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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#ifndef LO_CLANG_SHARED_PLUGINS
#include <cassert>
#include <stack>
#include <string>
#include "clang/AST/Attr.h"
#include "clang/Sema/SemaInternal.h" // warn_unused_function
#include "plugin.hxx"
namespace {
bool isFriendDecl(Decl const * decl) {
return decl->getFriendObjectKind() != Decl::FOK_None;
}
Decl const * getPreviousNonFriendDecl(Decl const * decl) {
for (;;) {
decl = decl->getPreviousDecl();
if (decl == nullptr || !isFriendDecl(decl)) {
return decl;
}
}
}
bool isSpecialMemberFunction(FunctionDecl const * decl) {
if (auto const ctor = dyn_cast<CXXConstructorDecl>(decl)) {
return ctor->isDefaultConstructor() || ctor->isCopyOrMoveConstructor();
}
if (isa<CXXDestructorDecl>(decl)) {
return true;
}
if (auto const meth = dyn_cast<CXXMethodDecl>(decl)) {
return meth->isCopyAssignmentOperator() || meth->isMoveAssignmentOperator();
}
return false;
}
class UnrefFun: public loplugin::FilteringPlugin<UnrefFun> {
public:
explicit UnrefFun(loplugin::InstantiationData const & data): FilteringPlugin(data) {}
void run() override
{ TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
bool PreTraverseFriendDecl(FriendDecl * decl) {
friendFunction.push( dyn_cast_or_null<FunctionDecl>(decl->getFriendDecl()));
return true;
}
bool PostTraverseFriendDecl(FriendDecl *, bool ) {
friendFunction.pop();
return true;
}
bool TraverseFriendDecl(FriendDecl * decl) {
PreTraverseFriendDecl(decl);
auto const ret = RecursiveASTVisitor::TraverseFriendDecl(decl);
PostTraverseFriendDecl(decl, ret);
return ret;
}
bool VisitFunctionDecl(FunctionDecl const * decl);
private:
std::stack<FunctionDecl const *> friendFunction;
};
bool UnrefFun::VisitFunctionDecl(FunctionDecl const * decl) {
if (ignoreLocation(decl)) {
return true;
}
//TODO, filtering out any functions relating to (class) templates for now:
CXXRecordDecl const * r = dyn_cast<CXXRecordDecl>(decl->getDeclContext());
if (r != nullptr
&& (r->getTemplateSpecializationKind() != TSK_Undeclared
|| r->isDependentContext()))
{
return true;
}
if (!friendFunction.empty() && decl == friendFunction.top()) {
if (auto const lex = dyn_cast<CXXRecordDecl>(decl->getLexicalDeclContext())) {
if (lex->isDependentContext()) {
return true;
}
}
}
if (!(decl->isThisDeclarationADefinition() || isFriendDecl(decl)
|| decl->isFunctionTemplateSpecialization()))
{
Decl const * prev = getPreviousNonFriendDecl(decl);
if (prev != nullptr/* && prev != decl->getPrimaryTemplate()*/) {
// Workaround for redeclarations that introduce visibility attributes
// (as is done with
//
// SAL_DLLPUBLIC_EXPORT GType lok_doc_view_get_type();
//
// in libreofficekit/source/gtk/lokdocview.cxx):
if (decl->getAttr<VisibilityAttr>() != nullptr
&& prev->getAttr<VisibilityAttr>() == nullptr)
{
return true;
}
report(
DiagnosticsEngine::Warning,
"redundant function%0 redeclaration", decl->getLocation())
<< ((decl->getTemplatedKind()
== FunctionDecl::TK_FunctionTemplate)
? " template" : "")
<< decl->getSourceRange();
report(
DiagnosticsEngine::Note, "previous declaration is here",
prev->getLocation())
<< prev->getSourceRange();
return true;
}
}
FunctionDecl const * canon = decl->getCanonicalDecl();
//TODO: is that the first?
if (canon->isDeleted() || canon->isReferenced()
|| !(canon->isDefined()
? decl->isThisDeclarationADefinition() : decl->isFirstDecl())
|| !compiler.getSourceManager().isInMainFile(canon->getLocation())
|| isInUnoIncludeFile(canon)
|| canon->isMain() || canon->isMSVCRTEntryPoint()
|| (decl->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate
&& (decl->getDescribedFunctionTemplate()->spec_begin()
!= decl->getDescribedFunctionTemplate()->spec_end()))
|| (compiler.getDiagnostics().getDiagnosticLevel(
diag::warn_unused_function, decl->getLocation())
< DiagnosticsEngine::Warning))
{
return true;
}
if (canon->isExplicitlyDefaulted() && isSpecialMemberFunction(canon)) {
// If a special member function is explicitly defaulted on the first declaration, assume
// that its presence is always due to some interface design consideration, not to explicitly
// request a definition that might be worth to flag as unused (and C++20 may extend
// defaultability beyond special member functions to comparison operators, therefore
// explicitly check here for special member functions only):
return true;
}
LinkageInfo info(canon->getLinkageAndVisibility());
if (info.getLinkage() == ExternalLinkage
&& loplugin::hasCLanguageLinkageType(canon) && canon->isDefined()
&& ((decl == canon && info.getVisibility() == DefaultVisibility)
|| ((canon->hasAttr<ConstructorAttr>()
|| canon->hasAttr<DestructorAttr>())
&& info.getVisibility() == HiddenVisibility)))
{
return true;
}
auto loc = decl->getLocation();
if (compiler.getSourceManager().isMacroBodyExpansion(loc)
&& (Lexer::getImmediateMacroName(
loc, compiler.getSourceManager(), compiler.getLangOpts())
== "MDDS_MTV_DEFINE_ELEMENT_CALLBACKS"))
{
return true;
}
report(
DiagnosticsEngine::Warning,
(canon->isDefined()
? (canon->isExternallyVisible()
? "Unreferenced externally visible function%0 definition"
: "Unreferenced externally invisible function%0 definition")
: "Unreferenced function%0 declaration"),
decl->getLocation())
<< (decl->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate
? " template" : "")
<< decl->getSourceRange();
if (canon->isDefined() && !decl->isFirstDecl()) {
report(
DiagnosticsEngine::Note, "first declaration is here",
canon->getLocation())
<< canon->getSourceRange();
}
return true;
}
loplugin::Plugin::Registration<UnrefFun> unreffun("unreffun");
}
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
