1543 lines
40 KiB
C
1543 lines
40 KiB
C
/* Parse C expressions for cpplib.
|
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Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
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2002 Free Software Foundation.
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Contributed by Per Bothner, 1994.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
|
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Free Software Foundation; either version 2, or (at your option) any
|
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later version.
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|
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This program is distributed in the hope that it will be useful,
|
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
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GNU General Public License for more details.
|
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|
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You should have received a copy of the GNU General Public License
|
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along with this program; if not, write to the Free Software
|
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Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "config.h"
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#include "system.h"
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#include "cpplib.h"
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#include "cpphash.h"
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#define PART_PRECISION (sizeof (cpp_num_part) * CHAR_BIT)
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#define HALF_MASK (~(cpp_num_part) 0 >> (PART_PRECISION / 2))
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#define LOW_PART(num_part) (num_part & HALF_MASK)
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#define HIGH_PART(num_part) (num_part >> (PART_PRECISION / 2))
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struct op
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{
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const cpp_token *token; /* The token forming op (for diagnostics). */
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cpp_num value; /* The value logically "right" of op. */
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enum cpp_ttype op;
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};
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/* Some simple utility routines on double integers. */
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#define num_zerop(num) ((num.low | num.high) == 0)
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#define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high)
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static bool num_positive (cpp_num, size_t);
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static bool num_greater_eq (cpp_num, cpp_num, size_t);
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static cpp_num num_trim (cpp_num, size_t);
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static cpp_num num_part_mul (cpp_num_part, cpp_num_part);
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static cpp_num num_unary_op (cpp_reader *, cpp_num, enum cpp_ttype);
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static cpp_num num_binary_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
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static cpp_num num_negate (cpp_num, size_t);
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static cpp_num num_bitwise_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
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static cpp_num num_inequality_op (cpp_reader *, cpp_num, cpp_num,
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enum cpp_ttype);
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static cpp_num num_equality_op (cpp_reader *, cpp_num, cpp_num,
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enum cpp_ttype);
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static cpp_num num_mul (cpp_reader *, cpp_num, cpp_num);
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static cpp_num num_div_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype);
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static cpp_num num_lshift (cpp_num, size_t, size_t);
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static cpp_num num_rshift (cpp_num, size_t, size_t);
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static cpp_num append_digit (cpp_num, int, int, size_t);
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static cpp_num parse_defined (cpp_reader *);
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static cpp_num eval_token (cpp_reader *, const cpp_token *);
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static struct op *reduce (cpp_reader *, struct op *, enum cpp_ttype);
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static unsigned int interpret_float_suffix (const uchar *, size_t);
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static unsigned int interpret_int_suffix (const uchar *, size_t);
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static void check_promotion (cpp_reader *, const struct op *);
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/* Token type abuse to create unary plus and minus operators. */
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#define CPP_UPLUS (CPP_LAST_CPP_OP + 1)
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#define CPP_UMINUS (CPP_LAST_CPP_OP + 2)
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/* With -O2, gcc appears to produce nice code, moving the error
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message load and subsequent jump completely out of the main path. */
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#define SYNTAX_ERROR(msgid) \
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do { cpp_error (pfile, CPP_DL_ERROR, msgid); goto syntax_error; } while(0)
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#define SYNTAX_ERROR2(msgid, arg) \
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do { cpp_error (pfile, CPP_DL_ERROR, msgid, arg); goto syntax_error; } \
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while(0)
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/* Subroutine of cpp_classify_number. S points to a float suffix of
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length LEN, possibly zero. Returns 0 for an invalid suffix, or a
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flag vector describing the suffix. */
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static unsigned int
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interpret_float_suffix (const uchar *s, size_t len)
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{
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size_t f = 0, l = 0, i = 0;
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while (len--)
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switch (s[len])
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{
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case 'f': case 'F': f++; break;
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case 'l': case 'L': l++; break;
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case 'i': case 'I':
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case 'j': case 'J': i++; break;
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default:
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return 0;
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}
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if (f + l > 1 || i > 1)
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return 0;
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return ((i ? CPP_N_IMAGINARY : 0)
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| (f ? CPP_N_SMALL :
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l ? CPP_N_LARGE : CPP_N_MEDIUM));
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}
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/* Subroutine of cpp_classify_number. S points to an integer suffix
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of length LEN, possibly zero. Returns 0 for an invalid suffix, or a
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flag vector describing the suffix. */
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static unsigned int
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interpret_int_suffix (const uchar *s, size_t len)
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{
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size_t u, l, i;
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u = l = i = 0;
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while (len--)
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switch (s[len])
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{
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case 'u': case 'U': u++; break;
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case 'i': case 'I':
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case 'j': case 'J': i++; break;
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case 'l': case 'L': l++;
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/* If there are two Ls, they must be adjacent and the same case. */
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if (l == 2 && s[len] != s[len + 1])
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return 0;
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break;
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default:
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return 0;
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}
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if (l > 2 || u > 1 || i > 1)
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return 0;
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return ((i ? CPP_N_IMAGINARY : 0)
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| (u ? CPP_N_UNSIGNED : 0)
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| ((l == 0) ? CPP_N_SMALL
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: (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE));
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}
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/* Categorize numeric constants according to their field (integer,
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floating point, or invalid), radix (decimal, octal, hexadecimal),
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and type suffixes. */
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unsigned int
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cpp_classify_number (cpp_reader *pfile, const cpp_token *token)
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{
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const uchar *str = token->val.str.text;
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const uchar *limit;
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unsigned int max_digit, result, radix;
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enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag;
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/* If the lexer has done its job, length one can only be a single
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digit. Fast-path this very common case. */
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if (token->val.str.len == 1)
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return CPP_N_INTEGER | CPP_N_SMALL | CPP_N_DECIMAL;
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limit = str + token->val.str.len;
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float_flag = NOT_FLOAT;
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max_digit = 0;
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radix = 10;
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/* First, interpret the radix. */
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if (*str == '0')
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{
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radix = 8;
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str++;
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/* Require at least one hex digit to classify it as hex. */
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if ((*str == 'x' || *str == 'X')
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&& (str[1] == '.' || ISXDIGIT (str[1])))
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{
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radix = 16;
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str++;
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}
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}
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/* Now scan for a well-formed integer or float. */
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for (;;)
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{
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unsigned int c = *str++;
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if (ISDIGIT (c) || (ISXDIGIT (c) && radix == 16))
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{
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c = hex_value (c);
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if (c > max_digit)
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max_digit = c;
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}
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else if (c == '.')
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{
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if (float_flag == NOT_FLOAT)
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float_flag = AFTER_POINT;
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else
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SYNTAX_ERROR ("too many decimal points in number");
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}
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else if ((radix <= 10 && (c == 'e' || c == 'E'))
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|| (radix == 16 && (c == 'p' || c == 'P')))
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{
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float_flag = AFTER_EXPON;
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break;
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}
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else
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{
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/* Start of suffix. */
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str--;
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break;
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}
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}
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if (float_flag != NOT_FLOAT && radix == 8)
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radix = 10;
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if (max_digit >= radix)
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SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit);
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if (float_flag != NOT_FLOAT)
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{
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if (radix == 16 && CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, c99))
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cpp_error (pfile, CPP_DL_PEDWARN,
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"use of C99 hexadecimal floating constant");
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if (float_flag == AFTER_EXPON)
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{
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if (*str == '+' || *str == '-')
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str++;
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/* Exponent is decimal, even if string is a hex float. */
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if (!ISDIGIT (*str))
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SYNTAX_ERROR ("exponent has no digits");
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do
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str++;
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while (ISDIGIT (*str));
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}
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else if (radix == 16)
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SYNTAX_ERROR ("hexadecimal floating constants require an exponent");
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result = interpret_float_suffix (str, limit - str);
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if (result == 0)
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{
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cpp_error (pfile, CPP_DL_ERROR,
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"invalid suffix \"%.*s\" on floating constant",
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(int) (limit - str), str);
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return CPP_N_INVALID;
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}
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/* Traditional C didn't accept any floating suffixes. */
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if (limit != str
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&& CPP_WTRADITIONAL (pfile)
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&& ! cpp_sys_macro_p (pfile))
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cpp_error (pfile, CPP_DL_WARNING,
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"traditional C rejects the \"%.*s\" suffix",
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(int) (limit - str), str);
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result |= CPP_N_FLOATING;
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}
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else
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{
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result = interpret_int_suffix (str, limit - str);
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if (result == 0)
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{
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cpp_error (pfile, CPP_DL_ERROR,
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"invalid suffix \"%.*s\" on integer constant",
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(int) (limit - str), str);
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return CPP_N_INVALID;
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}
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/* Traditional C only accepted the 'L' suffix.
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Suppress warning about 'LL' with -Wno-long-long. */
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if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile))
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{
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int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY));
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int large = (result & CPP_N_WIDTH) == CPP_N_LARGE;
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if (u_or_i || (large && CPP_OPTION (pfile, warn_long_long)))
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cpp_error (pfile, CPP_DL_WARNING,
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"traditional C rejects the \"%.*s\" suffix",
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(int) (limit - str), str);
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}
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if ((result & CPP_N_WIDTH) == CPP_N_LARGE
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&& ! CPP_OPTION (pfile, c99)
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&& CPP_OPTION (pfile, warn_long_long))
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cpp_error (pfile, CPP_DL_PEDWARN,
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"use of C99 long long integer constant");
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result |= CPP_N_INTEGER;
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}
|
||
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if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile))
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cpp_error (pfile, CPP_DL_PEDWARN,
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"imaginary constants are a GCC extension");
|
||
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if (radix == 10)
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result |= CPP_N_DECIMAL;
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else if (radix == 16)
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||
result |= CPP_N_HEX;
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else
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result |= CPP_N_OCTAL;
|
||
|
||
return result;
|
||
|
||
syntax_error:
|
||
return CPP_N_INVALID;
|
||
}
|
||
|
||
/* cpp_interpret_integer converts an integer constant into a cpp_num,
|
||
of precision options->precision.
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||
|
||
We do not provide any interface for decimal->float conversion,
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because the preprocessor doesn't need it and we don't want to
|
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drag in GCC's floating point emulator. */
|
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cpp_num
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||
cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token,
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unsigned int type)
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||
{
|
||
const uchar *p, *end;
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||
cpp_num result;
|
||
|
||
result.low = 0;
|
||
result.high = 0;
|
||
result.unsignedp = !!(type & CPP_N_UNSIGNED);
|
||
result.overflow = false;
|
||
|
||
p = token->val.str.text;
|
||
end = p + token->val.str.len;
|
||
|
||
/* Common case of a single digit. */
|
||
if (token->val.str.len == 1)
|
||
result.low = p[0] - '0';
|
||
else
|
||
{
|
||
cpp_num_part max;
|
||
size_t precision = CPP_OPTION (pfile, precision);
|
||
unsigned int base = 10, c = 0;
|
||
bool overflow = false;
|
||
|
||
if ((type & CPP_N_RADIX) == CPP_N_OCTAL)
|
||
{
|
||
base = 8;
|
||
p++;
|
||
}
|
||
else if ((type & CPP_N_RADIX) == CPP_N_HEX)
|
||
{
|
||
base = 16;
|
||
p += 2;
|
||
}
|
||
|
||
/* We can add a digit to numbers strictly less than this without
|
||
needing the precision and slowness of double integers. */
|
||
max = ~(cpp_num_part) 0;
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||
if (precision < PART_PRECISION)
|
||
max >>= PART_PRECISION - precision;
|
||
max = (max - base + 1) / base + 1;
|
||
|
||
for (; p < end; p++)
|
||
{
|
||
c = *p;
|
||
|
||
if (ISDIGIT (c) || (base == 16 && ISXDIGIT (c)))
|
||
c = hex_value (c);
|
||
else
|
||
break;
|
||
|
||
/* Strict inequality for when max is set to zero. */
|
||
if (result.low < max)
|
||
result.low = result.low * base + c;
|
||
else
|
||
{
|
||
result = append_digit (result, c, base, precision);
|
||
overflow |= result.overflow;
|
||
max = 0;
|
||
}
|
||
}
|
||
|
||
if (overflow)
|
||
cpp_error (pfile, CPP_DL_PEDWARN,
|
||
"integer constant is too large for its type");
|
||
/* If too big to be signed, consider it unsigned. Only warn for
|
||
decimal numbers. Traditional numbers were always signed (but
|
||
we still honor an explicit U suffix); but we only have
|
||
traditional semantics in directives. */
|
||
else if (!result.unsignedp
|
||
&& !(CPP_OPTION (pfile, traditional)
|
||
&& pfile->state.in_directive)
|
||
&& !num_positive (result, precision))
|
||
{
|
||
if (base == 10)
|
||
cpp_error (pfile, CPP_DL_WARNING,
|
||
"integer constant is so large that it is unsigned");
|
||
result.unsignedp = true;
|
||
}
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Append DIGIT to NUM, a number of PRECISION bits being read in base BASE. */
|
||
static cpp_num
|
||
append_digit (cpp_num num, int digit, int base, size_t precision)
|
||
{
|
||
cpp_num result;
|
||
unsigned int shift = 3 + (base == 16);
|
||
bool overflow;
|
||
cpp_num_part add_high, add_low;
|
||
|
||
/* Multiply by 8 or 16. Catching this overflow here means we don't
|
||
need to worry about add_high overflowing. */
|
||
overflow = !!(num.high >> (PART_PRECISION - shift));
|
||
result.high = num.high << shift;
|
||
result.low = num.low << shift;
|
||
result.high |= num.low >> (PART_PRECISION - shift);
|
||
|
||
if (base == 10)
|
||
{
|
||
add_low = num.low << 1;
|
||
add_high = (num.high << 1) + (num.low >> (PART_PRECISION - 1));
|
||
}
|
||
else
|
||
add_high = add_low = 0;
|
||
|
||
if (add_low + digit < add_low)
|
||
add_high++;
|
||
add_low += digit;
|
||
|
||
if (result.low + add_low < result.low)
|
||
add_high++;
|
||
if (result.high + add_high < result.high)
|
||
overflow = true;
|
||
|
||
result.low += add_low;
|
||
result.high += add_high;
|
||
|
||
/* The above code catches overflow of a cpp_num type. This catches
|
||
overflow of the (possibly shorter) target precision. */
|
||
num.low = result.low;
|
||
num.high = result.high;
|
||
result = num_trim (result, precision);
|
||
if (!num_eq (result, num))
|
||
overflow = true;
|
||
|
||
result.unsignedp = num.unsignedp;
|
||
result.overflow = overflow;
|
||
return result;
|
||
}
|
||
|
||
/* Handle meeting "defined" in a preprocessor expression. */
|
||
static cpp_num
|
||
parse_defined (cpp_reader *pfile)
|
||
{
|
||
cpp_num result;
|
||
int paren = 0;
|
||
cpp_hashnode *node = 0;
|
||
const cpp_token *token;
|
||
cpp_context *initial_context = pfile->context;
|
||
|
||
/* Don't expand macros. */
|
||
pfile->state.prevent_expansion++;
|
||
|
||
token = cpp_get_token (pfile);
|
||
if (token->type == CPP_OPEN_PAREN)
|
||
{
|
||
paren = 1;
|
||
token = cpp_get_token (pfile);
|
||
}
|
||
|
||
if (token->type == CPP_NAME)
|
||
{
|
||
node = token->val.node;
|
||
if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
|
||
{
|
||
cpp_error (pfile, CPP_DL_ERROR, "missing ')' after \"defined\"");
|
||
node = 0;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
cpp_error (pfile, CPP_DL_ERROR,
|
||
"operator \"defined\" requires an identifier");
|
||
if (token->flags & NAMED_OP)
|
||
{
|
||
cpp_token op;
|
||
|
||
op.flags = 0;
|
||
op.type = token->type;
|
||
cpp_error (pfile, CPP_DL_ERROR,
|
||
"(\"%s\" is an alternative token for \"%s\" in C++)",
|
||
cpp_token_as_text (pfile, token),
|
||
cpp_token_as_text (pfile, &op));
|
||
}
|
||
}
|
||
|
||
if (node)
|
||
{
|
||
if (pfile->context != initial_context && CPP_PEDANTIC (pfile))
|
||
cpp_error (pfile, CPP_DL_WARNING,
|
||
"this use of \"defined\" may not be portable");
|
||
|
||
_cpp_mark_macro_used (node);
|
||
|
||
/* A possible controlling macro of the form #if !defined ().
|
||
_cpp_parse_expr checks there was no other junk on the line. */
|
||
pfile->mi_ind_cmacro = node;
|
||
}
|
||
|
||
pfile->state.prevent_expansion--;
|
||
|
||
result.unsignedp = false;
|
||
result.high = 0;
|
||
result.overflow = false;
|
||
result.low = node && node->type == NT_MACRO;
|
||
return result;
|
||
}
|
||
|
||
/* Convert a token into a CPP_NUMBER (an interpreted preprocessing
|
||
number or character constant, or the result of the "defined" or "#"
|
||
operators). */
|
||
static cpp_num
|
||
eval_token (cpp_reader *pfile, const cpp_token *token)
|
||
{
|
||
cpp_num result;
|
||
unsigned int temp;
|
||
int unsignedp = 0;
|
||
|
||
switch (token->type)
|
||
{
|
||
case CPP_NUMBER:
|
||
temp = cpp_classify_number (pfile, token);
|
||
switch (temp & CPP_N_CATEGORY)
|
||
{
|
||
case CPP_N_FLOATING:
|
||
cpp_error (pfile, CPP_DL_ERROR,
|
||
"floating constant in preprocessor expression");
|
||
break;
|
||
case CPP_N_INTEGER:
|
||
if (!(temp & CPP_N_IMAGINARY))
|
||
return cpp_interpret_integer (pfile, token, temp);
|
||
cpp_error (pfile, CPP_DL_ERROR,
|
||
"imaginary number in preprocessor expression");
|
||
break;
|
||
|
||
case CPP_N_INVALID:
|
||
/* Error already issued. */
|
||
break;
|
||
}
|
||
result.high = result.low = 0;
|
||
break;
|
||
|
||
case CPP_WCHAR:
|
||
case CPP_CHAR:
|
||
{
|
||
cppchar_t cc = cpp_interpret_charconst (pfile, token,
|
||
&temp, &unsignedp);
|
||
|
||
result.high = 0;
|
||
result.low = cc;
|
||
/* Sign-extend the result if necessary. */
|
||
if (!unsignedp && (cppchar_signed_t) cc < 0)
|
||
{
|
||
if (PART_PRECISION > BITS_PER_CPPCHAR_T)
|
||
result.low |= ~(~(cpp_num_part) 0
|
||
>> (PART_PRECISION - BITS_PER_CPPCHAR_T));
|
||
result.high = ~(cpp_num_part) 0;
|
||
result = num_trim (result, CPP_OPTION (pfile, precision));
|
||
}
|
||
}
|
||
break;
|
||
|
||
case CPP_NAME:
|
||
if (token->val.node == pfile->spec_nodes.n_defined)
|
||
return parse_defined (pfile);
|
||
else if (CPP_OPTION (pfile, cplusplus)
|
||
&& (token->val.node == pfile->spec_nodes.n_true
|
||
|| token->val.node == pfile->spec_nodes.n_false))
|
||
{
|
||
result.high = 0;
|
||
result.low = (token->val.node == pfile->spec_nodes.n_true);
|
||
}
|
||
else
|
||
{
|
||
result.high = 0;
|
||
result.low = 0;
|
||
if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval)
|
||
cpp_error (pfile, CPP_DL_WARNING, "\"%s\" is not defined",
|
||
NODE_NAME (token->val.node));
|
||
}
|
||
break;
|
||
|
||
default: /* CPP_HASH */
|
||
_cpp_test_assertion (pfile, &temp);
|
||
result.high = 0;
|
||
result.low = temp;
|
||
}
|
||
|
||
result.unsignedp = !!unsignedp;
|
||
result.overflow = false;
|
||
return result;
|
||
}
|
||
|
||
/* Operator precedence and flags table.
|
||
|
||
After an operator is returned from the lexer, if it has priority less
|
||
than the operator on the top of the stack, we reduce the stack by one
|
||
operator and repeat the test. Since equal priorities do not reduce,
|
||
this is naturally right-associative.
|
||
|
||
We handle left-associative operators by decrementing the priority of
|
||
just-lexed operators by one, but retaining the priority of operators
|
||
already on the stack.
|
||
|
||
The remaining cases are '(' and ')'. We handle '(' by skipping the
|
||
reduction phase completely. ')' is given lower priority than
|
||
everything else, including '(', effectively forcing a reduction of the
|
||
parenthesized expression. If there is a matching '(', the routine
|
||
reduce() exits immediately. If the normal exit route sees a ')', then
|
||
there cannot have been a matching '(' and an error message is output.
|
||
|
||
The parser assumes all shifted operators require a left operand unless
|
||
the flag NO_L_OPERAND is set. These semantics are automatic; any
|
||
extra semantics need to be handled with operator-specific code. */
|
||
|
||
/* Flags. If CHECK_PROMOTION, we warn if the effective sign of an
|
||
operand changes because of integer promotions. */
|
||
#define NO_L_OPERAND (1 << 0)
|
||
#define LEFT_ASSOC (1 << 1)
|
||
#define CHECK_PROMOTION (1 << 2)
|
||
|
||
/* Operator to priority map. Must be in the same order as the first
|
||
N entries of enum cpp_ttype. */
|
||
static const struct operator
|
||
{
|
||
uchar prio;
|
||
uchar flags;
|
||
} optab[] =
|
||
{
|
||
/* EQ */ {0, 0}, /* Shouldn't happen. */
|
||
/* NOT */ {16, NO_L_OPERAND},
|
||
/* GREATER */ {12, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* LESS */ {12, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* PLUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* MINUS */ {14, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* MULT */ {15, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* DIV */ {15, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* MOD */ {15, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* AND */ {9, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* OR */ {7, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* XOR */ {8, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* RSHIFT */ {13, LEFT_ASSOC},
|
||
/* LSHIFT */ {13, LEFT_ASSOC},
|
||
|
||
/* MIN */ {10, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* MAX */ {10, LEFT_ASSOC | CHECK_PROMOTION},
|
||
|
||
/* COMPL */ {16, NO_L_OPERAND},
|
||
/* AND_AND */ {6, LEFT_ASSOC},
|
||
/* OR_OR */ {5, LEFT_ASSOC},
|
||
/* QUERY */ {3, 0},
|
||
/* COLON */ {4, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* COMMA */ {2, LEFT_ASSOC},
|
||
/* OPEN_PAREN */ {1, NO_L_OPERAND},
|
||
/* CLOSE_PAREN */ {0, 0},
|
||
/* EOF */ {0, 0},
|
||
/* EQ_EQ */ {11, LEFT_ASSOC},
|
||
/* NOT_EQ */ {11, LEFT_ASSOC},
|
||
/* GREATER_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* LESS_EQ */ {12, LEFT_ASSOC | CHECK_PROMOTION},
|
||
/* UPLUS */ {16, NO_L_OPERAND},
|
||
/* UMINUS */ {16, NO_L_OPERAND}
|
||
};
|
||
|
||
/* Parse and evaluate a C expression, reading from PFILE.
|
||
Returns the truth value of the expression.
|
||
|
||
The implementation is an operator precedence parser, i.e. a
|
||
bottom-up parser, using a stack for not-yet-reduced tokens.
|
||
|
||
The stack base is op_stack, and the current stack pointer is 'top'.
|
||
There is a stack element for each operator (only), and the most
|
||
recently pushed operator is 'top->op'. An operand (value) is
|
||
stored in the 'value' field of the stack element of the operator
|
||
that precedes it. */
|
||
bool
|
||
_cpp_parse_expr (cpp_reader *pfile)
|
||
{
|
||
struct op *top = pfile->op_stack;
|
||
unsigned int lex_count;
|
||
bool saw_leading_not, want_value = true;
|
||
|
||
pfile->state.skip_eval = 0;
|
||
|
||
/* Set up detection of #if ! defined(). */
|
||
pfile->mi_ind_cmacro = 0;
|
||
saw_leading_not = false;
|
||
lex_count = 0;
|
||
|
||
/* Lowest priority operator prevents further reductions. */
|
||
top->op = CPP_EOF;
|
||
|
||
for (;;)
|
||
{
|
||
struct op op;
|
||
|
||
lex_count++;
|
||
op.token = cpp_get_token (pfile);
|
||
op.op = op.token->type;
|
||
|
||
switch (op.op)
|
||
{
|
||
/* These tokens convert into values. */
|
||
case CPP_NUMBER:
|
||
case CPP_CHAR:
|
||
case CPP_WCHAR:
|
||
case CPP_NAME:
|
||
case CPP_HASH:
|
||
if (!want_value)
|
||
SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
|
||
cpp_token_as_text (pfile, op.token));
|
||
want_value = false;
|
||
top->value = eval_token (pfile, op.token);
|
||
continue;
|
||
|
||
case CPP_NOT:
|
||
saw_leading_not = lex_count == 1;
|
||
break;
|
||
case CPP_PLUS:
|
||
if (want_value)
|
||
op.op = CPP_UPLUS;
|
||
break;
|
||
case CPP_MINUS:
|
||
if (want_value)
|
||
op.op = CPP_UMINUS;
|
||
break;
|
||
|
||
default:
|
||
if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
|
||
SYNTAX_ERROR2 ("token \"%s\" is not valid in preprocessor expressions",
|
||
cpp_token_as_text (pfile, op.token));
|
||
break;
|
||
}
|
||
|
||
/* Check we have a value or operator as appropriate. */
|
||
if (optab[op.op].flags & NO_L_OPERAND)
|
||
{
|
||
if (!want_value)
|
||
SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
|
||
cpp_token_as_text (pfile, op.token));
|
||
}
|
||
else if (want_value)
|
||
{
|
||
/* We want a number (or expression) and haven't got one.
|
||
Try to emit a specific diagnostic. */
|
||
if (op.op == CPP_CLOSE_PAREN && top->op == CPP_OPEN_PAREN)
|
||
SYNTAX_ERROR ("missing expression between '(' and ')'");
|
||
|
||
if (op.op == CPP_EOF && top->op == CPP_EOF)
|
||
SYNTAX_ERROR ("#if with no expression");
|
||
|
||
if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN)
|
||
SYNTAX_ERROR2 ("operator '%s' has no right operand",
|
||
cpp_token_as_text (pfile, top->token));
|
||
else if (op.op == CPP_CLOSE_PAREN || op.op == CPP_EOF)
|
||
/* Complain about missing paren during reduction. */;
|
||
else
|
||
SYNTAX_ERROR2 ("operator '%s' has no left operand",
|
||
cpp_token_as_text (pfile, op.token));
|
||
}
|
||
|
||
top = reduce (pfile, top, op.op);
|
||
if (!top)
|
||
goto syntax_error;
|
||
|
||
if (op.op == CPP_EOF)
|
||
break;
|
||
|
||
switch (op.op)
|
||
{
|
||
case CPP_CLOSE_PAREN:
|
||
continue;
|
||
case CPP_OR_OR:
|
||
if (!num_zerop (top->value))
|
||
pfile->state.skip_eval++;
|
||
break;
|
||
case CPP_AND_AND:
|
||
case CPP_QUERY:
|
||
if (num_zerop (top->value))
|
||
pfile->state.skip_eval++;
|
||
break;
|
||
case CPP_COLON:
|
||
if (top->op != CPP_QUERY)
|
||
SYNTAX_ERROR (" ':' without preceding '?'");
|
||
if (!num_zerop (top[-1].value)) /* Was '?' condition true? */
|
||
pfile->state.skip_eval++;
|
||
else
|
||
pfile->state.skip_eval--;
|
||
default:
|
||
break;
|
||
}
|
||
|
||
want_value = true;
|
||
|
||
/* Check for and handle stack overflow. */
|
||
if (++top == pfile->op_limit)
|
||
top = _cpp_expand_op_stack (pfile);
|
||
|
||
top->op = op.op;
|
||
top->token = op.token;
|
||
}
|
||
|
||
/* The controlling macro expression is only valid if we called lex 3
|
||
times: <!> <defined expression> and <EOF>. push_conditional ()
|
||
checks that we are at top-of-file. */
|
||
if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
|
||
pfile->mi_ind_cmacro = 0;
|
||
|
||
if (top != pfile->op_stack)
|
||
{
|
||
cpp_error (pfile, CPP_DL_ICE, "unbalanced stack in #if");
|
||
syntax_error:
|
||
return false; /* Return false on syntax error. */
|
||
}
|
||
|
||
return !num_zerop (top->value);
|
||
}
|
||
|
||
/* Reduce the operator / value stack if possible, in preparation for
|
||
pushing operator OP. Returns NULL on error, otherwise the top of
|
||
the stack. */
|
||
static struct op *
|
||
reduce (cpp_reader *pfile, struct op *top, enum cpp_ttype op)
|
||
{
|
||
unsigned int prio;
|
||
|
||
if (top->op <= CPP_EQ || top->op > CPP_LAST_CPP_OP + 2)
|
||
{
|
||
bad_op:
|
||
cpp_error (pfile, CPP_DL_ICE, "impossible operator '%u'", top->op);
|
||
return 0;
|
||
}
|
||
|
||
if (op == CPP_OPEN_PAREN)
|
||
return top;
|
||
|
||
/* Decrement the priority of left-associative operators to force a
|
||
reduction with operators of otherwise equal priority. */
|
||
prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
|
||
while (prio < optab[top->op].prio)
|
||
{
|
||
if (CPP_OPTION (pfile, warn_num_sign_change)
|
||
&& optab[top->op].flags & CHECK_PROMOTION)
|
||
check_promotion (pfile, top);
|
||
|
||
switch (top->op)
|
||
{
|
||
case CPP_UPLUS:
|
||
case CPP_UMINUS:
|
||
case CPP_NOT:
|
||
case CPP_COMPL:
|
||
top[-1].value = num_unary_op (pfile, top->value, top->op);
|
||
break;
|
||
|
||
case CPP_PLUS:
|
||
case CPP_MINUS:
|
||
case CPP_RSHIFT:
|
||
case CPP_LSHIFT:
|
||
case CPP_MIN:
|
||
case CPP_MAX:
|
||
case CPP_COMMA:
|
||
top[-1].value = num_binary_op (pfile, top[-1].value,
|
||
top->value, top->op);
|
||
break;
|
||
|
||
case CPP_GREATER:
|
||
case CPP_LESS:
|
||
case CPP_GREATER_EQ:
|
||
case CPP_LESS_EQ:
|
||
top[-1].value
|
||
= num_inequality_op (pfile, top[-1].value, top->value, top->op);
|
||
break;
|
||
|
||
case CPP_EQ_EQ:
|
||
case CPP_NOT_EQ:
|
||
top[-1].value
|
||
= num_equality_op (pfile, top[-1].value, top->value, top->op);
|
||
break;
|
||
|
||
case CPP_AND:
|
||
case CPP_OR:
|
||
case CPP_XOR:
|
||
top[-1].value
|
||
= num_bitwise_op (pfile, top[-1].value, top->value, top->op);
|
||
break;
|
||
|
||
case CPP_MULT:
|
||
top[-1].value = num_mul (pfile, top[-1].value, top->value);
|
||
break;
|
||
|
||
case CPP_DIV:
|
||
case CPP_MOD:
|
||
top[-1].value = num_div_op (pfile, top[-1].value,
|
||
top->value, top->op);
|
||
break;
|
||
|
||
case CPP_OR_OR:
|
||
top--;
|
||
if (!num_zerop (top->value))
|
||
pfile->state.skip_eval--;
|
||
top->value.low = (!num_zerop (top->value)
|
||
|| !num_zerop (top[1].value));
|
||
top->value.high = 0;
|
||
top->value.unsignedp = false;
|
||
top->value.overflow = false;
|
||
continue;
|
||
|
||
case CPP_AND_AND:
|
||
top--;
|
||
if (num_zerop (top->value))
|
||
pfile->state.skip_eval--;
|
||
top->value.low = (!num_zerop (top->value)
|
||
&& !num_zerop (top[1].value));
|
||
top->value.high = 0;
|
||
top->value.unsignedp = false;
|
||
top->value.overflow = false;
|
||
continue;
|
||
|
||
case CPP_OPEN_PAREN:
|
||
if (op != CPP_CLOSE_PAREN)
|
||
{
|
||
cpp_error (pfile, CPP_DL_ERROR, "missing ')' in expression");
|
||
return 0;
|
||
}
|
||
top--;
|
||
top->value = top[1].value;
|
||
return top;
|
||
|
||
case CPP_COLON:
|
||
top -= 2;
|
||
if (!num_zerop (top->value))
|
||
{
|
||
pfile->state.skip_eval--;
|
||
top->value = top[1].value;
|
||
}
|
||
else
|
||
top->value = top[2].value;
|
||
top->value.unsignedp = (top[1].value.unsignedp
|
||
|| top[2].value.unsignedp);
|
||
continue;
|
||
|
||
case CPP_QUERY:
|
||
cpp_error (pfile, CPP_DL_ERROR, "'?' without following ':'");
|
||
return 0;
|
||
|
||
default:
|
||
goto bad_op;
|
||
}
|
||
|
||
top--;
|
||
if (top->value.overflow && !pfile->state.skip_eval)
|
||
cpp_error (pfile, CPP_DL_PEDWARN,
|
||
"integer overflow in preprocessor expression");
|
||
}
|
||
|
||
if (op == CPP_CLOSE_PAREN)
|
||
{
|
||
cpp_error (pfile, CPP_DL_ERROR, "missing '(' in expression");
|
||
return 0;
|
||
}
|
||
|
||
return top;
|
||
}
|
||
|
||
/* Returns the position of the old top of stack after expansion. */
|
||
struct op *
|
||
_cpp_expand_op_stack (cpp_reader *pfile)
|
||
{
|
||
size_t old_size = (size_t) (pfile->op_limit - pfile->op_stack);
|
||
size_t new_size = old_size * 2 + 20;
|
||
|
||
pfile->op_stack = xrealloc (pfile->op_stack, new_size * sizeof (struct op));
|
||
pfile->op_limit = pfile->op_stack + new_size;
|
||
|
||
return pfile->op_stack + old_size;
|
||
}
|
||
|
||
/* Emits a warning if the effective sign of either operand of OP
|
||
changes because of integer promotions. */
|
||
static void
|
||
check_promotion (cpp_reader *pfile, const struct op *op)
|
||
{
|
||
if (op->value.unsignedp == op[-1].value.unsignedp)
|
||
return;
|
||
|
||
if (op->value.unsignedp)
|
||
{
|
||
if (!num_positive (op[-1].value, CPP_OPTION (pfile, precision)))
|
||
cpp_error (pfile, CPP_DL_WARNING,
|
||
"the left operand of \"%s\" changes sign when promoted",
|
||
cpp_token_as_text (pfile, op->token));
|
||
}
|
||
else if (!num_positive (op->value, CPP_OPTION (pfile, precision)))
|
||
cpp_error (pfile, CPP_DL_WARNING,
|
||
"the right operand of \"%s\" changes sign when promoted",
|
||
cpp_token_as_text (pfile, op->token));
|
||
}
|
||
|
||
/* Clears the unused high order bits of the number pointed to by PNUM. */
|
||
static cpp_num
|
||
num_trim (cpp_num num, size_t precision)
|
||
{
|
||
if (precision > PART_PRECISION)
|
||
{
|
||
precision -= PART_PRECISION;
|
||
if (precision < PART_PRECISION)
|
||
num.high &= ((cpp_num_part) 1 << precision) - 1;
|
||
}
|
||
else
|
||
{
|
||
if (precision < PART_PRECISION)
|
||
num.low &= ((cpp_num_part) 1 << precision) - 1;
|
||
num.high = 0;
|
||
}
|
||
|
||
return num;
|
||
}
|
||
|
||
/* True iff A (presumed signed) >= 0. */
|
||
static bool
|
||
num_positive (cpp_num num, size_t precision)
|
||
{
|
||
if (precision > PART_PRECISION)
|
||
{
|
||
precision -= PART_PRECISION;
|
||
return (num.high & (cpp_num_part) 1 << (precision - 1)) == 0;
|
||
}
|
||
|
||
return (num.low & (cpp_num_part) 1 << (precision - 1)) == 0;
|
||
}
|
||
|
||
/* Sign extend a number, with PRECISION significant bits and all
|
||
others assumed clear, to fill out a cpp_num structure. */
|
||
cpp_num
|
||
cpp_num_sign_extend (cpp_num num, size_t precision)
|
||
{
|
||
if (!num.unsignedp)
|
||
{
|
||
if (precision > PART_PRECISION)
|
||
{
|
||
precision -= PART_PRECISION;
|
||
if (precision < PART_PRECISION
|
||
&& (num.high & (cpp_num_part) 1 << (precision - 1)))
|
||
num.high |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
|
||
}
|
||
else if (num.low & (cpp_num_part) 1 << (precision - 1))
|
||
{
|
||
if (precision < PART_PRECISION)
|
||
num.low |= ~(~(cpp_num_part) 0 >> (PART_PRECISION - precision));
|
||
num.high = ~(cpp_num_part) 0;
|
||
}
|
||
}
|
||
|
||
return num;
|
||
}
|
||
|
||
/* Returns the negative of NUM. */
|
||
static cpp_num
|
||
num_negate (cpp_num num, size_t precision)
|
||
{
|
||
cpp_num copy;
|
||
|
||
copy = num;
|
||
num.high = ~num.high;
|
||
num.low = ~num.low;
|
||
if (++num.low == 0)
|
||
num.high++;
|
||
num = num_trim (num, precision);
|
||
num.overflow = (!num.unsignedp && num_eq (num, copy) && !num_zerop (num));
|
||
|
||
return num;
|
||
}
|
||
|
||
/* Returns true if A >= B. */
|
||
static bool
|
||
num_greater_eq (cpp_num pa, cpp_num pb, size_t precision)
|
||
{
|
||
bool unsignedp;
|
||
|
||
unsignedp = pa.unsignedp || pb.unsignedp;
|
||
|
||
if (!unsignedp)
|
||
{
|
||
/* Both numbers have signed type. If they are of different
|
||
sign, the answer is the sign of A. */
|
||
unsignedp = num_positive (pa, precision);
|
||
|
||
if (unsignedp != num_positive (pb, precision))
|
||
return unsignedp;
|
||
|
||
/* Otherwise we can do an unsigned comparison. */
|
||
}
|
||
|
||
return (pa.high > pb.high) || (pa.high == pb.high && pa.low >= pb.low);
|
||
}
|
||
|
||
/* Returns LHS OP RHS, where OP is a bit-wise operation. */
|
||
static cpp_num
|
||
num_bitwise_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
|
||
cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
|
||
{
|
||
lhs.overflow = false;
|
||
lhs.unsignedp = lhs.unsignedp || rhs.unsignedp;
|
||
|
||
/* As excess precision is zeroed, there is no need to num_trim () as
|
||
these operations cannot introduce a set bit there. */
|
||
if (op == CPP_AND)
|
||
{
|
||
lhs.low &= rhs.low;
|
||
lhs.high &= rhs.high;
|
||
}
|
||
else if (op == CPP_OR)
|
||
{
|
||
lhs.low |= rhs.low;
|
||
lhs.high |= rhs.high;
|
||
}
|
||
else
|
||
{
|
||
lhs.low ^= rhs.low;
|
||
lhs.high ^= rhs.high;
|
||
}
|
||
|
||
return lhs;
|
||
}
|
||
|
||
/* Returns LHS OP RHS, where OP is an inequality. */
|
||
static cpp_num
|
||
num_inequality_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs,
|
||
enum cpp_ttype op)
|
||
{
|
||
bool gte = num_greater_eq (lhs, rhs, CPP_OPTION (pfile, precision));
|
||
|
||
if (op == CPP_GREATER_EQ)
|
||
lhs.low = gte;
|
||
else if (op == CPP_LESS)
|
||
lhs.low = !gte;
|
||
else if (op == CPP_GREATER)
|
||
lhs.low = gte && !num_eq (lhs, rhs);
|
||
else /* CPP_LESS_EQ. */
|
||
lhs.low = !gte || num_eq (lhs, rhs);
|
||
|
||
lhs.high = 0;
|
||
lhs.overflow = false;
|
||
lhs.unsignedp = false;
|
||
return lhs;
|
||
}
|
||
|
||
/* Returns LHS OP RHS, where OP is == or !=. */
|
||
static cpp_num
|
||
num_equality_op (cpp_reader *pfile ATTRIBUTE_UNUSED,
|
||
cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
|
||
{
|
||
/* Work around a 3.0.4 bug; see PR 6950. */
|
||
bool eq = num_eq (lhs, rhs);
|
||
if (op == CPP_NOT_EQ)
|
||
eq = !eq;
|
||
lhs.low = eq;
|
||
lhs.high = 0;
|
||
lhs.overflow = false;
|
||
lhs.unsignedp = false;
|
||
return lhs;
|
||
}
|
||
|
||
/* Shift NUM, of width PRECISION, right by N bits. */
|
||
static cpp_num
|
||
num_rshift (cpp_num num, size_t precision, size_t n)
|
||
{
|
||
cpp_num_part sign_mask;
|
||
|
||
if (num.unsignedp || num_positive (num, precision))
|
||
sign_mask = 0;
|
||
else
|
||
sign_mask = ~(cpp_num_part) 0;
|
||
|
||
if (n >= precision)
|
||
num.high = num.low = sign_mask;
|
||
else
|
||
{
|
||
/* Sign-extend. */
|
||
if (precision < PART_PRECISION)
|
||
num.high = sign_mask, num.low |= sign_mask << precision;
|
||
else if (precision < 2 * PART_PRECISION)
|
||
num.high |= sign_mask << (precision - PART_PRECISION);
|
||
|
||
if (n >= PART_PRECISION)
|
||
{
|
||
n -= PART_PRECISION;
|
||
num.low = num.high;
|
||
num.high = sign_mask;
|
||
}
|
||
|
||
if (n)
|
||
{
|
||
num.low = (num.low >> n) | (num.high << (PART_PRECISION - n));
|
||
num.high = (num.high >> n) | (sign_mask << (PART_PRECISION - n));
|
||
}
|
||
}
|
||
|
||
num = num_trim (num, precision);
|
||
num.overflow = false;
|
||
return num;
|
||
}
|
||
|
||
/* Shift NUM, of width PRECISION, left by N bits. */
|
||
static cpp_num
|
||
num_lshift (cpp_num num, size_t precision, size_t n)
|
||
{
|
||
if (n >= precision)
|
||
{
|
||
num.overflow = !num.unsignedp && !num_zerop (num);
|
||
num.high = num.low = 0;
|
||
}
|
||
else
|
||
{
|
||
cpp_num orig, maybe_orig;
|
||
size_t m = n;
|
||
|
||
orig = num;
|
||
if (m >= PART_PRECISION)
|
||
{
|
||
m -= PART_PRECISION;
|
||
num.high = num.low;
|
||
num.low = 0;
|
||
}
|
||
if (m)
|
||
{
|
||
num.high = (num.high << m) | (num.low >> (PART_PRECISION - m));
|
||
num.low <<= m;
|
||
}
|
||
num = num_trim (num, precision);
|
||
|
||
if (num.unsignedp)
|
||
num.overflow = false;
|
||
else
|
||
{
|
||
maybe_orig = num_rshift (num, precision, n);
|
||
num.overflow = !num_eq (orig, maybe_orig);
|
||
}
|
||
}
|
||
|
||
return num;
|
||
}
|
||
|
||
/* The four unary operators: +, -, ! and ~. */
|
||
static cpp_num
|
||
num_unary_op (cpp_reader *pfile, cpp_num num, enum cpp_ttype op)
|
||
{
|
||
switch (op)
|
||
{
|
||
case CPP_UPLUS:
|
||
if (CPP_WTRADITIONAL (pfile) && !pfile->state.skip_eval)
|
||
cpp_error (pfile, CPP_DL_WARNING,
|
||
"traditional C rejects the unary plus operator");
|
||
num.overflow = false;
|
||
break;
|
||
|
||
case CPP_UMINUS:
|
||
num = num_negate (num, CPP_OPTION (pfile, precision));
|
||
break;
|
||
|
||
case CPP_COMPL:
|
||
num.high = ~num.high;
|
||
num.low = ~num.low;
|
||
num = num_trim (num, CPP_OPTION (pfile, precision));
|
||
num.overflow = false;
|
||
break;
|
||
|
||
default: /* case CPP_NOT: */
|
||
num.low = num_zerop (num);
|
||
num.high = 0;
|
||
num.overflow = false;
|
||
num.unsignedp = false;
|
||
break;
|
||
}
|
||
|
||
return num;
|
||
}
|
||
|
||
/* The various binary operators. */
|
||
static cpp_num
|
||
num_binary_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
|
||
{
|
||
cpp_num result;
|
||
size_t precision = CPP_OPTION (pfile, precision);
|
||
bool gte;
|
||
size_t n;
|
||
|
||
switch (op)
|
||
{
|
||
/* Shifts. */
|
||
case CPP_LSHIFT:
|
||
case CPP_RSHIFT:
|
||
if (!rhs.unsignedp && !num_positive (rhs, precision))
|
||
{
|
||
/* A negative shift is a positive shift the other way. */
|
||
if (op == CPP_LSHIFT)
|
||
op = CPP_RSHIFT;
|
||
else
|
||
op = CPP_LSHIFT;
|
||
rhs = num_negate (rhs, precision);
|
||
}
|
||
if (rhs.high)
|
||
n = ~0; /* Maximal. */
|
||
else
|
||
n = rhs.low;
|
||
if (op == CPP_LSHIFT)
|
||
lhs = num_lshift (lhs, precision, n);
|
||
else
|
||
lhs = num_rshift (lhs, precision, n);
|
||
break;
|
||
|
||
/* Min / Max. */
|
||
case CPP_MIN:
|
||
case CPP_MAX:
|
||
{
|
||
bool unsignedp = lhs.unsignedp || rhs.unsignedp;
|
||
|
||
gte = num_greater_eq (lhs, rhs, precision);
|
||
if (op == CPP_MIN)
|
||
gte = !gte;
|
||
if (!gte)
|
||
lhs = rhs;
|
||
lhs.unsignedp = unsignedp;
|
||
}
|
||
break;
|
||
|
||
/* Arithmetic. */
|
||
case CPP_MINUS:
|
||
rhs = num_negate (rhs, precision);
|
||
case CPP_PLUS:
|
||
result.low = lhs.low + rhs.low;
|
||
result.high = lhs.high + rhs.high;
|
||
if (result.low < lhs.low)
|
||
result.high++;
|
||
|
||
result = num_trim (result, precision);
|
||
result.unsignedp = lhs.unsignedp || rhs.unsignedp;
|
||
if (result.unsignedp)
|
||
result.overflow = false;
|
||
else
|
||
{
|
||
bool lhsp = num_positive (lhs, precision);
|
||
result.overflow = (lhsp == num_positive (rhs, precision)
|
||
&& lhsp != num_positive (result, precision));
|
||
}
|
||
return result;
|
||
|
||
/* Comma. */
|
||
default: /* case CPP_COMMA: */
|
||
if (CPP_PEDANTIC (pfile) && (!CPP_OPTION (pfile, c99)
|
||
|| !pfile->state.skip_eval))
|
||
cpp_error (pfile, CPP_DL_PEDWARN,
|
||
"comma operator in operand of #if");
|
||
lhs = rhs;
|
||
break;
|
||
}
|
||
|
||
return lhs;
|
||
}
|
||
|
||
/* Multiplies two unsigned cpp_num_parts to give a cpp_num. This
|
||
cannot overflow. */
|
||
static cpp_num
|
||
num_part_mul (cpp_num_part lhs, cpp_num_part rhs)
|
||
{
|
||
cpp_num result;
|
||
cpp_num_part middle[2], temp;
|
||
|
||
result.low = LOW_PART (lhs) * LOW_PART (rhs);
|
||
result.high = HIGH_PART (lhs) * HIGH_PART (rhs);
|
||
|
||
middle[0] = LOW_PART (lhs) * HIGH_PART (rhs);
|
||
middle[1] = HIGH_PART (lhs) * LOW_PART (rhs);
|
||
|
||
temp = result.low;
|
||
result.low += LOW_PART (middle[0]) << (PART_PRECISION / 2);
|
||
if (result.low < temp)
|
||
result.high++;
|
||
|
||
temp = result.low;
|
||
result.low += LOW_PART (middle[1]) << (PART_PRECISION / 2);
|
||
if (result.low < temp)
|
||
result.high++;
|
||
|
||
result.high += HIGH_PART (middle[0]);
|
||
result.high += HIGH_PART (middle[1]);
|
||
result.unsignedp = 1;
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Multiply two preprocessing numbers. */
|
||
static cpp_num
|
||
num_mul (cpp_reader *pfile, cpp_num lhs, cpp_num rhs)
|
||
{
|
||
cpp_num result, temp;
|
||
bool unsignedp = lhs.unsignedp || rhs.unsignedp;
|
||
bool overflow, negate = false;
|
||
size_t precision = CPP_OPTION (pfile, precision);
|
||
|
||
/* Prepare for unsigned multiplication. */
|
||
if (!unsignedp)
|
||
{
|
||
if (!num_positive (lhs, precision))
|
||
negate = !negate, lhs = num_negate (lhs, precision);
|
||
if (!num_positive (rhs, precision))
|
||
negate = !negate, rhs = num_negate (rhs, precision);
|
||
}
|
||
|
||
overflow = lhs.high && rhs.high;
|
||
result = num_part_mul (lhs.low, rhs.low);
|
||
|
||
temp = num_part_mul (lhs.high, rhs.low);
|
||
result.high += temp.low;
|
||
if (temp.high)
|
||
overflow = true;
|
||
|
||
temp = num_part_mul (lhs.low, rhs.high);
|
||
result.high += temp.low;
|
||
if (temp.high)
|
||
overflow = true;
|
||
|
||
temp.low = result.low, temp.high = result.high;
|
||
result = num_trim (result, precision);
|
||
if (!num_eq (result, temp))
|
||
overflow = true;
|
||
|
||
if (negate)
|
||
result = num_negate (result, precision);
|
||
|
||
if (unsignedp)
|
||
result.overflow = false;
|
||
else
|
||
result.overflow = overflow || (num_positive (result, precision) ^ !negate
|
||
&& !num_zerop (result));
|
||
result.unsignedp = unsignedp;
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Divide two preprocessing numbers, returning the answer or the
|
||
remainder depending upon OP. */
|
||
static cpp_num
|
||
num_div_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op)
|
||
{
|
||
cpp_num result, sub;
|
||
cpp_num_part mask;
|
||
bool unsignedp = lhs.unsignedp || rhs.unsignedp;
|
||
bool negate = false, lhs_neg = false;
|
||
size_t i, precision = CPP_OPTION (pfile, precision);
|
||
|
||
/* Prepare for unsigned division. */
|
||
if (!unsignedp)
|
||
{
|
||
if (!num_positive (lhs, precision))
|
||
negate = !negate, lhs_neg = true, lhs = num_negate (lhs, precision);
|
||
if (!num_positive (rhs, precision))
|
||
negate = !negate, rhs = num_negate (rhs, precision);
|
||
}
|
||
|
||
/* Find the high bit. */
|
||
if (rhs.high)
|
||
{
|
||
i = precision - 1;
|
||
mask = (cpp_num_part) 1 << (i - PART_PRECISION);
|
||
for (; ; i--, mask >>= 1)
|
||
if (rhs.high & mask)
|
||
break;
|
||
}
|
||
else if (rhs.low)
|
||
{
|
||
if (precision > PART_PRECISION)
|
||
i = precision - PART_PRECISION - 1;
|
||
else
|
||
i = precision - 1;
|
||
mask = (cpp_num_part) 1 << i;
|
||
for (; ; i--, mask >>= 1)
|
||
if (rhs.low & mask)
|
||
break;
|
||
}
|
||
else
|
||
{
|
||
if (!pfile->state.skip_eval)
|
||
cpp_error (pfile, CPP_DL_ERROR, "division by zero in #if");
|
||
return lhs;
|
||
}
|
||
|
||
/* First nonzero bit of RHS is bit I. Do naive division by
|
||
shifting the RHS fully left, and subtracting from LHS if LHS is
|
||
at least as big, and then repeating but with one less shift.
|
||
This is not very efficient, but is easy to understand. */
|
||
|
||
rhs.unsignedp = true;
|
||
lhs.unsignedp = true;
|
||
i = precision - i - 1;
|
||
sub = num_lshift (rhs, precision, i);
|
||
|
||
result.high = result.low = 0;
|
||
for (;;)
|
||
{
|
||
if (num_greater_eq (lhs, sub, precision))
|
||
{
|
||
lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
|
||
if (i >= PART_PRECISION)
|
||
result.high |= (cpp_num_part) 1 << (i - PART_PRECISION);
|
||
else
|
||
result.low |= (cpp_num_part) 1 << i;
|
||
}
|
||
if (i-- == 0)
|
||
break;
|
||
sub.low = (sub.low >> 1) | (sub.high << (PART_PRECISION - 1));
|
||
sub.high >>= 1;
|
||
}
|
||
|
||
/* We divide so that the remainder has the sign of the LHS. */
|
||
if (op == CPP_DIV)
|
||
{
|
||
result.unsignedp = unsignedp;
|
||
if (unsignedp)
|
||
result.overflow = false;
|
||
else
|
||
{
|
||
if (negate)
|
||
result = num_negate (result, precision);
|
||
result.overflow = num_positive (result, precision) ^ !negate;
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
/* CPP_MOD. */
|
||
lhs.unsignedp = unsignedp;
|
||
lhs.overflow = false;
|
||
if (lhs_neg)
|
||
lhs = num_negate (lhs, precision);
|
||
|
||
return lhs;
|
||
}
|