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