git/grep.h, branch v2.14.2

grep: remove regflags from the public grep_opt API

2017-06-30T17:06:24Z

Refactor calls to the grep machinery to always pass opt.ignore_case & opt.extended_regexp_option instead of setting the equivalent regflags bits. The bug fixed when making -i work with -P in commit 9e3cbc59d5 ("log: make --regexp-ignore-case work with --perl-regexp", 2017-05-20) was really just plastering over the code smell which this change fixes. The reason for adding the extensive commentary here is that I discovered some subtle complexity in implementing this that really should be called out explicitly to future readers. Before this change we'd rely on the difference between `extended_regexp_option` and `regflags` to serve as a membrane between our preliminary parsing of grep.extendedRegexp and grep.patternType, and what we decided to do internally. Now that those two are the same thing, it's necessary to unset `extended_regexp_option` just before we commit in cases where both of those config variables are set. See 84befcd0a4 ("grep: add a grep.patternType configuration setting", 2012-08-03) for the code and documentation related to that. The explanation of why the if/else branches in grep_commit_pattern_type() are ordered the way they are exists in that commit message, but I think it's worth calling this subtlety out explicitly with a comment for future readers. Even though grep_commit_pattern_type() is the only caller of grep_set_pattern_type_option() it's simpler to reset the extended_regexp_option flag in the latter, since 2/3 branches in the former would otherwise need to reset it, this way we can do it in one place. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

Merge branch 'bw/object-id'

2017-06-19T19:38:44Z

Conversion from uchar[20] to struct object_id continues. * bw/object-id: (33 commits) diff: rename diff_fill_sha1_info to diff_fill_oid_info diffcore-rename: use is_empty_blob_oid tree-diff: convert path_appendnew to object_id tree-diff: convert diff_tree_paths to struct object_id tree-diff: convert try_to_follow_renames to struct object_id builtin/diff-tree: cleanup references to sha1 diff-tree: convert diff_tree_sha1 to struct object_id notes-merge: convert write_note_to_worktree to struct object_id notes-merge: convert verify_notes_filepair to struct object_id notes-merge: convert find_notes_merge_pair_ps to struct object_id notes-merge: convert merge_from_diffs to struct object_id notes-merge: convert notes_merge* to struct object_id tree-diff: convert diff_root_tree_sha1 to struct object_id combine-diff: convert find_paths_* to struct object_id combine-diff: convert diff_tree_combined to struct object_id diff: convert diff_flush_patch_id to struct object_id patch-ids: convert to struct object_id diff: finish conversion for prepare_temp_file to struct object_id diff: convert reuse_worktree_file to struct object_id diff: convert fill_filespec to struct object_id ...

grep: convert to struct object_id

2017-06-02T00:36:06Z

Convert the remaining parts of grep to use struct object_id. Signed-off-by: Brandon Williams Signed-off-by: Junio C Hamano

grep: add support for PCRE v2

2017-06-01T23:29:05Z

Add support for v2 of the PCRE API. This is a new major version of PCRE that came out in early 2015[1]. The regular expression syntax is the same, but while the API is similar, pretty much every function is either renamed or takes different arguments. Thus using it via entirely new functions makes sense, as opposed to trying to e.g. have one compile_pcre_pattern() that would call either PCRE v1 or v2 functions. Git can now be compiled with either USE_LIBPCRE1=YesPlease or USE_LIBPCRE2=YesPlease, with USE_LIBPCRE=YesPlease currently being a synonym for the former. Providing both is a compile-time error. With earlier patches to enable JIT for PCRE v1 the performance of the release versions of both libraries is almost exactly the same, with PCRE v2 being around 1% slower. However after I reported this to the pcre-dev mailing list[2] I got a lot of help with the API use from Zoltán Herczeg, he subsequently optimized some of the JIT functionality in v2 of the library. Running the p7820-grep-engines.sh performance test against the latest Subversion trunk of both, with both them and git compiled as -O3, and the test run against linux.git, gives the following results. Just the /perl/ tests shown: $ GIT_PERF_REPEAT_COUNT=30 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_MAKE_COMMAND='grep -q LIBPCRE2 Makefile && make -j8 USE_LIBPCRE2=YesPlease CC=~/perl5/installed/bin/gcc NO_R_TO_GCC_LINKER=YesPlease CFLAGS=-O3 LIBPCREDIR=/home/avar/g/pcre2/inst LDFLAGS=-Wl,-rpath,/home/avar/g/pcre2/inst/lib || make -j8 USE_LIBPCRE=YesPlease CC=~/perl5/installed/bin/gcc NO_R_TO_GCC_LINKER=YesPlease CFLAGS=-O3 LIBPCREDIR=/home/avar/g/pcre/inst LDFLAGS=-Wl,-rpath,/home/avar/g/pcre/inst/lib' ./run HEAD~5 HEAD~ HEAD p7820-grep-engines.sh [...] Test HEAD~5 HEAD~ HEAD ----------------------------------------------------------------------------------------------------------------- 7820.3: perl grep 'how.to' 0.31(1.10+0.48) 0.21(0.35+0.56) -32.3% 0.21(0.34+0.55) -32.3% 7820.7: perl grep '^how to' 0.56(2.70+0.40) 0.24(0.64+0.52) -57.1% 0.20(0.28+0.60) -64.3% 7820.11: perl grep '[how] to' 0.56(2.66+0.38) 0.29(0.95+0.45) -48.2% 0.23(0.45+0.54) -58.9% 7820.15: perl grep '(e.t[^ ]*|v.ry) rare' 1.02(5.77+0.42) 0.31(1.02+0.54) -69.6% 0.23(0.50+0.54) -77.5% 7820.19: perl grep 'm(ú|u)lt.b(æ|y)te' 0.38(1.57+0.42) 0.27(0.85+0.46) -28.9% 0.21(0.33+0.57) -44.7% See commit ("perf: add a comparison test of grep regex engines", 2017-04-19) for details on the machine the above test run was executed on. Here HEAD~2 is git with PCRE v1 without JIT, HEAD~ is PCRE v1 with JIT, and HEAD is PCRE v2 (also with JIT). See previous commits of mine mentioning p7820-grep-engines.sh for more details on the test setup. For ease of readability, a different run just of HEAD~ (PCRE v1 with JIT v.s. PCRE v2), again with just the /perl/ tests shown: [...] Test HEAD~ HEAD ---------------------------------------------------------------------------------------- 7820.3: perl grep 'how.to' 0.21(0.42+0.52) 0.21(0.31+0.58) +0.0% 7820.7: perl grep '^how to' 0.25(0.65+0.50) 0.20(0.31+0.57) -20.0% 7820.11: perl grep '[how] to' 0.30(0.90+0.50) 0.23(0.46+0.53) -23.3% 7820.15: perl grep '(e.t[^ ]*|v.ry) rare' 0.30(1.19+0.38) 0.23(0.51+0.51) -23.3% 7820.19: perl grep 'm(ú|u)lt.b(æ|y)te' 0.27(0.84+0.48) 0.21(0.34+0.57) -22.2% I.e. the two are either neck-to-neck, but PCRE v2 usually pulls ahead, when it does it's around 20% faster. A brief note on thread safety: As noted in pcre2api(3) & pcre2jit(3) the compiled pattern can be shared between threads, but not some of the JIT context, however the grep threading support does all pattern & JIT compilation in separate threads, so this code doesn't need to concern itself with thread safety. See commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09) for the initial addition of PCRE v1. This change follows some of the same patterns it did (and which were discussed on list at the time), e.g. mocking up types with typedef instead of ifdef-ing them out when USE_LIBPCRE2 isn't defined. This adds some trivial memory use to the program, but makes the code look nicer. 1. https://lists.exim.org/lurker/message/20150105.162835.0666407a.en.html 2. https://lists.exim.org/lurker/thread/20170419.172322.833ee099.en.html Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: un-break building with PCRE >= 8.32 without --enable-jit

2017-06-01T23:29:05Z

Amend my change earlier in this series ("grep: add support for the PCRE v1 JIT API", 2017-04-11) to un-break the build on PCRE v1 versions later than 8.31 compiled without --enable-jit. As explained in that change and a later compatibility change in this series ("grep: un-break building with PCRE < 8.32", 2017-05-10) the pcre_jit_exec() function is a faster path to execute the JIT. Unfortunately there's no compatibility stub for that function compiled into the library if pcre_config(PCRE_CONFIG_JIT, &ret) would return 0, and no macro that can be used to check for it, so the only portable option to support builds without --enable-jit is via a new NO_LIBPCRE1_JIT=UnfortunatelyYes Makefile option[1]. Another option would be to make the JIT opt-in via USE_LIBPCRE1_JIT=YesPlease, after all it's not a default option of PCRE v1. I think it makes more sense to make it opt-out since even though it's not a default option, most packagers of PCRE seem to turn it on by default, with the notable exception of the MinGW package. Make the MinGW platform work by default by changing the build defaults to turn on NO_LIBPCRE1_JIT=UnfortunatelyYes. It is the only platform that turns on USE_LIBPCRE=YesPlease by default, see commit df5218b4c3 ("config.mak.uname: support MSys2", 2016-01-13) for that change. 1. "How do I support pcre1 JIT on all versions?" (https://lists.exim.org/lurker/thread/20170601.103148.10253788.en.html) 2. https://github.com/Alexpux/MINGW-packages/blob/master/mingw-w64-pcre/PKGBUILD (referenced from "Re: PCRE v2 compile error, was Re: What's cooking in git.git (May 2017, #01; Mon, 1)"; ) Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: un-break building with PCRE < 8.20

2017-05-26T03:59:05Z

Amend my change earlier in this series ("grep: add support for the PCRE v1 JIT API", 2017-04-11) to un-break the build on PCRE v1 versions earlier than 8.20. The 8.20 release was the first release to have JIT & pcre_jit_stack in the headers, so a mock type needs to be provided for it on those releases. Now git should compile with all PCRE versions that it supported before my JIT change. I've tested it as far back as version 7.5 released on 2008-01-10, once I got down to version 7.0 it wouldn't build anymore with GCC 7.1.1, and I couldn't be bothered to anything older than 7.5 as I'm confident that if the build breaks on those older versions it's not because of my JIT change. See the "un-break" change in this series ("grep: un-break building with PCRE < 8.32", 2017-05-10) for why this isn't squashed into the main PCRE JIT commit. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: un-break building with PCRE < 8.32

2017-05-26T03:59:05Z

Amend my change earlier in this series ("grep: add support for the PCRE v1 JIT API", 2017-04-11) to un-break the build on PCRE v1 versions earlier than 8.32. The JIT support was added in version 8.20 released on 2011-10-21, but it wasn't until 8.32 released on 2012-11-30 that the fast code path to use the JIT via pcre_jit_exec() was added[1] (see also [2]). This means that versions 8.20 through 8.31 could still use the JIT, but supporting it on those versions would add to the already verbose macro soup around JIT support it, and I don't expect that the use-case of compiling a brand new git against a 5 year old PCRE is particularly common, and if someone does that they can just get the existing pre-JIT slow codepath. So just take the easy way out and disable the JIT on any version older than 8.32. The reason this change isn't part of the initial change PCRE JIT support is to have a cleaner history showing which parts of the implementation are only used for ancient PCRE versions. This also makes it easier to revert this change if we ever decide to stop supporting those old versions. 1. http://www.pcre.org/original/changelog.txt ("28. Introducing a native interface for JIT. Through this interface, the compiled[...]") 2. https://bugs.exim.org/show_bug.cgi?id=2121 Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: add support for the PCRE v1 JIT API

2017-05-26T03:59:05Z

Change the grep PCRE v1 code to use JIT when available. When PCRE support was initially added in commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09) PCRE had no JIT support, it was integrated into 8.20 released on 2011-10-21. Enabling JIT support usually improves performance by more than 40%. The pattern compilation times are relatively slower, but those relative numbers are tiny, and are easily made back in all but the most trivial cases of grep. Detailed benchmarks & overview of compilation times is at: http://sljit.sourceforge.net/pcre.html With this change the difference in a t/perf/p7820-grep-engines.sh run is, with just the /perl/ tests shown: $ GIT_PERF_REPEAT_COUNT=30 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_MAKE_OPTS='-j8 USE_LIBPCRE=YesPlease CC=~/perl5/installed/bin/gcc NO_R_TO_GCC_LINKER=YesPlease CFLAGS=-O3 LIBPCREDIR=/home/avar/g/pcre/inst LDFLAGS=-Wl,-rpath,/home/avar/g/pcre/inst/lib' ./run HEAD~ HEAD p7820-grep-engines.sh Test HEAD~ HEAD --------------------------------------------------------------------------------------- 7820.3: perl grep 'how.to' 0.35(1.11+0.43) 0.23(0.42+0.46) -34.3% 7820.7: perl grep '^how to' 0.64(2.71+0.36) 0.27(0.66+0.44) -57.8% 7820.11: perl grep '[how] to' 0.63(2.51+0.42) 0.33(0.98+0.39) -47.6% 7820.15: perl grep '(e.t[^ ]*|v.ry) rare' 1.17(5.61+0.35) 0.34(1.08+0.46) -70.9% 7820.19: perl grep 'm(ú|u)lt.b(æ|y)te' 0.43(1.52+0.44) 0.30(0.88+0.42) -30.2% The conditional support for JIT is implemented as suggested in the pcrejit(3) man page. E.g. defining PCRE_STUDY_JIT_COMPILE to 0 if it's not present. The implementation is relatively verbose because even if PCRE_CONFIG_JIT is defined only a call to pcre_config() can determine if the JIT is available, and if so the faster pcre_jit_exec() function should be called instead of pcre_exec(), and a different (but not complimentary!) function needs to be called to free pcre1_extra_info. There's no graceful fallback if pcre_jit_stack_alloc() fails under PCRE_CONFIG_JIT, instead the program will simply abort. I don't think this is worth handling gracefully, it'll only fail in cases where malloc() doesn't work, in which case we're screwed anyway. That there's no assignment of `p->pcre1_jit_on = 0` when PCRE_CONFIG_JIT isn't defined isn't a bug. The create_grep_pat() function allocates the grep_pat allocates it with calloc(), so it's guaranteed to be 0 when PCRE_CONFIG_JIT isn't defined. I you're bisecting and find this change, check that your PCRE isn't older than 8.32. This change intentionally broke really old versions of PCRE, but that's fixed in follow-up commits. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: change internal pcre variable & function names to be pcre1

2017-05-26T03:52:37Z

Change the internal PCRE variable & function names to have a "1" suffix. This is for preparation for libpcre2 support, where having non-versioned names would be confusing. An earlier change in this series ("grep: change the internal PCRE macro names to be PCRE1", 2017-04-07) elaborates on the motivations behind this change. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

grep: change the internal PCRE macro names to be PCRE1

2017-05-26T03:52:37Z

Change the internal USE_LIBPCRE define, & build options flag to use a naming convention ending in PCRE1, without changing the long-standing USE_LIBPCRE Makefile flag which enables this code. This is for preparation for libpcre2 support where having things like USE_LIBPCRE and USE_LIBPCRE2 in any more places than we absolutely need to for backwards compatibility with old Makefile arguments would be confusing. In some ways it would be better to change everything that now uses USE_LIBPCRE to use USE_LIBPCRE1, and to make specifying USE_LIBPCRE (or --with-pcre) an error. This would impose a one-time burden on packagers of git to s/USE_LIBPCRE/USE_LIBPCRE1/ in their build scripts. However I'd like to leave the door open to making USE_LIBPCRE=YesPlease eventually mean USE_LIBPCRE2=YesPlease, i.e. once PCRE v2 is ubiquitous enough that it makes sense to make it the default. This code and the USE_LIBPCRE Makefile argument was added in commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09). At the time there was no indication that the PCRE project would release an entirely new & incompatible API around 3 years later. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

git/grep.h, branch v2.14.2

grep: remove regflags from the public grep_opt API

Merge branch 'bw/object-id'

grep: convert to struct object_id

grep: add support for PCRE v2

grep: un-break building with PCRE >= 8.32 without --enable-jit

grep: un-break building with PCRE < 8.20

grep: un-break building with PCRE < 8.32

grep: add support for the PCRE v1 JIT API

grep: change internal *pcre* variable & function names to be *pcre1*

grep: change the internal PCRE macro names to be PCRE1

grep: change internal pcre variable & function names to be pcre1