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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 /* Buffer size for unformatted files. */
202 { "GFORTRAN_UNFORMATTED_BUFFER_SIZE", 0, &options
.unformatted_buffer_size
,
205 /* Buffer size for formatted files. */
206 { "GFORTRAN_FORMATTED_BUFFER_SIZE", 0, &options
.formatted_buffer_size
,
209 { NULL
, 0, NULL
, NULL
}
213 /* Initialize most runtime variables from
214 * environment variables. */
217 init_variables (void)
221 for (v
= variable_table
; v
->name
; v
++)
224 *v
->var
= v
->default_value
;
230 /* This is the handling of the GFORTRAN_CONVERT_UNITS environment variable.
231 It is called from environ.c to parse this variable, and from
232 open.c to determine if the user specified a default for an
234 The syntax of the environment variable is, in bison grammar:
236 GFORTRAN_CONVERT_UNITS: mode | mode ';' exception ;
237 mode: 'native' | 'swap' | 'big_endian' | 'little_endian' ;
238 exception: mode ':' unit_list | unit_list ;
239 unit_list: unit_spec | unit_list unit_spec ;
240 unit_spec: INTEGER | INTEGER '-' INTEGER ;
243 /* Defines for the tokens. Other valid tokens are ',', ':', '-'. */
250 /* Some space for additional tokens later. */
262 static char *p
; /* Main character pointer for parsing. */
263 static char *lastpos
; /* Auxiliary pointer, for backing up. */
264 static int unit_num
; /* The last unit number read. */
265 static int unit_count
; /* The number of units found. */
266 static int do_count
; /* Parsing is done twice - first to count the number
267 of units, then to fill in the table. This
268 variable controls what to do. */
269 static exception_t
*elist
; /* The list of exceptions to the default. This is
270 sorted according to unit number. */
271 static int n_elist
; /* Number of exceptions to the default. */
273 static unit_convert endian
; /* Current endianness. */
275 static unit_convert def
; /* Default as specified (if any). */
277 /* Search for a unit number, using a binary search. The
278 first argument is the unit number to search for. The second argument
279 is a pointer to an index.
280 If the unit number is found, the function returns 1, and the index
281 is that of the element.
282 If the unit number is not found, the function returns 0, and the
283 index is the one where the element would be inserted. */
286 search_unit (int unit
, int *ip
)
301 mid
= (low
+ high
) / 2;
302 if (unit
== elist
[mid
].unit
)
307 else if (unit
> elist
[mid
].unit
)
311 } while (low
<= high
);
313 if (unit
> elist
[mid
].unit
)
321 /* This matches a keyword. If it is found, return the token supplied,
322 otherwise return ILLEGAL. */
325 match_word (const char *word
, int tok
)
329 if (strncasecmp (p
, word
, strlen (word
)) == 0)
339 /* Match an integer and store its value in unit_num. This only works
340 if p actually points to the start of an integer. The caller has
348 unit_num
= unit_num
* 10 + (*p
++ - '0');
352 /* This reads the next token from the GFORTRAN_CONVERT_UNITS variable.
353 Returned values are the different tokens. */
377 result
= match_word ("big_endian", BIG
);
382 result
= match_word ("little_endian", LITTLE
);
387 result
= match_word ("native", NATIVE
);
392 result
= match_word ("swap", SWAP
);
395 case '1': case '2': case '3': case '4': case '5':
396 case '6': case '7': case '8': case '9':
397 result
= match_integer ();
407 /* Back up the last token by setting back the character pointer. */
415 /* This is called when a unit is identified. If do_count is nonzero,
416 increment the number of units by one. If do_count is zero,
417 put the unit into the table. */
420 mark_single (int unit
)
429 if (search_unit (unit
, &i
))
431 elist
[i
].conv
= endian
;
435 for (j
=n_elist
-1; j
>=i
; j
--)
436 elist
[j
+1] = elist
[j
];
439 elist
[i
].unit
= unit
;
440 elist
[i
].conv
= endian
;
444 /* This is called when a unit range is identified. If do_count is
445 nonzero, increase the number of units. If do_count is zero,
446 put the unit into the table. */
449 mark_range (int unit1
, int unit2
)
453 unit_count
+= abs (unit2
- unit1
) + 1;
457 for (i
=unit2
; i
<=unit1
; i
++)
460 for (i
=unit1
; i
<=unit2
; i
++)
465 /* Parse the GFORTRAN_CONVERT_UNITS variable. This is called
466 twice, once to count the units and once to actually mark them in
467 the table. When counting, we don't check for double occurrences
482 /* Parse the string. First, let's look for a default. */
487 endian
= GFC_CONVERT_NATIVE
;
491 endian
= GFC_CONVERT_SWAP
;
495 endian
= GFC_CONVERT_BIG
;
499 endian
= GFC_CONVERT_LITTLE
;
503 /* A leading digit means that we are looking at an exception.
504 Reset the position to the beginning, and continue processing
505 at the exception list. */
527 /* This isn't a default after all. Reset the position to the
528 beginning, and continue processing at the exception list. */
545 /* Loop over all exceptions. */
552 if (next_token () != ':')
554 endian
= GFC_CONVERT_NATIVE
;
558 if (next_token () != ':')
560 endian
= GFC_CONVERT_SWAP
;
564 if (next_token () != ':')
566 endian
= GFC_CONVERT_LITTLE
;
570 if (next_token () != ':')
572 endian
= GFC_CONVERT_BIG
;
587 /* We arrive here when we want to parse a list of
598 /* The number can be followed by a - and another number,
599 which means that this is a unit range, a comma
603 if (next_token () != INTEGER
)
606 mark_range (unit1
, unit_num
);
635 } while (continue_ulist
);
640 def
= GFC_CONVERT_NONE
;
644 void init_unformatted (variable
* v
)
647 val
= getenv (v
->name
);
648 def
= GFC_CONVERT_NONE
;
663 elist
= xmallocarray (unit_count
, sizeof (exception_t
));
670 /* Get the default conversion for for an unformatted unit. */
673 get_unformatted_convert (int unit
)
679 else if (search_unit (unit
, &i
))
680 return elist
[i
].conv
;