[PATCH] D69847: DWARFDebugLoc(v4): Add an incremental parsing function

[Pavel Labath via Phabricator via llvm-commits]

labath added a comment.

I'm sorry, but I'm confused. Are you saying that the `.debug_loc.dwo` (i.e. non-standardized dwarf4 fission) location lists should be terminated with a classical `.debug_loc` double-zero entry ? That doesn't seem right -- the .debug_loc.dwo lists are in reality very different from `.debug_loc` (they use DW_LLE_*** constants and everything), and are really more similar to `.debug_loclists(.dwo)` than .debug_loc (though there are some subtle differences). It also doesn't seem to be what gcc is doing now -- this is a typical location list I get from gcc-9 -gsplit-dwarf (comments added by me):

          .section        .debug_loc.dwo,"e", at progbits
  .Ldebug_loc0:
  .LVUS0: # gcc "view" stuff -- ignore that
          .uleb128 .LVU2
          .uleb128 0
  .LLST0: # DW_AT_location points here
          .byte   0x3                  # DW_LLE_startx_length
          .uleb128 0x1                 # index
          .long   .LFE0-.LVL0          # length
          .value  0x5                  # expression length
          .byte   0x75
          .sleb128 0
          .byte   0x31
          .byte   0x24
          .byte   0x9f
          .byte   0                # DW_LLE_end_of_list
  .LVUS1: # next "view" starts here

In practice, changing the `.byte 0` to two word-sized zeroes probably won't change anything, as the first byte of that will terminate the location list anyway. However, I don't think that's the right thing to do, and I think llvm-dwarfdump is right to display a bunch of end_of_list entries for something like that.


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  https://reviews.llvm.org/D69847/new/

https://reviews.llvm.org/D69847