RE: [PATCH v11 03/10] gdb: handle stepping through functions with DW_AT_trampoline

["Ijaz, Abdul B" <abdul.b.ijaz@intel.com>]

Thanks Tom, for the feedback.

Please see the inline reply below:

Tom> I was also wondering if this affects the "finish" command.
Tom> That is, suppose you have a call chain like A -> Trampoline -> B.
Tom> If you "finish" from B, then it seems like it ought to return all the way to A.
Tom> Similarly for "return"?
Tom> If that's intended then those cases need tests.

Abdul> Yes, that is intended, and it is handled in the later patches of this series, one per command:

gdb: Skip trampoline functions for the finish and reverse-finish commands.
gdb: Skip trampoline functions for the up command.
gdb: Skip trampoline functions for the return command.

With skip-trampoline-functions on (the default), each of them skips the trampoline frames, so "finish", "reverse-finish", "up" and "return" from B end up in A.  These patches add tests to gdb.fortran/func-trampoline.exp ("finish", "up" and "return" from second through its trampoline back to first) and gdb.reverse/finish-reverse-trampoline.exp ("reverse-finish").   Both of those tests need ifx, though.

Thanks & Best Regards,
Abdul Basit

-----Original Message-----
From: Tom Tromey <tom@tromey.com> 
Sent: Wednesday, October 21, 2026 10:44 PM
To: Ijaz, Abdul B <abdul.b.ijaz@intel.com>
Cc: gdb-patches@sourceware.org; JiniSusan.George@amd.com; tom@tromey.com; eliz@gnu.org; Nils-Christian Kempke <nils-christian.kempke@intel.com>
Subject: Re: [PATCH v11 03/10] gdb: handle stepping through functions with DW_AT_trampoline

>>>>> Abdul Basit Ijaz <abdul.b.ijaz@intel.com> writes:

> As currently only ifx emits the DW_AT_trampoline tag, a test has been 
> added to gdb.dwarf2 that artificially creates a set of trampoline 
> functions.

I was also wondering if this affects the "finish" command.

That is, suppose you have a call chain like A -> Trampoline -> B.
If you "finish" from B, then it seems like it ought to return all the way to A.

Similarly for "return"?

If that's intended then those cases need tests.

If it's not intended then I wonder whether you can end up in a situation where gdb is confused.

Tom
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