#!/bin/sh
#
# cosmopolitan c++ compiler
#
# getting started
#
#     sudo chmod 1777 /opt
#     git clone https://github.com/jart/cosmopolitan /opt/cosmo
#     (cd /opt/cosmo; make -j8 toolchain)
#     sudo ln -sf /opt/cosmo/tool/scripts/cosmocc /usr/local/bin/cosmocc
#     sudo ln -sf /opt/cosmo/tool/scripts/cosmoc++ /usr/local/bin/cosmoc++
#     cosmoc++ -o hello.com hello.cc
#     ./foo.com
#     ./foo.com.dbg
#
# building open source projects
#
#     export CC=cosmocc
#     export CXX=cosmoc++
#     ./configure --prefix=/opt/cosmos
#     make -j
#     make install
#
# cosmopolitan runtime flags
#
#     ./hello.com --strace
#     ./hello.com --ftrace
#
# cosmpolitan runtime libraries
#
#     #include <cosmo.h>
#     int main() {
#       ShowCrashReports();
#       __builtin_trap();
#     }
#
# building in tiny mode
#
#     export MODE=tiny
#     (cd /opt/cosmo; make -j8 toolchain)
#     cosmoc++ -Os -o foo.com foo.cc
#
# building in tiniest mode (linux only)
#
#     export MODE=tinylinux
#     (cd /opt/cosmo; make -j8 toolchain)
#     cosmoc++ -Os -o foo.com foo.c
#
# hardening programs with memory safety
#
#     export MODE=asan
#     (cd /opt/cosmo; make -j8 toolchain)
#     cosmoc++ -o foo.com foo.cc
#

MODE=${MODE:-$m}
COSMO=${COSMO:-/opt/cosmo}
COSMOS=${COSMOS:-/opt/cosmos}

if [ "$1" = "--version" ]; then
cat <<'EOF'
x86_64-unknown-cosmo-g++ (GCC) 11.2.0
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

PLATFORM="-D__COSMOPOLITAN__"
PREDEF="-include libc/integral/normalize.inc"
CCFLAGS="-fdata-sections -ffunction-sections -fno-pie -mno-tls-direct-seg-refs -mno-red-zone -fportcosmo"
CXXFLAGS="-fno-exceptions -fuse-cxa-atexit -fno-threadsafe-statics"
CPPFLAGS="-nostdinc -iquote $COSMO -isystem $COSMOS/include -isystem $COSMO/libc/isystem"
LDFLAGS="-static -no-pie -nostdlib -fuse-ld=bfd -Wl,-melf_x86_64"
APEFLAGS="-L$COSMOS/lib -Wl,--gc-sections -Wl,-T,$COSMO/o/$MODE/ape/public/ape.lds $COSMO/o/$MODE/ape/ape-no-modify-self.o $COSMO/o/$MODE/libc/crt/crt.o"
LDLIBS="$COSMO/o/$MODE/third_party/libcxx/libcxx.a $COSMO/o/$MODE/cosmopolitan.a"

CXX="$COSMO/o/third_party/gcc/bin/x86_64-linux-musl-g++"
OBJCOPY="$COSMO/o/third_party/gcc/bin/x86_64-linux-musl-objcopy"
FIXUPOBJ="$COSMO/o/$MODE/tool/build/fixupobj.com"
ZIPCOPY="$COSMO/o/$MODE/tool/build/zipcopy.com"

if [ ! -d "$COSMO" ]; then
  echo "you need to checkout cosmopolitan to your $COSMO directory" >&2
  exit 1
fi

if [ ! -d "$COSMOS" ]; then
  echo "you need to create your $COSMOS directory" >&2
  exit 1
fi

if [ ! -f "$CXX" ] ||
   [ ! -f "$OBJCOPY" ] ||
   [ ! -f "$FIXUPOBJ" ] ||
   [ ! -f "$ZIPCOPY" ]; then
  echo "error: cosmopolitan artifacts missing; please run" >&2
  echo "  cd $COSMOS" >&2
  echo "  make -j8 m=$MODE toolchain" >&2
  exit 1
fi

# auto-install some shell libraries
if [ ! -d "$COSMOS/lib" ]; then
  mkdir -p "$COSMOS/lib"
fi
for lib in c dl gcc_s m pthread resolv rt dl z stdc++; do
  if [ ! -f "$COSMOS/lib/lib$lib.a" ]; then
    printf '\041\074\141\162\143\150\076\012' >"$COSMOS/lib/lib$lib.a"
  fi
done

OPT=
FIRST=1
OUTPUT=
INTENT=ld
NEED_OUTPUT=
RELOCATABLE=0
FRAME=-fno-omit-frame-pointer
for x; do
  if [ $FIRST -eq 1 ]; then
    set --
    FIRST=0
  fi
  if [ x"$x" = x"-Werror" ]; then
    # this toolchain is intended for building other people's code
    # elevating warnings into errors, should only be done by devs
    continue
  elif [ x"$x" = x"-pedantic" ]; then
    # this toolchain is intended for building other people's code
    # we don't need the compiler's assistance to be more portable
    continue
  elif [ x"$x" != x"${x#-O}" ]; then
    OPT=$x
  elif [ x"$x" = x"-c" ]; then
    INTENT=cc
  elif [ x"$x" = x"-r" ]; then
    RELOCATABLE=1
  elif [ x"$x" = x"-E" ]; then
    INTENT=cpp
  elif [ x"$x" = x"-o" ]; then
    NEED_OUTPUT=1
  elif [ x"$x" != x"${x#-o}" ]; then
    OUTPUT=${x#-o}
  elif [ -n "$NEED_OUTPUT" ]; then
    NEED_OUTPUT=
    OUTPUT=$x
  elif [ x"$x" = x"-fpic" ]; then
    continue
  elif [ x"$x" = x"-fPIC" ]; then
    continue
  elif [ x"$x" = x"-shared" ]; then
    echo "error: cosmocc -shared isn't supported" >&2
    exit 1
  elif [ x"$x" = x"-fomit-frame-pointer" ] || [ x"$x" = x"-fno-omit-frame-pointer" ]; then
    FRAME=$x
    continue
  fi
  set -- "$@" "$x"
done

if [ $RELOCATABLE -eq 0 ]; then
  APEFLAGS=
fi

if [ x"$MODE" = x"nox87" ]; then
  CCFLAGS="$CCFLAGS -mlong-double-64"
fi

if [ x"$OPT" != x"-Os" ] && [ x"${MODE#tiny}" != x"${MODE}" ]; then
  # support --ftrace unless optimizing for size
  CXXFLAGS="$CXXFLAGS -fpatchable-function-entry=18,16"
fi

if [ $INTENT = cpp ]; then
  set -- $PLATFORM $CCFLAGS $CPPFLAGS "$@"
elif [ $INTENT = cc ]; then
  set -- $PLATFORM $PREDEF $CCFLAGS $CXXFLAGS $CPPFLAGS "$@" $FRAME
else
  set -- $PLATFORM $PREDEF $LDFLAGS $APEFLAGS $CXXFLAGS $CPPFLAGS "$@" \
         $LDLIBS -Wl,-z,common-page-size=4096 -Wl,-z,max-page-size=4096 $FRAME
fi

set -- "$CXX" "$@"
printf '(cd %s; %s)\n' "$PWD" "$*" >>/tmp/build.log
"$@" || exit

if [ -n "$OUTPUT" ] && [ -f "$OUTPUT" ]; then
  if [ $INTENT = cc ] || [ $INTENT = ld ]; then
    "$FIXUPOBJ" "$OUTPUT" || exit
  fi
  if [ $INTENT = ld ]; then
    if [ x"$OUTPUT" != x"${OUTPUT%.com}" ] ||
       [ x"$OUTPUT" != x"${OUTPUT%.exe}" ]; then
      # cosmocc -o foo.com ...
      # -> foo.com (ape)
      # -> foo.com.dbg (elf)
      mv -f "$OUTPUT" "$OUTPUT.dbg" || exit
      "$OBJCOPY" -S -O binary "$OUTPUT.dbg" "$OUTPUT" || exit
      "$ZIPCOPY" "$OUTPUT.dbg" "$OUTPUT" || exit
    fi
  fi
fi