llvm-project/clang-tools-extra/clang-tidy/misc/NonCopyableObjects.cpp

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2.8 KiB
C++

//===--- NonCopyableObjects.cpp - clang-tidy-------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "NonCopyableObjects.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include <algorithm>
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace misc {
void NonCopyableObjectsCheck::registerMatchers(MatchFinder *Finder) {
// There are two ways to get into trouble with objects like FILE *:
// dereferencing the pointer type to be a non-pointer type, and declaring
// the type as a non-pointer type in the first place. While the declaration
// itself could technically be well-formed in the case where the type is not
// an opaque type, it's highly suspicious behavior.
//
// POSIX types are a bit different in that it's reasonable to declare a
// non-pointer variable or data member of the type, but it is not reasonable
// to dereference a pointer to the type, or declare a parameter of non-pointer
// type.
// FIXME: it would be good to make a list that is also user-configurable so
// that users can add their own elements to the list. However, it may require
// some extra thought since POSIX types and FILE types are usable in different
// ways.
auto BadFILEType = hasType(
namedDecl(hasAnyName("::FILE", "FILE", "std::FILE")).bind("type_decl"));
auto BadPOSIXType =
hasType(namedDecl(hasAnyName("::pthread_cond_t", "::pthread_mutex_t",
"pthread_cond_t", "pthread_mutex_t"))
.bind("type_decl"));
auto BadEitherType = anyOf(BadFILEType, BadPOSIXType);
Finder->addMatcher(
namedDecl(anyOf(varDecl(BadFILEType), fieldDecl(BadFILEType)))
.bind("decl"),
this);
Finder->addMatcher(parmVarDecl(BadPOSIXType).bind("decl"), this);
Finder->addMatcher(
expr(unaryOperator(hasOperatorName("*"), BadEitherType)).bind("expr"),
this);
}
void NonCopyableObjectsCheck::check(const MatchFinder::MatchResult &Result) {
const auto *D = Result.Nodes.getNodeAs<NamedDecl>("decl");
const auto *BD = Result.Nodes.getNodeAs<NamedDecl>("type_decl");
const auto *E = Result.Nodes.getNodeAs<Expr>("expr");
if (D && BD)
diag(D->getLocation(), "%0 declared as type '%1', which is unsafe to copy"
"; did you mean '%1 *'?")
<< D << BD->getName();
else if (E)
diag(E->getExprLoc(),
"expression has opaque data structure type %0; type should only be "
"used as a pointer and not dereferenced")
<< BD;
}
} // namespace misc
} // namespace tidy
} // namespace clang