1 //===--- IncorrectEnableIfCheck.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 "IncorrectEnableIfCheck.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::bugprone {
16
17 namespace {
18
AST_MATCHER_P(TemplateTypeParmDecl,hasUnnamedDefaultArgument,ast_matchers::internal::Matcher<TypeLoc>,InnerMatcher)19 AST_MATCHER_P(TemplateTypeParmDecl, hasUnnamedDefaultArgument,
20 ast_matchers::internal::Matcher<TypeLoc>, InnerMatcher) {
21 if (Node.getIdentifier() != nullptr || !Node.hasDefaultArgument() ||
22 Node.getDefaultArgument().getArgument().isNull())
23 return false;
24
25 TypeLoc DefaultArgTypeLoc =
26 Node.getDefaultArgument().getTypeSourceInfo()->getTypeLoc();
27 return InnerMatcher.matches(DefaultArgTypeLoc, Finder, Builder);
28 }
29
30 } // namespace
31
registerMatchers(MatchFinder * Finder)32 void IncorrectEnableIfCheck::registerMatchers(MatchFinder *Finder) {
33 Finder->addMatcher(
34 templateTypeParmDecl(
35 hasUnnamedDefaultArgument(
36 elaboratedTypeLoc(
37 hasNamedTypeLoc(templateSpecializationTypeLoc(
38 loc(qualType(hasDeclaration(namedDecl(
39 hasName("::std::enable_if"))))))
40 .bind("enable_if_specialization")))
41 .bind("elaborated")))
42 .bind("enable_if"),
43 this);
44 }
45
check(const MatchFinder::MatchResult & Result)46 void IncorrectEnableIfCheck::check(const MatchFinder::MatchResult &Result) {
47 const auto *EnableIf =
48 Result.Nodes.getNodeAs<TemplateTypeParmDecl>("enable_if");
49 const auto *ElaboratedLoc =
50 Result.Nodes.getNodeAs<ElaboratedTypeLoc>("elaborated");
51 const auto *EnableIfSpecializationLoc =
52 Result.Nodes.getNodeAs<TemplateSpecializationTypeLoc>(
53 "enable_if_specialization");
54
55 if (!EnableIf || !ElaboratedLoc || !EnableIfSpecializationLoc)
56 return;
57
58 const SourceManager &SM = *Result.SourceManager;
59 SourceLocation RAngleLoc =
60 SM.getExpansionLoc(EnableIfSpecializationLoc->getRAngleLoc());
61
62 auto Diag = diag(EnableIf->getBeginLoc(),
63 "incorrect std::enable_if usage detected; use "
64 "'typename std::enable_if<...>::type'");
65 if (!getLangOpts().CPlusPlus20) {
66 Diag << FixItHint::CreateInsertion(ElaboratedLoc->getBeginLoc(),
67 "typename ");
68 }
69 Diag << FixItHint::CreateInsertion(RAngleLoc.getLocWithOffset(1), "::type");
70 }
71
72 } // namespace clang::tidy::bugprone
73