1 /* Handling of compile-time options that influence the library.
2    Copyright (C) 2005-2016 Free Software Foundation, Inc.
3 
4 This file is part of the GNU Fortran runtime library (libgfortran).
5 
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)
9 any later version.
10 
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.
15 
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.
19 
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/>.  */
24 
25 #include "libgfortran.h"
26 #include <signal.h>
27 
28 
29 /* Useful compile-time options will be stored in here.  */
30 compile_options_t compile_options;
31 
32 #ifndef LIBGFOR_MINIMAL
33 static volatile sig_atomic_t fatal_error_in_progress = 0;
34 
35 
36 /* Helper function for backtrace_handler to write information about the
37    received signal to stderr before actually giving the backtrace.  */
38 static void
show_signal(int signum)39 show_signal (int signum)
40 {
41   const char * name = NULL, * desc = NULL;
42 
43   switch (signum)
44     {
45 #if defined(SIGQUIT)
46       case SIGQUIT:
47 	name = "SIGQUIT";
48 	desc = "Terminal quit signal";
49 	break;
50 #endif
51 
52       /* The following 4 signals are defined by C89.  */
53       case SIGILL:
54 	name = "SIGILL";
55 	desc = "Illegal instruction";
56 	break;
57 
58       case SIGABRT:
59 	name = "SIGABRT";
60 	desc = "Process abort signal";
61 	break;
62 
63       case SIGFPE:
64 	name = "SIGFPE";
65 	desc = "Floating-point exception - erroneous arithmetic operation";
66 	break;
67 
68       case SIGSEGV:
69 	name = "SIGSEGV";
70 	desc = "Segmentation fault - invalid memory reference";
71 	break;
72 
73 #if defined(SIGBUS)
74       case SIGBUS:
75 	name = "SIGBUS";
76 	desc = "Access to an undefined portion of a memory object";
77 	break;
78 #endif
79 
80 #if defined(SIGSYS)
81       case SIGSYS:
82 	name = "SIGSYS";
83 	desc = "Bad system call";
84 	break;
85 #endif
86 
87 #if defined(SIGTRAP)
88       case SIGTRAP:
89 	name = "SIGTRAP";
90 	desc = "Trace/breakpoint trap";
91 	break;
92 #endif
93 
94 #if defined(SIGXCPU)
95       case SIGXCPU:
96 	name = "SIGXCPU";
97 	desc = "CPU time limit exceeded";
98 	break;
99 #endif
100 
101 #if defined(SIGXFSZ)
102       case SIGXFSZ:
103 	name = "SIGXFSZ";
104 	desc = "File size limit exceeded";
105 	break;
106 #endif
107     }
108 
109   if (name)
110     st_printf ("\nProgram received signal %s: %s.\n", name, desc);
111   else
112     st_printf ("\nProgram received signal %d.\n", signum);
113 }
114 
115 
116 /* A signal handler to allow us to output a backtrace.  */
117 void
backtrace_handler(int signum)118 backtrace_handler (int signum)
119 {
120   /* Since this handler is established for more than one kind of signal,
121      it might still get invoked recursively by delivery of some other kind
122      of signal.  Use a static variable to keep track of that. */
123   if (fatal_error_in_progress)
124     raise (signum);
125   fatal_error_in_progress = 1;
126 
127   show_signal (signum);
128   estr_write ("\nBacktrace for this error:\n");
129   show_backtrace (true);
130 
131   /* Now reraise the signal.  We reactivate the signal's
132      default handling, which is to terminate the process.
133      We could just call exit or abort,
134      but reraising the signal sets the return status
135      from the process correctly. */
136   signal (signum, SIG_DFL);
137   raise (signum);
138 }
139 #endif
140 
141 /* Set the usual compile-time options.  */
142 extern void set_options (int , int []);
143 export_proto(set_options);
144 
145 void
set_options(int num,int options[])146 set_options (int num, int options[])
147 {
148   if (num >= 1)
149     compile_options.warn_std = options[0];
150   if (num >= 2)
151     compile_options.allow_std = options[1];
152   if (num >= 3)
153     compile_options.pedantic = options[2];
154   /* options[3] is the removed -fdump-core option. Its place in the
155      options array is retained due to ABI compatibility. Remove when
156      bumping the library ABI.  */
157   if (num >= 5)
158     compile_options.backtrace = options[4];
159   if (num >= 6)
160     compile_options.sign_zero = options[5];
161   if (num >= 7)
162     compile_options.bounds_check = options[6];
163   /* options[7] is the -frange-check option, which no longer affects
164      the library behavior; range checking is now always done when
165      parsing integers. Its place in the options array is retained due
166      to ABI compatibility. Remove when bumping the library ABI.  */
167   if (num >= 9)
168     compile_options.fpe_summary = options[8];
169 
170 #ifndef LIBGFOR_MINIMAL
171   /* If backtrace is required, we set signal handlers on the POSIX
172      2001 signals with core action.  */
173   if (compile_options.backtrace)
174     {
175 #if defined(SIGQUIT)
176       signal (SIGQUIT, backtrace_handler);
177 #endif
178 
179       /* The following 4 signals are defined by C89.  */
180       signal (SIGILL, backtrace_handler);
181       signal (SIGABRT, backtrace_handler);
182       signal (SIGFPE, backtrace_handler);
183       signal (SIGSEGV, backtrace_handler);
184 
185 #if defined(SIGBUS)
186       signal (SIGBUS, backtrace_handler);
187 #endif
188 
189 #if defined(SIGSYS)
190       signal (SIGSYS, backtrace_handler);
191 #endif
192 
193 #if defined(SIGTRAP)
194       signal (SIGTRAP, backtrace_handler);
195 #endif
196 
197 #if defined(SIGXCPU)
198       signal (SIGXCPU, backtrace_handler);
199 #endif
200 
201 #if defined(SIGXFSZ)
202       signal (SIGXFSZ, backtrace_handler);
203 #endif
204     }
205 #endif
206 }
207 
208 
209 /* Default values for the compile-time options.  Keep in sync with
210    gcc/fortran/options.c (gfc_init_options).  */
211 void
init_compile_options(void)212 init_compile_options (void)
213 {
214   compile_options.warn_std = GFC_STD_F95_DEL | GFC_STD_LEGACY;
215   compile_options.allow_std = GFC_STD_F95_OBS | GFC_STD_F95_DEL
216     | GFC_STD_F2003 | GFC_STD_F2008 | GFC_STD_F95 | GFC_STD_F77
217     | GFC_STD_F2008_OBS | GFC_STD_GNU | GFC_STD_LEGACY;
218   compile_options.pedantic = 0;
219   compile_options.backtrace = 0;
220   compile_options.sign_zero = 1;
221   compile_options.fpe_summary = 0;
222 }
223 
224 /* Function called by the front-end to tell us the
225    default for unformatted data conversion.  */
226 
227 extern void set_convert (int);
228 export_proto (set_convert);
229 
230 void
set_convert(int conv)231 set_convert (int conv)
232 {
233   compile_options.convert = conv;
234 }
235 
236 extern void set_record_marker (int);
237 export_proto (set_record_marker);
238 
239 
240 void
set_record_marker(int val)241 set_record_marker (int val)
242 {
243 
244   switch(val)
245     {
246     case 4:
247       compile_options.record_marker = sizeof (GFC_INTEGER_4);
248       break;
249 
250     case 8:
251       compile_options.record_marker = sizeof (GFC_INTEGER_8);
252       break;
253 
254     default:
255       runtime_error ("Invalid value for record marker");
256       break;
257     }
258 }
259 
260 extern void set_max_subrecord_length (int);
261 export_proto (set_max_subrecord_length);
262 
set_max_subrecord_length(int val)263 void set_max_subrecord_length(int val)
264 {
265   if (val > GFC_MAX_SUBRECORD_LENGTH || val < 1)
266     {
267       runtime_error ("Invalid value for maximum subrecord length");
268       return;
269     }
270 
271   compile_options.max_subrecord_length = val;
272 }
273