1 /* Copyright (C) 2002-2019 Free Software Foundation, Inc.
2 Contributed by Andy Vaught
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 /* Implementation of secure_getenv() for targets where it is not
39 #ifdef FALLBACK_SECURE_GETENV
41 #if SUPPORTS_WEAKREF && defined(HAVE___SECURE_GETENV)
42 static char* weak_secure_getenv (const char*)
43 __attribute__((__weakref__("__secure_getenv")));
47 secure_getenv (const char *name
)
49 #if SUPPORTS_WEAKREF && defined(HAVE___SECURE_GETENV)
50 if (weak_secure_getenv
)
51 return weak_secure_getenv (name
);
54 if ((getuid () == geteuid ()) && (getgid () == getegid ()))
63 /* Examine the environment for controlling aspects of the program's
64 execution. Our philosophy here that the environment should not prevent
65 the program from running, so any invalid value will be ignored. */
70 typedef struct variable
75 void (*init
) (struct variable
*);
79 static void init_unformatted (variable
*);
82 /* Initialize an integer environment variable. */
85 init_integer (variable
* v
)
94 if (!isdigit (*q
) && (p
!= q
|| *q
!= '-'))
101 /* Initialize a boolean environment variable. We only look at the first
102 letter of the value. */
105 init_boolean (variable
* v
)
109 p
= getenv (v
->name
);
113 if (*p
== '1' || *p
== 'Y' || *p
== 'y')
115 else if (*p
== '0' || *p
== 'N' || *p
== 'n')
120 /* Initialize a list output separator. It may contain any number of spaces
121 and at most one comma. */
124 init_sep (variable
* v
)
129 p
= getenv (v
->name
);
133 options
.separator
= p
;
134 options
.separator_len
= strlen (p
);
136 /* Make sure the separator is valid */
138 if (options
.separator_len
== 0)
160 options
.separator
= " ";
161 options
.separator_len
= 1;
165 static variable variable_table
[] = {
167 /* Unit number that will be preconnected to standard input */
168 { "GFORTRAN_STDIN_UNIT", GFC_STDIN_UNIT_NUMBER
, &options
.stdin_unit
,
171 /* Unit number that will be preconnected to standard output */
172 { "GFORTRAN_STDOUT_UNIT", GFC_STDOUT_UNIT_NUMBER
, &options
.stdout_unit
,
175 /* Unit number that will be preconnected to standard error */
176 { "GFORTRAN_STDERR_UNIT", GFC_STDERR_UNIT_NUMBER
, &options
.stderr_unit
,
179 /* If TRUE, all output will be unbuffered */
180 { "GFORTRAN_UNBUFFERED_ALL", 0, &options
.all_unbuffered
, init_boolean
},
182 /* If TRUE, output to preconnected units will be unbuffered */
183 { "GFORTRAN_UNBUFFERED_PRECONNECTED", 0, &options
.unbuffered_preconnected
,
186 /* Whether to print filename and line number on runtime error */
187 { "GFORTRAN_SHOW_LOCUS", 1, &options
.locus
, init_boolean
},
189 /* Print optional plus signs in numbers where permitted */
190 { "GFORTRAN_OPTIONAL_PLUS", 0, &options
.optional_plus
, init_boolean
},
192 /* Separator to use when writing list output */
193 { "GFORTRAN_LIST_SEPARATOR", 0, NULL
, init_sep
},
195 /* Set the default data conversion for unformatted I/O */
196 { "GFORTRAN_CONVERT_UNIT", 0, 0, init_unformatted
},
198 /* Print out a backtrace if possible on runtime error */
199 { "GFORTRAN_ERROR_BACKTRACE", -1, &options
.backtrace
, init_boolean
},
201 { NULL
, 0, NULL
, NULL
}
205 /* Initialize most runtime variables from
206 * environment variables. */
209 init_variables (void)
213 for (v
= variable_table
; v
->name
; v
++)
216 *v
->var
= v
->default_value
;
222 /* This is the handling of the GFORTRAN_CONVERT_UNITS environment variable.
223 It is called from environ.c to parse this variable, and from
224 open.c to determine if the user specified a default for an
226 The syntax of the environment variable is, in bison grammar:
228 GFORTRAN_CONVERT_UNITS: mode | mode ';' exception ;
229 mode: 'native' | 'swap' | 'big_endian' | 'little_endian' ;
230 exception: mode ':' unit_list | unit_list ;
231 unit_list: unit_spec | unit_list unit_spec ;
232 unit_spec: INTEGER | INTEGER '-' INTEGER ;
235 /* Defines for the tokens. Other valid tokens are ',', ':', '-'. */
242 /* Some space for additional tokens later. */
254 static char *p
; /* Main character pointer for parsing. */
255 static char *lastpos
; /* Auxiliary pointer, for backing up. */
256 static int unit_num
; /* The last unit number read. */
257 static int unit_count
; /* The number of units found. */
258 static int do_count
; /* Parsing is done twice - first to count the number
259 of units, then to fill in the table. This
260 variable controls what to do. */
261 static exception_t
*elist
; /* The list of exceptions to the default. This is
262 sorted according to unit number. */
263 static int n_elist
; /* Number of exceptions to the default. */
265 static unit_convert endian
; /* Current endianness. */
267 static unit_convert def
; /* Default as specified (if any). */
269 /* Search for a unit number, using a binary search. The
270 first argument is the unit number to search for. The second argument
271 is a pointer to an index.
272 If the unit number is found, the function returns 1, and the index
273 is that of the element.
274 If the unit number is not found, the function returns 0, and the
275 index is the one where the element would be inserted. */
278 search_unit (int unit
, int *ip
)
293 mid
= (low
+ high
) / 2;
294 if (unit
== elist
[mid
].unit
)
299 else if (unit
> elist
[mid
].unit
)
303 } while (low
<= high
);
305 if (unit
> elist
[mid
].unit
)
313 /* This matches a keyword. If it is found, return the token supplied,
314 otherwise return ILLEGAL. */
317 match_word (const char *word
, int tok
)
321 if (strncasecmp (p
, word
, strlen (word
)) == 0)
331 /* Match an integer and store its value in unit_num. This only works
332 if p actually points to the start of an integer. The caller has
340 unit_num
= unit_num
* 10 + (*p
++ - '0');
344 /* This reads the next token from the GFORTRAN_CONVERT_UNITS variable.
345 Returned values are the different tokens. */
369 result
= match_word ("big_endian", BIG
);
374 result
= match_word ("little_endian", LITTLE
);
379 result
= match_word ("native", NATIVE
);
384 result
= match_word ("swap", SWAP
);
387 case '1': case '2': case '3': case '4': case '5':
388 case '6': case '7': case '8': case '9':
389 result
= match_integer ();
399 /* Back up the last token by setting back the character pointer. */
407 /* This is called when a unit is identified. If do_count is nonzero,
408 increment the number of units by one. If do_count is zero,
409 put the unit into the table. */
412 mark_single (int unit
)
421 if (search_unit (unit
, &i
))
423 elist
[i
].conv
= endian
;
427 for (j
=n_elist
-1; j
>=i
; j
--)
428 elist
[j
+1] = elist
[j
];
431 elist
[i
].unit
= unit
;
432 elist
[i
].conv
= endian
;
436 /* This is called when a unit range is identified. If do_count is
437 nonzero, increase the number of units. If do_count is zero,
438 put the unit into the table. */
441 mark_range (int unit1
, int unit2
)
445 unit_count
+= abs (unit2
- unit1
) + 1;
449 for (i
=unit2
; i
<=unit1
; i
++)
452 for (i
=unit1
; i
<=unit2
; i
++)
457 /* Parse the GFORTRAN_CONVERT_UNITS variable. This is called
458 twice, once to count the units and once to actually mark them in
459 the table. When counting, we don't check for double occurrences
474 /* Parse the string. First, let's look for a default. */
479 endian
= GFC_CONVERT_NATIVE
;
483 endian
= GFC_CONVERT_SWAP
;
487 endian
= GFC_CONVERT_BIG
;
491 endian
= GFC_CONVERT_LITTLE
;
495 /* A leading digit means that we are looking at an exception.
496 Reset the position to the beginning, and continue processing
497 at the exception list. */
519 /* This isn't a default after all. Reset the position to the
520 beginning, and continue processing at the exception list. */
537 /* Loop over all exceptions. */
544 if (next_token () != ':')
546 endian
= GFC_CONVERT_NATIVE
;
550 if (next_token () != ':')
552 endian
= GFC_CONVERT_SWAP
;
556 if (next_token () != ':')
558 endian
= GFC_CONVERT_LITTLE
;
562 if (next_token () != ':')
564 endian
= GFC_CONVERT_BIG
;
579 /* We arrive here when we want to parse a list of
590 /* The number can be followed by a - and another number,
591 which means that this is a unit range, a comma
595 if (next_token () != INTEGER
)
598 mark_range (unit1
, unit_num
);
627 } while (continue_ulist
);
632 def
= GFC_CONVERT_NONE
;
636 void init_unformatted (variable
* v
)
639 val
= getenv (v
->name
);
640 def
= GFC_CONVERT_NONE
;
655 elist
= xmallocarray (unit_count
, sizeof (exception_t
));
662 /* Get the default conversion for for an unformatted unit. */
665 get_unformatted_convert (int unit
)
671 else if (search_unit (unit
, &i
))
672 return elist
[i
].conv
;