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
|
/* 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 "runtime.h"
#include "go-string.h"
/* Get the function name, file name, and line number for a PC value.
We use the DWARF debug information to get this. Rather than write
a whole new library in C, we use the existing Go library.
Unfortunately, the Go library is only available if the debug/elf
package is imported (we use debug/elf for both ELF and Mach-O, in
this case). We arrange for the debug/elf package to register
itself, and tweak the various packages that need this information
to import debug/elf where possible. */
/* The function that returns function/file/line information. */
typedef _Bool (*infofn_type) (uintptr_t, struct __go_string *,
struct __go_string *, int *);
static infofn_type infofn;
/* The function that returns the value of a symbol, used to get the
entry address of a function. */
typedef _Bool (*symvalfn_type) (struct __go_string, uintptr_t *);
static symvalfn_type symvalfn;
/* This is called by debug/elf to register the function that returns
function/file/line information. */
void RegisterDebugLookup (infofn_type, symvalfn_type)
__asm__ ("runtime.RegisterDebugLookup");
void
RegisterDebugLookup (infofn_type pi, symvalfn_type ps)
{
infofn = pi;
symvalfn = ps;
}
/* Return function/file/line information for PC. */
_Bool
__go_file_line (uintptr pc, struct __go_string *fn, struct __go_string *file,
int *line)
{
if (infofn == NULL)
return 0;
return infofn (pc, fn, file, line);
}
/* Return the value of a symbol. */
_Bool
__go_symbol_value (struct __go_string sym, uintptr_t *val)
{
if (symvalfn == NULL)
return 0;
return symvalfn (sym, val);
}
/* The values returned by runtime.Caller. */
struct caller_ret
{
uintptr_t pc;
struct __go_string file;
int line;
_Bool ok;
};
struct caller_ret Caller (int n) asm ("runtime.Caller");
Func *FuncForPC (uintptr_t) asm ("runtime.FuncForPC");
/* Implement runtime.Caller. */
struct caller_ret
Caller (int skip)
{
struct caller_ret ret;
uintptr pc;
int32 n;
struct __go_string fn;
runtime_memclr (&ret, sizeof ret);
n = runtime_callers (skip + 1, &pc, 1);
if (n < 1)
return ret;
ret.pc = pc;
ret.ok = __go_file_line (pc, &fn, &ret.file, &ret.line);
return ret;
}
/* Implement runtime.FuncForPC. */
Func *
FuncForPC (uintptr_t pc)
{
Func *ret;
struct __go_string fn;
struct __go_string file;
int line;
uintptr_t val;
if (!__go_file_line (pc, &fn, &file, &line))
return NULL;
if (!__go_symbol_value (fn, &val))
return NULL;
ret = (Func *) runtime_malloc (sizeof (*ret));
ret->name = fn;
ret->entry = val;
return ret;
}
/* Look up the file and line information for a PC within a
function. */
struct funcline_go_return
{
struct __go_string retfile;
int retline;
};
struct funcline_go_return
runtime_funcline_go (Func *f, uintptr targetpc)
__asm__ ("runtime.funcline_go");
struct funcline_go_return
runtime_funcline_go (Func *f __attribute__((unused)), uintptr targetpc)
{
struct funcline_go_return ret;
struct __go_string fn;
if (!__go_file_line (targetpc, &fn, &ret.retfile, &ret.retline))
runtime_memclr (&ret, sizeof ret);
return ret;
}
|
