xref: /llvm-project/clang-tools-extra/clang-tidy/cppcoreguidelines/MacroUsageCheck.cpp (revision 1c705d9c538d1d4a24f34e93be2582bc7e3a3da4)
1 //===--- MacroUsageCheck.cpp - clang-tidy----------------------------------===//
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 #include "MacroUsageCheck.h"
10 #include "clang/Frontend/CompilerInstance.h"
11 #include "clang/Lex/PPCallbacks.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/Support/Regex.h"
14 #include <algorithm>
15 #include <cctype>
16 
17 namespace clang {
18 namespace tidy {
19 namespace cppcoreguidelines {
20 
21 namespace {
22 
23 bool isCapsOnly(StringRef Name) {
24   return std::all_of(Name.begin(), Name.end(), [](const char c) {
25     if (std::isupper(c) || std::isdigit(c) || c == '_')
26       return true;
27     return false;
28   });
29 }
30 
31 class MacroUsageCallbacks : public PPCallbacks {
32 public:
33   MacroUsageCallbacks(MacroUsageCheck *Check, const SourceManager &SM,
34                       StringRef RegExp, bool CapsOnly, bool IgnoreCommandLine)
35       : Check(Check), SM(SM), RegExp(RegExp), CheckCapsOnly(CapsOnly),
36         IgnoreCommandLineMacros(IgnoreCommandLine) {}
37   void MacroDefined(const Token &MacroNameTok,
38                     const MacroDirective *MD) override {
39     if (SM.isWrittenInBuiltinFile(MD->getLocation()) ||
40         MD->getMacroInfo()->isUsedForHeaderGuard() ||
41         MD->getMacroInfo()->getNumTokens() == 0)
42       return;
43 
44     if (IgnoreCommandLineMacros &&
45         SM.isWrittenInCommandLineFile(MD->getLocation()))
46       return;
47 
48     StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName();
49     if (!CheckCapsOnly && !llvm::Regex(RegExp).match(MacroName))
50       Check->warnMacro(MD, MacroName);
51 
52     if (CheckCapsOnly && !isCapsOnly(MacroName))
53       Check->warnNaming(MD, MacroName);
54   }
55 
56 private:
57   MacroUsageCheck *Check;
58   const SourceManager &SM;
59   StringRef RegExp;
60   bool CheckCapsOnly;
61   bool IgnoreCommandLineMacros;
62 };
63 } // namespace
64 
65 void MacroUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
66   Options.store(Opts, "AllowedRegexp", AllowedRegexp);
67   Options.store(Opts, "CheckCapsOnly", CheckCapsOnly);
68   Options.store(Opts, "IgnoreCommandLineMacros", IgnoreCommandLineMacros);
69 }
70 
71 void MacroUsageCheck::registerPPCallbacks(const SourceManager &SM,
72                                           Preprocessor *PP,
73                                           Preprocessor *ModuleExpanderPP) {
74   if (!getLangOpts().CPlusPlus11)
75     return;
76 
77   PP->addPPCallbacks(std::make_unique<MacroUsageCallbacks>(
78       this, SM, AllowedRegexp, CheckCapsOnly, IgnoreCommandLineMacros));
79 }
80 
81 void MacroUsageCheck::warnMacro(const MacroDirective *MD, StringRef MacroName) {
82   StringRef Message =
83       "macro '%0' used to declare a constant; consider using a 'constexpr' "
84       "constant";
85 
86   /// A variadic macro is function-like at the same time. Therefore variadic
87   /// macros are checked first and will be excluded for the function-like
88   /// diagnostic.
89   if (MD->getMacroInfo()->isVariadic())
90     Message = "variadic macro '%0' used; consider using a 'constexpr' "
91               "variadic template function";
92   else if (MD->getMacroInfo()->isFunctionLike())
93     Message = "function-like macro '%0' used; consider a 'constexpr' template "
94               "function";
95 
96   diag(MD->getLocation(), Message) << MacroName;
97 }
98 
99 void MacroUsageCheck::warnNaming(const MacroDirective *MD,
100                                  StringRef MacroName) {
101   diag(MD->getLocation(), "macro definition does not define the macro name "
102                           "'%0' using all uppercase characters")
103       << MacroName;
104 }
105 
106 } // namespace cppcoreguidelines
107 } // namespace tidy
108 } // namespace clang
109