Bump minimum version of Bison to 2.3

Since the retirement of some older buildfarm members, the oldest Bison
that gets regular testing is 2.3. MacOS ships that version, and will
continue doing so for the forseeable future because of Apple's policy
regarding GPLv3. While Mac users could use a package manager to install
a newer version, there is no compelling reason to force them do so at
this time.

Reviewed by Andres Freund
Discussion: https://www.postgresql.org/message-id/1097762.1662145681@sss.pgh.pa.us

config/programs.m4

@@ -22,8 +22,8 @@ fi
 # PGAC_PATH_BISON
 # ---------------
 # Look for Bison, set the output variable BISON to its path if found.
-# Reject versions before 1.875 (they have bugs or capacity limits).
-# Note we do not accept other implementations of yacc.
+# Reject versions before 2.3 (the earliest version in the buildfarm
+# as of 2022). Note we do not accept other implementations of yacc.
 
 AC_DEFUN([PGAC_PATH_BISON],
 [PGAC_PATH_PROGS(BISON, bison)
@@ -31,11 +31,11 @@ AC_DEFUN([PGAC_PATH_BISON],
 if test "$BISON"; then
   pgac_bison_version=`$BISON --version 2>/dev/null | sed q`
   AC_MSG_NOTICE([using $pgac_bison_version])
-  if echo "$pgac_bison_version" | $AWK '{ if ([$]4 < 1.875) exit 0; else exit 1;}'
+  if echo "$pgac_bison_version" | $AWK '{ if ([$]4 < 2.3) exit 0; else exit 1;}'
   then
     AC_MSG_WARN([
 *** The installed version of Bison, $BISON, is too old to use with PostgreSQL.
-*** Bison version 1.875 or later is required, but this is $pgac_bison_version.])
+*** Bison version 2.3 or later is required, but this is $pgac_bison_version.])
     BISON=""
   fi
   # Bison >=3.0 issues warnings about %name-prefix="base_yy", instead

configure

@@ -10218,14 +10218,14 @@ if test "$BISON"; then
   pgac_bison_version=`$BISON --version 2>/dev/null | sed q`
   { $as_echo "$as_me:${as_lineno-$LINENO}: using $pgac_bison_version" >&5
 $as_echo "$as_me: using $pgac_bison_version" >&6;}
-  if echo "$pgac_bison_version" | $AWK '{ if ($4 < 1.875) exit 0; else exit 1;}'
+  if echo "$pgac_bison_version" | $AWK '{ if ($4 < 2.3) exit 0; else exit 1;}'
   then
     { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING:
 *** The installed version of Bison, $BISON, is too old to use with PostgreSQL.
-*** Bison version 1.875 or later is required, but this is $pgac_bison_version." >&5
+*** Bison version 2.3 or later is required, but this is $pgac_bison_version." >&5
 $as_echo "$as_me: WARNING:
 *** The installed version of Bison, $BISON, is too old to use with PostgreSQL.
-*** Bison version 1.875 or later is required, but this is $pgac_bison_version." >&2;}
+*** Bison version 2.3 or later is required, but this is $pgac_bison_version." >&2;}
     BISON=""
   fi
   # Bison >=3.0 issues warnings about %name-prefix="base_yy", instead

contrib/cube/cubeparse.y

@@ -15,10 +15,7 @@
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

contrib/seg/segparse.y

@@ -13,10 +13,7 @@
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

doc/src/sgml/install-windows.sgml

@@ -219,7 +219,7 @@ $ENV{MSBFLAGS}="/m";
      <para>
       <productname>Bison</productname> and <productname>Flex</productname> are
       required to build from Git, but not required when building from a release
-      file. Only <productname>Bison</productname> 1.875 or versions 2.2 and later
+      file. Only <productname>Bison</productname> versions 2.3 and later
       will work. <productname>Flex</productname> must be version 2.5.31 or later.
      </para>
 

doc/src/sgml/installation.sgml

@@ -315,7 +315,7 @@ su - postgres
       are needed to build from a Git checkout, or if you changed the actual
       scanner and parser definition files. If you need them, be sure
       to get <application>Flex</application> 2.5.31 or later and
-      <application>Bison</application> 1.875 or later. Other <application>lex</application>
+      <application>Bison</application> 2.3 or later. Other <application>lex</application>
       and <application>yacc</application> programs cannot be used.
      </para>
     </listitem>

src/backend/bootstrap/bootparse.y

@@ -36,10 +36,7 @@
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/backend/parser/gram.y

@@ -103,10 +103,7 @@
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/backend/replication/repl_gram.y

@@ -29,10 +29,7 @@ Node *replication_parse_result;
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/backend/replication/syncrep_gram.y

@@ -26,10 +26,7 @@ static SyncRepConfigData *create_syncrep_config(const char *num_sync,
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/backend/utils/adt/jsonpath_gram.y

@@ -45,10 +45,7 @@ static JsonPathParseItem *makeItemLikeRegex(JsonPathParseItem *expr,
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/pl/plpgsql/src/pl_gram.y

@@ -39,10 +39,7 @@
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
  * so we can easily have it use palloc instead of malloc.  This prevents
- * memory leaks if we error out during parsing.  Note this only works with
- * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
- * if possible, so there's not really much problem anyhow, at least if
- * you're building with gcc.
+ * memory leaks if we error out during parsing.
  */
 #define YYMALLOC palloc
 #define YYFREE   pfree

src/tools/msvc/pgbison.pl

@@ -16,7 +16,7 @@ do './src/tools/msvc/buildenv.pl' if -e 'src/tools/msvc/buildenv.pl';
 my ($bisonver) = `bison -V`;    # grab first line
 $bisonver = (split(/\s+/, $bisonver))[3];    # grab version number
 
-unless ($bisonver eq '1.875' || $bisonver ge '2.2')
+unless ($bisonver ge '2.3')
 {
 	print "WARNING! Bison install not found, or unsupported Bison version.\n";
 	print "echo Attempting to build without.\n";