svn commit: r363679 - in head: contrib/netbsd-tests/lib/libc/regex/data lib/libc/regex

[Kyle Evans]

On Wed, Jul 29, 2020 at 10:53 PM Li-Wen Hsu <lwhsu at freebsd.org> wrote:
>
> On Thu, Jul 30, 2020 at 7:22 AM Kyle Evans <kevans at freebsd.org> wrote:
> >
> > Author: kevans
> > Date: Wed Jul 29 23:21:56 2020
> > New Revision: 363679
> > URL: https://svnweb.freebsd.org/changeset/base/363679
> >
> > Log:
> >   regex(3): Interpret many escaped ordinary characters as EESCAPE
> >
> >   In IEEE 1003.1-2008 [1] and earlier revisions, BRE/ERE grammar allows for
> >   any character to be escaped, but "ORD_CHAR preceded by an unescaped
> >   <backslash> character [gives undefined results]".
> >
> >   Historically, we've interpreted an escaped ordinary character as the
> >   ordinary character itself. This becomes problematic when some extensions
> >   give special meanings to an otherwise ordinary character
> >   (e.g. GNU's \b, \s, \w), meaning we may have two different valid
> >   interpretations of the same sequence.
> >
> >   To make this easier to deal with and given that the standard calls this
> >   undefined, we should throw an error (EESCAPE) if we run into this scenario
> >   to ease transition into a state where some escaped ordinaries are blessed
> >   with a special meaning -- it will either error out or have extended
> >   behavior, rather than have two entirely different versions of undefined
> >   behavior that leave the consumer of regex(3) guessing as to what behavior
> >   will be used or leaving them with false impressions.
> >
> >   This change bumps the symbol version of regcomp to FBSD_1.6 and provides the
> >   old escape semantics for legacy applications, just in case one has an older
> >   application that would immediately turn into a pumpkin because of an
> >   extraneous escape that's embehttps://ci.freebsd.org/job/FreeBSD-head-amd64-test/16011/testReport/junit/lib.googletest.gtest_main/googletest-port-test/main/dded or otherwise critical to its operation.
> >
> >   This is the final piece needed before enhancing libregex with GNU extensions
> >   and flipping the switch on bsdgrep.
> >
> >   [1] http://pubs.opengroup.org/onlinepubs/9699919799.2016edition/
> >
> >   PR:           229925 (exp-run, courtesy of antoine)
> >   Differential Revision:        https://reviews.freebsd.org/D10510
> >
> > Modified:
> >   head/contrib/netbsd-tests/lib/libc/regex/data/meta.in
> >   head/contrib/netbsd-tests/lib/libc/regex/data/subexp.in
> >   head/lib/libc/regex/Symbol.map
> >   head/lib/libc/regex/regcomp.c
>
> I think there are 3 test cases need to be modified after this change:
>
> https://ci.freebsd.org/job/FreeBSD-head-amd64-test/16011/testReport/junit/lib.googletest.gtest_main/googletest-port-test/main/
> https://ci.freebsd.org/job/FreeBSD-head-amd64-test/16011/testReport/junit/usr.bin.diff/diff_test/side_by_side/
> https://ci.freebsd.org/job/FreeBSD-head-amd64-test/16011/testReport/junit/usr.bin.sed/sed2_test/hex_subst/
>

CC'ing asomers@ and ngie@, because ISTR they have some googletest stock.

Testing my libregex GNU extensions revealed that I'm really not ready
to commit that just yet. We have two options here for googletest:

1. Disable it and create a PR to be fixed when my changes are done,
hopefully by the end of the week, or
2. Fix the expressions in
contrib/googletest/googletest/test/googletest-port-test.cc to be POSIX
compliant and upstream that.

#2 is generally a replacement of \w -> [[:alnum:]] and \W ->
[^[:alnum:]] and maybe \s -> [[:space:]].

Thoughts?

Thanks,

Kyle Evans