This was requested during the post-commit review for D55113.
I added/updated the comment and removed excessive things.
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| test/tools/llvm-dwarfdump/X86/no_debug_addr.s | ||
|---|---|---|
| 5–6 | 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:
Yep, looks like it does, so here's a really short example I worked up: .section .debug_info.dwo,"e",@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",@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",@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: | |
| test/tools/llvm-dwarfdump/X86/no_debug_addr.s | ||
|---|---|---|
| 5–6 | Idea about using the .dwo is interesting, thanks! I'll check it and probably update this patch tomorrow.
I faced this in LLD actually. Its implementation of the llvm::DWARFObject did not override the getRnglistsSection | |
| test/tools/llvm-dwarfdump/X86/no_debug_addr.s | ||
|---|---|---|
| 5–6 | Guess you meant "getAddrSection"/addr section is absent - yeah, could totally believe that - great find! & the same bug totally shows up in other places, like the dwo dumping - so handy to fix all around :) | |
| test/tools/llvm-dwarfdump/X86/no_debug_addr.s | ||
|---|---|---|
| 5–6 | Yeah, it was getAddrSection, I looked at the wrong place. | |
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:
Yep, looks like it does, so here's a really short example I worked up:
.section .debug_info.dwo,"e",@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",@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",@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: