1 //===--- CFGStmtMap.h - Map from Stmt* to CFGBlock* -----------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines the CFGStmtMap class, which defines a mapping from 10 // Stmt* to CFGBlock* 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/ADT/DenseMap.h" 15 #include "clang/AST/ParentMap.h" 16 #include "clang/Analysis/CFG.h" 17 #include "clang/Analysis/CFGStmtMap.h" 18 19 using namespace clang; 20 21 typedef llvm::DenseMap<const Stmt*, CFGBlock*> SMap; 22 static SMap *AsMap(void *m) { return (SMap*) m; } 23 24 CFGStmtMap::~CFGStmtMap() { delete AsMap(M); } 25 26 CFGBlock *CFGStmtMap::getBlock(Stmt *S) { 27 SMap *SM = AsMap(M); 28 Stmt *X = S; 29 30 // If 'S' isn't in the map, walk the ParentMap to see if one of its ancestors 31 // is in the map. 32 while (X) { 33 SMap::iterator I = SM->find(X); 34 if (I != SM->end()) { 35 CFGBlock *B = I->second; 36 // Memoize this lookup. 37 if (X != S) 38 (*SM)[X] = B; 39 return B; 40 } 41 42 X = PM->getParentIgnoreParens(X); 43 } 44 45 return nullptr; 46 } 47 48 static void Accumulate(SMap &SM, CFGBlock *B) { 49 // First walk the block-level expressions. 50 for (CFGBlock::iterator I = B->begin(), E = B->end(); I != E; ++I) { 51 const CFGElement &CE = *I; 52 Optional<CFGStmt> CS = CE.getAs<CFGStmt>(); 53 if (!CS) 54 continue; 55 56 CFGBlock *&Entry = SM[CS->getStmt()]; 57 // If 'Entry' is already initialized (e.g., a terminator was already), 58 // skip. 59 if (Entry) 60 continue; 61 62 Entry = B; 63 64 } 65 66 // Look at the label of the block. 67 if (Stmt *Label = B->getLabel()) 68 SM[Label] = B; 69 70 // Finally, look at the terminator. If the terminator was already added 71 // because it is a block-level expression in another block, overwrite 72 // that mapping. 73 if (Stmt *Term = B->getTerminatorStmt()) 74 SM[Term] = B; 75 } 76 77 CFGStmtMap *CFGStmtMap::Build(CFG *C, ParentMap *PM) { 78 if (!C || !PM) 79 return nullptr; 80 81 SMap *SM = new SMap(); 82 83 // Walk all blocks, accumulating the block-level expressions, labels, 84 // and terminators. 85 for (CFG::iterator I = C->begin(), E = C->end(); I != E; ++I) 86 Accumulate(*SM, *I); 87 88 return new CFGStmtMap(PM, SM); 89 } 90 91