Re: [PATCH] sim: use -Werror when probing for supported warning flags

[Simon Marchi via Gdb-patches <gdb-patches@sourceware.org>]

On 2021-04-21 6:38 p.m., Mike Frysinger wrote:> On 21 Apr 2021 17:04, Simon Marchi via Gdb-patches wrote:
>> On 2021-04-21 4:44 p.m., Mike Frysinger wrote:
>>> On 21 Apr 2021 14:51, Simon Marchi via Gdb-patches wrote:
>>>> When building with clang, we get:
>>>>
>>>>     error: unknown warning option '-Wmissing-parameter-type' [-Werror,-Wunknown-warning-option]
>>>>
>>>> This is because clang only warns by default when encountering an unknown
>>>> warning option, and the probe for supported warning flags is done
>>>> without -Werror.  All flags are therefore accepted by configure, but
>>>> then it breaks when actually compiling a source file with -Werror.
>>>>
>>>> This is equivalent to this commit in gdb:
>>>>
>>>>     3e019bdc20eb81b91ab5bc774386201b874c0bac
>>>>     gdb: Use -Werror when checking for (un)supported warning flags
>>>>
>>>> We then see some other compilation errors when building with clang and
>>>> -Werror, they can be dealt with later.
>>>>
>>>> sim/ChangeLog:
>>>>
>>>> 	* m4/sim_ac_option_warnings.m4 (SIM_AC_OPTION_WARNINGS):
>>>> 	Use -Werror when probing for supported warning flags.
>>>
>>> so this one file/line looks fine
>>>
>>> but the regen looks a little out of whack.  when i apply your patch and
>>> regenerate everything, i don't have any aclocal.m4 changes.  why do you ?
>>> are you running the tools manually and with a diff -I order ?
>>
>> I run `autoreconf -vf` inside sim/, using binaries compiled from
>> upstream (not my distro's versions).
> 
> if i use that, a ton more gets thrashed & imported from the OS :/

Ok, and all your tools (well, just autoconf in this case) are also
compiled from source, using the upstream releases?  You are running it
from sim/ and not from the top-level directory?

> do we have guidelines for how devs are supposed to do this ?  i've been
> running the individual tools, but i want to make sure we aren't constantly
> stepping on each other.

Yes, if we can document it or even have a script that does the right
thing it would be nice.  This is one of those things that were never
explained to me, how to re-generate those files, that's why I converged
towards using autoreconf.  So far it worked well for the other projects
in the tree (I don't get a different result than what is checked in).

Simon