don't collect bases for types without definitions

rdar://123430367

Author: QuietMisdreavus

clang/include/clang/ExtractAPI/ExtractAPIVisitor.h

@@ -173,6 +173,10 @@ class ExtractAPIVisitorBase : public RecursiveASTVisitor<Derived> {
 
 protected:
   SmallVector<SymbolReference> getBases(const CXXRecordDecl *Decl) {
+    if (!Decl->isCompleteDefinition()) {
+      return {};
+    }
+
     // FIXME: store AccessSpecifier given by inheritance
     SmallVector<SymbolReference> Bases;
     for (const auto &BaseSpecifier : Decl->bases()) {

clang/test/Index/extract-api-cursor-cpp.cpp

@@ -13,6 +13,11 @@ class MyClass {
     my_vec myVec;
 };
 
+struct OuterStruct {
+    struct InnerStruct;
+    int outer_field;
+};
+
 // RUN: c-index-test -single-symbol-sgf-at=%s:13:7 local %s | FileCheck --check-prefix=CHECK-VEC-TYPE %s
 // CHECK-VEC-TYPE: "parentContexts":[{"kind":"c++.typealias","name":"my_vec","usr":"c:@my_vec"}]
 // CHECK-VEC-TYPE: "declarationFragments":[{"kind":"keyword","spelling":"typedef"},{"kind":"text","spelling":" "},{"kind":"typeIdentifier","preciseIdentifier":"c:@ST>1#T@basic_vector","spelling":"basic_vector"},{"kind":"text","spelling":"<"},{"kind":"typeIdentifier","preciseIdentifier":"c:I","spelling":"int"},{"kind":"text","spelling":"> "},{"kind":"identifier","spelling":"my_vec"},{"kind":"text","spelling":";"}]
@@ -27,3 +32,10 @@ class MyClass {
 // CHECK-MYVEC: "kind":{"displayName":"Instance Property","identifier":"c++.property"}
 // CHECK-MYVEC: "title":"myVec"
 // CHECK-MYVEC: "pathComponents":["MyClass","myVec"]
+
+// RUN: c-index-test -single-symbol-sgf-at=%s:17:17 local %s | FileCheck --check-prefix=CHECK-INNER %s
+// CHECK-INNER: "parentContexts":[{"kind":"c++.struct","name":"OuterStruct","usr":"c:@S@OuterStruct"},{"kind":"c++.struct","name":"InnerStruct","usr":"c:@S@OuterStruct@S@InnerStruct"}]
+// CHECK-INNER: "identifier":{"interfaceLanguage":"c++","precise":"c:@S@OuterStruct@S@InnerStruct"}
+// CHECK-INNER: "kind":{"displayName":"Structure","identifier":"c++.struct"}
+// CHECK-INNER: "title":"InnerStruct"
+// CHECK-INNER: "pathComponents":["OuterStruct","InnerStruct"]