cosmocc script to simplify usage of the cosmopolitan.zip bundle

cosmocc

#!/bin/sh
[ "${COSMOXX-}" ] && set -x || :

# name: cosmocc
# self-contained replacement for the cc command which uses cosmopolitan libc
# see https://justine.lol/cosmopolitan/index.html
# home: https://gist.github.com/avih/467b307051bf01bc9c8475221a59513d
# based on: https://github.com/jart/cosmopolitan/blob/master/tool/scripts/cosmocc
# requires: gcc or clang installed
#
# how to use:
#   download a cosmopolitan[-variant].zip bundle of your choice from here
#   https://justine.lol/cosmopolitan/download.html  then extract it to some
#   dir X, place this file in X, ensure it's executable, link to it from PATH
#
#   or, create a dir X where the cosmopolitan files will be stored, then
#   copy this script into X, and link to it from someplace at PATH.
#   this will download the main cosmopolitan.zip bundle on first run.
#
#   or, set COSMO below to an absolute dir path which will hold the files,
#   and place or link to this file someplace at PATH. the dir will be created
#   automatically on first run, before downloading the zip.
#
#   E.g., assuming ~/.local/bin is in PATH, and that this file
#   is ~/cosmocc and executable:
#     mkdir ~/cosmo && cp ~/cosmocc ~/cosmo/ && ln -s ~/cosmo/cosmocc ~/.local/bin/
#
#   then use "cosmocc" instead of "cc", e.g:
#     cosmocc myapp.c -o myapp.com.dbg
#   or:
#     cosmocc -c file1.c file2.c && cosmocc file1.o file2.o -o myapp.com.dbg
#   or:
#     make CC=cosmocc ... && cosmocc --cosmo2ape path/to/myapp
#   etc.
#
#
#   first run does initial setup - create the dir if needed,
#   download and extract the cosmopolitan zip if needed, setup some
#   default include wrappers and shell lib files in that dir.
#
#   when creating binaries, e.g. cosmocc file.c -o myapp
#   then the resulting file runs on linux but is not actually APE.
#   it needs an additional step: objcopy -S -O binary myapp myapp.com
#   if the binary has a .com.dbg extension, then two things will happen:
#     - the objcopy command is invoked automatically to create a .com APE file
#     - the .com APE file will use the symbols at the .com.dbg file
#       when tracing functions, e.g. myapp.com --ftrace ...
#       (with default or "dbg" cosmopolitan.zip variants, but not "tiny")
#   for instance: cosmocc file.c -o file.com.dbg
#     creates file.com too, which can use the debug symbols at file.com.dbg
#   NOTE: don't use strip on the resulting binaries.
#
#   If the binary was created using a Makefile or some other build system
#   and the application ends up without .com.dbg suffix, then this command will
#   rename it and also create the APE file: cosmocc --cosmo2ape path/to/myapp
#
# ENV vars:
#   COSMOCC=...  set a specific compiler to use. default is gcc or clang or cc
#   COSMOX=1     trace the compiler commands
#   COSMOXX=1    trace the whole script


# if readlink -f is unavailable, or if this file is outside the cosmo dir
# then set COSMO manually to the full path to the dir (without trail /)
COSMO=$(dirname -- "$(readlink -f -- "$0")")

one_val() { [ "$#" = 1 ] && [ "$1" ]; }
one_val $COSMO ||
  { >&2 echo "$0: \$COSMO must be non-nul, no spaces -- '$COSMO'"; exit 1; }


if [ "${1-}" = --cosmo2ape ]; then
    shift
    [ "${1-}" != -- ] || shift
    [ -x "${1-}" ] ||
        { echo "Usage: $0 --cosmo2ape APP...   cosmo binary -> APE"; exit 1; }
    (   set -x
        for f; do
            mv -- "$f" "$f.com.dbg"
            objcopy -S -O binary -- "$f.com.dbg" "$f.com"
        done
    );  exit
fi


# download the archive if missing
[ -e "$COSMO"/cosmopolitan.a ] || (
    # for variants, see: https://justine.lol/cosmopolitan/download.html
    variant=  # <empty> | tiny | tinylinux | rel | asan | dbg
    f=cosmopolitan${variant:+-$variant}.zip

    mkdir -p -- "$COSMO" &&
    cd "$COSMO" &&
    { ! [ -e "$f" ] || mv -- "$f" "prev.$f"; } &&
    wget -- "https://justine.lol/cosmopolitan/$f" &&
    unzip -- "$f" &&
    rm -rf lib include
) || exit


# ensure shell includes
posix_includes="
    aio.h arpa/inet.h assert.h complex.h cpio.h ctype.h dirent.h dlfcn.h
    errno.h fcntl.h fenv.h float.h fmtmsg.h fnmatch.h ftw.h glob.h grp.h
    iconv.h inttypes.h iso646.h langinfo.h libgen.h limits.h locale.h
    math.h monetary.h mqueue.h ndbm.h net/if.h netdb.h netinet/in.h
    netinet/tcp.h nl_types.h poll.h pthread.h pwd.h regex.h sched.h
    search.h semaphore.h setjmp.h signal.h spawn.h stdarg.h stdbool.h
    stddef.h stdint.h stdio.h stdlib.h string.h strings.h stropts.h
    sys/ipc.h sys/mman.h sys/msg.h sys/resource.h sys/select.h sys/sem.h
    sys/shm.h sys/socket.h sys/stat.h sys/statvfs.h sys/time.h
    sys/times.h sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h
    syslog.h tar.h termios.h tgmath.h time.h trace.h ulimit.h unistd.h
    utime.h utmpx.h wchar.h wctype.h wordexp.h
"

if ! [ -d "$COSMO/include" ]; then
    mkdir -p "$COSMO/include"
    for inc in $posix_includes; do
        case $inc in */*) mkdir -p $COSMO/include/${inc%/*}; esac
        ln -s -- "$COSMO/cosmopolitan.h" "$COSMO/include/$inc" 2>/dev/null ||
        printf %s\\n "#include \"$COSMO/cosmopolitan.h\"" >"$COSMO/include/$inc"
    done
fi


# the following is adapted from:
#   https://github.com/jart/cosmopolitan/blob/master/tool/scripts/cosmocc

# auto-install some shell libraries
if [ ! -d $COSMO/lib ]; then
    mkdir $COSMO/lib
    # FIXME: other than libc, which of those actually exist at cosmopolitan.a?
    for lib in c dl gcc_s m pthread resolv rt z stdc++; do
        printf '\041\074\141\162\143\150\076\012' >$COSMO/lib/lib$lib.a
    done
fi


if [ "$1" = "--version" ]; then
cat <<'EOF'
x86_64-unknown-cosmo-gcc (GCC) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
EOF
exit 0
fi


has_nop_mcount() {
    echo "int main() {return 0;}" |
        "$1" -c -xc - -o /dev/null -mnop-mcount 2>/dev/null
}

: ${COSMOCC:=$(which gcc || which clang || which cc)}

has_nop_mcount "$COSMOCC" && NOPMCOUNT=-mnop-mcount || NOPMCOUNT=
CFLAGS="-g -O2 -fdata-sections -ffunction-sections -fno-pie -pg $NOPMCOUNT \
        -mno-tls-direct-seg-refs"

CPPFLAGS="-DNDEBUG -nostdinc -isystem $COSMO/include"

LDFLAGS="-static -no-pie -nostdlib -fuse-ld=bfd -Wl,-melf_x86_64 \
         -Wl,--gc-sections -Wl,-z,max-page-size=0x1000 \
         -L$COSMO/lib -Wl,-T,$COSMO/ape.lds \
         $COSMO/ape-no-modify-self.o $COSMO/crt.o"

LDLIBS=$COSMO/cosmopolitan.a


HAS_C=  HAS_E=
O=  NEXT_IS_O=

for x; do shift
    if [ "$NEXT_IS_O" ]; then
        O=$x  NEXT_IS_O=
        set -- "$@" "$x"
        continue
    fi

    case $x in
    -Werror|-pedantic)
            # this toolchain is intended for building other people's code
            # elevating warnings into errors, should only be done by devs
            # we don't need the compiler's assistance to be more portable
            >&2 printf %s\\n "$0: ignoring $x"
            continue
            ;;
    -c)     HAS_C=x ;;
    -E)     HAS_E=x ;;
    -o)     NEXT_IS_O=x ;;
    -o*)    O=${x#-o} ;;
    esac

    set -- "$@" "$x"
done


if [ "$HAS_E" ]; then
    set -- $CPPFLAGS "$@"
elif [ "$HAS_C" ]; then
    set -- $CFLAGS $CPPFLAGS "$@" -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer
else  # [compile and] link
    set -- $LDFLAGS $CFLAGS $CPPFLAGS "$@" $LDLIBS -Wl,-z,common-page-size=4096 -Wl,-z,max-page-size=4096
fi

set -- "$COSMOCC" "$@"
printf '(cd %s; %s)\n' "$PWD" "$*" >>/tmp/$(basename -- "$0").log

[ "${COSMOX-}" ] && set -x || :
"$@" && {
    if [ -x "$O" ]; then
        case $O in *.com.dbg)
            out=${O%.dbg}
            >&2 printf %s\\n "[auto: $O --> $out]"
            objcopy -S -O binary "$O" "$out"
        esac
    fi
}