1 //===--- CFGStmtMap.h - Map from Stmt* to CFGBlock* -----------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the CFGStmtMap class, which defines a mapping from 11 // Stmt* to CFGBlock* 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/ADT/DenseMap.h" 16 #include "clang/AST/ParentMap.h" 17 #include "clang/Analysis/CFG.h" 18 #include "clang/Analysis/CFGStmtMap.h" 19 20 using namespace clang; 21 22 typedef llvm::DenseMap<const Stmt*, CFGBlock*> SMap; 23 static SMap *AsMap(void *m) { return (SMap*) m; } 24 25 CFGStmtMap::~CFGStmtMap() { delete AsMap(M); } 26 27 CFGBlock *CFGStmtMap::getBlock(Stmt *S) { 28 SMap *SM = AsMap(M); 29 Stmt *X = S; 30 31 // If 'S' isn't in the map, walk the ParentMap to see if one of its ancestors 32 // is in the map. 33 while (X) { 34 SMap::iterator I = SM->find(X); 35 if (I != SM->end()) { 36 CFGBlock *B = I->second; 37 // Memoize this lookup. 38 if (X != S) 39 (*SM)[X] = B; 40 return B; 41 } 42 43 X = PM->getParentIgnoreParens(X); 44 } 45 46 return nullptr; 47 } 48 49 static void Accumulate(SMap &SM, CFGBlock *B) { 50 // First walk the block-level expressions. 51 for (CFGBlock::iterator I = B->begin(), E = B->end(); I != E; ++I) { 52 const CFGElement &CE = *I; 53 Optional<CFGStmt> CS = CE.getAs<CFGStmt>(); 54 if (!CS) 55 continue; 56 57 CFGBlock *&Entry = SM[CS->getStmt()]; 58 // If 'Entry' is already initialized (e.g., a terminator was already), 59 // skip. 60 if (Entry) 61 continue; 62 63 Entry = B; 64 65 } 66 67 // Look at the label of the block. 68 if (Stmt *Label = B->getLabel()) 69 SM[Label] = B; 70 71 // Finally, look at the terminator. If the terminator was already added 72 // because it is a block-level expression in another block, overwrite 73 // that mapping. 74 if (Stmt *Term = B->getTerminator()) 75 SM[Term] = B; 76 } 77 78 CFGStmtMap *CFGStmtMap::Build(CFG *C, ParentMap *PM) { 79 if (!C || !PM) 80 return nullptr; 81 82 SMap *SM = new SMap(); 83 84 // Walk all blocks, accumulating the block-level expressions, labels, 85 // and terminators. 86 for (CFG::iterator I = C->begin(), E = C->end(); I != E; ++I) 87 Accumulate(*SM, *I); 88 89 return new CFGStmtMap(PM, SM); 90 } 91 92
