C++: fix 'using' for templates in typedefs

Fix resolving typedef of templates which is from different namespace
and there was 'using' used for it.
Examples are in tests.
Another step to bring code completion for stl containters.

Task-number: QTCREATORBUG-7978

Change-Id: I2e9e71b45d60536c1e25cf2d371c4719b15edf79
Reviewed-by: Erik Verbruggen <[email protected]>

4 files changed, 119 insertions, 2 deletions

diff --git a/src/libs/cplusplus/LookupContext.cpp b/src/libs/cplusplus/LookupContext.cpp
index c20e85459ee..ef259bb2545 100644
--- a/src/libs/cplusplus/LookupContext.cpp
+++ b/src/libs/cplusplus/LookupContext.cpp
@@ -752,6 +752,12 @@ ClassOrNamespace *ClassOrNamespace::nestedType(const Name *name, ClassOrNamespac
 
     const TemplateNameId *templId = name->asTemplateNameId();
     if (templId) {
+        // for "using" we should use the real one ClassOrNamespace(it should be the first
+        // one item from usings list)
+        // we indicate that it is a 'using' by checking number of symbols(it should be 0)
+        if (reference->symbols().count() == 0 && reference->usings().count() != 0)
+            reference = reference->_usings[0];
+
         // if it is a TemplateNameId it could be a specialization(full or partial) or
         // instantiation of one of the specialization(reference->_specialization) or
         // base class(reference)
diff --git a/src/libs/cplusplus/ResolveExpression.cpp b/src/libs/cplusplus/ResolveExpression.cpp
index 23c9b201b86..db69deb0ed8 100644
--- a/src/libs/cplusplus/ResolveExpression.cpp
+++ b/src/libs/cplusplus/ResolveExpression.cpp
@@ -835,8 +835,9 @@ public:
     void resolve(FullySpecifiedType *type, Scope **scope, ClassOrNamespace *binding)
     {
         QSet<Symbol *> visited;
+        _binding = binding;
         while (NamedType *namedTy = getNamedType(*type)) {
-            QList<LookupItem> namedTypeItems = getNamedTypeItems(namedTy->name(), *scope, binding);
+            QList<LookupItem> namedTypeItems = getNamedTypeItems(namedTy->name(), *scope, _binding);
 
 #ifdef DEBUG_LOOKUP
             qDebug() << "-- we have" << namedTypeItems.size() << "candidates";
@@ -908,7 +909,7 @@ private:
     }
 
     bool findTypedef(const QList<LookupItem>& namedTypeItems, FullySpecifiedType *type,
-                     Scope **scope, QSet<Symbol *>& visited) const
+                     Scope **scope, QSet<Symbol *>& visited)
     {
         bool foundTypedef = false;
         foreach (const LookupItem &it, namedTypeItems) {
@@ -921,6 +922,7 @@ private:
                 // continue working with the typedefed type and scope
                 *type = declaration->type();
                 *scope = it.scope();
+                _binding = it.binding();
                 foundTypedef = true;
                 break;
             }
@@ -930,6 +932,8 @@ private:
     }
 
     const LookupContext &_context;
+    // binding has to be remembered in case of resolving typedefs for templates
+    ClassOrNamespace *_binding;
 };
 
 ClassOrNamespace *ResolveExpression::baseExpression(const QList<LookupItem> &baseResults,
diff --git a/src/plugins/cpptools/cppcompletion_test.cpp b/src/plugins/cpptools/cppcompletion_test.cpp
index 34ea48fee28..6e35e263dab 100644
--- a/src/plugins/cpptools/cppcompletion_test.cpp
+++ b/src/plugins/cpptools/cppcompletion_test.cpp
@@ -1646,3 +1646,108 @@ void CppToolsPlugin::test_completion_template_specialization_with_pointer()
     QVERIFY(completions.contains(QLatin1String("Template")));
     QVERIFY(completions.contains(QLatin1String("pointer")));
 }
+
+void CppToolsPlugin::test_completion_typedef_using_templates1()
+{
+    TestData data;
+    data.srcText = "\n"
+            "namespace NS1\n"
+            "{\n"
+            "template<typename T>\n"
+            "struct NS1Struct\n"
+            "{\n"
+            "    typedef T *pointer;\n"
+            "    pointer bar;\n"
+            "};\n"
+            "}\n"
+            "namespace NS2\n"
+            "{\n"
+            "using NS1::NS1Struct;\n"
+            "\n"
+            "template <typename T>\n"
+            "struct NS2Struct\n"
+            "{\n"
+            "    typedef NS1Struct<T> NS1StructTypedef;\n"
+            "    typedef typename NS1StructTypedef::pointer pointer;\n"
+            "    pointer p;\n"
+            "};\n"
+            "}\n"
+            "struct Foo\n"
+            "{\n"
+            "    int bar;\n"
+            "};\n"
+            "void fun()\n"
+            "{\n"
+            "    NS2::NS2Struct<Foo> s;\n"
+            "    @\n"
+            "    // padding so we get the scope right\n"
+            "}\n"
+            ;
+    setup(&data);
+
+    Utils::ChangeSet change;
+    QString txt = QLatin1String("s.p->");
+    change.insert(data.pos, txt);
+    QTextCursor cursor(data.doc);
+    change.apply(&cursor);
+    data.pos += txt.length();
+
+    QStringList completions = getCompletions(data);
+
+    QCOMPARE(completions.size(), 2);
+    QVERIFY(completions.contains(QLatin1String("Foo")));
+    QVERIFY(completions.contains(QLatin1String("bar")));
+}
+
+
+void CppToolsPlugin::test_completion_typedef_using_templates2()
+{
+    TestData data;
+    data.srcText = "\n"
+            "namespace NS1\n"
+            "{\n"
+            "template<typename T>\n"
+            "struct NS1Struct\n"
+            "{\n"
+            "    typedef T *pointer;\n"
+            "    pointer bar;\n"
+            "};\n"
+            "}\n"
+            "namespace NS2\n"
+            "{\n"
+            "using NS1::NS1Struct;\n"
+            "\n"
+            "template <typename T>\n"
+            "struct NS2Struct\n"
+            "{\n"
+            "    typedef NS1Struct<T> NS1StructTypedef;\n"
+            "    typedef typename NS1StructTypedef::pointer pointer;\n"
+            "    pointer p;\n"
+            "};\n"
+            "}\n"
+            "struct Foo\n"
+            "{\n"
+            "    int bar;\n"
+            "};\n"
+            "void fun()\n"
+            "{\n"
+            "    NS2::NS2Struct<Foo>::pointer p;\n"
+            "    @\n"
+            "    // padding so we get the scope right\n"
+            "}\n"
+            ;
+    setup(&data);
+
+    Utils::ChangeSet change;
+    QString txt = QLatin1String("p->");
+    change.insert(data.pos, txt);
+    QTextCursor cursor(data.doc);
+    change.apply(&cursor);
+    data.pos += txt.length();
+
+    QStringList completions = getCompletions(data);
+
+    QCOMPARE(completions.size(), 2);
+    QVERIFY(completions.contains(QLatin1String("Foo")));
+    QVERIFY(completions.contains(QLatin1String("bar")));
+}
diff --git a/src/plugins/cpptools/cpptoolsplugin.h b/src/plugins/cpptools/cpptoolsplugin.h
index fd9f18b7e8c..fcb4d417e32 100644
--- a/src/plugins/cpptools/cpptoolsplugin.h
+++ b/src/plugins/cpptools/cpptoolsplugin.h
@@ -124,6 +124,8 @@ private slots:
     void test_completion_typedef_is_inside_function_before_declaration_block();
     void test_completion_resolve_complex_typedef_with_template();
     void test_completion_template_specialization_with_pointer();
+    void test_completion_typedef_using_templates1();
+    void test_completion_typedef_using_templates2();
 
     void test_format_pointerdeclaration_in_simpledeclarations();
     void test_format_pointerdeclaration_in_simpledeclarations_data();