| //===- 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/ADT/iterator.h" |
| #include "llvm/ADT/iterator_range.h" |
| #include "llvm/IR/BasicBlock.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/InstrTypes.h" |
| #include "llvm/IR/Value.h" |
| #include "llvm/Support/Casting.h" |
| #include "llvm/Support/type_traits.h" |
| #include <cassert> |
| #include <cstddef> |
| #include <iterator> |
| |
| 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*> { |
| using super = |
| std::iterator<std::forward_iterator_tag, Ptr, ptrdiff_t, Ptr*, Ptr*>; |
| using Self = PredIterator<Ptr, USE_iterator>; |
| USE_iterator It; |
| |
| inline void advancePastNonTerminators() { |
| // Loop to ignore non-terminator uses (for example BlockAddresses). |
| while (!It.atEnd() && !isa<TerminatorInst>(*It)) |
| ++It; |
| } |
| |
| public: |
| using pointer = typename super::pointer; |
| using reference = typename super::reference; |
| |
| PredIterator() = default; |
| explicit inline PredIterator(Ptr *bb) : It(bb->user_begin()) { |
| advancePastNonTerminators(); |
| } |
| inline PredIterator(Ptr *bb, bool) : It(bb->user_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(); |
| } |
| }; |
| |
| using pred_iterator = PredIterator<BasicBlock, Value::user_iterator>; |
| using const_pred_iterator = |
| PredIterator<const BasicBlock, Value::const_user_iterator>; |
| using pred_range = iterator_range<pred_iterator>; |
| using pred_const_range = iterator_range<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); |
| } |
| inline bool pred_empty(const BasicBlock *BB) { |
| return pred_begin(BB) == pred_end(BB); |
| } |
| inline pred_range predecessors(BasicBlock *BB) { |
| return pred_range(pred_begin(BB), pred_end(BB)); |
| } |
| inline pred_const_range predecessors(const BasicBlock *BB) { |
| return pred_const_range(pred_begin(BB), pred_end(BB)); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // BasicBlock succ_iterator helpers |
| //===----------------------------------------------------------------------===// |
| |
| using succ_iterator = |
| TerminatorInst::SuccIterator<TerminatorInst *, BasicBlock>; |
| using succ_const_iterator = |
| TerminatorInst::SuccIterator<const TerminatorInst *, const BasicBlock>; |
| using succ_range = iterator_range<succ_iterator>; |
| using succ_const_range = iterator_range<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); |
| } |
| inline bool succ_empty(const BasicBlock *BB) { |
| return succ_begin(BB) == succ_end(BB); |
| } |
| inline succ_range successors(BasicBlock *BB) { |
| return succ_range(succ_begin(BB), succ_end(BB)); |
| } |
| inline succ_const_range successors(const BasicBlock *BB) { |
| return succ_const_range(succ_begin(BB), succ_end(BB)); |
| } |
| |
| template <typename T, typename U> |
| struct isPodLike<TerminatorInst::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*> { |
| using NodeRef = BasicBlock *; |
| using ChildIteratorType = succ_iterator; |
| |
| static NodeRef getEntryNode(BasicBlock *BB) { return BB; } |
| static ChildIteratorType child_begin(NodeRef N) { return succ_begin(N); } |
| static ChildIteratorType child_end(NodeRef N) { return succ_end(N); } |
| }; |
| |
| template <> struct GraphTraits<const BasicBlock*> { |
| using NodeRef = const BasicBlock *; |
| using ChildIteratorType = succ_const_iterator; |
| |
| static NodeRef getEntryNode(const BasicBlock *BB) { return BB; } |
| |
| static ChildIteratorType child_begin(NodeRef N) { return succ_begin(N); } |
| static ChildIteratorType child_end(NodeRef 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*>> { |
| using NodeRef = BasicBlock *; |
| using ChildIteratorType = pred_iterator; |
| |
| static NodeRef getEntryNode(Inverse<BasicBlock *> G) { return G.Graph; } |
| static ChildIteratorType child_begin(NodeRef N) { return pred_begin(N); } |
| static ChildIteratorType child_end(NodeRef N) { return pred_end(N); } |
| }; |
| |
| template <> struct GraphTraits<Inverse<const BasicBlock*>> { |
| using NodeRef = const BasicBlock *; |
| using ChildIteratorType = const_pred_iterator; |
| |
| static NodeRef getEntryNode(Inverse<const BasicBlock *> G) { return G.Graph; } |
| static ChildIteratorType child_begin(NodeRef N) { return pred_begin(N); } |
| static ChildIteratorType child_end(NodeRef 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 NodeRef getEntryNode(Function *F) { return &F->getEntryBlock(); } |
| |
| // nodes_iterator/begin/end - Allow iteration over all nodes in the graph |
| using nodes_iterator = pointer_iterator<Function::iterator>; |
| |
| static nodes_iterator nodes_begin(Function *F) { |
| return nodes_iterator(F->begin()); |
| } |
| |
| static nodes_iterator nodes_end(Function *F) { |
| return nodes_iterator(F->end()); |
| } |
| |
| static size_t size(Function *F) { return F->size(); } |
| }; |
| template <> struct GraphTraits<const Function*> : |
| public GraphTraits<const BasicBlock*> { |
| static NodeRef getEntryNode(const Function *F) { return &F->getEntryBlock(); } |
| |
| // nodes_iterator/begin/end - Allow iteration over all nodes in the graph |
| using nodes_iterator = pointer_iterator<Function::const_iterator>; |
| |
| static nodes_iterator nodes_begin(const Function *F) { |
| return nodes_iterator(F->begin()); |
| } |
| |
| static nodes_iterator nodes_end(const Function *F) { |
| return nodes_iterator(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 NodeRef getEntryNode(Inverse<Function *> G) { |
| return &G.Graph->getEntryBlock(); |
| } |
| }; |
| template <> struct GraphTraits<Inverse<const Function*>> : |
| public GraphTraits<Inverse<const BasicBlock*>> { |
| static NodeRef getEntryNode(Inverse<const Function *> G) { |
| return &G.Graph->getEntryBlock(); |
| } |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_IR_CFG_H |