Re: arm-eabi fails in libc/sys/arm/: No rule to make target 'lib_a-trap.o', needed by 'lib.a'.

[Richard Earnshaw <Richard.Earnshaw@foss.arm.com>]

On 01/02/2022 04:49, Mike Frysinger wrote:
> On 31 Jan 2022 16:08, Richard Earnshaw wrote:
>> This patch seems to have broken arm newlib builds (at least, when not
>> using libgloss).  I'm seeing:
>>
>> make[5]: Entering directory
>> '/work/rearnsha/scratch/nightly/arm/master/arm-eabi/
>> newlib/libc/sys/arm'
>>     CC       lib_a-access.o
>>     CC       lib_a-aeabi_atexit.o
>> make[5]: *** No rule to make target 'lib_a-trap.o', needed by 'lib.a'. Stop.
>>
>> And indeed, the Makefile in that directory now lacks anything to build
>> lib_a-trap.o from trap.S.  Something explicit is needed because of the
>> non-standard file rename that we use.
> 
> this patch series is unrelated.  this is due to a previous patch of mine:
> newlib: delete (most) redundant lib_a_CCASFLAGS=$(AM_CCASFLAGS)
> 

Ah, sorry, I was struggling to identify the exact patch and thought I'd 
found the right one.


> this is because i think newlib was relying on automake behavior that is
> undocumented or unintended.  that said, i'm not sure why this Makefile.am
> is written the way it is.  it'd be a lot simpler like:
> 
> --- a/newlib/libc/sys/arm/Makefile.am
> +++ b/newlib/libc/sys/arm/Makefile.am
> @@ -6,16 +6,10 @@ AM_CCASFLAGS = $(AM_CPPFLAGS)
>   
>   noinst_LIBRARIES = lib.a
>   
> +lib_a_SOURCES = access.c aeabi_atexit.c
>   if MAY_SUPPLY_SYSCALLS
> -extra_objs = $(lpfx)libcfunc.o $(lpfx)trap.o $(lpfx)syscalls.o
> -else
> -extra_objs =
> +lib_a_SOURCES += libcfunc.c trap.S syscalls.c
>   endif
> -
> -lib_a_SOURCES = access.c aeabi_atexit.c
> -lib_a_LIBADD = $(extra_objs)
> -EXTRA_lib_a_SOURCES = trap.S syscalls.c libcfunc.c
> -lib_a_DEPENDENCIES = $(extra_objs)
>   lib_a_CFLAGS = $(AM_CFLAGS)
>   
>   if MAY_SUPPLY_SYSCALLS

This seems to work although one small difference is that instead of 
building libc_a-trap.o it now builds trap.o.  I'm not sure if that 
really matters, though.

R.

> 
> maybe Jeff can remember why it was written this way since it comes from:
> 
> commit 313f13497935d2831e76f9b8b61ccc762dc1cc65
> Author: Jeff Johnston <jjohnstn@redhat.com>
> Date:   Sat Feb 8 04:30:58 2003 +0000
> 
>      2003-02-07  Jeff Johnston  <jjohnstn@redhat.com>
> 
>              * acinclude.m4 (--disable-newlib-supplied-syscalls): New configuration
>              option to allow disabling of syscalls being supplied in newlib.
>              * aclocal.m4: Regenerated.
>              * configure: Ditto.
>              * configure.host: Add support of new configuration option and add
>              -D__NO_SYSCALLS__ if newlib supplied syscalls are disabled.
>              * doc/aclocal.m4: Regenerated.
>              * doc/configure: Ditto.
>              * libc/*aclocal.m4: Ditto.
>              * libc/*configure: Ditto.
>              * libm/*aclocal.m4: Ditto.
>              * libm/*configure: Ditto.
>              * libc/sys/arm/Makefile.am: Don't build syscalls.o if new option
>              is disabled.
> -mike