From 38fc1545fe8cf8b97ff3b23f4a4279a0eb344881 Mon Sep 17 00:00:00 2001
From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Wed, 23 Jul 2025 11:04:30 +0300
Subject: [PATCH] autoconf: Add libcpre2 detection

---
 configure.ac    |  6 ++++++
 m4/want_pcre.m4 | 19 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 m4/want_pcre.m4

diff --git a/configure.ac b/configure.ac
index 1bbca6cee3..73c2fa4970 100644
--- a/configure.ac
+++ b/configure.ac
@@ -171,6 +171,11 @@ AS_HELP_STRING([--with-icu], [Build with libicu support (for lib-language normal
   want_icu=$withval,
   want_icu=auto)
 
+AC_ARG_WITH(pcre2,
+AS_HELP_STRING([--with-pcre2], [Build with libpcre2 support (for regular expression support) (auto)]),
+  want_pcre=$withval,
+  want_pcre=auto)
+
 AC_ARG_WITH(solr,
 AS_HELP_STRING([--with-solr], [Build with Solr full text search support]),
   TEST_WITH(solr, $withval),
@@ -721,6 +726,7 @@ DOVECOT_WANT_STEMMER
 DOVECOT_WANT_TEXTCAT
 
 DOVECOT_WANT_ICU
+DOVECOT_WANT_PCRE
 
 DOVECOT_WANT_APPARMOR
 
diff --git a/m4/want_pcre.m4 b/m4/want_pcre.m4
new file mode 100644
index 0000000000..ccf10ceb71
--- /dev/null
+++ b/m4/want_pcre.m4
@@ -0,0 +1,19 @@
+AC_DEFUN([DOVECOT_WANT_PCRE], [
+  have_pcre=no
+
+  AS_IF([test "$want_pcre" != "no"], [
+    PKG_CHECK_MODULES([LIBPCRE], [libpcre2-32], [have_pcre=yes], [
+      have_pcre=no
+
+      AS_IF([test "$want_pcre" = "yes"], [
+        AC_MSG_ERROR(cannot build with pcre support: pcre library (libpcre2-32) not found)
+      ])
+    ])
+  ])
+
+  AS_IF([test "$have_pcre" != "no"], [
+    AC_DEFINE(HAVE_LIBPCRE,, [Define if you have libpcre2 backed regular expressions])
+  ])
+
+  AM_CONDITIONAL(BUILD_LIBREGEX, test "$have_pcre" = "yes")
+])
-- 
2.47.3