clang-tools-extra/clang-tidy/llvm/PreferRegisterOverUnsignedCheck.cpp

   1 //===--- PreferRegisterOverUnsignedCheck.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 "PreferRegisterOverUnsignedCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace clang::tidy::llvm_check {
  16
  17 void PreferRegisterOverUnsignedCheck::registerMatchers(MatchFinder *Finder) {
  18   auto RegisterClassMatch = hasType(
  19       cxxRecordDecl(hasName("::llvm::Register")).bind("registerClassDecl"));
  20
  21   Finder->addMatcher(
  22       traverse(TK_AsIs,
  23                valueDecl(hasType(qualType(isUnsignedInteger()).bind("varType")),
  24                          varDecl(hasInitializer(exprWithCleanups(
  25                                      has(implicitCastExpr(has(cxxMemberCallExpr(
  26                                          on(RegisterClassMatch),
  27                                          has(memberExpr(hasDeclaration(
  28                                              cxxConversionDecl()))))))))))
  29                              .bind("var"))),
  30       this);
  31 }
  32
  33 void PreferRegisterOverUnsignedCheck::check(
  34     const MatchFinder::MatchResult &Result) {
  35   const auto *VarType = Result.Nodes.getNodeAs<QualType>("varType");
  36   const auto *UserVarDecl = Result.Nodes.getNodeAs<VarDecl>("var");
  37
  38   bool NeedsQualification = true;
  39   const DeclContext *Context = UserVarDecl->getDeclContext();
  40   while (Context) {
  41     if (const auto *Namespace = dyn_cast<NamespaceDecl>(Context))
  42       if (isa<TranslationUnitDecl>(Namespace->getDeclContext()) &&
  43           Namespace->getName() == "llvm")
  44         NeedsQualification = false;
  45     for (const auto *UsingDirective : Context->using_directives()) {
  46       const NamespaceDecl *Namespace = UsingDirective->getNominatedNamespace();
  47       if (isa<TranslationUnitDecl>(Namespace->getDeclContext()) &&
  48           Namespace->getName() == "llvm")
  49         NeedsQualification = false;
  50     }
  51     Context = Context->getParent();
  52   }
  53   diag(UserVarDecl->getLocation(),
  54        "variable %0 declared as %1; use '%select{|llvm::}2Register' instead")
  55       << UserVarDecl << *VarType << NeedsQualification
  56       << FixItHint::CreateReplacement(
  57              UserVarDecl->getTypeSourceInfo()->getTypeLoc().getSourceRange(),
  58              NeedsQualification ? "llvm::Register" : "Register");
  59 }
  60
  61 } // namespace clang::tidy::llvm_check