#!/usr/bin/env bash
#
# build-native-sdk.sh — Build the Montauk SDK: binutils + GCC compiled
# to run *on* MontaukOS (--host=x86_64-montauk), staged for the OS image.
#
# Usage:  ./toolchain/build-native-sdk.sh        (or: make sdk)
#
# Produces:
#   toolchain/native/sdk/      — native as/ld/ar/nm/... (stripped)
#   toolchain/native-gcc/sdk/  — native gcc/g++ driver + cc1/cc1plus/collect2
#
# The `devkit` target in programs/GNUmakefile ships these into the OS
# image at 0:/sdk. Without them the ISO builds WITHOUT the SDK.
#
# Requires the x86_64-montauk cross toolchain (build-montauk-toolchain.sh
# is invoked automatically; it also downloads/patches the shared sources
# and refreshes toolchain/sysroot from the current libc).
#
# This script is idempotent — each stage is skipped once its output
# exists. To force a rebuild (e.g. after libc changes, so the native
# tools relink against the fixed libc):
#   rm -rf toolchain/native toolchain/native-gcc \
#          toolchain/build/binutils-native toolchain/build/gcc-native

set -euo pipefail

BINUTILS_VERSION="2.43.1"
GCC_VERSION="14.2.0"
HOST="x86_64-montauk"

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PREFIX="${SCRIPT_DIR}/local"
SRC_DIR="${SCRIPT_DIR}/src"
BUILD_DIR="${SCRIPT_DIR}/build"
SYSROOT="${SCRIPT_DIR}/sysroot"
NATIVE_BINUTILS="${SCRIPT_DIR}/native"
NATIVE_GCC="${SCRIPT_DIR}/native-gcc"

JOBS="$(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)"

bold()  { printf '\033[1m%s\033[0m\n' "$*"; }
green() { printf '\033[1;32m%s\033[0m\n' "$*"; }

bold "=== Building the Montauk SDK (native ${HOST} binutils + GCC) ==="

# ── Cross toolchain + sources + sysroot ──────────────────────────────────────
# build-montauk-toolchain.sh is idempotent: it downloads and patches the
# shared binutils/GCC sources, always refreshes the sysroot from the
# current libc, and skips compiler builds once installed.
"${SCRIPT_DIR}/build-montauk-toolchain.sh"

export PATH="${PREFIX}/bin:${PATH}"

# ── Host-build fix-ups in the GCC source tree ────────────────────────────────
# The bundled gmp/mpfr/mpc/isl/gettext carry their own config.sub copies
# that predate the montauk target; overwrite each with the patched
# top-level one so they configure for --host=x86_64-montauk.
GCC_SRC="${SRC_DIR}/gcc-${GCC_VERSION}"
for sub in gmp mpfr mpc isl gettext; do
    for cs in "${GCC_SRC}/${sub}/config.sub" "${GCC_SRC}/${sub}/build-aux/config.sub"; do
        if [[ -f "${cs}" ]] && ! grep -q montauk "${cs}"; then
            bold "Patching config.sub: ${cs#"${SRC_DIR}/"}"
            cp "${GCC_SRC}/config.sub" "${cs}"
        fi
    done
done

# --disable-nls does not skip the bundled gettext, and its gnulib needs
# more locale surface than the Montauk libc has. Drop the symlink so the
# toplevel treats it as absent.
if [[ -L "${GCC_SRC}/gettext" ]]; then
    bold "Removing gettext symlink (not buildable against the Montauk libc)"
    rm "${GCC_SRC}/gettext"
fi

# The gcc subdir resolves --with-native-system-header-dir=/sdk/include
# inside the build sysroot at build time; give the sysroot an sdk -> usr
# alias so that path exists.
if [[ ! -e "${SYSROOT}/sdk" ]]; then
    ln -s usr "${SYSROOT}/sdk"
fi

# ── Native binutils ──────────────────────────────────────────────────────────
if [[ -x "${NATIVE_BINUTILS}/sdk/bin/ld" ]]; then
    bold "Native binutils already staged — skipping."
else
    bold "Building native binutils ${BINUTILS_VERSION} (host ${HOST})..."
    rm -rf "${BUILD_DIR}/binutils-native"
    mkdir -p "${BUILD_DIR}/binutils-native"
    (
        cd "${BUILD_DIR}/binutils-native"
        "${SRC_DIR}/binutils-${BINUTILS_VERSION}/configure" \
            --build=x86_64-pc-linux-gnu \
            --host="${HOST}" \
            --target="${HOST}" \
            --prefix=/sdk \
            --disable-nls \
            --disable-werror \
            --disable-gprofng \
            --disable-gold \
            --disable-plugins \
            --disable-shared \
            --enable-static
        # Only gas/ld/binutils: gprof needs fscanf %[] scansets the
        # Montauk libc lacks; gold and gprofng are disabled outright.
        make -j"${JOBS}" all-gas all-ld all-binutils
        make install-strip-gas install-strip-ld install-strip-binutils \
            DESTDIR="${NATIVE_BINUTILS}"
    )
    green "Native binutils staged into toolchain/native/sdk."
fi

# ── Native GCC ───────────────────────────────────────────────────────────────
if [[ -x "${NATIVE_GCC}/sdk/bin/gcc" ]]; then
    bold "Native GCC already staged — skipping."
else
    bold "Building native GCC ${GCC_VERSION} (host ${HOST})..."
    rm -rf "${BUILD_DIR}/gcc-native"
    mkdir -p "${BUILD_DIR}/gcc-native"
    (
        cd "${BUILD_DIR}/gcc-native"
        "${SRC_DIR}/gcc-${GCC_VERSION}/configure" \
            --build=x86_64-pc-linux-gnu \
            --host="${HOST}" \
            --target="${HOST}" \
            --prefix=/sdk \
            --with-native-system-header-dir=/sdk/include \
            --with-build-sysroot="${SYSROOT}" \
            --enable-languages=c,c++ \
            --disable-nls \
            --disable-shared \
            --disable-multilib \
            --disable-gcov \
            --disable-lto \
            --disable-plugin \
            --disable-bootstrap \
            --disable-fixincludes \
            --with-newlib \
            --enable-initfini-array \
            --disable-wchar_t \
            --disable-libstdcxx-pch \
            --with-gnu-as \
            --with-gnu-ld
        # The gcc subdir configure cannot run host (montauk) binaries to
        # probe endianness; preset it.
        ac_cv_c_bigendian=no make -j"${JOBS}" all-gcc
        make install-gcc DESTDIR="${NATIVE_GCC}"
    )

    # install-gcc does not strip, and cc1/cc1plus carry ~700 MB of debug
    # info between them (the ISO balloons to 1.7 GB if this is skipped).
    bold "Stripping native GCC binaries..."
    GCC_LIBEXEC="${NATIVE_GCC}/sdk/libexec/gcc/${HOST}/${GCC_VERSION}"
    for b in "${GCC_LIBEXEC}/cc1" "${GCC_LIBEXEC}/cc1plus" "${GCC_LIBEXEC}/collect2" \
             "${NATIVE_GCC}/sdk/bin/gcc" "${NATIVE_GCC}/sdk/bin/g++" \
             "${NATIVE_GCC}/sdk/bin/cpp"; do
        if [[ -f "${b}" ]]; then
            "${PREFIX}/bin/${HOST}-strip" "${b}"
        fi
    done
    green "Native GCC staged into toolchain/native-gcc/sdk."
fi

# ── Done ─────────────────────────────────────────────────────────────────────
echo
green "=== Montauk SDK ready ==="
bold "Staged trees:"
bold "  ${NATIVE_BINUTILS}/sdk  (as, ld, ar, nm, objdump, ...)"
bold "  ${NATIVE_GCC}/sdk       (gcc, g++, cpp, cc1, cc1plus, collect2)"
bold "The next 'make' ships them into the OS image at 0:/sdk (devkit target)."