Lichen

templates/native/buffer.c

694:734bddc017db
2017-03-10 Paul Boddie Prevent __data__ accesses via anonymous accessors from trying to find the attribute on classes since __data__ is always provided by the immediate object and because the check_and_load_via_any operation uses a null value internally to detect failure that can be confused with a genuine __data__ attribute with a zero value (such as the integer zero).
     1 /* Native functions for buffer operations.     2      3 Copyright (C) 2016, 2017 Paul Boddie <paul@boddie.org.uk>     4      5 This program is free software; you can redistribute it and/or modify it under     6 the terms of the GNU General Public License as published by the Free Software     7 Foundation; either version 3 of the License, or (at your option) any later     8 version.     9     10 This program is distributed in the hope that it will be useful, but WITHOUT    11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS    12 FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more    13 details.    14     15 You should have received a copy of the GNU General Public License along with    16 this program.  If not, see <http://www.gnu.org/licenses/>.    17 */    18     19 #include <string.h> /* strcmp, memcpy */    20 #include "native/common.h"    21 #include "types.h"    22 #include "exceptions.h"    23 #include "ops.h"    24 #include "progconsts.h"    25 #include "progops.h"    26 #include "progtypes.h"    27 #include "main.h"    28     29 __attr __fn_native_buffer_buffer_str(__attr __args[])    30 {    31     __attr * const _data = &__args[1];    32     /* _data interpreted as buffer */    33     __fragment *data = _data->seqvalue;    34     unsigned int size = 0, i, j, n;    35     char *s;    36     __attr o;    37     38     /* Calculate the size of the string. */    39     for (i = 0; i < data->size; i++)    40         size += __load_via_object(data->attrs[i].value, __size__).intvalue;    41     42     /* Reserve space for a new string. */    43     s = (char *) __ALLOCATE(size + 1, sizeof(char));    44     45     /* Build a single string from the buffer contents. */    46     for (i = 0, j = 0; i < data->size; i++)    47     {    48         o = __load_via_object(data->attrs[i].value, __data__);    49         n = __load_via_object(data->attrs[i].value, __size__).intvalue;    50         memcpy(s + j, o.strvalue, n); /* does not null terminate but final byte should be zero */    51         j += n;    52     }    53     54     /* Return a new string. */    55     return __new_str(s, size);    56 }    57     58 /* Module initialisation. */    59     60 void __main_native_buffer()    61 {    62 }