DebugInfo: Move line table zero-directory-index (compilation dir) handling into MCDwarf

Our handling of compilation directory in DwarfDebug was broken
(incorrectly using the 'last' compilation directory (that of the last
CU in the metadata list) for all function emission in any CU). By moving
this handling down into MCDwarf the issue is fixed as the compilation
dir is tracked correctly per line table.

llvm-svn: 204089

1 files changed, 69 insertions, 0 deletions

diff --git a/llvm/test/DebugInfo/lto-comp-dir.ll b/llvm/test/DebugInfo/lto-comp-dir.ll
new file mode 100644
index 00000000000..88d6bf56aef
--- /dev/null
+++ b/llvm/test/DebugInfo/lto-comp-dir.ll
@@ -0,0 +1,69 @@
+; RUN: %llc_dwarf < %s -filetype=obj | llvm-dwarfdump -debug-dump=line - | FileCheck %s
+
+; CHECK: .debug_line contents:
+; CHECK-NEXT: Line table prologue:
+; CHECK-NOT: include_directories
+; CHECK: file_names[   1]   0 {{.*}} a.cpp
+; CHECK-NOT: file_names
+
+; CHECK: Line table prologue:
+; CHECK-NOT: include_directories
+; CHECK: file_names[   1]   0 {{.*}} b.cpp
+; CHECK-NOT: file_names
+
+; Generated from the following source compiled to bitcode from within their
+; respective directories (with debug info) and linked together with llvm-link
+
+; a/a.cpp
+; void func() {
+; }
+
+; b/b.cpp
+; void func();
+; int main() {
+;   func();
+; }
+
+; Function Attrs: nounwind uwtable
+define void @_Z4funcv() #0 {
+entry:
+  ret void, !dbg !19
+}
+
+; Function Attrs: uwtable
+define i32 @main() #1 {
+entry:
+  call void @_Z4funcv(), !dbg !20
+  ret i32 0, !dbg !21
+}
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0, !8}
+!llvm.module.flags = !{!16, !17}
+!llvm.ident = !{!18, !18}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1}
+!1 = metadata !{metadata !"a.cpp", metadata !"/tmp/dbginfo/a"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"func", metadata !"func", metadata !"_Z4funcv", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void ()* @_Z4funcv, null, null, metadata !2, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [func]
+!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/tmp/dbginfo/a/a.cpp]
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{null}
+!8 = metadata !{i32 786449, metadata !9, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !10, metadata !2, metadata !2, metadata !"", i32 1}
+!9 = metadata !{metadata !"b.cpp", metadata !"/tmp/dbginfo/b"}
+!10 = metadata !{metadata !11}
+!11 = metadata !{i32 786478, metadata !9, metadata !12, metadata !"main", metadata !"main", metadata !"", i32 2, metadata !13, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, metadata !2, i32 2} ; [ DW_TAG_subprogram ] [line 2] [def] [main]
+!12 = metadata !{i32 786473, metadata !9}         ; [ DW_TAG_file_type ] [/tmp/dbginfo/b/b.cpp]
+!13 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !14, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!14 = metadata !{metadata !15}
+!15 = 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]
+!16 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!17 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!18 = metadata !{metadata !"clang version 3.5.0 "}
+!19 = metadata !{i32 2, i32 0, metadata !4, null}
+!20 = metadata !{i32 3, i32 0, metadata !11, null}
+!21 = metadata !{i32 4, i32 0, metadata !11, null}
+