shared musl with PCC as system compiler

shared musl with PCC as system compiler

[Isaac Dunham]

This is mainly a mix of what I've worked out previously and what Rich and I worked out on IRC. I figured posting it on the list would help those who want to use pcc as compiler...
0. Get today's (Oct 13) git HEAD or later! Otherwise libc.so will be broken.
Get a fairly recent pcc from CVS (the last month should be good enough)
When compiling pcc-libs, use 
make CFLAGS="-fPIC ${OPTFLAGS}"
(otherwise you get textrels in libc.so, which doesn't work)
1. Set LIBCC to -L$(dirname `pcc -print-file-name=libpcc.a`) -lpcc 
#-lpccsoftfloat may be needed for some systems
2. Add 
CFLAGS_ALL_SHARED += -D__PIC__=1
to config.mak (pcc doesn't define this with -fPIC at present, which is a bug)
3. Find the right -m* options:
ld -march=native 
#look for the elf_* in the "Supported emulations" that matches your CPU
Change all occurences of -m* in config.mak to "-melf_<arch>"
(pcc doesn't parse -m*, which is at best an incompatible behavior)
4. Now you should be set to compile.

-- 
Isaac Dunham <idunham@lavabit.com>

Re: shared musl with PCC as system compiler

[Luca Barbato]

On 10/14/2012 09:15 AM, Isaac Dunham wrote:
> This is mainly a mix of what I've worked out previously and what Rich and I worked
> out on IRC. I figured posting it on the list would help those who want to use pcc
> as compiler...
> 0. Get today's (Oct 13) git HEAD or later! Otherwise libc.so will be broken.
> Get a fairly recent pcc from CVS (the last month should be good enough)
> When compiling pcc-libs, use 
> make CFLAGS="-fPIC ${OPTFLAGS}"
> (otherwise you get textrels in libc.so, which doesn't work)
> 1. Set LIBCC to -L$(dirname `pcc -print-file-name=libpcc.a`) -lpcc 
> #-lpccsoftfloat may be needed for some systems
> 2. Add 
> CFLAGS_ALL_SHARED += -D__PIC__=1
> to config.mak (pcc doesn't define this with -fPIC at present, which is a bug)
> 3. Find the right -m* options:
> ld -march=native 
> #look for the elf_* in the "Supported emulations" that matches your CPU
> Change all occurences of -m* in config.mak to "-melf_<arch>"
> (pcc doesn't parse -m*, which is at best an incompatible behavior)
> 4. Now you should be set to compile.

Do you have/know of a git mirror for pcc?

lu

Re: shared musl with PCC as system compiler

[Rich Felker]

On Sun, Oct 14, 2012 at 12:15:34AM -0700, Isaac Dunham wrote:
> This is mainly a mix of what I've worked out previously and what Rich and I worked out on IRC. I figured posting it on the list would help those who want to use pcc as compiler...
> 0. Get today's (Oct 13) git HEAD or later! Otherwise libc.so will be broken.
> Get a fairly recent pcc from CVS (the last month should be good enough)
> When compiling pcc-libs, use 
> make CFLAGS="-fPIC ${OPTFLAGS}"
> (otherwise you get textrels in libc.so, which doesn't work)
> 1. Set LIBCC to -L$(dirname `pcc -print-file-name=libpcc.a`) -lpcc 
> #-lpccsoftfloat may be needed for some systems

I think just $(pcc -print-file-name=libpcc.a) would work.

> 3. Find the right -m* options:
> ld -march=native 
> #look for the elf_* in the "Supported emulations" that matches your CPU
> Change all occurences of -m* in config.mak to "-melf_<arch>"
> (pcc doesn't parse -m*, which is at best an incompatible behavior)

Step 3 is entirely unnecessary. No -m options are needed. The problem
is that pcc wrongly passes-thru -march as an option to the linker.
Just remove -march and -mtune from the CFLAGS and the problem goes
away.

Rich

Re: shared musl with PCC as system compiler

[Isaac Dunham]

On Sun, 14 Oct 2012 15:38:36 +0200
Luca Barbato <lu_zero@gentoo.org> wrote:

> On 10/14/2012 09:15 AM, Isaac Dunham wrote:
> > This is mainly a mix of what I've worked out previously and what Rich and I worked
> > out on IRC. I figured posting it on the list would help those who want to use pcc
> > as compiler...
> > 0. Get today's (Oct 13) git HEAD or later! Otherwise libc.so will be broken.
> > Get a fairly recent pcc from CVS (the last month should be good enough)
> > When compiling pcc-libs, use 
> > make CFLAGS="-fPIC ${OPTFLAGS}"
> > (otherwise you get textrels in libc.so, which doesn't work)
> > 1. Set LIBCC to -L$(dirname `pcc -print-file-name=libpcc.a`) -lpcc 
Or $(${CC} -print-file-name=libpcc.a), as Rich mentioned.
> > 2. Add 
> > CFLAGS_ALL_SHARED += -D__PIC__=1
> > to config.mak (pcc doesn't define this with -fPIC at present, which is a bug)
No longer necessary, with today's CVS (DATESTAMP=20121014).
(Additionally, array arguments passed to inline asm _should_ properly decay to pointers now).

> Do you have/know of a git mirror for pcc?
Not until a few minutes ago. ;)
See
git://github.com/idunham/pcc
and
git://github.com/idunham/pcc-libs
(they are not recommended for use unless you need to use git, as I may not keep them current all the time!)
-- 
Isaac Dunham <idunham@lavabit.com>