// 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 "api.h"
#include "ast.h"
#include "bootstrapper.h"
#include "codegen.h"
#include "compiler.h"
#include "func-name-inferrer.h"
#include "messages.h"
#include "parser.h"
#include "platform.h"
#include "preparser.h"
#include "runtime.h"
#include "scopeinfo.h"
#include "string-stream.h"
#include "ast-inl.h"
namespace v8 {
namespace internal {
// PositionStack is used for on-stack allocation of token positions for
// new expressions. Please look at ParseNewExpression.
class PositionStack {
public:
explicit PositionStack(bool* ok) : top_(NULL), ok_(ok) {}
~PositionStack() { ASSERT(!*ok_ || is_empty()); }
class Element {
public:
Element(PositionStack* stack, int value) {
previous_ = stack->top();
value_ = value;
stack->set_top(this);
}
private:
Element* previous() { return previous_; }
int value() { return value_; }
friend class PositionStack;
Element* previous_;
int value_;
};
bool is_empty() { return top_ == NULL; }
int pop() {
ASSERT(!is_empty());
int result = top_->value();
top_ = top_->previous();
return result;
}
private:
Element* top() { return top_; }
void set_top(Element* value) { top_ = value; }
Element* top_;
bool* ok_;
};
RegExpBuilder::RegExpBuilder()
: zone_(Isolate::Current()->zone()),
pending_empty_(false),
characters_(NULL),
terms_(),
alternatives_()
#ifdef DEBUG
, last_added_(ADD_NONE)
#endif
{}
void RegExpBuilder::FlushCharacters() {
pending_empty_ = false;
if (characters_ != NULL) {
RegExpTree* atom = new(zone()) RegExpAtom(characters_->ToConstVector());
characters_ = NULL;
text_.Add(atom);
LAST(ADD_ATOM);
}
}
void RegExpBuilder::FlushText() {
FlushCharacters();
int num_text = text_.length();
if (num_text == 0) {
return;
} else if (num_text == 1) {
terms_.Add(text_.last());
} else {
RegExpText* text = new(zone()) RegExpText();
for (int i = 0; i < num_text; i++)
text_.Get(i)->AppendToText(text);
terms_.Add(text);
}
text_.Clear();
}
void RegExpBuilder::AddCharacter(uc16 c) {
pending_empty_ = false;
if (characters_ == NULL) {
characters_ = new ZoneList<uc16>(4);
}
characters_->Add(c);
LAST(ADD_CHAR);
}
void RegExpBuilder::AddEmpty() {
pending_empty_ = true;
}
void RegExpBuilder::AddAtom(RegExpTree* term) {
if (term->IsEmpty()) {
AddEmpty();
return;
}
if (term->IsTextElement()) {
FlushCharacters();
text_.Add(term);
} else {
FlushText();
terms_.Add(term);
}
LAST(ADD_ATOM);
}
void RegExpBuilder::AddAssertion(RegExpTree* assert) {
FlushText();
terms_.Add(assert);
LAST(ADD_ASSERT);
}
void RegExpBuilder::NewAlternative() {
FlushTerms();
}
void RegExpBuilder::FlushTerms() {
FlushText();
int num_terms = terms_.length();
RegExpTree* alternative;
if (num_terms == 0) {
alternative = RegExpEmpty::GetInstance();
} else if (num_terms == 1) {
alternative = terms_.last();
} else {
alternative = new(zone()) RegExpAlternative(terms_.GetList());
}
alternatives_.Add(alternative);
terms_.Clear();
LAST(ADD_NONE);
}
RegExpTree* RegExpBuilder::ToRegExp() {
FlushTerms();
int num_alternatives = alternatives_.length();
if (num_alternatives == 0) {
return RegExpEmpty::GetInstance();
}
if (num_alternatives == 1) {
return alternatives_.last();
}
return new(zone()) RegExpDisjunction(alternatives_.GetList());
}
void RegExpBuilder::AddQuantifierToAtom(int min,
int max,
RegExpQuantifier::Type type) {
if (pending_empty_) {
pending_empty_ = false;
return;
}
RegExpTree* atom;
if (characters_ != NULL) {
ASSERT(last_added_ == ADD_CHAR);
// Last atom was character.
Vector<const uc16> char_vector = characters_->ToConstVector();
int num_chars = char_vector.length();
if (num_chars > 1) {
Vector<const uc16> prefix = char_vector.SubVector(0, num_chars - 1);
text_.Add(new(zone()) RegExpAtom(prefix));
char_vector = char_vector.SubVector(num_chars - 1, num_chars);
}
characters_ = NULL;
atom = new(zone()) RegExpAtom(char_vector);
FlushText();
} else if (text_.length() > 0) {
ASSERT(last_added_ == ADD_ATOM);
atom = text_.RemoveLast();
FlushText();
} else if (terms_.length() > 0) {
ASSERT(last_added_ == ADD_ATOM);
atom = terms_.RemoveLast();
if (atom->max_match() == 0) {
// Guaranteed to only match an empty string.
LAST(ADD_TERM);
if (min == 0) {
return;
}
terms_.Add(atom);
return;
}
} else {
// Only call immediately after adding an atom or character!
UNREACHABLE();
return;
}
terms_.Add(new(zone()) RegExpQuantifier(min, max, type, atom));
LAST(ADD_TERM);
}
Handle<String> Parser::LookupSymbol(int symbol_id) {
// Length of symbol cache is the number of identified symbols.
// If we are larger than that, or negative, it's not a cached symbol.
// This might also happen if there is no preparser symbol data, even
// if there is some preparser data.
if (static_cast<unsigned>(symbol_id)
>= static_cast<unsigned>(symbol_cache_.length())) {
if (scanner().is_literal_ascii()) {
return isolate()->factory()->LookupAsciiSymbol(
scanner().literal_ascii_string());
} else {
return isolate()->factory()->LookupTwoByteSymbol(
scanner().literal_uc16_string());
}
}
return LookupCachedSymbol(symbol_id);
}
Handle<String> Parser::LookupCachedSymbol(int symbol_id) {
// Make sure the cache is large enough to hold the symbol identifier.
if (symbol_cache_.length() <= symbol_id) {
// Increase length to index + 1.
symbol_cache_.AddBlock(Handle<String>::null(),
symbol_id + 1 - symbol_cache_.length());
}
Handle<String> result = symbol_cache_.at(symbol_id);
if (result.is_null()) {
if (scanner().is_literal_ascii()) {
result = isolate()->factory()->LookupAsciiSymbol(
scanner().literal_ascii_string());
} else {
result = isolate()->factory()->LookupTwoByteSymbol(
scanner().literal_uc16_string());
}
symbol_cache_.at(symbol_id) = result;
return result;
}
isolate()->counters()->total_preparse_symbols_skipped()->Increment();
return result;
}
FunctionEntry ScriptDataImpl::GetFunctionEntry(int start) {
// The current pre-data entry must be a FunctionEntry with the given
// start position.
if ((function_index_ + FunctionEntry::kSize <= store_.length())
&& (static_cast<int>(store_[function_index_]) == start)) {
int index = function_index_;
function_index_ += FunctionEntry::kSize;
return FunctionEntry(store_.SubVector(index,
index + FunctionEntry::kSize));
}
return FunctionEntry();
}
int ScriptDataImpl::GetSymbolIdentifier() {
return ReadNumber(&symbol_data_);
}
bool ScriptDataImpl::SanityCheck() {
// Check that the header data is valid and doesn't specify
// point to positions outside the store.
if (store_.length() < PreparseDataConstants::kHeaderSize) return false;
if (magic() != PreparseDataConstants::kMagicNumber) return false;
if (version() != PreparseDataConstants::kCurrentVersion) return false;
if (has_error()) {
// Extra sane sanity check for error message encoding.
if (store_.length() <= PreparseDataConstants::kHeaderSize
+ PreparseDataConstants::kMessageTextPos) {
return false;
}
if (Read(PreparseDataConstants::kMessageStartPos) >
Read(PreparseDataConstants::kMessageEndPos)) {
return false;
}
unsigned arg_count = Read(PreparseDataConstants::kMessageArgCountPos);
int pos = PreparseDataConstants::kMessageTextPos;
for (unsigned int i = 0; i <= arg_count; i++) {
if (store_.length() <= PreparseDataConstants::kHeaderSize + pos) {
return false;
}
int length = static_cast<int>(Read(pos));
if (length < 0) return false;
pos += 1 + length;
}
if (store_.length() < PreparseDataConstants::kHeaderSize + pos) {
return false;
}
return true;
}
// Check that the space allocated for function entries is sane.
int functions_size =
static_cast<int>(store_[PreparseDataConstants::kFunctionsSizeOffset]);
if (functions_size < 0) return false;
if (functions_size % FunctionEntry::kSize != 0) return false;
// Check that the count of symbols is non-negative.
int symbol_count =
static_cast<int>(store_[PreparseDataConstants::kSymbolCountOffset]);
if (symbol_count < 0) return false;
// Check that the total size has room for header and function entries.
int minimum_size =
PreparseDataConstants::kHeaderSize + functions_size;
if (store_.length() < minimum_size) return false;
return true;
}
const char* ScriptDataImpl::ReadString(unsigned* start, int* chars) {
int length = start[0];
char* result = NewArray<char>(length + 1);
for (int i = 0; i < length; i++) {
result[i] = start[i + 1];
}
result[length] = '\0';
if (chars != NULL) *chars = length;
return result;
}
Scanner::Location ScriptDataImpl::MessageLocation() {
int beg_pos = Read(PreparseDataConstants::kMessageStartPos);
int end_pos = Read(PreparseDataConstants::kMessageEndPos);
return Scanner::Location(beg_pos, end_pos);
}
const char* ScriptDataImpl::BuildMessage() {
unsigned* start = ReadAddress(PreparseDataConstants::kMessageTextPos);
return ReadString(start, NULL);
}
Vector<const char*> ScriptDataImpl::BuildArgs() {
int arg_count = Read(PreparseDataConstants::kMessageArgCountPos);
const char** array = NewArray<const char*>(arg_count);
// Position after text found by skipping past length field and
// length field content words.
int pos = PreparseDataConstants::kMessageTextPos + 1
+ Read(PreparseDataConstants::kMessageTextPos);
for (int i = 0; i < arg_count; i++) {
int count = 0;
array[i] = ReadString(ReadAddress(pos), &count);
pos += count + 1;
}
return Vector<const char*>(array, arg_count);
}
unsigned ScriptDataImpl::Read(int position) {
return store_[PreparseDataConstants::kHeaderSize + position];
}
unsigned* ScriptDataImpl::ReadAddress(int position) {
return &store_[PreparseDataConstants::kHeaderSize + position];
}
Scope* Parser::NewScope(Scope* parent, Scope::Type type, bool inside_with) {
Scope* result = new(zone()) Scope(parent, type);
result->Initialize(inside_with);
return result;
}
// ----------------------------------------------------------------------------
// Target is a support class to facilitate manipulation of the
// Parser's target_stack_ (the stack of potential 'break' and
// 'continue' statement targets). Upon construction, a new target is
// added; it is removed upon destruction.
class Target BASE_EMBEDDED {
public:
Target(Target** variable, AstNode* node)
: variable_(variable), node_(node), previous_(*variable) {
*variable = this;
}
~Target() {
*variable_ = previous_;
}
Target* previous() { return previous_; }
AstNode* node() { return node_; }
private:
Target** variable_;
AstNode* node_;
Target* previous_;
};
class TargetScope BASE_EMBEDDED {
public:
explicit TargetScope(Target** variable)
: variable_(variable), previous_(*variable) {
*variable = NULL;
}
~TargetScope() {
*variable_ = previous_;
}
private:
Target** variable_;
Target* previous_;
};
// ----------------------------------------------------------------------------
// LexicalScope is a support class to facilitate manipulation of the
// Parser's scope stack. The constructor sets the parser's top scope
// to the incoming scope, and the destructor resets it.
//
// Additionally, it stores transient information used during parsing.
// These scopes are not kept around after parsing or referenced by syntax
// trees so they can be stack-allocated and hence used by the pre-parser.
class LexicalScope BASE_EMBEDDED {
public:
LexicalScope(Parser* parser, Scope* scope, Isolate* isolate);
~LexicalScope();
int NextMaterializedLiteralIndex() {
int next_index =
materialized_literal_count_ + JSFunction::kLiteralsPrefixSize;
materialized_literal_count_++;
return next_index;
}
int materialized_literal_count() { return materialized_literal_count_; }
void SetThisPropertyAssignmentInfo(
bool only_simple_this_property_assignments,
Handle<FixedArray> this_property_assignments) {
only_simple_this_property_assignments_ =
only_simple_this_property_assignments;
this_property_assignments_ = this_property_assignments;
}
bool only_simple_this_property_assignments() {
return only_simple_this_property_assignments_;
}
Handle<FixedArray> this_property_assignments() {
return this_property_assignments_;
}
void AddProperty() { expected_property_count_++; }
int expected_property_count() { return expected_property_count_; }
private:
// Captures the number of literals that need materialization in the
// function. Includes regexp literals, and boilerplate for object
// and array literals.
int materialized_literal_count_;
// Properties count estimation.
int expected_property_count_;
// Keeps track of assignments to properties of this. Used for
// optimizing constructors.
bool only_simple_this_property_assignments_;
Handle<FixedArray> this_property_assignments_;
// Bookkeeping
Parser* parser_;
// Previous values
LexicalScope* lexical_scope_parent_;
Scope* previous_scope_;
int previous_with_nesting_level_;
unsigned previous_ast_node_id_;
};
LexicalScope::LexicalScope(Parser* parser, Scope* scope, Isolate* isolate)
: materialized_literal_count_(0),
expected_property_count_(0),
only_simple_this_property_assignments_(false),
this_property_assignments_(isolate->factory()->empty_fixed_array()),
parser_(parser),
lexical_scope_parent_(parser->lexical_scope_),
previous_scope_(parser->top_scope_),
previous_with_nesting_level_(parser->with_nesting_level_),
previous_ast_node_id_(isolate->ast_node_id()) {
parser->top_scope_ = scope;
parser->lexical_scope_ = this;
parser->with_nesting_level_ = 0;
isolate->set_ast_node_id(AstNode::kFunctionEntryId + 1);
}
LexicalScope::~LexicalScope() {
parser_->top_scope_->Leave();
parser_->top_scope_ = previous_scope_;
parser_->lexical_scope_ = lexical_scope_parent_;
parser_->with_nesting_level_ = previous_with_nesting_level_;
parser_->isolate()->set_ast_node_id(previous_ast_node_id_);
}
// ----------------------------------------------------------------------------
// The CHECK_OK macro is a convenient macro to enforce error
// handling for functions that may fail (by returning !*ok).
//
// CAUTION: This macro appends extra statements after a call,
// thus it must never be used where only a single statement
// is correct (e.g. an if statement branch w/o braces)!
#define CHECK_OK ok); \
if (!*ok) return NULL; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
#define CHECK_FAILED /**/); \
if (failed_) return NULL; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
// ----------------------------------------------------------------------------
// Implementation of Parser
Parser::Parser(Handle<Script> script,
bool allow_natives_syntax,
v8::Extension* extension,
ScriptDataImpl* pre_data)
: isolate_(script->GetIsolate()),
symbol_cache_(pre_data ? pre_data->symbol_count() : 0),
script_(script),
scanner_(isolate_->unicode_cache()),
top_scope_(NULL),
with_nesting_level_(0),
lexical_scope_(NULL),
target_stack_(NULL),
allow_natives_syntax_(allow_natives_syntax),
extension_(extension),
pre_data_(pre_data),
fni_(NULL),
stack_overflow_(false),
parenthesized_function_(false) {
AstNode::ResetIds();
}
FunctionLiteral* Parser::ParseProgram(Handle<String> source,
bool in_global_context,
StrictModeFlag strict_mode) {
CompilationZoneScope zone_scope(DONT_DELETE_ON_EXIT);
HistogramTimerScope timer(isolate()->counters()->parse());
isolate()->counters()->total_parse_size()->Increment(source->length());
fni_ = new(zone()) FuncNameInferrer();
// Initialize parser state.
source->TryFlatten();
if (source->IsExternalTwoByteString()) {
// Notice that the stream is destroyed at the end of the branch block.
// The last line of the blocks can't be moved outside, even though they're
// identical calls.
ExternalTwoByteStringUC16CharacterStream stream(
Handle<ExternalTwoByteString>::cast(source), 0, source->length());
scanner_.Initialize(&stream);
return DoParseProgram(source, in_global_context, strict_mode, &zone_scope);
} else {
GenericStringUC16CharacterStream stream(source, 0, source->length());
scanner_.Initialize(&stream);
return DoParseProgram(source, in_global_context, strict_mode, &zone_scope);
}
}
FunctionLiteral* Parser::DoParseProgram(Handle<String> source,
bool in_global_context,
StrictModeFlag strict_mode,
ZoneScope* zone_scope) {
ASSERT(target_stack_ == NULL);
if (pre_data_ != NULL) pre_data_->Initialize();
// Compute the parsing mode.
mode_ = FLAG_lazy ? PARSE_LAZILY : PARSE_EAGERLY;
if (allow_natives_syntax_ || extension_ != NULL) mode_ = PARSE_EAGERLY;
Scope::Type type =
in_global_context
? Scope::GLOBAL_SCOPE
: Scope::EVAL_SCOPE;
Handle<String> no_name = isolate()->factory()->empty_symbol();
FunctionLiteral* result = NULL;
{ Scope* scope = NewScope(top_scope_, type, inside_with());
LexicalScope lexical_scope(this, scope, isolate());
if (strict_mode == kStrictMode) {
top_scope_->EnableStrictMode();
}
ZoneList<Statement*>* body = new ZoneList<Statement*>(16);
bool ok = true;
int beg_loc = scanner().location().beg_pos;
ParseSourceElements(body, Token::EOS, &ok);
if (ok && top_scope_->is_strict_mode()) {
CheckOctalLiteral(beg_loc, scanner().location().end_pos, &ok);
}
if (ok) {
result = new(zone()) FunctionLiteral(
no_name,
top_scope_,
body,
lexical_scope.materialized_literal_count(),
lexical_scope.expected_property_count(),
lexical_scope.only_simple_this_property_assignments(),
lexical_scope.this_property_assignments(),
0,
0,
source->length(),
false);
} else if (stack_overflow_) {
isolate()->StackOverflow();
}
}
// Make sure the target stack is empty.
ASSERT(target_stack_ == NULL);
// If there was a syntax error we have to get rid of the AST
// and it is not safe to do so before the scope has been deleted.
if (result == NULL) zone_scope->DeleteOnExit();
return result;
}
FunctionLiteral* Parser::ParseLazy(CompilationInfo* info) {
CompilationZoneScope zone_scope(DONT_DELETE_ON_EXIT);
HistogramTimerScope timer(isolate()->counters()->parse_lazy());
Handle<String> source(String::cast(script_->source()));
isolate()->counters()->total_parse_size()->Increment(source->length());
Handle<SharedFunctionInfo> shared_info = info->shared_info();
// Initialize parser state.
source->TryFlatten();
if (source->IsExternalTwoByteString()) {
ExternalTwoByteStringUC16CharacterStream stream(
Handle<ExternalTwoByteString>::cast(source),
shared_info->start_position(),
shared_info->end_position());
FunctionLiteral* result = ParseLazy(info, &stream, &zone_scope);
return result;
} else {
GenericStringUC16CharacterStream stream(source,
shared_info->start_position(),
shared_info->end_position());
FunctionLiteral* result = ParseLazy(info, &stream, &zone_scope);
return result;
}
}
FunctionLiteral* Parser::ParseLazy(CompilationInfo* info,
UC16CharacterStream* source,
ZoneScope* zone_scope) {
Handle<SharedFunctionInfo> shared_info = info->shared_info();
scanner_.Initialize(source);
ASSERT(target_stack_ == NULL);
Handle<String> name(String::cast(shared_info->name()));
fni_ = new(zone()) FuncNameInferrer();
fni_->PushEnclosingName(name);
mode_ = PARSE_EAGERLY;
// Place holder for the result.
FunctionLiteral* result = NULL;
{
// Parse the function literal.
Handle<String> no_name = isolate()->factory()->empty_symbol();
Scope* scope = NewScope(top_scope_, Scope::GLOBAL_SCOPE, inside_with());
if (!info->closure().is_null()) {
scope = Scope::DeserializeScopeChain(info, scope);
}
LexicalScope lexical_scope(this, scope, isolate());
if (shared_info->strict_mode()) {
top_scope_->EnableStrictMode();
}
FunctionLiteralType type =
shared_info->is_expression() ? EXPRESSION : DECLARATION;
bool ok = true;
result = ParseFunctionLiteral(name,
false, // Strict mode name already checked.
RelocInfo::kNoPosition, type, &ok);
// Make sure the results agree.
ASSERT(ok == (result != NULL));
}
// Make sure the target stack is empty.
ASSERT(target_stack_ == NULL);
// If there was a stack overflow we have to get rid of AST and it is
// not safe to do before scope has been deleted.
if (result == NULL) {
zone_scope->DeleteOnExit();
if (stack_overflow_) isolate()->StackOverflow();
} else {
Handle<String> inferred_name(shared_info->inferred_name());
result->set_inferred_name(inferred_name);
}
return result;
}
Handle<String> Parser::GetSymbol(bool* ok) {
int symbol_id = -1;
if (pre_data() != NULL) {
symbol_id = pre_data()->GetSymbolIdentifier();
}
return LookupSymbol(symbol_id);
}
void Parser::ReportMessage(const char* type, Vector<const char*> args) {
Scanner::Location source_location = scanner().location();
ReportMessageAt(source_location, type, args);
}
void Parser::ReportMessageAt(Scanner::Location source_location,
const char* type,
Vector<const char*> args) {
MessageLocation location(script_,
source_location.beg_pos,
source_location.end_pos);
Factory* factory = isolate()->factory();
Handle<FixedArray> elements = factory->NewFixedArray(args.length());
for (int i = 0; i < args.length(); i++) {
Handle<String> arg_string = factory->NewStringFromUtf8(CStrVector(args[i]));
elements->set(i, *arg_string);
}
Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
Handle<Object> result = factory->NewSyntaxError(type, array);
isolate()->Throw(*result, &location);
}
void Parser::ReportMessageAt(Scanner::Location source_location,
const char* type,
Vector<Handle<String> > args) {
MessageLocation location(script_,
source_location.beg_pos,
source_location.end_pos);
Factory* factory = isolate()->factory();
Handle<FixedArray> elements = factory->NewFixedArray(args.length());
for (int i = 0; i < args.length(); i++) {
elements->set(i, *args[i]);
}
Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
Handle<Object> result = factory->NewSyntaxError(type, array);
isolate()->Throw(*result, &location);
}
// Base class containing common code for the different finder classes used by
// the parser.
class ParserFinder {
protected:
ParserFinder() {}
static Assignment* AsAssignment(Statement* stat) {
if (stat == NULL) return NULL;
ExpressionStatement* exp_stat = stat->AsExpressionStatement();
if (exp_stat == NULL) return NULL;
return exp_stat->expression()->AsAssignment();
}
};
// An InitializationBlockFinder finds and marks sequences of statements of the
// form expr.a = ...; expr.b = ...; etc.
class InitializationBlockFinder : public ParserFinder {
public:
InitializationBlockFinder()
: first_in_block_(NULL), last_in_block_(NULL), block_size_(0) {}
~InitializationBlockFinder() {
if (InBlock()) EndBlock();
}
void Update(Statement* stat) {
Assignment* assignment = AsAssignment(stat);
if (InBlock()) {
if (BlockContinues(assignment)) {
UpdateBlock(assignment);
} else {
EndBlock();
}
}
if (!InBlock() && (assignment != NULL) &&
(assignment->op() == Token::ASSIGN)) {
StartBlock(assignment);
}
}
private:
// The minimum number of contiguous assignment that will
// be treated as an initialization block. Benchmarks show that
// the overhead exceeds the savings below this limit.
static const int kMinInitializationBlock = 3;
// Returns true if the expressions appear to denote the same object.
// In the context of initialization blocks, we only consider expressions
// of the form 'expr.x' or expr["x"].
static bool SameObject(Expression* e1, Expression* e2) {
VariableProxy* v1 = e1->AsVariableProxy();
VariableProxy* v2 = e2->AsVariableProxy();
if (v1 != NULL && v2 != NULL) {
return v1->name()->Equals(*v2->name());
}
Property* p1 = e1->AsProperty();
Property* p2 = e2->AsProperty();
if ((p1 == NULL) || (p2 == NULL)) return false;
Literal* key1 = p1->key()->AsLiteral();
Literal* key2 = p2->key()->AsLiteral();
if ((key1 == NULL) || (key2 == NULL)) return false;
if (!key1->handle()->IsString() || !key2->handle()->IsString()) {
return false;
}
String* name1 = String::cast(*key1->handle());
String* name2 = String::cast(*key2->handle());
if (!name1->Equals(name2)) return false;
return SameObject(p1->obj(), p2->obj());
}
// Returns true if the expressions appear to denote different properties
// of the same object.
static bool PropertyOfSameObject(Expression* e1, Expression* e2) {
Property* p1 = e1->AsProperty();
Property* p2 = e2->AsProperty();
if ((p1 == NULL) || (p2 == NULL)) return false;
return SameObject(p1->obj(), p2->obj());
}
bool BlockContinues(Assignment* assignment) {
if ((assignment == NULL) || (first_in_block_ == NULL)) return false;
if (assignment->op() != Token::ASSIGN) return false;
return PropertyOfSameObject(first_in_block_->target(),
assignment->target());
}
void StartBlock(Assignment* assignment) {
first_in_block_ = assignment;
last_in_block_ = assignment;
block_size_ = 1;
}
void UpdateBlock(Assignment* assignment) {
last_in_block_ = assignment;
++block_size_;
}
void EndBlock() {
if (block_size_ >= kMinInitializationBlock) {
first_in_block_->mark_block_start();
last_in_block_->mark_block_end();
}
last_in_block_ = first_in_block_ = NULL;
block_size_ = 0;
}
bool InBlock() { return first_in_block_ != NULL; }
Assignment* first_in_block_;
Assignment* last_in_block_;
int block_size_;
DISALLOW_COPY_AND_ASSIGN(InitializationBlockFinder);
};
// A ThisNamedPropertyAssigmentFinder finds and marks statements of the form
// this.x = ...;, where x is a named property. It also determines whether a
// function contains only assignments of this type.
class ThisNamedPropertyAssigmentFinder : public ParserFinder {
public:
explicit ThisNamedPropertyAssigmentFinder(Isolate* isolate)
: isolate_(isolate),
only_simple_this_property_assignments_(true),
names_(NULL),
assigned_arguments_(NULL),
assigned_constants_(NULL) {}
void Update(Scope* scope, Statement* stat) {
// Bail out if function already has property assignment that are
// not simple this property assignments.
if (!only_simple_this_property_assignments_) {
return;
}
// Check whether this statement is of the form this.x = ...;
Assignment* assignment = AsAssignment(stat);
if (IsThisPropertyAssignment(assignment)) {
HandleThisPropertyAssignment(scope, assignment);
} else {
only_simple_this_property_assignments_ = false;
}
}
// Returns whether only statements of the form this.x = y; where y is either a
// constant or a function argument was encountered.
bool only_simple_this_property_assignments() {
return only_simple_this_property_assignments_;
}
// Returns a fixed array containing three elements for each assignment of the
// form this.x = y;
Handle<FixedArray> GetThisPropertyAssignments() {
if (names_ == NULL) {
return isolate_->factory()->empty_fixed_array();
}
ASSERT(names_ != NULL);
ASSERT(assigned_arguments_ != NULL);
ASSERT_EQ(names_->length(), assigned_arguments_->length());
ASSERT_EQ(names_->length(), assigned_constants_->length());
Handle<FixedArray> assignments =
isolate_->factory()->NewFixedArray(names_->length() * 3);
for (int i = 0; i < names_->length(); i++) {
assignments->set(i * 3, *names_->at(i));
assignments->set(i * 3 + 1, Smi::FromInt(assigned_arguments_->at(i)));
assignments->set(i * 3 + 2, *assigned_constants_->at(i));
}
return assignments;
}
private:
bool IsThisPropertyAssignment(Assignment* assignment) {
if (assignment != NULL) {
Property* property = assignment->target()->AsProperty();
return assignment->op() == Token::ASSIGN
&& property != NULL
&& property->obj()->AsVariableProxy() != NULL
&& property->obj()->AsVariableProxy()->is_this();
}
return false;
}
void HandleThisPropertyAssignment(Scope* scope, Assignment* assignment) {
// Check that the property assigned to is a named property, which is not
// __proto__.
Property* property = assignment->target()->AsProperty();
ASSERT(property != NULL);
Literal* literal = property->key()->AsLiteral();
uint32_t dummy;
if (literal != NULL &&
literal->handle()->IsString() &&
!String::cast(*(literal->handle()))->Equals(
isolate_->heap()->Proto_symbol()) &&
!String::cast(*(literal->handle()))->AsArrayIndex(&dummy)) {
Handle<String> key = Handle<String>::cast(literal->handle());
// Check whether the value assigned is either a constant or matches the
// name of one of the arguments to the function.
if (assignment->value()->AsLiteral() != NULL) {
// Constant assigned.
Literal* literal = assignment->value()->AsLiteral();
AssignmentFromConstant(key, literal->handle());
return;
} else if (assignment->value()->AsVariableProxy() != NULL) {
// Variable assigned.
Handle<String> name =
assignment->value()->AsVariableProxy()->name();
// Check whether the variable assigned matches an argument name.
for (int i = 0; i < scope->num_parameters(); i++) {
if (*scope->parameter(i)->name() == *name) {
// Assigned from function argument.
AssignmentFromParameter(key, i);
return;
}
}
}
}
// It is not a simple "this.x = value;" assignment with a constant
// or parameter value.
AssignmentFromSomethingElse();
}
void AssignmentFromParameter(Handle<String> name, int index) {
EnsureAllocation();
names_->Add(name);
assigned_arguments_->Add(index);
assigned_constants_->Add(isolate_->factory()->undefined_value());
}
void AssignmentFromConstant(Handle<String> name, Handle<Object> value) {
EnsureAllocation();
names_->Add(name);
assigned_arguments_->Add(-1);
assigned_constants_->Add(value);
}
void AssignmentFromSomethingElse() {
// The this assignment is not a simple one.
only_simple_this_property_assignments_ = false;
}
void EnsureAllocation() {
if (names_ == NULL) {
ASSERT(assigned_arguments_ == NULL);
ASSERT(assigned_constants_ == NULL);
names_ = new ZoneStringList(4);
assigned_arguments_ = new ZoneList<int>(4);
assigned_constants_ = new ZoneObjectList(4);
}
}
Isolate* isolate_;
bool only_simple_this_property_assignments_;
ZoneStringList* names_;
ZoneList<int>* assigned_arguments_;
ZoneObjectList* assigned_constants_;
};
void* Parser::ParseSourceElements(ZoneList<Statement*>* processor,
int end_token,
bool* ok) {
// SourceElements ::
// (Statement)* <end_token>
// Allocate a target stack to use for this set of source
// elements. This way, all scripts and functions get their own
// target stack thus avoiding illegal breaks and continues across
// functions.
TargetScope scope(&this->target_stack_);
ASSERT(processor != NULL);
InitializationBlockFinder block_finder;
ThisNamedPropertyAssigmentFinder this_property_assignment_finder(isolate());
bool directive_prologue = true; // Parsing directive prologue.
while (peek() != end_token) {
if (directive_prologue && peek() != Token::STRING) {
directive_prologue = false;
}
Scanner::Location token_loc = scanner().peek_location();
Statement* stat;
if (peek() == Token::FUNCTION) {
// FunctionDeclaration is only allowed in the context of SourceElements
// (Ecma 262 5th Edition, clause 14):
// SourceElement:
// Statement
// FunctionDeclaration
// Common language extension is to allow function declaration in place
// of any statement. This language extension is disabled in strict mode.
stat = ParseFunctionDeclaration(CHECK_OK);
} else {
stat = ParseStatement(NULL, CHECK_OK);
}
if (stat == NULL || stat->IsEmpty()) {
directive_prologue = false; // End of directive prologue.
continue;
}
if (directive_prologue) {
// A shot at a directive.
ExpressionStatement *e_stat;
Literal *literal;
// Still processing directive prologue?
if ((e_stat = stat->AsExpressionStatement()) != NULL &&
(literal = e_stat->expression()->AsLiteral()) != NULL &&
literal->handle()->IsString()) {
Handle<String> directive = Handle<String>::cast(literal->handle());
// Check "use strict" directive (ES5 14.1).
if (!top_scope_->is_strict_mode() &&
directive->Equals(isolate()->heap()->use_strict()) &&
token_loc.end_pos - token_loc.beg_pos ==
isolate()->heap()->use_strict()->length() + 2) {
top_scope_->EnableStrictMode();
// "use strict" is the only directive for now.
directive_prologue = false;
}
} else {
// End of the directive prologue.
directive_prologue = false;
}
}
// We find and mark the initialization blocks on top level code only.
// This is because the optimization prevents reuse of the map transitions,
// so it should be used only for code that will only be run once.
if (top_scope_->is_global_scope()) {
block_finder.Update(stat);
}
// Find and mark all assignments to named properties in this (this.x =)
if (top_scope_->is_function_scope()) {
this_property_assignment_finder.Update(top_scope_, stat);
}
processor->Add(stat);
}
// Propagate the collected information on this property assignments.
if (top_scope_->is_function_scope()) {
bool only_simple_this_property_assignments =
this_property_assignment_finder.only_simple_this_property_assignments()
&& top_scope_->declarations()->length() == 0;
if (only_simple_this_property_assignments) {
lexical_scope_->SetThisPropertyAssignmentInfo(
only_simple_this_property_assignments,
this_property_assignment_finder.GetThisPropertyAssignments());
}
}
return 0;
}
Statement* Parser::ParseStatement(ZoneStringList* labels, bool* ok) {
// Statement ::
// Block
// VariableStatement
// EmptyStatement
// ExpressionStatement
// IfStatement
// IterationStatement
// ContinueStatement
// BreakStatement
// ReturnStatement
// WithStatement
// LabelledStatement
// SwitchStatement
// ThrowStatement
// TryStatement
// DebuggerStatement
// Note: Since labels can only be used by 'break' and 'continue'
// statements, which themselves are only valid within blocks,
// iterations or 'switch' statements (i.e., BreakableStatements),
// labels can be simply ignored in all other cases; except for
// trivial labeled break statements 'label: break label' which is
// parsed into an empty statement.
// Keep the source position of the statement
int statement_pos = scanner().peek_location().beg_pos;
Statement* stmt = NULL;
switch (peek()) {
case Token::LBRACE:
return ParseBlock(labels, ok);
case Token::CONST: // fall through
case Token::VAR:
stmt = ParseVariableStatement(ok);
break;
case Token::SEMICOLON:
Next();
return EmptyStatement();
case Token::IF:
stmt = ParseIfStatement(labels, ok);
break;
case Token::DO:
stmt = ParseDoWhileStatement(labels, ok);
break;
case Token::WHILE:
stmt = ParseWhileStatement(labels, ok);
break;
case Token::FOR:
stmt = ParseForStatement(labels, ok);
break;
case Token::CONTINUE:
stmt = ParseContinueStatement(ok);
break;
case Token::BREAK:
stmt = ParseBreakStatement(labels, ok);
break;
case Token::RETURN:
stmt = ParseReturnStatement(ok);
break;
case Token::WITH:
stmt = ParseWithStatement(labels, ok);
break;
case Token::SWITCH:
stmt = ParseSwitchStatement(labels, ok);
break;
case Token::THROW:
stmt = ParseThrowStatement(ok);
break;
case Token::TRY: {
// NOTE: It is somewhat complicated to have labels on
// try-statements. When breaking out of a try-finally statement,
// one must take great care not to treat it as a
// fall-through. It is much easier just to wrap the entire
// try-statement in a statement block and put the labels there
Block* result = new(zone()) Block(labels, 1, false);
Target target(&this->target_stack_, result);
TryStatement* statement = ParseTryStatement(CHECK_OK);
if (statement) {
statement->set_statement_pos(statement_pos);
}
if (result) result->AddStatement(statement);
return result;
}
case Token::FUNCTION: {
// In strict mode, FunctionDeclaration is only allowed in the context
// of SourceElements.
if (top_scope_->is_strict_mode()) {
ReportMessageAt(scanner().peek_location(), "strict_function",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
return ParseFunctionDeclaration(ok);
}
case Token::NATIVE:
return ParseNativeDeclaration(ok);
case Token::DEBUGGER:
stmt = ParseDebuggerStatement(ok);
break;
default:
stmt = ParseExpressionOrLabelledStatement(labels, ok);
}
// Store the source position of the statement
if (stmt != NULL) stmt->set_statement_pos(statement_pos);
return stmt;
}
VariableProxy* Parser::Declare(Handle<String> name,
Variable::Mode mode,
FunctionLiteral* fun,
bool resolve,
bool* ok) {
Variable* var = NULL;
// If we are inside a function, a declaration of a variable
// is a truly local variable, and the scope of the variable
// is always the function scope.
// If a function scope exists, then we can statically declare this
// variable and also set its mode. In any case, a Declaration node
// will be added to the scope so that the declaration can be added
// to the corresponding activation frame at runtime if necessary.
// For instance declarations inside an eval scope need to be added
// to the calling function context.
if (top_scope_->is_function_scope()) {
// Declare the variable in the function scope.
var = top_scope_->LocalLookup(name);
if (var == NULL) {
// Declare the name.
var = top_scope_->DeclareLocal(name, mode, Scope::VAR_OR_CONST);
} else {
// The name was declared before; check for conflicting
// re-declarations. If the previous declaration was a const or the
// current declaration is a const then we have a conflict. There is
// similar code in runtime.cc in the Declare functions.
if ((mode == Variable::CONST) || (var->mode() == Variable::CONST)) {
// We only have vars and consts in declarations.
ASSERT(var->mode() == Variable::VAR ||
var->mode() == Variable::CONST);
const char* type = (var->mode() == Variable::VAR) ? "var" : "const";
Handle<String> type_string =
isolate()->factory()->NewStringFromUtf8(CStrVector(type), TENURED);
Expression* expression =
NewThrowTypeError(isolate()->factory()->redeclaration_symbol(),
type_string, name);
top_scope_->SetIllegalRedeclaration(expression);
}
}
}
// We add a declaration node for every declaration. The compiler
// will only generate code if necessary. In particular, declarations
// for inner local variables that do not represent functions won't
// result in any generated code.
//
// Note that we always add an unresolved proxy even if it's not
// used, simply because we don't know in this method (w/o extra
// parameters) if the proxy is needed or not. The proxy will be
// bound during variable resolution time unless it was pre-bound
// below.
//
// WARNING: This will lead to multiple declaration nodes for the
// same variable if it is declared several times. This is not a
// semantic issue as long as we keep the source order, but it may be
// a performance issue since it may lead to repeated
// Runtime::DeclareContextSlot() calls.
VariableProxy* proxy = top_scope_->NewUnresolved(name, inside_with());
top_scope_->AddDeclaration(new(zone()) Declaration(proxy, mode, fun));
// For global const variables we bind the proxy to a variable.
if (mode == Variable::CONST && top_scope_->is_global_scope()) {
ASSERT(resolve); // should be set by all callers
Variable::Kind kind = Variable::NORMAL;
var = new(zone()) Variable(top_scope_, name, Variable::CONST, true, kind);
}
// If requested and we have a local variable, bind the proxy to the variable
// at parse-time. This is used for functions (and consts) declared inside
// statements: the corresponding function (or const) variable must be in the
// function scope and not a statement-local scope, e.g. as provided with a
// 'with' statement:
//
// with (obj) {
// function f() {}
// }
//
// which is translated into:
//
// with (obj) {
// // in this case this is not: 'var f; f = function () {};'
// var f = function () {};
// }
//
// Note that if 'f' is accessed from inside the 'with' statement, it
// will be allocated in the context (because we must be able to look
// it up dynamically) but it will also be accessed statically, i.e.,
// with a context slot index and a context chain length for this
// initialization code. Thus, inside the 'with' statement, we need
// both access to the static and the dynamic context chain; the
// runtime needs to provide both.
if (resolve && var != NULL) proxy->BindTo(var);
return proxy;
}
// Language extension which is only enabled for source files loaded
// through the API's extension mechanism. A native function
// declaration is resolved by looking up the function through a
// callback provided by the extension.
Statement* Parser::ParseNativeDeclaration(bool* ok) {
if (extension_ == NULL) {
ReportUnexpectedToken(Token::NATIVE);
*ok = false;
return NULL;
}
Expect(Token::NATIVE, CHECK_OK);
Expect(Token::FUNCTION, CHECK_OK);
Handle<String> name = ParseIdentifier(CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
bool done = (peek() == Token::RPAREN);
while (!done) {
ParseIdentifier(CHECK_OK);
done = (peek() == Token::RPAREN);
if (!done) {
Expect(Token::COMMA, CHECK_OK);
}
}
Expect(Token::RPAREN, CHECK_OK);
Expect(Token::SEMICOLON, CHECK_OK);
// Make sure that the function containing the native declaration
// isn't lazily compiled. The extension structures are only
// accessible while parsing the first time not when reparsing
// because of lazy compilation.
top_scope_->ForceEagerCompilation();
// Compute the function template for the native function.
v8::Handle<v8::FunctionTemplate> fun_template =
extension_->GetNativeFunction(v8::Utils::ToLocal(name));
ASSERT(!fun_template.IsEmpty());
// Instantiate the function and create a shared function info from it.
Handle<JSFunction> fun = Utils::OpenHandle(*fun_template->GetFunction());
const int literals = fun->NumberOfLiterals();
Handle<Code> code = Handle<Code>(fun->shared()->code());
Handle<Code> construct_stub = Handle<Code>(fun->shared()->construct_stub());
Handle<SharedFunctionInfo> shared =
isolate()->factory()->NewSharedFunctionInfo(name, literals, code,
Handle<SerializedScopeInfo>(fun->shared()->scope_info()));
shared->set_construct_stub(*construct_stub);
// Copy the function data to the shared function info.
shared->set_function_data(fun->shared()->function_data());
int parameters = fun->shared()->formal_parameter_count();
shared->set_formal_parameter_count(parameters);
// TODO(1240846): It's weird that native function declarations are
// introduced dynamically when we meet their declarations, whereas
// other functions are setup when entering the surrounding scope.
SharedFunctionInfoLiteral* lit =
new(zone()) SharedFunctionInfoLiteral(shared);
VariableProxy* var = Declare(name, Variable::VAR, NULL, true, CHECK_OK);
return new(zone()) ExpressionStatement(new(zone()) Assignment(
Token::INIT_VAR, var, lit, RelocInfo::kNoPosition));
}
Statement* Parser::ParseFunctionDeclaration(bool* ok) {
// FunctionDeclaration ::
// 'function' Identifier '(' FormalParameterListopt ')' '{' FunctionBody '}'
Expect(Token::FUNCTION, CHECK_OK);
int function_token_position = scanner().location().beg_pos;
bool is_reserved = false;
Handle<String> name = ParseIdentifierOrReservedWord(&is_reserved, CHECK_OK);
FunctionLiteral* fun = ParseFunctionLiteral(name,
is_reserved,
function_token_position,
DECLARATION,
CHECK_OK);
// Even if we're not at the top-level of the global or a function
// scope, we treat is as such and introduce the function with it's
// initial value upon entering the corresponding scope.
Declare(name, Variable::VAR, fun, true, CHECK_OK);
return EmptyStatement();
}
Block* Parser::ParseBlock(ZoneStringList* labels, bool* ok) {
// Block ::
// '{' Statement* '}'
// Note that a Block does not introduce a new execution scope!
// (ECMA-262, 3rd, 12.2)
//
// Construct block expecting 16 statements.
Block* result = new(zone()) Block(labels, 16, false);
Target target(&this->target_stack_, result);
Expect(Token::LBRACE, CHECK_OK);
while (peek() != Token::RBRACE) {
Statement* stat = ParseStatement(NULL, CHECK_OK);
if (stat && !stat->IsEmpty()) result->AddStatement(stat);
}
Expect(Token::RBRACE, CHECK_OK);
return result;
}
Block* Parser::ParseVariableStatement(bool* ok) {
// VariableStatement ::
// VariableDeclarations ';'
Expression* dummy; // to satisfy the ParseVariableDeclarations() signature
Block* result = ParseVariableDeclarations(true, &dummy, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return result;
}
bool Parser::IsEvalOrArguments(Handle<String> string) {
return string.is_identical_to(isolate()->factory()->eval_symbol()) ||
string.is_identical_to(isolate()->factory()->arguments_symbol());
}
// If the variable declaration declares exactly one non-const
// variable, then *var is set to that variable. In all other cases,
// *var is untouched; in particular, it is the caller's responsibility
// to initialize it properly. This mechanism is used for the parsing
// of 'for-in' loops.
Block* Parser::ParseVariableDeclarations(bool accept_IN,
Expression** var,
bool* ok) {
// VariableDeclarations ::
// ('var' | 'const') (Identifier ('=' AssignmentExpression)?)+[',']
Variable::Mode mode = Variable::VAR;
bool is_const = false;
if (peek() == Token::VAR) {
Consume(Token::VAR);
} else if (peek() == Token::CONST) {
Consume(Token::CONST);
if (top_scope_->is_strict_mode()) {
ReportMessage("strict_const", Vector<const char*>::empty());
*ok = false;
return NULL;
}
mode = Variable::CONST;
is_const = true;
} else {
UNREACHABLE(); // by current callers
}
// The scope of a variable/const declared anywhere inside a function
// is the entire function (ECMA-262, 3rd, 10.1.3, and 12.2). Thus we can
// transform a source-level variable/const declaration into a (Function)
// Scope declaration, and rewrite the source-level initialization into an
// assignment statement. We use a block to collect multiple assignments.
//
// We mark the block as initializer block because we don't want the
// rewriter to add a '.result' assignment to such a block (to get compliant
// behavior for code such as print(eval('var x = 7')), and for cosmetic
// reasons when pretty-printing. Also, unless an assignment (initialization)
// is inside an initializer block, it is ignored.
//
// Create new block with one expected declaration.
Block* block = new(zone()) Block(NULL, 1, true);
VariableProxy* last_var = NULL; // the last variable declared
int nvars = 0; // the number of variables declared
do {
if (fni_ != NULL) fni_->Enter();
// Parse variable name.
if (nvars > 0) Consume(Token::COMMA);
Handle<String> name = ParseIdentifier(CHECK_OK);
if (fni_ != NULL) fni_->PushVariableName(name);
// Strict mode variables may not be named eval or arguments
if (top_scope_->is_strict_mode() && IsEvalOrArguments(name)) {
ReportMessage("strict_var_name", Vector<const char*>::empty());
*ok = false;
return NULL;
}
// Declare variable.
// Note that we *always* must treat the initial value via a separate init
// assignment for variables and constants because the value must be assigned
// when the variable is encountered in the source. But the variable/constant
// is declared (and set to 'undefined') upon entering the function within
// which the variable or constant is declared. Only function variables have
// an initial value in the declaration (because they are initialized upon
// entering the function).
//
// If we have a const declaration, in an inner scope, the proxy is always
// bound to the declared variable (independent of possibly surrounding with
// statements).
last_var = Declare(name, mode, NULL,
is_const /* always bound for CONST! */,
CHECK_OK);
nvars++;
if (top_scope_->num_var_or_const() > kMaxNumFunctionLocals) {
ReportMessageAt(scanner().location(), "too_many_variables",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
// Parse initialization expression if present and/or needed. A
// declaration of the form:
//
// var v = x;
//
// is syntactic sugar for:
//
// var v; v = x;
//
// In particular, we need to re-lookup 'v' as it may be a
// different 'v' than the 'v' in the declaration (if we are inside
// a 'with' statement that makes a object property with name 'v'
// visible).
//
// However, note that const declarations are different! A const
// declaration of the form:
//
// const c = x;
//
// is *not* syntactic sugar for:
//
// const c; c = x;
//
// The "variable" c initialized to x is the same as the declared
// one - there is no re-lookup (see the last parameter of the
// Declare() call above).
Expression* value = NULL;
int position = -1;
if (peek() == Token::ASSIGN) {
Expect(Token::ASSIGN, CHECK_OK);
position = scanner().location().beg_pos;
value = ParseAssignmentExpression(accept_IN, CHECK_OK);
// Don't infer if it is "a = function(){...}();"-like expression.
if (fni_ != NULL && value->AsCall() == NULL) fni_->Infer();
}
// Make sure that 'const c' actually initializes 'c' to undefined
// even though it seems like a stupid thing to do.
if (value == NULL && is_const) {
value = GetLiteralUndefined();
}
// Global variable declarations must be compiled in a specific
// way. When the script containing the global variable declaration
// is entered, the global variable must be declared, so that if it
// doesn't exist (not even in a prototype of the global object) it
// gets created with an initial undefined value. This is handled
// by the declarations part of the function representing the
// top-level global code; see Runtime::DeclareGlobalVariable. If
// it already exists (in the object or in a prototype), it is
// *not* touched until the variable declaration statement is
// executed.
//
// Executing the variable declaration statement will always
// guarantee to give the global object a "local" variable; a
// variable defined in the global object and not in any
// prototype. This way, global variable declarations can shadow
// properties in the prototype chain, but only after the variable
// declaration statement has been executed. This is important in
// browsers where the global object (window) has lots of
// properties defined in prototype objects.
if (top_scope_->is_global_scope()) {
// Compute the arguments for the runtime call.
ZoneList<Expression*>* arguments = new ZoneList<Expression*>(3);
// We have at least 1 parameter.
arguments->Add(new(zone()) Literal(name));
CallRuntime* initialize;
if (is_const) {
arguments->Add(value);
value = NULL; // zap the value to avoid the unnecessary assignment
// Construct the call to Runtime_InitializeConstGlobal
// and add it to the initialization statement block.
// Note that the function does different things depending on
// the number of arguments (1 or 2).
initialize =
new(zone()) CallRuntime(
isolate()->factory()->InitializeConstGlobal_symbol(),
Runtime::FunctionForId(Runtime::kInitializeConstGlobal),
arguments);
} else {
// Add strict mode.
// We may want to pass singleton to avoid Literal allocations.
arguments->Add(NewNumberLiteral(
top_scope_->is_strict_mode() ? kStrictMode : kNonStrictMode));
// Be careful not to assign a value to the global variable if
// we're in a with. The initialization value should not
// necessarily be stored in the global object in that case,
// which is why we need to generate a separate assignment node.
if (value != NULL && !inside_with()) {
arguments->Add(value);
value = NULL; // zap the value to avoid the unnecessary assignment
}
// Construct the call to Runtime_InitializeVarGlobal
// and add it to the initialization statement block.
// Note that the function does different things depending on
// the number of arguments (2 or 3).
initialize =
new(zone()) CallRuntime(
isolate()->factory()->InitializeVarGlobal_symbol(),
Runtime::FunctionForId(Runtime::kInitializeVarGlobal),
arguments);
}
block->AddStatement(new(zone()) ExpressionStatement(initialize));
}
// Add an assignment node to the initialization statement block if
// we still have a pending initialization value. We must distinguish
// between variables and constants: Variable initializations are simply
// assignments (with all the consequences if they are inside a 'with'
// statement - they may change a 'with' object property). Constant
// initializations always assign to the declared constant which is
// always at the function scope level. This is only relevant for
// dynamically looked-up variables and constants (the start context
// for constant lookups is always the function context, while it is
// the top context for variables). Sigh...
if (value != NULL) {
Token::Value op = (is_const ? Token::INIT_CONST : Token::INIT_VAR);
Assignment* assignment =
new(zone()) Assignment(op, last_var, value, position);
if (block) {
block->AddStatement(new(zone()) ExpressionStatement(assignment));
}
}
if (fni_ != NULL) fni_->Leave();
} while (peek() == Token::COMMA);
if (!is_const && nvars == 1) {
// We have a single, non-const variable.
ASSERT(last_var != NULL);
*var = last_var;
}
return block;
}
static bool ContainsLabel(ZoneStringList* labels, Handle<String> label) {
ASSERT(!label.is_null());
if (labels != NULL)
for (int i = labels->length(); i-- > 0; )
if (labels->at(i).is_identical_to(label))
return true;
return false;
}
Statement* Parser::ParseExpressionOrLabelledStatement(ZoneStringList* labels,
bool* ok) {
// ExpressionStatement | LabelledStatement ::
// Expression ';'
// Identifier ':' Statement
bool starts_with_idenfifier = peek_any_identifier();
Expression* expr = ParseExpression(true, CHECK_OK);
if (peek() == Token::COLON && starts_with_idenfifier && expr &&
expr->AsVariableProxy() != NULL &&
!expr->AsVariableProxy()->is_this()) {
// Expression is a single identifier, and not, e.g., a parenthesized
// identifier.
VariableProxy* var = expr->AsVariableProxy();
Handle<String> label = var->name();
// TODO(1240780): We don't check for redeclaration of labels
// during preparsing since keeping track of the set of active
// labels requires nontrivial changes to the way scopes are
// structured. However, these are probably changes we want to
// make later anyway so we should go back and fix this then.
if (ContainsLabel(labels, label) || TargetStackContainsLabel(label)) {
SmartPointer<char> c_string = label->ToCString(DISALLOW_NULLS);
const char* elms[2] = { "Label", *c_string };
Vector<const char*> args(elms, 2);
ReportMessage("redeclaration", args);
*ok = false;
return NULL;
}
if (labels == NULL) labels = new ZoneStringList(4);
labels->Add(label);
// Remove the "ghost" variable that turned out to be a label
// from the top scope. This way, we don't try to resolve it
// during the scope processing.
top_scope_->RemoveUnresolved(var);
Expect(Token::COLON, CHECK_OK);
return ParseStatement(labels, ok);
}
// Parsed expression statement.
ExpectSemicolon(CHECK_OK);
return new(zone()) ExpressionStatement(expr);
}
IfStatement* Parser::ParseIfStatement(ZoneStringList* labels, bool* ok) {
// IfStatement ::
// 'if' '(' Expression ')' Statement ('else' Statement)?
Expect(Token::IF, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* condition = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* then_statement = ParseStatement(labels, CHECK_OK);
Statement* else_statement = NULL;
if (peek() == Token::ELSE) {
Next();
else_statement = ParseStatement(labels, CHECK_OK);
} else {
else_statement = EmptyStatement();
}
return new(zone()) IfStatement(condition, then_statement, else_statement);
}
Statement* Parser::ParseContinueStatement(bool* ok) {
// ContinueStatement ::
// 'continue' Identifier? ';'
Expect(Token::CONTINUE, CHECK_OK);
Handle<String> label = Handle<String>::null();
Token::Value tok = peek();
if (!scanner().has_line_terminator_before_next() &&
tok != Token::SEMICOLON && tok != Token::RBRACE && tok != Token::EOS) {
label = ParseIdentifier(CHECK_OK);
}
IterationStatement* target = NULL;
target = LookupContinueTarget(label, CHECK_OK);
if (target == NULL) {
// Illegal continue statement.
const char* message = "illegal_continue";
Vector<Handle<String> > args;
if (!label.is_null()) {
message = "unknown_label";
args = Vector<Handle<String> >(&label, 1);
}
ReportMessageAt(scanner().location(), message, args);
*ok = false;
return NULL;
}
ExpectSemicolon(CHECK_OK);
return new(zone()) ContinueStatement(target);
}
Statement* Parser::ParseBreakStatement(ZoneStringList* labels, bool* ok) {
// BreakStatement ::
// 'break' Identifier? ';'
Expect(Token::BREAK, CHECK_OK);
Handle<String> label;
Token::Value tok = peek();
if (!scanner().has_line_terminator_before_next() &&
tok != Token::SEMICOLON && tok != Token::RBRACE && tok != Token::EOS) {
label = ParseIdentifier(CHECK_OK);
}
// Parse labeled break statements that target themselves into
// empty statements, e.g. 'l1: l2: l3: break l2;'
if (!label.is_null() && ContainsLabel(labels, label)) {
return EmptyStatement();
}
BreakableStatement* target = NULL;
target = LookupBreakTarget(label, CHECK_OK);
if (target == NULL) {
// Illegal break statement.
const char* message = "illegal_break";
Vector<Handle<String> > args;
if (!label.is_null()) {
message = "unknown_label";
args = Vector<Handle<String> >(&label, 1);
}
ReportMessageAt(scanner().location(), message, args);
*ok = false;
return NULL;
}
ExpectSemicolon(CHECK_OK);
return new(zone()) BreakStatement(target);
}
Statement* Parser::ParseReturnStatement(bool* ok) {
// ReturnStatement ::
// 'return' Expression? ';'
// Consume the return token. It is necessary to do the before
// reporting any errors on it, because of the way errors are
// reported (underlining).
Expect(Token::RETURN, CHECK_OK);
// An ECMAScript program is considered syntactically incorrect if it
// contains a return statement that is not within the body of a
// function. See ECMA-262, section 12.9, page 67.
//
// To be consistent with KJS we report the syntax error at runtime.
if (!top_scope_->is_function_scope()) {
Handle<String> type = isolate()->factory()->illegal_return_symbol();
Expression* throw_error = NewThrowSyntaxError(type, Handle<Object>::null());
return new(zone()) ExpressionStatement(throw_error);
}
Token::Value tok = peek();
if (scanner().has_line_terminator_before_next() ||
tok == Token::SEMICOLON ||
tok == Token::RBRACE ||
tok == Token::EOS) {
ExpectSemicolon(CHECK_OK);
return new(zone()) ReturnStatement(GetLiteralUndefined());
}
Expression* expr = ParseExpression(true, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return new(zone()) ReturnStatement(expr);
}
Block* Parser::WithHelper(Expression* obj,
ZoneStringList* labels,
bool is_catch_block,
bool* ok) {
// Parse the statement and collect escaping labels.
ZoneList<Label*>* target_list = new ZoneList<Label*>(0);
TargetCollector collector(target_list);
Statement* stat;
{ Target target(&this->target_stack_, &collector);
with_nesting_level_++;
top_scope_->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(NULL, 2, false);
if (result != NULL) {
result->AddStatement(new(zone()) WithEnterStatement(obj, is_catch_block));
// Create body block.
Block* body = new(zone()) Block(NULL, 1, false);
body->AddStatement(stat);
// Create exit block.
Block* exit = new(zone()) Block(NULL, 1, false);
exit->AddStatement(new(zone()) WithExitStatement());
// 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
Expect(Token::WITH, CHECK_OK);
if (top_scope_->is_strict_mode()) {
ReportMessage("strict_mode_with", Vector<const char*>::empty());
*ok = false;
return NULL;
}
Expect(Token::LPAREN, CHECK_OK);
Expression* expr = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
return WithHelper(expr, labels, false, CHECK_OK);
}
CaseClause* Parser::ParseCaseClause(bool* default_seen_ptr, bool* ok) {
// CaseClause ::
// 'case' Expression ':' Statement*
// 'default' ':' Statement*
Expression* label = NULL; // NULL expression indicates default case
if (peek() == Token::CASE) {
Expect(Token::CASE, CHECK_OK);
label = ParseExpression(true, CHECK_OK);
} else {
Expect(Token::DEFAULT, CHECK_OK);
if (*default_seen_ptr) {
ReportMessage("multiple_defaults_in_switch",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
*default_seen_ptr = true;
}
Expect(Token::COLON, CHECK_OK);
int pos = scanner().location().beg_pos;
ZoneList<Statement*>* statements = new ZoneList<Statement*>(5);
while (peek() != Token::CASE &&
peek() != Token::DEFAULT &&
peek() != Token::RBRACE) {
Statement* stat = ParseStatement(NULL, CHECK_OK);
statements->Add(stat);
}
return new(zone()) CaseClause(label, statements, pos);
}
SwitchStatement* Parser::ParseSwitchStatement(ZoneStringList* labels,
bool* ok) {
// SwitchStatement ::
// 'switch' '(' Expression ')' '{' CaseClause* '}'
SwitchStatement* statement = new(zone()) SwitchStatement(labels);
Target target(&this->target_stack_, statement);
Expect(Token::SWITCH, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* tag = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
bool default_seen = false;
ZoneList<CaseClause*>* cases = new ZoneList<CaseClause*>(4);
Expect(Token::LBRACE, CHECK_OK);
while (peek() != Token::RBRACE) {
CaseClause* clause = ParseCaseClause(&default_seen, CHECK_OK);
cases->Add(clause);
}
Expect(Token::RBRACE, CHECK_OK);
if (statement) statement->Initialize(tag, cases);
return statement;
}
Statement* Parser::ParseThrowStatement(bool* ok) {
// ThrowStatement ::
// 'throw' Expression ';'
Expect(Token::THROW, CHECK_OK);
int pos = scanner().location().beg_pos;
if (scanner().has_line_terminator_before_next()) {
ReportMessage("newline_after_throw", Vector<const char*>::empty());
*ok = false;
return NULL;
}
Expression* exception = ParseExpression(true, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return new(zone()) ExpressionStatement(new(zone()) Throw(exception, pos));
}
TryStatement* Parser::ParseTryStatement(bool* ok) {
// TryStatement ::
// 'try' Block Catch
// 'try' Block Finally
// 'try' Block Catch Finally
//
// Catch ::
// 'catch' '(' Identifier ')' Block
//
// Finally ::
// 'finally' Block
Expect(Token::TRY, CHECK_OK);
ZoneList<Label*>* target_list = new ZoneList<Label*>(0);
TargetCollector collector(target_list);
Block* try_block;
{ Target target(&this->target_stack_, &collector);
try_block = ParseBlock(NULL, CHECK_OK);
}
Block* catch_block = NULL;
Variable* catch_var = NULL;
Block* finally_block = NULL;
Token::Value tok = peek();
if (tok != Token::CATCH && tok != Token::FINALLY) {
ReportMessage("no_catch_or_finally", Vector<const char*>::empty());
*ok = false;
return NULL;
}
// If we can break out from the catch block and there is a finally block,
// then we will need to collect jump targets from the catch block. Since
// we don't know yet if there will be a finally block, we always collect
// the jump targets.
ZoneList<Label*>* catch_target_list = new ZoneList<Label*>(0);
TargetCollector catch_collector(catch_target_list);
bool has_catch = false;
if (tok == Token::CATCH) {
has_catch = true;
Consume(Token::CATCH);
Expect(Token::LPAREN, CHECK_OK);
Handle<String> name = ParseIdentifier(CHECK_OK);
if (top_scope_->is_strict_mode() && IsEvalOrArguments(name)) {
ReportMessage("strict_catch_variable", Vector<const char*>::empty());
*ok = false;
return NULL;
}
Expect(Token::RPAREN, CHECK_OK);
if (peek() == Token::LBRACE) {
// Allocate a temporary for holding the finally state while
// executing the finally block.
catch_var =
top_scope_->NewTemporary(isolate()->factory()->catch_var_symbol());
Literal* name_literal = new(zone()) Literal(name);
VariableProxy* catch_var_use = new(zone()) VariableProxy(catch_var);
Expression* obj =
new(zone()) CatchExtensionObject(name_literal, catch_var_use);
{ Target target(&this->target_stack_, &catch_collector);
catch_block = WithHelper(obj, NULL, true, CHECK_OK);
}
} else {
Expect(Token::LBRACE, CHECK_OK);
}
tok = peek();
}
if (tok == Token::FINALLY || !has_catch) {
Consume(Token::FINALLY);
// Declare a variable for holding the finally state while
// executing the finally block.
finally_block = ParseBlock(NULL, CHECK_OK);
}
// Simplify the AST nodes by converting:
// 'try { } catch { } finally { }'
// to:
// 'try { try { } catch { } } finally { }'
if (catch_block != NULL && finally_block != NULL) {
VariableProxy* catch_var_defn = new(zone()) VariableProxy(catch_var);
TryCatchStatement* statement =
new(zone()) TryCatchStatement(try_block, catch_var_defn, catch_block);
statement->set_escaping_targets(collector.targets());
try_block = new(zone()) Block(NULL, 1, false);
try_block->AddStatement(statement);
catch_block = NULL;
}
TryStatement* result = NULL;
if (catch_block != NULL) {
ASSERT(finally_block == NULL);
VariableProxy* catch_var_defn = new(zone()) VariableProxy(catch_var);
result =
new(zone()) TryCatchStatement(try_block, catch_var_defn, catch_block);
result->set_escaping_targets(collector.targets());
} else {
ASSERT(finally_block != NULL);
result = new(zone()) TryFinallyStatement(try_block, finally_block);
// Add the jump targets of the try block and the catch block.
for (int i = 0; i < collector.targets()->length(); i++) {
catch_collector.AddTarget(collector.targets()->at(i));
}
result->set_escaping_targets(catch_collector.targets());
}
return result;
}
DoWhileStatement* Parser::ParseDoWhileStatement(ZoneStringList* labels,
bool* ok) {
// DoStatement ::
// 'do' Statement 'while' '(' Expression ')' ';'
DoWhileStatement* loop = new(zone()) DoWhileStatement(labels);
Target target(&this->target_stack_, loop);
Expect(Token::DO, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
Expect(Token::WHILE, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
if (loop != NULL) {
int position = scanner().location().beg_pos;
loop->set_condition_position(position);
}
Expression* cond = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
// Allow do-statements to be terminated with and without
// semi-colons. This allows code such as 'do;while(0)return' to
// parse, which would not be the case if we had used the
// ExpectSemicolon() functionality here.
if (peek() == Token::SEMICOLON) Consume(Token::SEMICOLON);
if (loop != NULL) loop->Initialize(cond, body);
return loop;
}
WhileStatement* Parser::ParseWhileStatement(ZoneStringList* labels, bool* ok) {
// WhileStatement ::
// 'while' '(' Expression ')' Statement
WhileStatement* loop = new(zone()) WhileStatement(labels);
Target target(&this->target_stack_, loop);
Expect(Token::WHILE, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* cond = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
if (loop != NULL) loop->Initialize(cond, body);
return loop;
}
Statement* Parser::ParseForStatement(ZoneStringList* labels, bool* ok) {
// ForStatement ::
// 'for' '(' Expression? ';' Expression? ';' Expression? ')' Statement
Statement* init = NULL;
Expect(Token::FOR, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
if (peek() != Token::SEMICOLON) {
if (peek() == Token::VAR || peek() == Token::CONST) {
Expression* each = NULL;
Block* variable_statement =
ParseVariableDeclarations(false, &each, CHECK_OK);
if (peek() == Token::IN && each != NULL) {
ForInStatement* loop = new(zone()) ForInStatement(labels);
Target target(&this->target_stack_, loop);
Expect(Token::IN, CHECK_OK);
Expression* enumerable = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
loop->Initialize(each, enumerable, body);
Block* result = new(zone()) Block(NULL, 2, false);
result->AddStatement(variable_statement);
result->AddStatement(loop);
// Parsed for-in loop w/ variable/const declaration.
return result;
} else {
init = variable_statement;
}
} else {
Expression* expression = ParseExpression(false, CHECK_OK);
if (peek() == Token::IN) {
// Signal a reference error if the expression is an invalid
// left-hand side expression. We could report this as a syntax
// error here but for compatibility with JSC we choose to report
// the error at runtime.
if (expression == NULL || !expression->IsValidLeftHandSide()) {
Handle<String> type =
isolate()->factory()->invalid_lhs_in_for_in_symbol();
expression = NewThrowReferenceError(type);
}
ForInStatement* loop = new(zone()) ForInStatement(labels);
Target target(&this->target_stack_, loop);
Expect(Token::IN, CHECK_OK);
Expression* enumerable = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
if (loop) loop->Initialize(expression, enumerable, body);
// Parsed for-in loop.
return loop;
} else {
init = new(zone()) ExpressionStatement(expression);
}
}
}
// Standard 'for' loop
ForStatement* loop = new(zone()) ForStatement(labels);
Target target(&this->target_stack_, loop);
// Parsed initializer at this point.
Expect(Token::SEMICOLON, CHECK_OK);
Expression* cond = NULL;
if (peek() != Token::SEMICOLON) {
cond = ParseExpression(true, CHECK_OK);
}
Expect(Token::SEMICOLON, CHECK_OK);
Statement* next = NULL;
if (peek() != Token::RPAREN) {
Expression* exp = ParseExpression(true, CHECK_OK);
next = new(zone()) ExpressionStatement(exp);
}
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
if (loop) loop->Initialize(init, cond, next, body);
return loop;
}
// Precedence = 1
Expression* Parser::ParseExpression(bool accept_IN, bool* ok) {
// Expression ::
// AssignmentExpression
// Expression ',' AssignmentExpression
Expression* result = ParseAssignmentExpression(accept_IN, CHECK_OK);
while (peek() == Token::COMMA) {
Expect(Token::COMMA, CHECK_OK);
int position = scanner().location().beg_pos;
Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
result = new(zone()) BinaryOperation(Token::COMMA, result, right, position);
}
return result;
}
// Precedence = 2
Expression* Parser::ParseAssignmentExpression(bool accept_IN, bool* ok) {
// AssignmentExpression ::
// ConditionalExpression
// LeftHandSideExpression AssignmentOperator AssignmentExpression
if (fni_ != NULL) fni_->Enter();
Expression* expression = ParseConditionalExpression(accept_IN, CHECK_OK);
if (!Token::IsAssignmentOp(peek())) {
if (fni_ != NULL) fni_->Leave();
// Parsed conditional expression only (no assignment).
return expression;
}
// Signal a reference error if the expression is an invalid left-hand
// side expression. We could report this as a syntax error here but
// for compatibility with JSC we choose to report the error at
// runtime.
if (expression == NULL || !expression->IsValidLeftHandSide()) {
Handle<String> type =
isolate()->factory()->invalid_lhs_in_assignment_symbol();
expression = NewThrowReferenceError(type);
}
if (top_scope_->is_strict_mode()) {
// Assignment to eval or arguments is disallowed in strict mode.
CheckStrictModeLValue(expression, "strict_lhs_assignment", CHECK_OK);
}
Token::Value op = Next(); // Get assignment operator.
int pos = scanner().location().beg_pos;
Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
// TODO(1231235): We try to estimate the set of properties set by
// constructors. We define a new property whenever there is an
// assignment to a property of 'this'. We should probably only add
// properties if we haven't seen them before. Otherwise we'll
// probably overestimate the number of properties.
Property* property = expression ? expression->AsProperty() : NULL;
if (op == Token::ASSIGN &&
property != NULL &&
property->obj()->AsVariableProxy() != NULL &&
property->obj()->AsVariableProxy()->is_this()) {
lexical_scope_->AddProperty();
}
// If we assign a function literal to a property we pretenure the
// literal so it can be added as a constant function property.
if (property != NULL && right->AsFunctionLiteral() != NULL) {
right->AsFunctionLiteral()->set_pretenure(true);
}
if (fni_ != NULL) {
// Check if the right hand side is a call to avoid inferring a
// name if we're dealing with "a = function(){...}();"-like
// expression.
if ((op == Token::INIT_VAR
|| op == Token::INIT_CONST
|| op == Token::ASSIGN)
&& (right->AsCall() == NULL)) {
fni_->Infer();
}
fni_->Leave();
}
return new(zone()) Assignment(op, expression, right, pos);
}
// Precedence = 3
Expression* Parser::ParseConditionalExpression(bool accept_IN, bool* ok) {
// ConditionalExpression ::
// LogicalOrExpression
// LogicalOrExpression '?' AssignmentExpression ':' AssignmentExpression
// We start using the binary expression parser for prec >= 4 only!
Expression* expression = ParseBinaryExpression(4, accept_IN, CHECK_OK);
if (peek() != Token::CONDITIONAL) return expression;
Consume(Token::CONDITIONAL);
// In parsing the first assignment expression in conditional
// expressions we always accept the 'in' keyword; see ECMA-262,
// section 11.12, page 58.
int left_position = scanner().peek_location().beg_pos;
Expression* left = ParseAssignmentExpression(true, CHECK_OK);
Expect(Token::COLON, CHECK_OK);
int right_position = scanner().peek_location().beg_pos;
Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
return new(zone()) Conditional(expression, left, right,
left_position, right_position);
}
static int Precedence(Token::Value tok, bool accept_IN) {
if (tok == Token::IN && !accept_IN)
return 0; // 0 precedence will terminate binary expression parsing
return Token::Precedence(tok);
}
// Precedence >= 4
Expression* Parser::ParseBinaryExpression(int prec, bool accept_IN, bool* ok) {
ASSERT(prec >= 4);
Expression* x = ParseUnaryExpression(CHECK_OK);
for (int prec1 = Precedence(peek(), accept_IN); prec1 >= prec; prec1--) {
// prec1 >= 4
while (Precedence(peek(), accept_IN) == prec1) {
Token::Value op = Next();
int position = scanner().location().beg_pos;
Expression* y = ParseBinaryExpression(prec1 + 1, accept_IN, CHECK_OK);
// Compute some expressions involving only number literals.
if (x && x->AsLiteral() && x->AsLiteral()->handle()->IsNumber() &&
y && y->AsLiteral() && y->AsLiteral()->handle()->IsNumber()) {
double x_val = x->AsLiteral()->handle()->Number();
double y_val = y->AsLiteral()->handle()->Number();
switch (op) {
case Token::ADD:
x = NewNumberLiteral(x_val + y_val);
continue;
case Token::SUB:
x = NewNumberLiteral(x_val - y_val);
continue;
case Token::MUL:
x = NewNumberLiteral(x_val * y_val);
continue;
case Token::DIV:
x = NewNumberLiteral(x_val / y_val);
continue;
case Token::BIT_OR:
x = NewNumberLiteral(DoubleToInt32(x_val) | DoubleToInt32(y_val));
continue;
case Token::BIT_AND:
x = NewNumberLiteral(DoubleToInt32(x_val) & DoubleToInt32(y_val));
continue;
case Token::BIT_XOR:
x = NewNumberLiteral(DoubleToInt32(x_val) ^ DoubleToInt32(y_val));
continue;
case Token::SHL: {
int value = DoubleToInt32(x_val) << (DoubleToInt32(y_val) & 0x1f);
x = NewNumberLiteral(value);
continue;
}
case Token::SHR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
uint32_t value = DoubleToUint32(x_val) >> shift;
x = NewNumberLiteral(value);
continue;
}
case Token::SAR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
int value = ArithmeticShiftRight(DoubleToInt32(x_val), shift);
x = NewNumberLiteral(value);
continue;
}
default:
break;
}
}
// For now we distinguish between comparisons and other binary
// operations. (We could combine the two and get rid of this
// code and AST node eventually.)
if (Token::IsCompareOp(op)) {
// We have a comparison.
Token::Value cmp = op;
switch (op) {
case Token::NE: cmp = Token::EQ; break;
case Token::NE_STRICT: cmp = Token::EQ_STRICT; break;
default: break;
}
x = NewCompareNode(cmp, x, y, position);
if (cmp != op) {
// The comparison was negated - add a NOT.
x = new(zone()) UnaryOperation(Token::NOT, x);
}
} else {
// We have a "normal" binary operation.
x = new(zone()) BinaryOperation(op, x, y, position);
}
}
}
return x;
}
Expression* Parser::NewCompareNode(Token::Value op,
Expression* x,
Expression* y,
int position) {
ASSERT(op != Token::NE && op != Token::NE_STRICT);
if (op == Token::EQ || op == Token::EQ_STRICT) {
bool is_strict = (op == Token::EQ_STRICT);
Literal* x_literal = x->AsLiteral();
if (x_literal != NULL && x_literal->IsNull()) {
return new(zone()) CompareToNull(is_strict, y);
}
Literal* y_literal = y->AsLiteral();
if (y_literal != NULL && y_literal->IsNull()) {
return new(zone()) CompareToNull(is_strict, x);
}
}
return new(zone()) CompareOperation(op, x, y, position);
}
Expression* Parser::ParseUnaryExpression(bool* ok) {
// UnaryExpression ::
// PostfixExpression
// 'delete' UnaryExpression
// 'void' UnaryExpression
// 'typeof' UnaryExpression
// '++' UnaryExpression
// '--' UnaryExpression
// '+' UnaryExpression
// '-' UnaryExpression
// '~' UnaryExpression
// '!' UnaryExpression
Token::Value op = peek();
if (Token::IsUnaryOp(op)) {
op = Next();
Expression* expression = ParseUnaryExpression(CHECK_OK);
// Compute some expressions involving only number literals.
if (expression != NULL && expression->AsLiteral() &&
expression->AsLiteral()->handle()->IsNumber()) {
double value = expression->AsLiteral()->handle()->Number();
switch (op) {
case Token::ADD:
return expression;
case Token::SUB:
return NewNumberLiteral(-value);
case Token::BIT_NOT:
return NewNumberLiteral(~DoubleToInt32(value));
default: break;
}
}
// "delete identifier" is a syntax error in strict mode.
if (op == Token::DELETE && top_scope_->is_strict_mode()) {
VariableProxy* operand = expression->AsVariableProxy();
if (operand != NULL && !operand->is_this()) {
ReportMessage("strict_delete", Vector<const char*>::empty());
*ok = false;
return NULL;
}
}
return new(zone()) UnaryOperation(op, expression);
} else if (Token::IsCountOp(op)) {
op = Next();
Expression* expression = ParseUnaryExpression(CHECK_OK);
// Signal a reference error if the expression is an invalid
// left-hand side expression. We could report this as a syntax
// error here but for compatibility with JSC we choose to report the
// error at runtime.
if (expression == NULL || !expression->IsValidLeftHandSide()) {
Handle<String> type =
isolate()->factory()->invalid_lhs_in_prefix_op_symbol();
expression = NewThrowReferenceError(type);
}
if (top_scope_->is_strict_mode()) {
// Prefix expression operand in strict mode may not be eval or arguments.
CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
}
int position = scanner().location().beg_pos;
return new(zone()) CountOperation(op,
true /* prefix */,
expression,
position);
} else {
return ParsePostfixExpression(ok);
}
}
Expression* Parser::ParsePostfixExpression(bool* ok) {
// PostfixExpression ::
// LeftHandSideExpression ('++' | '--')?
Expression* expression = ParseLeftHandSideExpression(CHECK_OK);
if (!scanner().has_line_terminator_before_next() &&
Token::IsCountOp(peek())) {
// Signal a reference error if the expression is an invalid
// left-hand side expression. We could report this as a syntax
// error here but for compatibility with JSC we choose to report the
// error at runtime.
if (expression == NULL || !expression->IsValidLeftHandSide()) {
Handle<String> type =
isolate()->factory()->invalid_lhs_in_postfix_op_symbol();
expression = NewThrowReferenceError(type);
}
if (top_scope_->is_strict_mode()) {
// Postfix expression operand in strict mode may not be eval or arguments.
CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
}
Token::Value next = Next();
int position = scanner().location().beg_pos;
expression =
new(zone()) CountOperation(next,
false /* postfix */,
expression,
position);
}
return expression;
}
Expression* Parser::ParseLeftHandSideExpression(bool* ok) {
// LeftHandSideExpression ::
// (NewExpression | MemberExpression) ...
Expression* result;
if (peek() == Token::NEW) {
result = ParseNewExpression(CHECK_OK);
} else {
result = ParseMemberExpression(CHECK_OK);
}
while (true) {
switch (peek()) {
case Token::LBRACK: {
Consume(Token::LBRACK);
int pos = scanner().location().beg_pos;
Expression* index = ParseExpression(true, CHECK_OK);
result = new(zone()) Property(result, index, pos);
Expect(Token::RBRACK, CHECK_OK);
break;
}
case Token::LPAREN: {
int pos = scanner().location().beg_pos;
ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
// Keep track of eval() calls since they disable all local variable
// optimizations.
// The calls that need special treatment are the
// direct (i.e. not aliased) eval calls. These calls are all of the
// form eval(...) with no explicit receiver object where eval is not
// declared in the current scope chain.
// These calls are marked as potentially direct eval calls. Whether
// they are actually direct calls to eval is determined at run time.
// TODO(994): In ES5, it doesn't matter if the "eval" var is declared
// in the local scope chain. It only matters that it's called "eval",
// is called without a receiver and it refers to the original eval
// function.
VariableProxy* callee = result->AsVariableProxy();
if (callee != NULL &&
callee->IsVariable(isolate()->factory()->eval_symbol())) {
Handle<String> name = callee->name();
Variable* var = top_scope_->Lookup(name);
if (var == NULL) {
top_scope_->RecordEvalCall();
}
}
result = NewCall(result, args, pos);
break;
}
case Token::PERIOD: {
Consume(Token::PERIOD);
int pos = scanner().location().beg_pos;
Handle<String> name = ParseIdentifierName(CHECK_OK);
result = new(zone()) Property(result, new(zone()) Literal(name), pos);
if (fni_ != NULL) fni_->PushLiteralName(name);
break;
}
default:
return result;
}
}
}
Expression* Parser::ParseNewPrefix(PositionStack* stack, bool* ok) {
// NewExpression ::
// ('new')+ MemberExpression
// The grammar for new expressions is pretty warped. The keyword
// 'new' can either be a part of the new expression (where it isn't
// followed by an argument list) or a part of the member expression,
// where it must be followed by an argument list. To accommodate
// this, we parse the 'new' keywords greedily and keep track of how
// many we have parsed. This information is then passed on to the
// member expression parser, which is only allowed to match argument
// lists as long as it has 'new' prefixes left
Expect(Token::NEW, CHECK_OK);
PositionStack::Element pos(stack, scanner().location().beg_pos);
Expression* result;
if (peek() == Token::NEW) {
result = ParseNewPrefix(stack, CHECK_OK);
} else {
result = ParseMemberWithNewPrefixesExpression(stack, CHECK_OK);
}
if (!stack->is_empty()) {
int last = stack->pop();
result = new(zone()) CallNew(result, new ZoneList<Expression*>(0), last);
}
return result;
}
Expression* Parser::ParseNewExpression(bool* ok) {
PositionStack stack(ok);
return ParseNewPrefix(&stack, ok);
}
Expression* Parser::ParseMemberExpression(bool* ok) {
return ParseMemberWithNewPrefixesExpression(NULL, ok);
}
Expression* Parser::ParseMemberWithNewPrefixesExpression(PositionStack* stack,
bool* ok) {
// MemberExpression ::
// (PrimaryExpression | FunctionLiteral)
// ('[' Expression ']' | '.' Identifier | Arguments)*
// Parse the initial primary or function expression.
Expression* result = NULL;
if (peek() == Token::FUNCTION) {
Expect(Token::FUNCTION, CHECK_OK);
int function_token_position = scanner().location().beg_pos;
Handle<String> name;
bool is_reserved_name = false;
if (peek_any_identifier()) {
name = ParseIdentifierOrReservedWord(&is_reserved_name, CHECK_OK);
}
result = ParseFunctionLiteral(name, is_reserved_name,
function_token_position, NESTED, CHECK_OK);
} else {
result = ParsePrimaryExpression(CHECK_OK);
}
while (true) {
switch (peek()) {
case Token::LBRACK: {
Consume(Token::LBRACK);
int pos = scanner().location().beg_pos;
Expression* index = ParseExpression(true, CHECK_OK);
result = new(zone()) Property(result, index, pos);
Expect(Token::RBRACK, CHECK_OK);
break;
}
case Token::PERIOD: {
Consume(Token::PERIOD);
int pos = scanner().location().beg_pos;
Handle<String> name = ParseIdentifierName(CHECK_OK);
result = new(zone()) Property(result, new(zone()) Literal(name), pos);
if (fni_ != NULL) fni_->PushLiteralName(name);
break;
}
case Token::LPAREN: {
if ((stack == NULL) || stack->is_empty()) return result;
// Consume one of the new prefixes (already parsed).
ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
int last = stack->pop();
result = new CallNew(result, args, last);
break;
}
default:
return result;
}
}
}
DebuggerStatement* Parser::ParseDebuggerStatement(bool* ok) {
// In ECMA-262 'debugger' is defined as a reserved keyword. In some browser
// contexts this is used as a statement which invokes the debugger as i a
// break point is present.
// DebuggerStatement ::
// 'debugger' ';'
Expect(Token::DEBUGGER, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return new(zone()) DebuggerStatement();
}
void Parser::ReportUnexpectedToken(Token::Value token) {
// We don't report stack overflows here, to avoid increasing the
// stack depth even further. Instead we report it after parsing is
// over, in ParseProgram/ParseJson.
if (token == Token::ILLEGAL && stack_overflow_) return;
// Four of the tokens are treated specially
switch (token) {
case Token::EOS:
return ReportMessage("unexpected_eos", Vector<const char*>::empty());
case Token::NUMBER:
return ReportMessage("unexpected_token_number",
Vector<const char*>::empty());
case Token::STRING:
return ReportMessage("unexpected_token_string",
Vector<const char*>::empty());
case Token::IDENTIFIER:
return ReportMessage("unexpected_token_identifier",
Vector<const char*>::empty());
case Token::FUTURE_RESERVED_WORD:
return ReportMessage(top_scope_->is_strict_mode() ?
"unexpected_strict_reserved" :
"unexpected_token_identifier",
Vector<const char*>::empty());
default:
const char* name = Token::String(token);
ASSERT(name != NULL);
ReportMessage("unexpected_token", Vector<const char*>(&name, 1));
}
}
void Parser::ReportInvalidPreparseData(Handle<String> name, bool* ok) {
SmartPointer<char> name_string = name->ToCString(DISALLOW_NULLS);
const char* element[1] = { *name_string };
ReportMessage("invalid_preparser_data",
Vector<const char*>(element, 1));
*ok = false;
}
Expression* Parser::ParsePrimaryExpression(bool* ok) {
// PrimaryExpression ::
// 'this'
// 'null'
// 'true'
// 'false'
// Identifier
// Number
// String
// ArrayLiteral
// ObjectLiteral
// RegExpLiteral
// '(' Expression ')'
Expression* result = NULL;
switch (peek()) {
case Token::THIS: {
Consume(Token::THIS);
VariableProxy* recv = top_scope_->receiver();
result = recv;
break;
}
case Token::NULL_LITERAL:
Consume(Token::NULL_LITERAL);
result = new(zone()) Literal(isolate()->factory()->null_value());
break;
case Token::TRUE_LITERAL:
Consume(Token::TRUE_LITERAL);
result = new(zone()) Literal(isolate()->factory()->true_value());
break;
case Token::FALSE_LITERAL:
Consume(Token::FALSE_LITERAL);
result = new(zone()) Literal(isolate()->factory()->false_value());
break;
case Token::IDENTIFIER:
case Token::FUTURE_RESERVED_WORD: {
Handle<String> name = ParseIdentifier(CHECK_OK);
if (fni_ != NULL) fni_->PushVariableName(name);
result = top_scope_->NewUnresolved(name,
inside_with(),
scanner().location().beg_pos);
break;
}
case Token::NUMBER: {
Consume(Token::NUMBER);
ASSERT(scanner().is_literal_ascii());
double value = StringToDouble(isolate()->unicode_cache(),
scanner().literal_ascii_string(),
ALLOW_HEX | ALLOW_OCTALS);
result = NewNumberLiteral(value);
break;
}
case Token::STRING: {
Consume(Token::STRING);
Handle<String> symbol = GetSymbol(CHECK_OK);
result = new(zone()) Literal(symbol);
if (fni_ != NULL) fni_->PushLiteralName(symbol);
break;
}
case Token::ASSIGN_DIV:
result = ParseRegExpLiteral(true, CHECK_OK);
break;
case Token::DIV:
result = ParseRegExpLiteral(false, CHECK_OK);
break;
case Token::LBRACK:
result = ParseArrayLiteral(CHECK_OK);
break;
case Token::LBRACE:
result = ParseObjectLiteral(CHECK_OK);
break;
case Token::LPAREN:
Consume(Token::LPAREN);
// Heuristically try to detect immediately called functions before
// seeing the call parentheses.
parenthesized_function_ = (peek() == Token::FUNCTION);
result = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
break;
case Token::MOD:
if (allow_natives_syntax_ || extension_ != NULL) {
result = ParseV8Intrinsic(CHECK_OK);
break;
}
// If we're not allowing special syntax we fall-through to the
// default case.
default: {
Token::Value tok = Next();
ReportUnexpectedToken(tok);
*ok = false;
return NULL;
}
}
return result;
}
void Parser::BuildArrayLiteralBoilerplateLiterals(ZoneList<Expression*>* values,
Handle<FixedArray> literals,
bool* is_simple,
int* depth) {
// Fill in the literals.
// Accumulate output values in local variables.
bool is_simple_acc = true;
int depth_acc = 1;
for (int i = 0; i < values->length(); i++) {
MaterializedLiteral* m_literal = values->at(i)->AsMaterializedLiteral();
if (m_literal != NULL && m_literal->depth() >= depth_acc) {
depth_acc = m_literal->depth() + 1;
}
Handle<Object> boilerplate_value = GetBoilerplateValue(values->at(i));
if (boilerplate_value->IsUndefined()) {
literals->set_the_hole(i);
is_simple_acc = false;
} else {
literals->set(i, *boilerplate_value);
}
}
*is_simple = is_simple_acc;
*depth = depth_acc;
}
Expression* Parser::ParseArrayLiteral(bool* ok) {
// ArrayLiteral ::
// '[' Expression? (',' Expression?)* ']'
ZoneList<Expression*>* values = new ZoneList<Expression*>(4);
Expect(Token::LBRACK, CHECK_OK);
while (peek() != Token::RBRACK) {
Expression* elem;
if (peek() == Token::COMMA) {
elem = GetLiteralTheHole();
} else {
elem = ParseAssignmentExpression(true, CHECK_OK);
}
values->Add(elem);
if (peek() != Token::RBRACK) {
Expect(Token::COMMA, CHECK_OK);
}
}
Expect(Token::RBRACK, CHECK_OK);
// Update the scope information before the pre-parsing bailout.
int literal_index = lexical_scope_->NextMaterializedLiteralIndex();
// Allocate a fixed array with all the literals.
Handle<FixedArray> literals =
isolate()->factory()->NewFixedArray(values->length(), TENURED);
// Fill in the literals.
bool is_simple = true;
int depth = 1;
for (int i = 0, n = values->length(); i < n; i++) {
MaterializedLiteral* m_literal = values->at(i)->AsMaterializedLiteral();
if (m_literal != NULL && m_literal->depth() + 1 > depth) {
depth = m_literal->depth() + 1;
}
Handle<Object> boilerplate_value = GetBoilerplateValue(values->at(i));
if (boilerplate_value->IsUndefined()) {
literals->set_the_hole(i);
is_simple = false;
} else {
literals->set(i, *boilerplate_value);
}
}
// Simple and shallow arrays can be lazily copied, we transform the
// elements array to a copy-on-write array.
if (is_simple && depth == 1 && values->length() > 0) {
literals->set_map(isolate()->heap()->fixed_cow_array_map());
}
return new(zone()) ArrayLiteral(literals, values,
literal_index, is_simple, depth);
}
bool Parser::IsBoilerplateProperty(ObjectLiteral::Property* property) {
return property != NULL &&
property->kind() != ObjectLiteral::Property::PROTOTYPE;
}
bool CompileTimeValue::IsCompileTimeValue(Expression* expression) {
if (expression->AsLiteral() != NULL) return true;
MaterializedLiteral* lit = expression->AsMaterializedLiteral();
return lit != NULL && lit->is_simple();
}
bool CompileTimeValue::ArrayLiteralElementNeedsInitialization(
Expression* value) {
// If value is a literal the property value is already set in the
// boilerplate object.
if (value->AsLiteral() != NULL) return false;
// If value is a materialized literal the property value is already set
// in the boilerplate object if it is simple.
if (CompileTimeValue::IsCompileTimeValue(value)) return false;
return true;
}
Handle<FixedArray> CompileTimeValue::GetValue(Expression* expression) {
ASSERT(IsCompileTimeValue(expression));
Handle<FixedArray> result = FACTORY->NewFixedArray(2, TENURED);
ObjectLiteral* object_literal = expression->AsObjectLiteral();
if (object_literal != NULL) {
ASSERT(object_literal->is_simple());
if (object_literal->fast_elements()) {
result->set(kTypeSlot, Smi::FromInt(OBJECT_LITERAL_FAST_ELEMENTS));
} else {
result->set(kTypeSlot, Smi::FromInt(OBJECT_LITERAL_SLOW_ELEMENTS));
}
result->set(kElementsSlot, *object_literal->constant_properties());
} else {
ArrayLiteral* array_literal = expression->AsArrayLiteral();
ASSERT(array_literal != NULL && array_literal->is_simple());
result->set(kTypeSlot, Smi::FromInt(ARRAY_LITERAL));
result->set(kElementsSlot, *array_literal->constant_elements());
}
return result;
}
CompileTimeValue::Type CompileTimeValue::GetType(Handle<FixedArray> value) {
Smi* type_value = Smi::cast(value->get(kTypeSlot));
return static_cast<Type>(type_value->value());
}
Handle<FixedArray> CompileTimeValue::GetElements(Handle<FixedArray> value) {
return Handle<FixedArray>(FixedArray::cast(value->get(kElementsSlot)));
}
Handle<Object> Parser::GetBoilerplateValue(Expression* expression) {
if (expression->AsLiteral() != NULL) {
return expression->AsLiteral()->handle();
}
if (CompileTimeValue::IsCompileTimeValue(expression)) {
return CompileTimeValue::GetValue(expression);
}
return isolate()->factory()->undefined_value();
}
// Defined in ast.cc
bool IsEqualString(void* first, void* second);
bool IsEqualNumber(void* first, void* second);
// Validation per 11.1.5 Object Initialiser
class ObjectLiteralPropertyChecker {
public:
ObjectLiteralPropertyChecker(Parser* parser, bool strict) :
props(&IsEqualString),
elems(&IsEqualNumber),
parser_(parser),
strict_(strict) {
}
void CheckProperty(
ObjectLiteral::Property* property,
Scanner::Location loc,
bool* ok);
private:
enum PropertyKind {
kGetAccessor = 0x01,
kSetAccessor = 0x02,
kAccessor = kGetAccessor | kSetAccessor,
kData = 0x04
};
static intptr_t GetPropertyKind(ObjectLiteral::Property* property) {
switch (property->kind()) {
case ObjectLiteral::Property::GETTER:
return kGetAccessor;
case ObjectLiteral::Property::SETTER:
return kSetAccessor;
default:
return kData;
}
}
HashMap props;
HashMap elems;
Parser* parser_;
bool strict_;
};
void ObjectLiteralPropertyChecker::CheckProperty(
ObjectLiteral::Property* property,
Scanner::Location loc,
bool* ok) {
ASSERT(property != NULL);
Literal *lit = property->key();
Handle<Object> handle = lit->handle();
uint32_t hash;
HashMap* map;
void* key;
if (handle->IsSymbol()) {
Handle<String> name(String::cast(*handle));
if (name->AsArrayIndex(&hash)) {
Handle<Object> key_handle = FACTORY->NewNumberFromUint(hash);
key = key_handle.location();
map = &elems;
} else {
key = handle.location();
hash = name->Hash();
map = &props;
}
} else if (handle->ToArrayIndex(&hash)) {
key = handle.location();
map = &elems;
} else {
ASSERT(handle->IsNumber());
double num = handle->Number();
char arr[100];
Vector<char> buffer(arr, ARRAY_SIZE(arr));
const char* str = DoubleToCString(num, buffer);
Handle<String> name = FACTORY->NewStringFromAscii(CStrVector(str));
key = name.location();
hash = name->Hash();
map = &props;
}
// Lookup property previously defined, if any.
HashMap::Entry* entry = map->Lookup(key, hash, true);
intptr_t prev = reinterpret_cast<intptr_t> (entry->value);
intptr_t curr = GetPropertyKind(property);
// Duplicate data properties are illegal in strict mode.
if (strict_ && (curr & prev & kData) != 0) {
parser_->ReportMessageAt(loc, "strict_duplicate_property",
Vector<const char*>::empty());
*ok = false;
return;
}
// Data property conflicting with an accessor.
if (((curr & kData) && (prev & kAccessor)) ||
((prev & kData) && (curr & kAccessor))) {
parser_->ReportMessageAt(loc, "accessor_data_property",
Vector<const char*>::empty());
*ok = false;
return;
}
// Two accessors of the same type conflicting
if ((curr & prev & kAccessor) != 0) {
parser_->ReportMessageAt(loc, "accessor_get_set",
Vector<const char*>::empty());
*ok = false;
return;
}
// Update map
entry->value = reinterpret_cast<void*> (prev | curr);
*ok = true;
}
void Parser::BuildObjectLiteralConstantProperties(
ZoneList<ObjectLiteral::Property*>* properties,
Handle<FixedArray> constant_properties,
bool* is_simple,
bool* fast_elements,
int* depth) {
int position = 0;
// Accumulate the value in local variables and store it at the end.
bool is_simple_acc = true;
int depth_acc = 1;
uint32_t max_element_index = 0;
uint32_t elements = 0;
for (int i = 0; i < properties->length(); i++) {
ObjectLiteral::Property* property = properties->at(i);
if (!IsBoilerplateProperty(property)) {
is_simple_acc = false;
continue;
}
MaterializedLiteral* m_literal = property->value()->AsMaterializedLiteral();
if (m_literal != NULL && m_literal->depth() >= depth_acc) {
depth_acc = m_literal->depth() + 1;
}
// Add CONSTANT and COMPUTED properties to boilerplate. Use undefined
// value for COMPUTED properties, the real value is filled in at
// runtime. The enumeration order is maintained.
Handle<Object> key = property->key()->handle();
Handle<Object> value = GetBoilerplateValue(property->value());
is_simple_acc = is_simple_acc && !value->IsUndefined();
// Keep track of the number of elements in the object literal and
// the largest element index. If the largest element index is
// much larger than the number of elements, creating an object
// literal with fast elements will be a waste of space.
uint32_t element_index = 0;
if (key->IsString()
&& Handle<String>::cast(key)->AsArrayIndex(&element_index)
&& element_index > max_element_index) {
max_element_index = element_index;
elements++;
} else if (key->IsSmi()) {
int key_value = Smi::cast(*key)->value();
if (key_value > 0
&& static_cast<uint32_t>(key_value) > max_element_index) {
max_element_index = key_value;
}
elements++;
}
// Add name, value pair to the fixed array.
constant_properties->set(position++, *key);
constant_properties->set(position++, *value);
}
*fast_elements =
(max_element_index <= 32) || ((2 * elements) >= max_element_index);
*is_simple = is_simple_acc;
*depth = depth_acc;
}
ObjectLiteral::Property* Parser::ParseObjectLiteralGetSet(bool is_getter,
bool* ok) {
// Special handling of getter and setter syntax:
// { ... , get foo() { ... }, ... , set foo(v) { ... v ... } , ... }
// We have already read the "get" or "set" keyword.
Token::Value next = Next();
bool is_keyword = Token::IsKeyword(next);
if (next == Token::IDENTIFIER || next == Token::NUMBER ||
next == Token::FUTURE_RESERVED_WORD ||
next == Token::STRING || is_keyword) {
Handle<String> name;
if (is_keyword) {
name = isolate_->factory()->LookupAsciiSymbol(Token::String(next));
} else {
name = GetSymbol(CHECK_OK);
}
FunctionLiteral* value =
ParseFunctionLiteral(name,
false, // reserved words are allowed here
RelocInfo::kNoPosition,
DECLARATION,
CHECK_OK);
// Allow any number of parameters for compatiabilty with JSC.
// Specification only allows zero parameters for get and one for set.
ObjectLiteral::Property* property =
new(zone()) ObjectLiteral::Property(is_getter, value);
return property;
} else {
ReportUnexpectedToken(next);
*ok = false;
return NULL;
}
}
Expression* Parser::ParseObjectLiteral(bool* ok) {
// ObjectLiteral ::
// '{' (
// ((IdentifierName | String | Number) ':' AssignmentExpression)
// | (('get' | 'set') (IdentifierName | String | Number) FunctionLiteral)
// )*[','] '}'
ZoneList<ObjectLiteral::Property*>* properties =
new ZoneList<ObjectLiteral::Property*>(4);
int number_of_boilerplate_properties = 0;
bool has_function = false;
ObjectLiteralPropertyChecker checker(this, top_scope_->is_strict_mode());
Expect(Token::LBRACE, CHECK_OK);
Scanner::Location loc = scanner().location();
while (peek() != Token::RBRACE) {
if (fni_ != NULL) fni_->Enter();
Literal* key = NULL;
Token::Value next = peek();
// Location of the property name token
Scanner::Location loc = scanner().peek_location();
switch (next) {
case Token::FUTURE_RESERVED_WORD:
case Token::IDENTIFIER: {
bool is_getter = false;
bool is_setter = false;
Handle<String> id =
ParseIdentifierOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
if (fni_ != NULL) fni_->PushLiteralName(id);
if ((is_getter || is_setter) && peek() != Token::COLON) {
// Update loc to point to the identifier
loc = scanner().peek_location();
ObjectLiteral::Property* property =
ParseObjectLiteralGetSet(is_getter, CHECK_OK);
if (IsBoilerplateProperty(property)) {
number_of_boilerplate_properties++;
}
// Validate the property.
checker.CheckProperty(property, loc, CHECK_OK);
properties->Add(property);
if (peek() != Token::RBRACE) Expect(Token::COMMA, CHECK_OK);
if (fni_ != NULL) {
fni_->Infer();
fni_->Leave();
}
continue; // restart the while
}
// Failed to parse as get/set property, so it's just a property
// called "get" or "set".
key = new(zone()) Literal(id);
break;
}
case Token::STRING: {
Consume(Token::STRING);
Handle<String> string = GetSymbol(CHECK_OK);
if (fni_ != NULL) fni_->PushLiteralName(string);
uint32_t index;
if (!string.is_null() && string->AsArrayIndex(&index)) {
key = NewNumberLiteral(index);
break;
}
key = new(zone()) Literal(string);
break;
}
case Token::NUMBER: {
Consume(Token::NUMBER);
ASSERT(scanner().is_literal_ascii());
double value = StringToDouble(isolate()->unicode_cache(),
scanner().literal_ascii_string(),
ALLOW_HEX | ALLOW_OCTALS);
key = NewNumberLiteral(value);
break;
}
default:
if (Token::IsKeyword(next)) {
Consume(next);
Handle<String> string = GetSymbol(CHECK_OK);
key = new(zone()) Literal(string);
} else {
// Unexpected token.
Token::Value next = Next();
ReportUnexpectedToken(next);
*ok = false;
return NULL;
}
}
Expect(Token::COLON, CHECK_OK);
Expression* value = ParseAssignmentExpression(true, CHECK_OK);
ObjectLiteral::Property* property =
new(zone()) ObjectLiteral::Property(key, value);
// Mark object literals that contain function literals and pretenure the
// literal so it can be added as a constant function property.
if (value->AsFunctionLiteral() != NULL) {
has_function = true;
value->AsFunctionLiteral()->set_pretenure(true);
}
// Count CONSTANT or COMPUTED properties to maintain the enumeration order.
if (IsBoilerplateProperty(property)) number_of_boilerplate_properties++;
// Validate the property
checker.CheckProperty(property, loc, CHECK_OK);
properties->Add(property);
// TODO(1240767): Consider allowing trailing comma.
if (peek() != Token::RBRACE) Expect(Token::COMMA, CHECK_OK);
if (fni_ != NULL) {
fni_->Infer();
fni_->Leave();
}
}
Expect(Token::RBRACE, CHECK_OK);
// Computation of literal_index must happen before pre parse bailout.
int literal_index = lexical_scope_->NextMaterializedLiteralIndex();
Handle<FixedArray> constant_properties = isolate()->factory()->NewFixedArray(
number_of_boilerplate_properties * 2, TENURED);
bool is_simple = true;
bool fast_elements = true;
int depth = 1;
BuildObjectLiteralConstantProperties(properties,
constant_properties,
&is_simple,
&fast_elements,
&depth);
return new(zone()) ObjectLiteral(constant_properties,
properties,
literal_index,
is_simple,
fast_elements,
depth,
has_function);
}
Expression* Parser::ParseRegExpLiteral(bool seen_equal, bool* ok) {
if (!scanner().ScanRegExpPattern(seen_equal)) {
Next();
ReportMessage("unterminated_regexp", Vector<const char*>::empty());
*ok = false;
return NULL;
}
int literal_index = lexical_scope_->NextMaterializedLiteralIndex();
Handle<String> js_pattern = NextLiteralString(TENURED);
scanner().ScanRegExpFlags();
Handle<String> js_flags = NextLiteralString(TENURED);
Next();
return new(zone()) RegExpLiteral(js_pattern, js_flags, literal_index);
}
ZoneList<Expression*>* Parser::ParseArguments(bool* ok) {
// Arguments ::
// '(' (AssignmentExpression)*[','] ')'
ZoneList<Expression*>* result = new ZoneList<Expression*>(4);
Expect(Token::LPAREN, CHECK_OK);
bool done = (peek() == Token::RPAREN);
while (!done) {
Expression* argument = ParseAssignmentExpression(true, CHECK_OK);
result->Add(argument);
if (result->length() > kMaxNumFunctionParameters) {
ReportMessageAt(scanner().location(), "too_many_arguments",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
done = (peek() == Token::RPAREN);
if (!done) Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RPAREN, CHECK_OK);
return result;
}
FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
bool name_is_reserved,
int function_token_position,
FunctionLiteralType type,
bool* ok) {
// Function ::
// '(' FormalParameterList? ')' '{' FunctionBody '}'
bool is_named = !var_name.is_null();
// The name associated with this function. If it's a function expression,
// this is the actual function name, otherwise this is the name of the
// variable declared and initialized with the function (expression). In
// that case, we don't have a function name (it's empty).
Handle<String> name =
is_named ? var_name : isolate()->factory()->empty_symbol();
// The function name, if any.
Handle<String> function_name = isolate()->factory()->empty_symbol();
if (is_named && (type == EXPRESSION || type == NESTED)) {
function_name = name;
}
int num_parameters = 0;
Scope* scope = NewScope(top_scope_, Scope::FUNCTION_SCOPE, inside_with());
ZoneList<Statement*>* body = new ZoneList<Statement*>(8);
int materialized_literal_count;
int expected_property_count;
int start_pos;
int end_pos;
bool only_simple_this_property_assignments;
Handle<FixedArray> this_property_assignments;
// Parse function body.
{ LexicalScope lexical_scope(this, scope, isolate());
top_scope_->SetScopeName(name);
// FormalParameterList ::
// '(' (Identifier)*[','] ')'
Expect(Token::LPAREN, CHECK_OK);
start_pos = scanner().location().beg_pos;
Scanner::Location name_loc = Scanner::NoLocation();
Scanner::Location dupe_loc = Scanner::NoLocation();
Scanner::Location reserved_loc = Scanner::NoLocation();
bool done = (peek() == Token::RPAREN);
while (!done) {
bool is_reserved = false;
Handle<String> param_name =
ParseIdentifierOrReservedWord(&is_reserved, CHECK_OK);
// Store locations for possible future error reports.
if (!name_loc.IsValid() && IsEvalOrArguments(param_name)) {
name_loc = scanner().location();
}
if (!dupe_loc.IsValid() && top_scope_->IsDeclared(param_name)) {
dupe_loc = scanner().location();
}
if (!reserved_loc.IsValid() && is_reserved) {
reserved_loc = scanner().location();
}
Variable* parameter = top_scope_->DeclareLocal(param_name,
Variable::VAR,
Scope::PARAMETER);
top_scope_->AddParameter(parameter);
num_parameters++;
if (num_parameters > kMaxNumFunctionParameters) {
ReportMessageAt(scanner().location(), "too_many_parameters",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
done = (peek() == Token::RPAREN);
if (!done) Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RPAREN, CHECK_OK);
Expect(Token::LBRACE, CHECK_OK);
// If we have a named function expression, we add a local variable
// declaration to the body of the function with the name of the
// function and let it refer to the function itself (closure).
// NOTE: We create a proxy and resolve it here so that in the
// future we can change the AST to only refer to VariableProxies
// instead of Variables and Proxis as is the case now.
if (!function_name.is_null() && function_name->length() > 0) {
Variable* fvar = top_scope_->DeclareFunctionVar(function_name);
VariableProxy* fproxy =
top_scope_->NewUnresolved(function_name, inside_with());
fproxy->BindTo(fvar);
body->Add(new(zone()) ExpressionStatement(
new(zone()) Assignment(Token::INIT_CONST, fproxy,
new(zone()) ThisFunction(),
RelocInfo::kNoPosition)));
}
// Determine if the function will be lazily compiled. The mode can
// only be PARSE_LAZILY if the --lazy flag is true.
bool is_lazily_compiled = (mode() == PARSE_LAZILY &&
top_scope_->outer_scope()->is_global_scope() &&
top_scope_->HasTrivialOuterContext() &&
!parenthesized_function_);
parenthesized_function_ = false; // The bit was set for this function only.
int function_block_pos = scanner().location().beg_pos;
if (is_lazily_compiled && pre_data() != NULL) {
FunctionEntry entry = pre_data()->GetFunctionEntry(function_block_pos);
if (!entry.is_valid()) {
ReportInvalidPreparseData(name, CHECK_OK);
}
end_pos = entry.end_pos();
if (end_pos <= function_block_pos) {
// End position greater than end of stream is safe, and hard to check.
ReportInvalidPreparseData(name, CHECK_OK);
}
isolate()->counters()->total_preparse_skipped()->Increment(
end_pos - function_block_pos);
// Seek to position just before terminal '}'.
scanner().SeekForward(end_pos - 1);
materialized_literal_count = entry.literal_count();
expected_property_count = entry.property_count();
only_simple_this_property_assignments = false;
this_property_assignments = isolate()->factory()->empty_fixed_array();
Expect(Token::RBRACE, CHECK_OK);
} else {
ParseSourceElements(body, Token::RBRACE, CHECK_OK);
materialized_literal_count = lexical_scope.materialized_literal_count();
expected_property_count = lexical_scope.expected_property_count();
only_simple_this_property_assignments =
lexical_scope.only_simple_this_property_assignments();
this_property_assignments = lexical_scope.this_property_assignments();
Expect(Token::RBRACE, CHECK_OK);
end_pos = scanner().location().end_pos;
}
// Validate strict mode.
if (top_scope_->is_strict_mode()) {
if (IsEvalOrArguments(name)) {
int position = function_token_position != RelocInfo::kNoPosition
? function_token_position
: (start_pos > 0 ? start_pos - 1 : start_pos);
Scanner::Location location = Scanner::Location(position, start_pos);
ReportMessageAt(location,
"strict_function_name", Vector<const char*>::empty());
*ok = false;
return NULL;
}
if (name_loc.IsValid()) {
ReportMessageAt(name_loc, "strict_param_name",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
if (dupe_loc.IsValid()) {
ReportMessageAt(dupe_loc, "strict_param_dupe",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
if (name_is_reserved) {
int position = function_token_position != RelocInfo::kNoPosition
? function_token_position
: (start_pos > 0 ? start_pos - 1 : start_pos);
Scanner::Location location = Scanner::Location(position, start_pos);
ReportMessageAt(location, "strict_reserved_word",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
if (reserved_loc.IsValid()) {
ReportMessageAt(reserved_loc, "strict_reserved_word",
Vector<const char*>::empty());
*ok = false;
return NULL;
}
CheckOctalLiteral(start_pos, end_pos, CHECK_OK);
}
}
FunctionLiteral* function_literal =
new(zone()) FunctionLiteral(name,
scope,
body,
materialized_literal_count,
expected_property_count,
only_simple_this_property_assignments,
this_property_assignments,
num_parameters,
start_pos,
end_pos,
(function_name->length() > 0));
function_literal->set_function_token_position(function_token_position);
if (fni_ != NULL && !is_named) fni_->AddFunction(function_literal);
return function_literal;
}
Expression* Parser::ParseV8Intrinsic(bool* ok) {
// CallRuntime ::
// '%' Identifier Arguments
Expect(Token::MOD, CHECK_OK);
Handle<String> name = ParseIdentifier(CHECK_OK);
ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
if (extension_ != NULL) {
// The extension structures are only accessible while parsing the
// very first time not when reparsing because of lazy compilation.
top_scope_->ForceEagerCompilation();
}
const Runtime::Function* function = Runtime::FunctionForSymbol(name);
// Check for built-in IS_VAR macro.
if (function != NULL &&
function->intrinsic_type == Runtime::RUNTIME &&
function->function_id == Runtime::kIS_VAR) {
// %IS_VAR(x) evaluates to x if x is a variable,
// leads to a parse error otherwise. Could be implemented as an
// inline function %_IS_VAR(x) to eliminate this special case.
if (args->length() == 1 && args->at(0)->AsVariableProxy() != NULL) {
return args->at(0);
} else {
ReportMessage("unable_to_parse", Vector<const char*>::empty());
*ok = false;
return NULL;
}
}
// Check that the expected number of arguments are being passed.
if (function != NULL &&
function->nargs != -1 &&
function->nargs != args->length()) {
ReportMessage("illegal_access", Vector<const char*>::empty());
*ok = false;
return NULL;
}
// We have a valid intrinsics call or a call to a builtin.
return new(zone()) CallRuntime(name, function, args);
}
bool Parser::peek_any_identifier() {
Token::Value next = peek();
return next == Token::IDENTIFIER ||
next == Token::FUTURE_RESERVED_WORD;
}
void Parser::Consume(Token::Value token) {
Token::Value next = Next();
USE(next);
USE(token);
ASSERT(next == token);
}
void Parser::Expect(Token::Value token, bool* ok) {
Token::Value next = Next();
if (next == token) return;
ReportUnexpectedToken(next);
*ok = false;
}
bool Parser::Check(Token::Value token) {
Token::Value next = peek();
if (next == token) {
Consume(next);
return true;
}
return false;
}
void Parser::ExpectSemicolon(bool* ok) {
// Check for automatic semicolon insertion according to
// the rules given in ECMA-262, section 7.9, page 21.
Token::Value tok = peek();
if (tok == Token::SEMICOLON) {
Next();
return;
}
if (scanner().has_line_terminator_before_next() ||
tok == Token::RBRACE ||
tok == Token::EOS) {
return;
}
Expect(Token::SEMICOLON, ok);
}
Literal* Parser::GetLiteralUndefined() {
return new(zone()) Literal(isolate()->factory()->undefined_value());
}
Literal* Parser::GetLiteralTheHole() {
return new(zone()) Literal(isolate()->factory()->the_hole_value());
}
Literal* Parser::GetLiteralNumber(double value) {
return NewNumberLiteral(value);
}
Handle<String> Parser::ParseIdentifier(bool* ok) {
bool is_reserved;
return ParseIdentifierOrReservedWord(&is_reserved, ok);
}
Handle<String> Parser::ParseIdentifierOrReservedWord(bool* is_reserved,
bool* ok) {
*is_reserved = false;
if (top_scope_->is_strict_mode()) {
Expect(Token::IDENTIFIER, ok);
} else {
if (!Check(Token::IDENTIFIER)) {
Expect(Token::FUTURE_RESERVED_WORD, ok);
*is_reserved = true;
}
}
if (!*ok) return Handle<String>();
return GetSymbol(ok);
}
Handle<String> Parser::ParseIdentifierName(bool* ok) {
Token::Value next = Next();
if (next != Token::IDENTIFIER &&
next != Token::FUTURE_RESERVED_WORD &&
!Token::IsKeyword(next)) {
ReportUnexpectedToken(next);
*ok = false;
return Handle<String>();
}
return GetSymbol(ok);
}
// Checks LHS expression for assignment and prefix/postfix increment/decrement
// in strict mode.
void Parser::CheckStrictModeLValue(Expression* expression,
const char* error,
bool* ok) {
ASSERT(top_scope_->is_strict_mode());
VariableProxy* lhs = expression != NULL
? expression->AsVariableProxy()
: NULL;
if (lhs != NULL && !lhs->is_this() && IsEvalOrArguments(lhs->name())) {
ReportMessage(error, Vector<const char*>::empty());
*ok = false;
}
}
// Checks whether octal literal last seen is between beg_pos and end_pos.
// If so, reports an error.
void Parser::CheckOctalLiteral(int beg_pos, int end_pos, bool* ok) {
int octal = scanner().octal_position();
if (beg_pos <= octal && octal <= end_pos) {
ReportMessageAt(Scanner::Location(octal, octal + 1), "strict_octal_literal",
Vector<const char*>::empty());
scanner().clear_octal_position();
*ok = false;
}
}
// This function reads an identifier and determines whether or not it
// is 'get' or 'set'.
Handle<String> Parser::ParseIdentifierOrGetOrSet(bool* is_get,
bool* is_set,
bool* ok) {
Handle<String> result = ParseIdentifier(ok);
if (!*ok) return Handle<String>();
if (scanner().is_literal_ascii() && scanner().literal_length() == 3) {
const char* token = scanner().literal_ascii_string().start();
*is_get = strncmp(token, "get", 3) == 0;
*is_set = !*is_get && strncmp(token, "set", 3) == 0;
}
return result;
}
// ----------------------------------------------------------------------------
// Parser support
bool Parser::TargetStackContainsLabel(Handle<String> label) {
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
BreakableStatement* stat = t->node()->AsBreakableStatement();
if (stat != NULL && ContainsLabel(stat->labels(), label))
return true;
}
return false;
}
BreakableStatement* Parser::LookupBreakTarget(Handle<String> label, bool* ok) {
bool anonymous = label.is_null();
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
BreakableStatement* stat = t->node()->AsBreakableStatement();
if (stat == NULL) continue;
if ((anonymous && stat->is_target_for_anonymous()) ||
(!anonymous && ContainsLabel(stat->labels(), label))) {
RegisterTargetUse(stat->break_target(), t->previous());
return stat;
}
}
return NULL;
}
IterationStatement* Parser::LookupContinueTarget(Handle<String> label,
bool* ok) {
bool anonymous = label.is_null();
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
IterationStatement* stat = t->node()->AsIterationStatement();
if (stat == NULL) continue;
ASSERT(stat->is_target_for_anonymous());
if (anonymous || ContainsLabel(stat->labels(), label)) {
RegisterTargetUse(stat->continue_target(), t->previous());
return stat;
}
}
return NULL;
}
void Parser::RegisterTargetUse(Label* target, Target* stop) {
// Register that a break target found at the given stop in the
// target stack has been used from the top of the target stack. Add
// the break target to any TargetCollectors passed on the stack.
for (Target* t = target_stack_; t != stop; t = t->previous()) {
TargetCollector* collector = t->node()->AsTargetCollector();
if (collector != NULL) collector->AddTarget(target);
}
}
Literal* Parser::NewNumberLiteral(double number) {
return new(zone()) Literal(isolate()->factory()->NewNumber(number, TENURED));
}
Expression* Parser::NewThrowReferenceError(Handle<String> type) {
return NewThrowError(isolate()->factory()->MakeReferenceError_symbol(),
type, HandleVector<Object>(NULL, 0));
}
Expression* Parser::NewThrowSyntaxError(Handle<String> type,
Handle<Object> first) {
int argc = first.is_null() ? 0 : 1;
Vector< Handle<Object> > arguments = HandleVector<Object>(&first, argc);
return NewThrowError(
isolate()->factory()->MakeSyntaxError_symbol(), type, arguments);
}
Expression* Parser::NewThrowTypeError(Handle<String> type,
Handle<Object> first,
Handle<Object> second) {
ASSERT(!first.is_null() && !second.is_null());
Handle<Object> elements[] = { first, second };
Vector< Handle<Object> > arguments =
HandleVector<Object>(elements, ARRAY_SIZE(elements));
return NewThrowError(
isolate()->factory()->MakeTypeError_symbol(), type, arguments);
}
Expression* Parser::NewThrowError(Handle<String> constructor,
Handle<String> type,
Vector< Handle<Object> > arguments) {
int argc = arguments.length();
Handle<FixedArray> elements = isolate()->factory()->NewFixedArray(argc,
TENURED);
for (int i = 0; i < argc; i++) {
Handle<Object> element = arguments[i];
if (!element.is_null()) {
elements->set(i, *element);
}
}
Handle<JSArray> array = isolate()->factory()->NewJSArrayWithElements(elements,
TENURED);
ZoneList<Expression*>* args = new ZoneList<Expression*>(2);
args->Add(new(zone()) Literal(type));
args->Add(new(zone()) Literal(array));
return new(zone()) Throw(new(zone()) CallRuntime(constructor, NULL, args),
scanner().location().beg_pos);
}
// ----------------------------------------------------------------------------
// JSON
Handle<Object> JsonParser::ParseJson(Handle<String> script,
UC16CharacterStream* source) {
scanner_.Initialize(source);
stack_overflow_ = false;
Handle<Object> result = ParseJsonValue();
if (result.is_null() || scanner_.Next() != Token::EOS) {
if (stack_overflow_) {
// Scanner failed.
isolate()->StackOverflow();
} else {
// Parse failed. Scanner's current token is the unexpected token.
Token::Value token = scanner_.current_token();
const char* message;
const char* name_opt = NULL;
switch (token) {
case Token::EOS:
message = "unexpected_eos";
break;
case Token::NUMBER:
message = "unexpected_token_number";
break;
case Token::STRING:
message = "unexpected_token_string";
break;
case Token::IDENTIFIER:
case Token::FUTURE_RESERVED_WORD:
message = "unexpected_token_identifier";
break;
default:
message = "unexpected_token";
name_opt = Token::String(token);
ASSERT(name_opt != NULL);
break;
}
Scanner::Location source_location = scanner_.location();
Factory* factory = isolate()->factory();
MessageLocation location(factory->NewScript(script),
source_location.beg_pos,
source_location.end_pos);
Handle<JSArray> array;
if (name_opt == NULL) {
array = factory->NewJSArray(0);
} else {
Handle<String> name = factory->NewStringFromUtf8(CStrVector(name_opt));
Handle<FixedArray> element = factory->NewFixedArray(1);
element->set(0, *name);
array = factory->NewJSArrayWithElements(element);
}
Handle<Object> result = factory->NewSyntaxError(message, array);
isolate()->Throw(*result, &location);
return Handle<Object>::null();
}
}
return result;
}
Handle<String> JsonParser::GetString() {
int literal_length = scanner_.literal_length();
if (literal_length == 0) {
return isolate()->factory()->empty_string();
}
if (scanner_.is_literal_ascii()) {
return isolate()->factory()->NewStringFromAscii(
scanner_.literal_ascii_string());
} else {
return isolate()->factory()->NewStringFromTwoByte(
scanner_.literal_uc16_string());
}
}
// Parse any JSON value.
Handle<Object> JsonParser::ParseJsonValue() {
Token::Value token = scanner_.Next();
switch (token) {
case Token::STRING:
return GetString();
case Token::NUMBER:
return isolate()->factory()->NewNumber(scanner_.number());
case Token::FALSE_LITERAL:
return isolate()->factory()->false_value();
case Token::TRUE_LITERAL:
return isolate()->factory()->true_value();
case Token::NULL_LITERAL:
return isolate()->factory()->null_value();
case Token::LBRACE:
return ParseJsonObject();
case Token::LBRACK:
return ParseJsonArray();
default:
return ReportUnexpectedToken();
}
}
// Parse a JSON object. Scanner must be right after '{' token.
Handle<Object> JsonParser::ParseJsonObject() {
Handle<JSFunction> object_constructor(
isolate()->global_context()->object_function());
Handle<JSObject> json_object =
isolate()->factory()->NewJSObject(object_constructor);
if (scanner_.peek() == Token::RBRACE) {
scanner_.Next();
} else {
if (StackLimitCheck(isolate()).HasOverflowed()) {
stack_overflow_ = true;
return Handle<Object>::null();
}
do {
if (scanner_.Next() != Token::STRING) {
return ReportUnexpectedToken();
}
Handle<String> key = GetString();
if (scanner_.Next() != Token::COLON) {
return ReportUnexpectedToken();
}
Handle<Object> value = ParseJsonValue();
if (value.is_null()) return Handle<Object>::null();
uint32_t index;
if (key->AsArrayIndex(&index)) {
SetOwnElement(json_object, index, value, kNonStrictMode);
} else if (key->Equals(isolate()->heap()->Proto_symbol())) {
// We can't remove the __proto__ accessor since it's hardcoded
// in several places. Instead go along and add the value as
// the prototype of the created object if possible.
SetPrototype(json_object, value);
} else {
SetLocalPropertyIgnoreAttributes(json_object, key, value, NONE);
}
} while (scanner_.Next() == Token::COMMA);
if (scanner_.current_token() != Token::RBRACE) {
return ReportUnexpectedToken();
}
}
return json_object;
}
// Parse a JSON array. Scanner must be right after '[' token.
Handle<Object> JsonParser::ParseJsonArray() {
ZoneScope zone_scope(DELETE_ON_EXIT);
ZoneList<Handle<Object> > elements(4);
Token::Value token = scanner_.peek();
if (token == Token::RBRACK) {
scanner_.Next();
} else {
if (StackLimitCheck(isolate()).HasOverflowed()) {
stack_overflow_ = true;
return Handle<Object>::null();
}
do {
Handle<Object> element = ParseJsonValue();
if (element.is_null()) return Handle<Object>::null();
elements.Add(element);
token = scanner_.Next();
} while (token == Token::COMMA);
if (token != Token::RBRACK) {
return ReportUnexpectedToken();
}
}
// Allocate a fixed array with all the elements.
Handle<FixedArray> fast_elements =
isolate()->factory()->NewFixedArray(elements.length());
for (int i = 0, n = elements.length(); i < n; i++) {
fast_elements->set(i, *elements[i]);
}
return isolate()->factory()->NewJSArrayWithElements(fast_elements);
}
// ----------------------------------------------------------------------------
// Regular expressions
RegExpParser::RegExpParser(FlatStringReader* in,
Handle<String>* error,
bool multiline)
: isolate_(Isolate::Current()),
error_(error),
captures_(NULL),
in_(in),
current_(kEndMarker),
next_pos_(0),
capture_count_(0),
has_more_(true),
multiline_(multiline),
simple_(false),
contains_anchor_(false),
is_scanned_for_captures_(false),
failed_(false) {
Advance();
}
uc32 RegExpParser::Next() {
if (has_next()) {
return in()->Get(next_pos_);
} else {
return kEndMarker;
}
}
void RegExpParser::Advance() {
if (next_pos_ < in()->length()) {
StackLimitCheck check(isolate());
if (check.HasOverflowed()) {
ReportError(CStrVector(Isolate::kStackOverflowMessage));
} else if (isolate()->zone()->excess_allocation()) {
ReportError(CStrVector("Regular expression too large"));
} else {
current_ = in()->Get(next_pos_);
next_pos_++;
}
} else {
current_ = kEndMarker;
has_more_ = false;
}
}
void RegExpParser::Reset(int pos) {
next_pos_ = pos;
Advance();
}
void RegExpParser::Advance(int dist) {
next_pos_ += dist - 1;
Advance();
}
bool RegExpParser::simple() {
return simple_;
}
RegExpTree* RegExpParser::ReportError(Vector<const char> message) {
failed_ = true;
*error_ = isolate()->factory()->NewStringFromAscii(message, NOT_TENURED);
// Zip to the end to make sure the no more input is read.
current_ = kEndMarker;
next_pos_ = in()->length();
return NULL;
}
// Pattern ::
// Disjunction
RegExpTree* RegExpParser::ParsePattern() {
RegExpTree* result = ParseDisjunction(CHECK_FAILED);
ASSERT(!has_more());
// If the result of parsing is a literal string atom, and it has the
// same length as the input, then the atom is identical to the input.
if (result->IsAtom() && result->AsAtom()->length() == in()->length()) {
simple_ = true;
}
return result;
}
// Disjunction ::
// Alternative
// Alternative | Disjunction
// Alternative ::
// [empty]
// Term Alternative
// Term ::
// Assertion
// Atom
// Atom Quantifier
RegExpTree* RegExpParser::ParseDisjunction() {
// Used to store current state while parsing subexpressions.
RegExpParserState initial_state(NULL, INITIAL, 0);
RegExpParserState* stored_state = &initial_state;
// Cache the builder in a local variable for quick access.
RegExpBuilder* builder = initial_state.builder();
while (true) {
switch (current()) {
case kEndMarker:
if (stored_state->IsSubexpression()) {
// Inside a parenthesized group when hitting end of input.
ReportError(CStrVector("Unterminated group") CHECK_FAILED);
}
ASSERT_EQ(INITIAL, stored_state->group_type());
// Parsing completed successfully.
return builder->ToRegExp();
case ')': {
if (!stored_state->IsSubexpression()) {
ReportError(CStrVector("Unmatched ')'") CHECK_FAILED);
}
ASSERT_NE(INITIAL, stored_state->group_type());
Advance();
// End disjunction parsing and convert builder content to new single
// regexp atom.
RegExpTree* body = builder->ToRegExp();
int end_capture_index = captures_started();
int capture_index = stored_state->capture_index();
SubexpressionType type = stored_state->group_type();
// Restore previous state.
stored_state = stored_state->previous_state();
builder = stored_state->builder();
// Build result of subexpression.
if (type == CAPTURE) {
RegExpCapture* capture = new(zone()) RegExpCapture(body, capture_index);
captures_->at(capture_index - 1) = capture;
body = capture;
} else if (type != GROUPING) {
ASSERT(type == POSITIVE_LOOKAHEAD || type == NEGATIVE_LOOKAHEAD);
bool is_positive = (type == POSITIVE_LOOKAHEAD);
body = new(zone()) RegExpLookahead(body,
is_positive,
end_capture_index - capture_index,
capture_index);
}
builder->AddAtom(body);
// For compatability with JSC and ES3, we allow quantifiers after
// lookaheads, and break in all cases.
break;
}
case '|': {
Advance();
builder->NewAlternative();
continue;
}
case '*':
case '+':
case '?':
return ReportError(CStrVector("Nothing to repeat"));
case '^': {
Advance();
if (multiline_) {
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::START_OF_LINE));
} else {
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::START_OF_INPUT));
set_contains_anchor();
}
continue;
}
case '$': {
Advance();
RegExpAssertion::Type type =
multiline_ ? RegExpAssertion::END_OF_LINE :
RegExpAssertion::END_OF_INPUT;
builder->AddAssertion(new(zone()) RegExpAssertion(type));
continue;
}
case '.': {
Advance();
// everything except \x0a, \x0d, \u2028 and \u2029
ZoneList<CharacterRange>* ranges = new ZoneList<CharacterRange>(2);
CharacterRange::AddClassEscape('.', ranges);
RegExpTree* atom = new(zone()) RegExpCharacterClass(ranges, false);
builder->AddAtom(atom);
break;
}
case '(': {
SubexpressionType type = CAPTURE;
Advance();
if (current() == '?') {
switch (Next()) {
case ':':
type = GROUPING;
break;
case '=':
type = POSITIVE_LOOKAHEAD;
break;
case '!':
type = NEGATIVE_LOOKAHEAD;
break;
default:
ReportError(CStrVector("Invalid group") CHECK_FAILED);
break;
}
Advance(2);
} else {
if (captures_ == NULL) {
captures_ = new ZoneList<RegExpCapture*>(2);
}
if (captures_started() >= kMaxCaptures) {
ReportError(CStrVector("Too many captures") CHECK_FAILED);
}
captures_->Add(NULL);
}
// Store current state and begin new disjunction parsing.
stored_state = new(zone()) RegExpParserState(stored_state,
type,
captures_started());
builder = stored_state->builder();
continue;
}
case '[': {
RegExpTree* atom = ParseCharacterClass(CHECK_FAILED);
builder->AddAtom(atom);
break;
}
// Atom ::
// \ AtomEscape
case '\\':
switch (Next()) {
case kEndMarker:
return ReportError(CStrVector("\\ at end of pattern"));
case 'b':
Advance(2);
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::BOUNDARY));
continue;
case 'B':
Advance(2);
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::NON_BOUNDARY));
continue;
// AtomEscape ::
// CharacterClassEscape
//
// CharacterClassEscape :: one of
// d D s S w W
case 'd': case 'D': case 's': case 'S': case 'w': case 'W': {
uc32 c = Next();
Advance(2);
ZoneList<CharacterRange>* ranges = new ZoneList<CharacterRange>(2);
CharacterRange::AddClassEscape(c, ranges);
RegExpTree* atom = new(zone()) RegExpCharacterClass(ranges, false);
builder->AddAtom(atom);
break;
}
case '1': case '2': case '3': case '4': case '5': case '6':
case '7': case '8': case '9': {
int index = 0;
if (ParseBackReferenceIndex(&index)) {
RegExpCapture* capture = NULL;
if (captures_ != NULL && index <= captures_->length()) {
capture = captures_->at(index - 1);
}
if (capture == NULL) {
builder->AddEmpty();
break;
}
RegExpTree* atom = new(zone()) RegExpBackReference(capture);
builder->AddAtom(atom);
break;
}
uc32 first_digit = Next();
if (first_digit == '8' || first_digit == '9') {
// Treat as identity escape
builder->AddCharacter(first_digit);
Advance(2);
break;
}
}
// FALLTHROUGH
case '0': {
Advance();
uc32 octal = ParseOctalLiteral();
builder->AddCharacter(octal);
break;
}
// ControlEscape :: one of
// f n r t v
case 'f':
Advance(2);
builder->AddCharacter('\f');
break;
case 'n':
Advance(2);
builder->AddCharacter('\n');
break;
case 'r':
Advance(2);
builder->AddCharacter('\r');
break;
case 't':
Advance(2);
builder->AddCharacter('\t');
break;
case 'v':
Advance(2);
builder->AddCharacter('\v');
break;
case 'c': {
Advance();
uc32 controlLetter = Next();
// Special case if it is an ASCII letter.
// Convert lower case letters to uppercase.
uc32 letter = controlLetter & ~('a' ^ 'A');
if (letter < 'A' || 'Z' < letter) {
// controlLetter is not in range 'A'-'Z' or 'a'-'z'.
// This is outside the specification. We match JSC in
// reading the backslash as a literal character instead
// of as starting an escape.
builder->AddCharacter('\\');
} else {
Advance(2);
builder->AddCharacter(controlLetter & 0x1f);
}
break;
}
case 'x': {
Advance(2);
uc32 value;
if (ParseHexEscape(2, &value)) {
builder->AddCharacter(value);
} else {
builder->AddCharacter('x');
}
break;
}
case 'u': {
Advance(2);
uc32 value;
if (ParseHexEscape(4, &value)) {
builder->AddCharacter(value);
} else {
builder->AddCharacter('u');
}
break;
}
default:
// Identity escape.
builder->AddCharacter(Next());
Advance(2);
break;
}
break;
case '{': {
int dummy;
if (ParseIntervalQuantifier(&dummy, &dummy)) {
ReportError(CStrVector("Nothing to repeat") CHECK_FAILED);
}
// fallthrough
}
default:
builder->AddCharacter(current());
Advance();
break;
} // end switch(current())
int min;
int max;
switch (current()) {
// QuantifierPrefix ::
// *
// +
// ?
// {
case '*':
min = 0;
max = RegExpTree::kInfinity;
Advance();
break;
case '+':
min = 1;
max = RegExpTree::kInfinity;
Advance();
break;
case '?':
min = 0;
max = 1;
Advance();
break;
case '{':
if (ParseIntervalQuantifier(&min, &max)) {
if (max < min) {
ReportError(CStrVector("numbers out of order in {} quantifier.")
CHECK_FAILED);
}
break;
} else {
continue;
}
default:
continue;
}
RegExpQuantifier::Type type = RegExpQuantifier::GREEDY;
if (current() == '?') {
type = RegExpQuantifier::NON_GREEDY;
Advance();
} else if (FLAG_regexp_possessive_quantifier && current() == '+') {
// FLAG_regexp_possessive_quantifier is a debug-only flag.
type = RegExpQuantifier::POSSESSIVE;
Advance();
}
builder->AddQuantifierToAtom(min, max, type);
}
}
#ifdef DEBUG
// Currently only used in an ASSERT.
static bool IsSpecialClassEscape(uc32 c) {
switch (c) {
case 'd': case 'D':
case 's': case 'S':
case 'w': case 'W':
return true;
default:
return false;
}
}
#endif
// In order to know whether an escape is a backreference or not we have to scan
// the entire regexp and find the number of capturing parentheses. However we
// don't want to scan the regexp twice unless it is necessary. This mini-parser
// is called when needed. It can see the difference between capturing and
// noncapturing parentheses and can skip character classes and backslash-escaped
// characters.
void RegExpParser::ScanForCaptures() {
// Start with captures started previous to current position
int capture_count = captures_started();
// Add count of captures after this position.
int n;
while ((n = current()) != kEndMarker) {
Advance();
switch (n) {
case '\\':
Advance();
break;
case '[': {
int c;
while ((c = current()) != kEndMarker) {
Advance();
if (c == '\\') {
Advance();
} else {
if (c == ']') break;
}
}
break;
}
case '(':
if (current() != '?') capture_count++;
break;
}
}
capture_count_ = capture_count;
is_scanned_for_captures_ = true;
}
bool RegExpParser::ParseBackReferenceIndex(int* index_out) {
ASSERT_EQ('\\', current());
ASSERT('1' <= Next() && Next() <= '9');
// Try to parse a decimal literal that is no greater than the total number
// of left capturing parentheses in the input.
int start = position();
int value = Next() - '0';
Advance(2);
while (true) {
uc32 c = current();
if (IsDecimalDigit(c)) {
value = 10 * value + (c - '0');
if (value > kMaxCaptures) {
Reset(start);
return false;
}
Advance();
} else {
break;
}
}
if (value > captures_started()) {
if (!is_scanned_for_captures_) {
int saved_position = position();
ScanForCaptures();
Reset(saved_position);
}
if (value > capture_count_) {
Reset(start);
return false;
}
}
*index_out = value;
return true;
}
// QuantifierPrefix ::
// { DecimalDigits }
// { DecimalDigits , }
// { DecimalDigits , DecimalDigits }
//
// Returns true if parsing succeeds, and set the min_out and max_out
// values. Values are truncated to RegExpTree::kInfinity if they overflow.
bool RegExpParser::ParseIntervalQuantifier(int* min_out, int* max_out) {
ASSERT_EQ(current(), '{');
int start = position();
Advance();
int min = 0;
if (!IsDecimalDigit(current())) {
Reset(start);
return false;
}
while (IsDecimalDigit(current())) {
int next = current() - '0';
if (min > (RegExpTree::kInfinity - next) / 10) {
// Overflow. Skip past remaining decimal digits and return -1.
do {
Advance();
} while (IsDecimalDigit(current()));
min = RegExpTree::kInfinity;
break;
}
min = 10 * min + next;
Advance();
}
int max = 0;
if (current() == '}') {
max = min;
Advance();
} else if (current() == ',') {
Advance();
if (current() == '}') {
max = RegExpTree::kInfinity;
Advance();
} else {
while (IsDecimalDigit(current())) {
int next = current() - '0';
if (max > (RegExpTree::kInfinity - next) / 10) {
do {
Advance();
} while (IsDecimalDigit(current()));
max = RegExpTree::kInfinity;
break;
}
max = 10 * max + next;
Advance();
}
if (current() != '}') {
Reset(start);
return false;
}
Advance();
}
} else {
Reset(start);
return false;
}
*min_out = min;
*max_out = max;
return true;
}
uc32 RegExpParser::ParseOctalLiteral() {
ASSERT('0' <= current() && current() <= '7');
// For compatibility with some other browsers (not all), we parse
// up to three octal digits with a value below 256.
uc32 value = current() - '0';
Advance();
if ('0' <= current() && current() <= '7') {
value = value * 8 + current() - '0';
Advance();
if (value < 32 && '0' <= current() && current() <= '7') {
value = value * 8 + current() - '0';
Advance();
}
}
return value;
}
bool RegExpParser::ParseHexEscape(int length, uc32 *value) {
int start = position();
uc32 val = 0;
bool done = false;
for (int i = 0; !done; i++) {
uc32 c = current();
int d = HexValue(c);
if (d < 0) {
Reset(start);
return false;
}
val = val * 16 + d;
Advance();
if (i == length - 1) {
done = true;
}
}
*value = val;
return true;
}
uc32 RegExpParser::ParseClassCharacterEscape() {
ASSERT(current() == '\\');
ASSERT(has_next() && !IsSpecialClassEscape(Next()));
Advance();
switch (current()) {
case 'b':
Advance();
return '\b';
// ControlEscape :: one of
// f n r t v
case 'f':
Advance();
return '\f';
case 'n':
Advance();
return '\n';
case 'r':
Advance();
return '\r';
case 't':
Advance();
return '\t';
case 'v':
Advance();
return '\v';
case 'c': {
uc32 controlLetter = Next();
uc32 letter = controlLetter & ~('A' ^ 'a');
// For compatibility with JSC, inside a character class
// we also accept digits and underscore as control characters.
if ((controlLetter >= '0' && controlLetter <= '9') ||
controlLetter == '_' ||
(letter >= 'A' && letter <= 'Z')) {
Advance(2);
// Control letters mapped to ASCII control characters in the range
// 0x00-0x1f.
return controlLetter & 0x1f;
}
// We match JSC in reading the backslash as a literal
// character instead of as starting an escape.
return '\\';
}
case '0': case '1': case '2': case '3': case '4': case '5':
case '6': case '7':
// For compatibility, we interpret a decimal escape that isn't
// a back reference (and therefore either \0 or not valid according
// to the specification) as a 1..3 digit octal character code.
return ParseOctalLiteral();
case 'x': {
Advance();
uc32 value;
if (ParseHexEscape(2, &value)) {
return value;
}
// If \x is not followed by a two-digit hexadecimal, treat it
// as an identity escape.
return 'x';
}
case 'u': {
Advance();
uc32 value;
if (ParseHexEscape(4, &value)) {
return value;
}
// If \u is not followed by a four-digit hexadecimal, treat it
// as an identity escape.
return 'u';
}
default: {
// Extended identity escape. We accept any character that hasn't
// been matched by a more specific case, not just the subset required
// by the ECMAScript specification.
uc32 result = current();
Advance();
return result;
}
}
return 0;
}
CharacterRange RegExpParser::ParseClassAtom(uc16* char_class) {
ASSERT_EQ(0, *char_class);
uc32 first = current();
if (first == '\\') {
switch (Next()) {
case 'w': case 'W': case 'd': case 'D': case 's': case 'S': {
*char_class = Next();
Advance(2);
return CharacterRange::Singleton(0); // Return dummy value.
}
case kEndMarker:
return ReportError(CStrVector("\\ at end of pattern"));
default:
uc32 c = ParseClassCharacterEscape(CHECK_FAILED);
return CharacterRange::Singleton(c);
}
} else {
Advance();
return CharacterRange::Singleton(first);
}
}
static const uc16 kNoCharClass = 0;
// Adds range or pre-defined character class to character ranges.
// If char_class is not kInvalidClass, it's interpreted as a class
// escape (i.e., 's' means whitespace, from '\s').
static inline void AddRangeOrEscape(ZoneList<CharacterRange>* ranges,
uc16 char_class,
CharacterRange range) {
if (char_class != kNoCharClass) {
CharacterRange::AddClassEscape(char_class, ranges);
} else {
ranges->Add(range);
}
}
RegExpTree* RegExpParser::ParseCharacterClass() {
static const char* kUnterminated = "Unterminated character class";
static const char* kRangeOutOfOrder = "Range out of order in character class";
ASSERT_EQ(current(), '[');
Advance();
bool is_negated = false;
if (current() == '^') {
is_negated = true;
Advance();
}
ZoneList<CharacterRange>* ranges = new ZoneList<CharacterRange>(2);
while (has_more() && current() != ']') {
uc16 char_class = kNoCharClass;
CharacterRange first = ParseClassAtom(&char_class CHECK_FAILED);
if (current() == '-') {
Advance();
if (current() == kEndMarker) {
// If we reach the end we break out of the loop and let the
// following code report an error.
break;
} else if (current() == ']') {
AddRangeOrEscape(ranges, char_class, first);
ranges->Add(CharacterRange::Singleton('-'));
break;
}
uc16 char_class_2 = kNoCharClass;
CharacterRange next = ParseClassAtom(&char_class_2 CHECK_FAILED);
if (char_class != kNoCharClass || char_class_2 != kNoCharClass) {
// Either end is an escaped character class. Treat the '-' verbatim.
AddRangeOrEscape(ranges, char_class, first);
ranges->Add(CharacterRange::Singleton('-'));
AddRangeOrEscape(ranges, char_class_2, next);
continue;
}
if (first.from() > next.to()) {
return ReportError(CStrVector(kRangeOutOfOrder) CHECK_FAILED);
}
ranges->Add(CharacterRange::Range(first.from(), next.to()));
} else {
AddRangeOrEscape(ranges, char_class, first);
}
}
if (!has_more()) {
return ReportError(CStrVector(kUnterminated) CHECK_FAILED);
}
Advance();
if (ranges->length() == 0) {
ranges->Add(CharacterRange::Everything());
is_negated = !is_negated;
}
return new(zone()) RegExpCharacterClass(ranges, is_negated);
}
// ----------------------------------------------------------------------------
// The Parser interface.
ParserMessage::~ParserMessage() {
for (int i = 0; i < args().length(); i++)
DeleteArray(args()[i]);
DeleteArray(args().start());
}
ScriptDataImpl::~ScriptDataImpl() {
if (owns_store_) store_.Dispose();
}
int ScriptDataImpl::Length() {
return store_.length() * sizeof(unsigned);
}
const char* ScriptDataImpl::Data() {
return reinterpret_cast<const char*>(store_.start());
}
bool ScriptDataImpl::HasError() {
return has_error();
}
void ScriptDataImpl::Initialize() {
// Prepares state for use.
if (store_.length() >= PreparseDataConstants::kHeaderSize) {
function_index_ = PreparseDataConstants::kHeaderSize;
int symbol_data_offset = PreparseDataConstants::kHeaderSize
+ store_[PreparseDataConstants::kFunctionsSizeOffset];
if (store_.length() > symbol_data_offset) {
symbol_data_ = reinterpret_cast<byte*>(&store_[symbol_data_offset]);
} else {
// Partial preparse causes no symbol information.
symbol_data_ = reinterpret_cast<byte*>(&store_[0] + store_.length());
}
symbol_data_end_ = reinterpret_cast<byte*>(&store_[0] + store_.length());
}
}
int ScriptDataImpl::ReadNumber(byte** source) {
// Reads a number from symbol_data_ in base 128. The most significant
// bit marks that there are more digits.
// If the first byte is 0x80 (kNumberTerminator), it would normally
// represent a leading zero. Since that is useless, and therefore won't
// appear as the first digit of any actual value, it is used to
// mark the end of the input stream.
byte* data = *source;
if (data >= symbol_data_end_) return -1;
byte input = *data;
if (input == PreparseDataConstants::kNumberTerminator) {
// End of stream marker.
return -1;
}
int result = input & 0x7f;
data++;
while ((input & 0x80u) != 0) {
if (data >= symbol_data_end_) return -1;
input = *data;
result = (result << 7) | (input & 0x7f);
data++;
}
*source = data;
return result;
}
// Create a Scanner for the preparser to use as input, and preparse the source.
static ScriptDataImpl* DoPreParse(UC16CharacterStream* source,
bool allow_lazy,
ParserRecorder* recorder) {
Isolate* isolate = Isolate::Current();
V8JavaScriptScanner scanner(isolate->unicode_cache());
scanner.Initialize(source);
intptr_t stack_limit = isolate->stack_guard()->real_climit();
if (!preparser::PreParser::PreParseProgram(&scanner,
recorder,
allow_lazy,
stack_limit)) {
isolate->StackOverflow();
return NULL;
}
// Extract the accumulated data from the recorder as a single
// contiguous vector that we are responsible for disposing.
Vector<unsigned> store = recorder->ExtractData();
return new ScriptDataImpl(store);
}
// Preparse, but only collect data that is immediately useful,
// even if the preparser data is only used once.
ScriptDataImpl* ParserApi::PartialPreParse(UC16CharacterStream* source,
v8::Extension* extension) {
bool allow_lazy = FLAG_lazy && (extension == NULL);
if (!allow_lazy) {
// Partial preparsing is only about lazily compiled functions.
// If we don't allow lazy compilation, the log data will be empty.
return NULL;
}
PartialParserRecorder recorder;
return DoPreParse(source, allow_lazy, &recorder);
}
ScriptDataImpl* ParserApi::PreParse(UC16CharacterStream* source,
v8::Extension* extension) {
Handle<Script> no_script;
bool allow_lazy = FLAG_lazy && (extension == NULL);
CompleteParserRecorder recorder;
return DoPreParse(source, allow_lazy, &recorder);
}
bool RegExpParser::ParseRegExp(FlatStringReader* input,
bool multiline,
RegExpCompileData* result) {
ASSERT(result != NULL);
RegExpParser parser(input, &result->error, multiline);
RegExpTree* tree = parser.ParsePattern();
if (parser.failed()) {
ASSERT(tree == NULL);
ASSERT(!result->error.is_null());
} else {
ASSERT(tree != NULL);
ASSERT(result->error.is_null());
result->tree = tree;
int capture_count = parser.captures_started();
result->simple = tree->IsAtom() && parser.simple() && capture_count == 0;
result->contains_anchor = parser.contains_anchor();
result->capture_count = capture_count;
}
return !parser.failed();
}
bool ParserApi::Parse(CompilationInfo* info) {
ASSERT(info->function() == NULL);
FunctionLiteral* result = NULL;
Handle<Script> script = info->script();
if (info->is_lazy()) {
bool allow_natives_syntax =
FLAG_allow_natives_syntax ||
info->is_native();
Parser parser(script, allow_natives_syntax, NULL, NULL);
result = parser.ParseLazy(info);
} else {
bool allow_natives_syntax =
info->is_native() || FLAG_allow_natives_syntax;
ScriptDataImpl* pre_data = info->pre_parse_data();
Parser parser(script, allow_natives_syntax, info->extension(), pre_data);
if (pre_data != NULL && pre_data->has_error()) {
Scanner::Location loc = pre_data->MessageLocation();
const char* message = pre_data->BuildMessage();
Vector<const char*> args = pre_data->BuildArgs();
parser.ReportMessageAt(loc, message, args);
DeleteArray(message);
for (int i = 0; i < args.length(); i++) {
DeleteArray(args[i]);
}
DeleteArray(args.start());
ASSERT(info->isolate()->has_pending_exception());
} else {
Handle<String> source = Handle<String>(String::cast(script->source()));
result = parser.ParseProgram(source,
info->is_global(),
info->StrictMode());
}
}
info->SetFunction(result);
return (result != NULL);
}
} } // namespace v8::internal