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