clang-tools 10.0.0

NonCopyableObjects.cpp
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1 //===--- NonCopyableObjects.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 "NonCopyableObjects.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include <algorithm>
13
14 using namespace clang::ast_matchers;
15
16 namespace clang {
17 namespace tidy {
18 namespace misc {
19
20 void NonCopyableObjectsCheck::registerMatchers(MatchFinder *Finder) {
21 // There are two ways to get into trouble with objects like FILE *:
22 // dereferencing the pointer type to be a non-pointer type, and declaring
23 // the type as a non-pointer type in the first place. While the declaration
24 // itself could technically be well-formed in the case where the type is not
25 // an opaque type, it's highly suspicious behavior.
26 //
27 // POSIX types are a bit different in that it's reasonable to declare a
28 // non-pointer variable or data member of the type, but it is not reasonable
29 // to dereference a pointer to the type, or declare a parameter of non-pointer
30 // type.
31 // FIXME: it would be good to make a list that is also user-configurable so
32 // that users can add their own elements to the list. However, it may require
33 // some extra thought since POSIX types and FILE types are usable in different
34 // ways.
35
36 auto BadFILEType = hasType(
37 namedDecl(hasAnyName("::FILE", "FILE", "std::FILE")).bind("type_decl"));
38 auto BadPOSIXType =
39 hasType(namedDecl(hasAnyName("::pthread_cond_t", "::pthread_mutex_t",
40 "pthread_cond_t", "pthread_mutex_t"))
41 .bind("type_decl"));
42 auto BadEitherType = anyOf(BadFILEType, BadPOSIXType);
43
44 Finder->addMatcher(
45 namedDecl(anyOf(varDecl(BadFILEType), fieldDecl(BadFILEType)))
46 .bind("decl"),
47 this);
48 Finder->addMatcher(parmVarDecl(BadPOSIXType).bind("decl"), this);
49 Finder->addMatcher(
50 expr(unaryOperator(hasOperatorName("*"), BadEitherType)).bind("expr"),
51 this);
52 }
53
54 void NonCopyableObjectsCheck::check(const MatchFinder::MatchResult &Result) {
55 const auto *D = Result.Nodes.getNodeAs<NamedDecl>("decl");
56 const auto *BD = Result.Nodes.getNodeAs<NamedDecl>("type_decl");
57 const auto *E = Result.Nodes.getNodeAs<Expr>("expr");
58
59 if (D && BD)
60 diag(D->getLocation(), "%0 declared as type '%1', which is unsafe to copy"
61 "; did you mean '%1 *'?")
62 << D << BD->getName();
63 else if (E)
64 diag(E->getExprLoc(),
65 "expression has opaque data structure type %0; type should only be "
66 "used as a pointer and not dereferenced")
67 << BD;
68 }
69
70 } // namespace misc
71 } // namespace tidy
72 } // namespace clang
73
NonCopyableObjects.h
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
E
const Expr * E
Definition: AvoidBindCheck.cpp:82