Merge branch 'ab/pcre-v2'

Update "perl-compatible regular expression" support to enable JIT
and also allow linking with the newer PCRE v2 library.

* ab/pcre-v2:
  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
  log: add -P as a synonym for --perl-regexp
  grep: skip pthreads overhead when using one thread
  grep: don't redundantly compile throwaway patterns under threading

1 files changed, 41 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 7c621f7f7..f48480163 100644
--- a/Makefile
+++ b/Makefile
@@ -29,8 +29,23 @@ all::
 # Perl-compatible regular expressions instead of standard or extended
 # POSIX regular expressions.
 #
-# Define LIBPCREDIR=/foo/bar if your libpcre header and library files are in
-# /foo/bar/include and /foo/bar/lib directories.
+# Currently USE_LIBPCRE is a synonym for USE_LIBPCRE1, define
+# USE_LIBPCRE2 instead if you'd like to use version 2 of the PCRE
+# library. The USE_LIBPCRE flag will likely be changed to mean v2 by
+# default in future releases.
+#
+# When using USE_LIBPCRE1, define NO_LIBPCRE1_JIT if the PCRE v1
+# library is compiled without --enable-jit. We will auto-detect
+# whether the version of the PCRE v1 library in use has JIT support at
+# all, but we unfortunately can't auto-detect whether JIT support
+# hasn't been compiled in in an otherwise JIT-supporting version. If
+# you have link-time errors about a missing `pcre_jit_exec` define
+# this, or recompile PCRE v1 with --enable-jit.
+#
+# Define LIBPCREDIR=/foo/bar if your PCRE header and library files are
+# in /foo/bar/include and /foo/bar/lib directories. Which version of
+# PCRE this points to determined by the USE_LIBPCRE1 and USE_LIBPCRE2
+# variables.
 #
 # Define HAVE_ALLOCA_H if you have working alloca(3) defined in that header.
 #
@@ -1089,13 +1104,29 @@ ifdef NO_LIBGEN_H
 	COMPAT_OBJS += compat/basename.o
 endif
 
-ifdef USE_LIBPCRE
-	BASIC_CFLAGS += -DUSE_LIBPCRE1
-	ifdef LIBPCREDIR
-		BASIC_CFLAGS += -I$(LIBPCREDIR)/include
-		EXTLIBS += -L$(LIBPCREDIR)/$(lib) $(CC_LD_DYNPATH)$(LIBPCREDIR)/$(lib)
+USE_LIBPCRE1 ?= $(USE_LIBPCRE)
+
+ifneq (,$(USE_LIBPCRE1))
+	ifdef USE_LIBPCRE2
+$(error Only set USE_LIBPCRE1 (or its alias USE_LIBPCRE) or USE_LIBPCRE2, not both!)
 	endif
+
+	BASIC_CFLAGS += -DUSE_LIBPCRE1
 	EXTLIBS += -lpcre
+
+ifdef NO_LIBPCRE1_JIT
+	BASIC_CFLAGS += -DNO_LIBPCRE1_JIT
+endif
+endif
+
+ifdef USE_LIBPCRE2
+	BASIC_CFLAGS += -DUSE_LIBPCRE2
+	EXTLIBS += -lpcre2-8
+endif
+
+ifdef LIBPCREDIR
+	BASIC_CFLAGS += -I$(LIBPCREDIR)/include
+	EXTLIBS += -L$(LIBPCREDIR)/$(lib) $(CC_LD_DYNPATH)$(LIBPCREDIR)/$(lib)
 endif
 
 ifdef HAVE_ALLOCA_H
@@ -2249,7 +2280,9 @@ GIT-BUILD-OPTIONS: FORCE
 	@echo TAR=\''$(subst ','\'',$(subst ','\'',$(TAR)))'\' >>$@+
 	@echo NO_CURL=\''$(subst ','\'',$(subst ','\'',$(NO_CURL)))'\' >>$@+
 	@echo NO_EXPAT=\''$(subst ','\'',$(subst ','\'',$(NO_EXPAT)))'\' >>$@+
-	@echo USE_LIBPCRE1=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE)))'\' >>$@+
+	@echo USE_LIBPCRE1=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE1)))'\' >>$@+
+	@echo USE_LIBPCRE2=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE2)))'\' >>$@+
+	@echo NO_LIBPCRE1_JIT=\''$(subst ','\'',$(subst ','\'',$(NO_LIBPCRE1_JIT)))'\' >>$@+
 	@echo NO_PERL=\''$(subst ','\'',$(subst ','\'',$(NO_PERL)))'\' >>$@+
 	@echo NO_PTHREADS=\''$(subst ','\'',$(subst ','\'',$(NO_PTHREADS)))'\' >>$@+
 	@echo NO_PYTHON=\''$(subst ','\'',$(subst ','\'',$(NO_PYTHON)))'\' >>$@+