CppTools: Fix global completion after '&'

Regression introduced by

        commit 9fb5b0be15
        CppTools: Add basic completion support for qt5 style signals/slots

Change-Id: I0a8e5ef31c1394512a51a26ed08b0f445add5acd
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/cpptools/cppcompletion_test.cpp

@@ -162,6 +162,16 @@ private:
     IEditor *m_editor;
 };
 
+bool isProbablyGlobalCompletion(const QStringList &list)
+{
+    const int numberOfPrimitivesAndBasicKeywords = (T_LAST_PRIMITIVE - T_FIRST_PRIMITIVE)
+            + (T_FIRST_OBJC_AT_KEYWORD - T_FIRST_KEYWORD);
+
+    return list.size() >= numberOfPrimitivesAndBasicKeywords
+        && list.contains(QLatin1String("if"))
+        && list.contains(QLatin1String("bool"));
+}
+
 } // anonymous namespace
 
 void CppToolsPlugin::test_completion_basic_1()
@@ -327,6 +337,31 @@ void CppToolsPlugin::test_completion()
     QCOMPARE(actualCompletions, expectedCompletions);
 }
 
+void CppToolsPlugin::test_global_completion_data()
+{
+    QTest::addColumn<QByteArray>("code");
+    QTest::addColumn<QByteArray>("prefix");
+
+    // Check that special completion after '&' for Qt5 signal/slots does not
+    // interfere global completion after '&'
+    QTest::newRow("global completion after & in return expression")
+         << _("void f() { foo(myObject, @); }\n")
+         << _("&");
+    QTest::newRow("global completion after & in function argument")
+         << _("int f() { return @; }\n")
+         << _("&");
+}
+
+void CppToolsPlugin::test_global_completion()
+{
+    QFETCH(QByteArray, code);
+    QFETCH(QByteArray, prefix);
+
+    CompletionTestCase test(code, prefix);
+    QVERIFY(test.succeededSoFar());
+    QVERIFY(isProbablyGlobalCompletion(test.getCompletions()));
+}
+
 static void enumTestCase(const QByteArray &tag, const QByteArray &source,
                          const QByteArray &prefix = QByteArray())
 {
@@ -2337,14 +2372,6 @@ void CppToolsPlugin::test_completion_data()
            << QLatin1String("hiddenFunction")
            << QLatin1String("hiddenSignal"));
 
-    QTest::newRow("Qt5 signals: no class name completion if not after 'connect(' 1")
-         << commonSignalSlotCompletionTestCode
-         << _("foo(myObject, &") << (QStringList());
-
-    QTest::newRow("Qt5 signals/slots: no class name completion if not after 'connect(' 2")
-         << commonSignalSlotCompletionTestCode
-         << _("&") << (QStringList());
-
     QTest::newRow("Qt5 signals: fallback to scope completion")
          << commonSignalSlotCompletionTestCode
          << _("connect(myObject, &N::") << (QStringList()

src/plugins/cpptools/cppcompletionassist.cpp

@@ -1128,8 +1128,14 @@ int InternalCppCompletionAssistProcessor::startCompletionHelper()
             //  "connect(sender, &" or
             //  "connect(otherSender, &Foo::signal1, receiver, &"
             const int beforeExpression = startOfExpression - 1;
-            if (canCompleteClassNameAt2ndOr4thConnectArgument(m_interface.data(), beforeExpression))
+            if (canCompleteClassNameAt2ndOr4thConnectArgument(m_interface.data(),
+                                                              beforeExpression)) {
                 m_model->m_completionOperator = CompleteQt5SignalOrSlotClassNameTrigger;
+            } else { // Ensure global completion
+                startOfExpression = endOfExpression = m_startPosition;
+                expression.clear();
+                m_model->m_completionOperator = T_EOF_SYMBOL;
+            }
         } else if (m_model->m_completionOperator == T_COLON_COLON) {
             // We expect 'expression' to be "Foo" in
             //  "connect(sender, &Foo::" or

src/plugins/cpptools/cpptoolsplugin.h

@@ -112,6 +112,9 @@ private slots:
     void test_completion_data();
     void test_completion();
 
+    void test_global_completion_data();
+    void test_global_completion();
+
     void test_completion_member_access_operator_data();
     void test_completion_member_access_operator();