new clang plugin: rendercontext

to help with converting calls to OutputDevice to pass via
vcl::RenderContext.

Change-Id: I4b49d2f5e4afca46898d2a7c7ed33cbf5577e664

compilerplugins/clang/rendercontext.cxx

@@ -0,0 +1,93 @@
+/* -*- 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/.
+ */
+
+#include <string>
+#include <iostream>
+
+#include "plugin.hxx"
+#include "compat.hxx"
+#include "clang/AST/CXXInheritance.h"
+
+// Check for calls to OutputDevice methods that are not passing through RenderContext
+
+namespace {
+
+class RenderContext:
+    public RecursiveASTVisitor<RenderContext>, public loplugin::Plugin
+{
+public:
+    explicit RenderContext(InstantiationData const & data): Plugin(data) {}
+
+    virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    bool TraverseFunctionDecl(const FunctionDecl * decl);
+
+    bool VisitCXXMemberCallExpr(const CXXMemberCallExpr *);
+
+private:
+    bool        mbChecking = false;
+};
+
+bool RenderContext::TraverseFunctionDecl(const FunctionDecl * pFunctionDecl) {
+    if (ignoreLocation(pFunctionDecl)) {
+        return true;
+    }
+    if (!pFunctionDecl->hasBody()) {
+        return true;
+    }
+    if ( pFunctionDecl != pFunctionDecl->getCanonicalDecl() ) {
+        return true;
+    }
+    const CXXMethodDecl *pCXXMethodDecl = dyn_cast<CXXMethodDecl>(pFunctionDecl);
+    if (pCXXMethodDecl) {
+        std::string aParentName = pCXXMethodDecl->getParent()->getQualifiedNameAsString();
+        if (aParentName == "OutputDevice")
+            return true;
+    }
+    mbChecking = true;
+    TraverseStmt(pFunctionDecl->getBody());
+    mbChecking = false;
+    return true;
+}
+
+bool RenderContext::VisitCXXMemberCallExpr(const CXXMemberCallExpr* pCXXMemberCallExpr)
+{
+    if (!mbChecking)
+        return true;
+    if (ignoreLocation(pCXXMemberCallExpr)) {
+        return true;
+    }
+    const CXXRecordDecl *pCXXRecordDecl = pCXXMemberCallExpr->getRecordDecl();
+    if (pCXXRecordDecl->getQualifiedNameAsString() != "OutputDevice") {
+        return true;
+    }
+    const ImplicitCastExpr *pImplicitCastExpr = dyn_cast<ImplicitCastExpr>(pCXXMemberCallExpr->getImplicitObjectArgument());
+    std::string t2 = "0";
+    if (pImplicitCastExpr) {
+        t2 = "2";
+        QualType aType = pImplicitCastExpr->getSubExpr()->getType();
+        if (aType->isPointerType())
+            aType = aType->getPointeeType();
+        t2 = aType.getAsString();
+        if (t2 == "vcl::RenderContext")
+            return true;
+    }
+    report(
+        DiagnosticsEngine::Warning,
+        "Should be calling OutputDevice method through RenderContext.",
+        pCXXMemberCallExpr->getLocStart())
+      << pCXXMemberCallExpr->getSourceRange();
+    return true;
+}
+
+loplugin::Plugin::Registration< RenderContext > X("rendercontext", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */