diff mbox series

[1/2,gdb/symtab] Fix dwarf version of DWO TU

Message ID 20241028124040.19601-1-tdevries@suse.de
State Superseded
Headers
Series [1/2,gdb/symtab] Fix dwarf version of DWO TU |

Checks

Context Check Description
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linaro-tcwg-bot/tcwg_gdb_check--master-aarch64 success Test passed

Commit Message

Tom de Vries Oct. 28, 2024, 12:40 p.m. UTC 
  When running test-case gdb.ada/access_tagged_param.exp with target board
fission, we run into:
...
(gdb) break pck.adb:19^M
gdb/dwarf2/read.h:289: internal-error: version: \
  Assertion `m_dwarf_version != 0' failed.^M
...

The assertion happens when calling cu->per_cu->version () in this workaround
in read_subroutine_type:
...
  /* PR gas/29517 occurs in 2.39, and is fixed in 2.40, but it's only fixed
     for dwarf version >= 3 which supports DW_TAG_unspecified_type.  */
  if (type->code () == TYPE_CODE_VOID
      && !type->is_stub ()
      && die->child == nullptr
      && (cu->per_cu->version () == 2
	  || producer_is_gas_2_39 (cu)))
    {
...
for a TU in a dwo file.

Fix this by:
- adding a dwarf_version field to struct dwo_unit,
- initializing the new field in create_debug_type_hash_table, and
- using the new field in fill_in_sig_entry_from_dwo_entry to set the sig_entry
  dwarf version.

Tested on aarch64-linux.

PR symtab/32309
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32309
---
 gdb/dwarf2/read.c | 5 +++++
 1 file changed, 5 insertions(+)


base-commit: 917ed12066382c48459f85124cbeca1286c3bb53

Comments

Tom de Vries Jan. 20, 2025, 8:59 a.m. UTC | #1 
On 10/28/24 13:40, Tom de Vries wrote:
> When running test-case gdb.ada/access_tagged_param.exp with target board
> fission, we run into:
> ...
> (gdb) break pck.adb:19^M
> gdb/dwarf2/read.h:289: internal-error: version: \
>    Assertion `m_dwarf_version != 0' failed.^M
> ...
> 
> The assertion happens when calling cu->per_cu->version () in this workaround
> in read_subroutine_type:
> ...
>    /* PR gas/29517 occurs in 2.39, and is fixed in 2.40, but it's only fixed
>       for dwarf version >= 3 which supports DW_TAG_unspecified_type.  */
>    if (type->code () == TYPE_CODE_VOID
>        && !type->is_stub ()
>        && die->child == nullptr
>        && (cu->per_cu->version () == 2
> 	  || producer_is_gas_2_39 (cu)))
>      {
> ...
> for a TU in a dwo file.
> 
> Fix this by:
> - adding a dwarf_version field to struct dwo_unit,
> - initializing the new field in create_debug_type_hash_table, and
> - using the new field in fill_in_sig_entry_from_dwo_entry to set the sig_entry
>    dwarf version.
> 

I've submitted a v2 of this patch ( 
https://sourceware.org/pipermail/gdb-patches/2025-January/214885.html ) 
, which uses a simpler approach: just use cu->header.version.

Thanks,
- Tom

> Tested on aarch64-linux.
> 
> PR symtab/32309
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32309
> ---
>   gdb/dwarf2/read.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
> index 6ac6f7c6a39..b407f0a47aa 100644
> --- a/gdb/dwarf2/read.c
> +++ b/gdb/dwarf2/read.c
> @@ -324,6 +324,9 @@ struct dwo_unit
>   
>     /* For types, offset in the type's DIE of the type defined by this TU.  */
>     cu_offset type_offset_in_tu;
> +
> +  /* DWARF standard version of this DWO unit.  */
> +  unsigned char dwarf_version;
>   };
>   
>   /* include/dwarf2.h defines the DWP section codes.
> @@ -3449,6 +3452,7 @@ create_debug_type_hash_table (dwarf2_per_objfile *per_objfile,
>         dwo_tu->section = section;
>         dwo_tu->sect_off = sect_off;
>         dwo_tu->length = length;
> +      dwo_tu->dwarf_version = header.version;
>   
>         slot = htab_find_slot (types_htab.get (), dwo_tu, INSERT);
>         gdb_assert (slot != NULL);
> @@ -3545,6 +3549,7 @@ fill_in_sig_entry_from_dwo_entry (dwarf2_per_objfile *per_objfile,
>     sig_entry->per_bfd = per_bfd;
>     sig_entry->type_offset_in_tu = dwo_entry->type_offset_in_tu;
>     sig_entry->dwo_unit = dwo_entry;
> +  sig_entry->set_version (dwo_entry->dwarf_version);
>   }
>   
>   /* Subroutine of lookup_signatured_type.
> 
> base-commit: 917ed12066382c48459f85124cbeca1286c3bb53
diff mbox series

Patch

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 6ac6f7c6a39..b407f0a47aa 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -324,6 +324,9 @@  struct dwo_unit
 
   /* For types, offset in the type's DIE of the type defined by this TU.  */
   cu_offset type_offset_in_tu;
+
+  /* DWARF standard version of this DWO unit.  */
+  unsigned char dwarf_version;
 };
 
 /* include/dwarf2.h defines the DWP section codes.
@@ -3449,6 +3452,7 @@  create_debug_type_hash_table (dwarf2_per_objfile *per_objfile,
       dwo_tu->section = section;
       dwo_tu->sect_off = sect_off;
       dwo_tu->length = length;
+      dwo_tu->dwarf_version = header.version;
 
       slot = htab_find_slot (types_htab.get (), dwo_tu, INSERT);
       gdb_assert (slot != NULL);
@@ -3545,6 +3549,7 @@  fill_in_sig_entry_from_dwo_entry (dwarf2_per_objfile *per_objfile,
   sig_entry->per_bfd = per_bfd;
   sig_entry->type_offset_in_tu = dwo_entry->type_offset_in_tu;
   sig_entry->dwo_unit = dwo_entry;
+  sig_entry->set_version (dwo_entry->dwarf_version);
 }
 
 /* Subroutine of lookup_signatured_type.