1 //===--- InaccurateEraseCheck.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 "InaccurateEraseCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Lexer.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace bugprone {
19 
registerMatchers(MatchFinder * Finder)20 void InaccurateEraseCheck::registerMatchers(MatchFinder *Finder) {
21   const auto EndCall =
22       callExpr(
23           callee(functionDecl(hasAnyName("remove", "remove_if", "unique"))),
24           hasArgument(
25               1,
26               anyOf(cxxConstructExpr(has(ignoringImplicit(
27                         cxxMemberCallExpr(callee(cxxMethodDecl(hasName("end"))))
28                             .bind("end")))),
29                     anything())))
30           .bind("alg");
31 
32   const auto DeclInStd = type(hasUnqualifiedDesugaredType(
33       tagType(hasDeclaration(decl(isInStdNamespace())))));
34   Finder->addMatcher(
35       traverse(
36           ast_type_traits::TK_AsIs,
37           cxxMemberCallExpr(
38               on(anyOf(hasType(DeclInStd), hasType(pointsTo(DeclInStd)))),
39               callee(cxxMethodDecl(hasName("erase"))), argumentCountIs(1),
40               hasArgument(0, has(ignoringImplicit(anyOf(
41                                  EndCall, has(ignoringImplicit(EndCall)))))),
42               unless(isInTemplateInstantiation()))
43               .bind("erase")),
44       this);
45 }
46 
check(const MatchFinder::MatchResult & Result)47 void InaccurateEraseCheck::check(const MatchFinder::MatchResult &Result) {
48   const auto *MemberCall =
49       Result.Nodes.getNodeAs<CXXMemberCallExpr>("erase");
50   const auto *EndExpr =
51       Result.Nodes.getNodeAs<CXXMemberCallExpr>("end");
52   const SourceLocation Loc = MemberCall->getBeginLoc();
53 
54   FixItHint Hint;
55 
56   if (!Loc.isMacroID() && EndExpr) {
57     const auto *AlgCall = Result.Nodes.getNodeAs<CallExpr>("alg");
58     std::string ReplacementText = std::string(Lexer::getSourceText(
59         CharSourceRange::getTokenRange(EndExpr->getSourceRange()),
60         *Result.SourceManager, getLangOpts()));
61     const SourceLocation EndLoc = Lexer::getLocForEndOfToken(
62         AlgCall->getEndLoc(), 0, *Result.SourceManager, getLangOpts());
63     Hint = FixItHint::CreateInsertion(EndLoc, ", " + ReplacementText);
64   }
65 
66   diag(Loc, "this call will remove at most one item even when multiple items "
67             "should be removed")
68       << Hint;
69 }
70 
71 } // namespace bugprone
72 } // namespace tidy
73 } // namespace clang
74