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unaryNode Class Reference

Unary operator. More...

#include <ast.h>

Inheritance diagram for unaryNode::

exprNode Node List of all members.

Public Methods

 unaryNode (unsigned int op_id, exprNode *expr, const Coord coord=Coord::Unknown)
 Create a new unary expression. More...

 unaryNode (unsigned int op_id, typeNode *the_type, const Coord coord=Coord::Unknown)
 Create a sizeof expression. More...

virtual ~unaryNode ()
 Destroy a unaryNode. 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.

Operator * op () const
void op (Operator *op)
exprNode * expr () const
exprNode * get_expr ()
void expr (exprNode *expr)
typeNode * sizeof_type () const
typeNode * get_sizeof_type ()
void sizeof_type (typeNode *sizeof_type)
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

Operator * _op
 the operator. More...

TREE exprNode * _expr
 the sub-expression. More...

TREE typeNode * _sizeof_type
 the sizeof type. More...


Detailed Description

Unary operator.

This class represents most expression with one argument (unary operator expressions).

The NodeType is Unary.


Constructor & Destructor Documentation

unaryNode::unaryNode (  unsigned int    op_id,
exprNode *    expr,
const Coord    coord = Coord::Unknown
) 
 

Create a new unary expression.

The new expression has the given operator and subexpression. The operator is given using its identifier from the parser. For most operators, this is simply the char representation. For example, we pass '+' to get the addition operator. For ambiguous operators and multiple-character operators, you need to look up the proper identifier in the Operators table.

See also:
Operator , Operators , Operators::table
Parameters:
op_id  the id of the operator (usually, just the char representation)
expr  the sub-expression
coord  the location of the construct in the source file.

unaryNode::unaryNode (  unsigned int    op_id,
typeNode *    the_type,
const Coord    coord = Coord::Unknown
) 
 

Create a sizeof expression.

This constructor differs in that it takes a type as the subexpression.

Parameters:
op_id  the operator (should always be sizeof -- why is this optional?)
the_type  the type given to the sizeof operator
coord  the location of the construct in the source file.

unaryNode::~unaryNode (    )  [virtual]
 

Destroy a unaryNode.

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


Member Function Documentation

Node * unaryNode::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* unaryNode::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 unaryNode::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 unaryNode::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 unaryNode::expr (  exprNode *    expr )  [inline]
 

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

exprNode* unaryNode::get_expr (    )  [inline]
 

typeNode* unaryNode::get_sizeof_type (    )  [inline]
 

void unaryNode::op (  Operator *    op )  [inline]
 

Operator* unaryNode::op (    )  const [inline]
 

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

Output a expression.

Reimplemented from exprNode.

int unaryNode::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 unaryNode::sizeof_type (  typeNode *    sizeof_type )  [inline]
 

typeNode* unaryNode::sizeof_type (    )  const [inline]
 

void unaryNode::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 unaryNode::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.


Member Data Documentation

TREE exprNode* unaryNode::_expr [private]
 

the sub-expression.

Operator* unaryNode::_op [private]
 

the operator.

The operator object actually resides the Operators table.

See also:
Operator , Operators

TREE typeNode* unaryNode::_sizeof_type [private]
 

the sizeof type.

For sizeof expressions given with a type, this field holds that type.


The documentation for this class was generated from the following files:
Generated on Thu Jan 10 12:06:35 2002 for C-Breeze by doxygen1.2.13.1 written by Dimitri van Heesch, © 1997-2001