configure: check for system-wide installed jpcre2.hpp & use if new enough

Implements #2929.

NEWS.md

@@ -48,6 +48,13 @@
 * mkvmerge, mkvinfo, mkvextract, mkvpropedit: Matroska access class: fixed an
   invalid memory access under certain data conditions. Found by fuzzying.
 
+## Build system changes
+
+* `configure` now checks for the presence of the a system-wide installed copy
+  of the JPCRE2 C++ wrapper library for the PCRE2 library and uses that if
+  it's new enough (at least v10.32.1). If not, the bundled version will be
+  used as a fallback. Implements #2929.
+
 
 # Version 50.0.0 "Awakenings" 2020-09-06
 

README.md

@@ -128,6 +128,9 @@ These libraries are:
 - [fmt](http://fmtlib.net/) — a small, safe and fast formatting
   library. Version 3 or later is required.
 
+- [JPCRE2](https://github.com/jpcre2/jpcre2/) — C++ wrapper for the
+  PCRE2 library. Version 10.32.1 or newer is required.
+
 - [libEBML v1.4.0](http://dl.matroska.org/downloads/libebml/) or later
   and [libMatroska v1.6.1](http://dl.matroska.org/downloads/libmatroska/)
   or later for low-level access to Matroska files. Instructions on how to

Rakefile

@@ -86,6 +86,7 @@ def setup_globals
   $manpages                << "doc/man/mkvtoolnix-gui.1" if $build_mkvtoolnix_gui
 
   $system_includes         = "-I. -Ilib -Ilib/avilib-0.6.10 -Isrc"
+  $system_includes        += " -Ilib/jpcre2"          if c?(:JPCRE2_INTERNAL)
   $system_includes        += " -Ilib/utf8-cpp/source" if c?(:UTF8CPP_INTERNAL)
   $system_includes        += " -Ilib/pugixml/src"     if c?(:PUGIXML_INTERNAL)
   $system_libdirs          = "-Llib/avilib-0.6.10 -Llib/librmff -Lsrc/common"

ac/pcre2.m4

@@ -15,3 +15,45 @@ fi
 
 AC_SUBST(PCRE2_CFLAGS)
 AC_SUBST(PCRE2_LIBS)
+
+dnl
+dnl Check for jpcre2
+dnl
+
+AC_CACHE_CHECK([for JPCRE2],[ac_cv_jpcre2],[
+  AC_LANG_PUSH(C++)
+
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  ac_save_LIBS="$LIBS"
+  CXXFLAGS="$STD_CXX $CXXFLAGS"
+  LIBS="$LIBS -ljpcre2"
+
+  AC_TRY_COMPILE([
+    #include <jpcre2.hpp>
+
+    #if !defined(JPCRE2_VERSION) || (JPCRE2_VERSION < 103201)
+    #error jpcre2 is too old, need 10.32.1 or later
+    #endif
+  ],[
+    using jp = jpcre2::select<char>;
+    jp::Regex regex{"moo"};
+    jp::RegexMatch()
+      .setRegexObject(&regex)
+      .setSubject("cow")
+      .match();
+  ],[ac_cv_jpcre2=yes],[ac_cv_jpcre2=no])
+
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  LIBS="$ac_save_LIBS"
+
+  AC_LANG_POP
+])
+
+if test x"$ac_cv_jpcre2" = xyes; then
+  JPCRE2_INTERNAL=no
+else
+  AC_MSG_NOTICE([Using the internal version of jpcre2])
+  JPCRE2_INTERNAL=yes
+fi
+
+AC_SUBST(JPCRE2_INTERNAL)

build-config.in

@@ -103,6 +103,7 @@ GTEST_TYPE = @GTEST_TYPE@
 LDFLAGS_RPATHS = @LDFLAGS_RPATHS@
 FLAC_LIBS = @FLAC_LIBS@
 ICONV_LIBS = @ICONV_LIBS@
+JPCRE2_INTERNAL = @JPCRE2_INTERNAL@
 LIBINTL_LIBS = @LIBINTL_LIBS@
 LINK_STATICALLY=@LINK_STATICALLY@
 LLVM_LLD = @LLVM_LLD@

src/common/regex.h

@@ -15,7 +15,7 @@
 
 #include "common/common_pch.h"
 
-#include "jpcre2/jpcre2.hpp"
+#include <jpcre2.hpp>
 
 namespace mtx::regex {