ceph/src/civetweb/src/third_party/duktape-1.3.0/src-separate/duk_bi_proxy.c

   1 /*
   2  *  Proxy built-in (ES6)
   3  */
   4
   5 #include "duk_internal.h"
   6
   7 #if defined(DUK_USE_ES6_PROXY)
   8 DUK_INTERNAL duk_ret_t duk_bi_proxy_constructor(duk_context *ctx) {
   9         duk_hobject *h_target;
  10         duk_hobject *h_handler;
  11
  12         if (!duk_is_constructor_call(ctx)) {
  13                 return DUK_RET_TYPE_ERROR;
  14         }
  15
  16         /* Reject a proxy object as the target because it would need
  17          * special handler in property lookups.  (ES6 has no such restriction)
  18          */
  19         h_target = duk_require_hobject_or_lfunc_coerce(ctx, 0);
  20         DUK_ASSERT(h_target != NULL);
  21         if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(h_target)) {
  22                 return DUK_RET_TYPE_ERROR;
  23         }
  24
  25         /* Reject a proxy object as the handler because it would cause
  26          * potentially unbounded recursion.  (ES6 has no such restriction)
  27          */
  28         h_handler = duk_require_hobject_or_lfunc_coerce(ctx, 1);
  29         DUK_ASSERT(h_handler != NULL);
  30         if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(h_handler)) {
  31                 return DUK_RET_TYPE_ERROR;
  32         }
  33
  34         /* XXX: the returned value is exotic in ES6, but we use a
  35          * simple object here with no prototype.  Without a prototype,
  36          * [[DefaultValue]] coercion fails which is abit confusing.
  37          * No callable check/handling in the current Proxy subset.
  38          */
  39         (void) duk_push_object_helper_proto(ctx,
  40                                             DUK_HOBJECT_FLAG_EXTENSIBLE |
  41                                             DUK_HOBJECT_FLAG_EXOTIC_PROXYOBJ |
  42                                             DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_OBJECT),
  43                                             NULL);
  44         DUK_ASSERT_TOP(ctx, 3);
  45
  46         /* Make _Target and _Handler non-configurable and non-writable.
  47          * They can still be forcibly changed by C code (both user and
  48          * Duktape internal), but not by Ecmascript code.
  49          */
  50
  51         /* Proxy target */
  52         duk_dup(ctx, 0);
  53         duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_TARGET, DUK_PROPDESC_FLAGS_NONE);
  54
  55         /* Proxy handler */
  56         duk_dup(ctx, 1);
  57         duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_HANDLER, DUK_PROPDESC_FLAGS_NONE);
  58
  59         return 1;  /* replacement handler */
  60 }
  61 #else  /* DUK_USE_ES6_PROXY */
  62 DUK_INTERNAL duk_ret_t duk_bi_proxy_constructor(duk_context *ctx) {
  63         DUK_UNREF(ctx);
  64         return DUK_RET_UNSUPPORTED_ERROR;
  65 }
  66 #endif  /* DUK_USE_ES6_PROXY */