Starting with release 10.38 PCRE2 drops default support for using \K in lookaround patterns as described in [1]. Unfortunately, scripts/tags.sh relies on such functionality to collect all_compiled_soures() leading to the following error:
$ make COMPILED_SOURCE=1 tags GEN tags grep: \K is not allowed in lookarounds (but see PCRE2_EXTRA_ALLOW_LOOKAROUND_BSK)
The usage of \K for this pattern was introduced in commit 4f491bb6ea2a ("scripts/tags.sh: collect compiled source precisely") which speeds up the generation of tags significantly.
In order to fix this issue without compromising the performance we can switch over to an equivalent sed expression. The same matching pattern is preserved here except \K is replaced with a backreference \1.
[1] https://www.pcre.org/current/doc/html/pcre2syntax.html#SEC11
Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Cristian Ciocaltea cristian.ciocaltea@collabora.com Cc: Masahiro Yamada masahiroy@kernel.org Cc: Jialu Xu xujialu@vimux.org Cc: Vipin Sharma vipinsh@google.com Cc: stable@vger.kernel.org Fixes: 4f491bb6ea2a ("scripts/tags.sh: collect compiled source precisely") Signed-off-by: Carlos Llamas cmllamas@google.com --- v2: add Fixes tag and cc stable
scripts/tags.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/tags.sh b/scripts/tags.sh index e137cf15aae9..0d045182c08c 100755 --- a/scripts/tags.sh +++ b/scripts/tags.sh @@ -91,7 +91,7 @@ all_compiled_sources() { echo include/generated/autoconf.h find $ignore -name "*.cmd" -exec \ - grep -Poh '(?(?=^source_.* \K).*|(?=^ \K\S).*(?= \))' {} + | + sed -n -E 's/^source_.* (.*)/\1/p; s/^ (\S.*) \/\1/p' {} + | awk '!a[$0]++' } | xargs realpath -esq $([ -z "$KBUILD_ABS_SRCTREE" ] && echo --relative-to=.) | sort -u
Starting with release 10.38 PCRE2 drops default support for using \K in lookaround patterns as described in [1]. Unfortunately, scripts/tags.sh relies on such functionality to collect all_compiled_soures() leading to the following error:
$ make COMPILED_SOURCE=1 tags GEN tags grep: \K is not allowed in lookarounds (but see PCRE2_EXTRA_ALLOW_LOOKAROUND_BSK)
The usage of \K for this pattern was introduced in commit 4f491bb6ea2a ("scripts/tags.sh: collect compiled source precisely") which speeds up the generation of tags significantly.
In order to fix this issue without compromising the performance we can switch over to an equivalent sed expression. The same matching pattern is preserved here except \K is replaced with a backreference \1.
Just got a working grep without \K, seems that it is three times more efficient than sed in my test, is it necessary to update?
grep -Poh '(?<=^ )\S+|(?<== )\S+[^\](?=$)' {} + |
-- Jialu
On Fri, Mar 03, 2023 at 07:20:51PM +0800, Jialu Xu wrote:
Just got a working grep without \K, seems that it is three times more efficient than sed in my test, is it necessary to update?
grep -Poh '(?<=^ )\S+|(?<== )\S+[^\](?=$)' {} + |
-- Jialu
I just tried this and it does have better performance. Even better than your previous grep expression it seems, so I would definitely send a patch.
-- Carlos Llamas
linux-stable-mirror@lists.linaro.org
-
Carlos Llamas -
Jialu Xu