This patch set adds musl libc[0] support to GCC. The patches were originally developed by Gregor Richards[1][2], who I believe have already done the FSF copyright assignment and agrees with the changes I made (please verify). I only did minor cleanups to make the patches better suited for upstream.
Issues I don't have patches for: * On powerpc it seems the only configure option to choose the default long-double abi is --with-long-double-128, but that's the default with sufficiently new glibc. (musl gets 64bit long-double because the glibc version check fails, this is ok, because there is no ibm128 support in musl, but it would be better if --with-long-double-64 could be set explicitly or even ieee128 abi if gcc supports that). * libcilkrts uses pthread_yield on linux instead of sched_yield by default, but musl does not have the non-standard pthread_yield symbol. Tests: I only tested the C and C++ languages. GCJ needs further patching, I haven't tested gfortran nor Ada. libsanitizer has to be disabled for musl. I built cross compilers for various targets musl supports and ran x86_64-linux-musl cross compiler (musl target glibc host) and native musl make check. There were several errors, some of the causes: * libcilkrts.so has undefined ref to pthread_yield * ifunc is not supported by musl * ifunc is used in x86 libatomic.so for __atomic_store_16 * gcc stdatomic.h has some incompatible typedefs with musl stdint.h * musl does not support unwind across libc calls or signal handlers * splitstacks does not work (undef refs to __morestack* in libgcc) * musl does not yet have __memcpy_chk etc. * -fshort-wchar is not supported * i've seen x86 specific avx failures * atexit during exit fails with musl (some c++ destructor tests) This fixes BZ 58446 and 55807 which requested musl support. [0] http://www.musl-libc.org/ [1] https://github.com/GregorR/musl-gcc-patches [2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58446 -- Changes: fixincludes/mkfixinc.sh | 3 +- gcc/config.gcc | 9 ++- gcc/config/aarch64/aarch64-linux.h | 8 ++ gcc/config/arm/linux-eabi.h | 17 +++++ gcc/config/i386/linux.h | 1 + gcc/config/i386/linux64.h | 4 + gcc/config/i386/pmm_malloc.h | 9 ++- gcc/config/linux.h | 105 +++++++++++++++++++++++---- gcc/config/linux.opt | 4 + gcc/config/microblaze/linux.h | 16 +++- gcc/config/mips/linux.h | 7 ++ gcc/config/rs6000/linux64.h | 12 ++- gcc/config/rs6000/secureplt.h | 1 + gcc/config/rs6000/sysv4.h | 16 +++- gcc/config/sh/linux.h | 7 ++ gcc/configure | 7 ++ gcc/configure.ac | 7 ++ libgcc/unwind-dw2-fde-dip.c | 6 ++ libgfortran/acinclude.m4 | 2 +- libgfortran/configure | 2 +- libitm/config/arm/hwcap.cc | 2 +- libitm/config/linux/x86/tls.h | 8 +- libstdc++-v3/config/os/generic/os_defines.h | 5 ++ libstdc++-v3/configure.host | 3 + 24 files changed, 227 insertions(+), 34 deletions(-)
