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 74