The GNU extension bits in the base system are old, no longer faithful to upstream, and surprising in some regards. Switch to documenting WITH_GNU_GREP_COMPAT and default GNU_GREP_COMPAT to OFF in the name of good behavior.
PR: 184733, 191086
Details
Details
- Reviewers
emaste cem - Commits
- rS317255: bsdgrep: disable GNU_GREP_COMPAT by default
Run the kyua tests to ensure we've not caused any regressions
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Buildable 8244 Build 8487: arc lint + arc unit
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I think this is a reasonable change to make. It'd be good to have a list of what the "gnu extensions" are for the commit message, and perhaps to be mentioned in the WITH_GNU_GREP_COMPAT file though.
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PR191086: GNU grep and WITH_GNU_GREP_COMPAT bsdgrep do not accept [[:<:]] and [[:>:]] character classes.
| tools/build/options/WITH_GNU_GREP_COMPAT | ||
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| 2 |
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Heh, shucks. =) I'm not familiar with the GNU extensions myself outside of knowing that the mentioned PRs exhibited broken behavior with libgnuregex and was fine without -- it'll take me a little bit to scrape through our version of libgnuregex and make somewhat of an exhaustive list of differences.
| tools/build/options/WITH_GNU_GREP_COMPAT | ||
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| 2 | Something along the lines of Set this option to include the GNU extensions in BSD grep by linking against libgnuregex, which is licensed under the LGPL? | |
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I can't imagine many ports want to use /usr/bin/bsdgrep and not grep, and switching BSD grep to be installed as /usr/bin/grep really needs an exp-run. I suspect we should perform the exp-run with:
diff --git a/share/mk/src.opts.mk b/share/mk/src.opts.mk index 16c2527de51f..afc4a51e8e24 100644 --- a/share/mk/src.opts.mk +++ b/share/mk/src.opts.mk @@ -62,6 +62,7 @@ __DEFAULT_YES_OPTIONS = \ BOOTPARAMD \ BOOTPD \ BSD_CPIO \ + BSD_GREP \ BSDINSTALL \ BSNMP \ BZIP2 \ @@ -99,8 +100,6 @@ __DEFAULT_YES_OPTIONS = \ GDB \ GNU \ GNU_DIFF \ - GNU_GREP \ - GNU_GREP_COMPAT \ GPIO \ GPL_DTC \ GROFF \ @@ -179,9 +180,10 @@ __DEFAULT_YES_OPTIONS = \ ZONEINFO __DEFAULT_NO_OPTIONS = \ - BSD_GREP \ CLANG_EXTRAS \ DTRACE_TESTS \ + GNU_GREP \ + GNU_GREP_COMPAT \ HESIOD \ LIBSOFT \ NAND \
| tools/build/options/WITH_GNU_GREP_COMPAT | ||
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| 2 | There should be a hard/soft stop in that sentence. The first part is talking about GNU extensions being implemented. The second part is talking about libgnuregex's less permissive license. | |
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Ahhh, excellent! I had no idea that mdoc(7) was a thing, and I was just starting to worry about making man changes without a document similar to style(9) that I can reference. This looks to be exactly what I needed, though. Thanks!
| tools/build/options/WITH_GNU_GREP_COMPAT | ||
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| 2 | Or maybe we should just drop the LGPL comment: Set this option to include the GNU extensions in BSD grep, by linking against libgnuregex. | |
| tools/build/options/WITH_GNU_GREP_COMPAT | ||
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| 2 | The name "libgnuregex" alone would probably spur further investigation into the exact license of said library. It would be nice if the the license for libgnuregex was more prominent than it is now, though. | |
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According to http://www.regular-expressions.info, GNU extensions:
- Add missing quantifiers to BREs: \?, \+
- Add branching to BREs: \|
- Add backreferences (\1 through \9) to EREs
- Add \w, \W, \s, and \S corresponding to :alnum:, [^[:alnum:]], :space:, and [^[:space:]] respectively
- Add word boundaries and anchors:
- \b: word boundary
- \B: not word boundary
- \<: Strt of word
- \>: End of word
- \`: Start of subject string
- \': End of subject string
Additionally, I've noted that GNU utilities seem to allow patterns like "a{,}" or "a{,5}" to mean "any number of a" or "up to 5 a" respectively, rather than the format described by re_format(7) where the start of the interval at least must be specified, while the end may be omitted.
I could slowly implement some of these into regex(3) if that is deemed desirable, whether it be through some kind of additional flag or #define support.