From 3b0f20f6ce145b0cd5aefa147a7e425b60601a58 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 0c325f0dc4..135d732d83 100755
--- a/configure
+++ b/configure
@@ -5126,6 +5126,8 @@ 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