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7f2935c7 | 1 | /* Parse C expressions for CCCP. |
a3aa3d8c | 2 | Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998 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" |
7f2935c7 | 29 | #include "cpplib.h" |
a3aa3d8c | 30 | #include "gansidecl.h" |
7f2935c7 | 31 | |
52112c7c | 32 | extern char *xmalloc PARAMS ((unsigned)); |
1d300e19 | 33 | extern char *xrealloc PARAMS ((void *, unsigned)); |
52112c7c | 34 | |
9870475c | 35 | #ifdef MULTIBYTE_CHARS |
7f2935c7 PB |
36 | #include <locale.h> |
37 | #endif | |
38 | ||
7f2935c7 PB |
39 | /* This is used for communicating lists of keywords with cccp.c. */ |
40 | struct arglist { | |
41 | struct arglist *next; | |
42 | U_CHAR *name; | |
43 | int length; | |
44 | int argno; | |
45 | }; | |
46 | ||
7f2935c7 PB |
47 | #ifndef CHAR_TYPE_SIZE |
48 | #define CHAR_TYPE_SIZE BITS_PER_UNIT | |
49 | #endif | |
50 | ||
51 | #ifndef INT_TYPE_SIZE | |
52 | #define INT_TYPE_SIZE BITS_PER_WORD | |
53 | #endif | |
54 | ||
55 | #ifndef LONG_TYPE_SIZE | |
56 | #define LONG_TYPE_SIZE BITS_PER_WORD | |
57 | #endif | |
58 | ||
59 | #ifndef WCHAR_TYPE_SIZE | |
60 | #define WCHAR_TYPE_SIZE INT_TYPE_SIZE | |
61 | #endif | |
62 | ||
63 | #ifndef MAX_CHAR_TYPE_SIZE | |
64 | #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE | |
65 | #endif | |
66 | ||
67 | #ifndef MAX_INT_TYPE_SIZE | |
68 | #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE | |
69 | #endif | |
70 | ||
71 | #ifndef MAX_LONG_TYPE_SIZE | |
72 | #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE | |
73 | #endif | |
74 | ||
75 | #ifndef MAX_WCHAR_TYPE_SIZE | |
76 | #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE | |
77 | #endif | |
78 | ||
79 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a | |
80 | number with SUM's sign, where A, B, and SUM are all C integers. */ | |
81 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) | |
82 | ||
b04cd507 KG |
83 | static void integer_overflow PARAMS ((cpp_reader *)); |
84 | static long left_shift PARAMS ((cpp_reader *, long, int, unsigned long)); | |
85 | static long right_shift PARAMS ((cpp_reader *, long, int, unsigned long)); | |
7f2935c7 PB |
86 | |
87 | #define ERROR 299 | |
88 | #define OROR 300 | |
89 | #define ANDAND 301 | |
90 | #define EQUAL 302 | |
91 | #define NOTEQUAL 303 | |
92 | #define LEQ 304 | |
93 | #define GEQ 305 | |
94 | #define LSH 306 | |
95 | #define RSH 307 | |
96 | #define NAME 308 | |
97 | #define INT 309 | |
98 | #define CHAR 310 | |
99 | ||
100 | #define LEFT_OPERAND_REQUIRED 1 | |
101 | #define RIGHT_OPERAND_REQUIRED 2 | |
102 | #define HAVE_VALUE 4 | |
a4a315ef | 103 | /* SKIP_OPERAND is set for '&&' '||' '?' and ':' when the |
0f41302f | 104 | following operand should be short-circuited instead of evaluated. */ |
a4a315ef PB |
105 | #define SKIP_OPERAND 8 |
106 | /*#define UNSIGNEDP 16*/ | |
7f2935c7 | 107 | |
1d300e19 KG |
108 | /* Find the largest host integer type and set its size and type. |
109 | Watch out: on some crazy hosts `long' is shorter than `int'. */ | |
110 | ||
111 | #ifndef HOST_WIDE_INT | |
112 | # if HAVE_INTTYPES_H | |
113 | # include <inttypes.h> | |
114 | # define HOST_WIDE_INT intmax_t | |
115 | # else | |
116 | # if (HOST_BITS_PER_LONG <= HOST_BITS_PER_INT \ | |
117 | && HOST_BITS_PER_LONGLONG <= HOST_BITS_PER_INT) | |
118 | # define HOST_WIDE_INT int | |
119 | # else | |
120 | # if (HOST_BITS_PER_LONGLONG <= HOST_BITS_PER_LONG \ | |
121 | || ! (defined LONG_LONG_MAX || defined LLONG_MAX)) | |
122 | # define HOST_WIDE_INT long | |
123 | # else | |
124 | # define HOST_WIDE_INT long long | |
125 | # endif | |
126 | # endif | |
127 | # endif | |
128 | #endif | |
7e127823 | 129 | |
1d300e19 KG |
130 | #ifndef CHAR_BIT |
131 | #define CHAR_BIT 8 | |
7e127823 PB |
132 | #endif |
133 | ||
1d300e19 KG |
134 | #ifndef HOST_BITS_PER_WIDE_INT |
135 | #define HOST_BITS_PER_WIDE_INT (CHAR_BIT * sizeof (HOST_WIDE_INT)) | |
7e127823 PB |
136 | #endif |
137 | ||
7f2935c7 PB |
138 | struct operation { |
139 | short op; | |
0f41302f | 140 | char rprio; /* Priority of op (relative to it right operand). */ |
7f2935c7 PB |
141 | char flags; |
142 | char unsignedp; /* true if value should be treated as unsigned */ | |
0f41302f | 143 | HOST_WIDE_INT value; /* The value logically "right" of op. */ |
7f2935c7 PB |
144 | }; |
145 | \f | |
146 | /* Take care of parsing a number (anything that starts with a digit). | |
147 | LEN is the number of characters in it. */ | |
148 | ||
149 | /* maybe needs to actually deal with floating point numbers */ | |
150 | ||
151 | struct operation | |
152 | parse_number (pfile, start, olen) | |
153 | cpp_reader *pfile; | |
154 | char *start; | |
155 | int olen; | |
156 | { | |
157 | struct operation op; | |
158 | register char *p = start; | |
159 | register int c; | |
160 | register unsigned long n = 0, nd, ULONG_MAX_over_base; | |
161 | register int base = 10; | |
162 | register int len = olen; | |
163 | register int overflow = 0; | |
164 | register int digit, largest_digit = 0; | |
165 | int spec_long = 0; | |
166 | ||
167 | op.unsignedp = 0; | |
168 | ||
169 | for (c = 0; c < len; c++) | |
170 | if (p[c] == '.') { | |
171 | /* It's a float since it contains a point. */ | |
172 | cpp_error (pfile, | |
173 | "floating point numbers not allowed in #if expressions"); | |
174 | op.op = ERROR; | |
175 | return op; | |
176 | } | |
177 | ||
178 | if (len >= 3 && (!strncmp (p, "0x", 2) || !strncmp (p, "0X", 2))) { | |
179 | p += 2; | |
180 | base = 16; | |
181 | len -= 2; | |
182 | } | |
183 | else if (*p == '0') | |
184 | base = 8; | |
185 | ||
0f41302f | 186 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
7f2935c7 | 187 | ULONG_MAX_over_base = ((unsigned long) -1) / ((unsigned long) base); |
7f2935c7 PB |
188 | |
189 | for (; len > 0; len--) { | |
190 | c = *p++; | |
191 | ||
192 | if (c >= '0' && c <= '9') | |
193 | digit = c - '0'; | |
194 | else if (base == 16 && c >= 'a' && c <= 'f') | |
195 | digit = c - 'a' + 10; | |
196 | else if (base == 16 && c >= 'A' && c <= 'F') | |
197 | digit = c - 'A' + 10; | |
198 | else { | |
199 | /* `l' means long, and `u' means unsigned. */ | |
200 | while (1) { | |
201 | if (c == 'l' || c == 'L') | |
202 | { | |
203 | if (spec_long) | |
204 | cpp_error (pfile, "two `l's in integer constant"); | |
205 | spec_long = 1; | |
206 | } | |
207 | else if (c == 'u' || c == 'U') | |
208 | { | |
209 | if (op.unsignedp) | |
210 | cpp_error (pfile, "two `u's in integer constant"); | |
211 | op.unsignedp = 1; | |
212 | } | |
213 | else | |
214 | break; | |
215 | ||
216 | if (--len == 0) | |
217 | break; | |
218 | c = *p++; | |
219 | } | |
220 | /* Don't look for any more digits after the suffixes. */ | |
221 | break; | |
222 | } | |
223 | if (largest_digit < digit) | |
224 | largest_digit = digit; | |
225 | nd = n * base + digit; | |
1d300e19 | 226 | overflow |= ULONG_MAX_over_base < n || nd < n; |
7f2935c7 PB |
227 | n = nd; |
228 | } | |
229 | ||
230 | if (len != 0) | |
231 | { | |
232 | cpp_error (pfile, "Invalid number in #if expression"); | |
233 | op.op = ERROR; | |
234 | return op; | |
235 | } | |
236 | ||
237 | if (base <= largest_digit) | |
7c4033ff | 238 | cpp_pedwarn (pfile, "integer constant contains digits beyond the radix"); |
7f2935c7 PB |
239 | |
240 | if (overflow) | |
7c4033ff | 241 | cpp_pedwarn (pfile, "integer constant out of range"); |
7f2935c7 PB |
242 | |
243 | /* If too big to be signed, consider it unsigned. */ | |
244 | if ((long) n < 0 && ! op.unsignedp) | |
245 | { | |
246 | if (base == 10) | |
247 | cpp_warning (pfile, "integer constant is so large that it is unsigned"); | |
248 | op.unsignedp = 1; | |
249 | } | |
250 | ||
251 | op.value = n; | |
252 | op.op = INT; | |
253 | return op; | |
254 | } | |
255 | ||
256 | struct token { | |
257 | char *operator; | |
258 | int token; | |
259 | }; | |
260 | ||
261 | static struct token tokentab2[] = { | |
262 | {"&&", ANDAND}, | |
263 | {"||", OROR}, | |
264 | {"<<", LSH}, | |
265 | {">>", RSH}, | |
266 | {"==", EQUAL}, | |
267 | {"!=", NOTEQUAL}, | |
268 | {"<=", LEQ}, | |
269 | {">=", GEQ}, | |
270 | {"++", ERROR}, | |
271 | {"--", ERROR}, | |
272 | {NULL, ERROR} | |
273 | }; | |
274 | ||
0f41302f | 275 | /* Read one token. */ |
7f2935c7 PB |
276 | |
277 | struct operation | |
c9666c01 | 278 | cpp_lex (pfile, skip_evaluation) |
52529158 | 279 | cpp_reader *pfile; |
c9666c01 | 280 | int skip_evaluation; |
7f2935c7 PB |
281 | { |
282 | register int c; | |
7f2935c7 PB |
283 | register struct token *toktab; |
284 | enum cpp_token token; | |
285 | struct operation op; | |
286 | U_CHAR *tok_start, *tok_end; | |
287 | int old_written; | |
288 | ||
289 | retry: | |
290 | ||
1519594d PB |
291 | old_written = CPP_WRITTEN (pfile); |
292 | cpp_skip_hspace (pfile); | |
7f2935c7 PB |
293 | c = CPP_BUF_PEEK (CPP_BUFFER (pfile)); |
294 | if (c == '#') | |
295 | return parse_number (pfile, | |
296 | cpp_read_check_assertion (pfile) ? "1" : "0", 1); | |
297 | ||
7f2935c7 PB |
298 | if (c == '\n') |
299 | { | |
300 | op.op = 0; | |
301 | return op; | |
302 | } | |
303 | ||
304 | token = cpp_get_token (pfile); | |
305 | tok_start = pfile->token_buffer + old_written; | |
306 | tok_end = CPP_PWRITTEN (pfile); | |
307 | pfile->limit = tok_start; | |
308 | switch (token) | |
309 | { | |
0f41302f | 310 | case CPP_EOF: /* Should not happen ... */ |
a4a315ef | 311 | case CPP_VSPACE: |
7f2935c7 PB |
312 | op.op = 0; |
313 | return op; | |
7f2935c7 PB |
314 | case CPP_POP: |
315 | if (CPP_BUFFER (pfile)->fname != NULL) | |
316 | { | |
317 | op.op = 0; | |
318 | return op; | |
319 | } | |
a4a315ef | 320 | cpp_pop_buffer (pfile); |
7f2935c7 PB |
321 | goto retry; |
322 | case CPP_HSPACE: case CPP_COMMENT: | |
323 | goto retry; | |
324 | case CPP_NUMBER: | |
325 | return parse_number (pfile, tok_start, tok_end - tok_start); | |
326 | case CPP_STRING: | |
327 | cpp_error (pfile, "string constants not allowed in #if expressions"); | |
328 | op.op = ERROR; | |
329 | return op; | |
330 | case CPP_CHAR: | |
331 | /* This code for reading a character constant | |
332 | handles multicharacter constants and wide characters. | |
333 | It is mostly copied from c-lex.c. */ | |
334 | { | |
335 | register int result = 0; | |
9870475c | 336 | register int num_chars = 0; |
7f2935c7 PB |
337 | unsigned width = MAX_CHAR_TYPE_SIZE; |
338 | int wide_flag = 0; | |
339 | int max_chars; | |
340 | U_CHAR *ptr = tok_start; | |
341 | #ifdef MULTIBYTE_CHARS | |
342 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + MB_CUR_MAX]; | |
343 | #else | |
344 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + 1]; | |
345 | #endif | |
346 | ||
347 | if (*ptr == 'L') | |
348 | { | |
349 | ptr++; | |
350 | wide_flag = 1; | |
351 | width = MAX_WCHAR_TYPE_SIZE; | |
352 | #ifdef MULTIBYTE_CHARS | |
353 | max_chars = MB_CUR_MAX; | |
354 | #else | |
355 | max_chars = 1; | |
356 | #endif | |
357 | } | |
358 | else | |
359 | max_chars = MAX_LONG_TYPE_SIZE / width; | |
360 | ||
ae17bedb RK |
361 | ++ptr; |
362 | while (ptr < tok_end && ((c = *ptr++) != '\'')) | |
7f2935c7 | 363 | { |
7f2935c7 PB |
364 | if (c == '\\') |
365 | { | |
1d300e19 | 366 | c = cpp_parse_escape (pfile, (char **) &ptr); |
7f2935c7 PB |
367 | if (width < HOST_BITS_PER_INT |
368 | && (unsigned) c >= (1 << width)) | |
369 | cpp_pedwarn (pfile, | |
370 | "escape sequence out of range for character"); | |
371 | } | |
372 | ||
373 | num_chars++; | |
374 | ||
375 | /* Merge character into result; ignore excess chars. */ | |
376 | if (num_chars < max_chars + 1) | |
377 | { | |
378 | if (width < HOST_BITS_PER_INT) | |
379 | result = (result << width) | (c & ((1 << width) - 1)); | |
380 | else | |
381 | result = c; | |
382 | token_buffer[num_chars - 1] = c; | |
383 | } | |
384 | } | |
385 | ||
386 | token_buffer[num_chars] = 0; | |
387 | ||
388 | if (c != '\'') | |
389 | cpp_error (pfile, "malformatted character constant"); | |
390 | else if (num_chars == 0) | |
391 | cpp_error (pfile, "empty character constant"); | |
392 | else if (num_chars > max_chars) | |
393 | { | |
394 | num_chars = max_chars; | |
395 | cpp_error (pfile, "character constant too long"); | |
396 | } | |
397 | else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile)) | |
398 | cpp_warning (pfile, "multi-character character constant"); | |
399 | ||
400 | /* If char type is signed, sign-extend the constant. */ | |
401 | if (! wide_flag) | |
402 | { | |
403 | int num_bits = num_chars * width; | |
404 | ||
1d300e19 | 405 | if (cpp_lookup (pfile, (U_CHAR *)"__CHAR_UNSIGNED__", |
7f2935c7 PB |
406 | sizeof ("__CHAR_UNSIGNED__")-1, -1) |
407 | || ((result >> (num_bits - 1)) & 1) == 0) | |
408 | op.value | |
409 | = result & ((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); | |
410 | else | |
411 | op.value | |
412 | = result | ~((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); | |
413 | } | |
414 | else | |
415 | { | |
416 | #ifdef MULTIBYTE_CHARS | |
417 | /* Set the initial shift state and convert the next sequence. */ | |
418 | result = 0; | |
419 | /* In all locales L'\0' is zero and mbtowc will return zero, | |
420 | so don't use it. */ | |
421 | if (num_chars > 1 | |
422 | || (num_chars == 1 && token_buffer[0] != '\0')) | |
423 | { | |
424 | wchar_t wc; | |
425 | (void) mbtowc (NULL_PTR, NULL_PTR, 0); | |
426 | if (mbtowc (& wc, token_buffer, num_chars) == num_chars) | |
427 | result = wc; | |
428 | else | |
7c4033ff | 429 | cpp_pedwarn (pfile,"Ignoring invalid multibyte character"); |
7f2935c7 PB |
430 | } |
431 | #endif | |
432 | op.value = result; | |
433 | } | |
434 | } | |
435 | ||
436 | /* This is always a signed type. */ | |
437 | op.unsignedp = 0; | |
438 | op.op = CHAR; | |
439 | ||
440 | return op; | |
441 | ||
442 | case CPP_NAME: | |
c9666c01 RK |
443 | if (CPP_WARN_UNDEF (pfile) && !skip_evaluation) |
444 | cpp_warning (pfile, "`%.*s' is not defined", | |
445 | (int) (tok_end - tok_start), tok_start); | |
7f2935c7 PB |
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; | |
7c4033ff | 545 | cpp_pedwarn (pfile, |
7f2935c7 PB |
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; | |
7c4033ff | 576 | cpp_pedwarn (pfile, |
7f2935c7 PB |
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) | |
d6f4ec51 | 620 | cpp_reader *pfile ATTRIBUTE_UNUSED; |
7f2935c7 PB |
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 | |
0f41302f | 633 | /* These priorities are all even, so we can handle associatively. */ |
7f2935c7 PB |
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 */ | |
c9666c01 | 687 | op = cpp_lex (pfile, skip_evaluation); |
7f2935c7 PB |
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 | |
0f41302f | 691 | priorities, and then goto maybe_reduce. */ |
7f2935c7 PB |
692 | |
693 | switch (op.op) | |
694 | { | |
695 | case NAME: | |
c9666c01 | 696 | abort (); |
7f2935c7 PB |
697 | case INT: case CHAR: |
698 | top->value = op.value; | |
699 | top->unsignedp = op.unsignedp; | |
700 | goto set_value; | |
701 | case 0: | |
702 | lprio = 0; goto maybe_reduce; | |
703 | case '+': case '-': | |
704 | /* Is this correct if unary ? FIXME */ | |
705 | flags = RIGHT_OPERAND_REQUIRED; | |
706 | lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce; | |
707 | case '!': case '~': | |
708 | flags = RIGHT_OPERAND_REQUIRED; | |
709 | rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce; | |
710 | case '*': case '/': case '%': | |
711 | lprio = MUL_PRIO; goto binop; | |
712 | case '<': case '>': case LEQ: case GEQ: | |
713 | lprio = LESS_PRIO; goto binop; | |
714 | case EQUAL: case NOTEQUAL: | |
715 | lprio = EQUAL_PRIO; goto binop; | |
716 | case LSH: case RSH: | |
717 | lprio = SHIFT_PRIO; goto binop; | |
718 | case '&': lprio = AND_PRIO; goto binop; | |
719 | case '^': lprio = XOR_PRIO; goto binop; | |
720 | case '|': lprio = OR_PRIO; goto binop; | |
721 | case ANDAND: lprio = ANDAND_PRIO; goto binop; | |
722 | case OROR: lprio = OROR_PRIO; goto binop; | |
723 | case ',': | |
724 | lprio = COMMA_PRIO; goto binop; | |
725 | case '(': | |
726 | lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO; | |
727 | goto maybe_reduce; | |
728 | case ')': | |
729 | lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO; | |
730 | goto maybe_reduce; | |
731 | case ':': | |
732 | lprio = COND_PRIO; rprio = COND_PRIO; | |
733 | goto maybe_reduce; | |
734 | case '?': | |
735 | lprio = COND_PRIO + 1; rprio = COND_PRIO; | |
736 | goto maybe_reduce; | |
737 | binop: | |
738 | flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED; | |
739 | rprio = lprio + 1; | |
740 | goto maybe_reduce; | |
741 | default: | |
742 | cpp_error (pfile, "invalid character in #if"); | |
743 | goto syntax_error; | |
744 | } | |
745 | ||
746 | set_value: | |
0f41302f | 747 | /* Push a value onto the stack. */ |
7f2935c7 PB |
748 | if (top->flags & HAVE_VALUE) |
749 | { | |
750 | cpp_error (pfile, "syntax error in #if"); | |
751 | goto syntax_error; | |
752 | } | |
753 | top->flags |= HAVE_VALUE; | |
754 | continue; | |
755 | ||
756 | maybe_reduce: | |
0f41302f | 757 | /* Push an operator, and check if we can reduce now. */ |
7f2935c7 PB |
758 | while (top->rprio > lprio) |
759 | { | |
760 | long v1 = top[-1].value, v2 = top[0].value; | |
761 | int unsigned1 = top[-1].unsignedp, unsigned2 = top[0].unsignedp; | |
762 | top--; | |
763 | if ((top[1].flags & LEFT_OPERAND_REQUIRED) | |
764 | && ! (top[0].flags & HAVE_VALUE)) | |
765 | { | |
766 | cpp_error (pfile, "syntax error - missing left operand"); | |
767 | goto syntax_error; | |
768 | } | |
769 | if ((top[1].flags & RIGHT_OPERAND_REQUIRED) | |
770 | && ! (top[1].flags & HAVE_VALUE)) | |
771 | { | |
772 | cpp_error (pfile, "syntax error - missing right operand"); | |
773 | goto syntax_error; | |
774 | } | |
775 | /* top[0].value = (top[1].op)(v1, v2);*/ | |
776 | switch (top[1].op) | |
777 | { | |
778 | case '+': | |
779 | if (!(top->flags & HAVE_VALUE)) | |
780 | { /* Unary '+' */ | |
781 | top->value = v2; | |
782 | top->unsignedp = unsigned2; | |
783 | top->flags |= HAVE_VALUE; | |
784 | } | |
785 | else | |
786 | { | |
787 | top->value = v1 + v2; | |
788 | top->unsignedp = unsigned1 || unsigned2; | |
a4a315ef | 789 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
790 | && ! possible_sum_sign (v1, v2, top->value)) |
791 | integer_overflow (pfile); | |
792 | } | |
793 | break; | |
794 | case '-': | |
52529158 | 795 | if (!(top->flags & HAVE_VALUE)) |
7f2935c7 PB |
796 | { /* Unary '-' */ |
797 | top->value = - v2; | |
52529158 | 798 | if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2) |
7f2935c7 PB |
799 | integer_overflow (pfile); |
800 | top->unsignedp = unsigned2; | |
801 | top->flags |= HAVE_VALUE; | |
802 | } | |
803 | else | |
804 | { /* Binary '-' */ | |
805 | top->value = v1 - v2; | |
806 | top->unsignedp = unsigned1 || unsigned2; | |
52529158 | 807 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
808 | && ! possible_sum_sign (top->value, v2, v1)) |
809 | integer_overflow (pfile); | |
810 | } | |
811 | break; | |
812 | case '*': | |
813 | top->unsignedp = unsigned1 || unsigned2; | |
814 | if (top->unsignedp) | |
815 | top->value = (unsigned long) v1 * v2; | |
a4a315ef | 816 | else if (!skip_evaluation) |
7f2935c7 PB |
817 | { |
818 | top->value = v1 * v2; | |
819 | if (v1 | |
820 | && (top->value / v1 != v2 | |
821 | || (top->value & v1 & v2) < 0)) | |
822 | integer_overflow (pfile); | |
823 | } | |
824 | break; | |
825 | case '/': | |
a4a315ef PB |
826 | if (skip_evaluation) |
827 | break; | |
7f2935c7 PB |
828 | if (v2 == 0) |
829 | { | |
830 | cpp_error (pfile, "division by zero in #if"); | |
831 | v2 = 1; | |
832 | } | |
833 | top->unsignedp = unsigned1 || unsigned2; | |
834 | if (top->unsignedp) | |
835 | top->value = (unsigned long) v1 / v2; | |
836 | else | |
837 | { | |
838 | top->value = v1 / v2; | |
839 | if ((top->value & v1 & v2) < 0) | |
840 | integer_overflow (pfile); | |
841 | } | |
842 | break; | |
843 | case '%': | |
a4a315ef PB |
844 | if (skip_evaluation) |
845 | break; | |
7f2935c7 PB |
846 | if (v2 == 0) |
847 | { | |
848 | cpp_error (pfile, "division by zero in #if"); | |
849 | v2 = 1; | |
850 | } | |
851 | top->unsignedp = unsigned1 || unsigned2; | |
852 | if (top->unsignedp) | |
853 | top->value = (unsigned long) v1 % v2; | |
854 | else | |
855 | top->value = v1 % v2; | |
856 | break; | |
857 | case '!': | |
858 | if (top->flags & HAVE_VALUE) | |
859 | { | |
860 | cpp_error (pfile, "syntax error"); | |
861 | goto syntax_error; | |
862 | } | |
863 | top->value = ! v2; | |
864 | top->unsignedp = 0; | |
865 | top->flags |= HAVE_VALUE; | |
866 | break; | |
867 | case '~': | |
868 | if (top->flags & HAVE_VALUE) | |
869 | { | |
870 | cpp_error (pfile, "syntax error"); | |
871 | goto syntax_error; | |
872 | } | |
873 | top->value = ~ v2; | |
874 | top->unsignedp = unsigned2; | |
875 | top->flags |= HAVE_VALUE; | |
876 | break; | |
877 | case '<': COMPARE(<); break; | |
878 | case '>': COMPARE(>); break; | |
879 | case LEQ: COMPARE(<=); break; | |
880 | case GEQ: COMPARE(>=); break; | |
881 | case EQUAL: | |
882 | top->value = (v1 == v2); | |
883 | top->unsignedp = 0; | |
884 | break; | |
885 | case NOTEQUAL: | |
886 | top->value = (v1 != v2); | |
887 | top->unsignedp = 0; | |
888 | break; | |
889 | case LSH: | |
a4a315ef PB |
890 | if (skip_evaluation) |
891 | break; | |
7f2935c7 PB |
892 | top->unsignedp = unsigned1; |
893 | if (v2 < 0 && ! unsigned2) | |
894 | top->value = right_shift (pfile, v1, unsigned1, -v2); | |
895 | else | |
896 | top->value = left_shift (pfile, v1, unsigned1, v2); | |
897 | break; | |
898 | case RSH: | |
a4a315ef PB |
899 | if (skip_evaluation) |
900 | break; | |
7f2935c7 PB |
901 | top->unsignedp = unsigned1; |
902 | if (v2 < 0 && ! unsigned2) | |
903 | top->value = left_shift (pfile, v1, unsigned1, -v2); | |
904 | else | |
905 | top->value = right_shift (pfile, v1, unsigned1, v2); | |
906 | break; | |
907 | #define LOGICAL(OP) \ | |
908 | top->value = v1 OP v2;\ | |
909 | top->unsignedp = unsigned1 || unsigned2; | |
910 | case '&': LOGICAL(&); break; | |
911 | case '^': LOGICAL(^); break; | |
912 | case '|': LOGICAL(|); break; | |
913 | case ANDAND: | |
a4a315ef PB |
914 | top->value = v1 && v2; top->unsignedp = 0; |
915 | if (!v1) skip_evaluation--; | |
916 | break; | |
7f2935c7 | 917 | case OROR: |
a4a315ef PB |
918 | top->value = v1 || v2; top->unsignedp = 0; |
919 | if (v1) skip_evaluation--; | |
920 | break; | |
7f2935c7 PB |
921 | case ',': |
922 | if (CPP_PEDANTIC (pfile)) | |
923 | cpp_pedwarn (pfile, "comma operator in operand of `#if'"); | |
924 | top->value = v2; | |
925 | top->unsignedp = unsigned2; | |
926 | break; | |
927 | case '(': case '?': | |
928 | cpp_error (pfile, "syntax error in #if"); | |
929 | goto syntax_error; | |
930 | case ':': | |
931 | if (top[0].op != '?') | |
932 | { | |
933 | cpp_error (pfile, | |
934 | "syntax error ':' without preceding '?'"); | |
935 | goto syntax_error; | |
936 | } | |
937 | else if (! (top[1].flags & HAVE_VALUE) | |
938 | || !(top[-1].flags & HAVE_VALUE) | |
939 | || !(top[0].flags & HAVE_VALUE)) | |
940 | { | |
941 | cpp_error (pfile, "bad syntax for ?: operator"); | |
942 | goto syntax_error; | |
943 | } | |
944 | else | |
945 | { | |
946 | top--; | |
a4a315ef | 947 | if (top->value) skip_evaluation--; |
7f2935c7 PB |
948 | top->value = top->value ? v1 : v2; |
949 | top->unsignedp = unsigned1 || unsigned2; | |
950 | } | |
951 | break; | |
952 | case ')': | |
953 | if ((top[1].flags & HAVE_VALUE) | |
954 | || ! (top[0].flags & HAVE_VALUE) | |
955 | || top[0].op != '(' | |
956 | || (top[-1].flags & HAVE_VALUE)) | |
957 | { | |
958 | cpp_error (pfile, "mismatched parentheses in #if"); | |
959 | goto syntax_error; | |
960 | } | |
961 | else | |
962 | { | |
963 | top--; | |
964 | top->value = v1; | |
965 | top->unsignedp = unsigned1; | |
966 | top->flags |= HAVE_VALUE; | |
967 | } | |
968 | break; | |
969 | default: | |
970 | fprintf (stderr, | |
971 | top[1].op >= ' ' && top[1].op <= '~' | |
972 | ? "unimplemented operator '%c'\n" | |
973 | : "unimplemented operator '\\%03o'\n", | |
974 | top[1].op); | |
975 | } | |
976 | } | |
977 | if (op.op == 0) | |
978 | { | |
979 | if (top != stack) | |
980 | cpp_error (pfile, "internal error in #if expression"); | |
981 | if (stack != init_stack) | |
982 | free (stack); | |
983 | return top->value; | |
984 | } | |
985 | top++; | |
986 | ||
0f41302f | 987 | /* Check for and handle stack overflow. */ |
7f2935c7 PB |
988 | if (top == limit) |
989 | { | |
990 | struct operation *new_stack; | |
0f41302f | 991 | int old_size = (char *) limit - (char *) stack; |
7f2935c7 PB |
992 | int new_size = 2 * old_size; |
993 | if (stack != init_stack) | |
0f41302f | 994 | new_stack = (struct operation *) xrealloc (stack, new_size); |
7f2935c7 PB |
995 | else |
996 | { | |
0f41302f | 997 | new_stack = (struct operation *) xmalloc (new_size); |
52112c7c | 998 | bcopy ((char *) stack, (char *) new_stack, old_size); |
7f2935c7 PB |
999 | } |
1000 | stack = new_stack; | |
0f41302f MS |
1001 | top = (struct operation *) ((char *) new_stack + old_size); |
1002 | limit = (struct operation *) ((char *) new_stack + new_size); | |
7f2935c7 PB |
1003 | } |
1004 | ||
1005 | top->flags = flags; | |
1006 | top->rprio = rprio; | |
1007 | top->op = op.op; | |
a4a315ef PB |
1008 | if ((op.op == OROR && top[-1].value) |
1009 | || (op.op == ANDAND && !top[-1].value) | |
1010 | || (op.op == '?' && !top[-1].value)) | |
1011 | { | |
1012 | skip_evaluation++; | |
1013 | } | |
1014 | else if (op.op == ':') | |
1015 | { | |
1016 | if (top[-2].value) /* Was condition true? */ | |
1017 | skip_evaluation++; | |
1018 | else | |
1019 | skip_evaluation--; | |
1020 | } | |
7f2935c7 PB |
1021 | } |
1022 | syntax_error: | |
1023 | if (stack != init_stack) | |
1024 | free (stack); | |
1025 | skip_rest_of_line (pfile); | |
1026 | return 0; | |
1027 | } |