stubdom/ioemu link farm creation fixes

Replace the stubdom/ioemu link farm creation in stubdom/Makefile,
with code which arranges that:
 * No symlinks are made for output files - in particular, any
   symlinks for .d files would be written through by the compiler
   and cause damage to the original tree and other strange
   behaviours
 * All subdirectories are made as local subdirectories rather than
   links
 * Any interrupted or half-completed creation of the link farm
   leaves the directory in a state where the link farming will be
   restarted
 * We use make's inherent ability to test for the existence of files
   rather than using [ -f ... ] at the start of the rule's commands
 * The list of files to be excluded from the link farm can be
   easily updated
etc.

This should fix some problems particularly with parallel builds,
or by-hand builds where directories are entered in other than the
usual order.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

1 files changed, 20 insertions, 17 deletions

diff --git a/stubdom/Makefile b/stubdom/Makefile
index 9bab6b4036..141d64e1db 100644
--- a/stubdom/Makefile
+++ b/stubdom/Makefile
@@ -165,7 +165,26 @@ $(CROSS_ROOT): cross-newlib cross-zlib cross-libpci
 $(XEN_ROOT)/tools/ioemu-dir:
 	make -C $(XEN_ROOT)/tools ioemu-dir-find
 
-mk-headers-$(XEN_TARGET_ARCH): $(XEN_ROOT)/tools/ioemu-dir
+ioemu/linkfarm.stamp: $(XEN_ROOT)/tools/ioemu-dir
+	mkdir -p ioemu
+ifeq ($(CONFIG_QEMU),ioemu)
+	[ -h ioemu/Makefile ] || ( cd ioemu && \
+	  ln -sf ../$(XEN_ROOT)/tools/ioemu/* .)
+else
+	set -e;									\
+	$(absolutify_xen_root);							\
+	cd ioemu;								\
+	src="$$XEN_ROOT/tools/ioemu-dir"; export src;				\
+	(cd $$src && find * -type d -print) | xargs mkdir -p;			\
+	(cd $$src && find *	! -type l  -type f  $(addprefix ! -name ,	\
+			'*.[oda1]' 'config-*' config.mak qemu-dm qemu-img-xen	\
+			'*.html' '*.pod'					\
+			)) |							\
+	    while read f; do rm -f "$$f"; ln -s "$$src/$$f" "$$f"; done
+endif
+	touch ioemu/linkfarm.stamp
+
+mk-headers-$(XEN_TARGET_ARCH): ioemu/linkfarm.stamp
 	mkdir -p include/xen && \
           ln -sf $(addprefix ../../,$(wildcard $(XEN_ROOT)/xen/include/public/*.h)) include/xen && \
           ln -sf $(addprefix ../../$(XEN_ROOT)/xen/include/public/,arch-ia64 arch-x86 hvm io xsm) include/xen && \
@@ -184,22 +203,6 @@ mk-headers-$(XEN_TARGET_ARCH): $(XEN_ROOT)/tools/ioemu-dir
 	  ln -sf ../$(XEN_ROOT)/tools/libxc/$(XEN_TARGET_ARCH)/*.c . && \
 	  ln -sf ../$(XEN_ROOT)/tools/libxc/$(XEN_TARGET_ARCH)/*.h . && \
 	  ln -sf ../$(XEN_ROOT)/tools/libxc/$(XEN_TARGET_ARCH)/Makefile . )
-	mkdir -p ioemu
-ifeq ($(CONFIG_QEMU),ioemu)
-	[ -h ioemu/Makefile ] || ( cd ioemu && \
-	  ln -sf ../$(XEN_ROOT)/tools/ioemu/* .)
-else
-	[ -h ioemu/Makefile ] || ( cd ioemu && \
-	  ln -sf ../$(XEN_ROOT)/tools/ioemu-dir/* . && \
-          rm -fr i386-dm && \
-          rm -fr i386-stubdom && \
-          mkdir i386-dm && \
-          mkdir i386-stubdom && \
-	  ln -sf $(CONFIG_QEMU)/i386-dm/* i386-dm/ && \
-	  ln -sf $(CONFIG_QEMU)/i386-stubdom/* i386-stubdom/ )
-endif
-	[ ! -h ioemu/config-host.h ] || rm -f ioemu/config-host.h
-	[ ! -h ioemu/config-host.mak ] || rm -f ioemu/config-host.mak
 	$(MAKE) -C $(MINI_OS) links
 	touch mk-headers-$(XEN_TARGET_ARCH)