890 lines
26 KiB
C
890 lines
26 KiB
C
/* Parse C expressions for cpplib.
|
||
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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|
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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
|
||
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
|
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GNU General Public License for more details.
|
||
|
||
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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|
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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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|
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/* Yield nonzero if adding two numbers with A's and B's signs can yield a
|
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number with SUM's sign, where A, B, and SUM are all C integers. */
|
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#define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0)
|
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|
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static void integer_overflow PARAMS ((cpp_reader *));
|
||
static HOST_WIDEST_INT left_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
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unsigned int,
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unsigned HOST_WIDEST_INT));
|
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static HOST_WIDEST_INT right_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
|
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unsigned int,
|
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unsigned HOST_WIDEST_INT));
|
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static struct op parse_number PARAMS ((cpp_reader *, const cpp_token *));
|
||
static struct op parse_defined PARAMS ((cpp_reader *));
|
||
static struct op lex PARAMS ((cpp_reader *, int));
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||
static const unsigned char *op_as_text PARAMS ((cpp_reader *, enum cpp_ttype));
|
||
|
||
struct op
|
||
{
|
||
enum cpp_ttype op;
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||
U_CHAR prio; /* Priority of op. */
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||
U_CHAR flags;
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||
U_CHAR unsignedp; /* True if value should be treated as unsigned. */
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HOST_WIDEST_INT value; /* The value logically "right" of op. */
|
||
};
|
||
|
||
/* There is no "error" token, but we can't get comments in #if, so we can
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abuse that token type. */
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||
#define CPP_ERROR CPP_COMMENT
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|
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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 CPP_ICE(msgid) \
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do { cpp_ice (pfile, msgid); goto syntax_error; } while(0)
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#define SYNTAX_ERROR(msgid) \
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do { cpp_error (pfile, msgid); goto syntax_error; } while(0)
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#define SYNTAX_ERROR2(msgid, arg) \
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do { cpp_error (pfile, msgid, arg); goto syntax_error; } while(0)
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|
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struct suffix
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{
|
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const unsigned char s[4];
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const unsigned char u;
|
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const unsigned char l;
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};
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static const struct suffix vsuf_1[] = {
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{ "u", 1, 0 }, { "U", 1, 0 },
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{ "l", 0, 1 }, { "L", 0, 1 }
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};
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static const struct suffix vsuf_2[] = {
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{ "ul", 1, 1 }, { "UL", 1, 1 }, { "uL", 1, 1 }, { "Ul", 1, 1 },
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{ "lu", 1, 1 }, { "LU", 1, 1 }, { "Lu", 1, 1 }, { "lU", 1, 1 },
|
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{ "ll", 0, 2 }, { "LL", 0, 2 }
|
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};
|
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|
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static const struct suffix vsuf_3[] = {
|
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{ "ull", 1, 2 }, { "ULL", 1, 2 }, { "uLL", 1, 2 }, { "Ull", 1, 2 },
|
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{ "llu", 1, 2 }, { "LLU", 1, 2 }, { "LLu", 1, 2 }, { "llU", 1, 2 }
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};
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#define Nsuff(tab) (sizeof tab / sizeof (struct suffix))
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|
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/* Parse and convert what is presumably an integer in TOK. Accepts
|
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decimal, hex, or octal with or without size suffixes. Returned op
|
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is CPP_ERROR on error, otherwise it is a CPP_NUMBER. */
|
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static struct op
|
||
parse_number (pfile, tok)
|
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cpp_reader *pfile;
|
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const cpp_token *tok;
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{
|
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struct op op;
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const U_CHAR *start = tok->val.str.text;
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const U_CHAR *end = start + tok->val.str.len;
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const U_CHAR *p = start;
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int c = 0, i, nsuff;
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unsigned HOST_WIDEST_INT n = 0, nd, MAX_over_base;
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int base = 10;
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int overflow = 0;
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int digit, largest_digit = 0;
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const struct suffix *sufftab;
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|
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op.unsignedp = 0;
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if (p[0] == '0')
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{
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if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X'))
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{
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p += 2;
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base = 16;
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||
}
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else
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{
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p += 1;
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base = 8;
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}
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}
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||
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/* Some buggy compilers (e.g. MPW C) seem to need both casts. */
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MAX_over_base = (((unsigned HOST_WIDEST_INT) -1)
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/ ((unsigned HOST_WIDEST_INT) base));
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||
|
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for(; p < end; p++)
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||
{
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c = *p;
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||
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if (ISDIGIT (c)
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|| (base == 16 && ISXDIGIT (c)))
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digit = hex_value (c);
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else
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break;
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||
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if (largest_digit < digit)
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largest_digit = digit;
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nd = n * base + digit;
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overflow |= MAX_over_base < n || nd < n;
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n = nd;
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}
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if (p < end)
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{
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/* Check for a floating point constant. Note that float constants
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with an exponent or suffix but no decimal point are technically
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invalid (C99 6.4.4.2) but accepted elsewhere. */
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if ((c == '.' || c == 'F' || c == 'f')
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|| (base == 10 && (c == 'E' || c == 'e')
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&& p+1 < end && (p[1] == '+' || p[1] == '-'))
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|| (base == 16 && (c == 'P' || c == 'p')
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&& p+1 < end && (p[1] == '+' || p[1] == '-')))
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SYNTAX_ERROR ("floating point numbers are not valid in #if");
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/* Determine the suffix. l means long, and u means unsigned.
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See the suffix tables, above. */
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switch (end - p)
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{
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case 1: sufftab = vsuf_1; nsuff = Nsuff(vsuf_1); break;
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case 2: sufftab = vsuf_2; nsuff = Nsuff(vsuf_2); break;
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case 3: sufftab = vsuf_3; nsuff = Nsuff(vsuf_3); break;
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default: goto invalid_suffix;
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||
}
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for (i = 0; i < nsuff; i++)
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if (memcmp (p, sufftab[i].s, end - p) == 0)
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break;
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if (i == nsuff)
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goto invalid_suffix;
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op.unsignedp = sufftab[i].u;
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if (CPP_WTRADITIONAL (pfile)
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&& sufftab[i].u
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&& ! cpp_sys_macro_p (pfile))
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cpp_warning (pfile, "traditional C rejects the `U' suffix");
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if (sufftab[i].l == 2 && CPP_OPTION (pfile, pedantic)
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&& ! CPP_OPTION (pfile, c99))
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cpp_pedwarn (pfile, "too many 'l' suffixes in integer constant");
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}
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if (base <= largest_digit)
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cpp_pedwarn (pfile, "integer constant contains digits beyond the radix");
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if (overflow)
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cpp_pedwarn (pfile, "integer constant out of range");
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/* If too big to be signed, consider it unsigned. */
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else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp)
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{
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if (base == 10)
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cpp_warning (pfile, "integer constant is so large that it is unsigned");
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op.unsignedp = 1;
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}
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op.value = n;
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op.op = CPP_NUMBER;
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return op;
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invalid_suffix:
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cpp_error (pfile, "invalid suffix '%.*s' on integer constant",
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(int) (end - p), p);
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syntax_error:
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op.op = CPP_ERROR;
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return op;
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}
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/* Handle meeting "defined" in a preprocessor expression. */
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static struct op
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parse_defined (pfile)
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cpp_reader *pfile;
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{
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int paren = 0;
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cpp_hashnode *node = 0;
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const cpp_token *token;
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struct op op;
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cpp_context *initial_context = pfile->context;
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/* Don't expand macros. */
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pfile->state.prevent_expansion++;
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token = cpp_get_token (pfile);
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if (token->type == CPP_OPEN_PAREN)
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{
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paren = 1;
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token = cpp_get_token (pfile);
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}
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if (token->type == CPP_NAME)
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{
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node = token->val.node;
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if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
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{
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cpp_error (pfile, "missing ')' after \"defined\"");
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node = 0;
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}
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}
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else
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{
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cpp_error (pfile, "operator \"defined\" requires an identifier");
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if (token->flags & NAMED_OP)
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{
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cpp_token op;
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op.flags = 0;
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op.type = token->type;
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cpp_error (pfile,
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"(\"%s\" is an alternative token for \"%s\" in C++)",
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cpp_token_as_text (pfile, token),
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cpp_token_as_text (pfile, &op));
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}
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}
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if (!node)
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op.op = CPP_ERROR;
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else
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{
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if (pfile->context != initial_context)
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cpp_warning (pfile, "this use of \"defined\" may not be portable");
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op.value = node->type == NT_MACRO;
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op.unsignedp = 0;
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op.op = CPP_NUMBER;
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/* A possible controlling macro of the form #if !defined ().
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_cpp_parse_expr checks there was no other junk on the line. */
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pfile->mi_ind_cmacro = node;
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}
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pfile->state.prevent_expansion--;
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return op;
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}
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/* Read a token. The returned type is CPP_NUMBER for a valid number
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(an interpreted preprocessing number or character constant, or the
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result of the "defined" or "#" operators), CPP_ERROR on error,
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CPP_EOF, or the type of an operator token. */
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static struct op
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lex (pfile, skip_evaluation)
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cpp_reader *pfile;
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int skip_evaluation;
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{
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struct op op;
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const cpp_token *token = cpp_get_token (pfile);
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switch (token->type)
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{
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case CPP_NUMBER:
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return parse_number (pfile, token);
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|
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case CPP_CHAR:
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case CPP_WCHAR:
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{
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||
unsigned int chars_seen;
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|
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if (token->type == CPP_CHAR)
|
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op.unsignedp = 0;
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else
|
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op.unsignedp = WCHAR_UNSIGNED;
|
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op.op = CPP_NUMBER;
|
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op.value = cpp_interpret_charconst (pfile, token, 1, 0, &chars_seen);
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return op;
|
||
}
|
||
|
||
case CPP_STRING:
|
||
case CPP_WSTRING:
|
||
SYNTAX_ERROR ("string constants are not valid in #if");
|
||
|
||
case CPP_OTHER:
|
||
if (ISGRAPH (token->val.c))
|
||
SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c);
|
||
else
|
||
SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c);
|
||
|
||
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))
|
||
{
|
||
op.op = CPP_NUMBER;
|
||
op.unsignedp = 0;
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||
op.value = (token->val.node == pfile->spec_nodes.n_true);
|
||
|
||
/* Warn about use of true or false in #if when pedantic
|
||
and stdbool.h has not been included. */
|
||
if (CPP_PEDANTIC (pfile)
|
||
&& ! cpp_defined (pfile, DSC("__bool_true_false_are_defined")))
|
||
cpp_pedwarn (pfile, "ISO C++ does not permit \"%s\" in #if",
|
||
NODE_NAME (token->val.node));
|
||
return op;
|
||
}
|
||
else
|
||
{
|
||
op.op = CPP_NUMBER;
|
||
op.unsignedp = 0;
|
||
op.value = 0;
|
||
|
||
if (CPP_OPTION (pfile, warn_undef) && !skip_evaluation)
|
||
cpp_warning (pfile, "\"%s\" is not defined",
|
||
NODE_NAME (token->val.node));
|
||
return op;
|
||
}
|
||
|
||
case CPP_HASH:
|
||
{
|
||
int temp;
|
||
|
||
op.op = CPP_NUMBER;
|
||
if (_cpp_test_assertion (pfile, &temp))
|
||
op.op = CPP_ERROR;
|
||
op.unsignedp = 0;
|
||
op.value = temp;
|
||
return op;
|
||
}
|
||
|
||
default:
|
||
if (((int) token->type > (int) CPP_EQ
|
||
&& (int) token->type < (int) CPP_PLUS_EQ)
|
||
|| token->type == CPP_EOF)
|
||
{
|
||
op.op = token->type;
|
||
return op;
|
||
}
|
||
|
||
SYNTAX_ERROR2 ("\"%s\" is not valid in #if expressions",
|
||
cpp_token_as_text (pfile, token));
|
||
}
|
||
|
||
syntax_error:
|
||
op.op = CPP_ERROR;
|
||
return op;
|
||
}
|
||
|
||
/* Warn if appropriate on overflow. */
|
||
static void
|
||
integer_overflow (pfile)
|
||
cpp_reader *pfile;
|
||
{
|
||
if (CPP_PEDANTIC (pfile))
|
||
cpp_pedwarn (pfile, "integer overflow in preprocessor expression");
|
||
}
|
||
|
||
/* Handle shifting A left by B bits. UNSIGNEDP is non-zero if A is
|
||
unsigned. */
|
||
static HOST_WIDEST_INT
|
||
left_shift (pfile, a, unsignedp, b)
|
||
cpp_reader *pfile;
|
||
HOST_WIDEST_INT a;
|
||
unsigned int unsignedp;
|
||
unsigned HOST_WIDEST_INT b;
|
||
{
|
||
if (b >= HOST_BITS_PER_WIDEST_INT)
|
||
{
|
||
if (! unsignedp && a != 0)
|
||
integer_overflow (pfile);
|
||
return 0;
|
||
}
|
||
else if (unsignedp)
|
||
return (unsigned HOST_WIDEST_INT) a << b;
|
||
else
|
||
{
|
||
HOST_WIDEST_INT l = a << b;
|
||
if (l >> b != a)
|
||
integer_overflow (pfile);
|
||
return l;
|
||
}
|
||
}
|
||
|
||
/* Handle shifting A right by B bits. UNSIGNEDP is non-zero if A is
|
||
unsigned. */
|
||
static HOST_WIDEST_INT
|
||
right_shift (pfile, a, unsignedp, b)
|
||
cpp_reader *pfile ATTRIBUTE_UNUSED;
|
||
HOST_WIDEST_INT a;
|
||
unsigned int unsignedp;
|
||
unsigned HOST_WIDEST_INT b;
|
||
{
|
||
if (b >= HOST_BITS_PER_WIDEST_INT)
|
||
return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1);
|
||
else if (unsignedp)
|
||
return (unsigned HOST_WIDEST_INT) a >> b;
|
||
else
|
||
return a >> b;
|
||
}
|
||
|
||
/* Operator precedence and flags table.
|
||
|
||
After an operator is returned from the lexer, if it has priority less
|
||
than or equal to the operator on the top of the stack, we reduce the
|
||
stack by one operator and repeat the test. Since equal priorities
|
||
reduce, this is naturally left-associative.
|
||
|
||
We handle right-associative operators by clearing the lower bit of all
|
||
left-associative operators, and setting it for right-associative ones.
|
||
After the reduction phase of a new operator, just before it is pushed
|
||
onto the stack, its RIGHT_ASSOC bit is cleared. The effect is that
|
||
during the reduction phase, the current right-associative operator has
|
||
a priority one greater than any other operator of otherwise equal
|
||
precedence that has been pushed on the top of the stack. This avoids
|
||
a reduction pass, and effectively makes the logic right-associative.
|
||
|
||
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
|
||
parenthesised expression. If there is no matching '(', the stack will
|
||
be reduced all the way to the beginning, exiting the parser in the
|
||
same way as the ultra-low priority end-of-expression dummy operator.
|
||
The exit code checks to see if the operator that caused it is ')', and
|
||
if so outputs an appropriate error message.
|
||
|
||
The parser assumes all shifted operators require a right operand
|
||
unless the flag NO_R_OPERAND is set, and similarly for NO_L_OPERAND.
|
||
These semantics are automatically checked, any extra semantics need to
|
||
be handled with operator-specific code. */
|
||
|
||
#define FLAG_BITS 8
|
||
#define FLAG_MASK ((1 << FLAG_BITS) - 1)
|
||
#define PRIO_SHIFT (FLAG_BITS + 1)
|
||
#define EXTRACT_PRIO(CNST) ((CNST) >> FLAG_BITS)
|
||
#define EXTRACT_FLAGS(CNST) ((CNST) & FLAG_MASK)
|
||
|
||
/* Flags. */
|
||
#define HAVE_VALUE (1 << 0)
|
||
#define NO_L_OPERAND (1 << 1)
|
||
#define NO_R_OPERAND (1 << 2)
|
||
#define SHORT_CIRCUIT (1 << 3)
|
||
|
||
/* Priority and flag combinations. */
|
||
#define RIGHT_ASSOC (1 << FLAG_BITS)
|
||
#define FORCE_REDUCE_PRIO (0 << PRIO_SHIFT)
|
||
#define CLOSE_PAREN_PRIO (1 << PRIO_SHIFT)
|
||
#define OPEN_PAREN_PRIO ((2 << PRIO_SHIFT) | NO_L_OPERAND)
|
||
#define COMMA_PRIO (3 << PRIO_SHIFT)
|
||
#define COND_PRIO ((4 << PRIO_SHIFT) | RIGHT_ASSOC | SHORT_CIRCUIT)
|
||
#define COLON_PRIO ((5 << PRIO_SHIFT) | SHORT_CIRCUIT)
|
||
#define OROR_PRIO ((6 << PRIO_SHIFT) | SHORT_CIRCUIT)
|
||
#define ANDAND_PRIO ((7 << PRIO_SHIFT) | SHORT_CIRCUIT)
|
||
#define OR_PRIO (8 << PRIO_SHIFT)
|
||
#define XOR_PRIO (9 << PRIO_SHIFT)
|
||
#define AND_PRIO (10 << PRIO_SHIFT)
|
||
#define MINMAX_PRIO (11 << PRIO_SHIFT)
|
||
#define EQUAL_PRIO (12 << PRIO_SHIFT)
|
||
#define LESS_PRIO (13 << PRIO_SHIFT)
|
||
#define SHIFT_PRIO (14 << PRIO_SHIFT)
|
||
#define PLUS_PRIO (15 << PRIO_SHIFT)
|
||
#define MUL_PRIO (16 << PRIO_SHIFT)
|
||
#define UNARY_PRIO ((17 << PRIO_SHIFT) | RIGHT_ASSOC | NO_L_OPERAND)
|
||
|
||
/* Operator to priority map. Must be in the same order as the first
|
||
N entries of enum cpp_ttype. */
|
||
static const short
|
||
op_to_prio[] =
|
||
{
|
||
/* EQ */ 0, /* dummy entry - can't happen */
|
||
/* NOT */ UNARY_PRIO,
|
||
/* GREATER */ LESS_PRIO,
|
||
/* LESS */ LESS_PRIO,
|
||
/* PLUS */ UNARY_PRIO, /* note these two can be unary */
|
||
/* MINUS */ UNARY_PRIO, /* or binary */
|
||
/* MULT */ MUL_PRIO,
|
||
/* DIV */ MUL_PRIO,
|
||
/* MOD */ MUL_PRIO,
|
||
/* AND */ AND_PRIO,
|
||
/* OR */ OR_PRIO,
|
||
/* XOR */ XOR_PRIO,
|
||
/* RSHIFT */ SHIFT_PRIO,
|
||
/* LSHIFT */ SHIFT_PRIO,
|
||
/* MIN */ MINMAX_PRIO, /* C++ specific */
|
||
/* MAX */ MINMAX_PRIO, /* extensions */
|
||
|
||
/* COMPL */ UNARY_PRIO,
|
||
/* AND_AND */ ANDAND_PRIO,
|
||
/* OR_OR */ OROR_PRIO,
|
||
/* QUERY */ COND_PRIO,
|
||
/* COLON */ COLON_PRIO,
|
||
/* COMMA */ COMMA_PRIO,
|
||
/* OPEN_PAREN */ OPEN_PAREN_PRIO,
|
||
/* CLOSE_PAREN */ CLOSE_PAREN_PRIO,
|
||
/* EQ_EQ */ EQUAL_PRIO,
|
||
/* NOT_EQ */ EQUAL_PRIO,
|
||
/* GREATER_EQ */ LESS_PRIO,
|
||
/* LESS_EQ */ LESS_PRIO
|
||
};
|
||
|
||
#define COMPARE(OP) \
|
||
top->unsignedp = 0; \
|
||
top->value = (unsigned1 | unsigned2) \
|
||
? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 \
|
||
: (v1 OP v2)
|
||
#define EQUALITY(OP) \
|
||
top->value = v1 OP v2; \
|
||
top->unsignedp = 0;
|
||
#define BITWISE(OP) \
|
||
top->value = v1 OP v2; \
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
#define MINMAX(OP) \
|
||
top->value = (v1 OP v2) ? v1 : v2; \
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
#define UNARY(OP) \
|
||
top->value = OP v2; \
|
||
top->unsignedp = unsigned2; \
|
||
top->flags |= HAVE_VALUE;
|
||
#define SHIFT(PSH, MSH) \
|
||
if (skip_evaluation) \
|
||
break; \
|
||
top->unsignedp = unsigned1; \
|
||
if (v2 < 0 && ! unsigned2) \
|
||
top->value = MSH (pfile, v1, unsigned1, -v2); \
|
||
else \
|
||
top->value = PSH (pfile, v1, unsigned1, v2);
|
||
|
||
/* Parse and evaluate a C expression, reading from PFILE.
|
||
Returns the truth value of the expression. */
|
||
int
|
||
_cpp_parse_expr (pfile)
|
||
cpp_reader *pfile;
|
||
{
|
||
/* 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 '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.
|
||
In that case the 'flags' field has the HAVE_VALUE flag set. */
|
||
|
||
#define INIT_STACK_SIZE 20
|
||
struct op init_stack[INIT_STACK_SIZE];
|
||
struct op *stack = init_stack;
|
||
struct op *limit = stack + INIT_STACK_SIZE;
|
||
struct op *top = stack + 1;
|
||
int skip_evaluation = 0;
|
||
int result;
|
||
unsigned int lex_count, saw_leading_not;
|
||
|
||
/* Set up detection of #if ! defined(). */
|
||
pfile->mi_ind_cmacro = 0;
|
||
saw_leading_not = 0;
|
||
lex_count = 0;
|
||
|
||
/* We've finished when we try to reduce this. */
|
||
top->op = CPP_EOF;
|
||
/* Nifty way to catch missing '('. */
|
||
top->prio = EXTRACT_PRIO(CLOSE_PAREN_PRIO);
|
||
/* Avoid missing right operand checks. */
|
||
top->flags = NO_R_OPERAND;
|
||
|
||
for (;;)
|
||
{
|
||
unsigned int prio;
|
||
unsigned int flags;
|
||
struct op op;
|
||
|
||
/* Read a token */
|
||
op = lex (pfile, skip_evaluation);
|
||
lex_count++;
|
||
|
||
/* If the token is an operand, push its value and get next
|
||
token. If it is an operator, get its priority and flags, and
|
||
try to reduce the expression on the stack. */
|
||
switch (op.op)
|
||
{
|
||
case CPP_ERROR:
|
||
goto syntax_error;
|
||
push_immediate:
|
||
case CPP_NUMBER:
|
||
/* Push a value onto the stack. */
|
||
if (top->flags & HAVE_VALUE)
|
||
SYNTAX_ERROR ("missing binary operator");
|
||
top->value = op.value;
|
||
top->unsignedp = op.unsignedp;
|
||
top->flags |= HAVE_VALUE;
|
||
continue;
|
||
|
||
case CPP_EOF: prio = FORCE_REDUCE_PRIO; break;
|
||
|
||
case CPP_NOT:
|
||
saw_leading_not = lex_count == 1;
|
||
prio = op_to_prio[op.op];
|
||
break;
|
||
case CPP_PLUS:
|
||
case CPP_MINUS: prio = PLUS_PRIO; if (top->flags & HAVE_VALUE) break;
|
||
/* else unary; fall through */
|
||
default: prio = op_to_prio[op.op]; break;
|
||
}
|
||
|
||
/* Separate the operator's code into priority and flags. */
|
||
flags = EXTRACT_FLAGS(prio);
|
||
prio = EXTRACT_PRIO(prio);
|
||
if (prio == EXTRACT_PRIO(OPEN_PAREN_PRIO))
|
||
goto skip_reduction;
|
||
|
||
/* Check for reductions. Then push the operator. */
|
||
while (prio <= top->prio)
|
||
{
|
||
HOST_WIDEST_INT v1, v2;
|
||
unsigned int unsigned1, unsigned2;
|
||
|
||
/* Most operators that can appear on the stack require a
|
||
right operand. Check this before trying to reduce. */
|
||
if ((top->flags & (HAVE_VALUE | NO_R_OPERAND)) == 0)
|
||
{
|
||
if (top->op == CPP_OPEN_PAREN)
|
||
SYNTAX_ERROR ("void expression between '(' and ')'");
|
||
else
|
||
SYNTAX_ERROR2 ("operator '%s' has no right operand",
|
||
op_as_text (pfile, top->op));
|
||
}
|
||
|
||
unsigned2 = top->unsignedp, v2 = top->value;
|
||
top--;
|
||
unsigned1 = top->unsignedp, v1 = top->value;
|
||
|
||
/* Now set top->value = (top[1].op)(v1, v2); */
|
||
switch (top[1].op)
|
||
{
|
||
default:
|
||
cpp_ice (pfile, "impossible operator '%s'",
|
||
op_as_text (pfile, top[1].op));
|
||
goto syntax_error;
|
||
|
||
case CPP_NOT: UNARY(!); break;
|
||
case CPP_COMPL: UNARY(~); break;
|
||
case CPP_LESS: COMPARE(<); break;
|
||
case CPP_GREATER: COMPARE(>); break;
|
||
case CPP_LESS_EQ: COMPARE(<=); break;
|
||
case CPP_GREATER_EQ: COMPARE(>=); break;
|
||
case CPP_EQ_EQ: EQUALITY(==); break;
|
||
case CPP_NOT_EQ: EQUALITY(!=); break;
|
||
case CPP_AND: BITWISE(&); break;
|
||
case CPP_XOR: BITWISE(^); break;
|
||
case CPP_OR: BITWISE(|); break;
|
||
case CPP_LSHIFT: SHIFT(left_shift, right_shift); break;
|
||
case CPP_RSHIFT: SHIFT(right_shift, left_shift); break;
|
||
case CPP_MIN: MINMAX(<); break;
|
||
case CPP_MAX: MINMAX(>); break;
|
||
|
||
case CPP_PLUS:
|
||
if (!(top->flags & HAVE_VALUE))
|
||
{
|
||
/* Can't use UNARY(+) because K+R C did not have unary
|
||
plus. Can't use UNARY() because some compilers object
|
||
to the empty argument. */
|
||
top->value = v2;
|
||
top->unsignedp = unsigned2;
|
||
top->flags |= HAVE_VALUE;
|
||
|
||
if (CPP_WTRADITIONAL (pfile))
|
||
cpp_warning (pfile,
|
||
"traditional C rejects the unary plus operator");
|
||
}
|
||
else
|
||
{
|
||
top->value = v1 + v2;
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
if (! top->unsignedp && ! skip_evaluation
|
||
&& ! possible_sum_sign (v1, v2, top->value))
|
||
integer_overflow (pfile);
|
||
}
|
||
break;
|
||
case CPP_MINUS:
|
||
if (!(top->flags & HAVE_VALUE))
|
||
{
|
||
UNARY(-);
|
||
if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2)
|
||
integer_overflow (pfile);
|
||
}
|
||
else
|
||
{ /* Binary '-' */
|
||
top->value = v1 - v2;
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
if (! top->unsignedp && ! skip_evaluation
|
||
&& ! possible_sum_sign (top->value, v2, v1))
|
||
integer_overflow (pfile);
|
||
}
|
||
break;
|
||
case CPP_MULT:
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
if (top->unsignedp)
|
||
top->value = (unsigned HOST_WIDEST_INT) v1 * v2;
|
||
else if (!skip_evaluation)
|
||
{
|
||
top->value = v1 * v2;
|
||
if (v1 && (top->value / v1 != v2
|
||
|| (top->value & v1 & v2) < 0))
|
||
integer_overflow (pfile);
|
||
}
|
||
break;
|
||
case CPP_DIV:
|
||
case CPP_MOD:
|
||
if (skip_evaluation)
|
||
break;
|
||
if (v2 == 0)
|
||
SYNTAX_ERROR ("division by zero in #if");
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
if (top[1].op == CPP_DIV)
|
||
{
|
||
if (top->unsignedp)
|
||
top->value = (unsigned HOST_WIDEST_INT) v1 / v2;
|
||
else
|
||
{
|
||
top->value = v1 / v2;
|
||
if ((top->value & v1 & v2) < 0)
|
||
integer_overflow (pfile);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (top->unsignedp)
|
||
top->value = (unsigned HOST_WIDEST_INT) v1 % v2;
|
||
else
|
||
top->value = v1 % v2;
|
||
}
|
||
break;
|
||
|
||
case CPP_OR_OR:
|
||
top->value = v1 || v2;
|
||
top->unsignedp = 0;
|
||
if (v1) skip_evaluation--;
|
||
break;
|
||
case CPP_AND_AND:
|
||
top->value = v1 && v2;
|
||
top->unsignedp = 0;
|
||
if (!v1) skip_evaluation--;
|
||
break;
|
||
case CPP_COMMA:
|
||
if (CPP_PEDANTIC (pfile))
|
||
cpp_pedwarn (pfile, "comma operator in operand of #if");
|
||
top->value = v2;
|
||
top->unsignedp = unsigned2;
|
||
break;
|
||
case CPP_QUERY:
|
||
SYNTAX_ERROR ("syntax error '?' without following ':'");
|
||
case CPP_COLON:
|
||
if (top[0].op != CPP_QUERY)
|
||
SYNTAX_ERROR ("syntax error ':' without preceding '?'");
|
||
top--;
|
||
if (top->value) skip_evaluation--;
|
||
top->value = top->value ? v1 : v2;
|
||
top->unsignedp = unsigned1 | unsigned2;
|
||
break;
|
||
case CPP_OPEN_PAREN:
|
||
if (op.op != CPP_CLOSE_PAREN)
|
||
SYNTAX_ERROR ("missing ')' in expression");
|
||
op.value = v2;
|
||
op.unsignedp = unsigned2;
|
||
goto push_immediate;
|
||
case CPP_EOF:
|
||
/* Reducing this dummy operator indicates we've finished. */
|
||
if (op.op == CPP_CLOSE_PAREN)
|
||
SYNTAX_ERROR ("missing '(' in expression");
|
||
goto done;
|
||
}
|
||
}
|
||
|
||
/* Handle short-circuit evaluations. */
|
||
if (flags & SHORT_CIRCUIT)
|
||
switch (op.op)
|
||
{
|
||
case CPP_OR_OR: if (top->value) skip_evaluation++; break;
|
||
case CPP_AND_AND:
|
||
case CPP_QUERY: if (!top->value) skip_evaluation++; break;
|
||
case CPP_COLON:
|
||
if (top[-1].value) /* Was '?' condition true? */
|
||
skip_evaluation++;
|
||
else
|
||
skip_evaluation--;
|
||
default:
|
||
break;
|
||
}
|
||
|
||
skip_reduction:
|
||
/* Check we have a left operand iff we need one. */
|
||
if (flags & NO_L_OPERAND)
|
||
{
|
||
if (top->flags & HAVE_VALUE)
|
||
SYNTAX_ERROR2 ("missing binary operator before '%s'",
|
||
op_as_text (pfile, op.op));
|
||
}
|
||
else
|
||
{
|
||
if (!(top->flags & HAVE_VALUE))
|
||
SYNTAX_ERROR2 ("operator '%s' has no left operand",
|
||
op_as_text (pfile, op.op));
|
||
}
|
||
|
||
/* Check for and handle stack overflow. */
|
||
top++;
|
||
if (top == limit)
|
||
{
|
||
struct op *new_stack;
|
||
int old_size = (char *) limit - (char *) stack;
|
||
int new_size = 2 * old_size;
|
||
if (stack != init_stack)
|
||
new_stack = (struct op *) xrealloc (stack, new_size);
|
||
else
|
||
{
|
||
new_stack = (struct op *) xmalloc (new_size);
|
||
memcpy (new_stack, stack, old_size);
|
||
}
|
||
stack = new_stack;
|
||
top = (struct op *) ((char *) new_stack + old_size);
|
||
limit = (struct op *) ((char *) new_stack + new_size);
|
||
}
|
||
|
||
top->flags = flags;
|
||
top->prio = prio & ~EXTRACT_PRIO(RIGHT_ASSOC);
|
||
top->op = op.op;
|
||
}
|
||
|
||
done:
|
||
/* 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;
|
||
|
||
result = (top[1].value != 0);
|
||
|
||
if (top != stack)
|
||
CPP_ICE ("unbalanced stack in #if");
|
||
else if (!(top[1].flags & HAVE_VALUE))
|
||
{
|
||
SYNTAX_ERROR ("#if with no expression");
|
||
syntax_error:
|
||
result = 0; /* Return 0 on syntax error. */
|
||
}
|
||
|
||
/* Free dynamic stack if we allocated one. */
|
||
if (stack != init_stack)
|
||
free (stack);
|
||
return result;
|
||
}
|
||
|
||
/* Output OP as text for diagnostics. */
|
||
static const unsigned char *
|
||
op_as_text (pfile, op)
|
||
cpp_reader *pfile;
|
||
enum cpp_ttype op;
|
||
{
|
||
cpp_token token;
|
||
|
||
token.type = op;
|
||
token.flags = 0;
|
||
return cpp_token_as_text (pfile, &token);
|
||
}
|