[perl #56828] [PATCH] Add nativecall support for void** params

[via RT]

# New Ticket Created by  Donald Hunter 
# Please include the string:  [perl #56828]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=56828 >


Added support for void** params, i.e. for out parameters. This is 
required for functions such as:

int sqlite3_open(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb          /* OUT: SQLite db handle */
);

Changed tools/build/nativecall.pl

Added V to %proto_type and to %sig_char.
Added emitter for V to sub make_arg().

The changes allow me to pass a Pointer PMC into an NCI call that takes a 
void**. E.g.

.local pmc lib
lib = loadlib 'sqlite3'

.local pmc func
func = dlfunc lib, 'sqlite3_open', 'itV'
store_global 'sqlite3::open', func

.local pmc sqlite
sqlite = new 'Pointer'
$S0 = 'c:/dev/test.db'
$I0 = sqlite3::open($S0, sqlite)

Regards,
Donald Hunter.


Index: tools/build/nativecall.pl
===================================================================
--- tools/build/nativecall.pl   (revision 29223)
+++ tools/build/nativecall.pl   (working copy)
@@ -82,6 +82,7 @@
     B   => "void **",
     L   => "long *",
     T   => "char **",
+    V   => "void **",
     '@' => "PMC *",           # slurpy array
 );
 
@@ -186,6 +187,7 @@
     N   => "N",
     B   => "S",
     v   => "v",
+    V   => "P",
     J   => "",
     '@' => '@',
 );
@@ -439,6 +441,11 @@
         push @{$extra_preamble_ref}, "t_$temp_num = GET_NCI_P($reg_num);";
         return "PMC_data(t_$temp_num)";
     };
+    /V/ && do {
+        push @{$temps_ref},          "PMC *t_$temp_num;";
+        push @{$extra_preamble_ref}, "t_$temp_num = GET_NCI_P($reg_num);";
+        return "(void**)&PMC_data(t_$temp_num)";
+    };
     /i/ && do {
         push @{$temps_ref},          "int t_$temp_num;";
         push @{$extra_preamble_ref}, "t_$temp_num = (int)GET_NCI_I($reg_num);";