[CodeComplete] Collect visited contexts when scope specifier is invalid.

Eric Liu · Eric Liu · commit 206740e75679 · 2019-02-21T11:22:58.000Z
Summary: This will allow completion consumers to guess the specified scope by putting together scopes in the context with the specified scope (e.g. when the specified namespace is not imported yet). Reviewers: ilya-biryukov Subscribers: jdoerfert, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D58446 llvm-svn: 354570
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -5061,7 +5061,20 @@ void Sema::CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
   if (SS.isInvalid()) {
     CodeCompletionContext CC(CodeCompletionContext::CCC_Symbol);
     CC.setCXXScopeSpecifier(SS);
-    HandleCodeCompleteResults(this, CodeCompleter, CC, nullptr, 0);
+    // As SS is invalid, we try to collect accessible contexts from the current
+    // scope with a dummy lookup so that the completion consumer can try to
+    // guess what the specified scope is.
+    ResultBuilder DummyResults(*this, CodeCompleter->getAllocator(),
+                               CodeCompleter->getCodeCompletionTUInfo(), CC);
+    if (S->getEntity()) {
+      CodeCompletionDeclConsumer Consumer(DummyResults, S->getEntity(),
+                                          BaseType);
+      LookupVisibleDecls(S, LookupOrdinaryName, Consumer,
+                         /*IncludeGlobalScope=*/false,
+                         /*LoadExternal=*/false);
+    }
+    HandleCodeCompleteResults(this, CodeCompleter,
+                              DummyResults.getCompletionContext(), nullptr, 0);
     return;
   }
   // Always pretend to enter a context to ensure that a dependent type
diff --git a/clang/unittests/Sema/CodeCompleteTest.cpp b/clang/unittests/Sema/CodeCompleteTest.cpp
@@ -173,12 +173,16 @@ TEST(SemaCodeCompleteTest, VisitedNSForValidQualifiedId) {
                                               "foo::(anonymous)"));
 }
 
-TEST(SemaCodeCompleteTest, VisitedNSForInvalideQualifiedId) {
+TEST(SemaCodeCompleteTest, VisitedNSForInvalidQualifiedId) {
   auto VisitedNS = runCodeCompleteOnCode(R"cpp(
-     namespace ns { foo::^ }
+     namespace na {}
+     namespace ns1 {
+     using namespace na;
+     foo::^
+     }
   )cpp")
                        .VisitedNamespaces;
-  EXPECT_TRUE(VisitedNS.empty());
+  EXPECT_THAT(VisitedNS, UnorderedElementsAre("ns1", "na"));
 }
 
 TEST(SemaCodeCompleteTest, VisitedNSWithoutQualifier) {
