# Wrapper for the "crossdirect" compilation method.
# pmbootstrap mounts the native chroot in the foreign arch (e.g. armhf) chroot
# as /native. This package gets installed into the native chroot, and creates
# wrappers like:
#
# /native/usr/lib/crossdirect/armhf/gcc
# -> /native/usr/bin/armv6-alpine-linux-muslgnueabihf-gcc
# /native/usr/lib/crossdirect/armhf/rustc
# -> /native/usr/bin/rustc --target=armv6-alpine-linux-musleabihf ...
#
# When building packages in the armhf chroot, PATH will get prepended with
# "/native/usr/lib/crossdirect/armhf". The end game is of course invoking the
# cross compiler from the native chroot, running at native speed, whenever
# calling the compiler from the foreign arch chroot. See crossdirect.c for
# implementation details of the C version (llvm, fakeroot, rpath). The rust
# version is implemented as simple shell wrappers.

pkgname=crossdirect
pkgver=4
pkgrel=3
pkgdesc="Wrappers to launch native cross compilers in foreign chroots"
url="https://postmarketOS.org"
arch="all"
license="MIT"
options="!check"
source="crossdirect.c rustc.sh rust-qemu-linker.sh"

build() {
	cd "$srcdir"
	# Architectures and binaries
	_archs="x86_64 armhf armv7 aarch64"
	for _arch in $_archs; do
		[ "$_arch" == "$CARCH" ] && continue
		_hostspec="$(arch_to_hostspec $_arch)"

		# Build with -Werror, because we maintain this short program. (If
		# upstream is elsewhere, having -Werror is usually not desired.)
		$CC -o "crossdirect-$_arch" \
			-static \
			-Werror \
			-DHOSTSPEC="\"$_hostspec\"" \
			crossdirect.c

		# rustc
		sed "s/@ARCH@/$_arch/g" rustc.sh >rustc-"$_arch"
	done
}

package() {
	# Architectures and binaries
	_archs="x86_64 armhf armv7 aarch64"
	_bins="c++ cc cpp g++ gcc clang clang++"

	# Rust: qemu-linker
	install -Dm755 "$srcdir/rust-qemu-linker.sh" \
		"$pkgdir/usr/lib/crossdirect/rust-qemu-linker"

	# Iterate over architectures
	for _arch in $_archs; do
		[ "$_arch" == "$CARCH" ] && continue

		# GCC: put arch-specific crossdirect wrapper in arch-specific
		# bin folder
		_bindir="$pkgdir/usr/lib/crossdirect/$_arch"
		_hostspec="$(arch_to_hostspec $_arch)"
		mkdir -p "$_bindir"
		cd "$_bindir"
		cp "$srcdir/crossdirect-$_arch" "./"

		# GCC: create compiler symlinks
		for _bin in $_bins; do
			ln -s "crossdirect-$_arch" "$_bin"
			ln -s "crossdirect-$_arch" "$_hostspec-$_bin"
		done

		# Rust: arch-specific rustc wrapper
		install -Dm755 "$srcdir/rustc-$_arch" "$_bindir/rustc"
	done
}
sha512sums="500107e5aff8b34e74b54982ebcd447fc41bc8283956d506561b031a055cb30ec12698047c2604918b4b6d8560fe03db427a63dff2b83c907e8494b7f5233f29  crossdirect.c
6be16ba88720e628a3ecc8fa53f8e7a21d2af268b0509745d989139874d6b94b640bfcff09575eaa19073810be6ef91169c1f83e94f5cf8e6819f2670d9408de  rustc.sh
ea9bf8db3810d03d0a7395057f3d6e57f7127d87c55deaedc171c255288f5f3cc6fbcc680a5a1b92786cf573875d5dc22521173799fe2639acc97d0715ff905b  rust-qemu-linker.sh"
