[completion] complete ObjC interface names in an expression

Objective-C interfaces can be used in a class property expression.

rdar://26982192

llvm-svn: 318129

3 files changed, 30 insertions, 3 deletions

diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 9eeec37a758..c69d3676de6 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -264,8 +264,12 @@ static unsigned getDeclShowContexts(const NamedDecl *ND,
       Contexts |= (1LL << CodeCompletionContext::CCC_ObjCMessageReceiver);
     
     // In Objective-C, you can only be a subclass of another Objective-C class
-    if (isa<ObjCInterfaceDecl>(ND))
+    if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(ND)) {
+      // Objective-C interfaces can be used in a class property expression.
+      if (ID->getDefinition())
+        Contexts |= (1LL << CodeCompletionContext::CCC_Expression);
       Contexts |= (1LL << CodeCompletionContext::CCC_ObjCInterfaceName);
+    }
 
     // Deal with tag names.
     if (isa<EnumDecl>(ND)) {
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 26004cf3c36..7ee24b114cc 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -1082,9 +1082,16 @@ bool ResultBuilder::IsOrdinaryName(const NamedDecl *ND) const {
 /// ordinary name lookup but is not a type name.
 bool ResultBuilder::IsOrdinaryNonTypeName(const NamedDecl *ND) const {
   ND = cast<NamedDecl>(ND->getUnderlyingDecl());
-  if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND))
+  if (isa<TypeDecl>(ND))
     return false;
-  
+  // Objective-C interfaces names are not filtered by this method because they
+  // can be used in a class property expression. We can still filter out
+  // @class declarations though.
+  if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(ND)) {
+    if (!ID->getDefinition())
+      return false;
+  }
+
   unsigned IDNS = Decl::IDNS_Ordinary | Decl::IDNS_LocalExtern;
   if (SemaRef.getLangOpts().CPlusPlus)
     IDNS |= Decl::IDNS_Tag | Decl::IDNS_Namespace | Decl::IDNS_Member;
diff --git a/clang/test/Index/complete-interfaces.m b/clang/test/Index/complete-interfaces.m
index 2f86c3d8f43..3e90407c78d 100644
--- a/clang/test/Index/complete-interfaces.m
+++ b/clang/test/Index/complete-interfaces.m
@@ -45,3 +45,19 @@
 
 
 // RUN: env CINDEXTEST_EDITING=1 CINDEXTEST_COMPLETION_CACHING=1 c-index-test -code-completion-at=%s:11:12 %s | FileCheck -check-prefix=CHECK-CC2 %s
+
+
+void useClasses() {
+  int i = 0;
+  [Int3 message:1];
+}
+
+// RUN: c-index-test -code-completion-at=%s:51:11 %s | FileCheck -check-prefix=CHECK-USE %s
+// RUN: c-index-test -code-completion-at=%s:52:17 %s | FileCheck -check-prefix=CHECK-USE %s
+// CHECK-USE: ObjCInterfaceDecl:{TypedText Int2} (50)
+// CHECK-USE: ObjCInterfaceDecl:{TypedText Int3} (50)
+// CHECK-USE-NOT: Int1
+// CHECK-USE-NOT: Int4
+
+// Caching should work too:
+// RUN: env CINDEXTEST_EDITING=1 CINDEXTEST_COMPLETION_CACHING=1 c-index-test -code-completion-at=%s:51:11 %s | FileCheck -check-prefix=CHECK-USE %s