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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 "v8.h"
#include "codegen.h"
#include "compiler.h"
#include "debug.h"
#include "full-codegen.h"
#include "liveedit.h"
#include "macro-assembler.h"
#include "prettyprinter.h"
#include "scopes.h"
#include "scopeinfo.h"
#include "stub-cache.h"
namespace v8 {
namespace internal {
void BreakableStatementChecker::Check(Statement* stmt) {
Visit(stmt);
}
void BreakableStatementChecker::Check(Expression* expr) {
Visit(expr);
}
void BreakableStatementChecker::VisitDeclaration(Declaration* decl) {
}
void BreakableStatementChecker::VisitBlock(Block* stmt) {
}
void BreakableStatementChecker::VisitExpressionStatement(
ExpressionStatement* stmt) {
// Check if expression is breakable.
Visit(stmt->expression());
}
void BreakableStatementChecker::VisitEmptyStatement(EmptyStatement* stmt) {
}
void BreakableStatementChecker::VisitIfStatement(IfStatement* stmt) {
// If the condition is breakable the if statement is breakable.
Visit(stmt->condition());
}
void BreakableStatementChecker::VisitContinueStatement(
ContinueStatement* stmt) {
}
void BreakableStatementChecker::VisitBreakStatement(BreakStatement* stmt) {
}
void BreakableStatementChecker::VisitReturnStatement(ReturnStatement* stmt) {
// Return is breakable if the expression is.
Visit(stmt->expression());
}
void BreakableStatementChecker::VisitWithStatement(WithStatement* stmt) {
Visit(stmt->expression());
}
void BreakableStatementChecker::VisitSwitchStatement(SwitchStatement* stmt) {
// Switch statements breakable if the tag expression is.
Visit(stmt->tag());
}
void BreakableStatementChecker::VisitDoWhileStatement(DoWhileStatement* stmt) {
// Mark do while as breakable to avoid adding a break slot in front of it.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitWhileStatement(WhileStatement* stmt) {
// Mark while statements breakable if the condition expression is.
Visit(stmt->cond());
}
void BreakableStatementChecker::VisitForStatement(ForStatement* stmt) {
// Mark for statements breakable if the condition expression is.
if (stmt->cond() != NULL) {
Visit(stmt->cond());
}
}
void BreakableStatementChecker::VisitForInStatement(ForInStatement* stmt) {
// Mark for in statements breakable if the enumerable expression is.
Visit(stmt->enumerable());
}
void BreakableStatementChecker::VisitTryCatchStatement(
TryCatchStatement* stmt) {
// Mark try catch as breakable to avoid adding a break slot in front of it.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitTryFinallyStatement(
TryFinallyStatement* stmt) {
// Mark try finally as breakable to avoid adding a break slot in front of it.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitDebuggerStatement(
DebuggerStatement* stmt) {
// The debugger statement is breakable.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitFunctionLiteral(FunctionLiteral* expr) {
}
void BreakableStatementChecker::VisitSharedFunctionInfoLiteral(
SharedFunctionInfoLiteral* expr) {
}
void BreakableStatementChecker::VisitConditional(Conditional* expr) {
}
void BreakableStatementChecker::VisitVariableProxy(VariableProxy* expr) {
}
void BreakableStatementChecker::VisitLiteral(Literal* expr) {
}
void BreakableStatementChecker::VisitRegExpLiteral(RegExpLiteral* expr) {
}
void BreakableStatementChecker::VisitObjectLiteral(ObjectLiteral* expr) {
}
void BreakableStatementChecker::VisitArrayLiteral(ArrayLiteral* expr) {
}
void BreakableStatementChecker::VisitAssignment(Assignment* expr) {
// If assigning to a property (including a global property) the assignment is
// breakable.
VariableProxy* proxy = expr->target()->AsVariableProxy();
Property* prop = expr->target()->AsProperty();
if (prop != NULL || (proxy != NULL && proxy->var()->IsUnallocated())) {
is_breakable_ = true;
return;
}
// Otherwise the assignment is breakable if the assigned value is.
Visit(expr->value());
}
void BreakableStatementChecker::VisitThrow(Throw* expr) {
// Throw is breakable if the expression is.
Visit(expr->exception());
}
void BreakableStatementChecker::VisitProperty(Property* expr) {
// Property load is breakable.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitCall(Call* expr) {
// Function calls both through IC and call stub are breakable.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitCallNew(CallNew* expr) {
// Function calls through new are breakable.
is_breakable_ = true;
}
void BreakableStatementChecker::VisitCallRuntime(CallRuntime* expr) {
}
void BreakableStatementChecker::VisitUnaryOperation(UnaryOperation* expr) {
Visit(expr->expression());
}
void BreakableStatementChecker::VisitCountOperation(CountOperation* expr) {
Visit(expr->expression());
}
void BreakableStatementChecker::VisitBinaryOperation(BinaryOperation* expr) {
Visit(expr->left());
if (expr->op() != Token::AND &&
expr->op() != Token::OR) {
Visit(expr->right());
}
}
void BreakableStatementChecker::VisitCompareToNull(CompareToNull* expr) {
Visit(expr->expression());
}
void BreakableStatementChecker::VisitCompareOperation(CompareOperation* expr) {
Visit(expr->left());
Visit(expr->right());
}
void BreakableStatementChecker::VisitThisFunction(ThisFunction* expr) {
}
#define __ ACCESS_MASM(masm())
bool FullCodeGenerator::MakeCode(CompilationInfo* info) {
Isolate* isolate = info->isolate();
Handle<Script> script = info->script();
if (!script->IsUndefined() && !script->source()->IsUndefined()) {
int len = String::cast(script->source())->length();
isolate->counters()->total_full_codegen_source_size()->Increment(len);
}
if (FLAG_trace_codegen) {
PrintF("Full Compiler - ");
}
CodeGenerator::MakeCodePrologue(info);
const int kInitialBufferSize = 4 * KB;
MacroAssembler masm(info->isolate(), NULL, kInitialBufferSize);
#ifdef ENABLE_GDB_JIT_INTERFACE
masm.positions_recorder()->StartGDBJITLineInfoRecording();
#endif
FullCodeGenerator cgen(&masm);
cgen.Generate(info);
if (cgen.HasStackOverflow()) {
ASSERT(!isolate->has_pending_exception());
return false;
}
unsigned table_offset = cgen.EmitStackCheckTable();
Code::Flags flags = Code::ComputeFlags(Code::FUNCTION);
Handle<Code> code = CodeGenerator::MakeCodeEpilogue(&masm, flags, info);
code->set_optimizable(info->IsOptimizable());
cgen.PopulateDeoptimizationData(code);
code->set_has_deoptimization_support(info->HasDeoptimizationSupport());
code->set_has_debug_break_slots(
info->isolate()->debugger()->IsDebuggerActive());
code->set_allow_osr_at_loop_nesting_level(0);
code->set_stack_check_table_offset(table_offset);
CodeGenerator::PrintCode(code, info);
info->SetCode(code); // may be an empty handle.
#ifdef ENABLE_GDB_JIT_INTERFACE
if (FLAG_gdbjit && !code.is_null()) {
GDBJITLineInfo* lineinfo =
masm.positions_recorder()->DetachGDBJITLineInfo();
GDBJIT(RegisterDetailedLineInfo(*code, lineinfo));
}
#endif
return !code.is_null();
}
unsigned FullCodeGenerator::EmitStackCheckTable() {
// The stack check table consists of a length (in number of entries)
// field, and then a sequence of entries. Each entry is a pair of AST id
// and code-relative pc offset.
masm()->Align(kIntSize);
unsigned offset = masm()->pc_offset();
unsigned length = stack_checks_.length();
__ dd(length);
for (unsigned i = 0; i < length; ++i) {
__ dd(stack_checks_[i].id);
__ dd(stack_checks_[i].pc_and_state);
}
return offset;
}
void FullCodeGenerator::PopulateDeoptimizationData(Handle<Code> code) {
// Fill in the deoptimization information.
ASSERT(info_->HasDeoptimizationSupport() || bailout_entries_.is_empty());
if (!info_->HasDeoptimizationSupport()) return;
int length = bailout_entries_.length();
Handle<DeoptimizationOutputData> data =
isolate()->factory()->
NewDeoptimizationOutputData(length, TENURED);
for (int i = 0; i < length; i++) {
data->SetAstId(i, Smi::FromInt(bailout_entries_[i].id));
data->SetPcAndState(i, Smi::FromInt(bailout_entries_[i].pc_and_state));
}
code->set_deoptimization_data(*data);
}
void FullCodeGenerator::PrepareForBailout(Expression* node, State state) {
PrepareForBailoutForId(node->id(), state);
}
void FullCodeGenerator::RecordJSReturnSite(Call* call) {
// We record the offset of the function return so we can rebuild the frame
// if the function was inlined, i.e., this is the return address in the
// inlined function's frame.
//
// The state is ignored. We defensively set it to TOS_REG, which is the
// real state of the unoptimized code at the return site.
PrepareForBailoutForId(call->ReturnId(), TOS_REG);
#ifdef DEBUG
// In debug builds, mark the return so we can verify that this function
// was called.
ASSERT(!call->return_is_recorded_);
call->return_is_recorded_ = true;
#endif
}
void FullCodeGenerator::PrepareForBailoutForId(int id, State state) {
// There's no need to prepare this code for bailouts from already optimized
// code or code that can't be optimized.
if (!FLAG_deopt || !info_->HasDeoptimizationSupport()) return;
unsigned pc_and_state =
StateField::encode(state) | PcField::encode(masm_->pc_offset());
BailoutEntry entry = { id, pc_and_state };
#ifdef DEBUG
// Assert that we don't have multiple bailout entries for the same node.
for (int i = 0; i < bailout_entries_.length(); i++) {
if (bailout_entries_.at(i).id == entry.id) {
AstPrinter printer;
PrintF("%s", printer.PrintProgram(info_->function()));
UNREACHABLE();
}
}
#endif // DEBUG
bailout_entries_.Add(entry);
}
void FullCodeGenerator::RecordStackCheck(int ast_id) {
// The pc offset does not need to be encoded and packed together with a
// state.
BailoutEntry entry = { ast_id, masm_->pc_offset() };
stack_checks_.Add(entry);
}
bool FullCodeGenerator::ShouldInlineSmiCase(Token::Value op) {
// Inline smi case inside loops, but not division and modulo which
// are too complicated and take up too much space.
if (op == Token::DIV ||op == Token::MOD) return false;
if (FLAG_always_inline_smi_code) return true;
return loop_depth_ > 0;
}
void FullCodeGenerator::EffectContext::Plug(Register reg) const {
}
void FullCodeGenerator::AccumulatorValueContext::Plug(Register reg) const {
__ Move(result_register(), reg);
}
void FullCodeGenerator::StackValueContext::Plug(Register reg) const {
__ push(reg);
codegen()->increment_stack_height();
}
void FullCodeGenerator::TestContext::Plug(Register reg) const {
// For simplicity we always test the accumulator register.
__ Move(result_register(), reg);
codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
codegen()->DoTest(this);
}
void FullCodeGenerator::EffectContext::PlugTOS() const {
__ Drop(1);
codegen()->decrement_stack_height();
}
void FullCodeGenerator::AccumulatorValueContext::PlugTOS() const {
__ pop(result_register());
codegen()->decrement_stack_height();
}
void FullCodeGenerator::StackValueContext::PlugTOS() const {
}
void FullCodeGenerator::TestContext::PlugTOS() const {
// For simplicity we always test the accumulator register.
__ pop(result_register());
codegen()->decrement_stack_height();
codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
codegen()->DoTest(this);
}
void FullCodeGenerator::EffectContext::PrepareTest(
Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const {
// In an effect context, the true and the false case branch to the
// same label.
*if_true = *if_false = *fall_through = materialize_true;
}
void FullCodeGenerator::AccumulatorValueContext::PrepareTest(
Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const {
*if_true = *fall_through = materialize_true;
*if_false = materialize_false;
}
void FullCodeGenerator::StackValueContext::PrepareTest(
Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const {
*if_true = *fall_through = materialize_true;
*if_false = materialize_false;
}
void FullCodeGenerator::TestContext::PrepareTest(
Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const {
*if_true = true_label_;
*if_false = false_label_;
*fall_through = fall_through_;
}
void FullCodeGenerator::DoTest(const TestContext* context) {
DoTest(context->condition(),
context->true_label(),
context->false_label(),
context->fall_through());
}
void FullCodeGenerator::VisitDeclarations(
ZoneList<Declaration*>* declarations) {
int length = declarations->length();
int global_count = 0;
for (int i = 0; i < length; i++) {
Declaration* decl = declarations->at(i);
EmitDeclaration(decl->proxy(), decl->mode(), decl->fun(), &global_count);
}
// Batch declare global functions and variables.
if (global_count > 0) {
Handle<FixedArray> array =
isolate()->factory()->NewFixedArray(2 * global_count, TENURED);
for (int j = 0, i = 0; i < length; i++) {
Declaration* decl = declarations->at(i);
Variable* var = decl->proxy()->var();
if (var->IsUnallocated()) {
array->set(j++, *(var->name()));
if (decl->fun() == NULL) {
if (var->mode() == Variable::CONST) {
// In case this is const property use the hole.
array->set_the_hole(j++);
} else {
array->set_undefined(j++);
}
} else {
Handle<SharedFunctionInfo> function =
Compiler::BuildFunctionInfo(decl->fun(), script());
// Check for stack-overflow exception.
if (function.is_null()) {
SetStackOverflow();
return;
}
array->set(j++, *function);
}
}
}
// Invoke the platform-dependent code generator to do the actual
// declaration the global functions and variables.
DeclareGlobals(array);
}
}
int FullCodeGenerator::DeclareGlobalsFlags() {
int flags = 0;
if (is_eval()) flags |= kDeclareGlobalsEvalFlag;
if (is_strict_mode()) flags |= kDeclareGlobalsStrictModeFlag;
if (is_native()) flags |= kDeclareGlobalsNativeFlag;
return flags;
}
void FullCodeGenerator::SetFunctionPosition(FunctionLiteral* fun) {
CodeGenerator::RecordPositions(masm_, fun->start_position());
}
void FullCodeGenerator::SetReturnPosition(FunctionLiteral* fun) {
CodeGenerator::RecordPositions(masm_, fun->end_position() - 1);
}
void FullCodeGenerator::SetStatementPosition(Statement* stmt) {
#ifdef ENABLE_DEBUGGER_SUPPORT
if (!isolate()->debugger()->IsDebuggerActive()) {
CodeGenerator::RecordPositions(masm_, stmt->statement_pos());
} else {
// Check if the statement will be breakable without adding a debug break
// slot.
BreakableStatementChecker checker;
checker.Check(stmt);
// Record the statement position right here if the statement is not
// breakable. For breakable statements the actual recording of the
// position will be postponed to the breakable code (typically an IC).
bool position_recorded = CodeGenerator::RecordPositions(
masm_, stmt->statement_pos(), !checker.is_breakable());
// If the position recording did record a new position generate a debug
// break slot to make the statement breakable.
if (position_recorded) {
Debug::GenerateSlot(masm_);
}
}
#else
CodeGenerator::RecordPositions(masm_, stmt->statement_pos());
#endif
}
void FullCodeGenerator::SetExpressionPosition(Expression* expr, int pos) {
#ifdef ENABLE_DEBUGGER_SUPPORT
if (!isolate()->debugger()->IsDebuggerActive()) {
CodeGenerator::RecordPositions(masm_, pos);
} else {
// Check if the expression will be breakable without adding a debug break
// slot.
BreakableStatementChecker checker;
checker.Check(expr);
// Record a statement position right here if the expression is not
// breakable. For breakable expressions the actual recording of the
// position will be postponed to the breakable code (typically an IC).
// NOTE this will record a statement position for something which might
// not be a statement. As stepping in the debugger will only stop at
// statement positions this is used for e.g. the condition expression of
// a do while loop.
bool position_recorded = CodeGenerator::RecordPositions(
masm_, pos, !checker.is_breakable());
// If the position recording did record a new position generate a debug
// break slot to make the statement breakable.
if (position_recorded) {
Debug::GenerateSlot(masm_);
}
}
#else
CodeGenerator::RecordPositions(masm_, pos);
#endif
}
void FullCodeGenerator::SetStatementPosition(int pos) {
CodeGenerator::RecordPositions(masm_, pos);
}
void FullCodeGenerator::SetSourcePosition(int pos) {
if (pos != RelocInfo::kNoPosition) {
masm_->positions_recorder()->RecordPosition(pos);
}
}
// Lookup table for code generators for special runtime calls which are
// generated inline.
#define INLINE_FUNCTION_GENERATOR_ADDRESS(Name, argc, ressize) \
&FullCodeGenerator::Emit##Name,
const FullCodeGenerator::InlineFunctionGenerator
FullCodeGenerator::kInlineFunctionGenerators[] = {
INLINE_FUNCTION_LIST(INLINE_FUNCTION_GENERATOR_ADDRESS)
INLINE_RUNTIME_FUNCTION_LIST(INLINE_FUNCTION_GENERATOR_ADDRESS)
};
#undef INLINE_FUNCTION_GENERATOR_ADDRESS
FullCodeGenerator::InlineFunctionGenerator
FullCodeGenerator::FindInlineFunctionGenerator(Runtime::FunctionId id) {
int lookup_index =
static_cast<int>(id) - static_cast<int>(Runtime::kFirstInlineFunction);
ASSERT(lookup_index >= 0);
ASSERT(static_cast<size_t>(lookup_index) <
ARRAY_SIZE(kInlineFunctionGenerators));
return kInlineFunctionGenerators[lookup_index];
}
void FullCodeGenerator::EmitInlineRuntimeCall(CallRuntime* node) {
ZoneList<Expression*>* args = node->arguments();
const Runtime::Function* function = node->function();
ASSERT(function != NULL);
ASSERT(function->intrinsic_type == Runtime::INLINE);
InlineFunctionGenerator generator =
FindInlineFunctionGenerator(function->function_id);
((*this).*(generator))(args);
}
void FullCodeGenerator::VisitBinaryOperation(BinaryOperation* expr) {
switch (expr->op()) {
case Token::COMMA:
return VisitComma(expr);
case Token::OR:
case Token::AND:
return VisitLogicalExpression(expr);
default:
return VisitArithmeticExpression(expr);
}
}
void FullCodeGenerator::VisitComma(BinaryOperation* expr) {
Comment cmnt(masm_, "[ Comma");
VisitForEffect(expr->left());
if (context()->IsTest()) ForwardBailoutToChild(expr);
VisitInCurrentContext(expr->right());
}
void FullCodeGenerator::VisitLogicalExpression(BinaryOperation* expr) {
bool is_logical_and = expr->op() == Token::AND;
Comment cmnt(masm_, is_logical_and ? "[ Logical AND" : "[ Logical OR");
Expression* left = expr->left();
Expression* right = expr->right();
int right_id = expr->RightId();
Label done;
if (context()->IsTest()) {
Label eval_right;
const TestContext* test = TestContext::cast(context());
if (is_logical_and) {
VisitForControl(left, &eval_right, test->false_label(), &eval_right);
} else {
VisitForControl(left, test->true_label(), &eval_right, &eval_right);
}
PrepareForBailoutForId(right_id, NO_REGISTERS);
__ bind(&eval_right);
ForwardBailoutToChild(expr);
} else if (context()->IsAccumulatorValue()) {
VisitForAccumulatorValue(left);
// We want the value in the accumulator for the test, and on the stack in
// case we need it.
__ push(result_register());
Label discard, restore;
PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
if (is_logical_and) {
DoTest(left, &discard, &restore, &restore);
} else {
DoTest(left, &restore, &discard, &restore);
}
__ bind(&restore);
__ pop(result_register());
__ jmp(&done);
__ bind(&discard);
__ Drop(1);
PrepareForBailoutForId(right_id, NO_REGISTERS);
} else if (context()->IsStackValue()) {
VisitForAccumulatorValue(left);
// We want the value in the accumulator for the test, and on the stack in
// case we need it.
__ push(result_register());
Label discard;
PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
if (is_logical_and) {
DoTest(left, &discard, &done, &discard);
} else {
DoTest(left, &done, &discard, &discard);
}
__ bind(&discard);
__ Drop(1);
PrepareForBailoutForId(right_id, NO_REGISTERS);
} else {
ASSERT(context()->IsEffect());
Label eval_right;
if (is_logical_and) {
VisitForControl(left, &eval_right, &done, &eval_right);
} else {
VisitForControl(left, &done, &eval_right, &eval_right);
}
PrepareForBailoutForId(right_id, NO_REGISTERS);
__ bind(&eval_right);
}
VisitInCurrentContext(right);
__ bind(&done);
}
void FullCodeGenerator::VisitArithmeticExpression(BinaryOperation* expr) {
Token::Value op = expr->op();
Comment cmnt(masm_, "[ ArithmeticExpression");
Expression* left = expr->left();
Expression* right = expr->right();
OverwriteMode mode =
left->ResultOverwriteAllowed()
? OVERWRITE_LEFT
: (right->ResultOverwriteAllowed() ? OVERWRITE_RIGHT : NO_OVERWRITE);
VisitForStackValue(left);
VisitForAccumulatorValue(right);
SetSourcePosition(expr->position());
if (ShouldInlineSmiCase(op)) {
EmitInlineSmiBinaryOp(expr, op, mode, left, right);
} else {
EmitBinaryOp(expr, op, mode);
}
}
void FullCodeGenerator::ForwardBailoutToChild(Expression* expr) {
if (!info_->HasDeoptimizationSupport()) return;
ASSERT(context()->IsTest());
ASSERT(expr == forward_bailout_stack_->expr());
forward_bailout_pending_ = forward_bailout_stack_;
}
void FullCodeGenerator::VisitInCurrentContext(Expression* expr) {
if (context()->IsTest()) {
ForwardBailoutStack stack(expr, forward_bailout_pending_);
ForwardBailoutStack* saved = forward_bailout_stack_;
forward_bailout_pending_ = NULL;
forward_bailout_stack_ = &stack;
Visit(expr);
forward_bailout_stack_ = saved;
} else {
ASSERT(forward_bailout_pending_ == NULL);
Visit(expr);
State state = context()->IsAccumulatorValue() ? TOS_REG : NO_REGISTERS;
PrepareForBailout(expr, state);
// Forwarding bailouts to children is a one shot operation. It should have
// been processed at this point.
ASSERT(forward_bailout_pending_ == NULL);
}
}
void FullCodeGenerator::VisitBlock(Block* stmt) {
Comment cmnt(masm_, "[ Block");
NestedBlock nested_block(this, stmt);
SetStatementPosition(stmt);
Scope* saved_scope = scope();
// Push a block context when entering a block with block scoped variables.
if (stmt->block_scope() != NULL) {
{ Comment cmnt(masm_, "[ Extend block context");
scope_ = stmt->block_scope();
__ Push(scope_->GetSerializedScopeInfo());
PushFunctionArgumentForContextAllocation();
__ CallRuntime(Runtime::kPushBlockContext, 2);
StoreToFrameField(StandardFrameConstants::kContextOffset,
context_register());
}
{ Comment cmnt(masm_, "[ Declarations");
VisitDeclarations(scope_->declarations());
}
}
PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
VisitStatements(stmt->statements());
scope_ = saved_scope;
__ bind(nested_block.break_label());
PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
// Pop block context if necessary.
if (stmt->block_scope() != NULL) {
LoadContextField(context_register(), Context::PREVIOUS_INDEX);
// Update local stack frame context field.
StoreToFrameField(StandardFrameConstants::kContextOffset,
context_register());
}
}
void FullCodeGenerator::VisitExpressionStatement(ExpressionStatement* stmt) {
Comment cmnt(masm_, "[ ExpressionStatement");
SetStatementPosition(stmt);
VisitForEffect(stmt->expression());
}
void FullCodeGenerator::VisitEmptyStatement(EmptyStatement* stmt) {
Comment cmnt(masm_, "[ EmptyStatement");
SetStatementPosition(stmt);
}
void FullCodeGenerator::VisitIfStatement(IfStatement* stmt) {
Comment cmnt(masm_, "[ IfStatement");
SetStatementPosition(stmt);
Label then_part, else_part, done;
if (stmt->HasElseStatement()) {
VisitForControl(stmt->condition(), &then_part, &else_part, &then_part);
PrepareForBailoutForId(stmt->ThenId(), NO_REGISTERS);
__ bind(&then_part);
Visit(stmt->then_statement());
__ jmp(&done);
PrepareForBailoutForId(stmt->ElseId(), NO_REGISTERS);
__ bind(&else_part);
Visit(stmt->else_statement());
} else {
VisitForControl(stmt->condition(), &then_part, &done, &then_part);
PrepareForBailoutForId(stmt->ThenId(), NO_REGISTERS);
__ bind(&then_part);
Visit(stmt->then_statement());
PrepareForBailoutForId(stmt->ElseId(), NO_REGISTERS);
}
__ bind(&done);
PrepareForBailoutForId(stmt->IfId(), NO_REGISTERS);
}
void FullCodeGenerator::VisitContinueStatement(ContinueStatement* stmt) {
Comment cmnt(masm_, "[ ContinueStatement");
SetStatementPosition(stmt);
NestedStatement* current = nesting_stack_;
int stack_depth = 0;
int context_length = 0;
// When continuing, we clobber the unpredictable value in the accumulator
// with one that's safe for GC. If we hit an exit from the try block of
// try...finally on our way out, we will unconditionally preserve the
// accumulator on the stack.
ClearAccumulator();
while (!current->IsContinueTarget(stmt->target())) {
current = current->Exit(&stack_depth, &context_length);
}
__ Drop(stack_depth);
if (context_length > 0) {
while (context_length > 0) {
LoadContextField(context_register(), Context::PREVIOUS_INDEX);
--context_length;
}
StoreToFrameField(StandardFrameConstants::kContextOffset,
context_register());
}
__ jmp(current->AsIteration()->continue_label());
}
void FullCodeGenerator::VisitBreakStatement(BreakStatement* stmt) {
Comment cmnt(masm_, "[ BreakStatement");
SetStatementPosition(stmt);
NestedStatement* current = nesting_stack_;
int stack_depth = 0;
int context_length = 0;
// When breaking, we clobber the unpredictable value in the accumulator
// with one that's safe for GC. If we hit an exit from the try block of
// try...finally on our way out, we will unconditionally preserve the
// accumulator on the stack.
ClearAccumulator();
while (!current->IsBreakTarget(stmt->target())) {
current = current->Exit(&stack_depth, &context_length);
}
__ Drop(stack_depth);
if (context_length > 0) {
while (context_length > 0) {
LoadContextField(context_register(), Context::PREVIOUS_INDEX);
--context_length;
}
StoreToFrameField(StandardFrameConstants::kContextOffset,
context_register());
}
__ jmp(current->AsBreakable()->break_label());
}
void FullCodeGenerator::VisitReturnStatement(ReturnStatement* stmt) {
Comment cmnt(masm_, "[ ReturnStatement");
SetStatementPosition(stmt);
Expression* expr = stmt->expression();
VisitForAccumulatorValue(expr);
// Exit all nested statements.
NestedStatement* current = nesting_stack_;
int stack_depth = 0;
int context_length = 0;
while (current != NULL) {
current = current->Exit(&stack_depth, &context_length);
}
__ Drop(stack_depth);
EmitReturnSequence();
}
void FullCodeGenerator::VisitWithStatement(WithStatement* stmt) {
Comment cmnt(masm_, "[ WithStatement");
SetStatementPosition(stmt);
VisitForStackValue(stmt->expression());
PushFunctionArgumentForContextAllocation();
__ CallRuntime(Runtime::kPushWithContext, 2);
decrement_stack_height();
StoreToFrameField(StandardFrameConstants::kContextOffset, context_register());
{ WithOrCatch body(this);
Visit(stmt->statement());
}
// Pop context.
LoadContextField(context_register(), Context::PREVIOUS_INDEX);
// Update local stack frame context field.
StoreToFrameField(StandardFrameConstants::kContextOffset, context_register());
}
void FullCodeGenerator::VisitDoWhileStatement(DoWhileStatement* stmt) {
Comment cmnt(masm_, "[ DoWhileStatement");
SetStatementPosition(stmt);
Label body, stack_check;
Iteration loop_statement(this, stmt);
increment_loop_depth();
__ bind(&body);
Visit(stmt->body());
// Record the position of the do while condition and make sure it is
// possible to break on the condition.
__ bind(loop_statement.continue_label());
PrepareForBailoutForId(stmt->ContinueId(), NO_REGISTERS);
SetExpressionPosition(stmt->cond(), stmt->condition_position());
VisitForControl(stmt->cond(),
&stack_check,
loop_statement.break_label(),
&stack_check);
// Check stack before looping.
PrepareForBailoutForId(stmt->BackEdgeId(), NO_REGISTERS);
__ bind(&stack_check);
EmitStackCheck(stmt);
__ jmp(&body);
PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
__ bind(loop_statement.break_label());
decrement_loop_depth();
}
void FullCodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
Comment cmnt(masm_, "[ WhileStatement");
Label test, body;
Iteration loop_statement(this, stmt);
increment_loop_depth();
// Emit the test at the bottom of the loop.
__ jmp(&test);
PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
__ bind(&body);
Visit(stmt->body());
// Emit the statement position here as this is where the while
// statement code starts.
__ bind(loop_statement.continue_label());
SetStatementPosition(stmt);
// Check stack before looping.
EmitStackCheck(stmt);
__ bind(&test);
VisitForControl(stmt->cond(),
&body,
loop_statement.break_label(),
loop_statement.break_label());
PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
__ bind(loop_statement.break_label());
decrement_loop_depth();
}
void FullCodeGenerator::VisitForStatement(ForStatement* stmt) {
Comment cmnt(masm_, "[ ForStatement");
Label test, body;
Iteration loop_statement(this, stmt);
if (stmt->init() != NULL) {
Visit(stmt->init());
}
increment_loop_depth();
// Emit the test at the bottom of the loop (even if empty).
__ jmp(&test);
PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
__ bind(&body);
Visit(stmt->body());
PrepareForBailoutForId(stmt->ContinueId(), NO_REGISTERS);
__ bind(loop_statement.continue_label());
SetStatementPosition(stmt);
if (stmt->next() != NULL) {
Visit(stmt->next());
}
// Emit the statement position here as this is where the for
// statement code starts.
SetStatementPosition(stmt);
// Check stack before looping.
EmitStackCheck(stmt);
__ bind(&test);
if (stmt->cond() != NULL) {
VisitForControl(stmt->cond(),
&body,
loop_statement.break_label(),
loop_statement.break_label());
} else {
__ jmp(&body);
}
PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
__ bind(loop_statement.break_label());
decrement_loop_depth();
}
void FullCodeGenerator::VisitTryCatchStatement(TryCatchStatement* stmt) {
Comment cmnt(masm_, "[ TryCatchStatement");
SetStatementPosition(stmt);
// The try block adds a handler to the exception handler chain
// before entering, and removes it again when exiting normally.
// If an exception is thrown during execution of the try block,
// control is passed to the handler, which also consumes the handler.
// At this point, the exception is in a register, and store it in
// the temporary local variable (prints as ".catch-var") before
// executing the catch block. The catch block has been rewritten
// to introduce a new scope to bind the catch variable and to remove
// that scope again afterwards.
Label try_handler_setup, done;
__ Call(&try_handler_setup);
// Try handler code, exception in result register.
// Extend the context before executing the catch block.
{ Comment cmnt(masm_, "[ Extend catch context");
__ Push(stmt->variable()->name());
__ push(result_register());
PushFunctionArgumentForContextAllocation();
__ CallRuntime(Runtime::kPushCatchContext, 3);
StoreToFrameField(StandardFrameConstants::kContextOffset,
context_register());
}
Scope* saved_scope = scope();
scope_ = stmt->scope();
ASSERT(scope_->declarations()->is_empty());
{ WithOrCatch body(this);
Visit(stmt->catch_block());
}
// Restore the context.
LoadContextField(context_register(), Context::PREVIOUS_INDEX);
StoreToFrameField(StandardFrameConstants::kContextOffset, context_register());
scope_ = saved_scope;
__ jmp(&done);
// Try block code. Sets up the exception handler chain.
__ bind(&try_handler_setup);
{
const int delta = StackHandlerConstants::kSize / kPointerSize;
TryCatch try_block(this);
__ PushTryHandler(IN_JAVASCRIPT, TRY_CATCH_HANDLER);
increment_stack_height(delta);
Visit(stmt->try_block());
__ PopTryHandler();
decrement_stack_height(delta);
}
__ bind(&done);
}
void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
Comment cmnt(masm_, "[ TryFinallyStatement");
SetStatementPosition(stmt);
// Try finally is compiled by setting up a try-handler on the stack while
// executing the try body, and removing it again afterwards.
//
// The try-finally construct can enter the finally block in three ways:
// 1. By exiting the try-block normally. This removes the try-handler and
// calls the finally block code before continuing.
// 2. By exiting the try-block with a function-local control flow transfer
// (break/continue/return). The site of the, e.g., break removes the
// try handler and calls the finally block code before continuing
// its outward control transfer.
// 3. by exiting the try-block with a thrown exception.
// This can happen in nested function calls. It traverses the try-handler
// chain and consumes the try-handler entry before jumping to the
// handler code. The handler code then calls the finally-block before
// rethrowing the exception.
//
// The finally block must assume a return address on top of the stack
// (or in the link register on ARM chips) and a value (return value or
// exception) in the result register (rax/eax/r0), both of which must
// be preserved. The return address isn't GC-safe, so it should be
// cooked before GC.
Label finally_entry;
Label try_handler_setup;
const int original_stack_height = stack_height();
// Setup the try-handler chain. Use a call to
// Jump to try-handler setup and try-block code. Use call to put try-handler
// address on stack.
__ Call(&try_handler_setup);
// Try handler code. Return address of call is pushed on handler stack.
{
// This code is only executed during stack-handler traversal when an
// exception is thrown. The exception is in the result register, which
// is retained by the finally block.
// Call the finally block and then rethrow the exception if it returns.
__ Call(&finally_entry);
__ push(result_register());
__ CallRuntime(Runtime::kReThrow, 1);
}
__ bind(&finally_entry);
{
// Finally block implementation.
Finally finally_block(this);
EnterFinallyBlock();
set_stack_height(original_stack_height + Finally::kElementCount);
Visit(stmt->finally_block());
ExitFinallyBlock(); // Return to the calling code.
}
__ bind(&try_handler_setup);
{
// Setup try handler (stack pointer registers).
const int delta = StackHandlerConstants::kSize / kPointerSize;
TryFinally try_block(this, &finally_entry);
__ PushTryHandler(IN_JAVASCRIPT, TRY_FINALLY_HANDLER);
set_stack_height(original_stack_height + delta);
Visit(stmt->try_block());
__ PopTryHandler();
set_stack_height(original_stack_height);
}
// Execute the finally block on the way out. Clobber the unpredictable
// value in the accumulator with one that's safe for GC. The finally
// block will unconditionally preserve the accumulator on the stack.
ClearAccumulator();
__ Call(&finally_entry);
}
void FullCodeGenerator::VisitDebuggerStatement(DebuggerStatement* stmt) {
#ifdef ENABLE_DEBUGGER_SUPPORT
Comment cmnt(masm_, "[ DebuggerStatement");
SetStatementPosition(stmt);
__ DebugBreak();
// Ignore the return value.
#endif
}
void FullCodeGenerator::VisitConditional(Conditional* expr) {
Comment cmnt(masm_, "[ Conditional");
Label true_case, false_case, done;
VisitForControl(expr->condition(), &true_case, &false_case, &true_case);
PrepareForBailoutForId(expr->ThenId(), NO_REGISTERS);
__ bind(&true_case);
SetExpressionPosition(expr->then_expression(),
expr->then_expression_position());
int start_stack_height = stack_height();
if (context()->IsTest()) {
const TestContext* for_test = TestContext::cast(context());
VisitForControl(expr->then_expression(),
for_test->true_label(),
for_test->false_label(),
NULL);
} else {
VisitInCurrentContext(expr->then_expression());
__ jmp(&done);
}
PrepareForBailoutForId(expr->ElseId(), NO_REGISTERS);
__ bind(&false_case);
set_stack_height(start_stack_height);
if (context()->IsTest()) ForwardBailoutToChild(expr);
SetExpressionPosition(expr->else_expression(),
expr->else_expression_position());
VisitInCurrentContext(expr->else_expression());
// If control flow falls through Visit, merge it with true case here.
if (!context()->IsTest()) {
__ bind(&done);
}
}
void FullCodeGenerator::VisitLiteral(Literal* expr) {
Comment cmnt(masm_, "[ Literal");
context()->Plug(expr->handle());
}
void FullCodeGenerator::VisitFunctionLiteral(FunctionLiteral* expr) {
Comment cmnt(masm_, "[ FunctionLiteral");
// Build the function boilerplate and instantiate it.
Handle<SharedFunctionInfo> function_info =
Compiler::BuildFunctionInfo(expr, script());
if (function_info.is_null()) {
SetStackOverflow();
return;
}
EmitNewClosure(function_info, expr->pretenure());
}
void FullCodeGenerator::VisitSharedFunctionInfoLiteral(
SharedFunctionInfoLiteral* expr) {
Comment cmnt(masm_, "[ SharedFunctionInfoLiteral");
EmitNewClosure(expr->shared_function_info(), false);
}
void FullCodeGenerator::VisitThrow(Throw* expr) {
Comment cmnt(masm_, "[ Throw");
// Throw has no effect on the stack height or the current expression context.
// Usually the expression context is null, because throw is a statement.
VisitForStackValue(expr->exception());
__ CallRuntime(Runtime::kThrow, 1);
decrement_stack_height();
// Never returns here.
}
FullCodeGenerator::NestedStatement* FullCodeGenerator::TryCatch::Exit(
int* stack_depth,
int* context_length) {
// The macros used here must preserve the result register.
__ Drop(*stack_depth);
__ PopTryHandler();
*stack_depth = 0;
return previous_;
}
bool FullCodeGenerator::TryLiteralCompare(CompareOperation* compare,
Label* if_true,
Label* if_false,
Label* fall_through) {
Expression *expr;
Handle<String> check;
if (compare->IsLiteralCompareTypeof(&expr, &check)) {
EmitLiteralCompareTypeof(expr, check, if_true, if_false, fall_through);
return true;
}
if (compare->IsLiteralCompareUndefined(&expr)) {
EmitLiteralCompareUndefined(expr, if_true, if_false, fall_through);
return true;
}
return false;
}
#undef __
} } // namespace v8::internal
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