GCC-GNAT Ada Cross-Compiler (Debian/glibc -> AlpineLinux/uclibc)

Question

I compiled a GCC 4.8.1 Cross-Compiler (BUILD/HOST: debian/glibc, TARGET: alpinelinux/uclibc). The C compiler is working great, but Ada won't work at moment.

juan@debian:~/HelloAda$ x86_64-alpine-linux-uclibc-gnatmake hello.adb 
x86_64-alpine-linux-uclibc-gcc -c hello.adb
x86_64-alpine-linux-uclibc-gnatbind -x hello.ali
x86_64-alpine-linux-uclibc-gnatlink hello.ali
/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a(adaint.o): In function `__gnat_cpu_alloc':
/home/juan/GCC/obj/gcc/ada/rts/adaint.c:3797: undefined reference to `__sched_cpualloc'
/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a(adaint.o): In function `__gnat_cpu_free':
/home/juan/GCC/obj/gcc/ada/rts/adaint.c:3807: undefined reference to `__sched_cpufree'
collect2: error: ld returned 1 exit status
x86_64-alpine-linux-uclibc-gnatlink: error when calling /home/juan/opt/cross/bin/x86_64-alpine-linux-uclibc-gcc
x86_64-alpine-linux-uclibc-gnatmake: *** link failed.

/home/juan/GCC/obj/gcc/ada/rts/adaint.c: http://nopaste.info/ffcb612692.html

/usr/include/sched.h: http://nopaste.info/5332aed42a.html
/usr/include/bits/sched.h: http://nopaste.info/46323ab5d8.html

/opt/alpine/usr/include/sched.h: http://nopaste.info/998896bafe.html
/opt/alpine/usr/include/bits/sched.h: http://nopaste.info/e8cfbd2844.html

Does someone know, what's going wrong?

A more verbose output of what is going on:

juan@debian:~/HelloAda$ x86_64-alpine-linux-uclibc-gcc -c hello.adb 
juan@debian:~/HelloAda$ x86_64-alpine-linux-uclibc-gnatbind hello
juan@debian:~/HelloAda$ x86_64-alpine-linux-uclibc-gnatlink -v -v hello

GNATLINK 4.8.1
Copyright (C) 1995-2013, Free Software Foundation, Inc.
x86_64-alpine-linux-uclibc-gcc -c -mtune=generic -march=x86-64 -gnatA -gnatWb -gnatiw -v -gnatws /home/juan/HelloAda/b~hello.adb
Using built-in specs.
COLLECT_GCC=/home/juan/opt/cross/bin/x86_64-alpine-linux-uclibc-gcc
Target: x86_64-alpine-linux-uclibc
Configured with: ../src/configure --prefix=/home/juan/opt/cross --build=x86_64-cross-linux-gnu --host=x86_64-cross-linux-gnu --target=x86_64-alpine-linux-uclibc --disable-altivec --disable-build-with-cxx --disable-checking --disable-fixed-point --disable-libssp --disable-libstdcxx-pch --disable-multilib --disable-nls --disable-werror --enable-languages=c,ada --enable-shared --with-dynamic-linker=ld64-uClibc.so.0.9.32 --with-dynamic-linker-prefix=/opt/alpine/lib --with-system-zlib --without-system-libunwindmake --with-sysroot=/opt/alpine
Thread model: posix
gcc version 4.8.1 (GCC) 
COLLECT_GCC_OPTIONS='-c' '-mtune=generic' '-march=x86-64' '-gnatA' '-gnatWb' '-gnatiw' '-v' '-gnatws'
 /home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/gnat1 -quiet -dumpbase b~hello.adb -auxbase b~hello -mtune=generic -march=x86-64 -gnatA -gnatWb -gnatiw -gnatws /home/juan/HelloAda/b~hello.adb -o /tmp/ccG4vv8d.s
COLLECT_GCC_OPTIONS='-c' '-mtune=generic' '-march=x86-64' '-gnatA' '-gnatWb' '-gnatiw' '-v' '-gnatws'
 /home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/bin/as -v --64 -o b~hello.o /tmp/ccG4vv8d.s
GNU assembler version 2.23.2 (x86_64-alpine-linux-uclibc) using BFD version (GNU Binutils) 2.23.2
COMPILER_PATH=/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/bin/
LIBRARY_PATH=/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib/../lib/:/opt/alpine/lib/../lib/:/opt/alpine/usr/lib/../lib/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib/:/opt/alpine/lib/:/opt/alpine/usr/lib/
COLLECT_GCC_OPTIONS='-c' '-mtune=generic' '-march=x86-64' '-gnatA' '-gnatWb' '-gnatiw' '-v' '-gnatws'
/home/juan/opt/cross/bin/x86_64-alpine-linux-uclibc-gcc b~hello.o ./hello.o -v -o hello -L./ -L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/ /home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a -static-libgcc
Using built-in specs.
COLLECT_GCC=/home/juan/opt/cross/bin/x86_64-alpine-linux-uclibc-gcc
COLLECT_LTO_WRAPPER=/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/lto-wrapper
Target: x86_64-alpine-linux-uclibc
Configured with: ../src/configure --prefix=/home/juan/opt/cross --build=x86_64-cross-linux-gnu --host=x86_64-cross-linux-gnu --target=x86_64-alpine-linux-uclibc --disable-altivec --disable-build-with-cxx --disable-checking --disable-fixed-point --disable-libssp --disable-libstdcxx-pch --disable-multilib --disable-nls --disable-werror --enable-languages=c,ada --enable-shared --with-dynamic-linker=ld64-uClibc.so.0.9.32 --with-dynamic-linker-prefix=/opt/alpine/lib --with-system-zlib --without-system-libunwindmake --with-sysroot=/opt/alpine
Thread model: posix
gcc version 4.8.1 (GCC) 
COMPILER_PATH=/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/bin/
LIBRARY_PATH=/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib/../lib/:/opt/alpine/lib/../lib/:/opt/alpine/usr/lib/../lib/:/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib/:/opt/alpine/lib/:/opt/alpine/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-o' 'hello' '-L./' '-L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/' '-static-libgcc' '-mtune=generic' '-march=x86-64'
 /home/juan/opt/cross/libexec/gcc/x86_64-alpine-linux-uclibc/4.8.1/collect2 --sysroot=/opt/alpine --eh-frame-hdr -m elf_x86_64 -dynamic-linker /opt/alpine/lib/ld64-uClibc.so.0.9.32 -o hello /opt/alpine/usr/lib/../lib/crt1.o /opt/alpine/usr/lib/../lib/crti.o /home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/crtbegin.o -L./ -L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/ -L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1 -L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib/../lib -L/opt/alpine/lib/../lib -L/opt/alpine/usr/lib/../lib -L/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/../../../../x86_64-alpine-linux-uclibc/lib -L/opt/alpine/lib -L/opt/alpine/usr/lib b~hello.o ./hello.o /home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a -lgcc -lgcc_eh -lc -lgcc -lgcc_eh /home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/crtend.o /opt/alpine/usr/lib/../lib/crtn.o
/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a(adaint.o): In function `__gnat_cpu_alloc':
/home/juan/GCC/obj/gcc/ada/rts/adaint.c:3797: undefined reference to `__sched_cpualloc'
/home/juan/opt/cross/lib/gcc/x86_64-alpine-linux-uclibc/4.8.1/adalib/libgnat.a(adaint.o): In function `__gnat_cpu_free':
/home/juan/GCC/obj/gcc/ada/rts/adaint.c:3807: undefined reference to `__sched_cpufree'
collect2: error: ld returned 1 exit status
x86_64-alpine-linux-uclibc-gnatlink: error when calling /home/juan/opt/cross/bin/x86_64-alpine-linux-uclibc-gcc

Answer 1

It's quite clear that __sched_cpualloc/free* functions are either specific to Glibc 2.7 or not implemented in uclibc.

$ objdump -T libc.so.6 | grep __sched
000c4c30 g    DF .text  00000043  GLIBC_2.0   __sched_getparam
000c4d10 g    DF .text  00000037  GLIBC_2.0   __sched_yield
000c5540 g    DF .text  00000029  GLIBC_2.7   __sched_cpualloc
000c4d50 g    DF .text  0000003f  GLIBC_2.0   __sched_get_priority_max
000c5570 g    DF .text  00000020  GLIBC_2.7   __sched_cpufree
000c4d90 g    DF .text  0000003f  GLIBC_2.0   __sched_get_priority_min
000c5500 g   iD  .text  0000003f  GLIBC_2.6   __sched_cpucount
000c4c80 g    DF .text  00000045  GLIBC_2.0   __sched_setscheduler
000c4cd0 g    DF .text  0000003f  GLIBC_2.0   __sched_getscheduler

I guess these required for the CPU concurrency tasks.

If you have access to uclibc source, perhaps it will be possible to define these functions and recompile the library by referencing Glibc here.. Or better yet, just make a small library with these two functions and link that when creating the binary ELF image.

__sched_cpualloc and __sched_cpufree aren't rocket science, as it turns out. Here is the code as it appears in Glibc:

9 #include <sched.h>
20 #include <stdlib.h>
21 
22 
23 cpu_set_t *
24 __sched_cpualloc (size_t count)
25 {
26   return malloc (CPU_ALLOC_SIZE (count));
27 }

and

23 void
24 __sched_cpufree (cpu_set_t *set)
25 {
26   free (set);
27 }

finally, CPU_ALLOC_SIZE is also simple:

165 # define __CPU_ALLOC_SIZE(count) \
166   ((((count) + __NCPUBITS - 1) / __NCPUBITS) * 8)

So I guess you can write your own wrappers for uclibc now and test to see if it works.