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 "clang/Lex/Preprocessor.h" 13 #include "llvm/ADT/STLExtras.h" 14 #include "llvm/Support/Regex.h" 15 #include <algorithm> 16 #include <cctype> 17 #include <functional> 18 19 namespace clang::tidy::cppcoreguidelines { 20 21 static bool isCapsOnly(StringRef Name) { 22 return llvm::all_of(Name, [](const char C) { 23 return std::isupper(C) || std::isdigit(C) || C == '_'; 24 }); 25 } 26 27 namespace { 28 29 class MacroUsageCallbacks : public PPCallbacks { 30 public: 31 MacroUsageCallbacks(MacroUsageCheck *Check, const SourceManager &SM, 32 StringRef RegExpStr, bool CapsOnly, 33 bool IgnoreCommandLine) 34 : Check(Check), SM(SM), RegExp(RegExpStr), CheckCapsOnly(CapsOnly), 35 IgnoreCommandLineMacros(IgnoreCommandLine) {} 36 void MacroDefined(const Token &MacroNameTok, 37 const MacroDirective *MD) override { 38 if (SM.isWrittenInBuiltinFile(MD->getLocation()) || 39 MD->getMacroInfo()->isUsedForHeaderGuard() || 40 MD->getMacroInfo()->getNumTokens() == 0) 41 return; 42 43 if (IgnoreCommandLineMacros && 44 SM.isWrittenInCommandLineFile(MD->getLocation())) 45 return; 46 47 StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName(); 48 if (MacroName == "__GCC_HAVE_DWARF2_CFI_ASM") 49 return; 50 if (!CheckCapsOnly && !RegExp.match(MacroName)) 51 Check->warnMacro(MD, MacroName); 52 53 if (CheckCapsOnly && !isCapsOnly(MacroName)) 54 Check->warnNaming(MD, MacroName); 55 } 56 57 private: 58 MacroUsageCheck *Check; 59 const SourceManager &SM; 60 const llvm::Regex RegExp; 61 bool CheckCapsOnly; 62 bool IgnoreCommandLineMacros; 63 }; 64 } // namespace 65 66 void MacroUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { 67 Options.store(Opts, "AllowedRegexp", AllowedRegexp); 68 Options.store(Opts, "CheckCapsOnly", CheckCapsOnly); 69 Options.store(Opts, "IgnoreCommandLineMacros", IgnoreCommandLineMacros); 70 } 71 72 void MacroUsageCheck::registerPPCallbacks(const SourceManager &SM, 73 Preprocessor *PP, 74 Preprocessor *ModuleExpanderPP) { 75 PP->addPPCallbacks(std::make_unique<MacroUsageCallbacks>( 76 this, SM, AllowedRegexp, CheckCapsOnly, IgnoreCommandLineMacros)); 77 } 78 79 void MacroUsageCheck::warnMacro(const MacroDirective *MD, StringRef MacroName) { 80 const MacroInfo *Info = MD->getMacroInfo(); 81 StringRef Message; 82 83 if (llvm::all_of(Info->tokens(), std::mem_fn(&Token::isLiteral))) 84 Message = "macro '%0' used to declare a constant; consider using a " 85 "'constexpr' constant"; 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 else if (Info->isVariadic()) 90 Message = "variadic macro '%0' used; consider using a 'constexpr' " 91 "variadic template function"; 92 else if (Info->isFunctionLike()) 93 Message = "function-like macro '%0' used; consider a 'constexpr' template " 94 "function"; 95 96 if (!Message.empty()) 97 diag(MD->getLocation(), Message) << MacroName; 98 } 99 100 void MacroUsageCheck::warnNaming(const MacroDirective *MD, 101 StringRef MacroName) { 102 diag(MD->getLocation(), "macro definition does not define the macro name " 103 "'%0' using all uppercase characters") 104 << MacroName; 105 } 106 107 } // namespace clang::tidy::cppcoreguidelines 108