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castNode Class Reference

Cast expression. More...

#include <ast.h>

Inheritance diagram for castNode::

List of all members.

Public Methods
	castNode (typeNode *type, exprNode *expr, bool implicit=false, const Coord coord=Coord::Unknown)
	Create a new cast expression. More...
virtual	~castNode ()
	Destroy a castNode. More...
virtual void	eval ()
	Constant expression evaluator. More...
virtual void	dataflow (FlowVal *v, FlowProblem &fp)
	Run the dataflow analyzer. More...
virtual Node *	clone () const
	Clone the input node. More...
virtual void	output_expr (output_context &ct, Node *par, int prec, Assoc assoc)
	Output a expression. More...
virtual int	precedence (Assoc &assoc)
	Associativity and precedence. More...
Accessors
Methods to get and set fields in the class.
exprNode *	expr () const
exprNode *	get_expr ()
void	expr (exprNode *expr)
bool	is_implicit () const
AST Traversal
Methods to uniformly traverse the AST. See the documentation in the Node class.
virtual void	visit (Visitor *the_visitor)
	Dispatch a Visitor. More...
virtual void	walk (Walker &the_walker)
	Dispatch a Walker. More...
virtual Node *	change (Changer &the_changer, bool redispatch=false)
	Dispatch a Changer. More...
Private Attributes
TREE exprNode *	_expr
	the expression to which the cast is applied. More...
bool	_implicit
	true if the cast is implicit. More...

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Detailed Description

Cast expression.

This class represents casts that are explicit in the source code. This is really a binary operator, where one argument is a type and the other is an expression. The semantic checker also inserts casts for integral promotions and arithmetic conversions. These casts are called implicit casts, and do not appear in the output.

The NodeType is Cast.

See also:

exprNode::integral_promotions() , exprNode::usual_arithmetic_conversions() , implicitcastNode

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Constructor & Destructor Documentation

castNode::castNode (  typeNode *    type, exprNode *    expr, bool    implicit = false, const Coord    coord = Coord::Unknown )

Create a new cast expression. The new cast expression has the given type and subexpression. Parameters: type  the type to which the expression is being cast expr  the subexpression receiving the cast implicit  pass true to create an implicit cast coord  the location of the construct in the source file.

castNode::~castNode (    )  [virtual]

Destroy a castNode. Warning: Do not use the destructors to delete AST nodes. Instead, rely on the node garbage collector.

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Member Function Documentation

Node * castNode::change (  Changer &    the_changer, bool    redispatch = false )  [virtual]

Dispatch a Changer. This abstract method works much the walker, but allows the tree to be changed. Parameters: the_changer  the specific Changer object to use. redispatch  pass true to revisit parts of the tree that have changed. Reimplemented from Node.

virtual Node* castNode::clone (    )  const [inline, virtual]

Clone the input node. This is not a "deep" clone, so be careful. For a deep clone, use the clone_changer class. Returns: a shallow copy of the node (no subtrees are copied). Reimplemented from Node.

void castNode::dataflow (  FlowVal *    v, FlowProblem &    fp )  [virtual]

Run the dataflow analyzer. Each subclass overrides this method to define it's semantics for dataflow analysis. It alters the input flow value to reflect the effect of the node within the given flow problem, calling dataflow() on it's subtrees as necessary. See the dataflow analysis documentation for more information. Parameters: v  the flow value to pass through the node. fp  the flow problem (specifying the transfer functions). Reimplemented from Node.

void castNode::eval (    )  [virtual]

Constant expression evaluator. This method attempts to evaluate an expression at compile-time. This only yields a meaningful value when the leaves of the given expression are constants, enums, or other compile-time values (e.g., sizeof). The resulting value is stored on each exprNode, in the _value field. Each exprNode sublcass implements this method, calling it recursively when necessary. Reimplemented from exprNode.

void castNode::expr (  exprNode *    expr )  [inline]

exprNode* castNode::expr (    )  const [inline]

exprNode* castNode::get_expr (    )  [inline]

bool castNode::is_implicit (    )  const [inline]

void castNode::output_expr (  output_context &    ct, Node *    parent, int    prec, Assoc    assoc )  [virtual]

Output a expression. Reimplemented from exprNode.

int castNode::precedence (  Assoc &    assoc )  [virtual]

Associativity and precedence. Determine the associativity and precedence of the expression. Each exprNode subclass overrides this method to provide the specific results. The default is highest precedence and left-associative. See also: exprNode::output_expr() , exprNode::parens() Parameters: assoc  a reference parameter that is set to the associativity value Returns: the precedence value Reimplemented from exprNode.

void castNode::visit (  Visitor *    the_visitor )  [virtual]

Dispatch a Visitor. This abstract method is the entry point for the visitor design pattern. Each node subclass defines a visit() method that calls the appropriate at_ method in the visitor. For more information see the Visitor documentation. Parameters: the_visitor  the specific Visitor object to use. Reimplemented from Node.

void castNode::walk (  Walker &    the_walker )  [virtual]

Dispatch a Walker. This abstract method works much like the visitor, but instead walks the entire underlying subtree calling the appropriate at_ method at each node. For more information see the Walker documentation. Parameters: the_walker  the specific Walker object to use. Reimplemented from Node.

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Member Data Documentation

TREE exprNode* castNode::_expr [private]

the expression to which the cast is applied.

bool castNode::_implicit [private]

true if the cast is implicit. Implicit casts are generated by the semantic checker to make explicit any conversions between operands caused by the integral promotions and usual arithmetic conversions.

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The documentation for this class was generated from the following files:

• ast.h
• castnode.cc

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