new loplugin:cppunitassertequals

look for places we should be calling CPPUNIT_ASSERT_EQUALS instead of
CPPUNIT_ASSERT

Change-Id: Ia836555d569069c6d0dce592f1c9a78bf8d8adb8

compilerplugins/clang/cppunitassertequals.cxx

+/* -*- 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 <cassert>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <set>
+#include "plugin.hxx"
+#include "compat.hxx"
+
+/**
+  Check for calls to CPPUNIT_ASSERT when it should be using CPPUNIT_ASSERT_EQUALS
+*/
+
+namespace {
+
+class CppunitAssertEquals:
+    public RecursiveASTVisitor<CppunitAssertEquals>, public loplugin::Plugin
+{
+public:
+    explicit CppunitAssertEquals(InstantiationData const & data): Plugin(data) {}
+
+    virtual void run() override
+    {
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+    }
+
+    bool VisitCallExpr(const CallExpr*);
+    bool VisitBinaryOperator(const BinaryOperator*);
+private:
+    void checkExpr(const Stmt* stmt);
+};
+
+bool CppunitAssertEquals::VisitCallExpr(const CallExpr* callExpr)
+{
+    if (ignoreLocation(callExpr)) {
+        return true;
+    }
+    if (callExpr->getDirectCallee() == nullptr) {
+        return true;
+    }
+    const FunctionDecl* functionDecl = callExpr->getDirectCallee()->getCanonicalDecl();
+    if (functionDecl->getOverloadedOperator() != OO_EqualEqual) {
+        return true;
+    }
+    checkExpr(callExpr);
+    return true;
+}
+
+bool CppunitAssertEquals::VisitBinaryOperator(const BinaryOperator* binaryOp)
+{
+    if (ignoreLocation(binaryOp)) {
+        return true;
+    }
+    if (binaryOp->getOpcode() != BO_EQ) {
+        return true;
+    }
+    checkExpr(binaryOp);
+    return true;
+}
+
+/*
+ * check that we are not a compound expression
+ */
+void CppunitAssertEquals::checkExpr(const Stmt* stmt)
+{
+    const Stmt* parent = parentStmt(stmt);
+    if (!parent || !isa<ParenExpr>(parent)) {
+        return;
+    }
+    parent = parentStmt(parent);
+    if (!isa<UnaryOperator>(parent)) {
+        return;
+    }
+    parent = parentStmt(parent);
+    if (!isa<CallExpr>(parent)) {
+        return;
+    }
+    const CallExpr* callExpr = dyn_cast<CallExpr>(parent);
+    if (callExpr->getDirectCallee() == nullptr) {
+        return;
+    }
+    const FunctionDecl* functionDecl = callExpr->getDirectCallee()->getCanonicalDecl();
+    if (functionDecl->getQualifiedNameAsString().find("Asserter::failIf") == std::string::npos) {
+        return;
+    }
+    report(
+        DiagnosticsEngine::Warning, "rather call CPPUNIT_ASSERT_EQUALS",
+        stmt->getSourceRange().getBegin())
+      << stmt->getSourceRange();
+}
+
+loplugin::Plugin::Registration< CppunitAssertEquals > X("cppunitassertequals", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */