Trying to build a gcc 4.4.2 for 'baremetal' targets, in my case for later libc building, I find that the libiberty configure script at some stage checks for some libc headers to be available.
I'm calling the gcc main configure with "--without-headers". The total flags are: --prefix=/nix/store/bqyab4kls4czwyzazmrjbf2y62xiil48-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static --with-ppl=/nix/store/kdsz815whid3giyi9ll3bshxdmp3jyyj-ppl-0.10.2 --with-cloog=/nix/store/zidphypb94508svrm4b2dxj9bhwpp2fr-cloog-ppl-0.15.4 --with-gmp=/nix/store/sli4r6plz8bkbizia8mr8p0rhxvrk06v-gmp-4.3.1 --with-mpfr=/nix/store/q5x2ajrskdj5bv2md78k5yqapdiy0sqg-mpfr-2.4.1 --disable-libstdcxx-pch --without-included-gettext --with-system-zlib --enable-languages=c --target=armv5tel-unknown-linux-uclibceabi --disable-libssp --disable-nls --without-headers --disable-threads --disable-libmudflap --disable-libgomp --disable-shared I could build gcc 4.3.4 perfectly with the options I was using. The concerning contents at the directory build/armv5tel-unknown-linux-uclibceabi/libiberty/config.log give: configure:5359: /tmp/nix-build-12l4vcfky0013w4gx5fpky81s4gb90gd-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static.drv-0/build/./gcc/xgcc -B/tmp/nix-build-12l4vcfky0013w4gx5fpky81s4gb90gd-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static.drv-0/build/./gcc/ -B/nix/store/bqyab4kls4czwyzazmrjbf2y62xiil48-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static/armv5tel-unknown-linux-uclibceabi/bin/ -B/nix/store/bqyab4kls4czwyzazmrjbf2y62xiil48-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static/armv5tel-unknown-linux-uclibceabi/lib/ -isystem /nix/store/bqyab4kls4czwyzazmrjbf2y62xiil48-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static/armv5tel-unknown-linux-uclibceabi/include -isystem /nix/store/bqyab4kls4czwyzazmrjbf2y62xiil48-gcc-4.4.2-armv5tel-unknown-linux-uclibceabi-stage-static/armv5tel-unknown-linux-uclibceabi/sys-include -c -B/lib -idirafter /include -Wl,-L/lib conftest.c >&5 conftest.c:41:19: error: stdio.h: No such file or directory conftest.c:43:24: error: sys/types.h: No such file or directory conftest.c:46:23: error: sys/stat.h: No such file or directory conftest.c:53:22: error: stdlib.h: No such file or directory conftest.c:58:22: error: memory.h: No such file or directory conftest.c:60:21: error: string.h: No such file or directory conftest.c:63:22: error: strings.h: No such file or directory conftest.c:66:23: error: inttypes.h: No such file or directory conftest.c:73:21: error: unistd.h: No such file or directory conftest.c: In function 'main': conftest.c:78: error: 'pid_t' undeclared (first use in this function) conftest.c:78: error: (Each undeclared identifier is reported only once conftest.c:78: error: for each function it appears in.) conftest.c:78: error: expected expression before ')' token configure:5365: $? = 1 -- Summary: libiberty configure script fails checking pid_t when without-headers Product: gcc Version: 4.4.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: viriketo at gmail dot com GCC build triplet: x86_64-linux GCC host triplet: x86_64-linux GCC target triplet: armv5tel-unknown-linux-uclibceabi http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42280