/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/VarBypassDetector.h
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1 | | //===--- VarBypassDetector.h - Bypass jumps detector --------------*- 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 contains VarBypassDetector class, which is used to detect |
10 | | // local variable declarations which can be bypassed by jumps. |
11 | | // |
12 | | //===----------------------------------------------------------------------===// |
13 | | |
14 | | #ifndef LLVM_CLANG_LIB_CODEGEN_VARBYPASSDETECTOR_H |
15 | | #define LLVM_CLANG_LIB_CODEGEN_VARBYPASSDETECTOR_H |
16 | | |
17 | | #include "clang/AST/Decl.h" |
18 | | #include "llvm/ADT/DenseMap.h" |
19 | | #include "llvm/ADT/DenseSet.h" |
20 | | #include "llvm/ADT/SmallVector.h" |
21 | | |
22 | | namespace clang { |
23 | | |
24 | | class Decl; |
25 | | class Stmt; |
26 | | class VarDecl; |
27 | | |
28 | | namespace CodeGen { |
29 | | |
30 | | /// The class detects jumps which bypass local variables declaration: |
31 | | /// goto L; |
32 | | /// int a; |
33 | | /// L: |
34 | | /// |
35 | | /// This is simplified version of JumpScopeChecker. Primary differences: |
36 | | /// * Detects only jumps into the scope local variables. |
37 | | /// * Does not detect jumps out of the scope of local variables. |
38 | | /// * Not limited to variables with initializers, JumpScopeChecker is limited. |
39 | | class VarBypassDetector { |
40 | | // Scope information. Contains a parent scope and related variable |
41 | | // declaration. |
42 | | llvm::SmallVector<std::pair<unsigned, const VarDecl *>, 48> Scopes; |
43 | | // List of jumps with scopes. |
44 | | llvm::SmallVector<std::pair<const Stmt *, unsigned>, 16> FromScopes; |
45 | | // Lookup map to find scope for destinations. |
46 | | llvm::DenseMap<const Stmt *, unsigned> ToScopes; |
47 | | // Set of variables which were bypassed by some jump. |
48 | | llvm::DenseSet<const VarDecl *> Bypasses; |
49 | | // If true assume that all variables are being bypassed. |
50 | | bool AlwaysBypassed = false; |
51 | | |
52 | | public: |
53 | | void Init(const Stmt *Body); |
54 | | |
55 | | /// Returns true if the variable declaration was by bypassed by any goto or |
56 | | /// switch statement. |
57 | 254k | bool IsBypassed(const VarDecl *D) const { |
58 | 254k | return AlwaysBypassed || Bypasses.contains(D)254k ; |
59 | 254k | } |
60 | | |
61 | | private: |
62 | | bool BuildScopeInformation(const Decl *D, unsigned &ParentScope); |
63 | | bool BuildScopeInformation(const Stmt *S, unsigned &origParentScope); |
64 | | void Detect(); |
65 | | void Detect(unsigned From, unsigned To); |
66 | | }; |
67 | | } |
68 | | } |
69 | | |
70 | | #endif |