Improve build system

.gitignore

@@ -1,2 +1,3 @@
 /build/
 /dest/
+/musl-gcc.specs

Makefile

@@ -11,6 +11,9 @@ DEST_TARGETS = \
 
 all: fhs $(DEST_TARGETS)
 
+clean:
+	rm -rf build dest musl-gcc.specs
+
 include make/busybox.mk
 include make/fhs.mk
 include make/libkernaux.mk

make/busybox.mk

@@ -4,15 +4,11 @@ dest/bin/busybox: build/busybox/busybox
 build/busybox/busybox: build/busybox/.config dest/usr/lib/libc.a
 	$(MAKE) -C build/busybox
 
-build/busybox/musl-gcc.specs:
-	mkdir -p build/busybox
-	./musl-gcc-specs.sh $(ABS_REPO)/dest/usr/include $(ABS_REPO)/dest/usr/lib /lib/ld-musl-x86_64.so.1 > build/busybox/musl-gcc.specs
-
-build/busybox/.config: build/busybox/musl-gcc.specs
+build/busybox/.config: musl-gcc.specs
 	mkdir -p build/busybox
 	$(MAKE) -C build/busybox -f $(ABS_REPO)/vendor/busybox/Makefile KBUILD_SRC=$(ABS_REPO)/vendor/busybox defconfig
 	cp build/busybox/.config build/busybox/.config.bak
-	sed -i 's!^#* *CONFIG_EXTRA_CFLAGS[ =].*$$!CONFIG_EXTRA_CFLAGS="-specs $(ABS_REPO)/build/busybox/musl-gcc.specs"!' build/busybox/.config
+	sed -i 's!^#* *CONFIG_EXTRA_CFLAGS[ =].*$$!CONFIG_EXTRA_CFLAGS="-specs $(ABS_REPO)/musl-gcc.specs"!' build/busybox/.config
 	sed -i 's!^#* *CONFIG_PREFIX[ =].*$$!CONFIG_PREFIX="$(ABS_REPO)/dest"!'       build/busybox/.config
 	#sed -i 's!^#* *CONFIG_STATIC[ =].*$$!CONFIG_STATIC=y!'                        build/busybox/.config
 	sed -i 's!^#* *CONFIG_SYSROOT[ =].*$$!CONFIG_SYSROOT="$(ABS_REPO)/dest"!'     build/busybox/.config

make/musl.mk

@@ -1,3 +1,6 @@
+musl-gcc.specs: dest/usr/lib/libc.a
+	./musl-gcc.specs.sh $(ABS_REPO)/dest/usr/include $(ABS_REPO)/dest/usr/lib /lib/ld-musl-x86_64.so.1 > musl-gcc.specs
+
 dest/usr/lib/libc.a:
 	mkdir -p build/musl
 	cd build/musl && '../../vendor/musl/configure' --prefix=/usr