[RFC PATCH 3/3] scripts: headers_install: avoid license check fork

[David Disseldorp <ddiss@suse.de>]

headers_install runs a sed script to check that any GPL variant
SPDX-License-Identifier line carries a "WITH Linux-syscall-note".
A subsequent sed invocation then handles removal of a few things that
aren't desired in installed headers (e.g. __attribute_const__).

Combine these two sed scripts to avoid re-processing the same file.
License check errors, as opposed to write errors, are indicated via a
special sed exit status of 9.

Signed-off-by: David Disseldorp <ddiss@suse.de>
---
 scripts/headers_install.sh | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
index f46e91aa416cf..7dbb8eb6f0a0b 100755
--- a/scripts/headers_install.sh
+++ b/scripts/headers_install.sh
@@ -23,20 +23,25 @@ TMPFILE=$OUTFILE.tmp
 
 trap 'rm -f $OUTFILE $TMPFILE' EXIT
 
-# SPDX-License-Identifier with GPL variants must have "WITH Linux-syscall-note"
-if [ -n "$(sed -n -e "/SPDX-License-Identifier:.*GPL-/{/WITH Linux-syscall-note/!p}" $INFILE)" ]; then
-	echo "error: $INFILE: missing \"WITH Linux-syscall-note\" for SPDX-License-Identifier" >&2
-	exit 1
-fi
-
+# returns 9 if GPL SPDX-License-Identifier omits "WITH Linux-syscall-note"
 sed -E -e '
+	/SPDX-License-Identifier:.*GPL-/{/WITH Linux-syscall-note/! Q9}
 	s/([[:space:](])(__user|__force|__iomem)[[:space:]]/\1/g
 	s/__attribute_const__([[:space:]]|$)/\1/g
 	s@^#include <linux/compiler.h>@@
 	s/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g
 	s/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g
 	s@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @
-' $INFILE > $TMPFILE || exit 1
+' $INFILE > $TMPFILE
+case $? in
+9)
+	echo "error: $INFILE: missing \"WITH Linux-syscall-note\" for SPDX-License-Identifier" >&2
+	exit 1
+	;;
+1)
+	exit 1
+	;;
+esac
 
 # The entries in the following list do not result in an error.
 # Please do not add a new entry. This list is only for existing ones.
-- 
2.51.0