configuring in-tree gmp/mpfr with "none"?

configuring in-tree gmp/mpfr with "none"?

[Jay]

When gcc configures the in-tree gmp/mpfr, why
does it use --host=none-${host_vendor}-${host_os} --target=none-${host_vendor}-${host_os} 

instead of  --host=${host_alias} --target=${target_alias}

This "breaks" config.cache if used across directories, because the platforms change.

I'm trying like:
  mkdir /obj  
  cd /obj  
  /src/gcc/configure -cache-file=`pwd`/config.cache  
  # must delete the initial one as well, else another problem 
  rem config.cache  
  make  

With the 4.3.1 release.

Thanks,
 - Jay

Re: configuring in-tree gmp/mpfr with "none"?

[Andrew Pinski]

On Sun, Jun 15, 2008 at 12:49 PM, Jay <jayk123@hotmail.com> wrote:
>
> When gcc configures the in-tree gmp/mpfr, why
> does it use --host=none-${host_vendor}-${host_os} --target=none-${host_vendor}-${host_os}
>
> instead of  --host=${host_alias} --target=${target_alias}
>
> This "breaks" config.cache if used across directories, because the platforms change.

The reason why it is configured with none is so that it can be
transfered to more computers than your own.

-- Pinski

RE: configuring in-tree gmp/mpfr with "none"?

[Jay]

[again as plain text]

Ah, I didn't realize any C or C++ code could be configured for other than a specific processor but I guess that makes sense -- it is Makefile, config.h, and such that are being modified, not the .o files, and they might be the same across many configurations, like if the compiler command lines and #defines can be the same, like if there is no need to know the size of a pointer or the endianness, etc.. I guess more code should work this way if possible. Thanks Andrew.
(Obviously a lot of source code is independent of pointer size, endianness, but I haven't seen such configure processor=none use.).

 - Jay

> Date: Tue, 17 Jun 2008 13:39:42 -0400
> From: pinskia@gmail.com
> To: jayk123@hotmail.com
> Subject: Re: configuring in-tree gmp/mpfr with "none"?
> CC: gcc@gcc.gnu.org
>
> On Sun, Jun 15, 2008 at 12:49 PM, Jay  wrote:
>>
>> When gcc configures the in-tree gmp/mpfr, why
>> does it use --host=none-${host_vendor}-${host_os} --target=none-${host_vendor}-${host_os}
>>
>> instead of --host=${host_alias} --target=${target_alias}
>>
>> This "breaks" config.cache if used across directories, because the platforms change.
>
> The reason why it is configured with none is so that it can be
> transfered to more computers than your own.
>
> -- Pinski

Re: configuring in-tree gmp/mpfr with "none"?

[Andrew Pinski]

On Wed, Jun 18, 2008 at 12:40 AM, Jay <jayk123@hotmail.com> wrote:
> Ah, I didn't realize any C or C++ code could be configured for other than a
> specific processor but I guess that makes sense -- it is Makefile, config.h,
> and such that are being modified, not the .o files, and they might be the
> same across many configurations, like if the compiler command lines and
> #defines can be the same, like if there is no need to know the size of a
> pointer or the endianness, etc.. I guess more code should work this way if
> possible. Thanks Andrew.

Well gmp/mpfr are special in that they try to do the same thing as
-mcpu=native with their configure script and they have some assembly
files.

Thanks,
Andrew Pinski

RE: configuring in-tree gmp/mpfr with "none"?

[Jay]

Andrew, Can you explain more why?

Why I'm asking again now:

I have found another "problem" because of this (besides the
 reduced ability to share config.cache files).

This exacerbates what looks like a minor bug in gmp's configure.

Sometimes, depending on build/host/target, gmp's configure
sets M4=m4-not-needed.

Setting the processor to "none" is a good way to get it down the "not needed" path.
Though there might be other ways there, granted.

And then gmp/configure runs flex.
And then sometimes?always flex tries to run getenv("M4") || "m4".

Flex fails, sometimes creating lex.yy.c, sometimes not.
I haven't tracked down this "sometimes".
When I run build under Python, no lex.yy.c, outside of Python, ok.
I still have to dig in further to find out why.
When lex.yy.c is not created, configure fails. It is looking for what file is the output.

gmp/configure probably should not be setting M4, at least not when it runs flex.

But gcc using processor=none doesn't help.

I'll follow up with gmp folks.

Thanks,
 - Jay


> Date: Wed, 18 Jun 2008 06:53:35 -0400
> From: pinskia@gmail.com
> To: jayk123@hotmail.com
> Subject: Re: configuring in-tree gmp/mpfr with "none"?
> CC: gcc@gcc.gnu.org
>
> On Wed, Jun 18, 2008 at 12:40 AM, Jay  wrote:
>> Ah, I didn't realize any C or C++ code could be configured for other than a
>> specific processor but I guess that makes sense -- it is Makefile, config.h,
>> and such that are being modified, not the .o files, and they might be the
>> same across many configurations, like if the compiler command lines and
>> #defines can be the same, like if there is no need to know the size of a
>> pointer or the endianness, etc.. I guess more code should work this way if
>> possible. Thanks Andrew.
>
> Well gmp/mpfr are special in that they try to do the same thing as
> -mcpu=native with their configure script and they have some assembly
> files.
>
> Thanks,
> Andrew Pinski

Re: configuring in-tree gmp/mpfr with "none"?

[Paolo Bonzini]

Jay wrote:
> Andrew, Can you explain more why?

Because at some point, no released version worked on intel macs.

> And then gmp/configure runs flex.
> And then sometimes?always flex tries to run getenv("M4") || "m4".

Yes, Flex uses m4.

> gmp/configure probably should not be setting M4

Yes, I think that setting M4=m4-not-needed should be done only for 
debugging purposes.  Otherwise, GMP should always look for m4 in its 
configure script, and set it to a valid value in the makefile.

Paolo

RE: configuring in-tree gmp/mpfr with "none"?

[Jay]

> Because at some point, no released version worked on intel macs.

Long since passed and can be removed?
Or only do it on those machines??
  Granted, the Python-wrapping-build I'm doing ought to work as well on Intel Macs as anywhere else.

Here is what ends up happening:

 #include  
 #include  

 int main() 
 { 
    signal(SIGPIPE, SIG_IGN);   << Python does like this 
    putenv("M4=foo");    << gmp/configure does like this  
    system("flex 1.l");    <<  gmp/configure does like this  
    return 0; 
 }

Without ignoring sigpipe, flex dies in filter_tee_header reading the output of a failed exec.
Ignoring the signal under a Python wrapper however, it continues on
and deletes the output, causing gmp/configure to fail because it is looking
for the output.

gmp/configure is where the blame really lies, but if gcc configured gmp "normally",
this wouldn't occur. Or, is cpu=none not so abnormal? Just that I hadn't seen it?
(Everything new and normal is initially new and abnormal, of course.)

 - Jay

> Date: Thu, 31 Jul 2008 15:53:43 +0200
> From: bonzini@gnu.org
> To: jayk123@hotmail.com
> CC: pinskia@gmail.com; gcc@gcc.gnu.org
> Subject: Re: configuring in-tree gmp/mpfr with "none"?
>
> Jay wrote:
>> Andrew, Can you explain more why?
>
> Because at some point, no released version worked on intel macs.
>
>> And then gmp/configure runs flex.
>> And then sometimes?always flex tries to run getenv("M4") || "m4".
>
> Yes, Flex uses m4.
>
>> gmp/configure probably should not be setting M4
>
> Yes, I think that setting M4=m4-not-needed should be done only for
> debugging purposes. Otherwise, GMP should always look for m4 in its
> configure script, and set it to a valid value in the makefile.
>
> Paolo

Re: configuring in-tree gmp/mpfr with "none"?

[Paolo Bonzini]

Jay wrote:
>> Because at some point, no released version worked on intel macs.
> 
> Long since passed and can be removed?

I don't think so, http://gmp.darwinports.com/ shows that it is still a 
problem with 4.2.2.  Besides, GMP's authors say that it is often a 
stress test for compilers, so using more C and less assembly can be a 
good thing (GCC's usage of GMP does not include manipulating really 
really huge numbers).

> gmp/configure is where the blame really lies, but if gcc configured gmp "normally",
> this wouldn't occur. Or, is cpu=none not so abnormal? Just that I hadn't seen it?

It's a GMP-only thing.

Given that this is a problem because of Python's apparently broken 
handling of signals, we cannot do anything about it.  Complain with the 
Python maintainers that they should reset the signals they ignore, 
before exec-ing another program.

Paolo

Re: configuring in-tree gmp/mpfr with "none"?

[Vincent Lefevre]

On 2008-08-04 13:05:09 +0200, Paolo Bonzini wrote:
> I don't think so, http://gmp.darwinports.com/ shows that it is still a  
> problem with 4.2.2.

This is a commercial and out-of-date web site. You should look at
MacPorts instead:

  http://trac.macports.org/browser/trunk/dports/devel/gmp/Portfile

But the --host=none-apple-darwin was initially added on 2004-12-03
(revision 9565), and I don't know if removing it has been tested.

-- 
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/>
Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)