clang-tools-extra/clang-tidy/modernize/ReplaceDisallowCopyAndAssignMacroCheck.cpp

   1 //===--- ReplaceDisallowCopyAndAssignMacroCheck.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 "ReplaceDisallowCopyAndAssignMacroCheck.h"
  10 #include "clang/Frontend/CompilerInstance.h"
  11 #include "clang/Lex/MacroArgs.h"
  12 #include "clang/Lex/PPCallbacks.h"
  13 #include "clang/Lex/Preprocessor.h"
  14 #include "llvm/Support/FormatVariadic.h"
  15 #include <optional>
  16
  17 namespace clang::tidy::modernize {
  18
  19 namespace {
  20
  21 class ReplaceDisallowCopyAndAssignMacroCallbacks : public PPCallbacks {
  22 public:
  23   explicit ReplaceDisallowCopyAndAssignMacroCallbacks(
  24       ReplaceDisallowCopyAndAssignMacroCheck &Check, Preprocessor &PP)
  25       : Check(Check), PP(PP) {}
  26
  27   void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,
  28                     SourceRange Range, const MacroArgs *Args) override {
  29     IdentifierInfo *Info = MacroNameTok.getIdentifierInfo();
  30     if (!Info || !Args || Args->getNumMacroArguments() != 1)
  31       return;
  32     if (Info->getName() != Check.getMacroName())
  33       return;
  34     // The first argument to the DISALLOW_COPY_AND_ASSIGN macro is expected to
  35     // be the class name.
  36     const Token *ClassNameTok = Args->getUnexpArgument(0);
  37     if (Args->ArgNeedsPreexpansion(ClassNameTok, PP))
  38       // For now we only support simple argument that don't need to be
  39       // pre-expanded.
  40       return;
  41     clang::IdentifierInfo *ClassIdent = ClassNameTok->getIdentifierInfo();
  42     if (!ClassIdent)
  43       return;
  44
  45     std::string Replacement = llvm::formatv(
  46         R"cpp({0}(const {0} &) = delete;
  47 const {0} &operator=(const {0} &) = delete{1})cpp",
  48         ClassIdent->getName(), shouldAppendSemi(Range) ? ";" : "");
  49
  50     Check.diag(MacroNameTok.getLocation(),
  51                "prefer deleting copy constructor and assignment operator over "
  52                "using macro '%0'")
  53         << Check.getMacroName()
  54         << FixItHint::CreateReplacement(
  55                PP.getSourceManager().getExpansionRange(Range), Replacement);
  56   }
  57
  58 private:
  59   /// \returns \c true if the next token after the given \p MacroLoc is \b not a
  60   /// semicolon.
  61   bool shouldAppendSemi(SourceRange MacroLoc) {
  62     std::optional<Token> Next = Lexer::findNextToken(
  63         MacroLoc.getEnd(), PP.getSourceManager(), PP.getLangOpts());
  64     return !(Next && Next->is(tok::semi));
  65   }
  66
  67   ReplaceDisallowCopyAndAssignMacroCheck &Check;
  68   Preprocessor &PP;
  69 };
  70 } // namespace
  71
  72 ReplaceDisallowCopyAndAssignMacroCheck::ReplaceDisallowCopyAndAssignMacroCheck(
  73     StringRef Name, ClangTidyContext *Context)
  74     : ClangTidyCheck(Name, Context),
  75       MacroName(Options.get("MacroName", "DISALLOW_COPY_AND_ASSIGN")) {}
  76
  77 void ReplaceDisallowCopyAndAssignMacroCheck::registerPPCallbacks(
  78     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
  79   PP->addPPCallbacks(
  80       ::std::make_unique<ReplaceDisallowCopyAndAssignMacroCallbacks>(
  81           *this, *ModuleExpanderPP));
  82 }
  83
  84 void ReplaceDisallowCopyAndAssignMacroCheck::storeOptions(
  85     ClangTidyOptions::OptionMap &Opts) {
  86   Options.store(Opts, "MacroName", MacroName);
  87 }
  88
  89 } // namespace clang::tidy::modernize