C-Breeze
C Compiler Infrastructure

[ Project home page]
Main Page | Modules | Namespace List | Class Hierarchy | Alphabetical List | Class List | Directories | File List | Namespace Members | Class Members | File Members | Related Pages

basicblockNode Class Reference
[The AST nodes]

Basic block. More...

#include <ast.h>

Inheritance diagram for basicblockNode:

blockNode stmtNode Node List of all members.

Garbage collection.

bool mark
static node_list nodes
static map< Node *, bool > deleted_nodes

Public Member Functions

 basicblockNode (decl_list *decls, stmt_list *stmts, const Coord left_coord=Coord::Unknown, const Coord right_brace=Coord::Unknown)
 Create a new basic block.
virtual ~basicblockNode ()
 Destroy a basicblockNode.
virtual Node * clone () const
 Clone the input node.
typeNode * base_type (bool TdefIndir) const
 Return the base data type of a node.
virtual void dataflow (FlowVal *v, FlowProblem &fp)
 Run the dataflow analyzer.
virtual void output_stmt (output_context &ct, Node *par)
 Output a statement.
virtual void output (output_context &ct, Node *par)
 Generate C code.
void output_comment (output_context &ct)
virtual typeNode * type () const
 Return the node data type.
typeNode * datatype () const
 Call base_type() with the argument true.
typeNode * datatype_superior () const
 Call base_type() with the argument false.
Accessors
Methods to get and set fields in the class.

basicblock_list & preds ()
const basicblock_list & preds () const
basicblock_list & succs ()
const basicblock_list & succs () const
basicblockNode * parent () const
void parent (basicblockNode *par)
basicblock_list & children ()
const basicblock_list & children () const
algorithm_info * info () const
void info (algorithm_info *i)
int dfn () const
void dfn (int d)
FlowVal * at_entry () const
void at_entry (FlowVal *ae)
FlowVal * at_exit () const
void at_exit (FlowVal *ae)
AST Traversal
Methods to uniformly traverse the AST. See the documentation in the Node class.

virtual void visit (Visitor *the_visitor)
 Dispatch a Visitor.
virtual void walk (Walker &the_walker)
 Dispatch a Walker.
virtual Node * change (Changer &the_changer, bool redispatch=false)
 Dispatch a Changer.
Accessors
Methods to get and set fields in the class.

decl_list & decls ()
const decl_list & decls () const
stmt_list & stmts ()
const stmt_list & stmts () const
Coord right_brace () const
void right_brace (const Coord right_brace)
Accessors
Methods to get and set fields in the class.

string & comment ()
Accessors
Methods to get and set fields in the class.

NodeType typ () const
 Get the node type.
Coord coord () const
 Get the source location.
void coord (const Coord coord)
 Set the source location.
bool parenthesized () const
 Get the parenthesized boolean.
void parenthesized (bool paren)
 Set the parenthesized boolean.
annote_list & annotations ()
 Get the annotations list.
FlowVal * gen () const
 Get the "gen" flow value.
void gen (FlowVal *g)
 Set the "gen" flow value.
FlowVal * kill () const
 Get the "kill" flow value.
void kill (FlowVal *k)
 Set the "kill" flow value.

Static Public Member Functions

static blockNode * toBlock (stmtNode *stmt, Coord coord)
 Convert to block.
static void report ()
 Report node count statistics.

Private Attributes

basicblock_list _preds
 the control-flow predecessors
basicblock_list _succs
 the control-flow successors
basicblockNode * _parent
 the parent in the dominator tree
basicblock_list _children
 the children in the dominator tree
algorithm_info * _info
 algorithm info
int _dfn
 depth-first numbering
FlowVal * _at_entry
 dataflow analysis entry value
FlowVal * _at_exit
 dataflow analysis exit value

Detailed Description

Basic block.

This subclass of blockNode represents code in basic block form to support the construction of a control-flow graph and algorithms based on that graph. Initial parsing does not produce this form. To convert the AST into a control-flow graph, first dismantle the code (using the Dismantle class) then invoke the control-flow graph algorithm (using the cfg_changer). This form also supports several other analysis algorithms, such as dominators (using the Dominators class), dominance frontiers (using the DominanceFrontiers class) and pointer analysis (using the Pointers class).

Each basicblockNode has added fields for specifying control-flow predecessors and successors, as well as fields for representing a dominator tree.

The NodeType is Block (from the superclass)

See also:
Dismantle

cfg_changer

Dominators

DominanceFrontiers

Pointers

Definition at line 4485 of file ast.h.

Constructor & Destructor Documentation

basicblockNode::basicblockNode (  decl_list *  decls,
stmt_list *  stmts,
const Coord  left_coord = Coord::Unknown,
const Coord  right_brace = Coord::Unknown
) 
 

Create a new basic block.

The basic block has the given declarations and statements (see the constructor for blockNode). By default, all the lists are empty, and the other references are null.

Parameters:
decls the list of declarations
stmts the list of statements
coord the location of the left curly brace in the source file.
coord the location of the right curly brace in the source file.

Referenced by clone().

virtual basicblockNode::~basicblockNode (   )  [virtual]
 

Destroy a basicblockNode.

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

Member Function Documentation

annote_list& Node::annotations (   )  [inline, inherited]
 

Get the annotations list.

This method returns a modifiable reference to the list of annotations on the node. Users can add new annotations, search for annotations, or remove annotations. Users are responsible for ensuring that every element of the annotation list points to a valid annotation. In particular, no element should be NULL.

See also:
Annote class

Definition at line 274 of file ast.h.

References Node::_annotations.

void basicblockNode::at_entry (  FlowVal *  ae  )  [inline]
 

Definition at line 4592 of file ast.h.

References _at_entry.

FlowVal* basicblockNode::at_entry (   )  const [inline]
 

Definition at line 4591 of file ast.h.

References _at_entry.

void basicblockNode::at_exit (  FlowVal *  ae  )  [inline]
 

Reimplemented from stmtNode.

Definition at line 4595 of file ast.h.

References _at_exit.

FlowVal* basicblockNode::at_exit (   )  const [inline]
 

Reimplemented from stmtNode.

Definition at line 4594 of file ast.h.

References _at_exit.

typeNode* blockNode::base_type (  bool  TdefIndir  )  const [virtual, inherited]
 

Return the base data type of a node.

This method differs from the Node::type() method in two respects. First, it follows some of the simple type inferences. For example, calling it on an idNode will return the type of its declaration. Second, the boolean argument indicates whether or not to follow typedef links.

Parameters:
TdefIndir pass true to follow typedefs to their definitions.

Reimplemented from Node.

virtual Node* basicblockNode::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 blockNode.

const basicblock_list& basicblockNode::children (   )  const [inline]
 

Definition at line 4581 of file ast.h.

References _children.

basicblock_list& basicblockNode::children (   )  [inline]
 

Definition at line 4580 of file ast.h.

References _children.

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

Clone the input node.

This is not a "deep" clone, so be careful. For a deep clone, use the ref_clone_changer class.

Returns:
a shallow copy of the node (no subtrees are copied).

Reimplemented from blockNode.

Definition at line 4614 of file ast.h.

References basicblockNode().

string& stmtNode::comment (   )  [inline, inherited]
 

Definition at line 4286 of file ast.h.

References stmtNode::_comment.

void Node::coord (  const Coord  coord  )  [inline, inherited]
 

Set the source location.

This location should indicate the position in the source text that this Node represents, or Coord::Unknown if it does not represent any node in the source text.

It is not common to set the source location of a node. Currently, only the compiler error messages actually make use of it.

Parameters:
coord the new location.

Definition at line 243 of file ast.h.

References Node::_coord.

Coord Node::coord (   )  const [inline, inherited]
 

Get the source location.

The Coord class holds a location in the input source (file, line, position). During parsing, each AST node created records the position of the source text that it represents. However, subsequent phases may create or change nodes, so no guarantee is given about how the source location corresponds to the original source text.

Returns:
the Coord structure indicating where the node came from in the source file.

Definition at line 230 of file ast.h.

References Node::_coord.

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

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).

Implements Node.

typeNode* Node::datatype (   )  const [inherited]
 

Call base_type() with the argument true.

typeNode* Node::datatype_superior (   )  const [inherited]
 

Call base_type() with the argument false.

const decl_list& blockNode::decls (   )  const [inline, inherited]
 

Definition at line 4418 of file ast.h.

References blockNode::_decls.

decl_list& blockNode::decls (   )  [inline, inherited]
 

Definition at line 4417 of file ast.h.

References blockNode::_decls.

Referenced by UnusedDeclarationCleanupChanger::at_proc().

void basicblockNode::dfn (  int  d  )  [inline]
 

Definition at line 4587 of file ast.h.

References _dfn.

int basicblockNode::dfn (   )  const [inline]
 

Definition at line 4586 of file ast.h.

References _dfn.

void Node::gen (  FlowVal *  g  )  [inline, inherited]
 

Set the "gen" flow value.

This value is used in dataflow analyses to store information that is generated at this node. Note that each node has exactly one "gen" flow value.

In order to set the flow value to be empty, call this method with a value of NULL.

Parameters:
g the new gen flow value.

Definition at line 297 of file ast.h.

References Node::_gen.

FlowVal* Node::gen (   )  const [inline, inherited]
 

Get the "gen" flow value.

This value is used in dataflow analyses to store information that is generated at this node. Note that each node has exactly one "gen" flow value.

Returns:
the "gen" flow value.

Definition at line 284 of file ast.h.

References Node::_gen.

void basicblockNode::info (  algorithm_info *  i  )  [inline]
 

Definition at line 4584 of file ast.h.

References _info.

algorithm_info* basicblockNode::info (   )  const [inline]
 

Definition at line 4583 of file ast.h.

References _info.

void Node::kill (  FlowVal *  k  )  [inline, inherited]
 

Set the "kill" flow value.

This value is used in dataflow analyses to store information that is killed at this node. Note that each node has exactly one "kill" flow value.

To set the flow value to be empty, call this method with a value of NULL.

Parameters:
k the new kill flow value.

Definition at line 320 of file ast.h.

References Node::_kill.

FlowVal* Node::kill (   )  const [inline, inherited]
 

Get the "kill" flow value.

This value is used in dataflow analyses to store information that is killed at this node. Note that each node has exactly one "kill" flow value.

Returns:
the "kill" flow value.

Definition at line 307 of file ast.h.

References Node::_kill.

virtual void stmtNode::output (  output_context &  ct,
Node *  par
)  [virtual, inherited]
 

Generate C code.

Each subclass overrides this method to define how to produce the output C code. To use this method, pass an output_context and a null parent.

Parameters:
ct the output context which describes the formatting.
par the parent node (or null, if at the top of a subtree).

Implements Node.

void stmtNode::output_comment (  output_context &  ct  )  [inherited]
 

virtual void blockNode::output_stmt (  output_context &  ct,
Node *  par
)  [virtual, inherited]
 

Output a statement.

Implements stmtNode.

void basicblockNode::parent (  basicblockNode *  par  )  [inline]
 

Definition at line 4578 of file ast.h.

References _parent.

basicblockNode* basicblockNode::parent (   )  const [inline]
 

Definition at line 4577 of file ast.h.

References _parent.

void Node::parenthesized (  bool  paren  )  [inline, inherited]
 

Set the parenthesized boolean.

This boolean determines whether this expression will be parenthesized in the output. Note that that the parentheses will always be added when they are needed to disambiguate the output. This variable only controls the use of "un-necessary" parentheses.

Parameters:
paren the new value of the parenthesized boolean.

Definition at line 262 of file ast.h.

References Node::_parenthesized.

bool Node::parenthesized (   )  const [inline, inherited]
 

Get the parenthesized boolean.

Returns:
true if the construct corresponding to this Node was parenthesized in the source.

Definition at line 250 of file ast.h.

References Node::_parenthesized.

const basicblock_list& basicblockNode::preds (   )  const [inline]
 

Definition at line 4572 of file ast.h.

References _preds.

basicblock_list& basicblockNode::preds (   )  [inline]
 

Definition at line 4571 of file ast.h.

References _preds.

static void Node::report (   )  [static, inherited]
 

Report node count statistics.

The code can be configured to gather statistics about node usage according to type. This method prints the current state of that accounting information to standard out.

void blockNode::right_brace (  const Coord  right_brace  )  [inline, inherited]
 

Definition at line 4424 of file ast.h.

References blockNode::_right_brace.

Coord blockNode::right_brace (   )  const [inline, inherited]
 

Definition at line 4423 of file ast.h.

References blockNode::_right_brace.

const stmt_list& blockNode::stmts (   )  const [inline, inherited]
 

Definition at line 4421 of file ast.h.

References blockNode::_stmts.

stmt_list& blockNode::stmts (   )  [inline, inherited]
 

Definition at line 4420 of file ast.h.

References blockNode::_stmts.

Referenced by DismantleUtil::empty_block().

const basicblock_list& basicblockNode::succs (   )  const [inline]
 

Definition at line 4575 of file ast.h.

References _succs.

basicblock_list& basicblockNode::succs (   )  [inline]
 

Definition at line 4574 of file ast.h.

References _succs.

static blockNode* blockNode::toBlock (  stmtNode *  stmt,
Coord  coord
)  [static, inherited]
 

Convert to block.

This method is used primarily by the parser to make sure that all branch bodies and loop bodies are represented by blockNodes, even if they aren't in the source code. For example:

  if (cond) x = x + 1;

Even though the body of the branch is just a single statement, we build a block containing that one statement:

  if (cond) { x = x + 1; }

This simplifies many other kinds of processing. For example, it makes it easy to add statements to the branch body.

The method looks at the type of the input statement. If it is already a compound statement, it is return unchanged. Otherwise, it creates a compound statement, puts the statement in it, and then returns the compound statement.

Parameters:
stmt the statement to covert, if necessary
coord the location of the construct in the source file.
Returns:
the statement as a blockNode

NodeType Node::typ (   )  const [inline, inherited]
 

Get the node type.

This has nothing to do with types in the source code. It indicates what kind of AST node this is (e.g., a unary expression node or a while node).

Returns:
the node type.

Definition at line 216 of file ast.h.

References Node::_typ.

Referenced by gcWalker::delete_nodes(), and NodeInfo::nodeIndex().

virtual typeNode* Node::type (   )  const [inline, virtual, inherited]
 

Return the node data type.

This method returns the C data type of a node. Several different kinds of nodes contain typeNode pointers. This method is just a unified way to access them. It does not attempt to compute the type, it just returns whatever typeNode pointer resides on the node. The subclasses that have types return them, and the others return null.

Returns:
the typeNode pointer on the node.

Reimplemented in declNode, typeNode, exprNode, and operandNode.

Definition at line 342 of file ast.h.

virtual void basicblockNode::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 blockNode.

virtual void basicblockNode::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 blockNode.

Member Data Documentation

FlowVal* basicblockNode::_at_entry [private]
 

dataflow analysis entry value

This field is used by the dataflow analysis framework to accumulate the flow-value coming into the basic block from it's predecessors. Sometimes, it's referred to as IN[B].

Definition at line 4531 of file ast.h.

Referenced by at_entry().

FlowVal* basicblockNode::_at_exit [private]
 

dataflow analysis exit value

This field is used by the dataflow analysis framework to hold the flow value exiting the basic block. It is typically computed by passing the _at_entry through the transfer functions of the statements in the block. Sometimes, it's referred to as OUT[B].

Reimplemented from stmtNode.

Definition at line 4540 of file ast.h.

Referenced by at_exit().

basicblock_list basicblockNode::_children [private]
 

the children in the dominator tree

This is the set of basic blocks that are immediately dominated by this one.

Definition at line 4508 of file ast.h.

Referenced by children().

int basicblockNode::_dfn [private]
 

depth-first numbering

Each basic block can be assignmed a number, usually in depth-first order. This is useful for building a bit-vector representation of sets of basic blocks.

Definition at line 4523 of file ast.h.

Referenced by dfn().

algorithm_info* basicblockNode::_info [private]
 

algorithm info

This field is used by various algorithms to temporarily attach some information to a basic block.

Definition at line 4515 of file ast.h.

Referenced by info().

basicblockNode* basicblockNode::_parent [private]
 

the parent in the dominator tree

This is the immediate dominator of this basic block.

Definition at line 4501 of file ast.h.

Referenced by parent().

basicblock_list basicblockNode::_preds [private]
 

the control-flow predecessors

Definition at line 4491 of file ast.h.

Referenced by preds().

basicblock_list basicblockNode::_succs [private]
 

the control-flow successors

Definition at line 4495 of file ast.h.

Referenced by succs().

map<Node *, bool> Node::deleted_nodes [static, inherited]
 

Definition at line 165 of file ast.h.

Referenced by gcWalker::delete_nodes().

bool Node::mark [inherited]
 

Definition at line 168 of file ast.h.

Referenced by gcWalker::at_binary(), and gcWalker::delete_nodes().

node_list Node::nodes [static, inherited]
 

Definition at line 162 of file ast.h.

Referenced by gcWalker::delete_nodes(), and gcWalker::gcWalker().

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

Generated on February 1, 2006
Back to the C-Breeze home page