diff mbox series

[v2,10/17] Empty hash table fix in .debug_names reader

Message ID 20240117-debug-names-fix-v2-10-dbd5971a9c31@tromey.com
State New
Headers
Series Rewrite .debug_names reader and writer |

Checks

Context Check Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 fail Patch failed to apply
linaro-tcwg-bot/tcwg_gdb_build--master-arm fail Patch failed to apply

Commit Message

Tom Tromey Jan. 17, 2024, 4:39 p.m. UTC 
  The handling of an empty hash table in the .debug_names reader is
slightly wrong.

Currently the code assumes there is always an array of hashes.
However, section 6.1.1.4.5 Hash Lookup Table says:

    The optional hash lookup table immediately follows the list of
    type signatures.

and then:

    The hash lookup table is actually two separate arrays: an array of
    buckets, followed immediately by an array of hashes.

My reading of this is that the hash table as a whole is optional, and
so the hashes will not exist in this case.  (This also makes sense
because the hashes are not useful without the buckets anyway.)

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=25950
---
 gdb/dwarf2/read-debug-names.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/gdb/dwarf2/read-debug-names.c b/gdb/dwarf2/read-debug-names.c
index a2a9fd425ae..b4ff36f0ed6 100644
--- a/gdb/dwarf2/read-debug-names.c
+++ b/gdb/dwarf2/read-debug-names.c
@@ -294,7 +294,8 @@  read_debug_names_from_section (struct objfile *objfile,
   map.bucket_table_reordered = reinterpret_cast<const uint32_t *> (addr);
   addr += map.bucket_count * 4;
   map.hash_table_reordered = reinterpret_cast<const uint32_t *> (addr);
-  addr += map.name_count * 4;
+  if (map.bucket_count != 0)
+    addr += map.name_count * 4;
 
   /* Name Table */
   map.name_table_string_offs_reordered = addr;