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Fixed the readme file based on the information on the web page.
[splint.git] / src / cppexp.c
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616915dd 1/*
11db3170 2** Splint - annotation-assisted static program checker
77d37419 3** Copyright (C) 1994-2002 University of Virginia,
616915dd 4** Massachusetts Institute of Technology
5**
6** This program is free software; you can redistribute it and/or modify it
7** under the terms of the GNU General Public License as published by the
8** Free Software Foundation; either version 2 of the License, or (at your
9** option) any later version.
10**
11** This program is distributed in the hope that it will be useful, but
12** WITHOUT ANY WARRANTY; without even the implied warranty of
13** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14** General Public License for more details.
15**
16** The GNU General Public License is available from http://www.gnu.org/ or
17** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
18** MA 02111-1307, USA.
19**
1b8ae690 20** For information on splint: splint@cs.virginia.edu
21** To report a bug: splint-bug@cs.virginia.edu
11db3170 22** For more information: http://www.splint.org
616915dd 23*/
24/*
25** cppexp.c
26*/
27/* Parse C expressions for CCCP.
28 Copyright (C) 1987, 1992, 1994, 1995, 1997 Free Software Foundation.
29
30This program is free software; you can redistribute it and/or modify it
31under the terms of the GNU General Public License as published by the
32Free Software Foundation; either version 2, or (at your option) any
33later version.
34
35This program is distributed in the hope that it will be useful,
36but WITHOUT ANY WARRANTY; without even the implied warranty of
37MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38GNU General Public License for more details.
39
40You should have received a copy of the GNU General Public License
41along with this program; if not, write to the Free Software
42Foundation, 59 Temple Place - Suite 330,
43Boston, MA 02111-1307, USA.
44
45 In other words, you are welcome to use, share and improve this program.
46 You are forbidden to forbid anyone else to use, share and improve
47 what you give them. Help stamp out software-hoarding!
48
49Written by Per Bothner 1994. */
50
51/* Parse a C expression from text in a string */
52
53/*@+charint@*/
54/*@+ignorequals@*/
55/*@+ignoresigns@*/
56/*@+matchanyintegral@*/
616915dd 57
58# include <string.h>
1b8ae690 59# include "splintMacros.nf"
616915dd 60# include "llbasic.h"
616915dd 61# include "cpplib.h"
62# include "cpphash.h"
63# include "cppexp.h"
64# include "cpperror.h"
65
66/* Yield nonzero if adding two numbers with A's and B's signs can yield a
67 number with SUM's sign, where A, B, and SUM are all C integers. */
68
69/*@function static bool possibleSumSign (sef int, int, int)
70 modifies nothing ; @*/
71
72#define possibleSumSign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0)
73
74/* these are guesses! */
75
a956d444 76/*@constant int BITS_PER_UNIT = 8@*/
616915dd 77# define BITS_PER_UNIT 8
78
79/*@constant size_t BITS_PER_CHAR@*/
80# define BITS_PER_CHAR 8
81
82/*@constant size_t BITS_PER_WORD@*/
83# define BITS_PER_WORD 32
84
85/*@constant size_t HOST_BITS_PER_INT@*/
86# define HOST_BITS_PER_INT 32
87
a956d444 88/*@constant size_t HOST_BITS_PER_LONG = 32@*/
616915dd 89# define HOST_BITS_PER_LONG 32
90
91/*@constant char TARGET_BELL@*/
92# define TARGET_BELL (char) 6
93
94/*@constant char TARGET_BS@*/
95# define TARGET_BS (char) 7
96
97/*@constant char TARGET_FF@*/
98# define TARGET_FF (char) 8
99
100/*@constant char TARGET_NEWLINE@*/
101# define TARGET_NEWLINE '\n'
102
103/*@constant char TARGET_CR@*/
104# define TARGET_CR '\n'
105
106/*@constant char TARGET_TAB@*/
107# define TARGET_TAB '\t'
108
109/*@constant char TARGET_VT@*/
110# define TARGET_VT '\v'
111
112#ifdef MULTIBYTE_CHARS
113#include <stdlib.h>
114#include <locale.h>
115#endif
116
117#include <stdio.h>
118
119#ifndef INT_TYPE_SIZE
120/*@constant size_t INT_TYPE_SIZE@*/
121#define INT_TYPE_SIZE BITS_PER_WORD
122#endif
123
124#ifndef LONG_TYPE_SIZE
125/*@constant size_t LONG_TYPE_SIZE@*/
126#define LONG_TYPE_SIZE BITS_PER_WORD
127#endif
128
129#ifndef WCHAR_TYPE_SIZE
130/*@constant size_t WCHAR_TYPE_SIZE@*/
131#define WCHAR_TYPE_SIZE INT_TYPE_SIZE
132#endif
133
134# ifndef CHAR_TYPE_SIZE
135/*@constant size_t CHAR_TYPE_SIZE@*/
136# define CHAR_TYPE_SIZE BITS_PER_CHAR
137# endif
138
139#ifndef MAX_CHAR_TYPE_SIZE
140/*@constant size_t MAX_CHAR_TYPE_SIZE@*/
141#define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE
142#endif
143
144#ifndef MAX_LONG_TYPE_SIZE
145/*@constant size_t MAX_LONG_TYPE_SIZE@*/
146#define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE
147#endif
148
149#ifndef MAX_WCHAR_TYPE_SIZE
150/*@constant size_t MAX_WCHAR_TYPE_SIZE@*/
151#define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE
152#endif
153
3e3ec469 154static struct operation cppexp_lex (cppReader *);
616915dd 155static void integer_overflow (cppReader *);
156static long left_shift (cppReader *, long, bool p_unsignedp, size_t);
157static long right_shift (long, bool p_unsignedp, unsigned long);
158
159/*@constant short CPPREADER_ERRORTOK@*/
160#define CPPREADER_ERRORTOK 299
161
162/*@constant int OROR@*/
163#define OROR 300
164
165/*@constant int ANDAND@*/
166#define ANDAND 301
167
168/*@constant int CPP_EQUALTOK@*/
169#define CPP_EQUALTOK 302
170
171/*@constant int NOTEQUAL@*/
172#define NOTEQUAL 303
173
174/*@constant int LEQ@*/
175#define LEQ 304
176
177/*@constant int GEQ@*/
178#define GEQ 305
179
180/*@constant int LSH@*/
181#define LSH 306
182
183/*@constant int RSH@*/
184#define RSH 307
185
186/*@constant int NAME@*/
187#define NAME 308
188
189/*@constant short CPPEXP_INT@*/
190#define CPPEXP_INT 309
191
192/*@constant short CPPEXP_CHAR@*/
193#define CPPEXP_CHAR 310
194
195/*@constant int LEFT_OPERAND_REQUIRED@*/
196#define LEFT_OPERAND_REQUIRED 1
197
198/*@constant int RIGHT_OPERAND_REQUIRED@*/
199#define RIGHT_OPERAND_REQUIRED 2
200
201/*@constant int HAVE_VALUE@*/
202#define HAVE_VALUE 4
203
204#ifndef HOST_BITS_PER_WIDE_INT
205
206#if HOST_BITS_PER_LONG > HOST_BITS_PER_INT
207/*@constant int HOST_BITS_PER_WIDE_INT@*/
208#define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_LONG
209/*@notfunction@*/
210#define HOST_WIDE_INT long
211#else
212/*@constant int HOST_BITS_PER_WIDE_INT@*/
213#define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_INT
214/*@notfunction@*/
215#define HOST_WIDE_INT long
216#endif
217
218#endif
219
220struct operation {
221 short op;
222
223 /* Priority of op (relative to it right operand). */
224 /*@reldef@*/ char rprio;
225
226 /*@reldef@*/ char flags;
227
228 /* true if value should be treated as unsigned */
229 /*@reldef@*/ bool unsignedp;
230
231 /* The value logically "right" of op. */
232 /*@reldef@*/ HOST_WIDE_INT value;
233} ;
234
235/* Take care of parsing a number (anything that starts with a digit).
236 LEN is the number of characters in it. */
237
238/* maybe needs to actually deal with floating point numbers */
239
240struct operation
86d93ed3 241cppReader_parseNumber (cppReader *pfile, char *start, int olen) /*@requires maxRead(start) >= (olen - 1) @*/
616915dd 242{
243 struct operation op;
244 char *p = start;
245 char c;
246 int i;
247 long n = 0;
248 unsigned long nd, ULONG_MAX_over_base;
249 int base = 10;
250 int len = olen;
251 bool overflow = FALSE;
252 int digit, largest_digit = 0;
253 bool spec_long = FALSE;
254
255 op.unsignedp = FALSE;
256
257 for (i = 0; i < len; i++)
258 {
86d93ed3 259 /*drl bee: is*/ if (p[i] == '.') {
616915dd 260 /* It's a float since it contains a point. */
261 cppReader_errorLit
262 (pfile,
263 cstring_makeLiteralTemp
264 ("Floating point numbers not allowed in #if expressions"));
265 op.op = CPPREADER_ERRORTOK;
266 return op;
267 }
268 }
269
270 if (len >= 3 && (mstring_equalPrefix (p, "0x")
271 || mstring_equalPrefix (p, "0X")))
272 {
273 p += 2;
274 base = 16;
275 len -= 2;
276 }
277 else if (*p == '0')
278 {
86d93ed3 279 /*@i3434*/
280 /* drl: see if there is a reason that we shouldn't do
281 p++;
282 len--; */
283
616915dd 284 base = 8;
285 }
286 else
287 {
288 ;
289 }
290
291 /* Some buggy compilers (e.g. MPW C) seem to need both casts. */
292 ULONG_MAX_over_base = ((unsigned long) -1) / ((unsigned long) base);
293
294 for (; len > 0; len--) {
295 c = *p++;
296
297 if (c >= '0' && c <= '9')
298 {
299 digit = (int) (c - '0');
300 }
301 else if (base == 16 && c >= 'a' && c <= 'f')
302 {
303 digit = (int) (c - 'a') + 10;
304 }
305 else if (base == 16 && c >= 'A' && c <= 'F')
306 {
307 digit = (int) (c - 'A') + 10;
308 }
309 else
310 {
311 /* `l' means long, and `u' means unsigned. */
312 while (TRUE)
313 {
314 if (c == 'l' || c == 'L')
315 {
316 if (spec_long)
317 cppReader_errorLit (pfile,
318 cstring_makeLiteralTemp ("two `l's in integer constant"));
319 spec_long = TRUE;
320 }
321 else if (c == 'u' || c == 'U')
322 {
323 if (op.unsignedp)
324 cppReader_errorLit (pfile,
325 cstring_makeLiteralTemp ("two `u's in integer constant"));
326 op.unsignedp = TRUE;
327 }
328 else
329 {
330 /*@innerbreak@*/ break;
331 }
332
333 if (--len == 0)
334 {
335 /*@innerbreak@*/ break;
336 }
337
86d93ed3 338 /*drl bee: ltc*/ c = *p++;
616915dd 339 }
340 /* Don't look for any more digits after the suffixes. */
341 break;
342 }
343
344 if (largest_digit < digit)
345 {
346 largest_digit = digit;
347 }
348
349 nd = (long unsigned) (n * base + digit);
350 overflow |= (ULONG_MAX_over_base < (unsigned long) n)
351 | (nd < (unsigned long) n);
352 n = (long) nd;
353 }
354
355 if (len != 0)
356 {
357 cppReader_errorLit
358 (pfile,
359 cstring_makeLiteralTemp ("Invalid number in #if expression"));
360 op.op = CPPREADER_ERRORTOK;
361 return op;
362 }
363
364 if (base <= largest_digit)
365 {
366 cppReader_pedwarnLit
367 (pfile,
368 cstring_makeLiteralTemp
369 ("Integer constant contains digits beyond the radix"));
370 }
371
372 if (overflow)
373 {
28bf4b0b 374 /*@i23 add flags for all these...*/
616915dd 375 cppReader_pedwarnLit
376 (pfile,
377 cstring_makeLiteralTemp ("Integer constant out of range"));
378 }
379
380 /* If too big to be signed, consider it unsigned. */
381 if ((long) n < 0 && ! op.unsignedp)
382 {
383 if (base == 10)
384 {
385 cppReader_warningLit
386 (pfile,
387 cstring_makeLiteralTemp ("Integer constant is so large that it is unsigned"));
388 }
389
390 op.unsignedp = TRUE;
391 }
392
393 op.value = n;
394 op.op = CPPEXP_INT;
3e3ec469 395 DPRINTF (("Parse number: %d", op.value));
616915dd 396 return op;
397}
398
399struct token {
400 /*@null@*/ /*@observer@*/ char *operator;
401 int token;
402};
403
404static struct token tokentab2[] = {
405 { "&&", ANDAND },
406 { "||", OROR },
407 { "<<", LSH },
408 { ">>", RSH },
409 { "==", CPP_EQUALTOK },
410 { "!=", NOTEQUAL },
411 { "<=", LEQ },
412 { ">=", GEQ },
413 { "++", CPPREADER_ERRORTOK },
414 { "--", CPPREADER_ERRORTOK },
415 { NULL, CPPREADER_ERRORTOK }
416} ;
417
418/* Read one token. */
419
3e3ec469 420struct operation cppexp_lex (cppReader *pfile)
616915dd 421{
422 int ic;
423 char c;
424 register struct token *toktab;
425 enum cpp_token token;
426 struct operation op;
427 char *tok_start, *tok_end;
428 int old_written;
429
430 retry:
3e3ec469 431
432 old_written = size_toInt (cpplib_getWritten (pfile));
616915dd 433 cppSkipHspace (pfile);
3e3ec469 434 ic = cpplib_bufPeek (cppReader_getBufferSafe (pfile));
616915dd 435
436 c = (char) ic;
437 llassert (c != '#');
3e3ec469 438 DPRINTF (("Read: %c", c));
439
616915dd 440 if (c == '\n')
441 {
442 op.op = 0;
443 return op;
444 }
445
3e3ec469 446 token = cpplib_getTokenForceExpand (pfile);
447
616915dd 448 tok_start = pfile->token_buffer + old_written;
3e3ec469 449 tok_end = cpplib_getPWritten (pfile);
450
451 DPRINTF (("Token: %s < %s", tok_start, tok_end));
452
616915dd 453 pfile->limit = tok_start;
454
455 switch (token)
3e3ec469 456 {
616915dd 457 case CPP_EOF: /* Should not happen ... */
458 case CPP_VSPACE:
459 op.op = 0;
460 return op;
461 case CPP_POP:
462 if (cstring_isDefined (cppReader_getBufferSafe (pfile)->fname))
463 {
464 op.op = 0;
465 return op;
466 }
467 (void) cppReader_popBuffer (pfile);
468 goto retry;
469 case CPP_HSPACE: case CPP_COMMENT:
470 goto retry;
471 case CPP_NUMBER:
472 return cppReader_parseNumber (pfile, tok_start, tok_end - tok_start);
473 case CPP_STRING:
474 cppReader_errorLit (pfile,
3e3ec469 475 cstring_makeLiteralTemp ("string constants not allowed in #if expressions"));
616915dd 476 op.op = CPPREADER_ERRORTOK;
477 return op;
478 case CPP_CHAR:
479 /* This code for reading a character constant
480 handles multicharacter constants and wide characters.
481 It is mostly copied from c-lex.c. */
482 {
483 int result = 0;
484 int num_chars = 0;
485 size_t width = MAX_CHAR_TYPE_SIZE;
486 int wide_flag = 0;
487 int max_chars;
488 char *ptr = tok_start;
489#ifdef MULTIBYTE_CHARS
490 char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + MB_CUR_MAX];
491#else
492 char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + 1];
493#endif
3e3ec469 494
616915dd 495 if (*ptr == 'L')
496 {
497 ptr++;
498 wide_flag = 1;
499 width = MAX_WCHAR_TYPE_SIZE;
500#ifdef MULTIBYTE_CHARS
501 max_chars = MB_CUR_MAX;
502#else
503 max_chars = 1;
504#endif
505 }
506 else
507 {
508 max_chars = size_toInt (MAX_LONG_TYPE_SIZE / width);
509 }
3e3ec469 510
616915dd 511 ++ptr;
86d93ed3 512 /*drl bee: hda*/ while (ptr < tok_end && ((c = *ptr++) != '\''))
616915dd 513 {
514 if (c == '\\')
515 {
516 c = cppReader_parseEscape (pfile, &ptr);
517 if (width < HOST_BITS_PER_INT && c >= (1 << width))
518 {
519 cppReader_pedwarnLit
520 (pfile,
521 cstring_makeLiteralTemp ("Escape sequence out of range for character"));
522 }
523 }
524
525 num_chars++;
526
527 /* Merge character into result; ignore excess chars. */
528 if (num_chars < max_chars + 1)
529 {
530 if (width < HOST_BITS_PER_INT)
531 {
532 result = (int) ((unsigned) result << width) | (c & ((1 << width) - 1));
533 }
534 else
535 {
536 result = c;
537 }
538
539 token_buffer[num_chars - 1] = c;
540 }
541 }
542
86d93ed3 543 /*drl bee: dad*/ token_buffer[num_chars] = 0;
616915dd 544
545 if (c != '\'')
546 cppReader_errorLit (pfile,
547 cstring_makeLiteralTemp ("malformatted character constant"));
548 else if (num_chars == 0)
549 cppReader_errorLit (pfile,
550 cstring_makeLiteralTemp ("empty character constant"));
551 else if (num_chars > max_chars)
552 {
553 num_chars = max_chars;
554 cppReader_errorLit (pfile,
555 cstring_makeLiteralTemp ("character constant too long"));
556 }
557 else if (num_chars != 1 && ! cppReader_isTraditional (pfile))
558 {
559 cppReader_warningLit (pfile,
560 cstring_makeLiteralTemp ("multi-character character constant"));
561 }
562 else
563 {
564 ;
565 }
566
567 /* If char type is signed, sign-extend the constant. */
568 if (wide_flag == 0)
569 {
570 int num_bits = num_chars * width;
571
3e3ec469 572 if ((cpphash_lookup ("__CHAR_UNSIGNED__",
616915dd 573 sizeof ("__CHAR_UNSIGNED__") - 1, -1) != NULL)
a956d444 574 || (((unsigned) result >> (int_toNonNegative (num_bits - 1))) & 1) == 0)
616915dd 575 {
576 op.value
a956d444 577 = result & ((unsigned long) ~0
578 >> int_toNonNegative ((HOST_BITS_PER_LONG - num_bits)));
616915dd 579 }
580 else
581 {
582 op.value
a956d444 583 = result | ~((unsigned long) ~0
584 >> int_toNonNegative ((HOST_BITS_PER_LONG - num_bits)));
616915dd 585 }
586 }
587 else
588 {
589#ifdef MULTIBYTE_CHARS
590 /* Set the initial shift state and convert the next sequence. */
591 result = 0;
592 /* In all locales L'\0' is zero and mbtowc will return zero,
593 so don't use it. */
594 if (num_chars > 1
595 || (num_chars == 1 && token_buffer[0] != '\0'))
596 {
597 wchar_t wc;
598 (void) mbtowc (NULL, NULL, 0);
599 if (mbtowc (& wc, token_buffer, num_chars) == num_chars)
600 result = wc;
601 else
602 cppReader_pedwarn (pfile,"Ignoring invalid multibyte character");
603 }
604#endif
605 op.value = result;
606 }
607 }
608
609 /* This is always a signed type. */
610 op.unsignedp = FALSE;
611 op.op = CPPEXP_CHAR;
612
613 return op;
614
615 case CPP_NAME:
3e3ec469 616 DPRINTF (("Name!"));
616915dd 617 return cppReader_parseNumber (pfile, "0", 0);
618
619 case CPP_OTHER:
620 /* See if it is a special token of length 2. */
621 if (tok_start + 2 == tok_end)
622 {
623 for (toktab = tokentab2; toktab->operator != NULL; toktab++)
624 {
86d93ed3 625 /*drl bee: hda*/ if (tok_start[0] == /*drl bee: hda*/ toktab->operator[0]
626 && /*drl bee: hda*/ tok_start[1] == /*drl bee: hda*/ toktab->operator[1])
616915dd 627 {
628 /*@loopbreak@*/ break;
629 }
630 }
631
632 if (toktab->token == CPPREADER_ERRORTOK)
633 {
634 cppReader_error (pfile, message ("`%s' not allowed in operand of `#if'", cstring_fromChars (tok_start)));
635 }
636
637 op.op = toktab->token;
638 return op;
639 }
640 /*@fallthrough@*/
641 default:
642 op.op = *tok_start;
643 return op;
644 }
645
646 BADEXIT;
647 /*@notreached@*/
648}
649
650
651/* Parse a C escape sequence. STRING_PTR points to a variable
652 containing a pointer to the string to parse. That pointer
653 is updated past the characters we use. The value of the
654 escape sequence is returned.
655
656 A negative value means the sequence \ newline was seen,
657 which is supposed to be equivalent to nothing at all.
658
659 If \ is followed by a null character, we return a negative
660 value and leave the string pointer pointing at the null character.
661
662 If \ is followed by 000, we return 0 and leave the string pointer
663 after the zeros. A value of 0 does not mean end of string. */
664
665int
666cppReader_parseEscape (cppReader *pfile, char **string_ptr)
667{
86d93ed3 668 /*drl bee: pbr*/ char c = *(*string_ptr)++;
616915dd 669
670 switch (c)
671 {
672 case 'a':
673 return TARGET_BELL;
674 case 'b':
675 return TARGET_BS;
676 case 'e':
677 case 'E':
678 if (cppReader_isPedantic (pfile))
679 {
680 cppReader_pedwarn (pfile,
681 message ("non-ANSI-standard escape sequence, `\\%c'", c));
682 }
683 return (char) 033;
684 case 'f':
685 return TARGET_FF;
686 case 'n':
687 return TARGET_NEWLINE;
688 case 'r':
689 return TARGET_CR;
690 case 't':
691 return TARGET_TAB;
692 case 'v':
693 return TARGET_VT;
694 case '\n':
695 return -2;
696 case 0:
697 (*string_ptr)--;
698 return 0;
699
700 case '0':
701 case '1':
702 case '2':
703 case '3':
704 case '4':
705 case '5':
706 case '6':
707 case '7':
708 {
709 int i = (int) c - '0';
710 int count = 0;
711
712 while (++count < 3)
713 {
714 c = *(*string_ptr)++;
715 if (c >= '0' && c <= '7')
716 {
717 i = ((unsigned) i << 3) + c - '0';
718 }
719
720 else
721 {
86d93ed3 722 /*drl bee: pbr*/ (*string_ptr)--;
616915dd 723 /*@loopbreak@*/ break;
724 }
725 }
726 if ((i & ~((1 << MAX_CHAR_TYPE_SIZE) - 1)) != 0)
727 {
728 i &= (1 << MAX_CHAR_TYPE_SIZE) - 1;
729 cppReader_pedwarnLit (pfile,
730 cstring_makeLiteralTemp ("octal character constant does not fit in a byte"));
731 }
732 return i;
733 }
734 case 'x':
735 {
736 register unsigned i = 0, overflow = 0, digits_found = 0, digit;
737 for (;;)
738 {
739 c = *(*string_ptr)++;
740
741 if (c >= '0' && c <= '9')
742 {
743 digit = (unsigned int) (c - '0');
744 }
745 else if (c >= 'a' && c <= 'f')
746 {
747 digit = (unsigned int) (c - 'a') + 10;
748 }
749 else if (c >= 'A' && c <= 'F')
750 {
751 digit = (unsigned int) (c - 'A') + 10;
752 }
753 else
754 {
755 (*string_ptr)--;
756 /*@loopbreak@*/ break;
757 }
758 overflow |= i ^ (i << 4 >> 4);
759 i = (i << 4) + digit;
760 digits_found = 1;
761 }
762
763 if (digits_found == 0)
764 {
765 cppReader_errorLit (pfile,
766 cstring_makeLiteralTemp ("\\x used with no following hex digits"));
767 }
768
a956d444 769 if ((overflow | (i & ~((1 << int_toNonNegative (BITS_PER_UNIT)) - 1))) != 0)
616915dd 770 {
771 i &= (1 << BITS_PER_UNIT) - 1;
772 cppReader_pedwarnLit (pfile,
773 cstring_makeLiteralTemp ("hex character constant does not fit in a byte"));
774 }
775
776 return i;
777 }
778 default:
779 return c;
780 }
781}
782
783static void
784integer_overflow (cppReader *pfile)
785{
786 if (cppReader_isPedantic (pfile))
787 cppReader_pedwarnLit (pfile,
788 cstring_makeLiteralTemp ("integer overflow in preprocessor expression"));
789}
790
791static long
792left_shift (cppReader *pfile, long a, bool unsignedp, size_t b)
793{
794 if (b >= HOST_BITS_PER_LONG)
795 {
796 if (!unsignedp && a != 0)
797 {
798 integer_overflow (pfile);
799 }
800
801 return 0;
802 }
803 else if (unsignedp)
804 {
805 return (unsigned long) a << b;
806 }
807 else
808 {
a956d444 809 long l = int_toNonNegative (a) << b;
616915dd 810
a956d444 811 if (int_toNonNegative (l) >> b != a)
616915dd 812 {
813 integer_overflow (pfile);
814 }
815
816 return l;
817 }
818}
819
820static long
821right_shift (long a, bool unsignedp, unsigned long b)
822{
823 if (b >= HOST_BITS_PER_LONG)
a956d444 824 return (unsignedp ? 0 : int_toNonNegative (a) >> (HOST_BITS_PER_LONG - 1));
616915dd 825 else if (unsignedp)
826 return (unsigned long) a >> b;
827 else
a956d444 828 return int_toNonNegative (a) >> b;
616915dd 829}
830
831/* These priorities are all even, so we can handle associatively. */
832
833/*@constant int PAREN_INNER_PRIO@*/
834#define PAREN_INNER_PRIO 0
835
836/*@constant int COMMA_PRIO@*/
837#define COMMA_PRIO 4
838
839/*@constant int COND_PRIO@*/
840#define COND_PRIO (COMMA_PRIO+2)
841
842/*@constant int OROR_PRIO@*/
843#define OROR_PRIO (COND_PRIO+2)
844
845/*@constant int ANDAND_PRIO@*/
846#define ANDAND_PRIO (OROR_PRIO+2)
847
848/*@constant int OR_PRIO@*/
849#define OR_PRIO (ANDAND_PRIO+2)
850
851/*@constant int XOR_PRIO@*/
852#define XOR_PRIO (OR_PRIO+2)
853
854/*@constant int AND_PRIO@*/
855#define AND_PRIO (XOR_PRIO+2)
856
857/*@constant int CPP_EQUAL_PRIO@*/
858#define CPP_EQUAL_PRIO (AND_PRIO+2)
859
860/*@constant int LESS_PRIO@*/
861#define LESS_PRIO (CPP_EQUAL_PRIO+2)
862
863/*@constant int SHIFT_PRIO@*/
864#define SHIFT_PRIO (LESS_PRIO+2)
865
866/*@constant int PLUS_PRIO@*/
867#define PLUS_PRIO (SHIFT_PRIO+2)
868
869/*@constant int MUL_PRIO@*/
870#define MUL_PRIO (PLUS_PRIO+2)
871
872/*@constant int UNARY_PRIO@*/
873#define UNARY_PRIO (MUL_PRIO+2)
874
875/*@constant int PAREN_OUTER_PRIO@*/
876#define PAREN_OUTER_PRIO (UNARY_PRIO+2)
877
878/*@notfunction@*/
879#define COMPARE(OP) \
880 top->unsignedp = FALSE;\
881 top->value = ((unsigned1 || unsigned2) \
882 ? (unsigned long) v1 OP (unsigned long) v2 \
883 : ((long) v1 OP (long) v2)) ? 1 : 0
884
885/* Parse and evaluate a C expression, reading from PFILE.
886 Returns the value of the expression. */
887
888/*@constant int INIT_STACK_SIZE@*/
889# define INIT_STACK_SIZE 20
890
891HOST_WIDE_INT
892cppReader_parseExpression (cppReader *pfile)
893{
894 /* The implementation is an operator precedence parser,
895 i.e. a bottom-up parser, using a stack for not-yet-reduced tokens.
896
897 The stack base is 'stack', and the current stack pointer is 'top'.
898 There is a stack element for each operator (only),
899 and the most recently pushed operator is 'top->op'.
900 An operand (value) is stored in the 'value' field of the stack
901 element of the operator that precedes it.
902 In that case the 'flags' field has the HAVE_VALUE flag set. */
903
904 struct operation init_stack[INIT_STACK_SIZE];
905 struct operation *stack = init_stack;
906 struct operation *limit = stack + INIT_STACK_SIZE;
907 register struct operation *top = stack;
908 int lprio, rprio = 0;
909 int skip_evaluation = 0;
910
911 top->rprio = 0;
912 top->flags = 0;
913
914 for (;;)
915 {
916 struct operation op;
917 int flags = 0;
918
919 /* Read a token */
3e3ec469 920 op = cppexp_lex (pfile);
616915dd 921
922 /* See if the token is an operand, in which case go to set_value.
923 If the token is an operator, figure out its left and right
924 priorities, and then goto maybe_reduce. */
925
926 switch (op.op)
927 {
928 case NAME:
929 top->value = 0, top->unsignedp = FALSE;
930 goto set_value;
931 case CPPEXP_INT:
932 case CPPEXP_CHAR:
933 top->value = op.value;
934 top->unsignedp = op.unsignedp;
935 goto set_value;
936 case 0:
937 lprio = 0; goto maybe_reduce;
938 case '+': case '-':
939 /* Is this correct if unary ? FIXME */
940 flags = RIGHT_OPERAND_REQUIRED;
941 lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce;
942 case '!': case '~':
943 flags = RIGHT_OPERAND_REQUIRED;
944 rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce;
945 case '*': case '/': case '%':
946 lprio = MUL_PRIO; goto binop;
947 case '<': case '>': case LEQ: case GEQ:
948 lprio = LESS_PRIO; goto binop;
949 case CPP_EQUALTOK: case NOTEQUAL:
950 lprio = CPP_EQUAL_PRIO; goto binop;
951 case LSH: case RSH:
952 lprio = SHIFT_PRIO; goto binop;
953 case '&': lprio = AND_PRIO; goto binop;
954 case '^': lprio = XOR_PRIO; goto binop;
955 case '|': lprio = OR_PRIO; goto binop;
956 case ANDAND: lprio = ANDAND_PRIO; goto binop;
957 case OROR: lprio = OROR_PRIO; goto binop;
958 case ',':
959 lprio = COMMA_PRIO; goto binop;
960 case '(':
961 lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO;
962 goto maybe_reduce;
963 case ')':
964 lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO;
965 goto maybe_reduce;
966 case ':':
967 lprio = COND_PRIO; rprio = COND_PRIO;
968 goto maybe_reduce;
969 case '?':
970 lprio = COND_PRIO + 1; rprio = COND_PRIO;
971 goto maybe_reduce;
972 binop:
973 flags = LEFT_OPERAND_REQUIRED | RIGHT_OPERAND_REQUIRED;
974 rprio = lprio + 1;
975 goto maybe_reduce;
976 default:
977 cppReader_error
978 (pfile,
979 message ("Invalid character in #if: %c",
980 (char) op.op));
981 goto syntax_error;
982 }
983
984 set_value:
985 /* Push a value onto the stack. */
986 if ((top->flags & HAVE_VALUE) != 0)
987 {
988 cppReader_errorLit (pfile,
989 cstring_makeLiteralTemp ("syntax error in #if"));
990 goto syntax_error;
991 }
992 top->flags |= HAVE_VALUE;
993 continue;
994
995 maybe_reduce:
996 /* Push an operator, and check if we can reduce now. */
997 while (top->rprio > lprio)
998 {
999 /*@-usedef@*/
1000 long v1 = top[-1].value, v2 = top[0].value;
1001 bool unsigned1 = top[-1].unsignedp;
1002 bool unsigned2 = top[0].unsignedp;
1003
1004 top--;
1005
1006 if (((top[1].flags & LEFT_OPERAND_REQUIRED) != 0)
1007 && ((top[0].flags & HAVE_VALUE) == 0))
1008 {
1009 cppReader_errorLit (pfile,
1010 cstring_makeLiteralTemp ("syntax error - missing left operand"));
1011 goto syntax_error;
1012 }
1013 if (((top[1].flags & RIGHT_OPERAND_REQUIRED) != 0)
1014 && ((top[1].flags & HAVE_VALUE) == 0))
1015 {
1016 cppReader_errorLit (pfile,
1017 cstring_makeLiteralTemp ("syntax error - missing right operand"));
1018 goto syntax_error;
1019 }
1020 /* top[0].value = (top[1].op)(v1, v2);*/
1021 switch (top[1].op)
1022 {
1023 case '+':
1024 if ((top->flags & HAVE_VALUE) == 0)
1025 { /* Unary '+' */
1026 top->value = v2;
1027 top->unsignedp = unsigned2;
1028 top->flags |= HAVE_VALUE;
1029 }
1030 else
1031 {
1032 top->value = v1 + v2;
1033 top->unsignedp = unsigned1 || unsigned2;
1034 if (!top->unsignedp && (skip_evaluation == 0)
1035 && ! possibleSumSign (v1, v2, top->value))
1036 integer_overflow (pfile);
1037 }
1038 /*@switchbreak@*/ break;
1039 case '-':
1040 if ((top->flags & HAVE_VALUE) == 0)
1041 { /* Unary '-' */
1042 top->value = - v2;
1043 if ((skip_evaluation == 0)
1044 && (top->value & v2) < 0 && !unsigned2)
1045 integer_overflow (pfile);
1046 top->unsignedp = unsigned2;
1047 top->flags |= HAVE_VALUE;
1048 }
1049 else
1050 { /* Binary '-' */
1051 top->value = v1 - v2;
1052 top->unsignedp = unsigned1 || unsigned2;
1053 if (!top->unsignedp && (skip_evaluation == 0)
1054 && !possibleSumSign (top->value, v2, v1))
1055 {
1056 integer_overflow (pfile);
1057 }
1058 }
1059 /*@switchbreak@*/ break;
1060 case '*':
1061 top->unsignedp = unsigned1 || unsigned2;
1062
1063 if (top->unsignedp)
1064 {
1065 top->value = (unsigned long) v1 * v2;
1066 }
1067 else if (skip_evaluation == 0)
1068 {
1069 top->value = v1 * v2;
1070 if ((v1 != 0)
1071 && (top->value / v1 != v2
1072 || (top->value & v1 & v2) < 0))
1073 {
1074 integer_overflow (pfile);
1075 }
1076 }
1077 else
1078 {
1079 ;
1080 }
1081
1082 /*@switchbreak@*/ break;
1083 case '/':
1084 if (skip_evaluation != 0)
1085 /*@switchbreak@*/ break;
1086 if (v2 == 0)
1087 {
1088 cppReader_errorLit (pfile,
1089 cstring_makeLiteralTemp ("Division by zero in #if"));
1090 v2 = 1;
1091 }
1092 top->unsignedp = unsigned1 || unsigned2;
1093 if (top->unsignedp)
1094 top->value = (unsigned long) v1 / v2;
1095 else
1096 {
1097 top->value = v1 / v2;
1098 if ((top->value & v1 & v2) < 0)
1099 integer_overflow (pfile);
1100 }
1101 /*@switchbreak@*/ break;
1102 case '%':
1103 if (skip_evaluation != 0)
1104 /*@switchbreak@*/ break;
1105 if (v2 == 0)
1106 {
1107 cppReader_errorLit (pfile,
1108 cstring_makeLiteralTemp ("Division by zero in #if"));
1109 v2 = 1;
1110 }
1111 top->unsignedp = unsigned1 || unsigned2;
1112 if (top->unsignedp)
1113 top->value = (unsigned long) v1 % v2;
1114 else
1115 top->value = v1 % v2;
1116 /*@switchbreak@*/ break;
1117 case '!':
1118 if ((top->flags & HAVE_VALUE) != 0)
1119 {
1120 cppReader_errorLit (pfile,
1121 cstring_makeLiteralTemp ("Syntax error"));
1122 goto syntax_error;
1123 }
1124
1125 top->value = (v2 == 0) ? 1 : 0;
1126 top->unsignedp = FALSE;
1127 top->flags |= HAVE_VALUE;
1128 /*@switchbreak@*/ break;
1129 case '~':
1130 if ((top->flags & HAVE_VALUE) != 0)
1131 {
1132 cppReader_errorLit (pfile,
1133 cstring_makeLiteralTemp ("syntax error"));
1134 goto syntax_error;
1135 }
1136 top->value = ~ v2;
1137 top->unsignedp = unsigned2;
1138 top->flags |= HAVE_VALUE;
1139 /*@switchbreak@*/ break;
1140 case '<': COMPARE(<); /*@switchbreak@*/ break;
1141 case '>': COMPARE(>); /*@switchbreak@*/ break;
1142 case LEQ: COMPARE(<=); /*@switchbreak@*/ break;
1143 case GEQ: COMPARE(>=); /*@switchbreak@*/ break;
1144 case CPP_EQUALTOK:
1145 top->value = (v1 == v2) ? 1 : 0;
1146 top->unsignedp = FALSE;
1147 /*@switchbreak@*/ break;
1148 case NOTEQUAL:
1149 top->value = (v1 != v2) ? 1 : 0;
1150 top->unsignedp = FALSE;
1151 /*@switchbreak@*/ break;
1152 case LSH:
1153 if (skip_evaluation != 0)
1154 {
1155 /*@switchbreak@*/ break;
1156 }
1157
1158 top->unsignedp = unsigned1;
1159 if (v2 < 0 && ! unsigned2)
1160 top->value = right_shift (v1, unsigned1, -v2);
1161 else
1162 top->value = left_shift (pfile, v1, unsigned1, v2);
1163 /*@switchbreak@*/ break;
1164 case RSH:
1165 if (skip_evaluation != 0)
1166 {
1167 /*@switchbreak@*/ break;
1168 }
1169 top->unsignedp = unsigned1;
1170 if (v2 < 0 && ! unsigned2)
1171 top->value = left_shift (pfile, v1, unsigned1, -v2);
1172 else
1173 top->value = right_shift (v1, unsigned1, v2);
1174 /*@switchbreak@*/ break;
1175
1176/*@notfunction@*/
1177#define LOGICAL(OP) \
1178 top->value = v1 OP v2;\
1179 top->unsignedp = unsigned1 || unsigned2;
1180
1181 case '&': LOGICAL(&); /*@switchbreak@*/ break;
1182 case '^': LOGICAL(^); /*@switchbreak@*/ break;
1183 case '|': LOGICAL(|); /*@switchbreak@*/ break;
1184 case ANDAND:
1185 top->value = ((v1 != 0) && (v2 != 0)) ? 1 : 0;
1186 top->unsignedp = FALSE;
1187
1188 if (v1 == 0)
1189 {
1190 skip_evaluation--;
1191 }
1192 /*@switchbreak@*/ break;
1193 case OROR:
1194 top->value = ((v1 != 0) || (v2 != 0)) ? 1 : 0;
1195 top->unsignedp = FALSE;
1196 if (v1 != 0)
1197 {
1198 skip_evaluation--;
1199 }
1200 /*@switchbreak@*/ break;
1201 case ',':
1202 if (cppReader_isPedantic (pfile))
1203 cppReader_pedwarnLit (pfile,
1204 cstring_makeLiteralTemp ("comma operator in operand of `#if'"));
1205 top->value = v2;
1206 top->unsignedp = unsigned2;
1207 /*@switchbreak@*/ break;
1208 case '(': case '?':
1209 cppReader_errorLit (pfile,
1210 cstring_makeLiteralTemp ("syntax error in #if"));
1211 goto syntax_error;
1212 case ':':
1213 if (top[0].op != '?')
1214 {
1215 cppReader_errorLit (pfile,
1216 cstring_makeLiteralTemp ("syntax error ':' without preceding '?'"));
1217 goto syntax_error;
1218 }
1219 else if (((top[1].flags & HAVE_VALUE) == 0)
1220 || ((top[-1].flags & HAVE_VALUE) == 0)
1221 || ((top[0].flags & HAVE_VALUE) == 0))
1222 {
1223 cppReader_errorLit (pfile,
1224 cstring_makeLiteralTemp ("bad syntax for ?: operator"));
1225 goto syntax_error;
1226 }
1227 else
1228 {
1229 top--;
1230 if (top->value != 0)
1231 {
1232 skip_evaluation--;
1233 }
1234
1235 top->value = (top->value != 0) ? v1 : v2;
1236 top->unsignedp = unsigned1 || unsigned2;
1237 }
1238 /*@switchbreak@*/ break;
1239 case ')':
1240 if (((top[1].flags & HAVE_VALUE) != 0)
1241 || ((top[0].flags & HAVE_VALUE) == 0)
1242 || top[0].op != '('
1243 || ((top[-1].flags & HAVE_VALUE) != 0))
1244 {
1245 cppReader_errorLit (pfile,
1246 cstring_makeLiteralTemp ("mismatched parentheses in #if"));
1247 goto syntax_error;
1248 }
1249 else
1250 {
1251 top--;
1252 top->value = v1;
1253 top->unsignedp = unsigned1;
1254 top->flags |= HAVE_VALUE;
1255 }
1256 /*@switchbreak@*/ break;
1257 default:
28bf4b0b 1258 /*@-formatconst@*/
616915dd 1259 fprintf (stderr,
1260 top[1].op >= ' ' && top[1].op <= '~'
1261 ? "unimplemented operator '%c'\n"
1262 : "unimplemented operator '\\%03o'\n",
1263 top[1].op);
28bf4b0b 1264 /*@=formatconst@*/
616915dd 1265 }
1266 }
1267 if (op.op == 0)
1268 {
1269 long val;
1270
1271 if (top != stack)
1272 {
1273 cppReader_errorLit (pfile,
1274 cstring_makeLiteralTemp ("internal error in #if expression"));
1275 }
1276
1277 val = top->value;
1278
1279 if (stack != init_stack)
1280 {
1281 sfree (stack);
1282 /*@-branchstate@*/
1283 } /*@=branchstate@*/
1284
1285 return val;
1286 }
1287 top++;
1288
1289 /* Check for and handle stack overflow. */
1290 if (top == limit)
1291 {
1292 struct operation *new_stack;
1293 int old_size = (char *) limit - (char *) stack;
1294 size_t new_size = size_fromInt (2 * old_size);
1295
1296 if (stack != init_stack)
1297 {
1298 new_stack = (struct operation *) drealloc ((char *) stack,
1299 new_size);
1300 }
1301 else
1302 {
1303 new_stack = (struct operation *) dmalloc (new_size);
1304
1305 /* Bug: the parameters were in the wrong order! */
1306 memcpy ((char *) new_stack, (char *) stack, old_size);
1307 /*@-branchstate@*/
1308 } /*@=branchstate@*/
1309
1310 stack = new_stack;
1311 top = (struct operation *) ((char *) new_stack + old_size);
1312 limit = (struct operation *) ((char *) new_stack + new_size);
1313 /*@-branchstate@*/
1314 } /*@=branchstate@*/
1315
1316 top->flags = flags;
1317 top->rprio = rprio;
1318 top->op = op.op;
1319 if ((op.op == OROR && (top[-1].value != 0))
1320 || (op.op == ANDAND && (top[-1].value == 0))
1321 || (op.op == '?' && (top[-1].value == 0)))
1322 {
1323 skip_evaluation++;
1324 }
1325 else if (op.op == ':')
1326 {
1327 if (top[-2].value != 0) /* Was condition true? */
1328 {
1329 skip_evaluation++;
1330 }
1331 else
1332 {
1333 skip_evaluation--;
1334 }
1335 }
1336 else
1337 {
1338 ;
1339 }
1340 }
1341 syntax_error:
1342 /*@-usereleased@*/
1343 if (stack != init_stack)
1344 {
1345 sfree (stack);
1346 /*@-branchstate@*/
1347 } /*@=branchstate@*/
1348 /*@=usereleased@*/
1349
1350 cppReader_skipRestOfLine (pfile);
1351 return 0;
1352}
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