1 /* Parse C expressions for cpplib.
2 Copyright (C) 1987, 92, 94, 95, 97, 98, 1999, 2000 Free Software Foundation.
3 Contributed by Per Bothner, 1994.
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 2, or (at your option) any
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
20 /* Parse a C expression from text in a string */
28 #ifndef MAX_CHAR_TYPE_SIZE
29 #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE
32 #ifndef MAX_INT_TYPE_SIZE
33 #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE
36 #ifndef MAX_LONG_TYPE_SIZE
37 #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE
40 #ifndef MAX_WCHAR_TYPE_SIZE
41 #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE
44 #define MAX_CHAR_TYPE_MASK (MAX_CHAR_TYPE_SIZE < HOST_BITS_PER_WIDEST_INT \
45 ? (~(~(HOST_WIDEST_INT) 0 << MAX_CHAR_TYPE_SIZE)) \
46 : ~ (HOST_WIDEST_INT) 0)
48 #define MAX_WCHAR_TYPE_MASK (MAX_WCHAR_TYPE_SIZE < HOST_BITS_PER_WIDEST_INT \
49 ? ~(~(HOST_WIDEST_INT) 0 << MAX_WCHAR_TYPE_SIZE) \
50 : ~ (HOST_WIDEST_INT) 0)
52 /* Yield nonzero if adding two numbers with A's and B's signs can yield a
53 number with SUM's sign, where A, B, and SUM are all C integers. */
54 #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0)
56 static void integer_overflow PARAMS ((cpp_reader *));
57 static HOST_WIDEST_INT left_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
59 unsigned HOST_WIDEST_INT));
60 static HOST_WIDEST_INT right_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
62 unsigned HOST_WIDEST_INT));
63 static struct op parse_number PARAMS ((cpp_reader *, const cpp_token *));
64 static struct op parse_charconst PARAMS ((cpp_reader *, const cpp_token *));
65 static struct op parse_defined PARAMS ((cpp_reader *));
66 static HOST_WIDEST_INT parse_escape PARAMS ((cpp_reader *, const U_CHAR **,
67 const U_CHAR *, HOST_WIDEST_INT));
68 static struct op lex PARAMS ((cpp_reader *, int, cpp_token *));
69 static const unsigned char *op_as_text PARAMS ((cpp_reader *, enum cpp_ttype));
74 U_CHAR prio; /* Priority of op. */
76 U_CHAR unsignedp; /* True if value should be treated as unsigned. */
77 HOST_WIDEST_INT value; /* The value logically "right" of op. */
80 /* There is no "error" token, but we can't get comments in #if, so we can
81 abuse that token type. */
82 #define CPP_ERROR CPP_COMMENT
84 /* With -O2, gcc appears to produce nice code, moving the error
85 message load and subsequent jump completely out of the main path. */
86 #define CPP_ICE(msgid) \
87 do { cpp_ice (pfile, msgid); goto syntax_error; } while(0)
88 #define SYNTAX_ERROR(msgid) \
89 do { cpp_error (pfile, msgid); goto syntax_error; } while(0)
90 #define SYNTAX_ERROR2(msgid, arg) \
91 do { cpp_error (pfile, msgid, arg); goto syntax_error; } while(0)
93 /* Parse and convert an integer for #if. Accepts decimal, hex, or octal
94 with or without size suffixes. */
102 const struct suffix vsuf_1[] = {
103 { "u", 1, 0 }, { "U", 1, 0 },
104 { "l", 0, 1 }, { "L", 0, 1 }
107 const struct suffix vsuf_2[] = {
108 { "ul", 1, 1 }, { "UL", 1, 1 }, { "uL", 1, 1 }, { "Ul", 1, 1 },
109 { "lu", 1, 1 }, { "LU", 1, 1 }, { "Lu", 1, 1 }, { "lU", 1, 1 },
110 { "ll", 0, 2 }, { "LL", 0, 2 }
113 const struct suffix vsuf_3[] = {
114 { "ull", 1, 2 }, { "ULL", 1, 2 }, { "uLL", 1, 2 }, { "Ull", 1, 2 },
115 { "llu", 1, 2 }, { "LLU", 1, 2 }, { "LLu", 1, 2 }, { "llU", 1, 2 }
117 #define Nsuff(tab) (sizeof tab / sizeof (struct suffix))
120 parse_number (pfile, tok)
122 const cpp_token *tok;
125 const U_CHAR *start = tok->val.str.text;
126 const U_CHAR *end = start + tok->val.str.len;
127 const U_CHAR *p = start;
129 unsigned HOST_WIDEST_INT n = 0, nd, MAX_over_base;
132 int digit, largest_digit = 0;
133 const struct suffix *sufftab;
139 if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X'))
151 /* Some buggy compilers (e.g. MPW C) seem to need both casts. */
152 MAX_over_base = (((unsigned HOST_WIDEST_INT) -1)
153 / ((unsigned HOST_WIDEST_INT) base));
159 if (c >= '0' && c <= '9')
161 /* We believe that in all live character sets, a-f are
162 consecutive, and so are A-F. */
163 else if (base == 16 && c >= 'a' && c <= 'f')
164 digit = c - 'a' + 10;
165 else if (base == 16 && c >= 'A' && c <= 'F')
166 digit = c - 'A' + 10;
170 if (largest_digit < digit)
171 largest_digit = digit;
172 nd = n * base + digit;
173 overflow |= MAX_over_base < n || nd < n;
179 /* Check for a floating point constant. Note that float constants
180 with an exponent or suffix but no decimal point are technically
181 invalid (C99 6.4.4.2) but accepted elsewhere. */
182 if ((c == '.' || c == 'F' || c == 'f')
183 || (base == 10 && (c == 'E' || c == 'e')
184 && p+1 < end && (p[1] == '+' || p[1] == '-'))
185 || (base == 16 && (c == 'P' || c == 'p')
186 && p+1 < end && (p[1] == '+' || p[1] == '-')))
187 SYNTAX_ERROR ("floating point numbers are not valid in #if");
189 /* Determine the suffix. l means long, and u means unsigned.
190 See the suffix tables, above. */
193 case 1: sufftab = vsuf_1; nsuff = Nsuff(vsuf_1); break;
194 case 2: sufftab = vsuf_2; nsuff = Nsuff(vsuf_2); break;
195 case 3: sufftab = vsuf_3; nsuff = Nsuff(vsuf_3); break;
196 default: goto invalid_suffix;
199 for (i = 0; i < nsuff; i++)
200 if (memcmp (p, sufftab[i].s, end - p) == 0)
204 op.unsignedp = sufftab[i].u;
206 if (CPP_WTRADITIONAL (pfile) && sufftab[i].u)
207 cpp_warning (pfile, "traditional C rejects the `U' suffix");
208 if (CPP_OPTION (pfile, c89) && sufftab[i].l == 2)
209 SYNTAX_ERROR ("too many 'l' suffixes in integer constant");
212 if (base <= largest_digit)
213 cpp_pedwarn (pfile, "integer constant contains digits beyond the radix");
216 cpp_pedwarn (pfile, "integer constant out of range");
218 /* If too big to be signed, consider it unsigned. */
219 else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp)
222 cpp_warning (pfile, "integer constant is so large that it is unsigned");
231 cpp_error (pfile, "invalid suffix '%.*s' on integer constant",
238 /* Parse and convert a character constant for #if. Understands backslash
239 escapes (\n, \031) and multibyte characters (if so configured). */
241 parse_charconst (pfile, tok)
243 const cpp_token *tok;
246 HOST_WIDEST_INT result = 0;
249 unsigned int width = MAX_CHAR_TYPE_SIZE, mask = MAX_CHAR_TYPE_MASK;
251 const U_CHAR *ptr = tok->val.str.text;
252 const U_CHAR *end = ptr + tok->val.str.len;
256 if (tok->type == CPP_WCHAR)
257 width = MAX_WCHAR_TYPE_SIZE, mask = MAX_WCHAR_TYPE_MASK;
258 max_chars = MAX_LONG_TYPE_SIZE / width;
264 CPP_ICE ("unescaped ' in character constant");
267 c = parse_escape (pfile, &ptr, end, mask);
268 if (width < HOST_BITS_PER_INT
269 && (unsigned int) c >= (unsigned int)(1 << width))
271 "escape sequence out of range for character");
274 /* Merge character into result; ignore excess chars. */
275 if (++num_chars <= max_chars)
277 if (width < HOST_BITS_PER_INT)
278 result = (result << width) | (c & ((1 << width) - 1));
285 SYNTAX_ERROR ("empty character constant");
286 else if (num_chars > max_chars)
287 SYNTAX_ERROR ("character constant too long");
288 else if (num_chars != 1)
289 cpp_warning (pfile, "multi-character character constant");
291 /* If char type is signed, sign-extend the constant. */
292 num_bits = num_chars * width;
294 if (pfile->spec_nodes.n__CHAR_UNSIGNED__->type == NT_MACRO
295 || ((result >> (num_bits - 1)) & 1) == 0)
296 op.value = result & ((unsigned HOST_WIDEST_INT) ~0
297 >> (HOST_BITS_PER_WIDEST_INT - num_bits));
299 op.value = result | ~((unsigned HOST_WIDEST_INT) ~0
300 >> (HOST_BITS_PER_WIDEST_INT - num_bits));
302 /* This is always a signed type. */
313 parse_defined (pfile)
317 cpp_hashnode *node = 0;
321 /* Don't expand macros. */
322 pfile->state.prevent_expansion++;
324 _cpp_get_token (pfile, &token);
325 if (token.type == CPP_OPEN_PAREN)
328 _cpp_get_token (pfile, &token);
331 if (token.type == CPP_NAME)
333 node = token.val.node;
336 _cpp_get_token (pfile, &token);
337 if (token.type != CPP_CLOSE_PAREN)
339 cpp_error (pfile, "missing ')' after \"defined\"");
345 cpp_error (pfile, "\"defined\" without an identifier");
351 op.value = node->type == NT_MACRO;
355 /* No macros? At top of file? */
356 if (pfile->mi_state == MI_OUTSIDE && pfile->mi_cmacro == 0
357 && pfile->mi_if_not_defined == MI_IND_NOT && pfile->mi_lexed == 1)
359 cpp_start_lookahead (pfile);
360 cpp_get_token (pfile, &token);
361 if (token.type == CPP_EOF)
362 pfile->mi_ind_cmacro = node;
363 cpp_stop_lookahead (pfile, 0);
367 pfile->state.prevent_expansion--;
371 /* Read one token. */
374 lex (pfile, skip_evaluation, token)
382 _cpp_get_token (pfile, token);
386 case CPP_PLACEMARKER:
391 return parse_number (pfile, token);
394 return parse_charconst (pfile, token);
398 SYNTAX_ERROR ("string constants are not valid in #if");
401 SYNTAX_ERROR ("floating point numbers are not valid in #if");
404 if (ISGRAPH (token->val.c))
405 SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c);
407 SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c);
410 if (token->val.node == pfile->spec_nodes.n_defined)
412 if (pfile->context->prev && CPP_PEDANTIC (pfile))
413 cpp_pedwarn (pfile, "\"defined\" operator appears during macro expansion");
415 return parse_defined (pfile);
417 /* Controlling #if expressions cannot contain identifiers (they
418 could become macros in the future). */
419 pfile->mi_state = MI_FAILED;
425 if (CPP_OPTION (pfile, warn_undef) && !skip_evaluation)
426 cpp_warning (pfile, "\"%s\" is not defined", token->val.node->name);
435 if (_cpp_test_assertion (pfile, &temp))
443 /* We don't worry about its position here. */
444 pfile->mi_if_not_defined = MI_IND_NOT;
448 if ((token->type > CPP_EQ && token->type < CPP_PLUS_EQ)
449 || token->type == CPP_EOF)
455 SYNTAX_ERROR2 ("\"%s\" is not valid in #if expressions",
456 cpp_token_as_text (pfile, token));
464 /* Parse a C escape sequence. STRING_PTR points to a variable
465 containing a pointer to the string to parse. That pointer
466 is updated past the characters we use. The value of the
467 escape sequence is returned.
469 If \ is followed by 000, we return 0 and leave the string pointer
470 after the zeros. A value of 0 does not mean end of string. */
472 static HOST_WIDEST_INT
473 parse_escape (pfile, string_ptr, limit, result_mask)
475 const U_CHAR **string_ptr;
477 HOST_WIDEST_INT result_mask;
479 const U_CHAR *ptr = *string_ptr;
480 /* We know we have at least one following character. */
484 case 'a': c = TARGET_BELL; break;
485 case 'b': c = TARGET_BS; break;
486 case 'f': c = TARGET_FF; break;
487 case 'n': c = TARGET_NEWLINE; break;
488 case 'r': c = TARGET_CR; break;
489 case 't': c = TARGET_TAB; break;
490 case 'v': c = TARGET_VT; break;
493 if (CPP_PEDANTIC (pfile))
494 cpp_pedwarn (pfile, "non-ISO-standard escape sequence, '\\%c'", c);
498 case '0': case '1': case '2': case '3':
499 case '4': case '5': case '6': case '7':
501 unsigned int i = c - '0';
509 if (c < '0' || c > '7')
512 i = (i << 3) + c - '0';
514 if (i != (i & result_mask))
517 cpp_pedwarn (pfile, "octal escape sequence out of range");
525 unsigned int i = 0, overflow = 0;
526 int digits_found = 0, digit;
532 if (c >= '0' && c <= '9')
534 else if (c >= 'a' && c <= 'f')
535 digit = c - 'a' + 10;
536 else if (c >= 'A' && c <= 'F')
537 digit = c - 'A' + 10;
541 overflow |= i ^ (i << 4 >> 4);
542 i = (i << 4) + digit;
546 cpp_error (pfile, "\\x used with no following hex digits");
547 if (overflow | (i != (i & result_mask)))
550 cpp_pedwarn (pfile, "hex escape sequence out of range");
561 integer_overflow (pfile)
564 if (CPP_PEDANTIC (pfile))
565 cpp_pedwarn (pfile, "integer overflow in preprocessor expression");
568 static HOST_WIDEST_INT
569 left_shift (pfile, a, unsignedp, b)
572 unsigned int unsignedp;
573 unsigned HOST_WIDEST_INT b;
575 if (b >= HOST_BITS_PER_WIDEST_INT)
577 if (! unsignedp && a != 0)
578 integer_overflow (pfile);
582 return (unsigned HOST_WIDEST_INT) a << b;
585 HOST_WIDEST_INT l = a << b;
587 integer_overflow (pfile);
592 static HOST_WIDEST_INT
593 right_shift (pfile, a, unsignedp, b)
594 cpp_reader *pfile ATTRIBUTE_UNUSED;
596 unsigned int unsignedp;
597 unsigned HOST_WIDEST_INT b;
599 if (b >= HOST_BITS_PER_WIDEST_INT)
600 return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1);
602 return (unsigned HOST_WIDEST_INT) a >> b;
607 /* Operator precedence and flags table.
609 After an operator is returned from the lexer, if it has priority less
610 than or equal to the operator on the top of the stack, we reduce the
611 stack by one operator and repeat the test. Since equal priorities
612 reduce, this is naturally left-associative.
614 We handle right-associative operators by clearing the lower bit of all
615 left-associative operators, and setting it for right-associative ones.
616 After the reduction phase of a new operator, just before it is pushed
617 onto the stack, its RIGHT_ASSOC bit is cleared. The effect is that
618 during the reduction phase, the current right-associative operator has
619 a priority one greater than any other operator of otherwise equal
620 precedence that has been pushed on the top of the stack. This avoids
621 a reduction pass, and effectively makes the logic right-associative.
623 The remaining cases are '(' and ')'. We handle '(' by skipping the
624 reduction phase completely. ')' is given lower priority than
625 everything else, including '(', effectively forcing a reduction of the
626 parenthesised expression. If there is no matching '(', the stack will
627 be reduced all the way to the beginning, exiting the parser in the
628 same way as the ultra-low priority end-of-expression dummy operator.
629 The exit code checks to see if the operator that caused it is ')', and
630 if so outputs an appropriate error message.
632 The parser assumes all shifted operators require a right operand
633 unless the flag NO_R_OPERAND is set, and similarly for NO_L_OPERAND.
634 These semantics are automatically checked, any extra semantics need to
635 be handled with operator-specific code. */
638 #define FLAG_MASK ((1 << FLAG_BITS) - 1)
639 #define PRIO_SHIFT (FLAG_BITS + 1)
640 #define EXTRACT_PRIO(cnst) (cnst >> FLAG_BITS)
641 #define EXTRACT_FLAGS(cnst) (cnst & FLAG_MASK)
644 #define HAVE_VALUE (1 << 0)
645 #define NO_L_OPERAND (1 << 1)
646 #define NO_R_OPERAND (1 << 2)
647 #define SHORT_CIRCUIT (1 << 3)
649 /* Priority and flag combinations. */
650 #define RIGHT_ASSOC (1 << FLAG_BITS)
651 #define FORCE_REDUCE_PRIO (0 << PRIO_SHIFT)
652 #define CLOSE_PAREN_PRIO (1 << PRIO_SHIFT)
653 #define OPEN_PAREN_PRIO ((2 << PRIO_SHIFT) | NO_L_OPERAND)
654 #define COMMA_PRIO (3 << PRIO_SHIFT)
655 #define COND_PRIO ((4 << PRIO_SHIFT) | RIGHT_ASSOC | SHORT_CIRCUIT)
656 #define COLON_PRIO ((5 << PRIO_SHIFT) | SHORT_CIRCUIT)
657 #define OROR_PRIO ((6 << PRIO_SHIFT) | SHORT_CIRCUIT)
658 #define ANDAND_PRIO ((7 << PRIO_SHIFT) | SHORT_CIRCUIT)
659 #define OR_PRIO (8 << PRIO_SHIFT)
660 #define XOR_PRIO (9 << PRIO_SHIFT)
661 #define AND_PRIO (10 << PRIO_SHIFT)
662 #define MINMAX_PRIO (11 << PRIO_SHIFT)
663 #define EQUAL_PRIO (12 << PRIO_SHIFT)
664 #define LESS_PRIO (13 << PRIO_SHIFT)
665 #define SHIFT_PRIO (14 << PRIO_SHIFT)
666 #define PLUS_PRIO (15 << PRIO_SHIFT)
667 #define MUL_PRIO (16 << PRIO_SHIFT)
668 #define UNARY_PRIO ((17 << PRIO_SHIFT) | RIGHT_ASSOC | NO_L_OPERAND)
670 /* Operator to priority map. Must be in the same order as the first
671 N entries of enum cpp_ttype. */
675 /* EQ */ 0, /* dummy entry - can't happen */
676 /* NOT */ UNARY_PRIO,
677 /* GREATER */ LESS_PRIO,
678 /* LESS */ LESS_PRIO,
679 /* PLUS */ UNARY_PRIO, /* note these two can be unary */
680 /* MINUS */ UNARY_PRIO, /* or binary */
687 /* RSHIFT */ SHIFT_PRIO,
688 /* LSHIFT */ SHIFT_PRIO,
689 /* MIN */ MINMAX_PRIO, /* C++ specific */
690 /* MAX */ MINMAX_PRIO, /* extensions */
692 /* COMPL */ UNARY_PRIO,
693 /* AND_AND */ ANDAND_PRIO,
694 /* OR_OR */ OROR_PRIO,
695 /* QUERY */ COND_PRIO,
696 /* COLON */ COLON_PRIO,
697 /* COMMA */ COMMA_PRIO,
698 /* OPEN_PAREN */ OPEN_PAREN_PRIO,
699 /* CLOSE_PAREN */ CLOSE_PAREN_PRIO,
700 /* EQ_EQ */ EQUAL_PRIO,
701 /* NOT_EQ */ EQUAL_PRIO,
702 /* GREATER_EQ */ LESS_PRIO,
703 /* LESS_EQ */ LESS_PRIO
706 #define COMPARE(OP) \
707 top->unsignedp = 0; \
708 top->value = (unsigned1 | unsigned2) \
709 ? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 \
711 #define EQUALITY(OP) \
712 top->value = v1 OP v2; \
714 #define BITWISE(OP) \
715 top->value = v1 OP v2; \
716 top->unsignedp = unsigned1 | unsigned2;
718 top->value = (v1 OP v2) ? v1 : v2; \
719 top->unsignedp = unsigned1 | unsigned2;
721 top->value = OP v2; \
722 top->unsignedp = unsigned2; \
723 top->flags |= HAVE_VALUE;
724 #define SHIFT(PSH, MSH) \
725 if (skip_evaluation) \
727 top->unsignedp = unsigned1; \
728 if (v2 < 0 && ! unsigned2) \
729 top->value = MSH (pfile, v1, unsigned1, -v2); \
731 top->value = PSH (pfile, v1, unsigned1, v2);
733 /* Parse and evaluate a C expression, reading from PFILE.
734 Returns the truth value of the expression. */
737 _cpp_parse_expr (pfile)
740 /* The implementation is an operator precedence parser, i.e. a
741 bottom-up parser, using a stack for not-yet-reduced tokens.
743 The stack base is 'stack', and the current stack pointer is 'top'.
744 There is a stack element for each operator (only),
745 and the most recently pushed operator is 'top->op'.
746 An operand (value) is stored in the 'value' field of the stack
747 element of the operator that precedes it.
748 In that case the 'flags' field has the HAVE_VALUE flag set. */
750 #define INIT_STACK_SIZE 20
751 struct op init_stack[INIT_STACK_SIZE];
752 struct op *stack = init_stack;
753 struct op *limit = stack + INIT_STACK_SIZE;
755 register struct op *top = stack + 1;
756 int skip_evaluation = 0;
759 /* Save parser state and set it to something sane. */
760 int save_skipping = pfile->skipping;
763 /* Set up detection of #if ! defined(). */
765 pfile->mi_if_not_defined = MI_IND_NONE;
767 /* We've finished when we try to reduce this. */
769 /* Nifty way to catch missing '('. */
770 top->prio = EXTRACT_PRIO(CLOSE_PAREN_PRIO);
771 /* Avoid missing right operand checks. */
772 top->flags = NO_R_OPERAND;
781 op = lex (pfile, skip_evaluation, &token);
784 /* If the token is an operand, push its value and get next
785 token. If it is an operator, get its priority and flags, and
786 try to reduce the expression on the stack. */
793 /* Push a value onto the stack. */
794 if (top->flags & HAVE_VALUE)
795 SYNTAX_ERROR ("missing binary operator");
796 top->value = op.value;
797 top->unsignedp = op.unsignedp;
798 top->flags |= HAVE_VALUE;
801 case CPP_EOF: prio = FORCE_REDUCE_PRIO; break;
803 case CPP_MINUS: prio = PLUS_PRIO; if (top->flags & HAVE_VALUE) break;
804 /* else unary; fall through */
805 default: prio = op_to_prio[op.op]; break;
808 /* Separate the operator's code into priority and flags. */
809 flags = EXTRACT_FLAGS(prio);
810 prio = EXTRACT_PRIO(prio);
811 if (prio == EXTRACT_PRIO(OPEN_PAREN_PRIO))
814 /* Check for reductions. Then push the operator. */
815 while (prio <= top->prio)
817 HOST_WIDEST_INT v1, v2;
818 unsigned int unsigned1, unsigned2;
820 /* Most operators that can appear on the stack require a
821 right operand. Check this before trying to reduce. */
822 if ((top->flags & (HAVE_VALUE | NO_R_OPERAND)) == 0)
824 if (top->op == CPP_OPEN_PAREN)
825 SYNTAX_ERROR ("void expression between '(' and ')'");
827 SYNTAX_ERROR2 ("operator '%s' has no right operand",
828 op_as_text (pfile, top->op));
831 unsigned2 = top->unsignedp, v2 = top->value;
833 unsigned1 = top->unsignedp, v1 = top->value;
835 /* Now set top->value = (top[1].op)(v1, v2); */
839 cpp_ice (pfile, "impossible operator '%s'",
840 op_as_text (pfile, top[1].op));
843 case CPP_NOT: UNARY(!); break;
844 case CPP_COMPL: UNARY(~); break;
845 case CPP_LESS: COMPARE(<); break;
846 case CPP_GREATER: COMPARE(>); break;
847 case CPP_LESS_EQ: COMPARE(<=); break;
848 case CPP_GREATER_EQ: COMPARE(>=); break;
849 case CPP_EQ_EQ: EQUALITY(==); break;
850 case CPP_NOT_EQ: EQUALITY(!=); break;
851 case CPP_AND: BITWISE(&); break;
852 case CPP_XOR: BITWISE(^); break;
853 case CPP_OR: BITWISE(|); break;
854 case CPP_LSHIFT: SHIFT(left_shift, right_shift); break;
855 case CPP_RSHIFT: SHIFT(right_shift, left_shift); break;
856 case CPP_MIN: MINMAX(<); break;
857 case CPP_MAX: MINMAX(>); break;
860 if (!(top->flags & HAVE_VALUE))
862 /* Can't use UNARY(+) because K+R C did not have unary
863 plus. Can't use UNARY() because some compilers object
864 to the empty argument. */
866 top->unsignedp = unsigned2;
867 top->flags |= HAVE_VALUE;
869 if (CPP_WTRADITIONAL (pfile))
871 "traditional C rejects the unary plus operator");
875 top->value = v1 + v2;
876 top->unsignedp = unsigned1 | unsigned2;
877 if (! top->unsignedp && ! skip_evaluation
878 && ! possible_sum_sign (v1, v2, top->value))
879 integer_overflow (pfile);
883 if (!(top->flags & HAVE_VALUE))
886 if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2)
887 integer_overflow (pfile);
891 top->value = v1 - v2;
892 top->unsignedp = unsigned1 | unsigned2;
893 if (! top->unsignedp && ! skip_evaluation
894 && ! possible_sum_sign (top->value, v2, v1))
895 integer_overflow (pfile);
899 top->unsignedp = unsigned1 | unsigned2;
901 top->value = (unsigned HOST_WIDEST_INT) v1 * v2;
902 else if (!skip_evaluation)
904 top->value = v1 * v2;
905 if (v1 && (top->value / v1 != v2
906 || (top->value & v1 & v2) < 0))
907 integer_overflow (pfile);
915 SYNTAX_ERROR ("division by zero in #if");
916 top->unsignedp = unsigned1 | unsigned2;
917 if (top[1].op == CPP_DIV)
920 top->value = (unsigned HOST_WIDEST_INT) v1 / v2;
923 top->value = v1 / v2;
924 if ((top->value & v1 & v2) < 0)
925 integer_overflow (pfile);
931 top->value = (unsigned HOST_WIDEST_INT) v1 % v2;
933 top->value = v1 % v2;
938 top->value = v1 || v2;
940 if (v1) skip_evaluation--;
943 top->value = v1 && v2;
945 if (!v1) skip_evaluation--;
948 if (CPP_PEDANTIC (pfile))
949 cpp_pedwarn (pfile, "comma operator in operand of #if");
951 top->unsignedp = unsigned2;
954 SYNTAX_ERROR ("syntax error '?' without following ':'");
956 if (top[0].op != CPP_QUERY)
957 SYNTAX_ERROR ("syntax error ':' without preceding '?'");
959 if (top->value) skip_evaluation--;
960 top->value = top->value ? v1 : v2;
961 top->unsignedp = unsigned1 | unsigned2;
964 if (op.op != CPP_CLOSE_PAREN)
965 SYNTAX_ERROR ("missing ')' in expression");
967 op.unsignedp = unsigned2;
970 /* Reducing this dummy operator indicates we've finished. */
971 if (op.op == CPP_CLOSE_PAREN)
972 SYNTAX_ERROR ("missing '(' in expression");
977 /* Handle short-circuit evaluations. */
978 if (flags & SHORT_CIRCUIT)
981 case CPP_OR_OR: if (top->value) skip_evaluation++; break;
983 case CPP_QUERY: if (!top->value) skip_evaluation++; break;
985 if (top[-1].value) /* Was '?' condition true? */
994 /* Check we have a left operand iff we need one. */
995 if (flags & NO_L_OPERAND)
997 if (top->flags & HAVE_VALUE)
998 SYNTAX_ERROR2 ("missing binary operator before '%s'",
999 op_as_text (pfile, top->op));
1003 if (!(top->flags & HAVE_VALUE))
1004 SYNTAX_ERROR2 ("operator '%s' has no left operand",
1005 op_as_text (pfile, top->op));
1008 /* Check for and handle stack overflow. */
1012 struct op *new_stack;
1013 int old_size = (char *) limit - (char *) stack;
1014 int new_size = 2 * old_size;
1015 if (stack != init_stack)
1016 new_stack = (struct op *) xrealloc (stack, new_size);
1019 new_stack = (struct op *) xmalloc (new_size);
1020 memcpy (new_stack, stack, old_size);
1023 top = (struct op *) ((char *) new_stack + old_size);
1024 limit = (struct op *) ((char *) new_stack + new_size);
1028 top->prio = prio & ~EXTRACT_PRIO(RIGHT_ASSOC);
1033 result = (top[1].value != 0);
1035 CPP_ICE ("unbalanced stack in #if");
1036 else if (!(top[1].flags & HAVE_VALUE))
1038 SYNTAX_ERROR ("#if with no expression");
1040 result = 0; /* Return 0 on syntax error. */
1043 /* Free dynamic stack if we allocated one. */
1044 if (stack != init_stack)
1046 pfile->skipping = save_skipping;
1050 static const unsigned char *
1051 op_as_text (pfile, op)
1059 return cpp_token_as_text (pfile, &token);