libgo/runtime/go-check-interface.c

   1 /* go-check-interface.c -- check an interface type for a conversion
   2
   3    Copyright 2010 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include "go-panic.h"
   8 #include "interface.h"
   9 #include "runtime.h"
  10
  11 /* Check that an interface type matches for a conversion to a
  12    non-interface type.  This panics if the types are bad.  The actual
  13    extraction of the object is inlined.  */
  14
  15 void
  16 __go_check_interface_type (
  17     const struct __go_type_descriptor *lhs_descriptor,
  18     const struct __go_type_descriptor *rhs_descriptor,
  19     const struct __go_type_descriptor *rhs_inter_descriptor)
  20 {
  21   if (rhs_descriptor == NULL)
  22     {
  23       struct __go_empty_interface panic_arg;
  24
  25       runtime_newTypeAssertionError(NULL, NULL, lhs_descriptor->__reflection,
  26                                     NULL, &panic_arg);
  27       __go_panic(panic_arg);
  28     }
  29
  30   if (lhs_descriptor != rhs_descriptor
  31       && !__go_type_descriptors_equal (lhs_descriptor, rhs_descriptor)
  32       && (lhs_descriptor->__code != GO_UNSAFE_POINTER
  33           || !__go_is_pointer_type (rhs_descriptor))
  34       && (rhs_descriptor->__code != GO_UNSAFE_POINTER
  35           || !__go_is_pointer_type (lhs_descriptor)))
  36     {
  37       struct __go_empty_interface panic_arg;
  38
  39       runtime_newTypeAssertionError(rhs_inter_descriptor->__reflection,
  40                                     rhs_descriptor->__reflection,
  41                                     lhs_descriptor->__reflection,
  42                                     NULL, &panic_arg);
  43       __go_panic(panic_arg);
  44     }
  45 }