scripts/tags.sh: fix incompatibility with PCRE2
authorCarlos Llamas <cmllamas@google.com>
Wed, 15 Feb 2023 18:38:50 +0000 (18:38 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 3 Mar 2023 10:52:25 +0000 (11:52 +0100)
commitc49bd6c2dd1bd67abd2b638ae10deb65c4f4031e
treea009eb27afa8a2ef6488657d96a4f9f45aba34e7
parenta591d9fd7001f9a71d648ef17a42aef19a3fd9f1
scripts/tags.sh: fix incompatibility with PCRE2

commit 6ec363fc6142226b9ab5a6528f65333d729d2b6b upstream.

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>
Link: https://lore.kernel.org/r/20230215183850.3353198-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scripts/tags.sh