Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of ltrace. |
| 3 | * Copyright (C) 2011,2012 Petr Machata, Red Hat Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as |
| 7 | * published by the Free Software Foundation; either version 2 of the |
| 8 | * License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
| 18 | * 02110-1301 USA |
| 19 | */ |
| 20 | |
Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 21 | #include <errno.h> |
| 22 | |
| 23 | #include "zero.h" |
| 24 | #include "common.h" |
| 25 | #include "type.h" |
| 26 | #include "value.h" |
| 27 | #include "expr.h" |
| 28 | |
| 29 | static int |
| 30 | zero_callback_max(struct value *ret_value, struct value *lhs, |
| 31 | struct value_dict *arguments, |
| 32 | size_t max, void *data) |
| 33 | { |
| 34 | size_t i; |
| 35 | for (i = 0; i < max; ++i) { |
| 36 | struct value element; |
| 37 | if (value_init_element(&element, lhs, i) < 0) |
| 38 | return -1; |
| 39 | |
| 40 | int zero = value_is_zero(&element, arguments); |
| 41 | |
| 42 | value_destroy(&element); |
| 43 | |
| 44 | if (zero) |
| 45 | break; |
| 46 | } |
| 47 | |
| 48 | struct arg_type_info *long_type = type_get_simple(ARGTYPE_LONG); |
| 49 | value_init_detached(ret_value, NULL, long_type, 0); |
Petr Machata | da442f4 | 2012-05-04 02:22:09 +0200 | [diff] [blame] | 50 | value_set_word(ret_value, i); |
Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | /* LHS->zero(RHS). Looks for a length of zero-terminated array, but |
| 55 | * looks no further than first RHS bytes. */ |
| 56 | static int |
| 57 | zero_callback(struct value *ret_value, struct value *lhs, |
| 58 | struct value *rhs, struct value_dict *arguments, void *data) |
| 59 | { |
| 60 | long l; |
| 61 | if (value_extract_word(rhs, &l, arguments) < 0) |
| 62 | return -1; |
| 63 | if (l < 0) |
| 64 | /* It might just be a positive value >2GB, but that's |
| 65 | * not likely. */ |
| 66 | report_global_error("maximum array length seems negative"); |
| 67 | size_t max = (size_t)l; |
| 68 | return zero_callback_max(ret_value, lhs, arguments, max, data); |
| 69 | } |
| 70 | |
| 71 | /* LHS->zero. Looks for a length of zero-terminated array, without |
| 72 | * limit. */ |
| 73 | static int |
| 74 | zero1_callback(struct value *ret_value, struct value *lhs, |
| 75 | struct value_dict *arguments, void *data) |
| 76 | { |
| 77 | return zero_callback_max(ret_value, lhs, arguments, (size_t)-1, data); |
| 78 | } |
| 79 | |
| 80 | struct expr_node * |
| 81 | build_zero_w_arg(struct expr_node *expr, int own) |
| 82 | { |
| 83 | struct expr_node *e_z = malloc(sizeof(*e_z)); |
| 84 | if (e_z == NULL) |
| 85 | return NULL; |
| 86 | |
| 87 | expr_init_cb2(e_z, &zero_callback, |
| 88 | expr_self(), 0, expr, own, NULL); |
| 89 | return e_z; |
| 90 | } |
| 91 | |
| 92 | struct expr_node * |
| 93 | expr_node_zero(void) |
| 94 | { |
Petr Machata | 1233b37 | 2012-12-08 03:13:29 +0100 | [diff] [blame] | 95 | static struct expr_node *nodep = NULL; |
| 96 | if (nodep == NULL) { |
| 97 | static struct expr_node node; |
| 98 | expr_init_cb1(&node, &zero1_callback, |
Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 99 | expr_self(), 0, (void *)-1); |
Petr Machata | 1233b37 | 2012-12-08 03:13:29 +0100 | [diff] [blame] | 100 | nodep = &node; |
Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 101 | } |
Petr Machata | 1233b37 | 2012-12-08 03:13:29 +0100 | [diff] [blame] | 102 | return nodep; |
Petr Machata | d7b2292 | 2012-01-06 18:34:22 +0100 | [diff] [blame] | 103 | } |