Debug Info: Use identifier to reference DIType in base type field of

ptr_to_member.

We introduce a new class DITypeRef that represents a reference to a DIType.
It wraps around a Value*, which can be either an identifier in MDString
or an actual MDNode. The class has a helper function "resolve" that
finds the actual MDNode for a given DITypeRef.

We specialize getFieldAs to return a field that is a reference to a
DIType. To correctly access the base type field of ptr_to_member,
getClassType now calls getFieldAs<DITypeRef> to return a DITypeRef.

Also add a typedef for DITypeIdentifierMap and a helper
generateDITypeIdentifierMap in DebugInfo.h. In DwarfDebug.cpp, we keep
a DITypeIdentifierMap and call generateDITypeIdentifierMap to actually
populate the map.

Verifier is updated accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190081 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/test/DebugInfo/tu-member-pointer.ll b/test/DebugInfo/tu-member-pointer.ll
new file mode 100644
index 0000000000..b8f6719bc3
--- /dev/null
+++ b/test/DebugInfo/tu-member-pointer.ll
@@ -0,0 +1,29 @@
+; REQUIRES: object-emission
+
+; RUN: llc -filetype=obj -O0 < %s > %t
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
+; CHECK: [[TYPE:.*]]:   DW_TAG_base_type
+; CHECK: DW_TAG_ptr_to_member_type
+; CHECK-NEXT: DW_AT_type [DW_FORM_ref4]       (cu + {{.*}} => {[[TYPE]]})
+; IR generated from clang -g with the following source:
+; struct Foo {
+;   int e;
+; };
+; int Foo:*x = 0;
+
+@x = global i64 -1, align 8
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!10}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.4", i1 false, metadata !"", i32 0, metadata !2, metadata !3, metadata !2, metadata !5, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [foo.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"foo.cpp", metadata !"."}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786451, metadata !1, null, metadata !"Foo", i32 1, i64 0, i64 0, i32 0, i32 4, null, null, i32 0, null, null, metadata !"_ZTS3Foo"} ; [ DW_TAG_structure_type ] [Foo] [line 1, size 0, align 0, offset 0] [decl] [from ]
+!5 = metadata !{metadata !6}
+!6 = metadata !{i32 786484, i32 0, null, metadata !"x", metadata !"x", metadata !"", metadata !7, i32 4, metadata !8, i32 0, i32 1, i64* @x, null} ; [ DW_TAG_variable ] [x] [line 4] [def]
+!7 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [foo.cpp]
+!8 = metadata !{i32 786463, null, null, null, i32 0, i64 0, i64 0, i64 0, i32 0, metadata !9, metadata !"_ZTS3Foo"} ; [ DW_TAG_ptr_to_member_type ] [line 0, size 0, align 0, offset 0] [from int]
+!9 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!10 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}