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
|
/* go-caller.c -- runtime.Caller and runtime.FuncForPC for Go.
Copyright 2009 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
/* Implement runtime.Caller. */
#include <stdint.h>
#include "backtrace.h"
#include "runtime.h"
/* Get the function name, file name, and line number for a PC value.
We use the backtrace library to get this. */
/* Data structure to gather file/line information. */
struct caller
{
String fn;
String file;
intgo line;
};
/* Collect file/line information for a PC value. If this is called
more than once, due to inlined functions, we use the last call, as
that is usually the most useful one. */
static int
callback (void *data, uintptr_t pc __attribute__ ((unused)),
const char *filename, int lineno, const char *function)
{
struct caller *c = (struct caller *) data;
if (function == NULL)
{
c->fn.str = NULL;
c->fn.len = 0;
}
else
{
byte *s;
c->fn.len = __builtin_strlen (function);
s = runtime_malloc (c->fn.len);
__builtin_memcpy (s, function, c->fn.len);
c->fn.str = s;
}
if (filename == NULL)
{
c->file.str = NULL;
c->file.len = 0;
}
else
{
byte *s;
c->file.len = __builtin_strlen (filename);
s = runtime_malloc (c->file.len);
__builtin_memcpy (s, filename, c->file.len);
c->file.str = s;
}
c->line = lineno;
return 0;
}
/* The error callback for backtrace_pcinfo and backtrace_syminfo. */
static void
error_callback (void *data __attribute__ ((unused)),
const char *msg, int errnum)
{
if (errnum == -1)
return;
if (errnum > 0)
runtime_printf ("%s errno %d\n", msg, errnum);
runtime_throw (msg);
}
/* The backtrace library state. */
static void *back_state;
/* A lock to control creating back_state. */
static Lock back_state_lock;
/* Fetch back_state, creating it if necessary. */
struct backtrace_state *
__go_get_backtrace_state ()
{
runtime_lock (&back_state_lock);
if (back_state == NULL)
{
const char *filename;
filename = (const char *) runtime_progname ();
back_state = backtrace_create_state (filename, 1, error_callback, NULL);
}
runtime_unlock (&back_state_lock);
return back_state;
}
/* Return function/file/line information for PC. */
_Bool
__go_file_line (uintptr pc, String *fn, String *file, intgo *line)
{
struct caller c;
runtime_memclr (&c, sizeof c);
backtrace_pcinfo (__go_get_backtrace_state (), pc, callback,
error_callback, &c);
*fn = c.fn;
*file = c.file;
*line = c.line;
return c.file.len > 0;
}
/* Collect symbol information. */
static void
syminfo_callback (void *data, uintptr_t pc __attribute__ ((unused)),
const char *symname __attribute__ ((unused)),
uintptr_t address)
{
uintptr_t *pval = (uintptr_t *) data;
*pval = address;
}
/* Set *VAL to the value of the symbol for PC. */
static _Bool
__go_symbol_value (uintptr_t pc, uintptr_t *val)
{
*val = 0;
backtrace_syminfo (__go_get_backtrace_state (), pc, syminfo_callback,
error_callback, val);
return *val != 0;
}
/* The values returned by runtime.Caller. */
struct caller_ret
{
uintptr_t pc;
String file;
intgo line;
_Bool ok;
};
struct caller_ret Caller (int n) __asm__ (GOSYM_PREFIX "runtime.Caller");
Func *FuncForPC (uintptr_t) __asm__ (GOSYM_PREFIX "runtime.FuncForPC");
/* Implement runtime.Caller. */
struct caller_ret
Caller (int skip)
{
struct caller_ret ret;
Location loc;
int32 n;
runtime_memclr (&ret, sizeof ret);
n = runtime_callers (skip + 1, &loc, 1);
if (n < 1)
return ret;
ret.pc = loc.pc;
ret.file = loc.filename;
ret.line = loc.lineno;
ret.ok = 1;
return ret;
}
/* Implement runtime.FuncForPC. */
Func *
FuncForPC (uintptr_t pc)
{
Func *ret;
String fn;
String file;
intgo line;
uintptr_t val;
if (!__go_file_line (pc, &fn, &file, &line))
return NULL;
ret = (Func *) runtime_malloc (sizeof (*ret));
ret->name = fn;
if (__go_symbol_value (pc, &val))
ret->entry = val;
else
ret->entry = 0;
return ret;
}
/* Look up the file and line information for a PC within a
function. */
struct funcline_go_return
{
String retfile;
intgo retline;
};
struct funcline_go_return
runtime_funcline_go (Func *f, uintptr targetpc)
__asm__ (GOSYM_PREFIX "runtime.funcline_go");
struct funcline_go_return
runtime_funcline_go (Func *f __attribute__((unused)), uintptr targetpc)
{
struct funcline_go_return ret;
String fn;
if (!__go_file_line (targetpc, &fn, &ret.retfile, &ret.retline))
runtime_memclr (&ret, sizeof ret);
return ret;
}
|
