[PATCH V2] multilib_header: Place a #include guard to avoid infinite inclusion of headers

[Khem Raj <raj.khem@gmail.com>]

In cases where extra preprocessing tools are used such as clang-tidy
e.g. and these tools are not passed the knowledge about architecture
then a corner case comes where we enter into include loop for
bits/wordsize.h, since this template does explicitly include
bits/wordsize.h

so it synthesized a guard out of file name e.g.

bits/wordsize.h -> __BITS_WORDSIZE_H__

and emits the guard at beginning of file

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
v2: Drop space changes, not needed, and fix a typo > to >>

 meta/classes/multilib_header.bbclass | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/meta/classes/multilib_header.bbclass b/meta/classes/multilib_header.bbclass
index e03f5b13b2..70b7117da8 100644
--- a/meta/classes/multilib_header.bbclass
+++ b/meta/classes/multilib_header.bbclass
@@ -33,10 +33,13 @@ oe_multilib_header() {
 	      continue
 	   fi
 	   stem=$(echo $each_header | sed 's#\.h$##')
+	   include_guard=$(echo $each_header | tr '/.' '_' | tr '[a-z]' '[A-Z]' | sed 's/^/__/' | sed 's/$/__/')
 	   # if mips64/n32 set ident to n32
 	   mv ${D}/${includedir}/$each_header ${D}/${includedir}/${stem}-${ident}.h
-
-	   sed -e "s#ENTER_HEADER_FILENAME_HERE#${stem}#g" ${COREBASE}/scripts/multilib_header_wrapper.h > ${D}/${includedir}/$each_header
+	   echo "#ifndef $include_guard" > ${D}/${includedir}/$each_header
+	   echo "#define $include_guard" >> ${D}/${includedir}/$each_header
+	   sed -e "s#ENTER_HEADER_FILENAME_HERE#${stem}#g" ${COREBASE}/scripts/multilib_header_wrapper.h >> ${D}/${includedir}/$each_header
+	   echo "#endif /* $include_guard */" >> ${D}/${includedir}/$each_header
 	done
 }
 
-- 
2.20.1