen interface if something else is overriding it (because that
// other interface would be potentially chosen instead if it was default). If the other
// interface was abstract then we wouldn't select this interface as chosen anyway since
// the abstract method masks it.
*out_default_method = current_method;
chosen_iface.Assign(iface.Get());
// We should now finish traversing the graph to find if we have default methods that
// conflict.
} else {
VLOG(class_linker) << "A default method '" << PrettyMethod(current_method) << "' was "
<< "skipped because it was overridden by an abstract method in a "
<< "subinterface on class '" << PrettyClass(klass.Get()) << "'";
}
}
break;
}
}
if (*out_default_method != nullptr) {
VLOG(class_linker) << "Default method '" << PrettyMethod(*out_default_method) << "' selected "
<< "as the implementation for '" << PrettyMethod(target_method) << "' "
<< "in '" << PrettyClass(klass.Get()) << "'";
return DefaultMethodSearchResult::kDefaultFound;
} else {
return DefaultMethodSearchResult::kAbstractFound;
}
}
// Sets imt_ref appropriately for LinkInterfaceMethods.
// If there is no method in the imt location of imt_ref it will store the given method there.
// Otherwise it will set the conflict method which will figure out which method to use during
// runtime.
static void SetIMTRef(ArtMethod* unimplemented_method,
ArtMethod* imt_conflict_method,
size_t image_pointer_size,
ArtMethod* current_method,
/*out*/ArtMethod** imt_ref)
SHARED_REQUIRES(Locks::mutator_lock_) {
// Place method in imt if entry is empty, place conflict otherwise.
if (*imt_ref == unimplemented_method) {
*imt_ref = current_method;
} else if (*imt_ref != imt_conflict_method) {
// If we are not a conflict and we have the same signature and name as the imt
// entry, it must be that we overwrote a superclass vtable entry.
MethodNameAndSignatureComparator imt_comparator(
(*imt_ref)->GetInterfaceMethodIfProxy(image_pointer_size));
if (imt_comparator.HasSameNameAndSignature(
current_method->GetInterfaceMethodIfProxy(image_pointer_size))) {
*imt_ref = current_method;
} else {
*imt_ref = imt_conflict_method;
}
}
}
// Simple helper function that checks that no subtypes of 'val' are contained within the 'classes'
// set.
static bool NotSubinterfaceOfAny(const std::unordered_set<mirror::Class*>& classes,
mirror::Class* val)
REQUIRES(Roles::uninterruptible_)
SHARED_REQUIRES(Locks::mutator_lock_) {
DCHECK(val != nullptr);
for (auto c : classes) {
if (val->IsAssignableFrom(&*c)) {
return false;
}
}
return true;
}
// Fills in and flattens the interface inheritance hierarchy.
//
// By the end of this function all interfaces in the transitive closure of to_process are added to
// the iftable and every interface precedes all of its sub-interfaces in this list.
//
// all I, J: Interface | I <: J implies J precedes I
//
// (note A <: B means that A is a subtype of B)
//
// This returns the total number of items in the iftable. The iftable might be resized down after
// this call.
//
// We order this backwards so that we do not need to reorder superclass interfaces when new
// interfaces are added in subclass's interface tables.
//
// Upon entry into this function iftable is a copy of the superclass's iftable with the first
// super_ifcount entries filled in with the transitive closure of the interfaces of the superclass.
// The other entries are uninitialized. We will fill in the remaining entries in this function. The
// iftable must be large enough to hold all interfaces without changing its size.
static size_t FillIfTable(mirror::IfTable* iftable,
size_t super_ifcount,
std::vector<mirror::Class*> to_process)
REQUIRES(Roles::uninterruptible_)
SHARED_REQUIRES(Locks::mutator_lock_) {
// This is the set of all class's already in the iftable. Used to make checking if a class has
// already been added quicker.
std::unordered_set<mirror::Class*> classes_in_iftable;
// The first super_ifcount elements are from the superclass. We note that they are already added.
for (size_t i = 0; i < super_ifcount; i++) {
mirror::Class* iface = iftable->GetInterface(i);
DCHECK(NotSubinterfaceOfAny(classes_in_iftable, iface)) << "Bad ordering.";
classes_in_iftable.insert(iface);
}
size_t filled_ifcount = super_ifcount;
for (mirror::Class* interface : to_process) {
// Let us call the first filled_ifcount elements of iftable the current-iface-list.
// At this point in the loop current-iface-list has the invariant that:
// for every pair of interfaces I,J within it:
// if index_of(I) < index_of(J) then I is not a subtype of J
// If we have already seen this element then all of its super-interfaces must already be in the
// current-iface-list so we can skip adding it.
if (!ContainsElement(classes_in_iftable, interface)) {
// We haven't seen this interface so add all of its super-interfaces onto the
// current-iface-list, skipping those already on it.
int32_t ifcount = interface->GetIfTableCount();
for (int32_t j = 0; j < ifcount; j++) {
mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j);
if (!ContainsElement(classes_in_iftable, super_interface)) {
DCHECK(NotSubinterfaceOfAny(classes_in_iftable, super_interface)) << "Bad ordering.";
classes_in_iftable.insert(super_interface);
iftable->SetInterface(filled_ifcount, super_interface);
filled_ifcount++;
}
}
DCHECK(NotSubinterfaceOfAny(classes_in_iftable, interface)) << "Bad ordering";
// Place this interface onto the current-iface-list after all of its super-interfaces.
classes_in_iftable.insert(interface);
iftable->SetInterface(filled_ifcount, interface);
filled_ifcount++;
} else if (kIsDebugBuild) {
// Check all super-interfaces are already in the list.
int32_t ifcount = interface->GetIfTableCount();
for (int32_t j = 0; j < ifcount; j++) {
mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j);
DCHECK(ContainsElement(classes_in_iftable, super_interface))
<< "Iftable does not contain " << PrettyClass(super_interface)
<< ", a superinterface of " << PrettyClass(interface);
}
}
}
if (kIsDebugBuild) {
// Check that the iftable is ordered correctly.
for (size_t i = 0; i < filled_ifcount; i++) {
mirror::Class* if_a = iftable->GetInterface(i);
for (size_t j = i + 1; j < filled_ifcount; j++) {
mirror::Class* if_b = iftable->GetInterface(j);
// !(if_a <: if_b)
CHECK(!if_b->IsAssignableFrom(if_a))
<< "Bad interface order: " << PrettyClass(if_a) << " (index " << i << ") extends "
<< PrettyClass(if_b) << " (index " << j << ") and so should be after it in the "
<< "interface list.";
}
}
}
return filled_ifcount;
}
bool ClassLinker::SetupInterfaceLookupTable(Thread* self, Handle<mirror::Class> klass,
Handle<mirror::ObjectArray<mirror::Class>> interfaces) {
StackHandleScope<1> hs(self);
const size_t super_ifcount =
klass->HasSuperClass() ? klass->GetSuperClass()->GetIfTableCount() : 0U;
const bool have_interfaces = interfaces.Get() != nullptr;
const size_t num_interfaces =
have_interfaces ? interfaces->GetLength() : klass->NumDirectInterfaces();
if (num_interfaces == 0) {
if (super_ifcount == 0) {
// Class implements no interfaces.
DCHECK_EQ(klass->GetIfTableCount(), 0);
DCHECK(klass->GetIfTable() == nullptr);
return true;
}
// Class implements same interfaces as parent, are any of these not marker interfaces?
bool has_non_marker_interface = false;
mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable();
for (size_t i = 0; i < super_ifcount; ++i) {
if (super_iftable->GetMethodArrayCount(i) > 0) {
has_non_marker_interface = true;
break;
}
}
// Class just inherits marker interfaces from parent so recycle parent's iftable.
if (!has_non_marker_interface) {
klass->SetIfTable(super_iftable);
return true;
}
}
size_t ifcount = super_ifcount + num_interfaces;
// Check that every class being implemented is an interface.
for (size_t i = 0; i < num_interfaces; i++) {
mirror::Class* interface = have_interfaces
? interfaces->GetWithoutChecks(i)
: mirror::Class::GetDirectInterface(self, klass, i);
DCHECK(interface != nullptr);
if (UNLIKELY(!interface->IsInterface())) {
std::string temp;
ThrowIncompatibleClassChangeError(klass.Get(),
"Class %s implements non-interface class %s",
PrettyDescriptor(klass.Get()).c_str(),
PrettyDescriptor(interface->GetDescriptor(&temp)).c_str());
return false;
}
ifcount += interface->GetIfTableCount();
}
// Create the interface function table.
MutableHandle<mirror::IfTable> iftable(hs.NewHandle(AllocIfTable(self, ifcount)));
if (UNLIKELY(iftable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
// Fill in table with superclass's iftable.
if (super_ifcount != 0) {
mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable();
for (size_t i = 0; i < super_ifcount; i++) {
mirror::Class* super_interface = super_iftable->GetInterface(i);
iftable->SetInterface(i, super_interface);
}
}
// Note that AllowThreadSuspension is to thread suspension as pthread_testcancel is to pthread
// cancellation. That is it will suspend if one has a pending suspend request but otherwise
// doesn't really do anything.
self->AllowThreadSuspension();
size_t new_ifcount;
{
ScopedAssertNoThreadSuspension nts(self, "Copying mirror::Class*'s for FillIfTable");
std::vector<mirror::Class*> to_add;
for (size_t i = 0; i < num_interfaces; i++) {
mirror::Class* interface = have_interfaces ? interfaces->Get(i) :
mirror::Class::GetDirectInterface(self, klass, i);
to_add.push_back(interface);
}
new_ifcount = FillIfTable(iftable.Get(), super_ifcount, std::move(to_add));
}
self->AllowThreadSuspension();
// Shrink iftable in case duplicates were found
if (new_ifcount < ifcount) {
DCHECK_NE(num_interfaces, 0U);
iftable.Assign(down_cast<mirror::IfTable*>(
iftable->CopyOf(self, new_ifcount * mirror::IfTable::kMax)));
if (UNLIKELY(iftable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
ifcount = new_ifcount;
} else {
DCHECK_EQ(new_ifcount, ifcount);
}
klass->SetIfTable(iftable.Get());
return true;
}
// Finds the method with a name/signature that matches cmp in the given list of methods. The list of
// methods must be unique.
static ArtMethod* FindSameNameAndSignature(MethodNameAndSignatureComparator& cmp,
const ScopedArenaVector<ArtMethod*>& list)
SHARED_REQUIRES(Locks::mutator_lock_) {
for (ArtMethod* method : list) {
if (cmp.HasSameNameAndSignature(method)) {
return method;
}
}
return nullptr;
}
bool ClassLinker::LinkInterfaceMethods(
Thread* self,
Handle<mirror::Class> klass,
const std::unordered_map<size_t, ClassLinker::MethodTranslation>& default_translations,
ArtMethod** out_imt) {
StackHandleScope<3> hs(self);
Runtime* const runtime = Runtime::Current();
const bool has_superclass = klass->HasSuperClass();
const size_t super_ifcount = has_superclass ? klass->GetSuperClass()->GetIfTableCount() : 0U;
const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_);
const size_t method_size = ArtMethod::Size(image_pointer_size_);
const size_t ifcount = klass->GetIfTableCount();
MutableHandle<mirror::IfTable> iftable(hs.NewHandle(klass->GetIfTable()));
// If we're an interface, we don't need the vtable pointers, so we're done.
if (klass->IsInterface()) {
return true;
}
// These are allocated on the heap to begin, we then transfer to linear alloc when we re-create
// the virtual methods array.
// Need to use low 4GB arenas for compiler or else the pointers wont fit in 32 bit method array
// during cross compilation.
// Use the linear alloc pool since this one is in the low 4gb for the compiler.
ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool());
ScopedArenaAllocator allocator(&stack);
ScopedArenaVector<ArtMethod*> default_conflict_methods(allocator.Adapter());
ScopedArenaVector<ArtMethod*> miranda_methods(allocator.Adapter());
ScopedArenaVector<ArtMethod*> default_methods(allocator.Adapter());
MutableHandle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking()));
ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod();
ArtMethod* const imt_conflict_method = runtime->GetImtConflictMethod();
// Copy the IMT from the super class if possible.
bool extend_super_iftable = false;
if (has_superclass) {
mirror::Class* super_class = klass->GetSuperClass();
extend_super_iftable = true;
if (super_class->ShouldHaveEmbeddedImtAndVTable()) {
for (size_t i = 0; i < mirror::Class::kImtSize; ++i) {
out_imt[i] = super_class->GetEmbeddedImTableEntry(i, image_pointer_size_);
}
} else {
// No imt in the super class, need to reconstruct from the iftable.
mirror::IfTable* if_table = super_class->GetIfTable();
const size_t length = super_class->GetIfTableCount();
for (size_t i = 0; i < length; ++i) {
mirror::Class* interface = iftable->GetInterface(i);
const size_t num_virtuals = interface->NumVirtualMethods();
const size_t method_array_count = if_table->GetMethodArrayCount(i);
DCHECK_EQ(num_virtuals, method_array_count);
if (method_array_count == 0) {
continue;
}
auto* method_array = if_table->GetMethodArray(i);
for (size_t j = 0; j < num_virtuals; ++j) {
auto method = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_);
DCHECK(method != nullptr) << PrettyClass(super_class);
// Miranda methods cannot be used to implement an interface method and defaults should be
// skipped in case we override it.
if (method->IsDefault() || method->IsMiranda()) {
continue;
}
ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_);
uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize;
auto** imt_ref = &out_imt[imt_index];
if (*imt_ref == unimplemented_method) {
*imt_ref = method;
} else if (*imt_ref != imt_conflict_method) {
*imt_ref = imt_conflict_method;
}
}
}
}
}
// Allocate method arrays before since we don't want miss visiting miranda method roots due to
// thread suspension.
for (size_t i = 0; i < ifcount; ++i) {
size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods();
if (num_methods > 0) {
const bool is_super = i < super_ifcount;
// This is an interface implemented by a super-class. Therefore we can just copy the method
// array from the superclass.
const bool super_interface = is_super && extend_super_iftable;
mirror::PointerArray* method_array;
if (super_interface) {
mirror::IfTable* if_table = klass->GetSuperClass()->GetIfTable();
DCHECK(if_table != nullptr);
DCHECK(if_table->GetMethodArray(i) != nullptr);
// If we are working on a super interface, try extending the existing method array.
method_array = down_cast<mirror::PointerArray*>(if_table->GetMethodArray(i)->Clone(self));
} else {
method_array = AllocPointerArray(self, num_methods);
}
if (UNLIKELY(method_array == nullptr)) {
self->AssertPendingOOMException();
return false;
}
iftable->SetMethodArray(i, method_array);
}
}
auto* old_cause = self->StartAssertNoThreadSuspension(
"Copying ArtMethods for LinkInterfaceMethods");
// Going in reverse to ensure that we will hit abstract methods that override defaults before the
// defaults. This means we don't need to do any trickery when creating the Miranda methods, since
// they will already be null. This has the additional benefit that the declarer of a miranda
// method will actually declare an abstract method.
for (size_t i = ifcount; i != 0; ) {
--i;
DCHECK_GE(i, 0u);
DCHECK_LT(i, ifcount);
size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods();
if (num_methods > 0) {
StackHandleScope<2> hs2(self);
const bool is_super = i < super_ifcount;
const bool super_interface = is_super && extend_super_iftable;
auto method_array(hs2.NewHandle(iftable->GetMethodArray(i)));
LengthPrefixedArray<ArtMethod>* input_virtual_methods = nullptr;
Handle<mirror::PointerArray> input_vtable_array = NullHandle<mirror::PointerArray>();
int32_t input_array_length = 0;
// TODO Cleanup Needed: In the presence of default methods this optimization is rather dirty
// and confusing. Default methods should always look through all the superclasses
// because they are the last choice of an implementation. We get around this by looking
// at the super-classes iftable methods (copied into method_array previously) when we are
// looking for the implementation of a super-interface method but that is rather dirty.
if (super_interface) {
// We are overwriting a super class interface, try to only virtual methods instead of the
// whole vtable.
input_virtual_methods = klass->GetVirtualMethodsPtr();
input_array_length = klass->NumVirtualMethods();
} else {
// A new interface, we need the whole vtable in case a new interface method is implemented
// in the whole superclass.
input_vtable_array = vtable;
input_array_length = input_vtable_array->GetLength();
}
// For each method in interface
for (size_t j = 0; j < num_methods; ++j) {
auto* interface_method = iftable->GetInterface(i)->GetVirtualMethod(j, image_pointer_size_);
MethodNameAndSignatureComparator interface_name_comparator(
interface_method->GetInterfaceMethodIfProxy(image_pointer_size_));
uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize;
ArtMethod** imt_ptr = &out_imt[imt_index];
// For each method listed in the interface's method list, find the
// matching method in our class's method list. We want to favor the
// subclass over the superclass, which just requires walking
// back from the end of the vtable. (This only matters if the
// superclass defines a private method and this class redefines
// it -- otherwise it would use the same vtable slot. In .dex files
// those don't end up in the virtual method table, so it shouldn't
// matter which direction we go. We walk it backward anyway.)
//
// To find defaults we need to do the same but also go over interfaces.
bool found_impl = false;
ArtMethod* vtable_impl = nullptr;
for (int32_t k = input_array_length - 1; k >= 0; --k) {
ArtMethod* vtable_method = input_virtual_methods != nullptr ?
&input_virtual_methods->At(k, method_size, method_alignment) :
input_vtable_array->GetElementPtrSize<ArtMethod*>(k, image_pointer_size_);
ArtMethod* vtable_method_for_name_comparison =
vtable_method->GetInterfaceMethodIfProxy(image_pointer_size_);
if (interface_name_comparator.HasSameNameAndSignature(
vtable_method_for_name_comparison)) {
if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) {
// Must do EndAssertNoThreadSuspension before throw since the throw can cause
// allocations.
self->EndAssertNoThreadSuspension(old_cause);
ThrowIllegalAccessError(klass.Get(),
"Method '%s' implementing interface method '%s' is not public",
PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str());
return false;
} else if (UNLIKELY(vtable_method->IsOverridableByDefaultMethod())) {
// We might have a newer, better, default method for this, so we just skip it. If we
// are still using this we will select it again when scanning for default methods. To
// obviate the need to copy the method again we will make a note that we already found
// a default here.
// TODO This should be much cleaner.
vtable_impl = vtable_method;
break;
} else {
found_impl = true;
method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_);
// Place method in imt if entry is empty, place conflict otherwise.
SetIMTRef(unimplemented_method,
imt_conflict_method,
image_pointer_size_,
vtable_method,
/*out*/imt_ptr);
break;
}
}
}
// Continue on to the next method if we are done.
if (LIKELY(found_impl)) {
continue;
} else if (LIKELY(super_interface)) {
// Don't look for a default implementation when the super-method is implemented directly
// by the class.
//
// See if we can use the superclasses method and skip searching everything else.
// Note: !found_impl && super_interface
CHECK(extend_super_iftable);
// If this is a super_interface method it is possible we shouldn't override it because a
// superclass could have implemented it directly. We get the method the superclass used
// to implement this to know if we can override it with a default method. Doing this is
// safe since we know that the super_iftable is filled in so we can simply pull it from
// there. We don't bother if this is not a super-classes interface since in that case we
// have scanned the entire vtable anyway and would have found it.
// TODO This is rather dirty but it is faster than searching through the entire vtable
// every time.
ArtMethod* supers_method =
method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_);
DCHECK(supers_method != nullptr);
DCHECK(interface_name_comparator.HasSameNameAndSignature(supers_method));
if (!supers_method->IsOverridableByDefaultMethod()) {
// The method is not overridable by a default method (i.e. it is directly implemented
// in some class). Therefore move onto the next interface method.
continue;
}
}
// If we haven't found it yet we should search through the interfaces for default methods.
ArtMethod* current_method = nullptr;
switch (FindDefaultMethodImplementation(self,
interface_method,
klass,
/*out*/&current_method)) {
case DefaultMethodSearchResult::kDefaultConflict: {
// Default method conflict.
DCHECK(current_method == nullptr);
ArtMethod* default_conflict_method = nullptr;
if (vtable_impl != nullptr && vtable_impl->IsDefaultConflicting()) {
// We can reuse the method from the superclass, don't bother adding it to virtuals.
default_conflict_method = vtable_impl;
} else {
// See if we already have a conflict method for this method.
ArtMethod* preexisting_conflict = FindSameNameAndSignature(interface_name_comparator,
default_conflict_methods);
if (LIKELY(preexisting_conflict != nullptr)) {
// We already have another conflict we can reuse.
default_conflict_method = preexisting_conflict;
} else {
// Create a new conflict method for this to use.
default_conflict_method =
reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size));
new(default_conflict_method) ArtMethod(interface_method, image_pointer_size_);
default_conflict_methods.push_back(default_conflict_method);
}
}
current_method = default_conflict_method;
break;
}
case DefaultMethodSearchResult::kDefaultFound: {
DCHECK(current_method != nullptr);
// Found a default method.
if (vtable_impl != nullptr &&
current_method->GetDeclaringClass() == vtable_impl->GetDeclaringClass()) {
// We found a default method but it was the same one we already have from our
// superclass. Don't bother adding it to our vtable again.
current_method = vtable_impl;
} else {
// Only record this default method if it is new to save space.
ArtMethod* old = FindSameNameAndSignature(interface_name_comparator, default_methods);
if (old == nullptr) {
// We found a default method implementation and there were no conflicts.
// Save the default method. We need to add it to the vtable.
default_methods.push_back(current_method);
} else {
CHECK(old == current_method) << "Multiple default implementations selected!";
}
}
break;
}
case DefaultMethodSearchResult::kAbstractFound: {
DCHECK(current_method == nullptr);
// Abstract method masks all defaults.
if (vtable_impl != nullptr &&
vtable_impl->IsAbstract() &&
!vtable_impl->IsDefaultConflicting()) {
// We need to make this an abstract method but the version in the vtable already is so
// don't do anything.
current_method = vtable_impl;
}
break;
}
}
if (current_method != nullptr) {
// We found a default method implementation. Record it in the iftable and IMT.
method_array->SetElementPtrSize(j, current_method, image_pointer_size_);
SetIMTRef(unimplemented_method,
imt_conflict_method,
image_pointer_size_,
current_method,
/*out*/imt_ptr);
} else if (!super_interface) {
// We could not find an implementation for this method and since it is a brand new
// interface we searched the entire vtable (and all default methods) for an implementation
// but couldn't find one. We therefore need to make a miranda method.
//
// Find out if there is already a miranda method we can use.
ArtMethod* miranda_method = FindSameNameAndSignature(interface_name_comparator,
miranda_methods);
if (miranda_method == nullptr) {
DCHECK(interface_method->IsAbstract()) << PrettyMethod(interface_method);
miranda_method = reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size));
CHECK(miranda_method != nullptr);
// Point the interface table at a phantom slot.
new(miranda_method) ArtMethod(interface_method, image_pointer_size_);
miranda_methods.push_back(miranda_method);
}
method_array->SetElementPtrSize(j, miranda_method, image_pointer_size_);
}
}
}
}
if (!miranda_methods.empty() || !default_methods.empty() || !default_conflict_methods.empty()) {
VLOG(class_linker) << PrettyClass(klass.Get()) << ": miranda_methods=" << miranda_methods.size()
<< " default_methods=" << default_methods.size()
<< " default_conflict_methods=" << default_conflict_methods.size();
const size_t old_method_count = klass->NumVirtualMethods();
const size_t new_method_count = old_method_count +
miranda_methods.size() +
default_methods.size() +
default_conflict_methods.size();
// Attempt to realloc to save RAM if possible.
LengthPrefixedArray<ArtMethod>* old_virtuals = klass->GetVirtualMethodsPtr();
// The Realloced virtual methods aren't visiblef from the class roots, so there is no issue
// where GCs could attempt to mark stale pointers due to memcpy. And since we overwrite the
// realloced memory with out->CopyFrom, we are guaranteed to have objects in the to space since
// CopyFrom has internal read barriers.
const size_t old_size = old_virtuals != nullptr
? LengthPrefixedArray<ArtMethod>::ComputeSize(old_method_count,
method_size,
method_alignment)
: 0u;
const size_t new_size = LengthPrefixedArray<ArtMethod>::ComputeSize(new_method_count,
method_size,
method_alignment);
auto* virtuals = reinterpret_cast<LengthPrefixedArray<ArtMethod>*>(
runtime->GetLinearAlloc()->Realloc(self, old_virtuals, old_size, new_size));
if (UNLIKELY(virtuals == nullptr)) {
self->AssertPendingOOMException();
self->EndAssertNoThreadSuspension(old_cause);
return false;
}
ScopedArenaUnorderedMap<ArtMethod*, ArtMethod*> move_table(allocator.Adapter());
if (virtuals != old_virtuals) {
// Maps from heap allocated miranda method to linear alloc miranda method.
StrideIterator<ArtMethod> out = virtuals->begin(method_size, method_alignment);
// Copy over the old methods + miranda methods.
for (auto& m : klass->GetVirtualMethods(image_pointer_size_)) {
move_table.emplace(&m, &*out);
// The CopyFrom is only necessary to not miss read barriers since Realloc won't do read
// barriers when it copies.
out->CopyFrom(&m, image_pointer_size_);
++out;
}
}
StrideIterator<ArtMethod> out(virtuals->begin(method_size, method_alignment)
+ old_method_count);
// Copy over miranda methods before copying vtable since CopyOf may cause thread suspension and
// we want the roots of the miranda methods to get visited.
for (ArtMethod* mir_method : miranda_methods) {
ArtMethod& new_method = *out;
new_method.CopyFrom(mir_method, image_pointer_size_);
new_method.SetAccessFlags(new_method.GetAccessFlags() | kAccMiranda);
DCHECK_NE(new_method.GetAccessFlags() & kAccAbstract, 0u)
<< "Miranda method should be abstract!";
move_table.emplace(mir_method, &new_method);
++out;
}
// We need to copy the default methods into our own virtual method table since the runtime
// requires that every method on a class's vtable be in that respective class's virtual method
// table.
// NOTE This means that two classes might have the same implementation of a method from the same
// interface but will have different ArtMethod*s for them. This also means we cannot compare a
// default method found on a class with one found on the declaring interface directly and must
// look at the declaring class to determine if they are the same.
for (ArtMethod* def_method : default_methods) {
ArtMethod& new_method = *out;
new_method.CopyFrom(def_method, image_pointer_size_);
// Clear the preverified flag if it is present. Since this class hasn't been verified yet it
// shouldn't have methods that are preverified.
// TODO This is rather arbitrary. We should maybe support classes where only some of its
// methods are preverified.
new_method.SetAccessFlags((new_method.GetAccessFlags() | kAccDefault) & ~kAccPreverified);
move_table.emplace(def_method, &new_method);
++out;
}
for (ArtMethod* conf_method : default_conflict_methods) {
ArtMethod& new_method = *out;
new_method.CopyFrom(conf_method, image_pointer_size_);
// This is a type of default method (there are default method impls, just a conflict) so mark
// this as a default, non-abstract method, since thats what it is. Also clear the preverified
// bit since this class hasn't been verified yet it shouldn't have methods that are
// preverified.
constexpr uint32_t kSetFlags = kAccDefault | kAccDefaultConflict;
constexpr uint32_t kMaskFlags = ~(kAccAbstract | kAccPreverified);
new_method.SetAccessFlags((new_method.GetAccessFlags() | kSetFlags) & kMaskFlags);
DCHECK(new_method.IsDefaultConflicting());
// The actual method might or might not be marked abstract since we just copied it from a
// (possibly default) interface method. We need to set it entry point to be the bridge so that
// the compiler will not invoke the implementation of whatever method we copied from.
EnsureThrowsInvocationError(&new_method);
move_table.emplace(conf_method, &new_method);
++out;
}
virtuals->SetSize(new_method_count);
UpdateClassVirtualMethods(klass.Get(), virtuals);
// Done copying methods, they are all roots in the class now, so we can end the no thread
// suspension assert.
self->EndAssertNoThreadSuspension(old_cause);
const size_t old_vtable_count = vtable->GetLength();
const size_t new_vtable_count = old_vtable_count +
miranda_methods.size() +
default_methods.size() +
default_conflict_methods.size();
miranda_methods.clear();
vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, new_vtable_count)));
if (UNLIKELY(vtable.Get() == nullptr)) {
self->AssertPendingOOMException();
return false;
}
out = virtuals->begin(method_size, method_alignment) + old_method_count;
size_t vtable_pos = old_vtable_count;
for (size_t i = old_method_count; i < new_method_count; ++i) {
// Leave the declaring class alone as type indices are relative to it
out->SetMethodIndex(0xFFFF & vtable_pos);
vtable->SetElementPtrSize(vtable_pos, &*out, image_pointer_size_);
++out;
++vtable_pos;
}
CHECK_EQ(vtable_pos, new_vtable_count);
// Update old vtable methods. We use the default_translations map to figure out what each vtable
// entry should be updated to, if they need to be at all.
for (size_t i = 0; i < old_vtable_count; ++i) {
ArtMethod* translated_method = vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_);
// Try and find what we need to change this method to.
auto translation_it = default_translations.find(i);
bool found_translation = false;
if (translation_it != default_translations.end()) {
if (translation_it->second.IsInConflict()) {
// Find which conflict method we are to use for this method.
MethodNameAndSignatureComparator old_method_comparator(
translated_method->GetInterfaceMethodIfProxy(image_pointer_size_));
ArtMethod* new_conflict_method = FindSameNameAndSignature(old_method_comparator,
default_conflict_methods);
CHECK(new_conflict_method != nullptr) << "Expected a conflict method!";
translated_method = new_conflict_method;
} else if (translation_it->second.IsAbstract()) {
// Find which miranda method we are to use for this method.
MethodNameAndSignatureComparator old_method_comparator(
translated_method->GetInterfaceMethodIfProxy(image_pointer_size_));
ArtMethod* miranda_method = FindSameNameAndSignature(old_method_comparator,
miranda_methods);
DCHECK(miranda_method != nullptr);
translated_method = miranda_method;
} else {
// Normal default method (changed from an older default or abstract interface method).
DCHECK(translation_it->second.IsTranslation());
translated_method = translation_it->second.GetTranslation();
}
found_translation = true;
}
DCHECK(translated_method != nullptr);
auto it = move_table.find(translated_method);
if (it != move_table.end()) {
auto* new_method = it->second;
DCHECK(new_method != nullptr);
vtable->SetElementPtrSize(i, new_method, image_pointer_size_);
} else {
// If it was not going to be updated we wouldn't have put it into the default_translations
// map.
CHECK(!found_translation) << "We were asked to update this vtable entry. Must not fail.";
}
}
klass->SetVTable(vtable.Get());
// Go fix up all the stale miranda pointers.
for (size_t i = 0; i < ifcount; ++i) {
for (size_t j = 0, count = iftable->GetMethodArrayCount(i); j < count; ++j) {
auto* method_array = iftable->GetMethodArray(i);
auto* m = method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_);
DCHECK(m != nullptr) << PrettyClass(klass.Get());
auto it = move_table.find(m);
if (it != move_table.end()) {
auto* new_m = it->second;
DCHECK(new_m != nullptr) << PrettyClass(klass.Get());
method_array->SetElementPtrSize(j, new_m, image_pointer_size_);
}
}
}
// Fix up IMT in case it has any miranda methods in it.
for (size_t i = 0; i < mirror::Class::kImtSize; ++i) {
auto it = move_table.find(out_imt[i]);
if (it != move_table.end()) {
out_imt[i] = it->second;
}
}
// Check that there are no stale methods are in the dex cache array.
if (kIsDebugBuild) {
auto* resolved_methods = klass->GetDexCache()->GetResolvedMethods();
for (size_t i = 0, count = klass->GetDexCache()->NumResolvedMethods(); i < count; ++i) {
auto* m = mirror::DexCache::GetElementPtrSize(resolved_methods, i, image_pointer_size_);
// We don't remove default methods from the move table since we need them to update the
// vtable. Therefore just skip them for this check.
if (!m->IsDefault()) {
CHECK(move_table.find(m) == move_table.end()) << PrettyMethod(m);
}
}
}
// Put some random garbage in old virtuals to help find stale pointers.
if (virtuals != old_virtuals) {
memset(old_virtuals, 0xFEu, old_size);
}
} else {
self->EndAssertNoThreadSuspension(old_cause);
}
if (kIsDebugBuild) {
auto* check_vtable = klass->GetVTableDuringLinking();
for (int i = 0; i < check_vtable->GetLength(); ++i) {
CHECK(check_vtable->GetElementPtrSize<ArtMethod*>(i, image_pointer_size_) != nullptr);
}
}
return true;
}
bool ClassLinker::LinkInstanceFields(Thread* self, Handle<mirror::Class> klass) {
CHECK(klass.Get() != nullptr);
return LinkFields(self, klass, false, nullptr);
}
bool ClassLinker::LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size) {
CHECK(klass.Get() != nullptr);
return LinkFields(self, klass, true, class_size);
}
struct LinkFieldsComparator {
explicit LinkFieldsComparator() SHARED_REQUIRES(Locks::mutator_lock_) {
}
// No thread safety analysis as will be called from STL. Checked lock held in constructor.
bool operator()(ArtField* field1, ArtField* field2)
NO_THREAD_SAFETY_ANALYSIS {
// First come reference fields, then 64-bit, then 32-bit, and then 16-bit, then finally 8-bit.
Primitive::Type type1 = field1->GetTypeAsPrimitiveType();
Primitive::Type type2 = field2->GetTypeAsPrimitiveType();
if (type1 != type2) {
if (type1 == Primitive::kPrimNot) {
// Reference always goes first.
return true;
}
if (type2 == Primitive::kPrimNot) {
// Reference always goes first.
return false;
}
size_t size1 = Primitive::ComponentSize(type1);
size_t size2 = Primitive::ComponentSize(type2);
if (size1 != size2) {
// Larger primitive types go first.
return size1 > size2;
}
// Primitive types differ but sizes match. Arbitrarily order by primitive type.
return type1 < type2;
}
// Same basic group? Then sort by dex field index. This is guaranteed to be sorted
// by name and for equal names by type id index.
// NOTE: This works also for proxies. Their static fields are assigned appropriate indexes.
return field1->GetDexFieldIndex() < field2->GetDexFieldIndex();
}
};
bool ClassLinker::LinkFields(Thread* self,
Handle<mirror::Class> klass,
bool is_static,
size_t* class_size) {
self->AllowThreadSuspension();
const size_t num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields();
LengthPrefixedArray<ArtField>* const fields = is_static ? klass->GetSFieldsPtr() :
klass->GetIFieldsPtr();
// Initialize field_offset
MemberOffset field_offset(0);
if (is_static) {
field_offset = klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_);
} else {
mirror::Class* super_class = klass->GetSuperClass();
if (super_class != nullptr) {
CHECK(super_class->IsResolved())
<< PrettyClass(klass.Get()) << " " << PrettyClass(super_class);
field_offset = MemberOffset(super_class->GetObjectSize());
}
}
CHECK_EQ(num_fields == 0, fields == nullptr) << PrettyClass(klass.Get());
// we want a relatively stable order so that adding new fields
// minimizes disruption of C++ version such as Class and Method.
std::deque<ArtField*> grouped_and_sorted_fields;
const char* old_no_suspend_cause = self->StartAssertNoThreadSuspension(
"Naked ArtField references in deque");
for (size_t i = 0; i < num_fields; i++) {
grouped_and_sorted_fields.push_back(&fields->At(i));
}
std::sort(grouped_and_sorted_fields.begin(), grouped_and_sorted_fields.end(),
LinkFieldsComparator());
// References should be at the front.
size_t current_field = 0;
size_t num_reference_fields = 0;
FieldGaps gaps;
for (; current_field < num_fields; current_field++) {
ArtField* field = grouped_and_sorted_fields.front();
Primitive::Type type = field->GetTypeAsPrimitiveType();
bool isPrimitive = type != Primitive::kPrimNot;
if (isPrimitive) {
break; // past last reference, move on to the next phase
}
if (UNLIKELY(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(
field_offset.Uint32Value()))) {
MemberOffset old_offset = field_offset;
field_offset = MemberOffset(RoundUp(field_offset.Uint32Value(), 4));
AddFieldGap(old_offset.Uint32Value(), field_offset.Uint32Value(), &gaps);
}
DCHECK_ALIGNED(field_offset.Uint32Value(), sizeof(mirror::HeapReference<mirror::Object>));
grouped_and_sorted_fields.pop_front();
num_reference_fields++;
field->SetOffset(field_offset);
field_offset = MemberOffset(field_offset.Uint32Value() +
sizeof(mirror::HeapReference<mirror::Object>));
}
// Gaps are stored as a max heap which means that we must shuffle from largest to smallest
// otherwise we could end up with suboptimal gap fills.
ShuffleForward<8>(&current_field, &field_offset, &grouped_and_sorted_fields, &gaps);
ShuffleForward<4>(&current_field, &field_offset, &grouped_and_sorted_fields, &gaps);
ShuffleForward<2>(&current_field, &field_offset, &grouped_and_sorted_fields, &gaps);
ShuffleForward<1>(&current_field, &field_offset, &grouped_and_sorted_fields, &gaps);
CHECK(grouped_and_sorted_fields.empty()) << "Missed " << grouped_and_sorted_fields.size() <<
" fields.";
self->EndAssertNoThreadSuspension(old_no_suspend_cause);
// We lie to the GC about the java.lang.ref.Reference.referent field, so it doesn't scan it.
if (!is_static && klass->DescriptorEquals("Ljava/lang/ref/Reference;")) {
// We know there are no non-reference fields in the Reference classes, and we know
// that 'referent' is alphabetically last, so this is easy...
CHECK_EQ(num_reference_fields, num_fields) << PrettyClass(klass.Get());
CHECK_STREQ(fields->At(num_fields - 1).GetName(), "referent")
<< PrettyClass(klass.Get());
--num_reference_fields;
}
size_t size = field_offset.Uint32Value();
// Update klass
if (is_static) {
klass->SetNumReferenceStaticFields(num_reference_fields);
*class_size = size;
} else {
klass->SetNumReferenceInstanceFields(num_reference_fields);
mirror::Class* super_class = klass->GetSuperClass();
if (num_reference_fields == 0 || super_class == nullptr) {
// object has one reference field, klass, but we ignore it since we always visit the class.
// super_class is null iff the class is java.lang.Object.
if (super_class == nullptr ||
(super_class->GetClassFlags() & mirror::kClassFlagNoReferenceFields) != 0) {
klass->SetClassFlags(klass->GetClassFlags() | mirror::kClassFlagNoReferenceFields);
}
}
if (kIsDebugBuild) {
DCHECK_EQ(super_class == nullptr, klass->DescriptorEquals("Ljava/lang/Object;"));
size_t total_reference_instance_fields = 0;
mirror::Class* cur_super = klass.Get();
while (cur_super != nullptr) {
total_reference_instance_fields += cur_super->NumReferenceInstanceFieldsDuringLinking();
cur_super = cur_super->GetSuperClass();
}
if (super_class == nullptr) {
CHECK_EQ(total_reference_instance_fields, 1u) << PrettyDescriptor(klass.Get());
} else {
// Check that there is at least num_reference_fields other than Object.class.
CHECK_GE(total_reference_instance_fields, 1u + num_reference_fields)
<< PrettyClass(klass.Get());
}
}
if (!klass->IsVariableSize()) {
std::string temp;
DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp);
size_t previous_size = klass->GetObjectSize();
if (previous_size != 0) {
// Make sure that we didn't originally have an incorrect size.
CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp);
}
klass->SetObjectSize(size);
}
}
if (kIsDebugBuild) {
// Make sure that the fields array is ordered by name but all reference
// offsets are at the beginning as far as alignment allows.
MemberOffset start_ref_offset = is_static
? klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_)
: klass->GetFirstReferenceInstanceFieldOffset();
MemberOffset end_ref_offset(start_ref_offset.Uint32Value() +
num_reference_fields *
sizeof(mirror::HeapReference<mirror::Object>));
MemberOffset current_ref_offset = start_ref_offset;
for (size_t i = 0; i < num_fields; i++) {
ArtField* field = &fields->At(i);
VLOG(class_linker) << "LinkFields: " << (is_static ? "static" : "instance")
<< " class=" << PrettyClass(klass.Get()) << " field=" << PrettyField(field) << " offset="
<< field->GetOffsetDuringLinking();
if (i != 0) {
ArtField* const prev_field = &fields->At(i - 1);
// NOTE: The field names can be the same. This is not possible in the Java language
// but it's valid Java/dex bytecode and for example proguard can generate such bytecode.
DCHECK_LE(strcmp(prev_field->GetName(), field->GetName()), 0);
}
Primitive::Type type = field->GetTypeAsPrimitiveType();
bool is_primitive = type != Primitive::kPrimNot;
if (klass->DescriptorEquals("Ljava/lang/ref/Reference;") &&
strcmp("referent", field->GetName()) == 0) {
is_primitive = true; // We lied above, so we have to expect a lie here.
}
MemberOffset offset = field->GetOffsetDuringLinking();
if (is_primitive) {
if (offset.Uint32Value() < end_ref_offset.Uint32Value()) {
// Shuffled before references.
size_t type_size = Primitive::ComponentSize(type);
CHECK_LT(type_size, sizeof(mirror::HeapReference<mirror::Object>));
CHECK_LT(offset.Uint32Value(), start_ref_offset.Uint32Value());
CHECK_LE(offset.Uint32Value() + type_size, start_ref_offset.Uint32Value());
CHECK(!IsAligned<sizeof(mirror::HeapReference<mirror::Object>)>(offset.Uint32Value()));
}
} else {
CHECK_EQ(current_ref_offset.Uint32Value(), offset.Uint32Value());
current_ref_offset = MemberOffset(current_ref_offset.Uint32Value() +
sizeof(mirror::HeapReference<mirror::Object>));
}
}
CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value());
}
return true;
}
// Set the bitmap of reference instance field offsets.
void ClassLinker::CreateReferenceInstanceOffsets(Handle<mirror::Class> klass) {
uint32_t reference_offsets = 0;
mirror::Class* super_class = klass->GetSuperClass();
// Leave the reference offsets as 0 for mirror::Object (the class field is handled specially).
if (super_class != nullptr) {
reference_offsets = super_class->GetReferenceInstanceOffsets();
// Compute reference offsets unless our superclass overflowed.
if (reference_offsets != mirror::Class::kClassWalkSuper) {
size_t num_reference_fields = klass->NumReferenceInstanceFieldsDuringLinking();
if (num_reference_fields != 0u) {
// All of the fields that contain object references are guaranteed be grouped in memory
// starting at an appropriately aligned address after super class object data.
uint32_t start_offset = RoundUp(super_class->GetObjectSize(),
sizeof(mirror::HeapReference<mirror::Object>));
uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) /
sizeof(mirror::HeapReference<mirror::Object>);
if (start_bit + num_reference_fields > 32) {
reference_offsets = mirror::Class::kClassWalkSuper;
} else {
reference_offsets |= (0xffffffffu << start_bit) &
(0xffffffffu >> (32 - (start_bit + num_reference_fields)));
}
}
}
}
klass->SetReferenceInstanceOffsets(reference_offsets);
}
mirror::String* ClassLinker::ResolveString(const DexFile& dex_file,
uint32_t string_idx,
Handle<mirror::DexCache> dex_cache) {
DCHECK(dex_cache.Get() != nullptr);
mirror::String* resolved = dex_cache->GetResolvedString(string_idx);
if (resolved != nullptr) {
return resolved;
}
uint32_t utf16_length;
const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length);
mirror::String* string = intern_table_->InternStrong(utf16_length, utf8_data);
dex_cache->SetResolvedString(string_idx, string);
return string;
}
mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file,
uint16_t type_idx,
mirror::Class* referrer) {
StackHandleScope<2> hs(Thread::Current());
Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referrer->GetClassLoader()));
return ResolveType(dex_file, type_idx, dex_cache, class_loader);
}
mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file,
uint16_t type_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader) {
DCHECK(dex_cache.Get() != nullptr);
mirror::Class* resolved = dex_cache->GetResolvedType(type_idx);
if (resolved == nullptr) {
Thread* self = Thread::Current();
const char* descriptor = dex_file.StringByTypeIdx(type_idx);
resolved = FindClass(self, descriptor, class_loader);
if (resolved != nullptr) {
// TODO: we used to throw here if resolved's class loader was not the
// boot class loader. This was to permit different classes with the
// same name to be loaded simultaneously by different loaders
dex_cache->SetResolvedType(type_idx, resolved);
} else {
CHECK(self->IsExceptionPending())
<< "Expected pending exception for failed resolution of: " << descriptor;
// Convert a ClassNotFoundException to a NoClassDefFoundError.
StackHandleScope<1> hs(self);
Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException()));
if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) {
DCHECK(resolved == nullptr); // No Handle needed to preserve resolved.
self->ClearException();
ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor);
self->GetException()->SetCause(cause.Get());
}
}
}
DCHECK((resolved == nullptr) || resolved->IsResolved() || resolved->IsErroneous())
<< PrettyDescriptor(resolved) << " " << resolved->GetStatus();
return resolved;
}
template <ClassLinker::ResolveMode kResolveMode>
ArtMethod* ClassLinker::ResolveMethod(const DexFile& dex_file,
uint32_t method_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
ArtMethod* referrer,
InvokeType type) {
DCHECK(dex_cache.Get() != nullptr);
// Check for hit in the dex cache.
ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_);
if (resolved != nullptr && !resolved->IsRuntimeMethod()) {
DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex();
if (kResolveMode == ClassLinker::kForceICCECheck) {
if (resolved->CheckIncompatibleClassChange(type)) {
ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer);
return nullptr;
}
}
return resolved;
}
// Fail, get the declaring class.
const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx);
mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader);
if (klass == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
// Scan using method_idx, this saves string compares but will only hit for matching dex
// caches/files.
switch (type) {
case kDirect: // Fall-through.
case kStatic:
resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_);
DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr);
break;
case kInterface:
// We have to check whether the method id really belongs to an interface (dex static bytecode
// constraint A15). Otherwise you must not invoke-interface on it.
//
// This is not symmetric to A12-A14 (direct, static, virtual), as using FindInterfaceMethod
// assumes that the given type is an interface, and will check the interface table if the
// method isn't declared in the class. So it may find an interface method (usually by name
// in the handling below, but we do the constraint check early). In that case,
// CheckIncompatibleClassChange will succeed (as it is called on an interface method)
// unexpectedly.
// Example:
// interface I {
// foo()
// }
// class A implements I {
// ...
// }
// class B extends A {
// ...
// }
// invoke-interface B.foo
// -> FindInterfaceMethod finds I.foo (interface method), not A.foo (miranda method)
if (UNLIKELY(!klass->IsInterface())) {
ThrowIncompatibleClassChangeError(klass,
"Found class %s, but interface was expected",
PrettyDescriptor(klass).c_str());
return nullptr;
} else {
resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_);
DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface());
}
break;
case kSuper: // Fall-through.
case kVirtual:
resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_);
break;
default:
LOG(FATAL) << "Unreachable - invocation type: " << type;
UNREACHABLE();
}
if (resolved == nullptr) {
// Search by name, which works across dex files.
const char* name = dex_file.StringDataByIdx(method_id.name_idx_);
const Signature signature = dex_file.GetMethodSignature(method_id);
switch (type) {
case kDirect: // Fall-through.
case kStatic:
resolved = klass->FindDirectMethod(name, signature, image_pointer_size_);
DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr);
break;
case kInterface:
resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_);
DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface());
break;
case kSuper: // Fall-through.
case kVirtual:
resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_);
break;
}
}
// If we found a method, check for incompatible class changes.
if (LIKELY(resolved != nullptr && !resolved->CheckIncompatibleClassChange(type))) {
// Be a good citizen and update the dex cache to speed subsequent calls.
dex_cache->SetResolvedMethod(method_idx, resolved, image_pointer_size_);
return resolved;
} else {
// If we had a method, it's an incompatible-class-change error.
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer);
} else {
// We failed to find the method which means either an access error, an incompatible class
// change, or no such method. First try to find the method among direct and virtual methods.
const char* name = dex_file.StringDataByIdx(method_id.name_idx_);
const Signature signature = dex_file.GetMethodSignature(method_id);
switch (type) {
case kDirect:
case kStatic:
resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_);
// Note: kDirect and kStatic are also mutually exclusive, but in that case we would
// have had a resolved method before, which triggers the "true" branch above.
break;
case kInterface:
case kVirtual:
case kSuper:
resolved = klass->FindDirectMethod(name, signature, image_pointer_size_);
break;
}
// If we found something, check that it can be accessed by the referrer.
bool exception_generated = false;
if (resolved != nullptr && referrer != nullptr) {
mirror::Class* methods_class = resolved->GetDeclaringClass();
mirror::Class* referring_class = referrer->GetDeclaringClass();
if (!referring_class->CanAccess(methods_class)) {
ThrowIllegalAccessErrorClassForMethodDispatch(referring_class,
methods_class,
resolved,
type);
exception_generated = true;
} else if (!referring_class->CanAccessMember(methods_class, resolved->GetAccessFlags())) {
ThrowIllegalAccessErrorMethod(referring_class, resolved);
exception_generated = true;
}
}
if (!exception_generated) {
// Otherwise, throw an IncompatibleClassChangeError if we found something, and check
// interface methods and throw if we find the method there. If we find nothing, throw a
// NoSuchMethodError.
switch (type) {
case kDirect:
case kStatic:
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer);
} else {
resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_);
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer);
} else {
ThrowNoSuchMethodError(type, klass, name, signature);
}
}
break;
case kInterface:
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer);
} else {
resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_);
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer);
} else {
ThrowNoSuchMethodError(type, klass, name, signature);
}
}
break;
case kSuper:
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer);
} else {
ThrowNoSuchMethodError(type, klass, name, signature);
}
break;
case kVirtual:
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer);
} else {
resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_);
if (resolved != nullptr) {
ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer);
} else {
ThrowNoSuchMethodError(type, klass, name, signature);
}
}
break;
}
}
}
Thread::Current()->AssertPendingException();
return nullptr;
}
}
ArtMethod* ClassLinker::ResolveMethodWithoutInvokeType(const DexFile& dex_file,
uint32_t method_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader) {
ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_);
if (resolved != nullptr && !resolved->IsRuntimeMethod()) {
DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex();
return resolved;
}
// Fail, get the declaring class.
const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx);
mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader);
if (klass == nullptr) {
Thread::Current()->AssertPendingException();
return nullptr;
}
if (klass->IsInterface()) {
LOG(FATAL) << "ResolveAmbiguousMethod: unexpected method in interface: " << PrettyClass(klass);
return nullptr;
}
// Search both direct and virtual methods
resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_);
if (resolved == nullptr) {
resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_);
}
return resolved;
}
ArtField* ClassLinker::ResolveField(const DexFile& dex_file,
uint32_t field_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
bool is_static) {
DCHECK(dex_cache.Get() != nullptr);
ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_);
if (resolved != nullptr) {
return resolved;
}
const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx);
Thread* const self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Class> klass(
hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader)));
if (klass.Get() == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
if (is_static) {
resolved = mirror::Class::FindStaticField(self, klass, dex_cache.Get(), field_idx);
} else {
resolved = klass->FindInstanceField(dex_cache.Get(), field_idx);
}
if (resolved == nullptr) {
const char* name = dex_file.GetFieldName(field_id);
const char* type = dex_file.GetFieldTypeDescriptor(field_id);
if (is_static) {
resolved = mirror::Class::FindStaticField(self, klass, name, type);
} else {
resolved = klass->FindInstanceField(name, type);
}
if (resolved == nullptr) {
ThrowNoSuchFieldError(is_static ? "static " : "instance ", klass.Get(), type, name);
return nullptr;
}
}
dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_);
return resolved;
}
ArtField* ClassLinker::ResolveFieldJLS(const DexFile& dex_file,
uint32_t field_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader) {
DCHECK(dex_cache.Get() != nullptr);
ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_);
if (resolved != nullptr) {
return resolved;
}
const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx);
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<mirror::Class> klass(
hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader)));
if (klass.Get() == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
StringPiece name(dex_file.StringDataByIdx(field_id.name_idx_));
StringPiece type(dex_file.StringDataByIdx(
dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_));
resolved = mirror::Class::FindField(self, klass, name, type);
if (resolved != nullptr) {
dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_);
} else {
ThrowNoSuchFieldError("", klass.Get(), type, name);
}
return resolved;
}
const char* ClassLinker::MethodShorty(uint32_t method_idx,
ArtMethod* referrer,
uint32_t* length) {
mirror::Class* declaring_class = referrer->GetDeclaringClass();
mirror::DexCache* dex_cache = declaring_class->GetDexCache();
const DexFile& dex_file = *dex_cache->GetDexFile();
const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx);
return dex_file.GetMethodShorty(method_id, length);
}
class DumpClassVisitor : public ClassVisitor {
public:
explicit DumpClassVisitor(int flags) : flags_(flags) {}
bool Visit(mirror::Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
klass->DumpClass(LOG(ERROR), flags_);
return true;
}
private:
const int flags_;
};
void ClassLinker::DumpAllClasses(int flags) {
DumpClassVisitor visitor(flags);
VisitClasses(&visitor);
}
static OatFile::OatMethod CreateOatMethod(const void* code) {
CHECK(code != nullptr);
const uint8_t* base = reinterpret_cast<const uint8_t*>(code); // Base of data points at code.
base -= sizeof(void*); // Move backward so that code_offset != 0.
const uint32_t code_offset = sizeof(void*);
return OatFile::OatMethod(base, code_offset);
}
bool ClassLinker::IsQuickResolutionStub(const void* entry_point) const {
return (entry_point == GetQuickResolutionStub()) ||
(quick_resolution_trampoline_ == entry_point);
}
bool ClassLinker::IsQuickToInterpreterBridge(const void* entry_point) const {
return (entry_point == GetQuickToInterpreterBridge()) ||
(quick_to_interpreter_bridge_trampoline_ == entry_point);
}
bool ClassLinker::IsQuickGenericJniStub(const void* entry_point) const {
return (entry_point == GetQuickGenericJniStub()) ||
(quick_generic_jni_trampoline_ == entry_point);
}
const void* ClassLinker::GetRuntimeQuickGenericJniStub() const {
return GetQuickGenericJniStub();
}
void ClassLinker::SetEntryPointsToCompiledCode(ArtMethod* method,
const void* method_code) const {
OatFile::OatMethod oat_method = CreateOatMethod(method_code);
oat_method.LinkMethod(method);
}
void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const {
if (!method->IsNative()) {
method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge());
} else {
const void* quick_method_code = GetQuickGenericJniStub();
OatFile::OatMethod oat_method = CreateOatMethod(quick_method_code);
oat_method.LinkMethod(method);
}
}
void ClassLinker::DumpForSigQuit(std::ostream& os) {
ScopedObjectAccess soa(Thread::Current());
if (dex_cache_boot_image_class_lookup_required_) {
AddBootImageClassesToClassTable();
}
ReaderMutexLock mu(soa.Self(), *Locks::classlinker_classes_lock_);
os << "Zygote loaded classes=" << NumZygoteClasses() << " post zygote classes="
<< NumNonZygoteClasses() << "\n";
}
class CountClassesVisitor : public ClassLoaderVisitor {
public:
CountClassesVisitor() : num_zygote_classes(0), num_non_zygote_classes(0) {}
void Visit(mirror::ClassLoader* class_loader)
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) OVERRIDE {
ClassTable* const class_table = class_loader->GetClassTable();
if (class_table != nullptr) {
num_zygote_classes += class_table->NumZygoteClasses();
num_non_zygote_classes += class_table->NumNonZygoteClasses();
}
}
size_t num_zygote_classes;
size_t num_non_zygote_classes;
};
size_t ClassLinker::NumZygoteClasses() const {
CountClassesVisitor visitor;
VisitClassLoaders(&visitor);
return visitor.num_zygote_classes + boot_class_table_.NumZygoteClasses();
}
size_t ClassLinker::NumNonZygoteClasses() const {
CountClassesVisitor visitor;
VisitClassLoaders(&visitor);
return visitor.num_non_zygote_classes + boot_class_table_.NumNonZygoteClasses();
}
size_t ClassLinker::NumLoadedClasses() {
if (dex_cache_boot_image_class_lookup_required_) {
AddBootImageClassesToClassTable();
}
ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
// Only return non zygote classes since these are the ones which apps which care about.
return NumNonZygoteClasses();
}
pid_t ClassLinker::GetClassesLockOwner() {
return Locks::classlinker_classes_lock_->GetExclusiveOwnerTid();
}
pid_t ClassLinker::GetDexLockOwner() {
return dex_lock_.GetExclusiveOwnerTid();
}
void ClassLinker::SetClassRoot(ClassRoot class_root, mirror::Class* klass) {
DCHECK(!init_done_);
DCHECK(klass != nullptr);
DCHECK(klass->GetClassLoader() == nullptr);
mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
DCHECK(class_roots != nullptr);
DCHECK(class_roots->Get(class_root) == nullptr);
class_roots->Set<false>(class_root, klass);
}
const char* ClassLinker::GetClassRootDescriptor(ClassRoot class_root) {
static const char* class_roots_descriptors[] = {
"Ljava/lang/Class;",
"Ljava/lang/Object;",
"[Ljava/lang/Class;",
"[Ljava/lang/Object;",
"Ljava/lang/String;",
"Ljava/lang/DexCache;",
"Ljava/lang/ref/Reference;",
"Ljava/lang/reflect/Constructor;",
"Ljava/lang/reflect/Field;",
"Ljava/lang/reflect/Method;",
"Ljava/lang/reflect/Proxy;",
"[Ljava/lang/String;",
"[Ljava/lang/reflect/Constructor;",
"[Ljava/lang/reflect/Field;",
"[Ljava/lang/reflect/Method;",
"Ljava/lang/ClassLoader;",
"Ljava/lang/Throwable;",
"Ljava/lang/ClassNotFoundException;",
"Ljava/lang/StackTraceElement;",
"Z",
"B",
"C",
"D",
"F",
"I",
"J",
"S",
"V",
"[Z",
"[B",
"[C",
"[D",
"[F",
"[I",
"[J",
"[S",
"[Ljava/lang/StackTraceElement;",
};
static_assert(arraysize(class_roots_descriptors) == size_t(kClassRootsMax),
"Mismatch between class descriptors and class-root enum");
const char* descriptor = class_roots_descriptors[class_root];
CHECK(descriptor != nullptr);
return descriptor;
}
bool ClassLinker::MayBeCalledWithDirectCodePointer(ArtMethod* m) {
Runtime* const runtime = Runtime::Current();
if (runtime->UseJit()) {
// JIT can have direct code pointers from any method to any other method.
return true;
}
// Non-image methods don't use direct code pointer.
if (!m->GetDeclaringClass()->IsBootStrapClassLoaded()) {
return false;
}
if (m->IsPrivate()) {
// The method can only be called inside its own oat file. Therefore it won't be called using
// its direct code if the oat file has been compiled in PIC mode.
const DexFile& dex_file = m->GetDeclaringClass()->GetDexFile();
const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile();
if (oat_dex_file == nullptr) {
// No oat file: the method has not been compiled.
return false;
}
const OatFile* oat_file = oat_dex_file->GetOatFile();
return oat_file != nullptr && !oat_file->IsPic();
} else {
// The method can be called outside its own oat file. Therefore it won't be called using its
// direct code pointer only if all loaded oat files have been compiled in PIC mode.
return runtime->GetOatFileManager().HaveNonPicOatFile();
}
}
jobject ClassLinker::CreatePathClassLoader(Thread* self,
std::vector<const DexFile*>& dex_files,
jobject parent_loader) {
// SOAAlreadyRunnable is protected, and we need something to add a global reference.
// We could move the jobject to the callers, but all call-sites do this...
ScopedObjectAccessUnchecked soa(self);
// For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex.
StackHandleScope<10> hs(self);
ArtField* dex_elements_field =
soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements);
mirror::Class* dex_elements_class = dex_elements_field->GetType<true>();
DCHECK(dex_elements_class != nullptr);
DCHECK(dex_elements_class->IsArrayClass());
Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements(hs.NewHandle(
mirror::ObjectArray<mirror::Object>::Alloc(self, dex_elements_class, dex_files.size())));
Handle<mirror::Class> h_dex_element_class =
hs.NewHandle(dex_elements_class->GetComponentType());
ArtField* element_file_field =
soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile);
DCHECK_EQ(h_dex_element_class.Get(), element_file_field->GetDeclaringClass());
ArtField* cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie);
DCHECK_EQ(cookie_field->GetDeclaringClass(), element_file_field->GetType<false>());
// Fill the elements array.
int32_t index = 0;
for (const DexFile* dex_file : dex_files) {
StackHandleScope<3> hs2(self);
// CreatePathClassLoader is only used by gtests and dex2oat. Index 0 of h_long_array is
// supposed to be the oat file but we can leave it null.
Handle<mirror::LongArray> h_long_array = hs2.NewHandle(mirror::LongArray::Alloc(
self,
kDexFileIndexStart + 1));
DCHECK(h_long_array.Get() != nullptr);
h_long_array->Set(kDexFileIndexStart, reinterpret_cast<intptr_t>(dex_file));
Handle<mirror::Object> h_dex_file = hs2.NewHandle(
cookie_field->GetDeclaringClass()->AllocObject(self));
DCHECK(h_dex_file.Get() != nullptr);
cookie_field->SetObject<false>(h_dex_file.Get(), h_long_array.Get());
Handle<mirror::Object> h_element = hs2.NewHandle(h_dex_element_class->AllocObject(self));
DCHECK(h_element.Get() != nullptr);
element_file_field->SetObject<false>(h_element.Get(), h_dex_file.Get());
h_dex_elements->Set(index, h_element.Get());
index++;
}
DCHECK_EQ(index, h_dex_elements->GetLength());
// Create DexPathList.
Handle<mirror::Object> h_dex_path_list = hs.NewHandle(
dex_elements_field->GetDeclaringClass()->AllocObject(self));
DCHECK(h_dex_path_list.Get() != nullptr);
// Set elements.
dex_elements_field->SetObject<false>(h_dex_path_list.Get(), h_dex_elements.Get());
// Create PathClassLoader.
Handle<mirror::Class> h_path_class_class = hs.NewHandle(
soa.Decode<mirror::Class*>(WellKnownClasses::dalvik_system_PathClassLoader));
Handle<mirror::Object> h_path_class_loader = hs.NewHandle(
h_path_class_class->AllocObject(self));
DCHECK(h_path_class_loader.Get() != nullptr);
// Set DexPathList.
ArtField* path_list_field =
soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList);
DCHECK(path_list_field != nullptr);
path_list_field->SetObject<false>(h_path_class_loader.Get(), h_dex_path_list.Get());
// Make a pretend boot-classpath.
// TODO: Should we scan the image?
ArtField* const parent_field =
mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent",
"Ljava/lang/ClassLoader;");
DCHECK(parent_field != nullptr);
mirror::Object* parent = (parent_loader != nullptr)
? soa.Decode<mirror::ClassLoader*>(parent_loader)
: soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self);
parent_field->SetObject<false>(h_path_class_loader.Get(), parent);
// Make it a global ref and return.
ScopedLocalRef<jobject> local_ref(
soa.Env(), soa.Env()->AddLocalReference<jobject>(h_path_class_loader.Get()));
return soa.Env()->NewGlobalRef(local_ref.get());
}
ArtMethod* ClassLinker::CreateRuntimeMethod() {
const size_t method_alignment = ArtMethod::Alignment(image_pointer_size_);
const size_t method_size = ArtMethod::Size(image_pointer_size_);
LengthPrefixedArray<ArtMethod>* method_array = AllocArtMethodArray(
Thread::Current(),
Runtime::Current()->GetLinearAlloc(),
1);
ArtMethod* method = &method_array->At(0, method_size, method_alignment);
CHECK(method != nullptr);
method->SetDexMethodIndex(DexFile::kDexNoIndex);
CHECK(method->IsRuntimeMethod());
return method;
}
void ClassLinker::DropFindArrayClassCache() {
std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr));
find_array_class_cache_next_victim_ = 0;
}
void ClassLinker::VisitClassLoaders(ClassLoaderVisitor* visitor) const {
Thread* const self = Thread::Current();
for (const ClassLoaderData& data : class_loaders_) {
// Need to use DecodeJObject so that we get null for cleared JNI weak globals.
auto* const class_loader = down_cast<mirror::ClassLoader*>(self->DecodeJObject(data.weak_root));
if (class_loader != nullptr) {
visitor->Visit(class_loader);
}
}
}
void ClassLinker::InsertDexFileInToClassLoader(mirror::Object* dex_file,
mirror::ClassLoader* class_loader) {
DCHECK(dex_file != nullptr);
DCHECK(class_loader != nullptr);
Thread* const self = Thread::Current();
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
ClassTable* const table = class_loader->GetClassTable();
DCHECK(table != nullptr);
if (table->InsertDexFile(dex_file)) {
// It was not already inserted, perform the write barrier to let the GC know the class loader's
// class table was modified.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader);
}
}
void ClassLinker::CleanupClassLoaders() {
Thread* const self = Thread::Current();
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
for (auto it = class_loaders_.begin(); it != class_loaders_.end(); ) {
const ClassLoaderData& data = *it;
// Need to use DecodeJObject so that we get null for cleared JNI weak globals.
auto* const class_loader = down_cast<mirror::ClassLoader*>(self->DecodeJObject(data.weak_root));
if (class_loader != nullptr) {
++it;
} else {
DeleteClassLoader(self, data);
it = class_loaders_.erase(it);
}
}
}
// Instantiate ResolveMethod.
template ArtMethod* ClassLinker::ResolveMethod<ClassLinker::kForceICCECheck>(
const DexFile& dex_file,
uint32_t method_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
ArtMethod* referrer,
InvokeType type);
template ArtMethod* ClassLinker::ResolveMethod<ClassLinker::kNoICCECheckForCache>(
const DexFile& dex_file,
uint32_t method_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
ArtMethod* referrer,
InvokeType type);
} // namespace art