[meta-networking][PATCH v2] dovecot: Work around clang 23 hang

[sunilkumar.dora@windriver.com]

From: Khem Raj <raj.khem@gmail.com>

clang 23 enables DFAJumpThreading by default and takes over 90
minutes on the switch based state machine loops in the lib-json
tests, where clang 22 needs under a second. Reported upstream with a
bisect and reduced testcase:
https://github.com/llvm/llvm-project/issues/221391

Disable just that pass for clang builds until the fix lands. gcc
builds are not affected.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Sunil Dora <sunilkumar.dora@windriver.com>
---
  v2: disable DFAJumpThreading instead of LSR (bisected root cause,
  keeps LSR enabled); https://github.com/llvm/llvm-project/issues/221391

 meta-networking/recipes-support/dovecot/dovecot_2.4.5.bb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/meta-networking/recipes-support/dovecot/dovecot_2.4.5.bb b/meta-networking/recipes-support/dovecot/dovecot_2.4.5.bb
index 2f4981bee1..993453eaa3 100644
--- a/meta-networking/recipes-support/dovecot/dovecot_2.4.5.bb
+++ b/meta-networking/recipes-support/dovecot/dovecot_2.4.5.bb
@@ -20,6 +20,9 @@ SRC_URI[sha256sum] = "868c2686a61b5f8e00a3e4721789b1ab46e6528fd773a5fbed07a6ecba
 
 DEPENDS = "openssl xz zlib bzip2 libcap icu libtirpc bison-native"
 CFLAGS += "-I${STAGING_INCDIR}/tirpc"
+# clang 23 takes hours to compile the lib-json tests, drop when
+# https://github.com/llvm/llvm-project/issues/221391 is fixed
+CFLAGS:append:toolchain-clang = " -mllvm -enable-dfa-jump-thread=false"
 LDFLAGS += "-ltirpc"
 
 inherit autotools pkgconfig systemd useradd gettext multilib_header
-- 
2.43.0