GNU Arm Embedded Toolchain

ICE in constexpr ctor using iterators

Bug #1798655 reported by Doug Brunner on 2018-10-18

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	GNU Arm Embedded Toolchain	Won't Fix	Undecided	Przemyslaw Wirkus

Bug Description

Attempting to compile the attached file produces an internal compiler error in cxx_eval_constant_expression, cp/constexpr.c:4633.

This occurs on Windows 10 64 bit with 7-2018Q2, Ubuntu under WSL with 7-2018Q2, and in a Docker container with 7-2017Q4. It does not occur compiling natively with Ubuntu under WSL with gcc 7.3.0 (and produces the expected output when the resulting binary is run), so reporting here rather than upstream. All tests were performed with the prepackaged binary toolchain.

Full output from Ubuntu/WSL/7-2018Q2 test is below.
***SNIP***
xxxx@yyyy:/foo/bar$ arm-none-eabi-g++ -v -save-temps -o evil evil.cpp -std=c++17 -g3 -Wall -Wextra
Using built-in specs.
COLLECT_GCC=arm-none-eabi-g++
COLLECT_LTO_WRAPPER=/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/lto-wrapper
Target: arm-none-eabi
Configured with: /tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/src/gcc/configure --target=arm-none-eabi --prefix=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native --libexecdir=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/lib --infodir=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/share/doc/gcc-arm-none-eabi/info --mandir=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/share/doc/gcc-arm-none-eabi/man --htmldir=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/share/doc/gcc-arm-none-eabi/html --pdfdir=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/share/doc/gcc-arm-none-eabi/pdf --enable-languages=c,c++ --enable-plugins --disable-decimal-float --disable-libffi --disable-libgomp --disable-libmudflap --disable-libquadmath --disable-libssp --disable-libstdcxx-pch --disable-nls --disable-shared --disable-threads --disable-tls --with-gnu-as --with-gnu-ld --with-newlib --with-headers=yes --with-python-dir=share/gcc-arm-none-eabi --with-sysroot=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/install-native/arm-none-eabi --build=x86_64-linux-gnu --host=x86_64-linux-gnu --with-gmp=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/build-native/host-libs/usr --with-mpfr=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/build-native/host-libs/usr --with-mpc=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/build-native/host-libs/usr --with-isl=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/build-native/host-libs/usr --with-libelf=/tmp/jenkins/jenkins-GCC-7-build_toolchain_docker-775_20180622_1529687456/build-native/host-libs/usr --with-host-libstdcxx='-static-libgcc -Wl,-Bstatic,-lstdc++,-Bdynamic -lm' --with-pkgversion='GNU Tools for Arm Embedded Processors 7-2018-q2-update' --with-multilib-list=rmprofile
Thread model: single
gcc version 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907] (GNU Tools for Arm Embedded Processors 7-2018-q2-update)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra'
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/cc1plus -E -quiet -v -iprefix /home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/ -isysroot /home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../arm-none-eabi -dD -D__USES_INITFINI__ evil.cpp -std=c++1z -Wall -Wextra -g3 -fworking-directory -fpch-preprocess -o evil.ii
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1"
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1/arm-none-eabi"
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1/backward"
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/include"
ignoring nonexistent directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../arm-none-eabi/usr/local/include"
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/include-fixed"
ignoring duplicate directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/../../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include"
ignoring nonexistent directory "/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../arm-none-eabi/usr/include"
#include "..." search starts here:
#include <...> search starts here:
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1/arm-none-eabi
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include/c++/7.3.1/backward
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/include
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/include-fixed
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra'
/home/xxxx/gcc-arm-none-eabi-7-2018-q2-update/bin/../lib/gcc/arm-none-eabi/7.3.1/cc1plus -fpreprocessed evil.ii -quiet -dumpbase evil.cpp -auxbase evil -g3 -Wall -Wextra -std=c++1z -version -o evil.s
GNU C++14 (GNU Tools for Arm Embedded Processors 7-2018-q2-update) version 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907] (arm-none-eabi)
compiled by GNU C version 4.8.4, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.15-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++14 (GNU Tools for Arm Embedded Processors 7-2018-q2-update) version 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907] (arm-none-eabi)
compiled by GNU C version 4.8.4, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.15-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 62353cd5102bba936abfe473d9a75a86
evil.cpp:84:65: in constexpr expansion of 'Uuid(((const char*)"aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))'
evil.cpp:84:65: internal compiler error: in cxx_eval_constant_expression, at cp/constexpr.c:4633
static constexpr Uuid foo("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee");
^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.
***SNIP***

Now the same with native build:
***SNIP***
xxxx@yyyy:/foo/bar$ g++ -v -o evil evil.cpp -std=c++17 -g3 -Wall -Wextra && ./evil
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.3.0-27ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.3.0 (Ubuntu 7.3.0-27ubuntu1~18.04)
COLLECT_GCC_OPTIONS='-v' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/7/cc1plus -quiet -v -imultiarch x86_64-linux-gnu -dD -D_GNU_SOURCE evil.cpp -quiet -dumpbase evil.cpp -mtune=generic -march=x86-64 -auxbase evil -g3 -Wall -Wextra -std=c++1z -version -fstack-protector-strong -Wformat-security -o /tmp/cchAoLgS.s
GNU C++14 (Ubuntu 7.3.0-27ubuntu1~18.04) version 7.3.0 (x86_64-linux-gnu)
compiled by GNU C version 7.3.0, GMP version 6.1.2, MPFR version 4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/7"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/7/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/include/c++/7
/usr/include/x86_64-linux-gnu/c++/7
/usr/include/c++/7/backward
/usr/lib/gcc/x86_64-linux-gnu/7/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/7/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
GNU C++14 (Ubuntu 7.3.0-27ubuntu1~18.04) version 7.3.0 (x86_64-linux-gnu)
compiled by GNU C version 7.3.0, GMP version 6.1.2, MPFR version 4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 1bfae38ae5df64de6196cbd8c3b07d86
COLLECT_GCC_OPTIONS='-v' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
as -v --64 -o /tmp/ccpLQtvv.o /tmp/cchAoLgS.s
GNU assembler version 2.30 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.30
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/7/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/7/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper -plugin-opt=-fresolution=/tmp/ccU5XjT8.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -z now -z relro -o evil /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/7/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/7 -L/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/7/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/7/../../.. /tmp/ccpLQtvv.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/7/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/crtn.o
COLLECT_GCC_OPTIONS='-v' '-o' 'evil' '-std=c++1z' '-g3' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
ee ee ee ee ee ee dd dd cc cc bb bb aa aa aa aa
xxxx@yyyy:/foo/bar$
***SNIP***

Tags:

Revision history for this message

Doug Brunner (madengineer10) wrote on 2018-10-18:

Preprocessed source Edit (819.4 KiB, text/plain)

Revision history for this message

Doug Brunner (madengineer10) wrote on 2018-10-18:

I just discovered that replacing the first "return" inside the while loop with "break" prevents the bug from being triggered.

Revision history for this message

Doug Brunner (madengineer10) wrote on 2018-10-18:

Also, bug still occurs when the function is rewritten to use indices instead of iterators. Appears the control flow statements are the issue.

Przemyslaw Wirkus (wirkus) on 2020-02-26

tags:

added: ice

Przemyslaw Wirkus (wirkus) on 2020-02-26

Changed in gcc-arm-embedded:
assignee:	nobody → Przemyslaw Wirkus (wirkus)

Przemyslaw Wirkus (wirkus) on 2020-03-02

tags:

added: 2018q2

Revision history for this message

Przemyslaw Wirkus (wirkus) wrote on 2020-03-02:

Download full text (5.7 KiB)

Hi,
I can't reproduce with latest toolchain release:

$ wine $WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/arm-none-eabi-g++.exe evil.ii -std=c++17 -g3 -Wall -Wextra

Hi,
I can't reproduce with latest toolchain release:

$ wine $WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/arm-none-eabi-g++.exe evil.ii -std=c++17 -g3 -Wall -Wextra

z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libstdc++.a(cxx11-ios_failure.o): in function `(anonymous namespace)::__io_category_instance()':
cxx11-ios_failure.cc:(.text._ZN12_GLOBAL__N_122__io_category_instanceEv+0xc): undefined reference to `__sync_synchronize'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-exit.o): in function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libstdc++.a(locale.o): in function `std::locale::_Impl::_M_install_cache(std::locale::facet const*, unsigned int)':
locale.cc:(.text._ZNSt6locale5_Impl16_M_install_cacheEPKNS_5facetEj+0x18): undefined reference to `__sync_synchronize'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libstdc++.a(locale_init.o): in function `(anonymous namespace)::get_locale_mutex()':
locale_init.cc:(.text._ZN12_GLOBAL__N_116get_locale_mutexEv+0xc): undefined reference to `__sync_synchronize'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-abort.o): in function `abort':
abort.c:(.text.abort+0x10): undefined reference to `_exit'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-fstatr.o): in function `_fstat_r':
fstatr.c:(.text._fstat_r+0x20): undefined reference to `_fstat'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-openr.o): in function `_open_r':
openr.c:(.text._open_r+0x28): undefined reference to `_open'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-sbrkr.o): in function `_sbrk_r':
sbrkr.c:(.text._sbrk_r+0x18): undefined reference to `_sbrk'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-signalr.o): in function `_kill_r':
signalr.c:(.text._kill_r+0x20): undefined reference to `_kill'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-signalr.o): in function `_getpid_r':
signalr.c:(.text._getpid_r+0x4): undefined reference to `_getpid'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-writer.o): in function `_write_r':
writer.c:(.text._write_r+0x28): undefined reference to `_write'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-closer.o): in function `_close_r':
closer.c:(.text._close_r+0x18): undefined reference to `_close'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-isattyr.o): in function `_isatty_r':
isattyr.c:(.text._isatty_r+0x18): undefined reference to `_isatty'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-lseekr.o): in function `_lseek_r':
lseekr.c:(.text._lseek_r+0x28): undefined reference to `_lseek'
z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: z:$WORK/gcc-arm-none-eabi-9-2019-q4-major-win32/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib\libg.a(lib_a-readr.o): in function `_read_r':
readr.c:(.text._read_r+0x28): undefined reference to `_read'
collect2.exe: error: ld returned 1 exit status

If this is still relevant please let me know if error still occurs on your side with your setup.