FROM buildpack-deps@sha256:8465175ca53f8f2e756d069658b3f353bb3732926b1f33f34332cfbf597ad0c0 as build

# https://gcc.gnu.org/mirrors.html
ENV GPG_KEYS \
# 1024D/745C015A 1999-11-09 Gerald Pfeifer <gerald@pfeifer.com>
	B215C1633BCA0477615F1B35A5B3A004745C015A \
# 1024D/B75C61B8 2003-04-10 Mark Mitchell <mark@codesourcery.com>
	B3C42148A44E6983B3E4CC0793FA9B1AB75C61B8 \
# 1024D/902C9419 2004-12-06 Gabriel Dos Reis <gdr@acm.org>
	90AA470469D3965A87A5DCB494D03953902C9419 \
# 1024D/F71EDF1C 2000-02-13 Joseph Samuel Myers <jsm@polyomino.org.uk>
	80F98B2E0DAB6C8281BDF541A7C8C3B2F71EDF1C \
# 2048R/FC26A641 2005-09-13 Richard Guenther <richard.guenther@gmail.com>
	7F74F97C103468EE5D750B583AB00996FC26A641 \
# 1024D/C3C45C06 2004-04-21 Jakub Jelinek <jakub@redhat.com>
	33C235A34C46AA3FFB293709A328C3A2C3C45C06 \
# 4096R/09B5FA62 2020-05-28 Jakub Jelinek <jakub@redhat.com>
	D3A93CAD751C2AF4F8C7AD516C35B99309B5FA62

RUN set -ex; \
	apt-get update; \
	apt-get install -y --no-install-recommends \
		gnupg \
	; \
	rm -rf /var/lib/apt/lists/*; \
	for key in $GPG_KEYS; do \
		gpg --batch --keyserver keyserver.ubuntu.com --recv-keys "$key"; \
	done

# https://gcc.gnu.org/mirrors.html
ENV GCC_MIRRORS \
		https://ftpmirror.gnu.org/gcc \
		https://mirrors.kernel.org/gnu/gcc \
		https://bigsearcher.com/mirrors/gcc/releases \
		http://www.netgull.com/gcc/releases \
		https://ftpmirror.gnu.org/gcc \
# only attempt the origin FTP as a mirror of last resort
		ftp://ftp.gnu.org/gnu/gcc

ENV GCC_VERSION 13.2.0

RUN set -ex; \
	\
	savedAptMark="$(apt-mark showmanual)"; \
	apt-get update; \
	apt-get install -y --no-install-recommends \
		dpkg-dev \
		flex \
	; \
	rm -r /var/lib/apt/lists/*; \
	\
	_fetch() { \
		local fetch="$1"; shift; \
		local file="$1"; shift; \
		for mirror in $GCC_MIRRORS; do \
			if curl -fL "$mirror/$fetch" -o "$file"; then \
				return 0; \
			fi; \
		done; \
		echo >&2 "error: failed to download '$fetch' from several mirrors"; \
		return 1; \
	}; \
	\
	_fetch "gcc-$GCC_VERSION/gcc-$GCC_VERSION.tar.xz.sig" 'gcc.tar.xz.sig'; \
	_fetch "gcc-$GCC_VERSION/gcc-$GCC_VERSION.tar.xz" 'gcc.tar.xz'; \
	gpg --batch --verify gcc.tar.xz.sig gcc.tar.xz; \
	mkdir -p /usr/src/gcc; \
	tar -xf gcc.tar.xz -C /usr/src/gcc --strip-components=1; \
	rm gcc.tar.xz*; \
	\
	cd /usr/src/gcc; \
	\
# "download_prerequisites" pulls down a bunch of tarballs and extracts them,
# but then leaves the tarballs themselves lying around
	./contrib/download_prerequisites; \
	{ rm *.tar.* || true; }; \
	\
# explicitly update autoconf config.guess and config.sub so they support more arches/libcs
	for f in config.guess config.sub; do \
		wget -O "$f" "https://git.savannah.gnu.org/cgit/config.git/plain/$f?id=7d3d27baf8107b630586c962c057e22149653deb"; \
# find any more (shallow) copies of the file we grabbed and update them too
		find -mindepth 2 -name "$f" -exec cp -v "$f" '{}' ';'; \
	done; \
	\
	dir="$(mktemp -d)"; \
	cd "$dir"; \
	\
	extraConfigureArgs=''; \
	dpkgArch="$(dpkg --print-architecture)"; \
	case "$dpkgArch" in \
# with-arch: https://salsa.debian.org/toolchain-team/gcc/-/blob/gcc-11-debian/debian/rules2#L462-502
# with-float: https://salsa.debian.org/toolchain-team/gcc/-/blob/gcc-11-debian/debian/rules.defs#L502-512
# with-mode: https://salsa.debian.org/toolchain-team/gcc/-/blob/gcc-11-debian/debian/rules.defs#L480
		armel) \
			extraConfigureArgs="$extraConfigureArgs --with-arch=armv5te --with-float=soft" \
			;; \
		armhf) \
			# https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1939379/comments/2
			extraConfigureArgs="$extraConfigureArgs --with-arch=armv7-a+fp --with-float=hard --with-mode=thumb" \
			;; \
		\
# with-arch-32: https://salsa.debian.org/toolchain-team/gcc/-/blob/gcc-11-debian/debian/rules2#L598
		i386) \
			extraConfigureArgs="$extraConfigureArgs --with-arch-32=i686"; \
			;; \
	esac; \
	\
	gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \
	/usr/src/gcc/configure \
		--build="$gnuArch" \
		--disable-multilib \
		--enable-languages=c,c++,fortran,go \
        --prefix /opt/gcc \
		$extraConfigureArgs \
	; \
	make -j "$(nproc)"; \
	make install-strip; \
	cd ..; \
	\
	rm -rf "$dir" /usr/src/gcc; \
	\
	apt-mark auto '.*' > /dev/null; \
	[ -z "$savedAptMark" ] || apt-mark manual $savedAptMark; \
	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false

COPY --from=library/busybox@sha256:f553b7484625f0c73bfa3888e013e70e99ec6ae1c424ee0e8a85052bd135a28a / rootfs/

RUN \
  echo "nogroup:*:100:nobody" > rootfs/etc/group \
  && echo "nobody:*:100:100:::" > rootfs/etc/passwd \
  && mkdir -p rootfs \
  && cp -RHp /opt/gcc/* rootfs/

FROM scratch
COPY --from=build --chown=100:100 /rootfs /usr/local
ENTRYPOINT ["/bin/gcc"]
CMD ["--version"]