From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
"Jeffrey Walton" <noloader@gmail.com>,
"Michał Kiedrowicz" <michal.kiedrowicz@gmail.com>,
"J Smith" <dark.panda@gmail.com>,
"Victor Leschuk" <vleschuk@gmail.com>,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
"Fredrik Kuivinen" <frekui@gmail.com>,
"Brandon Williams" <bmwill@google.com>,
"Stefan Beller" <sbeller@google.com>,
"Johannes Schindelin" <johannes.schindelin@gmx.de>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: [PATCH v4 5/8] grep: un-break building with PCRE < 8.32
Date: Thu, 1 Jun 2017 18:20:53 +0000 [thread overview]
Message-ID: <20170601182056.31142-6-avarab@gmail.com> (raw)
In-Reply-To: <20170601182056.31142-1-avarab@gmail.com>
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 <avarab@gmail.com>
---
grep.c | 6 +++---
grep.h | 5 +++++
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/grep.c b/grep.c
index ffe95995ee..19fa67c34c 100644
--- a/grep.c
+++ b/grep.c
@@ -369,7 +369,7 @@ static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
if (!p->pcre1_extra_info && error)
die("%s", error);
-#ifdef PCRE_CONFIG_JIT
+#ifdef GIT_PCRE1_USE_JIT
pcre_config(PCRE_CONFIG_JIT, &p->pcre1_jit_on);
if (p->pcre1_jit_on == 1) {
p->pcre1_jit_stack = pcre_jit_stack_alloc(1, 1024 * 1024);
@@ -391,7 +391,7 @@ static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
if (eflags & REG_NOTBOL)
flags |= PCRE_NOTBOL;
-#ifdef PCRE_CONFIG_JIT
+#ifdef GIT_PCRE1_USE_JIT
if (p->pcre1_jit_on) {
ret = pcre_jit_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
eol - line, 0, flags, ovector,
@@ -418,7 +418,7 @@ static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
static void free_pcre1_regexp(struct grep_pat *p)
{
pcre_free(p->pcre1_regexp);
-#ifdef PCRE_CONFIG_JIT
+#ifdef GIT_PCRE1_USE_JIT
if (p->pcre1_jit_on) {
pcre_free_study(p->pcre1_extra_info);
pcre_jit_stack_free(p->pcre1_jit_stack);
diff --git a/grep.h b/grep.h
index 14f47189f9..3b948d9155 100644
--- a/grep.h
+++ b/grep.h
@@ -3,6 +3,11 @@
#include "color.h"
#ifdef USE_LIBPCRE1
#include <pcre.h>
+#ifdef PCRE_CONFIG_JIT
+#if PCRE_MAJOR >= 8 && PCRE_MINOR >= 32
+#define GIT_PCRE1_USE_JIT
+#endif
+#endif
#ifndef PCRE_STUDY_JIT_COMPILE
#define PCRE_STUDY_JIT_COMPILE 0
#endif
--
2.13.0.303.g4ebf302169
next prev parent reply other threads:[~2017-06-01 18:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-01 18:20 [PATCH v4 0/8] PCRE v2, PCRE v1 JIT, log -P & fixes Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` [PATCH v4 1/8] grep: don't redundantly compile throwaway patterns under threading Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` [PATCH v4 2/8] grep: skip pthreads overhead when using one thread Ævar Arnfjörð Bjarmason
2017-06-01 21:20 ` Stefan Beller
2017-06-01 21:36 ` Ævar Arnfjörð Bjarmason
2017-06-01 21:38 ` Ævar Arnfjörð Bjarmason
2017-06-01 21:45 ` Stefan Beller
2017-06-01 21:55 ` Ævar Arnfjörð Bjarmason
2017-06-01 22:08 ` Stefan Beller
2017-06-01 18:20 ` [PATCH v4 3/8] log: add -P as a synonym for --perl-regexp Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` [PATCH v4 4/8] grep: add support for the PCRE v1 JIT API Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` Ævar Arnfjörð Bjarmason [this message]
2017-06-01 18:20 ` [PATCH v4 6/8] grep: un-break building with PCRE < 8.20 Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` [PATCH v4 7/8] grep: un-break building with PCRE >= 8.32 without --enable-jit Ævar Arnfjörð Bjarmason
2017-06-01 18:20 ` [PATCH v4 8/8] grep: add support for PCRE v2 Ævar Arnfjörð Bjarmason
2017-06-01 23:30 ` [PATCH v4 0/8] PCRE v2, PCRE v1 JIT, log -P & fixes Junio C Hamano
2017-06-02 16:10 ` Johannes Schindelin
2017-06-02 16:45 ` Ævar Arnfjörð Bjarmason
2017-06-05 0:38 ` Junio C Hamano
2017-06-07 15:50 ` Johannes Schindelin
2017-06-07 16:14 ` Ævar Arnfjörð Bjarmason
2017-06-09 13:09 ` Junio C Hamano
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