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