improve Makefile handling of git checkouts with missing lib/ and config.mak

diff --git a/Makefile b/Makefile
index 13a24e3c1e506d9f107bfa45ed7a192f74a6a0bd..c3d29d240c64646083efbd6d6b666cfeda8fea05 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -54,6 +54,7 @@ clean:
        rm -f include/bits
 
 include/bits:
+       @test "$(ARCH)" || { echo "Please set ARCH in config.mak before running make." ; exit 1 ; }
        ln -sf ../arch/$(ARCH)/bits $@
 
 include/bits/alltypes.h.sh: include/bits
@@ -73,19 +74,22 @@ include/bits/alltypes.h: include/bits/alltypes.h.sh
 %.lo: %.c $(GENH)
        $(CC) $(CFLAGS) $(INC) $(PIC) -c -o $@ $<
 
-lib/libc.so: $(LOBJS)
+lib:
+       mkdir -p lib
+
+lib/libc.so: $(LOBJS) lib
        $(CC) $(LDFLAGS) -o $@ $(LOBJS) -lgcc
        $(OBJCOPY) --weaken $@
 
-lib/libc.a: $(OBJS)
+lib/libc.a: $(OBJS) lib
        rm -f $@
        $(AR) rc $@ $(OBJS)
        $(RANLIB) $@
 
-$(EMPTY_LIBS):
+$(EMPTY_LIBS): lib
        $(AR) rc $@
 
-lib/%.o: crt/%.o
+lib/%.o: crt/%.o lib
        cp $< $@
 
 tools/musl-gcc: tools/gen-musl-gcc.sh config.mak