1 //===- ControlFlowContext.cpp ---------------------------------------------===// 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 a ControlFlowContext class that is used by dataflow 10 // analyses that run over Control-Flow Graphs (CFGs). 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/Analysis/FlowSensitive/ControlFlowContext.h" 15 #include "clang/AST/ASTContext.h" 16 #include "clang/AST/Decl.h" 17 #include "clang/AST/Stmt.h" 18 #include "clang/Analysis/CFG.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/Support/Error.h" 21 #include <utility> 22 23 namespace clang { 24 namespace dataflow { 25 26 /// Returns a map from statements to basic blocks that contain them. 27 static llvm::DenseMap<const Stmt *, const CFGBlock *> 28 buildStmtToBasicBlockMap(const CFG &Cfg) { 29 llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock; 30 for (const CFGBlock *Block : Cfg) { 31 if (Block == nullptr) 32 continue; 33 34 for (const CFGElement &Element : *Block) { 35 auto Stmt = Element.getAs<CFGStmt>(); 36 if (!Stmt.hasValue()) 37 continue; 38 39 StmtToBlock[Stmt.getValue().getStmt()] = Block; 40 } 41 } 42 return StmtToBlock; 43 } 44 45 llvm::Expected<ControlFlowContext> 46 ControlFlowContext::build(const Decl *D, Stmt *S, ASTContext *C) { 47 CFG::BuildOptions Options; 48 Options.PruneTriviallyFalseEdges = false; 49 Options.AddImplicitDtors = true; 50 Options.AddTemporaryDtors = true; 51 Options.AddInitializers = true; 52 Options.AddCXXDefaultInitExprInCtors = true; 53 54 // Ensure that all sub-expressions in basic blocks are evaluated. 55 Options.setAllAlwaysAdd(); 56 57 auto Cfg = CFG::buildCFG(D, S, C, Options); 58 if (Cfg == nullptr) 59 return llvm::createStringError( 60 std::make_error_code(std::errc::invalid_argument), 61 "CFG::buildCFG failed"); 62 63 llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock = 64 buildStmtToBasicBlockMap(*Cfg); 65 return ControlFlowContext(std::move(Cfg), std::move(StmtToBlock)); 66 } 67 68 } // namespace dataflow 69 } // namespace clang 70