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116 lines
3.7 KiB
C++
116 lines
3.7 KiB
C++
//===- PostOrderCFGView.h - Post order view of CFG blocks ---------*- C++ --*-//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements post order view of the blocks in a CFG.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_POSTORDERCFGVIEW_H
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#define LLVM_CLANG_ANALYSIS_ANALYSES_POSTORDERCFGVIEW_H
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#include <vector>
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//#include <algorithm>
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#include "llvm/ADT/PostOrderIterator.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/BitVector.h"
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#include "clang/Analysis/AnalysisContext.h"
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#include "clang/Analysis/CFG.h"
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namespace clang {
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class PostOrderCFGView : public ManagedAnalysis {
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virtual void anchor();
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public:
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/// \brief Implements a set of CFGBlocks using a BitVector.
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///
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/// This class contains a minimal interface, primarily dictated by the SetType
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/// template parameter of the llvm::po_iterator template, as used with
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/// external storage. We also use this set to keep track of which CFGBlocks we
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/// visit during the analysis.
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class CFGBlockSet {
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llvm::BitVector VisitedBlockIDs;
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public:
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// po_iterator requires this iterator, but the only interface needed is the
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// value_type typedef.
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struct iterator { typedef const CFGBlock *value_type; };
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CFGBlockSet() {}
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CFGBlockSet(const CFG *G) : VisitedBlockIDs(G->getNumBlockIDs(), false) {}
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/// \brief Set the bit associated with a particular CFGBlock.
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/// This is the important method for the SetType template parameter.
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bool insert(const CFGBlock *Block) {
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// Note that insert() is called by po_iterator, which doesn't check to
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// make sure that Block is non-null. Moreover, the CFGBlock iterator will
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// occasionally hand out null pointers for pruned edges, so we catch those
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// here.
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if (!Block)
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return false; // if an edge is trivially false.
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if (VisitedBlockIDs.test(Block->getBlockID()))
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return false;
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VisitedBlockIDs.set(Block->getBlockID());
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return true;
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}
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/// \brief Check if the bit for a CFGBlock has been already set.
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/// This method is for tracking visited blocks in the main threadsafety
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/// loop. Block must not be null.
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bool alreadySet(const CFGBlock *Block) {
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return VisitedBlockIDs.test(Block->getBlockID());
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}
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};
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private:
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typedef llvm::po_iterator<const CFG*, CFGBlockSet, true> po_iterator;
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std::vector<const CFGBlock*> Blocks;
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typedef llvm::DenseMap<const CFGBlock *, unsigned> BlockOrderTy;
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BlockOrderTy BlockOrder;
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public:
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typedef std::vector<const CFGBlock *>::reverse_iterator iterator;
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typedef std::vector<const CFGBlock *>::const_reverse_iterator const_iterator;
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PostOrderCFGView(const CFG *cfg);
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iterator begin() { return Blocks.rbegin(); }
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iterator end() { return Blocks.rend(); }
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const_iterator begin() const { return Blocks.rbegin(); }
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const_iterator end() const { return Blocks.rend(); }
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bool empty() const { return begin() == end(); }
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struct BlockOrderCompare;
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friend struct BlockOrderCompare;
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struct BlockOrderCompare {
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const PostOrderCFGView &POV;
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public:
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BlockOrderCompare(const PostOrderCFGView &pov) : POV(pov) {}
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bool operator()(const CFGBlock *b1, const CFGBlock *b2) const;
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};
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BlockOrderCompare getComparator() const {
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return BlockOrderCompare(*this);
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}
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// Used by AnalyisContext to construct this object.
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static const void *getTag();
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static PostOrderCFGView *create(AnalysisDeclContext &analysisContext);
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};
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} // end clang namespace
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#endif
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