| 1 | /* cond.c - conditional assembly pseudo-ops, and .include |
| 2 | Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GAS, the GNU Assembler. |
| 5 | |
| 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) |
| 9 | any later version. |
| 10 | |
| 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. |
| 15 | |
| 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. */ |
| 19 | |
| 20 | #include "as.h" |
| 21 | |
| 22 | #include "obstack.h" |
| 23 | |
| 24 | /* This is allocated to grow and shrink as .ifdef/.endif pairs are scanned. */ |
| 25 | struct obstack cond_obstack; |
| 26 | |
| 27 | struct file_line |
| 28 | { |
| 29 | char *file; |
| 30 | unsigned int line; |
| 31 | }; /* file_line */ |
| 32 | |
| 33 | /* This is what we push and pop. */ |
| 34 | struct conditional_frame |
| 35 | { |
| 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 */ |
| 43 | |
| 44 | static void initialize_cframe PARAMS ((struct conditional_frame *cframe)); |
| 45 | static char *get_mri_string PARAMS ((int, int *)); |
| 46 | |
| 47 | static struct conditional_frame *current_cframe = NULL; |
| 48 | |
| 49 | void |
| 50 | s_ifdef (arg) |
| 51 | int arg; |
| 52 | { |
| 53 | register char *name; /* points to name of symbol */ |
| 54 | register struct symbol *symbolP; /* Points to symbol */ |
| 55 | struct conditional_frame cframe; |
| 56 | |
| 57 | SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */ |
| 58 | name = input_line_pointer; |
| 59 | |
| 60 | if (!is_name_beginner (*name)) |
| 61 | { |
| 62 | as_bad ("invalid identifier for \".ifdef\""); |
| 63 | obstack_1grow (&cond_obstack, 0); |
| 64 | ignore_rest_of_line (); |
| 65 | } |
| 66 | else |
| 67 | { |
| 68 | char c; |
| 69 | |
| 70 | c = get_symbol_end (); |
| 71 | symbolP = symbol_find (name); |
| 72 | *input_line_pointer = c; |
| 73 | |
| 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, |
| 78 | sizeof (cframe))); |
| 79 | demand_empty_rest_of_line (); |
| 80 | } /* if a valid identifyer name */ |
| 81 | } /* s_ifdef() */ |
| 82 | |
| 83 | void |
| 84 | s_if (arg) |
| 85 | int arg; |
| 86 | { |
| 87 | expressionS operand; |
| 88 | struct conditional_frame cframe; |
| 89 | int t; |
| 90 | |
| 91 | SKIP_WHITESPACE (); /* Leading whitespace is part of operand. */ |
| 92 | |
| 93 | if (current_cframe != NULL && current_cframe->ignoring) |
| 94 | { |
| 95 | operand.X_add_number = 0; |
| 96 | while (! is_end_of_line[(unsigned char) *input_line_pointer]) |
| 97 | ++input_line_pointer; |
| 98 | } |
| 99 | else |
| 100 | { |
| 101 | expression (&operand); |
| 102 | if (operand.X_op != O_constant) |
| 103 | as_bad ("non-constant expression in \".if\" statement"); |
| 104 | } |
| 105 | |
| 106 | switch ((operatorT) arg) |
| 107 | { |
| 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; |
| 114 | default: |
| 115 | abort (); |
| 116 | } |
| 117 | |
| 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))); |
| 124 | |
| 125 | demand_empty_rest_of_line (); |
| 126 | } /* s_if() */ |
| 127 | |
| 128 | /* Get a string for the MRI IFC or IFNC pseudo-ops. */ |
| 129 | |
| 130 | static char * |
| 131 | get_mri_string (terminator, len) |
| 132 | int terminator; |
| 133 | int *len; |
| 134 | { |
| 135 | char *ret; |
| 136 | char *s; |
| 137 | |
| 138 | SKIP_WHITESPACE (); |
| 139 | s = ret = input_line_pointer; |
| 140 | if (*input_line_pointer == '\'') |
| 141 | { |
| 142 | ++s; |
| 143 | ++input_line_pointer; |
| 144 | while (! is_end_of_line[(unsigned char) *input_line_pointer]) |
| 145 | { |
| 146 | *s++ = *input_line_pointer++; |
| 147 | if (s[-1] == '\'') |
| 148 | { |
| 149 | if (*input_line_pointer != '\'') |
| 150 | break; |
| 151 | ++input_line_pointer; |
| 152 | } |
| 153 | } |
| 154 | SKIP_WHITESPACE (); |
| 155 | } |
| 156 | else |
| 157 | { |
| 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')) |
| 163 | --s; |
| 164 | } |
| 165 | |
| 166 | *len = s - ret; |
| 167 | return ret; |
| 168 | } |
| 169 | |
| 170 | /* The MRI IFC and IFNC pseudo-ops. */ |
| 171 | |
| 172 | void |
| 173 | s_ifc (arg) |
| 174 | int arg; |
| 175 | { |
| 176 | char *s1, *s2; |
| 177 | int len1, len2; |
| 178 | int res; |
| 179 | struct conditional_frame cframe; |
| 180 | |
| 181 | s1 = get_mri_string (',', &len1); |
| 182 | |
| 183 | if (*input_line_pointer != ',') |
| 184 | as_bad ("bad format for ifc or ifnc"); |
| 185 | else |
| 186 | ++input_line_pointer; |
| 187 | |
| 188 | s2 = get_mri_string (';', &len2); |
| 189 | |
| 190 | res = len1 == len2 && strncmp (s1, s2, len1) == 0; |
| 191 | |
| 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))); |
| 196 | } |
| 197 | |
| 198 | void |
| 199 | s_endif (arg) |
| 200 | int arg; |
| 201 | { |
| 202 | struct conditional_frame *hold; |
| 203 | |
| 204 | if (current_cframe == NULL) |
| 205 | { |
| 206 | as_bad ("\".endif\" without \".if\""); |
| 207 | } |
| 208 | else |
| 209 | { |
| 210 | hold = current_cframe; |
| 211 | current_cframe = current_cframe->previous_cframe; |
| 212 | obstack_free (&cond_obstack, hold); |
| 213 | } /* if one pop too many */ |
| 214 | |
| 215 | return; |
| 216 | } /* s_endif() */ |
| 217 | |
| 218 | void |
| 219 | s_else (arg) |
| 220 | int arg; |
| 221 | { |
| 222 | if (current_cframe == NULL) |
| 223 | { |
| 224 | as_bad (".else without matching .if - ignored"); |
| 225 | |
| 226 | } |
| 227 | else if (current_cframe->else_seen) |
| 228 | { |
| 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\""); |
| 236 | } |
| 237 | else |
| 238 | { |
| 239 | as_where (¤t_cframe->else_file_line.file, |
| 240 | ¤t_cframe->else_file_line.line); |
| 241 | |
| 242 | if (!current_cframe->dead_tree) |
| 243 | { |
| 244 | current_cframe->ignoring = !current_cframe->ignoring; |
| 245 | } /* if not a dead tree */ |
| 246 | |
| 247 | current_cframe->else_seen = 1; |
| 248 | } /* if error else do it */ |
| 249 | |
| 250 | return; |
| 251 | } /* s_else() */ |
| 252 | |
| 253 | void |
| 254 | s_ifeqs (arg) |
| 255 | int arg; |
| 256 | { |
| 257 | as_bad ("ifeqs not implemented."); |
| 258 | |
| 259 | return; |
| 260 | } /* s_ifeqs() */ |
| 261 | |
| 262 | int |
| 263 | ignore_input () |
| 264 | { |
| 265 | char *s; |
| 266 | |
| 267 | s = input_line_pointer; |
| 268 | |
| 269 | if (flag_mri |
| 270 | #ifdef NO_PSEUDO_DOT |
| 271 | || 1 |
| 272 | #endif |
| 273 | ) |
| 274 | { |
| 275 | if (s[-1] != '.') |
| 276 | --s; |
| 277 | } |
| 278 | else |
| 279 | { |
| 280 | if (s[-1] != '.') |
| 281 | return (current_cframe != NULL) && (current_cframe->ignoring); |
| 282 | } |
| 283 | |
| 284 | /* We cannot ignore certain pseudo ops. */ |
| 285 | if (((s[0] == 'i' |
| 286 | || s[0] == 'I') |
| 287 | && (!strncasecmp (s, "if", 2) |
| 288 | || !strncasecmp (s, "ifdef", 5) |
| 289 | || !strncasecmp (s, "ifndef", 6))) |
| 290 | || ((s[0] == 'e' |
| 291 | || s[0] == 'E') |
| 292 | && (!strncasecmp (s, "else", 4) |
| 293 | || !strncasecmp (s, "endif", 5) |
| 294 | || !strncasecmp (s, "endc", 4)))) |
| 295 | return 0; |
| 296 | |
| 297 | return (current_cframe != NULL) && (current_cframe->ignoring); |
| 298 | } /* ignore_input() */ |
| 299 | |
| 300 | static void |
| 301 | initialize_cframe (cframe) |
| 302 | struct conditional_frame *cframe; |
| 303 | { |
| 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; |
| 309 | |
| 310 | return; |
| 311 | } /* initialize_cframe() */ |
| 312 | |
| 313 | /* |
| 314 | * Local Variables: |
| 315 | * fill-column: 131 |
| 316 | * comment-column: 0 |
| 317 | * End: |
| 318 | */ |
| 319 | |
| 320 | /* end of cond.c */ |