1 /* Parse C expressions for cpplib.
2 Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001
3 Free Software Foundation.
4 Contributed by Per Bothner, 1994.
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, or (at your option) any
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /* 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 (sufftab[i].l == 2 && CPP_OPTION (pfile, pedantic)
209 && ! CPP_OPTION (pfile, c99))
210 cpp_pedwarn (pfile, "too many 'l' suffixes in integer constant");
213 if (base <= largest_digit)
214 cpp_pedwarn (pfile, "integer constant contains digits beyond the radix");
217 cpp_pedwarn (pfile, "integer constant out of range");
219 /* If too big to be signed, consider it unsigned. */
220 else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp)
223 cpp_warning (pfile, "integer constant is so large that it is unsigned");
232 cpp_error (pfile, "invalid suffix '%.*s' on integer constant",
239 /* Parse and convert a character constant for #if. Understands backslash
240 escapes (\n, \031) and multibyte characters (if so configured). */
242 parse_charconst (pfile, tok)
244 const cpp_token *tok;
247 HOST_WIDEST_INT result = 0;
250 unsigned int width = MAX_CHAR_TYPE_SIZE;
251 HOST_WIDEST_INT mask = MAX_CHAR_TYPE_MASK;
253 const U_CHAR *ptr = tok->val.str.text;
254 const U_CHAR *end = ptr + tok->val.str.len;
258 if (tok->type == CPP_WCHAR)
259 width = MAX_WCHAR_TYPE_SIZE, mask = MAX_WCHAR_TYPE_MASK;
260 max_chars = MAX_LONG_TYPE_SIZE / width;
266 CPP_ICE ("unescaped ' in character constant");
269 c = parse_escape (pfile, &ptr, end, mask);
270 if (width < HOST_BITS_PER_INT
271 && (unsigned int) c >= (unsigned int)(1 << width))
273 "escape sequence out of range for character");
276 /* Merge character into result; ignore excess chars. */
277 if (++num_chars <= max_chars)
279 if (width < HOST_BITS_PER_INT)
280 result = (result << width) | (c & ((1 << width) - 1));
287 SYNTAX_ERROR ("empty character constant");
288 else if (num_chars > max_chars)
289 SYNTAX_ERROR ("character constant too long");
290 else if (num_chars != 1)
291 cpp_warning (pfile, "multi-character character constant");
293 /* If char type is signed, sign-extend the constant. */
294 num_bits = num_chars * width;
296 if (pfile->spec_nodes.n__CHAR_UNSIGNED__->type == NT_MACRO
297 || ((result >> (num_bits - 1)) & 1) == 0)
298 op.value = result & ((unsigned HOST_WIDEST_INT) ~0
299 >> (HOST_BITS_PER_WIDEST_INT - num_bits));
301 op.value = result | ~((unsigned HOST_WIDEST_INT) ~0
302 >> (HOST_BITS_PER_WIDEST_INT - num_bits));
304 /* This is always a signed type. */
315 parse_defined (pfile)
319 cpp_hashnode *node = 0;
323 /* Don't expand macros. */
324 pfile->state.prevent_expansion++;
326 cpp_get_token (pfile, &token);
327 if (token.type == CPP_OPEN_PAREN)
330 cpp_get_token (pfile, &token);
333 if (token.type == CPP_NAME)
335 node = token.val.node;
338 cpp_get_token (pfile, &token);
339 if (token.type != CPP_CLOSE_PAREN)
341 cpp_error (pfile, "missing ')' after \"defined\"");
348 cpp_error (pfile, "operator \"defined\" requires an identifier");
349 if (token.flags & NAMED_OP)
354 op.type = token.type;
356 "(\"%s\" is an alternative token for \"%s\" in C++)",
357 cpp_token_as_text (pfile, &token),
358 cpp_token_as_text (pfile, &op));
366 op.value = node->type == NT_MACRO;
370 /* No macros? At top of file? */
371 if (pfile->mi_state == MI_OUTSIDE && pfile->mi_cmacro == 0
372 && pfile->mi_if_not_defined == MI_IND_NOT && pfile->mi_lexed == 1)
374 cpp_start_lookahead (pfile);
375 cpp_get_token (pfile, &token);
376 if (token.type == CPP_EOF)
377 pfile->mi_ind_cmacro = node;
378 cpp_stop_lookahead (pfile, 0);
382 pfile->state.prevent_expansion--;
386 /* Read one token. */
389 lex (pfile, skip_evaluation, token)
396 cpp_get_token (pfile, token);
402 return parse_number (pfile, token);
406 return parse_charconst (pfile, token);
410 SYNTAX_ERROR ("string constants are not valid in #if");
413 SYNTAX_ERROR ("floating point numbers are not valid in #if");
416 if (ISGRAPH (token->val.c))
417 SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c);
419 SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c);
422 if (token->val.node == pfile->spec_nodes.n_defined)
424 if (pfile->context->prev && CPP_PEDANTIC (pfile))
425 cpp_pedwarn (pfile, "\"defined\" operator appears during macro expansion");
427 return parse_defined (pfile);
429 /* Controlling #if expressions cannot contain identifiers (they
430 could become macros in the future). */
431 pfile->mi_state = MI_FAILED;
437 if (CPP_OPTION (pfile, warn_undef) && !skip_evaluation)
438 cpp_warning (pfile, "\"%s\" is not defined", token->val.node->name);
447 if (_cpp_test_assertion (pfile, &temp))
455 /* We don't worry about its position here. */
456 pfile->mi_if_not_defined = MI_IND_NOT;
460 if ((token->type > CPP_EQ && token->type < CPP_PLUS_EQ)
461 || token->type == CPP_EOF)
467 SYNTAX_ERROR2 ("\"%s\" is not valid in #if expressions",
468 cpp_token_as_text (pfile, token));
476 /* Parse a C escape sequence. STRING_PTR points to a variable
477 containing a pointer to the string to parse. That pointer
478 is updated past the characters we use. The value of the
479 escape sequence is returned.
481 If \ is followed by 000, we return 0 and leave the string pointer
482 after the zeros. A value of 0 does not mean end of string. */
484 static HOST_WIDEST_INT
485 parse_escape (pfile, string_ptr, limit, result_mask)
487 const U_CHAR **string_ptr;
489 HOST_WIDEST_INT result_mask;
491 const U_CHAR *ptr = *string_ptr;
492 /* We know we have at least one following character. */
496 case 'a': c = TARGET_BELL; break;
497 case 'b': c = TARGET_BS; break;
498 case 'f': c = TARGET_FF; break;
499 case 'n': c = TARGET_NEWLINE; break;
500 case 'r': c = TARGET_CR; break;
501 case 't': c = TARGET_TAB; break;
502 case 'v': c = TARGET_VT; break;
505 if (CPP_PEDANTIC (pfile))
506 cpp_pedwarn (pfile, "non-ISO-standard escape sequence, '\\%c'", c);
510 case '0': case '1': case '2': case '3':
511 case '4': case '5': case '6': case '7':
513 unsigned int i = c - '0';
521 if (c < '0' || c > '7')
524 i = (i << 3) + c - '0';
526 if (i != (i & result_mask))
529 cpp_pedwarn (pfile, "octal escape sequence out of range");
537 unsigned int i = 0, overflow = 0;
538 int digits_found = 0, digit;
544 if (c >= '0' && c <= '9')
546 else if (c >= 'a' && c <= 'f')
547 digit = c - 'a' + 10;
548 else if (c >= 'A' && c <= 'F')
549 digit = c - 'A' + 10;
553 overflow |= i ^ (i << 4 >> 4);
554 i = (i << 4) + digit;
558 cpp_error (pfile, "\\x used with no following hex digits");
559 if (overflow | (i != (i & result_mask)))
562 cpp_pedwarn (pfile, "hex escape sequence out of range");
573 integer_overflow (pfile)
576 if (CPP_PEDANTIC (pfile))
577 cpp_pedwarn (pfile, "integer overflow in preprocessor expression");
580 static HOST_WIDEST_INT
581 left_shift (pfile, a, unsignedp, b)
584 unsigned int unsignedp;
585 unsigned HOST_WIDEST_INT b;
587 if (b >= HOST_BITS_PER_WIDEST_INT)
589 if (! unsignedp && a != 0)
590 integer_overflow (pfile);
594 return (unsigned HOST_WIDEST_INT) a << b;
597 HOST_WIDEST_INT l = a << b;
599 integer_overflow (pfile);
604 static HOST_WIDEST_INT
605 right_shift (pfile, a, unsignedp, b)
606 cpp_reader *pfile ATTRIBUTE_UNUSED;
608 unsigned int unsignedp;
609 unsigned HOST_WIDEST_INT b;
611 if (b >= HOST_BITS_PER_WIDEST_INT)
612 return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1);
614 return (unsigned HOST_WIDEST_INT) a >> b;
619 /* Operator precedence and flags table.
621 After an operator is returned from the lexer, if it has priority less
622 than or equal to the operator on the top of the stack, we reduce the
623 stack by one operator and repeat the test. Since equal priorities
624 reduce, this is naturally left-associative.
626 We handle right-associative operators by clearing the lower bit of all
627 left-associative operators, and setting it for right-associative ones.
628 After the reduction phase of a new operator, just before it is pushed
629 onto the stack, its RIGHT_ASSOC bit is cleared. The effect is that
630 during the reduction phase, the current right-associative operator has
631 a priority one greater than any other operator of otherwise equal
632 precedence that has been pushed on the top of the stack. This avoids
633 a reduction pass, and effectively makes the logic right-associative.
635 The remaining cases are '(' and ')'. We handle '(' by skipping the
636 reduction phase completely. ')' is given lower priority than
637 everything else, including '(', effectively forcing a reduction of the
638 parenthesised expression. If there is no matching '(', the stack will
639 be reduced all the way to the beginning, exiting the parser in the
640 same way as the ultra-low priority end-of-expression dummy operator.
641 The exit code checks to see if the operator that caused it is ')', and
642 if so outputs an appropriate error message.
644 The parser assumes all shifted operators require a right operand
645 unless the flag NO_R_OPERAND is set, and similarly for NO_L_OPERAND.
646 These semantics are automatically checked, any extra semantics need to
647 be handled with operator-specific code. */
650 #define FLAG_MASK ((1 << FLAG_BITS) - 1)
651 #define PRIO_SHIFT (FLAG_BITS + 1)
652 #define EXTRACT_PRIO(cnst) (cnst >> FLAG_BITS)
653 #define EXTRACT_FLAGS(cnst) (cnst & FLAG_MASK)
656 #define HAVE_VALUE (1 << 0)
657 #define NO_L_OPERAND (1 << 1)
658 #define NO_R_OPERAND (1 << 2)
659 #define SHORT_CIRCUIT (1 << 3)
661 /* Priority and flag combinations. */
662 #define RIGHT_ASSOC (1 << FLAG_BITS)
663 #define FORCE_REDUCE_PRIO (0 << PRIO_SHIFT)
664 #define CLOSE_PAREN_PRIO (1 << PRIO_SHIFT)
665 #define OPEN_PAREN_PRIO ((2 << PRIO_SHIFT) | NO_L_OPERAND)
666 #define COMMA_PRIO (3 << PRIO_SHIFT)
667 #define COND_PRIO ((4 << PRIO_SHIFT) | RIGHT_ASSOC | SHORT_CIRCUIT)
668 #define COLON_PRIO ((5 << PRIO_SHIFT) | SHORT_CIRCUIT)
669 #define OROR_PRIO ((6 << PRIO_SHIFT) | SHORT_CIRCUIT)
670 #define ANDAND_PRIO ((7 << PRIO_SHIFT) | SHORT_CIRCUIT)
671 #define OR_PRIO (8 << PRIO_SHIFT)
672 #define XOR_PRIO (9 << PRIO_SHIFT)
673 #define AND_PRIO (10 << PRIO_SHIFT)
674 #define MINMAX_PRIO (11 << PRIO_SHIFT)
675 #define EQUAL_PRIO (12 << PRIO_SHIFT)
676 #define LESS_PRIO (13 << PRIO_SHIFT)
677 #define SHIFT_PRIO (14 << PRIO_SHIFT)
678 #define PLUS_PRIO (15 << PRIO_SHIFT)
679 #define MUL_PRIO (16 << PRIO_SHIFT)
680 #define UNARY_PRIO ((17 << PRIO_SHIFT) | RIGHT_ASSOC | NO_L_OPERAND)
682 /* Operator to priority map. Must be in the same order as the first
683 N entries of enum cpp_ttype. */
687 /* EQ */ 0, /* dummy entry - can't happen */
688 /* NOT */ UNARY_PRIO,
689 /* GREATER */ LESS_PRIO,
690 /* LESS */ LESS_PRIO,
691 /* PLUS */ UNARY_PRIO, /* note these two can be unary */
692 /* MINUS */ UNARY_PRIO, /* or binary */
699 /* RSHIFT */ SHIFT_PRIO,
700 /* LSHIFT */ SHIFT_PRIO,
701 /* MIN */ MINMAX_PRIO, /* C++ specific */
702 /* MAX */ MINMAX_PRIO, /* extensions */
704 /* COMPL */ UNARY_PRIO,
705 /* AND_AND */ ANDAND_PRIO,
706 /* OR_OR */ OROR_PRIO,
707 /* QUERY */ COND_PRIO,
708 /* COLON */ COLON_PRIO,
709 /* COMMA */ COMMA_PRIO,
710 /* OPEN_PAREN */ OPEN_PAREN_PRIO,
711 /* CLOSE_PAREN */ CLOSE_PAREN_PRIO,
712 /* EQ_EQ */ EQUAL_PRIO,
713 /* NOT_EQ */ EQUAL_PRIO,
714 /* GREATER_EQ */ LESS_PRIO,
715 /* LESS_EQ */ LESS_PRIO
718 #define COMPARE(OP) \
719 top->unsignedp = 0; \
720 top->value = (unsigned1 | unsigned2) \
721 ? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 \
723 #define EQUALITY(OP) \
724 top->value = v1 OP v2; \
726 #define BITWISE(OP) \
727 top->value = v1 OP v2; \
728 top->unsignedp = unsigned1 | unsigned2;
730 top->value = (v1 OP v2) ? v1 : v2; \
731 top->unsignedp = unsigned1 | unsigned2;
733 top->value = OP v2; \
734 top->unsignedp = unsigned2; \
735 top->flags |= HAVE_VALUE;
736 #define SHIFT(PSH, MSH) \
737 if (skip_evaluation) \
739 top->unsignedp = unsigned1; \
740 if (v2 < 0 && ! unsigned2) \
741 top->value = MSH (pfile, v1, unsigned1, -v2); \
743 top->value = PSH (pfile, v1, unsigned1, v2);
745 /* Parse and evaluate a C expression, reading from PFILE.
746 Returns the truth value of the expression. */
749 _cpp_parse_expr (pfile)
752 /* The implementation is an operator precedence parser, i.e. a
753 bottom-up parser, using a stack for not-yet-reduced tokens.
755 The stack base is 'stack', and the current stack pointer is 'top'.
756 There is a stack element for each operator (only),
757 and the most recently pushed operator is 'top->op'.
758 An operand (value) is stored in the 'value' field of the stack
759 element of the operator that precedes it.
760 In that case the 'flags' field has the HAVE_VALUE flag set. */
762 #define INIT_STACK_SIZE 20
763 struct op init_stack[INIT_STACK_SIZE];
764 struct op *stack = init_stack;
765 struct op *limit = stack + INIT_STACK_SIZE;
767 register struct op *top = stack + 1;
768 int skip_evaluation = 0;
771 /* Set up detection of #if ! defined(). */
773 pfile->mi_if_not_defined = MI_IND_NONE;
775 /* We've finished when we try to reduce this. */
777 /* Nifty way to catch missing '('. */
778 top->prio = EXTRACT_PRIO(CLOSE_PAREN_PRIO);
779 /* Avoid missing right operand checks. */
780 top->flags = NO_R_OPERAND;
789 op = lex (pfile, skip_evaluation, &token);
792 /* If the token is an operand, push its value and get next
793 token. If it is an operator, get its priority and flags, and
794 try to reduce the expression on the stack. */
801 /* Push a value onto the stack. */
802 if (top->flags & HAVE_VALUE)
803 SYNTAX_ERROR ("missing binary operator");
804 top->value = op.value;
805 top->unsignedp = op.unsignedp;
806 top->flags |= HAVE_VALUE;
809 case CPP_EOF: prio = FORCE_REDUCE_PRIO; break;
811 case CPP_MINUS: prio = PLUS_PRIO; if (top->flags & HAVE_VALUE) break;
812 /* else unary; fall through */
813 default: prio = op_to_prio[op.op]; break;
816 /* Separate the operator's code into priority and flags. */
817 flags = EXTRACT_FLAGS(prio);
818 prio = EXTRACT_PRIO(prio);
819 if (prio == EXTRACT_PRIO(OPEN_PAREN_PRIO))
822 /* Check for reductions. Then push the operator. */
823 while (prio <= top->prio)
825 HOST_WIDEST_INT v1, v2;
826 unsigned int unsigned1, unsigned2;
828 /* Most operators that can appear on the stack require a
829 right operand. Check this before trying to reduce. */
830 if ((top->flags & (HAVE_VALUE | NO_R_OPERAND)) == 0)
832 if (top->op == CPP_OPEN_PAREN)
833 SYNTAX_ERROR ("void expression between '(' and ')'");
835 SYNTAX_ERROR2 ("operator '%s' has no right operand",
836 op_as_text (pfile, top->op));
839 unsigned2 = top->unsignedp, v2 = top->value;
841 unsigned1 = top->unsignedp, v1 = top->value;
843 /* Now set top->value = (top[1].op)(v1, v2); */
847 cpp_ice (pfile, "impossible operator '%s'",
848 op_as_text (pfile, top[1].op));
851 case CPP_NOT: UNARY(!); break;
852 case CPP_COMPL: UNARY(~); break;
853 case CPP_LESS: COMPARE(<); break;
854 case CPP_GREATER: COMPARE(>); break;
855 case CPP_LESS_EQ: COMPARE(<=); break;
856 case CPP_GREATER_EQ: COMPARE(>=); break;
857 case CPP_EQ_EQ: EQUALITY(==); break;
858 case CPP_NOT_EQ: EQUALITY(!=); break;
859 case CPP_AND: BITWISE(&); break;
860 case CPP_XOR: BITWISE(^); break;
861 case CPP_OR: BITWISE(|); break;
862 case CPP_LSHIFT: SHIFT(left_shift, right_shift); break;
863 case CPP_RSHIFT: SHIFT(right_shift, left_shift); break;
864 case CPP_MIN: MINMAX(<); break;
865 case CPP_MAX: MINMAX(>); break;
868 if (!(top->flags & HAVE_VALUE))
870 /* Can't use UNARY(+) because K+R C did not have unary
871 plus. Can't use UNARY() because some compilers object
872 to the empty argument. */
874 top->unsignedp = unsigned2;
875 top->flags |= HAVE_VALUE;
877 if (CPP_WTRADITIONAL (pfile))
879 "traditional C rejects the unary plus operator");
883 top->value = v1 + v2;
884 top->unsignedp = unsigned1 | unsigned2;
885 if (! top->unsignedp && ! skip_evaluation
886 && ! possible_sum_sign (v1, v2, top->value))
887 integer_overflow (pfile);
891 if (!(top->flags & HAVE_VALUE))
894 if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2)
895 integer_overflow (pfile);
899 top->value = v1 - v2;
900 top->unsignedp = unsigned1 | unsigned2;
901 if (! top->unsignedp && ! skip_evaluation
902 && ! possible_sum_sign (top->value, v2, v1))
903 integer_overflow (pfile);
907 top->unsignedp = unsigned1 | unsigned2;
909 top->value = (unsigned HOST_WIDEST_INT) v1 * v2;
910 else if (!skip_evaluation)
912 top->value = v1 * v2;
913 if (v1 && (top->value / v1 != v2
914 || (top->value & v1 & v2) < 0))
915 integer_overflow (pfile);
923 SYNTAX_ERROR ("division by zero in #if");
924 top->unsignedp = unsigned1 | unsigned2;
925 if (top[1].op == CPP_DIV)
928 top->value = (unsigned HOST_WIDEST_INT) v1 / v2;
931 top->value = v1 / v2;
932 if ((top->value & v1 & v2) < 0)
933 integer_overflow (pfile);
939 top->value = (unsigned HOST_WIDEST_INT) v1 % v2;
941 top->value = v1 % v2;
946 top->value = v1 || v2;
948 if (v1) skip_evaluation--;
951 top->value = v1 && v2;
953 if (!v1) skip_evaluation--;
956 if (CPP_PEDANTIC (pfile))
957 cpp_pedwarn (pfile, "comma operator in operand of #if");
959 top->unsignedp = unsigned2;
962 SYNTAX_ERROR ("syntax error '?' without following ':'");
964 if (top[0].op != CPP_QUERY)
965 SYNTAX_ERROR ("syntax error ':' without preceding '?'");
967 if (top->value) skip_evaluation--;
968 top->value = top->value ? v1 : v2;
969 top->unsignedp = unsigned1 | unsigned2;
972 if (op.op != CPP_CLOSE_PAREN)
973 SYNTAX_ERROR ("missing ')' in expression");
975 op.unsignedp = unsigned2;
978 /* Reducing this dummy operator indicates we've finished. */
979 if (op.op == CPP_CLOSE_PAREN)
980 SYNTAX_ERROR ("missing '(' in expression");
985 /* Handle short-circuit evaluations. */
986 if (flags & SHORT_CIRCUIT)
989 case CPP_OR_OR: if (top->value) skip_evaluation++; break;
991 case CPP_QUERY: if (!top->value) skip_evaluation++; break;
993 if (top[-1].value) /* Was '?' condition true? */
1002 /* Check we have a left operand iff we need one. */
1003 if (flags & NO_L_OPERAND)
1005 if (top->flags & HAVE_VALUE)
1006 SYNTAX_ERROR2 ("missing binary operator before '%s'",
1007 op_as_text (pfile, top->op));
1011 if (!(top->flags & HAVE_VALUE))
1012 SYNTAX_ERROR2 ("operator '%s' has no left operand",
1013 op_as_text (pfile, top->op));
1016 /* Check for and handle stack overflow. */
1020 struct op *new_stack;
1021 int old_size = (char *) limit - (char *) stack;
1022 int new_size = 2 * old_size;
1023 if (stack != init_stack)
1024 new_stack = (struct op *) xrealloc (stack, new_size);
1027 new_stack = (struct op *) xmalloc (new_size);
1028 memcpy (new_stack, stack, old_size);
1031 top = (struct op *) ((char *) new_stack + old_size);
1032 limit = (struct op *) ((char *) new_stack + new_size);
1036 top->prio = prio & ~EXTRACT_PRIO(RIGHT_ASSOC);
1041 result = (top[1].value != 0);
1043 CPP_ICE ("unbalanced stack in #if");
1044 else if (!(top[1].flags & HAVE_VALUE))
1046 SYNTAX_ERROR ("#if with no expression");
1048 result = 0; /* Return 0 on syntax error. */
1051 /* Free dynamic stack if we allocated one. */
1052 if (stack != init_stack)
1057 static const unsigned char *
1058 op_as_text (pfile, op)
1066 return cpp_token_as_text (pfile, &token);