1 | //===--- MagicNumbersCheck.h - clang-tidy-----------------------*- 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 | #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MAGICNUMBERSCHECK_H |
10 | #define |
11 | |
12 | #include "../ClangTidyCheck.h" |
13 | #include "clang/Lex/Lexer.h" |
14 | #include <llvm/ADT/APFloat.h> |
15 | #include <llvm/ADT/SmallVector.h> |
16 | |
17 | namespace clang::tidy::readability { |
18 | |
19 | /// Detects magic numbers, integer and floating point literals embedded in code. |
20 | /// |
21 | /// For the user-facing documentation see: |
22 | /// http://clang.llvm.org/extra/clang-tidy/checks/readability/magic-numbers.html |
23 | class MagicNumbersCheck : public ClangTidyCheck { |
24 | public: |
25 | MagicNumbersCheck(StringRef Name, ClangTidyContext *Context); |
26 | void storeOptions(ClangTidyOptions::OptionMap &Opts) override; |
27 | void registerMatchers(ast_matchers::MatchFinder *Finder) override; |
28 | void check(const ast_matchers::MatchFinder::MatchResult &Result) override; |
29 | |
30 | private: |
31 | bool isConstant(const clang::ast_matchers::MatchFinder::MatchResult &Result, |
32 | const clang::Expr &ExprResult) const; |
33 | |
34 | bool isIgnoredValue(const IntegerLiteral *Literal) const; |
35 | bool isIgnoredValue(const FloatingLiteral *Literal) const; |
36 | |
37 | bool isSyntheticValue(const clang::SourceManager *, |
38 | const FloatingLiteral *) const { |
39 | return false; |
40 | } |
41 | bool isSyntheticValue(const clang::SourceManager *SourceManager, |
42 | const IntegerLiteral *Literal) const; |
43 | |
44 | bool isBitFieldWidth(const clang::ast_matchers::MatchFinder::MatchResult &, |
45 | const FloatingLiteral &) const { |
46 | return false; |
47 | } |
48 | |
49 | bool |
50 | isBitFieldWidth(const clang::ast_matchers::MatchFinder::MatchResult &Result, |
51 | const IntegerLiteral &Literal) const; |
52 | |
53 | bool isUserDefinedLiteral( |
54 | const clang::ast_matchers::MatchFinder::MatchResult &Result, |
55 | const clang::Expr &Literal) const; |
56 | |
57 | template <typename L> |
58 | void checkBoundMatch(const ast_matchers::MatchFinder::MatchResult &Result, |
59 | const char *BoundName) { |
60 | const L *MatchedLiteral = Result.Nodes.getNodeAs<L>(BoundName); |
61 | if (!MatchedLiteral) |
62 | return; |
63 | |
64 | if (Result.SourceManager->isMacroBodyExpansion( |
65 | Loc: MatchedLiteral->getLocation())) |
66 | return; |
67 | |
68 | if (isIgnoredValue(MatchedLiteral)) |
69 | return; |
70 | |
71 | if (isConstant(Result, ExprResult: *MatchedLiteral)) |
72 | return; |
73 | |
74 | if (isSyntheticValue(Result.SourceManager, MatchedLiteral)) |
75 | return; |
76 | |
77 | if (isBitFieldWidth(Result, *MatchedLiteral)) |
78 | return; |
79 | |
80 | if (IgnoreUserDefinedLiterals && |
81 | isUserDefinedLiteral(Result, Literal: *MatchedLiteral)) |
82 | return; |
83 | |
84 | const StringRef LiteralSourceText = Lexer::getSourceText( |
85 | Range: CharSourceRange::getTokenRange(MatchedLiteral->getSourceRange()), |
86 | SM: *Result.SourceManager, LangOpts: getLangOpts()); |
87 | |
88 | diag(MatchedLiteral->getLocation(), |
89 | "%0 is a magic number; consider replacing it with a named constant" ) |
90 | << LiteralSourceText; |
91 | } |
92 | |
93 | const bool IgnoreAllFloatingPointValues; |
94 | const bool IgnoreBitFieldsWidths; |
95 | const bool IgnorePowersOf2IntegerValues; |
96 | const bool IgnoreTypeAliases; |
97 | const bool IgnoreUserDefinedLiterals; |
98 | const StringRef RawIgnoredIntegerValues; |
99 | const StringRef RawIgnoredFloatingPointValues; |
100 | |
101 | constexpr static unsigned SensibleNumberOfMagicValueExceptions = 16; |
102 | |
103 | constexpr static llvm::APFloat::roundingMode DefaultRoundingMode = |
104 | llvm::APFloat::rmNearestTiesToEven; |
105 | |
106 | llvm::SmallVector<int64_t, SensibleNumberOfMagicValueExceptions> |
107 | IgnoredIntegerValues; |
108 | llvm::SmallVector<float, SensibleNumberOfMagicValueExceptions> |
109 | IgnoredFloatingPointValues; |
110 | llvm::SmallVector<double, SensibleNumberOfMagicValueExceptions> |
111 | IgnoredDoublePointValues; |
112 | }; |
113 | |
114 | } // namespace clang::tidy::readability |
115 | |
116 | #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MAGICNUMBERSCHECK_H |
117 | |