From 0a6e2c7f86940f6d7c18c5dc2c50bf5f7ed3654d Mon Sep 17 00:00:00 2001
From: Thomas Munro <tmunro@postgresql.org>
Date: Sun, 22 Oct 2023 14:17:00 +1300
Subject: [PATCH] Log LLVM library version in configure output.

When scanning build farm results, it's useful to be able to see which
version is in use.  For the Meson build system, this information was
already displayed.

Back-patch to all supported branches.

Discussion: https://postgr.es/m/4022690.1697852728%40sss.pgh.pa.us
---
 config/llvm.m4 | 1 +
 configure      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/config/llvm.m4 b/config/llvm.m4
index d5ddee3e6d..5104328971 100644
--- a/config/llvm.m4
+++ b/config/llvm.m4
@@ -28,6 +28,7 @@ AC_DEFUN([PGAC_LLVM_SUPPORT],
   if echo $pgac_llvm_version | $AWK -F '.' '{ if ([$]1 >= 4 || ([$]1 == 3 && [$]2 >= 9)) exit 1; else exit 0;}';then
     AC_MSG_ERROR([$LLVM_CONFIG version is $pgac_llvm_version but at least 3.9 is required])
   fi
+  AC_MSG_NOTICE([using llvm $pgac_llvm_version])
 
   # need clang to create some bitcode files
   AC_ARG_VAR(CLANG, [path to clang compiler to generate bitcode])
diff --git a/configure b/configure
index f74c9e65f0..a62f129012 100755
--- a/configure
+++ b/configure
@@ -4893,6 +4893,8 @@ fi
   if echo $pgac_llvm_version | $AWK -F '.' '{ if ($1 >= 4 || ($1 == 3 && $2 >= 9)) exit 1; else exit 0;}';then
     as_fn_error $? "$LLVM_CONFIG version is $pgac_llvm_version but at least 3.9 is required" "$LINENO" 5
   fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: using llvm $pgac_llvm_version" >&5
+$as_echo "$as_me: using llvm $pgac_llvm_version" >&6;}
 
   # need clang to create some bitcode files