DebugInfo: Simplify/tidy/correct global variable decl/def emission handling.

This fixes a bug (introduced by fixing the IR emitted from Clang where
the definition of a static member would be scoped within the class,
rather than within its lexical decl context) where the definition of a
static variable would be placed inside a class.

It also improves source fidelity by scoping static class member
definitions inside the lexical decl context in which tehy are written
(eg: namespace n { class foo { static int i; } int foo::i; } - the
definition of 'i' will be within the namespace 'n' in the DWARF output
now).

Lastly, and the original goal, this reduces debug info size slightly
(and makes debug info easier to read, etc) by placing the definitions of
non-member global variables within their namespace, rather than using a
separate namespace-scoped declaration along with a definition at global
scope.

Based on patches and discussion with Frédéric.

llvm-svn: 220497

1 files changed, 12 insertions, 12 deletions

diff --git a/llvm/test/DebugInfo/X86/debug-info-static-member.ll b/llvm/test/DebugInfo/X86/debug-info-static-member.ll
index 9f1cbacf3a6..37fe99710c3 100644
--- a/llvm/test/DebugInfo/X86/debug-info-static-member.ll
+++ b/llvm/test/DebugInfo/X86/debug-info-static-member.ll
@@ -1,5 +1,5 @@
 ; RUN: llc %s -o %t -filetype=obj -O0 -mtriple=x86_64-unknown-linux-gnu -dwarf-version=4
-; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=PRESENT
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=PRESENT 
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=ABSENT
 ; RUN: llc %s -o %t -filetype=obj -O0 -mtriple=x86_64-apple-darwin -dwarf-version=4
 ; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s -check-prefix=DARWINP
@@ -68,7 +68,7 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 !8 = metadata !{metadata !9}
 !9 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
 !10 = metadata !{metadata !12, metadata !27, metadata !28}
-!12 = metadata !{metadata !"0x34\00a\00a\00_ZN1C1aE\0014\000\001", metadata !13, metadata !6, metadata !9, i32* @_ZN1C1aE, metadata !15} ; [ DW_TAG_variable ] [a] [line 14] [def]
+!12 = metadata !{metadata !"0x34\00a\00a\00_ZN1C1aE\0014\000\001", null, metadata !6, metadata !9, i32* @_ZN1C1aE, metadata !15} ; [ DW_TAG_variable ] [a] [line 14] [def]
 !13 = metadata !{metadata !"0x2\00C\001\0032\0032\000\000\000", metadata !33, null, null, metadata !14, null, null, null} ; [ DW_TAG_class_type ] [C] [line 1, size 32, align 32, offset 0] [def] [from ]
 !14 = metadata !{metadata !15, metadata !16, metadata !19, metadata !20, metadata !23, metadata !24, metadata !26}
 !15 = metadata !{metadata !"0xd\00a\003\000\000\000\004097", metadata !33, metadata !13, metadata !9, null} ; [ DW_TAG_member ] [a] [line 3, size 0, align 0, offset 0] [private] [static] [from int]
@@ -83,8 +83,8 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 !24 = metadata !{metadata !"0xd\00const_c\0010\000\000\000\004099", metadata !33, metadata !13, metadata !25, i32 18} ; [ DW_TAG_member ] [const_c] [line 10, size 0, align 0, offset 0] [static] [from ]
 !25 = metadata !{metadata !"0x26\00\000\000\000\000\000", null, null, metadata !9} ; [ DW_TAG_const_type ] [line 0, size 0, align 0, offset 0] [from int]
 !26 = metadata !{metadata !"0xd\00d\0011\0032\0032\000\003", metadata !33, metadata !13, metadata !9} ; [ DW_TAG_member ] [d] [line 11, size 32, align 32, offset 0] [from int]
-!27 = metadata !{metadata !"0x34\00b\00b\00_ZN1C1bE\0015\000\001", metadata !13, metadata !6, metadata !9, i32* @_ZN1C1bE, metadata !19} ; [ DW_TAG_variable ] [b] [line 15] [def]
-!28 = metadata !{metadata !"0x34\00c\00c\00_ZN1C1cE\0016\000\001", metadata !13, metadata !6, metadata !9, i32* @_ZN1C1cE, metadata !23} ; [ DW_TAG_variable ] [c] [line 16] [def]
+!27 = metadata !{metadata !"0x34\00b\00b\00_ZN1C1bE\0015\000\001", null, metadata !6, metadata !9, i32* @_ZN1C1bE, metadata !19} ; [ DW_TAG_variable ] [b] [line 15] [def]
+!28 = metadata !{metadata !"0x34\00c\00c\00_ZN1C1cE\0016\000\001", null, metadata !6, metadata !9, i32* @_ZN1C1cE, metadata !23} ; [ DW_TAG_variable ] [c] [line 16] [def]
 !29 = metadata !{metadata !"0x100\00instance_C\0020\000", metadata !5, metadata !6, metadata !13} ; [ DW_TAG_auto_variable ] [instance_C] [line 20]
 !30 = metadata !{i32 20, i32 0, metadata !5, null}
 !31 = metadata !{i32 21, i32 0, metadata !5, null}
@@ -95,6 +95,10 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 ; (for variables) or DW_AT_const_value (for constants).
 ;
 ; PRESENT:      .debug_info contents:
+; PRESENT:      DW_TAG_variable
+; PRESENT-NEXT: DW_AT_specification {{.*}} "a"
+; PRESENT-NEXT: DW_AT_location
+; PRESENT-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1aE"
 ; PRESENT:      DW_TAG_class_type
 ; PRESENT-NEXT: DW_AT_name {{.*}} "C"
 ; PRESENT:      DW_TAG_member
@@ -131,10 +135,6 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 ; PRESENT:      NULL
 ; Definitions point back to their declarations, and have a location.
 ; PRESENT:      DW_TAG_variable
-; PRESENT-NEXT: DW_AT_specification {{.*}} "a"
-; PRESENT-NEXT: DW_AT_location
-; PRESENT-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1aE"
-; PRESENT:      DW_TAG_variable
 ; PRESENT-NEXT: DW_AT_specification {{.*}} "b"
 ; PRESENT-NEXT: DW_AT_location
 ; PRESENT-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1bE"
@@ -145,6 +145,10 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 
 ; For Darwin gdb:
 ; DARWINP:      .debug_info contents:
+; DARWINP:      DW_TAG_variable
+; DARWINP-NEXT: DW_AT_specification {{.*}} "a"
+; DARWINP-NEXT: DW_AT_location
+; DARWINP-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1aE"
 ; DARWINP:      DW_TAG_class_type
 ; DARWINP-NEXT: DW_AT_name {{.*}} "C"
 ; DARWINP:      DW_TAG_member
@@ -181,10 +185,6 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 ; DARWINP:      NULL
 ; Definitions point back to their declarations, and have a location.
 ; DARWINP:      DW_TAG_variable
-; DARWINP-NEXT: DW_AT_specification {{.*}} "a"
-; DARWINP-NEXT: DW_AT_location
-; DARWINP-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1aE"
-; DARWINP:      DW_TAG_variable
 ; DARWINP-NEXT: DW_AT_specification {{.*}} "b"
 ; DARWINP-NEXT: DW_AT_location
 ; DARWINP-NEXT: DW_AT_linkage_name {{.*}} "_ZN1C1bE"