Re: [PATCH 3/4] gdb: distinguish GNU and MSVC flavors of the Windows OS ABI

[Simon Marchi <simark@simark.ca>]

On 2026-07-14 18:15, Pedro Alves wrote:
> On 2026-07-14 12:57, Eli Zaretskii wrote:
> 
>>> diff --git a/gdb/NEWS b/gdb/NEWS
>>> index ec9b5a33787..cf3948f87e4 100644
>>> --- a/gdb/NEWS
>>> +++ b/gdb/NEWS
>>> @@ -103,6 +103,16 @@
>>>    everywhere GDB shows a filename/dirname: source filenames,
>>>    executable filename, shared libraries, the cd/pwd commands, etc.
>>>  
>>> +* GDB now distinguishes between the GNU (MinGW) and MSVC Windows ABIs.
>>> +
>>> +  The "set osabi" command accepts two new values, "Windows-GNU" and
>>> +  "Windows-MSVC".  The existing "Windows" value continues to work and
>>> +  now means "let GDB pick the flavor": GDB uses the configured default
>>> +  OS ABI (from --target) when that is a Windows flavor, and otherwise
>>> +  assumes the GNU flavor.  E.g., --target=x86_64-pc-windows-msvc
>>> +  defaults to the MSVC ABI, and --target=x86_64-w64-mingw32 defaults
>>> +  to GNU ABI.  See "New targets" entry below.
>>
>> This part is okay, but I think it would make sense to tell which
>> compilers produce binaries of Windows-MSVC ABI.  E.g., does the above
>> mean that GDB will now be able to debug programs produces by MSVC,
>> including use of the PDB debug data files?
>>
>> Also, you only mention the 64-bit host and target triplets, but does
>> that mean this is limited to 64-bit Windows programs?
> 
> That was an example, and the "New targets" section being pointed at has the
> 32-bit x86 and AArch64 triplets.  But I can try to make it clearer, along with
> addressing your other points.
> 
> How about this?
> 
> * GDB now distinguishes between the GNU (MinGW) and MSVC Windows ABIs.
> 
>   The "set osabi" command accepts two new values, "Windows-GNU" and
>   "Windows-MSVC".  The GNU ABI is for code produced by MinGW
>   toolchains, while the MSVC ABI is for code produced by Microsoft's
>   MSVC compiler (though see the PDB note below), or Clang targeting
>   one of {i686,aarch64,x86_64}-pc-windows-msvc.  The existing
>   "Windows" value continues to work and now means "let GDB pick the
>   flavor": GDB uses the configured default OS ABI (from --target) when
>   that is a Windows flavor, and otherwise assumes the GNU flavor.  For
>   example, --target=x86_64-pc-windows-msvc defaults to the MSVC ABI,
>   and --target=x86_64-w64-mingw32 defaults to GNU ABI.  Similarly for
>   the i686 and AArch64 variants.  See "New targets" entry below.

What happens if you build a GDB with --enable-targets=all and load a
.exe?  Is either ABI preferred over the other?  Would it be possible to
"sniff" what ABI it is, for instance with the presence of some
particular symbol?

Simon