# SPDX-License-Identifier: GPL-2.0-or-later
# musl libc — MIT-licensed: https://musl.libc.org/
#
# Installs into $(PREFIX) (= build/ports/musl/prefix), which port.mk exports
# to every other port as $(MUSL). Nothing is written into this directory.

include ../mk/port.mk

MUSL_VERSION := 1.2.5
MUSL_URL     := https://musl.libc.org/releases/musl-$(MUSL_VERSION).tar.gz
MUSL_SHA256  := a9a118bbe84d8764da0ea0d28b3ab3fae8477fc7e4085d90102b8596fc7c75e4

TARBALL := $(DISTDIR)/musl-$(MUSL_VERSION).tar.gz

$(TARBALL): | $(DISTDIR)
	curl -fsSL -o $@ $(MUSL_URL)
	sh $(SHA256CHECK) "$(MUSL_SHA256)" "$@"

download: $(TARBALL)

$(SRCDIR): $(TARBALL)
	mkdir -p $(PORTDIR)
	tar -xzf $< -C $(PORTDIR)
	mv $(PORTDIR)/musl-$(MUSL_VERSION) $@

# $(SRCDIR) is order-only (|) on purpose. The stamp lives INSIDE $(SRCDIR),
# so creating it bumps that directory's mtime — making the directory forever
# newer than the stamp it contains, and re-running this rule on every single
# build. The second run then fails, because the patch does not apply twice.
$(SRCDIR)/.patched: patches/0001-schos-tls.patch | $(SRCDIR)
	cd $(SRCDIR) && patch -p1 < $(CURDIR)/patches/0001-schos-tls.patch
	touch $@

# Shared as well as static: libc.so is also the dynamic linker, and it is
# what a dynamically linked program names as its interpreter. Every port
# still links -static on purpose; this only makes the other kind possible.
#
# --syslibdir into the prefix, not the default /lib: `make install` puts a
# symlink to the loader there, and the default is the *host's* /lib. The copy
# the OS ships is placed by the sysroot rule below.
#
# Reconfigured when this file changes, so a tree configured before shared
# libraries were turned on does not quietly stay static-only.
$(BUILDDIR)/config.mak: $(SRCDIR)/.patched Makefile
	rm -rf $(BUILDDIR)
	mkdir -p $(BUILDDIR)
	cd $(BUILDDIR) && $(SRCDIR)/configure \
		--prefix=$(PREFIX) \
		--syslibdir=$(PREFIX)/lib \
		CC=$(CC) \
		CFLAGS="-D__SCHOS__ -fno-stack-protector"

$(BUILDDIR)/lib/libc.a: $(BUILDDIR)/config.mak
	$(MAKE) -C $(BUILDDIR)

$(PREFIX)/lib/libc.a: $(BUILDDIR)/lib/libc.a
	$(MAKE) -C $(BUILDDIR) install

# The dynamic linker, under the name every dynamically linked x86_64 musl
# program asks for. A copy rather than the prefix's symlink: that one points
# at a path on the build host.
$(SYSROOT)/lib/ld-musl-x86_64.so.1: $(PREFIX)/lib/libc.a
	mkdir -p $(SYSROOT)/lib
	cp $(PREFIX)/lib/libc.so $@

install: $(PREFIX)/lib/libc.a $(SYSROOT)/lib/ld-musl-x86_64.so.1

clean:
	rm -rf $(PORTDIR)

distclean: clean
	rm -f $(TARBALL)