src/nci/api.c

   1 /* nci.c
   2 Copyright (C) 2001-2009, Parrot Foundation.
   3 $Id$
   4
   5 =head1 NAME
   6
   7 src/nci/api.c - Native Call Interface routines
   8
   9 =head1 DESCRIPTION
  10
  11 This file implements the interface to the Parrot Native Call Interface system,
  12 which builds parrot to C call frames.
  13
  14 =head2 Functions
  15
  16 =over 4
  17
  18 =cut
  19
  20 */
  21
  22 #include "parrot/parrot.h"
  23 #include "parrot/nci.h"
  24 #include "api.str"
  25
  26 /* HEADERIZER HFILE: include/parrot/nci.h */
  27
  28 /*
  29
  30 =item C<PMC * build_call_func(PARROT_INTERP, STRING *signature)>
  31
  32 This function serves a single purpose. It takes the function signature for a
  33 C function we want to call and returns a PMC with a pointer to a function
  34 that can call it.
  35
  36 =cut
  37
  38 */
  39
  40 PARROT_CANNOT_RETURN_NULL
  41 PMC *
  42 build_call_func(PARROT_INTERP, ARGIN(STRING *signature))
  43 {
  44     ASSERT_ARGS(build_call_func)
  45
  46     PMC * const iglobals = interp->iglobals;
  47     PMC *nci_funcs;
  48     PMC *thunk;
  49
  50     /* fixup empty signatures */
  51     if (STRING_IS_EMPTY(signature))
  52         signature = CONST_STRING(interp, "v");
  53
  54     if (PMC_IS_NULL(iglobals))
  55         PANIC(interp, "iglobals isn't created yet");
  56
  57     nci_funcs = VTABLE_get_pmc_keyed_int(interp, iglobals, IGLOBALS_NCI_FUNCS);
  58     if (PMC_IS_NULL(nci_funcs))
  59         PANIC(interp, "iglobals.nci_funcs isn't created_yet");
  60
  61     thunk = VTABLE_get_pmc_keyed_str(interp, nci_funcs, signature);
  62
  63     if (PMC_IS_NULL(thunk)) {
  64         /* try to dynamically build a thunk */
  65         PMC *nci_fb_cb = VTABLE_get_pmc_keyed_int(interp, iglobals, IGLOBALS_NCI_FB_CB);
  66         if (!PMC_IS_NULL(nci_fb_cb)) {
  67             void *cb_ptr = VTABLE_get_pointer(interp, nci_fb_cb);
  68             nci_fb_func_t cb = (nci_fb_func_t)D2FPTR(cb_ptr);
  69             if (cb_ptr) {
  70                 PMC *nci_fb_ud = VTABLE_get_pmc_keyed_int(interp, iglobals, IGLOBALS_NCI_FB_UD);
  71                 thunk = cb(interp, nci_fb_ud, signature);
  72             }
  73         }
  74     }
  75
  76     if (!PMC_IS_NULL(thunk)) {
  77         PARROT_ASSERT(thunk->vtable);
  78         return thunk;
  79     }
  80
  81     Parrot_ex_throw_from_c_args(interp, NULL,
  82         EXCEPTION_UNIMPLEMENTED,
  83         "No NCI thunk available for signature '%S'", signature);
  84 }
  85
  86 /*
  87
  88 =back
  89
  90 =cut
  91
  92 */
  93
  94 /*
  95  * Local variables:
  96  *   c-file-style: "parrot"
  97  * End:
  98  * vim: expandtab shiftwidth=4:
  99  */