xref: /llvm-project/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.cpp (revision cc740ae5bbe7a1bcc0bd3e4a21af75a0d29b7ce5)
1 //===--- SimplifySubscriptExprCheck.cpp - clang-tidy-----------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "SimplifySubscriptExprCheck.h"
11 #include "../utils/OptionsUtils.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace readability {
20 
21 static const char kDefaultTypes[] =
22     "::std::basic_string;::std::basic_string_view;::std::vector;::std::array";
23 
24 SimplifySubscriptExprCheck::SimplifySubscriptExprCheck(
25     StringRef Name, ClangTidyContext *Context)
26     : ClangTidyCheck(Name, Context), Types(utils::options::parseStringList(
27                                          Options.get("Types", kDefaultTypes))) {
28 }
29 
30 void SimplifySubscriptExprCheck::registerMatchers(MatchFinder *Finder) {
31   if (!getLangOpts().CPlusPlus)
32     return;
33 
34   const auto TypesMatcher = hasUnqualifiedDesugaredType(
35       recordType(hasDeclaration(cxxRecordDecl(hasAnyName(
36           llvm::SmallVector<StringRef, 8>(Types.begin(), Types.end()))))));
37 
38   Finder->addMatcher(
39       arraySubscriptExpr(hasBase(ignoringParenImpCasts(
40           cxxMemberCallExpr(
41               has(memberExpr().bind("member")),
42               on(hasType(qualType(
43                   unless(anyOf(substTemplateTypeParmType(),
44                                hasDescendant(substTemplateTypeParmType()))),
45                   anyOf(TypesMatcher, pointerType(pointee(TypesMatcher)))))),
46               callee(namedDecl(hasName("data"))))
47               .bind("call")))),
48       this);
49 }
50 
51 void SimplifySubscriptExprCheck::check(const MatchFinder::MatchResult &Result) {
52   const auto *Call = Result.Nodes.getNodeAs<CXXMemberCallExpr>("call");
53   if (Result.Context->getSourceManager().isMacroBodyExpansion(
54           Call->getExprLoc()))
55     return;
56 
57   const auto *Member = Result.Nodes.getNodeAs<MemberExpr>("member");
58   auto DiagBuilder =
59       diag(Member->getMemberLoc(),
60            "accessing an element of the container does not require a call to "
61            "'data()'; did you mean to use 'operator[]'?");
62   if (Member->isArrow())
63     DiagBuilder << FixItHint::CreateInsertion(Member->getLocStart(), "(*")
64                 << FixItHint::CreateInsertion(Member->getOperatorLoc(), ")");
65   DiagBuilder << FixItHint::CreateRemoval(
66       {Member->getOperatorLoc(), Call->getLocEnd()});
67 }
68 
69 void SimplifySubscriptExprCheck::storeOptions(
70     ClangTidyOptions::OptionMap &Opts) {
71   Options.store(Opts, "Types", utils::options::serializeStringList(Types));
72 }
73 
74 } // namespace readability
75 } // namespace tidy
76 } // namespace clang
77