1 /* Parse C expressions for cpplib.
2 Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
3 2002 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. */
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 (CPP_LAST_CPP_OP + 1)
69 #define CPP_UMINUS (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 = 0, l = 0, i = 0;
90 case 'f': case 'F': f++; break;
91 case 'l': case 'L': l++; break;
93 case 'j': case 'J': i++; break;
98 if (f + l > 1 || i > 1)
101 return ((i ? CPP_N_IMAGINARY : 0)
103 l ? CPP_N_LARGE : CPP_N_MEDIUM));
106 /* Subroutine of cpp_classify_number. S points to an integer suffix
107 of length LEN, possibly zero. Returns 0 for an invalid suffix, or a
108 flag vector describing the suffix. */
110 interpret_int_suffix (const uchar *s, size_t len)
119 case 'u': case 'U': u++; break;
121 case 'j': case 'J': i++; break;
122 case 'l': case 'L': l++;
123 /* If there are two Ls, they must be adjacent and the same case. */
124 if (l == 2 && s[len] != s[len + 1])
131 if (l > 2 || u > 1 || i > 1)
134 return ((i ? CPP_N_IMAGINARY : 0)
135 | (u ? CPP_N_UNSIGNED : 0)
136 | ((l == 0) ? CPP_N_SMALL
137 : (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE));
140 /* Categorize numeric constants according to their field (integer,
141 floating point, or invalid), radix (decimal, octal, hexadecimal),
142 and type suffixes. */
144 cpp_classify_number (cpp_reader *pfile, const cpp_token *token)
146 const uchar *str = token->val.str.text;
148 unsigned int max_digit, result, radix;
149 enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag;
151 /* If the lexer has done its job, length one can only be a single
152 digit. Fast-path this very common case. */
153 if (token->val.str.len == 1)
154 return CPP_N_INTEGER | CPP_N_SMALL | CPP_N_DECIMAL;
156 limit = str + token->val.str.len;
157 float_flag = NOT_FLOAT;
161 /* First, interpret the radix. */
167 /* Require at least one hex digit to classify it as hex. */
168 if ((*str == 'x' || *str == 'X')
169 && (str[1] == '.' || ISXDIGIT (str[1])))
176 /* Now scan for a well-formed integer or float. */
179 unsigned int c = *str++;
181 if (ISDIGIT (c) || (ISXDIGIT (c) && radix == 16))
189 if (float_flag == NOT_FLOAT)
190 float_flag = AFTER_POINT;
192 SYNTAX_ERROR ("too many decimal points in number");
194 else if ((radix <= 10 && (c == 'e' || c == 'E'))
195 || (radix == 16 && (c == 'p' || c == 'P')))
197 float_flag = AFTER_EXPON;
202 /* Start of suffix. */
208 if (float_flag != NOT_FLOAT && radix == 8)
211 if (max_digit >= radix)
212 SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit);
214 if (float_flag != NOT_FLOAT)
216 if (radix == 16 && CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, c99))
217 cpp_error (pfile, CPP_DL_PEDWARN,
218 "use of C99 hexadecimal floating constant");
220 if (float_flag == AFTER_EXPON)
222 if (*str == '+' || *str == '-')
225 /* Exponent is decimal, even if string is a hex float. */
227 SYNTAX_ERROR ("exponent has no digits");
231 while (ISDIGIT (*str));
233 else if (radix == 16)
234 SYNTAX_ERROR ("hexadecimal floating constants require an exponent");
236 result = interpret_float_suffix (str, limit - str);
239 cpp_error (pfile, CPP_DL_ERROR,
240 "invalid suffix \"%.*s\" on floating constant",
241 (int) (limit - str), str);
242 return CPP_N_INVALID;
245 /* Traditional C didn't accept any floating suffixes. */
247 && CPP_WTRADITIONAL (pfile)
248 && ! cpp_sys_macro_p (pfile))
249 cpp_error (pfile, CPP_DL_WARNING,
250 "traditional C rejects the \"%.*s\" suffix",
251 (int) (limit - str), str);
253 result |= CPP_N_FLOATING;
257 result = interpret_int_suffix (str, limit - str);
260 cpp_error (pfile, CPP_DL_ERROR,
261 "invalid suffix \"%.*s\" on integer constant",
262 (int) (limit - str), str);
263 return CPP_N_INVALID;
266 /* Traditional C only accepted the 'L' suffix.
267 Suppress warning about 'LL' with -Wno-long-long. */
268 if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile))
270 int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY));
271 int large = (result & CPP_N_WIDTH) == CPP_N_LARGE;
273 if (u_or_i || (large && CPP_OPTION (pfile, warn_long_long)))
274 cpp_error (pfile, CPP_DL_WARNING,
275 "traditional C rejects the \"%.*s\" suffix",
276 (int) (limit - str), str);
279 if ((result & CPP_N_WIDTH) == CPP_N_LARGE
280 && ! CPP_OPTION (pfile, c99)
281 && CPP_OPTION (pfile, warn_long_long))
282 cpp_error (pfile, CPP_DL_PEDWARN,
283 "use of C99 long long integer constant");
285 result |= CPP_N_INTEGER;
288 if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile))
289 cpp_error (pfile, CPP_DL_PEDWARN,
290 "imaginary constants are a GCC extension");
293 result |= CPP_N_DECIMAL;
294 else if (radix == 16)
297 result |= CPP_N_OCTAL;
302 return CPP_N_INVALID;
305 /* cpp_interpret_integer converts an integer constant into a cpp_num,
306 of precision options->precision.
308 We do not provide any interface for decimal->float conversion,
309 because the preprocessor doesn't need it and we don't want to
310 drag in GCC's floating point emulator. */
312 cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token,
315 const uchar *p, *end;
320 result.unsignedp = !!(type & CPP_N_UNSIGNED);
321 result.overflow = false;
323 p = token->val.str.text;
324 end = p + token->val.str.len;
326 /* Common case of a single digit. */
327 if (token->val.str.len == 1)
328 result.low = p[0] - '0';
332 size_t precision = CPP_OPTION (pfile, precision);
333 unsigned int base = 10, c = 0;
334 bool overflow = false;
336 if ((type & CPP_N_RADIX) == CPP_N_OCTAL)
341 else if ((type & CPP_N_RADIX) == CPP_N_HEX)
347 /* We can add a digit to numbers strictly less than this without
348 needing the precision and slowness of double integers. */
349 max = ~(cpp_num_part) 0;
350 if (precision < PART_PRECISION)
351 max >>= PART_PRECISION - precision;
352 max = (max - base + 1) / base + 1;
358 if (ISDIGIT (c) || (base == 16 && ISXDIGIT (c)))
363 /* Strict inequality for when max is set to zero. */
364 if (result.low < max)
365 result.low = result.low * base + c;
368 result = append_digit (result, c, base, precision);
369 overflow |= result.overflow;
375 cpp_error (pfile, CPP_DL_PEDWARN,
376 "integer constant is too large for its type");
377 /* If too big to be signed, consider it unsigned. Only warn for
378 decimal numbers. Traditional numbers were always signed (but
379 we still honor an explicit U suffix); but we only have
380 traditional semantics in directives. */
381 else if (!result.unsignedp
382 && !(CPP_OPTION (pfile, traditional)
383 && pfile->state.in_directive)
384 && !num_positive (result, precision))
387 cpp_error (pfile, CPP_DL_WARNING,
388 "integer constant is so large that it is unsigned");
389 result.unsignedp = true;
396 /* Append DIGIT to NUM, a number of PRECISION bits being read in base BASE. */
398 append_digit (cpp_num num, int digit, int base, size_t precision)
401 unsigned int shift = 3 + (base == 16);
403 cpp_num_part add_high, add_low;
405 /* Multiply by 8 or 16. Catching this overflow here means we don't
406 need to worry about add_high overflowing. */
407 overflow = !!(num.high >> (PART_PRECISION - shift));
408 result.high = num.high << shift;
409 result.low = num.low << shift;
410 result.high |= num.low >> (PART_PRECISION - shift);
414 add_low = num.low << 1;
415 add_high = (num.high << 1) + (num.low >> (PART_PRECISION - 1));
418 add_high = add_low = 0;
420 if (add_low + digit < add_low)
424 if (result.low + add_low < result.low)
426 if (result.high + add_high < result.high)
429 result.low += add_low;
430 result.high += add_high;
432 /* The above code catches overflow of a cpp_num type. This catches
433 overflow of the (possibly shorter) target precision. */
434 num.low = result.low;
435 num.high = result.high;
436 result = num_trim (result, precision);
437 if (!num_eq (result, num))
440 result.unsignedp = num.unsignedp;
441 result.overflow = overflow;
445 /* Handle meeting "defined" in a preprocessor expression. */
447 parse_defined (cpp_reader *pfile)
451 cpp_hashnode *node = 0;
452 const cpp_token *token;
453 cpp_context *initial_context = pfile->context;
455 /* Don't expand macros. */
456 pfile->state.prevent_expansion++;
458 token = cpp_get_token (pfile);
459 if (token->type == CPP_OPEN_PAREN)
462 token = cpp_get_token (pfile);
465 if (token->type == CPP_NAME)
467 node = token->val.node;
468 if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
470 cpp_error (pfile, CPP_DL_ERROR, "missing ')' after \"defined\"");
476 cpp_error (pfile, CPP_DL_ERROR,
477 "operator \"defined\" requires an identifier");
478 if (token->flags & NAMED_OP)
483 op.type = token->type;
484 cpp_error (pfile, CPP_DL_ERROR,
485 "(\"%s\" is an alternative token for \"%s\" in C++)",
486 cpp_token_as_text (pfile, token),
487 cpp_token_as_text (pfile, &op));
493 if (pfile->context != initial_context && CPP_PEDANTIC (pfile))
494 cpp_error (pfile, CPP_DL_WARNING,
495 "this use of \"defined\" may not be portable");
497 _cpp_mark_macro_used (node);
499 /* A possible controlling macro of the form #if !defined ().
500 _cpp_parse_expr checks there was no other junk on the line. */
501 pfile->mi_ind_cmacro = node;
504 pfile->state.prevent_expansion--;
506 result.unsignedp = false;
508 result.overflow = false;
509 result.low = node && node->type == NT_MACRO;
513 /* Convert a token into a CPP_NUMBER (an interpreted preprocessing
514 number or character constant, or the result of the "defined" or "#"
517 eval_token (cpp_reader *pfile, const cpp_token *token)
526 temp = cpp_classify_number (pfile, token);
527 switch (temp & CPP_N_CATEGORY)
530 cpp_error (pfile, CPP_DL_ERROR,
531 "floating constant in preprocessor expression");
534 if (!(temp & CPP_N_IMAGINARY))
535 return cpp_interpret_integer (pfile, token, temp);
536 cpp_error (pfile, CPP_DL_ERROR,
537 "imaginary number in preprocessor expression");
541 /* Error already issued. */
544 result.high = result.low = 0;
550 cppchar_t cc = cpp_interpret_charconst (pfile, token,
555 /* Sign-extend the result if necessary. */
556 if (!unsignedp && (cppchar_signed_t) cc < 0)
558 if (PART_PRECISION > BITS_PER_CPPCHAR_T)
559 result.low |= ~(~(cpp_num_part) 0
560 >> (PART_PRECISION - BITS_PER_CPPCHAR_T));
561 result.high = ~(cpp_num_part) 0;
562 result = num_trim (result, CPP_OPTION (pfile, precision));
568 if (token->val.node == pfile->spec_nodes.n_defined)
569 return parse_defined (pfile);
570 else if (CPP_OPTION (pfile, cplusplus)
571 && (token->val.node == pfile->spec_nodes.n_true
572 || token->val.node == pfile->spec_nodes.n_false))
575 result.low = (token->val.node == pfile->spec_nodes.n_true);
581 if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval)
582 cpp_error (pfile, CPP_DL_WARNING, "\"%s\" is not defined",
583 NODE_NAME (token->val.node));
587 default: /* CPP_HASH */
588 _cpp_test_assertion (pfile, &temp);
593 result.unsignedp = !!unsignedp;
594 result.overflow = false;
598 /* Operator precedence and flags table.
600 After an operator is returned from the lexer, if it has priority less
601 than the operator on the top of the stack, we reduce the stack by one
602 operator and repeat the test. Since equal priorities do not reduce,
603 this is naturally right-associative.
605 We handle left-associative operators by decrementing the priority of
606 just-lexed operators by one, but retaining the priority of operators
607 already on the stack.
609 The remaining cases are '(' and ')'. We handle '(' by skipping the
610 reduction phase completely. ')' is given lower priority than
611 everything else, including '(', effectively forcing a reduction of the
612 parenthesized expression. If there is a matching '(', the routine
613 reduce() exits immediately. If the normal exit route sees a ')', then
614 there cannot have been a matching '(' and an error message is output.
616 The parser assumes all shifted operators require a left operand unless
617 the flag NO_L_OPERAND is set. These semantics are automatic; any
618 extra semantics need to be handled with operator-specific code. */
620 /* Flags. If CHECK_PROMOTION, we warn if the effective sign of an
621 operand changes because of integer promotions. */
622 #define NO_L_OPERAND (1 << 0)
623 #define LEFT_ASSOC (1 << 1)
624 #define CHECK_PROMOTION (1 << 2)
626 /* Operator to priority map. Must be in the same order as the first
627 N entries of enum cpp_ttype. */
628 static const struct operator
634 /* EQ */ {0, 0}, /* Shouldn't happen. */
635 /* NOT */ {16, NO_L_OPERAND},
636 /* GREATER */ {12, LEFT_ASSOC | CHECK_PROMOTION},
637 /* LESS */ {12, LEFT_ASSOC | CHECK_PROMOTION},
638 /* PLUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
639 /* MINUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
640 /* MULT */ {15, LEFT_ASSOC | CHECK_PROMOTION},
641 /* DIV */ {15, LEFT_ASSOC | CHECK_PROMOTION},
642 /* MOD */ {15, LEFT_ASSOC | CHECK_PROMOTION},
643 /* AND */ {9, LEFT_ASSOC | CHECK_PROMOTION},
644 /* OR */ {7, LEFT_ASSOC | CHECK_PROMOTION},
645 /* XOR */ {8, LEFT_ASSOC | CHECK_PROMOTION},
646 /* RSHIFT */ {13, LEFT_ASSOC},
647 /* LSHIFT */ {13, LEFT_ASSOC},
649 /* MIN */ {10, LEFT_ASSOC | CHECK_PROMOTION},
650 /* MAX */ {10, LEFT_ASSOC | CHECK_PROMOTION},
652 /* COMPL */ {16, NO_L_OPERAND},
653 /* AND_AND */ {6, LEFT_ASSOC},
654 /* OR_OR */ {5, LEFT_ASSOC},
656 /* COLON */ {4, LEFT_ASSOC | CHECK_PROMOTION},
657 /* COMMA */ {2, LEFT_ASSOC},
658 /* OPEN_PAREN */ {1, NO_L_OPERAND},
659 /* CLOSE_PAREN */ {0, 0},
661 /* EQ_EQ */ {11, LEFT_ASSOC},
662 /* NOT_EQ */ {11, LEFT_ASSOC},
663 /* GREATER_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
664 /* LESS_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
665 /* UPLUS */ {16, NO_L_OPERAND},
666 /* UMINUS */ {16, NO_L_OPERAND}
669 /* Parse and evaluate a C expression, reading from PFILE.
670 Returns the truth value of the expression.
672 The implementation is an operator precedence parser, i.e. a
673 bottom-up parser, using a stack for not-yet-reduced tokens.
675 The stack base is op_stack, and the current stack pointer is 'top'.
676 There is a stack element for each operator (only), and the most
677 recently pushed operator is 'top->op'. An operand (value) is
678 stored in the 'value' field of the stack element of the operator
681 _cpp_parse_expr (cpp_reader *pfile)
683 struct op *top = pfile->op_stack;
684 unsigned int lex_count;
685 bool saw_leading_not, want_value = true;
687 pfile->state.skip_eval = 0;
689 /* Set up detection of #if ! defined(). */
690 pfile->mi_ind_cmacro = 0;
691 saw_leading_not = false;
694 /* Lowest priority operator prevents further reductions. */
702 op.token = cpp_get_token (pfile);
703 op.op = op.token->type;
707 /* These tokens convert into values. */
714 SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
715 cpp_token_as_text (pfile, op.token));
717 top->value = eval_token (pfile, op.token);
721 saw_leading_not = lex_count == 1;
733 if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
734 SYNTAX_ERROR2 ("token \"%s\" is not valid in preprocessor expressions",
735 cpp_token_as_text (pfile, op.token));
739 /* Check we have a value or operator as appropriate. */
740 if (optab[op.op].flags & NO_L_OPERAND)
743 SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
744 cpp_token_as_text (pfile, op.token));
748 /* We want a number (or expression) and haven't got one.
749 Try to emit a specific diagnostic. */
750 if (op.op == CPP_CLOSE_PAREN && top->op == CPP_OPEN_PAREN)
751 SYNTAX_ERROR ("missing expression between '(' and ')'");
753 if (op.op == CPP_EOF && top->op == CPP_EOF)
754 SYNTAX_ERROR ("#if with no expression");
756 if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN)
757 SYNTAX_ERROR2 ("operator '%s' has no right operand",
758 cpp_token_as_text (pfile, top->token));
759 else if (op.op == CPP_CLOSE_PAREN || op.op == CPP_EOF)
760 /* Complain about missing paren during reduction. */;
762 SYNTAX_ERROR2 ("operator '%s' has no left operand",
763 cpp_token_as_text (pfile, op.token));
766 top = reduce (pfile, top, op.op);
770 if (op.op == CPP_EOF)
775 case CPP_CLOSE_PAREN:
778 if (!num_zerop (top->value))
779 pfile->state.skip_eval++;
783 if (num_zerop (top->value))
784 pfile->state.skip_eval++;
787 if (top->op != CPP_QUERY)
788 SYNTAX_ERROR (" ':' without preceding '?'");
789 if (!num_zerop (top[-1].value)) /* Was '?' condition true? */
790 pfile->state.skip_eval++;
792 pfile->state.skip_eval--;
799 /* Check for and handle stack overflow. */
800 if (++top == pfile->op_limit)
801 top = _cpp_expand_op_stack (pfile);
804 top->token = op.token;
807 /* The controlling macro expression is only valid if we called lex 3
808 times: <!> <defined expression> and <EOF>. push_conditional ()
809 checks that we are at top-of-file. */
810 if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
811 pfile->mi_ind_cmacro = 0;
813 if (top != pfile->op_stack)
815 cpp_error (pfile, CPP_DL_ICE, "unbalanced stack in #if");
817 return false; /* Return false on syntax error. */
820 return !num_zerop (top->value);
823 /* Reduce the operator / value stack if possible, in preparation for
824 pushing operator OP. Returns NULL on error, otherwise the top of
827 reduce (cpp_reader *pfile, struct op *top, enum cpp_ttype op)
831 if (top->op <= CPP_EQ || top->op > CPP_LAST_CPP_OP + 2)
834 cpp_error (pfile, CPP_DL_ICE, "impossible operator '%u'", top->op);
838 if (op == CPP_OPEN_PAREN)
841 /* Decrement the priority of left-associative operators to force a
842 reduction with operators of otherwise equal priority. */
843 prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
844 while (prio < optab[top->op].prio)
846 if (CPP_OPTION (pfile, warn_num_sign_change)
847 && optab[top->op].flags & CHECK_PROMOTION)
848 check_promotion (pfile, top);
856 top[-1].value = num_unary_op (pfile, top->value, top->op);
866 top[-1].value = num_binary_op (pfile, top[-1].value,
867 top->value, top->op);
875 = num_inequality_op (pfile, top[-1].value, top->value, top->op);
881 = num_equality_op (pfile, top[-1].value, top->value, top->op);
888 = num_bitwise_op (pfile, top[-1].value, top->value, top->op);
892 top[-1].value = num_mul (pfile, top[-1].value, top->value);
897 top[-1].value = num_div_op (pfile, top[-1].value,
898 top->value, top->op);
903 if (!num_zerop (top->value))
904 pfile->state.skip_eval--;
905 top->value.low = (!num_zerop (top->value)
906 || !num_zerop (top[1].value));
908 top->value.unsignedp = false;
909 top->value.overflow = false;
914 if (num_zerop (top->value))
915 pfile->state.skip_eval--;
916 top->value.low = (!num_zerop (top->value)
917 && !num_zerop (top[1].value));
919 top->value.unsignedp = false;
920 top->value.overflow = false;
924 if (op != CPP_CLOSE_PAREN)
926 cpp_error (pfile, CPP_DL_ERROR, "missing ')' in expression");
930 top->value = top[1].value;
935 if (!num_zerop (top->value))
937 pfile->state.skip_eval--;
938 top->value = top[1].value;
941 top->value = top[2].value;
942 top->value.unsignedp = (top[1].value.unsignedp
943 || top[2].value.unsignedp);
947 cpp_error (pfile, CPP_DL_ERROR, "'?' without following ':'");
955 if (top->value.overflow && !pfile->state.skip_eval)
956 cpp_error (pfile, CPP_DL_PEDWARN,
957 "integer overflow in preprocessor expression");
960 if (op == CPP_CLOSE_PAREN)
962 cpp_error (pfile, CPP_DL_ERROR, "missing '(' in expression");
969 /* Returns the position of the old top of stack after expansion. */
971 _cpp_expand_op_stack (cpp_reader *pfile)
973 size_t old_size = (size_t) (pfile->op_limit - pfile->op_stack);
974 size_t new_size = old_size * 2 + 20;
976 pfile->op_stack = xrealloc (pfile->op_stack, new_size * sizeof (struct op));
977 pfile->op_limit = pfile->op_stack + new_size;
979 return pfile->op_stack + old_size;
982 /* Emits a warning if the effective sign of either operand of OP
983 changes because of integer promotions. */
985 check_promotion (cpp_reader *pfile, const struct op *op)
987 if (op->value.unsignedp == op[-1].value.unsignedp)
990 if (op->value.unsignedp)
992 if (!num_positive (op[-1].value, CPP_OPTION (pfile, precision)))
993 cpp_error (pfile, CPP_DL_WARNING,
994 "the left operand of \"%s\" changes sign when promoted",
995 cpp_token_as_text (pfile, op->token));
997 else if (!num_positive (op->value, CPP_OPTION (pfile, precision)))
998 cpp_error (pfile, CPP_DL_WARNING,
999 "the right operand of \"%s\" changes sign when promoted",
1000 cpp_token_as_text (pfile, op->token));
1003 /* Clears the unused high order bits of the number pointed to by PNUM. */
1005 num_trim (cpp_num num, size_t precision)
1007 if (precision > PART_PRECISION)
1009 precision -= PART_PRECISION;
1010 if (precision < PART_PRECISION)
1011 num.high &= ((cpp_num_part) 1 << precision) - 1;
1015 if (precision < PART_PRECISION)
1016 num.low &= ((cpp_num_part) 1 << precision) - 1;
1023 /* True iff A (presumed signed) >= 0. */
1025 num_positive (cpp_num num, size_t precision)
1027 if (precision > PART_PRECISION)
1029 precision -= PART_PRECISION;
1030 return (num.high & (cpp_num_part) 1 << (precision - 1)) == 0;
1033 return (num.low & (cpp_num_part) 1 << (precision - 1)) == 0;
1036 /* Sign extend a number, with PRECISION significant bits and all
1037 others assumed clear, to fill out a cpp_num structure. */
1039 cpp_num_sign_extend (cpp_num num, size_t precision)
1043 if (precision > PART_PRECISION)
1045 precision -= PART_PRECISION;
1046 if (precision < PART_PRECISION
1047 && (num.high & (cpp_num_part) 1 << (precision - 1)))
1048 num.high |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
1050 else if (num.low & (cpp_num_part) 1 << (precision - 1))
1052 if (precision < PART_PRECISION)
1053 num.low |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
1054 num.high = ~(cpp_num_part) 0;
1061 /* Returns the negative of NUM. */
1063 num_negate (cpp_num num, size_t precision)
1068 num.high = ~num.high;
1072 num = num_trim (num, precision);
1073 num.overflow = (!num.unsignedp && num_eq (num, copy) && !num_zerop (num));
1078 /* Returns true if A >= B. */
1080 num_greater_eq (cpp_num pa, cpp_num pb, size_t precision)
1084 unsignedp = pa.unsignedp || pb.unsignedp;
1088 /* Both numbers have signed type. If they are of different
1089 sign, the answer is the sign of A. */
1090 unsignedp = num_positive (pa, precision);
1092 if (unsignedp != num_positive (pb, precision))
1095 /* Otherwise we can do an unsigned comparison. */
1098 return (pa.high > pb.high) || (pa.high == pb.high && pa.low >= pb.low);
1101 /* Returns LHS OP RHS, where OP is a bit-wise operation. */
1103 num_bitwise_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
1104 cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1106 lhs.overflow = false;
1107 lhs.unsignedp = lhs.unsignedp || rhs.unsignedp;
1109 /* As excess precision is zeroed, there is no need to num_trim () as
1110 these operations cannot introduce a set bit there. */
1114 lhs.high &= rhs.high;
1116 else if (op == CPP_OR)
1119 lhs.high |= rhs.high;
1124 lhs.high ^= rhs.high;
1130 /* Returns LHS OP RHS, where OP is an inequality. */
1132 num_inequality_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs,
1135 bool gte = num_greater_eq (lhs, rhs, CPP_OPTION (pfile, precision));
1137 if (op == CPP_GREATER_EQ)
1139 else if (op == CPP_LESS)
1141 else if (op == CPP_GREATER)
1142 lhs.low = gte && !num_eq (lhs, rhs);
1143 else /* CPP_LESS_EQ. */
1144 lhs.low = !gte || num_eq (lhs, rhs);
1147 lhs.overflow = false;
1148 lhs.unsignedp = false;
1152 /* Returns LHS OP RHS, where OP is == or !=. */
1154 num_equality_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
1155 cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1157 /* Work around a 3.0.4 bug; see PR 6950. */
1158 bool eq = num_eq (lhs, rhs);
1159 if (op == CPP_NOT_EQ)
1163 lhs.overflow = false;
1164 lhs.unsignedp = false;
1168 /* Shift NUM, of width PRECISION, right by N bits. */
1170 num_rshift (cpp_num num, size_t precision, size_t n)
1172 cpp_num_part sign_mask;
1174 if (num.unsignedp || num_positive (num, precision))
1177 sign_mask = ~(cpp_num_part) 0;
1180 num.high = num.low = sign_mask;
1184 if (precision < PART_PRECISION)
1185 num.high = sign_mask, num.low |= sign_mask << precision;
1186 else if (precision < 2 * PART_PRECISION)
1187 num.high |= sign_mask << (precision - PART_PRECISION);
1189 if (n >= PART_PRECISION)
1191 n -= PART_PRECISION;
1193 num.high = sign_mask;
1198 num.low = (num.low >> n) | (num.high << (PART_PRECISION - n));
1199 num.high = (num.high >> n) | (sign_mask << (PART_PRECISION - n));
1203 num = num_trim (num, precision);
1204 num.overflow = false;
1208 /* Shift NUM, of width PRECISION, left by N bits. */
1210 num_lshift (cpp_num num, size_t precision, size_t n)
1214 num.overflow = !num.unsignedp && !num_zerop (num);
1215 num.high = num.low = 0;
1219 cpp_num orig, maybe_orig;
1223 if (m >= PART_PRECISION)
1225 m -= PART_PRECISION;
1231 num.high = (num.high << m) | (num.low >> (PART_PRECISION - m));
1234 num = num_trim (num, precision);
1237 num.overflow = false;
1240 maybe_orig = num_rshift (num, precision, n);
1241 num.overflow = !num_eq (orig, maybe_orig);
1248 /* The four unary operators: +, -, ! and ~. */
1250 num_unary_op (cpp_reader *pfile, cpp_num num, enum cpp_ttype op)
1255 if (CPP_WTRADITIONAL (pfile) && !pfile->state.skip_eval)
1256 cpp_error (pfile, CPP_DL_WARNING,
1257 "traditional C rejects the unary plus operator");
1258 num.overflow = false;
1262 num = num_negate (num, CPP_OPTION (pfile, precision));
1266 num.high = ~num.high;
1268 num = num_trim (num, CPP_OPTION (pfile, precision));
1269 num.overflow = false;
1272 default: /* case CPP_NOT: */
1273 num.low = num_zerop (num);
1275 num.overflow = false;
1276 num.unsignedp = false;
1283 /* The various binary operators. */
1285 num_binary_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1288 size_t precision = CPP_OPTION (pfile, precision);
1297 if (!rhs.unsignedp && !num_positive (rhs, precision))
1299 /* A negative shift is a positive shift the other way. */
1300 if (op == CPP_LSHIFT)
1304 rhs = num_negate (rhs, precision);
1307 n = ~0; /* Maximal. */
1310 if (op == CPP_LSHIFT)
1311 lhs = num_lshift (lhs, precision, n);
1313 lhs = num_rshift (lhs, precision, n);
1320 bool unsignedp = lhs.unsignedp || rhs.unsignedp;
1322 gte = num_greater_eq (lhs, rhs, precision);
1327 lhs.unsignedp = unsignedp;
1333 rhs = num_negate (rhs, precision);
1335 result.low = lhs.low + rhs.low;
1336 result.high = lhs.high + rhs.high;
1337 if (result.low < lhs.low)
1340 result = num_trim (result, precision);
1341 result.unsignedp = lhs.unsignedp || rhs.unsignedp;
1342 if (result.unsignedp)
1343 result.overflow = false;
1346 bool lhsp = num_positive (lhs, precision);
1347 result.overflow = (lhsp == num_positive (rhs, precision)
1348 && lhsp != num_positive (result, precision));
1353 default: /* case CPP_COMMA: */
1354 if (CPP_PEDANTIC (pfile) && (!CPP_OPTION (pfile, c99)
1355 || !pfile->state.skip_eval))
1356 cpp_error (pfile, CPP_DL_PEDWARN,
1357 "comma operator in operand of #if");
1365 /* Multiplies two unsigned cpp_num_parts to give a cpp_num. This
1368 num_part_mul (cpp_num_part lhs, cpp_num_part rhs)
1371 cpp_num_part middle[2], temp;
1373 result.low = LOW_PART (lhs) * LOW_PART (rhs);
1374 result.high = HIGH_PART (lhs) * HIGH_PART (rhs);
1376 middle[0] = LOW_PART (lhs) * HIGH_PART (rhs);
1377 middle[1] = HIGH_PART (lhs) * LOW_PART (rhs);
1380 result.low += LOW_PART (middle[0]) << (PART_PRECISION / 2);
1381 if (result.low < temp)
1385 result.low += LOW_PART (middle[1]) << (PART_PRECISION / 2);
1386 if (result.low < temp)
1389 result.high += HIGH_PART (middle[0]);
1390 result.high += HIGH_PART (middle[1]);
1391 result.unsignedp = 1;
1396 /* Multiply two preprocessing numbers. */
1398 num_mul (cpp_reader *pfile, cpp_num lhs, cpp_num rhs)
1400 cpp_num result, temp;
1401 bool unsignedp = lhs.unsignedp || rhs.unsignedp;
1402 bool overflow, negate = false;
1403 size_t precision = CPP_OPTION (pfile, precision);
1405 /* Prepare for unsigned multiplication. */
1408 if (!num_positive (lhs, precision))
1409 negate = !negate, lhs = num_negate (lhs, precision);
1410 if (!num_positive (rhs, precision))
1411 negate = !negate, rhs = num_negate (rhs, precision);
1414 overflow = lhs.high && rhs.high;
1415 result = num_part_mul (lhs.low, rhs.low);
1417 temp = num_part_mul (lhs.high, rhs.low);
1418 result.high += temp.low;
1422 temp = num_part_mul (lhs.low, rhs.high);
1423 result.high += temp.low;
1427 temp.low = result.low, temp.high = result.high;
1428 result = num_trim (result, precision);
1429 if (!num_eq (result, temp))
1433 result = num_negate (result, precision);
1436 result.overflow = false;
1438 result.overflow = overflow || (num_positive (result, precision) ^ !negate
1439 && !num_zerop (result));
1440 result.unsignedp = unsignedp;
1445 /* Divide two preprocessing numbers, returning the answer or the
1446 remainder depending upon OP. */
1448 num_div_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
1450 cpp_num result, sub;
1452 bool unsignedp = lhs.unsignedp || rhs.unsignedp;
1453 bool negate = false, lhs_neg = false;
1454 size_t i, precision = CPP_OPTION (pfile, precision);
1456 /* Prepare for unsigned division. */
1459 if (!num_positive (lhs, precision))
1460 negate = !negate, lhs_neg = true, lhs = num_negate (lhs, precision);
1461 if (!num_positive (rhs, precision))
1462 negate = !negate, rhs = num_negate (rhs, precision);
1465 /* Find the high bit. */
1469 mask = (cpp_num_part) 1 << (i - PART_PRECISION);
1470 for (; ; i--, mask >>= 1)
1471 if (rhs.high & mask)
1476 if (precision > PART_PRECISION)
1477 i = precision - PART_PRECISION - 1;
1480 mask = (cpp_num_part) 1 << i;
1481 for (; ; i--, mask >>= 1)
1487 if (!pfile->state.skip_eval)
1488 cpp_error (pfile, CPP_DL_ERROR, "division by zero in #if");
1492 /* First nonzero bit of RHS is bit I. Do naive division by
1493 shifting the RHS fully left, and subtracting from LHS if LHS is
1494 at least as big, and then repeating but with one less shift.
1495 This is not very efficient, but is easy to understand. */
1497 rhs.unsignedp = true;
1498 lhs.unsignedp = true;
1499 i = precision - i - 1;
1500 sub = num_lshift (rhs, precision, i);
1502 result.high = result.low = 0;
1505 if (num_greater_eq (lhs, sub, precision))
1507 lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
1508 if (i >= PART_PRECISION)
1509 result.high |= (cpp_num_part) 1 << (i - PART_PRECISION);
1511 result.low |= (cpp_num_part) 1 << i;
1515 sub.low = (sub.low >> 1) | (sub.high << (PART_PRECISION - 1));
1519 /* We divide so that the remainder has the sign of the LHS. */
1522 result.unsignedp = unsignedp;
1524 result.overflow = false;
1528 result = num_negate (result, precision);
1529 result.overflow = num_positive (result, precision) ^ !negate;
1536 lhs.unsignedp = unsignedp;
1537 lhs.overflow = false;
1539 lhs = num_negate (lhs, precision);