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
21 #include <stdlib.h>
22 #include <assert.h>
23 #include <string.h>
24
25 #include "lens_enum.h"
26 #include "lens_default.h"
27 #include "value.h"
28 #include "sysdep.h"
29 #include "type.h"
30
31 struct enum_entry {
32 char *key;
33 int own_key;
34 struct value *value;
35 int own_value;
36 };
37
38 static void
enum_entry_dtor(struct enum_entry * entry,void * data)39 enum_entry_dtor(struct enum_entry *entry, void *data)
40 {
41 if (entry->own_key)
42 free(entry->key);
43 if (entry->own_value) {
44 value_destroy(entry->value);
45 free(entry->value);
46 }
47 }
48
49 static void
enum_lens_destroy_cb(struct lens * lens)50 enum_lens_destroy_cb(struct lens *lens)
51 {
52 struct enum_lens *self = (void *)lens;
53
54 VECT_DESTROY(&self->entries, struct enum_entry,
55 enum_entry_dtor, NULL);
56 }
57
58 enum {
59 #ifdef ARCH_ENDIAN_BIG
60 big_endian = 1,
61 #elif defined (ARCH_ENDIAN_LITTLE)
62 big_endian = 0,
63 #else
64 # error Undefined endianness.
65 #endif
66 };
67
68 /* Returns 0 if they are not equal, >0 if they are, and <0 if there
69 * was an error. */
70 static int
enum_values_equal(struct value * inf_value,struct value * enum_value,struct value_dict * arguments)71 enum_values_equal(struct value *inf_value, struct value *enum_value,
72 struct value_dict *arguments)
73 {
74 /* Width may not match between what's defined in config file
75 * and what arrives from the back end. Typically, if there is
76 * a mismatch, the config file size will be larger, as we are
77 * in a situation where 64-bit tracer traces 32-bit process.
78 * But opposite situation can occur e.g. on PPC, where it's
79 * apparently possible for 32-bit tracer to trace 64-bit
80 * inferior, or hypothetically in a x32/x86_64 situation. */
81
82 unsigned char *inf_data = value_get_data(inf_value, arguments);
83 size_t inf_sz = value_size(inf_value, arguments);
84 if (inf_data == NULL || inf_sz == (size_t)-1)
85 return -1;
86
87 assert(inf_value->type->type == enum_value->type->type);
88
89 unsigned char *enum_data = value_get_data(enum_value, arguments);
90 size_t enum_sz = value_size(enum_value, arguments);
91 if (enum_data == NULL || enum_sz == (size_t)-1)
92 return -1;
93
94 size_t sz = enum_sz > inf_sz ? inf_sz : enum_sz;
95
96 if (big_endian)
97 return memcmp(enum_data + enum_sz - sz,
98 inf_data + inf_sz - sz, sz) == 0;
99 else
100 return memcmp(enum_data, inf_data, sz) == 0;
101 }
102
103 static const char *
enum_get(struct enum_lens * lens,struct value * value,struct value_dict * arguments)104 enum_get(struct enum_lens *lens, struct value *value,
105 struct value_dict *arguments)
106 {
107 size_t i;
108 for (i = 0; i < vect_size(&lens->entries); ++i) {
109 struct enum_entry *entry = VECT_ELEMENT(&lens->entries,
110 struct enum_entry, i);
111 int st = enum_values_equal(value, entry->value, arguments);
112 if (st < 0)
113 return NULL;
114 else if (st != 0)
115 return entry->key;
116 }
117 return NULL;
118 }
119
120 static int
enum_lens_format_cb(struct lens * lens,FILE * stream,struct value * value,struct value_dict * arguments)121 enum_lens_format_cb(struct lens *lens, FILE *stream,
122 struct value *value, struct value_dict *arguments)
123 {
124 struct enum_lens *self = (void *)lens;
125
126 const char *name = enum_get(self, value, arguments);
127 if (name != NULL)
128 return fprintf(stream, "%s", name);
129
130 return lens_format(&default_lens, stream, value, arguments);
131 }
132
133
134 void
lens_init_enum(struct enum_lens * lens)135 lens_init_enum(struct enum_lens *lens)
136 {
137 *lens = (struct enum_lens){
138 {
139 .format_cb = enum_lens_format_cb,
140 .destroy_cb = enum_lens_destroy_cb,
141 },
142 };
143 VECT_INIT(&lens->entries, struct enum_entry);
144 }
145
146 int
lens_enum_add(struct enum_lens * lens,const char * key,int own_key,struct value * value,int own_value)147 lens_enum_add(struct enum_lens *lens,
148 const char *key, int own_key,
149 struct value *value, int own_value)
150 {
151 struct enum_entry entry = { (char *)key, own_key, value, own_value };
152 return VECT_PUSHBACK(&lens->entries, &entry);
153 }
154
155 size_t
lens_enum_size(struct enum_lens * lens)156 lens_enum_size(struct enum_lens *lens)
157 {
158 return vect_size(&lens->entries);
159 }
160