From 03e749c2b89e880e0a226458e9446fca4440696f 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 3a75cd8b4d..21d8cd4f90 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 49500d61c2..7d81d1812e 100755
--- a/configure
+++ b/configure
@@ -5077,6 +5077,8 @@ 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