Re: [PATCH] Disable building libgcc with -O0

[Lei Liu <layliu@gmail.com>]

On 2013年11月13日 07:58, Phil Blundell wrote:
> On Mon, 2013-11-11 at 12:30 +0800, Lei Liu wrote:
>> +def get_optimization(d):
>> +    selected_optimization = d.getVar("SELECTED_OPTIMIZATION", True)
>> +    if base_contains("SELECTED_OPTIMIZATION", "-O0", "x", "", d) == "x":
>> +        bb.note("libgcc can't be built with -O0, -O2 will be used instead.")
>> +        return selected_optimization.replace("-O0", "-O2")
>> +    return selected_optimization
>> +
>> +SELECTED_OPTIMIZATION := "${@get_optimization(d)}"
> Do we really need a Python function for this?  It seems like a rather
> heavyweight mechanism to detect what is basically just a distro
> misconfiguration.

The python function is copied from eglibc recipe which does similar
job to force build the package with optimization enabled.  I think
it's not just a distro misconfiguration.  Sometimes it would be
convenient for user to select a global -O0 optimization level (to
create a more debug-friendly rootfs) for most packages, while
automatically switching to -O2 for those which can't be built without
optimizations.

>
> How about just patching the appropriate bit of libgcc to include:
>
> #if __OPTIMIZE__ == 0
> #error libgcc can't be built with -O0, please fix your distro to use at least -O1
> #endif

I think it would be more helpful if we can switch to -O1 or -O2 in
such case, instead of throwing out an error.

Lei

>
> or some such?  Even this seems slightly dubious, since it will prevent
> you from building an unoptimised libgcc even if you have no intention of
> running valgrind with it, but at least this doesn't add extra overhead
> within bitbake.
>
> p.
>
>