configure

#!/usr/bin/env sh

CMAKE_FILE="CMakeLists.txt"

show_help() {
    echo "Usage: ./configure [OPTIONS]"
    echo
    echo "Standard options:"
    echo "  --fresh                                  Fresh reconfigure"
    echo "  -B=DIR --dir=DIR --build-dir=DIR         Build directory (./ by default)"
    echo "  -G=GEN --generator=GEN                   CMake generator (Ninja, Unix Makefiles, etc.)"
    echo "  --cc=PATH                                C compiler"
    echo "  --cxx=PATH                               C++ compiler"
    echo "  --ld=PATH                                Linker"
    echo "  --ar=PATH                                Archiver"
    echo "  --cflags=FLAGS                           C compiler flags"
    echo "  --cxxflags=FLAGS                         C++ compiler flags"
    echo "  --ldflags=FLAGS                          Linker flags"
    echo
    echo "Project options (from $CMAKE_FILE):"
    echo

    awk '
        {
            if ($0 ~ /^[[:space:]]*option[[:space:]]*\(/) {
                line = $0
                match(line, /option[[:space:]]*\(([A-Za-z0-9_]+)[[:space:]]*"([^"]*)"[[:space:]]*([A-Za-z0-9_]*)/, arr)
                name = arr[1]
                desc = arr[2]
                def  = arr[3]
                printf("  %-22s %s", name, desc)
                if (def != "") printf(" (default: %s)", def)
                printf("\n")
            }
        }
    ' "$CMAKE_FILE"

    echo
    exit 0
}

# Initialize variables
FRESH=false
BUILDDIR=""
GENERATOR=""
CC=""
CXX=""
LD=""
AR=""
CFLAGS=""
CXXFLAGS=""
LDFLAGS=""
CMAKE_EXTRA=""

# Parse arguments
for arg in "$@"; do
    case "$arg" in
        --help|-h) show_help ;;
        --fresh) FRESH=true ;;
        -B=*|--dir=*|--build-dir=*) BUILDDIR="${arg#*=}" ;;
        --generator=*) GENERATOR="${arg#*=}" ;;
        --cc=*) CC="${arg#*=}" ;;
        --cxx=*) CXX="${arg#*=}" ;;
        --ld=*) LD="${arg#*=}" ;;
        --ar=*) AR="${arg#*=}" ;;
        --cflags=*) CFLAGS="${arg#*=}" ;;
        --cxxflags=*) CXXFLAGS="${arg#*=}" ;;
        --ldflags=*) LDFLAGS="${arg#*=}" ;;
        *)
            CMAKE_EXTRA="$CMAKE_EXTRA -D$arg"
            ;;
    esac
done

# Build CMake flags
CMAKE_FLAGS=""

[ -n "$FRESH" ] && CMAKE_FLAGS="$CMAKE_FLAGS --fresh"
[ -n "$BUILDDIR" ] && CMAKE_FLAGS="$CMAKE_FLAGS -B \"$BUILDDIR\""
[ -n "$GENERATOR" ] && CMAKE_FLAGS="$CMAKE_FLAGS -G \"$GENERATOR\""
[ -n "$CC" ]      && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_C_COMPILER=$CC"
[ -n "$CXX" ]     && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_CXX_COMPILER=$CXX"
[ -n "$LD" ]      && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_LINKER=$LD"
[ -n "$AR" ]      && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_LINKER=$AR"
[ -n "$CFLAGS" ]  && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_C_FLAGS='$CFLAGS'"
[ -n "$CXXFLAGS" ]&& CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_CXX_FLAGS='$CXXFLAGS'"
[ -n "$LDFLAGS" ] && CMAKE_FLAGS="$CMAKE_FLAGS -DCMAKE_EXE_LINKER_FLAGS='$LDFLAGS'"

# Finally execute CMake
eval cmake -S . -B build $CMAKE_FLAGS $CMAKE_EXTRA