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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
3 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, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, 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)
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 (&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 /* Get a string for the MRI IFC or IFNC pseudo-ops. */
186 static char *
187 get_mri_string (int terminator, int *len)
189 char *ret;
190 char *s;
192 SKIP_WHITESPACE ();
193 s = ret = input_line_pointer;
194 if (*input_line_pointer == '\'')
196 ++s;
197 ++input_line_pointer;
198 while (! is_end_of_line[(unsigned char) *input_line_pointer])
200 *s++ = *input_line_pointer++;
201 if (s[-1] == '\'')
203 if (*input_line_pointer != '\'')
204 break;
205 ++input_line_pointer;
208 SKIP_WHITESPACE ();
210 else
212 while (*input_line_pointer != terminator
213 && ! is_end_of_line[(unsigned char) *input_line_pointer])
214 ++input_line_pointer;
215 s = input_line_pointer;
216 while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
217 --s;
220 *len = s - ret;
221 return ret;
224 /* The MRI IFC and IFNC pseudo-ops. */
226 void
227 s_ifc (int arg)
229 char *stop = NULL;
230 char stopc;
231 char *s1, *s2;
232 int len1, len2;
233 int res;
234 struct conditional_frame cframe;
236 if (flag_mri)
237 stop = mri_comment_field (&stopc);
239 s1 = get_mri_string (',', &len1);
241 if (*input_line_pointer != ',')
242 as_bad (_("bad format for ifc or ifnc"));
243 else
244 ++input_line_pointer;
246 s2 = get_mri_string (';', &len2);
248 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
250 initialize_cframe (&cframe);
251 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
252 current_cframe = ((struct conditional_frame *)
253 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
255 if (LISTING_SKIP_COND ()
256 && cframe.ignoring
257 && (cframe.previous_cframe == NULL
258 || ! cframe.previous_cframe->ignoring))
259 listing_list (2);
261 if (flag_mri)
262 mri_comment_end (stop, stopc);
264 demand_empty_rest_of_line ();
267 void
268 s_elseif (int arg)
270 if (current_cframe == NULL)
272 as_bad (_("\".elseif\" without matching \".if\""));
274 else if (current_cframe->else_seen)
276 as_bad (_("\".elseif\" after \".else\""));
277 as_bad_where (current_cframe->else_file_line.file,
278 current_cframe->else_file_line.line,
279 _("here is the previous \"else\""));
280 as_bad_where (current_cframe->if_file_line.file,
281 current_cframe->if_file_line.line,
282 _("here is the previous \"if\""));
284 else
286 as_where (&current_cframe->else_file_line.file,
287 &current_cframe->else_file_line.line);
289 current_cframe->dead_tree |= !current_cframe->ignoring;
290 current_cframe->ignoring = current_cframe->dead_tree;
293 if (current_cframe == NULL || current_cframe->ignoring)
295 while (! is_end_of_line[(unsigned char) *input_line_pointer])
296 ++input_line_pointer;
298 if (current_cframe == NULL)
299 return;
301 else
303 expressionS operand;
304 int t;
306 /* Leading whitespace is part of operand. */
307 SKIP_WHITESPACE ();
309 expression (&operand);
310 if (operand.X_op != O_constant)
311 as_bad (_("non-constant expression in \".elseif\" statement"));
313 switch ((operatorT) arg)
315 case O_eq: t = operand.X_add_number == 0; break;
316 case O_ne: t = operand.X_add_number != 0; break;
317 case O_lt: t = operand.X_add_number < 0; break;
318 case O_le: t = operand.X_add_number <= 0; break;
319 case O_ge: t = operand.X_add_number >= 0; break;
320 case O_gt: t = operand.X_add_number > 0; break;
321 default:
322 abort ();
323 return;
326 current_cframe->ignoring = current_cframe->dead_tree || ! t;
329 if (LISTING_SKIP_COND ()
330 && (current_cframe->previous_cframe == NULL
331 || ! current_cframe->previous_cframe->ignoring))
333 if (! current_cframe->ignoring)
334 listing_list (1);
335 else
336 listing_list (2);
339 demand_empty_rest_of_line ();
342 void
343 s_endif (int arg ATTRIBUTE_UNUSED)
345 struct conditional_frame *hold;
347 if (current_cframe == NULL)
349 as_bad (_("\".endif\" without \".if\""));
351 else
353 if (LISTING_SKIP_COND ()
354 && current_cframe->ignoring
355 && (current_cframe->previous_cframe == NULL
356 || ! current_cframe->previous_cframe->ignoring))
357 listing_list (1);
359 hold = current_cframe;
360 current_cframe = current_cframe->previous_cframe;
361 obstack_free (&cond_obstack, hold);
362 } /* if one pop too many */
364 if (flag_mri)
366 while (! is_end_of_line[(unsigned char) *input_line_pointer])
367 ++input_line_pointer;
370 demand_empty_rest_of_line ();
373 void
374 s_else (int arg ATTRIBUTE_UNUSED)
376 if (current_cframe == NULL)
378 as_bad (_("\".else\" without matching \".if\""));
380 else if (current_cframe->else_seen)
382 as_bad (_("duplicate \"else\""));
383 as_bad_where (current_cframe->else_file_line.file,
384 current_cframe->else_file_line.line,
385 _("here is the previous \"else\""));
386 as_bad_where (current_cframe->if_file_line.file,
387 current_cframe->if_file_line.line,
388 _("here is the previous \"if\""));
390 else
392 as_where (&current_cframe->else_file_line.file,
393 &current_cframe->else_file_line.line);
395 current_cframe->ignoring =
396 current_cframe->dead_tree | !current_cframe->ignoring;
398 if (LISTING_SKIP_COND ()
399 && (current_cframe->previous_cframe == NULL
400 || ! current_cframe->previous_cframe->ignoring))
402 if (! current_cframe->ignoring)
403 listing_list (1);
404 else
405 listing_list (2);
408 current_cframe->else_seen = 1;
411 if (flag_mri)
413 while (! is_end_of_line[(unsigned char) *input_line_pointer])
414 ++input_line_pointer;
417 demand_empty_rest_of_line ();
420 void
421 s_ifeqs (int arg)
423 char *s1, *s2;
424 int len1, len2;
425 int res;
426 struct conditional_frame cframe;
428 s1 = demand_copy_C_string (&len1);
430 SKIP_WHITESPACE ();
431 if (*input_line_pointer != ',')
433 as_bad (_(".ifeqs syntax error"));
434 ignore_rest_of_line ();
435 return;
438 ++input_line_pointer;
440 s2 = demand_copy_C_string (&len2);
442 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
444 initialize_cframe (&cframe);
445 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
446 current_cframe = ((struct conditional_frame *)
447 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
449 if (LISTING_SKIP_COND ()
450 && cframe.ignoring
451 && (cframe.previous_cframe == NULL
452 || ! cframe.previous_cframe->ignoring))
453 listing_list (2);
455 demand_empty_rest_of_line ();
459 ignore_input (void)
461 char *s;
463 s = input_line_pointer;
465 if (NO_PSEUDO_DOT || flag_m68k_mri)
467 if (s[-1] != '.')
468 --s;
470 else
472 if (s[-1] != '.')
473 return (current_cframe != NULL) && (current_cframe->ignoring);
476 /* We cannot ignore certain pseudo ops. */
477 if (((s[0] == 'i'
478 || s[0] == 'I')
479 && (!strncasecmp (s, "if", 2)
480 || !strncasecmp (s, "ifdef", 5)
481 || !strncasecmp (s, "ifndef", 6)))
482 || ((s[0] == 'e'
483 || s[0] == 'E')
484 && (!strncasecmp (s, "else", 4)
485 || !strncasecmp (s, "endif", 5)
486 || !strncasecmp (s, "endc", 4))))
487 return 0;
489 return (current_cframe != NULL) && (current_cframe->ignoring);
492 static void
493 initialize_cframe (struct conditional_frame *cframe)
495 memset (cframe, 0, sizeof (*cframe));
496 as_where (&cframe->if_file_line.file,
497 &cframe->if_file_line.line);
498 cframe->previous_cframe = current_cframe;
499 cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
500 cframe->macro_nest = macro_nest;
503 /* Give an error if a conditional is unterminated inside a macro or
504 the assembly as a whole. If NEST is non negative, we are being
505 called because of the end of a macro expansion. If NEST is
506 negative, we are being called at the of the input files. */
508 void
509 cond_finish_check (int nest)
511 if (current_cframe != NULL && current_cframe->macro_nest >= nest)
513 if (nest >= 0)
514 as_bad (_("end of macro inside conditional"));
515 else
516 as_bad (_("end of file inside conditional"));
517 as_bad_where (current_cframe->if_file_line.file,
518 current_cframe->if_file_line.line,
519 _("here is the start of the unterminated conditional"));
520 if (current_cframe->else_seen)
521 as_bad_where (current_cframe->else_file_line.file,
522 current_cframe->else_file_line.line,
523 _("here is the \"else\" of the unterminated conditional"));
527 /* This function is called when we exit out of a macro. We assume
528 that any conditionals which began within the macro are correctly
529 nested, and just pop them off the stack. */
531 void
532 cond_exit_macro (int nest)
534 while (current_cframe != NULL && current_cframe->macro_nest >= nest)
536 struct conditional_frame *hold;
538 hold = current_cframe;
539 current_cframe = current_cframe->previous_cframe;
540 obstack_free (&cond_obstack, hold);