clang-tools 20.0.0git
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
9#include "ContainerContainsCheck.h"
10#include "clang/AST/ASTContext.h"
11#include "clang/ASTMatchers/ASTMatchFinder.h"
12
13using namespace clang::ast_matchers;
14
15namespace clang::tidy::readability {
16void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
17 const auto HasContainsMatchingParamType = hasMethod(
18 cxxMethodDecl(isConst(), parameterCountIs(1), returns(booleanType()),
19 hasName("contains"), unless(isDeleted()), isPublic(),
20 hasParameter(0, hasType(hasUnqualifiedDesugaredType(
21 equalsBoundNode("parameterType"))))));
22
23 const auto CountCall =
24 cxxMemberCallExpr(
25 argumentCountIs(1),
26 callee(cxxMethodDecl(
27 hasName("count"),
28 hasParameter(0, hasType(hasUnqualifiedDesugaredType(
29 type().bind("parameterType")))),
30 ofClass(cxxRecordDecl(HasContainsMatchingParamType)))))
31 .bind("call");
32
33 const auto FindCall =
34 cxxMemberCallExpr(
35 argumentCountIs(1),
36 callee(cxxMethodDecl(
37 hasName("find"),
38 hasParameter(0, hasType(hasUnqualifiedDesugaredType(
39 type().bind("parameterType")))),
40 ofClass(cxxRecordDecl(HasContainsMatchingParamType)))))
41 .bind("call");
42
43 const auto EndCall = cxxMemberCallExpr(
44 argumentCountIs(0),
45 callee(
46 cxxMethodDecl(hasName("end"),
47 // In the matchers below, FindCall should always appear
48 // before EndCall so 'parameterType' is properly bound.
49 ofClass(cxxRecordDecl(HasContainsMatchingParamType)))));
50
51 const auto Literal0 = integerLiteral(equals(0));
52 const auto Literal1 = integerLiteral(equals(1));
53
54 auto AddSimpleMatcher = [&](auto Matcher) {
55 Finder->addMatcher(
56 traverse(TK_IgnoreUnlessSpelledInSource, std::move(Matcher)), this);
57 };
58
59 // Find membership tests which use `count()`.
60 Finder->addMatcher(implicitCastExpr(hasImplicitDestinationType(booleanType()),
61 hasSourceExpression(CountCall))
62 .bind("positiveComparison"),
63 this);
64 AddSimpleMatcher(
65 binaryOperation(hasOperatorName("!="), hasOperands(CountCall, Literal0))
66 .bind("positiveComparison"));
67 AddSimpleMatcher(
68 binaryOperation(hasLHS(CountCall), hasOperatorName(">"), hasRHS(Literal0))
69 .bind("positiveComparison"));
70 AddSimpleMatcher(
71 binaryOperation(hasLHS(Literal0), hasOperatorName("<"), hasRHS(CountCall))
72 .bind("positiveComparison"));
73 AddSimpleMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName(">="),
74 hasRHS(Literal1))
75 .bind("positiveComparison"));
76 AddSimpleMatcher(binaryOperation(hasLHS(Literal1), hasOperatorName("<="),
77 hasRHS(CountCall))
78 .bind("positiveComparison"));
79
80 // Find inverted membership tests which use `count()`.
81 AddSimpleMatcher(
82 binaryOperation(hasOperatorName("=="), hasOperands(CountCall, Literal0))
83 .bind("negativeComparison"));
84 AddSimpleMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName("<="),
85 hasRHS(Literal0))
86 .bind("negativeComparison"));
87 AddSimpleMatcher(binaryOperation(hasLHS(Literal0), hasOperatorName(">="),
88 hasRHS(CountCall))
89 .bind("negativeComparison"));
90 AddSimpleMatcher(
91 binaryOperation(hasLHS(CountCall), hasOperatorName("<"), hasRHS(Literal1))
92 .bind("negativeComparison"));
93 AddSimpleMatcher(
94 binaryOperation(hasLHS(Literal1), hasOperatorName(">"), hasRHS(CountCall))
95 .bind("negativeComparison"));
96
97 // Find membership tests based on `find() == end()`.
98 AddSimpleMatcher(
99 binaryOperation(hasOperatorName("!="), hasOperands(FindCall, EndCall))
100 .bind("positiveComparison"));
101 AddSimpleMatcher(
102 binaryOperation(hasOperatorName("=="), hasOperands(FindCall, EndCall))
103 .bind("negativeComparison"));
104}
105
106void ContainerContainsCheck::check(const MatchFinder::MatchResult &Result) {
107 // Extract the information about the match
108 const auto *Call = Result.Nodes.getNodeAs<CXXMemberCallExpr>("call");
109 const auto *PositiveComparison =
110 Result.Nodes.getNodeAs<Expr>("positiveComparison");
111 const auto *NegativeComparison =
112 Result.Nodes.getNodeAs<Expr>("negativeComparison");
113 assert((!PositiveComparison || !NegativeComparison) &&
114 "only one of PositiveComparison or NegativeComparison should be set");
115 bool Negated = NegativeComparison != nullptr;
116 const auto *Comparison = Negated ? NegativeComparison : PositiveComparison;
117
118 // Diagnose the issue.
119 auto Diag =
120 diag(Call->getExprLoc(), "use 'contains' to check for membership");
121
122 // Don't fix it if it's in a macro invocation. Leave fixing it to the user.
123 SourceLocation FuncCallLoc = Comparison->getEndLoc();
124 if (!FuncCallLoc.isValid() || FuncCallLoc.isMacroID())
125 return;
126
127 // Create the fix it.
128 const auto *Member = cast<MemberExpr>(Call->getCallee());
129 Diag << FixItHint::CreateReplacement(
130 Member->getMemberNameInfo().getSourceRange(), "contains");
131 SourceLocation ComparisonBegin = Comparison->getSourceRange().getBegin();
132 SourceLocation ComparisonEnd = Comparison->getSourceRange().getEnd();
133 SourceLocation CallBegin = Call->getSourceRange().getBegin();
134 SourceLocation CallEnd = Call->getSourceRange().getEnd();
135 Diag << FixItHint::CreateReplacement(
136 CharSourceRange::getCharRange(ComparisonBegin, CallBegin),
137 Negated ? "!" : "");
138 Diag << FixItHint::CreateRemoval(CharSourceRange::getTokenRange(
139 CallEnd.getLocWithOffset(1), ComparisonEnd));
140}
141
142} // namespace clang::tidy::readability
clang::tidy::ClangTidyCheck::diag
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
Definition: ClangTidyCheck.cpp:25
clang::tidy::readability::ContainerContainsCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) final
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: ContainerContainsCheck.cpp:106
clang::tidy::readability::ContainerContainsCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) final
Override this to register AST matchers with Finder.
Definition: ContainerContainsCheck.cpp:16
clang::ast_matchers
Definition: AbseilMatcher.h:13
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