[Qemu-devel] [PATCH] build: sort objects to remove duplicates for link

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

Avoid duplicate object files during the link.  There are legitimate
cases where a link command-line would include duplicate object files
because two independent subsystems both depend on common infrastructure.

Use GNU make's $(sort) function to remove duplicate object files from
the link command-line.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
Your patch seems fine but we need to avoid duplicate object files during the
link phase.  Otherwise we run into linker warnings because qemu-timer-common.o
is linked multiple times.  Please include this patch and resend the two
together with this patch as 1/2 and yours as 2/2.

 rules.mak |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/rules.mak b/rules.mak
index 884d421..04a9198 100644
--- a/rules.mak
+++ b/rules.mak
@@ -31,7 +31,7 @@ endif
 %.o: %.m
 	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
 
-LINK = $(call quiet-command,$(CC) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(1) $(LIBS),"  LINK  $(TARGET_DIR)$@")
+LINK = $(call quiet-command,$(CC) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(sort $(1)) $(LIBS),"  LINK  $(TARGET_DIR)$@")
 
 %$(EXESUF): %.o
 	$(call LINK,$^)
-- 
1.7.5.4