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Diffstat (limited to 'gcc-4.2.1-5666.3/libcpp/expr.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/libcpp/expr.c | 1571 |
1 files changed, 1571 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/libcpp/expr.c b/gcc-4.2.1-5666.3/libcpp/expr.c new file mode 100644 index 000000000..24214a8b7 --- /dev/null +++ b/gcc-4.2.1-5666.3/libcpp/expr.c @@ -0,0 +1,1571 @@ +/* Parse C expressions for cpplib. + Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001, + 2002, 2004 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 2, 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; if not, write to the Free Software +Foundation, 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ + +#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. */ + 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); +/* APPLE LOCAL CW asm blocks */ +static unsigned int interpret_int_suffix (cpp_reader *, 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 = 0, l = 0, i = 0, d = 0; + + while (len--) + switch (s[len]) + { + case 'f': case 'F': f++; break; + case 'l': case 'L': l++; break; + case 'i': case 'I': + case 'j': case 'J': i++; break; + case 'd': case 'D': + /* Disallow fd, ld suffixes. */ + if (d && (f || l)) + return 0; + d++; + break; + default: + return 0; + } + + if (f + l > 1 || i > 1) + 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 : 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 +/* APPLE LOCAL CW asm blocks */ +interpret_int_suffix (cpp_reader *pfile, 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; + /* APPLE LOCAL begin CW asm blocks */ + case 'h': + if (! cpp_get_options (pfile)->h_suffix) + return 0; + break; + /* APPLE LOCAL end CW asm blocks */ + 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 +/* APPLE LOCAL CW asm blocks C++ comments 6338079 */ +cpp_classify_number (cpp_reader *pfile, const cpp_token *token, int defer) +{ + 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++; + } + } + /* APPLE LOCAL begin CW asm blocks */ + if (cpp_get_options (pfile)->h_suffix && limit[-1] == 'h') + radix = 16; + /* APPLE LOCAL end CW asm blocks */ + + /* 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; + } + } + + if (float_flag != NOT_FLOAT && radix == 8) + radix = 10; + + if (max_digit >= radix) + SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit); + + if (float_flag != NOT_FLOAT) + { + 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; + } + + result |= CPP_N_FLOATING; + } + else + { + /* APPLE LOCAL CW asm blocks */ + result = interpret_int_suffix (pfile, str, limit - str); + if (result == 0) + { + /* APPLE LOCAL begin CW asm blocks C++ comments 4248139 */ + /* Because we don't regonize inline asm comments during + lexing, we have to avoid erroring out now. */ + if (defer && cpp_get_options (pfile)->h_suffix) + return CPP_N_INVALID | CPP_N_DEFER; + /* APPLE LOCAL end CW asm blocks C++ comments 4248139 */ + + 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; + } + + if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile)) + cpp_error (pfile, CPP_DL_PEDWARN, + "imaginary constants are a GCC extension"); + + if (radix == 10) + result |= CPP_N_DECIMAL; + else if (radix == 16) + result |= CPP_N_HEX; + 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; + /* APPLE LOCAL begin CW asm blocks */ + if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) + p += 2; + /* APPLE LOCAL end CW asm blocks */ + } + + /* 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 = 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); + 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); + + /* 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: + /* APPLE LOCAL CW asm blocks C++ comments 6338079 */ + temp = cpp_classify_number (pfile, token, 0); + 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; + 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}, + /* 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_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 = 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 (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; + 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); + /* APPLE LOCAL begin mainline */ + result.overflow = (num_positive (result, precision) ^ !negate + && !num_zerop (result)); + /* APPLE LOCAL end mainline */ + } + + return result; + } + + /* CPP_MOD. */ + lhs.unsignedp = unsignedp; + lhs.overflow = false; + if (lhs_neg) + lhs = num_negate (lhs, precision); + + return lhs; +} |