1 /* Parse C expressions for cpplib.
2 Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
3 2002, 2004 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, 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, USA. */
26 #define PART_PRECISION (sizeof (cpp_num_part) * CHAR_BIT)
27 #define HALF_MASK (~(cpp_num_part) 0 >> (PART_PRECISION / 2))
28 #define LOW_PART(num_part) (num_part & HALF_MASK)
29 #define HIGH_PART(num_part) (num_part >> (PART_PRECISION / 2))
33 const cpp_token *token; /* The token forming op (for diagnostics). */
34 cpp_num value; /* The value logically "right" of op. */
38 /* Some simple utility routines on double integers. */
39 #define num_zerop(num) ((num.low | num.high) == 0)
40 #define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high)
41 static bool num_positive (cpp_num, size_t);
42 static bool num_greater_eq (cpp_num, cpp_num, size_t);
43 static cpp_num num_trim (cpp_num, size_t);
44 static cpp_num num_part_mul (cpp_num_part, cpp_num_part);
46 static cpp_num num_unary_op (cpp_reader *, cpp_num, enum cpp_ttype);
47 static cpp_num num_binary_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
48 static cpp_num num_negate (cpp_num, size_t);
49 static cpp_num num_bitwise_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
50 static cpp_num num_inequality_op (cpp_reader *, cpp_num, cpp_num,
52 static cpp_num num_equality_op (cpp_reader *, cpp_num, cpp_num,
54 static cpp_num num_mul (cpp_reader *, cpp_num, cpp_num);
55 static cpp_num num_div_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
56 static cpp_num num_lshift (cpp_num, size_t, size_t);
57 static cpp_num num_rshift (cpp_num, size_t, size_t);
59 static cpp_num append_digit (cpp_num, int, int, size_t);
60 static cpp_num parse_defined (cpp_reader *);
61 static cpp_num eval_token (cpp_reader *, const cpp_token *);
62 static struct op *reduce (cpp_reader *, struct op *, enum cpp_ttype);
63 static unsigned int interpret_float_suffix (const uchar *, size_t);
64 static unsigned int interpret_int_suffix (const uchar *, size_t);
65 static void check_promotion (cpp_reader *, const struct op *);
67 /* Token type abuse to create unary plus and minus operators. */
68 #define CPP_UPLUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 1))
69 #define CPP_UMINUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 2))
71 /* With -O2, gcc appears to produce nice code, moving the error
72 message load and subsequent jump completely out of the main path. */
73 #define SYNTAX_ERROR(msgid) \
74 do { cpp_error (pfile, CPP_DL_ERROR, msgid); goto syntax_error; } while(0)
75 #define SYNTAX_ERROR2(msgid, arg) \
76 do { cpp_error (pfile, CPP_DL_ERROR, msgid, arg); goto syntax_error; } \
79 /* Subroutine of cpp_classify_number. S points to a float suffix of
80 length LEN, possibly zero. Returns 0 for an invalid suffix, or a
81 flag vector describing the suffix. */
83 interpret_float_suffix (const uchar *s, size_t len)
85 size_t f, l, w, q, i, d;
88 f = l = w = q = i = d = 0;
94 case 'r': case 'R': r++; break;
95 case 'k': case 'K': k++; break;
96 case 'u': case 'U': u++; break;
97 case 'h': case 'H': h++; break;
107 /* If there are two Ls, they must be adjacent and the same case. */
108 if (l == 2 && s[len] != s[len + 1])
122 case 'j': case 'J': i++; break;
123 case 'd': case 'D': d++; break;
128 if (r + k > 1 || h > 1 || l > 2 || u > 1)
133 if (f || i || d || w || q)
137 | (u ? CPP_N_UNSIGNED : 0)
139 l == 2 ? CPP_N_LARGE :
140 l == 1 ? CPP_N_MEDIUM : 0));
145 if (f || i || d || w || q)
149 | (u ? CPP_N_UNSIGNED : 0)
151 l == 2 ? CPP_N_LARGE :
152 l == 1 ? CPP_N_MEDIUM : 0));
155 if (f + l + w + q > 1 || i > 1 || h + u > 0)
158 /* Allow dd, df, dl suffixes for decimal float constants. */
159 if (d && ((d + f + l != 2) || i))
162 return ((i ? CPP_N_IMAGINARY : 0)
166 q ? CPP_N_MD_Q : CPP_N_MEDIUM)
167 | (d ? CPP_N_DFLOAT : 0));
170 /* Subroutine of cpp_classify_number. S points to an integer suffix
171 of length LEN, possibly zero. Returns 0 for an invalid suffix, or a
172 flag vector describing the suffix. */
174 interpret_int_suffix (const uchar *s, size_t len)
183 case 'u': case 'U': u++; break;
185 case 'j': case 'J': i++; break;
186 case 'l': case 'L': l++;
187 /* If there are two Ls, they must be adjacent and the same case. */
188 if (l == 2 && s[len] != s[len + 1])
195 if (l > 2 || u > 1 || i > 1)
198 return ((i ? CPP_N_IMAGINARY : 0)
199 | (u ? CPP_N_UNSIGNED : 0)
200 | ((l == 0) ? CPP_N_SMALL
201 : (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE));
204 /* Categorize numeric constants according to their field (integer,
205 floating point, or invalid), radix (decimal, octal, hexadecimal),
206 and type suffixes. */
208 cpp_classify_number (cpp_reader *pfile, const cpp_token *token)
210 const uchar *str = token->val.str.text;
212 unsigned int max_digit, result, radix;
213 enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag;
215 /* If the lexer has done its job, length one can only be a single
216 digit. Fast-path this very common case. */
217 if (token->val.str.len == 1)
218 return CPP_N_INTEGER | CPP_N_SMALL | CPP_N_DECIMAL;
220 limit = str + token->val.str.len;
221 float_flag = NOT_FLOAT;
225 /* First, interpret the radix. */
231 /* Require at least one hex digit to classify it as hex. */
232 if ((*str == 'x' || *str == 'X')
233 && (str[1] == '.' || ISXDIGIT (str[1])))
238 else if ((*str == 'b' || *str == 'B') && (str[1] == '0' || str[1] == '1'))
245 /* Now scan for a well-formed integer or float. */
248 unsigned int c = *str++;
250 if (ISDIGIT (c) || (ISXDIGIT (c) && radix == 16))
258 if (float_flag == NOT_FLOAT)
259 float_flag = AFTER_POINT;
261 SYNTAX_ERROR ("too many decimal points in number");
263 else if ((radix <= 10 && (c == 'e' || c == 'E'))
264 || (radix == 16 && (c == 'p' || c == 'P')))
266 float_flag = AFTER_EXPON;
271 /* Start of suffix. */
277 /* The suffix may be for decimal fixed-point constants without exponent. */
278 if (radix != 16 && float_flag == NOT_FLOAT)
280 result = interpret_float_suffix (str, limit - str);
281 if ((result & CPP_N_FRACT) || (result & CPP_N_ACCUM))
283 result |= CPP_N_FLOATING;
284 /* We need to restore the radix to 10, if the radix is 8. */
288 if (CPP_PEDANTIC (pfile))
289 cpp_error (pfile, CPP_DL_PEDWARN,
290 "fixed-point constants are a GCC extension");
297 if (float_flag != NOT_FLOAT && radix == 8)
300 if (max_digit >= radix)
303 SYNTAX_ERROR2 ("invalid digit \"%c\" in binary constant", '0' + max_digit);
305 SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit);
308 if (float_flag != NOT_FLOAT)
312 cpp_error (pfile, CPP_DL_ERROR,
313 "invalid prefix \"0b\" for floating constant");
314 return CPP_N_INVALID;
317 if (radix == 16 && CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, c99))
318 cpp_error (pfile, CPP_DL_PEDWARN,
319 "use of C99 hexadecimal floating constant");
321 if (float_flag == AFTER_EXPON)
323 if (*str == '+' || *str == '-')
326 /* Exponent is decimal, even if string is a hex float. */
328 SYNTAX_ERROR ("exponent has no digits");
332 while (ISDIGIT (*str));
334 else if (radix == 16)
335 SYNTAX_ERROR ("hexadecimal floating constants require an exponent");
337 result = interpret_float_suffix (str, limit - str);
340 cpp_error (pfile, CPP_DL_ERROR,
341 "invalid suffix \"%.*s\" on floating constant",
342 (int) (limit - str), str);
343 return CPP_N_INVALID;
346 /* Traditional C didn't accept any floating suffixes. */
348 && CPP_WTRADITIONAL (pfile)
349 && ! cpp_sys_macro_p (pfile))
350 cpp_error (pfile, CPP_DL_WARNING,
351 "traditional C rejects the \"%.*s\" suffix",
352 (int) (limit - str), str);
354 /* Radix must be 10 for decimal floats. */
355 if ((result & CPP_N_DFLOAT) && radix != 10)
357 cpp_error (pfile, CPP_DL_ERROR,
358 "invalid suffix \"%.*s\" with hexadecimal floating constant",
359 (int) (limit - str), str);
360 return CPP_N_INVALID;
363 if ((result & (CPP_N_FRACT | CPP_N_ACCUM)) && CPP_PEDANTIC (pfile))
364 cpp_error (pfile, CPP_DL_PEDWARN,
365 "fixed-point constants are a GCC extension");
367 if ((result & CPP_N_DFLOAT) && CPP_PEDANTIC (pfile))
368 cpp_error (pfile, CPP_DL_PEDWARN,
369 "decimal float constants are a GCC extension");
371 result |= CPP_N_FLOATING;
375 result = interpret_int_suffix (str, limit - str);
378 cpp_error (pfile, CPP_DL_ERROR,
379 "invalid suffix \"%.*s\" on integer constant",
380 (int) (limit - str), str);
381 return CPP_N_INVALID;
384 /* Traditional C only accepted the 'L' suffix.
385 Suppress warning about 'LL' with -Wno-long-long. */
386 if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile))
388 int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY));
389 int large = (result & CPP_N_WIDTH) == CPP_N_LARGE;
391 if (u_or_i || (large && CPP_OPTION (pfile, warn_long_long)))
392 cpp_error (pfile, CPP_DL_WARNING,
393 "traditional C rejects the \"%.*s\" suffix",
394 (int) (limit - str), str);
397 if ((result & CPP_N_WIDTH) == CPP_N_LARGE
398 && ! CPP_OPTION (pfile, c99)
399 && CPP_OPTION (pfile, warn_long_long))
400 cpp_error (pfile, CPP_DL_PEDWARN,
401 "use of C99 long long integer constant");
403 result |= CPP_N_INTEGER;
407 if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile))
408 cpp_error (pfile, CPP_DL_PEDWARN,
409 "imaginary constants are a GCC extension");
410 if (radix == 2 && CPP_PEDANTIC (pfile))
411 cpp_error (pfile, CPP_DL_PEDWARN,
412 "binary constants are a GCC extension");
415 result |= CPP_N_DECIMAL;
416 else if (radix == 16)
419 result |= CPP_N_BINARY;
421 result |= CPP_N_OCTAL;
426 return CPP_N_INVALID;
429 /* cpp_interpret_integer converts an integer constant into a cpp_num,
430 of precision options->precision.
432 We do not provide any interface for decimal->float conversion,
433 because the preprocessor doesn't need it and we don't want to
434 drag in GCC's floating point emulator. */
436 cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token,
439 const uchar *p, *end;
444 result.unsignedp = !!(type & CPP_N_UNSIGNED);
445 result.overflow = false;
447 p = token->val.str.text;
448 end = p + token->val.str.len;
450 /* Common case of a single digit. */
451 if (token->val.str.len == 1)
452 result.low = p[0] - '0';
456 size_t precision = CPP_OPTION (pfile, precision);
457 unsigned int base = 10, c = 0;
458 bool overflow = false;
460 if ((type & CPP_N_RADIX) == CPP_N_OCTAL)
465 else if ((type & CPP_N_RADIX) == CPP_N_HEX)
470 else if ((type & CPP_N_RADIX) == CPP_N_BINARY)
476 /* We can add a digit to numbers strictly less than this without
477 needing the precision and slowness of double integers. */
478 max = ~(cpp_num_part) 0;
479 if (precision < PART_PRECISION)
480 max >>= PART_PRECISION - precision;
481 max = (max - base + 1) / base + 1;
487 if (ISDIGIT (c) || (base == 16 && ISXDIGIT (c)))
492 /* Strict inequality for when max is set to zero. */
493 if (result.low < max)
494 result.low = result.low * base + c;
497 result = append_digit (result, c, base, precision);
498 overflow |= result.overflow;
504 cpp_error (pfile, CPP_DL_PEDWARN,
505 "integer constant is too large for its type");
506 /* If too big to be signed, consider it unsigned. Only warn for
507 decimal numbers. Traditional numbers were always signed (but
508 we still honor an explicit U suffix); but we only have
509 traditional semantics in directives. */
510 else if (!result.unsignedp
511 && !(CPP_OPTION (pfile, traditional)
512 && pfile->state.in_directive)
513 && !num_positive (result, precision))
516 cpp_error (pfile, CPP_DL_WARNING,
517 "integer constant is so large that it is unsigned");
518 result.unsignedp = true;
525 /* Append DIGIT to NUM, a number of PRECISION bits being read in base BASE. */
527 append_digit (cpp_num num, int digit, int base, size_t precision)
532 cpp_num_part add_high, add_low;
534 /* Multiply by 2, 8 or 16. Catching this overflow here means we don't
535 need to worry about add_high overflowing. */
549 overflow = !!(num.high >> (PART_PRECISION - shift));
550 result.high = num.high << shift;
551 result.low = num.low << shift;
552 result.high |= num.low >> (PART_PRECISION - shift);
553 result.unsignedp = num.unsignedp;
557 add_low = num.low << 1;
558 add_high = (num.high << 1) + (num.low >> (PART_PRECISION - 1));
561 add_high = add_low = 0;
563 if (add_low + digit < add_low)
567 if (result.low + add_low < result.low)
569 if (result.high + add_high < result.high)
572 result.low += add_low;
573 result.high += add_high;
574 result.overflow = overflow;
576 /* The above code catches overflow of a cpp_num type. This catches
577 overflow of the (possibly shorter) target precision. */
578 num.low = result.low;
579 num.high = result.high;
580 result = num_trim (result, precision);
581 if (!num_eq (result, num))
582 result.overflow = true;
587 /* Handle meeting "defined" in a preprocessor expression. */
589 parse_defined (cpp_reader *pfile)
593 cpp_hashnode *node = 0;
594 const cpp_token *token;
595 cpp_context *initial_context = pfile->context;
597 /* Don't expand macros. */
598 pfile->state.prevent_expansion++;
600 token = cpp_get_token (pfile);
601 if (token->type == CPP_OPEN_PAREN)
604 token = cpp_get_token (pfile);
607 if (token->type == CPP_NAME)
609 node = token->val.node;
610 if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
612 cpp_error (pfile, CPP_DL_ERROR, "missing ')' after \"defined\"");
618 cpp_error (pfile, CPP_DL_ERROR,
619 "operator \"defined\" requires an identifier");
620 if (token->flags & NAMED_OP)
625 op.type = token->type;
626 cpp_error (pfile, CPP_DL_ERROR,
627 "(\"%s\" is an alternative token for \"%s\" in C++)",
628 cpp_token_as_text (pfile, token),
629 cpp_token_as_text (pfile, &op));
635 if (pfile->context != initial_context && CPP_PEDANTIC (pfile))
636 cpp_error (pfile, CPP_DL_WARNING,
637 "this use of \"defined\" may not be portable");
639 _cpp_mark_macro_used (node);
640 if (!(node->flags & NODE_USED))
642 node->flags |= NODE_USED;
643 if (node->type == NT_MACRO)
645 if (pfile->cb.used_define)
646 pfile->cb.used_define (pfile, pfile->directive_line, node);
650 if (pfile->cb.used_undef)
651 pfile->cb.used_undef (pfile, pfile->directive_line, node);
655 /* A possible controlling macro of the form #if !defined ().
656 _cpp_parse_expr checks there was no other junk on the line. */
657 pfile->mi_ind_cmacro = node;
660 pfile->state.prevent_expansion--;
662 result.unsignedp = false;
664 result.overflow = false;
665 result.low = node && node->type == NT_MACRO;
669 /* Convert a token into a CPP_NUMBER (an interpreted preprocessing
670 number or character constant, or the result of the "defined" or "#"
673 eval_token (cpp_reader *pfile, const cpp_token *token)
679 result.unsignedp = false;
680 result.overflow = false;
685 temp = cpp_classify_number (pfile, token);
686 switch (temp & CPP_N_CATEGORY)
689 cpp_error (pfile, CPP_DL_ERROR,
690 "floating constant in preprocessor expression");
693 if (!(temp & CPP_N_IMAGINARY))
694 return cpp_interpret_integer (pfile, token, temp);
695 cpp_error (pfile, CPP_DL_ERROR,
696 "imaginary number in preprocessor expression");
700 /* Error already issued. */
703 result.high = result.low = 0;
711 cppchar_t cc = cpp_interpret_charconst (pfile, token,
716 /* Sign-extend the result if necessary. */
717 if (!unsignedp && (cppchar_signed_t) cc < 0)
719 if (PART_PRECISION > BITS_PER_CPPCHAR_T)
720 result.low |= ~(~(cpp_num_part) 0
721 >> (PART_PRECISION - BITS_PER_CPPCHAR_T));
722 result.high = ~(cpp_num_part) 0;
723 result = num_trim (result, CPP_OPTION (pfile, precision));
729 if (token->val.node == pfile->spec_nodes.n_defined)
730 return parse_defined (pfile);
731 else if (CPP_OPTION (pfile, cplusplus)
732 && (token->val.node == pfile->spec_nodes.n_true
733 || token->val.node == pfile->spec_nodes.n_false))
736 result.low = (token->val.node == pfile->spec_nodes.n_true);
742 if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval)
743 cpp_error (pfile, CPP_DL_WARNING, "\"%s\" is not defined",
744 NODE_NAME (token->val.node));
748 default: /* CPP_HASH */
749 _cpp_test_assertion (pfile, &temp);
754 result.unsignedp = !!unsignedp;
758 /* Operator precedence and flags table.
760 After an operator is returned from the lexer, if it has priority less
761 than the operator on the top of the stack, we reduce the stack by one
762 operator and repeat the test. Since equal priorities do not reduce,
763 this is naturally right-associative.
765 We handle left-associative operators by decrementing the priority of
766 just-lexed operators by one, but retaining the priority of operators
767 already on the stack.
769 The remaining cases are '(' and ')'. We handle '(' by skipping the
770 reduction phase completely. ')' is given lower priority than
771 everything else, including '(', effectively forcing a reduction of the
772 parenthesized expression. If there is a matching '(', the routine
773 reduce() exits immediately. If the normal exit route sees a ')', then
774 there cannot have been a matching '(' and an error message is output.
776 The parser assumes all shifted operators require a left operand unless
777 the flag NO_L_OPERAND is set. These semantics are automatic; any
778 extra semantics need to be handled with operator-specific code. */
780 /* Flags. If CHECK_PROMOTION, we warn if the effective sign of an
781 operand changes because of integer promotions. */
782 #define NO_L_OPERAND (1 << 0)
783 #define LEFT_ASSOC (1 << 1)
784 #define CHECK_PROMOTION (1 << 2)
786 /* Operator to priority map. Must be in the same order as the first
787 N entries of enum cpp_ttype. */
788 static const struct cpp_operator
794 /* EQ */ {0, 0}, /* Shouldn't happen. */
795 /* NOT */ {16, NO_L_OPERAND},
796 /* GREATER */ {12, LEFT_ASSOC | CHECK_PROMOTION},
797 /* LESS */ {12, LEFT_ASSOC | CHECK_PROMOTION},
798 /* PLUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
799 /* MINUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
800 /* MULT */ {15, LEFT_ASSOC | CHECK_PROMOTION},
801 /* DIV */ {15, LEFT_ASSOC | CHECK_PROMOTION},
802 /* MOD */ {15, LEFT_ASSOC | CHECK_PROMOTION},
803 /* AND */ {9, LEFT_ASSOC | CHECK_PROMOTION},
804 /* OR */ {7, LEFT_ASSOC | CHECK_PROMOTION},
805 /* XOR */ {8, LEFT_ASSOC | CHECK_PROMOTION},
806 /* RSHIFT */ {13, LEFT_ASSOC},
807 /* LSHIFT */ {13, LEFT_ASSOC},
809 /* COMPL */ {16, NO_L_OPERAND},
810 /* AND_AND */ {6, LEFT_ASSOC},
811 /* OR_OR */ {5, LEFT_ASSOC},
813 /* COLON */ {4, LEFT_ASSOC | CHECK_PROMOTION},
814 /* COMMA */ {2, LEFT_ASSOC},
815 /* OPEN_PAREN */ {1, NO_L_OPERAND},
816 /* CLOSE_PAREN */ {0, 0},
818 /* EQ_EQ */ {11, LEFT_ASSOC},
819 /* NOT_EQ */ {11, LEFT_ASSOC},
820 /* GREATER_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
821 /* LESS_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
822 /* UPLUS */ {16, NO_L_OPERAND},
823 /* UMINUS */ {16, NO_L_OPERAND}
826 /* Parse and evaluate a C expression, reading from PFILE.
827 Returns the truth value of the expression.
829 The implementation is an operator precedence parser, i.e. a
830 bottom-up parser, using a stack for not-yet-reduced tokens.
832 The stack base is op_stack, and the current stack pointer is 'top'.
833 There is a stack element for each operator (only), and the most
834 recently pushed operator is 'top->op'. An operand (value) is
835 stored in the 'value' field of the stack element of the operator
838 _cpp_parse_expr (cpp_reader *pfile)
840 struct op *top = pfile->op_stack;
841 unsigned int lex_count;
842 bool saw_leading_not, want_value = true;
844 pfile->state.skip_eval = 0;
846 /* Set up detection of #if ! defined(). */
847 pfile->mi_ind_cmacro = 0;
848 saw_leading_not = false;
851 /* Lowest priority operator prevents further reductions. */
859 op.token = cpp_get_token (pfile);
860 op.op = op.token->type;
864 /* These tokens convert into values. */
873 SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
874 cpp_token_as_text (pfile, op.token));
876 top->value = eval_token (pfile, op.token);
880 saw_leading_not = lex_count == 1;
892 if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
893 SYNTAX_ERROR2 ("token \"%s\" is not valid in preprocessor expressions",
894 cpp_token_as_text (pfile, op.token));
898 /* Check we have a value or operator as appropriate. */
899 if (optab[op.op].flags & NO_L_OPERAND)
902 SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
903 cpp_token_as_text (pfile, op.token));
907 /* We want a number (or expression) and haven't got one.
908 Try to emit a specific diagnostic. */
909 if (op.op == CPP_CLOSE_PAREN && top->op == CPP_OPEN_PAREN)
910 SYNTAX_ERROR ("missing expression between '(' and ')'");
912 if (op.op == CPP_EOF && top->op == CPP_EOF)
913 SYNTAX_ERROR ("#if with no expression");
915 if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN)
916 SYNTAX_ERROR2 ("operator '%s' has no right operand",
917 cpp_token_as_text (pfile, top->token));
918 else if (op.op == CPP_CLOSE_PAREN || op.op == CPP_EOF)
919 /* Complain about missing paren during reduction. */;
921 SYNTAX_ERROR2 ("operator '%s' has no left operand",
922 cpp_token_as_text (pfile, op.token));
925 top = reduce (pfile, top, op.op);
929 if (op.op == CPP_EOF)
934 case CPP_CLOSE_PAREN:
937 if (!num_zerop (top->value))
938 pfile->state.skip_eval++;
942 if (num_zerop (top->value))
943 pfile->state.skip_eval++;
946 if (top->op != CPP_QUERY)
947 SYNTAX_ERROR (" ':' without preceding '?'");
948 if (!num_zerop (top[-1].value)) /* Was '?' condition true? */
949 pfile->state.skip_eval++;
951 pfile->state.skip_eval--;
958 /* Check for and handle stack overflow. */
959 if (++top == pfile->op_limit)
960 top = _cpp_expand_op_stack (pfile);
963 top->token = op.token;
966 /* The controlling macro expression is only valid if we called lex 3
967 times: <!> <defined expression> and <EOF>. push_conditional ()
968 checks that we are at top-of-file. */
969 if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
970 pfile->mi_ind_cmacro = 0;
972 if (top != pfile->op_stack)
974 cpp_error (pfile, CPP_DL_ICE, "unbalanced stack in #if");
976 return false; /* Return false on syntax error. */
979 return !num_zerop (top->value);
982 /* Reduce the operator / value stack if possible, in preparation for
983 pushing operator OP. Returns NULL on error, otherwise the top of
986 reduce (cpp_reader *pfile, struct op *top, enum cpp_ttype op)
990 if (top->op <= CPP_EQ || top->op > CPP_LAST_CPP_OP + 2)
993 cpp_error (pfile, CPP_DL_ICE, "impossible operator '%u'", top->op);
997 if (op == CPP_OPEN_PAREN)
1000 /* Decrement the priority of left-associative operators to force a
1001 reduction with operators of otherwise equal priority. */
1002 prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
1003 while (prio < optab[top->op].prio)
1005 if (CPP_OPTION (pfile, warn_num_sign_change)
1006 && optab[top->op].flags & CHECK_PROMOTION)
1007 check_promotion (pfile, top);
1015 top[-1].value = num_unary_op (pfile, top->value, top->op);
1023 top[-1].value = num_binary_op (pfile, top[-1].value,
1024 top->value, top->op);
1029 case CPP_GREATER_EQ:
1032 = num_inequality_op (pfile, top[-1].value, top->value, top->op);
1038 = num_equality_op (pfile, top[-1].value, top->value, top->op);
1045 = num_bitwise_op (pfile, top[-1].value, top->value, top->op);
1049 top[-1].value = num_mul (pfile, top[-1].value, top->value);
1054 top[-1].value = num_div_op (pfile, top[-1].value,
1055 top->value, top->op);
1060 if (!num_zerop (top->value))
1061 pfile->state.skip_eval--;
1062 top->value.low = (!num_zerop (top->value)
1063 || !num_zerop (top[1].value));
1064 top->value.high = 0;
1065 top->value.unsignedp = false;
1066 top->value.overflow = false;
1071 if (num_zerop (top->value))
1072 pfile->state.skip_eval--;
1073 top->value.low = (!num_zerop (top->value)
1074 && !num_zerop (top[1].value));
1075 top->value.high = 0;
1076 top->value.unsignedp = false;
1077 top->value.overflow = false;
1080 case CPP_OPEN_PAREN:
1081 if (op != CPP_CLOSE_PAREN)
1083 cpp_error (pfile, CPP_DL_ERROR, "missing ')' in expression");
1087 top->value = top[1].value;
1092 if (!num_zerop (top->value))
1094 pfile->state.skip_eval--;
1095 top->value = top[1].value;
1098 top->value = top[2].value;
1099 top->value.unsignedp = (top[1].value.unsignedp
1100 || top[2].value.unsignedp);
1104 cpp_error (pfile, CPP_DL_ERROR, "'?' without following ':'");
1112 if (top->value.overflow && !pfile->state.skip_eval)
1113 cpp_error (pfile, CPP_DL_PEDWARN,
1114 "integer overflow in preprocessor expression");
1117 if (op == CPP_CLOSE_PAREN)
1119 cpp_error (pfile, CPP_DL_ERROR, "missing '(' in expression");
1126 /* Returns the position of the old top of stack after expansion. */
1128 _cpp_expand_op_stack (cpp_reader *pfile)
1130 size_t old_size = (size_t) (pfile->op_limit - pfile->op_stack);
1131 size_t new_size = old_size * 2 + 20;
1133 pfile->op_stack = XRESIZEVEC (struct op, pfile->op_stack, new_size);
1134 pfile->op_limit = pfile->op_stack + new_size;
1136 return pfile->op_stack + old_size;
1139 /* Emits a warning if the effective sign of either operand of OP
1140 changes because of integer promotions. */
1142 check_promotion (cpp_reader *pfile, const struct op *op)
1144 if (op->value.unsignedp == op[-1].value.unsignedp)
1147 if (op->value.unsignedp)
1149 if (!num_positive (op[-1].value, CPP_OPTION (pfile, precision)))
1150 cpp_error (pfile, CPP_DL_WARNING,
1151 "the left operand of \"%s\" changes sign when promoted",
1152 cpp_token_as_text (pfile, op->token));
1154 else if (!num_positive (op->value, CPP_OPTION (pfile, precision)))
1155 cpp_error (pfile, CPP_DL_WARNING,
1156 "the right operand of \"%s\" changes sign when promoted",
1157 cpp_token_as_text (pfile, op->token));
1160 /* Clears the unused high order bits of the number pointed to by PNUM. */
1162 num_trim (cpp_num num, size_t precision)
1164 if (precision > PART_PRECISION)
1166 precision -= PART_PRECISION;
1167 if (precision < PART_PRECISION)
1168 num.high &= ((cpp_num_part) 1 << precision) - 1;
1172 if (precision < PART_PRECISION)
1173 num.low &= ((cpp_num_part) 1 << precision) - 1;
1180 /* True iff A (presumed signed) >= 0. */
1182 num_positive (cpp_num num, size_t precision)
1184 if (precision > PART_PRECISION)
1186 precision -= PART_PRECISION;
1187 return (num.high & (cpp_num_part) 1 << (precision - 1)) == 0;
1190 return (num.low & (cpp_num_part) 1 << (precision - 1)) == 0;
1193 /* Sign extend a number, with PRECISION significant bits and all
1194 others assumed clear, to fill out a cpp_num structure. */
1196 cpp_num_sign_extend (cpp_num num, size_t precision)
1200 if (precision > PART_PRECISION)
1202 precision -= PART_PRECISION;
1203 if (precision < PART_PRECISION
1204 && (num.high & (cpp_num_part) 1 << (precision - 1)))
1205 num.high |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
1207 else if (num.low & (cpp_num_part) 1 << (precision - 1))
1209 if (precision < PART_PRECISION)
1210 num.low |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
1211 num.high = ~(cpp_num_part) 0;
1218 /* Returns the negative of NUM. */
1220 num_negate (cpp_num num, size_t precision)
1225 num.high = ~num.high;
1229 num = num_trim (num, precision);
1230 num.overflow = (!num.unsignedp && num_eq (num, copy) && !num_zerop (num));
1235 /* Returns true if A >= B. */
1237 num_greater_eq (cpp_num pa, cpp_num pb, size_t precision)
1241 unsignedp = pa.unsignedp || pb.unsignedp;
1245 /* Both numbers have signed type. If they are of different
1246 sign, the answer is the sign of A. */
1247 unsignedp = num_positive (pa, precision);
1249 if (unsignedp != num_positive (pb, precision))
1252 /* Otherwise we can do an unsigned comparison. */
1255 return (pa.high > pb.high) || (pa.high == pb.high && pa.low >= pb.low);
1258 /* Returns LHS OP RHS, where OP is a bit-wise operation. */
1260 num_bitwise_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
1261 cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1263 lhs.overflow = false;
1264 lhs.unsignedp = lhs.unsignedp || rhs.unsignedp;
1266 /* As excess precision is zeroed, there is no need to num_trim () as
1267 these operations cannot introduce a set bit there. */
1271 lhs.high &= rhs.high;
1273 else if (op == CPP_OR)
1276 lhs.high |= rhs.high;
1281 lhs.high ^= rhs.high;
1287 /* Returns LHS OP RHS, where OP is an inequality. */
1289 num_inequality_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs,
1292 bool gte = num_greater_eq (lhs, rhs, CPP_OPTION (pfile, precision));
1294 if (op == CPP_GREATER_EQ)
1296 else if (op == CPP_LESS)
1298 else if (op == CPP_GREATER)
1299 lhs.low = gte && !num_eq (lhs, rhs);
1300 else /* CPP_LESS_EQ. */
1301 lhs.low = !gte || num_eq (lhs, rhs);
1304 lhs.overflow = false;
1305 lhs.unsignedp = false;
1309 /* Returns LHS OP RHS, where OP is == or !=. */
1311 num_equality_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
1312 cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1314 /* Work around a 3.0.4 bug; see PR 6950. */
1315 bool eq = num_eq (lhs, rhs);
1316 if (op == CPP_NOT_EQ)
1320 lhs.overflow = false;
1321 lhs.unsignedp = false;
1325 /* Shift NUM, of width PRECISION, right by N bits. */
1327 num_rshift (cpp_num num, size_t precision, size_t n)
1329 cpp_num_part sign_mask;
1330 bool x = num_positive (num, precision);
1332 if (num.unsignedp || x)
1335 sign_mask = ~(cpp_num_part) 0;
1338 num.high = num.low = sign_mask;
1342 if (precision < PART_PRECISION)
1343 num.high = sign_mask, num.low |= sign_mask << precision;
1344 else if (precision < 2 * PART_PRECISION)
1345 num.high |= sign_mask << (precision - PART_PRECISION);
1347 if (n >= PART_PRECISION)
1349 n -= PART_PRECISION;
1351 num.high = sign_mask;
1356 num.low = (num.low >> n) | (num.high << (PART_PRECISION - n));
1357 num.high = (num.high >> n) | (sign_mask << (PART_PRECISION - n));
1361 num = num_trim (num, precision);
1362 num.overflow = false;
1366 /* Shift NUM, of width PRECISION, left by N bits. */
1368 num_lshift (cpp_num num, size_t precision, size_t n)
1372 num.overflow = !num.unsignedp && !num_zerop (num);
1373 num.high = num.low = 0;
1377 cpp_num orig, maybe_orig;
1381 if (m >= PART_PRECISION)
1383 m -= PART_PRECISION;
1389 num.high = (num.high << m) | (num.low >> (PART_PRECISION - m));
1392 num = num_trim (num, precision);
1395 num.overflow = false;
1398 maybe_orig = num_rshift (num, precision, n);
1399 num.overflow = !num_eq (orig, maybe_orig);
1406 /* The four unary operators: +, -, ! and ~. */
1408 num_unary_op (cpp_reader *pfile, cpp_num num, enum cpp_ttype op)
1413 if (CPP_WTRADITIONAL (pfile) && !pfile->state.skip_eval)
1414 cpp_error (pfile, CPP_DL_WARNING,
1415 "traditional C rejects the unary plus operator");
1416 num.overflow = false;
1420 num = num_negate (num, CPP_OPTION (pfile, precision));
1424 num.high = ~num.high;
1426 num = num_trim (num, CPP_OPTION (pfile, precision));
1427 num.overflow = false;
1430 default: /* case CPP_NOT: */
1431 num.low = num_zerop (num);
1433 num.overflow = false;
1434 num.unsignedp = false;
1441 /* The various binary operators. */
1443 num_binary_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1446 size_t precision = CPP_OPTION (pfile, precision);
1454 if (!rhs.unsignedp && !num_positive (rhs, precision))
1456 /* A negative shift is a positive shift the other way. */
1457 if (op == CPP_LSHIFT)
1461 rhs = num_negate (rhs, precision);
1464 n = ~0; /* Maximal. */
1467 if (op == CPP_LSHIFT)
1468 lhs = num_lshift (lhs, precision, n);
1470 lhs = num_rshift (lhs, precision, n);
1475 rhs = num_negate (rhs, precision);
1477 result.low = lhs.low + rhs.low;
1478 result.high = lhs.high + rhs.high;
1479 if (result.low < lhs.low)
1481 result.unsignedp = lhs.unsignedp || rhs.unsignedp;
1482 result.overflow = false;
1484 result = num_trim (result, precision);
1485 if (!result.unsignedp)
1487 bool lhsp = num_positive (lhs, precision);
1488 result.overflow = (lhsp == num_positive (rhs, precision)
1489 && lhsp != num_positive (result, precision));
1494 default: /* case CPP_COMMA: */
1495 if (CPP_PEDANTIC (pfile) && (!CPP_OPTION (pfile, c99)
1496 || !pfile->state.skip_eval))
1497 cpp_error (pfile, CPP_DL_PEDWARN,
1498 "comma operator in operand of #if");
1506 /* Multiplies two unsigned cpp_num_parts to give a cpp_num. This
1509 num_part_mul (cpp_num_part lhs, cpp_num_part rhs)
1512 cpp_num_part middle[2], temp;
1514 result.low = LOW_PART (lhs) * LOW_PART (rhs);
1515 result.high = HIGH_PART (lhs) * HIGH_PART (rhs);
1517 middle[0] = LOW_PART (lhs) * HIGH_PART (rhs);
1518 middle[1] = HIGH_PART (lhs) * LOW_PART (rhs);
1521 result.low += LOW_PART (middle[0]) << (PART_PRECISION / 2);
1522 if (result.low < temp)
1526 result.low += LOW_PART (middle[1]) << (PART_PRECISION / 2);
1527 if (result.low < temp)
1530 result.high += HIGH_PART (middle[0]);
1531 result.high += HIGH_PART (middle[1]);
1532 result.unsignedp = true;
1533 result.overflow = false;
1538 /* Multiply two preprocessing numbers. */
1540 num_mul (cpp_reader *pfile, cpp_num lhs, cpp_num rhs)
1542 cpp_num result, temp;
1543 bool unsignedp = lhs.unsignedp || rhs.unsignedp;
1544 bool overflow, negate = false;
1545 size_t precision = CPP_OPTION (pfile, precision);
1547 /* Prepare for unsigned multiplication. */
1550 if (!num_positive (lhs, precision))
1551 negate = !negate, lhs = num_negate (lhs, precision);
1552 if (!num_positive (rhs, precision))
1553 negate = !negate, rhs = num_negate (rhs, precision);
1556 overflow = lhs.high && rhs.high;
1557 result = num_part_mul (lhs.low, rhs.low);
1559 temp = num_part_mul (lhs.high, rhs.low);
1560 result.high += temp.low;
1564 temp = num_part_mul (lhs.low, rhs.high);
1565 result.high += temp.low;
1569 temp.low = result.low, temp.high = result.high;
1570 result = num_trim (result, precision);
1571 if (!num_eq (result, temp))
1575 result = num_negate (result, precision);
1578 result.overflow = false;
1580 result.overflow = overflow || (num_positive (result, precision) ^ !negate
1581 && !num_zerop (result));
1582 result.unsignedp = unsignedp;
1587 /* Divide two preprocessing numbers, returning the answer or the
1588 remainder depending upon OP. */
1590 num_div_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1592 cpp_num result, sub;
1594 bool unsignedp = lhs.unsignedp || rhs.unsignedp;
1595 bool negate = false, lhs_neg = false;
1596 size_t i, precision = CPP_OPTION (pfile, precision);
1598 /* Prepare for unsigned division. */
1601 if (!num_positive (lhs, precision))
1602 negate = !negate, lhs_neg = true, lhs = num_negate (lhs, precision);
1603 if (!num_positive (rhs, precision))
1604 negate = !negate, rhs = num_negate (rhs, precision);
1607 /* Find the high bit. */
1611 mask = (cpp_num_part) 1 << (i - PART_PRECISION);
1612 for (; ; i--, mask >>= 1)
1613 if (rhs.high & mask)
1618 if (precision > PART_PRECISION)
1619 i = precision - PART_PRECISION - 1;
1622 mask = (cpp_num_part) 1 << i;
1623 for (; ; i--, mask >>= 1)
1629 if (!pfile->state.skip_eval)
1630 cpp_error (pfile, CPP_DL_ERROR, "division by zero in #if");
1634 /* First nonzero bit of RHS is bit I. Do naive division by
1635 shifting the RHS fully left, and subtracting from LHS if LHS is
1636 at least as big, and then repeating but with one less shift.
1637 This is not very efficient, but is easy to understand. */
1639 rhs.unsignedp = true;
1640 lhs.unsignedp = true;
1641 i = precision - i - 1;
1642 sub = num_lshift (rhs, precision, i);
1644 result.high = result.low = 0;
1647 if (num_greater_eq (lhs, sub, precision))
1649 lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
1650 if (i >= PART_PRECISION)
1651 result.high |= (cpp_num_part) 1 << (i - PART_PRECISION);
1653 result.low |= (cpp_num_part) 1 << i;
1657 sub.low = (sub.low >> 1) | (sub.high << (PART_PRECISION - 1));
1661 /* We divide so that the remainder has the sign of the LHS. */
1664 result.unsignedp = unsignedp;
1665 result.overflow = false;
1669 result = num_negate (result, precision);
1670 result.overflow = (num_positive (result, precision) ^ !negate
1671 && !num_zerop (result));
1678 lhs.unsignedp = unsignedp;
1679 lhs.overflow = false;
1681 lhs = num_negate (lhs, precision);