llvm-6502/include/llvm/Support/CFG.h
2008-03-06 06:54:53 +00:00

276 lines
9.6 KiB
C++

//===-- llvm/Support/CFG.h - Process LLVM structures as graphs --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines specializations of GraphTraits that allow Function and
// BasicBlock graphs to be treated as proper graphs for generic algorithms.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_CFG_H
#define LLVM_SUPPORT_CFG_H
#include "llvm/ADT/GraphTraits.h"
#include "llvm/Function.h"
#include "llvm/InstrTypes.h"
#include "llvm/ADT/iterator"
namespace llvm {
//===--------------------------------------------------------------------===//
// BasicBlock pred_iterator definition
//===--------------------------------------------------------------------===//
template <class _Ptr, class _USE_iterator> // Predecessor Iterator
class PredIterator : public forward_iterator<_Ptr, ptrdiff_t> {
typedef forward_iterator<_Ptr, ptrdiff_t> super;
_USE_iterator It;
public:
typedef PredIterator<_Ptr,_USE_iterator> _Self;
typedef typename super::pointer pointer;
inline void advancePastNonPreds() {
// Loop to ignore non predecessor uses (for example PHI nodes)...
while (!It.atEnd() && !isa<TerminatorInst>(*It) && !isa<BasicBlock>(*It))
++It;
}
inline PredIterator(_Ptr *bb) : It(bb->use_begin()) {
advancePastNonPreds();
}
inline PredIterator(_Ptr *bb, bool) : It(bb->use_end()) {}
inline bool operator==(const _Self& x) const { return It == x.It; }
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
assert(!It.atEnd() && "pred_iterator out of range!");
if (isa<TerminatorInst>(*It)) // not dyn_cast due to const-correctness
return cast<TerminatorInst>(*It)->getParent();
return cast<_Ptr>(*It);
}
inline pointer *operator->() const { return &(operator*()); }
inline _Self& operator++() { // Preincrement
assert(!It.atEnd() && "pred_iterator out of range!");
++It; advancePastNonPreds();
return *this;
}
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
};
typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
typedef PredIterator<const BasicBlock,
Value::use_const_iterator> pred_const_iterator;
inline pred_iterator pred_begin(BasicBlock *BB) { return pred_iterator(BB); }
inline pred_const_iterator pred_begin(const BasicBlock *BB) {
return pred_const_iterator(BB);
}
inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);}
inline pred_const_iterator pred_end(const BasicBlock *BB) {
return pred_const_iterator(BB, true);
}
//===--------------------------------------------------------------------===//
// BasicBlock succ_iterator definition
//===--------------------------------------------------------------------===//
template <class Term_, class BB_> // Successor Iterator
class SuccIterator : public bidirectional_iterator<BB_, ptrdiff_t> {
const Term_ Term;
unsigned idx;
typedef bidirectional_iterator<BB_, ptrdiff_t> super;
public:
typedef SuccIterator<Term_, BB_> _Self;
typedef typename super::pointer pointer;
// TODO: This can be random access iterator, need operator+ and stuff tho
inline SuccIterator(Term_ T) : Term(T), idx(0) { // begin iterator
assert(T && "getTerminator returned null!");
}
inline SuccIterator(Term_ T, bool) // end iterator
: Term(T), idx(Term->getNumSuccessors()) {
assert(T && "getTerminator returned null!");
if (Term->getParent()->getUnwindDest())
++idx;
}
inline const _Self &operator=(const _Self &I) {
assert(Term == I.Term &&"Cannot assign iterators to two different blocks!");
idx = I.idx;
return *this;
}
/// getSuccessorIndex - This is used to interface between code that wants to
/// operate on terminator instructions directly.
unsigned getSuccessorIndex() const { return idx; }
inline bool operator==(const _Self& x) const { return idx == x.idx; }
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
if (idx == Term->getNumSuccessors())
return Term->getParent()->getUnwindDest();
return Term->getSuccessor(idx);
}
inline pointer operator->() const { return operator*(); }
inline _Self& operator++() { ++idx; return *this; } // Preincrement
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
inline _Self& operator--() { --idx; return *this; } // Predecrement
inline _Self operator--(int) { // Postdecrement
_Self tmp = *this; --*this; return tmp;
}
};
typedef SuccIterator<TerminatorInst*, BasicBlock> succ_iterator;
typedef SuccIterator<const TerminatorInst*,
const BasicBlock> succ_const_iterator;
inline succ_iterator succ_begin(BasicBlock *BB) {
return succ_iterator(BB->getTerminator());
}
inline succ_const_iterator succ_begin(const BasicBlock *BB) {
return succ_const_iterator(BB->getTerminator());
}
inline succ_iterator succ_end(BasicBlock *BB) {
return succ_iterator(BB->getTerminator(), true);
}
inline succ_const_iterator succ_end(const BasicBlock *BB) {
return succ_const_iterator(BB->getTerminator(), true);
}
//===--------------------------------------------------------------------===//
// GraphTraits specializations for basic block graphs (CFGs)
//===--------------------------------------------------------------------===//
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks...
template <> struct GraphTraits<BasicBlock*> {
typedef BasicBlock NodeType;
typedef succ_iterator ChildIteratorType;
static NodeType *getEntryNode(BasicBlock *BB) { return BB; }
static inline ChildIteratorType child_begin(NodeType *N) {
return succ_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return succ_end(N);
}
};
template <> struct GraphTraits<const BasicBlock*> {
typedef const BasicBlock NodeType;
typedef succ_const_iterator ChildIteratorType;
static NodeType *getEntryNode(const BasicBlock *BB) { return BB; }
static inline ChildIteratorType child_begin(NodeType *N) {
return succ_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return succ_end(N);
}
};
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks... and to walk it in inverse order. Inverse order for
// a function is considered to be when traversing the predecessor edges of a BB
// instead of the successor edges.
//
template <> struct GraphTraits<Inverse<BasicBlock*> > {
typedef BasicBlock NodeType;
typedef pred_iterator ChildIteratorType;
static NodeType *getEntryNode(Inverse<BasicBlock *> G) { return G.Graph; }
static inline ChildIteratorType child_begin(NodeType *N) {
return pred_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return pred_end(N);
}
};
template <> struct GraphTraits<Inverse<const BasicBlock*> > {
typedef const BasicBlock NodeType;
typedef pred_const_iterator ChildIteratorType;
static NodeType *getEntryNode(Inverse<const BasicBlock*> G) {
return G.Graph;
}
static inline ChildIteratorType child_begin(NodeType *N) {
return pred_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return pred_end(N);
}
};
//===--------------------------------------------------------------------===//
// GraphTraits specializations for function basic block graphs (CFGs)
//===--------------------------------------------------------------------===//
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks... these are the same as the basic block iterators,
// except that the root node is implicitly the first node of the function.
//
template <> struct GraphTraits<Function*> : public GraphTraits<BasicBlock*> {
static NodeType *getEntryNode(Function *F) { return &F->getEntryBlock(); }
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef Function::iterator nodes_iterator;
static nodes_iterator nodes_begin(Function *F) { return F->begin(); }
static nodes_iterator nodes_end (Function *F) { return F->end(); }
};
template <> struct GraphTraits<const Function*> :
public GraphTraits<const BasicBlock*> {
static NodeType *getEntryNode(const Function *F) {return &F->getEntryBlock();}
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef Function::const_iterator nodes_iterator;
static nodes_iterator nodes_begin(const Function *F) { return F->begin(); }
static nodes_iterator nodes_end (const Function *F) { return F->end(); }
};
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks... and to walk it in inverse order. Inverse order for
// a function is considered to be when traversing the predecessor edges of a BB
// instead of the successor edges.
//
template <> struct GraphTraits<Inverse<Function*> > :
public GraphTraits<Inverse<BasicBlock*> > {
static NodeType *getEntryNode(Inverse<Function*> G) {
return &G.Graph->getEntryBlock();
}
};
template <> struct GraphTraits<Inverse<const Function*> > :
public GraphTraits<Inverse<const BasicBlock*> > {
static NodeType *getEntryNode(Inverse<const Function *> G) {
return &G.Graph->getEntryBlock();
}
};
} // End llvm namespace
#endif