Remove flex version checks

Remove the flex version checks from configure and meson. The cutoff versions are all so ancient that this is no longer relevant, and what the actual cutoff should be is a bit fuzzy. This also removes the ancient behavior that configure would also accept a "lex" program if it is actuall flex. This aligns the check with meson in this respect. For future reference, as of this commit, these are relevant flex versions: - The hard required minimum is flex 2.5.34 as of commit b1ef48980d, but this has not actually been tested. - Prior to this, the minimum enforced by configure/meson was flex 2.5.35, which is the oldest present in the buildfarm right now. - As of commit 6fdd5d9563, the oldest version that will compile without warnings due to flex-generated code is flex 2.5.36. - The oldest version that probably still has some practical relevance is flex 2.5.37, which ships with CentOS/RHEL 7. Discussion: https://www.postgresql.org/message-id/1a204ccd-7ae6-478c-a431-407b5c48ccc6@eisentraut.org
2025-01-30 19:00:29 +08:00 · 2025-01-17 08:35:52 +01:00 · 2025-01-17 08:35:52 +01:00 · 0869ea43e9
commit 0869ea43e9
parent b0eff10988
5 changed files with 67 additions and 101 deletions
--- a/config/programs.m4
+++ b/config/programs.m4
@ -59,57 +59,16 @@ AC_SUBST(BISONFLAGS)
 # PGAC_PATH_FLEX
 # --------------
 # Look for Flex, set the output variable FLEX to its path if found.
-# Reject versions before 2.5.35 (the earliest version in the buildfarm
-# as of 2022). Also find Flex if its installed under `lex', but do not
-# accept other Lex programs.

 AC_DEFUN([PGAC_PATH_FLEX],
-[AC_CACHE_CHECK([for flex], pgac_cv_path_flex,
-[# Let the user override the test
-if test -n "$FLEX"; then
-  pgac_cv_path_flex=$FLEX
-else
-  pgac_save_IFS=$IFS
-  IFS=$PATH_SEPARATOR
-  for pgac_dir in $PATH; do
-    IFS=$pgac_save_IFS
-    if test -z "$pgac_dir" || test x"$pgac_dir" = x"."; then
-      pgac_dir=`pwd`
-    fi
-    for pgac_prog in flex lex; do
-      pgac_candidate="$pgac_dir/$pgac_prog"
-      if test -f "$pgac_candidate" \
-        && $pgac_candidate --version </dev/null >/dev/null 2>&1
-      then
-        echo '%%'  > conftest.l
-        if $pgac_candidate -t conftest.l 2>/dev/null | grep FLEX_SCANNER >/dev/null 2>&1; then
-          pgac_flex_version=`$pgac_candidate --version 2>/dev/null`
-          if echo "$pgac_flex_version" | sed ['s/[.a-z]/ /g'] | $AWK '{ if ([$]1 == 2 && ([$]2 > 5 || ([$]2 == 5 && [$]3 >= 35))) exit 0; else exit 1;}'
-          then
-            pgac_cv_path_flex=$pgac_candidate
-            break 2
-          else
-            AC_MSG_ERROR([
-*** The installed version of Flex, $pgac_candidate, is too old to use with PostgreSQL.
-*** Flex version 2.5.35 or later is required, but this is $pgac_flex_version.])
-          fi
-        fi
-      fi
-    done
-  done
-  rm -f conftest.l lex.yy.c
-  : ${pgac_cv_path_flex=no}
-fi
-])[]dnl AC_CACHE_CHECK
-
-if test x"$pgac_cv_path_flex" = x"no"; then
+[PGAC_PATH_PROGS(FLEX, flex)
+if test -z "$FLEX"; then
  AC_MSG_ERROR([flex not found])
-else
-  FLEX=$pgac_cv_path_flex
-  pgac_flex_version=`$FLEX --version 2>/dev/null`
-  AC_MSG_NOTICE([using $pgac_flex_version])
 fi

+pgac_flex_version=`$FLEX --version 2>/dev/null`
+AC_MSG_NOTICE([using $pgac_flex_version])
+
 AC_SUBST(FLEX)
 AC_SUBST(FLEXFLAGS)
 ])# PGAC_PATH_FLEX
--- a/99
+++ b/99
@ -9931,59 +9931,68 @@ if test -z "$BISON"; then
 fi


-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for flex" >&5
-$as_echo_n "checking for flex... " >&6; }
-if ${pgac_cv_path_flex+:} false; then :
+if test -z "$FLEX"; then
+  for ac_prog in flex
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; 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_path_FLEX+:} false; then :
  $as_echo_n "(cached) " >&6
 else
-  # Let the user override the test
-if test -n "$FLEX"; then
-  pgac_cv_path_flex=$FLEX
-else
-  pgac_save_IFS=$IFS
-  IFS=$PATH_SEPARATOR
-  for pgac_dir in $PATH; do
-    IFS=$pgac_save_IFS
-    if test -z "$pgac_dir" || test x"$pgac_dir" = x"."; then
-      pgac_dir=`pwd`
-    fi
-    for pgac_prog in flex lex; do
-      pgac_candidate="$pgac_dir/$pgac_prog"
-      if test -f "$pgac_candidate" \
-        && $pgac_candidate --version </dev/null >/dev/null 2>&1
-      then
-        echo '%%'  > conftest.l
-        if $pgac_candidate -t conftest.l 2>/dev/null | grep FLEX_SCANNER >/dev/null 2>&1; then
-          pgac_flex_version=`$pgac_candidate --version 2>/dev/null`
-          if echo "$pgac_flex_version" | sed 's/[.a-z]/ /g' | $AWK '{ if ($1 == 2 && ($2 > 5 || ($2 == 5 && $3 >= 35))) exit 0; else exit 1;}'
-          then
-            pgac_cv_path_flex=$pgac_candidate
-            break 2
-          else
-            as_fn_error $? "
-*** The installed version of Flex, $pgac_candidate, is too old to use with PostgreSQL.
-*** Flex version 2.5.35 or later is required, but this is $pgac_flex_version." "$LINENO" 5
-          fi
-        fi
-      fi
-    done
+  case $FLEX in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_FLEX="$FLEX" # Let the user override the test with a path.
+  ;;
+  *)
+  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_path_FLEX="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
  done
-  rm -f conftest.l lex.yy.c
-  : ${pgac_cv_path_flex=no}
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+FLEX=$ac_cv_path_FLEX
+if test -n "$FLEX"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $FLEX" >&5
+$as_echo "$FLEX" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_path_flex" >&5
-$as_echo "$pgac_cv_path_flex" >&6; }
-if test x"$pgac_cv_path_flex" = x"no"; then
-  as_fn_error $? "flex not found" "$LINENO" 5
+
+  test -n "$FLEX" && break
+done
+
 else
-  FLEX=$pgac_cv_path_flex
-  pgac_flex_version=`$FLEX --version 2>/dev/null`
-  { $as_echo "$as_me:${as_lineno-$LINENO}: using $pgac_flex_version" >&5
-$as_echo "$as_me: using $pgac_flex_version" >&6;}
+  # Report the value of FLEX in configure's output in all cases.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for FLEX" >&5
+$as_echo_n "checking for FLEX... " >&6; }
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $FLEX" >&5
+$as_echo "$FLEX" >&6; }
 fi

+if test -z "$FLEX"; then
+  as_fn_error $? "flex not found" "$LINENO" 5
+fi
+
+pgac_flex_version=`$FLEX --version 2>/dev/null`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: using $pgac_flex_version" >&5
+$as_echo "$as_me: using $pgac_flex_version" >&6;}
+



--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@ -100,10 +100,10 @@
       <primary>yacc</primary>
      </indexterm>

-      <application>Flex</application> 2.5.35 or later and
-      <application>Bison</application> 2.3 or later are required.  Other
-      <application>lex</application> and <application>yacc</application>
-      programs cannot be used.
+      <application>Flex</application> and <application>Bison</application> are
+      required.  Other <application>lex</application> and
+      <application>yacc</application> programs cannot be used.
+      <application>Bison</application> needs to be at least version 2.3.
     </para>
    </listitem>

@ -3811,10 +3811,8 @@ make: *** [postgres] Error 1
        <productname>Flex</productname></term>
       <listitem>
       <para>
-        <productname>Bison</productname> and <productname>Flex</productname> are
-        required.  Only <productname>Bison</productname> versions 2.3 and later
-        will work. <productname>Flex</productname> must be version 2.5.35 or later.
-        Binaries can be downloaded from <ulink
+        Binaries for <productname>Bison</productname> and
+        <productname>Flex</productname> can be downloaded from <ulink
        url="https://github.com/lexxmark/winflexbison"></ulink>.
       </para>
       </listitem>
--- a/meson.build
+++ b/meson.build
@ -334,7 +334,7 @@ endif
 # External programs
 perl = find_program(get_option('PERL'), required: true, native: true)
 python = find_program(get_option('PYTHON'), required: true, native: true)
-flex = find_program(get_option('FLEX'), native: true, version: '>= 2.5.35')
+flex = find_program(get_option('FLEX'), native: true)
 bison = find_program(get_option('BISON'), native: true, version: '>= 2.3')
 sed = find_program(get_option('SED'), 'sed', native: true, required: false)
 prove = find_program(get_option('PROVE'), native: true, required: false)
--- a/src/backend/utils/misc/guc-file.l
+++ b/src/backend/utils/misc/guc-file.l
@ -302,7 +302,7 @@ record_config_file_error(const char *errmsg,
 /*
 * Flex fatal errors bring us here.  Stash the error message and jump back to
 * ParseConfigFp().  Assume all msg arguments point to string constants; this
- * holds for flex 2.5.35 (earliest we support). Otherwise, we would need to
+ * holds for all currently known flex versions. Otherwise, we would need to
 * copy the message.
 *
 * We return "int" since this takes the place of calls to fprintf().