text: /*
   *  Duktape built-ins
   *
   *  Size optimization note: it might seem that vararg multipurpose functions
   *  like fin(), enc(), and dec() are not very size optimal, but using a single
   *  user-visible Ecmascript function saves a lot of run-time footprint; each
   *  Function instance takes >100 bytes.  Using a shared native helper and a
   *  'magic' value won't save much if there are multiple Function instances
   *  anyway.
   */
  
  #include "duk_internal.h"
  
  /* Raw helper to extract internal information / statistics about a value.
   * The return values are version specific and must not expose anything
   * that would lead to security issues (e.g. exposing compiled function
   * 'data' buffer might be an issue).  Currently only counts and sizes and
   * such are given so there should not be a security impact.
   */
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_info(duk_context *ctx) {
  	duk_hthread *thr = (duk_hthread *) ctx;
  	duk_tval *tv;
  	duk_heaphdr *h;
  	duk_int_t i, n;
  
  	DUK_UNREF(thr);
  
  	/* result array */
  	duk_push_array(ctx);  /* -> [ val arr ] */
  
  	/* type tag (public) */
  	duk_push_int(ctx, duk_get_type(ctx, 0));
  
  	/* address */
  	tv = duk_get_tval(ctx, 0);
  	DUK_ASSERT(tv != NULL);  /* because arg count is 1 */
  	if (DUK_TVAL_IS_HEAP_ALLOCATED(tv)) {
  		h = DUK_TVAL_GET_HEAPHDR(tv);
  		duk_push_pointer(ctx, (void *) h);
  	} else {
  		/* internal type tag */
  		duk_push_int(ctx, (duk_int_t) DUK_TVAL_GET_TAG(tv));
  		goto done;
  	}
  	DUK_ASSERT(h != NULL);
  
  	/* refcount */
  #ifdef DUK_USE_REFERENCE_COUNTING
  	duk_push_size_t(ctx, DUK_HEAPHDR_GET_REFCOUNT(h));
  #else
  	duk_push_undefined(ctx);
  #endif
  
  	/* heaphdr size and additional allocation size, followed by
  	 * type specific stuff (with varying value count)
  	 */
  	switch ((duk_small_int_t) DUK_HEAPHDR_GET_TYPE(h)) {
  	case DUK_HTYPE_STRING: {
  		duk_hstring *h_str = (duk_hstring *) h;
  		duk_push_uint(ctx, (duk_uint_t) (sizeof(duk_hstring) + DUK_HSTRING_GET_BYTELEN(h_str) + 1));
  		break;
  	}
  	case DUK_HTYPE_OBJECT: {
  		duk_hobject *h_obj = (duk_hobject *) h;
  		duk_small_uint_t hdr_size;
  		if (DUK_HOBJECT_IS_COMPILEDFUNCTION(h_obj)) {
  			hdr_size = (duk_small_uint_t) sizeof(duk_hcompiledfunction);
  		} else if (DUK_HOBJECT_IS_NATIVEFUNCTION(h_obj)) {
  			hdr_size = (duk_small_uint_t) sizeof(duk_hnativefunction);
  		} else if (DUK_HOBJECT_IS_THREAD(h_obj)) {
  			hdr_size = (duk_small_uint_t) sizeof(duk_hthread);
  		} else {
  			hdr_size = (duk_small_uint_t) sizeof(duk_hobject);
  		}
  		duk_push_uint(ctx, (duk_uint_t) hdr_size);
  		duk_push_uint(ctx, (duk_uint_t) DUK_HOBJECT_E_ALLOC_SIZE(h_obj));
  		duk_push_uint(ctx, (duk_uint_t) DUK_HOBJECT_GET_ESIZE(h_obj));
  		/* Note: e_next indicates the number of gc-reachable entries
  		 * in the entry part, and also indicates the index where the
  		 * next new property would be inserted.  It does *not* indicate
  		 * the number of non-NULL keys present in the object.  That
  		 * value could be counted separately but requires a pass through
  		 * the key list.
  		 */
  		duk_push_uint(ctx, (duk_uint_t) DUK_HOBJECT_GET_ENEXT(h_obj));
  		duk_push_uint(ctx, (duk_uint_t) DUK_HOBJECT_GET_ASIZE(h_obj));
  		duk_push_uint(ctx, (duk_uint_t) DUK_HOBJECT_GET_HSIZE(h_obj));
  		if (DUK_HOBJECT_IS_COMPILEDFUNCTION(h_obj)) {
  			duk_hbuffer *h_data = (duk_hbuffer *) DUK_HCOMPILEDFUNCTION_GET_DATA(thr->heap, (duk_hcompiledfunction *) h_obj);
  			if (h_data) {
  				duk_push_uint(ctx, (duk_uint_t) DUK_HBUFFER_GET_SIZE(h_data));
  			} else {
  				duk_push_uint(ctx, 0);
  			}
  		}
  		break;
  	}
  	case DUK_HTYPE_BUFFER: {
  		duk_hbuffer *h_buf = (duk_hbuffer *) h;
  		if (DUK_HBUFFER_HAS_DYNAMIC(h_buf)) {
  			if (DUK_HBUFFER_HAS_EXTERNAL(h_buf)) {
  				duk_push_uint(ctx, (duk_uint_t) (sizeof(duk_hbuffer_external)));
  			} else {
  				/* When alloc_size == 0 the second allocation may not
  				 * actually exist.
  				 */
  				duk_push_uint(ctx, (duk_uint_t) (sizeof(duk_hbuffer_dynamic)));
  			}
  			duk_push_uint(ctx, (duk_uint_t) (DUK_HBUFFER_GET_SIZE(h_buf)));
  		} else {
  			duk_push_uint(ctx, (duk_uint_t) (sizeof(duk_hbuffer_fixed) + DUK_HBUFFER_GET_SIZE(h_buf) + 1));
  		}
  		break;
  
  	}
  	}
  
   done:
  	/* set values into ret array */
  	/* XXX: primitive to make array from valstack slice */
  	n = duk_get_top(ctx);
  	for (i = 2; i < n; i++) {
  		duk_dup(ctx, i);
  		duk_put_prop_index(ctx, 1, i - 2);
  	}
  	duk_dup(ctx, 1);
  	return 1;
  }
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_act(duk_context *ctx) {
  	duk_hthread *thr = (duk_hthread *) ctx;
  	duk_activation *act;
  	duk_uint_fast32_t pc;
  	duk_uint_fast32_t line;
  	duk_int_t level;
  
  	/* -1             = top callstack entry, callstack[callstack_top - 1]
  	 * -callstack_top = bottom callstack entry, callstack[0]
  	 */
  	level = duk_to_int(ctx, 0);
  	if (level >= 0 || -level > (duk_int_t) thr->callstack_top) {
  		return 0;
  	}
  	DUK_ASSERT(level >= -((duk_int_t) thr->callstack_top) && level <= -1);
  	act = thr->callstack + thr->callstack_top + level;
  
  	duk_push_object(ctx);
  
  	duk_push_tval(ctx, &act->tv_func);
  
  	/* Relevant PC is just before current one because PC is
  	 * post-incremented.  This should match what error augment
  	 * code does.
  	 */
  	pc = duk_hthread_get_act_prev_pc(thr, act);
  	duk_push_uint(ctx, (duk_uint_t) pc);
  
  #if defined(DUK_USE_PC2LINE)
  	line = duk_hobject_pc2line_query(ctx, -2, pc);
  #else
  	line = 0;
  #endif
  	duk_push_uint(ctx, (duk_uint_t) line);
  
  	/* Providing access to e.g. act->lex_env would be dangerous: these
  	 * internal structures must never be accessible to the application.
  	 * Duktape relies on them having consistent data, and this consistency
  	 * is only asserted for, not checked for.
  	 */
  
  	/* [ level obj func pc line ] */
  
  	/* XXX: version specific array format instead? */
  	duk_xdef_prop_stridx_wec(ctx, -4, DUK_STRIDX_LINE_NUMBER);
  	duk_xdef_prop_stridx_wec(ctx, -3, DUK_STRIDX_PC);
  	duk_xdef_prop_stridx_wec(ctx, -2, DUK_STRIDX_LC_FUNCTION);
  	return 1;
  }
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_gc(duk_context *ctx) {
  #ifdef DUK_USE_MARK_AND_SWEEP
  	duk_hthread *thr = (duk_hthread *) ctx;
  	duk_small_uint_t flags;
  	duk_bool_t rc;
  
  	flags = (duk_small_uint_t) duk_get_uint(ctx, 0);
  	rc = duk_heap_mark_and_sweep(thr->heap, flags);
  
  	/* XXX: Not sure what the best return value would be in the API.
  	 * Return a boolean for now.  Note that rc == 0 is success (true).
  	 */
  	duk_push_boolean(ctx, !rc);
  	return 1;
  #else
  	DUK_UNREF(ctx);
  	return 0;
  #endif
  }
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_fin(duk_context *ctx) {
  	(void) duk_require_hobject(ctx, 0);
  	if (duk_get_top(ctx) >= 2) {
  		/* Set: currently a finalizer is disabled by setting it to
  		 * undefined; this does not remove the property at the moment.
  		 * The value could be type checked to be either a function
  		 * or something else; if something else, the property could
  		 * be deleted.
  		 */
  		duk_set_top(ctx, 2);
  		(void) duk_put_prop_stridx(ctx, 0, DUK_STRIDX_INT_FINALIZER);
  		return 0;
  	} else {
  		/* Get. */
  		DUK_ASSERT(duk_get_top(ctx) == 1);
  		duk_get_prop_stridx(ctx, 0, DUK_STRIDX_INT_FINALIZER);
  		return 1;
  	}
  }
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_enc(duk_context *ctx) {
  	duk_hthread *thr = (duk_hthread *) ctx;
  	duk_hstring *h_str;
  
  	/* Vararg function: must be careful to check/require arguments.
  	 * The JSON helpers accept invalid indices and treat them like
  	 * non-existent optional parameters.
  	 */
  
  	h_str = duk_require_hstring(ctx, 0);
  	duk_require_valid_index(ctx, 1);
  
  	if (h_str == DUK_HTHREAD_STRING_HEX(thr)) {
  		duk_set_top(ctx, 2);
  		duk_hex_encode(ctx, 1);
  		DUK_ASSERT_TOP(ctx, 2);
  	} else if (h_str == DUK_HTHREAD_STRING_BASE64(thr)) {
  		duk_set_top(ctx, 2);
  		duk_base64_encode(ctx, 1);
  		DUK_ASSERT_TOP(ctx, 2);
  #ifdef DUK_USE_JX
  	} else if (h_str == DUK_HTHREAD_STRING_JX(thr)) {
  		duk_bi_json_stringify_helper(ctx,
  		                             1 /*idx_value*/,
  		                             2 /*idx_replacer*/,
  		                             3 /*idx_space*/,
  		                             DUK_JSON_FLAG_EXT_CUSTOM |
  		                             DUK_JSON_FLAG_ASCII_ONLY |
  		                             DUK_JSON_FLAG_AVOID_KEY_QUOTES /*flags*/);
  #endif
  #ifdef DUK_USE_JC
  	} else if (h_str == DUK_HTHREAD_STRING_JC(thr)) {
  		duk_bi_json_stringify_helper(ctx,
  		                             1 /*idx_value*/,
  		                             2 /*idx_replacer*/,
  		                             3 /*idx_space*/,
  		                             DUK_JSON_FLAG_EXT_COMPATIBLE |
  		                             DUK_JSON_FLAG_ASCII_ONLY /*flags*/);
  #endif
  	} else {
  		return DUK_RET_TYPE_ERROR;
  	}
  	return 1;
  }
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_dec(duk_context *ctx) {
  	duk_hthread *thr = (duk_hthread *) ctx;
  	duk_hstring *h_str;
  
  	/* Vararg function: must be careful to check/require arguments.
  	 * The JSON helpers accept invalid indices and treat them like
  	 * non-existent optional parameters.
  	 */
  
  	h_str = duk_require_hstring(ctx, 0);
  	duk_require_valid_index(ctx, 1);
  
  	if (h_str == DUK_HTHREAD_STRING_HEX(thr)) {
  		duk_set_top(ctx, 2);
  		duk_hex_decode(ctx, 1);
  		DUK_ASSERT_TOP(ctx, 2);
  	} else if (h_str == DUK_HTHREAD_STRING_BASE64(thr)) {
  		duk_set_top(ctx, 2);
  		duk_base64_decode(ctx, 1);
  		DUK_ASSERT_TOP(ctx, 2);
  #ifdef DUK_USE_JX
  	} else if (h_str == DUK_HTHREAD_STRING_JX(thr)) {
  		duk_bi_json_parse_helper(ctx,
  		                         1 /*idx_value*/,
  		                         2 /*idx_replacer*/,
  		                         DUK_JSON_FLAG_EXT_CUSTOM /*flags*/);
  #endif
  #ifdef DUK_USE_JC
  	} else if (h_str == DUK_HTHREAD_STRING_JC(thr)) {
  		duk_bi_json_parse_helper(ctx,
  		                         1 /*idx_value*/,
  		                         2 /*idx_replacer*/,
  		                         DUK_JSON_FLAG_EXT_COMPATIBLE /*flags*/);
  #endif
  	} else {
  		return DUK_RET_TYPE_ERROR;
  	}
  	return 1;
  }
  
  /*
   *  Compact an object
   */
  
  DUK_INTERNAL duk_ret_t duk_bi_duktape_object_compact(duk_context *ctx) {
  	DUK_ASSERT_TOP(ctx, 1);
  	duk_compact(ctx, 0);
  	return 1;  /* return the argument object */
  }
  