[llvm] r289954 - dwarfdump: Support/process relocations on a CU's abbrev_off

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Fri Dec 16 10:31:10 2016
New Revision: 289954

URL: http://llvm.org/viewvc/llvm-project?rev=289954&view=rev
Log:
dwarfdump: Support/process relocations on a CU's abbrev_off

Input can be produced by ld -r, for example (a normal LLVM workflow
never hits this - LLVM only ever produces a single abbrev table in an
object (shared by multiple CUs), so the reloc's always 0, and when it's
linked together the relocation's resolved so it doesn't need to be
handled)

Added:
    llvm/trunk/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64
    llvm/trunk/test/DebugInfo/dwarfdump-abbrev-off.test
Modified:
    llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp?rev=289954&r1=289953&r2=289954&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp Fri Dec 16 10:31:10 2016
@@ -87,7 +87,10 @@ bool DWARFUnit::getStringOffsetSectionIt
 bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
   Length = debug_info.getU32(offset_ptr);
   Version = debug_info.getU16(offset_ptr);
+  auto AI = InfoSection.Relocs.find(*offset_ptr);
   uint64_t AbbrOffset = debug_info.getU32(offset_ptr);
+  if (AI != InfoSection.Relocs.end())
+    AbbrOffset += AI->second.second;
   if (IndexEntry) {
     if (AbbrOffset)
       return false;

Added: llvm/trunk/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64?rev=289954&view=auto
==============================================================================
Binary files llvm/trunk/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64 (added) and llvm/trunk/test/DebugInfo/Inputs/dwarfdump-abbrev-off.elf-x86-64 Fri Dec 16 10:31:10 2016 differ

Added: llvm/trunk/test/DebugInfo/dwarfdump-abbrev-off.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/dwarfdump-abbrev-off.test?rev=289954&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/dwarfdump-abbrev-off.test (added)
+++ llvm/trunk/test/DebugInfo/dwarfdump-abbrev-off.test Fri Dec 16 10:31:10 2016
@@ -0,0 +1,8 @@
+RUN: llvm-dwarfdump -debug-dump=info %p/Inputs/dwarfdump-abbrev-off.elf-x86-64 | FileCheck %s
+
+Check that we apply relocations to the abbr_offset - while LLVM never produces
+an object file like this, a reproduction can be produced by linking two simple
+object files together with ld -r.
+
+CHECK: abbr_offset = 0x0000
+CHECK: abbr_offset = 0x0010