clang-tools 18.0.0git
ContainerContainsCheck.cpp
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1//===--- ContainerContainsCheck.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
10#include "clang/AST/ASTContext.h"
11#include "clang/ASTMatchers/ASTMatchFinder.h"
12
13using namespace clang::ast_matchers;
14
16
18 const auto SupportedContainers = hasType(
19 hasUnqualifiedDesugaredType(recordType(hasDeclaration(cxxRecordDecl(
20 hasAnyName("::std::set", "::std::unordered_set", "::std::map",
21 "::std::unordered_map", "::std::multiset",
22 "::std::unordered_multiset", "::std::multimap",
23 "::std::unordered_multimap"))))));
24
25 const auto CountCall =
26 cxxMemberCallExpr(on(SupportedContainers),
27 callee(cxxMethodDecl(hasName("count"))),
28 argumentCountIs(1))
29 .bind("call");
30
31 const auto FindCall =
32 cxxMemberCallExpr(on(SupportedContainers),
33 callee(cxxMethodDecl(hasName("find"))),
34 argumentCountIs(1))
35 .bind("call");
36
37 const auto EndCall = cxxMemberCallExpr(on(SupportedContainers),
38 callee(cxxMethodDecl(hasName("end"))),
39 argumentCountIs(0));
40
41 const auto Literal0 = integerLiteral(equals(0));
42 const auto Literal1 = integerLiteral(equals(1));
43
44 auto AddSimpleMatcher = [&](auto Matcher) {
45 Finder->addMatcher(
46 traverse(TK_IgnoreUnlessSpelledInSource, std::move(Matcher)), this);
47 };
48
49 // Find membership tests which use `count()`.
50 Finder->addMatcher(implicitCastExpr(hasImplicitDestinationType(booleanType()),
51 hasSourceExpression(CountCall))
52 .bind("positiveComparison"),
53 this);
54 AddSimpleMatcher(
55 binaryOperator(hasLHS(CountCall), hasOperatorName("!="), hasRHS(Literal0))
56 .bind("positiveComparison"));
57 AddSimpleMatcher(
58 binaryOperator(hasLHS(Literal0), hasOperatorName("!="), hasRHS(CountCall))
59 .bind("positiveComparison"));
60 AddSimpleMatcher(
61 binaryOperator(hasLHS(CountCall), hasOperatorName(">"), hasRHS(Literal0))
62 .bind("positiveComparison"));
63 AddSimpleMatcher(
64 binaryOperator(hasLHS(Literal0), hasOperatorName("<"), hasRHS(CountCall))
65 .bind("positiveComparison"));
66 AddSimpleMatcher(
67 binaryOperator(hasLHS(CountCall), hasOperatorName(">="), hasRHS(Literal1))
68 .bind("positiveComparison"));
69 AddSimpleMatcher(
70 binaryOperator(hasLHS(Literal1), hasOperatorName("<="), hasRHS(CountCall))
71 .bind("positiveComparison"));
72
73 // Find inverted membership tests which use `count()`.
74 AddSimpleMatcher(
75 binaryOperator(hasLHS(CountCall), hasOperatorName("=="), hasRHS(Literal0))
76 .bind("negativeComparison"));
77 AddSimpleMatcher(
78 binaryOperator(hasLHS(Literal0), hasOperatorName("=="), hasRHS(CountCall))
79 .bind("negativeComparison"));
80 AddSimpleMatcher(
81 binaryOperator(hasLHS(CountCall), hasOperatorName("<="), hasRHS(Literal0))
82 .bind("negativeComparison"));
83 AddSimpleMatcher(
84 binaryOperator(hasLHS(Literal0), hasOperatorName(">="), hasRHS(CountCall))
85 .bind("negativeComparison"));
86 AddSimpleMatcher(
87 binaryOperator(hasLHS(CountCall), hasOperatorName("<"), hasRHS(Literal1))
88 .bind("negativeComparison"));
89 AddSimpleMatcher(
90 binaryOperator(hasLHS(Literal1), hasOperatorName(">"), hasRHS(CountCall))
91 .bind("negativeComparison"));
92
93 // Find membership tests based on `find() == end()`.
94 AddSimpleMatcher(
95 binaryOperator(hasLHS(FindCall), hasOperatorName("!="), hasRHS(EndCall))
96 .bind("positiveComparison"));
97 AddSimpleMatcher(
98 binaryOperator(hasLHS(FindCall), hasOperatorName("=="), hasRHS(EndCall))
99 .bind("negativeComparison"));
100}
101
102void ContainerContainsCheck::check(const MatchFinder::MatchResult &Result) {
103 // Extract the information about the match
104 const auto *Call = Result.Nodes.getNodeAs<CXXMemberCallExpr>("call");
105 const auto *PositiveComparison =
106 Result.Nodes.getNodeAs<Expr>("positiveComparison");
107 const auto *NegativeComparison =
108 Result.Nodes.getNodeAs<Expr>("negativeComparison");
109 assert((!PositiveComparison || !NegativeComparison) &&
110 "only one of PositiveComparison or NegativeComparison should be set");
111 bool Negated = NegativeComparison != nullptr;
112 const auto *Comparison = Negated ? NegativeComparison : PositiveComparison;
113
114 // Diagnose the issue.
115 auto Diag =
116 diag(Call->getExprLoc(), "use 'contains' to check for membership");
117
118 // Don't fix it if it's in a macro invocation. Leave fixing it to the user.
119 SourceLocation FuncCallLoc = Comparison->getEndLoc();
120 if (!FuncCallLoc.isValid() || FuncCallLoc.isMacroID())
121 return;
122
123 // Create the fix it.
124 const auto *Member = cast<MemberExpr>(Call->getCallee());
125 Diag << FixItHint::CreateReplacement(
126 Member->getMemberNameInfo().getSourceRange(), "contains");
127 SourceLocation ComparisonBegin = Comparison->getSourceRange().getBegin();
128 SourceLocation ComparisonEnd = Comparison->getSourceRange().getEnd();
129 SourceLocation CallBegin = Call->getSourceRange().getBegin();
130 SourceLocation CallEnd = Call->getSourceRange().getEnd();
131 Diag << FixItHint::CreateReplacement(
132 CharSourceRange::getCharRange(ComparisonBegin, CallBegin),
133 Negated ? "!" : "");
134 Diag << FixItHint::CreateRemoval(CharSourceRange::getCharRange(
135 CallEnd.getLocWithOffset(1), ComparisonEnd.getLocWithOffset(1)));
136}
137
138} // namespace clang::tidy::readability
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
void check(const ast_matchers::MatchFinder::MatchResult &Result) final
ClangTidyChecks that register ASTMatchers should do the actual work in here.
void registerMatchers(ast_matchers::MatchFinder *Finder) final
Override this to register AST matchers with Finder.