diff options
Diffstat (limited to 'include/clang/Analysis/FlowSensitive/DataflowSolver.h')
| -rw-r--r-- | include/clang/Analysis/FlowSensitive/DataflowSolver.h | 129 |
1 files changed, 68 insertions, 61 deletions
diff --git a/include/clang/Analysis/FlowSensitive/DataflowSolver.h b/include/clang/Analysis/FlowSensitive/DataflowSolver.h index 38612593368b..f505bca9519c 100644 --- a/include/clang/Analysis/FlowSensitive/DataflowSolver.h +++ b/include/clang/Analysis/FlowSensitive/DataflowSolver.h @@ -14,7 +14,7 @@ #ifndef LLVM_CLANG_ANALYSES_DATAFLOW_SOLVER #define LLVM_CLANG_ANALYSES_DATAFLOW_SOLVER -#include "clang/AST/CFG.h" +#include "clang/Analysis/CFG.h" #include "clang/Analysis/ProgramPoint.h" #include "llvm/ADT/SmallPtrSet.h" #include "functional" // STL @@ -24,7 +24,7 @@ namespace clang { //===----------------------------------------------------------------------===// /// DataflowWorkListTy - Data structure representing the worklist used for /// dataflow algorithms. -//===----------------------------------------------------------------------===// +//===----------------------------------------------------------------------===// class DataflowWorkListTy { typedef llvm::SmallPtrSet<const CFGBlock*,20> BlockSet; @@ -33,15 +33,15 @@ public: /// enqueue - Add a block to the worklist. Blocks already on the /// worklist are not added a second time. void enqueue(const CFGBlock* B) { wlist.insert(B); } - + /// dequeue - Remove a block from the worklist. const CFGBlock* dequeue() { assert (!wlist.empty()); const CFGBlock* B = *wlist.begin(); wlist.erase(B); - return B; + return B; } - + /// isEmpty - Return true if the worklist is empty. bool isEmpty() const { return wlist.empty(); } }; @@ -59,22 +59,22 @@ template <> struct ItrTraits<forward_analysis_tag> { typedef CFGBlock::const_pred_iterator PrevBItr; typedef CFGBlock::const_succ_iterator NextBItr; typedef CFGBlock::const_iterator StmtItr; - + static PrevBItr PrevBegin(const CFGBlock* B) { return B->pred_begin(); } static PrevBItr PrevEnd(const CFGBlock* B) { return B->pred_end(); } - - static NextBItr NextBegin(const CFGBlock* B) { return B->succ_begin(); } + + static NextBItr NextBegin(const CFGBlock* B) { return B->succ_begin(); } static NextBItr NextEnd(const CFGBlock* B) { return B->succ_end(); } - + static StmtItr StmtBegin(const CFGBlock* B) { return B->begin(); } static StmtItr StmtEnd(const CFGBlock* B) { return B->end(); } - + static BlockEdge PrevEdge(const CFGBlock* B, const CFGBlock* Prev) { - return BlockEdge(Prev, B); + return BlockEdge(Prev, B, 0); } - + static BlockEdge NextEdge(const CFGBlock* B, const CFGBlock* Next) { - return BlockEdge(B, Next); + return BlockEdge(B, Next, 0); } }; @@ -82,22 +82,22 @@ template <> struct ItrTraits<backward_analysis_tag> { typedef CFGBlock::const_succ_iterator PrevBItr; typedef CFGBlock::const_pred_iterator NextBItr; typedef CFGBlock::const_reverse_iterator StmtItr; - - static PrevBItr PrevBegin(const CFGBlock* B) { return B->succ_begin(); } + + static PrevBItr PrevBegin(const CFGBlock* B) { return B->succ_begin(); } static PrevBItr PrevEnd(const CFGBlock* B) { return B->succ_end(); } - - static NextBItr NextBegin(const CFGBlock* B) { return B->pred_begin(); } + + static NextBItr NextBegin(const CFGBlock* B) { return B->pred_begin(); } static NextBItr NextEnd(const CFGBlock* B) { return B->pred_end(); } - + static StmtItr StmtBegin(const CFGBlock* B) { return B->rbegin(); } - static StmtItr StmtEnd(const CFGBlock* B) { return B->rend(); } - + static StmtItr StmtEnd(const CFGBlock* B) { return B->rend(); } + static BlockEdge PrevEdge(const CFGBlock* B, const CFGBlock* Prev) { - return BlockEdge(B, Prev); + return BlockEdge(B, Prev, 0); } - + static BlockEdge NextEdge(const CFGBlock* B, const CFGBlock* Next) { - return BlockEdge(Next, B); + return BlockEdge(Next, B, 0); } }; } // end namespace dataflow @@ -105,7 +105,7 @@ template <> struct ItrTraits<backward_analysis_tag> { //===----------------------------------------------------------------------===// /// DataflowSolverTy - Generic dataflow solver. //===----------------------------------------------------------------------===// - + template <typename _DFValuesTy, // Usually a subclass of DataflowValues typename _TransferFuncsTy, typename _MergeOperatorTy, @@ -120,7 +120,7 @@ public: typedef _DFValuesTy DFValuesTy; typedef _TransferFuncsTy TransferFuncsTy; typedef _MergeOperatorTy MergeOperatorTy; - + typedef typename _DFValuesTy::AnalysisDirTag AnalysisDirTag; typedef typename _DFValuesTy::ValTy ValTy; typedef typename _DFValuesTy::EdgeDataMapTy EdgeDataMapTy; @@ -130,24 +130,24 @@ public: typedef typename ItrTraits::NextBItr NextBItr; typedef typename ItrTraits::PrevBItr PrevBItr; typedef typename ItrTraits::StmtItr StmtItr; - + //===----------------------------------------------------===// // External interface: constructing and running the solver. //===----------------------------------------------------===// - + public: DataflowSolver(DFValuesTy& d) : D(d), TF(d.getAnalysisData()) {} - ~DataflowSolver() {} - + ~DataflowSolver() {} + /// runOnCFG - Computes dataflow values for all blocks in a CFG. void runOnCFG(CFG& cfg, bool recordStmtValues = false) { // Set initial dataflow values and boundary conditions. - D.InitializeValues(cfg); + D.InitializeValues(cfg); // Solve the dataflow equations. This will populate D.EdgeDataMap // with dataflow values. SolveDataflowEquations(cfg, recordStmtValues); } - + /// runOnBlock - Computes dataflow values for a given block. This /// should usually be invoked only after previously computing /// dataflow values using runOnCFG, as runOnBlock is intended to @@ -162,10 +162,10 @@ public: ProcessBlock(B, recordStmtValues, AnalysisDirTag()); } } - + void runOnBlock(const CFGBlock& B, bool recordStmtValues) { runOnBlock(&B, recordStmtValues); - } + } void runOnBlock(CFG::iterator& I, bool recordStmtValues) { runOnBlock(*I, recordStmtValues); } @@ -177,81 +177,87 @@ public: for (CFG::const_iterator I=cfg.begin(), E=cfg.end(); I!=E; ++I) runOnBlock(I, recordStmtValues); } - + //===----------------------------------------------------===// // Internal solver logic. //===----------------------------------------------------===// - + private: - + /// SolveDataflowEquations - Perform the actual worklist algorithm /// to compute dataflow values. void SolveDataflowEquations(CFG& cfg, bool recordStmtValues) { // Enqueue all blocks to ensure the dataflow values are computed // for every block. Not all blocks are guaranteed to reach the exit block. for (CFG::iterator I=cfg.begin(), E=cfg.end(); I!=E; ++I) - WorkList.enqueue(&*I); - + WorkList.enqueue(&**I); + while (!WorkList.isEmpty()) { const CFGBlock* B = WorkList.dequeue(); - ProcessMerge(cfg,B); + ProcessMerge(cfg, B); ProcessBlock(B, recordStmtValues, AnalysisDirTag()); - UpdateEdges(cfg,B,TF.getVal()); + UpdateEdges(cfg, B, TF.getVal()); } - } - + } + void ProcessMerge(CFG& cfg, const CFGBlock* B) { - ValTy& V = TF.getVal(); + ValTy& V = TF.getVal(); TF.SetTopValue(V); // Merge dataflow values from all predecessors of this block. MergeOperatorTy Merge; - + EdgeDataMapTy& M = D.getEdgeDataMap(); bool firstMerge = true; - + for (PrevBItr I=ItrTraits::PrevBegin(B),E=ItrTraits::PrevEnd(B); I!=E; ++I){ + CFGBlock *PrevBlk = *I; + + if (!PrevBlk) + continue; + typename EdgeDataMapTy::iterator EI = - M.find(ItrTraits::PrevEdge(B, *I)); + M.find(ItrTraits::PrevEdge(B, PrevBlk)); if (EI != M.end()) { if (firstMerge) { firstMerge = false; V.copyValues(EI->second); } - else Merge(V,EI->second); + else + Merge(V, EI->second); } } - + // Set the data for the block. D.getBlockDataMap()[B].copyValues(V); - } + } /// ProcessBlock - Process the transfer functions for a given block. void ProcessBlock(const CFGBlock* B, bool recordStmtValues, dataflow::forward_analysis_tag) { - + for (StmtItr I=ItrTraits::StmtBegin(B), E=ItrTraits::StmtEnd(B); I!=E;++I) ProcessStmt(*I, recordStmtValues, AnalysisDirTag()); - - TF.VisitTerminator(const_cast<CFGBlock*>(B)); + + TF.VisitTerminator(const_cast<CFGBlock*>(B)); } - + void ProcessBlock(const CFGBlock* B, bool recordStmtValues, dataflow::backward_analysis_tag) { - + TF.VisitTerminator(const_cast<CFGBlock*>(B)); for (StmtItr I=ItrTraits::StmtBegin(B), E=ItrTraits::StmtEnd(B); I!=E;++I) ProcessStmt(*I, recordStmtValues, AnalysisDirTag()); } - + void ProcessStmt(const Stmt* S, bool record, dataflow::forward_analysis_tag) { if (record) D.getStmtDataMap()[S] = TF.getVal(); - TF.BlockStmt_Visit(const_cast<Stmt*>(S)); + TF.BlockStmt_Visit(const_cast<Stmt*>(S)); } - + void ProcessStmt(const Stmt* S, bool record, dataflow::backward_analysis_tag){ TF.BlockStmt_Visit(const_cast<Stmt*>(S)); if (record) D.getStmtDataMap()[S] = TF.getVal(); @@ -263,14 +269,15 @@ private: // forward/backward analysis respectively) void UpdateEdges(CFG& cfg, const CFGBlock* B, ValTy& V) { for (NextBItr I=ItrTraits::NextBegin(B), E=ItrTraits::NextEnd(B); I!=E; ++I) - UpdateEdgeValue(ItrTraits::NextEdge(B, *I),V,*I); + if (CFGBlock *NextBlk = *I) + UpdateEdgeValue(ItrTraits::NextEdge(B, NextBlk),V, NextBlk); } - + /// UpdateEdgeValue - Update the value associated with a given edge. void UpdateEdgeValue(BlockEdge E, ValTy& V, const CFGBlock* TargetBlock) { EdgeDataMapTy& M = D.getEdgeDataMap(); typename EdgeDataMapTy::iterator I = M.find(E); - + if (I == M.end()) { // First computed value for this edge? M[E].copyValues(V); WorkList.enqueue(TargetBlock); @@ -280,7 +287,7 @@ private: WorkList.enqueue(TargetBlock); } } - + private: DFValuesTy& D; DataflowWorkListTy WorkList; |