clang-tools 8.0.0

DanglingHandleCheck.cpp
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1 //===--- DanglingHandleCheck.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 "DanglingHandleCheck.h"
11 #include "../utils/Matchers.h"
12 #include "../utils/OptionsUtils.h"
13 #include "clang/AST/ASTContext.h"
14 #include "clang/ASTMatchers/ASTMatchFinder.h"
15
16 using namespace clang::ast_matchers;
17 using namespace clang::tidy::matchers;
18
19 namespace clang {
20 namespace tidy {
21 namespace bugprone {
22
23 namespace {
24
25 ast_matchers::internal::BindableMatcher<Stmt>
26 handleFrom(const ast_matchers::internal::Matcher<RecordDecl> &IsAHandle,
27 const ast_matchers::internal::Matcher<Expr> &Arg) {
28 return expr(
29 anyOf(cxxConstructExpr(hasDeclaration(cxxMethodDecl(ofClass(IsAHandle))),
30 hasArgument(0, Arg)),
31 cxxMemberCallExpr(hasType(cxxRecordDecl(IsAHandle)),
32 callee(memberExpr(member(cxxConversionDecl()))),
33 on(Arg))));
34 }
35
36 ast_matchers::internal::Matcher<Stmt> handleFromTemporaryValue(
37 const ast_matchers::internal::Matcher<RecordDecl> &IsAHandle) {
38 // If a ternary operator returns a temporary value, then both branches hold a
39 // temporary value. If one of them is not a temporary then it must be copied
40 // into one to satisfy the type of the operator.
41 const auto TemporaryTernary =
42 conditionalOperator(hasTrueExpression(cxxBindTemporaryExpr()),
43 hasFalseExpression(cxxBindTemporaryExpr()));
44
45 return handleFrom(IsAHandle, anyOf(cxxBindTemporaryExpr(), TemporaryTernary));
46 }
47
48 ast_matchers::internal::Matcher<RecordDecl> isASequence() {
49 return hasAnyName("::std::deque", "::std::forward_list", "::std::list",
50 "::std::vector");
51 }
52
53 ast_matchers::internal::Matcher<RecordDecl> isASet() {
54 return hasAnyName("::std::set", "::std::multiset", "::std::unordered_set",
55 "::std::unordered_multiset");
56 }
57
58 ast_matchers::internal::Matcher<RecordDecl> isAMap() {
59 return hasAnyName("::std::map", "::std::multimap", "::std::unordered_map",
60 "::std::unordered_multimap");
61 }
62
63 ast_matchers::internal::BindableMatcher<Stmt> makeContainerMatcher(
64 const ast_matchers::internal::Matcher<RecordDecl> &IsAHandle) {
65 // This matcher could be expanded to detect:
66 // - Constructors: eg. vector<string_view>(3, string("A"));
67 // - emplace*(): This requires a different logic to determine that
68 // the conversion will happen inside the container.
69 // - map's insert: This requires detecting that the pair conversion triggers
70 // the bug. A little more complicated than what we have now.
71 return callExpr(
72 hasAnyArgument(
73 ignoringParenImpCasts(handleFromTemporaryValue(IsAHandle))),
74 anyOf(
75 // For sequences: assign, push_back, resize.
76 cxxMemberCallExpr(
77 callee(functionDecl(hasAnyName("assign", "push_back", "resize"))),
78 on(expr(hasType(hasUnqualifiedDesugaredType(
79 recordType(hasDeclaration(recordDecl(isASequence())))))))),
80 // For sequences and sets: insert.
81 cxxMemberCallExpr(callee(functionDecl(hasName("insert"))),
82 on(expr(hasType(hasUnqualifiedDesugaredType(
83 recordType(hasDeclaration(recordDecl(
84 anyOf(isASequence(), isASet()))))))))),
85 // For maps: operator[].
86 cxxOperatorCallExpr(callee(cxxMethodDecl(ofClass(isAMap()))),
87 hasOverloadedOperatorName("[]"))));
88 }
89
90 } // anonymous namespace
91
92 DanglingHandleCheck::DanglingHandleCheck(StringRef Name,
93 ClangTidyContext *Context)
94 : ClangTidyCheck(Name, Context),
95 HandleClasses(utils::options::parseStringList(Options.get(
96 "HandleClasses",
97 "std::basic_string_view;std::experimental::basic_string_view"))),
98 IsAHandle(cxxRecordDecl(hasAnyName(std::vector<StringRef>(
99 HandleClasses.begin(), HandleClasses.end())))
100 .bind("handle")) {}
101
102 void DanglingHandleCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
103 Options.store(Opts, "HandleClasses",
104 utils::options::serializeStringList(HandleClasses));
105 }
106
107 void DanglingHandleCheck::registerMatchersForVariables(MatchFinder *Finder) {
108 const auto ConvertedHandle = handleFromTemporaryValue(IsAHandle);
109
110 // Find 'Handle foo(ReturnsAValue());'
111 Finder->addMatcher(
112 varDecl(hasType(hasUnqualifiedDesugaredType(
113 recordType(hasDeclaration(cxxRecordDecl(IsAHandle))))),
114 hasInitializer(
115 exprWithCleanups(has(ignoringParenImpCasts(ConvertedHandle)))
116 .bind("bad_stmt"))),
117 this);
118
119 // Find 'Handle foo = ReturnsAValue();'
120 Finder->addMatcher(
121 varDecl(
122 hasType(hasUnqualifiedDesugaredType(
123 recordType(hasDeclaration(cxxRecordDecl(IsAHandle))))),
124 unless(parmVarDecl()),
125 hasInitializer(exprWithCleanups(has(ignoringParenImpCasts(handleFrom(
126 IsAHandle, ConvertedHandle))))
127 .bind("bad_stmt"))),
128 this);
129 // Find 'foo = ReturnsAValue(); // foo is Handle'
130 Finder->addMatcher(
131 cxxOperatorCallExpr(callee(cxxMethodDecl(ofClass(IsAHandle))),
132 hasOverloadedOperatorName("="),
133 hasArgument(1, ConvertedHandle))
134 .bind("bad_stmt"),
135 this);
136
137 // Container insertions that will dangle.
138 Finder->addMatcher(makeContainerMatcher(IsAHandle).bind("bad_stmt"), this);
139 }
140
141 void DanglingHandleCheck::registerMatchersForReturn(MatchFinder *Finder) {
142 // Return a local.
143 Finder->addMatcher(
144 returnStmt(
145 // The AST contains two constructor calls:
146 // 1. Value to Handle conversion.
147 // 2. Handle copy construction.
148 // We have to match both.
149 has(ignoringImplicit(handleFrom(
150 IsAHandle,
151 handleFrom(IsAHandle,
152 declRefExpr(to(varDecl(
153 // Is function scope ...
154 hasAutomaticStorageDuration(),
155 // ... and it is a local array or Value.
156 anyOf(hasType(arrayType()),
157 hasType(hasUnqualifiedDesugaredType(
158 recordType(hasDeclaration(recordDecl(
159 unless(IsAHandle)))))))))))))),
160 // Temporary fix for false positives inside lambdas.
161 unless(hasAncestor(lambdaExpr())))
162 .bind("bad_stmt"),
163 this);
164
165 // Return a temporary.
166 Finder->addMatcher(
167 returnStmt(
168 has(ignoringParenImpCasts(exprWithCleanups(has(ignoringParenImpCasts(
169 handleFrom(IsAHandle, handleFromTemporaryValue(IsAHandle))))))))
170 .bind("bad_stmt"),
171 this);
172 }
173
174 void DanglingHandleCheck::registerMatchers(MatchFinder *Finder) {
175 registerMatchersForVariables(Finder);
176 registerMatchersForReturn(Finder);
177 }
178
179 void DanglingHandleCheck::check(const MatchFinder::MatchResult &Result) {
180 auto *Handle = Result.Nodes.getNodeAs<CXXRecordDecl>("handle");
181 diag(Result.Nodes.getNodeAs<Stmt>("bad_stmt")->getBeginLoc(),
182 "%0 outlives its value")
183 << Handle->getQualifiedNameAsString();
184 }
185
186 } // namespace bugprone
187 } // namespace tidy
188 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:15
clang::tidy::OptionsView::store
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
Definition: ClangTidy.cpp:473
clang::tidy::bugprone::DanglingHandleCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: DanglingHandleCheck.cpp:179
clang::tidy::utils::options::serializeStringList
std::string serializeStringList(ArrayRef< std::string > Strings)
Serialize a sequence of names that can be parsed by parseStringList.
Definition: OptionsUtils.cpp:31
clang::tidy::bugprone::DanglingHandleCheck::storeOptions
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
Definition: DanglingHandleCheck.cpp:102
clang::tidy::matchers
Definition: Matchers.h:18
clang::tidy::ClangTidyCheck
Base class for all clang-tidy checks.
Definition: ClangTidy.h:127
clang::tidy::utils::options::parseStringList
std::vector< std::string > parseStringList(StringRef Option)
Parse a semicolon separated list of strings.
Definition: OptionsUtils.cpp:19
clang::tidy::ClangTidyCheck::Options
OptionsView Options
Definition: ClangTidy.h:183
Name
static constexpr llvm::StringLiteral Name
Definition: UppercaseLiteralSuffixCheck.cpp:28
clang::tidy::ClangTidyOptions::OptionMap
std::map< std::string, std::string > OptionMap
Definition: ClangTidyOptions.h:98
DanglingHandleCheck.h
Result
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: ClangdServer.cpp:60
clang::tidy::bugprone::DanglingHandleCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: DanglingHandleCheck.cpp:174
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ChangeNamespace.cpp:18
clang::tidy::ClangTidyContext
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Definition: ClangTidyDiagnosticConsumer.h:100
clang::tidy::ClangTidyCheck::diag
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
Definition: ClangTidy.cpp:438