DebugInfo: Assert that DbgVariables have associated DIEs

This was previously committed in r209680 and reverted in r209683 after
it caused sanitizer builds to crash.

The issue seems to be that the DebugLoc associated with dbg.value IR
intrinsics isn't necessarily accurate. Instead, we duplicate the
DIVariables and add an InlinedAt field to them to record their
location.

We were using this InlinedAt field to compute the LexicalScope for the
variable, but not using it in the abstract DbgVariable construction and
mapping. This resulted in a formal parameter to the current concrete
function, correctly having no InlinedAt information, but incorrectly
having a DebugLoc that described an inlined location within the
function... thus an abstract DbgVariable was created for the variable,
but its DIE was never constructed (since the LexicalScope had no such
variable). This DbgVariable was silently ignored (by testing for a
non-null DIE on the abstract DbgVariable).

So, fix this by using the right scoping information when constructing
abstract DbgVariables.

In the long run, I suspect we want to undo the work that added this
second kind of location tracking and fix the places where the DebugLoc
propagation on the dbg.value intrinsic fails. This will shrink debug
info (by not duplicating DIVariables), make it more efficient (by not
having to construct new DIVariable metadata nodes to try to map back to
a single variable), and benefit all instructions.

But perhaps there are insurmountable issues with DebugLoc quality that
I'm unaware of... I just don't know how we can't /just keep the DebugLoc
from the dbg.declare to the dbg.values and never get this wrong/.

Some history context:

http://llvm.org/viewvc/llvm-project?view=revision&revision=135629
http://llvm.org/viewvc/llvm-project?view=revision&revision=137253

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209984 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 391 insertions, 0 deletions

diff --git a/test/DebugInfo/incorrect-variable-debugloc.ll b/test/DebugInfo/incorrect-variable-debugloc.ll
new file mode 100644
index 0000000000..284704c54a
--- /dev/null
+++ b/test/DebugInfo/incorrect-variable-debugloc.ll
@@ -0,0 +1,391 @@
+; REQUIRES: object-emission
+
+; RUN: %llc_dwarf -O2 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; This is a test case that's as reduced as I can get it, though I haven't fully
+; understood the mechanisms by which this bug occurs, so perhaps there's further
+; simplification to be had (it's certainly a bit non-obvious what's going on). I
+; hesitate to hand-craft or otherwise simplify the IR compared to what Clang
+; generates as this is a particular tickling of optimizations and debug location
+; propagation I want a realistic example of.
+
+; Generated with clang-tot -cc1 -g -O2 -w -std=c++11  -fsanitize=address,use-after-return -fcxx-exceptions -fexceptions -x c++ incorrect-variable-debug-loc.cpp -emit-llvm
+
+; struct A {
+;   int m_fn1();
+; };
+;
+; struct B {
+;   void __attribute__((always_inline)) m_fn2() { i = 0; }
+;   int i;
+; };
+;
+; struct C {
+;   void m_fn3();
+;   int j;
+;   B b;
+; };
+;
+; int fn1() {
+;   C A;
+;   A.b.m_fn2();
+;   A.m_fn3();
+; }
+; void C::m_fn3() {
+;   A().m_fn1();
+;   b.m_fn2();
+; }
+
+; CHECK: DW_TAG_structure_type
+; CHECK-NEXT: DW_AT_name {{.*}} "C"
+; CHECK: [[FN3_DECL:.*]]: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK: DW_AT_name {{.*}} "m_fn3"
+
+; CHECK: DW_AT_specification {{.*}} {[[FN3_DECL]]}
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_name {{.*}} "this"
+
+%struct.C = type { i32, %struct.B }
+%struct.B = type { i32 }
+%struct.A = type { i8 }
+
+@llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32, void ()* } { i32 1, void ()* @asan.module_ctor }]
+@__asan_option_detect_stack_use_after_return = external global i32
+@__asan_gen_ = private unnamed_addr constant [11 x i8] c"1 32 8 1 A\00", align 1
+@__asan_gen_1 = private unnamed_addr constant [13 x i8] c"1 32 1 3 tmp\00", align 1
+
+; Function Attrs: noreturn sanitize_address
+define i32 @_Z3fn1v() #0 {
+entry:
+  %MyAlloca = alloca [64 x i8], align 32, !dbg !39
+  %0 = ptrtoint [64 x i8]* %MyAlloca to i64, !dbg !39
+  %1 = load i32* @__asan_option_detect_stack_use_after_return, !dbg !39
+  %2 = icmp ne i32 %1, 0, !dbg !39
+  br i1 %2, label %3, label %5
+
+; <label>:3                                       ; preds = %entry
+  %4 = call i64 @__asan_stack_malloc_0(i64 64, i64 %0), !dbg !39
+  br label %5
+
+; <label>:5                                       ; preds = %entry, %3
+  %6 = phi i64 [ %0, %entry ], [ %4, %3 ], !dbg !39
+  %7 = add i64 %6, 32, !dbg !39
+  %8 = inttoptr i64 %7 to %struct.C*, !dbg !39
+  %9 = inttoptr i64 %6 to i64*, !dbg !39
+  store i64 1102416563, i64* %9, !dbg !39
+  %10 = add i64 %6, 8, !dbg !39
+  %11 = inttoptr i64 %10 to i64*, !dbg !39
+  store i64 ptrtoint ([11 x i8]* @__asan_gen_ to i64), i64* %11, !dbg !39
+  %12 = add i64 %6, 16, !dbg !39
+  %13 = inttoptr i64 %12 to i64*, !dbg !39
+  store i64 ptrtoint (i32 ()* @_Z3fn1v to i64), i64* %13, !dbg !39
+  %14 = lshr i64 %6, 3, !dbg !39
+  %15 = add i64 %14, 2147450880, !dbg !39
+  %16 = add i64 %15, 0, !dbg !39
+  %17 = inttoptr i64 %16 to i64*, !dbg !39
+  store i64 -868083117767659023, i64* %17, !dbg !39
+  %i.i = getelementptr inbounds %struct.C* %8, i64 0, i32 1, i32 0, !dbg !39
+  %18 = ptrtoint i32* %i.i to i64, !dbg !39
+  %19 = lshr i64 %18, 3, !dbg !39
+  %20 = add i64 %19, 2147450880, !dbg !39
+  %21 = inttoptr i64 %20 to i8*, !dbg !39
+  %22 = load i8* %21, !dbg !39
+  %23 = icmp ne i8 %22, 0, !dbg !39
+  br i1 %23, label %24, label %30, !dbg !39
+
+; <label>:24                                      ; preds = %5
+  %25 = and i64 %18, 7, !dbg !39
+  %26 = add i64 %25, 3, !dbg !39
+  %27 = trunc i64 %26 to i8, !dbg !39
+  %28 = icmp sge i8 %27, %22, !dbg !39
+  br i1 %28, label %29, label %30
+
+; <label>:29                                      ; preds = %24
+  call void @__asan_report_store4(i64 %18), !dbg !39
+  call void asm sideeffect "", ""()
+  unreachable
+
+; <label>:30                                      ; preds = %24, %5
+  store i32 0, i32* %i.i, align 4, !dbg !39, !tbaa !41
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %8}, i64 0, metadata !27), !dbg !46
+  call void @_ZN1C5m_fn3Ev(%struct.C* %8), !dbg !47
+  unreachable, !dbg !47
+}
+
+; Function Attrs: sanitize_address
+define void @_ZN1C5m_fn3Ev(%struct.C* nocapture %this) #1 align 2 {
+entry:
+  %MyAlloca = alloca [64 x i8], align 32, !dbg !48
+  %0 = ptrtoint [64 x i8]* %MyAlloca to i64, !dbg !48
+  %1 = load i32* @__asan_option_detect_stack_use_after_return, !dbg !48
+  %2 = icmp ne i32 %1, 0, !dbg !48
+  br i1 %2, label %3, label %5
+
+; <label>:3                                       ; preds = %entry
+  %4 = call i64 @__asan_stack_malloc_0(i64 64, i64 %0), !dbg !48
+  br label %5
+
+; <label>:5                                       ; preds = %entry, %3
+  %6 = phi i64 [ %0, %entry ], [ %4, %3 ], !dbg !48
+  %7 = add i64 %6, 32, !dbg !48
+  %8 = inttoptr i64 %7 to %struct.A*, !dbg !48
+  %9 = inttoptr i64 %6 to i64*, !dbg !48
+  store i64 1102416563, i64* %9, !dbg !48
+  %10 = add i64 %6, 8, !dbg !48
+  %11 = inttoptr i64 %10 to i64*, !dbg !48
+  store i64 ptrtoint ([13 x i8]* @__asan_gen_1 to i64), i64* %11, !dbg !48
+  %12 = add i64 %6, 16, !dbg !48
+  %13 = inttoptr i64 %12 to i64*, !dbg !48
+  store i64 ptrtoint (void (%struct.C*)* @_ZN1C5m_fn3Ev to i64), i64* %13, !dbg !48
+  %14 = lshr i64 %6, 3, !dbg !48
+  %15 = add i64 %14, 2147450880, !dbg !48
+  %16 = add i64 %15, 0, !dbg !48
+  %17 = inttoptr i64 %16 to i64*, !dbg !48
+  store i64 -868083113472691727, i64* %17, !dbg !48
+  tail call void @llvm.dbg.value(metadata !{%struct.C* %this}, i64 0, metadata !30), !dbg !48
+  %call = call i32 @_ZN1A5m_fn1Ev(%struct.A* %8), !dbg !49
+  %i.i = getelementptr inbounds %struct.C* %this, i64 0, i32 1, i32 0, !dbg !50
+  %18 = ptrtoint i32* %i.i to i64, !dbg !50
+  %19 = lshr i64 %18, 3, !dbg !50
+  %20 = add i64 %19, 2147450880, !dbg !50
+  %21 = inttoptr i64 %20 to i8*, !dbg !50
+  %22 = load i8* %21, !dbg !50
+  %23 = icmp ne i8 %22, 0, !dbg !50
+  br i1 %23, label %24, label %30, !dbg !50
+
+; <label>:24                                      ; preds = %5
+  %25 = and i64 %18, 7, !dbg !50
+  %26 = add i64 %25, 3, !dbg !50
+  %27 = trunc i64 %26 to i8, !dbg !50
+  %28 = icmp sge i8 %27, %22, !dbg !50
+  br i1 %28, label %29, label %30
+
+; <label>:29                                      ; preds = %24
+  call void @__asan_report_store4(i64 %18), !dbg !50
+  call void asm sideeffect "", ""()
+  unreachable
+
+; <label>:30                                      ; preds = %24, %5
+  store i32 0, i32* %i.i, align 4, !dbg !50, !tbaa !41
+  store i64 1172321806, i64* %9, !dbg !52
+  %31 = icmp ne i64 %6, %0, !dbg !52
+  br i1 %31, label %32, label %39, !dbg !52
+
+; <label>:32                                      ; preds = %30
+  %33 = add i64 %15, 0, !dbg !52
+  %34 = inttoptr i64 %33 to i64*, !dbg !52
+  store i64 -723401728380766731, i64* %34, !dbg !52
+  %35 = add i64 %6, 56, !dbg !52
+  %36 = inttoptr i64 %35 to i64*, !dbg !52
+  %37 = load i64* %36, !dbg !52
+  %38 = inttoptr i64 %37 to i8*, !dbg !52
+  store i8 0, i8* %38, !dbg !52
+  br label %42, !dbg !52
+
+; <label>:39                                      ; preds = %30
+  %40 = add i64 %15, 0, !dbg !52
+  %41 = inttoptr i64 %40 to i64*, !dbg !52
+  store i64 0, i64* %41, !dbg !52
+  br label %42, !dbg !52
+
+; <label>:42                                      ; preds = %39, %32
+  ret void, !dbg !52
+}
+
+declare i32 @_ZN1A5m_fn1Ev(%struct.A*) #2
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata) #3
+
+define internal void @asan.module_ctor() {
+  tail call void @__asan_init_v3()
+  ret void
+}
+
+declare void @__asan_init_v3()
+
+declare void @__asan_report_load1(i64)
+
+declare void @__asan_load1(i64)
+
+declare void @__asan_report_load2(i64)
+
+declare void @__asan_load2(i64)
+
+declare void @__asan_report_load4(i64)
+
+declare void @__asan_load4(i64)
+
+declare void @__asan_report_load8(i64)
+
+declare void @__asan_load8(i64)
+
+declare void @__asan_report_load16(i64)
+
+declare void @__asan_load16(i64)
+
+declare void @__asan_report_store1(i64)
+
+declare void @__asan_store1(i64)
+
+declare void @__asan_report_store2(i64)
+
+declare void @__asan_store2(i64)
+
+declare void @__asan_report_store4(i64)
+
+declare void @__asan_store4(i64)
+
+declare void @__asan_report_store8(i64)
+
+declare void @__asan_store8(i64)
+
+declare void @__asan_report_store16(i64)
+
+declare void @__asan_store16(i64)
+
+declare void @__asan_report_load_n(i64, i64)
+
+declare void @__asan_report_store_n(i64, i64)
+
+declare void @__asan_loadN(i64, i64)
+
+declare void @__asan_storeN(i64, i64)
+
+declare i8* @__asan_memmove(i8*, i8*, i64)
+
+declare i8* @__asan_memcpy(i8*, i8*, i64)
+
+declare i8* @__asan_memset(i8*, i32, i64)
+
+declare void @__asan_handle_no_return()
+
+declare void @__sanitizer_cov()
+
+declare void @__sanitizer_ptr_cmp(i64, i64)
+
+declare void @__sanitizer_ptr_sub(i64, i64)
+
+declare i64 @__asan_stack_malloc_0(i64, i64)
+
+declare void @__asan_stack_free_0(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_1(i64, i64)
+
+declare void @__asan_stack_free_1(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_2(i64, i64)
+
+declare void @__asan_stack_free_2(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_3(i64, i64)
+
+declare void @__asan_stack_free_3(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_4(i64, i64)
+
+declare void @__asan_stack_free_4(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_5(i64, i64)
+
+declare void @__asan_stack_free_5(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_6(i64, i64)
+
+declare void @__asan_stack_free_6(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_7(i64, i64)
+
+declare void @__asan_stack_free_7(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_8(i64, i64)
+
+declare void @__asan_stack_free_8(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_9(i64, i64)
+
+declare void @__asan_stack_free_9(i64, i64, i64)
+
+declare i64 @__asan_stack_malloc_10(i64, i64)
+
+declare void @__asan_stack_free_10(i64, i64, i64)
+
+declare void @__asan_poison_stack_memory(i64, i64)
+
+declare void @__asan_unpoison_stack_memory(i64, i64)
+
+declare void @__asan_before_dynamic_init(i64)
+
+declare void @__asan_after_dynamic_init()
+
+declare void @__asan_register_globals(i64, i64)
+
+declare void @__asan_unregister_globals(i64, i64)
+
+declare void @__sanitizer_cov_module_init(i64)
+
+attributes #0 = { noreturn sanitize_address "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { sanitize_address "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!36, !37}
+!llvm.ident = !{!38}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 ", i1 true, metadata !"", i32 0, metadata !2, metadata !3, metadata !21, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/<stdin>] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"<stdin>", metadata !"/tmp/dbginfo"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4, metadata !14}
+!4 = metadata !{i32 786451, metadata !5, null, metadata !"C", i32 10, i64 64, i64 32, i32 0, i32 0, null, metadata !6, i32 0, null, null, metadata !"_ZTS1C"} ; [ DW_TAG_structure_type ] [C] [line 10, size 64, align 32, offset 0] [def] [from ]
+!5 = metadata !{metadata !"incorrect-variable-debug-loc.cpp", metadata !"/tmp/dbginfo"}
+!6 = metadata !{metadata !7, metadata !9, metadata !10}
+!7 = metadata !{i32 786445, metadata !5, metadata !"_ZTS1C", metadata !"j", i32 12, i64 32, i64 32, i64 0, i32 0, metadata !8} ; [ DW_TAG_member ] [j] [line 12, size 32, align 32, offset 0] [from int]
+!8 = 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]
+!9 = metadata !{i32 786445, metadata !5, metadata !"_ZTS1C", metadata !"b", i32 13, i64 32, i64 32, i64 32, i32 0, metadata !"_ZTS1B"} ; [ DW_TAG_member ] [b] [line 13, size 32, align 32, offset 32] [from _ZTS1B]
+!10 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1C", metadata !"m_fn3", metadata !"m_fn3", metadata !"_ZN1C5m_fn3Ev", i32 11, metadata !11, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, null, i32 11} ; [ DW_TAG_subprogram ] [line 11] [m_fn3]
+!11 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !12, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!12 = metadata !{null, metadata !13}
+!13 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !"_ZTS1C"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS1C]
+!14 = metadata !{i32 786451, metadata !5, null, metadata !"B", i32 5, i64 32, i64 32, i32 0, i32 0, null, metadata !15, i32 0, null, null, metadata !"_ZTS1B"} ; [ DW_TAG_structure_type ] [B] [line 5, size 32, align 32, offset 0] [def] [from ]
+!15 = metadata !{metadata !16, metadata !17}
+!16 = metadata !{i32 786445, metadata !5, metadata !"_ZTS1B", metadata !"i", i32 7, i64 32, i64 32, i64 0, i32 0, metadata !8} ; [ DW_TAG_member ] [i] [line 7, size 32, align 32, offset 0] [from int]
+!17 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1B", metadata !"m_fn2", metadata !"m_fn2", metadata !"_ZN1B5m_fn2Ev", i32 6, metadata !18, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, null, i32 6} ; [ DW_TAG_subprogram ] [line 6] [m_fn2]
+!18 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !19, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!19 = metadata !{null, metadata !20}
+!20 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !"_ZTS1B"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS1B]
+!21 = metadata !{metadata !22, metadata !28, metadata !32}
+!22 = metadata !{i32 786478, metadata !5, metadata !23, metadata !"fn1", metadata !"fn1", metadata !"_Z3fn1v", i32 16, metadata !24, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, i32 ()* @_Z3fn1v, null, null, metadata !26, i32 16} ; [ DW_TAG_subprogram ] [line 16] [def] [fn1]
+!23 = metadata !{i32 786473, metadata !5}         ; [ DW_TAG_file_type ] [/tmp/dbginfo/incorrect-variable-debug-loc.cpp]
+!24 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !25, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!25 = metadata !{metadata !8}
+!26 = metadata !{metadata !27}
+!27 = metadata !{i32 786688, metadata !22, metadata !"A", metadata !23, i32 17, metadata !"_ZTS1C", i32 0, i32 0} ; [ DW_TAG_auto_variable ] [A] [line 17]
+!28 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1C", metadata !"m_fn3", metadata !"m_fn3", metadata !"_ZN1C5m_fn3Ev", i32 21, metadata !11, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (%struct.C*)* @_ZN1C5m_fn3Ev, null, metadata !10, metadata !29, i32 21} ; [ DW_TAG_subprogram ] [line 21] [def] [m_fn3]
+!29 = metadata !{metadata !30}
+!30 = metadata !{i32 786689, metadata !28, metadata !"this", null, i32 16777216, metadata !31, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!31 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 0, metadata !"_ZTS1C"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from _ZTS1C]
+!32 = metadata !{i32 786478, metadata !5, metadata !"_ZTS1B", metadata !"m_fn2", metadata !"m_fn2", metadata !"_ZN1B5m_fn2Ev", i32 6, metadata !18, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, null, null, metadata !17, metadata !33, i32 6} ; [ DW_TAG_subprogram ] [line 6] [def] [m_fn2]
+!33 = metadata !{metadata !34}
+!34 = metadata !{i32 786689, metadata !32, metadata !"this", null, i32 16777216, metadata !35, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!35 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 0, metadata !"_ZTS1B"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from _ZTS1B]
+!36 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!37 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!38 = metadata !{metadata !"clang version 3.5.0 "}
+!39 = metadata !{i32 6, i32 0, metadata !32, metadata !40}
+!40 = metadata !{i32 18, i32 0, metadata !22, null}
+!41 = metadata !{metadata !42, metadata !43, i64 0}
+!42 = metadata !{metadata !"_ZTS1B", metadata !43, i64 0}
+!43 = metadata !{metadata !"int", metadata !44, i64 0}
+!44 = metadata !{metadata !"omnipotent char", metadata !45, i64 0}
+!45 = metadata !{metadata !"Simple C/C++ TBAA"}
+!46 = metadata !{i32 17, i32 0, metadata !22, null}
+!47 = metadata !{i32 19, i32 0, metadata !22, null}
+!48 = metadata !{i32 0, i32 0, metadata !28, null}
+!49 = metadata !{i32 22, i32 0, metadata !28, null}
+!50 = metadata !{i32 6, i32 0, metadata !32, metadata !51}
+!51 = metadata !{i32 23, i32 0, metadata !28, null}
+!52 = metadata !{i32 24, i32 0, metadata !28, null}