C++: fix 'using' in separate block of scope

Task-number: QTCREATORBUG-12357
Change-Id: I7397b0e66783d3249daa5a8ee422bfd5f5bc7bea
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/libs/cplusplus/LookupContext.cpp

@@ -242,15 +242,19 @@ const Name *LookupContext::minimalName(Symbol *symbol, ClassOrNamespace *target,
     return n;
 }
 
-QList<LookupItem> LookupContext::lookupByUsing(const Name *name, Scope *scope) const
+QList<LookupItem> LookupContext::lookupByUsing(const Name *name,
+                                               ClassOrNamespace *bindingScope) const
 {
     QList<LookupItem> candidates;
     // if it is a nameId there can be a using declaration for it
     if (name->isNameId() || name->isTemplateNameId()) {
+        foreach (Symbol *s, bindingScope->symbols()) {
+            if (Scope *scope = s->asScope()) {
                 for (unsigned i = 0, count = scope->memberCount(); i < count; ++i) {
                     if (UsingDeclaration *u = scope->memberAt(i)->asUsingDeclaration()) {
                         if (const Name *usingDeclarationName = u->name()) {
-                    if (const QualifiedNameId *q = usingDeclarationName->asQualifiedNameId()) {
+                            if (const QualifiedNameId *q
+                                    = usingDeclarationName->asQualifiedNameId()) {
                                 if (q->name() && q->identifier() && name->identifier()
                                         && q->name()->identifier()->match(name->identifier())) {
                                     candidates = bindings()->globalNamespace()->find(q);
@@ -268,10 +272,18 @@ QList<LookupItem> LookupContext::lookupByUsing(const Name *name, Scope *scope) c
                         }
                     }
                 }
+            }
+        }
     } else if (const QualifiedNameId *q = name->asQualifiedNameId()) {
+        foreach (Symbol *s, bindingScope->symbols()) {
+            if (Scope *scope = s->asScope()) {
                 ClassOrNamespace *base = lookupType(q->base(), scope);
-        if (base && base->symbols().size() > 0 && base->symbols().first()->asScope())
+                if (base)
-            return lookupByUsing(q->name(), base->symbols().first()->asScope());
+                    candidates = lookupByUsing(q->name(), base);
+                if (!candidates.isEmpty())
+                    return candidates;
+            }
+        }
     }
     return candidates;
 }
@@ -400,13 +412,13 @@ QList<LookupItem> LookupContext::lookup(const Name *name, Scope *scope) const
                 }
             }
 
-            candidates = lookupByUsing(name, scope);
+            if (ClassOrNamespace *bindingScope = bindings()->lookupType(scope)) {
+                if (ClassOrNamespace *bindingBlock = bindingScope->findBlock(scope->asBlock())) {
+                    candidates = lookupByUsing(name, bindingBlock);
                     if (! candidates.isEmpty())
                         return candidates;
 
-            if (ClassOrNamespace *binding = bindings()->lookupType(scope)) {
+                    candidates = bindingBlock->find(name);
-                if (ClassOrNamespace *block = binding->findBlock(scope->asBlock())) {
-                    candidates = block->find(name);
 
                     if (! candidates.isEmpty())
                         return candidates;
@@ -461,15 +473,17 @@ QList<LookupItem> LookupContext::lookup(const Name *name, Scope *scope) const
         } else if (scope->asNamespace()
                    || scope->asClass()
                    || (scope->asEnum() && scope->asEnum()->isScoped())) {
-            if (ClassOrNamespace *binding = bindings()->lookupType(scope))
+
-                candidates = binding->find(name);
+            if (ClassOrNamespace *bindingScope = bindings()->lookupType(scope)) {
+                candidates = bindingScope->find(name);
 
                 if (! candidates.isEmpty())
                     return candidates;
 
-            candidates = lookupByUsing(name, scope);
+                candidates = lookupByUsing(name, bindingScope);
                 if (!candidates.isEmpty())
                     return candidates;
+            }
 
             // the scope can be defined inside a block, try to find it
             if (Block *block = scope->enclosingBlock()) {

src/libs/cplusplus/LookupContext.h

@@ -328,7 +328,7 @@ public:
     }
 
 private:
-    QList<LookupItem> lookupByUsing(const Name *name, Scope *scope) const;
+    QList<LookupItem> lookupByUsing(const Name *name, ClassOrNamespace *bindingScope) const;
 
     // The current expression.
     Document::Ptr _expressionDocument;

tests/auto/cplusplus/checksymbols/tst_checksymbols.cpp

@@ -1596,6 +1596,51 @@ void tst_CheckSymbols::test_checksymbols_data()
             << Use(12, 20, 1, Highlighting::TypeUse)
             << Use(12, 23, 1, Highlighting::LocalUse));
 
+    QTest::newRow("using_inside_different_block_of_scope_unnamed_namespace_QTCREATORBUG12357")
+            << _("namespace \n"
+                 "{\n"
+                 "    namespace Ns { struct Foo {}; }\n"
+                 "    using Ns::Foo;\n"
+                 "}\n"
+                 "void fun()\n"
+                 "{\n"
+                 "    Foo foo;\n"
+                 "}\n")
+            << (QList<Use>()
+                << Use(3, 15, 2, CppHighlightingSupport::TypeUse)
+                << Use(3, 27, 3, CppHighlightingSupport::TypeUse)
+                << Use(4, 11, 2, CppHighlightingSupport::TypeUse)
+                << Use(4, 15, 3, CppHighlightingSupport::TypeUse)
+                << Use(6, 6, 3, CppHighlightingSupport::FunctionUse)
+                << Use(8, 5, 3, CppHighlightingSupport::TypeUse)
+                << Use(8, 9, 3, CppHighlightingSupport::LocalUse)
+                );
+
+    QTest::newRow("using_inside_different_block_of_scope_named_namespace_QTCREATORBUG12357")
+            << _("namespace NS1\n"
+                 "{\n"
+                 "    namespace Ns { struct Foo {}; }\n"
+                 "    using Ns::Foo;\n"
+                 "}\n"
+                 "namespace NS1\n"
+                 "{\n"
+                 "    void fun()\n"
+                 "    {\n"
+                 "        Foo foo;\n"
+                 "    }\n"
+                 "}\n"
+                 )
+            << (QList<Use>()
+                << Use(1, 11, 3, CppHighlightingSupport::TypeUse)
+                << Use(3, 15, 2, CppHighlightingSupport::TypeUse)
+                << Use(3, 27, 3, CppHighlightingSupport::TypeUse)
+                << Use(4, 11, 2, CppHighlightingSupport::TypeUse)
+                << Use(4, 15, 3, CppHighlightingSupport::TypeUse)
+                << Use(6, 11, 3, CppHighlightingSupport::TypeUse)
+                << Use(8, 10, 3, CppHighlightingSupport::FunctionUse)
+                << Use(10, 13, 3, CppHighlightingSupport::LocalUse)
+                );
+
     QTest::newRow("using_inside_different_namespace_QTCREATORBUG7978")
         << _("class My" TEST_UNICODE_IDENTIFIER "Type { int " TEST_UNICODE_IDENTIFIER "Member; };\n"
              "void f(My" TEST_UNICODE_IDENTIFIER "Type var" TEST_UNICODE_IDENTIFIER ")\n"