Avoid maintaining three separate copies of the error codes list.

src/pl/plpgsql/src/plerrcodes.h, src/include/utils/errcodes.h, and a
big chunk of errcodes.sgml are now automatically generated from a single
file, src/backend/utils/errcodes.txt.

Jan Urbański, reviewed by Tom Lane.

doc/src/sgml/generate-errcodes-table.pl

@@ -0,0 +1,63 @@
+#!/usr/bin/perl
+#
+# Generate the errcodes-table.sgml file from errcodes.txt
+# Copyright (c) 2000-2011, PostgreSQL Global Development Group
+
+use warnings;
+use strict;
+
+print "<!-- autogenerated from src/backend/utils/errcodes.txt, do not edit -->\n";
+
+open my $errcodes, $ARGV[0] or die;
+
+while (<$errcodes>) {
+    chomp;
+
+    # Skip comments
+    next if /^#/;
+    next if /^\s*$/;
+
+    # Emit section headers
+    if (/^Section:/) {
+
+	# Remove the Section: string
+	s/^Section: //;
+	# Escape dashes for SGML
+	s/-/&mdash;/;
+	# Wrap PostgreSQL in <productname/>
+	s/PostgreSQL/<productname>PostgreSQL<\/>/g;
+
+	print "\n\n";
+	print "<row>\n";
+	print "<entry spanname=\"span13\">";
+	print "<emphasis role=\"bold\">$_</></entry>\n";
+	print "</row>\n";
+
+	next;
+    }
+
+    die unless /^([^\s]{5})\s+([EWS])\s+([^\s]+)(?:\s+)?([^\s]+)?/;
+
+    (my $sqlstate,
+     my $type,
+     my $errcode_macro,
+     my $condition_name) = ($1, $2, $3, $4);
+
+    # Skip lines without PL/pgSQL condition names
+    next unless defined($condition_name);
+
+    my $meaning = $condition_name;
+    # Remove underscores
+    $meaning =~ s/_/ /g;
+    # And capitalize
+    $meaning =~ tr/[a-z]/[A-Z]/;
+
+    print "\n";
+    print "<row>\n";
+    print "<entry><literal>$sqlstate</literal></entry>\n";
+    print "<entry>$meaning</entry>\n";
+    print "<entry>$condition_name</entry>\n";
+    print "</row>\n";
+}
+
+close $errcodes;