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 { 20 namespace tidy { 21 namespace cppcoreguidelines { 22 23 static bool isCapsOnly(StringRef Name) { 24 return llvm::all_of(Name, [](const char C) { 25 return std::isupper(C) || std::isdigit(C) || C == '_'; 26 }); 27 } 28 29 namespace { 30 31 class MacroUsageCallbacks : public PPCallbacks { 32 public: 33 MacroUsageCallbacks(MacroUsageCheck *Check, const SourceManager &SM, 34 StringRef RegExpStr, bool CapsOnly, 35 bool IgnoreCommandLine) 36 : Check(Check), SM(SM), RegExp(RegExpStr), CheckCapsOnly(CapsOnly), 37 IgnoreCommandLineMacros(IgnoreCommandLine) {} 38 void MacroDefined(const Token &MacroNameTok, 39 const MacroDirective *MD) override { 40 if (SM.isWrittenInBuiltinFile(MD->getLocation()) || 41 MD->getMacroInfo()->isUsedForHeaderGuard() || 42 MD->getMacroInfo()->getNumTokens() == 0) 43 return; 44 45 if (IgnoreCommandLineMacros && 46 SM.isWrittenInCommandLineFile(MD->getLocation())) 47 return; 48 49 StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName(); 50 if (MacroName == "__GCC_HAVE_DWARF2_CFI_ASM") 51 return; 52 if (!CheckCapsOnly && !RegExp.match(MacroName)) 53 Check->warnMacro(MD, MacroName); 54 55 if (CheckCapsOnly && !isCapsOnly(MacroName)) 56 Check->warnNaming(MD, MacroName); 57 } 58 59 private: 60 MacroUsageCheck *Check; 61 const SourceManager &SM; 62 const llvm::Regex RegExp; 63 bool CheckCapsOnly; 64 bool IgnoreCommandLineMacros; 65 }; 66 } // namespace 67 68 void MacroUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { 69 Options.store(Opts, "AllowedRegexp", AllowedRegexp); 70 Options.store(Opts, "CheckCapsOnly", CheckCapsOnly); 71 Options.store(Opts, "IgnoreCommandLineMacros", IgnoreCommandLineMacros); 72 } 73 74 void MacroUsageCheck::registerPPCallbacks(const SourceManager &SM, 75 Preprocessor *PP, 76 Preprocessor *ModuleExpanderPP) { 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 const MacroInfo *Info = MD->getMacroInfo(); 83 StringRef Message; 84 85 if (llvm::all_of(Info->tokens(), std::mem_fn(&Token::isLiteral))) 86 Message = "macro '%0' used to declare a constant; consider using a " 87 "'constexpr' constant"; 88 // A variadic macro is function-like at the same time. Therefore variadic 89 // macros are checked first and will be excluded for the function-like 90 // diagnostic. 91 else if (Info->isVariadic()) 92 Message = "variadic macro '%0' used; consider using a 'constexpr' " 93 "variadic template function"; 94 else if (Info->isFunctionLike()) 95 Message = "function-like macro '%0' used; consider a 'constexpr' template " 96 "function"; 97 98 if (!Message.empty()) 99 diag(MD->getLocation(), Message) << MacroName; 100 } 101 102 void MacroUsageCheck::warnNaming(const MacroDirective *MD, 103 StringRef MacroName) { 104 diag(MD->getLocation(), "macro definition does not define the macro name " 105 "'%0' using all uppercase characters") 106 << MacroName; 107 } 108 109 } // namespace cppcoreguidelines 110 } // namespace tidy 111 } // namespace clang 112