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// Copyright 2011 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.
#include <stdlib.h>
#include "v8.h"
#include "scopeinfo.h"
#include "scopes.h"
#include "allocation-inl.h"
namespace v8 {
namespace internal {
Handle<ScopeInfo> ScopeInfo::Create(Scope* scope) {
// Collect stack and context locals.
ZoneList<Variable*> stack_locals(scope->StackLocalCount());
ZoneList<Variable*> context_locals(scope->ContextLocalCount());
scope->CollectStackAndContextLocals(&stack_locals, &context_locals);
const int stack_local_count = stack_locals.length();
const int context_local_count = context_locals.length();
// Make sure we allocate the correct amount.
ASSERT(scope->StackLocalCount() == stack_local_count);
ASSERT(scope->ContextLocalCount() == context_local_count);
// Determine use and location of the function variable if it is present.
FunctionVariableInfo function_name_info;
VariableMode function_variable_mode;
if (scope->is_function_scope() && scope->function() != NULL) {
Variable* var = scope->function()->var();
if (!var->is_used()) {
function_name_info = UNUSED;
} else if (var->IsContextSlot()) {
function_name_info = CONTEXT;
} else {
ASSERT(var->IsStackLocal());
function_name_info = STACK;
}
function_variable_mode = var->mode();
} else {
function_name_info = NONE;
function_variable_mode = VAR;
}
const bool has_function_name = function_name_info != NONE;
const int parameter_count = scope->num_parameters();
const int length = kVariablePartIndex
+ parameter_count + stack_local_count + 2 * context_local_count
+ (has_function_name ? 2 : 0);
Handle<ScopeInfo> scope_info = FACTORY->NewScopeInfo(length);
// Encode the flags.
int flags = TypeField::encode(scope->type()) |
CallsEvalField::encode(scope->calls_eval()) |
LanguageModeField::encode(scope->language_mode()) |
FunctionVariableField::encode(function_name_info) |
FunctionVariableMode::encode(function_variable_mode);
scope_info->SetFlags(flags);
scope_info->SetParameterCount(parameter_count);
scope_info->SetStackLocalCount(stack_local_count);
scope_info->SetContextLocalCount(context_local_count);
int index = kVariablePartIndex;
// Add parameters.
ASSERT(index == scope_info->ParameterEntriesIndex());
for (int i = 0; i < parameter_count; ++i) {
scope_info->set(index++, *scope->parameter(i)->name());
}
// Add stack locals' names. We are assuming that the stack locals'
// slots are allocated in increasing order, so we can simply add
// them to the ScopeInfo object.
ASSERT(index == scope_info->StackLocalEntriesIndex());
for (int i = 0; i < stack_local_count; ++i) {
ASSERT(stack_locals[i]->index() == i);
scope_info->set(index++, *stack_locals[i]->name());
}
// Due to usage analysis, context-allocated locals are not necessarily in
// increasing order: Some of them may be parameters which are allocated before
// the non-parameter locals. When the non-parameter locals are sorted
// according to usage, the allocated slot indices may not be in increasing
// order with the variable list anymore. Thus, we first need to sort them by
// context slot index before adding them to the ScopeInfo object.
context_locals.Sort(&Variable::CompareIndex);
// Add context locals' names.
ASSERT(index == scope_info->ContextLocalNameEntriesIndex());
for (int i = 0; i < context_local_count; ++i) {
scope_info->set(index++, *context_locals[i]->name());
}
// Add context locals' info.
ASSERT(index == scope_info->ContextLocalInfoEntriesIndex());
for (int i = 0; i < context_local_count; ++i) {
Variable* var = context_locals[i];
uint32_t value = ContextLocalMode::encode(var->mode()) |
ContextLocalInitFlag::encode(var->initialization_flag());
scope_info->set(index++, Smi::FromInt(value));
}
// If present, add the function variable name and its index.
ASSERT(index == scope_info->FunctionNameEntryIndex());
if (has_function_name) {
int var_index = scope->function()->var()->index();
scope_info->set(index++, *scope->function()->name());
scope_info->set(index++, Smi::FromInt(var_index));
ASSERT(function_name_info != STACK ||
(var_index == scope_info->StackLocalCount() &&
var_index == scope_info->StackSlotCount() - 1));
ASSERT(function_name_info != CONTEXT ||
var_index == scope_info->ContextLength() - 1);
}
ASSERT(index == scope_info->length());
ASSERT(scope->num_parameters() == scope_info->ParameterCount());
ASSERT(scope->num_stack_slots() == scope_info->StackSlotCount());
ASSERT(scope->num_heap_slots() == scope_info->ContextLength());
return scope_info;
}
ScopeInfo* ScopeInfo::Empty() {
return reinterpret_cast<ScopeInfo*>(HEAP->empty_fixed_array());
}
ScopeType ScopeInfo::Type() {
ASSERT(length() > 0);
return TypeField::decode(Flags());
}
bool ScopeInfo::CallsEval() {
return length() > 0 && CallsEvalField::decode(Flags());
}
LanguageMode ScopeInfo::language_mode() {
return length() > 0 ? LanguageModeField::decode(Flags()) : CLASSIC_MODE;
}
int ScopeInfo::LocalCount() {
return StackLocalCount() + ContextLocalCount();
}
int ScopeInfo::StackSlotCount() {
if (length() > 0) {
bool function_name_stack_slot =
FunctionVariableField::decode(Flags()) == STACK;
return StackLocalCount() + (function_name_stack_slot ? 1 : 0);
}
return 0;
}
int ScopeInfo::ContextLength() {
if (length() > 0) {
int context_locals = ContextLocalCount();
bool function_name_context_slot =
FunctionVariableField::decode(Flags()) == CONTEXT;
bool has_context = context_locals > 0 ||
function_name_context_slot ||
Type() == WITH_SCOPE ||
(Type() == FUNCTION_SCOPE && CallsEval());
if (has_context) {
return Context::MIN_CONTEXT_SLOTS + context_locals +
(function_name_context_slot ? 1 : 0);
}
}
return 0;
}
bool ScopeInfo::HasFunctionName() {
if (length() > 0) {
return NONE != FunctionVariableField::decode(Flags());
} else {
return false;
}
}
bool ScopeInfo::HasHeapAllocatedLocals() {
if (length() > 0) {
return ContextLocalCount() > 0;
} else {
return false;
}
}
bool ScopeInfo::HasContext() {
if (length() > 0) {
return ContextLength() > 0;
} else {
return false;
}
}
String* ScopeInfo::FunctionName() {
ASSERT(HasFunctionName());
return String::cast(get(FunctionNameEntryIndex()));
}
String* ScopeInfo::ParameterName(int var) {
ASSERT(0 <= var && var < ParameterCount());
int info_index = ParameterEntriesIndex() + var;
return String::cast(get(info_index));
}
String* ScopeInfo::LocalName(int var) {
ASSERT(0 <= var && var < LocalCount());
ASSERT(StackLocalEntriesIndex() + StackLocalCount() ==
ContextLocalNameEntriesIndex());
int info_index = StackLocalEntriesIndex() + var;
return String::cast(get(info_index));
}
String* ScopeInfo::StackLocalName(int var) {
ASSERT(0 <= var && var < StackLocalCount());
int info_index = StackLocalEntriesIndex() + var;
return String::cast(get(info_index));
}
String* ScopeInfo::ContextLocalName(int var) {
ASSERT(0 <= var && var < ContextLocalCount());
int info_index = ContextLocalNameEntriesIndex() + var;
return String::cast(get(info_index));
}
VariableMode ScopeInfo::ContextLocalMode(int var) {
ASSERT(0 <= var && var < ContextLocalCount());
int info_index = ContextLocalInfoEntriesIndex() + var;
int value = Smi::cast(get(info_index))->value();
return ContextLocalMode::decode(value);
}
InitializationFlag ScopeInfo::ContextLocalInitFlag(int var) {
ASSERT(0 <= var && var < ContextLocalCount());
int info_index = ContextLocalInfoEntriesIndex() + var;
int value = Smi::cast(get(info_index))->value();
return ContextLocalInitFlag::decode(value);
}
int ScopeInfo::StackSlotIndex(String* name) {
ASSERT(name->IsSymbol());
if (length() > 0) {
int start = StackLocalEntriesIndex();
int end = StackLocalEntriesIndex() + StackLocalCount();
for (int i = start; i < end; ++i) {
if (name == get(i)) {
return i - start;
}
}
}
return -1;
}
int ScopeInfo::ContextSlotIndex(String* name,
VariableMode* mode,
InitializationFlag* init_flag) {
ASSERT(name->IsSymbol());
ASSERT(mode != NULL);
ASSERT(init_flag != NULL);
if (length() > 0) {
ContextSlotCache* context_slot_cache = GetIsolate()->context_slot_cache();
int result = context_slot_cache->Lookup(this, name, mode, init_flag);
if (result != ContextSlotCache::kNotFound) {
ASSERT(result < ContextLength());
return result;
}
int start = ContextLocalNameEntriesIndex();
int end = ContextLocalNameEntriesIndex() + ContextLocalCount();
for (int i = start; i < end; ++i) {
if (name == get(i)) {
int var = i - start;
*mode = ContextLocalMode(var);
*init_flag = ContextLocalInitFlag(var);
result = Context::MIN_CONTEXT_SLOTS + var;
context_slot_cache->Update(this, name, *mode, *init_flag, result);
ASSERT(result < ContextLength());
return result;
}
}
context_slot_cache->Update(this, name, INTERNAL, kNeedsInitialization, -1);
}
return -1;
}
int ScopeInfo::ParameterIndex(String* name) {
ASSERT(name->IsSymbol());
if (length() > 0) {
// We must read parameters from the end since for
// multiply declared parameters the value of the
// last declaration of that parameter is used
// inside a function (and thus we need to look
// at the last index). Was bug# 1110337.
int start = ParameterEntriesIndex();
int end = ParameterEntriesIndex() + ParameterCount();
for (int i = end - 1; i >= start; --i) {
if (name == get(i)) {
return i - start;
}
}
}
return -1;
}
int ScopeInfo::FunctionContextSlotIndex(String* name, VariableMode* mode) {
ASSERT(name->IsSymbol());
ASSERT(mode != NULL);
if (length() > 0) {
if (FunctionVariableField::decode(Flags()) == CONTEXT &&
FunctionName() == name) {
*mode = FunctionVariableMode::decode(Flags());
return Smi::cast(get(FunctionNameEntryIndex() + 1))->value();
}
}
return -1;
}
int ScopeInfo::ParameterEntriesIndex() {
ASSERT(length() > 0);
return kVariablePartIndex;
}
int ScopeInfo::StackLocalEntriesIndex() {
return ParameterEntriesIndex() + ParameterCount();
}
int ScopeInfo::ContextLocalNameEntriesIndex() {
return StackLocalEntriesIndex() + StackLocalCount();
}
int ScopeInfo::ContextLocalInfoEntriesIndex() {
return ContextLocalNameEntriesIndex() + ContextLocalCount();
}
int ScopeInfo::FunctionNameEntryIndex() {
return ContextLocalInfoEntriesIndex() + ContextLocalCount();
}
int ContextSlotCache::Hash(Object* data, String* name) {
// Uses only lower 32 bits if pointers are larger.
uintptr_t addr_hash =
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(data)) >> 2;
return static_cast<int>((addr_hash ^ name->Hash()) % kLength);
}
int ContextSlotCache::Lookup(Object* data,
String* name,
VariableMode* mode,
InitializationFlag* init_flag) {
int index = Hash(data, name);
Key& key = keys_[index];
if ((key.data == data) && key.name->Equals(name)) {
Value result(values_[index]);
if (mode != NULL) *mode = result.mode();
if (init_flag != NULL) *init_flag = result.initialization_flag();
return result.index() + kNotFound;
}
return kNotFound;
}
void ContextSlotCache::Update(Object* data,
String* name,
VariableMode mode,
InitializationFlag init_flag,
int slot_index) {
String* symbol;
ASSERT(slot_index > kNotFound);
if (HEAP->LookupSymbolIfExists(name, &symbol)) {
int index = Hash(data, symbol);
Key& key = keys_[index];
key.data = data;
key.name = symbol;
// Please note value only takes a uint as index.
values_[index] = Value(mode, init_flag, slot_index - kNotFound).raw();
#ifdef DEBUG
ValidateEntry(data, name, mode, init_flag, slot_index);
#endif
}
}
void ContextSlotCache::Clear() {
for (int index = 0; index < kLength; index++) keys_[index].data = NULL;
}
#ifdef DEBUG
void ContextSlotCache::ValidateEntry(Object* data,
String* name,
VariableMode mode,
InitializationFlag init_flag,
int slot_index) {
String* symbol;
if (HEAP->LookupSymbolIfExists(name, &symbol)) {
int index = Hash(data, name);
Key& key = keys_[index];
ASSERT(key.data == data);
ASSERT(key.name->Equals(name));
Value result(values_[index]);
ASSERT(result.mode() == mode);
ASSERT(result.initialization_flag() == init_flag);
ASSERT(result.index() + kNotFound == slot_index);
}
}
static void PrintList(const char* list_name,
int nof_internal_slots,
int start,
int end,
ScopeInfo* scope_info) {
if (start < end) {
PrintF("\n // %s\n", list_name);
if (nof_internal_slots > 0) {
PrintF(" %2d - %2d [internal slots]\n", 0 , nof_internal_slots - 1);
}
for (int i = nof_internal_slots; start < end; ++i, ++start) {
PrintF(" %2d ", i);
String::cast(scope_info->get(start))->ShortPrint();
PrintF("\n");
}
}
}
void ScopeInfo::Print() {
PrintF("ScopeInfo ");
if (HasFunctionName()) {
FunctionName()->ShortPrint();
} else {
PrintF("/* no function name */");
}
PrintF("{");
PrintList("parameters", 0,
ParameterEntriesIndex(),
ParameterEntriesIndex() + ParameterCount(),
this);
PrintList("stack slots", 0,
StackLocalEntriesIndex(),
StackLocalEntriesIndex() + StackLocalCount(),
this);
PrintList("context slots",
Context::MIN_CONTEXT_SLOTS,
ContextLocalNameEntriesIndex(),
ContextLocalNameEntriesIndex() + ContextLocalCount(),
this);
PrintF("}\n");
}
#endif // DEBUG
} } // namespace v8::internal