lexical warnings update, ability to inspect bitmask in calling

scope, among other things (from Paul Marquess)

p4raw-id: //depot/perl@5170

3 files changed, 355 insertions, 272 deletions

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index d660f9495e..80616d956c 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -9,15 +9,26 @@ desperation):
 
     (W) A warning (optional).
     (D) A deprecation (optional).
-    (S) A severe warning (mandatory).
+    (S) A severe warning (default).
     (F) A fatal error (trappable).
     (P) An internal error you should never see (trappable).
     (X) A very fatal error (nontrappable).
     (A) An alien error message (not generated by Perl).
 
-Optional warnings are enabled by using the B<-w> switch.  Warnings may
-be captured by setting C<$SIG{__WARN__}> to a reference to a routine that
-will be called on each warning instead of printing it.  See L<perlvar>.
+The majority of messages from the first three classifications above (W,
+D & S) can be controlled using the C<warnings> pragma. 
+
+If a message can be controlled by the C<warnings> pragma, its warning
+category is included with the classification letter in the description
+below.
+
+Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
+and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
+to a reference to a routine that will be called on each warning instead
+of printing it.  See L<perlvar>.
+
+Default warnings are always enabled unless they are explicitly disabled
+with the C<warnings> pragma or the B<-X> switch.
 
 Trappable errors may be trapped using the eval operator.  See
 L<perlfunc/eval>.  In almost all cases, warnings may be selectively
@@ -33,7 +44,7 @@ C<"%(-?@> sort before the letters, while C<[> and C<\> sort after.
 
 =item "%s" variable %s masks earlier declaration in same %s
 
-(W) A "my" or "our" variable has been redeclared in the current scope or statement,
+(W misc) A "my" or "our" variable has been redeclared in the current scope or statement,
 effectively eliminating all access to the previous instance.  This is almost
 always a typographical error.  Note that the earlier variable will still exist
 until the end of the scope or until all closure referents to it are
@@ -57,7 +68,7 @@ no useful value.  See L<perlmod>.
 
 =item "our" variable %s redeclared
 
-(W) You seem to have already declared the same global once before in the
+(W misc) You seem to have already declared the same global once before in the
 current lexical scope.
 
 =item "use" not allowed in expression
@@ -113,31 +124,31 @@ your signed integers.  See L<perlfunc/unpack>.
 
 =item /%s/: Unrecognized escape \\%c passed through
 
-(W) You used a backslash-character combination which is not recognized
+(W regexp) You used a backslash-character combination which is not recognized
 by Perl.  This combination appears in an interpolated variable or a 
 C<'>-delimited regular expression.  The character was understood literally.
 
 =item /%s/: Unrecognized escape \\%c in character class passed through
 
-(W) You used a backslash-character combination which is not recognized
+(W regexp) You used a backslash-character combination which is not recognized
 by Perl inside character classes.  The character was understood literally.
 
 =item /%s/ should probably be written as "%s"
 
-(W) You have used a pattern where Perl expected to find a string,
+(W syntax) You have used a pattern where Perl expected to find a string,
 as in the first argument to C<join>.  Perl will treat the true
 or false result of matching the pattern against $_ as the string,
 which is probably not what you had in mind.
 
 =item %s (...) interpreted as function
 
-(W) You've run afoul of the rule that says that any list operator followed
+(W syntax) You've run afoul of the rule that says that any list operator followed
 by parentheses turns into a function, with all the list operators arguments
 found inside the parentheses.  See L<perlop/Terms and List Operators (Leftward)>.
 
 =item %s() called too early to check prototype
 
-(W) You've called a function that has a prototype before the parser saw a
+(W prototype) You've called a function that has a prototype before the parser saw a
 definition or declaration for it, and Perl could not check that the call
 conforms to the prototype.  You need to either add an early prototype
 declaration for the subroutine in question, or move the subroutine
@@ -194,17 +205,17 @@ Further error messages would likely be uninformative.
 
 =item %s matches null string many times
 
-(W) The pattern you've specified would be an infinite loop if the
+(W regexp) The pattern you've specified would be an infinite loop if the
 regular expression engine didn't specifically check for that.  See L<perlre>.
 
 =item %s never introduced
 
-(S) The symbol in question was declared but somehow went out of scope
+(S internal) The symbol in question was declared but somehow went out of scope
 before it could possibly have been used.
 
 =item %s package attribute may clash with future reserved word: %s
 
-(W) A lowercase attribute name was used that had a package-specific handler.
+(W reserved) A lowercase attribute name was used that had a package-specific handler.
 That name might have a meaning to Perl itself some day, even though it
 doesn't yet.  Perhaps you should use a mixed-case attribute name, instead.
 See L<attributes>.
@@ -239,7 +250,7 @@ into Perl yourself.
 
 =item         (in cleanup) %s
 
-(W) This prefix usually indicates that a DESTROY() method raised
+(W misc) This prefix usually indicates that a DESTROY() method raised
 the indicated exception.  Since destructors are usually called by
 the system at arbitrary points during execution, and often a vast
 number of times, the warning is issued only once for any number
@@ -292,7 +303,7 @@ C<require 'file'>.
 
 =item accept() on closed socket %s
 
-(W) You tried to do an accept on a closed socket.  Did you forget to check
+(W closed) You tried to do an accept on a closed socket.  Did you forget to check
 the return value of your socket() call?  See L<perlfunc/accept>.
 
 =item Allocation too large: %lx
@@ -301,7 +312,7 @@ the return value of your socket() call?  See L<perlfunc/accept>.
 
 =item Applying %s to %s will act on scalar(%s)
 
-(W) The pattern match (//), substitution (s///), and transliteration (tr///)
+(W misc) The pattern match (//), substitution (s///), and transliteration (tr///)
 operators work on scalar values.  If you apply one of them to an array
 or a hash, it will convert the array or hash to a scalar value -- the
 length of an array, or the population info of a hash -- and then work on
@@ -314,13 +325,13 @@ L<perlfunc/grep> and L<perlfunc/map> for alternatives.
 
 =item Ambiguous use of %s resolved as %s
 
-(W)(S) You said something that may not be interpreted the way
+(W ambiguous)(S) You said something that may not be interpreted the way
 you thought.  Normally it's pretty easy to disambiguate it by supplying
 a missing quote, operator, parenthesis pair or declaration.
 
 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
 
-(W) A subroutine you have declared has the same name as a Perl keyword,
+(W ambiguous) A subroutine you have declared has the same name as a Perl keyword,
 and you have used the name without qualification for calling one or the
 other.  Perl decided to call the builtin because the subroutine is
 not imported.
@@ -344,13 +355,13 @@ for example, turn C<-w -U> into C<-wU>.
 
 =item Argument "%s" isn't numeric%s
 
-(W) The indicated string was fed as an argument to an operator that
+(W numeric) The indicated string was fed as an argument to an operator that
 expected a numeric value instead.  If you're fortunate the message
 will identify which operator was so unfortunate.
 
 =item Array @%s missing the @ in argument %d of %s()
 
-(D) Really old Perl let you omit the @ on array names in some spots.  This
+(D deprecated) Really old Perl let you omit the @ on array names in some spots.  This
 is now heavily deprecated.
 
 =item assertion botched: %s
@@ -369,20 +380,20 @@ know which context to supply to the right side.
 
 =item Attempt to free non-arena SV: 0x%lx
 
-(P) All SV objects are supposed to be allocated from arenas that will
+(P internal) All SV objects are supposed to be allocated from arenas that will
 be garbage collected on exit.  An SV was discovered to be outside any
 of those arenas.
 
 =item Attempt to free nonexistent shared string
 
-(P) Perl maintains a reference counted internal table of strings to
+(P internal) Perl maintains a reference counted internal table of strings to
 optimize the storage and access of hash keys and other strings.  This
 indicates someone tried to decrement the reference count of a string
 that can no longer be found in the table.
 
 =item Attempt to free temp prematurely
 
-(W) Mortalized values are supposed to be freed by the free_tmps()
+(W debugging) Mortalized values are supposed to be freed by the free_tmps()
 routine.  This indicates that something else is freeing the SV before
 the free_tmps() routine gets a chance, which means that the free_tmps()
 routine will be freeing an unreferenced scalar when it does try to free
@@ -390,11 +401,11 @@ it.
 
 =item Attempt to free unreferenced glob pointers
 
-(P) The reference counts got screwed up on symbol aliases.
+(P internal) The reference counts got screwed up on symbol aliases.
 
 =item Attempt to free unreferenced scalar
 
-(W) Perl went to decrement the reference count of a scalar to see if it
+(W internal) Perl went to decrement the reference count of a scalar to see if it
 would go to 0, and discovered that it had already gone to 0 earlier,
 and should have been freed, and in fact, probably was freed.  This
 could indicate that SvREFCNT_dec() was called too many times, or that
@@ -409,7 +420,7 @@ need to move the join() to some other thread.
 
 =item Attempt to pack pointer to temporary value
 
-(W) You tried to pass a temporary value (like the result of a
+(W pack) You tried to pass a temporary value (like the result of a
 function, or a computed expression) to the "p" pack() template.  This
 means the result contains a pointer to a location that could become
 invalid anytime, even before the end of the current statement.  Use
@@ -418,7 +429,7 @@ avoid this warning.
 
 =item Attempt to use reference as lvalue in substr
 
-(W) You supplied a reference as the first argument to substr() used
+(W substr) You supplied a reference as the first argument to substr() used
 as an lvalue, which is pretty strange.  Perhaps you forgot to
 dereference it first.  See L<perlfunc/substr>.
 
@@ -437,7 +448,7 @@ did it in another package.
 
 =item Bad free() ignored
 
-(S) An internal routine called free() on something that had never been
+(S malloc) An internal routine called free() on something that had never been
 malloc()ed in the first place. Mandatory, but can be disabled by
 setting environment variable C<PERL_BADFREE> to 1.
 
@@ -472,7 +483,7 @@ is not the same as
 
 =item Bad realloc() ignored
 
-(S) An internal routine called realloc() on something that had never been
+(S malloc) An internal routine called realloc() on something that had never been
 malloc()ed in the first place. Mandatory, but can be disabled by
 setting environment variable C<PERL_BADFREE> to 1.
 
@@ -505,13 +516,13 @@ Perhaps you need to predeclare a subroutine?
 
 =item Bareword "%s" refers to nonexistent package
 
-(W) You used a qualified bareword of the form C<Foo::>, but
+(W bareword) You used a qualified bareword of the form C<Foo::>, but
 the compiler saw no other uses of that namespace before that point.
 Perhaps you need to predeclare a package?
 
 =item Bareword found in conditional
 
-(W) The compiler found a bareword where it expected a conditional,
+(W bareword) The compiler found a bareword where it expected a conditional,
 which often indicates that an || or && was parsed as part of the
 last argument of the previous construct, for example:
 
@@ -540,18 +551,18 @@ likely depends on its correct operation, Perl just gave up.
 
 =item Binary number > 0b11111111111111111111111111111111 non-portable
 
-(W) The binary number you specified is larger than 2**32-1
+(W portable) The binary number you specified is larger than 2**32-1
 (4294967295) and therefore non-portable between systems.  See
 L<perlport> for more on portability concerns.
 
 =item bind() on closed socket %s
 
-(W) You tried to do a bind on a closed socket.  Did you forget to check
+(W closed) You tried to do a bind on a closed socket.  Did you forget to check
 the return value of your socket() call?  See L<perlfunc/bind>.
 
 =item Bit vector size > 32 non-portable
 
-(W) Using bit vector sizes larger than 32 is non-portable.
+(W portable) Using bit vector sizes larger than 32 is non-portable.
 
 =item Bizarre copy of %s in %s
 
@@ -559,7 +570,7 @@ the return value of your socket() call?  See L<perlfunc/bind>.
 
 =item Buffer overflow in prime_env_iter: %s
 
-(W) A warning peculiar to VMS.  While Perl was preparing to iterate over
+(W internal) A warning peculiar to VMS.  While Perl was preparing to iterate over
 %ENV, it encountered a logical name or symbol definition which was too long,
 so it was truncated to the string shown.
 
@@ -622,7 +633,7 @@ encapsulation of objects.  See L<perlobj>.
 
 =item Can't break at that line
 
-(S) A warning intended to only be printed while running within the debugger, indicating
+(S internal) A warning intended to only be printed while running within the debugger, indicating
 the line number specified wasn't the location of a statement that could
 be stopped at.
 
@@ -718,7 +729,7 @@ for other types of variables in future.
 
 =item Can't do inplace edit on %s: %s
 
-(S) The creation of the new file failed for the indicated reason.
+(S inplace) The creation of the new file failed for the indicated reason.
 
 =item Can't do inplace edit without backup
 
@@ -728,13 +739,13 @@ such.
 
 =item Can't do inplace edit: %s would not be unique
 
-(S) Your filesystem does not support filenames longer than 14
+(S inplace) Your filesystem does not support filenames longer than 14
 characters and Perl was unable to create a unique filename during
 inplace editing with the B<-i> switch.  The file was ignored.
 
 =item Can't do inplace edit: %s is not a regular file
 
-(S) You tried to use the B<-i> switch on a special file, such as a file in
+(S inplace) You tried to use the B<-i> switch on a special file, such as a file in
 /dev, or a FIFO.  The file was ignored.
 
 =item Can't do setegid!
@@ -772,7 +783,7 @@ For example, it'd be kind of silly to put a B<-x> on the #! line.
 
 =item Can't exec "%s": %s
 
-(W) An system(), exec(), or piped open call could not execute the named
+(W exec) An system(), exec(), or piped open call could not execute the named
 program for the indicated reason.  Typical reasons include: the permissions
 were wrong on the file, the file wasn't found in C<$ENV{PATH}>, the
 executable in question was compiled for another architecture, or the
@@ -863,7 +874,7 @@ L<perlfunc/goto>.
 
 =item Can't ignore signal CHLD, forcing to default
 
-(W) Perl has detected that it is being run with the SIGCHLD signal
+(W signal) Perl has detected that it is being run with the SIGCHLD signal
 (sometimes known as SIGCLD) disabled.  Since disabling this signal
 will interfere with proper determination of exit status of child
 processes, Perl has reset the signal to its default value.
@@ -916,7 +927,7 @@ method, nor does any of its base classes.  See L<perlobj>.
 
 =item Can't locate package %s for @%s::ISA
 
-(W) The @ISA array contained the name of another package that doesn't seem
+(W syntax) The @ISA array contained the name of another package that doesn't seem
 to exist.
 
 =item Can't make list assignment to \%ENV on this system
@@ -945,7 +956,7 @@ buffer.
 
 =item Can't open %s: %s
 
-(S) The implicit opening of a file through use of the C<E<lt>E<gt>>
+(S inplace) The implicit opening of a file through use of the C<E<lt>E<gt>>
 filehandle, either implicitly under the C<-n> or C<-p> command-line
 switches, or explicitly, failed for the indicated reason.  Usually this
 is because you don't have read permission for a file which you named
@@ -953,7 +964,7 @@ on the command line.
 
 =item Can't open bidirectional pipe
 
-(W) You tried to say C<open(CMD, "|cmd|")>, which is not supported.  You can
+(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.  You can
 try any of several modules in the Perl library to do this, such as
 IPC::Open2.  Alternately, direct the pipe's output to a file using "E<gt>",
 and then read it in under a different file handle.
@@ -993,13 +1004,13 @@ this, you should write C<sort { &func } @x> instead of C<sort func @x>.
 
 =item Can't remove %s: %s, skipping file 
 
-(S) You requested an inplace edit without creating a backup file.  Perl
+(S inplace) You requested an inplace edit without creating a backup file.  Perl
 was unable to remove the original file to replace it with the modified
 file.  The file was left unmodified.
 
 =item Can't rename %s to %s: %s, skipping file
 
-(S) The rename done by the B<-i> switch failed for some reason,
+(S inplace) The rename done by the B<-i> switch failed for some reason,
 probably because you don't have write permission to the directory.
 
 =item Can't reopen input pipe (name: %s) in binary mode
@@ -1102,7 +1113,7 @@ test the type of the reference, if need be.
 
 =item Can't use \%c to mean $%c in expression
 
-(W) In an ordinary expression, backslash is a unary operator that creates
+(W syntax) In an ordinary expression, backslash is a unary operator that creates
 a reference to its argument.  The use of backslash to indicate a backreference
 to a matched substring is valid only as part of a regular expression pattern.
 Trying to do this in ordinary Perl code produces a value that prints
@@ -1166,7 +1177,7 @@ See L<perlre>.
 
 =item Character class syntax [%s] belongs inside character classes
 
-(W) The character class constructs [: :], [= =], and [. .]  go
+(W unsafe) The character class constructs [: :], [= =], and [. .]  go
 I<inside> character classes, the [] are part of the construct,
 for example: /[012[:alpha:]345]/.  Note that [= =] and [. .]
 are not currently implemented; they are simply placeholders for
@@ -1174,7 +1185,7 @@ future extensions.
 
 =item Character class syntax [. .] is reserved for future extensions
 
-(W) Within regular expression character classes ([]) the syntax beginning
+(W regexp) Within regular expression character classes ([]) the syntax beginning
 with "[." and ending with ".]" is reserved for future extensions.
 If you need to represent those character sequences inside a regular
 expression character class, just quote the square brackets with the
@@ -1182,7 +1193,7 @@ backslash: "\[." and ".\]".
 
 =item Character class syntax [= =] is reserved for future extensions
 
-(W) Within regular expression character classes ([]) the syntax
+(W regexp) Within regular expression character classes ([]) the syntax
 beginning with "[=" and ending with "=]" is reserved for future extensions.
 If you need to represent those character sequences inside a regular
 expression character class, just quote the square brackets with the
@@ -1190,7 +1201,7 @@ backslash: "\[=" and "=\]".
 
 =item chmod() mode argument is missing initial 0
 
-(W) A novice will sometimes say
+(W chmod) A novice will sometimes say
 
     chmod 777, $filename
 
@@ -1199,7 +1210,7 @@ to 01411.  Octal constants are introduced with a leading 0 in Perl, as in C.
 
 =item Close on unopened file E<lt>%sE<gt>
 
-(W) You tried to close a filehandle that was never opened.
+(W unopened) You tried to close a filehandle that was never opened.
 
 =item Compilation failed in require
 
@@ -1209,7 +1220,7 @@ were severe enough to halt compilation immediately.
 
 =item Complex regular subexpression recursion limit (%d) exceeded
 
-(W) The regular expression engine uses recursion in complex situations
+(W regexp) The regular expression engine uses recursion in complex situations
 where back-tracking is required.  Recursion depth is limited to 32766,
 or perhaps less in architectures where the stack cannot grow
 arbitrarily.  ("Simple" and "medium" situations are handled without
@@ -1221,7 +1232,7 @@ for information on I<Mastering Regular Expressions>.)
 
 =item connect() on closed socket %s
 
-(W) You tried to do a connect on a closed socket.  Did you forget to check
+(W closed) You tried to do a connect on a closed socket.  Did you forget to check
 the return value of your socket() call?  See L<perlfunc/connect>.
 
 =item Constant is not %s reference
@@ -1234,13 +1245,13 @@ See L<perlsub/"Constant Functions"> and L<constant>.
 
 =item Constant subroutine %s redefined
 
-(S|W) You redefined a subroutine which had previously been eligible for
+(S|W redefine) You redefined a subroutine which had previously been eligible for
 inlining.  See L<perlsub/"Constant Functions"> for commentary and
 workarounds.
 
 =item Constant subroutine %s undefined
 
-(W) You undefined a subroutine which had previously been eligible for
+(W misc) You undefined a subroutine which had previously been eligible for
 inlining.  See L<perlsub/"Constant Functions"> for commentary and
 workarounds.
 
@@ -1274,20 +1285,20 @@ a valid magic number.
 
 =item Deep recursion on subroutine "%s"
 
-(W) This subroutine has called itself (directly or indirectly) 100
+(W recursion) This subroutine has called itself (directly or indirectly) 100
 times more than it has returned.  This probably indicates an infinite
 recursion, unless you're writing strange benchmark programs, in which
 case it indicates something else.
 
 =item defined(@array) is deprecated
 
-(D) defined() is not usually useful on arrays because it checks for an
+(D deprecated) defined() is not usually useful on arrays because it checks for an
 undefined I<scalar> value.  If you want to see if the array is empty,
 just use C<if (@array) { # not empty }> for example.  
 
 =item defined(%hash) is deprecated
 
-(D) defined() is not usually useful on hashes because it checks for an
+(D deprecated) defined() is not usually useful on hashes because it checks for an
 undefined I<scalar> value.  If you want to see if the hash is empty,
 just use C<if (%hash) { # not empty }> for example.  
 
@@ -1307,7 +1318,7 @@ See Server error.
 
 =item Did you mean "local" instead of "our"?
 
-(W) Remember that "our" does not localize the declared global variable.
+(W misc) Remember that "our" does not localize the declared global variable.
 You have declared it again in the same lexical scope, which seems superfluous.
 
 =item Did you mean $ or @ instead of %?
@@ -1346,7 +1357,7 @@ See Server error.
 
 =item Duplicate free() ignored
 
-(S) An internal routine called free() on something that had already
+(S malloc) An internal routine called free() on something that had already
 been freed.
 
 =item elseif should be elsif
@@ -1409,35 +1420,40 @@ variable and glob that.
 
 =item Exiting eval via %s
 
-(W) You are exiting an eval by unconventional means, such as
+(W exiting) You are exiting an eval by unconventional means, such as
+a goto, or a loop control statement.
+
+=item Exiting format via %s
+
+(W exiting) You are exiting an eval by unconventional means, such as
 a goto, or a loop control statement.
 
 =item Exiting pseudo-block via %s
 
-(W) You are exiting a rather special block construct (like a sort block or
+(W exiting) You are exiting a rather special block construct (like a sort block or
 subroutine) by unconventional means, such as a goto, or a loop control
 statement.  See L<perlfunc/sort>.
 
 =item Exiting subroutine via %s
 
-(W) You are exiting a subroutine by unconventional means, such as
+(W exiting) You are exiting a subroutine by unconventional means, such as
 a goto, or a loop control statement.
 
 =item Exiting substitution via %s
 
-(W) You are exiting a substitution by unconventional means, such as
+(W exiting) You are exiting a substitution by unconventional means, such as
 a return, a goto, or a loop control statement.
 
 =item Explicit blessing to '' (assuming package main)
 
-(W) You are blessing a reference to a zero length string.  This has
+(W misc) You are blessing a reference to a zero length string.  This has
 the effect of blessing the reference into the package main.  This is
 usually not what you want.  Consider providing a default target
 package, e.g. bless($ref, $p || 'MyPackage');
 
 =item false [] range "%s" in regexp
 
-(W) A character class range must start and end at a literal character, not
+(W regexp) A character class range must start and end at a literal character, not
 another character class like C<\d> or C<[:alpha:]>.  The "-" in your false
 range is interpreted as a literal "-".  Consider quoting the "-",  "\-".
 See L<perlre>.
@@ -1456,13 +1472,13 @@ PDP-11 or something?
 
 =item Filehandle %s never opened
 
-(W) An I/O operation was attempted on a filehandle that was never initialized.
+(W unopened) An I/O operation was attempted on a filehandle that was never initialized.
 You need to do an open() or a socket() call, or call a constructor from
 the FileHandle package.
 
 =item Filehandle %s opened only for input
 
-(W) You tried to write on a read-only filehandle.  If you
+(W io) You tried to write on a read-only filehandle.  If you
 intended it to be a read-write filehandle, you needed to open it with
 "+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing.  If
 you intended only to write the file, use "E<gt>" or "E<gt>E<gt>".  See
@@ -1470,7 +1486,7 @@ L<perlfunc/open>.
 
 =item Filehandle %s opened only for output
 
-(W) You tried to read from a filehandle opened only for writing.  If you
+(W io) You tried to read from a filehandle opened only for writing.  If you
 intended it to be a read/write filehandle, you needed to open it with
 "+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing.  If
 you intended only to read from the file, use "E<lt>".  See
@@ -1492,13 +1508,13 @@ the name.
 
 =item flock() on closed filehandle %s
 
-(W) The filehandle you're attempting to flock() got itself closed some
+(W closed) The filehandle you're attempting to flock() got itself closed some
 time before now.  Check your logic flow.  flock() operates on filehandles.
 Are you attempting to call flock() on a dirhandle by the same name?
 
 =item Format %s redefined
 
-(W) You redefined a format.  To suppress this warning, say
+(W redefine) You redefined a format.  To suppress this warning, say
 
     {
 	no warnings;
@@ -1512,7 +1528,7 @@ to the end of your file without finding such a line.
 
 =item Found = in conditional, should be ==
 
-(W) You said
+(W syntax) You said
 
     if ($foo = 123)
 
@@ -1534,7 +1550,7 @@ on the Internet.
 
 =item get%sname() on closed socket %s
 
-(W) You tried to get a socket or peer socket name on a closed socket.
+(W closed) You tried to get a socket or peer socket name on a closed socket.
 Did you forget to check the return value of your socket() call?
 
 =item getpwnam returned invalid UIC %#o for user "%s"
@@ -1542,6 +1558,20 @@ Did you forget to check the return value of your socket() call?
 (S) A warning peculiar to VMS.  The call to C<sys$getuai> underlying the
 C<getpwnam> operator returned an invalid UIC.
 
+=item glob failed (%s)
+
+(W glob) Something went wrong with the external program(s) used for C<glob>
+and C<E<lt>*.cE<gt>>.  Usually, this means that you supplied a C<glob>
+pattern that caused the external program to fail and exit with a nonzero
+status.  If the message indicates that the abnormal exit resulted in a
+coredump, this may also mean that your csh (C shell) is broken.  If so,
+you should change all of the csh-related variables in config.sh:  If you
+have tcsh, make the variables refer to it as if it were csh (e.g.
+C<full_csh='/usr/bin/tcsh'>); otherwise, make them all empty (except that
+C<d_csh> should be C<'undef'>) so that Perl will think csh is missing.
+In either case, after editing config.sh, run C<./Configure -S> and
+rebuild Perl.
+
 =item Glob not terminated
 
 (F) The lexer saw a left angle bracket in a place where it was expecting
@@ -1563,18 +1593,18 @@ unspecified destination.  See L<perlfunc/goto>.
 
 =item Had to create %s unexpectedly
 
-(S) A routine asked for a symbol from a symbol table that ought to have
+(S internal) A routine asked for a symbol from a symbol table that ought to have
 existed already, but for some reason it didn't, and had to be created on
 an emergency basis to prevent a core dump.
 
 =item Hash %%s missing the % in argument %d of %s()
 
-(D) Really old Perl let you omit the % on hash names in some spots.  This
+(D deprecated) Really old Perl let you omit the % on hash names in some spots.  This
 is now heavily deprecated.
 
 =item Hexadecimal number > 0xffffffff non-portable
 
-(W) The hexadecimal number you specified is larger than 2**32-1
+(W portable) The hexadecimal number you specified is larger than 2**32-1
 (4294967295) and therefore non-portable between systems.  See
 L<perlport> for more on portability concerns.
 
@@ -1587,13 +1617,13 @@ versions of Perl are likely to eliminate these arbitrary limitations.
 
 =item Ill-formed CRTL environ value "%s"
 
-(W) A warning peculiar to VMS.  Perl tried to read the CRTL's internal
+(W internal) A warning peculiar to VMS.  Perl tried to read the CRTL's internal
 environ array, and encountered an element without the C<=> delimiter
 used to spearate keys from values.  The element is ignored.
 
 =item Ill-formed message in prime_env_iter: |%s|
 
-(W) A warning peculiar to VMS.  Perl tried to read a logical name
+(W internal) A warning peculiar to VMS.  Perl tried to read a logical name
 or CLI symbol definition when preparing to iterate over %ENV, and
 didn't see the expected delimiter between key and value, so the
 line was ignored.
@@ -1626,17 +1656,17 @@ don't take to this kindly.
 
 =item Illegal binary digit %s ignored
 
-(W) You may have tried to use a digit other than 0 or 1 in a binary number.
+(W digit) You may have tried to use a digit other than 0 or 1 in a binary number.
 Interpretation of the binary number stopped before the offending digit.
 
 =item Illegal octal digit %s ignored
 
-(W) You may have tried to use an 8 or 9 in a octal number.  Interpretation
+(W digit) You may have tried to use an 8 or 9 in a octal number.  Interpretation
 of the octal number stopped before the 8 or 9.
 
 =item Illegal hexadecimal digit %s ignored
 
-(W) You may have tried to use a character other than 0 - 9 or A - F, a - f
+(W digit) You may have tried to use a character other than 0 - 9 or A - F, a - f
 in a hexadecimal number.  Interpretation of the hexadecimal number stopped
 before the illegal character.
 
@@ -1686,7 +1716,7 @@ known value, using trustworthy data.  See L<perlsec>.
 
 =item Integer overflow in %s number
 
-(W) The hexadecimal, octal or binary number you have specified either
+(W overflow) The hexadecimal, octal or binary number you have specified either
 as a literal or as an argument to hex() or oct() is too big for your
 architecture, and has been converted to a floating point number.  On a
 32-bit architecture the largest hexadecimal, octal or binary number
@@ -1710,20 +1740,6 @@ and execute the specified command.
 
 (P) Something went badly wrong in the regular expression parser.
 
-=item glob failed (%s)
-
-(W) Something went wrong with the external program(s) used for C<glob>
-and C<E<lt>*.cE<gt>>.  Usually, this means that you supplied a C<glob>
-pattern that caused the external program to fail and exit with a nonzero
-status.  If the message indicates that the abnormal exit resulted in a
-coredump, this may also mean that your csh (C shell) is broken.  If so,
-you should change all of the csh-related variables in config.sh:  If you
-have tcsh, make the variables refer to it as if it were csh (e.g.
-C<full_csh='/usr/bin/tcsh'>); otherwise, make them all empty (except that
-C<d_csh> should be C<'undef'>) so that Perl will think csh is missing.
-In either case, after editing config.sh, run C<./Configure -S> and
-rebuild Perl.
-
 =item internal urp in regexp at /%s/
 
 (P) Something went badly awry in the regular expression parser.
@@ -1745,7 +1761,7 @@ greater than the maximum character.  See L<perlre>.
 
 =item Invalid conversion in %s: "%s"
 
-(W) Perl does not understand the given format conversion.
+(W printf) Perl does not understand the given format conversion.
 See L<perlfunc/sprintf>.
 
 =item Invalid separator character %s in attribute list
@@ -1758,13 +1774,13 @@ too soon.  See L<attributes>.
 =item Invalid type in pack: '%s'
 
 (F) The given character is not a valid pack type.  See L<perlfunc/pack>.
-(W) The given character is not a valid pack type but used to be silently
+(W pack) The given character is not a valid pack type but used to be silently
 ignored.
 
 =item Invalid type in unpack: '%s'
 
 (F) The given character is not a valid unpack type.  See L<perlfunc/unpack>.
-(W) The given character is not a valid unpack type but used to be silently
+(W unpack) The given character is not a valid unpack type but used to be silently
 ignored.
 
 =item ioctl is not implemented
@@ -1801,7 +1817,7 @@ effective uids or gids failed.
 
 =item listen() on closed socket %s
 
-(W) You tried to do a listen on a closed socket.  Did you forget to check
+(W closed) You tried to do a listen on a closed socket.  Did you forget to check
 the return value of your socket() call?  See L<perlfunc/listen>.
 
 =item Lvalue subs returning %s not implemented yet
@@ -1827,7 +1843,7 @@ ended earlier on the current line.
 
 =item Misplaced _ in number
 
-(W) An underline in a decimal constant wasn't on a 3-digit boundary.
+(W syntax) An underline in a decimal constant wasn't on a 3-digit boundary.
 
 =item Missing $ on loop variable
 
@@ -1847,7 +1863,7 @@ double-quotish context.
 
 =item Missing command in piped open
 
-(W) You used the C<open(FH, "| command")> or C<open(FH, "command |")>
+(W pipe) You used the C<open(FH, "| command")> or C<open(FH, "command |")>
 construction, but the command was missing or blank.
 
 =item Missing operator before %s?
@@ -1893,7 +1909,7 @@ be created for some peculiar reason.
 
 =item Multidimensional syntax %s not supported
 
-(W) Multidimensional arrays aren't written like C<$foo[1,2,3]>.  They're written
+(W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.  They're written
 like C<$foo[1][2][3]>, as in C.
 
 =item Missing name in "my sub"
@@ -1903,7 +1919,7 @@ have a name with which they can be found.
 
 =item Name "%s::%s" used only once: possible typo
 
-(W) Typographical errors often show up as unique variable names.
+(W once) Typographical errors often show up as unique variable names.
 If you had a good reason for having a unique name, then just mention
 it again somehow to suppress the message.  The C<our> declaration is
 provided for this purpose.
@@ -2058,7 +2074,7 @@ an attempt to close an unopened filehandle.
 
 =item No such signal: SIG%s
 
-(W) You specified a signal name as a subscript to %SIG that was not recognized.
+(W signal) You specified a signal name as a subscript to %SIG that was not recognized.
 Say C<kill -l> in your shell to see the valid signal names on your system.
 
 =item no UTC offset information; assuming local time is UTC
@@ -2130,7 +2146,7 @@ function to find out what kind of ref it really was.  See L<perlref>.
 
 =item Not enough format arguments
 
-(W) A format specified more picture fields than the next line supplied.
+(W syntax) A format specified more picture fields than the next line supplied.
 See L<perlform>.
 
 =item Null filename used
@@ -2146,7 +2162,7 @@ supplied it an uninitialized value.  See L<perlform>.
 
 =item NULL OP IN RUN
 
-(P) Some internal routine called run() with a null opcode pointer.
+(P debugging) Some internal routine called run() with a null opcode pointer.
 
 =item Null realloc
 
@@ -2169,7 +2185,7 @@ try using scientific notation (e.g. "1e6" instead of "1_000_000").
 
 =item Octal number > 037777777777 non-portable
 
-(W) The octal number you specified is larger than 2**32-1 (4294967295)
+(W portable) The octal number you specified is larger than 2**32-1 (4294967295)
 and therefore non-portable between systems.  See L<perlport> for more
 on portability concerns.
 
@@ -2183,7 +2199,7 @@ version.
 
 =item Odd number of elements in hash assignment
 
-(W) You specified an odd number of elements to initialize a hash, which
+(W misc) You specified an odd number of elements to initialize a hash, which
 is odd, because hashes come in key/value pairs.
 
 =item Offset outside string
@@ -2195,11 +2211,11 @@ will extend the buffer and zero pad the new area.
 
 =item oops: oopsAV
 
-(S) An internal warning that the grammar is screwed up.
+(S internal) An internal warning that the grammar is screwed up.
 
 =item oops: oopsHV
 
-(S) An internal warning that the grammar is screwed up.
+(S internal) An internal warning that the grammar is screwed up.
 
 =item Operation `%s': no method found, %s
 
@@ -2211,7 +2227,7 @@ true.  See L<overload>.
 
 =item Operator or semicolon missing before %s
 
-(S) You used a variable or subroutine call where the parser was
+(S ambiguous) You used a variable or subroutine call where the parser was
 expecting an operator.  The parser has assumed you really meant
 to use an operator, but this is highly likely to be incorrect.
 For example, if you say "*foo *foo" it will be interpreted as
@@ -2254,7 +2270,7 @@ instead of C<$arr[$time]>.
 
 =item page overflow
 
-(W) A single call to write() produced more lines than can fit on a page.
+(W io) A single call to write() produced more lines than can fit on a page.
 See L<perlform>.
 
 =item panic: ck_grep
@@ -2421,7 +2437,7 @@ was string.
 
 =item Parentheses missing around "%s" list
 
-(W) You said something like
+(W parenthesis) You said something like
 
     my $foo, $bar = @_;
 
@@ -2443,7 +2459,7 @@ anyway?  See L<perlfunc/require>.
 
 =item pid %x not a child
 
-(W) A warning peculiar to VMS.  Waitpid() was asked to wait for a process which
+(W exec) A warning peculiar to VMS.  Waitpid() was asked to wait for a process which
 isn't a subprocess of the current process.  While this is fine from VMS'
 perspective, it's probably not what you intended.
 
@@ -2454,12 +2470,12 @@ the BSD version, which takes a pid.
 
 =item Possible Y2K bug: %s
 
-(W) You are concatenating the number 19 with another number, which
+(W y2k) You are concatenating the number 19 with another number, which
 could be a potential Year 2000 problem.
 
 =item Possible attempt to put comments in qw() list
 
-(W) qw() lists contain items separated by whitespace; as with literal
+(W qw) qw() lists contain items separated by whitespace; as with literal
 strings, comment characters are not ignored, but are instead treated
 as literal data.  (You may have used different delimiters than the
 parentheses shown here; braces are also frequently used.)
@@ -2488,7 +2504,7 @@ old-fashioned way, with quotes and commas:
 
 =item Possible attempt to separate words with commas
 
-(W) qw() lists contain items separated by whitespace; therefore commas
+(W qw) qw() lists contain items separated by whitespace; therefore commas
 aren't needed to separate the items.  (You may have used different
 delimiters than the parentheses shown here; braces are also frequently
 used.)
@@ -2511,7 +2527,7 @@ Perl assumes that memory is now corrupted.  See L<perlfunc/ioctl>.
 
 =item Precedence problem: open %s should be open(%s)
 
-(S) The old irregular construct
+(S precedence) The old irregular construct
 
     open FOO || die;
 
@@ -2530,17 +2546,17 @@ See Server error.
 
 =item print() on closed filehandle %s
 
-(W) The filehandle you're printing on got itself closed sometime before now.
+(W closed) The filehandle you're printing on got itself closed sometime before now.
 Check your logic flow.
 
 =item printf() on closed filehandle %s
 
-(W) The filehandle you're writing to got itself closed sometime before now.
+(W closed) The filehandle you're writing to got itself closed sometime before now.
 Check your logic flow.
 
 =item Prototype mismatch: %s vs %s
 
-(S) The subroutine being declared or defined had previously been declared
+(S unsafe) The subroutine being declared or defined had previously been declared
 or defined with a different function prototype.
 
 =item Range iterator outside integer range
@@ -2552,12 +2568,12 @@ increment by prepending "0" to your numbers.
 
 =item readline() on closed filehandle %s
 
-(W) The filehandle you're reading from got itself closed sometime before now.
+(W closed) The filehandle you're reading from got itself closed sometime before now.
 Check your logic flow.
 
 =item realloc() of freed memory ignored
 
-(S) An internal routine called realloc() on something that had already
+(S malloc) An internal routine called realloc() on something that had already
 been freed.
 
 =item Reallocation too large: %lx
@@ -2566,7 +2582,7 @@ been freed.
 
 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
 
-(F) You can't use the B<-D> option unless the code to produce the
+(F debugging) You can't use the B<-D> option unless the code to produce the
 desired output is compiled into Perl, which entails some overhead,
 which is why it's currently left out of your copy.
 
@@ -2582,7 +2598,7 @@ method.  Probably indicates an unintended loop in your inheritance hierarchy.
 
 =item Reference found where even-sized list expected
 
-(W) You gave a single reference where Perl was expecting a list with
+(W misc) You gave a single reference where Perl was expecting a list with
 an even number of elements (for assignment to a hash). This
 usually means that you used the anon hash constructor when you meant 
 to use parens. In any case, a hash requires key/value B<pairs>.
@@ -2594,12 +2610,12 @@ to use parens. In any case, a hash requires key/value B<pairs>.
 
 =item Reference is already weak
 
-(W) You have attempted to weaken a reference that is already weak.
+(W misc) You have attempted to weaken a reference that is already weak.
 Doing so has no effect.
 
 =item Reference miscount in sv_replace()
 
-(W) The internal sv_replace() function was handed a new SV with a
+(W internal) The internal sv_replace() function was handed a new SV with a
 reference count of other than 1.
 
 =item regexp *+ operand could be empty
@@ -2618,7 +2634,7 @@ expression compiler gave it.
 
 =item Reversed %s= operator
 
-(W) You wrote your assignment operator backwards.  The = must always
+(W syntax) You wrote your assignment operator backwards.  The = must always
 comes last, to avoid ambiguity with subsequent unary operators.
 
 =item Runaway format
@@ -2631,7 +2647,7 @@ shifting or popping (for array variables).  See L<perlform>.
 
 =item Scalar value @%s[%s] better written as $%s[%s]
 
-(W) You've used an array slice (indicated by @) to select a single element of
+(W syntax) You've used an array slice (indicated by @) to select a single element of
 an array.  Generally it's better to ask for a scalar value (indicated by $).
 The difference is that C<$foo[&bar]> always behaves like a scalar, both when
 assigning to it and when evaluating its argument, while C<@foo[&bar]> behaves
@@ -2645,7 +2661,7 @@ L<perlref>.
 
 =item Scalar value @%s{%s} better written as $%s{%s}
 
-(W) You've used a hash slice (indicated by @) to select a single element of
+(W syntax) You've used a hash slice (indicated by @) to select a single element of
 a hash.  Generally it's better to ask for a scalar value (indicated by $).
 The difference is that C<$foo{&bar}> always behaves like a scalar, both when
 assigning to it and when evaluating its argument, while C<@foo{&bar}> behaves
@@ -2670,7 +2686,7 @@ Missing the leading C<$> from a variable C<$m> may cause this error.
 
 =item %sseek() on unopened file
 
-(W) You tried to use the seek() or sysseek() function on a filehandle that
+(W unopened) You tried to use the seek() or sysseek() function on a filehandle that
 was either never opened or has since been closed.
 
 =item select not implemented
@@ -2683,17 +2699,17 @@ was either never opened or has since been closed.
 
 =item semi-panic: attempt to dup freed string
 
-(S) The internal newSVsv() routine was called to duplicate a scalar
+(S internal) The internal newSVsv() routine was called to duplicate a scalar
 that had previously been marked as free.
 
 =item Semicolon seems to be missing
 
-(W) A nearby syntax error was probably caused by a missing semicolon,
+(W semicolon) A nearby syntax error was probably caused by a missing semicolon,
 or possibly some other missing operator, such as a comma.
 
 =item send() on closed socket %s
 
-(W) The socket you're sending to got itself closed sometime before now.
+(W closed) The socket you're sending to got itself closed sometime before now.
 Check your logic flow.
 
 =item Sequence (? incomplete
@@ -2782,11 +2798,11 @@ because the world might have written on it already.
 
 =item shutdown() on closed socket %s
 
-(W) You tried to do a shutdown on a closed socket.  Seems a bit superfluous.
+(W closed) You tried to do a shutdown on a closed socket.  Seems a bit superfluous.
 
 =item SIG%s handler "%s" not defined
 
-(W) The signal handler named in %SIG doesn't, in fact, exist.  Perhaps you
+(W signal) The signal handler named in %SIG doesn't, in fact, exist.  Perhaps you
 put it into the wrong package?
 
 =item sort is now a reserved word
@@ -2813,12 +2829,12 @@ See L<perlfunc/split>.
 
 =item Stat on unopened file E<lt>%sE<gt>
 
-(W) You tried to use the stat() function (or an equivalent file test)
+(W unopened) You tried to use the stat() function (or an equivalent file test)
 on a filehandle that was either never opened or has since been closed.
 
 =item Statement unlikely to be reached
 
-(W) You did an exec() with some statement after it other than a die().
+(W exec) You did an exec() with some statement after it other than a die().
 This is almost always an error, because exec() never returns unless
 there was a failure.  You probably wanted to use system() instead,
 which does return.  To suppress this warning, put the exec() in a block
@@ -2826,7 +2842,7 @@ by itself.
 
 =item Strange *+?{} on zero-length expression
 
-(W) You applied a regular expression quantifier in a place where it
+(W regexp) You applied a regular expression quantifier in a place where it
 makes no sense, such as on a zero-width assertion.
 Try putting the quantifier inside the assertion instead.  For example,
 the way to match "abc" provided that it is followed by three
@@ -2840,7 +2856,7 @@ may break this.
 
 =item Subroutine %s redefined
 
-(W) You redefined a subroutine.  To suppress this warning, say
+(W redefine) You redefined a subroutine.  To suppress this warning, say
 
     {
 	no warnings;
@@ -2868,10 +2884,10 @@ Missing the leading C<$> from variable C<$s> may cause this error.
 
 =item substr outside of string
 
-(S),(W) You tried to reference a substr() that pointed outside of a
+(W substr),(F) You tried to reference a substr() that pointed outside of a
 string.  That is, the absolute value of the offset was larger than the
 length of the string.  See L<perlfunc/substr>.  This warning is
-mandatory if substr is used in an lvalue context (as the left hand side
+fatal if substr is used in an lvalue context (as the left hand side
 of an assignment or as a subroutine argument for example).
 
 =item suidperl is no longer needed since %s
@@ -2920,7 +2936,7 @@ unconfigured.  Consult your system support.
 
 =item syswrite() on closed filehandle %s
 
-(W) The filehandle you're writing to got itself closed sometime before now.
+(W closed) The filehandle you're writing to got itself closed sometime before now.
 Check your logic flow.
 
 =item Target of goto is too deeply nested
@@ -2930,12 +2946,12 @@ nested for Perl to reach.  Perl is doing you a favor by refusing.
 
 =item tell() on unopened file
 
-(W) You tried to use the tell() function on a filehandle that was either
+(W unopened) You tried to use the tell() function on a filehandle that was either
 never opened or has since been closed.
 
 =item Test on unopened file E<lt>%sE<gt>
 
-(W) You tried to invoke a file test operator on a filehandle that isn't
+(W unopened) You tried to invoke a file test operator on a filehandle that isn't
 open.  Check your logic.  See also L<perlfunc/-X>.
 
 =item That use of $[ is unsupported
@@ -2976,7 +2992,7 @@ the symlink to get to the real file.  Use an actual filename instead.
 
 =item This Perl can't set CRTL environ elements (%s=%s)
 
-(W) Warnings peculiar to VMS.  You tried to change or delete an element
+(W internal) Warnings peculiar to VMS.  You tried to change or delete an element
 of the CRTL's internal environ array, but your copy of Perl wasn't
 built with a CRTL that contained the setenv() function.  You'll need to
 rebuild Perl with a CRTL that does, or redefine F<PERL_ENV_TABLES> (see
@@ -3061,7 +3077,7 @@ certain type.  Arrays must be @NAME or C<@{EXPR}>.  Hashes must be
 
 =item umask: argument is missing initial 0
 
-(W) A umask of 222 is incorrect.  It should be 0222, because octal
+(W umask) A umask of 222 is incorrect.  It should be 0222, because octal
 literals always start with 0 in Perl, as in C.
 
 =item umask not implemented
@@ -3075,22 +3091,22 @@ to use it to restrict permissions for yourself (EXPR & 0700).
 
 =item Unbalanced context: %d more PUSHes than POPs
 
-(W) The exit code detected an internal inconsistency in how many execution
+(W internal) The exit code detected an internal inconsistency in how many execution
 contexts were entered and left.
 
 =item Unbalanced saves: %d more saves than restores
 
-(W) The exit code detected an internal inconsistency in how many
+(W internal) The exit code detected an internal inconsistency in how many
 values were temporarily localized.
 
 =item Unbalanced scopes: %d more ENTERs than LEAVEs
 
-(W) The exit code detected an internal inconsistency in how many blocks
+(W internal) The exit code detected an internal inconsistency in how many blocks
 were entered and left.
 
 =item Unbalanced tmps: %d more allocs than frees
 
-(W) The exit code detected an internal inconsistency in how many mortal
+(W internal) The exit code detected an internal inconsistency in how many mortal
 scalars were allocated and freed.
 
 =item Undefined format "%s" called
@@ -3125,7 +3141,7 @@ another package?  See L<perlform>.
 
 =item Undefined value assigned to typeglob
 
-(W) An undefined value was assigned to a typeglob, a la C<*foo = undef>.
+(W misc) An undefined value was assigned to a typeglob, a la C<*foo = undef>.
 This does nothing.  It's possible that you really mean C<undef *foo>.
 
 =item unexec of %s into %s failed!
@@ -3171,7 +3187,7 @@ See L<perlre>.
 
 =item Unquoted string "%s" may clash with future reserved word
 
-(W) You used a bareword that might someday be claimed as a reserved word.
+(W reserved) You used a bareword that might someday be claimed as a reserved word.
 It's best to put such a word in quotes, or capitalize it somehow, or insert
 an underbar into it.  You might also declare it as a subroutine.
 
@@ -3183,7 +3199,7 @@ script, a binary program, or a directory as a Perl program.
 
 =item Unrecognized escape \\%c passed through
 
-(W) You used a backslash-character combination which is not recognized
+(W misc) You used a backslash-character combination which is not recognized
 by Perl.
 
 =item Unrecognized signal name "%s"
@@ -3199,7 +3215,7 @@ supplying the bad switch on your behalf.)
 
 =item Unsuccessful %s on filename containing newline
 
-(W) A file operation was attempted on a filename, and that operation
+(W newline) A file operation was attempted on a filename, and that operation
 failed, PROBABLY because the filename contained a newline, PROBABLY
 because you forgot to chop() or chomp() it off.  See L<perlfunc/chomp>.
 
@@ -3248,12 +3264,12 @@ too soon.  See L<attributes>.
 
 =item Use of $# is deprecated
 
-(D) This was an ill-advised attempt to emulate a poorly defined B<awk> feature.
+(D deprecated) This was an ill-advised attempt to emulate a poorly defined B<awk> feature.
 Use an explicit printf() or sprintf() instead.
 
 =item Use of $* is deprecated
 
-(D) This variable magically turned on multi-line pattern matching, both for
+(D deprecated) This variable magically turned on multi-line pattern matching, both for
 you and for any luckless subroutine that you happen to call.  You should
 use the new C<//m> and C<//s> modifiers now to do that without the dangerous
 action-at-a-distance effects of C<$*>.
@@ -3265,18 +3281,18 @@ only C.  This usually means there's a better way to do it in Perl.
 
 =item Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated
 
-(D) You are now encouraged to use the explicitly quoted form if you
+(D deprecated) You are now encouraged to use the explicitly quoted form if you
 wish to use an empty line as the terminator of the here-document.
 
 =item Use of implicit split to @_ is deprecated
 
-(D) It makes a lot of work for the compiler when you clobber a
+(D deprecated) It makes a lot of work for the compiler when you clobber a
 subroutine's argument list, so it's better if you assign the results of
 a split() explicitly to an array (or list).
 
 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
 
-(D) As an (ahem) accidental feature, C<AUTOLOAD> subroutines are looked
+(D deprecated) As an (ahem) accidental feature, C<AUTOLOAD> subroutines are looked
 up as methods (using the C<@ISA> hierarchy) even when the subroutines to
 be autoloaded were called as plain functions (e.g. C<Foo::bar()>), not
 as methods (e.g. C<Foo-E<gt>bar()> or C<$obj-E<gt>bar()>).
@@ -3298,7 +3314,7 @@ C<use AutoLoader 'AUTOLOAD';>.
 
 =item Use of reserved word "%s" is deprecated
 
-(D) The indicated bareword is a reserved word.  Future versions of perl
+(D deprecated) The indicated bareword is a reserved word.  Future versions of perl
 may use it as a keyword, so you're better off either explicitly quoting
 the word in a manner appropriate for its context of use, or using a
 different name altogether.  The warning can be suppressed for subroutine
@@ -3307,13 +3323,13 @@ e.g. C<&our()>, or C<Foo::our()>.
 
 =item Use of %s is deprecated
 
-(D) The construct indicated is no longer recommended for use, generally
+(D deprecated) The construct indicated is no longer recommended for use, generally
 because there's a better way to do it, and also because the old way has
 bad side effects.
 
 =item Use of uninitialized value%s
 
-(W) An undefined value was used as if it were already defined.  It was
+(W uninitialized) An undefined value was used as if it were already defined.  It was
 interpreted as a "" or a 0, but maybe it was a mistake.  To suppress this
 warning assign a defined value to your variables.
 
@@ -3323,7 +3339,7 @@ warning assign a defined value to your variables.
 
 =item Useless use of %s in void context
 
-(W) You did something without a side effect in a context that does nothing
+(W void) You did something without a side effect in a context that does nothing
 with the return value, such as a statement that doesn't return a value
 from a block, or the left side of a scalar comma operator.  Very often
 this points not to stupidity on your part, but a failure of Perl to parse
@@ -3354,12 +3370,12 @@ L<perlref> for more on this.
 
 =item untie attempted while %d inner references still exist
 
-(W) A copy of the object returned from C<tie> (or C<tied>) was still
+(W untie) A copy of the object returned from C<tie> (or C<tied>) was still
 valid when C<untie> was called.
 
 =item Value of %s can be "0"; test with defined()
 
-(W) In a conditional expression, you used <HANDLE>, <*> (glob), C<each()>,
+(W misc) In a conditional expression, you used <HANDLE>, <*> (glob), C<each()>,
 or C<readdir()> as a boolean value.  Each of these constructs can return a
 value of "0"; that would make the conditional expression false, which is
 probably not what you intended.  When using these constructs in conditional
@@ -3367,7 +3383,7 @@ expressions, test their values with the C<defined> operator.
 
 =item Value of CLI symbol "%s" too long
 
-(W) A warning peculiar to VMS.  Perl tried to read the value of an %ENV
+(W misc) A warning peculiar to VMS.  Perl tried to read the value of an %ENV
 element from a CLI symbol table, and found a resultant string longer
 than 1024 characters.  The return value has been truncated to 1024
 characters.
@@ -3382,7 +3398,7 @@ on the front of your variable.
 
 =item Variable "%s" may be unavailable
 
-(W) An inner (nested) I<anonymous> subroutine is inside a I<named>
+(W closure) An inner (nested) I<anonymous> subroutine is inside a I<named>
 subroutine, and outside that is another subroutine; and the anonymous
 (innermost) subroutine is referencing a lexical variable defined in
 the outermost subroutine.  For example:
@@ -3404,7 +3420,7 @@ subroutine in between interferes with this feature.
 
 =item Variable "%s" will not stay shared
 
-(W) An inner (nested) I<named> subroutine is referencing a lexical
+(W closure) An inner (nested) I<named> subroutine is referencing a lexical
 variable defined in an outer subroutine.
 
 When the inner subroutine is called, it will probably see the value of
@@ -3469,7 +3485,7 @@ close().  This usually indicates your file system ran out of disk space.
 
 =item Warning: Use of "%s" without parentheses is ambiguous
 
-(S) You wrote a unary operator followed by something that looks like a
+(S ambiguous) You wrote a unary operator followed by something that looks like a
 binary operator that could also have been interpreted as a term or
 unary operator.  For instance, if you know that the rand function
 has a default argument of 1.0, and you write
@@ -3488,7 +3504,7 @@ So put in parentheses to say what you really mean.
 
 =item write() on closed filehandle %s
 
-(W) The filehandle you're writing to got itself closed sometime before now.
+(W closed) The filehandle you're writing to got itself closed sometime before now.
 Check your logic flow.
 
 =item X outside of string
@@ -3524,20 +3540,20 @@ the eg directory to put a setuid C wrapper around your script.
 
 =item You need to quote "%s"
 
-(W) You assigned a bareword as a signal handler name.  Unfortunately, you
+(W syntax) You assigned a bareword as a signal handler name.  Unfortunately, you
 already have a subroutine of that name declared, which means that Perl 5
 will try to call the subroutine when the assignment is executed, which is
 probably not what you want.  (If it IS what you want, put an & in front.)
 
 =item %cetsockopt() on closed socket %s
 
-(W) You tried to get or set a socket option on a closed socket.
+(W closed) You tried to get or set a socket option on a closed socket.
 Did you forget to check the return value of your socket() call?
 See L<perlfunc/getsockopt> and L<perlfunc/setsockopt>.
 
 =item \1 better written as $1
 
-(W) Outside of patterns, backreferences live on as variables.  The use
+(W syntax) Outside of patterns, backreferences live on as variables.  The use
 of backslashes is grandfathered on the right-hand side of a
 substitution, but stylistically it's better to use the variable form
 because other Perl programmers will expect it, and it works better
diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod
index 5de9dc7947..e11364d509 100644
--- a/pod/perlfunc.pod
+++ b/pod/perlfunc.pod
@@ -517,7 +517,7 @@ print a stack trace.  The value of EXPR indicates how many call frames
 to go back before the current one.
 
     ($package, $filename, $line, $subroutine, $hasargs,
-    $wantarray, $evaltext, $is_require, $hints) = caller($i);
+    $wantarray, $evaltext, $is_require, $hints, $bitmask) = caller($i);
 
 Here $subroutine may be C<(eval)> if the frame is not a subroutine
 call, but an C<eval>.  In such a case additional elements $evaltext and
@@ -526,9 +526,9 @@ C<require> or C<use> statement, $evaltext contains the text of the
 C<eval EXPR> statement.  In particular, for a C<eval BLOCK> statement,
 $filename is C<(eval)>, but $evaltext is undefined.  (Note also that
 each C<use> statement creates a C<require> frame inside an C<eval EXPR>)
-frame.  C<$hints> contains pragmatic hints that the caller was
-compiled with.  The C<$hints> value is subject to change between versions
-of Perl, and is not meant for external use.
+frame.  C<$hints> and C<$bitmask> contain pragmatic hints that the caller
+was compiled with.  The C<$hints> and C<$bitmask> values are subject to
+change between versions of Perl, and are not meant for external use.
 
 Furthermore, when called from within the DB package, caller returns more
 detailed information: it sets the list variable C<@DB::args> to be the
diff --git a/pod/perllexwarn.pod b/pod/perllexwarn.pod
index 6078aefd96..d370f04412 100644
--- a/pod/perllexwarn.pod
+++ b/pod/perllexwarn.pod
@@ -55,13 +55,11 @@ warning about the "2:".
 
     my $a = "2:" + 3;
 
-though the result will be 5.
-
 With the introduction of lexical warnings, mandatory warnings now become
 I<default> warnings. The difference is that although the previously
 mandatory warnings are still enabled by default, they can then be
 subsequently enabled or disabled with the lexical warning pragma. For
-example, in the code below, an C<"integer overflow"> warning will only
+example, in the code below, an C<"isn't numeric"> warning will only
 be reported for the C<$a> variable.
 
     my $a = "2:" + 3;
@@ -166,8 +164,9 @@ How Lexical Warnings interact with B<-w>/C<$^W>:
 =item 1.
 
 If none of the three command line flags (B<-w>, B<-W> or B<-X>) that
-control warnings is used and neither C<$^W> or lexical warnings are used,
-then default warnings will be enabled and optional warnings disabled.
+control warnings is used and neither C<$^W> or the C<warnings> pragma
+are used, then default warnings will be enabled and optional warnings
+disabled.
 This means that legacy code that doesn't attempt to control the warnings
 will work unchanged.
 
@@ -185,7 +184,7 @@ disable/enable default warnings.
 
 =item 4.
  
-If a piece of code is under the control of the lexical warning pragma,
+If a piece of code is under the control of the C<warnings> pragma,
 both the C<$^W> variable and the B<-w> flag will be ignored for the
 scope of the lexical warning.
 
@@ -197,82 +196,109 @@ or B<-X> command line flags.
 =back
 
 The combined effect of 3 & 4 is that it will will allow code which uses
-the lexical warnings pragma to control the warning behavior of $^W-type
+the C<warnings> pragma to control the warning behavior of $^W-type
 code (using a C<local $^W=0>) if it really wants to, but not vice-versa.
 
-=head1 EXPERIMENTAL FEATURES
-
-The features described in this section are experimental, and so subject
-to change.
-
 =head2 Category Hierarchy
  
-A B<tentative> hierarchy of "categories" have been defined to allow groups
-of warnings to be enabled/disabled in isolation.  The current
-hierarchy is:
-
-    all - +--- unsafe -------+--- taint
-          |                  |
-          |                  +--- substr
-          |                  |
-          |                  +--- signal
-          |                  |
-          |                  +--- closure
-          |                  |
-          |                  +--- overflow
-          |                  |
-          |                  +--- portable
-          |                  |
-          |                  +--- untie
-          |                  |
-          |                  +--- utf8
-          |                  
-          +--- io   ---------+--- pipe
-          |                  |
-          |                  +--- unopened
-          |                  |
-          |                  +--- closed
-          |                  |
-          |                  +--- newline
-          |                  |
-          |                  +--- exec
-          |
-          +--- syntax    ----+--- ambiguous
-          |                  |
-          |                  +--- semicolon
-          |                  |
-          |                  +--- precedence
-          |                  |
-          |                  +--- reserved
-          |                  |
-          |                  +--- digit
-          |                  |
-          |                  +--- parenthesis
-          |                  |
-          |                  +--- deprecated
-          |                  |
-          |                  +--- printf
-          |
-          +--- severe    ----+--- inplace
-          |                  |
-          |                  +--- internal
-          |                  |
-          |                  +--- debugging
-          |
-          |--- uninitialized
-          |
-          +--- void
-          |
-          +--- recursion
-          |
-          +--- redefine
-          |
-          +--- numeric
-          |
-          +--- once
-          |
-          +--- misc
-
+A hierarchy of "categories" have been defined to allow groups of warnings
+to be enabled/disabled in isolation.
+
+The current hierarchy is:
+
+  all -+
+       |
+       +- chmod
+       |
+       +- closure
+       |
+       +- exiting
+       |
+       +- glob
+       |
+       +- io -----------+
+       |                |
+       |                +- closed
+       |                |
+       |                +- exec
+       |                |
+       |                +- newline
+       |                |
+       |                +- pipe
+       |                |
+       |                +- unopened
+       |
+       +- misc
+       |
+       +- numeric
+       |
+       +- once
+       |
+       +- overflow
+       |
+       +- pack
+       |
+       +- portable
+       |
+       +- recursion
+       |
+       +- redefine
+       |
+       +- regexp
+       |
+       +- severe -------+
+       |                |
+       |                +- debugging
+       |                |
+       |                +- inplace
+       |                |
+       |                +- internal
+       |                |
+       |                +- malloc
+       |
+       +- signal
+       |
+       +- substr
+       |
+       +- syntax -------+
+       |                |
+       |                +- ambiguous
+       |                |
+       |                +- bareword
+       |                |
+       |                +- deprecated
+       |                |
+       |                +- digit
+       |                |
+       |                +- parenthesis
+       |                |
+       |                +- precedence
+       |                |
+       |                +- printf
+       |                |
+       |                +- prototype
+       |                |
+       |                +- qw
+       |                |
+       |                +- reserved
+       |                |
+       |                +- semicolon
+       |
+       +- taint
+       |
+       +- umask
+       |
+       +- uninitialized
+       |
+       +- unpack
+       |
+       +- untie
+       |
+       +- utf8
+       |
+       +- void
+       |
+       +- y2k
 
 Just like the "strict" pragma any of these categories can be combined
 
@@ -280,7 +306,7 @@ Just like the "strict" pragma any of these categories can be combined
     no warnings qw(io syntax untie) ;
 
 Also like the "strict" pragma, if there is more than one instance of the
-warnings pragma in a given scope the cumulative effect is additive. 
+C<warnings> pragma in a given scope the cumulative effect is additive. 
 
     use warnings qw(void) ; # only "void" warnings enabled
     ...
@@ -288,14 +314,16 @@ warnings pragma in a given scope the cumulative effect is additive.
     ...
     no warnings qw(void) ;  # only "io" warnings enabled
 
+To determine which category a specific warning has been assigned to see
+L<perldiag>.
 
 =head2 Fatal Warnings
  
 The presence of the word "FATAL" in the category list will escalate any
-warnings from the category/categories specified that are detected in
-the lexical scope into fatal errors. In the code below, there are 3
-places where a deprecated warning will be detected, the middle one will
-produce a fatal error.
+warnings detected from the categories specified in the lexical scope
+into fatal errors. In the code below, there are 3 places where a
+deprecated warning will be detected, the middle one will produce a
+fatal error.
 
 
     use warnings ;
@@ -308,15 +336,54 @@ produce a fatal error.
     }
  
     $a = 1 if $a EQ $b ;
- 
-=head1 TODO
- 
-The experimental features need bottomed out.
 
-  perldiag.pod
-    Need to add warning class information and notes on
-    how to use the class info with the warnings pragma.
+=head2 Reporting Warnings from a Module
+
+The C<warnings> pragma provides two functions, namely C<warnings::enabled>
+and C<warnings::warn>, that are useful for module authors. They are
+used when you want to report a module-specific warning, but only when
+the calling module has enabled warnings via the C<warnings> pragma.
+
+Consider the module C<abc> below.
+
+    package abc;
+
+    sub open
+    {
+        if (warnings::enabled("deprecated")) {
+            warnings::warn("deprecated", 
+                           "abc::open is deprecated. Use abc:new") ;
+        }
+        new(@_) ;
+    }
 
+    sub new
+    ...
+    1 ;
+
+The function C<open> has been deprecated, so code has been included to
+display a warning message whenever the calling module has (at least) the
+"deprecated" warnings category enabled. Something like this, say.
+
+    use warnings 'deprecated';
+    use abc;
+    ...
+    abc::open($filename) ;
+
+
+If the calling module has escalated the "deprecated" warnings category
+into a fatal error like this:
+
+    use warnings 'FATAL deprecated';
+    use abc;
+    ...
+    abc::open($filename) ;
+
+then C<warnings::warn> will detect this and die after displaying the
+warning message.
+
+=head1 TODO
+ 
   perl5db.pl
     The debugger saves and restores C<$^W> at runtime. I haven't checked
     whether the debugger will still work with the lexical warnings
@@ -330,7 +397,7 @@ The experimental features need bottomed out.
 
 =head1 SEE ALSO
 
-L<warnings>.
+L<warnings>, L<perldiag>.
  
 =head1 AUTHOR