1 files changed, 155 insertions, 0 deletions
diff --git a/ext/fiddle/function.c b/ext/fiddle/function.c
new file mode 100644
index 0000000000..c547d82554
--- /dev/null
+++ b/ext/fiddle/function.c
@@ -0,0 +1,155 @@
+#include <fiddle.h>
+
+VALUE cFiddleFunction;
+
+static void
+deallocate(void *p)
+{
+    ffi_cif *ptr = p;
+    if (ptr->arg_types) xfree(ptr->arg_types);
+    xfree(ptr);
+}
+
+static size_t
+function_memsize(const void *p)
+{
+    /* const */ffi_cif *ptr = (ffi_cif *)p;
+    size_t size = 0;
+
+    if (ptr) {
+	size += sizeof(*ptr);
+#if !defined(FFI_NO_RAW_API) || !FFI_NO_RAW_API
+	size += ffi_raw_size(ptr);
+#endif
+    }
+    return size;
+}
+
+const rb_data_type_t function_data_type = {
+    "fiddle/function",
+    0, deallocate, function_memsize,
+};
+
+static VALUE
+allocate(VALUE klass)
+{
+    ffi_cif * cif;
+
+    return TypedData_Make_Struct(klass, ffi_cif, &function_data_type, cif);
+}
+
+static VALUE
+initialize(int argc, VALUE argv[], VALUE self)
+{
+    ffi_cif * cif;
+    ffi_type **arg_types;
+    ffi_status result;
+    VALUE ptr, args, ret_type, abi;
+    int i;
+
+    rb_scan_args(argc, argv, "31", &ptr, &args, &ret_type, &abi);
+    if(NIL_P(abi)) abi = INT2NUM(FFI_DEFAULT_ABI);
+
+    Check_Type(args, T_ARRAY);
+
+    rb_iv_set(self, "@ptr", ptr);
+    rb_iv_set(self, "@args", args);
+    rb_iv_set(self, "@return_type", ret_type);
+    rb_iv_set(self, "@abi", abi);
+
+    TypedData_Get_Struct(self, ffi_cif, &function_data_type, cif);
+
+    arg_types = xcalloc(RARRAY_LEN(args) + 1, sizeof(ffi_type *));
+
+    for (i = 0; i < RARRAY_LEN(args); i++) {
+	int type = NUM2INT(RARRAY_PTR(args)[i]);
+	arg_types[i] = INT2FFI_TYPE(type);
+    }
+    arg_types[RARRAY_LEN(args)] = NULL;
+
+    result = ffi_prep_cif (
+	    cif,
+	    NUM2INT(abi),
+	    RARRAY_LENINT(args),
+	    INT2FFI_TYPE(NUM2INT(ret_type)),
+	    arg_types);
+
+    if (result)
+	rb_raise(rb_eRuntimeError, "error creating CIF %d", result);
+
+    return self;
+}
+
+static VALUE
+function_call(int argc, VALUE argv[], VALUE self)
+{
+    ffi_cif * cif;
+    fiddle_generic retval;
+    fiddle_generic *generic_args;
+    void **values;
+    void * fun_ptr;
+    VALUE cfunc, types, cPointer;
+    int i;
+
+    cfunc    = rb_iv_get(self, "@ptr");
+    types    = rb_iv_get(self, "@args");
+    cPointer = rb_const_get(mFiddle, rb_intern("Pointer"));
+
+    if(argc != RARRAY_LENINT(types)) {
+	rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)",
+		argc, RARRAY_LENINT(types));
+    }
+
+    TypedData_Get_Struct(self, ffi_cif, &function_data_type, cif);
+
+    values = xcalloc((size_t)argc + 1, (size_t)sizeof(void *));
+    generic_args = xcalloc((size_t)argc, (size_t)sizeof(fiddle_generic));
+
+    for (i = 0; i < argc; i++) {
+	VALUE type = RARRAY_PTR(types)[i];
+	VALUE src = argv[i];
+
+	if(NUM2INT(type) == TYPE_VOIDP) {
+	    if(NIL_P(src)) {
+		src = INT2NUM(0);
+	    } else if(cPointer != CLASS_OF(src)) {
+	        src = rb_funcall(cPointer, rb_intern("[]"), 1, src);
+	    }
+	    src = rb_Integer(src);
+	}
+
+	VALUE2GENERIC(NUM2INT(type), src, &generic_args[i]);
+	values[i] = (void *)&generic_args[i];
+    }
+    values[argc] = NULL;
+
+    ffi_call(cif, NUM2PTR(rb_Integer(cfunc)), &retval, values);
+
+    rb_funcall(mFiddle, rb_intern("last_error="), 1, INT2NUM(errno));
+#if defined(HAVE_WINDOWS_H)
+    rb_funcall(mFiddle, rb_intern("win32_last_error="), 1, INT2NUM(errno));
+#endif
+
+    xfree(values);
+    xfree(generic_args);
+
+    return GENERIC2VALUE(rb_iv_get(self, "@return_type"), retval);
+}
+
+void
+Init_fiddle_function(void)
+{
+    cFiddleFunction = rb_define_class_under(mFiddle, "Function", rb_cObject);
+
+    rb_define_const(cFiddleFunction, "DEFAULT", INT2NUM(FFI_DEFAULT_ABI));
+
+#ifdef FFI_STDCALL
+    rb_define_const(cFiddleFunction, "STDCALL", INT2NUM(FFI_STDCALL));
+#endif
+
+    rb_define_alloc_func(cFiddleFunction, allocate);
+
+    rb_define_method(cFiddleFunction, "call", function_call, -1);
+    rb_define_method(cFiddleFunction, "initialize", initialize, -1);
+}
+/* vim: set noet sws=4 sw=4: */