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| //===--- PostfixOperatorCheck.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 "PostfixOperatorCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace cert {
void PostfixOperatorCheck::registerMatchers(MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus)
return;
Finder->addMatcher(functionDecl(anyOf(hasOverloadedOperatorName("++"),
hasOverloadedOperatorName("--")),
unless(isInstantiated()))
.bind("decl"),
this);
}
void PostfixOperatorCheck::check(const MatchFinder::MatchResult &Result) {
const auto *FuncDecl = Result.Nodes.getNodeAs<FunctionDecl>("decl");
bool HasThis = false;
if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
HasThis = MethodDecl->isInstance();
// Check if the operator is a postfix one.
if (FuncDecl->getNumParams() != (HasThis ? 1 : 2))
return;
SourceRange ReturnRange = FuncDecl->getReturnTypeSourceRange();
SourceLocation Location = ReturnRange.getBegin();
if (!Location.isValid())
return;
QualType ReturnType = FuncDecl->getReturnType();
// Warn when the operators return a reference.
if (const auto *RefType = ReturnType->getAs<ReferenceType>()) {
auto Diag = diag(Location, "overloaded %0 returns a reference instead of a "
"constant object type")
<< FuncDecl;
if (Location.isMacroID() || ReturnType->getAs<TypedefType>() ||
RefType->getPointeeTypeAsWritten()->getAs<TypedefType>())
return;
QualType ReplaceType =
ReturnType.getNonReferenceType().getLocalUnqualifiedType();
// The getReturnTypeSourceRange omits the qualifiers. We do not want to
// duplicate the const.
if (!ReturnType->getPointeeType().isConstQualified())
ReplaceType.addConst();
Diag << FixItHint::CreateReplacement(
ReturnRange,
ReplaceType.getAsString(Result.Context->getPrintingPolicy()) + " ");
return;
}
if (ReturnType.isConstQualified() || ReturnType->isBuiltinType() ||
ReturnType->isPointerType())
return;
auto Diag =
diag(Location, "overloaded %0 returns a non-constant object instead of a "
"constant object type")
<< FuncDecl;
if (!Location.isMacroID() && !ReturnType->getAs<TypedefType>())
Diag << FixItHint::CreateInsertion(Location, "const ");
}
} // namespace cert
} // namespace tidy
} // namespace clang
|