[PATCH] D105469: [Debug-Info] [llvm-dwarfdump] Don't treat DW_FORM_data4/8 to be section offsets in DWARF3.

[EsmeYi via Phabricator via llvm-commits]

Esme created this revision.
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We found a similar error as the description in D58698 <https://reviews.llvm.org/D58698> when dumping the debug info of the SPEC xalancbmk_r with llvm-dwarfdump under DWARF3, ie. the location list overflows the debug_loc section.

Although in DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset, but they may actually be size values instead of offsets in some scenarios. The overflow-error occurred when we try to dump the location list for such scenarios.

After narrowing down the cases, we found the error occurs for three attributes, DW_AT_data_member_location, DW_AT_count and DW_AT_byte_size.

DW_FORM_data4 and DW_FORM_data8 are obviously not offsets in DWARF3+, but it’s hard to tell whether they are offsets in DWARF3.  In this patch, we are dropping the support of dumping location for DW_AT_data_member_location, DW_AT_count and DW_AT_byte_size if the form is DW_FORM_data4 and DW_FORM_data8.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D105469

Files:
  llvm/include/llvm/DebugInfo/DWARF/DWARFAttribute.h
  llvm/lib/DWARFLinker/DWARFLinker.cpp
  llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
  llvm/test/tools/llvm-dwarfdump/ELF/formclass3-atcount.s
  llvm/test/tools/llvm-dwarfdump/ELF/formclass3-atmemloc.s

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