[lldb] Avoid returning a false positive error when reaching an ObjC base class

in SwiftLanguageRuntime::GetIndexOfChildMemberWithName().

My understanding is that the loop should stop once we reach an ObjC
base class, because any ivars in the base class will be children of
the artificial base class child.

rdar://149329166

Author: adrian-prantl

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntimeDynamicTypeResolution.cpp

@@ -1059,6 +1059,8 @@ SwiftLanguageRuntime::GetIndexOfChildMemberWithName(
       // superclass, and ends on null.
       auto *current_tr = tr;
       while (current_tr) {
+        if (llvm::isa<swift::reflection::ObjCClassTypeRef>(current_tr))
+          break;
         auto cti_or_err = reflection_ctx->GetClassInstanceTypeInfo(
             *current_tr, &tip, ts.GetDescriptorFinder());
         const TypeInfo *cti = nullptr;

lldb/test/API/lang/swift/clangimporter/objc_baseclass/Makefile

@@ -0,0 +1,3 @@
+SWIFT_SOURCES := main.swift
+
+include Makefile.rules

lldb/test/API/lang/swift/clangimporter/objc_baseclass/TestSwiftObjCBaseClassMemberLookup.py

@@ -0,0 +1,18 @@
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+
+class TestSwiftObjCBaseClassMemberLookup(TestBase):
+    NO_DEBUG_INFO_TESTCASE = True
+    @skipUnlessDarwin
+    @swiftTest
+    def test(self):
+        """Test accessing a static member from a member function"""
+        self.build()
+        lldbutil.run_to_source_breakpoint(
+            self, 'break here', lldb.SBFileSpec('main.swift')
+        )
+
+        # dwim-print start by checking whether a member 'A' exists in 'self'.
+        self.expect("dwim-print A.shared", substrs=["42"])

lldb/test/API/lang/swift/clangimporter/objc_baseclass/main.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+class A {
+  public static var shared = A()
+  let a = 42
+}
+
+class C : NSObject {
+  var c = 0
+  func foo() {
+    print("break here")
+    c = 1
+  }
+}
+
+C().foo()
+