regen/embed.pl: Avoid use of hard-coded list

The list consists of exactly the functions that have the O flag set in
embed.fnc.  No need to keep this data twice.  The entries are trivially
generatable from existing entries as we go along

And those generated entries have the added advantage of not using the
short name, so potentially less name space pollution

Author: khwilliamson

embed.h

@@ -49,25 +49,23 @@
 # define sv_setptrref(rv,ptr)                   sv_setref_iv(rv,NULL,PTR2IV(ptr))
 # if !defined(PERL_NOCOMPAT)
 
-/* Compatibility for various misnamed functions.  All functions
-   in the API that begin with "perl_" (not "Perl_") take an explicit
-   interpreter context pointer.
-   The following are not like that, but since they had a "perl_"
-   prefix in previous versions, we provide compatibility macros.
- */
-#   define perl_atexit(a,b)                     call_atexit(a,b)
-#   define perl_call_argv(a,b,c)                call_argv(a,b,c)
-#   define perl_call_method(a,b)                call_method(a,b)
-#   define perl_call_pv(a,b)                    call_pv(a,b)
-#   define perl_call_sv(a,b)                    call_sv(a,b)
-#   define perl_eval_pv(a,b)                    eval_pv(a,b)
-#   define perl_eval_sv(a,b)                    eval_sv(a,b)
-#   define perl_get_av(a,b)                     get_av(a,b)
-#   define perl_get_cv(a,b)                     get_cv(a,b)
-#   define perl_get_hv(a,b)                     get_hv(a,b)
-#   define perl_get_sv(a,b)                     get_sv(a,b)
-#   define perl_init_i18nl10n(a)                init_i18nl10n(a)
-#   define perl_require_pv(a)                   require_pv(a)
+/* Compatibility for this renamed function. */
+#   define perl_atexit(a,b)                     Perl_call_atexit(aTHX_ a,b)
+
+/* Compatibility for these functions that had a 'perl_' prefix before
+ * 'Perl_' became the standard */
+#   define perl_call_argv(a,b,c)                Perl_call_argv(aTHX_ a,b,c)
+#   define perl_call_method(a,b)                Perl_call_method(aTHX_ a,b)
+#   define perl_call_pv(a,b)                    Perl_call_pv(aTHX_ a,b)
+#   define perl_call_sv(a,b)                    Perl_call_sv(aTHX_ a,b)
+#   define perl_eval_pv(a,b)                    Perl_eval_pv(aTHX_ a,b)
+#   define perl_eval_sv(a,b)                    Perl_eval_sv(aTHX_ a,b)
+#   define perl_get_av(a,b)                     Perl_get_av(aTHX_ a,b)
+#   define perl_get_cv(a,b)                     Perl_get_cv(aTHX_ a,b)
+#   define perl_get_hv(a,b)                     Perl_get_hv(aTHX_ a,b)
+#   define perl_get_sv(a,b)                     Perl_get_sv(aTHX_ a,b)
+#   define perl_init_i18nl10n(a)                Perl_init_i18nl10n(aTHX_ a)
+#   define perl_require_pv(a)                   Perl_require_pv(aTHX_ a)
 
 /* Before C99, macros could not wrap varargs functions. This
    provides a set of compatibility functions that don't take an

regen/embed.pl

@@ -55,6 +55,7 @@ BEGIN
                                   );
 my %has_compat_macro;
 $has_compat_macro{$_} = 1 for @have_compatibility_macros;
+my %perl_compats;   # Have 'perl_' prefix
 
 my $unflagged_pointers;
 my @az = ('a'..'z');
@@ -848,7 +849,19 @@ sub embed_h {
                         die "Can't use W without other args (currently)";
                     }
                 }
-                $ret .= ")\n";
+                $ret .= ")";
+
+                # For functions that have an old 'perl_' name, create an entry
+                # here while we have all the information, for output later
+                # (when not under NO_SHORT_NAMES)
+                if ($flags =~ /O/) {
+                    my $extra_entry = $ret;
+                    $extra_entry =~ s/define /define perl_/;
+                    $perl_compats{$extra_entry} = 1;
+                }
+
+                $ret .= "\n";
+
                 if($has_compat_macro{$func}) {
                     # Make older ones available only when !MULTIPLICITY or
                     # PERL_CORE or PERL_WANT_VARARGS.  These should not be
@@ -860,6 +873,7 @@ sub embed_h {
                          . $ret
                          . "#${ind}endif\n";
                 }
+
             }
             $ret = "#${ind}ifndef NO_MATHOMS\n$ret#${ind}endif\n"
                                                              if $flags =~ /b/;
@@ -915,25 +929,15 @@ sub generate_embed_h {
 
     #if !defined(PERL_CORE) && !defined(PERL_NOCOMPAT)
 
-    /* Compatibility for various misnamed functions.  All functions
-       in the API that begin with "perl_" (not "Perl_") take an explicit
-       interpreter context pointer.
-       The following are not like that, but since they had a "perl_"
-       prefix in previous versions, we provide compatibility macros.
-     */
-    #  define perl_atexit(a,b)          call_atexit(a,b)
-    END
+    /* Compatibility for this renamed function. */
+    #  define perl_atexit(a,b)          Perl_call_atexit(aTHX_ a,b)
 
-    foreach (@$all) {
-        my $embed= $_->{embed} or next;
-        my ($flags, $retval, $func, $args) =
-                                @{$embed}{qw(flags return_type name args)};
-        next unless $flags =~ /O/;
+    /* Compatibility for these functions that had a 'perl_' prefix before
+     * 'Perl_' became the standard */
+    END
 
-        my $alist = join ",", @az[0..$#$args];
-        my $ret = "#  define perl_$func($alist) ";
-        print $em add_indent($ret,"$func($alist)\n");
-    }
+    # These have been saved up for now
+    print $em map { "$_\n" } sort keys %perl_compats;
 
     print $em <<~'END';