1 /* cond.c - conditional assembly pseudo-ops, and .include
2 Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS 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 2, or (at your option)
11 GAS 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 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
24 /* This is allocated to grow and shrink as .ifdef/.endif pairs are scanned. */
25 struct obstack cond_obstack
;
33 /* This is what we push and pop. */
34 struct conditional_frame
36 struct file_line if_file_line
; /* the source file & line number of the "if" */
37 struct file_line else_file_line
; /* the source file & line of the "else" */
38 struct conditional_frame
*previous_cframe
;
39 int else_seen
; /* have we seen an else yet? */
40 int ignoring
; /* if we are currently ignoring input. */
41 int dead_tree
; /* if a conditional at a higher level is ignoring input. */
42 }; /* conditional_frame */
44 static void initialize_cframe
PARAMS ((struct conditional_frame
*cframe
));
45 static char *get_mri_string
PARAMS ((int, int *));
47 static struct conditional_frame
*current_cframe
= NULL
;
53 register char *name
; /* points to name of symbol */
54 register struct symbol
*symbolP
; /* Points to symbol */
55 struct conditional_frame cframe
;
57 SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */
58 name
= input_line_pointer
;
60 if (!is_name_beginner (*name
))
62 as_bad ("invalid identifier for \".ifdef\"");
63 obstack_1grow (&cond_obstack
, 0);
64 ignore_rest_of_line ();
70 c
= get_symbol_end ();
71 symbolP
= symbol_find (name
);
72 *input_line_pointer
= c
;
74 initialize_cframe (&cframe
);
75 cframe
.ignoring
= cframe
.dead_tree
|| !((symbolP
!= 0) ^ arg
);
76 current_cframe
= ((struct conditional_frame
*)
77 obstack_copy (&cond_obstack
, &cframe
,
79 demand_empty_rest_of_line ();
80 } /* if a valid identifyer name */
88 struct conditional_frame cframe
;
91 SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */
93 if (current_cframe
!= NULL
&& current_cframe
->ignoring
)
95 operand
.X_add_number
= 0;
96 while (! is_end_of_line
[(unsigned char) *input_line_pointer
])
101 expression (&operand
);
102 if (operand
.X_op
!= O_constant
)
103 as_bad ("non-constant expression in \".if\" statement");
106 switch ((operatorT
) arg
)
108 case O_eq
: t
= operand
.X_add_number
== 0; break;
109 case O_ne
: t
= operand
.X_add_number
!= 0; break;
110 case O_lt
: t
= operand
.X_add_number
< 0; break;
111 case O_le
: t
= operand
.X_add_number
<= 0; break;
112 case O_ge
: t
= operand
.X_add_number
>= 0; break;
113 case O_gt
: t
= operand
.X_add_number
> 0; break;
118 /* If the above error is signaled, this will dispatch
119 using an undefined result. No big deal. */
120 initialize_cframe (&cframe
);
121 cframe
.ignoring
= cframe
.dead_tree
|| ! t
;
122 current_cframe
= ((struct conditional_frame
*)
123 obstack_copy (&cond_obstack
, &cframe
, sizeof (cframe
)));
125 demand_empty_rest_of_line ();
128 /* Get a string for the MRI IFC or IFNC pseudo-ops. */
131 get_mri_string (terminator
, len
)
139 s
= ret
= input_line_pointer
;
140 if (*input_line_pointer
== '\'')
143 ++input_line_pointer
;
144 while (! is_end_of_line
[(unsigned char) *input_line_pointer
])
146 *s
++ = *input_line_pointer
++;
149 if (*input_line_pointer
!= '\'')
151 ++input_line_pointer
;
158 while (*input_line_pointer
!= terminator
159 && ! is_end_of_line
[(unsigned char) *input_line_pointer
])
160 ++input_line_pointer
;
161 s
= input_line_pointer
;
162 while (s
> ret
&& (s
[-1] == ' ' || s
[-1] == '\t'))
170 /* The MRI IFC and IFNC pseudo-ops. */
179 struct conditional_frame cframe
;
181 s1
= get_mri_string (',', &len1
);
183 if (*input_line_pointer
!= ',')
184 as_bad ("bad format for ifc or ifnc");
186 ++input_line_pointer
;
188 s2
= get_mri_string (';', &len2
);
190 res
= len1
== len2
&& strncmp (s1
, s2
, len1
) == 0;
192 initialize_cframe (&cframe
);
193 cframe
.ignoring
= cframe
.dead_tree
|| ! (res
^ arg
);
194 current_cframe
= ((struct conditional_frame
*)
195 obstack_copy (&cond_obstack
, &cframe
, sizeof (cframe
)));
202 struct conditional_frame
*hold
;
204 if (current_cframe
== NULL
)
206 as_bad ("\".endif\" without \".if\"");
210 hold
= current_cframe
;
211 current_cframe
= current_cframe
->previous_cframe
;
212 obstack_free (&cond_obstack
, hold
);
213 } /* if one pop too many */
222 if (current_cframe
== NULL
)
224 as_bad (".else without matching .if - ignored");
227 else if (current_cframe
->else_seen
)
229 as_bad ("duplicate \"else\" - ignored");
230 as_bad_where (current_cframe
->else_file_line
.file
,
231 current_cframe
->else_file_line
.line
,
232 "here is the previous \"else\"");
233 as_bad_where (current_cframe
->if_file_line
.file
,
234 current_cframe
->if_file_line
.line
,
235 "here is the previous \"if\"");
239 as_where (¤t_cframe
->else_file_line
.file
,
240 ¤t_cframe
->else_file_line
.line
);
242 if (!current_cframe
->dead_tree
)
244 current_cframe
->ignoring
= !current_cframe
->ignoring
;
245 } /* if not a dead tree */
247 current_cframe
->else_seen
= 1;
248 } /* if error else do it */
257 as_bad ("ifeqs not implemented.");
267 s
= input_line_pointer
;
281 return (current_cframe
!= NULL
) && (current_cframe
->ignoring
);
284 /* We cannot ignore certain pseudo ops. */
287 && (!strncasecmp (s
, "if", 2)
288 || !strncasecmp (s
, "ifdef", 5)
289 || !strncasecmp (s
, "ifndef", 6)))
292 && (!strncasecmp (s
, "else", 4)
293 || !strncasecmp (s
, "endif", 5)
294 || !strncasecmp (s
, "endc", 4))))
297 return (current_cframe
!= NULL
) && (current_cframe
->ignoring
);
298 } /* ignore_input() */
301 initialize_cframe (cframe
)
302 struct conditional_frame
*cframe
;
304 memset (cframe
, 0, sizeof (*cframe
));
305 as_where (&cframe
->if_file_line
.file
,
306 &cframe
->if_file_line
.line
);
307 cframe
->previous_cframe
= current_cframe
;
308 cframe
->dead_tree
= current_cframe
!= NULL
&& current_cframe
->ignoring
;
311 } /* initialize_cframe() */
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