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// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_TOP_H_
#define V8_TOP_H_
#include "frames-inl.h"
namespace v8 {
namespace internal {
#define RETURN_IF_SCHEDULED_EXCEPTION() \
if (Top::has_scheduled_exception()) return Top::PromoteScheduledException()
// Top has static variables used for JavaScript execution.
class SaveContext; // Forward declaration.
class ThreadVisitor; // Defined in v8threads.h
class ThreadLocalTop BASE_EMBEDDED {
public:
// Initialize the thread data.
void Initialize();
// Get the top C++ try catch handler or NULL if none are registered.
//
// This method is not guarenteed to return an address that can be
// used for comparison with addresses into the JS stack. If such an
// address is needed, use try_catch_handler_address.
v8::TryCatch* TryCatchHandler();
// Get the address of the top C++ try catch handler or NULL if
// none are registered.
//
// This method always returns an address that can be compared to
// pointers into the JavaScript stack. When running on actual
// hardware, try_catch_handler_address and TryCatchHandler return
// the same pointer. When running on a simulator with a separate JS
// stack, try_catch_handler_address returns a JS stack address that
// corresponds to the place on the JS stack where the C++ handler
// would have been if the stack were not separate.
inline Address try_catch_handler_address() {
return try_catch_handler_address_;
}
// Set the address of the top C++ try catch handler.
inline void set_try_catch_handler_address(Address address) {
try_catch_handler_address_ = address;
}
void Free() {
ASSERT(!has_pending_message_);
ASSERT(!external_caught_exception_);
ASSERT(try_catch_handler_address_ == NULL);
}
// The context where the current execution method is created and for variable
// lookups.
Context* context_;
int thread_id_;
Object* pending_exception_;
bool has_pending_message_;
const char* pending_message_;
Object* pending_message_obj_;
Script* pending_message_script_;
int pending_message_start_pos_;
int pending_message_end_pos_;
// Use a separate value for scheduled exceptions to preserve the
// invariants that hold about pending_exception. We may want to
// unify them later.
Object* scheduled_exception_;
bool external_caught_exception_;
SaveContext* save_context_;
v8::TryCatch* catcher_;
// Stack.
Address c_entry_fp_; // the frame pointer of the top c entry frame
Address handler_; // try-blocks are chained through the stack
#ifdef ENABLE_LOGGING_AND_PROFILING
Address js_entry_sp_; // the stack pointer of the bottom js entry frame
#endif
bool stack_is_cooked_;
inline bool stack_is_cooked() { return stack_is_cooked_; }
inline void set_stack_is_cooked(bool value) { stack_is_cooked_ = value; }
// Generated code scratch locations.
int32_t formal_count_;
// Call back function to report unsafe JS accesses.
v8::FailedAccessCheckCallback failed_access_check_callback_;
private:
Address try_catch_handler_address_;
};
#define TOP_ADDRESS_LIST(C) \
C(handler_address) \
C(c_entry_fp_address) \
C(context_address) \
C(pending_exception_address) \
C(external_caught_exception_address)
#ifdef ENABLE_LOGGING_AND_PROFILING
#define TOP_ADDRESS_LIST_PROF(C) \
C(js_entry_sp_address)
#else
#define TOP_ADDRESS_LIST_PROF(C)
#endif
class Top {
public:
enum AddressId {
#define C(name) k_##name,
TOP_ADDRESS_LIST(C)
TOP_ADDRESS_LIST_PROF(C)
#undef C
k_top_address_count
};
static Address get_address_from_id(AddressId id);
// Access to top context (where the current function object was created).
static Context* context() { return thread_local_.context_; }
static void set_context(Context* context) {
thread_local_.context_ = context;
}
static Context** context_address() { return &thread_local_.context_; }
static SaveContext* save_context() {return thread_local_.save_context_; }
static void set_save_context(SaveContext* save) {
thread_local_.save_context_ = save;
}
// Access to current thread id.
static int thread_id() { return thread_local_.thread_id_; }
static void set_thread_id(int id) { thread_local_.thread_id_ = id; }
// Interface to pending exception.
static Object* pending_exception() {
ASSERT(has_pending_exception());
return thread_local_.pending_exception_;
}
static bool external_caught_exception() {
return thread_local_.external_caught_exception_;
}
static void set_pending_exception(Object* exception) {
thread_local_.pending_exception_ = exception;
}
static void clear_pending_exception() {
thread_local_.pending_exception_ = Heap::the_hole_value();
}
static Object** pending_exception_address() {
return &thread_local_.pending_exception_;
}
static bool has_pending_exception() {
return !thread_local_.pending_exception_->IsTheHole();
}
static void clear_pending_message() {
thread_local_.has_pending_message_ = false;
thread_local_.pending_message_ = NULL;
thread_local_.pending_message_obj_ = Heap::the_hole_value();
thread_local_.pending_message_script_ = NULL;
}
static v8::TryCatch* try_catch_handler() {
return thread_local_.TryCatchHandler();
}
static Address try_catch_handler_address() {
return thread_local_.try_catch_handler_address();
}
// This method is called by the api after operations that may throw
// exceptions. If an exception was thrown and not handled by an external
// handler the exception is scheduled to be rethrown when we return to running
// JavaScript code. If an exception is scheduled true is returned.
static bool OptionalRescheduleException(bool is_bottom_call);
static bool* external_caught_exception_address() {
return &thread_local_.external_caught_exception_;
}
static Object** scheduled_exception_address() {
return &thread_local_.scheduled_exception_;
}
static Object* scheduled_exception() {
ASSERT(has_scheduled_exception());
return thread_local_.scheduled_exception_;
}
static bool has_scheduled_exception() {
return !thread_local_.scheduled_exception_->IsTheHole();
}
static void clear_scheduled_exception() {
thread_local_.scheduled_exception_ = Heap::the_hole_value();
}
static void setup_external_caught() {
thread_local_.external_caught_exception_ =
has_pending_exception() &&
(thread_local_.catcher_ != NULL) &&
(try_catch_handler() == thread_local_.catcher_);
}
// Tells whether the current context has experienced an out of memory
// exception.
static bool is_out_of_memory();
// JS execution stack (see frames.h).
static Address c_entry_fp(ThreadLocalTop* thread) {
return thread->c_entry_fp_;
}
static Address handler(ThreadLocalTop* thread) { return thread->handler_; }
static inline Address* c_entry_fp_address() {
return &thread_local_.c_entry_fp_;
}
static inline Address* handler_address() { return &thread_local_.handler_; }
#ifdef ENABLE_LOGGING_AND_PROFILING
// Bottom JS entry (see StackTracer::Trace in log.cc).
static Address js_entry_sp(ThreadLocalTop* thread) {
return thread->js_entry_sp_;
}
static inline Address* js_entry_sp_address() {
return &thread_local_.js_entry_sp_;
}
#endif
// Generated code scratch locations.
static void* formal_count_address() { return &thread_local_.formal_count_; }
static void MarkCompactPrologue(bool is_compacting);
static void MarkCompactEpilogue(bool is_compacting);
static void MarkCompactPrologue(bool is_compacting,
char* archived_thread_data);
static void MarkCompactEpilogue(bool is_compacting,
char* archived_thread_data);
static void PrintCurrentStackTrace(FILE* out);
static void PrintStackTrace(FILE* out, char* thread_data);
static void PrintStack(StringStream* accumulator);
static void PrintStack();
static Handle<String> StackTraceString();
static Local<StackTrace> CaptureCurrentStackTrace(
int frame_limit,
StackTrace::StackTraceOptions options);
// Returns if the top context may access the given global object. If
// the result is false, the pending exception is guaranteed to be
// set.
static bool MayNamedAccess(JSObject* receiver,
Object* key,
v8::AccessType type);
static bool MayIndexedAccess(JSObject* receiver,
uint32_t index,
v8::AccessType type);
static void SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback);
static void ReportFailedAccessCheck(JSObject* receiver, v8::AccessType type);
// Exception throwing support. The caller should use the result
// of Throw() as its return value.
static Failure* Throw(Object* exception, MessageLocation* location = NULL);
// Re-throw an exception. This involves no error reporting since
// error reporting was handled when the exception was thrown
// originally.
static Failure* ReThrow(Object* exception, MessageLocation* location = NULL);
static void ScheduleThrow(Object* exception);
static void ReportPendingMessages();
static Failure* ThrowIllegalOperation();
// Promote a scheduled exception to pending. Asserts has_scheduled_exception.
static Object* PromoteScheduledException();
static void DoThrow(Object* exception,
MessageLocation* location,
const char* message);
static bool ShouldReturnException(bool* is_caught_externally,
bool catchable_by_javascript);
static void ReportUncaughtException(Handle<Object> exception,
MessageLocation* location,
Handle<String> stack_trace);
// Attempts to compute the current source location, storing the
// result in the target out parameter.
static void ComputeLocation(MessageLocation* target);
// Override command line flag.
static void TraceException(bool flag);
// Out of resource exception helpers.
static Failure* StackOverflow();
static Failure* TerminateExecution();
// Administration
static void Initialize();
static void TearDown();
static void Iterate(ObjectVisitor* v);
static void Iterate(ObjectVisitor* v, ThreadLocalTop* t);
static char* Iterate(ObjectVisitor* v, char* t);
static void IterateThread(ThreadVisitor* v);
static void IterateThread(ThreadVisitor* v, char* t);
// Returns the global object of the current context. It could be
// a builtin object, or a js global object.
static Handle<GlobalObject> global() {
return Handle<GlobalObject>(context()->global());
}
// Returns the global proxy object of the current context.
static Object* global_proxy() {
return context()->global_proxy();
}
// Returns the current global context.
static Handle<Context> global_context();
// Returns the global context of the calling JavaScript code. That
// is, the global context of the top-most JavaScript frame.
static Handle<Context> GetCallingGlobalContext();
static Handle<JSBuiltinsObject> builtins() {
return Handle<JSBuiltinsObject>(thread_local_.context_->builtins());
}
static void RegisterTryCatchHandler(v8::TryCatch* that);
static void UnregisterTryCatchHandler(v8::TryCatch* that);
#define TOP_GLOBAL_CONTEXT_FIELD_ACCESSOR(index, type, name) \
static Handle<type> name() { \
return Handle<type>(context()->global_context()->name()); \
}
GLOBAL_CONTEXT_FIELDS(TOP_GLOBAL_CONTEXT_FIELD_ACCESSOR)
#undef TOP_GLOBAL_CONTEXT_FIELD_ACCESSOR
static inline ThreadLocalTop* GetCurrentThread() { return &thread_local_; }
static int ArchiveSpacePerThread() { return sizeof(ThreadLocalTop); }
static char* ArchiveThread(char* to);
static char* RestoreThread(char* from);
static void FreeThreadResources() { thread_local_.Free(); }
static const char* kStackOverflowMessage;
private:
// The context that initiated this JS execution.
static ThreadLocalTop thread_local_;
static void InitializeThreadLocal();
static void PrintStackTrace(FILE* out, ThreadLocalTop* thread);
static void MarkCompactPrologue(bool is_compacting,
ThreadLocalTop* archived_thread_data);
static void MarkCompactEpilogue(bool is_compacting,
ThreadLocalTop* archived_thread_data);
// Debug.
// Mutex for serializing access to break control structures.
static Mutex* break_access_;
friend class SaveContext;
friend class AssertNoContextChange;
friend class ExecutionAccess;
static void FillCache();
};
// If the GCC version is 4.1.x or 4.2.x an additional field is added to the
// class as a work around for a bug in the generated code found with these
// versions of GCC. See V8 issue 122 for details.
class SaveContext BASE_EMBEDDED {
public:
SaveContext()
: context_(Top::context()),
#if __GNUC_VERSION__ >= 40100 && __GNUC_VERSION__ < 40300
dummy_(Top::context()),
#endif
prev_(Top::save_context()) {
Top::set_save_context(this);
// If there is no JS frame under the current C frame, use the value 0.
JavaScriptFrameIterator it;
js_sp_ = it.done() ? 0 : it.frame()->sp();
}
~SaveContext() {
Top::set_context(*context_);
Top::set_save_context(prev_);
}
Handle<Context> context() { return context_; }
SaveContext* prev() { return prev_; }
// Returns true if this save context is below a given JavaScript frame.
bool below(JavaScriptFrame* frame) {
return (js_sp_ == 0) || (frame->sp() < js_sp_);
}
private:
Handle<Context> context_;
#if __GNUC_VERSION__ >= 40100 && __GNUC_VERSION__ < 40300
Handle<Context> dummy_;
#endif
SaveContext* prev_;
Address js_sp_; // The top JS frame's sp when saving context.
};
class AssertNoContextChange BASE_EMBEDDED {
#ifdef DEBUG
public:
AssertNoContextChange() :
context_(Top::context()) {
}
~AssertNoContextChange() {
ASSERT(Top::context() == *context_);
}
private:
HandleScope scope_;
Handle<Context> context_;
#else
public:
AssertNoContextChange() { }
#endif
};
class ExecutionAccess BASE_EMBEDDED {
public:
ExecutionAccess();
~ExecutionAccess();
};
} } // namespace v8::internal
#endif // V8_TOP_H_