https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107728
Bug ID: 107728
Summary: with -O0, libgcc in the first stage compiler has
reference to libc functions
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: bootstrap
Assignee: unassigned at gcc dot gnu.org
Reporter: thomas.petazz...@free-electrons.com
Target Milestone: ---
We've started doing builds with -O0 in Buildroot, and we get build failures in
glibc that look like this:
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `__register_frame':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:138:
undefined reference to `malloc'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `__register_frame_table':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:186:
undefined reference to `malloc'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `__deregister_frame_info_bases':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:246:
undefined reference to `free'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `__deregister_frame':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:260:
undefined reference to `free'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `start_fde_sort':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:449:
undefined reference to `malloc'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:449:
undefined reference to `malloc'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `end_fde_sort':
/home/autobuild/autobuild/instance-11/output-1/build/host-gcc-initial-11.3.0/build/sh4eb-buildroot-linux-gnu/libgcc/../../../libgcc/unwind-dw2-fde.c:629:
undefined reference to `free'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/librtld.os:
in function `abort':
(.text+0x2345c): undefined reference to `__pthread_mutex_lock'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
(.text+0x23464): undefined reference to `__pthread_mutex_unlock'
/home/autobuild/autobuild/instance-11/output-1/host/lib/gcc/sh4eb-buildroot-linux-gnu/11.3.0/../../../../sh4eb-buildroot-linux-gnu/bin/ld:
(.text+0x2346c): undefined reference to `__pthread_mutex_lock'
collect2: error: ld returned 1 exit status
make[3]: *** [Makefile:1339:
/home/autobuild/autobuild/instance-11/output-1/build/glibc-2.36-66-ga1dc0be03c9dd850b864bd7a9c03cf8e396eb7ca/build/elf/ld.so]
Error 1
See
http://autobuild.buildroot.net/results/7df/7df2d0648dd666dd07845614b34f59d6afba96c1/build-end.log
for a more complete build log.
The reason is that a number of functions in libgcc/unwind-dw2-fde.c call into C
library functions. With an optimization level of -O1 at least, these functions
get compiled out, and there is no problem. But at -O0, the code of those
functions is kept, causing the above build failure.
To reproduce:
$ git clone https://gitlab.com/buildroot.org/buildroot.git
$ cd buildroot
$ cat > .config <<EOF
BR2_sh=y
BR2_sh4eb=y
BR2_KERNEL_HEADERS_4_14=y
BR2_GCC_VERSION_12_X=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
# BR2_STRIP_strip is not set
BR2_OPTIMIZE_0=y
EOF
$ make olddefconfig
$ make
(and wait)
