1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
|
/* Exception handling and frame unwind runtime interface routines.
Copyright (C) 2001-2014 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* @@@ Really this should be out of line, but this also causes link
compatibility problems with the base ABI. This is slightly better
than duplicating code, however. */
#ifndef GCC_UNWIND_PE_H
#define GCC_UNWIND_PE_H
/* If using C++, references to abort have to be qualified with std::. */
#if __cplusplus
#define __gxx_abort std::abort
#else
#define __gxx_abort abort
#endif
/* Pointer encodings, from dwarf2.h. */
#define DW_EH_PE_absptr 0x00
#define DW_EH_PE_omit 0xff
#define DW_EH_PE_uleb128 0x01
#define DW_EH_PE_udata2 0x02
#define DW_EH_PE_udata4 0x03
#define DW_EH_PE_udata8 0x04
#define DW_EH_PE_sleb128 0x09
#define DW_EH_PE_sdata2 0x0A
#define DW_EH_PE_sdata4 0x0B
#define DW_EH_PE_sdata8 0x0C
#define DW_EH_PE_signed 0x08
#define DW_EH_PE_pcrel 0x10
#define DW_EH_PE_textrel 0x20
#define DW_EH_PE_datarel 0x30
#define DW_EH_PE_funcrel 0x40
#define DW_EH_PE_aligned 0x50
#define DW_EH_PE_indirect 0x80
#ifndef NO_SIZE_OF_ENCODED_VALUE
/* Given an encoding, return the number of bytes the format occupies.
This is only defined for fixed-size encodings, and so does not
include leb128. */
static unsigned int
size_of_encoded_value (unsigned char encoding) __attribute__ ((unused));
static unsigned int
size_of_encoded_value (unsigned char encoding)
{
if (encoding == DW_EH_PE_omit)
return 0;
switch (encoding & 0x07)
{
case DW_EH_PE_absptr:
return sizeof (void *);
case DW_EH_PE_udata2:
return 2;
case DW_EH_PE_udata4:
return 4;
case DW_EH_PE_udata8:
return 8;
}
__gxx_abort ();
}
#endif
#ifndef NO_BASE_OF_ENCODED_VALUE
/* Given an encoding and an _Unwind_Context, return the base to which
the encoding is relative. This base may then be passed to
read_encoded_value_with_base for use when the _Unwind_Context is
not available. */
static _Unwind_Ptr
base_of_encoded_value (unsigned char encoding, struct _Unwind_Context *context)
{
if (encoding == DW_EH_PE_omit)
return 0;
switch (encoding & 0x70)
{
case DW_EH_PE_absptr:
case DW_EH_PE_pcrel:
case DW_EH_PE_aligned:
return 0;
case DW_EH_PE_textrel:
return _Unwind_GetTextRelBase (context);
case DW_EH_PE_datarel:
return _Unwind_GetDataRelBase (context);
case DW_EH_PE_funcrel:
return _Unwind_GetRegionStart (context);
}
__gxx_abort ();
}
#endif
/* Read an unsigned leb128 value from P, store the value in VAL, return
P incremented past the value. We assume that a word is large enough to
hold any value so encoded; if it is smaller than a pointer on some target,
pointers should not be leb128 encoded on that target. */
static const unsigned char *
read_uleb128 (const unsigned char *p, _uleb128_t *val)
{
unsigned int shift = 0;
unsigned char byte;
_uleb128_t result;
result = 0;
do
{
byte = *p++;
result |= ((_uleb128_t)byte & 0x7f) << shift;
shift += 7;
}
while (byte & 0x80);
*val = result;
return p;
}
/* Similar, but read a signed leb128 value. */
static const unsigned char *
read_sleb128 (const unsigned char *p, _sleb128_t *val)
{
unsigned int shift = 0;
unsigned char byte;
_uleb128_t result;
result = 0;
do
{
byte = *p++;
result |= ((_uleb128_t)byte & 0x7f) << shift;
shift += 7;
}
while (byte & 0x80);
/* Sign-extend a negative value. */
if (shift < 8 * sizeof(result) && (byte & 0x40) != 0)
result |= -(((_uleb128_t)1L) << shift);
*val = (_sleb128_t) result;
return p;
}
/* Load an encoded value from memory at P. The value is returned in VAL;
The function returns P incremented past the value. BASE is as given
by base_of_encoded_value for this encoding in the appropriate context. */
static const unsigned char *
read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
const unsigned char *p, _Unwind_Ptr *val)
{
union unaligned
{
void *ptr;
unsigned u2 __attribute__ ((mode (HI)));
unsigned u4 __attribute__ ((mode (SI)));
unsigned u8 __attribute__ ((mode (DI)));
signed s2 __attribute__ ((mode (HI)));
signed s4 __attribute__ ((mode (SI)));
signed s8 __attribute__ ((mode (DI)));
} __attribute__((__packed__));
const union unaligned *u = (const union unaligned *) p;
_Unwind_Internal_Ptr result;
if (encoding == DW_EH_PE_aligned)
{
_Unwind_Internal_Ptr a = (_Unwind_Internal_Ptr) p;
a = (a + sizeof (void *) - 1) & - sizeof(void *);
result = *(_Unwind_Internal_Ptr *) a;
p = (const unsigned char *) (_Unwind_Internal_Ptr) (a + sizeof (void *));
}
else
{
switch (encoding & 0x0f)
{
case DW_EH_PE_absptr:
result = (_Unwind_Internal_Ptr) u->ptr;
p += sizeof (void *);
break;
case DW_EH_PE_uleb128:
{
_uleb128_t tmp;
p = read_uleb128 (p, &tmp);
result = (_Unwind_Internal_Ptr) tmp;
}
break;
case DW_EH_PE_sleb128:
{
_sleb128_t tmp;
p = read_sleb128 (p, &tmp);
result = (_Unwind_Internal_Ptr) tmp;
}
break;
case DW_EH_PE_udata2:
result = u->u2;
p += 2;
break;
case DW_EH_PE_udata4:
result = u->u4;
p += 4;
break;
case DW_EH_PE_udata8:
result = u->u8;
p += 8;
break;
case DW_EH_PE_sdata2:
result = u->s2;
p += 2;
break;
case DW_EH_PE_sdata4:
result = u->s4;
p += 4;
break;
case DW_EH_PE_sdata8:
result = u->s8;
p += 8;
break;
default:
__gxx_abort ();
}
if (result != 0)
{
result += ((encoding & 0x70) == DW_EH_PE_pcrel
? (_Unwind_Internal_Ptr) u : base);
if (encoding & DW_EH_PE_indirect)
result = *(_Unwind_Internal_Ptr *) result;
}
}
*val = result;
return p;
}
#ifndef NO_BASE_OF_ENCODED_VALUE
/* Like read_encoded_value_with_base, but get the base from the context
rather than providing it directly. */
static inline const unsigned char *
read_encoded_value (struct _Unwind_Context *context, unsigned char encoding,
const unsigned char *p, _Unwind_Ptr *val)
{
return read_encoded_value_with_base (encoding,
base_of_encoded_value (encoding, context),
p, val);
}
#endif
#endif /* unwind-pe.h */
|
