Re: [PATCH 2/2] gdb/testsuite: Add gdb.base/memops-watchpoint.exp

[Kevin Buettner <kevinb@redhat.com>]

On Sun, 21 Apr 2024 21:24:42 -0300
Thiago Jung Bauermann <thiago.bauermann@linaro.org> wrote:

> >> +require libc_has_debug_info  
> >
> > I'm wondering about the need for this requirement.  When I comment it
> > out and run it on a machine without libc debuginfo, I do see 3 FAILs,
> > but it seems to me that those could be turned into PASSes by changing
> > the regular expressions for the "continue until..." tests.
[...]
> 
> I added the requirement because in my aarch64-linux system without libc6
> debug info I get:
> 
> continue
> Continuing.
> 
> Hardware watchpoint 2: -location a[28]
> 
> Old value = 104 'h'
> New value = 0 '\000'
> 0x0000fffff7e90664 in ?? () from /lib/aarch64-linux-gnu/libc.so.6
> (gdb) FAIL: gdb.base/memops-watchpoint.exp: continue until memset watchpoint hits
> 
> And I just tested removing libc6-dbg from my x86_64-linux laptop:
> 
> continue
> Continuing.
> 
> Hardware watchpoint 2: -location a[28]
> 
> Old value = 104 'h'
> New value = 0 '\000'
> 0x00007ffff7d8e05f in ?? () from /lib/x86_64-linux-gnu/libc.so.6
> (gdb) FAIL: gdb.base/memops-watchpoint.exp: continue until memset watchpoint hits
> 
> So it depends on the system.

What distro are you using?

> One alternative would be to not use the require statement and run the
> test until the watchpoint hits, and have a case in gdb_test_multiple to
> mark as UNRESOLVED if the function name is '??'.

I'm in favor of this approach.

If we stick with the require statement, I think that Fedora testing
will frequently show this new test as unsupported since installing
debuginfo is less common / important that it used to be.  (This is
due to debuginfod doing it for you.  But I think that debuginfod is
mostly disabled when running the GDB tests.)