clang-tools 20.0.0git
MagicNumbersCheck.h
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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 LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MAGICNUMBERSCHECK_H
11
12#include "../ClangTidyCheck.h"
13#include "clang/Lex/Lexer.h"
14#include <llvm/ADT/APFloat.h>
15#include <llvm/ADT/SmallVector.h>
16
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
24public:
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
30private:
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 isBitFieldWidth(const clang::ast_matchers::MatchFinder::MatchResult &Result,
50 const IntegerLiteral &Literal) const;
51
52 bool isUserDefinedLiteral(
53 const clang::ast_matchers::MatchFinder::MatchResult &Result,
54 const clang::Expr &Literal) const;
55
56 template <typename L>
57 void checkBoundMatch(const ast_matchers::MatchFinder::MatchResult &Result,
58 const char *BoundName) {
59 const L *MatchedLiteral = Result.Nodes.getNodeAs<L>(BoundName);
60 if (!MatchedLiteral)
61 return;
62
63 if (Result.SourceManager->isMacroBodyExpansion(
64 MatchedLiteral->getLocation()))
65 return;
66
67 if (isIgnoredValue(MatchedLiteral))
68 return;
69
70 if (isConstant(Result, *MatchedLiteral))
71 return;
72
73 if (isSyntheticValue(Result.SourceManager, MatchedLiteral))
74 return;
75
76 if (isBitFieldWidth(Result, *MatchedLiteral))
77 return;
78
79 if (IgnoreUserDefinedLiterals &&
80 isUserDefinedLiteral(Result, *MatchedLiteral))
81 return;
82
83 const StringRef LiteralSourceText = Lexer::getSourceText(
84 CharSourceRange::getTokenRange(MatchedLiteral->getSourceRange()),
85 *Result.SourceManager, getLangOpts());
86
87 diag(MatchedLiteral->getLocation(),
88 "%0 is a magic number; consider replacing it with a named constant")
89 << LiteralSourceText;
90 }
91
92 const bool IgnoreAllFloatingPointValues;
93 const bool IgnoreBitFieldsWidths;
94 const bool IgnorePowersOf2IntegerValues;
95 const bool IgnoreTypeAliases;
96 const bool IgnoreUserDefinedLiterals;
97 const StringRef RawIgnoredIntegerValues;
98 const StringRef RawIgnoredFloatingPointValues;
99
100 constexpr static unsigned SensibleNumberOfMagicValueExceptions = 16;
101
102 constexpr static llvm::APFloat::roundingMode DefaultRoundingMode =
103 llvm::APFloat::rmNearestTiesToEven;
104
105 llvm::SmallVector<int64_t, SensibleNumberOfMagicValueExceptions>
106 IgnoredIntegerValues;
107 llvm::SmallVector<float, SensibleNumberOfMagicValueExceptions>
108 IgnoredFloatingPointValues;
109 llvm::SmallVector<double, SensibleNumberOfMagicValueExceptions>
110 IgnoredDoublePointValues;
111};
112
113} // namespace clang::tidy::readability
114
115#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MAGICNUMBERSCHECK_H
llvm::SmallString< 256U > Name
Base class for all clang-tidy checks.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
const LangOptions & getLangOpts() const
Returns the language options from the context.
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Detects magic numbers, integer and floating point literals embedded in code.
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
llvm::StringMap< ClangTidyValue > OptionMap