1 //===--- ReplaceAutoPtrCheck.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 "ReplaceAutoPtrCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Frontend/CompilerInstance.h"
13 #include "clang/Lex/Lexer.h"
14 #include "clang/Lex/Preprocessor.h"
15
16 using namespace clang;
17 using namespace clang::ast_matchers;
18
19 namespace clang {
20 namespace tidy {
21 namespace modernize {
22
23 namespace {
24 static const char AutoPtrTokenId[] = "AutoPrTokenId";
25 static const char AutoPtrOwnershipTransferId[] = "AutoPtrOwnershipTransferId";
26
27 /// Matches expressions that are lvalues.
28 ///
29 /// In the following example, a[0] matches expr(isLValue()):
30 /// \code
31 /// std::string a[2];
32 /// std::string b;
33 /// b = a[0];
34 /// b = "this string won't match";
35 /// \endcode
AST_MATCHER(Expr,isLValue)36 AST_MATCHER(Expr, isLValue) { return Node.getValueKind() == VK_LValue; }
37
38 } // namespace
39
ReplaceAutoPtrCheck(StringRef Name,ClangTidyContext * Context)40 ReplaceAutoPtrCheck::ReplaceAutoPtrCheck(StringRef Name,
41 ClangTidyContext *Context)
42 : ClangTidyCheck(Name, Context),
43 Inserter(Options.getLocalOrGlobal("IncludeStyle",
44 utils::IncludeSorter::IS_LLVM),
45 areDiagsSelfContained()) {}
46
storeOptions(ClangTidyOptions::OptionMap & Opts)47 void ReplaceAutoPtrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
48 Options.store(Opts, "IncludeStyle", Inserter.getStyle());
49 }
50
registerMatchers(MatchFinder * Finder)51 void ReplaceAutoPtrCheck::registerMatchers(MatchFinder *Finder) {
52 auto AutoPtrDecl = recordDecl(hasName("auto_ptr"), isInStdNamespace());
53 auto AutoPtrType = qualType(hasDeclaration(AutoPtrDecl));
54
55 // std::auto_ptr<int> a;
56 // ^~~~~~~~~~~~~
57 //
58 // typedef std::auto_ptr<int> int_ptr_t;
59 // ^~~~~~~~~~~~~
60 //
61 // std::auto_ptr<int> fn(std::auto_ptr<int>);
62 // ^~~~~~~~~~~~~ ^~~~~~~~~~~~~
63 Finder->addMatcher(typeLoc(loc(qualType(AutoPtrType,
64 // Skip elaboratedType() as the named
65 // type will match soon thereafter.
66 unless(elaboratedType()))))
67 .bind(AutoPtrTokenId),
68 this);
69
70 // using std::auto_ptr;
71 // ^~~~~~~~~~~~~~~~~~~
72 Finder->addMatcher(usingDecl(hasAnyUsingShadowDecl(hasTargetDecl(namedDecl(
73 hasName("auto_ptr"), isInStdNamespace()))))
74 .bind(AutoPtrTokenId),
75 this);
76
77 // Find ownership transfers via copy construction and assignment.
78 // AutoPtrOwnershipTransferId is bound to the part that has to be wrapped
79 // into std::move().
80 // std::auto_ptr<int> i, j;
81 // i = j;
82 // ~~~~^
83 auto MovableArgumentMatcher =
84 expr(isLValue(), hasType(AutoPtrType)).bind(AutoPtrOwnershipTransferId);
85
86 Finder->addMatcher(
87 cxxOperatorCallExpr(hasOverloadedOperatorName("="),
88 callee(cxxMethodDecl(ofClass(AutoPtrDecl))),
89 hasArgument(1, MovableArgumentMatcher)),
90 this);
91 Finder->addMatcher(
92 traverse(TK_AsIs,
93 cxxConstructExpr(hasType(AutoPtrType), argumentCountIs(1),
94 hasArgument(0, MovableArgumentMatcher))),
95 this);
96 }
97
registerPPCallbacks(const SourceManager & SM,Preprocessor * PP,Preprocessor * ModuleExpanderPP)98 void ReplaceAutoPtrCheck::registerPPCallbacks(const SourceManager &SM,
99 Preprocessor *PP,
100 Preprocessor *ModuleExpanderPP) {
101 Inserter.registerPreprocessor(PP);
102 }
103
check(const MatchFinder::MatchResult & Result)104 void ReplaceAutoPtrCheck::check(const MatchFinder::MatchResult &Result) {
105 SourceManager &SM = *Result.SourceManager;
106 if (const auto *E =
107 Result.Nodes.getNodeAs<Expr>(AutoPtrOwnershipTransferId)) {
108 CharSourceRange Range = Lexer::makeFileCharRange(
109 CharSourceRange::getTokenRange(E->getSourceRange()), SM, LangOptions());
110
111 if (Range.isInvalid())
112 return;
113
114 auto Diag = diag(Range.getBegin(), "use std::move to transfer ownership")
115 << FixItHint::CreateInsertion(Range.getBegin(), "std::move(")
116 << FixItHint::CreateInsertion(Range.getEnd(), ")")
117 << Inserter.createMainFileIncludeInsertion("<utility>");
118
119 return;
120 }
121
122 SourceLocation AutoPtrLoc;
123 if (const auto *TL = Result.Nodes.getNodeAs<TypeLoc>(AutoPtrTokenId)) {
124 // std::auto_ptr<int> i;
125 // ^
126 if (auto Loc = TL->getAs<TemplateSpecializationTypeLoc>())
127 AutoPtrLoc = Loc.getTemplateNameLoc();
128 } else if (const auto *D =
129 Result.Nodes.getNodeAs<UsingDecl>(AutoPtrTokenId)) {
130 // using std::auto_ptr;
131 // ^
132 AutoPtrLoc = D->getNameInfo().getBeginLoc();
133 } else {
134 llvm_unreachable("Bad Callback. No node provided.");
135 }
136
137 if (AutoPtrLoc.isMacroID())
138 AutoPtrLoc = SM.getSpellingLoc(AutoPtrLoc);
139
140 // Ensure that only the 'auto_ptr' token is replaced and not the template
141 // aliases.
142 if (StringRef(SM.getCharacterData(AutoPtrLoc), strlen("auto_ptr")) !=
143 "auto_ptr")
144 return;
145
146 SourceLocation EndLoc =
147 AutoPtrLoc.getLocWithOffset(strlen("auto_ptr") - 1);
148 diag(AutoPtrLoc, "auto_ptr is deprecated, use unique_ptr instead")
149 << FixItHint::CreateReplacement(SourceRange(AutoPtrLoc, EndLoc),
150 "unique_ptr");
151 }
152
153 } // namespace modernize
154 } // namespace tidy
155 } // namespace clang
156