1 | //===-- AdornedCFG.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 an AdornedCFG class that is used by dataflow analyses that |
10 | // run over Control-Flow Graphs (CFGs). |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_H |
15 | #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_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 with additional information derived from it that is needed to |
31 | /// perform dataflow analysis. |
32 | class AdornedCFG { |
33 | public: |
34 | /// Builds an `AdornedCFG` from a `FunctionDecl`. |
35 | /// `Func.doesThisDeclarationHaveABody()` must be true, and |
36 | /// `Func.isTemplated()` must be false. |
37 | static llvm::Expected<AdornedCFG> build(const FunctionDecl &Func); |
38 | |
39 | /// Builds an `AdornedCFG` from an AST node. `D` is the function in which |
40 | /// `S` resides. `D.isTemplated()` must be false. |
41 | static llvm::Expected<AdornedCFG> build(const Decl &D, Stmt &S, |
42 | ASTContext &C); |
43 | |
44 | /// Returns the `Decl` containing the statement used to construct the CFG, if |
45 | /// available. |
46 | const Decl &getDecl() const { return ContainingDecl; } |
47 | |
48 | /// Returns the CFG that is stored in this context. |
49 | const CFG &getCFG() const { return *Cfg; } |
50 | |
51 | /// Returns a mapping from statements to basic blocks that contain them. |
52 | const llvm::DenseMap<const Stmt *, const CFGBlock *> &getStmtToBlock() const { |
53 | return StmtToBlock; |
54 | } |
55 | |
56 | /// Returns whether `B` is reachable from the entry block. |
57 | bool isBlockReachable(const CFGBlock &B) const { |
58 | return BlockReachable[B.getBlockID()]; |
59 | } |
60 | |
61 | /// Returns whether `B` contains an expression that is consumed in a |
62 | /// different block than `B` (i.e. the parent of the expression is in a |
63 | /// different block). |
64 | /// This happens if there is control flow within a full-expression (triggered |
65 | /// by `&&`, `||`, or the conditional operator). Note that the operands of |
66 | /// these operators are not the only expressions that can be consumed in a |
67 | /// different block. For example, in the function call |
68 | /// `f(&i, cond() ? 1 : 0)`, `&i` is in a different block than the `CallExpr`. |
69 | bool containsExprConsumedInDifferentBlock(const CFGBlock &B) const { |
70 | return ContainsExprConsumedInDifferentBlock.contains(V: &B); |
71 | } |
72 | |
73 | private: |
74 | AdornedCFG( |
75 | const Decl &D, std::unique_ptr<CFG> Cfg, |
76 | llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock, |
77 | llvm::BitVector BlockReachable, |
78 | llvm::DenseSet<const CFGBlock *> ContainsExprConsumedInDifferentBlock) |
79 | : ContainingDecl(D), Cfg(std::move(Cfg)), |
80 | StmtToBlock(std::move(StmtToBlock)), |
81 | BlockReachable(std::move(BlockReachable)), |
82 | ContainsExprConsumedInDifferentBlock( |
83 | std::move(ContainsExprConsumedInDifferentBlock)) {} |
84 | |
85 | /// The `Decl` containing the statement used to construct the CFG. |
86 | const Decl &ContainingDecl; |
87 | std::unique_ptr<CFG> Cfg; |
88 | llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock; |
89 | llvm::BitVector BlockReachable; |
90 | llvm::DenseSet<const CFGBlock *> ContainsExprConsumedInDifferentBlock; |
91 | }; |
92 | |
93 | } // namespace dataflow |
94 | } // namespace clang |
95 | |
96 | #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_H |
97 | |