[binutils-gdb] Display entry offset for .debug_names

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ef8975b494c8c9bca73cda76c33244bb5fd1677f

commit ef8975b494c8c9bca73cda76c33244bb5fd1677f
Author: Tom Tromey <tom@tromey.com>
Date:   Thu Feb 13 17:47:23 2025 -0700

    Display entry offset for .debug_names
    
    Since commit ad6dde5aaae ("gdb/dwarf: write offset to parent entry for
    DW_IDX_parent"), gdb now emits a .debug_names where the DW_IDX_parent
    attribute refers to the parent entry's offset -- previously, due to
    some confusion in the standard, gdb used the index of the parent's
    name table entry.
    
    This patch changes the .debug_names display code to display each
    entry's offset.  This makes it easy to refer from a DW_IDX_parent to
    the correct entry.
    
    The new output looks like this:
    
    [...]
    Symbol table:
    [  1] circular1: <0><1> DW_TAG_module DW_IDX_compile_unit=1 DW_IDX_die_offset=<0x19> DW_IDX_GNU_language=19
    [...]
    [  6] found: <0x28><2> DW_TAG_subprogram DW_IDX_compile_unit=1 DW_IDX_die_offset=<0x38> DW_IDX_GNU_language=19 DW_IDX_parent=<0x0>
    
    Here you can see that DW_IDX_parent=0 refers to "circular1: <0>".

Diff:
---
 binutils/dwarf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index fcf32ec6703..08bb623e405 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -10828,6 +10828,7 @@ display_debug_names (struct dwarf_section *section, void *file)
 	      uint64_t abbrev_tag;
 	      uint64_t dwarf_tag;
 	      const struct abbrev_lookup_entry *entry;
+	      uint64_t this_entry = entryptr - entry_pool;
 
 	      READ_ULEB (abbrev_tag, entryptr, unit_end);
 	      if (tagno == -1)
@@ -10840,9 +10841,9 @@ display_debug_names (struct dwarf_section *section, void *file)
 	      if (abbrev_tag == 0)
 		break;
 	      if (tagno >= 0)
-		printf ("%s<%" PRIu64 ">",
+		printf ("%s<%#" PRIx64 "><%" PRIu64 ">",
 			(tagno == 0 && second_abbrev_tag == 0 ? " " : "\n\t"),
-			abbrev_tag);
+			this_entry, abbrev_tag);
 
 	      for (entry = abbrev_lookup;
 		   entry < abbrev_lookup + abbrev_lookup_used;