Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 198 insertions, 0 deletions

diff --git a/compilerplugins/clang/unreffun.cxx b/compilerplugins/clang/unreffun.cxx
new file mode 100644
index 000000000..353eee5f0
--- /dev/null
+++ b/compilerplugins/clang/unreffun.cxx
@@ -0,0 +1,198 @@
+/* -*- 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: */