configure

#!/usr/bin/env bash
rootdir=$(cd "$(dirname "$0")"; pwd)
libdir=$(cd "${rootdir}/src/lib"; pwd)
exampledir=$(cd "${rootdir}/examples"; pwd)
checkdir=$(cd "${rootdir}/src/casemate-check-c"; pwd)

cc='clang'
ld='ld'
objdump='objdump'
objcopy='objcopy'

casemate_o="${libdir}/casemate.o"
casemate_h="${libdir}/casemate.h"
lib_includes="${libdir}/include"

arch=`uname -m`
cross_prefix=
clangd=1

force=0
warned=0

usage() {
  echo "Usage $0 [OPTIONS]";
  echo
  echo "Options:";
  echo " -h --help               print this help";
  echo " --cross-prefix=PREFIX   compilation tool prefix";
  echo " --cc=CC                 compiler";
  echo " --ld=LD                 linker";
  echo " --arch=ARCH             machine architecture (aarch64 or x86)";
  echo " --[no-]clangd           force enable/disable clangd targets";
  echo " --force                 overrule checks";
}

warning() {
  if [ ${force} -eq 0 ]; then
    echo "configure: $1. use --force to force generation of config anyway"
    exit 1
  else
    echo "configure: $1"
    warned=$((warned + 1))
  fi
}

# collect all the -arg and --args
while [[ "$1" = -* ]]; do
    opt="$1"; shift
    arg=
    if [[ "$opt" = *=* ]]; then
      arg="${opt#*=}";
      opt="${opt%%=*}";
    fi
    case "$opt" in
    --cross-prefix)
        cross_prefix="$arg"
        ;;
    --arch)
        arch="$arg"
        ;;
    --cc)
        cc="$arg"
        ;;
    --ld)
        ld="$arg"
        ;;
    --clangd)
        clangd=1
        ;;
    --no-clangd)
        clangd=
        ;;
    --force)
      force=1
      ;;
    -h|--help)
        usage
        exit 0
        ;;
    *)
        usage
        exit 1
        ;;
    esac
done

tool_prefix=${cross_prefix}

cc=${tool_prefix}${cc}
ld=${tool_prefix}${ld}
objcopy=${tool_prefix}${objcopy}
objdump=${tool_prefix}${objdump}

# check for existence of tools
check_tool () {
  if ! which $2 >/dev/null; then
    warning "--$1: cannot find '$2'"
  fi
}

check_tool "cc" ${cc}
check_tool "ld" ${ld}
check_tool "objcopy" ${objcopy}
check_tool "objdump" ${objdump}

# normalise arch name
[ "$arch" = "arm64" ] && arch="aarch64"
[ "$arch" = "i386" ] && arch="x86"
[ "$arch" = "i686" ] && arch="x86"
[ "$arch" = "x86_64" ] && arch="x86"

arch_name=
if [ "$arch" = "aarch64" ]; then
  arch_name="AARCH64";
elif [ "$arch" = "x86" ]; then
  arch_name="X86";
else
  echo "unknown architecture '${arch}'"
  exit 1
fi

if [ ${warned} -eq 1 ]; then
  echo "configure: warning suppressed, writing config anyway"
elif [ ${warned} -gt 1 ]; then
  echo "configure: multiple warnings suppressed, writing config anyway"
fi

cat <<EOF > config.mk
# Auto-generated, see ./configure script.

root = ${rootdir}

CC = ${cc}
LD = ${ld}
OBJDUMP = ${objdump}
OBJCOPY = ${objcopy}
ARCH = ${arch_name}

CFLAGS = -Wall -MD -g -gdwarf-4 -D__${arch_name}__
LDFLAGS =

CLANGD = ${clangd}

casemate_o = ${casemate_o}
casemate_h = ${casemate_h}
lib_includes = ${lib_includes}
EOF