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[binutils.git] / gas / cond.c
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1 /* cond.c - conditional assembly pseudo-ops, and .include
2 Copyright 1990, 1991, 1992, 1993, 1995, 1997, 1998, 2000, 2001, 2002,
3 2003 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
12 GAS is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GAS; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
20 02110-1301, USA. */
22 #include "as.h"
23 #include "macro.h"
25 #include "obstack.h"
27 /* This is allocated to grow and shrink as .ifdef/.endif pairs are
28 scanned. */
29 struct obstack cond_obstack;
31 struct file_line {
32 char *file;
33 unsigned int line;
36 /* We push one of these structures for each .if, and pop it at the
37 .endif. */
39 struct conditional_frame {
40 /* The source file & line number of the "if". */
41 struct file_line if_file_line;
42 /* The source file & line of the "else". */
43 struct file_line else_file_line;
44 /* The previous conditional. */
45 struct conditional_frame *previous_cframe;
46 /* Have we seen an else yet? */
47 int else_seen;
48 /* Whether we are currently ignoring input. */
49 int ignoring;
50 /* Whether a conditional at a higher level is ignoring input.
51 Set also when a branch of an "if .. elseif .." tree has matched
52 to prevent further matches. */
53 int dead_tree;
54 /* Macro nesting level at which this conditional was created. */
55 int macro_nest;
58 static void initialize_cframe (struct conditional_frame *cframe);
59 static char *get_mri_string (int, int *);
61 static struct conditional_frame *current_cframe = NULL;
63 /* Performs the .ifdef (test_defined == 1) and
64 the .ifndef (test_defined == 0) pseudo op. */
66 void
67 s_ifdef (int test_defined)
69 /* Points to name of symbol. */
70 char *name;
71 /* Points to symbol. */
72 symbolS *symbolP;
73 struct conditional_frame cframe;
74 char c;
76 /* Leading whitespace is part of operand. */
77 SKIP_WHITESPACE ();
78 name = input_line_pointer;
80 if (!is_name_beginner (*name))
82 as_bad (_("invalid identifier for \".ifdef\""));
83 obstack_1grow (&cond_obstack, 0);
84 ignore_rest_of_line ();
85 return;
88 c = get_symbol_end ();
89 symbolP = symbol_find (name);
90 *input_line_pointer = c;
92 initialize_cframe (&cframe);
94 if (cframe.dead_tree)
95 cframe.ignoring = 1;
96 else
98 int is_defined;
100 /* Use the same definition of 'defined' as .equiv so that a symbol
101 which has been referenced but not yet given a value/address is
102 considered to be undefined. */
103 is_defined =
104 symbolP != NULL
105 && (S_IS_DEFINED (symbolP) || symbol_equated_p (symbolP))
106 && S_GET_SEGMENT (symbolP) != reg_section;
108 cframe.ignoring = ! (test_defined ^ is_defined);
111 current_cframe = ((struct conditional_frame *)
112 obstack_copy (&cond_obstack, &cframe,
113 sizeof (cframe)));
115 if (LISTING_SKIP_COND ()
116 && cframe.ignoring
117 && (cframe.previous_cframe == NULL
118 || ! cframe.previous_cframe->ignoring))
119 listing_list (2);
121 demand_empty_rest_of_line ();
124 void
125 s_if (int arg)
127 expressionS operand;
128 struct conditional_frame cframe;
129 int t;
130 char *stop = NULL;
131 char stopc;
133 if (flag_mri)
134 stop = mri_comment_field (&stopc);
136 /* Leading whitespace is part of operand. */
137 SKIP_WHITESPACE ();
139 if (current_cframe != NULL && current_cframe->ignoring)
141 operand.X_add_number = 0;
142 while (! is_end_of_line[(unsigned char) *input_line_pointer])
143 ++input_line_pointer;
145 else
147 expression_and_evaluate (&operand);
148 if (operand.X_op != O_constant)
149 as_bad (_("non-constant expression in \".if\" statement"));
152 switch ((operatorT) arg)
154 case O_eq: t = operand.X_add_number == 0; break;
155 case O_ne: t = operand.X_add_number != 0; break;
156 case O_lt: t = operand.X_add_number < 0; break;
157 case O_le: t = operand.X_add_number <= 0; break;
158 case O_ge: t = operand.X_add_number >= 0; break;
159 case O_gt: t = operand.X_add_number > 0; break;
160 default:
161 abort ();
162 return;
165 /* If the above error is signaled, this will dispatch
166 using an undefined result. No big deal. */
167 initialize_cframe (&cframe);
168 cframe.ignoring = cframe.dead_tree || ! t;
169 current_cframe = ((struct conditional_frame *)
170 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
172 if (LISTING_SKIP_COND ()
173 && cframe.ignoring
174 && (cframe.previous_cframe == NULL
175 || ! cframe.previous_cframe->ignoring))
176 listing_list (2);
178 if (flag_mri)
179 mri_comment_end (stop, stopc);
181 demand_empty_rest_of_line ();
184 /* Performs the .ifb (test_blank == 1) and
185 the .ifnb (test_blank == 0) pseudo op. */
187 void
188 s_ifb (int test_blank)
190 struct conditional_frame cframe;
192 initialize_cframe (&cframe);
194 if (cframe.dead_tree)
195 cframe.ignoring = 1;
196 else
198 int is_eol;
200 SKIP_WHITESPACE ();
201 is_eol = is_end_of_line[(unsigned char) *input_line_pointer];
202 cframe.ignoring = (test_blank == !is_eol);
205 current_cframe = ((struct conditional_frame *)
206 obstack_copy (&cond_obstack, &cframe,
207 sizeof (cframe)));
209 if (LISTING_SKIP_COND ()
210 && cframe.ignoring
211 && (cframe.previous_cframe == NULL
212 || ! cframe.previous_cframe->ignoring))
213 listing_list (2);
215 ignore_rest_of_line ();
218 /* Get a string for the MRI IFC or IFNC pseudo-ops. */
220 static char *
221 get_mri_string (int terminator, int *len)
223 char *ret;
224 char *s;
226 SKIP_WHITESPACE ();
227 s = ret = input_line_pointer;
228 if (*input_line_pointer == '\'')
230 ++s;
231 ++input_line_pointer;
232 while (! is_end_of_line[(unsigned char) *input_line_pointer])
234 *s++ = *input_line_pointer++;
235 if (s[-1] == '\'')
237 if (*input_line_pointer != '\'')
238 break;
239 ++input_line_pointer;
242 SKIP_WHITESPACE ();
244 else
246 while (*input_line_pointer != terminator
247 && ! is_end_of_line[(unsigned char) *input_line_pointer])
248 ++input_line_pointer;
249 s = input_line_pointer;
250 while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
251 --s;
254 *len = s - ret;
255 return ret;
258 /* The MRI IFC and IFNC pseudo-ops. */
260 void
261 s_ifc (int arg)
263 char *stop = NULL;
264 char stopc;
265 char *s1, *s2;
266 int len1, len2;
267 int res;
268 struct conditional_frame cframe;
270 if (flag_mri)
271 stop = mri_comment_field (&stopc);
273 s1 = get_mri_string (',', &len1);
275 if (*input_line_pointer != ',')
276 as_bad (_("bad format for ifc or ifnc"));
277 else
278 ++input_line_pointer;
280 s2 = get_mri_string (';', &len2);
282 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
284 initialize_cframe (&cframe);
285 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
286 current_cframe = ((struct conditional_frame *)
287 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
289 if (LISTING_SKIP_COND ()
290 && cframe.ignoring
291 && (cframe.previous_cframe == NULL
292 || ! cframe.previous_cframe->ignoring))
293 listing_list (2);
295 if (flag_mri)
296 mri_comment_end (stop, stopc);
298 demand_empty_rest_of_line ();
301 void
302 s_elseif (int arg)
304 if (current_cframe == NULL)
306 as_bad (_("\".elseif\" without matching \".if\""));
308 else if (current_cframe->else_seen)
310 as_bad (_("\".elseif\" after \".else\""));
311 as_bad_where (current_cframe->else_file_line.file,
312 current_cframe->else_file_line.line,
313 _("here is the previous \"else\""));
314 as_bad_where (current_cframe->if_file_line.file,
315 current_cframe->if_file_line.line,
316 _("here is the previous \"if\""));
318 else
320 as_where (&current_cframe->else_file_line.file,
321 &current_cframe->else_file_line.line);
323 current_cframe->dead_tree |= !current_cframe->ignoring;
324 current_cframe->ignoring = current_cframe->dead_tree;
327 if (current_cframe == NULL || current_cframe->ignoring)
329 while (! is_end_of_line[(unsigned char) *input_line_pointer])
330 ++input_line_pointer;
332 if (current_cframe == NULL)
333 return;
335 else
337 expressionS operand;
338 int t;
340 /* Leading whitespace is part of operand. */
341 SKIP_WHITESPACE ();
343 expression_and_evaluate (&operand);
344 if (operand.X_op != O_constant)
345 as_bad (_("non-constant expression in \".elseif\" statement"));
347 switch ((operatorT) arg)
349 case O_eq: t = operand.X_add_number == 0; break;
350 case O_ne: t = operand.X_add_number != 0; break;
351 case O_lt: t = operand.X_add_number < 0; break;
352 case O_le: t = operand.X_add_number <= 0; break;
353 case O_ge: t = operand.X_add_number >= 0; break;
354 case O_gt: t = operand.X_add_number > 0; break;
355 default:
356 abort ();
357 return;
360 current_cframe->ignoring = current_cframe->dead_tree || ! t;
363 if (LISTING_SKIP_COND ()
364 && (current_cframe->previous_cframe == NULL
365 || ! current_cframe->previous_cframe->ignoring))
367 if (! current_cframe->ignoring)
368 listing_list (1);
369 else
370 listing_list (2);
373 demand_empty_rest_of_line ();
376 void
377 s_endif (int arg ATTRIBUTE_UNUSED)
379 struct conditional_frame *hold;
381 if (current_cframe == NULL)
383 as_bad (_("\".endif\" without \".if\""));
385 else
387 if (LISTING_SKIP_COND ()
388 && current_cframe->ignoring
389 && (current_cframe->previous_cframe == NULL
390 || ! current_cframe->previous_cframe->ignoring))
391 listing_list (1);
393 hold = current_cframe;
394 current_cframe = current_cframe->previous_cframe;
395 obstack_free (&cond_obstack, hold);
396 } /* if one pop too many */
398 if (flag_mri)
400 while (! is_end_of_line[(unsigned char) *input_line_pointer])
401 ++input_line_pointer;
404 demand_empty_rest_of_line ();
407 void
408 s_else (int arg ATTRIBUTE_UNUSED)
410 if (current_cframe == NULL)
412 as_bad (_("\".else\" without matching \".if\""));
414 else if (current_cframe->else_seen)
416 as_bad (_("duplicate \"else\""));
417 as_bad_where (current_cframe->else_file_line.file,
418 current_cframe->else_file_line.line,
419 _("here is the previous \"else\""));
420 as_bad_where (current_cframe->if_file_line.file,
421 current_cframe->if_file_line.line,
422 _("here is the previous \"if\""));
424 else
426 as_where (&current_cframe->else_file_line.file,
427 &current_cframe->else_file_line.line);
429 current_cframe->ignoring =
430 current_cframe->dead_tree | !current_cframe->ignoring;
432 if (LISTING_SKIP_COND ()
433 && (current_cframe->previous_cframe == NULL
434 || ! current_cframe->previous_cframe->ignoring))
436 if (! current_cframe->ignoring)
437 listing_list (1);
438 else
439 listing_list (2);
442 current_cframe->else_seen = 1;
445 if (flag_mri)
447 while (! is_end_of_line[(unsigned char) *input_line_pointer])
448 ++input_line_pointer;
451 demand_empty_rest_of_line ();
454 void
455 s_ifeqs (int arg)
457 char *s1, *s2;
458 int len1, len2;
459 int res;
460 struct conditional_frame cframe;
462 s1 = demand_copy_C_string (&len1);
464 SKIP_WHITESPACE ();
465 if (*input_line_pointer != ',')
467 as_bad (_(".ifeqs syntax error"));
468 ignore_rest_of_line ();
469 return;
472 ++input_line_pointer;
474 s2 = demand_copy_C_string (&len2);
476 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
478 initialize_cframe (&cframe);
479 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
480 current_cframe = ((struct conditional_frame *)
481 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
483 if (LISTING_SKIP_COND ()
484 && cframe.ignoring
485 && (cframe.previous_cframe == NULL
486 || ! cframe.previous_cframe->ignoring))
487 listing_list (2);
489 demand_empty_rest_of_line ();
493 ignore_input (void)
495 char *s;
497 s = input_line_pointer;
499 if (NO_PSEUDO_DOT || flag_m68k_mri)
501 if (s[-1] != '.')
502 --s;
504 else
506 if (s[-1] != '.')
507 return (current_cframe != NULL) && (current_cframe->ignoring);
510 /* We cannot ignore certain pseudo ops. */
511 if (((s[0] == 'i'
512 || s[0] == 'I')
513 && (!strncasecmp (s, "if", 2)
514 || !strncasecmp (s, "ifdef", 5)
515 || !strncasecmp (s, "ifndef", 6)))
516 || ((s[0] == 'e'
517 || s[0] == 'E')
518 && (!strncasecmp (s, "else", 4)
519 || !strncasecmp (s, "endif", 5)
520 || !strncasecmp (s, "endc", 4))))
521 return 0;
523 return (current_cframe != NULL) && (current_cframe->ignoring);
526 static void
527 initialize_cframe (struct conditional_frame *cframe)
529 memset (cframe, 0, sizeof (*cframe));
530 as_where (&cframe->if_file_line.file,
531 &cframe->if_file_line.line);
532 cframe->previous_cframe = current_cframe;
533 cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
534 cframe->macro_nest = macro_nest;
537 /* Give an error if a conditional is unterminated inside a macro or
538 the assembly as a whole. If NEST is non negative, we are being
539 called because of the end of a macro expansion. If NEST is
540 negative, we are being called at the of the input files. */
542 void
543 cond_finish_check (int nest)
545 if (current_cframe != NULL && current_cframe->macro_nest >= nest)
547 if (nest >= 0)
548 as_bad (_("end of macro inside conditional"));
549 else
550 as_bad (_("end of file inside conditional"));
551 as_bad_where (current_cframe->if_file_line.file,
552 current_cframe->if_file_line.line,
553 _("here is the start of the unterminated conditional"));
554 if (current_cframe->else_seen)
555 as_bad_where (current_cframe->else_file_line.file,
556 current_cframe->else_file_line.line,
557 _("here is the \"else\" of the unterminated conditional"));
561 /* This function is called when we exit out of a macro. We assume
562 that any conditionals which began within the macro are correctly
563 nested, and just pop them off the stack. */
565 void
566 cond_exit_macro (int nest)
568 while (current_cframe != NULL && current_cframe->macro_nest >= nest)
570 struct conditional_frame *hold;
572 hold = current_cframe;
573 current_cframe = current_cframe->previous_cframe;
574 obstack_free (&cond_obstack, hold);