Thread: configure sets GCC=yes for clang

configure sets GCC=yes for clang

From
Tomas Vondra
Date:
Hi,

I've been doing some experiments with compilers, and I've noticed that 
when using clang configure still ends up setting

GCC='yes'

which seems somewhat strange. FWIW I've noticed because when building 
with "-Ofast" (yeah, I'm just playing with stuff) it fails like this:

checking whether the C compiler still works... yes
configure: error: do not put -ffast-math in CFLAGS

which is in $GCC=yes check, and clang doesn't even have such option.

Not a huge issue, but I wonder if this might confuse configure in other 
places, or something.


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



Re: configure sets GCC=yes for clang

From
Tom Lane
Date:
Tomas Vondra <tomas.vondra@enterprisedb.com> writes:
> I've been doing some experiments with compilers, and I've noticed that 
> when using clang configure still ends up setting
> GCC='yes'
> which seems somewhat strange.

I'm pretty sure that's intentional.  clang tries to be a gcc-alike,
and mostly succeeds, other than variations in command line options.
It's better to set GCC=yes and deal with the small discrepancies
than not set it and have to deal with clang as a whole separate case.

> FWIW I've noticed because when building 
> with "-Ofast" (yeah, I'm just playing with stuff) it fails like this:

> checking whether the C compiler still works... yes
> configure: error: do not put -ffast-math in CFLAGS

> which is in $GCC=yes check, and clang doesn't even have such option.

Well, the error is correct, even if clang doesn't spell the switch the
same way: you enabled fast-math optimizations and we don't want that.

[ wanders away wondering how meson handles this stuff ... ]

            regards, tom lane