Multi-arch MinGW build wrapper

compile.sh

#!/bin/sh
# compile.sh - multi-arch MinGW build wrapper
# Examples:
#  ./compile.sh test.c
#  ./compile.sh --64 test.c
#  ./compile.sh --64 --dll mydll.c
#  ./compile.sh --32 --windows test.c
#  ./compile.sh --32 --windows --unicode test.c -- -D_DEBUG

set -eu

usage() {
  cat <<EOF
Usage: $0 [--32|--64] [--windows] [--unicode] [--dll] <file.c|.cc|.cpp> [-- extra flags]
Defaults: --32 if neither --32 nor --64 supplied.
--windows   GUI subsystem (-mwindows) for executables only.
--unicode   Adds -DUNICODE -D_UNICODE. For executables with --windows, also adds -municode.
--dll       Build a DLL (.dll) and import lib (.a). Ignores --windows.
EOF
  exit 1
}

# defaults
ARCH=32
WINDOWS=0
UNICODE=0
DLL=0
EXTRA_FLAGS=""
SRC=""

# parse args
while [ "$#" -gt 0 ]; do
  case "$1" in
    --32) ARCH=32; shift ;;
    --64) ARCH=64; shift ;;
    --windows) WINDOWS=1; shift ;;
    --unicode) UNICODE=1; shift ;;
    --dll) DLL=1; shift ;;
    --help|-h) usage ;;
    --)
      shift
      [ "$#" -gt 0 ] && EXTRA_FLAGS="$*"
      break
      ;;
    -*)
      EXTRA_FLAGS="$EXTRA_FLAGS $1"
      shift
      ;;
    *)
      if [ -z "$SRC" ]; then
        SRC="$1"; shift
      else
        EXTRA_FLAGS="$EXTRA_FLAGS $1"
        shift
      fi
      ;;
  esac
done

[ -n "$SRC" ] || usage

case "$SRC" in
  *.c|*.cc|*.cpp) ;;
  *) echo "Source should be .c, .cc, or .cpp" >&2; exit 1 ;;
esac

# toolchain
if [ "$ARCH" -eq 64 ]; then
  CC="x86_64-w64-mingw32-g++"
else
  CC="i686-w64-mingw32-g++"
fi
command -v "$CC" >/dev/null 2>&1 || { echo "Missing $CC in PATH"; exit 1; }

# names
BASE_NAME="$(basename "$SRC")"
BASE_NOEXT="${BASE_NAME%.*}"

if [ "$DLL" -eq 1 ]; then
  OUT="${BASE_NOEXT}.dll"
  IMPLIB="${BASE_NOEXT}.a"
else
  OUT="${BASE_NOEXT}.exe"
fi

COMMON_FLAGS="
-O2
-ffunction-sections
-fdata-sections
-Wno-write-strings
-fno-exceptions
-fmerge-all-constants
-static-libstdc++
-static-libgcc
-fpermissive
-s
-Wl,--gc-sections
-DSECURITY_WIN32
"

LINK_LIBS="
-lws2_32
-ladvapi32
-lcrypt32
-liphlpapi
-lsecur32
-lole32
-loleaut32
-lshell32
-lpathcch
-lshlwapi
"

CMD="$CC \"$SRC\" -o \"$OUT\" $COMMON_FLAGS $LINK_LIBS"

# DLLs ignore subsystem flags
if [ "$DLL" -eq 0 ] && [ "$WINDOWS" -eq 1 ]; then
  CMD="$CMD -mwindows"
fi

# unicode macros always OK; -municode only for GUI executables
if [ "$UNICODE" -eq 1 ]; then
  CMD="$CMD -DUNICODE -D_UNICODE"
  if [ "$DLL" -eq 0 ] && [ "$WINDOWS" -eq 1 ]; then
    CMD="$CMD -municode"
  fi
fi

# dll specifics
if [ "$DLL" -eq 1 ] ; then
  CMD="$CMD -shared -Wl,--out-implib,\"$IMPLIB\""
  if [ "$ARCH" -eq 32 ]; then
    CMD="$CMD -Wl,--add-stdcall-alias"
  fi
fi

# append user extras
[ -n "$EXTRA_FLAGS" ] && CMD="$CMD $EXTRA_FLAGS"

printf '%s\n' "Running: $CMD"
# shellcheck disable=SC2086
eval $CMD