#!/usr/bin/env bash
# Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
# See LICENSE.md for license information.
# SPDX-License-Identifier: MIT
#
# The macOS port's C compiler (make/macos.mk; the installer builds SDL with
# it too): zig cc once for each architecture in MACOS_ARCHS -- by default
# Apple silicon and Intel -- with the results joined into one universal file
# by llvm-lipo, as Apple's own clang does when given two -arch flags. It
# takes what a C compiler takes: with -c it makes a universal object, else a
# universal program. The first architecture's run is exactly the call it was
# given, so its dependency file (-MMD) comes out as a plain compiler's; the
# other runs leave theirs out. With one architecture, or with no -o (a
# preprocessing run), it is zig cc for the first architecture alone.
#
# Programs run on macOS MACOS_MIN or newer: Ventura, which every Apple
# silicon Mac runs and the Intel ones from 2017 on.
#
# From the environment (toolchains/config.mk, which make exports): ZIG and
# its cache folders, MACOS_SDK and MACOS_LIPO.
#
# Usage: cc.sh COMPILER-ARGUMENTS...
#        cc.sh --minimum              prints MACOS_MIN (for an Info.plist)

set -euo pipefail

MACOS_MIN=13.0
read -r -a archs <<< "${MACOS_ARCHS:-aarch64 x86_64}"

if [[ "${1:-}" == --minimum ]]; then
    printf '%s\n' "$MACOS_MIN"
    exit 0
fi
if [[ -z "${ZIG:-}" || -z "${MACOS_SDK:-}" || -z "${MACOS_LIPO:-}" ]]; then
    echo "$0: ZIG, MACOS_SDK or MACOS_LIPO is not set; run ./install.sh install toolchain:macos" >&2
    exit 1
fi

out=""
compile=0
preprocess=0
prev=""
for arg in "$@"; do
    if [[ "$prev" == -o ]]; then
        out="$arg"
    fi
    case "$arg" in
        -c) compile=1 ;;
        -E) preprocess=1 ;;
    esac
    prev="$arg"
done

# zig brings the C library's headers and libSystem's stubs; the SDK the
# rest, after them (so the caller's own come first): its other headers, its
# frameworks, and, for a link, the stub libraries beside them. zig cc
# builds for UBSan unless told not to, and would then want its runtime; and
# it warns, as no other port's compiler does, at __DATE__ and __TIME__ (a
# build that uses them cannot be reproduced), which -Werror would make fatal.
flags=(-fno-sanitize=undefined -Wno-date-time -idirafter "$MACOS_SDK/usr/include" -F"$MACOS_SDK/System/Library/Frameworks")
if [[ $compile -eq 0 && $preprocess -eq 0 ]]; then
    flags+=(-L"$MACOS_SDK/usr/lib")
fi

# zig refuses a target with a version for a run that only preprocesses (a
# build system asking what the compiler defines), and the version makes no
# difference to that.
target() {
    if [[ $preprocess -eq 1 ]]; then
        printf '%s-macos\n' "$1"
    else
        printf '%s-macos.%s\n' "$1" "$MACOS_MIN"
    fi
}

if [[ ${#archs[@]} -eq 1 || -z "$out" ]]; then
    exec "$ZIG" cc -target "$(target "${archs[0]}")" "$@" "${flags[@]}"
fi

slices=()
trap 'rm -f "${slices[@]}"' EXIT
for arch in "${archs[@]}"; do
    slice="$out.$arch"
    slices+=("$slice")
    if [[ ${#slices[@]} -eq 1 ]]; then
        "$ZIG" cc -target "$(target "$arch")" "$@" "${flags[@]}"
        mv -f "$out" "$slice"
        continue
    fi
    args=()
    skip=0
    for arg in "$@"; do
        if [[ $skip -eq 1 ]]; then
            skip=0
            continue
        fi
        case "$arg" in
            -o)           args+=(-o "$slice"); skip=1 ;;
            -MD|-MMD|-MP) ;;
            -MF|-MT|-MQ)  skip=1 ;;
            *)            args+=("$arg") ;;
        esac
    done
    "$ZIG" cc -target "$(target "$arch")" "${args[@]}" "${flags[@]}"
done
"$MACOS_LIPO" -create "${slices[@]}" -output "$out"