From 73b594851aaf5cee291f805b50bf565334d44c2c Mon Sep 17 00:00:00 2001
From: Fred Morcos <fred.morcos@open-xchange.com>
Date: Mon, 3 Aug 2026 21:40:27 +0200
Subject: [PATCH] meson: pcre

---
 meson.build            |  1 +
 meson.options          |  1 +
 meson/pcre/meson.build | 25 +++++++++++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 meson/pcre/meson.build

diff --git a/meson.build b/meson.build
index 714134631e..cf4a78fa5b 100644
--- a/meson.build
+++ b/meson.build
@@ -130,6 +130,7 @@ subdir('meson' / 'ssl')
 subdir('meson' / 'iconv')
 subdir('meson' / 'zlib')
 subdir('meson' / 'sodium')
+subdir('meson' / 'pcre')
 
 dovecot_moduledir = get_option('moduledir')
 if dovecot_moduledir == ''
diff --git a/meson.options b/meson.options
index 0ff2937545..fa7280b4e5 100644
--- a/meson.options
+++ b/meson.options
@@ -14,3 +14,4 @@ option('random-source', type: 'string', value : '/dev/urandom', description: 'De
 option('ioloop', type: 'combo', choices: ['best', 'epoll', 'kqueue', 'poll', 'select'], value: 'best', description: 'I/O loop method to use (best for the fastest available)')
 option('notify', type: 'combo', choices: ['best', 'inotify', 'kqueue', 'none'], value: 'best', description: 'File system notification method to use (best for the fastest available)')
 option('sodium', type: 'feature', value: 'auto', description: 'Build with libsodium support (enables argon2)')
+option('pcre', type: 'feature', value: 'auto', description: 'Build with libpcre2 support (enables regular expressions)')
diff --git a/meson/pcre/meson.build b/meson/pcre/meson.build
new file mode 100644
index 0000000000..6acc13b5d3
--- /dev/null
+++ b/meson/pcre/meson.build
@@ -0,0 +1,25 @@
+opt_pcre = get_option('pcre')
+ext_pcre = dependency('libpcre2-32', required: opt_pcre)
+
+conf.set(
+  'HAVE_LIBPCRE',
+  ext_pcre.found(),
+  description: 'Have libpcre2 backed regular expressions',
+)
+
+if ext_pcre.found()
+  # pcre2.h needs PCRE2_CODE_UNIT_WIDTH before it will declare anything; 0 asks for the
+  # width-agnostic names.
+  conf.set(
+    'HAVE_PCRE2_SUBSTITUTE_CALLOUT_BLOCK',
+    cc.has_header_symbol(
+      'pcre2.h',
+      'pcre2_substitute_callout_block',
+      prefix: '#define PCRE2_CODE_UNIT_WIDTH 0',
+      dependencies: ext_pcre,
+    ),
+    description: 'Have pcre2_substitute_callout_block',
+  )
+endif
+
+summary({'PCRE': ext_pcre}, section: 'Features')