DebugInfo: Support debug_loc under fission

Implement debug_loc.dwo, as well as llvm-dwarfdump support for dumping
this section.

Outlined in the DWARF5 spec and http://gcc.gnu.org/wiki/DebugFission the
debug_loc.dwo section has more variation than the standard debug_loc,
allowing 3 different forms of entry (plus the end of list entry). GCC
seems to, and Clang certainly, only use one form, so I've just
implemented dumping support for that for now.

It wasn't immediately obvious that there was a good refactoring to share
the implementation of dumping support between debug_loc and
debug_loc.dwo, so they're separate for now - ideas welcome or I may come
back to it at some point.

As per a comment in the code, we could choose different forms that may
reduce the number of debug_addr entries we emit, but that will require
further study.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204697 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 32 insertions, 7 deletions

diff --git a/test/DebugInfo/X86/fission-ranges.ll b/test/DebugInfo/X86/fission-ranges.ll
index b95038bacc..a48896f5a5 100644
--- a/test/DebugInfo/X86/fission-ranges.ll
+++ b/test/DebugInfo/X86/fission-ranges.ll
@@ -1,14 +1,39 @@
 ; RUN: llc -split-dwarf=Enable -O0 %s -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
-; RUN: llvm-dwarfdump -debug-dump=info.dwo %t | FileCheck %s
-; RUN: llvm-objdump -r %t | FileCheck --check-prefix=RELA %s
-
+; RUN: llvm-dwarfdump %t | FileCheck %s
+; RUN: llvm-objdump -h %t | FileCheck --check-prefix=HDR %s
+
+; CHECK: .debug_info.dwo contents:
+; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[A:0x[0-9a-z]*]])
+; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[E:0x[0-9a-z]*]])
+; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[B:0x[0-9a-z]*]])
+; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[D:0x[0-9a-z]*]])
 ; CHECK: DW_AT_ranges [DW_FORM_sec_offset]   (0x000000a0)
+; CHECK: .debug_loc contents:
+; CHECK-NOT: Beginning address offset
+; CHECK: .debug_loc.dwo contents:
+
+; Don't assume these locations are entirely correct - feel free to update them
+; if they've changed due to a bugfix, change in register allocation, etc.
+
+; CHECK: [[A]]: Beginning address index: 2
+; CHECK-NEXT:                    Length: 199
+; CHECK-NEXT:      Location description: 10 00
+; CHECK-NEXT: {{^$}}
+; CHECK-NEXT:   Beginning address index: 3
+; CHECK-NEXT:                    Length: 23
+; CHECK-NEXT:      Location description: 50 93 04
+; CHECK: [[E]]: Beginning address index: 4
+; CHECK-NEXT:                    Length: 21
+; CHECK-NEXT:      Location description: 50 93 04
+; CHECK: [[B]]: Beginning address index: 5
+; CHECK-NEXT:                    Length: 19
+; CHECK-NEXT:      Location description: 50 93 04
+; CHECK: [[D]]: Beginning address index: 6
+; CHECK-NEXT:                    Length: 23
+; CHECK-NEXT:      Location description: 50 93 04
 
 ; Make sure we don't produce any relocations in any .dwo section (though in particular, debug_info.dwo)
-; FIXME: There should be no relocations in .dwo sections at all, but for now there are debug_loc relocs here.
-; RELA: RELOCATION RECORDS FOR [.rela.debug_info.dwo]
-; RELA-NOT: R_X86_64_32 .debug_ranges
-; RELA: RELOCATION RECORDS FOR
+; HDR-NOT: .rela.{{.*}}.dwo
 
 ; From the code: