[PATCH] xen: add header guards to generated asm generic headers

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

MISRA D4.10 requires to have proper header guards in place in all header
files. Add header guards for generated asm generic headers as well.

Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>

diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
index b0d356bfa3..a44844bed0 100644
--- a/xen/scripts/Makefile.asm-generic
+++ b/xen/scripts/Makefile.asm-generic
@@ -32,7 +32,12 @@ old-headers := $(wildcard $(obj)/*.h)
 unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))
 
 quiet_cmd_wrap = WRAP    $@
-      cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
+      cmd_wrap = \
+       upper=$$(echo $*.h | tr a-z A-Z | tr '/.' '__'); \
+       printf "\#ifndef ASM_GENERIC_$${upper}\n" > $@; \
+       printf "\#define ASM_GENERIC_$${upper}\n" >> $@; \
+       printf "\#include <asm-generic/$*.h>\n" >> $@; \
+       printf "\#endif /* ASM_GENERIC_$${upper} */\n" >> $@
 
 quiet_cmd_remove = REMOVE  $(unwanted)
       cmd_remove = rm -f $(unwanted)