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Speed up access to global variables from eval scopes. Traverse the

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surrounding context to figure out if the variable could be global.  If
the variable could be global we check context extension objects at
runtime and use a global LoadIC if no variables have been introduced
by eval.

Fix crash bug when loading function arguments from inside eval.  The 
shadowed variable in the DYNAMIC_LOCAL case does not rewrite to a slot in 
that case.

Review URL: http://codereview.chromium.org/28027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1348 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
ager@chromium.org 2009-02-24 13:11:53 +00:00
parent 6ea0862592
commit 0c7af39737
17 changed files with 515 additions and 72 deletions
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41
src/codegen-arm.cc
View File

@ -2022,12 +2022,16 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
} else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
__ ldr(r0,
ContextSlotOperandCheckExtensions(potential_slot,
r1,
r2,
&slow));
__ b(&done);
// Only generate the fast case for locals that rewrite to slots.
// This rules out argument loads.
if (potential_slot != NULL) {
__ ldr(r0,
ContextSlotOperandCheckExtensions(potential_slot,
r1,
r2,
&slow));
__ b(&done);
}
}
__ bind(&slow);
@ -2074,7 +2078,8 @@ void CodeGenerator::LoadFromGlobalSlotCheckExtensions(Slot* slot,
// Check that no extension objects have been created by calls to
// eval from the current scope to the global scope.
Register context = cp;
for (Scope* s = scope(); s != NULL; s = s->outer_scope()) {
Scope* s = scope();
while (s != NULL) {
if (s->num_heap_slots() > 0) {
if (s->calls_eval()) {
// Check that extension is NULL.
@ -2089,7 +2094,27 @@ void CodeGenerator::LoadFromGlobalSlotCheckExtensions(Slot* slot,
}
// If no outer scope calls eval, we do not need to check more
// context extensions.
if (!s->outer_scope_calls_eval()) break;
if (!s->outer_scope_calls_eval() || s->is_eval_scope()) break;
s = s->outer_scope();
}
if (s->is_eval_scope()) {
Label next, fast;
if (!context.is(tmp)) __ mov(tmp, Operand(context));
__ bind(&next);
// Terminate at global context.
__ ldr(tmp2, FieldMemOperand(tmp, HeapObject::kMapOffset));
__ cmp(tmp2, Operand(Factory::global_context_map()));
__ b(eq, &fast);
// Check that extension is NULL.
__ ldr(tmp2, ContextOperand(tmp, Context::EXTENSION_INDEX));
__ tst(tmp2, tmp2);
__ b(ne, slow);
// Load next context in chain.
__ ldr(tmp, ContextOperand(tmp, Context::CLOSURE_INDEX));
__ ldr(tmp, FieldMemOperand(tmp, JSFunction::kContextOffset));
__ b(&next);
__ bind(&fast);
}
// All extension objects were empty and it is safe to use a global

41
src/codegen-ia32.cc
View File

@ -2365,11 +2365,15 @@ void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
} else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
__ mov(eax,
ContextSlotOperandCheckExtensions(potential_slot,
ebx,
&slow));
__ jmp(&done);
// Only generate the fast case for locals that rewrite to slots.
// This rules out argument loads.
if (potential_slot != NULL) {
__ mov(eax,
ContextSlotOperandCheckExtensions(potential_slot,
ebx,
&slow));
__ jmp(&done);
}
}
__ bind(&slow);
@ -2414,7 +2418,8 @@ void CodeGenerator::LoadFromGlobalSlotCheckExtensions(Slot* slot,
// Check that no extension objects have been created by calls to
// eval from the current scope to the global scope.
Register context = esi;
for (Scope* s = scope(); s != NULL; s = s->outer_scope()) {
Scope* s = scope();
while (s != NULL) {
if (s->num_heap_slots() > 0) {
if (s->calls_eval()) {
// Check that extension is NULL.
@ -2427,8 +2432,28 @@ void CodeGenerator::LoadFromGlobalSlotCheckExtensions(Slot* slot,
context = tmp;
}
// If no outer scope calls eval, we do not need to check more
// context extensions.
if (!s->outer_scope_calls_eval()) break;
// context extensions. If we have reached an eval scope, we check
// all extensions from this point.
if (!s->outer_scope_calls_eval() || s->is_eval_scope()) break;
s = s->outer_scope();
}
if (s->is_eval_scope()) {
Label next, fast;
if (!context.is(tmp)) __ mov(tmp, Operand(context));
__ bind(&next);
// Terminate at global context.
__ cmp(FieldOperand(tmp, HeapObject::kMapOffset),
Immediate(Factory::global_context_map()));
__ j(equal, &fast);
// Check that extension is NULL.
__ cmp(ContextOperand(tmp, Context::EXTENSION_INDEX), Immediate(0));
__ j(not_equal, slow, not_taken);
// Load next context in chain.
__ mov(tmp, ContextOperand(tmp, Context::CLOSURE_INDEX));
__ mov(tmp, FieldOperand(tmp, JSFunction::kContextOffset));
__ jmp(&next);
__ bind(&fast);
}
// All extension objects were empty and it is safe to use a global

33
src/compilation-cache.cc
View File

@ -102,6 +102,25 @@ static Handle<JSFunction> Lookup(Handle<String> source,
}
static Handle<JSFunction> Lookup(Handle<String> source,
Handle<Context> context,
CompilationCache::Entry entry) {
// Make sure not to leak the table into the surrounding handle
// scope. Otherwise, we risk keeping old tables around even after
// having cleared the cache.
Object* result;
{ HandleScope scope;
Handle<CompilationCacheTable> table = GetTable(entry);
result = table->LookupEval(*source, *context);
}
if (result->IsJSFunction()) {
return Handle<JSFunction>(JSFunction::cast(result));
} else {
return Handle<JSFunction>::null();
}
}
Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source,
Handle<Object> name,
int line_offset,
@ -120,9 +139,10 @@ Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source,
Handle<JSFunction> CompilationCache::LookupEval(Handle<String> source,
Handle<Context> context,
Entry entry) {
ASSERT(entry == EVAL_GLOBAL || entry == EVAL_CONTEXTUAL);
Handle<JSFunction> result = Lookup(source, entry);
Handle<JSFunction> result = Lookup(source, context, entry);
if (result.is_null()) {
Counters::compilation_cache_misses.Increment();
} else {
@ -142,6 +162,17 @@ void CompilationCache::PutFunction(Handle<String> source,
}
void CompilationCache::PutEvalFunction(Handle<String> source,
Handle<Context> context,
Entry entry,
Handle<JSFunction> boilerplate) {
HandleScope scope;
ASSERT(boilerplate->IsBoilerplate());
Handle<CompilationCacheTable> table = GetTable(entry);
CALL_HEAP_FUNCTION_VOID(table->PutEval(*source, *context, *boilerplate));
}
Handle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
JSRegExp::Flags flags) {
Handle<CompilationCacheTable> table = GetTable(REGEXP);

15
src/compilation-cache.h
View File

@ -55,10 +55,11 @@ class CompilationCache {
int line_offset,
int column_offset);
// Finds the function boilerplate for a source string for
// eval. Returns an empty handle if the cache doesn't contain a
// script for the given source string.
// Finds the function boilerplate for a source string for eval in a
// given context. Returns an empty handle if the cache doesn't
// contain a script for the given source string.
static Handle<JSFunction> LookupEval(Handle<String> source,
Handle<Context> context,
Entry entry);
// Returns the regexp data associated with the given regexp if it
@ -78,6 +79,14 @@ class CompilationCache {
Entry entry,
Handle<JSFunction> boilerplate);
// Associate the (source, context->closure()->shared(), kind)
// triple with the boilerplate. This may overwrite an existing
// mapping.
static void PutEvalFunction(Handle<String> source,
Handle<Context> context,
Entry entry,
Handle<JSFunction> boilerplate);
// Clear the cache - also used to initialize the cache at startup.
static void Clear();

23
src/compiler.cc
View File

@ -40,6 +40,7 @@ namespace v8 { namespace internal {
static Handle<Code> MakeCode(FunctionLiteral* literal,
Handle<Script> script,
Handle<Context> context,
bool is_eval) {
ASSERT(literal != NULL);
@ -55,7 +56,7 @@ static Handle<Code> MakeCode(FunctionLiteral* literal,
// so this doesn't re-allocate variables repeatedly.
Scope* top = literal->scope();
while (top->outer_scope() != NULL) top = top->outer_scope();
top->AllocateVariables();
top->AllocateVariables(context);
#ifdef DEBUG
if (Bootstrapper::IsActive() ?
@ -81,6 +82,7 @@ static Handle<Code> MakeCode(FunctionLiteral* literal,
static Handle<JSFunction> MakeFunction(bool is_global,
bool is_eval,
Handle<Script> script,
Handle<Context> context,
v8::Extension* extension,
ScriptDataImpl* pre_data) {
ZoneScope zone_scope(DELETE_ON_EXIT);
@ -113,7 +115,7 @@ static Handle<JSFunction> MakeFunction(bool is_global,
StatsRateScope timer(rate);
// Compile the code.
Handle<Code> code = MakeCode(lit, script, is_eval);
Handle<Code> code = MakeCode(lit, script, context, is_eval);
// Check for stack-overflow exceptions.
if (code.is_null()) {
@ -201,7 +203,12 @@ Handle<JSFunction> Compiler::Compile(Handle<String> source,
}
// Compile the function and add it to the cache.
result = MakeFunction(true, false, script, extension, pre_data);
result = MakeFunction(true,
false,
script,
Handle<Context>::null(),
extension,
pre_data);
if (extension == NULL && !result.is_null()) {
CompilationCache::PutFunction(source, CompilationCache::SCRIPT, result);
}
@ -219,6 +226,7 @@ Handle<JSFunction> Compiler::Compile(Handle<String> source,
Handle<JSFunction> Compiler::CompileEval(Handle<String> source,
Handle<Context> context,
int line_offset,
bool is_global) {
int source_length = source->length();
@ -233,14 +241,15 @@ Handle<JSFunction> Compiler::CompileEval(Handle<String> source,
// Do a lookup in the compilation cache; if the entry is not there,
// invoke the compiler and add the result to the cache.
Handle<JSFunction> result = CompilationCache::LookupEval(source, entry);
Handle<JSFunction> result =
CompilationCache::LookupEval(source, context, entry);
if (result.is_null()) {
// Create a script object describing the script to be compiled.
Handle<Script> script = Factory::NewScript(source);
script->set_line_offset(Smi::FromInt(line_offset));
result = MakeFunction(is_global, true, script, NULL, NULL);
result = MakeFunction(is_global, true, script, context, NULL, NULL);
if (!result.is_null()) {
CompilationCache::PutFunction(source, entry, result);
CompilationCache::PutEvalFunction(source, context, entry, result);
}
}
@ -290,7 +299,7 @@ bool Compiler::CompileLazy(Handle<SharedFunctionInfo> shared,
StatsRateScope timer(&Counters::compile_lazy);
// Compile the code.
Handle<Code> code = MakeCode(lit, script, false);
Handle<Code> code = MakeCode(lit, script, Handle<Context>::null(), false);
// Check for stack-overflow exception.
if (code.is_null()) {

1
src/compiler.h
View File

@ -58,6 +58,7 @@ class Compiler : public AllStatic {
// Compile a String source within a context for Eval.
static Handle<JSFunction> CompileEval(Handle<String> source,
Handle<Context> context,
int line_offset,
bool is_global);

36
src/contexts.cc
View File

@ -198,6 +198,42 @@ Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
}
bool Context::GlobalIfNotShadowedByEval(Handle<String> name) {
Context* context = this;
// Check that there is no local with the given name in contexts
// before the global context and check that there are no context
// extension objects (conservative check for with statements).
while (!context->IsGlobalContext()) {
// Check if the context is a potentially a with context.
if (context->has_extension()) return false;
// Not a with context so it must be a function context.
ASSERT(context->is_function_context());
// Check non-parameter locals.
Handle<Code> code(context->closure()->code());
Variable::Mode mode;
int index = ScopeInfo<>::ContextSlotIndex(*code, *name, &mode);
ASSERT(index < 0 || index >= MIN_CONTEXT_SLOTS);
if (index >= 0) return false;
// Check parameter locals.
int param_index = ScopeInfo<>::ParameterIndex(*code, *name);
if (param_index >= 0) return false;
// Check context only holding the function name variable.
index = ScopeInfo<>::FunctionContextSlotIndex(*code, *name);
if (index >= 0) return false;
context = Context::cast(context->closure()->context());
}
// No local or potential with statement found so the variable is
// global unless it is shadowed by an eval-introduced variable.
return true;
}
#ifdef DEBUG
bool Context::IsBootstrappingOrContext(Object* object) {
// During bootstrapping we allow all objects to pass as

9
src/contexts.h
View File

@ -304,6 +304,15 @@ class Context: public FixedArray {
Handle<Object> Lookup(Handle<String> name, ContextLookupFlags flags,
int* index_, PropertyAttributes* attributes);
// Determine if a local variable with the given name exists in a
// context. Do not consider context extension objects. This is
// used for compiling code using eval. If the context surrounding
// the eval call does not have a local variable with this name and
// does not contain a with statement the property is global unless
// it is shadowed by a property in an extension object introduced by
// eval.
bool GlobalIfNotShadowedByEval(Handle<String> name);
// Code generation support.
static int SlotOffset(int index) {
return kHeaderSize + index * kPointerSize - kHeapObjectTag;

124
src/objects.cc
View File

@ -5850,6 +5850,20 @@ int JSObject::GetEnumElementKeys(FixedArray* storage) {
}
// Thomas Wang, Integer Hash Functions.
// http://www.concentric.net/~Ttwang/tech/inthash.htm
static uint32_t ComputeIntegerHash(uint32_t key) {
uint32_t hash = key;
hash = ~hash + (hash << 15); // hash = (hash << 15) - hash - 1;
hash = hash ^ (hash >> 12);
hash = hash + (hash << 2);
hash = hash ^ (hash >> 4);
hash = hash * 2057; // hash = (hash + (hash << 3)) + (hash << 11);
hash = hash ^ (hash >> 16);
return hash;
}
// The NumberKey uses carries the uint32_t as key.
// This avoids allocation in HasProperty.
class NumberKey : public HashTableKey {
@ -5861,20 +5875,7 @@ class NumberKey : public HashTableKey {
return number_ == ToUint32(number);
}
// Thomas Wang, Integer Hash Functions.
// http://www.concentric.net/~Ttwang/tech/inthash.htm
static uint32_t ComputeHash(uint32_t key) {
uint32_t hash = key;
hash = ~hash + (hash << 15); // hash = (hash << 15) - hash - 1;
hash = hash ^ (hash >> 12);
hash = hash + (hash << 2);
hash = hash ^ (hash >> 4);
hash = hash * 2057; // hash = (hash + (hash << 3)) + (hash << 11);
hash = hash ^ (hash >> 16);
return hash;
}
uint32_t Hash() { return ComputeHash(number_); }
uint32_t Hash() { return ComputeIntegerHash(number_); }
HashFunction GetHashFunction() { return NumberHash; }
@ -5883,7 +5884,7 @@ class NumberKey : public HashTableKey {
}
static uint32_t NumberHash(Object* obj) {
return ComputeHash(ToUint32(obj));
return ComputeIntegerHash(ToUint32(obj));
}
static uint32_t ToUint32(Object* obj) {
@ -5921,6 +5922,70 @@ class StringKey : public HashTableKey {
String* string_;
};
// StringSharedKeys are used as keys in the eval cache.
class StringSharedKey : public HashTableKey {
public:
StringSharedKey(String* source, SharedFunctionInfo* shared)
: source_(source), shared_(shared) { }
bool IsMatch(Object* other) {
if (!other->IsFixedArray()) return false;
FixedArray* pair = FixedArray::cast(other);
SharedFunctionInfo* shared = SharedFunctionInfo::cast(pair->get(0));
if (shared != shared_) return false;
String* source = String::cast(pair->get(1));
return source->Equals(source_);
}
typedef uint32_t (*HashFunction)(Object* obj);
virtual HashFunction GetHashFunction() { return StringSharedHash; }
static uint32_t StringSharedHashHelper(String* source,
SharedFunctionInfo* shared) {
uint32_t hash = source->Hash();
if (shared->HasSourceCode()) {
// Instead of using the SharedFunctionInfo pointer in the hash
// code computation, we use a combination of the hash of the
// script source code and the start and end positions. We do
// this to ensure that the cache entries can survive garbage
// collection.
Script* script = Script::cast(shared->script());
hash ^= String::cast(script->source())->Hash();
hash += shared->start_position();
}
return hash;
}
static uint32_t StringSharedHash(Object* obj) {
FixedArray* pair = FixedArray::cast(obj);
SharedFunctionInfo* shared = SharedFunctionInfo::cast(pair->get(0));
String* source = String::cast(pair->get(1));
return StringSharedHashHelper(source, shared);
}
virtual uint32_t Hash() {
return StringSharedHashHelper(source_, shared_);
}
virtual Object* GetObject() {
Object* obj = Heap::AllocateFixedArray(2);
if (obj->IsFailure()) return obj;
FixedArray* pair = FixedArray::cast(obj);
pair->set(0, shared_);
pair->set(1, source_);
return pair;
}
virtual bool IsStringKey() { return false; }
private:
String* source_;
SharedFunctionInfo* shared_;
};
// RegExpKey carries the source and flags of a regular expression as key.
class RegExpKey : public HashTableKey {
public:
@ -6234,6 +6299,14 @@ Object* CompilationCacheTable::Lookup(String* src) {
}
Object* CompilationCacheTable::LookupEval(String* src, Context* context) {
StringSharedKey key(src, context->closure()->shared());
int entry = FindEntry(&key);
if (entry == -1) return Heap::undefined_value();
return get(EntryToIndex(entry) + 1);
}
Object* CompilationCacheTable::LookupRegExp(String* src,
JSRegExp::Flags flags) {
RegExpKey key(src, flags);
@ -6258,6 +6331,27 @@ Object* CompilationCacheTable::Put(String* src, Object* value) {
}
Object* CompilationCacheTable::PutEval(String* src,
Context* context,
Object* value) {
StringSharedKey key(src, context->closure()->shared());
Object* obj = EnsureCapacity(1, &key);
if (obj->IsFailure()) return obj;
CompilationCacheTable* cache =
reinterpret_cast<CompilationCacheTable*>(obj);
int entry = cache->FindInsertionEntry(src, key.Hash());
Object* k = key.GetObject();
if (k->IsFailure()) return k;
cache->set(EntryToIndex(entry), k);
cache->set(EntryToIndex(entry) + 1, value);
cache->ElementAdded();
return cache;
}
Object* CompilationCacheTable::PutRegExp(String* src,
JSRegExp::Flags flags,
FixedArray* value) {

2
src/objects.h
View File

@ -2994,8 +2994,10 @@ class CompilationCacheTable: public HashTable<0, 2> {
public:
// Find cached value for a string key, otherwise return null.
Object* Lookup(String* src);
Object* LookupEval(String* src, Context* context);
Object* LookupRegExp(String* source, JSRegExp::Flags flags);
Object* Put(String* src, Object* value);
Object* PutEval(String* src, Context* context, Object* value);
Object* PutRegExp(String* src, JSRegExp::Flags flags, FixedArray* value);
static inline CompilationCacheTable* cast(Object* obj);

21
src/runtime.cc
View File

@ -4007,11 +4007,11 @@ static Object* Runtime_CompileString(Arguments args) {
CONVERT_ARG_CHECKED(String, source, 0);
CONVERT_ARG_CHECKED(Smi, line_offset, 1);
// Compile source string.
Handle<JSFunction> boilerplate =
Compiler::CompileEval(source, line_offset->value(), true);
if (boilerplate.is_null()) return Failure::Exception();
// Compile source string in the global context.
Handle<Context> context(Top::context()->global_context());
Handle<JSFunction> boilerplate =
Compiler::CompileEval(source, context, line_offset->value(), true);
if (boilerplate.is_null()) return Failure::Exception();
Handle<JSFunction> fun =
Factory::NewFunctionFromBoilerplate(boilerplate, context);
return *fun;
@ -4033,8 +4033,9 @@ static Object* CompileDirectEval(Handle<String> source) {
Handle<Context> context(Context::cast(frame->context()));
bool is_global = context->IsGlobalContext();
// Compile source string.
Handle<JSFunction> boilerplate = Compiler::CompileEval(source, 0, is_global);
// Compile source string in the current context.
Handle<JSFunction> boilerplate =
Compiler::CompileEval(source, context, 0, is_global);
if (boilerplate.is_null()) return Failure::Exception();
Handle<JSFunction> fun =
Factory::NewFunctionFromBoilerplate(boilerplate, context);
@ -5594,7 +5595,10 @@ static Object* Runtime_DebugEvaluate(Arguments args) {
Factory::NewStringFromAscii(Vector<const char>(source_str,
source_str_length));
Handle<JSFunction> boilerplate =
Compiler::CompileEval(function_source, 0, context->IsGlobalContext());
Compiler::CompileEval(function_source,
context,
0,
context->IsGlobalContext());
if (boilerplate.is_null()) return Failure::Exception();
Handle<JSFunction> compiled_function =
Factory::NewFunctionFromBoilerplate(boilerplate, context);
@ -5651,7 +5655,8 @@ static Object* Runtime_DebugEvaluateGlobal(Arguments args) {
Handle<Context> context = Top::global_context();
// Compile the source to be evaluated.
Handle<JSFunction> boilerplate(Compiler::CompileEval(source, 0, true));
Handle<JSFunction> boilerplate =
Handle<JSFunction>(Compiler::CompileEval(source, context, 0, true));
if (boilerplate.is_null()) return Failure::Exception();
Handle<JSFunction> compiled_function =
Handle<JSFunction>(Factory::NewFunctionFromBoilerplate(boilerplate,

30
src/scopeinfo.cc
View File

@ -50,6 +50,7 @@ static int CompareLocal(Variable* const* v, Variable* const* w) {
template<class Allocator>
ScopeInfo<Allocator>::ScopeInfo(Scope* scope)
: function_name_(Factory::empty_symbol()),
calls_eval_(scope->calls_eval()),
parameters_(scope->num_parameters()),
stack_slots_(scope->num_stack_slots()),
context_slots_(scope->num_heap_slots()),
@ -254,6 +255,7 @@ ScopeInfo<Allocator>::ScopeInfo(Code* code)
Object** p0 = &Memory::Object_at(code->sinfo_start());
Object** p = p0;
p = ReadSymbol(p, &function_name_);
p = ReadBool(p, &calls_eval_);
p = ReadList<Allocator>(p, &context_slots_, &context_modes_);
p = ReadList<Allocator>(p, &parameters_);
p = ReadList<Allocator>(p, &stack_slots_);
@ -267,6 +269,12 @@ static inline Object** WriteInt(Object** p, int x) {
}
static inline Object** WriteBool(Object** p, bool b) {
*p++ = Smi::FromInt(b ? 1 : 0);
return p;
}
static inline Object** WriteSymbol(Object** p, Handle<String> s) {
*p++ = *s;
return p;
@ -306,8 +314,8 @@ static Object** WriteList(Object** p,
template<class Allocator>
int ScopeInfo<Allocator>::Serialize(Code* code) {
// function name, length & sentinel for 3 tables:
const int extra_slots = 1 + 2 * 3;
// function name, calls eval, length & sentinel for 3 tables:
const int extra_slots = 1 + 1 + 2 * 3;
int size = (extra_slots +
context_slots_.length() * 2 +
parameters_.length() +
@ -318,6 +326,7 @@ int ScopeInfo<Allocator>::Serialize(Code* code) {
Object** p0 = &Memory::Object_at(code->sinfo_start());
Object** p = p0;
p = WriteSymbol(p, function_name_);
p = WriteBool(p, calls_eval_);
p = WriteList(p, &context_slots_, &context_modes_);
p = WriteList(p, &parameters_);
p = WriteList(p, &stack_slots_);
@ -338,8 +347,8 @@ void ScopeInfo<Allocator>::IterateScopeInfo(Code* code, ObjectVisitor* v) {
static Object** ContextEntriesAddr(Code* code) {
ASSERT(code->sinfo_size() > 0);
// +1 for function name:
return &Memory::Object_at(code->sinfo_start()) + 1;
// +2 for function name and calls eval:
return &Memory::Object_at(code->sinfo_start()) + 2;
}
@ -361,6 +370,19 @@ static Object** StackSlotEntriesAddr(Code* code) {
}
template<class Allocator>
bool ScopeInfo<Allocator>::CallsEval(Code* code) {
if (code->sinfo_size() > 0) {
// +1 for function name:
Object** p = &Memory::Object_at(code->sinfo_start()) + 1;
bool calls_eval;
p = ReadBool(p, &calls_eval);
return calls_eval;
}
return true;
}
template<class Allocator>
int ScopeInfo<Allocator>::NumberOfStackSlots(Code* code) {
if (code->sinfo_size() > 0) {

6
src/scopeinfo.h
View File

@ -92,7 +92,6 @@ class ScopeInfo BASE_EMBEDDED {
Handle<String> LocalName(int i) const;
int NumberOfLocals() const;
// --------------------------------------------------------------------------
// The following functions provide quick access to scope info details
// for runtime routines w/o the need to explicitly create a ScopeInfo
@ -102,6 +101,9 @@ class ScopeInfo BASE_EMBEDDED {
// encoding of it's information in a Code object, which is why these
// functions are in this class.
// Does this scope call eval.
static bool CallsEval(Code* code);
// Return the number of stack slots for code.
static int NumberOfStackSlots(Code* code);
@ -132,7 +134,6 @@ class ScopeInfo BASE_EMBEDDED {
// must be a symbol (canonicalized).
static int FunctionContextSlotIndex(Code* code, String* name);
// --------------------------------------------------------------------------
// Debugging support
@ -142,6 +143,7 @@ class ScopeInfo BASE_EMBEDDED {
private:
Handle<String> function_name_;
bool calls_eval_;
List<Handle<String>, Allocator > parameters_;
List<Handle<String>, Allocator > stack_slots_;
List<Handle<String>, Allocator > context_slots_;

29
src/scopes.cc
View File

@ -304,7 +304,7 @@ template void Scope::CollectUsedVariables(
List<Variable*, PreallocatedStorage>* locals);
void Scope::AllocateVariables() {
void Scope::AllocateVariables(Handle<Context> context) {
ASSERT(outer_scope_ == NULL); // eval or global scopes only
// 1) Propagate scope information.
@ -319,7 +319,7 @@ void Scope::AllocateVariables() {
// 2) Resolve variables.
Scope* global_scope = NULL;
if (is_global_scope()) global_scope = this;
ResolveVariablesRecursively(global_scope);
ResolveVariablesRecursively(global_scope, context);
// 3) Allocate variables.
AllocateVariablesRecursively();
@ -577,7 +577,9 @@ Variable* Scope::LookupRecursive(Handle<String> name,
}
void Scope::ResolveVariable(Scope* global_scope, VariableProxy* proxy) {
void Scope::ResolveVariable(Scope* global_scope,
Handle<Context> context,
VariableProxy* proxy) {
ASSERT(global_scope == NULL || global_scope->is_global_scope());
// If the proxy is already resolved there's nothing to do
@ -638,10 +640,16 @@ void Scope::ResolveVariable(Scope* global_scope, VariableProxy* proxy) {
} else if (outer_scope_is_eval_scope_) {
// No with statements and we did not find a local and the code
// is executed with a call to eval. We don't know anything
// because we do not have information about the scopes
// surrounding the eval call.
var = NonLocal(proxy->name(), Variable::DYNAMIC);
// is executed with a call to eval. The context contains
// scope information that we can use to determine if the
// variable is global if it is not shadowed by eval-introduced
// variables.
if (context->GlobalIfNotShadowedByEval(proxy->name())) {
var = NonLocal(proxy->name(), Variable::DYNAMIC_GLOBAL);
} else {
var = NonLocal(proxy->name(), Variable::DYNAMIC);
}
} else {
// No with statements and we did not find a local and the code
@ -657,17 +665,18 @@ void Scope::ResolveVariable(Scope* global_scope, VariableProxy* proxy) {
}
void Scope::ResolveVariablesRecursively(Scope* global_scope) {
void Scope::ResolveVariablesRecursively(Scope* global_scope,
Handle<Context> context) {
ASSERT(global_scope == NULL || global_scope->is_global_scope());
// Resolve unresolved variables for this scope.
for (int i = 0; i < unresolved_.length(); i++) {
ResolveVariable(global_scope, unresolved_[i]);
ResolveVariable(global_scope, context, unresolved_[i]);
}
// Resolve unresolved variables for inner scopes.
for (int i = 0; i < inner_scopes_.length(); i++) {
inner_scopes_[i]->ResolveVariablesRecursively(global_scope);
inner_scopes_[i]->ResolveVariablesRecursively(global_scope, context);
}
}

25
src/scopes.h
View File

@ -170,6 +170,11 @@ class Scope: public ZoneObject {
bool calls_eval() const { return scope_calls_eval_; }
bool outer_scope_calls_eval() const { return outer_scope_calls_eval_; }
// Is this scope inside a with statement.
bool inside_with() const { return scope_inside_with_; }
// Does this scope contain a with statement.
bool contains_with() const { return scope_contains_with_; }
// The scope immediately surrounding this scope, or NULL.
Scope* outer_scope() const { return outer_scope_; }
@ -216,10 +221,15 @@ class Scope: public ZoneObject {
template<class Allocator>
void CollectUsedVariables(List<Variable*, Allocator>* locals);
// Resolve and fill in the allocation information for all variables in
// this scopes. Must be called *after* all scopes have been processed
// (parsed) to ensure that unresolved variables can be resolved properly.
void AllocateVariables();
// Resolve and fill in the allocation information for all variables
// in this scopes. Must be called *after* all scopes have been
// processed (parsed) to ensure that unresolved variables can be
// resolved properly.
//
// In the case of code compiled and run using 'eval', the context
// parameter is the context in which eval was called. In all other
// cases the context parameter is an empty handle.
void AllocateVariables(Handle<Context> context);
// Result of variable allocation.
int num_stack_slots() const { return num_stack_slots_; }
@ -308,8 +318,11 @@ class Scope: public ZoneObject {
Variable* LookupRecursive(Handle<String> name,
bool inner_lookup,
Variable** invalidated_local);
void ResolveVariable(Scope* global_scope, VariableProxy* proxy);
void ResolveVariablesRecursively(Scope* global_scope);
void ResolveVariable(Scope* global_scope,
Handle<Context> context,
VariableProxy* proxy);
void ResolveVariablesRecursively(Scope* global_scope,
Handle<Context> context);
// Scope analysis.
bool PropagateScopeInfo(bool outer_scope_calls_eval,

85
test/mjsunit/global-load-from-eval.js Normal file
View File

@ -0,0 +1,85 @@
// Copyright 2009 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.
// Tests global loads from eval.
var x = 27;
function test() {
function g() {
assertEquals(27, eval('x'));
function h() {
// Shadow with local variable.
var x = 22;
assertEquals(22, eval('x'));
function i(x) {
// Shadow with parameter.
assertEquals(44, eval('x'));
function j() {
assertEquals(x, eval('x'));
// Shadow with function name.
function x() {
assertEquals(x, eval('x'));
}
x();
}
j();
}
i(44);
}
h();
}
g();
}
test();
// Test loading of globals from deeply nested eval. This code is a
// bit complicated, but the complication is needed to check that the
// code that loads the global variable accounts for the fact that the
// global variable becomes shadowed by an eval-introduced variable.
var result = 0;
function testDeep(source, load, test) {
eval(source);
function f() {
var y = 23;
function g() {
var z = 25;
function h() {
eval(load);
eval(test);
}
h();
}
g();
}
f();
}
testDeep('1', 'result = x', 'assertEquals(27, result)');
// Because of the eval-cache, the 'result = x' code gets reused. This
// time in a context where the 'x' variable has been shadowed.
testDeep('var x = 1', 'result = x', 'assertEquals(1, result)');

66
test/mjsunit/global-load-from-nested-eval.js Normal file
View File

@ -0,0 +1,66 @@
// Copyright 2009 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.
// Tests global loads from nested eval.
var x = 42;
// Load the global.
function test(source) {
eval('eval(' + source +')');
}
test('assertEquals(42, x)');
// Shadow variable with a with statement.
function testWith(source) {
with ({ x: 1 }) {
eval('eval(' + source +')');
}
}
testWith('assertEquals(1, x)');
// Shadow variable with an eval-introduced variable.
function testEval(source) {
eval('var x = 1');
function f() {
eval('eval('+ source + ')');
}
f();
}
testEval('assertEquals(1, x)');
// Eval that does not shadow.
function testEvalDontShadow(source) {
eval('1');
eval('eval(' + source +')');
}
testEvalDontShadow('assertEquals(42, x)');