Simplify handling of exits from with and catch.

Remove the try/finally used for with and catch.  Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.

And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.

BUG=
TEST=

Review URL: http://codereview.chromium.org/7618007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 6549163a
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// 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:
......@@ -95,8 +95,9 @@ class StackHandlerConstants : public AllStatic {
public:
static const int kNextOffset = 0 * kPointerSize;
static const int kStateOffset = 1 * kPointerSize;
static const int kFPOffset = 2 * kPointerSize;
static const int kPCOffset = 3 * kPointerSize;
static const int kContextOffset = 2 * kPointerSize;
static const int kFPOffset = 3 * kPointerSize;
static const int kPCOffset = 4 * kPointerSize;
static const int kSize = kPCOffset + kPointerSize;
};
......
......@@ -1102,7 +1102,13 @@ void MacroAssembler::DebugBreak() {
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// The pc (return address) is passed in register lr.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
......@@ -1110,14 +1116,10 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
} else {
mov(r3, Operand(StackHandler::TRY_FINALLY));
}
ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize
&& StackHandlerConstants::kFPOffset == 2 * kPointerSize
&& StackHandlerConstants::kPCOffset == 3 * kPointerSize);
stm(db_w, sp, r3.bit() | fp.bit() | lr.bit());
stm(db_w, sp, r3.bit() | cp.bit() | fp.bit() | lr.bit());
// Save the current handler as the next handler.
mov(r3, Operand(ExternalReference(Isolate::k_handler_address, isolate())));
ldr(r1, MemOperand(r3));
ASSERT(StackHandlerConstants::kNextOffset == 0);
push(r1);
// Link this handler as the new current one.
str(sp, MemOperand(r3));
......@@ -1127,16 +1129,13 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
// The frame pointer does not point to a JS frame so we save NULL
// for fp. We expect the code throwing an exception to check fp
// before dereferencing it to restore the context.
mov(ip, Operand(0, RelocInfo::NONE)); // To save a NULL frame pointer.
mov(r6, Operand(StackHandler::ENTRY));
ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize
&& StackHandlerConstants::kFPOffset == 2 * kPointerSize
&& StackHandlerConstants::kPCOffset == 3 * kPointerSize);
stm(db_w, sp, r6.bit() | ip.bit() | lr.bit());
mov(r5, Operand(StackHandler::ENTRY)); // State.
mov(r6, Operand(Smi::FromInt(0))); // Indicates no context.
mov(r7, Operand(0, RelocInfo::NONE)); // NULL frame pointer.
stm(db_w, sp, r5.bit() | r6.bit() | r7.bit() | lr.bit());
// Save the current handler as the next handler.
mov(r7, Operand(ExternalReference(Isolate::k_handler_address, isolate())));
ldr(r6, MemOperand(r7));
ASSERT(StackHandlerConstants::kNextOffset == 0);
push(r6);
// Link this handler as the new current one.
str(sp, MemOperand(r7));
......@@ -1145,7 +1144,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
void MacroAssembler::PopTryHandler() {
ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
pop(r1);
mov(ip, Operand(ExternalReference(Isolate::k_handler_address, isolate())));
add(sp, sp, Operand(StackHandlerConstants::kSize - kPointerSize));
......@@ -1154,39 +1153,40 @@ void MacroAssembler::PopTryHandler() {
void MacroAssembler::Throw(Register value) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// r0 is expected to hold the exception.
if (!value.is(r0)) {
mov(r0, value);
}
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
// Drop the sp to the top of the handler.
mov(r3, Operand(ExternalReference(Isolate::k_handler_address, isolate())));
ldr(sp, MemOperand(r3));
// Restore the next handler and frame pointer, discard handler state.
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
// Restore the next handler.
pop(r2);
str(r2, MemOperand(r3));
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
ldm(ia_w, sp, r3.bit() | fp.bit()); // r3: discarded state.
// Before returning we restore the context from the frame pointer if
// not NULL. The frame pointer is NULL in the exception handler of a
// JS entry frame.
cmp(fp, Operand(0, RelocInfo::NONE));
// Set cp to NULL if fp is NULL.
mov(cp, Operand(0, RelocInfo::NONE), LeaveCC, eq);
// Restore cp otherwise.
ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
// Restore context and frame pointer, discard state (r3).
ldm(ia_w, sp, r3.bit() | cp.bit() | fp.bit());
// If the handler is a JS frame, restore the context to the frame.
// (r3 == ENTRY) == (fp == 0) == (cp == 0), so we could test any
// of them.
cmp(r3, Operand(StackHandler::ENTRY));
str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
#ifdef DEBUG
if (emit_debug_code()) {
mov(lr, Operand(pc));
}
#endif
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
pop(pc);
}
......@@ -1194,8 +1194,12 @@ void MacroAssembler::Throw(Register value) {
void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
Register value) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// r0 is expected to hold the exception.
if (!value.is(r0)) {
mov(r0, value);
......@@ -1220,7 +1224,6 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
bind(&done);
// Set the top handler address to next handler past the current ENTRY handler.
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
pop(r2);
str(r2, MemOperand(r3));
......@@ -1242,26 +1245,17 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
// Stack layout at this point. See also StackHandlerConstants.
// sp -> state (ENTRY)
// cp
// fp
// lr
// Discard handler state (r2 is not used) and restore frame pointer.
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
ldm(ia_w, sp, r2.bit() | fp.bit()); // r2: discarded state.
// Before returning we restore the context from the frame pointer if
// not NULL. The frame pointer is NULL in the exception handler of a
// JS entry frame.
cmp(fp, Operand(0, RelocInfo::NONE));
// Set cp to NULL if fp is NULL.
mov(cp, Operand(0, RelocInfo::NONE), LeaveCC, eq);
// Restore cp otherwise.
ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
// Restore context and frame pointer, discard state (r2).
ldm(ia_w, sp, r2.bit() | cp.bit() | fp.bit());
#ifdef DEBUG
if (emit_debug_code()) {
mov(lr, Operand(pc));
}
#endif
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
pop(pc);
}
......
......@@ -426,7 +426,7 @@ bool ForInStatement::IsInlineable() const {
}
bool EnterWithContextStatement::IsInlineable() const {
bool WithStatement::IsInlineable() const {
return false;
}
......
......@@ -60,7 +60,7 @@ namespace internal {
V(ContinueStatement) \
V(BreakStatement) \
V(ReturnStatement) \
V(EnterWithContextStatement) \
V(WithStatement) \
V(ExitContextStatement) \
V(SwitchStatement) \
V(DoWhileStatement) \
......@@ -631,19 +631,21 @@ class ReturnStatement: public Statement {
};
class EnterWithContextStatement: public Statement {
class WithStatement: public Statement {
public:
explicit EnterWithContextStatement(Expression* expression)
: expression_(expression) { }
WithStatement(Expression* expression, Statement* statement)
: expression_(expression), statement_(statement) { }
DECLARE_NODE_TYPE(EnterWithContextStatement)
DECLARE_NODE_TYPE(WithStatement)
Expression* expression() const { return expression_; }
Statement* statement() const { return statement_; }
virtual bool IsInlineable() const;
private:
Expression* expression_;
Statement* statement_;
};
......
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// 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:
......@@ -67,6 +67,7 @@ inline bool StackHandler::includes(Address address) const {
inline void StackHandler::Iterate(ObjectVisitor* v, Code* holder) const {
v->VisitPointer(context_address());
StackFrame::IteratePc(v, pc_address(), holder);
}
......@@ -82,6 +83,12 @@ inline StackHandler::State StackHandler::state() const {
}
inline Object** StackHandler::context_address() const {
const int offset = StackHandlerConstants::kContextOffset;
return reinterpret_cast<Object**>(address() + offset);
}
inline Address* StackHandler::pc_address() const {
const int offset = StackHandlerConstants::kPCOffset;
return reinterpret_cast<Address*>(address() + offset);
......
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// 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:
......@@ -114,6 +114,7 @@ class StackHandler BASE_EMBEDDED {
// Accessors.
inline State state() const;
inline Object** context_address() const;
inline Address* pc_address() const;
DISALLOW_IMPLICIT_CONSTRUCTORS(StackHandler);
......
......@@ -91,8 +91,7 @@ void BreakableStatementChecker::VisitReturnStatement(ReturnStatement* stmt) {
}
void BreakableStatementChecker::VisitEnterWithContextStatement(
EnterWithContextStatement* stmt) {
void BreakableStatementChecker::VisitWithStatement(WithStatement* stmt) {
Visit(stmt->expression());
}
......@@ -914,16 +913,24 @@ void FullCodeGenerator::VisitContinueStatement(ContinueStatement* stmt) {
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())) {
stack_depth = current->Exit(stack_depth);
current = current->outer();
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());
}
Iteration* loop = current->AsIteration();
__ jmp(loop->continue_target());
......@@ -935,16 +942,24 @@ void FullCodeGenerator::VisitBreakStatement(BreakStatement* stmt) {
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())) {
stack_depth = current->Exit(stack_depth);
current = current->outer();
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());
}
Breakable* target = current->AsBreakable();
__ jmp(target->break_target());
......@@ -960,9 +975,9 @@ void FullCodeGenerator::VisitReturnStatement(ReturnStatement* stmt) {
// Exit all nested statements.
NestedStatement* current = nesting_stack_;
int stack_depth = 0;
int context_length = 0;
while (current != NULL) {
stack_depth = current->Exit(stack_depth);
current = current->outer();
current = current->Exit(&stack_depth, &context_length);
}
__ Drop(stack_depth);
......@@ -970,9 +985,8 @@ void FullCodeGenerator::VisitReturnStatement(ReturnStatement* stmt) {
}
void FullCodeGenerator::VisitEnterWithContextStatement(
EnterWithContextStatement* stmt) {
Comment cmnt(masm_, "[ EnterWithContextStatement");
void FullCodeGenerator::VisitWithStatement(WithStatement* stmt) {
Comment cmnt(masm_, "[ WithStatement");
SetStatementPosition(stmt);
VisitForStackValue(stmt->expression());
......@@ -980,6 +994,15 @@ void FullCodeGenerator::VisitEnterWithContextStatement(
__ 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());
}
......@@ -1138,7 +1161,9 @@ void FullCodeGenerator::VisitTryCatchStatement(TryCatchStatement* stmt) {
Scope* saved_scope = scope();
scope_ = stmt->scope();
ASSERT(scope_->declarations()->is_empty());
{ WithOrCatch body(this);
Visit(stmt->catch_block());
}
scope_ = saved_scope;
__ jmp(&done);
......@@ -1184,8 +1209,8 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
Label try_handler_setup;
const int original_stack_height = stack_height();
const int finally_block_stack_height = original_stack_height + 2;
const int try_block_stack_height = original_stack_height + 4;
STATIC_ASSERT(StackHandlerConstants::kSize / kPointerSize == 4);
const int try_block_stack_height = original_stack_height + 5;
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
// Setup the try-handler chain. Use a call to
// Jump to try-handler setup and try-block code. Use call to put try-handler
......@@ -1314,20 +1339,33 @@ void FullCodeGenerator::VisitThrow(Throw* expr) {
}
int FullCodeGenerator::TryFinally::Exit(int stack_depth) {
FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
int* stack_depth,
int* context_length) {
// The macros used here must preserve the result register.
__ Drop(stack_depth);
__ Drop(*stack_depth);
__ PopTryHandler();
*stack_depth = 0;
Register context = FullCodeGenerator::context_register();
while (*context_length > 0) {
codegen_->LoadContextField(context, Context::PREVIOUS_INDEX);
--(*context_length);
}
__ Call(finally_entry_);
return 0;
return previous_;
}
int FullCodeGenerator::TryCatch::Exit(int stack_depth) {
FullCodeGenerator::NestedStatement* FullCodeGenerator::TryCatch::Exit(
int* stack_depth,
int* context_length) {
// The macros used here must preserve the result register.
__ Drop(stack_depth);
__ Drop(*stack_depth);
__ PopTryHandler();
return 0;
*stack_depth = 0;
return previous_;
}
......
......@@ -140,25 +140,19 @@ class FullCodeGenerator: public AstVisitor {
virtual bool IsContinueTarget(Statement* target) { return false; }
virtual bool IsBreakTarget(Statement* target) { return false; }
// Generate code to leave the nested statement. This includes
// cleaning up any stack elements in use and restoring the
// stack to the expectations of the surrounding statements.
// Takes a number of stack elements currently on top of the
// nested statement's stack, and returns a number of stack
// elements left on top of the surrounding statement's stack.
// The generated code must preserve the result register (which
// contains the value in case of a return).
virtual int Exit(int stack_depth) {
// Default implementation for the case where there is
// nothing to clean up.
return stack_depth;
// Notify the statement that we are exiting it via break, continue, or
// return and give it a chance to generate cleanup code. Return the
// next outer statement in the nesting stack. We accumulate in
// *stack_depth the amount to drop the stack and in *context_length the
// number of context chain links to unwind as we traverse the nesting
// stack from an exit to its target.
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
return previous_;
}
NestedStatement* outer() { return previous_; }
protected:
MacroAssembler* masm() { return codegen_->masm(); }
private:
FullCodeGenerator* codegen_;
NestedStatement* previous_;
DISALLOW_COPY_AND_ASSIGN(NestedStatement);
......@@ -207,7 +201,7 @@ class FullCodeGenerator: public AstVisitor {
virtual ~TryCatch() {}
virtual TryCatch* AsTryCatch() { return this; }
Label* catch_entry() { return catch_entry_; }
virtual int Exit(int stack_depth);
virtual NestedStatement* Exit(int* stack_depth, int* context_length);
private:
Label* catch_entry_;
DISALLOW_COPY_AND_ASSIGN(TryCatch);
......@@ -221,7 +215,7 @@ class FullCodeGenerator: public AstVisitor {
virtual ~TryFinally() {}
virtual TryFinally* AsTryFinally() { return this; }
Label* finally_entry() { return finally_entry_; }
virtual int Exit(int stack_depth);
virtual NestedStatement* Exit(int* stack_depth, int* context_length);
private:
Label* finally_entry_;
DISALLOW_COPY_AND_ASSIGN(TryFinally);
......@@ -235,8 +229,9 @@ class FullCodeGenerator: public AstVisitor {
explicit Finally(FullCodeGenerator* codegen) : NestedStatement(codegen) { }
virtual ~Finally() {}
virtual Finally* AsFinally() { return this; }
virtual int Exit(int stack_depth) {
return stack_depth + kFinallyStackElementCount;
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
*stack_depth += kFinallyStackElementCount;
return previous_;
}
private:
// Number of extra stack slots occupied during a finally block.
......@@ -254,14 +249,32 @@ class FullCodeGenerator: public AstVisitor {
: Iteration(codegen, statement) { }
virtual ~ForIn() {}
virtual ForIn* AsForIn() { return this; }
virtual int Exit(int stack_depth) {
return stack_depth + kForInStackElementCount;
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
*stack_depth += kForInStackElementCount;
return previous_;
}
private:
static const int kForInStackElementCount = 5;
DISALLOW_COPY_AND_ASSIGN(ForIn);
};
// A WithOrCatch represents being inside the body of a with or catch
// statement. Exiting the body needs to remove a link from the context
// chain.
class WithOrCatch : public NestedStatement {
public:
explicit WithOrCatch(FullCodeGenerator* codegen)
: NestedStatement(codegen) {
}
virtual ~WithOrCatch() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
++(*context_length);
return previous_;
}
};
// The forward bailout stack keeps track of the expressions that can
// bail out to just before the control flow is split in a child
// node. The stack elements are linked together through the parent
......
......@@ -2634,12 +2634,11 @@ void HGraphBuilder::VisitReturnStatement(ReturnStatement* stmt) {
}
void HGraphBuilder::VisitEnterWithContextStatement(
EnterWithContextStatement* stmt) {
void HGraphBuilder::VisitWithStatement(WithStatement* stmt) {
ASSERT(!HasStackOverflow());
ASSERT(current_block() != NULL);
ASSERT(current_block()->HasPredecessor());
return Bailout("EnterWithContextStatement");
return Bailout("WithStatement");
}
......
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// 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:
......@@ -59,9 +59,10 @@ static const int kNumSafepointRegisters = 8;
class StackHandlerConstants : public AllStatic {
public:
static const int kNextOffset = 0 * kPointerSize;
static const int kFPOffset = 1 * kPointerSize;
static const int kStateOffset = 2 * kPointerSize;
static const int kPCOffset = 3 * kPointerSize;
static const int kContextOffset = 1 * kPointerSize;
static const int kFPOffset = 2 * kPointerSize;
static const int kStateOffset = 3 * kPointerSize;
static const int kPCOffset = 4 * kPointerSize;
static const int kSize = kPCOffset + kPointerSize;
};
......
......@@ -542,7 +542,12 @@ void MacroAssembler::LeaveApiExitFrame() {
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// The pc (return address) is already on TOS.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
......@@ -551,6 +556,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
push(Immediate(StackHandler::TRY_FINALLY));
}
push(ebp);
push(esi);
} else {
ASSERT(try_location == IN_JS_ENTRY);
// The frame pointer does not point to a JS frame so we save NULL
......@@ -558,6 +564,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
// before dereferencing it to restore the context.
push(Immediate(StackHandler::ENTRY));
push(Immediate(0)); // NULL frame pointer.
push(Immediate(Smi::FromInt(0))); // No context.
}
// Save the current handler as the next handler.
push(Operand::StaticVariable(ExternalReference(Isolate::k_handler_address,
......@@ -570,7 +577,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
void MacroAssembler::PopTryHandler() {
ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
pop(Operand::StaticVariable(ExternalReference(Isolate::k_handler_address,
isolate())));
add(Operand(esp), Immediate(StackHandlerConstants::kSize - kPointerSize));
......@@ -579,8 +586,12 @@ void MacroAssembler::PopTryHandler() {
void MacroAssembler::Throw(Register value) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// eax must hold the exception.
if (!value.is(eax)) {
mov(eax, value);
......@@ -591,24 +602,21 @@ void MacroAssembler::Throw(Register value) {
isolate());
mov(esp, Operand::StaticVariable(handler_address));
// Restore next handler and frame pointer, discard handler state.
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
// Restore next handler, context, and frame pointer; discard handler state.
pop(Operand::StaticVariable(handler_address));
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 1 * kPointerSize);
pop(ebp);
pop(edx); // Remove state.
pop(esi); // Context.
pop(ebp); // Frame pointer.
pop(edx); // State.
// Before returning we restore the context from the frame pointer if
// not NULL. The frame pointer is NULL in the exception handler of
// a JS entry frame.
Set(esi, Immediate(0)); // Tentatively set context pointer to NULL.
// If the handler is a JS frame, restore the context to the frame.
// (edx == ENTRY) == (ebp == 0) == (esi == 0), so we could test any
// of them.
Label skip;
cmp(ebp, 0);
cmp(Operand(edx), Immediate(StackHandler::ENTRY));
j(equal, &skip, Label::kNear);
mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
bind(&skip);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
ret(0);
}
......@@ -616,7 +624,12 @@ void MacroAssembler::Throw(Register value) {
void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
Register value) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// eax must hold the exception.
if (!value.is(eax)) {
......@@ -642,7 +655,6 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
bind(&done);
// Set the top handler address to next handler past the current ENTRY handler.
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
pop(Operand::StaticVariable(handler_address));
if (type == OUT_OF_MEMORY) {
......@@ -660,15 +672,14 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
mov(Operand::StaticVariable(pending_exception), eax);
}
// Clear the context pointer.
// Discard the context saved in the handler and clear the context pointer.
pop(edx);
Set(esi, Immediate(0));
// Restore fp from handler and discard handler state.
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 1 * kPointerSize);
pop(ebp);
pop(edx); // State.
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
ret(0);
}
......
......@@ -2012,41 +2012,6 @@ Statement* Parser::ParseReturnStatement(bool* ok) {
}
Block* Parser::WithHelper(Expression* obj, ZoneStringList* labels, bool* ok) {
// Parse the statement and collect escaping labels.
TargetCollector collector;
Statement* stat;
{ Target target(&this->target_stack_, &collector);
with_nesting_level_++;
top_scope_->DeclarationScope()->RecordWithStatement();
stat = ParseStatement(labels, CHECK_OK);
with_nesting_level_--;
}
// Create resulting block with two statements.
// 1: Evaluate the with expression.
// 2: The try-finally block evaluating the body.
Block* result = new(zone()) Block(isolate(), NULL, 2, false);
if (result != NULL) {
result->AddStatement(new(zone()) EnterWithContextStatement(obj));
// Create body block.
Block* body = new(zone()) Block(isolate(), NULL, 1, false);
body->AddStatement(stat);
// Create exit block.
Block* exit = new(zone()) Block(isolate(), NULL, 1, false);
exit->AddStatement(new(zone()) ExitContextStatement());
// Return a try-finally statement.
TryFinallyStatement* wrapper = new(zone()) TryFinallyStatement(body, exit);
wrapper->set_escaping_targets(collector.targets());
result->AddStatement(wrapper);
}
return result;
}
Statement* Parser::ParseWithStatement(ZoneStringList* labels, bool* ok) {
// WithStatement ::
// 'with' '(' Expression ')' Statement
......@@ -2063,7 +2028,11 @@ Statement* Parser::ParseWithStatement(ZoneStringList* labels, bool* ok) {
Expression* expr = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
return WithHelper(expr, labels, CHECK_OK);
++with_nesting_level_;
top_scope_->DeclarationScope()->RecordWithStatement();
Statement* stmt = ParseStatement(labels, CHECK_OK);
--with_nesting_level_;
return new(zone()) WithStatement(expr, stmt);
}
......@@ -2198,39 +2167,22 @@ TryStatement* Parser::ParseTryStatement(bool* ok) {
Expect(Token::RPAREN, CHECK_OK);
if (peek() == Token::LBRACE) {
// Rewrite the catch body B to a single statement block
// { try B finally { PopContext }}.
Block* inner_body;
// We need to collect escapes from the body for both the inner
// try/finally used to pop the catch context and any possible outer
// try/finally.
TargetCollector inner_collector;
{ Target target(&this->target_stack_, &catch_collector);
{ Target target(&this->target_stack_, &inner_collector);
// Rewrite the catch body { B } to a block:
// { { B } ExitContext; }.
Target target(&this->target_stack_, &catch_collector);
catch_scope = NewScope(top_scope_, Scope::CATCH_SCOPE, inside_with());
if (top_scope_->is_strict_mode()) {
catch_scope->EnableStrictMode();
}
catch_variable = catch_scope->DeclareLocal(name, Variable::VAR);
catch_block = new(zone()) Block(isolate(), NULL, 2, false);
Scope* saved_scope = top_scope_;
top_scope_ = catch_scope;
inner_body = ParseBlock(NULL, CHECK_OK);
Block* catch_body = ParseBlock(NULL, CHECK_OK);
top_scope_ = saved_scope;
}
}
// Create exit block.
Block* inner_finally = new(zone()) Block(isolate(), NULL, 1, false);
inner_finally->AddStatement(new(zone()) ExitContextStatement());
// Create a try/finally statement.
TryFinallyStatement* inner_try_finally =
new(zone()) TryFinallyStatement(inner_body, inner_finally);
inner_try_finally->set_escaping_targets(inner_collector.targets());
catch_block = new(zone()) Block(isolate(), NULL, 1, false);
catch_block->AddStatement(inner_try_finally);
catch_block->AddStatement(catch_body);
catch_block->AddStatement(new(zone()) ExitContextStatement());
} else {
Expect(Token::LBRACE, CHECK_OK);
}
......
......@@ -495,7 +495,6 @@ class Parser {
Statement* ParseContinueStatement(bool* ok);
Statement* ParseBreakStatement(ZoneStringList* labels, bool* ok);
Statement* ParseReturnStatement(bool* ok);
Block* WithHelper(Expression* obj, ZoneStringList* labels, bool* ok);
Statement* ParseWithStatement(ZoneStringList* labels, bool* ok);
CaseClause* ParseCaseClause(bool* default_seen_ptr, bool* ok);
SwitchStatement* ParseSwitchStatement(ZoneStringList* labels, bool* ok);
......
......@@ -123,11 +123,11 @@ void PrettyPrinter::VisitReturnStatement(ReturnStatement* node) {
}
void PrettyPrinter::VisitEnterWithContextStatement(
EnterWithContextStatement* node) {
Print("<enter with context> (");
void PrettyPrinter::VisitWithStatement(WithStatement* node) {
Print("with (");
Visit(node->expression());
Print(") ");
Visit(node->statement());
}
......@@ -798,9 +798,10 @@ void AstPrinter::VisitReturnStatement(ReturnStatement* node) {
}
void AstPrinter::VisitEnterWithContextStatement(
EnterWithContextStatement* node) {
PrintIndentedVisit("ENTER WITH CONTEXT", node->expression());
void AstPrinter::VisitWithStatement(WithStatement* node) {
IndentedScope indent(this, "WITH");
PrintIndentedVisit("OBJECT", node->expression());
PrintIndentedVisit("BODY", node->statement());
}
......@@ -1194,10 +1195,10 @@ void JsonAstBuilder::VisitReturnStatement(ReturnStatement* stmt) {
}
void JsonAstBuilder::VisitEnterWithContextStatement(
EnterWithContextStatement* stmt) {
TagScope tag(this, "EnterWithContextStatement");
void JsonAstBuilder::VisitWithStatement(WithStatement* stmt) {
TagScope tag(this, "WithStatement");
Visit(stmt->expression());
Visit(stmt->statement());
}
......
......@@ -197,13 +197,17 @@ void Processor::VisitBreakStatement(BreakStatement* node) {
}
void Processor::VisitWithStatement(WithStatement* node) {
bool set_after_body = is_set_;
Visit(node->statement());
is_set_ = is_set_ && set_after_body;
}
// Do nothing:
void Processor::VisitDeclaration(Declaration* node) {}
void Processor::VisitEmptyStatement(EmptyStatement* node) {}
void Processor::VisitReturnStatement(ReturnStatement* node) {}
void Processor::VisitEnterWithContextStatement(
EnterWithContextStatement* node) {
}
void Processor::VisitExitContextStatement(ExitContextStatement* node) {}
void Processor::VisitDebuggerStatement(DebuggerStatement* node) {}
......
// Copyright 2010 the V8 project authors. All rights reserved.
// 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:
......@@ -51,11 +51,12 @@ static const int kNumSafepointRegisters = 16;
class StackHandlerConstants : public AllStatic {
public:
static const int kNextOffset = 0 * kPointerSize;
static const int kFPOffset = 1 * kPointerSize;
static const int kStateOffset = 2 * kPointerSize;
static const int kPCOffset = 3 * kPointerSize;
static const int kContextOffset = 1 * kPointerSize;
static const int kFPOffset = 2 * kPointerSize;
static const int kStateOffset = 3 * kPointerSize;
static const int kPCOffset = 4 * kPointerSize;
static const int kSize = 4 * kPointerSize;
static const int kSize = kPCOffset + kPointerSize;
};
......
......@@ -2387,18 +2387,15 @@ Operand MacroAssembler::SafepointRegisterSlot(Register reg) {
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// The pc (return address) is already on TOS. This code pushes state,
// frame pointer and current handler. Check that they are expected
// next on the stack, in that order.
ASSERT_EQ(StackHandlerConstants::kStateOffset,
StackHandlerConstants::kPCOffset - kPointerSize);
ASSERT_EQ(StackHandlerConstants::kFPOffset,
StackHandlerConstants::kStateOffset - kPointerSize);
ASSERT_EQ(StackHandlerConstants::kNextOffset,
StackHandlerConstants::kFPOffset - kPointerSize);
// frame pointer, context, and current handler.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
push(Immediate(StackHandler::TRY_CATCH));
......@@ -2406,6 +2403,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
push(Immediate(StackHandler::TRY_FINALLY));
}
push(rbp);
push(rsi);
} else {
ASSERT(try_location == IN_JS_ENTRY);
// The frame pointer does not point to a JS frame so we save NULL
......@@ -2413,6 +2411,7 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
// before dereferencing it to restore the context.
push(Immediate(StackHandler::ENTRY));
push(Immediate(0)); // NULL frame pointer.
Push(Smi::FromInt(0)); // No context.
}
// Save the current handler.
Operand handler_operand =
......@@ -2435,12 +2434,13 @@ void MacroAssembler::PopTryHandler() {
void MacroAssembler::Throw(Register value) {
// Check that stack should contain next handler, frame pointer, state and
// return address in that order.
STATIC_ASSERT(StackHandlerConstants::kFPOffset + kPointerSize ==
StackHandlerConstants::kStateOffset);
STATIC_ASSERT(StackHandlerConstants::kStateOffset + kPointerSize ==
StackHandlerConstants::kPCOffset);
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// Keep thrown value in rax.
if (!value.is(rax)) {
movq(rax, value);
......@@ -2451,23 +2451,32 @@ void MacroAssembler::Throw(Register value) {
movq(rsp, handler_operand);
// get next in chain
pop(handler_operand);
pop(rbp); // pop frame pointer
pop(rdx); // remove state
pop(rsi); // Context.
pop(rbp); // Frame pointer.
pop(rdx); // State.
// Before returning we restore the context from the frame pointer if not NULL.
// The frame pointer is NULL in the exception handler of a JS entry frame.
Set(rsi, 0); // Tentatively set context pointer to NULL
// If the handler is a JS frame, restore the context to the frame.
// (rdx == ENTRY) == (rbp == 0) == (rsi == 0), so we could test any
// of them.
Label skip;
cmpq(rbp, Immediate(0));
cmpq(rdx, Immediate(StackHandler::ENTRY));
j(equal, &skip, Label::kNear);
movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);
bind(&skip);
ret(0);
}
void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
Register value) {
// Adjust this code if not the case.
STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kPCOffset == 4 * kPointerSize);
// Keep thrown value in rax.
if (!value.is(rax)) {
movq(rax, value);
......@@ -2507,19 +2516,13 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
Store(pending_exception, rax);
}
// Clear the context pointer.
// Discard the context saved in the handler and clear the context pointer.
pop(rdx);
Set(rsi, 0);
// Restore registers from handler.
STATIC_ASSERT(StackHandlerConstants::kNextOffset + kPointerSize ==
StackHandlerConstants::kFPOffset);
pop(rbp); // FP
STATIC_ASSERT(StackHandlerConstants::kFPOffset + kPointerSize ==
StackHandlerConstants::kStateOffset);
pop(rdx); // State
pop(rbp); // Restore frame pointer.
pop(rdx); // Discard state.
STATIC_ASSERT(StackHandlerConstants::kStateOffset + kPointerSize ==
StackHandlerConstants::kPCOffset);
ret(0);
}
......
// Copyright 2008 the V8 project authors. All rights reserved.
// 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:
......@@ -59,3 +59,162 @@ try {
}
assertTrue(caught);
// We want to test the context chain shape. In each of the tests cases
// below, the outer with is to force a runtime lookup of the identifier 'x'
// to actually verify that the inner context has been discarded. A static
// lookup of 'x' might accidentally succeed.
with ({x: 'outer'}) {
label: {
with ({x: 'inner'}) {
break label;
}
}
assertEquals('outer', x);
}
with ({x: 'outer'}) {
label: {
with ({x: 'middle'}) {
with ({x: 'inner'}) {
break label;
}
}
}
assertEquals('outer', x);
}
with ({x: 'outer'}) {
for (var i = 0; i < 10; ++i) {
with ({x: 'inner' + i}) {
continue;
}
}
assertEquals('outer', x);
}
with ({x: 'outer'}) {
label: for (var i = 0; i < 10; ++i) {
with ({x: 'middle' + i}) {
for (var j = 0; j < 10; ++j) {
with ({x: 'inner' + j}) {
continue label;
}
}
}
}
assertEquals('outer', x);
}
with ({x: 'outer'}) {
try {
with ({x: 'inner'}) {
throw 0;
}
} catch (e) {
assertEquals('outer', x);
}
}
with ({x: 'outer'}) {
try {
with ({x: 'middle'}) {
with ({x: 'inner'}) {
throw 0;
}
}
} catch (e) {
assertEquals('outer', x);
}
}
try {
with ({x: 'outer'}) {
try {
with ({x: 'inner'}) {
throw 0;
}
} finally {
assertEquals('outer', x);
}
}
} catch (e) {
if (e instanceof MjsUnitAssertionError) throw e;
}
try {
with ({x: 'outer'}) {
try {
with ({x: 'middle'}) {
with ({x: 'inner'}) {
throw 0;
}
}
} finally {
assertEquals('outer', x);
}
}
} catch (e) {
if (e instanceof MjsUnitAssertionError) throw e;
}
// Verify that the context is correctly set in the stack frame after exiting
// from with.
function f() {}
with ({x: 'outer'}) {
label: {
with ({x: 'inner'}) {
break label;
}
}
f(); // The context could be restored from the stack after the call.
assertEquals('outer', x);
}
with ({x: 'outer'}) {
for (var i = 0; i < 10; ++i) {
with ({x: 'inner' + i}) {
continue;
}
}
f();
assertEquals('outer', x);
}
with ({x: 'outer'}) {
try {
with ({x: 'inner'}) {
throw 0;
}
} catch (e) {
f();
assertEquals('outer', x);
}
}
try {
with ({x: 'outer'}) {
try {
with ({x: 'inner'}) {
throw 0;
}
} finally {
f();
assertEquals('outer', x);
}
}
} catch (e) {
if (e instanceof MjsUnitAssertionError) throw e;
}
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment