#!/bin/sh
#
# fat cosmopolitan c/c++ compiler
#
#   - this command is a drop-in replacement for the cc or gcc command.
#     the difference is that (1) your binaries will be linked with the
#     cosmopolitan c library, rather than your system specific tooling
#     and (2) they'll be fat ape executables that run on the platforms
#
#     * amd64
#       + linux
#       + macos
#       + windows
#       + freebsd
#       + openbsd
#       + netbsd
#     * arm64
#       + linux
#       + macos
#       + windows (non-native)
#
#   - you need to use linux to build your binaries currently, but you
#     can scp and distribute the output files to the above platforms!
#
# installation
#
#     sudo chmod 1777 /opt  # sticky bit isn't required
#     git clone https://github.com/jart/cosmopolitan /opt/cosmo
#     export PATH="/opt/cosmo/bin:/opt/cosmos/bin:$PATH"
#     echo 'export PATH="/opt/cosmo/bin:/opt/cosmos/bin:$PATH"' >>~/.profile
#     ape-install  # optionally install a faster systemwide ape loader
#     fatcosmocc --update  # pull and rebuild toolchain artifacts
#
# getting started
#
#     fatcosmocc -o hello.com hello.c
#     ./foo.com
#     unzip -vl ./foo.com
#     ./foo.com --strace
#     ./foo.com --ftrace
#
# building in tiny mode
#
#     export MODE=tiny
#     fatcosmocc --update
#     fatcosmocc -Os -o foo.com foo.c
#
# building in debug mode
#
#     export MODE=dbg
#     fatcosmocc --update
#     fatcosmocc -g -o foo.com foo.c
#
# how to build a project like lua 5.4.6
#
#     make all test CC=fatcosmocc AR='fatcosmoar rcu'
#     make install INSTALL_TOP=/opt/cosmos INSTALL=fatcosmoinstall
#
# how to build a project like ncurses 6.4
#
#     ./configure CC=fatcosmocc \
#                 CXX=fatcosmoc++ \
#                 AR=fatcosmoar \
#                 INSTALL="$(command -v fatcosmoinstall)" \
#                 --prefix=/opt/cosmos \
#                 --disable-shared
#     make -j8
#     make install
#
# detecting this environment
#
#   - `__FATCOSMOCC__` is defined by fatcosmocc
#   - `__COSMOCC__` is defined by cosmocc and fatcosmocc
#   - `__COSMOPOLITAN__` is always defined by cosmopolitan
#
# some notes on this compiler
#
#   - the underlying compiler itself is gcc
#   - we use cosmopolitan libc rather than glibc
#   - we use llvm's compiler-rt and libcxx runtimes
#   - we patched gcc so switch case can have symbols
#   - our scanf() implementation is somewhat troubled
#   - you may need to recalibrate `make -jN` as `N/2`
#
# compiler flags that work differently
#
#   - `-v` will log fatcosmocc subcommands to stderr
#          you can also use `export BUILDLOG=/tmp/build.log`
#   - `-s` will ask apelink to not embed symbol tables in zip
#   - `-E` can't be fat and runs once with x86_64 macros undefined
#   - `-save-temps` will prevent deleting your arch-specific executables
#
# compiler flags that aren't supported
#
#   - `-fexceptions` cosmopolitan doesn't support c++ exceptions yet
#   - `-frtti` cosmopolitan doesn't support c++ runtime reflection yet
#   - `-mred-zone` the system v red zone doesn't exist on windows and metal
#   - `-fpic`, '-fPIC', `-shared`, `-pie`, etc. no shared object support yet
#   - `-fsanitize=thread` cosmopolitan doesn't have thread sanitizer runtime yet
#   - `-fomit-frame-pointer` is partially supported (apple forbids full removal)
#
# for further details, run `man gcc`

export PROG=${0##*/}
export COSMO=${COSMO:-/opt/cosmo}
export COSMOS=${COSMOS:-/opt/cosmos}
export ORIGINAL="$0 $*"
export TMPDIR=${TMPDIR:-/tmp}
GCC_VERSION=11.2.0

if [ "$1" = "--version" ]; then
cat <<EOF
$PROG (GCC) $GCC_VERSION
Copyright (c) 2023 Justine Alexandra Roberts Tunney
Cosmopolitan Libc and LLVM libcxx/compiler-rt are subject to non-GPL
notice licenses, e.g. ISC, MIT, etc. Your compiled programs must embed
our copyright notices. This toolchain is configured to do so default.
Cosmopolitan comes with absolutely NO WARRANTY of any kind.
For more information, see the Cosmopolitan LICENSE files.
Copyright (C) 2019 Free Software Foundation, Inc.
This launches GNU GCC/Binutils subprocesses, which is free software; see
Cosmopolitan's third_party/gcc/ for source code and copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
EOF
exit 0
fi

if [ "$1" = "--help" ]; then
  if [ -t 1 ]; then
    exec less "$0"
  else
    exec cat "$0"
  fi
fi

MODE=${MODE:-$m}
if [ x"$MODE" = x"" ]; then
  MODE_AARCH64=aarch64
elif [ x"$MODE" = x"tiny" ]; then
  MODE_AARCH64=aarch64-tiny
elif [ x"$MODE" = x"zero" ]; then
  MODE_AARCH64=aarch64-zero
elif [ x"$MODE" = x"dbg" ]; then
  MODE_AARCH64=aarch64-dbg
else
  echo "$PROG: build MODE=$MODE not supported by fatcosmocc" >&2
  exit 1
fi

if [ "$1" = "--update" ]; then
  cd /opt/cosmo || exit
  if GIT=$(command -v git); then
    echo "running git pull on cosmo..." >&2
    "$GIT" pull --quiet || exit
  fi
  echo "building cosmo host toolchain..." >&2
  make --silent -j toolchain MODE= || exit
  echo "building cosmo x86_64 target (MODE=$MODE) toolchain..." >&2
  make --silent -j toolchain MODE="$MODE" || exit
  echo "building cosmo aarch64 target (MODE=$MODE_AARCH64) toolchain..." >&2
  make --silent -j toolchain MODE="$MODE_AARCH64" || exit
  echo "setting up your cosmos..." >&2
  for arch in "" .aarch64/; do
    mkdir -p "$COSMOS/lib/$arch" || exit
    for lib in c dl gcc_s m pthread resolv rt dl z stdc++; do
      if [ ! -f "$COSMOS/lib/${arch}lib${lib}.a" ]; then
        printf '\041\074\141\162\143\150\076\012' >"$COSMOS/lib/${arch}lib${lib}.a" || exit
      fi
    done
  done
  echo "successfully updated your cosmo toolchain" >&2
  exit
fi

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

if [ ! -f "$COSMOS/lib/libc.a" ] ||
   [ ! -f "$COSMOS/lib/.aarch64/libc.a" ] ||
   [ ! -f "$COSMO/o/$MODE/cosmopolitan.a" ] ||
   [ ! -f "$COSMO/o/$MODE_AARCH64/cosmopolitan.a" ]; then
  echo "$PROG: you need to run: $PROG --update" >&2
  exit 1
fi

export FIXUPOBJ="$COSMO/o//tool/build/fixupobj.com"

TEMP_FILES=
SAVE_TEMPS=0

Exit() {
  rc=${1:-$?}
  if [ $SAVE_TEMPS -eq 0 ]; then
    rm -f $TEMP_FILES
  fi
  exit $rc
}

show_warning() {
  echo "$PROG: warning: $1" >&2
}

fatal_error() {
  echo "$PROG: fatal error: $1" >&2
  echo "compilation terminated." >&2
  Exit 1
}

log_command() {
  if [ -n "$BUILDLOG" ]; then
    printf '# %s\n(cd %s; %s)\n' "$ORIGINAL" "$PWD" "$*" >>"$BUILDLOG"
  fi
}

if [ x"$TMPDIR" != x"${TMPDIR#* }" ]; then
  fatal_error '$TMPDIR containing spaces not supported'
elif [ ! -d "$TMPDIR" ]; then
  if ! mkdir -p "$TMPDIR" 2>/dev/null; then
    fatal_error "$TMPDIR: not a directory"
  fi
fi

OPT=
ARGS=
FLAGS=
OUTPUT=
INTENT=ld
NEED_JOIN=
NEED_EQUAL=
NEED_OUTPUT=
APELINKFLAGS=
INPUT_FILE_COUNT=0
for x; do
  if [ x"$x" != x"${x#* }" ]; then
    fatal_error "arguments containing spaces unsupported: $x"
  fi
  if [ -n "$NEED_OUTPUT" ]; then
    NEED_OUTPUT=
    OUTPUT=$x
    continue
  elif [ -n "$NEED_JOIN" ]; then
    x="${NEED_JOIN}${x}"
    NEED_JOIN=
  elif [ -n "$NEED_EQUAL" ]; then
    x="${NEED_EQUAL}=${x}"
    NEED_EQUAL=
  elif [ x"$x" = x"-" ] ||           # is alias for stdin
       [ x"$x" = x"${x#-*}" ]; then  # !startswith(x, "-")
    if [ x"$x" != x"${x%.s}" ] ||
       [ x"$x" != x"${x%.S}" ]; then
      fatal_error "$x: assembler input files not supported"
    elif [ x"$x" != x"${x%.so}" ] ||
         [ x"$x" != x"${x%.dll}" ] ||
         [ x"$x" != x"${x%.dylib}" ]; then
      fatal_error "$x: dynamic shared object input files not supported"
    elif [ x"$x" != x"-" ] && [ ! -f "$x" ]; then
      fatal_error "$x: no such file"
    fi
    INPUT_FILE_COUNT=$((INPUT_FILE_COUNT + 1))
    ARGS="$ARGS $x"  # don't add to $FLAGS array
    continue
  elif [ x"$x" = x"-o" ]; then
    NEED_OUTPUT=1
    continue
  elif [ x"$x" != x"${x#-o}" ]; then  # startswith(x, "-o")
    OUTPUT=${x#-o}
    continue
  elif [ x"$x" != x"${x#-O}" ]; then  # startswith(x, "-O")
    OPT=$x
  elif [ x"$x" = x"-c" ]; then
    INTENT=cc
  elif [ x"$x" = x"-E" ]; then
    INTENT=cpp
  elif [ x"$x" = x"-s" ]; then
    APELINKFLAGS="$APELINKFLAGS -s"
    continue
  elif [ x"$x" = x"-v" ]; then
    exec 3<&2  # dup2(2, 3) b/c stderr will be redirected later
    export BUILDLOG=/dev/fd/3
    continue
  elif [ x"$x" = x"-save-temps" ]; then
    SAVE_TEMPS=1
  elif [ x"$x" = x"-fomit-frame-pointer" ]; then
    # Quoth Apple: "The frame pointer register must always address a
    # valid frame record. Some functions — such as leaf functions or
    # tail calls — may opt not to create an entry in this list. As a
    # result, stack traces are always meaningful, even without debug
    # information."
    x="-momit-leaf-frame-pointer -foptimize-sibling-calls"
  elif [ x"$x" = x"-r" ] ||
       [ x"$x" = x"-S" ] ||
       [ x"$x" = x"-pie" ] ||
       [ x"$x" = x"-frtti" ] ||
       [ x"$x" = x"-shared" ] ||
       [ x"$x" = x"-nostdlib" ] ||
       [ x"$x" = x"-mred-zone" ] ||
       [ x"$x" = x"-fexceptions" ] ||
       [ x"$x" = x"-fsanitize=thread" ]; then
    fatal_error "$x flag not supported"
  elif [ x"$x" = x"-fsanitize=all" ] ||
       [ x"$x" = x"-fsanitize=address" ] ||
       [ x"$x" = x"-fsanitize=undefined" ]; then
    fatal_error "$x use cosmo MODE=dbg rather than passing $x"
  elif [ x"$x" = x"-mno-red-zone" ]; then
    # "Any memory below the stack beyond the red zone is considered
    # volatile and may be modified by the operating system at any time."
    # https://devblogs.microsoft.com/oldnewthing/20190111-00/?p=100685
    continue
  elif [ x"$x" = x"-fpic" ] || [ x"$x" = x"-fPIC" ]; then
    # no support for building dynamic shared objects yet. reports
    # indicate that ignoring these flags, helps let autoconf know
    continue
  elif [ x"$x" = x"-Werror" ] || \
       [ x"$x" = x"-pedantic-errors" ]; then
    # this toolchain is intended for building other people's code
    # elevating warnings into errors, should only be done by devs
    continue
  elif [ x"$x" = x"-static-libgcc" ] || \
       [ x"$x" = x"-shared-libgcc" ]; then
    # cosmopolitan.a always has llvm compiler runtime static code
    continue
  elif [ x"$x" = x"-march=native" ]; then
    fatal_error "-march=native can't be used when building fat binaries"
  elif [ x"$x" = x"-dumpversion" ]; then
    echo $GCC_VERSION
    Exit 0
  elif [ x"$x" = x"-e" ] ||
       [ x"$x" = x"-z" ] ||
       [ x"$x" = x"-T" ] ||
       [ x"$x" = x"-L" ] ||
       [ x"$x" = x"-I" ] ||
       [ x"$x" = x"-D" ] ||
       [ x"$x" = x"-U" ] ||
       [ x"$x" = x"-iquote" ] ||
       [ x"$x" = x"-isystem" ] ||
       [ x"$x" = x"-include" ]; then
    NEED_JOIN=$x
    continue
  elif [ x"$x" = x"--param" ]; then
    NEED_EQUAL=$x
    continue
  fi
  FLAGS="$FLAGS $x"
  ARGS="$ARGS $x"
done

if [ $INPUT_FILE_COUNT -eq 0 ]; then
  fatal_error "no input files"
elif [ -z "$INPUT" ] &&
     [ $INTENT != ld ] &&
     [ $INPUT_FILE_COUNT -gt 1 ]; then
  fatal_error "cannot specify '-o' with '-c', or '-E' with multiple files"
fi

PLATFORM="-D__COSMOPOLITAN__ -D__COSMOCC__ -D__FATCOSMOCC__"
PREDEF="-include libc/integral/normalize.inc"
CPPFLAGS="-nostdinc -iquote $COSMO -isystem $COSMOS/include -isystem $COSMO/libc/isystem -fno-pie -fno-math-errno"
CCFLAGS_START="-fportcosmo -fno-dwarf2-cfi-asm -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-semantic-interposition"
CCFLAGS_END="-fno-omit-frame-pointer"
if [ x"$MODE" = x"dbg" ]; then
  CPPFLAGS_START="-fsanitize=address -fsanitize=undefined"
fi
if [ x"$OPT" != x"-Os" ] &&
   [ x"${MODE#tiny}" != x"${MODE}" ]; then
  CCFLAGS_START="${CCFLAGS_START} -fno-optimize-sibling-calls -mno-omit-leaf-frame-pointer"
fi

if [ $INTENT = cpp ]; then
  if [ -n "$OUTPUT" ]; then
    ARGS="$ARGS -o$OUTPUT"
  fi
  CC="$COSMO/o/third_party/gcc/bin/x86_64-linux-musl-gcc"
  if [ x"$PROG" != x"${PROG%++}" ]; then
    CC="$COSMO/o/third_party/gcc/bin/x86_64-linux-musl-g++"
  fi
  set -- \
      "$CC" \
      -U__k8 \
      -U__k8__ \
      -U__amd64 \
      -U__amd64__ \
      -U__x86_64 \
      -U__x86_64__ \
      -U__SSE__ \
      -U__SSE2__ \
      -U__SSE2_MATH__ \
      -mno-red-zone \
      $PLATFORM \
      $CPPFLAGS \
      $ARGS
  log_command "$@"
  MODE="$MODE" exec "$@"
fi

mangle_object_path() {
  path=$1
  arch=$2
  outdir=${path%/*}
  outbas=${path##*/}
  if [ x"$outdir" = x"$path" ]; then
    outdir=
  elif [ -n "$outdir" ]; then
    outdir="$outdir/"
  fi
  if [ ! -d "$outdir.$arch" ]; then
    mkdir -p "$outdir.$arch" || Exit
  fi
  mangled_path="${outdir}.$arch/$outbas"
}

mktemper() {
  "$COSMO/o//tool/build/mktemper.com" \
    "$TMPDIR/fatcosmocc.XXXXXXXXXXXXX$1"
}

build_object() {
  out2=$(mktemper .txt) || Exit
  TEMP_FILES="${TEMP_FILES} $out2"
  MODE="$MODE" \
    "$COSMO/tool/scripts/fat-x86_64" \
      -o"$OUTPUT_X86_64" \
      $PLATFORM \
      $PREDEF \
      $CPPFLAGS \
      $CCFLAGS_START \
      "$@" \
      $CCFLAGS_END &
  pid1=$!
  MODE="$MODE_AARCH64" \
    "$COSMO/tool/scripts/fat-aarch64" \
      -o"$OUTPUT_AARCH64" \
      $PLATFORM \
      $PREDEF \
      $CPPFLAGS \
      $CCFLAGS_START \
      "$@" \
      $CCFLAGS_END \
      2>"$out2" &
  pid2=$!
  if ! wait $pid1; then
    kill $pid2 2>/dev/null
    wait
    Exit 1
  fi
  if ! wait $pid2; then
    echo "$PROG: x86_64 succeeded but failed to build object for aarch64:" >&2
    cat "$out2" >&2
    Exit 1
  fi
}

# turn source files into objects
LDARGS_X86_64=
LDARGS_AARCH64=
for x in $ARGS; do
  if [ x"$x" != x"-" ] &&           # is alias for stdin
     [ x"$x" != x"${x#-*}" ]; then  # startswith(x, "-")
    # this argument is a flag
    LDARGS_X86_64="${LDARGS_X86_64} $x"
    LDARGS_AARCH64="${LDARGS_AARCH64} $x"
  else
    # this argument is an input file
    if [ x"$x" != x"${x%.o}" ] ||
       [ x"$x" != x"${x%.a}" ]; then
      if [ $INTENT = cc ]; then
        show_warning "$x: linker input file unused because linking not done"
      else
        mangle_object_path "$x" aarch64
        if [ ! -f "$mangled_path" ]; then
          fatal_error "$x: linker input missing concomitant $mangled_path file"
        fi
        LDARGS_X86_64="${LDARGS_X86_64} $x"
        LDARGS_AARCH64="${LDARGS_AARCH64} $mangled_path"
      fi
    elif [ $INTENT = cc ]; then
      if [ -n "$OUTPUT" ]; then
        # e.g. `cc -c -o bar.o foo.c` is specified by user
        OUTPUT_X86_64=$OUTPUT
        mangle_object_path "$OUTPUT" aarch64
        OUTPUT_AARCH64="$mangled_path"
        build_object $FLAGS -c "$x"
      else
        # e.g. `cc -c dir/foo.c` builds foo.o
        o=${x##*/}
        OUTPUT_X86_64="${o%.*}.o"
        mangle_object_path "${o%.*}.o" aarch64
        OUTPUT_AARCH64="$mangled_path"
        build_object $FLAGS -c "$x"
      fi
    else
      # e.g. `cc foo.c` should build a.out
      if [ -z "$OUTPUT" ]; then
        OUTPUT=a.out
      fi
      # e.g. `cc -o foo foo.c` should *not* build foo.o
      OUTPUT_X86_64=$(mktemper .o) || Exit
      OUTPUT_AARCH64=$(mktemper .o) || Exit
      TEMP_FILES="${TEMP_FILES} ${OUTPUT_X86_64} ${OUTPUT_AARCH64}"
      build_object $FLAGS -c "$x"
      LDARGS_X86_64="${LDARGS_X86_64} ${OUTPUT_X86_64}"
      LDARGS_AARCH64="${LDARGS_AARCH64} ${OUTPUT_AARCH64}"
    fi
  fi
done

if [ $INTENT != ld ]; then
  Exit
fi

OUTPUT_X86_64=$(mktemper ".com.dbg") || Exit
OUTPUT_AARCH64=$(mktemper ".aarch64.elf") || Exit

out2=$(mktemper .txt) || Exit
TEMP_FILES="${TEMP_FILES} $out2"
MODE="$MODE" \
"$COSMO/tool/scripts/fat-x86_64" -o"$OUTPUT_X86_64" $LDARGS_X86_64 &
pid1=$!
MODE="$MODE_AARCH64" \
"$COSMO/tool/scripts/fat-aarch64" -o"$OUTPUT_AARCH64" $LDARGS_AARCH64 2>"$out2" &
pid2=$!
if ! wait $pid1; then
  kill $pid2 2>/dev/null
  wait
  Exit 1
fi
if ! wait $pid2; then
  echo "$PROG: x86_64 succeeded but failed to link executable for aarch64:" >&2
  cat "$out2" >&2
  Exit 1
fi

set -- \
"$COSMO/o//tool/build/apelink.com" \
  -l "$COSMO/o/$MODE/ape/ape.elf" \
  -l "$COSMO/o/$MODE_AARCH64/ape/ape.elf" \
  -M "$COSMO/ape/ape-m1.c" \
  -o "$OUTPUT" \
  $APELINKFLAGS \
  "$OUTPUT_X86_64" \
  "$OUTPUT_AARCH64"
log_command "$@"
"$@" || Exit

set -- \
"$COSMO/o//tool/build/pecheck.com" "$OUTPUT"
log_command "$@"
"$@" || Exit

if [ $INTENT = ld ] && [ $SAVE_TEMPS -eq 0 ]; then
  mv -f "$OUTPUT_X86_64" "${OUTPUT%.com}.com.dbg" || Exit
  mv -f "$OUTPUT_AARCH64" "${OUTPUT%.com}.aarch64.elf" || Exit
fi

Exit