]>
Commit | Line | Data |
---|---|---|
b0699dad | 1 | /* Parse C expressions for cpplib. |
525bc95d | 2 | Copyright (C) 1987, 92, 94, 95, 97, 98, 1999, 2000 Free Software Foundation. |
7f2935c7 PB |
3 | |
4 | This program is free software; you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published by the | |
6 | Free Software Foundation; either version 2, or (at your option) any | |
7 | later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
940d9d63 RK |
16 | Foundation, 59 Temple Place - Suite 330, |
17 | Boston, MA 02111-1307, USA. | |
7f2935c7 PB |
18 | |
19 | In other words, you are welcome to use, share and improve this program. | |
20 | You are forbidden to forbid anyone else to use, share and improve | |
21 | what you give them. Help stamp out software-hoarding! | |
22 | ||
0f41302f | 23 | Written by Per Bothner 1994. */ |
7f2935c7 PB |
24 | |
25 | /* Parse a C expression from text in a string */ | |
26 | ||
27 | #include "config.h" | |
b04cd507 | 28 | #include "system.h" |
487a6e06 | 29 | #include "cpplib.h" |
88ae23e7 | 30 | #include "cpphash.h" |
7f2935c7 | 31 | |
7f2935c7 PB |
32 | #ifndef CHAR_TYPE_SIZE |
33 | #define CHAR_TYPE_SIZE BITS_PER_UNIT | |
34 | #endif | |
35 | ||
36 | #ifndef INT_TYPE_SIZE | |
37 | #define INT_TYPE_SIZE BITS_PER_WORD | |
38 | #endif | |
39 | ||
40 | #ifndef LONG_TYPE_SIZE | |
41 | #define LONG_TYPE_SIZE BITS_PER_WORD | |
42 | #endif | |
43 | ||
44 | #ifndef WCHAR_TYPE_SIZE | |
45 | #define WCHAR_TYPE_SIZE INT_TYPE_SIZE | |
46 | #endif | |
47 | ||
48 | #ifndef MAX_CHAR_TYPE_SIZE | |
49 | #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE | |
50 | #endif | |
51 | ||
52 | #ifndef MAX_INT_TYPE_SIZE | |
53 | #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE | |
54 | #endif | |
55 | ||
56 | #ifndef MAX_LONG_TYPE_SIZE | |
57 | #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE | |
58 | #endif | |
59 | ||
60 | #ifndef MAX_WCHAR_TYPE_SIZE | |
61 | #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE | |
62 | #endif | |
63 | ||
e915b770 | 64 | #define MAX_CHAR_TYPE_MASK (MAX_CHAR_TYPE_SIZE < HOST_BITS_PER_WIDEST_INT \ |
b0699dad | 65 | ? (~(~(HOST_WIDEST_INT) 0 << MAX_CHAR_TYPE_SIZE)) \ |
e915b770 | 66 | : ~ (HOST_WIDEST_INT) 0) |
f1a86df6 | 67 | |
e915b770 | 68 | #define MAX_WCHAR_TYPE_MASK (MAX_WCHAR_TYPE_SIZE < HOST_BITS_PER_WIDEST_INT \ |
b0699dad | 69 | ? ~(~(HOST_WIDEST_INT) 0 << MAX_WCHAR_TYPE_SIZE) \ |
e915b770 | 70 | : ~ (HOST_WIDEST_INT) 0) |
f1a86df6 | 71 | |
7f2935c7 PB |
72 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a |
73 | number with SUM's sign, where A, B, and SUM are all C integers. */ | |
74 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) | |
75 | ||
b04cd507 | 76 | static void integer_overflow PARAMS ((cpp_reader *)); |
b0699dad | 77 | static HOST_WIDEST_INT left_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT, |
e23c0ba3 ZW |
78 | unsigned int, |
79 | unsigned HOST_WIDEST_INT)); | |
b0699dad | 80 | static HOST_WIDEST_INT right_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT, |
e23c0ba3 ZW |
81 | unsigned int, |
82 | unsigned HOST_WIDEST_INT)); | |
b0699dad ZW |
83 | static struct operation parse_number PARAMS ((cpp_reader *, U_CHAR *, |
84 | U_CHAR *)); | |
85 | static struct operation parse_charconst PARAMS ((cpp_reader *, U_CHAR *, | |
86 | U_CHAR *)); | |
ba412f14 | 87 | static struct operation parse_defined PARAMS ((cpp_reader *)); |
b0699dad ZW |
88 | static HOST_WIDEST_INT parse_escape PARAMS ((cpp_reader *, U_CHAR **, |
89 | HOST_WIDEST_INT)); | |
90 | static struct operation lex PARAMS ((cpp_reader *, int)); | |
91 | ||
7f2935c7 PB |
92 | |
93 | #define ERROR 299 | |
94 | #define OROR 300 | |
95 | #define ANDAND 301 | |
96 | #define EQUAL 302 | |
97 | #define NOTEQUAL 303 | |
98 | #define LEQ 304 | |
99 | #define GEQ 305 | |
100 | #define LSH 306 | |
101 | #define RSH 307 | |
102 | #define NAME 308 | |
103 | #define INT 309 | |
104 | #define CHAR 310 | |
105 | ||
b0699dad ZW |
106 | struct operation |
107 | { | |
108 | short op; | |
e23c0ba3 ZW |
109 | U_CHAR rprio; /* Priority of op (relative to it right operand). */ |
110 | U_CHAR flags; | |
111 | U_CHAR unsignedp; /* true if value should be treated as unsigned */ | |
b0699dad | 112 | HOST_WIDEST_INT value; /* The value logically "right" of op. */ |
7f2935c7 | 113 | }; |
7f2935c7 | 114 | |
f13eb63a ZW |
115 | /* Parse and convert an integer for #if. Accepts decimal, hex, or octal |
116 | with or without size suffixes. */ | |
7f2935c7 | 117 | |
f13eb63a ZW |
118 | static struct operation |
119 | parse_number (pfile, start, end) | |
7f2935c7 | 120 | cpp_reader *pfile; |
f13eb63a ZW |
121 | U_CHAR *start; |
122 | U_CHAR *end; | |
7f2935c7 PB |
123 | { |
124 | struct operation op; | |
f13eb63a ZW |
125 | U_CHAR *p = start; |
126 | int c; | |
e915b770 | 127 | unsigned HOST_WIDEST_INT n = 0, nd, MAX_over_base; |
f13eb63a ZW |
128 | int base = 10; |
129 | int overflow = 0; | |
130 | int digit, largest_digit = 0; | |
7f2935c7 PB |
131 | int spec_long = 0; |
132 | ||
133 | op.unsignedp = 0; | |
134 | ||
f13eb63a ZW |
135 | if (p[0] == '0') |
136 | { | |
137 | if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X')) | |
138 | { | |
139 | p += 2; | |
140 | base = 16; | |
141 | } | |
142 | else | |
143 | { | |
144 | p += 1; | |
145 | base = 8; | |
146 | } | |
7f2935c7 PB |
147 | } |
148 | ||
0f41302f | 149 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
e915b770 KG |
150 | MAX_over_base = (((unsigned HOST_WIDEST_INT) -1) |
151 | / ((unsigned HOST_WIDEST_INT) base)); | |
7f2935c7 | 152 | |
f13eb63a ZW |
153 | while (p < end) |
154 | { | |
155 | c = *p++; | |
156 | ||
157 | if (c >= '0' && c <= '9') | |
158 | digit = c - '0'; | |
159 | else if (base == 16 && c >= 'a' && c <= 'f') /* FIXME: assumes ASCII */ | |
160 | digit = c - 'a' + 10; | |
161 | else if (base == 16 && c >= 'A' && c <= 'F') | |
162 | digit = c - 'A' + 10; | |
163 | else if (c == '.') | |
164 | { | |
165 | /* It's a float since it contains a point. */ | |
166 | cpp_error (pfile, | |
167 | "floating point numbers are not allowed in #if expressions"); | |
168 | goto error; | |
169 | } | |
170 | else | |
171 | { | |
172 | /* `l' means long, and `u' means unsigned. */ | |
173 | for (;;) | |
174 | { | |
175 | if (c == 'l' || c == 'L') | |
176 | spec_long++; | |
177 | else if (c == 'u' || c == 'U') | |
178 | op.unsignedp++; | |
179 | else | |
180 | { | |
181 | /* Decrement p here so that the error for an invalid number | |
182 | will be generated below in the case where this is the | |
183 | last character in the buffer. */ | |
184 | p--; | |
185 | break; | |
186 | } | |
187 | if (p == end) | |
188 | break; | |
189 | c = *p++; | |
190 | } | |
191 | /* Don't look for any more digits after the suffixes. */ | |
7f2935c7 | 192 | break; |
f13eb63a ZW |
193 | } |
194 | ||
195 | if (largest_digit < digit) | |
196 | largest_digit = digit; | |
197 | nd = n * base + digit; | |
198 | overflow |= MAX_over_base < n || nd < n; | |
199 | n = nd; | |
7f2935c7 | 200 | } |
7f2935c7 | 201 | |
f13eb63a | 202 | if (p != end) |
7f2935c7 | 203 | { |
f13eb63a ZW |
204 | cpp_error (pfile, "invalid number in #if expression"); |
205 | goto error; | |
7f2935c7 | 206 | } |
ae79697b | 207 | else if (spec_long > (CPP_OPTION (pfile, c89) ? 1 : 2)) |
f13eb63a ZW |
208 | { |
209 | cpp_error (pfile, "too many `l' suffixes in integer constant"); | |
210 | goto error; | |
211 | } | |
212 | else if (op.unsignedp > 1) | |
213 | { | |
214 | cpp_error (pfile, "too many `u' suffixes in integer constant"); | |
215 | goto error; | |
216 | } | |
217 | ||
7f2935c7 | 218 | if (base <= largest_digit) |
7c4033ff | 219 | cpp_pedwarn (pfile, "integer constant contains digits beyond the radix"); |
7f2935c7 PB |
220 | |
221 | if (overflow) | |
7c4033ff | 222 | cpp_pedwarn (pfile, "integer constant out of range"); |
7f2935c7 PB |
223 | |
224 | /* If too big to be signed, consider it unsigned. */ | |
e915b770 | 225 | else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp) |
7f2935c7 PB |
226 | { |
227 | if (base == 10) | |
f13eb63a ZW |
228 | cpp_warning (pfile, |
229 | "integer constant is so large that it is unsigned"); | |
7f2935c7 PB |
230 | op.unsignedp = 1; |
231 | } | |
232 | ||
233 | op.value = n; | |
234 | op.op = INT; | |
235 | return op; | |
f13eb63a ZW |
236 | |
237 | error: | |
238 | op.op = ERROR; | |
239 | return op; | |
7f2935c7 PB |
240 | } |
241 | ||
f13eb63a ZW |
242 | /* Parse and convert a character constant for #if. Understands backslash |
243 | escapes (\n, \031) and multibyte characters (if so configured). */ | |
244 | static struct operation | |
245 | parse_charconst (pfile, start, end) | |
246 | cpp_reader *pfile; | |
247 | U_CHAR *start; | |
248 | U_CHAR *end; | |
249 | { | |
250 | struct operation op; | |
e915b770 | 251 | HOST_WIDEST_INT result = 0; |
f13eb63a ZW |
252 | int num_chars = 0; |
253 | int num_bits; | |
254 | unsigned int width = MAX_CHAR_TYPE_SIZE, mask = MAX_CHAR_TYPE_MASK; | |
255 | int max_chars; | |
256 | U_CHAR *ptr = start; | |
257 | ||
099a9dd0 | 258 | int c = -1; |
f13eb63a ZW |
259 | |
260 | if (*ptr == 'L') | |
261 | { | |
262 | ++ptr; | |
263 | width = MAX_WCHAR_TYPE_SIZE, mask = MAX_WCHAR_TYPE_MASK; | |
264 | } | |
265 | max_chars = MAX_LONG_TYPE_SIZE / width; | |
266 | ||
267 | ++ptr; /* skip initial quote */ | |
268 | ||
269 | while (ptr < end) | |
270 | { | |
f13eb63a | 271 | c = *ptr++; |
f13eb63a ZW |
272 | if (c == '\'' || c == '\0') |
273 | break; | |
274 | else if (c == '\\') | |
275 | { | |
b0699dad | 276 | c = parse_escape (pfile, &ptr, mask); |
f13eb63a ZW |
277 | if (width < HOST_BITS_PER_INT |
278 | && (unsigned int) c >= (unsigned int)(1 << width)) | |
279 | cpp_pedwarn (pfile, "escape sequence out of range for character"); | |
280 | } | |
281 | ||
282 | /* Merge character into result; ignore excess chars. */ | |
283 | if (++num_chars <= max_chars) | |
284 | { | |
285 | if (width < HOST_BITS_PER_INT) | |
286 | result = (result << width) | (c & ((1 << width) - 1)); | |
287 | else | |
288 | result = c; | |
289 | } | |
290 | } | |
291 | ||
292 | if (num_chars == 0) | |
293 | { | |
294 | cpp_error (pfile, "empty character constant"); | |
295 | goto error; | |
296 | } | |
297 | else if (c != '\'') | |
298 | { | |
299 | /* cpp_get_token has already emitted an error if !traditional. */ | |
300 | if (! CPP_TRADITIONAL (pfile)) | |
301 | cpp_error (pfile, "malformatted character constant"); | |
302 | goto error; | |
303 | } | |
304 | else if (num_chars > max_chars) | |
305 | { | |
306 | cpp_error (pfile, "character constant too long"); | |
307 | goto error; | |
308 | } | |
309 | else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile)) | |
310 | cpp_warning (pfile, "multi-character character constant"); | |
311 | ||
312 | /* If char type is signed, sign-extend the constant. */ | |
313 | num_bits = num_chars * width; | |
314 | ||
cf4ed945 ZW |
315 | if (cpp_defined (pfile, (const U_CHAR *)"__CHAR_UNSIGNED__", |
316 | sizeof ("__CHAR_UNSIGNED__")-1) | |
f13eb63a | 317 | || ((result >> (num_bits - 1)) & 1) == 0) |
ca261cb4 KG |
318 | op.value = result & ((unsigned HOST_WIDEST_INT) ~0 |
319 | >> (HOST_BITS_PER_WIDEST_INT - num_bits)); | |
f13eb63a | 320 | else |
ca261cb4 KG |
321 | op.value = result | ~((unsigned HOST_WIDEST_INT) ~0 |
322 | >> (HOST_BITS_PER_WIDEST_INT - num_bits)); | |
f13eb63a ZW |
323 | |
324 | /* This is always a signed type. */ | |
325 | op.unsignedp = 0; | |
326 | op.op = CHAR; | |
327 | return op; | |
328 | ||
329 | error: | |
330 | op.op = ERROR; | |
331 | return op; | |
332 | } | |
333 | ||
ba412f14 ZW |
334 | static struct operation |
335 | parse_defined (pfile) | |
336 | cpp_reader *pfile; | |
337 | { | |
338 | int paren = 0, len; | |
339 | U_CHAR *tok; | |
340 | enum cpp_token token; | |
341 | struct operation op; | |
342 | long old_written = CPP_WRITTEN (pfile); | |
343 | ||
344 | op.unsignedp = 0; | |
345 | op.op = INT; | |
346 | ||
347 | pfile->no_macro_expand++; | |
45b966db | 348 | token = _cpp_get_directive_token (pfile); |
ba412f14 ZW |
349 | if (token == CPP_LPAREN) |
350 | { | |
351 | paren++; | |
352 | CPP_SET_WRITTEN (pfile, old_written); | |
45b966db | 353 | token = _cpp_get_directive_token (pfile); |
ba412f14 ZW |
354 | } |
355 | ||
356 | if (token != CPP_NAME) | |
357 | goto oops; | |
358 | ||
359 | tok = pfile->token_buffer + old_written; | |
360 | len = CPP_PWRITTEN (pfile) - tok; | |
361 | op.value = cpp_defined (pfile, tok, len); | |
362 | ||
363 | if (paren) | |
364 | { | |
45b966db | 365 | if (_cpp_get_directive_token (pfile) != CPP_RPAREN) |
ba412f14 ZW |
366 | goto oops; |
367 | } | |
368 | CPP_SET_WRITTEN (pfile, old_written); | |
369 | pfile->no_macro_expand--; | |
370 | return op; | |
371 | ||
372 | oops: | |
373 | CPP_SET_WRITTEN (pfile, old_written); | |
374 | pfile->no_macro_expand--; | |
375 | cpp_error (pfile, "`defined' without an identifier"); | |
376 | ||
377 | op.op = ERROR; | |
378 | return op; | |
379 | } | |
380 | ||
f13eb63a | 381 | |
7f2935c7 | 382 | struct token { |
bcc5cac9 | 383 | const char *operator; |
7f2935c7 PB |
384 | int token; |
385 | }; | |
386 | ||
455d2586 | 387 | static const struct token tokentab2[] = { |
7f2935c7 PB |
388 | {"&&", ANDAND}, |
389 | {"||", OROR}, | |
390 | {"<<", LSH}, | |
391 | {">>", RSH}, | |
392 | {"==", EQUAL}, | |
393 | {"!=", NOTEQUAL}, | |
394 | {"<=", LEQ}, | |
395 | {">=", GEQ}, | |
396 | {"++", ERROR}, | |
397 | {"--", ERROR}, | |
398 | {NULL, ERROR} | |
399 | }; | |
400 | ||
0f41302f | 401 | /* Read one token. */ |
7f2935c7 | 402 | |
6de1e2a9 | 403 | static struct operation |
b0699dad | 404 | lex (pfile, skip_evaluation) |
52529158 | 405 | cpp_reader *pfile; |
c9666c01 | 406 | int skip_evaluation; |
7f2935c7 | 407 | { |
455d2586 | 408 | const struct token *toktab; |
7f2935c7 PB |
409 | enum cpp_token token; |
410 | struct operation op; | |
411 | U_CHAR *tok_start, *tok_end; | |
cf4ed945 | 412 | long old_written; |
7f2935c7 | 413 | |
1519594d | 414 | old_written = CPP_WRITTEN (pfile); |
45b966db | 415 | token = _cpp_get_directive_token (pfile); |
7f2935c7 | 416 | |
7f2935c7 PB |
417 | tok_start = pfile->token_buffer + old_written; |
418 | tok_end = CPP_PWRITTEN (pfile); | |
cf4ed945 | 419 | CPP_SET_WRITTEN (pfile, old_written); |
7f2935c7 | 420 | switch (token) |
ba412f14 | 421 | { |
0f41302f | 422 | case CPP_EOF: /* Should not happen ... */ |
a4a315ef | 423 | case CPP_VSPACE: |
7f2935c7 PB |
424 | op.op = 0; |
425 | return op; | |
7f2935c7 | 426 | case CPP_NUMBER: |
f13eb63a | 427 | return parse_number (pfile, tok_start, tok_end); |
7f2935c7 | 428 | case CPP_STRING: |
525bc95d | 429 | case CPP_WSTRING: |
cf4ed945 | 430 | cpp_error (pfile, "string constants are not allowed in #if expressions"); |
7f2935c7 PB |
431 | op.op = ERROR; |
432 | return op; | |
525bc95d | 433 | |
7f2935c7 | 434 | case CPP_CHAR: |
525bc95d | 435 | case CPP_WCHAR: |
f13eb63a | 436 | return parse_charconst (pfile, tok_start, tok_end); |
7f2935c7 PB |
437 | |
438 | case CPP_NAME: | |
ba412f14 ZW |
439 | if (!strcmp (tok_start, "defined")) |
440 | return parse_defined (pfile); | |
441 | ||
f13eb63a ZW |
442 | op.op = INT; |
443 | op.unsignedp = 0; | |
444 | op.value = 0; | |
5dfa4da1 | 445 | |
ae79697b | 446 | if (CPP_OPTION (pfile, warn_undef) && !skip_evaluation) |
ba412f14 ZW |
447 | cpp_warning (pfile, "`%.*s' is not defined", |
448 | (int) (tok_end - tok_start), tok_start); | |
5dfa4da1 ZW |
449 | return op; |
450 | ||
ba412f14 ZW |
451 | case CPP_ASSERTION: |
452 | op.op = INT; | |
453 | op.unsignedp = 0; | |
454 | op.value = cpp_defined (pfile, tok_start, tok_end - tok_start); | |
f13eb63a | 455 | return op; |
7f2935c7 PB |
456 | |
457 | case CPP_OTHER: | |
458 | /* See if it is a special token of length 2. */ | |
459 | if (tok_start + 2 == tok_end) | |
460 | { | |
461 | for (toktab = tokentab2; toktab->operator != NULL; toktab++) | |
462 | if (tok_start[0] == toktab->operator[0] | |
463 | && tok_start[1] == toktab->operator[1]) | |
464 | break; | |
465 | if (toktab->token == ERROR) | |
ab87f8c8 JL |
466 | cpp_error (pfile, "`%s' not allowed in operand of `#if'", |
467 | tok_start); | |
7f2935c7 PB |
468 | op.op = toktab->token; |
469 | return op; | |
470 | } | |
471 | /* fall through */ | |
472 | default: | |
473 | op.op = *tok_start; | |
474 | return op; | |
475 | } | |
476 | } | |
477 | ||
478 | ||
479 | /* Parse a C escape sequence. STRING_PTR points to a variable | |
480 | containing a pointer to the string to parse. That pointer | |
481 | is updated past the characters we use. The value of the | |
482 | escape sequence is returned. | |
483 | ||
484 | A negative value means the sequence \ newline was seen, | |
485 | which is supposed to be equivalent to nothing at all. | |
486 | ||
487 | If \ is followed by a null character, we return a negative | |
488 | value and leave the string pointer pointing at the null character. | |
489 | ||
490 | If \ is followed by 000, we return 0 and leave the string pointer | |
491 | after the zeros. A value of 0 does not mean end of string. */ | |
492 | ||
a2c8e144 | 493 | static HOST_WIDEST_INT |
b0699dad | 494 | parse_escape (pfile, string_ptr, result_mask) |
7f2935c7 | 495 | cpp_reader *pfile; |
a2c8e144 | 496 | U_CHAR **string_ptr; |
e915b770 | 497 | HOST_WIDEST_INT result_mask; |
7f2935c7 PB |
498 | { |
499 | register int c = *(*string_ptr)++; | |
500 | switch (c) | |
501 | { | |
502 | case 'a': | |
503 | return TARGET_BELL; | |
504 | case 'b': | |
505 | return TARGET_BS; | |
506 | case 'e': | |
507 | case 'E': | |
ae79697b | 508 | if (CPP_PEDANTIC (pfile)) |
7f2935c7 | 509 | cpp_pedwarn (pfile, "non-ANSI-standard escape sequence, `\\%c'", c); |
f3ad1f9c | 510 | return TARGET_ESC; |
7f2935c7 PB |
511 | case 'f': |
512 | return TARGET_FF; | |
513 | case 'n': | |
514 | return TARGET_NEWLINE; | |
515 | case 'r': | |
516 | return TARGET_CR; | |
517 | case 't': | |
518 | return TARGET_TAB; | |
519 | case 'v': | |
520 | return TARGET_VT; | |
521 | case '\n': | |
522 | return -2; | |
523 | case 0: | |
524 | (*string_ptr)--; | |
525 | return 0; | |
526 | ||
527 | case '0': | |
528 | case '1': | |
529 | case '2': | |
530 | case '3': | |
531 | case '4': | |
532 | case '5': | |
533 | case '6': | |
534 | case '7': | |
535 | { | |
e915b770 | 536 | register HOST_WIDEST_INT i = c - '0'; |
7f2935c7 PB |
537 | register int count = 0; |
538 | while (++count < 3) | |
539 | { | |
540 | c = *(*string_ptr)++; | |
541 | if (c >= '0' && c <= '7') | |
542 | i = (i << 3) + c - '0'; | |
543 | else | |
544 | { | |
545 | (*string_ptr)--; | |
546 | break; | |
547 | } | |
548 | } | |
f1a86df6 | 549 | if (i != (i & result_mask)) |
7f2935c7 | 550 | { |
f1a86df6 ZW |
551 | i &= result_mask; |
552 | cpp_pedwarn (pfile, "octal escape sequence out of range"); | |
7f2935c7 PB |
553 | } |
554 | return i; | |
555 | } | |
556 | case 'x': | |
557 | { | |
e915b770 | 558 | register unsigned HOST_WIDEST_INT i = 0, overflow = 0; |
f1a86df6 | 559 | register int digits_found = 0, digit; |
7f2935c7 PB |
560 | for (;;) |
561 | { | |
562 | c = *(*string_ptr)++; | |
563 | if (c >= '0' && c <= '9') | |
564 | digit = c - '0'; | |
565 | else if (c >= 'a' && c <= 'f') | |
566 | digit = c - 'a' + 10; | |
567 | else if (c >= 'A' && c <= 'F') | |
568 | digit = c - 'A' + 10; | |
569 | else | |
570 | { | |
571 | (*string_ptr)--; | |
572 | break; | |
573 | } | |
574 | overflow |= i ^ (i << 4 >> 4); | |
575 | i = (i << 4) + digit; | |
576 | digits_found = 1; | |
577 | } | |
578 | if (!digits_found) | |
579 | cpp_error (pfile, "\\x used with no following hex digits"); | |
f1a86df6 | 580 | if (overflow | (i != (i & result_mask))) |
7f2935c7 | 581 | { |
f1a86df6 ZW |
582 | i &= result_mask; |
583 | cpp_pedwarn (pfile, "hex escape sequence out of range"); | |
7f2935c7 PB |
584 | } |
585 | return i; | |
586 | } | |
587 | default: | |
588 | return c; | |
589 | } | |
590 | } | |
591 | ||
592 | static void | |
593 | integer_overflow (pfile) | |
594 | cpp_reader *pfile; | |
595 | { | |
596 | if (CPP_PEDANTIC (pfile)) | |
597 | cpp_pedwarn (pfile, "integer overflow in preprocessor expression"); | |
598 | } | |
599 | ||
ca261cb4 | 600 | static HOST_WIDEST_INT |
7f2935c7 PB |
601 | left_shift (pfile, a, unsignedp, b) |
602 | cpp_reader *pfile; | |
ca261cb4 | 603 | HOST_WIDEST_INT a; |
e23c0ba3 | 604 | unsigned int unsignedp; |
ca261cb4 | 605 | unsigned HOST_WIDEST_INT b; |
7f2935c7 | 606 | { |
ca261cb4 | 607 | if (b >= HOST_BITS_PER_WIDEST_INT) |
7f2935c7 PB |
608 | { |
609 | if (! unsignedp && a != 0) | |
610 | integer_overflow (pfile); | |
611 | return 0; | |
612 | } | |
613 | else if (unsignedp) | |
ca261cb4 | 614 | return (unsigned HOST_WIDEST_INT) a << b; |
7f2935c7 PB |
615 | else |
616 | { | |
ca261cb4 | 617 | HOST_WIDEST_INT l = a << b; |
7f2935c7 PB |
618 | if (l >> b != a) |
619 | integer_overflow (pfile); | |
620 | return l; | |
621 | } | |
622 | } | |
623 | ||
ca261cb4 | 624 | static HOST_WIDEST_INT |
7f2935c7 | 625 | right_shift (pfile, a, unsignedp, b) |
d6f4ec51 | 626 | cpp_reader *pfile ATTRIBUTE_UNUSED; |
ca261cb4 | 627 | HOST_WIDEST_INT a; |
e23c0ba3 | 628 | unsigned int unsignedp; |
ca261cb4 | 629 | unsigned HOST_WIDEST_INT b; |
7f2935c7 | 630 | { |
ca261cb4 KG |
631 | if (b >= HOST_BITS_PER_WIDEST_INT) |
632 | return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1); | |
7f2935c7 | 633 | else if (unsignedp) |
ca261cb4 | 634 | return (unsigned HOST_WIDEST_INT) a >> b; |
7f2935c7 PB |
635 | else |
636 | return a >> b; | |
637 | } | |
638 | \f | |
0f41302f | 639 | /* These priorities are all even, so we can handle associatively. */ |
eba30526 | 640 | #define PAREN_INNER_PRIO 2 |
7f2935c7 PB |
641 | #define COMMA_PRIO 4 |
642 | #define COND_PRIO (COMMA_PRIO+2) | |
643 | #define OROR_PRIO (COND_PRIO+2) | |
644 | #define ANDAND_PRIO (OROR_PRIO+2) | |
645 | #define OR_PRIO (ANDAND_PRIO+2) | |
646 | #define XOR_PRIO (OR_PRIO+2) | |
647 | #define AND_PRIO (XOR_PRIO+2) | |
648 | #define EQUAL_PRIO (AND_PRIO+2) | |
649 | #define LESS_PRIO (EQUAL_PRIO+2) | |
650 | #define SHIFT_PRIO (LESS_PRIO+2) | |
651 | #define PLUS_PRIO (SHIFT_PRIO+2) | |
652 | #define MUL_PRIO (PLUS_PRIO+2) | |
653 | #define UNARY_PRIO (MUL_PRIO+2) | |
654 | #define PAREN_OUTER_PRIO (UNARY_PRIO+2) | |
655 | ||
eba30526 NB |
656 | #define LEFT_OPERAND_REQUIRED 1 |
657 | #define RIGHT_OPERAND_REQUIRED 2 | |
658 | #define HAVE_VALUE 4 | |
659 | #define SIGN_QUALIFIED 8 | |
660 | ||
7f2935c7 PB |
661 | #define COMPARE(OP) \ |
662 | top->unsignedp = 0;\ | |
faa76596 | 663 | top->value = (unsigned1 || unsigned2) \ |
ca261cb4 | 664 | ? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 : (v1 OP v2) |
7f2935c7 PB |
665 | |
666 | /* Parse and evaluate a C expression, reading from PFILE. | |
88ae23e7 | 667 | Returns the truth value of the expression. */ |
7f2935c7 | 668 | |
88ae23e7 | 669 | int |
b0699dad | 670 | _cpp_parse_expr (pfile) |
7f2935c7 PB |
671 | cpp_reader *pfile; |
672 | { | |
673 | /* The implementation is an operator precedence parser, | |
674 | i.e. a bottom-up parser, using a stack for not-yet-reduced tokens. | |
675 | ||
676 | The stack base is 'stack', and the current stack pointer is 'top'. | |
677 | There is a stack element for each operator (only), | |
678 | and the most recently pushed operator is 'top->op'. | |
679 | An operand (value) is stored in the 'value' field of the stack | |
680 | element of the operator that precedes it. | |
681 | In that case the 'flags' field has the HAVE_VALUE flag set. */ | |
682 | ||
683 | #define INIT_STACK_SIZE 20 | |
684 | struct operation init_stack[INIT_STACK_SIZE]; | |
685 | struct operation *stack = init_stack; | |
686 | struct operation *limit = stack + INIT_STACK_SIZE; | |
687 | register struct operation *top = stack; | |
e23c0ba3 | 688 | unsigned int lprio, rprio = 0; |
a4a315ef | 689 | int skip_evaluation = 0; |
45b966db ZW |
690 | long old_written = CPP_WRITTEN (pfile); |
691 | int result; | |
7f2935c7 | 692 | |
45b966db | 693 | pfile->parsing_if_directive++; |
7f2935c7 PB |
694 | top->rprio = 0; |
695 | top->flags = 0; | |
696 | for (;;) | |
697 | { | |
698 | struct operation op; | |
e23c0ba3 | 699 | U_CHAR flags = 0; |
7f2935c7 PB |
700 | |
701 | /* Read a token */ | |
9ee70313 | 702 | op = lex (pfile, skip_evaluation); |
7f2935c7 PB |
703 | |
704 | /* See if the token is an operand, in which case go to set_value. | |
705 | If the token is an operator, figure out its left and right | |
0f41302f | 706 | priorities, and then goto maybe_reduce. */ |
7f2935c7 PB |
707 | |
708 | switch (op.op) | |
709 | { | |
710 | case NAME: | |
b0699dad | 711 | cpp_ice (pfile, "lex returns a NAME"); |
34ca9541 | 712 | goto syntax_error; |
9ee70313 NB |
713 | case ERROR: |
714 | goto syntax_error; | |
715 | default: | |
716 | cpp_error (pfile, "invalid character in #if"); | |
717 | goto syntax_error; | |
718 | ||
7f2935c7 | 719 | case INT: case CHAR: |
9ee70313 NB |
720 | push_immediate: |
721 | /* Push a value onto the stack. */ | |
cf4ed945 ZW |
722 | if (top->flags & HAVE_VALUE) |
723 | { | |
9ee70313 NB |
724 | cpp_error (pfile, "suspected missing binary operator in #if"); |
725 | goto syntax_error; | |
cf4ed945 | 726 | } |
9ee70313 NB |
727 | top->value = op.value; |
728 | top->unsignedp = op.unsignedp; | |
729 | top->flags |= HAVE_VALUE; | |
730 | continue; | |
731 | ||
732 | case '+': case '-': | |
733 | lprio = PLUS_PRIO; | |
734 | if (top->flags & HAVE_VALUE) | |
735 | break; | |
eba30526 NB |
736 | if (top->flags & SIGN_QUALIFIED) |
737 | { | |
738 | cpp_error (pfile, "more than one sign operator given"); | |
739 | goto syntax_error; | |
740 | } | |
741 | flags = SIGN_QUALIFIED; | |
cf4ed945 | 742 | /* else fall through */ |
7f2935c7 | 743 | case '!': case '~': |
eba30526 | 744 | flags |= RIGHT_OPERAND_REQUIRED; |
7f2935c7 | 745 | rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce; |
9ee70313 | 746 | |
7f2935c7 | 747 | case '*': case '/': case '%': |
9ee70313 | 748 | lprio = MUL_PRIO; break; |
7f2935c7 | 749 | case '<': case '>': case LEQ: case GEQ: |
9ee70313 | 750 | lprio = LESS_PRIO; break; |
7f2935c7 | 751 | case EQUAL: case NOTEQUAL: |
9ee70313 | 752 | lprio = EQUAL_PRIO; break; |
7f2935c7 | 753 | case LSH: case RSH: |
9ee70313 NB |
754 | lprio = SHIFT_PRIO; break; |
755 | case '&': lprio = AND_PRIO; break; | |
756 | case '^': lprio = XOR_PRIO; break; | |
757 | case '|': lprio = OR_PRIO; break; | |
758 | case ANDAND: lprio = ANDAND_PRIO; break; | |
759 | case OROR: lprio = OROR_PRIO; break; | |
7f2935c7 | 760 | case ',': |
9ee70313 | 761 | lprio = COMMA_PRIO; break; |
7f2935c7 | 762 | case '(': |
9ee70313 NB |
763 | lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO + 1; |
764 | goto skip_reduction; | |
7f2935c7 PB |
765 | case ')': |
766 | lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO; | |
eba30526 | 767 | flags = HAVE_VALUE; /* At least, we will have after reduction. */ |
7f2935c7 PB |
768 | goto maybe_reduce; |
769 | case ':': | |
eba30526 | 770 | lprio = COND_PRIO; rprio = COND_PRIO + 1; |
7f2935c7 PB |
771 | goto maybe_reduce; |
772 | case '?': | |
eba30526 | 773 | lprio = COND_PRIO; rprio = COND_PRIO; |
7f2935c7 | 774 | goto maybe_reduce; |
9ee70313 NB |
775 | case 0: |
776 | lprio = 0; goto maybe_reduce; | |
7f2935c7 | 777 | } |
7f2935c7 | 778 | |
9ee70313 | 779 | /* Binary operation. */ |
cf4ed945 ZW |
780 | flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED; |
781 | rprio = lprio + 1; | |
782 | ||
7f2935c7 | 783 | maybe_reduce: |
0f41302f | 784 | /* Push an operator, and check if we can reduce now. */ |
7f2935c7 PB |
785 | while (top->rprio > lprio) |
786 | { | |
ca261cb4 | 787 | HOST_WIDEST_INT v1 = top[-1].value, v2 = top[0].value; |
e23c0ba3 ZW |
788 | unsigned int unsigned1 = top[-1].unsignedp; |
789 | unsigned int unsigned2 = top[0].unsignedp; | |
7f2935c7 PB |
790 | top--; |
791 | if ((top[1].flags & LEFT_OPERAND_REQUIRED) | |
792 | && ! (top[0].flags & HAVE_VALUE)) | |
793 | { | |
794 | cpp_error (pfile, "syntax error - missing left operand"); | |
795 | goto syntax_error; | |
796 | } | |
797 | if ((top[1].flags & RIGHT_OPERAND_REQUIRED) | |
798 | && ! (top[1].flags & HAVE_VALUE)) | |
799 | { | |
800 | cpp_error (pfile, "syntax error - missing right operand"); | |
801 | goto syntax_error; | |
802 | } | |
803 | /* top[0].value = (top[1].op)(v1, v2);*/ | |
804 | switch (top[1].op) | |
805 | { | |
806 | case '+': | |
807 | if (!(top->flags & HAVE_VALUE)) | |
808 | { /* Unary '+' */ | |
809 | top->value = v2; | |
810 | top->unsignedp = unsigned2; | |
811 | top->flags |= HAVE_VALUE; | |
812 | } | |
813 | else | |
814 | { | |
815 | top->value = v1 + v2; | |
816 | top->unsignedp = unsigned1 || unsigned2; | |
a4a315ef | 817 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
818 | && ! possible_sum_sign (v1, v2, top->value)) |
819 | integer_overflow (pfile); | |
820 | } | |
821 | break; | |
822 | case '-': | |
52529158 | 823 | if (!(top->flags & HAVE_VALUE)) |
7f2935c7 PB |
824 | { /* Unary '-' */ |
825 | top->value = - v2; | |
52529158 | 826 | if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2) |
7f2935c7 PB |
827 | integer_overflow (pfile); |
828 | top->unsignedp = unsigned2; | |
829 | top->flags |= HAVE_VALUE; | |
830 | } | |
831 | else | |
832 | { /* Binary '-' */ | |
833 | top->value = v1 - v2; | |
834 | top->unsignedp = unsigned1 || unsigned2; | |
52529158 | 835 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
836 | && ! possible_sum_sign (top->value, v2, v1)) |
837 | integer_overflow (pfile); | |
838 | } | |
839 | break; | |
840 | case '*': | |
841 | top->unsignedp = unsigned1 || unsigned2; | |
842 | if (top->unsignedp) | |
ca261cb4 | 843 | top->value = (unsigned HOST_WIDEST_INT) v1 * v2; |
a4a315ef | 844 | else if (!skip_evaluation) |
7f2935c7 PB |
845 | { |
846 | top->value = v1 * v2; | |
847 | if (v1 | |
848 | && (top->value / v1 != v2 | |
849 | || (top->value & v1 & v2) < 0)) | |
850 | integer_overflow (pfile); | |
851 | } | |
852 | break; | |
853 | case '/': | |
a4a315ef PB |
854 | if (skip_evaluation) |
855 | break; | |
7f2935c7 PB |
856 | if (v2 == 0) |
857 | { | |
858 | cpp_error (pfile, "division by zero in #if"); | |
859 | v2 = 1; | |
860 | } | |
861 | top->unsignedp = unsigned1 || unsigned2; | |
862 | if (top->unsignedp) | |
ca261cb4 | 863 | top->value = (unsigned HOST_WIDEST_INT) v1 / v2; |
7f2935c7 PB |
864 | else |
865 | { | |
866 | top->value = v1 / v2; | |
867 | if ((top->value & v1 & v2) < 0) | |
868 | integer_overflow (pfile); | |
869 | } | |
870 | break; | |
871 | case '%': | |
a4a315ef PB |
872 | if (skip_evaluation) |
873 | break; | |
7f2935c7 PB |
874 | if (v2 == 0) |
875 | { | |
876 | cpp_error (pfile, "division by zero in #if"); | |
877 | v2 = 1; | |
878 | } | |
879 | top->unsignedp = unsigned1 || unsigned2; | |
880 | if (top->unsignedp) | |
ca261cb4 | 881 | top->value = (unsigned HOST_WIDEST_INT) v1 % v2; |
7f2935c7 PB |
882 | else |
883 | top->value = v1 % v2; | |
884 | break; | |
885 | case '!': | |
886 | if (top->flags & HAVE_VALUE) | |
887 | { | |
888 | cpp_error (pfile, "syntax error"); | |
889 | goto syntax_error; | |
890 | } | |
891 | top->value = ! v2; | |
892 | top->unsignedp = 0; | |
893 | top->flags |= HAVE_VALUE; | |
894 | break; | |
895 | case '~': | |
896 | if (top->flags & HAVE_VALUE) | |
897 | { | |
898 | cpp_error (pfile, "syntax error"); | |
899 | goto syntax_error; | |
900 | } | |
901 | top->value = ~ v2; | |
902 | top->unsignedp = unsigned2; | |
903 | top->flags |= HAVE_VALUE; | |
904 | break; | |
905 | case '<': COMPARE(<); break; | |
906 | case '>': COMPARE(>); break; | |
907 | case LEQ: COMPARE(<=); break; | |
908 | case GEQ: COMPARE(>=); break; | |
909 | case EQUAL: | |
910 | top->value = (v1 == v2); | |
911 | top->unsignedp = 0; | |
912 | break; | |
913 | case NOTEQUAL: | |
914 | top->value = (v1 != v2); | |
915 | top->unsignedp = 0; | |
916 | break; | |
917 | case LSH: | |
a4a315ef PB |
918 | if (skip_evaluation) |
919 | break; | |
7f2935c7 PB |
920 | top->unsignedp = unsigned1; |
921 | if (v2 < 0 && ! unsigned2) | |
922 | top->value = right_shift (pfile, v1, unsigned1, -v2); | |
923 | else | |
924 | top->value = left_shift (pfile, v1, unsigned1, v2); | |
925 | break; | |
926 | case RSH: | |
a4a315ef PB |
927 | if (skip_evaluation) |
928 | break; | |
7f2935c7 PB |
929 | top->unsignedp = unsigned1; |
930 | if (v2 < 0 && ! unsigned2) | |
931 | top->value = left_shift (pfile, v1, unsigned1, -v2); | |
932 | else | |
933 | top->value = right_shift (pfile, v1, unsigned1, v2); | |
934 | break; | |
935 | #define LOGICAL(OP) \ | |
936 | top->value = v1 OP v2;\ | |
937 | top->unsignedp = unsigned1 || unsigned2; | |
938 | case '&': LOGICAL(&); break; | |
939 | case '^': LOGICAL(^); break; | |
940 | case '|': LOGICAL(|); break; | |
941 | case ANDAND: | |
a4a315ef PB |
942 | top->value = v1 && v2; top->unsignedp = 0; |
943 | if (!v1) skip_evaluation--; | |
944 | break; | |
7f2935c7 | 945 | case OROR: |
a4a315ef PB |
946 | top->value = v1 || v2; top->unsignedp = 0; |
947 | if (v1) skip_evaluation--; | |
948 | break; | |
7f2935c7 PB |
949 | case ',': |
950 | if (CPP_PEDANTIC (pfile)) | |
951 | cpp_pedwarn (pfile, "comma operator in operand of `#if'"); | |
952 | top->value = v2; | |
953 | top->unsignedp = unsigned2; | |
954 | break; | |
9ee70313 | 955 | case '?': |
7f2935c7 PB |
956 | cpp_error (pfile, "syntax error in #if"); |
957 | goto syntax_error; | |
958 | case ':': | |
959 | if (top[0].op != '?') | |
960 | { | |
961 | cpp_error (pfile, | |
962 | "syntax error ':' without preceding '?'"); | |
963 | goto syntax_error; | |
964 | } | |
965 | else if (! (top[1].flags & HAVE_VALUE) | |
966 | || !(top[-1].flags & HAVE_VALUE) | |
967 | || !(top[0].flags & HAVE_VALUE)) | |
968 | { | |
969 | cpp_error (pfile, "bad syntax for ?: operator"); | |
970 | goto syntax_error; | |
971 | } | |
972 | else | |
973 | { | |
974 | top--; | |
a4a315ef | 975 | if (top->value) skip_evaluation--; |
7f2935c7 PB |
976 | top->value = top->value ? v1 : v2; |
977 | top->unsignedp = unsigned1 || unsigned2; | |
978 | } | |
979 | break; | |
980 | case ')': | |
9ee70313 NB |
981 | cpp_error (pfile, "missing '(' in expression"); |
982 | goto syntax_error; | |
983 | case '(': | |
984 | if (op.op != ')') | |
7f2935c7 | 985 | { |
9ee70313 | 986 | cpp_error (pfile, "missing ')' in expression"); |
7f2935c7 PB |
987 | goto syntax_error; |
988 | } | |
9ee70313 | 989 | if (!(top[1].flags & HAVE_VALUE)) |
7f2935c7 | 990 | { |
9ee70313 NB |
991 | cpp_error (pfile, "void expression between '(' and ')'"); |
992 | goto syntax_error; | |
7f2935c7 | 993 | } |
9ee70313 NB |
994 | op.value = v2; |
995 | op.unsignedp = unsigned2; | |
996 | goto push_immediate; | |
7f2935c7 | 997 | default: |
a9ae4483 ZW |
998 | if (ISGRAPH (top[1].op)) |
999 | cpp_error (pfile, "unimplemented operator '%c'\n", top[1].op); | |
1000 | else | |
1001 | cpp_error (pfile, "unimplemented operator '\\%03o'\n", | |
1002 | top[1].op); | |
7f2935c7 PB |
1003 | } |
1004 | } | |
9ee70313 | 1005 | |
7f2935c7 | 1006 | if (op.op == 0) |
9ee70313 NB |
1007 | break; |
1008 | ||
1009 | skip_reduction: | |
0f41302f | 1010 | /* Check for and handle stack overflow. */ |
9ee70313 | 1011 | top++; |
7f2935c7 PB |
1012 | if (top == limit) |
1013 | { | |
1014 | struct operation *new_stack; | |
0f41302f | 1015 | int old_size = (char *) limit - (char *) stack; |
7f2935c7 PB |
1016 | int new_size = 2 * old_size; |
1017 | if (stack != init_stack) | |
0f41302f | 1018 | new_stack = (struct operation *) xrealloc (stack, new_size); |
7f2935c7 PB |
1019 | else |
1020 | { | |
0f41302f | 1021 | new_stack = (struct operation *) xmalloc (new_size); |
b0699dad | 1022 | memcpy (new_stack, stack, old_size); |
7f2935c7 PB |
1023 | } |
1024 | stack = new_stack; | |
0f41302f MS |
1025 | top = (struct operation *) ((char *) new_stack + old_size); |
1026 | limit = (struct operation *) ((char *) new_stack + new_size); | |
7f2935c7 PB |
1027 | } |
1028 | ||
1029 | top->flags = flags; | |
1030 | top->rprio = rprio; | |
1031 | top->op = op.op; | |
9ee70313 NB |
1032 | |
1033 | /* Handle short circuiting. */ | |
a4a315ef PB |
1034 | if ((op.op == OROR && top[-1].value) |
1035 | || (op.op == ANDAND && !top[-1].value) | |
1036 | || (op.op == '?' && !top[-1].value)) | |
1037 | { | |
1038 | skip_evaluation++; | |
1039 | } | |
1040 | else if (op.op == ':') | |
1041 | { | |
1042 | if (top[-2].value) /* Was condition true? */ | |
1043 | skip_evaluation++; | |
1044 | else | |
1045 | skip_evaluation--; | |
1046 | } | |
7f2935c7 | 1047 | } |
9ee70313 NB |
1048 | |
1049 | if (top != stack) | |
1050 | cpp_ice (pfile, "unbalanced stack in #if expression"); | |
1051 | if (!(top->flags & HAVE_VALUE)) | |
1052 | cpp_error (pfile, "#if with no expression"); | |
1053 | result = (top->value != 0); | |
1054 | ||
1055 | tidy_up: | |
45b966db ZW |
1056 | pfile->parsing_if_directive--; |
1057 | CPP_SET_WRITTEN (pfile, old_written); | |
7f2935c7 PB |
1058 | if (stack != init_stack) |
1059 | free (stack); | |
45b966db | 1060 | return result; |
9ee70313 NB |
1061 | |
1062 | syntax_error: | |
1063 | _cpp_skip_rest_of_line (pfile); | |
1064 | result = 0; | |
1065 | goto tidy_up; | |
7f2935c7 | 1066 | } |