Re: [PATCH] Fixup gdb.python/py-value.exp for bare-metal aarch64-elf

[Kevin Buettner <kevin@buettner.to>]

On Thu, 6 Oct 2016 11:27:11 -0500
Luis Machado <lgustavo@codesourcery.com> wrote:

> I noticed that testing aarch64-elf gdb with a physical board
> ran into issues with gdb.python/py-value.exp. Further investigation showed
> that we were actually trying to dereference a NULL pointer (argv) when trying
> to access argv[0].
> 
> Being bare-metal, argv is not guaranteed to be there. So we need to make sure
> argv is sane before accessing argv[0].
> 
> After fixing that, i noticed we were assuming a value of 1 for argc, which is
> also not true, as i see 0 in my tests.
> 
> The following patch fixes up the test program to check for a NULL argv and also
> touches the testcase itself to expect either 0 or 1 for argc depending on the
> presence of argv, which is something we check early in the test.
> 
> This gives me full passes for aarch64-elf when running gdb.python/py-value.exp
> and doesn't regress things on x86-64.
> 
> Ok?

FWIW, I've run into some of these same problems while testing against
some of the simulators.  In such an environment, I think it makes
sense to pass in NULL for argv.

I'd like to see your patch (or something like it) go in.  I think it's easier to
adjust the tests than it is to adjust the startup code in a bunch of different
places.

Kevin