CGDebugInfo: Use DIBuilder API for self-referencing DICompositeTypes

Use new `DIBuilder` API from LLVM r224482 to mutate `DICompositeType`s,
rather than changing them directly.  This allows `DIBuilder` to track
otherwise orphaned cycles when `CollectContainingType()` creates a
self-reference.

Fixes PR21941.

llvm-svn: 224483

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/vtable-holder-self-reference.cpp b/clang/test/CodeGenCXX/vtable-holder-self-reference.cpp
new file mode 100644
index 00000000000..d311ea65942
--- /dev/null
+++ b/clang/test/CodeGenCXX/vtable-holder-self-reference.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -emit-llvm -gdwarf-2 -x c++ -o - %s | FileCheck %s
+//
+// PR21941: crasher for self-referencing DW_TAG_structure_type node.  If we get
+// rid of self-referenceing structure_types (PR21902), then it should be safe
+// to just kill this test.
+//
+// CHECK: ![[SELF:[0-9]+]] = !{!"0x13\00B\00{{[^"]*}}", {{[^,]+}}, {{[^,]+}}, {{[^,]+}}, {{[^,]+}}, ![[SELF]], {{[^}]+}}} ; [ DW_TAG_structure_type ] [B]
+
+void foo() {
+  struct V {
+    int vi;
+  };
+  struct B : virtual V {};
+  B b;
+}