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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, 2006, 2007 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 3, 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 "sb.h"
24 #include "macro.h"
26 #include "obstack.h"
28 /* This is allocated to grow and shrink as .ifdef/.endif pairs are
29 scanned. */
30 struct obstack cond_obstack;
32 struct file_line {
33 char *file;
34 unsigned int line;
37 /* We push one of these structures for each .if, and pop it at the
38 .endif. */
40 struct conditional_frame {
41 /* The source file & line number of the "if". */
42 struct file_line if_file_line;
43 /* The source file & line of the "else". */
44 struct file_line else_file_line;
45 /* The previous conditional. */
46 struct conditional_frame *previous_cframe;
47 /* Have we seen an else yet? */
48 int else_seen;
49 /* Whether we are currently ignoring input. */
50 int ignoring;
51 /* Whether a conditional at a higher level is ignoring input.
52 Set also when a branch of an "if .. elseif .." tree has matched
53 to prevent further matches. */
54 int dead_tree;
55 /* Macro nesting level at which this conditional was created. */
56 int macro_nest;
59 static void initialize_cframe (struct conditional_frame *cframe);
60 static char *get_mri_string (int, int *);
62 static struct conditional_frame *current_cframe = NULL;
64 /* Performs the .ifdef (test_defined == 1) and
65 the .ifndef (test_defined == 0) pseudo op. */
67 void
68 s_ifdef (int test_defined)
70 /* Points to name of symbol. */
71 char *name;
72 /* Points to symbol. */
73 symbolS *symbolP;
74 struct conditional_frame cframe;
75 char c;
77 /* Leading whitespace is part of operand. */
78 SKIP_WHITESPACE ();
79 name = input_line_pointer;
81 if (!is_name_beginner (*name))
83 as_bad (_("invalid identifier for \".ifdef\""));
84 obstack_1grow (&cond_obstack, 0);
85 ignore_rest_of_line ();
86 return;
89 c = get_symbol_end ();
90 symbolP = symbol_find (name);
91 *input_line_pointer = c;
93 initialize_cframe (&cframe);
95 if (cframe.dead_tree)
96 cframe.ignoring = 1;
97 else
99 int is_defined;
101 /* Use the same definition of 'defined' as .equiv so that a symbol
102 which has been referenced but not yet given a value/address is
103 considered to be undefined. */
104 is_defined =
105 symbolP != NULL
106 && (S_IS_DEFINED (symbolP) || symbol_equated_p (symbolP))
107 && S_GET_SEGMENT (symbolP) != reg_section;
109 cframe.ignoring = ! (test_defined ^ is_defined);
112 current_cframe = ((struct conditional_frame *)
113 obstack_copy (&cond_obstack, &cframe,
114 sizeof (cframe)));
116 if (LISTING_SKIP_COND ()
117 && cframe.ignoring
118 && (cframe.previous_cframe == NULL
119 || ! cframe.previous_cframe->ignoring))
120 listing_list (2);
122 demand_empty_rest_of_line ();
125 void
126 s_if (int arg)
128 expressionS operand;
129 struct conditional_frame cframe;
130 int t;
131 char *stop = NULL;
132 char stopc;
134 if (flag_mri)
135 stop = mri_comment_field (&stopc);
137 /* Leading whitespace is part of operand. */
138 SKIP_WHITESPACE ();
140 if (current_cframe != NULL && current_cframe->ignoring)
142 operand.X_add_number = 0;
143 while (! is_end_of_line[(unsigned char) *input_line_pointer])
144 ++input_line_pointer;
146 else
148 expression_and_evaluate (&operand);
149 if (operand.X_op != O_constant)
150 as_bad (_("non-constant expression in \".if\" statement"));
153 switch ((operatorT) arg)
155 case O_eq: t = operand.X_add_number == 0; break;
156 case O_ne: t = operand.X_add_number != 0; break;
157 case O_lt: t = operand.X_add_number < 0; break;
158 case O_le: t = operand.X_add_number <= 0; break;
159 case O_ge: t = operand.X_add_number >= 0; break;
160 case O_gt: t = operand.X_add_number > 0; break;
161 default:
162 abort ();
163 return;
166 /* If the above error is signaled, this will dispatch
167 using an undefined result. No big deal. */
168 initialize_cframe (&cframe);
169 cframe.ignoring = cframe.dead_tree || ! t;
170 current_cframe = ((struct conditional_frame *)
171 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
173 if (LISTING_SKIP_COND ()
174 && cframe.ignoring
175 && (cframe.previous_cframe == NULL
176 || ! cframe.previous_cframe->ignoring))
177 listing_list (2);
179 if (flag_mri)
180 mri_comment_end (stop, stopc);
182 demand_empty_rest_of_line ();
185 /* Performs the .ifb (test_blank == 1) and
186 the .ifnb (test_blank == 0) pseudo op. */
188 void
189 s_ifb (int test_blank)
191 struct conditional_frame cframe;
193 initialize_cframe (&cframe);
195 if (cframe.dead_tree)
196 cframe.ignoring = 1;
197 else
199 int is_eol;
201 SKIP_WHITESPACE ();
202 is_eol = is_end_of_line[(unsigned char) *input_line_pointer];
203 cframe.ignoring = (test_blank == !is_eol);
206 current_cframe = ((struct conditional_frame *)
207 obstack_copy (&cond_obstack, &cframe,
208 sizeof (cframe)));
210 if (LISTING_SKIP_COND ()
211 && cframe.ignoring
212 && (cframe.previous_cframe == NULL
213 || ! cframe.previous_cframe->ignoring))
214 listing_list (2);
216 ignore_rest_of_line ();
219 /* Get a string for the MRI IFC or IFNC pseudo-ops. */
221 static char *
222 get_mri_string (int terminator, int *len)
224 char *ret;
225 char *s;
227 SKIP_WHITESPACE ();
228 s = ret = input_line_pointer;
229 if (*input_line_pointer == '\'')
231 ++s;
232 ++input_line_pointer;
233 while (! is_end_of_line[(unsigned char) *input_line_pointer])
235 *s++ = *input_line_pointer++;
236 if (s[-1] == '\'')
238 if (*input_line_pointer != '\'')
239 break;
240 ++input_line_pointer;
243 SKIP_WHITESPACE ();
245 else
247 while (*input_line_pointer != terminator
248 && ! is_end_of_line[(unsigned char) *input_line_pointer])
249 ++input_line_pointer;
250 s = input_line_pointer;
251 while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
252 --s;
255 *len = s - ret;
256 return ret;
259 /* The MRI IFC and IFNC pseudo-ops. */
261 void
262 s_ifc (int arg)
264 char *stop = NULL;
265 char stopc;
266 char *s1, *s2;
267 int len1, len2;
268 int res;
269 struct conditional_frame cframe;
271 if (flag_mri)
272 stop = mri_comment_field (&stopc);
274 s1 = get_mri_string (',', &len1);
276 if (*input_line_pointer != ',')
277 as_bad (_("bad format for ifc or ifnc"));
278 else
279 ++input_line_pointer;
281 s2 = get_mri_string (';', &len2);
283 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
285 initialize_cframe (&cframe);
286 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
287 current_cframe = ((struct conditional_frame *)
288 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
290 if (LISTING_SKIP_COND ()
291 && cframe.ignoring
292 && (cframe.previous_cframe == NULL
293 || ! cframe.previous_cframe->ignoring))
294 listing_list (2);
296 if (flag_mri)
297 mri_comment_end (stop, stopc);
299 demand_empty_rest_of_line ();
302 void
303 s_elseif (int arg)
305 if (current_cframe == NULL)
307 as_bad (_("\".elseif\" without matching \".if\""));
309 else if (current_cframe->else_seen)
311 as_bad (_("\".elseif\" after \".else\""));
312 as_bad_where (current_cframe->else_file_line.file,
313 current_cframe->else_file_line.line,
314 _("here is the previous \"else\""));
315 as_bad_where (current_cframe->if_file_line.file,
316 current_cframe->if_file_line.line,
317 _("here is the previous \"if\""));
319 else
321 as_where (&current_cframe->else_file_line.file,
322 &current_cframe->else_file_line.line);
324 current_cframe->dead_tree |= !current_cframe->ignoring;
325 current_cframe->ignoring = current_cframe->dead_tree;
328 if (current_cframe == NULL || current_cframe->ignoring)
330 while (! is_end_of_line[(unsigned char) *input_line_pointer])
331 ++input_line_pointer;
333 if (current_cframe == NULL)
334 return;
336 else
338 expressionS operand;
339 int t;
341 /* Leading whitespace is part of operand. */
342 SKIP_WHITESPACE ();
344 expression_and_evaluate (&operand);
345 if (operand.X_op != O_constant)
346 as_bad (_("non-constant expression in \".elseif\" statement"));
348 switch ((operatorT) arg)
350 case O_eq: t = operand.X_add_number == 0; break;
351 case O_ne: t = operand.X_add_number != 0; break;
352 case O_lt: t = operand.X_add_number < 0; break;
353 case O_le: t = operand.X_add_number <= 0; break;
354 case O_ge: t = operand.X_add_number >= 0; break;
355 case O_gt: t = operand.X_add_number > 0; break;
356 default:
357 abort ();
358 return;
361 current_cframe->ignoring = current_cframe->dead_tree || ! t;
364 if (LISTING_SKIP_COND ()
365 && (current_cframe->previous_cframe == NULL
366 || ! current_cframe->previous_cframe->ignoring))
368 if (! current_cframe->ignoring)
369 listing_list (1);
370 else
371 listing_list (2);
374 demand_empty_rest_of_line ();
377 void
378 s_endif (int arg ATTRIBUTE_UNUSED)
380 struct conditional_frame *hold;
382 if (current_cframe == NULL)
384 as_bad (_("\".endif\" without \".if\""));
386 else
388 if (LISTING_SKIP_COND ()
389 && current_cframe->ignoring
390 && (current_cframe->previous_cframe == NULL
391 || ! current_cframe->previous_cframe->ignoring))
392 listing_list (1);
394 hold = current_cframe;
395 current_cframe = current_cframe->previous_cframe;
396 obstack_free (&cond_obstack, hold);
397 } /* if one pop too many */
399 if (flag_mri)
401 while (! is_end_of_line[(unsigned char) *input_line_pointer])
402 ++input_line_pointer;
405 demand_empty_rest_of_line ();
408 void
409 s_else (int arg ATTRIBUTE_UNUSED)
411 if (current_cframe == NULL)
413 as_bad (_("\".else\" without matching \".if\""));
415 else if (current_cframe->else_seen)
417 as_bad (_("duplicate \"else\""));
418 as_bad_where (current_cframe->else_file_line.file,
419 current_cframe->else_file_line.line,
420 _("here is the previous \"else\""));
421 as_bad_where (current_cframe->if_file_line.file,
422 current_cframe->if_file_line.line,
423 _("here is the previous \"if\""));
425 else
427 as_where (&current_cframe->else_file_line.file,
428 &current_cframe->else_file_line.line);
430 current_cframe->ignoring =
431 current_cframe->dead_tree | !current_cframe->ignoring;
433 if (LISTING_SKIP_COND ()
434 && (current_cframe->previous_cframe == NULL
435 || ! current_cframe->previous_cframe->ignoring))
437 if (! current_cframe->ignoring)
438 listing_list (1);
439 else
440 listing_list (2);
443 current_cframe->else_seen = 1;
446 if (flag_mri)
448 while (! is_end_of_line[(unsigned char) *input_line_pointer])
449 ++input_line_pointer;
452 demand_empty_rest_of_line ();
455 void
456 s_ifeqs (int arg)
458 char *s1, *s2;
459 int len1, len2;
460 int res;
461 struct conditional_frame cframe;
463 s1 = demand_copy_C_string (&len1);
465 SKIP_WHITESPACE ();
466 if (*input_line_pointer != ',')
468 as_bad (_(".ifeqs syntax error"));
469 ignore_rest_of_line ();
470 return;
473 ++input_line_pointer;
475 s2 = demand_copy_C_string (&len2);
477 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
479 initialize_cframe (&cframe);
480 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
481 current_cframe = ((struct conditional_frame *)
482 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
484 if (LISTING_SKIP_COND ()
485 && cframe.ignoring
486 && (cframe.previous_cframe == NULL
487 || ! cframe.previous_cframe->ignoring))
488 listing_list (2);
490 demand_empty_rest_of_line ();
494 ignore_input (void)
496 char *s;
498 s = input_line_pointer;
500 if (NO_PSEUDO_DOT || flag_m68k_mri)
502 if (s[-1] != '.')
503 --s;
505 else
507 if (s[-1] != '.')
508 return (current_cframe != NULL) && (current_cframe->ignoring);
511 /* We cannot ignore certain pseudo ops. */
512 if (((s[0] == 'i'
513 || s[0] == 'I')
514 && (!strncasecmp (s, "if", 2)
515 || !strncasecmp (s, "ifdef", 5)
516 || !strncasecmp (s, "ifndef", 6)))
517 || ((s[0] == 'e'
518 || s[0] == 'E')
519 && (!strncasecmp (s, "else", 4)
520 || !strncasecmp (s, "endif", 5)
521 || !strncasecmp (s, "endc", 4))))
522 return 0;
524 return (current_cframe != NULL) && (current_cframe->ignoring);
527 static void
528 initialize_cframe (struct conditional_frame *cframe)
530 memset (cframe, 0, sizeof (*cframe));
531 as_where (&cframe->if_file_line.file,
532 &cframe->if_file_line.line);
533 cframe->previous_cframe = current_cframe;
534 cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
535 cframe->macro_nest = macro_nest;
538 /* Give an error if a conditional is unterminated inside a macro or
539 the assembly as a whole. If NEST is non negative, we are being
540 called because of the end of a macro expansion. If NEST is
541 negative, we are being called at the of the input files. */
543 void
544 cond_finish_check (int nest)
546 if (current_cframe != NULL && current_cframe->macro_nest >= nest)
548 if (nest >= 0)
549 as_bad (_("end of macro inside conditional"));
550 else
551 as_bad (_("end of file inside conditional"));
552 as_bad_where (current_cframe->if_file_line.file,
553 current_cframe->if_file_line.line,
554 _("here is the start of the unterminated conditional"));
555 if (current_cframe->else_seen)
556 as_bad_where (current_cframe->else_file_line.file,
557 current_cframe->else_file_line.line,
558 _("here is the \"else\" of the unterminated conditional"));
562 /* This function is called when we exit out of a macro. We assume
563 that any conditionals which began within the macro are correctly
564 nested, and just pop them off the stack. */
566 void
567 cond_exit_macro (int nest)
569 while (current_cframe != NULL && current_cframe->macro_nest >= nest)
571 struct conditional_frame *hold;
573 hold = current_cframe;
574 current_cframe = current_cframe->previous_cframe;
575 obstack_free (&cond_obstack, hold);