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// Copyright 2006-2008 Google Inc. 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.

#ifndef V8_AST_H_
#define V8_AST_H_

#include "execution.h"
#include "factory.h"
#include "runtime.h"
#include "token.h"
#include "variables.h"
#include "macro-assembler.h"

namespace v8 { namespace internal {

// The abstract syntax tree is an intermediate, light-weight
// representation of the parsed JavaScript code suitable for
// compilation to native code.

// Nodes are allocated in a separate zone, which allows faster
// allocation and constant-time deallocation of the entire syntax
// tree.


// ----------------------------------------------------------------------------
// Nodes of the abstract syntax tree. Only concrete classes are
// enumerated here.

#define NODE_LIST(V) \
V(Block) \
V(Declaration) \
V(ExpressionStatement) \
V(EmptyStatement) \
V(IfStatement) \
V(ContinueStatement) \
V(BreakStatement) \
V(ReturnStatement) \
V(WithEnterStatement) \
V(WithExitStatement) \
V(SwitchStatement) \
V(LoopStatement) \
V(ForInStatement) \
V(TryCatch) \
V(TryFinally) \
V(DebuggerStatement) \
V(FunctionLiteral) \
V(FunctionBoilerplateLiteral) \
V(Conditional) \
V(Slot) \
V(VariableProxy) \
V(Literal) \
V(RegExpLiteral) \
V(ObjectLiteral) \
V(ArrayLiteral) \
V(Assignment) \
V(Throw) \
V(Property) \
V(Call) \
V(CallNew) \
V(CallRuntime) \
V(UnaryOperation) \
V(CountOperation) \
V(BinaryOperation) \
V(CompareOperation) \
V(ThisFunction)


#define DEF_FORWARD_DECLARATION(type) class type;
NODE_LIST(DEF_FORWARD_DECLARATION)
#undef DEF_FORWARD_DECLARATION


// Typedef only introduced to avoid unreadable code.
// Please do appreciate the required space in "> >".
typedef ZoneList<Handle<String> > ZoneStringList;


class Node: public ZoneObject {
public:
Node(): statement_pos_(kNoPosition) { }
virtual ~Node() { }
virtual void Accept(Visitor* v) = 0;

// Type testing & conversion.
virtual Statement* AsStatement() { return NULL; }
virtual ExpressionStatement* AsExpressionStatement() { return NULL; }
virtual EmptyStatement* AsEmptyStatement() { return NULL; }
virtual Expression* AsExpression() { return NULL; }
virtual Literal* AsLiteral() { return NULL; }
virtual Slot* AsSlot() { return NULL; }
virtual VariableProxy* AsVariableProxy() { return NULL; }
virtual Property* AsProperty() { return NULL; }
virtual Call* AsCall() { return NULL; }
virtual LabelCollector* AsLabelCollector() { return NULL; }
virtual BreakableStatement* AsBreakableStatement() { return NULL; }
virtual IterationStatement* AsIterationStatement() { return NULL; }
virtual UnaryOperation* AsUnaryOperation() { return NULL; }
virtual BinaryOperation* AsBinaryOperation() { return NULL; }
virtual Assignment* AsAssignment() { return NULL; }
virtual FunctionLiteral* AsFunctionLiteral() { return NULL; }

void set_statement_pos(int statement_pos) { statement_pos_ = statement_pos; }
int statement_pos() const { return statement_pos_; }

private:
int statement_pos_;
};


class Statement: public Node {
public:
virtual Statement* AsStatement() { return this; }
virtual ReturnStatement* AsReturnStatement() { return NULL; }

bool IsEmpty() { return AsEmptyStatement() != NULL; }
};


class Expression: public Node {
public:
virtual Expression* AsExpression() { return this; }

virtual bool IsValidLeftHandSide() { return false; }

// Mark the expression as being compiled as an expression
// statement. This is used to transform postfix increments to
// (faster) prefix increments.
virtual void MarkAsStatement() { /* do nothing */ }
};


/**
* A sentinel used during pre parsing that represents some expression
* that is a valid left hand side without having to actually build
* the expression.
*/
class ValidLeftHandSideSentinel: public Expression {
public:
virtual bool IsValidLeftHandSide() { return true; }
virtual void Accept(Visitor* v) { UNREACHABLE(); }
static ValidLeftHandSideSentinel* instance() { return &instance_; }
private:
static ValidLeftHandSideSentinel instance_;
};


class BreakableStatement: public Statement {
public:
enum Type {
TARGET_FOR_ANONYMOUS,
TARGET_FOR_NAMED_ONLY
};

// The labels associated with this statement. May be NULL;
// if it is != NULL, guaranteed to contain at least one entry.
ZoneStringList* labels() const { return labels_; }

// Type testing & conversion.
virtual BreakableStatement* AsBreakableStatement() { return this; }

// Code generation
Label* break_target() { return &break_target_; }

// Used during code generation for restoring the stack when a
// break/continue crosses a statement that keeps stuff on the stack.
int break_stack_height() { return break_stack_height_; }
void set_break_stack_height(int height) { break_stack_height_ = height; }

// Testers.
bool is_target_for_anonymous() const { return type_ == TARGET_FOR_ANONYMOUS; }

protected:
BreakableStatement(ZoneStringList* labels, Type type)
: labels_(labels), type_(type) {
ASSERT(labels == NULL || labels->length() > 0);
}

private:
ZoneStringList* labels_;
Type type_;
Label break_target_;
int break_stack_height_;
};


class Block: public BreakableStatement {
public:
Block(ZoneStringList* labels, int capacity, bool is_initializer_block)
: BreakableStatement(labels, TARGET_FOR_NAMED_ONLY),
statements_(capacity),
is_initializer_block_(is_initializer_block) { }

virtual void Accept(Visitor* v);

void AddStatement(Statement* statement) { statements_.Add(statement); }

ZoneList<Statement*>* statements() { return &statements_; }
bool is_initializer_block() const { return is_initializer_block_; }

private:
ZoneList<Statement*> statements_;
bool is_initializer_block_;
};


class Declaration: public Node {
public:
Declaration(VariableProxy* proxy, Variable::Mode mode, FunctionLiteral* fun)
: proxy_(proxy),
mode_(mode),
fun_(fun) {
ASSERT(mode == Variable::VAR || mode == Variable::CONST);
// At the moment there are no "const functions"'s in JavaScript...
ASSERT(fun == NULL || mode == Variable::VAR);
}

virtual void Accept(Visitor* v);

VariableProxy* proxy() const { return proxy_; }
Variable::Mode mode() const { return mode_; }
FunctionLiteral* fun() const { return fun_; } // may be NULL

private:
VariableProxy* proxy_;
Variable::Mode mode_;
FunctionLiteral* fun_;
};


class IterationStatement: public BreakableStatement {
public:
// Type testing & conversion.
virtual IterationStatement* AsIterationStatement() { return this; }

Statement* body() const { return body_; }

// Code generation
Label* continue_target() { return &continue_target_; }

protected:
explicit IterationStatement(ZoneStringList* labels)
: BreakableStatement(labels, TARGET_FOR_ANONYMOUS), body_(NULL) { }

void Initialize(Statement* body) {
body_ = body;
}

private:
Statement* body_;
Label continue_target_;
};


class LoopStatement: public IterationStatement {
public:
enum Type { DO_LOOP, FOR_LOOP, WHILE_LOOP };

LoopStatement(ZoneStringList* labels, Type type)
: IterationStatement(labels), type_(type), init_(NULL),
cond_(NULL), next_(NULL) { }

void Initialize(Statement* init,
Expression* cond,
Statement* next,
Statement* body) {
ASSERT(init == NULL || type_ == FOR_LOOP);
ASSERT(next == NULL || type_ == FOR_LOOP);
IterationStatement::Initialize(body);
init_ = init;
cond_ = cond;
next_ = next;
}

virtual void Accept(Visitor* v);

Type type() const { return type_; }
Statement* init() const { return init_; }
Expression* cond() const { return cond_; }
Statement* next() const { return next_; }

#ifdef DEBUG
const char* OperatorString() const;
#endif

private:
Type type_;
Statement* init_;
Expression* cond_;
Statement* next_;
};


class ForInStatement: public IterationStatement {
public:
explicit ForInStatement(ZoneStringList* labels)
: IterationStatement(labels), each_(NULL), enumerable_(NULL) { }

void Initialize(Expression* each, Expression* enumerable, Statement* body) {
IterationStatement::Initialize(body);
each_ = each;
enumerable_ = enumerable;
}

virtual void Accept(Visitor* v);

Expression* each() const { return each_; }
Expression* enumerable() const { return enumerable_; }

private:
Expression* each_;
Expression* enumerable_;
};


class ExpressionStatement: public Statement {
public:
explicit ExpressionStatement(Expression* expression)
: expression_(expression) { }

virtual void Accept(Visitor* v);

// Type testing & conversion.
virtual ExpressionStatement* AsExpressionStatement() { return this; }

void set_expression(Expression* e) { expression_ = e; }
Expression* expression() { return expression_; }

private:
Expression* expression_;
};


class ContinueStatement: public Statement {
public:
explicit ContinueStatement(IterationStatement* target)
: target_(target) { }

virtual void Accept(Visitor* v);

IterationStatement* target() const { return target_; }

private:
IterationStatement* target_;
};


class BreakStatement: public Statement {
public:
explicit BreakStatement(BreakableStatement* target)
: target_(target) { }

virtual void Accept(Visitor* v);

BreakableStatement* target() const { return target_; }

private:
BreakableStatement* target_;
};


class ReturnStatement: public Statement {
public:
explicit ReturnStatement(Expression* expression)
: expression_(expression) { }

virtual void Accept(Visitor* v);

// Type testing & conversion.
virtual ReturnStatement* AsReturnStatement() { return this; }

Expression* expression() { return expression_; }

private:
Expression* expression_;
};


class WithEnterStatement: public Statement {
public:
explicit WithEnterStatement(Expression* expression)
: expression_(expression) { }

virtual void Accept(Visitor* v);

Expression* expression() const { return expression_; }

private:
Expression* expression_;
};


class WithExitStatement: public Statement {
public:
WithExitStatement() { }

virtual void Accept(Visitor* v);
};


class CaseClause: public ZoneObject {
public:
CaseClause(Expression* label, ZoneList<Statement*>* statements)
: label_(label), statements_(statements) { }

bool is_default() const { return label_ == NULL; }
Expression* label() const {
CHECK(!is_default());
return label_;
}
ZoneList<Statement*>* statements() const { return statements_; }

private:
Expression* label_;
ZoneList<Statement*>* statements_;
};


class SwitchStatement: public BreakableStatement {
public:
explicit SwitchStatement(ZoneStringList* labels)
: BreakableStatement(labels, TARGET_FOR_ANONYMOUS),
tag_(NULL), cases_(NULL) { }

void Initialize(Expression* tag, ZoneList<CaseClause*>* cases) {
tag_ = tag;
cases_ = cases;
}

virtual void Accept(Visitor* v);

Expression* tag() const { return tag_; }
ZoneList<CaseClause*>* cases() const { return cases_; }

private:
Expression* tag_;
ZoneList<CaseClause*>* cases_;
};


// If-statements always have non-null references to their then- and
// else-parts. When parsing if-statements with no explicit else-part,
// the parser implicitly creates an empty statement. Use the
// HasThenStatement() and HasElseStatement() functions to check if a
// given if-statement has a then- or an else-part containing code.
class IfStatement: public Statement {
public:
IfStatement(Expression* condition,
Statement* then_statement,
Statement* else_statement)
: condition_(condition),
then_statement_(then_statement),
else_statement_(else_statement) { }

virtual void Accept(Visitor* v);

bool HasThenStatement() const { return !then_statement()->IsEmpty(); }
bool HasElseStatement() const { return !else_statement()->IsEmpty(); }

Expression* condition() const { return condition_; }
Statement* then_statement() const { return then_statement_; }
Statement* else_statement() const { return else_statement_; }

private:
Expression* condition_;
Statement* then_statement_;
Statement* else_statement_;
};


// NOTE: LabelCollectors are represented as nodes to fit in the target
// stack in the compiler; this should probably be reworked.
class LabelCollector: public Node {
public:
explicit LabelCollector(ZoneList<Label*>* labels) : labels_(labels) { }

// Adds a label to the collector. The collector stores a pointer not
// a copy of the label to make binding work, so make sure not to
// pass in references to something on the stack.
void AddLabel(Label* label);

// Virtual behaviour. LabelCollectors are never part of the AST.
virtual void Accept(Visitor* v) { UNREACHABLE(); }
virtual LabelCollector* AsLabelCollector() { return this; }

ZoneList<Label*>* labels() { return labels_; }

private:
ZoneList<Label*>* labels_;
};


class TryStatement: public Statement {
public:
explicit TryStatement(Block* try_block)
: try_block_(try_block), escaping_labels_(NULL) { }

void set_escaping_labels(ZoneList<Label*>* labels) {
escaping_labels_ = labels;
}

Block* try_block() const { return try_block_; }
ZoneList<Label*>* escaping_labels() const { return escaping_labels_; }

private:
Block* try_block_;
ZoneList<Label*>* escaping_labels_;
};


class TryCatch: public TryStatement {
public:
TryCatch(Block* try_block, Expression* catch_var, Block* catch_block)
: TryStatement(try_block),
catch_var_(catch_var),
catch_block_(catch_block) {
ASSERT(catch_var->AsVariableProxy() != NULL);
}

virtual void Accept(Visitor* v);

Expression* catch_var() const { return catch_var_; }
Block* catch_block() const { return catch_block_; }

private:
Expression* catch_var_;
Block* catch_block_;
};


class TryFinally: public TryStatement {
public:
TryFinally(Block* try_block, Expression* finally_var, Block* finally_block)
: TryStatement(try_block),
finally_var_(finally_var),
finally_block_(finally_block) { }

virtual void Accept(Visitor* v);

// If the finally block is non-trivial it may be problematic to have
// extra stuff on the expression stack while evaluating it. The
// finally variable is used to hold the state instead of storing it
// on the stack. It may be NULL in which case the state is stored on
// the stack.
Expression* finally_var() const { return finally_var_; }

Block* finally_block() const { return finally_block_; }

private:
Expression* finally_var_;
Block* finally_block_;
};


class DebuggerStatement: public Statement {
public:
virtual void Accept(Visitor* v);
};


class EmptyStatement: public Statement {
public:
virtual void Accept(Visitor* v);

// Type testing & conversion.
virtual EmptyStatement* AsEmptyStatement() { return this; }
};


class Literal: public Expression {
public:
explicit Literal(Handle<Object> handle) : handle_(handle) { }

virtual void Accept(Visitor* v);

// Type testing & conversion.
virtual Literal* AsLiteral() { return this; }

// Check if this literal is identical to the other literal.
bool IsIdenticalTo(const Literal* other) const {
return handle_.is_identical_to(other->handle_);
}

// Identity testers.
bool IsNull() const { return handle_.is_identical_to(Factory::null_value()); }
bool IsTrue() const { return handle_.is_identical_to(Factory::true_value()); }
bool IsFalse() const {
return handle_.is_identical_to(Factory::false_value());
}

Handle<Object> handle() const { return handle_; }

private:
Handle<Object> handle_;
};


// Base class for literals that needs space in the corresponding JSFunction.
class MaterializedLiteral: public Expression {
public:
explicit MaterializedLiteral(int literal_index)
: literal_index_(literal_index) {}
int literal_index() { return literal_index_; }
private:
int literal_index_;
};


// An object literal has a boilerplate object that is used
// for minimizing the work when constructing it at runtime.
class ObjectLiteral: public MaterializedLiteral {
public:
// Property is used for passing information
// about an object literal's properties from the parser
// to the code generator.
class Property: public ZoneObject {
public:

enum Kind {
CONSTANT, // Property with constant value (at compile time).
COMPUTED, // Property with computed value (at execution time).
GETTER, SETTER, // Property is an accessor function.
PROTOTYPE // Property is __proto__.
};

Property(Literal* key, Expression* value);
Property(bool is_getter, FunctionLiteral* value);

Literal* key() { return key_; }
Expression* value() { return value_; }
Kind kind() { return kind_; }

private:
Literal* key_;
Expression* value_;
Kind kind_;
};

ObjectLiteral(Handle<FixedArray> constant_properties,
Expression* result,
ZoneList<Property*>* properties,
int literal_index)
: MaterializedLiteral(literal_index),
constant_properties_(constant_properties),
result_(result),
properties_(properties) {
}

virtual void Accept(Visitor* v);

Handle<FixedArray> constant_properties() const {
return constant_properties_;
}
Expression* result() const { return result_; }
ZoneList<Property*>* properties() const { return properties_; }

private:
Handle<FixedArray> constant_properties_;
Expression* result_;
ZoneList<Property*>* properties_;
};


// Node for capturing a regexp literal.
class RegExpLiteral: public MaterializedLiteral {
public:
RegExpLiteral(Handle<String> pattern,
Handle<String> flags,
int literal_index)
: MaterializedLiteral(literal_index),
pattern_(pattern),
flags_(flags) {}

virtual void Accept(Visitor* v);

Handle<String> pattern() const { return pattern_; }
Handle<String> flags() const { return flags_; }

private:
Handle<String> pattern_;
Handle<String> flags_;
};

// An array literal has a literals object that is used
// used for minimizing the work when contructing it at runtime.
class ArrayLiteral: public Expression {
public:
ArrayLiteral(Handle<FixedArray> literals,
Expression* result,
ZoneList<Expression*>* values)
: literals_(literals), result_(result), values_(values) {
}

virtual void Accept(Visitor* v);

Handle<FixedArray> literals() const { return literals_; }
Expression* result() const { return result_; }
ZoneList<Expression*>* values() const { return values_; }

private:
Handle<FixedArray> literals_;
Expression* result_;
ZoneList<Expression*>* values_;
};


class VariableProxy: public Expression {
public:
virtual void Accept(Visitor* v);

// Type testing & conversion
virtual Property* AsProperty() {
return var_ == NULL ? NULL : var_->AsProperty();
}
virtual VariableProxy* AsVariableProxy() { return this; }

Variable* AsVariable() {
return this == NULL || var_ == NULL ? NULL : var_->AsVariable();
}
virtual bool IsValidLeftHandSide() {
return var_ == NULL ? true : var_->IsValidLeftHandSide();
}
bool IsVariable(Handle<String> n) {
return !is_this() && name().is_identical_to(n);
}

// If this assertion fails it means that some code has tried to
// treat the special "this" variable as an ordinary variable with
// the name "this".
Handle<String> name() const { return name_; }
Variable* var() const { return var_; }
UseCount* var_uses() { return &var_uses_; }
UseCount* obj_uses() { return &obj_uses_; }
bool is_this() const { return is_this_; }
bool inside_with() const { return inside_with_; }

// Bind this proxy to the variable var.
void BindTo(Variable* var);

protected:
Handle<String> name_;
Variable* var_; // resolved variable, or NULL
bool is_this_;
bool inside_with_;

// VariableProxy usage info.
UseCount var_uses_; // uses of the variable value
UseCount obj_uses_; // uses of the object the variable points to

VariableProxy(Handle<String> name, bool is_this, bool inside_with);
explicit VariableProxy(bool is_this);

friend class Scope;
};


class VariableProxySentinel: public VariableProxy {
public:
virtual bool IsValidLeftHandSide() { return !is_this(); }
static VariableProxySentinel* this_proxy() { return &this_proxy_; }
static VariableProxySentinel* identifier_proxy() {
return &identifier_proxy_;
}

private:
explicit VariableProxySentinel(bool is_this) : VariableProxy(is_this) { }
static VariableProxySentinel this_proxy_;
static VariableProxySentinel identifier_proxy_;
};


class Slot: public Expression {
public:
enum Type {
// A slot in the parameter section on the stack. index() is
// the parameter index, counting left-to-right, starting at 0.
PARAMETER,

// A slot in the local section on the stack. index() is
// the variable index in the stack frame, starting at 0.
LOCAL,

// An indexed slot in a heap context. index() is the
// variable index in the context object on the heap,
// starting at 0. var()->scope() is the corresponding
// scope.
CONTEXT,

// A named slot in a heap context. var()->name() is the
// variable name in the context object on the heap,
// with lookup starting at the current context. index()
// is invalid.
LOOKUP,

// A property in the global object. var()->name() is
// the property name.
GLOBAL
};

Slot(Variable* var, Type type, int index)
: var_(var), type_(type), index_(index) {
ASSERT(var != NULL);
}

virtual void Accept(Visitor* v);

// Type testing & conversion
virtual Slot* AsSlot() { return this; }

// Accessors
Variable* var() const { return var_; }
Type type() const { return type_; }
int index() const { return index_; }

private:
Variable* var_;
Type type_;
int index_;
};


class Property: public Expression {
public:
Property(Expression* obj, Expression* key, int pos)
: obj_(obj), key_(key), pos_(pos) { }

virtual void Accept(Visitor* v);

// Type testing & conversion
virtual Property* AsProperty() { return this; }

virtual bool IsValidLeftHandSide() { return true; }

Expression* obj() const { return obj_; }
Expression* key() const { return key_; }
int position() const { return pos_; }

// Returns a property singleton property access on 'this'. Used
// during preparsing.
static Property* this_property() { return &this_property_; }

private:
Expression* obj_;
Expression* key_;
int pos_;

// Dummy property used during preparsing
static Property this_property_;
};


class Call: public Expression {
public:
Call(Expression* expression,
ZoneList<Expression*>* arguments,
bool is_eval,
int pos)
: expression_(expression),
arguments_(arguments),
is_eval_(is_eval),
pos_(pos) { }

virtual void Accept(Visitor* v);

// Type testing and conversion.
virtual Call* AsCall() { return this; }

Expression* expression() const { return expression_; }
ZoneList<Expression*>* arguments() const { return arguments_; }
bool is_eval() { return is_eval_; }
int position() { return pos_; }

static Call* sentinel() { return &sentinel_; }

private:
Expression* expression_;
ZoneList<Expression*>* arguments_;
bool is_eval_;
int pos_;

static Call sentinel_;
};


class CallNew: public Call {
public:
CallNew(Expression* expression, ZoneList<Expression*>* arguments, int pos)
: Call(expression, arguments, false, pos) { }

virtual void Accept(Visitor* v);
};


// The CallRuntime class does not represent any official JavaScript
// language construct. Instead it is used to call a C or JS function
// with a set of arguments. This is used from the builtins that are
// implemented in JavaScript (see "v8natives.js").
class CallRuntime: public Expression {
public:
CallRuntime(Handle<String> name,
Runtime::Function* function,
ZoneList<Expression*>* arguments)
: name_(name), function_(function), arguments_(arguments) { }

virtual void Accept(Visitor* v);

Handle<String> name() const { return name_; }
Runtime::Function* function() const { return function_; }
ZoneList<Expression*>* arguments() const { return arguments_; }

private:
Handle<String> name_;
Runtime::Function* function_;
ZoneList<Expression*>* arguments_;
};


class UnaryOperation: public Expression {
public:
UnaryOperation(Token::Value op, Expression* expression)
: op_(op), expression_(expression) {
ASSERT(Token::IsUnaryOp(op));
}

virtual void Accept(Visitor* v);

// Type testing & conversion
virtual UnaryOperation* AsUnaryOperation() { return this; }

Token::Value op() const { return op_; }
Expression* expression() const { return expression_; }

private:
Token::Value op_;
Expression* expression_;
};


class BinaryOperation: public Expression {
public:
BinaryOperation(Token::Value op, Expression* left, Expression* right)
: op_(op), left_(left), right_(right) {
ASSERT(Token::IsBinaryOp(op));
}

virtual void Accept(Visitor* v);

// Type testing & conversion
virtual BinaryOperation* AsBinaryOperation() { return this; }

// True iff the result can be safely overwritten (to avoid allocation).
// False for operations that can return one of their operands.
bool ResultOverwriteAllowed() {
switch (op_) {
case Token::COMMA:
case Token::OR:
case Token::AND:
return false;
case Token::BIT_OR:
case Token::BIT_XOR:
case Token::BIT_AND:
case Token::SHL:
case Token::SAR:
case Token::SHR:
case Token::ADD:
case Token::SUB:
case Token::MUL:
case Token::DIV:
case Token::MOD:
return true;
default:
UNREACHABLE();
}
return false;
}

Token::Value op() const { return op_; }
Expression* left() const { return left_; }
Expression* right() const { return right_; }

private:
Token::Value op_;
Expression* left_;
Expression* right_;
};


class CountOperation: public Expression {
public:
CountOperation(bool is_prefix, Token::Value op, Expression* expression)
: is_prefix_(is_prefix), op_(op), expression_(expression) {
ASSERT(Token::IsCountOp(op));
}

virtual void Accept(Visitor* v);

bool is_prefix() const { return is_prefix_; }
bool is_postfix() const { return !is_prefix_; }
Token::Value op() const { return op_; }
Expression* expression() const { return expression_; }

virtual void MarkAsStatement() { is_prefix_ = true; }

private:
bool is_prefix_;
Token::Value op_;
Expression* expression_;
};


class CompareOperation: public Expression {
public:
CompareOperation(Token::Value op, Expression* left, Expression* right)
: op_(op), left_(left), right_(right) {
ASSERT(Token::IsCompareOp(op));
}

virtual void Accept(Visitor* v);

Token::Value op() const { return op_; }
Expression* left() const { return left_; }
Expression* right() const { return right_; }

private:
Token::Value op_;
Expression* left_;
Expression* right_;
};


class Conditional: public Expression {
public:
Conditional(Expression* condition,
Expression* then_expression,
Expression* else_expression)
: condition_(condition),
then_expression_(then_expression),
else_expression_(else_expression) { }

virtual void Accept(Visitor* v);

Expression* condition() const { return condition_; }
Expression* then_expression() const { return then_expression_; }
Expression* else_expression() const { return else_expression_; }

private:
Expression* condition_;
Expression* then_expression_;
Expression* else_expression_;
};


class Assignment: public Expression {
public:
Assignment(Token::Value op, Expression* target, Expression* value, int pos)
: op_(op), target_(target), value_(value), pos_(pos) {
ASSERT(Token::IsAssignmentOp(op));
}

virtual void Accept(Visitor* v);
virtual Assignment* AsAssignment() { return this; }

Token::Value binary_op() const;

Token::Value op() const { return op_; }
Expression* target() const { return target_; }
Expression* value() const { return value_; }
int position() { return pos_; }

private:
Token::Value op_;
Expression* target_;
Expression* value_;
int pos_;
};


class Throw: public Expression {
public:
Throw(Expression* exception, int pos)
: exception_(exception), pos_(pos) {}

virtual void Accept(Visitor* v);
Expression* exception() const { return exception_; }
int position() const { return pos_; }

private:
Expression* exception_;
int pos_;
};


class FunctionLiteral: public Expression {
public:
FunctionLiteral(Handle<String> name,
Scope* scope,
ZoneList<Statement*>* body,
int materialized_literal_count,
int expected_property_count,
int num_parameters,
int start_position,
int end_position,
bool is_expression)
: name_(name),
scope_(scope),
body_(body),
materialized_literal_count_(materialized_literal_count),
expected_property_count_(expected_property_count),
num_parameters_(num_parameters),
start_position_(start_position),
end_position_(end_position),
is_expression_(is_expression),
function_token_position_(kNoPosition) {
}

virtual void Accept(Visitor* v);

// Type testing & conversion
virtual FunctionLiteral* AsFunctionLiteral() { return this; }

Handle<String> name() const { return name_; }
Scope* scope() const { return scope_; }
ZoneList<Statement*>* body() const { return body_; }
void set_function_token_position(int pos) { function_token_position_ = pos; }
int function_token_position() const { return function_token_position_; }
int start_position() const { return start_position_; }
int end_position() const { return end_position_; }
bool is_expression() const { return is_expression_; }

int materialized_literal_count() { return materialized_literal_count_; }
int expected_property_count() { return expected_property_count_; }
int num_parameters() { return num_parameters_; }

bool AllowsLazyCompilation();

private:
Handle<String> name_;
Scope* scope_;
ZoneList<Statement*>* body_;
int materialized_literal_count_;
int expected_property_count_;
int num_parameters_;
int start_position_;
int end_position_;
bool is_expression_;
int function_token_position_;
};


class FunctionBoilerplateLiteral: public Expression {
public:
explicit FunctionBoilerplateLiteral(Handle<JSFunction> boilerplate)
: boilerplate_(boilerplate) {
ASSERT(boilerplate->IsBoilerplate());
}

Handle<JSFunction> boilerplate() const { return boilerplate_; }

virtual void Accept(Visitor* v);

private:
Handle<JSFunction> boilerplate_;
};


class ThisFunction: public Expression {
public:
virtual void Accept(Visitor* v);
};


// ----------------------------------------------------------------------------
// Basic visitor
// - leaf node visitors are abstract.

class Visitor BASE_EMBEDDED {
public:
Visitor() : stack_overflow_(false) { }
virtual ~Visitor() { }

// Dispatch
void Visit(Node* node) { node->Accept(this); }

// Iteration
virtual void VisitStatements(ZoneList<Statement*>* statements);
virtual void VisitExpressions(ZoneList<Expression*>* expressions);

// Stack overflow tracking support.
bool HasStackOverflow() const { return stack_overflow_; }
bool CheckStackOverflow() {
if (stack_overflow_) return true;
StackLimitCheck check;
if (!check.HasOverflowed()) return false;
return (stack_overflow_ = true);
}

// If a stack-overflow exception is encountered when visiting a
// node, calling SetStackOverflow will make sure that the visitor
// bails out without visiting more nodes.
void SetStackOverflow() { stack_overflow_ = true; }


// Individual nodes
#define DEF_VISIT(type) \
virtual void Visit##type(type* node) = 0;
NODE_LIST(DEF_VISIT)
#undef DEF_VISIT

private:
bool stack_overflow_;
};


} } // namespace v8::internal

#endif // V8_AST_H_

Change log

r8 by kasper.lund on Jul 30, 2008   Diff
Changed all text files to have native svn
:eol-style.

Added a few samples and support for
building them. The samples include a
simple shell that can be used to benchmark
and test V8.

Changed V8::GetVersion to return the
version as a string.

Added source for lazily loaded scripts to
...
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