Shorter version: -m elf32ppc_fbsd (and elf_i386_fbsd ?) vs. -Wl, -m, elf32ppc_fbsd problems (11.0-CURRENT and 10.1-STABLE)

[Mark Millard]

On 2015-Apr-9, at 07:35 PM, Warner Losh <imp at bsdimp.com> wrote:

> 
>> On Apr 9, 2015, at 7:56 PM, Mark Millard <markmi at dsl-only.net> wrote:
>> 
>> From share/mk/bsd.README :
>> 
>> LDFLAGS         Additional loader flags. Passed to the loader via CC,
>>               since that's used to link programs as well, so loader
>>               specific flags need to be prefixed with -Wl, to work.
>> 
>> But the following 3 powerpc (non-64) examples do not use the -Wl, notation:
>> 
>>> LDFLAGS+=       -m elf32ppc_fbsd
>>> /usr/src/sys/boot/ofw/Makefile.inc
>> 
>> 
>>> LDFLAGS+=       -m elf32ppc_fbsd
>>> /usr/src/sys/boot/uboot/Makefile.inc
>> 
>> 
>>> LDFLAGS+=       -m elf32ppc_fbsd
>>> /usr/src/sys/boot/powerpc/Makefile.inc
>> 
>> In fact I get errors such as (for that last one when using powerpc64-gcc via powerpc64-xtoolchain-gcc, executed on a powerpc64):
>> 
>>> powerpc64-portbld-freebsd11.0-gcc: error: elf32ppc_fbsd: No such file or directory
>>> powerpc64-portbld-freebsd11.0-gcc: error: elf32ppc_fbsd: No such file or directory
>>> powerpc64-portbld-freebsd11.0-gcc: error: unrecognized command line option '-m'
>>> powerpc64-portbld-freebsd11.0-gcc: error: unrecognized command line option '-m'
>>> 
>>> *** [boot1.elf] Error code 1
>>> 
>>> make[6]: stopped in /usr/srcC/sys/boot/powerpc/boot1.chrp
>>> 1 error
>> 
>> I do not know if the space between -m and elf... creates a problem for -Wl, use or not. I would guess that
>> 
>> -Wl,-m,elf32pcc_fbsd
>> 
>> is the proper notation for putting the space through to the ld variant used. But I’m not to the point of testing the behavior of that yet.
>> 
>> 
>> 
>> i386 seems to have a similar example, although I’m not using such a FreeBSD environment.
>> 
>>> LD_FLAGS+=      -m elf_i386_fbsd
>>> /usr/src/sys/boot/i386/Makefile.inc
>> 
>> 
>> 
>> (This note is shorter in part because figured out more context than I had last time.)
> 
> I think much of this is historical accident where the boot Makefiles used to call ld directly, then were converted to call gcc, and gcc allowed the -m notation like this as a historical compatibility.
> 
> Do thinks still work if you use -Wl, notation?
> 
> Warner
> 

I have a powerpc64-xtoolchain-gcc build going now but that will take a while. I’ll also need to try a normal one from a gcc 4.2.1 environment and I’ve not started that yet. And I’m only set up to test powerpc64 and powerpc. The tier 1 consequences (i386 and amd64) are outside my environment.

Also I sent out another note after discovering a potential problem...

> I now see one place where "-Wl,-m,elf32ppc_fbsd" type of notation in LDFLAGS would not be handled if it ended up involved:
> 
> share/mk/sys.mk:_LDFLAGS        =       ${LDFLAGS:S/-Wl,//g}    # strip -Wl, for LD
> 
> This notation does not deal with turning the extra comma back into a space.


===
Mark Millard
markmi at dsl-only.net