// Copyright 2006-2008 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 "ast.h" #include "parser.h" #include "scopes.h" #include "string-stream.h" namespace v8 { namespace internal { VariableProxySentinel VariableProxySentinel::this_proxy_(true); VariableProxySentinel VariableProxySentinel::identifier_proxy_(false); ValidLeftHandSideSentinel ValidLeftHandSideSentinel::instance_; Property Property::this_property_(VariableProxySentinel::this_proxy(), NULL, 0); Call Call::sentinel_(NULL, NULL, 0); // ---------------------------------------------------------------------------- // All the Accept member functions for each syntax tree node type. #define DECL_ACCEPT(type) \ void type::Accept(AstVisitor* v) { \ if (v->CheckStackOverflow()) return; \ v->Visit##type(this); \ } AST_NODE_LIST(DECL_ACCEPT) #undef DECL_ACCEPT // ---------------------------------------------------------------------------- // Implementation of other node functionality. Assignment* ExpressionStatement::StatementAsSimpleAssignment() { return (expression()->AsAssignment() != NULL && !expression()->AsAssignment()->is_compound()) ? expression()->AsAssignment() : NULL; } CountOperation* ExpressionStatement::StatementAsCountOperation() { return expression()->AsCountOperation(); } VariableProxy::VariableProxy(Handle name, bool is_this, bool inside_with) : name_(name), var_(NULL), is_this_(is_this), inside_with_(inside_with), is_trivial_(false), reaching_definitions_(NULL) { // names must be canonicalized for fast equality checks ASSERT(name->IsSymbol()); } VariableProxy::VariableProxy(bool is_this) : is_this_(is_this), reaching_definitions_(NULL) { } void VariableProxy::BindTo(Variable* var) { ASSERT(var_ == NULL); // must be bound only once ASSERT(var != NULL); // must bind ASSERT((is_this() && var->is_this()) || name_.is_identical_to(var->name())); // Ideally CONST-ness should match. However, this is very hard to achieve // because we don't know the exact semantics of conflicting (const and // non-const) multiple variable declarations, const vars introduced via // eval() etc. Const-ness and variable declarations are a complete mess // in JS. Sigh... var_ = var; var->set_is_used(true); } Token::Value Assignment::binary_op() const { switch (op_) { case Token::ASSIGN_BIT_OR: return Token::BIT_OR; case Token::ASSIGN_BIT_XOR: return Token::BIT_XOR; case Token::ASSIGN_BIT_AND: return Token::BIT_AND; case Token::ASSIGN_SHL: return Token::SHL; case Token::ASSIGN_SAR: return Token::SAR; case Token::ASSIGN_SHR: return Token::SHR; case Token::ASSIGN_ADD: return Token::ADD; case Token::ASSIGN_SUB: return Token::SUB; case Token::ASSIGN_MUL: return Token::MUL; case Token::ASSIGN_DIV: return Token::DIV; case Token::ASSIGN_MOD: return Token::MOD; default: UNREACHABLE(); } return Token::ILLEGAL; } bool FunctionLiteral::AllowsLazyCompilation() { return scope()->AllowsLazyCompilation(); } ObjectLiteral::Property::Property(Literal* key, Expression* value) { key_ = key; value_ = value; Object* k = *key->handle(); if (k->IsSymbol() && Heap::Proto_symbol()->Equals(String::cast(k))) { kind_ = PROTOTYPE; } else if (value_->AsMaterializedLiteral() != NULL) { kind_ = MATERIALIZED_LITERAL; } else if (value_->AsLiteral() != NULL) { kind_ = CONSTANT; } else { kind_ = COMPUTED; } } ObjectLiteral::Property::Property(bool is_getter, FunctionLiteral* value) { key_ = new Literal(value->name()); value_ = value; kind_ = is_getter ? GETTER : SETTER; } bool ObjectLiteral::Property::IsCompileTimeValue() { return kind_ == CONSTANT || (kind_ == MATERIALIZED_LITERAL && CompileTimeValue::IsCompileTimeValue(value_)); } void TargetCollector::AddTarget(BreakTarget* target) { // Add the label to the collector, but discard duplicates. int length = targets_->length(); for (int i = 0; i < length; i++) { if (targets_->at(i) == target) return; } targets_->Add(target); } // ---------------------------------------------------------------------------- // Implementation of AstVisitor void AstVisitor::VisitDeclarations(ZoneList* declarations) { for (int i = 0; i < declarations->length(); i++) { Visit(declarations->at(i)); } } void AstVisitor::VisitStatements(ZoneList* statements) { for (int i = 0; i < statements->length(); i++) { Visit(statements->at(i)); } } void AstVisitor::VisitExpressions(ZoneList* expressions) { for (int i = 0; i < expressions->length(); i++) { // The variable statement visiting code may pass NULL expressions // to this code. Maybe this should be handled by introducing an // undefined expression or literal? Revisit this code if this // changes Expression* expression = expressions->at(i); if (expression != NULL) Visit(expression); } } // ---------------------------------------------------------------------------- // Regular expressions #define MAKE_ACCEPT(Name) \ void* RegExp##Name::Accept(RegExpVisitor* visitor, void* data) { \ return visitor->Visit##Name(this, data); \ } FOR_EACH_REG_EXP_TREE_TYPE(MAKE_ACCEPT) #undef MAKE_ACCEPT #define MAKE_TYPE_CASE(Name) \ RegExp##Name* RegExpTree::As##Name() { \ return NULL; \ } \ bool RegExpTree::Is##Name() { return false; } FOR_EACH_REG_EXP_TREE_TYPE(MAKE_TYPE_CASE) #undef MAKE_TYPE_CASE #define MAKE_TYPE_CASE(Name) \ RegExp##Name* RegExp##Name::As##Name() { \ return this; \ } \ bool RegExp##Name::Is##Name() { return true; } FOR_EACH_REG_EXP_TREE_TYPE(MAKE_TYPE_CASE) #undef MAKE_TYPE_CASE RegExpEmpty RegExpEmpty::kInstance; static Interval ListCaptureRegisters(ZoneList* children) { Interval result = Interval::Empty(); for (int i = 0; i < children->length(); i++) result = result.Union(children->at(i)->CaptureRegisters()); return result; } Interval RegExpAlternative::CaptureRegisters() { return ListCaptureRegisters(nodes()); } Interval RegExpDisjunction::CaptureRegisters() { return ListCaptureRegisters(alternatives()); } Interval RegExpLookahead::CaptureRegisters() { return body()->CaptureRegisters(); } Interval RegExpCapture::CaptureRegisters() { Interval self(StartRegister(index()), EndRegister(index())); return self.Union(body()->CaptureRegisters()); } Interval RegExpQuantifier::CaptureRegisters() { return body()->CaptureRegisters(); } bool RegExpAssertion::IsAnchored() { return type() == RegExpAssertion::START_OF_INPUT; } bool RegExpAlternative::IsAnchored() { ZoneList* nodes = this->nodes(); for (int i = 0; i < nodes->length(); i++) { RegExpTree* node = nodes->at(i); if (node->IsAnchored()) { return true; } if (node->max_match() > 0) { return false; } } return false; } bool RegExpDisjunction::IsAnchored() { ZoneList* alternatives = this->alternatives(); for (int i = 0; i < alternatives->length(); i++) { if (!alternatives->at(i)->IsAnchored()) return false; } return true; } bool RegExpLookahead::IsAnchored() { return is_positive() && body()->IsAnchored(); } bool RegExpCapture::IsAnchored() { return body()->IsAnchored(); } // Convert regular expression trees to a simple sexp representation. // This representation should be different from the input grammar // in as many cases as possible, to make it more difficult for incorrect // parses to look as correct ones which is likely if the input and // output formats are alike. class RegExpUnparser: public RegExpVisitor { public: RegExpUnparser(); void VisitCharacterRange(CharacterRange that); SmartPointer ToString() { return stream_.ToCString(); } #define MAKE_CASE(Name) virtual void* Visit##Name(RegExp##Name*, void* data); FOR_EACH_REG_EXP_TREE_TYPE(MAKE_CASE) #undef MAKE_CASE private: StringStream* stream() { return &stream_; } HeapStringAllocator alloc_; StringStream stream_; }; RegExpUnparser::RegExpUnparser() : stream_(&alloc_) { } void* RegExpUnparser::VisitDisjunction(RegExpDisjunction* that, void* data) { stream()->Add("(|"); for (int i = 0; i < that->alternatives()->length(); i++) { stream()->Add(" "); that->alternatives()->at(i)->Accept(this, data); } stream()->Add(")"); return NULL; } void* RegExpUnparser::VisitAlternative(RegExpAlternative* that, void* data) { stream()->Add("(:"); for (int i = 0; i < that->nodes()->length(); i++) { stream()->Add(" "); that->nodes()->at(i)->Accept(this, data); } stream()->Add(")"); return NULL; } void RegExpUnparser::VisitCharacterRange(CharacterRange that) { stream()->Add("%k", that.from()); if (!that.IsSingleton()) { stream()->Add("-%k", that.to()); } } void* RegExpUnparser::VisitCharacterClass(RegExpCharacterClass* that, void* data) { if (that->is_negated()) stream()->Add("^"); stream()->Add("["); for (int i = 0; i < that->ranges()->length(); i++) { if (i > 0) stream()->Add(" "); VisitCharacterRange(that->ranges()->at(i)); } stream()->Add("]"); return NULL; } void* RegExpUnparser::VisitAssertion(RegExpAssertion* that, void* data) { switch (that->type()) { case RegExpAssertion::START_OF_INPUT: stream()->Add("@^i"); break; case RegExpAssertion::END_OF_INPUT: stream()->Add("@$i"); break; case RegExpAssertion::START_OF_LINE: stream()->Add("@^l"); break; case RegExpAssertion::END_OF_LINE: stream()->Add("@$l"); break; case RegExpAssertion::BOUNDARY: stream()->Add("@b"); break; case RegExpAssertion::NON_BOUNDARY: stream()->Add("@B"); break; } return NULL; } void* RegExpUnparser::VisitAtom(RegExpAtom* that, void* data) { stream()->Add("'"); Vector chardata = that->data(); for (int i = 0; i < chardata.length(); i++) { stream()->Add("%k", chardata[i]); } stream()->Add("'"); return NULL; } void* RegExpUnparser::VisitText(RegExpText* that, void* data) { if (that->elements()->length() == 1) { that->elements()->at(0).data.u_atom->Accept(this, data); } else { stream()->Add("(!"); for (int i = 0; i < that->elements()->length(); i++) { stream()->Add(" "); that->elements()->at(i).data.u_atom->Accept(this, data); } stream()->Add(")"); } return NULL; } void* RegExpUnparser::VisitQuantifier(RegExpQuantifier* that, void* data) { stream()->Add("(# %i ", that->min()); if (that->max() == RegExpTree::kInfinity) { stream()->Add("- "); } else { stream()->Add("%i ", that->max()); } stream()->Add(that->is_greedy() ? "g " : that->is_possessive() ? "p " : "n "); that->body()->Accept(this, data); stream()->Add(")"); return NULL; } void* RegExpUnparser::VisitCapture(RegExpCapture* that, void* data) { stream()->Add("(^ "); that->body()->Accept(this, data); stream()->Add(")"); return NULL; } void* RegExpUnparser::VisitLookahead(RegExpLookahead* that, void* data) { stream()->Add("(-> "); stream()->Add(that->is_positive() ? "+ " : "- "); that->body()->Accept(this, data); stream()->Add(")"); return NULL; } void* RegExpUnparser::VisitBackReference(RegExpBackReference* that, void* data) { stream()->Add("(<- %i)", that->index()); return NULL; } void* RegExpUnparser::VisitEmpty(RegExpEmpty* that, void* data) { stream()->Put('%'); return NULL; } SmartPointer RegExpTree::ToString() { RegExpUnparser unparser; Accept(&unparser, NULL); return unparser.ToString(); } RegExpDisjunction::RegExpDisjunction(ZoneList* alternatives) : alternatives_(alternatives) { ASSERT(alternatives->length() > 1); RegExpTree* first_alternative = alternatives->at(0); min_match_ = first_alternative->min_match(); max_match_ = first_alternative->max_match(); for (int i = 1; i < alternatives->length(); i++) { RegExpTree* alternative = alternatives->at(i); min_match_ = Min(min_match_, alternative->min_match()); max_match_ = Max(max_match_, alternative->max_match()); } } RegExpAlternative::RegExpAlternative(ZoneList* nodes) : nodes_(nodes) { ASSERT(nodes->length() > 1); min_match_ = 0; max_match_ = 0; for (int i = 0; i < nodes->length(); i++) { RegExpTree* node = nodes->at(i); min_match_ += node->min_match(); int node_max_match = node->max_match(); if (kInfinity - max_match_ < node_max_match) { max_match_ = kInfinity; } else { max_match_ += node->max_match(); } } } // IsPrimitive implementation. IsPrimitive is true if the value of an // expression is known at compile-time to be any JS type other than Object // (e.g, it is Undefined, Null, Boolean, String, or Number). // The following expression types are never primitive because they express // Object values. bool FunctionLiteral::IsPrimitive() { return false; } bool FunctionBoilerplateLiteral::IsPrimitive() { return false; } bool RegExpLiteral::IsPrimitive() { return false; } bool ObjectLiteral::IsPrimitive() { return false; } bool ArrayLiteral::IsPrimitive() { return false; } bool CatchExtensionObject::IsPrimitive() { return false; } bool CallNew::IsPrimitive() { return false; } bool ThisFunction::IsPrimitive() { return false; } // The following expression types are not always primitive because we do not // have enough information to conclude that they are. bool VariableProxy::IsPrimitive() { return false; } bool Property::IsPrimitive() { return false; } bool Call::IsPrimitive() { return false; } bool CallRuntime::IsPrimitive() { return false; } // The value of a conditional is the value of one of the alternatives. It's // always primitive if both alternatives are always primitive. bool Conditional::IsPrimitive() { return then_expression()->IsPrimitive() && else_expression()->IsPrimitive(); } // A literal is primitive when it is not a JSObject. bool Literal::IsPrimitive() { return !handle()->IsJSObject(); } // The value of an assignment is the value of its right-hand side. bool Assignment::IsPrimitive() { switch (op()) { case Token::INIT_VAR: case Token::INIT_CONST: case Token::ASSIGN: return value()->IsPrimitive(); default: // {|=, ^=, &=, <<=, >>=, >>>=, +=, -=, *=, /=, %=} // Arithmetic operations are always primitive. They express Numbers // with the exception of +, which expresses a Number or a String. return true; } } // Throw does not express a value, so it's trivially always primitive. bool Throw::IsPrimitive() { return true; } // Unary operations always express primitive values. delete and ! express // Booleans, void Undefined, typeof String, +, -, and ~ Numbers. bool UnaryOperation::IsPrimitive() { return true; } // Count operations (pre- and post-fix increment and decrement) always // express primitive values (Numbers). See ECMA-262-3, 11.3.1, 11.3.2, // 11.4.4, ane 11.4.5. bool CountOperation::IsPrimitive() { return true; } // Binary operations depend on the operator. bool BinaryOperation::IsPrimitive() { switch (op()) { case Token::COMMA: // Value is the value of the right subexpression. return right()->IsPrimitive(); case Token::OR: case Token::AND: // Value is the value one of the subexpressions. return left()->IsPrimitive() && right()->IsPrimitive(); default: // {|, ^, &, <<, >>, >>>, +, -, *, /, %} // Arithmetic operations are always primitive. They express Numbers // with the exception of +, which expresses a Number or a String. return true; } } // Compare operations always express Boolean values. bool CompareOperation::IsPrimitive() { return true; } } } // namespace v8::internal