From eb6550a6c5813c4334bab86dbe3d838dc3b18b5e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilmari@ilmari.org>
Date: Tue, 20 Mar 2018 16:40:53 +0000
Subject: [PATCH 2/2] Check for all modules needed by PL/Perl

Several distributions, notably Fedora-based ones, provide a 'perl'
package which doesn't actually ship all Perl core modules.  Guard
against this by checking for all modules we use, including core
ones (but not pragmata like 'strict' and 'warnings') in configure.
---
 configure    | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 configure.in |  2 ++
 2 files changed, 73 insertions(+)

diff --git a/configure b/configure
index ba736aa262..eddbdb8849 100755
--- a/configure
+++ b/configure
@@ -7849,6 +7849,77 @@ else
 $as_echo "$perl_embed_ldflags" >&6; }
 fi
 
+# Make sure we have perl
+if test -z "$PERL"; then
+# Extract the first word of "perl", so it can be a program name with args.
+set dummy perl; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_PERL+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$PERL"; then
+  ac_cv_prog_PERL="$PERL" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_PERL="perl"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+PERL=$ac_cv_prog_PERL
+if test -n "$PERL"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PERL" >&5
+$as_echo "$PERL" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+
+if test "x$PERL" != x; then
+  ax_perl_modules_failed=0
+  for ax_perl_module in 'Carp' 'Getopt::Long' 'Opcode' ; do
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for perl module $ax_perl_module" >&5
+$as_echo_n "checking for perl module $ax_perl_module... " >&6; }
+
+    # Would be nice to log result here, but can't rely on autoconf internals
+    $PERL -e "use $ax_perl_module; exit" > /dev/null 2>&1
+    if test $? -ne 0; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; };
+      ax_perl_modules_failed=1
+   else
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: ok" >&5
+$as_echo "ok" >&6; };
+    fi
+  done
+
+  # Run optional shell commands
+  if test "$ax_perl_modules_failed" = 0; then
+    :
+
+  else
+    :
+    as_fn_error $? "Perl needed to build PL/Perl not found" "$LINENO" 5
+  fi
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: could not find perl" >&5
+$as_echo "$as_me: WARNING: could not find perl" >&2;}
+fi
 fi
 
 if test "$with_python" = yes; then
diff --git a/configure.in b/configure.in
index 1152b7f536..3cbaa71481 100644
--- a/configure.in
+++ b/configure.in
@@ -912,6 +912,8 @@ PL/Perl.])
   fi
   PGAC_CHECK_PERL_EMBED_CCFLAGS
   PGAC_CHECK_PERL_EMBED_LDFLAGS
+  AX_PROG_PERL_MODULES(Carp Getopt::Long Opcode, ,
+      AC_MSG_ERROR([Perl needed to build PL/Perl not found]))
 fi
 
 if test "$with_python" = yes; then
-- 
2.16.2