[PATCH] D55261: [llvm-dwarfdump] - Simplify the test case.

[David Blaikie via Phabricator via llvm-commits]

dblaikie added inline comments.


================
Comment at: test/tools/llvm-dwarfdump/X86/no_debug_addr.s:5-6
+## When .debug_addr is absent for some reason, check we do not print a bogus section name.
+## We had a bug that could be a reason of that when
+## DW_RLE_startx_length/DW_RLE_base_addressx/DW_RLE_offset_pair tags were used.
 
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Not sure I understand this comment - but I think I get where you're going with it, might just be some grammar improvement to make it more clear?

Oh, actually, here's a thought - did this bug pop-up when using rnglists in .dwo files? They certainly won't have a debug_addr & would then be a fully realistic scenario rather than one where a section of debug info would have to be dropped to demonstrate the failure?

So maybe a comment like this:

  ## Ensure bogus empty section names are not printed when dumping rnglists that reference debug_addr when it is not present (such as in .dwo files).

Yep, looks like it does, so here's a really short example I worked up:

        .section        .debug_info.dwo,"e", at progbits
        .long   .Ldebug_info_dwo_end1-.Ldebug_info_dwo_start1   # Length of Unit
  .Ldebug_info_dwo_start1:
        .short  5                       # DWARF version number
        .byte   5                       # DWARF Unit Type
        .byte   8                       # Address Size (in bytes)
        .long   0                       # Offset Into Abbrev. Section
        .quad   -6809755978868859807
        .byte   1                       # Abbrev [1] 0x14:0x32 DW_TAG_compile_unit
        .byte   0                       # DW_AT_ranges
  .Ldebug_info_dwo_end1:
        .section        .debug_abbrev.dwo,"e", at progbits
        .byte   1                       # Abbreviation Code
        .byte   17                      # DW_TAG_compile_unit
        .byte   0                       # DW_CHILDREN_no
        .byte   85                      # DW_AT_ranges
        .byte   35                      # DW_FORM_rnglistx
        .byte   0                       # EOM(1)
        .byte   0                       # EOM(2)
        .section        .debug_rnglists.dwo,"e", at progbits
        .long   .Ldebug_rnglist_table_end1-.Ldebug_rnglist_table_start1 # Length
  .Ldebug_rnglist_table_start1:
        .short  5                       # Version
        .byte   8                       # Address size
        .byte   0                       # Segment selector size
        .long   1                       # Offset entry count
  .Lrnglists_dwo_table_base0:
        .long   .Ldebug_ranges0-.Lrnglists_dwo_table_base0
  .Ldebug_ranges0:
        .byte   1                       # DW_RLE_base_addressx
        .byte   0                       #   base address index
        .byte   4                       # DW_RLE_offset_pair
        .byte   0                       #   starting offset
        .byte   1                       #   ending offset
        .byte   3                       # DW_RLE_startx_length
        .byte   1                       #   start index
        .byte   2                       #   length
        .byte   0                       # DW_RLE_end_of_list
  .Ldebug_rnglist_table_end1:





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  https://reviews.llvm.org/D55261/new/

https://reviews.llvm.org/D55261