(Please CC me as I am not subscribed) It seems that when building a cross-compiler with a default --target but no default --with-sysroot, the default -isystem =/usr/include path is not automatically included when using --sysroot but default -L =/lib and -L =/usr/lib are included.
(Full example output at end) I did not realize that --sysroot would not add in -isystem =/usr/include. Clang does auto include -isystem =/usr/include with --sysroot. The use-case here is for cross-building FreeBSD's userland against a fully populated sysroot that has target headers and libraries. The cross-compiler is provided in a pre-built package and does not have a hard-coded default TARGET_SYSTEM_ROOT in it. It is required to pass -isystem =/usr/include to do what I'm expecting. This behavior of not including =/usr/include is not documented in --sysroot or otherwise as far as I can tell. Adding the library search paths in but not /usr/include seems odd. In gcc.c the default library paths (standard_startfile_prefix_1, standard_startfile_prefix_2) are added in when cross_compile == '0' (not the case here) or if there is a target_system_root set. The target_system_root comes from both TARGET_SYSTEM_ROOT or dynamically from --sysroot. The include paths are only hard-coded at build time in cppdefault.c and the "native paths" of /usr/include are not added using basically the same logic as in gcc.c but only relies on the build-time TARGET_SYSTEM_ROOT not being defined. Granted the logic in cppdefault.c is intended to only bring in /usr/include and not =/usr/include, I think that --sysroot should also default to adding in -isystem =/usr/include. Otherwise something should be documented here. Here's the cross-compiler being used: > # /usr/local/bin/powerpc64-portbld-freebsd11.0-g++ -v > Using built-in specs. > COLLECT_GCC=/usr/local/bin/powerpc64-portbld-freebsd11.0-g++ > COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/lto-wrapper > Target: powerpc64-portbld-freebsd11.0 > Configured with: ./../gcc-5.3.0/configure > --target=powerpc64-portbld-freebsd11.0 --disable-nls --enable-languages=c,c++ > --without-headers --with-gmp=/usr/local --with-pkgversion='FreeBSD Ports > Collection for powerpc64' --with-system-zlib > --with-as=/usr/local/bin/powerpc64-freebsd-as > --with-ld=/usr/local/bin/powerpc64-freebsd-ld --prefix=/usr/local > --localstatedir=/var --mandir=/usr/local/man --infodir=/usr/local/info/ > --build=x86_64-portbld-freebsd11.0 > Thread model: posix > gcc version 5.3.0 (FreeBSD Ports Collection for powerpc64) Library search paths with and without sysroot: > # /usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/bin/cc -print-search-dirs > install: /usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/libexec/ > programs: > =/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/bin/:/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/bin/:/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/libexec/:/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/libexec/:/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/libexec/ > libraries: > =/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/lib/:/usr/obj/sparc64.sparc64/root/git/freebsd/tmp/usr/lib/ > # /usr/local/bin/powerpc64-portbld-freebsd11.0-g++ -print-search-dirs > --sysroot /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp > install: /usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/ > programs: > =/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/bin/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/bin/ > libraries: > =/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/lib/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/lib/:/usr/obj/powerpc.powerpc64/root/git/freebsd/tmp/lib/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/obj/powerpc.powerpc64/root/git/freebsd/tmp/lib/:/usr/obj/powerpc.powerpc64/root/git/freebsd/tmp/usr/lib/powerpc64-portbld-freebsd11.0/5.3.0/:/usr/obj/powerpc.powerpc64/root/git/freebsd/tmp/usr/lib/ Include path with --sysroot: > # echo '' | /usr/local/bin/powerpc64-portbld-freebsd11.0-g++ -v -x c - -o > /dev/null --sysroot /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp > Using built-in specs. > COLLECT_GCC=/usr/local/bin/powerpc64-portbld-freebsd11.0-g++ > COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/lto-wrapper > Target: powerpc64-portbld-freebsd11.0 > Configured with: ./../gcc-5.3.0/configure > --target=powerpc64-portbld-freebsd11.0 --disable-nls --enable-languages=c,c++ > --without-headers --with-gmp=/usr/local --with-pkgversion='FreeBSD Ports > Collection for powerpc64' --with-system-zlib > --with-as=/usr/local/bin/powerpc64-freebsd-as > --with-ld=/usr/local/bin/powerpc64-freebsd-ld --prefix=/usr/local > --localstatedir=/var --mandir=/usr/local/man --infodir=/usr/local/info/ > --build=x86_64-portbld-freebsd11.0 > Thread model: posix > gcc version 5.3.0 (FreeBSD Ports Collection for powerpc64) > COLLECT_GCC_OPTIONS='-v' '-o' '/dev/null' '-shared-libgcc' > /usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/cc1 -quiet -v > -isysroot /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp - -quiet -dumpbase > - -auxbase - -version -o /tmp//ccfwtn99.s > GNU C11 (FreeBSD Ports Collection for powerpc64) version 5.3.0 > (powerpc64-portbld-freebsd11.0) > compiled by GNU C version 4.2.1 Compatible FreeBSD Clang 3.8.0 > (tags/RELEASE_380/final 262564), GMP version 5.1.3, MPFR version 3.1.3, MPC > version 1.0.3 > GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 > ignoring nonexistent directory > "/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/sys-include" > ignoring nonexistent directory > "/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/include" > #include "..." search starts here: > #include <...> search starts here: > /usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/include > /usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/include-fixed > End of search list. With -isystem =/usr/include: > # echo '' |/usr/local/bin/powerpc64-portbld-freebsd11.0-g++ -v -x c - -o > /dev/null --sysroot /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp -isystem > '=/usr/include' > Using built-in specs. > COLLECT_GCC=/usr/local/bin/powerpc64-portbld-freebsd11.0-g++ > COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/lto-wrapper > Target: powerpc64-portbld-freebsd11.0 > Configured with: ./../gcc-5.3.0/configure > --target=powerpc64-portbld-freebsd11.0 --disable-nls --enable-languages=c,c++ > --without-headers --with-gmp=/usr/local --with-pkgversion='FreeBSD Ports > Collection for powerpc64' --with-system-zlib > --with-as=/usr/local/bin/powerpc64-freebsd-as > --with-ld=/usr/local/bin/powerpc64-freebsd-ld --prefix=/usr/local > --localstatedir=/var --mandir=/usr/local/man --infodir=/usr/local/info/ > --build=x86_64-portbld-freebsd11.0 > Thread model: posix > gcc version 5.3.0 (FreeBSD Ports Collection for powerpc64) > COLLECT_GCC_OPTIONS='-v' '-o' '/dev/null' '-isystem' '=/usr/include' > '-shared-libgcc' > /usr/local/libexec/gcc/powerpc64-portbld-freebsd11.0/5.3.0/cc1 -quiet -v > -isysroot /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp -isystem > =/usr/include - -quiet -dumpbase - -auxbase - -version -o /tmp//ccYf1oTQ.s > GNU C11 (FreeBSD Ports Collection for powerpc64) version 5.3.0 > (powerpc64-portbld-freebsd11.0) > compiled by GNU C version 4.2.1 Compatible FreeBSD Clang 3.8.0 > (tags/RELEASE_380/final 262564), GMP version 5.1.3, MPFR version 3.1.3, MPC > version 1.0.3 > GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 > ignoring nonexistent directory > "/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/sys-include" > ignoring nonexistent directory > "/usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/../../../../powerpc64-portbld-freebsd11.0/include" > #include "..." search starts here: > #include <...> search starts here: > /usr/obj/powerpc.powerpc64/root/git/freebsd/tmp/usr/include > /usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/include > /usr/local/lib/gcc/powerpc64-portbld-freebsd11.0/5.3.0/include-fixed > End of search list. -- Regards, Bryan Drewery
