1 //===-- ControlFlowContext.h ------------------------------------*- 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 a ControlFlowContext class that is used by dataflow 10 // analyses that run over Control-Flow Graphs (CFGs). 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_CONTROLFLOWCONTEXT_H 15 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_CONTROLFLOWCONTEXT_H 16 17 #include "clang/AST/ASTContext.h" 18 #include "clang/AST/Decl.h" 19 #include "clang/AST/Stmt.h" 20 #include "clang/Analysis/CFG.h" 21 #include "llvm/ADT/BitVector.h" 22 #include "llvm/ADT/DenseMap.h" 23 #include "llvm/Support/Error.h" 24 #include <memory> 25 #include <utility> 26 27 namespace clang { 28 namespace dataflow { 29 30 /// Holds CFG and other derived context that is needed to perform dataflow 31 /// analysis. 32 class ControlFlowContext { 33 public: 34 /// Builds a ControlFlowContext from a `FunctionDecl`. 35 /// `Func.hasBody()` must be true, and `Func.isTemplated()` must be false. 36 static llvm::Expected<ControlFlowContext> build(const FunctionDecl &Func); 37 38 /// Builds a ControlFlowContext from an AST node. `D` is the function in which 39 /// `S` resides. `D.isTemplated()` must be false. 40 static llvm::Expected<ControlFlowContext> build(const Decl &D, Stmt &S, 41 ASTContext &C); 42 43 /// Builds a ControlFlowContext from an AST node. `D` is the function in which 44 /// `S` resides. `D` must not be null and `D->isTemplated()` must be false. 45 LLVM_DEPRECATED("Use the version that takes a const Decl & instead", "") 46 static llvm::Expected<ControlFlowContext> build(const Decl *D, Stmt &S, 47 ASTContext &C); 48 49 /// Returns the `Decl` containing the statement used to construct the CFG, if 50 /// available. 51 const Decl *getDecl() const { return ContainingDecl; } 52 53 /// Returns the CFG that is stored in this context. 54 const CFG &getCFG() const { return *Cfg; } 55 56 /// Returns a mapping from statements to basic blocks that contain them. 57 const llvm::DenseMap<const Stmt *, const CFGBlock *> &getStmtToBlock() const { 58 return StmtToBlock; 59 } 60 61 /// Returns whether `B` is reachable from the entry block. 62 bool isBlockReachable(const CFGBlock &B) const { 63 return BlockReachable[B.getBlockID()]; 64 } 65 66 private: 67 // FIXME: Once the deprecated `build` method is removed, mark `D` as "must not 68 // be null" and add an assertion. 69 ControlFlowContext(const Decl *D, std::unique_ptr<CFG> Cfg, 70 llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock, 71 llvm::BitVector BlockReachable) 72 : ContainingDecl(D), Cfg(std::move(Cfg)), 73 StmtToBlock(std::move(StmtToBlock)), 74 BlockReachable(std::move(BlockReachable)) {} 75 76 /// The `Decl` containing the statement used to construct the CFG. 77 const Decl *ContainingDecl; 78 std::unique_ptr<CFG> Cfg; 79 llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock; 80 llvm::BitVector BlockReachable; 81 }; 82 83 } // namespace dataflow 84 } // namespace clang 85 86 #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_CONTROLFLOWCONTEXT_H 87