Re: [PATCH,tests] Run to main before doing any tests in structs3.exp

[Luis Machado <lgustavo@codesourcery.com>]

Hi Joel,

On 11/06/2012 03:30 PM, Joel Brobecker wrote:
>> On remote targets, we don't always start at the entry point. Thus,
>> it is safer to get to main and do the tests from that point onwards.
>
> Can you elaborate more? Your patch looks reasonable at first sight,
> but then at the same time now introduces a new requirement that it
> needs to be run on the target, whereas that was not the case before.
>
> The testcase only prints global variables. I don't suppose there
> is much of a guaranty that you could print global variables without
> starting the program first, but it's been generally working. So
> I am curious as to why it isn't working in your case.

We've been generally only testing these with native targets or with 
gdbserver on linux, both of which have well-known inferior startup 
procedures.

Consider, for example, a target that runs on QEMU. QEMU won't start the 
binary in exactly the same way as gdbserver running on linux. Thus, 
global variable initialization procedures may not have happened at that 
point yet. Consider that we start even before the dynamic loader had a 
chance to run and do all the relocation magic.

In this case, it makes no sense to try to print global variables since 
they will only contain garbage.

Effectively starting the binary and running to a known location helps 
avoid such a situation, and it does not change much for targets that 
already passed these tests.

Hopefully this explains things a little better.

Luis