clang-tools 6.0.0

StringCompareCheck.cpp
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1 //===--- MiscStringCompare.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 "StringCompareCheck.h"
11 #include "../utils/FixItHintUtils.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 #include "clang/Tooling/FixIt.h"
15
16 using namespace clang::ast_matchers;
17
18 namespace clang {
19 namespace tidy {
20 namespace misc {
21
22 static const StringRef CompareMessage = "do not use 'compare' to test equality "
23 "of strings; use the string equality "
24 "operator instead";
25
26 void StringCompareCheck::registerMatchers(MatchFinder *Finder) {
27 if (!getLangOpts().CPlusPlus)
28 return;
29
30 const auto StrCompare = cxxMemberCallExpr(
31 callee(cxxMethodDecl(hasName("compare"),
32 ofClass(classTemplateSpecializationDecl(
33 hasName("::std::basic_string"))))),
34 hasArgument(0, expr().bind("str2")), argumentCountIs(1),
35 callee(memberExpr().bind("str1")));
36
37 // First and second case: cast str.compare(str) to boolean.
38 Finder->addMatcher(implicitCastExpr(hasImplicitDestinationType(booleanType()),
39 has(StrCompare))
40 .bind("match1"),
41 this);
42
43 // Third and fourth case: str.compare(str) == 0 and str.compare(str) != 0.
44 Finder->addMatcher(
45 binaryOperator(anyOf(hasOperatorName("=="), hasOperatorName("!=")),
46 hasEitherOperand(StrCompare.bind("compare")),
47 hasEitherOperand(integerLiteral(equals(0)).bind("zero")))
48 .bind("match2"),
49 this);
50 }
51
52 void StringCompareCheck::check(const MatchFinder::MatchResult &Result) {
53 if (const auto *Matched = Result.Nodes.getNodeAs<Stmt>("match1")) {
54 diag(Matched->getLocStart(), CompareMessage);
55 return;
56 }
57
58 if (const auto *Matched = Result.Nodes.getNodeAs<Stmt>("match2")) {
59 const ASTContext &Ctx = *Result.Context;
60
61 if (const auto *Zero = Result.Nodes.getNodeAs<Stmt>("zero")) {
62 const auto *Str1 = Result.Nodes.getNodeAs<MemberExpr>("str1");
63 const auto *Str2 = Result.Nodes.getNodeAs<Stmt>("str2");
64 const auto *Compare = Result.Nodes.getNodeAs<Stmt>("compare");
65
66 auto Diag = diag(Matched->getLocStart(), CompareMessage);
67
68 if (Str1->isArrow())
69 Diag << FixItHint::CreateInsertion(Str1->getLocStart(), "*");
70
71 Diag << tooling::fixit::createReplacement(*Zero, *Str2, Ctx)
72 << tooling::fixit::createReplacement(*Compare, *Str1->getBase(),
73 Ctx);
74 }
75 }
76
77 // FIXME: Add fixit to fix the code for case one and two (match1).
78 }
79
80 } // namespace misc
81 } // namespace tidy
82 } // namespace clang
clang::ast_matchers
Definition: ClangTidyDiagnosticConsumer.h:27
clang::tidy::misc::CompareMessage
static const StringRef CompareMessage
Definition: StringCompareCheck.cpp:22
StringCompareCheck.h
clang
Definition: AndroidTidyModule.cpp:28