[Bug bootstrap/62099] New: bootstrap build fails on ARM hard float system

[pab at pabigot dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62099

            Bug ID: 62099
           Summary: bootstrap build fails on ARM hard float system
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pab at pabigot dot com

gcc 4.9.1 bootstrap on an ARM hard-float system (TI AM3358 Cortex-A8 beaglebone
using Yocto: arm-poky-linux-gnueabi) fails with:

/home/pab/build/./gcc/xgcc -B/home/pab/build/./gcc/
-B/usr/local/gcc/armv7l-unknown-linux-gnueabihf/bin/
-B/usr/local/gcc/armv7l-unknown-linux-gnueabihf/lib/ -isystem
/usr/local/gcc/armv7l-unknown-linux-gnueabihf/include -isystem
/usr/local/gcc/armv7l-unknown-linux-gnueabihf/sys-include    -g -O2 -O2  -g -O2
-DIN_GCC    -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format
-Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem
./include   -fPIC -fno-inline -g -DIN_LIBGCC2 -fbuilding-libgcc
-fno-stack-protector   -fPIC -fno-inline -I. -I. -I../.././gcc
-I../../../gcc-4.9.1/libgcc -I../../../gcc-4.9.1/libgcc/.
-I../../../gcc-4.9.1/libgcc/../gcc -I../../../gcc-4.9.1/libgcc/../include 
-DHAVE_CC_TLS  -o _muldi3.o -MT _muldi3.o -MD -MP -MF _muldi3.dep -DL_muldi3 -c
../../../gcc-4.9.1/libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS
In file included from /usr/include/features.h:402:0,
                 from /usr/include/stdio.h:27,
                 from ../../../gcc-4.9.1/libgcc/../gcc/tsystem.h:87,
                 from ../../../gcc-4.9.1/libgcc/libgcc2.c:27:
/usr/include/gnu/stubs.h:7:29: fatal error: gnu/stubs-soft.h: No such file or
directory
 # include <gnu/stubs-soft.h>

Unlike the stage1 compiler, the host compiler always defines __ARM_PCS_VFP and
there is no gnu/stubs-soft.h available.

gcc-4.9.1 configured with only: --enable-languages=c,c++
--prefix=/usr/local/gcc

The gross workaround is to symlink stubs-soft.h -> stubs-hard.h and restart the
build.

https://gcc.gnu.org/ml/gcc-help/2013-02/msg00141.html suggests this has been
present since at least gcc 4.8.0.