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
  10 /* Check that an interface type matches for a conversion to a
  11    non-interface type.  This panics if the types are bad.  The actual
  12    extraction of the object is inlined.  */
  13
  14 void
  15 __go_check_interface_type (
  16     const struct __go_type_descriptor *lhs_descriptor,
  17     const struct __go_type_descriptor *rhs_descriptor,
  18     const struct __go_type_descriptor *rhs_inter_descriptor)
  19 {
  20   if (rhs_descriptor == NULL)
  21     {
  22       struct __go_empty_interface panic_arg;
  23
  24       newTypeAssertionError(NULL, NULL, lhs_descriptor, NULL, NULL,
  25                             lhs_descriptor->__reflection, NULL, &panic_arg);
  26       __go_panic(panic_arg);
  27     }
  28
  29   if (lhs_descriptor != rhs_descriptor
  30       && !__go_type_descriptors_equal (lhs_descriptor, rhs_descriptor)
  31       && (lhs_descriptor->__code != GO_UNSAFE_POINTER
  32           || !__go_is_pointer_type (rhs_descriptor))
  33       && (rhs_descriptor->__code != GO_UNSAFE_POINTER
  34           || !__go_is_pointer_type (lhs_descriptor)))
  35     {
  36       struct __go_empty_interface panic_arg;
  37
  38       newTypeAssertionError(rhs_inter_descriptor, rhs_descriptor,
  39                             lhs_descriptor,
  40                             rhs_inter_descriptor->__reflection,
  41                             rhs_descriptor->__reflection,
  42                             lhs_descriptor->__reflection,
  43                             NULL, &panic_arg);
  44       __go_panic(panic_arg);
  45     }
  46 }