From 72df1d3f1b9d39373edfa8ceed21a000a3cba66f Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Tue, 4 Jul 2023 07:25:34 +0900
Subject: [PATCH] Show information about flex (version and command path) in
 meson output

Like bison, this is useful to know which version and command of flex are
detected by meson.  For example, this was useful for me when using
win_flex.exe on Windows.

Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/ZDT3FbmrjBuBthmR@paquier.xyz
---
 meson.build | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/meson.build b/meson.build
index aaa9daf266f..3ea4b0d72a0 100644
--- a/meson.build
+++ b/meson.build
@@ -361,6 +361,10 @@ bison_kw = {
 }
 
 flex_flags = []
+if flex.found()
+  flex_version_c = run_command(flex, '--version', check: true)
+  flex_version = flex_version_c.stdout().split(' ')[1].split('\n')[0]
+endif
 flex_wrapper = files('src/tools/pgflex')
 flex_cmd = [python, flex_wrapper,
   '--builddir', '@BUILD_ROOT@',
@@ -3370,6 +3374,7 @@ if meson.version().version_compare('>=0.57')
     {
       'bison': '@0@ @1@'.format(bison.full_path(), bison_version),
       'dtrace': dtrace,
+      'flex': '@0@ @1@'.format(flex.full_path(), flex_version),
     },
     section: 'Programs',
   )