Hide function prototyes from unauthorized callers

0351a629e71de127cbfd1b142e9eaa6069deabf5 extended hiding private
functions from callers into the gcc world.

Some functions are allowed only in extensions; so can not be marked as
hidden; this commit discourages their use however, by hiding their
prototypes to all but the core and extensions.

It turns out that four functions were being used in modules we ship
with that were marked as extensions-only; so they had to be made
globally accessible.

embed.fnc

@@ -3906,7 +3906,10 @@ Adp	|bool	|valid_identifier_pvn					\
 				|U32 flags
 Adp	|bool	|valid_identifier_sv					\
 				|NULLOK SV *sv
-CRTdip	|UV	|valid_utf8_to_uvchr					\
+CRTdip	|UV	|valid_utf8_to_uv					\
+				|NN const U8 *s 			\
+				|NULLOK STRLEN *retlen
+CRTdmp	|UV	|valid_utf8_to_uvchr					\
 				|NN const U8 *s 			\
 				|NULLOK STRLEN *retlen
 Adp	|int	|vcmp		|NN SV *lhv				\

embed.h

@@ -841,7 +841,8 @@
 # define valid_identifier_pve(a,b,c)            Perl_valid_identifier_pve(aTHX_ a,b,c)
 # define valid_identifier_pvn(a,b,c)            Perl_valid_identifier_pvn(aTHX_ a,b,c)
 # define valid_identifier_sv(a)                 Perl_valid_identifier_sv(aTHX_ a)
-# define valid_utf8_to_uvchr                    Perl_valid_utf8_to_uvchr
+# define valid_utf8_to_uv                       Perl_valid_utf8_to_uv
+# define Perl_valid_utf8_to_uvchr               valid_utf8_to_uvchr
 # define vcmp(a,b)                              Perl_vcmp(aTHX_ a,b)
 # define vcroak(a,b)                            Perl_vcroak(aTHX_ a,b)
 # define vdeb(a,b)                              Perl_vdeb(aTHX_ a,b)

inline.h

@@ -1306,25 +1306,36 @@ Perl_utf8_to_bytes_overwrite(pTHX_ U8 **s_ptr, STRLEN *lenp)
 }
 
 /*
-=for apidoc valid_utf8_to_uvchr
-Like C<L<perlapi/utf8_to_uv>>, but should only be called when it is
+=for apidoc      valid_utf8_to_uv
+=for apidoc_item valid_utf8_to_uvchr
+
+These are synonymous.
+
+These are like C<L<perlapi/utf8_to_uv>>, but should only be called when it is
 known that the next character in the input UTF-8 string C<s> is well-formed
 (I<e.g.>, it passes C<L<perlapi/isUTF8_CHAR>>.  Surrogates, non-character code
 points, and non-Unicode code points are allowed.
 
+The only use for these is that they should run slightly faster than
+C<utf8_to_uv> because no error checking is done.
+
+The C<_uv> form is slightly preferred so as to have a consistent spelling with
+the other C<_uv> forms that are definitely preferred over the older and
+problematic C<_uvchr> forms.
+
 =cut
 
  */
 
 PERL_STATIC_INLINE UV
-Perl_valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
+Perl_valid_utf8_to_uv(const U8 *s, STRLEN *retlen)
 {
+    PERL_ARGS_ASSERT_VALID_UTF8_TO_UV;
+
     const UV expectlen = UTF8SKIP(s);
     const U8* send = s + expectlen;
     UV uv = *s;
 
-    PERL_ARGS_ASSERT_VALID_UTF8_TO_UVCHR;
-
     if (retlen) {
         *retlen = expectlen;
     }

pod/perldelta.pod

@@ -350,6 +350,13 @@ well.
 
 XXX
 
+=item *
+
+A new function C<valid_utf8_to_uv> has been added.  This is synonymous
+with C<valid_utf8_to_uvchr>; its reason for existence is to have
+consistent spelling with the names of the other functions that translate
+from UTF-8, so you don't have to remember a different spelling.
+
 =back
 
 =head1 Selected Bug Fixes

proto.h

@@ -5428,6 +5428,10 @@ PERL_CALLCONV bool
 Perl_valid_identifier_sv(pTHX_ SV *sv);
 #define PERL_ARGS_ASSERT_VALID_IDENTIFIER_SV
 
+/* PERL_CALLCONV UV
+Perl_valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
+        __attribute__warn_unused_result__; */
+
 #define PERL_ARGS_ASSERT_VALIDATE_PROTO         \
         assert(name)
 
@@ -10298,9 +10302,9 @@ Perl_uv_to_utf8_flags(pTHX_ U8 *d, UV uv, UV flags);
         assert(d)
 
 PERL_STATIC_INLINE UV
-Perl_valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
+Perl_valid_utf8_to_uv(const U8 *s, STRLEN *retlen)
         __attribute__warn_unused_result__;
-# define PERL_ARGS_ASSERT_VALID_UTF8_TO_UVCHR   \
+# define PERL_ARGS_ASSERT_VALID_UTF8_TO_UV      \
         assert(s)
 
 PERL_STATIC_INLINE void

utf8.h

@@ -191,6 +191,7 @@ For details, see the description for L<perlapi/uv_to_utf8_flags>.
 #define c9strict_utf8_to_uv(s, e, cp_p, advance_p)                      \
         utf8_to_uv_flags(   s, e, cp_p, advance_p,                      \
                                  UTF8_DISALLOW_ILLEGAL_C9_INTERCHANGE)
+#define valid_utf8_to_uvchr(s, advance_p)  valid_utf8_to_uv(s, advance_p)
 
 #define utf16_to_utf8(p, d, bytelen, newlen)                                \
                             utf16_to_utf8_base(p, d, bytelen, newlen, 0, 1)