Fix up \cX for 5.14

Throughout 5.13 there was temporary code to deprecate and forbid
certain values of X following a \c in qq strings.  This patch fixes
this to the final 5.14 semantics.

These are:

1) a utf8 non-ASCII character will croak.  This is the same
behavior as pre-5.13, but it gives a correct error message, rather than
the malformed utf8 message previously.

2) \c{ and \cX where X is above ASCII will generate a deprecated
message.  The intent is to remove these capabilities in 5.16.  The
original agreement was to croak on above ASCII, but that does violate
our stability policy, so I'm deprecating it instead.

3) A non-deprecated warning is generated for all other \cX; this is the
same as throughout the 5.13 series.

I did not have the tuits to use \c{} as I had planned in 5.14, but \N{}
can be used instead.

2 files changed, 19 insertions, 5 deletions

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index bf22e1e511..3d35b1ce6f 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -1258,7 +1258,12 @@ Perhaps you need to copy the value to a temporary, and repeat that.
 
 =item Character following "\c" must be ASCII
 
-(F) In C<\cI<X>>, I<X> must be an ASCII character.
+(F|W deprecated, syntax) In C<\cI<X>>, I<X> must be an ASCII character.
+It is planned to make this fatal in all instances in Perl 5.16.  In the
+cases where it isn't fatal, the character this evaluates to is
+derived by exclusive or'ing the code point of this character with 0x40.
+
+Note that non-alphabetic ASCII characters are discouraged here as well.
 
 =item Character in 'C' format wrapped in pack
 
@@ -1498,12 +1503,20 @@ valid magic number.
 you have also specified an explicit size for the string.  See
 L<perlfunc/pack>.
 
-=item "\c%c" more clearly written simply as "%s"
+=item "\c{" is deprecated and is more clearly written as ";"
+
+(D deprecated, syntax) The C<\cI<X>> construct is intended to be a way
+to specify non-printable characters.  You used it with a "{" which
+evaluates to ";", which is printable.  It is planned to remove the
+ability to specify a semi-colon this way in Perl 5.16.  Just use a
+semi-colon or a backslash-semi-colon without the "\c".
+
+=item "\c%c" is more clearly written simply as "%s"
 
-(D deprecated) The C<\cI<X>> construct is intended to be a way to specify
+(W syntax) The C<\cI<X>> construct is intended to be a way to specify
 non-printable characters.  You used it for a printable one, which is better
 written as simply itself, perhaps preceded by a backslash for non-word
-characters.  This message may not remain as Deprecated beyond 5.13.
+characters.
 
 =item Deep recursion on subroutine "%s"
 
diff --git a/pod/perlop.pod b/pod/perlop.pod
index eb71b89a83..e11fff2019 100644
--- a/pod/perlop.pod
+++ b/pod/perlop.pod
@@ -1114,7 +1114,8 @@ L<perlebcdic/OPERATOR DIFFERENCES> for the complete list of what these
 sequences mean on both ASCII and EBCDIC platforms.
 
 Use of any other character following the "c" besides those listed above is
-discouraged, and may become deprecated or forbidden.  What happens for those
+discouraged, and some are deprecated with the intention of removing
+those in Perl 5.16.  What happens for any of these
 other characters currently though, is that the value is derived by inverting
 the 7th bit (0x40).