diff options
Diffstat (limited to 'gcc-4.4.3/libcpp/expr.c')
| -rw-r--r-- | gcc-4.4.3/libcpp/expr.c | 1723 |
1 files changed, 0 insertions, 1723 deletions
diff --git a/gcc-4.4.3/libcpp/expr.c b/gcc-4.4.3/libcpp/expr.c deleted file mode 100644 index edefd389c..000000000 --- a/gcc-4.4.3/libcpp/expr.c +++ /dev/null @@ -1,1723 +0,0 @@ -/* Parse C expressions for cpplib. - Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001, - 2002, 2004, 2008, 2009 Free Software Foundation. - Contributed by Per Bothner, 1994. - -This program is free software; you can redistribute it and/or modify it -under the terms of the GNU General Public License as published by the -Free Software Foundation; either version 3, or (at your option) any -later version. - -This program is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this program; see the file COPYING3. If not see -<http://www.gnu.org/licenses/>. */ - -#include "config.h" -#include "system.h" -#include "cpplib.h" -#include "internal.h" - -#define PART_PRECISION (sizeof (cpp_num_part) * CHAR_BIT) -#define HALF_MASK (~(cpp_num_part) 0 >> (PART_PRECISION / 2)) -#define LOW_PART(num_part) (num_part & HALF_MASK) -#define HIGH_PART(num_part) (num_part >> (PART_PRECISION / 2)) - -struct op -{ - const cpp_token *token; /* The token forming op (for diagnostics). */ - cpp_num value; /* The value logically "right" of op. */ - source_location loc; /* The location of this value. */ - enum cpp_ttype op; -}; - -/* Some simple utility routines on double integers. */ -#define num_zerop(num) ((num.low | num.high) == 0) -#define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high) -static bool num_positive (cpp_num, size_t); -static bool num_greater_eq (cpp_num, cpp_num, size_t); -static cpp_num num_trim (cpp_num, size_t); -static cpp_num num_part_mul (cpp_num_part, cpp_num_part); - -static cpp_num num_unary_op (cpp_reader *, cpp_num, enum cpp_ttype); -static cpp_num num_binary_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype); -static cpp_num num_negate (cpp_num, size_t); -static cpp_num num_bitwise_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype); -static cpp_num num_inequality_op (cpp_reader *, cpp_num, cpp_num, - enum cpp_ttype); -static cpp_num num_equality_op (cpp_reader *, cpp_num, cpp_num, - enum cpp_ttype); -static cpp_num num_mul (cpp_reader *, cpp_num, cpp_num); -static cpp_num num_div_op (cpp_reader *, cpp_num, cpp_num, enum cpp_ttype); -static cpp_num num_lshift (cpp_num, size_t, size_t); -static cpp_num num_rshift (cpp_num, size_t, size_t); - -static cpp_num append_digit (cpp_num, int, int, size_t); -static cpp_num parse_defined (cpp_reader *); -static cpp_num eval_token (cpp_reader *, const cpp_token *); -static struct op *reduce (cpp_reader *, struct op *, enum cpp_ttype); -static unsigned int interpret_float_suffix (const uchar *, size_t); -static unsigned int interpret_int_suffix (const uchar *, size_t); -static void check_promotion (cpp_reader *, const struct op *); - -/* Token type abuse to create unary plus and minus operators. */ -#define CPP_UPLUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 1)) -#define CPP_UMINUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 2)) - -/* With -O2, gcc appears to produce nice code, moving the error - message load and subsequent jump completely out of the main path. */ -#define SYNTAX_ERROR(msgid) \ - do { cpp_error (pfile, CPP_DL_ERROR, msgid); goto syntax_error; } while(0) -#define SYNTAX_ERROR2(msgid, arg) \ - do { cpp_error (pfile, CPP_DL_ERROR, msgid, arg); goto syntax_error; } \ - while(0) - -/* Subroutine of cpp_classify_number. S points to a float suffix of - length LEN, possibly zero. Returns 0 for an invalid suffix, or a - flag vector describing the suffix. */ -static unsigned int -interpret_float_suffix (const uchar *s, size_t len) -{ - size_t f, l, w, q, i, d; - size_t r, k, u, h; - - f = l = w = q = i = d = 0; - r = k = u = h = 0; - - while (len--) - switch (s[len]) - { - case 'r': case 'R': r++; break; - case 'k': case 'K': k++; break; - case 'u': case 'U': u++; break; - case 'h': case 'H': h++; break; - case 'f': case 'F': - if (d > 0) - return 0; - f++; - break; - case 'l': case 'L': - if (d > 0) - return 0; - l++; - /* If there are two Ls, they must be adjacent and the same case. */ - if (l == 2 && s[len] != s[len + 1]) - return 0; - break; - case 'w': case 'W': - if (d > 0) - return 0; - w++; - break; - case 'q': case 'Q': - if (d > 0) - return 0; - q++; - break; - case 'i': case 'I': - case 'j': case 'J': i++; break; - case 'd': case 'D': d++; break; - default: - return 0; - } - - if (r + k > 1 || h > 1 || l > 2 || u > 1) - return 0; - - if (r == 1) - { - if (f || i || d || w || q) - return 0; - - return (CPP_N_FRACT - | (u ? CPP_N_UNSIGNED : 0) - | (h ? CPP_N_SMALL : - l == 2 ? CPP_N_LARGE : - l == 1 ? CPP_N_MEDIUM : 0)); - } - - if (k == 1) - { - if (f || i || d || w || q) - return 0; - - return (CPP_N_ACCUM - | (u ? CPP_N_UNSIGNED : 0) - | (h ? CPP_N_SMALL : - l == 2 ? CPP_N_LARGE : - l == 1 ? CPP_N_MEDIUM : 0)); - } - - if (f + l + w + q > 1 || i > 1 || h + u > 0) - return 0; - - /* Allow dd, df, dl suffixes for decimal float constants. */ - if (d && ((d + f + l != 2) || i)) - return 0; - - return ((i ? CPP_N_IMAGINARY : 0) - | (f ? CPP_N_SMALL : - l ? CPP_N_LARGE : - w ? CPP_N_MD_W : - q ? CPP_N_MD_Q : CPP_N_MEDIUM) - | (d ? CPP_N_DFLOAT : 0)); -} - -/* Subroutine of cpp_classify_number. S points to an integer suffix - of length LEN, possibly zero. Returns 0 for an invalid suffix, or a - flag vector describing the suffix. */ -static unsigned int -interpret_int_suffix (const uchar *s, size_t len) -{ - size_t u, l, i; - - u = l = i = 0; - - while (len--) - switch (s[len]) - { - case 'u': case 'U': u++; break; - case 'i': case 'I': - case 'j': case 'J': i++; break; - case 'l': case 'L': l++; - /* If there are two Ls, they must be adjacent and the same case. */ - if (l == 2 && s[len] != s[len + 1]) - return 0; - break; - default: - return 0; - } - - if (l > 2 || u > 1 || i > 1) - return 0; - - return ((i ? CPP_N_IMAGINARY : 0) - | (u ? CPP_N_UNSIGNED : 0) - | ((l == 0) ? CPP_N_SMALL - : (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE)); -} - -/* Categorize numeric constants according to their field (integer, - floating point, or invalid), radix (decimal, octal, hexadecimal), - and type suffixes. */ -unsigned int -cpp_classify_number (cpp_reader *pfile, const cpp_token *token) -{ - const uchar *str = token->val.str.text; - const uchar *limit; - unsigned int max_digit, result, radix; - enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag; - - /* If the lexer has done its job, length one can only be a single - digit. Fast-path this very common case. */ - if (token->val.str.len == 1) - return CPP_N_INTEGER | CPP_N_SMALL | CPP_N_DECIMAL; - - limit = str + token->val.str.len; - float_flag = NOT_FLOAT; - max_digit = 0; - radix = 10; - - /* First, interpret the radix. */ - if (*str == '0') - { - radix = 8; - str++; - - /* Require at least one hex digit to classify it as hex. */ - if ((*str == 'x' || *str == 'X') - && (str[1] == '.' || ISXDIGIT (str[1]))) - { - radix = 16; - str++; - } - else if ((*str == 'b' || *str == 'B') && (str[1] == '0' || str[1] == '1')) - { - radix = 2; - str++; - } - } - - /* Now scan for a well-formed integer or float. */ - for (;;) - { - unsigned int c = *str++; - - if (ISDIGIT (c) || (ISXDIGIT (c) && radix == 16)) - { - c = hex_value (c); - if (c > max_digit) - max_digit = c; - } - else if (c == '.') - { - if (float_flag == NOT_FLOAT) - float_flag = AFTER_POINT; - else - SYNTAX_ERROR ("too many decimal points in number"); - } - else if ((radix <= 10 && (c == 'e' || c == 'E')) - || (radix == 16 && (c == 'p' || c == 'P'))) - { - float_flag = AFTER_EXPON; - break; - } - else - { - /* Start of suffix. */ - str--; - break; - } - } - - /* The suffix may be for decimal fixed-point constants without exponent. */ - if (radix != 16 && float_flag == NOT_FLOAT) - { - result = interpret_float_suffix (str, limit - str); - if ((result & CPP_N_FRACT) || (result & CPP_N_ACCUM)) - { - result |= CPP_N_FLOATING; - /* We need to restore the radix to 10, if the radix is 8. */ - if (radix == 8) - radix = 10; - - if (CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "fixed-point constants are a GCC extension"); - goto syntax_ok; - } - else - result = 0; - } - - if (float_flag != NOT_FLOAT && radix == 8) - radix = 10; - - if (max_digit >= radix) - { - if (radix == 2) - SYNTAX_ERROR2 ("invalid digit \"%c\" in binary constant", '0' + max_digit); - else - SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit); - } - - if (float_flag != NOT_FLOAT) - { - if (radix == 2) - { - cpp_error (pfile, CPP_DL_ERROR, - "invalid prefix \"0b\" for floating constant"); - return CPP_N_INVALID; - } - - if (radix == 16 && CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, c99)) - cpp_error (pfile, CPP_DL_PEDWARN, - "use of C99 hexadecimal floating constant"); - - if (float_flag == AFTER_EXPON) - { - if (*str == '+' || *str == '-') - str++; - - /* Exponent is decimal, even if string is a hex float. */ - if (!ISDIGIT (*str)) - SYNTAX_ERROR ("exponent has no digits"); - - do - str++; - while (ISDIGIT (*str)); - } - else if (radix == 16) - SYNTAX_ERROR ("hexadecimal floating constants require an exponent"); - - result = interpret_float_suffix (str, limit - str); - if (result == 0) - { - cpp_error (pfile, CPP_DL_ERROR, - "invalid suffix \"%.*s\" on floating constant", - (int) (limit - str), str); - return CPP_N_INVALID; - } - - /* Traditional C didn't accept any floating suffixes. */ - if (limit != str - && CPP_WTRADITIONAL (pfile) - && ! cpp_sys_macro_p (pfile)) - cpp_error (pfile, CPP_DL_WARNING, - "traditional C rejects the \"%.*s\" suffix", - (int) (limit - str), str); - - /* Radix must be 10 for decimal floats. */ - if ((result & CPP_N_DFLOAT) && radix != 10) - { - cpp_error (pfile, CPP_DL_ERROR, - "invalid suffix \"%.*s\" with hexadecimal floating constant", - (int) (limit - str), str); - return CPP_N_INVALID; - } - - if ((result & (CPP_N_FRACT | CPP_N_ACCUM)) && CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "fixed-point constants are a GCC extension"); - - if ((result & CPP_N_DFLOAT) && CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "decimal float constants are a GCC extension"); - - result |= CPP_N_FLOATING; - } - else - { - result = interpret_int_suffix (str, limit - str); - if (result == 0) - { - cpp_error (pfile, CPP_DL_ERROR, - "invalid suffix \"%.*s\" on integer constant", - (int) (limit - str), str); - return CPP_N_INVALID; - } - - /* Traditional C only accepted the 'L' suffix. - Suppress warning about 'LL' with -Wno-long-long. */ - if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile)) - { - int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY)); - int large = (result & CPP_N_WIDTH) == CPP_N_LARGE; - - if (u_or_i || (large && CPP_OPTION (pfile, warn_long_long))) - cpp_error (pfile, CPP_DL_WARNING, - "traditional C rejects the \"%.*s\" suffix", - (int) (limit - str), str); - } - - if ((result & CPP_N_WIDTH) == CPP_N_LARGE - && ! CPP_OPTION (pfile, c99) - && CPP_OPTION (pfile, warn_long_long)) - cpp_error (pfile, CPP_DL_PEDWARN, - "use of C99 long long integer constant"); - - result |= CPP_N_INTEGER; - } - - syntax_ok: - if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "imaginary constants are a GCC extension"); - if (radix == 2 && CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "binary constants are a GCC extension"); - - if (radix == 10) - result |= CPP_N_DECIMAL; - else if (radix == 16) - result |= CPP_N_HEX; - else if (radix == 2) - result |= CPP_N_BINARY; - else - 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. - - We do not provide any interface for decimal->float conversion, - because the preprocessor doesn't need it and we don't want to - drag in GCC's floating point emulator. */ -cpp_num -cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token, - unsigned int type) -{ - const uchar *p, *end; - 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; - } - else if ((type & CPP_N_RADIX) == CPP_N_BINARY) - { - base = 2; - 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; - 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; - bool overflow; - cpp_num_part add_high, add_low; - - /* Multiply by 2, 8 or 16. Catching this overflow here means we don't - need to worry about add_high overflowing. */ - switch (base) - { - case 2: - shift = 1; - break; - - case 16: - shift = 4; - break; - - default: - shift = 3; - } - overflow = !!(num.high >> (PART_PRECISION - shift)); - result.high = num.high << shift; - result.low = num.low << shift; - result.high |= num.low >> (PART_PRECISION - shift); - result.unsignedp = num.unsignedp; - - 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; - result.overflow = overflow; - - /* 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)) - result.overflow = true; - - 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); - if (!(node->flags & NODE_USED)) - { - node->flags |= NODE_USED; - if (node->type == NT_MACRO) - { - if (pfile->cb.used_define) - pfile->cb.used_define (pfile, pfile->directive_line, node); - } - else - { - if (pfile->cb.used_undef) - pfile->cb.used_undef (pfile, pfile->directive_line, 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; - - result.unsignedp = false; - result.overflow = false; - - 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: - case CPP_CHAR16: - case CPP_CHAR32: - { - 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; - - case CPP_HASH: - if (!pfile->state.skipping) - { - /* A pedantic warning takes precedence over a deprecated - warning here. */ - if (CPP_PEDANTIC (pfile)) - cpp_error (pfile, CPP_DL_PEDWARN, - "assertions are a GCC extension"); - else if (CPP_OPTION (pfile, warn_deprecated)) - cpp_error (pfile, CPP_DL_WARNING, - "assertions are a deprecated extension"); - } - _cpp_test_assertion (pfile, &temp); - result.high = 0; - result.low = temp; - break; - - default: - abort (); - } - - result.unsignedp = !!unsignedp; - 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 cpp_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}, - - /* COMPL */ {16, NO_L_OPERAND}, - /* AND_AND */ {6, LEFT_ASSOC}, - /* OR_OR */ {5, LEFT_ASSOC}, - /* Note that QUERY, COLON, and COMMA must have the same precedence. - However, there are some special cases for these in reduce(). */ - /* QUERY */ {4, 0}, - /* COLON */ {4, LEFT_ASSOC | CHECK_PROMOTION}, - /* COMMA */ {4, 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, bool is_if) -{ - 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; - op.loc = op.token->src_loc; - - switch (op.op) - { - /* These tokens convert into values. */ - case CPP_NUMBER: - case CPP_CHAR: - case CPP_WCHAR: - case CPP_CHAR16: - case CPP_CHAR32: - 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_ERROR2 ("%s with no expression", is_if ? "#if" : "#elif"); - - 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; - top->loc = op.token->src_loc; - } - - /* 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 %s", - is_if ? "#if" : "#elif"); - 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); - top[-1].loc = top->loc; - break; - - case CPP_PLUS: - case CPP_MINUS: - case CPP_RSHIFT: - case CPP_LSHIFT: - case CPP_COMMA: - top[-1].value = num_binary_op (pfile, top[-1].value, - top->value, top->op); - top[-1].loc = top->loc; - 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); - top[-1].loc = top->loc; - break; - - case CPP_EQ_EQ: - case CPP_NOT_EQ: - top[-1].value - = num_equality_op (pfile, top[-1].value, top->value, top->op); - top[-1].loc = top->loc; - break; - - case CPP_AND: - case CPP_OR: - case CPP_XOR: - top[-1].value - = num_bitwise_op (pfile, top[-1].value, top->value, top->op); - top[-1].loc = top->loc; - break; - - case CPP_MULT: - top[-1].value = num_mul (pfile, top[-1].value, top->value); - top[-1].loc = top->loc; - break; - - case CPP_DIV: - case CPP_MOD: - top[-1].value = num_div_op (pfile, top[-1].value, - top->value, top->op); - top[-1].loc = top->loc; - 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; - top->loc = top[1].loc; - 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; - top->loc = top[1].loc; - continue; - - case CPP_OPEN_PAREN: - if (op != CPP_CLOSE_PAREN) - { - cpp_error_with_line (pfile, CPP_DL_ERROR, - top->token->src_loc, - 0, "missing ')' in expression"); - return 0; - } - top--; - top->value = top[1].value; - top->loc = top[1].loc; - return top; - - case CPP_COLON: - top -= 2; - if (!num_zerop (top->value)) - { - pfile->state.skip_eval--; - top->value = top[1].value; - top->loc = top[1].loc; - } - else - { - top->value = top[2].value; - top->loc = top[2].loc; - } - top->value.unsignedp = (top[1].value.unsignedp - || top[2].value.unsignedp); - continue; - - case CPP_QUERY: - /* COMMA and COLON should not reduce a QUERY operator. */ - if (op == CPP_COMMA || op == CPP_COLON) - return top; - 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 = XRESIZEVEC (struct op, pfile->op_stack, new_size); - 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_with_line (pfile, CPP_DL_WARNING, op[-1].loc, 0, - "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_with_line (pfile, CPP_DL_WARNING, op->loc, 0, - "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; - bool x = num_positive (num, precision); - - if (num.unsignedp || x) - 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); - 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; - - /* 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.unsignedp = lhs.unsignedp || rhs.unsignedp; - result.overflow = false; - - result = num_trim (result, precision); - if (!result.unsignedp) - { - 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 = true; - result.overflow = false; - - 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; - result.overflow = false; - if (!unsignedp) - { - if (negate) - result = num_negate (result, precision); - result.overflow = (num_positive (result, precision) ^ !negate - && !num_zerop (result)); - } - - return result; - } - - /* CPP_MOD. */ - lhs.unsignedp = unsignedp; - lhs.overflow = false; - if (lhs_neg) - lhs = num_negate (lhs, precision); - - return lhs; -} |