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

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3.3 KiB
C++

//===--- NonCopyableObjects.cpp - clang-tidy-------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "NonCopyableObjects.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include <algorithm>
using namespace clang::ast_matchers;
namespace clang {
namespace {
// 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.
bool isPOSIXTypeName(StringRef ClassName) {
static const char *const TypeNames[] = {
"::pthread_cond_t",
"::pthread_mutex_t",
"pthread_cond_t",
"pthread_mutex_t"
};
return std::binary_search(std::begin(TypeNames), std::end(TypeNames),
ClassName);
}
bool isFILETypeName(StringRef ClassName) {
static const char *const TypeNames[] = {
"::FILE",
"FILE",
"std::FILE"
};
return std::binary_search(std::begin(TypeNames), std::end(TypeNames),
ClassName);
}
AST_MATCHER(NamedDecl, isFILEType) {
return isFILETypeName(Node.getQualifiedNameAsString());
}
AST_MATCHER(NamedDecl, isPOSIXType) {
return isPOSIXTypeName(Node.getQualifiedNameAsString());
}
} // namespace
namespace tidy {
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.
auto BadFILEType = hasType(namedDecl(isFILEType()).bind("type_decl"));
auto BadPOSIXType = hasType(namedDecl(isPOSIXType()).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->getName() << 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->getName();
}
} // namespace tidy
} // namespace clang