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7f2935c7 PB |
1 | /* Parse C expressions for CCCP. |
2 | Copyright (C) 1987, 1992, 1994, 1995 Free Software Foundation. | |
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 | ||
23 | Written by Per Bothner 1994. */ | |
24 | ||
25 | /* Parse a C expression from text in a string */ | |
26 | ||
27 | #include "config.h" | |
28 | #include "cpplib.h" | |
29 | ||
52112c7c RK |
30 | extern char *xmalloc PARAMS ((unsigned)); |
31 | extern char *xrealloc PARAMS ((char *, unsigned)); | |
32 | ||
7f2935c7 PB |
33 | #ifdef MULTIBYTE_CHARS |
34 | #include <stdlib.h> | |
35 | #include <locale.h> | |
36 | #endif | |
37 | ||
38 | #include <stdio.h> | |
39 | ||
40 | /* This is used for communicating lists of keywords with cccp.c. */ | |
41 | struct arglist { | |
42 | struct arglist *next; | |
43 | U_CHAR *name; | |
44 | int length; | |
45 | int argno; | |
46 | }; | |
47 | ||
48 | /* Define a generic NULL if one hasn't already been defined. */ | |
49 | ||
50 | #ifndef NULL | |
51 | #define NULL 0 | |
52 | #endif | |
53 | ||
54 | #ifndef GENERIC_PTR | |
55 | #if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__) | |
56 | #define GENERIC_PTR void * | |
57 | #else | |
58 | #define GENERIC_PTR char * | |
59 | #endif | |
60 | #endif | |
61 | ||
62 | #ifndef NULL_PTR | |
63 | #define NULL_PTR ((GENERIC_PTR)0) | |
64 | #endif | |
65 | ||
66 | extern char *xmalloc (); | |
67 | ||
68 | #ifndef CHAR_TYPE_SIZE | |
69 | #define CHAR_TYPE_SIZE BITS_PER_UNIT | |
70 | #endif | |
71 | ||
72 | #ifndef INT_TYPE_SIZE | |
73 | #define INT_TYPE_SIZE BITS_PER_WORD | |
74 | #endif | |
75 | ||
76 | #ifndef LONG_TYPE_SIZE | |
77 | #define LONG_TYPE_SIZE BITS_PER_WORD | |
78 | #endif | |
79 | ||
80 | #ifndef WCHAR_TYPE_SIZE | |
81 | #define WCHAR_TYPE_SIZE INT_TYPE_SIZE | |
82 | #endif | |
83 | ||
84 | #ifndef MAX_CHAR_TYPE_SIZE | |
85 | #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE | |
86 | #endif | |
87 | ||
88 | #ifndef MAX_INT_TYPE_SIZE | |
89 | #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE | |
90 | #endif | |
91 | ||
92 | #ifndef MAX_LONG_TYPE_SIZE | |
93 | #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE | |
94 | #endif | |
95 | ||
96 | #ifndef MAX_WCHAR_TYPE_SIZE | |
97 | #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE | |
98 | #endif | |
99 | ||
100 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a | |
101 | number with SUM's sign, where A, B, and SUM are all C integers. */ | |
102 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) | |
103 | ||
104 | static void integer_overflow (); | |
105 | static long left_shift (); | |
106 | static long right_shift (); | |
107 | ||
108 | #define ERROR 299 | |
109 | #define OROR 300 | |
110 | #define ANDAND 301 | |
111 | #define EQUAL 302 | |
112 | #define NOTEQUAL 303 | |
113 | #define LEQ 304 | |
114 | #define GEQ 305 | |
115 | #define LSH 306 | |
116 | #define RSH 307 | |
117 | #define NAME 308 | |
118 | #define INT 309 | |
119 | #define CHAR 310 | |
120 | ||
121 | #define LEFT_OPERAND_REQUIRED 1 | |
122 | #define RIGHT_OPERAND_REQUIRED 2 | |
123 | #define HAVE_VALUE 4 | |
a4a315ef PB |
124 | /* SKIP_OPERAND is set for '&&' '||' '?' and ':' when the |
125 | following operand should be short-circuited instead of evaluated. */ | |
126 | #define SKIP_OPERAND 8 | |
127 | /*#define UNSIGNEDP 16*/ | |
7f2935c7 | 128 | |
7e127823 PB |
129 | #ifndef HOST_BITS_PER_WIDE_INT |
130 | ||
131 | #if HOST_BITS_PER_LONG > HOST_BITS_PER_INT | |
132 | #define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_LONG | |
133 | #define HOST_WIDE_INT long | |
134 | #else | |
135 | #define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_INT | |
136 | #define HOST_WIDE_INT int | |
137 | #endif | |
138 | ||
139 | #endif | |
140 | ||
7f2935c7 PB |
141 | struct operation { |
142 | short op; | |
143 | char rprio; /* Priority of op (relative to it right operand). */ | |
144 | char flags; | |
145 | char unsignedp; /* true if value should be treated as unsigned */ | |
7e127823 | 146 | HOST_WIDE_INT value; /* The value logically "right" of op. */ |
7f2935c7 PB |
147 | }; |
148 | \f | |
149 | /* Take care of parsing a number (anything that starts with a digit). | |
150 | LEN is the number of characters in it. */ | |
151 | ||
152 | /* maybe needs to actually deal with floating point numbers */ | |
153 | ||
154 | struct operation | |
155 | parse_number (pfile, start, olen) | |
156 | cpp_reader *pfile; | |
157 | char *start; | |
158 | int olen; | |
159 | { | |
160 | struct operation op; | |
161 | register char *p = start; | |
162 | register int c; | |
163 | register unsigned long n = 0, nd, ULONG_MAX_over_base; | |
164 | register int base = 10; | |
165 | register int len = olen; | |
166 | register int overflow = 0; | |
167 | register int digit, largest_digit = 0; | |
168 | int spec_long = 0; | |
169 | ||
170 | op.unsignedp = 0; | |
171 | ||
172 | for (c = 0; c < len; c++) | |
173 | if (p[c] == '.') { | |
174 | /* It's a float since it contains a point. */ | |
175 | cpp_error (pfile, | |
176 | "floating point numbers not allowed in #if expressions"); | |
177 | op.op = ERROR; | |
178 | return op; | |
179 | } | |
180 | ||
181 | if (len >= 3 && (!strncmp (p, "0x", 2) || !strncmp (p, "0X", 2))) { | |
182 | p += 2; | |
183 | base = 16; | |
184 | len -= 2; | |
185 | } | |
186 | else if (*p == '0') | |
187 | base = 8; | |
188 | ||
8f4686fa | 189 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
7f2935c7 | 190 | ULONG_MAX_over_base = ((unsigned long) -1) / ((unsigned long) base); |
7f2935c7 PB |
191 | |
192 | for (; len > 0; len--) { | |
193 | c = *p++; | |
194 | ||
195 | if (c >= '0' && c <= '9') | |
196 | digit = c - '0'; | |
197 | else if (base == 16 && c >= 'a' && c <= 'f') | |
198 | digit = c - 'a' + 10; | |
199 | else if (base == 16 && c >= 'A' && c <= 'F') | |
200 | digit = c - 'A' + 10; | |
201 | else { | |
202 | /* `l' means long, and `u' means unsigned. */ | |
203 | while (1) { | |
204 | if (c == 'l' || c == 'L') | |
205 | { | |
206 | if (spec_long) | |
207 | cpp_error (pfile, "two `l's in integer constant"); | |
208 | spec_long = 1; | |
209 | } | |
210 | else if (c == 'u' || c == 'U') | |
211 | { | |
212 | if (op.unsignedp) | |
213 | cpp_error (pfile, "two `u's in integer constant"); | |
214 | op.unsignedp = 1; | |
215 | } | |
216 | else | |
217 | break; | |
218 | ||
219 | if (--len == 0) | |
220 | break; | |
221 | c = *p++; | |
222 | } | |
223 | /* Don't look for any more digits after the suffixes. */ | |
224 | break; | |
225 | } | |
226 | if (largest_digit < digit) | |
227 | largest_digit = digit; | |
228 | nd = n * base + digit; | |
229 | overflow |= ULONG_MAX_over_base < n | nd < n; | |
230 | n = nd; | |
231 | } | |
232 | ||
233 | if (len != 0) | |
234 | { | |
235 | cpp_error (pfile, "Invalid number in #if expression"); | |
236 | op.op = ERROR; | |
237 | return op; | |
238 | } | |
239 | ||
240 | if (base <= largest_digit) | |
241 | cpp_warning (pfile, "integer constant contains digits beyond the radix"); | |
242 | ||
243 | if (overflow) | |
244 | cpp_warning (pfile, "integer constant out of range"); | |
245 | ||
246 | /* If too big to be signed, consider it unsigned. */ | |
247 | if ((long) n < 0 && ! op.unsignedp) | |
248 | { | |
249 | if (base == 10) | |
250 | cpp_warning (pfile, "integer constant is so large that it is unsigned"); | |
251 | op.unsignedp = 1; | |
252 | } | |
253 | ||
254 | op.value = n; | |
255 | op.op = INT; | |
256 | return op; | |
257 | } | |
258 | ||
259 | struct token { | |
260 | char *operator; | |
261 | int token; | |
262 | }; | |
263 | ||
264 | static struct token tokentab2[] = { | |
265 | {"&&", ANDAND}, | |
266 | {"||", OROR}, | |
267 | {"<<", LSH}, | |
268 | {">>", RSH}, | |
269 | {"==", EQUAL}, | |
270 | {"!=", NOTEQUAL}, | |
271 | {"<=", LEQ}, | |
272 | {">=", GEQ}, | |
273 | {"++", ERROR}, | |
274 | {"--", ERROR}, | |
275 | {NULL, ERROR} | |
276 | }; | |
277 | ||
278 | /* Read one token. */ | |
279 | ||
280 | struct operation | |
281 | cpp_lex (pfile) | |
282 | cpp_reader *pfile; | |
283 | { | |
284 | register int c; | |
285 | register int namelen; | |
286 | register struct token *toktab; | |
287 | enum cpp_token token; | |
288 | struct operation op; | |
289 | U_CHAR *tok_start, *tok_end; | |
290 | int old_written; | |
291 | ||
292 | retry: | |
293 | ||
1519594d PB |
294 | old_written = CPP_WRITTEN (pfile); |
295 | cpp_skip_hspace (pfile); | |
7f2935c7 PB |
296 | c = CPP_BUF_PEEK (CPP_BUFFER (pfile)); |
297 | if (c == '#') | |
298 | return parse_number (pfile, | |
299 | cpp_read_check_assertion (pfile) ? "1" : "0", 1); | |
300 | ||
7f2935c7 PB |
301 | if (c == '\n') |
302 | { | |
303 | op.op = 0; | |
304 | return op; | |
305 | } | |
306 | ||
307 | token = cpp_get_token (pfile); | |
308 | tok_start = pfile->token_buffer + old_written; | |
309 | tok_end = CPP_PWRITTEN (pfile); | |
310 | pfile->limit = tok_start; | |
311 | switch (token) | |
312 | { | |
313 | case CPP_EOF: /* Should not happen ... */ | |
a4a315ef | 314 | case CPP_VSPACE: |
7f2935c7 PB |
315 | op.op = 0; |
316 | return op; | |
7f2935c7 PB |
317 | case CPP_POP: |
318 | if (CPP_BUFFER (pfile)->fname != NULL) | |
319 | { | |
320 | op.op = 0; | |
321 | return op; | |
322 | } | |
a4a315ef | 323 | cpp_pop_buffer (pfile); |
7f2935c7 PB |
324 | goto retry; |
325 | case CPP_HSPACE: case CPP_COMMENT: | |
326 | goto retry; | |
327 | case CPP_NUMBER: | |
328 | return parse_number (pfile, tok_start, tok_end - tok_start); | |
329 | case CPP_STRING: | |
330 | cpp_error (pfile, "string constants not allowed in #if expressions"); | |
331 | op.op = ERROR; | |
332 | return op; | |
333 | case CPP_CHAR: | |
334 | /* This code for reading a character constant | |
335 | handles multicharacter constants and wide characters. | |
336 | It is mostly copied from c-lex.c. */ | |
337 | { | |
338 | register int result = 0; | |
339 | register num_chars = 0; | |
340 | unsigned width = MAX_CHAR_TYPE_SIZE; | |
341 | int wide_flag = 0; | |
342 | int max_chars; | |
343 | U_CHAR *ptr = tok_start; | |
344 | #ifdef MULTIBYTE_CHARS | |
345 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + MB_CUR_MAX]; | |
346 | #else | |
347 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + 1]; | |
348 | #endif | |
349 | ||
350 | if (*ptr == 'L') | |
351 | { | |
352 | ptr++; | |
353 | wide_flag = 1; | |
354 | width = MAX_WCHAR_TYPE_SIZE; | |
355 | #ifdef MULTIBYTE_CHARS | |
356 | max_chars = MB_CUR_MAX; | |
357 | #else | |
358 | max_chars = 1; | |
359 | #endif | |
360 | } | |
361 | else | |
362 | max_chars = MAX_LONG_TYPE_SIZE / width; | |
363 | ||
ae17bedb RK |
364 | ++ptr; |
365 | while (ptr < tok_end && ((c = *ptr++) != '\'')) | |
7f2935c7 | 366 | { |
7f2935c7 PB |
367 | if (c == '\\') |
368 | { | |
369 | c = cpp_parse_escape (pfile, &ptr); | |
370 | if (width < HOST_BITS_PER_INT | |
371 | && (unsigned) c >= (1 << width)) | |
372 | cpp_pedwarn (pfile, | |
373 | "escape sequence out of range for character"); | |
374 | } | |
375 | ||
376 | num_chars++; | |
377 | ||
378 | /* Merge character into result; ignore excess chars. */ | |
379 | if (num_chars < max_chars + 1) | |
380 | { | |
381 | if (width < HOST_BITS_PER_INT) | |
382 | result = (result << width) | (c & ((1 << width) - 1)); | |
383 | else | |
384 | result = c; | |
385 | token_buffer[num_chars - 1] = c; | |
386 | } | |
387 | } | |
388 | ||
389 | token_buffer[num_chars] = 0; | |
390 | ||
391 | if (c != '\'') | |
392 | cpp_error (pfile, "malformatted character constant"); | |
393 | else if (num_chars == 0) | |
394 | cpp_error (pfile, "empty character constant"); | |
395 | else if (num_chars > max_chars) | |
396 | { | |
397 | num_chars = max_chars; | |
398 | cpp_error (pfile, "character constant too long"); | |
399 | } | |
400 | else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile)) | |
401 | cpp_warning (pfile, "multi-character character constant"); | |
402 | ||
403 | /* If char type is signed, sign-extend the constant. */ | |
404 | if (! wide_flag) | |
405 | { | |
406 | int num_bits = num_chars * width; | |
407 | ||
408 | if (cpp_lookup (pfile, "__CHAR_UNSIGNED__", | |
409 | sizeof ("__CHAR_UNSIGNED__")-1, -1) | |
410 | || ((result >> (num_bits - 1)) & 1) == 0) | |
411 | op.value | |
412 | = result & ((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); | |
413 | else | |
414 | op.value | |
415 | = result | ~((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); | |
416 | } | |
417 | else | |
418 | { | |
419 | #ifdef MULTIBYTE_CHARS | |
420 | /* Set the initial shift state and convert the next sequence. */ | |
421 | result = 0; | |
422 | /* In all locales L'\0' is zero and mbtowc will return zero, | |
423 | so don't use it. */ | |
424 | if (num_chars > 1 | |
425 | || (num_chars == 1 && token_buffer[0] != '\0')) | |
426 | { | |
427 | wchar_t wc; | |
428 | (void) mbtowc (NULL_PTR, NULL_PTR, 0); | |
429 | if (mbtowc (& wc, token_buffer, num_chars) == num_chars) | |
430 | result = wc; | |
431 | else | |
432 | cpp_warning (pfile,"Ignoring invalid multibyte character"); | |
433 | } | |
434 | #endif | |
435 | op.value = result; | |
436 | } | |
437 | } | |
438 | ||
439 | /* This is always a signed type. */ | |
440 | op.unsignedp = 0; | |
441 | op.op = CHAR; | |
442 | ||
443 | return op; | |
444 | ||
445 | case CPP_NAME: | |
446 | return parse_number (pfile, "0", 0); | |
447 | ||
448 | case CPP_OTHER: | |
449 | /* See if it is a special token of length 2. */ | |
450 | if (tok_start + 2 == tok_end) | |
451 | { | |
452 | for (toktab = tokentab2; toktab->operator != NULL; toktab++) | |
453 | if (tok_start[0] == toktab->operator[0] | |
454 | && tok_start[1] == toktab->operator[1]) | |
455 | break; | |
456 | if (toktab->token == ERROR) | |
457 | { | |
458 | char *buf = (char *) alloca (40); | |
459 | sprintf (buf, "`%s' not allowed in operand of `#if'", tok_start); | |
460 | cpp_error (pfile, buf); | |
461 | } | |
462 | op.op = toktab->token; | |
463 | return op; | |
464 | } | |
465 | /* fall through */ | |
466 | default: | |
467 | op.op = *tok_start; | |
468 | return op; | |
469 | } | |
470 | } | |
471 | ||
472 | ||
473 | /* Parse a C escape sequence. STRING_PTR points to a variable | |
474 | containing a pointer to the string to parse. That pointer | |
475 | is updated past the characters we use. The value of the | |
476 | escape sequence is returned. | |
477 | ||
478 | A negative value means the sequence \ newline was seen, | |
479 | which is supposed to be equivalent to nothing at all. | |
480 | ||
481 | If \ is followed by a null character, we return a negative | |
482 | value and leave the string pointer pointing at the null character. | |
483 | ||
484 | If \ is followed by 000, we return 0 and leave the string pointer | |
485 | after the zeros. A value of 0 does not mean end of string. */ | |
486 | ||
487 | int | |
488 | cpp_parse_escape (pfile, string_ptr) | |
489 | cpp_reader *pfile; | |
490 | char **string_ptr; | |
491 | { | |
492 | register int c = *(*string_ptr)++; | |
493 | switch (c) | |
494 | { | |
495 | case 'a': | |
496 | return TARGET_BELL; | |
497 | case 'b': | |
498 | return TARGET_BS; | |
499 | case 'e': | |
500 | case 'E': | |
501 | if (CPP_PEDANTIC (pfile)) | |
502 | cpp_pedwarn (pfile, "non-ANSI-standard escape sequence, `\\%c'", c); | |
503 | return 033; | |
504 | case 'f': | |
505 | return TARGET_FF; | |
506 | case 'n': | |
507 | return TARGET_NEWLINE; | |
508 | case 'r': | |
509 | return TARGET_CR; | |
510 | case 't': | |
511 | return TARGET_TAB; | |
512 | case 'v': | |
513 | return TARGET_VT; | |
514 | case '\n': | |
515 | return -2; | |
516 | case 0: | |
517 | (*string_ptr)--; | |
518 | return 0; | |
519 | ||
520 | case '0': | |
521 | case '1': | |
522 | case '2': | |
523 | case '3': | |
524 | case '4': | |
525 | case '5': | |
526 | case '6': | |
527 | case '7': | |
528 | { | |
529 | register int i = c - '0'; | |
530 | register int count = 0; | |
531 | while (++count < 3) | |
532 | { | |
533 | c = *(*string_ptr)++; | |
534 | if (c >= '0' && c <= '7') | |
535 | i = (i << 3) + c - '0'; | |
536 | else | |
537 | { | |
538 | (*string_ptr)--; | |
539 | break; | |
540 | } | |
541 | } | |
542 | if ((i & ~((1 << MAX_CHAR_TYPE_SIZE) - 1)) != 0) | |
543 | { | |
544 | i &= (1 << MAX_CHAR_TYPE_SIZE) - 1; | |
545 | cpp_warning (pfile, | |
546 | "octal character constant does not fit in a byte"); | |
547 | } | |
548 | return i; | |
549 | } | |
550 | case 'x': | |
551 | { | |
552 | register unsigned i = 0, overflow = 0, digits_found = 0, digit; | |
553 | for (;;) | |
554 | { | |
555 | c = *(*string_ptr)++; | |
556 | if (c >= '0' && c <= '9') | |
557 | digit = c - '0'; | |
558 | else if (c >= 'a' && c <= 'f') | |
559 | digit = c - 'a' + 10; | |
560 | else if (c >= 'A' && c <= 'F') | |
561 | digit = c - 'A' + 10; | |
562 | else | |
563 | { | |
564 | (*string_ptr)--; | |
565 | break; | |
566 | } | |
567 | overflow |= i ^ (i << 4 >> 4); | |
568 | i = (i << 4) + digit; | |
569 | digits_found = 1; | |
570 | } | |
571 | if (!digits_found) | |
572 | cpp_error (pfile, "\\x used with no following hex digits"); | |
573 | if (overflow | (i & ~((1 << BITS_PER_UNIT) - 1))) | |
574 | { | |
575 | i &= (1 << BITS_PER_UNIT) - 1; | |
576 | cpp_warning (pfile, | |
577 | "hex character constant does not fit in a byte"); | |
578 | } | |
579 | return i; | |
580 | } | |
581 | default: | |
582 | return c; | |
583 | } | |
584 | } | |
585 | ||
586 | static void | |
587 | integer_overflow (pfile) | |
588 | cpp_reader *pfile; | |
589 | { | |
590 | if (CPP_PEDANTIC (pfile)) | |
591 | cpp_pedwarn (pfile, "integer overflow in preprocessor expression"); | |
592 | } | |
593 | ||
594 | static long | |
595 | left_shift (pfile, a, unsignedp, b) | |
596 | cpp_reader *pfile; | |
597 | long a; | |
598 | int unsignedp; | |
599 | unsigned long b; | |
600 | { | |
601 | if (b >= HOST_BITS_PER_LONG) | |
602 | { | |
603 | if (! unsignedp && a != 0) | |
604 | integer_overflow (pfile); | |
605 | return 0; | |
606 | } | |
607 | else if (unsignedp) | |
608 | return (unsigned long) a << b; | |
609 | else | |
610 | { | |
611 | long l = a << b; | |
612 | if (l >> b != a) | |
613 | integer_overflow (pfile); | |
614 | return l; | |
615 | } | |
616 | } | |
617 | ||
618 | static long | |
619 | right_shift (pfile, a, unsignedp, b) | |
620 | cpp_reader *pfile; | |
621 | long a; | |
622 | int unsignedp; | |
623 | unsigned long b; | |
624 | { | |
625 | if (b >= HOST_BITS_PER_LONG) | |
626 | return unsignedp ? 0 : a >> (HOST_BITS_PER_LONG - 1); | |
627 | else if (unsignedp) | |
628 | return (unsigned long) a >> b; | |
629 | else | |
630 | return a >> b; | |
631 | } | |
632 | \f | |
633 | /* These priorities are all even, so we can handle associatively. */ | |
634 | #define PAREN_INNER_PRIO 0 | |
635 | #define COMMA_PRIO 4 | |
636 | #define COND_PRIO (COMMA_PRIO+2) | |
637 | #define OROR_PRIO (COND_PRIO+2) | |
638 | #define ANDAND_PRIO (OROR_PRIO+2) | |
639 | #define OR_PRIO (ANDAND_PRIO+2) | |
640 | #define XOR_PRIO (OR_PRIO+2) | |
641 | #define AND_PRIO (XOR_PRIO+2) | |
642 | #define EQUAL_PRIO (AND_PRIO+2) | |
643 | #define LESS_PRIO (EQUAL_PRIO+2) | |
644 | #define SHIFT_PRIO (LESS_PRIO+2) | |
645 | #define PLUS_PRIO (SHIFT_PRIO+2) | |
646 | #define MUL_PRIO (PLUS_PRIO+2) | |
647 | #define UNARY_PRIO (MUL_PRIO+2) | |
648 | #define PAREN_OUTER_PRIO (UNARY_PRIO+2) | |
649 | ||
650 | #define COMPARE(OP) \ | |
651 | top->unsignedp = 0;\ | |
652 | top->value = (unsigned1 || unsigned2) ? (unsigned long) v1 OP v2 : (v1 OP v2) | |
653 | ||
654 | /* Parse and evaluate a C expression, reading from PFILE. | |
655 | Returns the value of the expression. */ | |
656 | ||
7e127823 | 657 | HOST_WIDE_INT |
7f2935c7 PB |
658 | cpp_parse_expr (pfile) |
659 | cpp_reader *pfile; | |
660 | { | |
661 | /* The implementation is an operator precedence parser, | |
662 | i.e. a bottom-up parser, using a stack for not-yet-reduced tokens. | |
663 | ||
664 | The stack base is 'stack', and the current stack pointer is 'top'. | |
665 | There is a stack element for each operator (only), | |
666 | and the most recently pushed operator is 'top->op'. | |
667 | An operand (value) is stored in the 'value' field of the stack | |
668 | element of the operator that precedes it. | |
669 | In that case the 'flags' field has the HAVE_VALUE flag set. */ | |
670 | ||
671 | #define INIT_STACK_SIZE 20 | |
672 | struct operation init_stack[INIT_STACK_SIZE]; | |
673 | struct operation *stack = init_stack; | |
674 | struct operation *limit = stack + INIT_STACK_SIZE; | |
675 | register struct operation *top = stack; | |
676 | int lprio, rprio; | |
a4a315ef | 677 | int skip_evaluation = 0; |
7f2935c7 PB |
678 | |
679 | top->rprio = 0; | |
680 | top->flags = 0; | |
681 | for (;;) | |
682 | { | |
683 | struct operation op; | |
684 | char flags = 0; | |
685 | ||
686 | /* Read a token */ | |
687 | op = cpp_lex (pfile); | |
688 | ||
689 | /* See if the token is an operand, in which case go to set_value. | |
690 | If the token is an operator, figure out its left and right | |
691 | priorities, and then goto maybe_reduce. */ | |
692 | ||
693 | switch (op.op) | |
694 | { | |
695 | case NAME: | |
696 | top->value = 0, top->unsignedp = 0; | |
697 | goto set_value; | |
698 | case INT: case CHAR: | |
699 | top->value = op.value; | |
700 | top->unsignedp = op.unsignedp; | |
701 | goto set_value; | |
702 | case 0: | |
703 | lprio = 0; goto maybe_reduce; | |
704 | case '+': case '-': | |
705 | /* Is this correct if unary ? FIXME */ | |
706 | flags = RIGHT_OPERAND_REQUIRED; | |
707 | lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce; | |
708 | case '!': case '~': | |
709 | flags = RIGHT_OPERAND_REQUIRED; | |
710 | rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce; | |
711 | case '*': case '/': case '%': | |
712 | lprio = MUL_PRIO; goto binop; | |
713 | case '<': case '>': case LEQ: case GEQ: | |
714 | lprio = LESS_PRIO; goto binop; | |
715 | case EQUAL: case NOTEQUAL: | |
716 | lprio = EQUAL_PRIO; goto binop; | |
717 | case LSH: case RSH: | |
718 | lprio = SHIFT_PRIO; goto binop; | |
719 | case '&': lprio = AND_PRIO; goto binop; | |
720 | case '^': lprio = XOR_PRIO; goto binop; | |
721 | case '|': lprio = OR_PRIO; goto binop; | |
722 | case ANDAND: lprio = ANDAND_PRIO; goto binop; | |
723 | case OROR: lprio = OROR_PRIO; goto binop; | |
724 | case ',': | |
725 | lprio = COMMA_PRIO; goto binop; | |
726 | case '(': | |
727 | lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO; | |
728 | goto maybe_reduce; | |
729 | case ')': | |
730 | lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO; | |
731 | goto maybe_reduce; | |
732 | case ':': | |
733 | lprio = COND_PRIO; rprio = COND_PRIO; | |
734 | goto maybe_reduce; | |
735 | case '?': | |
736 | lprio = COND_PRIO + 1; rprio = COND_PRIO; | |
737 | goto maybe_reduce; | |
738 | binop: | |
739 | flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED; | |
740 | rprio = lprio + 1; | |
741 | goto maybe_reduce; | |
742 | default: | |
743 | cpp_error (pfile, "invalid character in #if"); | |
744 | goto syntax_error; | |
745 | } | |
746 | ||
747 | set_value: | |
748 | /* Push a value onto the stack. */ | |
749 | if (top->flags & HAVE_VALUE) | |
750 | { | |
751 | cpp_error (pfile, "syntax error in #if"); | |
752 | goto syntax_error; | |
753 | } | |
754 | top->flags |= HAVE_VALUE; | |
755 | continue; | |
756 | ||
757 | maybe_reduce: | |
758 | /* Push an operator, and check if we can reduce now. */ | |
759 | while (top->rprio > lprio) | |
760 | { | |
761 | long v1 = top[-1].value, v2 = top[0].value; | |
762 | int unsigned1 = top[-1].unsignedp, unsigned2 = top[0].unsignedp; | |
763 | top--; | |
764 | if ((top[1].flags & LEFT_OPERAND_REQUIRED) | |
765 | && ! (top[0].flags & HAVE_VALUE)) | |
766 | { | |
767 | cpp_error (pfile, "syntax error - missing left operand"); | |
768 | goto syntax_error; | |
769 | } | |
770 | if ((top[1].flags & RIGHT_OPERAND_REQUIRED) | |
771 | && ! (top[1].flags & HAVE_VALUE)) | |
772 | { | |
773 | cpp_error (pfile, "syntax error - missing right operand"); | |
774 | goto syntax_error; | |
775 | } | |
776 | /* top[0].value = (top[1].op)(v1, v2);*/ | |
777 | switch (top[1].op) | |
778 | { | |
779 | case '+': | |
780 | if (!(top->flags & HAVE_VALUE)) | |
781 | { /* Unary '+' */ | |
782 | top->value = v2; | |
783 | top->unsignedp = unsigned2; | |
784 | top->flags |= HAVE_VALUE; | |
785 | } | |
786 | else | |
787 | { | |
788 | top->value = v1 + v2; | |
789 | top->unsignedp = unsigned1 || unsigned2; | |
a4a315ef | 790 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
791 | && ! possible_sum_sign (v1, v2, top->value)) |
792 | integer_overflow (pfile); | |
793 | } | |
794 | break; | |
795 | case '-': | |
a4a315ef PB |
796 | if (skip_evaluation) ; /* do nothing */ |
797 | else if (!(top->flags & HAVE_VALUE)) | |
7f2935c7 PB |
798 | { /* Unary '-' */ |
799 | top->value = - v2; | |
800 | if ((top->value & v2) < 0 && ! unsigned2) | |
801 | integer_overflow (pfile); | |
802 | top->unsignedp = unsigned2; | |
803 | top->flags |= HAVE_VALUE; | |
804 | } | |
805 | else | |
806 | { /* Binary '-' */ | |
807 | top->value = v1 - v2; | |
808 | top->unsignedp = unsigned1 || unsigned2; | |
809 | if (! top->unsignedp | |
810 | && ! possible_sum_sign (top->value, v2, v1)) | |
811 | integer_overflow (pfile); | |
812 | } | |
813 | break; | |
814 | case '*': | |
815 | top->unsignedp = unsigned1 || unsigned2; | |
816 | if (top->unsignedp) | |
817 | top->value = (unsigned long) v1 * v2; | |
a4a315ef | 818 | else if (!skip_evaluation) |
7f2935c7 PB |
819 | { |
820 | top->value = v1 * v2; | |
821 | if (v1 | |
822 | && (top->value / v1 != v2 | |
823 | || (top->value & v1 & v2) < 0)) | |
824 | integer_overflow (pfile); | |
825 | } | |
826 | break; | |
827 | case '/': | |
a4a315ef PB |
828 | if (skip_evaluation) |
829 | break; | |
7f2935c7 PB |
830 | if (v2 == 0) |
831 | { | |
832 | cpp_error (pfile, "division by zero in #if"); | |
833 | v2 = 1; | |
834 | } | |
835 | top->unsignedp = unsigned1 || unsigned2; | |
836 | if (top->unsignedp) | |
837 | top->value = (unsigned long) v1 / v2; | |
838 | else | |
839 | { | |
840 | top->value = v1 / v2; | |
841 | if ((top->value & v1 & v2) < 0) | |
842 | integer_overflow (pfile); | |
843 | } | |
844 | break; | |
845 | case '%': | |
a4a315ef PB |
846 | if (skip_evaluation) |
847 | break; | |
7f2935c7 PB |
848 | if (v2 == 0) |
849 | { | |
850 | cpp_error (pfile, "division by zero in #if"); | |
851 | v2 = 1; | |
852 | } | |
853 | top->unsignedp = unsigned1 || unsigned2; | |
854 | if (top->unsignedp) | |
855 | top->value = (unsigned long) v1 % v2; | |
856 | else | |
857 | top->value = v1 % v2; | |
858 | break; | |
859 | case '!': | |
860 | if (top->flags & HAVE_VALUE) | |
861 | { | |
862 | cpp_error (pfile, "syntax error"); | |
863 | goto syntax_error; | |
864 | } | |
865 | top->value = ! v2; | |
866 | top->unsignedp = 0; | |
867 | top->flags |= HAVE_VALUE; | |
868 | break; | |
869 | case '~': | |
870 | if (top->flags & HAVE_VALUE) | |
871 | { | |
872 | cpp_error (pfile, "syntax error"); | |
873 | goto syntax_error; | |
874 | } | |
875 | top->value = ~ v2; | |
876 | top->unsignedp = unsigned2; | |
877 | top->flags |= HAVE_VALUE; | |
878 | break; | |
879 | case '<': COMPARE(<); break; | |
880 | case '>': COMPARE(>); break; | |
881 | case LEQ: COMPARE(<=); break; | |
882 | case GEQ: COMPARE(>=); break; | |
883 | case EQUAL: | |
884 | top->value = (v1 == v2); | |
885 | top->unsignedp = 0; | |
886 | break; | |
887 | case NOTEQUAL: | |
888 | top->value = (v1 != v2); | |
889 | top->unsignedp = 0; | |
890 | break; | |
891 | case LSH: | |
a4a315ef PB |
892 | if (skip_evaluation) |
893 | break; | |
7f2935c7 PB |
894 | top->unsignedp = unsigned1; |
895 | if (v2 < 0 && ! unsigned2) | |
896 | top->value = right_shift (pfile, v1, unsigned1, -v2); | |
897 | else | |
898 | top->value = left_shift (pfile, v1, unsigned1, v2); | |
899 | break; | |
900 | case RSH: | |
a4a315ef PB |
901 | if (skip_evaluation) |
902 | break; | |
7f2935c7 PB |
903 | top->unsignedp = unsigned1; |
904 | if (v2 < 0 && ! unsigned2) | |
905 | top->value = left_shift (pfile, v1, unsigned1, -v2); | |
906 | else | |
907 | top->value = right_shift (pfile, v1, unsigned1, v2); | |
908 | break; | |
909 | #define LOGICAL(OP) \ | |
910 | top->value = v1 OP v2;\ | |
911 | top->unsignedp = unsigned1 || unsigned2; | |
912 | case '&': LOGICAL(&); break; | |
913 | case '^': LOGICAL(^); break; | |
914 | case '|': LOGICAL(|); break; | |
915 | case ANDAND: | |
a4a315ef PB |
916 | top->value = v1 && v2; top->unsignedp = 0; |
917 | if (!v1) skip_evaluation--; | |
918 | break; | |
7f2935c7 | 919 | case OROR: |
a4a315ef PB |
920 | top->value = v1 || v2; top->unsignedp = 0; |
921 | if (v1) skip_evaluation--; | |
922 | break; | |
7f2935c7 PB |
923 | case ',': |
924 | if (CPP_PEDANTIC (pfile)) | |
925 | cpp_pedwarn (pfile, "comma operator in operand of `#if'"); | |
926 | top->value = v2; | |
927 | top->unsignedp = unsigned2; | |
928 | break; | |
929 | case '(': case '?': | |
930 | cpp_error (pfile, "syntax error in #if"); | |
931 | goto syntax_error; | |
932 | case ':': | |
933 | if (top[0].op != '?') | |
934 | { | |
935 | cpp_error (pfile, | |
936 | "syntax error ':' without preceding '?'"); | |
937 | goto syntax_error; | |
938 | } | |
939 | else if (! (top[1].flags & HAVE_VALUE) | |
940 | || !(top[-1].flags & HAVE_VALUE) | |
941 | || !(top[0].flags & HAVE_VALUE)) | |
942 | { | |
943 | cpp_error (pfile, "bad syntax for ?: operator"); | |
944 | goto syntax_error; | |
945 | } | |
946 | else | |
947 | { | |
948 | top--; | |
a4a315ef | 949 | if (top->value) skip_evaluation--; |
7f2935c7 PB |
950 | top->value = top->value ? v1 : v2; |
951 | top->unsignedp = unsigned1 || unsigned2; | |
952 | } | |
953 | break; | |
954 | case ')': | |
955 | if ((top[1].flags & HAVE_VALUE) | |
956 | || ! (top[0].flags & HAVE_VALUE) | |
957 | || top[0].op != '(' | |
958 | || (top[-1].flags & HAVE_VALUE)) | |
959 | { | |
960 | cpp_error (pfile, "mismatched parentheses in #if"); | |
961 | goto syntax_error; | |
962 | } | |
963 | else | |
964 | { | |
965 | top--; | |
966 | top->value = v1; | |
967 | top->unsignedp = unsigned1; | |
968 | top->flags |= HAVE_VALUE; | |
969 | } | |
970 | break; | |
971 | default: | |
972 | fprintf (stderr, | |
973 | top[1].op >= ' ' && top[1].op <= '~' | |
974 | ? "unimplemented operator '%c'\n" | |
975 | : "unimplemented operator '\\%03o'\n", | |
976 | top[1].op); | |
977 | } | |
978 | } | |
979 | if (op.op == 0) | |
980 | { | |
981 | if (top != stack) | |
982 | cpp_error (pfile, "internal error in #if expression"); | |
983 | if (stack != init_stack) | |
984 | free (stack); | |
985 | return top->value; | |
986 | } | |
987 | top++; | |
988 | ||
989 | /* Check for and handle stack overflow. */ | |
990 | if (top == limit) | |
991 | { | |
992 | struct operation *new_stack; | |
993 | int old_size = (char*)limit - (char*)stack; | |
994 | int new_size = 2 * old_size; | |
995 | if (stack != init_stack) | |
996 | new_stack = (struct operation*) xrealloc (stack, new_size); | |
997 | else | |
998 | { | |
999 | new_stack = (struct operation*) xmalloc (new_size); | |
52112c7c | 1000 | bcopy ((char *) stack, (char *) new_stack, old_size); |
7f2935c7 PB |
1001 | } |
1002 | stack = new_stack; | |
1003 | top = (struct operation*)((char*) new_stack + old_size); | |
1004 | limit = (struct operation*)((char*) new_stack + new_size); | |
1005 | } | |
1006 | ||
1007 | top->flags = flags; | |
1008 | top->rprio = rprio; | |
1009 | top->op = op.op; | |
a4a315ef PB |
1010 | if ((op.op == OROR && top[-1].value) |
1011 | || (op.op == ANDAND && !top[-1].value) | |
1012 | || (op.op == '?' && !top[-1].value)) | |
1013 | { | |
1014 | skip_evaluation++; | |
1015 | } | |
1016 | else if (op.op == ':') | |
1017 | { | |
1018 | if (top[-2].value) /* Was condition true? */ | |
1019 | skip_evaluation++; | |
1020 | else | |
1021 | skip_evaluation--; | |
1022 | } | |
7f2935c7 PB |
1023 | } |
1024 | syntax_error: | |
1025 | if (stack != init_stack) | |
1026 | free (stack); | |
1027 | skip_rest_of_line (pfile); | |
1028 | return 0; | |
1029 | } |