duktape-1.5.2/src-separate/duk_bi_duktape.c

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/*
 *  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);
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
        } else if (DUK_HOBJECT_IS_BUFFEROBJECT(h_obj)) {
            hdr_size = (duk_small_uint_t) sizeof(duk_hbufferobject);
#endif
        } 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_P_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;
 
    DUK_UNREF(thr);
 
    /* 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;
 
    DUK_UNREF(thr);
 
    /* 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 */
}