1 /* cond.c - conditional assembly pseudo-ops, and .include
2 Copyright (C) 1990, 91, 92, 93, 95, 96, 97, 1998
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)
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
27 /* This is allocated to grow and shrink as .ifdef/.endif pairs are scanned. */
28 struct obstack cond_obstack;
36 /* We push one of these structures for each .if, and pop it at the
39 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? */
49 /* Whether we are currently ignoring input. */
51 /* Whether a conditional at a higher level is ignoring input. */
53 /* Macro nesting level at which this conditional was created. */
57 static void initialize_cframe PARAMS ((struct conditional_frame *cframe));
58 static char *get_mri_string PARAMS ((int, int *));
60 static struct conditional_frame *current_cframe = NULL;
66 register char *name; /* points to name of symbol */
67 register struct symbol *symbolP; /* Points to symbol */
68 struct conditional_frame cframe;
70 SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */
71 name = input_line_pointer;
73 if (!is_name_beginner (*name))
75 as_bad ("invalid identifier for \".ifdef\"");
76 obstack_1grow (&cond_obstack, 0);
77 ignore_rest_of_line ();
83 c = get_symbol_end ();
84 symbolP = symbol_find (name);
85 *input_line_pointer = c;
87 initialize_cframe (&cframe);
88 cframe.ignoring = cframe.dead_tree || !((symbolP != 0) ^ arg);
89 current_cframe = ((struct conditional_frame *)
90 obstack_copy (&cond_obstack, &cframe,
93 if (LISTING_SKIP_COND ()
95 && (cframe.previous_cframe == NULL
96 || ! cframe.previous_cframe->ignoring))
99 demand_empty_rest_of_line ();
100 } /* if a valid identifyer name */
108 struct conditional_frame cframe;
114 stop = mri_comment_field (&stopc);
116 SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */
118 if (current_cframe != NULL && current_cframe->ignoring)
120 operand.X_add_number = 0;
121 while (! is_end_of_line[(unsigned char) *input_line_pointer])
122 ++input_line_pointer;
126 expression (&operand);
127 if (operand.X_op != O_constant)
128 as_bad ("non-constant expression in \".if\" statement");
131 switch ((operatorT) arg)
133 case O_eq: t = operand.X_add_number == 0; break;
134 case O_ne: t = operand.X_add_number != 0; break;
135 case O_lt: t = operand.X_add_number < 0; break;
136 case O_le: t = operand.X_add_number <= 0; break;
137 case O_ge: t = operand.X_add_number >= 0; break;
138 case O_gt: t = operand.X_add_number > 0; break;
144 /* If the above error is signaled, this will dispatch
145 using an undefined result. No big deal. */
146 initialize_cframe (&cframe);
147 cframe.ignoring = cframe.dead_tree || ! t;
148 current_cframe = ((struct conditional_frame *)
149 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
151 if (LISTING_SKIP_COND ()
153 && (cframe.previous_cframe == NULL
154 || ! cframe.previous_cframe->ignoring))
158 mri_comment_end (stop, stopc);
160 demand_empty_rest_of_line ();
163 /* Get a string for the MRI IFC or IFNC pseudo-ops. */
166 get_mri_string (terminator, len)
174 s = ret = input_line_pointer;
175 if (*input_line_pointer == '\'')
178 ++input_line_pointer;
179 while (! is_end_of_line[(unsigned char) *input_line_pointer])
181 *s++ = *input_line_pointer++;
184 if (*input_line_pointer != '\'')
186 ++input_line_pointer;
193 while (*input_line_pointer != terminator
194 && ! is_end_of_line[(unsigned char) *input_line_pointer])
195 ++input_line_pointer;
196 s = input_line_pointer;
197 while (s > ret && (s[-1] == ' ' || s[-1] == '\t'))
205 /* The MRI IFC and IFNC pseudo-ops. */
216 struct conditional_frame cframe;
219 stop = mri_comment_field (&stopc);
221 s1 = get_mri_string (',', &len1);
223 if (*input_line_pointer != ',')
224 as_bad ("bad format for ifc or ifnc");
226 ++input_line_pointer;
228 s2 = get_mri_string (';', &len2);
230 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
232 initialize_cframe (&cframe);
233 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
234 current_cframe = ((struct conditional_frame *)
235 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
237 if (LISTING_SKIP_COND ()
239 && (cframe.previous_cframe == NULL
240 || ! cframe.previous_cframe->ignoring))
244 mri_comment_end (stop, stopc);
246 demand_empty_rest_of_line ();
253 struct conditional_frame *hold;
255 if (current_cframe == NULL)
257 as_bad ("\".endif\" without \".if\"");
261 if (LISTING_SKIP_COND ()
262 && current_cframe->ignoring
263 && (current_cframe->previous_cframe == NULL
264 || ! current_cframe->previous_cframe->ignoring))
267 hold = current_cframe;
268 current_cframe = current_cframe->previous_cframe;
269 obstack_free (&cond_obstack, hold);
270 } /* if one pop too many */
274 while (! is_end_of_line[(unsigned char) *input_line_pointer])
275 ++input_line_pointer;
278 demand_empty_rest_of_line ();
285 if (current_cframe == NULL)
287 as_bad (".else without matching .if - ignored");
290 else if (current_cframe->else_seen)
292 as_bad ("duplicate \"else\" - ignored");
293 as_bad_where (current_cframe->else_file_line.file,
294 current_cframe->else_file_line.line,
295 "here is the previous \"else\"");
296 as_bad_where (current_cframe->if_file_line.file,
297 current_cframe->if_file_line.line,
298 "here is the previous \"if\"");
302 as_where (¤t_cframe->else_file_line.file,
303 ¤t_cframe->else_file_line.line);
305 if (!current_cframe->dead_tree)
307 current_cframe->ignoring = !current_cframe->ignoring;
308 if (LISTING_SKIP_COND ())
310 if (! current_cframe->ignoring)
315 } /* if not a dead tree */
317 current_cframe->else_seen = 1;
318 } /* if error else do it */
322 while (! is_end_of_line[(unsigned char) *input_line_pointer])
323 ++input_line_pointer;
326 demand_empty_rest_of_line ();
336 struct conditional_frame cframe;
338 s1 = demand_copy_C_string (&len1);
341 if (*input_line_pointer != ',')
343 as_bad (".ifeqs syntax error");
344 ignore_rest_of_line ();
348 ++input_line_pointer;
350 s2 = demand_copy_C_string (&len2);
352 res = len1 == len2 && strncmp (s1, s2, len1) == 0;
354 initialize_cframe (&cframe);
355 cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
356 current_cframe = ((struct conditional_frame *)
357 obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
359 if (LISTING_SKIP_COND ()
361 && (cframe.previous_cframe == NULL
362 || ! cframe.previous_cframe->ignoring))
365 demand_empty_rest_of_line ();
373 s = input_line_pointer;
387 return (current_cframe != NULL) && (current_cframe->ignoring);
390 /* We cannot ignore certain pseudo ops. */
393 && (!strncasecmp (s, "if", 2)
394 || !strncasecmp (s, "ifdef", 5)
395 || !strncasecmp (s, "ifndef", 6)))
398 && (!strncasecmp (s, "else", 4)
399 || !strncasecmp (s, "endif", 5)
400 || !strncasecmp (s, "endc", 4))))
403 return (current_cframe != NULL) && (current_cframe->ignoring);
404 } /* ignore_input() */
407 initialize_cframe (cframe)
408 struct conditional_frame *cframe;
410 memset (cframe, 0, sizeof (*cframe));
411 as_where (&cframe->if_file_line.file,
412 &cframe->if_file_line.line);
413 cframe->previous_cframe = current_cframe;
414 cframe->dead_tree = current_cframe != NULL && current_cframe->ignoring;
415 cframe->macro_nest = macro_nest;
418 /* Give an error if a conditional is unterminated inside a macro or
419 the assembly as a whole. If NEST is non negative, we are being
420 called because of the end of a macro expansion. If NEST is
421 negative, we are being called at the of the input files. */
424 cond_finish_check (nest)
427 if (current_cframe != NULL && current_cframe->macro_nest >= nest)
429 as_bad ("end of %s inside conditional",
430 nest >= 0 ? "macro" : "file");
431 as_bad_where (current_cframe->if_file_line.file,
432 current_cframe->if_file_line.line,
433 "here is the start of the unterminated conditional");
434 if (current_cframe->else_seen)
435 as_bad_where (current_cframe->else_file_line.file,
436 current_cframe->else_file_line.line,
437 "here is the \"else\" of the unterminated conditional");
441 /* This function is called when we exit out of a macro. We assume
442 that any conditionals which began within the macro are correctly
443 nested, and just pop them off the stack. */
446 cond_exit_macro (nest)
449 while (current_cframe != NULL && current_cframe->macro_nest >= nest)
451 struct conditional_frame *hold;
453 hold = current_cframe;
454 current_cframe = current_cframe->previous_cframe;
455 obstack_free (&cond_obstack, hold);