1 /* Copyright (C) 2006-2021 Free Software Foundation, Inc.
2 Contributed by François-Xavier Coudert
4 This file is part of the GNU Fortran runtime library (libgfortran).
6 Libgfortran is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 Libgfortran is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
25 #include "libgfortran.h"
36 #include "backtrace-supported.h"
37 #include "backtrace.h"
40 /* Store our own state while backtracing. */
45 bool in_signal_handler
;
49 /* Does a function name have "_gfortran_" or "_gfortrani_" prefix, possibly
50 with additional underscore(s) at the beginning? Cannot use strncmp()
51 because we might be called from a signal handler. */
54 has_gfortran_prefix (const char *s
)
62 return (s
[0] == 'g' && s
[1] == 'f' && s
[2] == 'o' && s
[3] == 'r'
63 && s
[4] == 't' && s
[5] == 'r' && s
[6] == 'a' && s
[7] == 'n'
64 && (s
[8] == '_' || (s
[8] == 'i' && s
[9] == '_')));
68 error_callback (void *data
, const char *msg
, int errnum
)
70 struct mystate
*state
= (struct mystate
*) data
;
72 #define ERRHDR "\nCould not print backtrace: "
76 state
->try_simple
= true;
81 iov
[0].iov_base
= (char*) ERRHDR
;
82 iov
[0].iov_len
= strlen (ERRHDR
);
83 iov
[1].iov_base
= (char*) msg
;
84 iov
[1].iov_len
= strlen (msg
);
85 iov
[2].iov_base
= (char*) "\n";
92 if (state
->in_signal_handler
)
94 iov
[0].iov_base
= (char*) ERRHDR
;
95 iov
[0].iov_len
= strlen (ERRHDR
);
96 iov
[1].iov_base
= (char*) msg
;
97 iov
[1].iov_len
= strlen (msg
);
98 iov
[2].iov_base
= (char*) ", errno: ";
99 iov
[2].iov_len
= strlen (iov
[2].iov_base
);
100 const char *p
= gfc_itoa (errnum
, errbuf
, sizeof (errbuf
));
101 iov
[3].iov_base
= (char*) p
;
102 iov
[3].iov_len
= strlen (p
);
103 iov
[4].iov_base
= (char*) "\n";
105 estr_writev (iov
, 5);
108 st_printf (ERRHDR
"%s: %s\n", msg
,
109 gf_strerror (errnum
, errbuf
, sizeof (errbuf
)));
114 simple_callback (void *data
, uintptr_t pc
)
116 struct mystate
*state
= (struct mystate
*) data
;
117 st_printf ("#%d 0x%lx\n", state
->frame
, (unsigned long) pc
);
123 full_callback (void *data
, uintptr_t pc
, const char *filename
,
124 int lineno
, const char *function
)
126 struct mystate
*state
= (struct mystate
*) data
;
128 if (has_gfortran_prefix (function
))
131 st_printf ("#%d 0x%lx in %s\n", state
->frame
,
132 (unsigned long) pc
, function
== NULL
? "???" : function
);
133 if (filename
|| lineno
!= 0)
134 st_printf ("\tat %s:%d\n", filename
== NULL
? "???" : filename
, lineno
);
137 if (function
!= NULL
&& strcmp (function
, "main") == 0)
144 /* Display the backtrace. */
147 show_backtrace (bool in_signal_handler
)
149 /* Note that libbacktrace allows the state to be accessed from
150 multiple threads, so we don't need to use a TLS variable for the
152 static struct backtrace_state
*lbstate_saved
;
153 struct backtrace_state
*lbstate
;
154 struct mystate state
= { 0, false, in_signal_handler
};
156 lbstate
= __atomic_load_n (&lbstate_saved
, __ATOMIC_RELAXED
);
159 lbstate
= backtrace_create_state (NULL
, __gthread_active_p (),
160 error_callback
, NULL
);
162 __atomic_store_n (&lbstate_saved
, lbstate
, __ATOMIC_RELAXED
);
167 if (!BACKTRACE_SUPPORTED
|| (in_signal_handler
&& BACKTRACE_USES_MALLOC
))
169 /* If symbolic backtrace is not supported on this target, or would
170 require malloc() and we are in a signal handler, go with a
173 backtrace_simple (lbstate
, 0, simple_callback
, error_callback
, &state
);
177 /* libbacktrace uses mmap, which is safe to call from a signal handler
178 (in practice, if not in theory). Thus we can generate a symbolic
179 backtrace, if debug symbols are available. */
181 backtrace_full (lbstate
, 0, full_callback
, error_callback
, &state
);
182 if (state
.try_simple
)
183 backtrace_simple (lbstate
, 0, simple_callback
, error_callback
, &state
);
189 /* Function called by the front-end translating the BACKTRACE intrinsic. */
191 extern void backtrace (void);
192 export_proto (backtrace
);
197 show_backtrace (false);