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Diffstat (limited to 'include/llvm/IR/CFG.h')
| -rw-r--r-- | include/llvm/IR/CFG.h | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/include/llvm/IR/CFG.h b/include/llvm/IR/CFG.h new file mode 100644 index 000000000000..a7ff4aeaa0d6 --- /dev/null +++ b/include/llvm/IR/CFG.h @@ -0,0 +1,383 @@ +//===- 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_IR_CFG_H +#define LLVM_IR_CFG_H + +#include "llvm/ADT/GraphTraits.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/InstrTypes.h" + +namespace llvm { + +//===----------------------------------------------------------------------===// +// BasicBlock pred_iterator definition +//===----------------------------------------------------------------------===// + +template <class Ptr, class USE_iterator> // Predecessor Iterator +class PredIterator : public std::iterator<std::forward_iterator_tag, + Ptr, ptrdiff_t, Ptr*, Ptr*> { + typedef std::iterator<std::forward_iterator_tag, Ptr, ptrdiff_t, Ptr*, + Ptr*> super; + typedef PredIterator<Ptr, USE_iterator> Self; + USE_iterator It; + + inline void advancePastNonTerminators() { + // Loop to ignore non-terminator uses (for example BlockAddresses). + while (!It.atEnd() && !isa<TerminatorInst>(*It)) + ++It; + } + +public: + typedef typename super::pointer pointer; + typedef typename super::reference reference; + + PredIterator() {} + explicit inline PredIterator(Ptr *bb) : It(bb->use_begin()) { + advancePastNonTerminators(); + } + 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 reference operator*() const { + assert(!It.atEnd() && "pred_iterator out of range!"); + return cast<TerminatorInst>(*It)->getParent(); + } + inline pointer *operator->() const { return &operator*(); } + + inline Self& operator++() { // Preincrement + assert(!It.atEnd() && "pred_iterator out of range!"); + ++It; advancePastNonTerminators(); + return *this; + } + + inline Self operator++(int) { // Postincrement + Self tmp = *this; ++*this; return tmp; + } + + /// getOperandNo - Return the operand number in the predecessor's + /// terminator of the successor. + unsigned getOperandNo() const { + return It.getOperandNo(); + } + + /// getUse - Return the operand Use in the predecessor's terminator + /// of the successor. + Use &getUse() const { + return It.getUse(); + } +}; + +typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator; +typedef PredIterator<const BasicBlock, + Value::const_use_iterator> const_pred_iterator; + +inline pred_iterator pred_begin(BasicBlock *BB) { return pred_iterator(BB); } +inline const_pred_iterator pred_begin(const BasicBlock *BB) { + return const_pred_iterator(BB); +} +inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);} +inline const_pred_iterator pred_end(const BasicBlock *BB) { + return const_pred_iterator(BB, true); +} + + + +//===----------------------------------------------------------------------===// +// BasicBlock succ_iterator definition +//===----------------------------------------------------------------------===// + +template <class Term_, class BB_> // Successor Iterator +class SuccIterator : public std::iterator<std::random_access_iterator_tag, BB_, + int, BB_ *, BB_ *> { + typedef std::iterator<std::random_access_iterator_tag, BB_, int, BB_ *, BB_ *> + super; + +public: + typedef typename super::pointer pointer; + typedef typename super::reference reference; + +private: + const Term_ Term; + unsigned idx; + typedef SuccIterator<Term_, BB_> Self; + + inline bool index_is_valid(int idx) { + return idx >= 0 && (unsigned) idx < Term->getNumSuccessors(); + } + + /// \brief Proxy object to allow write access in operator[] + class SuccessorProxy { + Self it; + + public: + explicit SuccessorProxy(const Self &it) : it(it) {} + + SuccessorProxy &operator=(SuccessorProxy r) { + *this = reference(r); + return *this; + } + + SuccessorProxy &operator=(reference r) { + it.Term->setSuccessor(it.idx, r); + return *this; + } + + operator reference() const { return *it; } + }; + +public: + explicit inline SuccIterator(Term_ T) : Term(T), idx(0) {// begin iterator + } + inline SuccIterator(Term_ T, bool) // end iterator + : Term(T) { + if (Term) + idx = Term->getNumSuccessors(); + else + // Term == NULL happens, if a basic block is not fully constructed and + // consequently getTerminator() returns NULL. In this case we construct a + // SuccIterator which describes a basic block that has zero successors. + // Defining SuccIterator for incomplete and malformed CFGs is especially + // useful for debugging. + idx = 0; + } + + 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 reference operator*() const { 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; + } + + inline bool operator<(const Self& x) const { + assert(Term == x.Term && "Cannot compare iterators of different blocks!"); + return idx < x.idx; + } + + inline bool operator<=(const Self& x) const { + assert(Term == x.Term && "Cannot compare iterators of different blocks!"); + return idx <= x.idx; + } + inline bool operator>=(const Self& x) const { + assert(Term == x.Term && "Cannot compare iterators of different blocks!"); + return idx >= x.idx; + } + + inline bool operator>(const Self& x) const { + assert(Term == x.Term && "Cannot compare iterators of different blocks!"); + return idx > x.idx; + } + + inline Self& operator+=(int Right) { + unsigned new_idx = idx + Right; + assert(index_is_valid(new_idx) && "Iterator index out of bound"); + idx = new_idx; + return *this; + } + + inline Self operator+(int Right) const { + Self tmp = *this; + tmp += Right; + return tmp; + } + + inline Self& operator-=(int Right) { + return operator+=(-Right); + } + + inline Self operator-(int Right) const { + return operator+(-Right); + } + + inline int operator-(const Self& x) const { + assert(Term == x.Term && "Cannot work on iterators of different blocks!"); + int distance = idx - x.idx; + return distance; + } + + inline SuccessorProxy operator[](int offset) { + Self tmp = *this; + tmp += offset; + return SuccessorProxy(tmp); + } + + /// Get the source BB of this iterator. + inline BB_ *getSource() { + assert(Term && "Source not available, if basic block was malformed"); + return Term->getParent(); + } +}; + +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); +} + +template <typename T, typename U> struct isPodLike<SuccIterator<T, U> > { + static const bool value = isPodLike<T>::value; +}; + + + +//===--------------------------------------------------------------------===// +// 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 const_pred_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(); } + static size_t size (Function *F) { return F->size(); } +}; +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(); } + static size_t size (const Function *F) { return F->size(); } +}; + + +// 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 |