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
|
/* Copyright (C) 2006-2017 Free Software Foundation, Inc.
Contributed by François-Xavier Coudert
This file is part of the GNU Fortran runtime library (libgfortran).
Libgfortran 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.
Libgfortran 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/>. */
#include "libgfortran.h"
#include <gthr.h>
#include <string.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "backtrace-supported.h"
#include "backtrace.h"
/* Store our own state while backtracing. */
struct mystate
{
int frame;
bool try_simple;
bool in_signal_handler;
};
/* Does a function name have "_gfortran_" or "_gfortrani_" prefix, possibly
with additional underscore(s) at the beginning? Cannot use strncmp()
because we might be called from a signal handler. */
static int
has_gfortran_prefix (const char *s)
{
if (!s)
return 0;
while (*s == '_')
s++;
return (s[0] == 'g' && s[1] == 'f' && s[2] == 'o' && s[3] == 'r'
&& s[4] == 't' && s[5] == 'r' && s[6] == 'a' && s[7] == 'n'
&& (s[8] == '_' || (s[8] == 'i' && s[9] == '_')));
}
static void
error_callback (void *data, const char *msg, int errnum)
{
struct mystate *state = (struct mystate *) data;
#define ERRHDR "\nCould not print backtrace: "
if (errnum < 0)
{
state->try_simple = true;
return;
}
else if (errnum == 0)
{
estr_write (ERRHDR);
estr_write (msg);
estr_write ("\n");
}
else
{
char errbuf[256];
if (state->in_signal_handler)
{
estr_write (ERRHDR);
estr_write (msg);
estr_write (", errno: ");
const char *p = gfc_itoa (errnum, errbuf, sizeof (errbuf));
estr_write (p);
estr_write ("\n");
}
else
st_printf (ERRHDR "%s: %s\n", msg,
gf_strerror (errnum, errbuf, sizeof (errbuf)));
}
}
static int
simple_callback (void *data, uintptr_t pc)
{
struct mystate *state = (struct mystate *) data;
st_printf ("#%d 0x%lx\n", state->frame, (unsigned long) pc);
(state->frame)++;
return 0;
}
static int
full_callback (void *data, uintptr_t pc, const char *filename,
int lineno, const char *function)
{
struct mystate *state = (struct mystate *) data;
if (has_gfortran_prefix (function))
return 0;
st_printf ("#%d 0x%lx in %s\n", state->frame,
(unsigned long) pc, function == NULL ? "???" : function);
if (filename || lineno != 0)
st_printf ("\tat %s:%d\n", filename == NULL ? "???" : filename, lineno);
(state->frame)++;
if (function != NULL && strcmp (function, "main") == 0)
return 1;
return 0;
}
/* Display the backtrace. */
void
show_backtrace (bool in_signal_handler)
{
/* Note that libbacktrace allows the state to be accessed from
multiple threads, so we don't need to use a TLS variable for the
state here. */
static struct backtrace_state *lbstate_saved;
struct backtrace_state *lbstate;
struct mystate state = { 0, false, in_signal_handler };
lbstate = __atomic_load_n (&lbstate_saved, __ATOMIC_RELAXED);
if (!lbstate)
{
lbstate = backtrace_create_state (NULL, __gthread_active_p (),
error_callback, NULL);
if (lbstate)
__atomic_store_n (&lbstate_saved, lbstate, __ATOMIC_RELAXED);
else
return;
}
if (!BACKTRACE_SUPPORTED || (in_signal_handler && BACKTRACE_USES_MALLOC))
{
/* If symbolic backtrace is not supported on this target, or would
require malloc() and we are in a signal handler, go with a
simple backtrace. */
backtrace_simple (lbstate, 0, simple_callback, error_callback, &state);
}
else
{
/* libbacktrace uses mmap, which is safe to call from a signal handler
(in practice, if not in theory). Thus we can generate a symbolic
backtrace, if debug symbols are available. */
backtrace_full (lbstate, 0, full_callback, error_callback, &state);
if (state.try_simple)
backtrace_simple (lbstate, 0, simple_callback, error_callback, &state);
}
}
/* Function called by the front-end translating the BACKTRACE intrinsic. */
extern void backtrace (void);
export_proto (backtrace);
void
backtrace (void)
{
show_backtrace (false);
}
|
