It's a follow-up to the breakage caused by 21966e13d2
("gcc: pass --with-build-sysroot=/"). It caused `pkgsLLVM`
cross-toolchain bootstrap breakage:
$ nix build --no-link -f. pkgsLLVM.hello
...
failed: /nix/store/...-x86_64-unknown-linux-gnu-stage-static-gcc-13.0.0.drv:
...
configure flags: ... --enable-languages=c --disable-multilib \
--disable-shared --enable-plugin ... --disable-libssp --disable-nls \
--without-headers --disable-threads --disable-libgomp --disable-libquadmath \
--disable-shared --disable-libatomic --disable-decimal-float --disable-libmpx \
--disable-bootstrap \
\
--build=x86_64-unknown-linux-gnu \
--host=x86_64-unknown-linux-gnu \
--target=x86_64-unknown-linux-gnu
...
The directory that should contain system headers does not exist:
/usr/include
make[2]: *** [Makefile:3279: stmp-fixinc] Error 1 shuffle=1658621302
rm gfdl.pod gcc.pod gcov-dump.pod gcov-tool.pod fsf-funding.pod gpl.pod cpp.pod gcov.pod lto-dump.pod
make[2]: Leaving directory '/build/build/gcc'
Note: it's a no-libc build. It's not expected to use any libc headers.
But in this case fixincludes tries to run and uses default /usr/include
location.
Fixinsludes is not normally expected to run during cross-compilation
on --without-headers. gcc/configure.ac:
: ${inhibit_libc=false}
if { { test x$host != x$target && test "x$with_sysroot" = x ; } ||
test x$with_newlib = xyes ; } &&
{ test "x$with_headers" = xno || test ! -f "$target_header_dir/stdio.h"; } ; then
inhibit_libc=true
fi
The change explicitly passes inhibit_libc=true to configure to disable
include fixing on such cases.
Fixed `nix build --no-link -f. pkgsLLVM.hello` toolchain bootstrap.
Without this change cross-built gcc fails to detect stack protector style:
$ nix log -f pkgs/stdenv/linux/make-bootstrap-tools-cross.nix powerpc64le.bootGCC | fgrep __stack_chk_fail
checking __stack_chk_fail in target C library... no
checking __stack_chk_fail in target C library... no
It happens because gcc treats search paths differently:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/configure.ac;h=446747311a6aec3c810ad6aa4190f7bd383b94f7;hb=HEAD#l2458
if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x ||
test x$build != x$host || test "x$with_build_sysroot" != x; then
...
if test "x$with_build_sysroot" != "x"; then
target_header_dir="${with_build_sysroot}${native_system_header_dir}"
elif test "x$with_sysroot" = x; then
target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-include"
elif test "x$with_sysroot" = xyes; then
target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-root${native_system_header_dir}"
else
target_header_dir="${with_sysroot}${native_system_header_dir}"
fi
else
target_header_dir=${native_system_header_dir}
fi
By passing --with-build-sysroot=/ we trick cross-case to use
`target_header_dir="${with_sysroot}${native_system_header_dir}"`
which makes it equivalent to non-cross
`target_header_dir="${with_build_sysroot}${native_system_header_dir}"`
Tested the following setups:
- cross-compiler without libc headers (powerpc64le-static)
- cross-compiler with libc headers (powerpc64le-debug)
- cross-build compiler with libc headers (powerpc64le bootstrapTools)
Before the change only 2 of 3 compilers detected libc headers.
After the change all 3 compilers detected libc headers.
For darwin we silently ignore '-syslibroot //' argument as it does not
introduce impurities.
While at it dropped mingw special case for no-libc build. Before the change
we passed both '--without-headers --with-native-system-headers-dir' for
no-libc gcc-static builds. This tricked darwin builds to find sys/sdt.h
and fail inhibid_libc builds. Now all targets avoid passing native headers
for gcc-static builds.
While at it fixed correct headers passing to
--with-native-system-headers-dir= in host != target case: we were passing
host's headers where intention was to pass target's headers.
Noticed the mismatch as a build failure on pkgsCross.powernv.stdenv.cc
on darwin where `sys/sdt.h` is present in host's headers (libSystem)
but not target's headers (`glibc`).
Co-authored-by: Adam Joseph <54836058+amjoseph-nixpkgs@users.noreply.github.com>
This change allows detecting configuration errors during
switch-to-configuration instead of them being reported asynchronously
*after* switch-to-configuration has exited.
(And update the NixOS test accordingly.)
