1028 lines
25 KiB
C
1028 lines
25 KiB
C
/* Parse C expressions for CCCP.
|
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Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998 Free Software Foundation.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option) any
|
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later version.
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||
|
||
This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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||
|
||
You should have received a copy of the GNU General Public License
|
||
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.
|
||
|
||
In other words, you are welcome to use, share and improve this program.
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||
You are forbidden to forbid anyone else to use, share and improve
|
||
what you give them. Help stamp out software-hoarding!
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|
||
Written by Per Bothner 1994. */
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|
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/* Parse a C expression from text in a string */
|
||
|
||
#include "config.h"
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||
#include "system.h"
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#include "gansidecl.h"
|
||
#include "cpplib.h"
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||
|
||
extern char *xmalloc PARAMS ((unsigned));
|
||
extern char *xrealloc PARAMS ((void *, unsigned));
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||
|
||
#ifdef MULTIBYTE_CHARS
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||
#include <locale.h>
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||
#endif
|
||
|
||
/* This is used for communicating lists of keywords with cccp.c. */
|
||
struct arglist {
|
||
struct arglist *next;
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||
U_CHAR *name;
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||
int length;
|
||
int argno;
|
||
};
|
||
|
||
#ifndef CHAR_TYPE_SIZE
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||
#define CHAR_TYPE_SIZE BITS_PER_UNIT
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||
#endif
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||
|
||
#ifndef INT_TYPE_SIZE
|
||
#define INT_TYPE_SIZE BITS_PER_WORD
|
||
#endif
|
||
|
||
#ifndef LONG_TYPE_SIZE
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||
#define LONG_TYPE_SIZE BITS_PER_WORD
|
||
#endif
|
||
|
||
#ifndef WCHAR_TYPE_SIZE
|
||
#define WCHAR_TYPE_SIZE INT_TYPE_SIZE
|
||
#endif
|
||
|
||
#ifndef MAX_CHAR_TYPE_SIZE
|
||
#define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE
|
||
#endif
|
||
|
||
#ifndef MAX_INT_TYPE_SIZE
|
||
#define MAX_INT_TYPE_SIZE INT_TYPE_SIZE
|
||
#endif
|
||
|
||
#ifndef MAX_LONG_TYPE_SIZE
|
||
#define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE
|
||
#endif
|
||
|
||
#ifndef MAX_WCHAR_TYPE_SIZE
|
||
#define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE
|
||
#endif
|
||
|
||
/* Yield nonzero if adding two numbers with A's and B's signs can yield a
|
||
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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||
|
||
static void integer_overflow PARAMS ((cpp_reader *));
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||
static long left_shift PARAMS ((cpp_reader *, long, int, unsigned long));
|
||
static long right_shift PARAMS ((cpp_reader *, long, int, unsigned long));
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||
|
||
#define ERROR 299
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||
#define OROR 300
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||
#define ANDAND 301
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||
#define EQUAL 302
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||
#define NOTEQUAL 303
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||
#define LEQ 304
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||
#define GEQ 305
|
||
#define LSH 306
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||
#define RSH 307
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||
#define NAME 308
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||
#define INT 309
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||
#define CHAR 310
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||
|
||
#define LEFT_OPERAND_REQUIRED 1
|
||
#define RIGHT_OPERAND_REQUIRED 2
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||
#define HAVE_VALUE 4
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||
/* SKIP_OPERAND is set for '&&' '||' '?' and ':' when the
|
||
following operand should be short-circuited instead of evaluated. */
|
||
#define SKIP_OPERAND 8
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||
/*#define UNSIGNEDP 16*/
|
||
|
||
/* Find the largest host integer type and set its size and type.
|
||
Watch out: on some crazy hosts `long' is shorter than `int'. */
|
||
|
||
#ifndef HOST_WIDE_INT
|
||
# if HAVE_INTTYPES_H
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||
# include <inttypes.h>
|
||
# define HOST_WIDE_INT intmax_t
|
||
# else
|
||
# if (HOST_BITS_PER_LONG <= HOST_BITS_PER_INT \
|
||
&& HOST_BITS_PER_LONGLONG <= HOST_BITS_PER_INT)
|
||
# define HOST_WIDE_INT int
|
||
# else
|
||
# if (HOST_BITS_PER_LONGLONG <= HOST_BITS_PER_LONG \
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||
|| ! (defined LONG_LONG_MAX || defined LLONG_MAX))
|
||
# define HOST_WIDE_INT long
|
||
# else
|
||
# define HOST_WIDE_INT long long
|
||
# endif
|
||
# endif
|
||
# endif
|
||
#endif
|
||
|
||
#ifndef CHAR_BIT
|
||
#define CHAR_BIT 8
|
||
#endif
|
||
|
||
#ifndef HOST_BITS_PER_WIDE_INT
|
||
#define HOST_BITS_PER_WIDE_INT (CHAR_BIT * sizeof (HOST_WIDE_INT))
|
||
#endif
|
||
|
||
struct operation {
|
||
short op;
|
||
char rprio; /* Priority of op (relative to it right operand). */
|
||
char flags;
|
||
char unsignedp; /* true if value should be treated as unsigned */
|
||
HOST_WIDE_INT value; /* The value logically "right" of op. */
|
||
};
|
||
|
||
/* Take care of parsing a number (anything that starts with a digit).
|
||
LEN is the number of characters in it. */
|
||
|
||
/* maybe needs to actually deal with floating point numbers */
|
||
|
||
struct operation
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||
parse_number (pfile, start, olen)
|
||
cpp_reader *pfile;
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||
char *start;
|
||
int olen;
|
||
{
|
||
struct operation op;
|
||
register char *p = start;
|
||
register int c;
|
||
register unsigned long n = 0, nd, ULONG_MAX_over_base;
|
||
register int base = 10;
|
||
register int len = olen;
|
||
register int overflow = 0;
|
||
register int digit, largest_digit = 0;
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||
int spec_long = 0;
|
||
|
||
op.unsignedp = 0;
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||
|
||
for (c = 0; c < len; c++)
|
||
if (p[c] == '.') {
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||
/* It's a float since it contains a point. */
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||
cpp_error (pfile,
|
||
"floating point numbers not allowed in #if expressions");
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||
op.op = ERROR;
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||
return op;
|
||
}
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||
|
||
if (len >= 3 && (!strncmp (p, "0x", 2) || !strncmp (p, "0X", 2))) {
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||
p += 2;
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||
base = 16;
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||
len -= 2;
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||
}
|
||
else if (*p == '0')
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||
base = 8;
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||
|
||
/* Some buggy compilers (e.g. MPW C) seem to need both casts. */
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ULONG_MAX_over_base = ((unsigned long) -1) / ((unsigned long) base);
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||
|
||
for (; len > 0; len--) {
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||
c = *p++;
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||
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||
if (c >= '0' && c <= '9')
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||
digit = c - '0';
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||
else if (base == 16 && c >= 'a' && c <= 'f')
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||
digit = c - 'a' + 10;
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||
else if (base == 16 && c >= 'A' && c <= 'F')
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||
digit = c - 'A' + 10;
|
||
else {
|
||
/* `l' means long, and `u' means unsigned. */
|
||
while (1) {
|
||
if (c == 'l' || c == 'L')
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||
{
|
||
if (spec_long)
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||
cpp_error (pfile, "two `l's in integer constant");
|
||
spec_long = 1;
|
||
}
|
||
else if (c == 'u' || c == 'U')
|
||
{
|
||
if (op.unsignedp)
|
||
cpp_error (pfile, "two `u's in integer constant");
|
||
op.unsignedp = 1;
|
||
}
|
||
else
|
||
break;
|
||
|
||
if (--len == 0)
|
||
break;
|
||
c = *p++;
|
||
}
|
||
/* Don't look for any more digits after the suffixes. */
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||
break;
|
||
}
|
||
if (largest_digit < digit)
|
||
largest_digit = digit;
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||
nd = n * base + digit;
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||
overflow |= ULONG_MAX_over_base < n || nd < n;
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||
n = nd;
|
||
}
|
||
|
||
if (len != 0)
|
||
{
|
||
cpp_error (pfile, "Invalid number in #if expression");
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||
op.op = ERROR;
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||
return op;
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||
}
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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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||
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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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||
if ((long) 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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||
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||
op.value = n;
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||
op.op = INT;
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||
return op;
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||
}
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||
|
||
struct token {
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||
char *operator;
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||
int token;
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||
};
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||
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||
static struct token tokentab2[] = {
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||
{"&&", ANDAND},
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{"||", OROR},
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{"<<", LSH},
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{">>", RSH},
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{"==", EQUAL},
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{"!=", NOTEQUAL},
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{"<=", LEQ},
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{">=", GEQ},
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{"++", ERROR},
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||
{"--", ERROR},
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{NULL, ERROR}
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||
};
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||
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/* Read one token. */
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||
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struct operation
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cpp_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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||
register int c;
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||
register struct token *toktab;
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||
enum cpp_token token;
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||
struct operation op;
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U_CHAR *tok_start, *tok_end;
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||
int old_written;
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||
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retry:
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||
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old_written = CPP_WRITTEN (pfile);
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||
cpp_skip_hspace (pfile);
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c = CPP_BUF_PEEK (CPP_BUFFER (pfile));
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if (c == '#')
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return parse_number (pfile,
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cpp_read_check_assertion (pfile) ? "1" : "0", 1);
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||
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||
if (c == '\n')
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||
{
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||
op.op = 0;
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||
return op;
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||
}
|
||
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||
token = cpp_get_token (pfile);
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tok_start = pfile->token_buffer + old_written;
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||
tok_end = CPP_PWRITTEN (pfile);
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||
pfile->limit = tok_start;
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||
switch (token)
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{
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||
case CPP_EOF: /* Should not happen ... */
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||
case CPP_VSPACE:
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||
op.op = 0;
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||
return op;
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||
case CPP_POP:
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||
if (CPP_BUFFER (pfile)->fname != NULL)
|
||
{
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||
op.op = 0;
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||
return op;
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||
}
|
||
cpp_pop_buffer (pfile);
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||
goto retry;
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||
case CPP_HSPACE: case CPP_COMMENT:
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||
goto retry;
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||
case CPP_NUMBER:
|
||
return parse_number (pfile, tok_start, tok_end - tok_start);
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||
case CPP_STRING:
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||
cpp_error (pfile, "string constants not allowed in #if expressions");
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||
op.op = ERROR;
|
||
return op;
|
||
case CPP_CHAR:
|
||
/* This code for reading a character constant
|
||
handles multicharacter constants and wide characters.
|
||
It is mostly copied from c-lex.c. */
|
||
{
|
||
register int result = 0;
|
||
register int num_chars = 0;
|
||
unsigned width = MAX_CHAR_TYPE_SIZE;
|
||
int wide_flag = 0;
|
||
int max_chars;
|
||
U_CHAR *ptr = tok_start;
|
||
#ifdef MULTIBYTE_CHARS
|
||
char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + MB_CUR_MAX];
|
||
#else
|
||
char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + 1];
|
||
#endif
|
||
|
||
if (*ptr == 'L')
|
||
{
|
||
ptr++;
|
||
wide_flag = 1;
|
||
width = MAX_WCHAR_TYPE_SIZE;
|
||
#ifdef MULTIBYTE_CHARS
|
||
max_chars = MB_CUR_MAX;
|
||
#else
|
||
max_chars = 1;
|
||
#endif
|
||
}
|
||
else
|
||
max_chars = MAX_LONG_TYPE_SIZE / width;
|
||
|
||
++ptr;
|
||
while (ptr < tok_end && ((c = *ptr++) != '\''))
|
||
{
|
||
if (c == '\\')
|
||
{
|
||
c = cpp_parse_escape (pfile, (char **) &ptr);
|
||
if (width < HOST_BITS_PER_INT
|
||
&& (unsigned) c >= (1 << width))
|
||
cpp_pedwarn (pfile,
|
||
"escape sequence out of range for character");
|
||
}
|
||
|
||
num_chars++;
|
||
|
||
/* Merge character into result; ignore excess chars. */
|
||
if (num_chars < max_chars + 1)
|
||
{
|
||
if (width < HOST_BITS_PER_INT)
|
||
result = (result << width) | (c & ((1 << width) - 1));
|
||
else
|
||
result = c;
|
||
token_buffer[num_chars - 1] = c;
|
||
}
|
||
}
|
||
|
||
token_buffer[num_chars] = 0;
|
||
|
||
if (c != '\'')
|
||
cpp_error (pfile, "malformatted character constant");
|
||
else if (num_chars == 0)
|
||
cpp_error (pfile, "empty character constant");
|
||
else if (num_chars > max_chars)
|
||
{
|
||
num_chars = max_chars;
|
||
cpp_error (pfile, "character constant too long");
|
||
}
|
||
else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile))
|
||
cpp_warning (pfile, "multi-character character constant");
|
||
|
||
/* If char type is signed, sign-extend the constant. */
|
||
if (! wide_flag)
|
||
{
|
||
int num_bits = num_chars * width;
|
||
|
||
if (cpp_lookup (pfile, (U_CHAR *)"__CHAR_UNSIGNED__",
|
||
sizeof ("__CHAR_UNSIGNED__")-1, -1)
|
||
|| ((result >> (num_bits - 1)) & 1) == 0)
|
||
op.value
|
||
= result & ((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits));
|
||
else
|
||
op.value
|
||
= result | ~((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits));
|
||
}
|
||
else
|
||
{
|
||
#ifdef MULTIBYTE_CHARS
|
||
/* Set the initial shift state and convert the next sequence. */
|
||
result = 0;
|
||
/* In all locales L'\0' is zero and mbtowc will return zero,
|
||
so don't use it. */
|
||
if (num_chars > 1
|
||
|| (num_chars == 1 && token_buffer[0] != '\0'))
|
||
{
|
||
wchar_t wc;
|
||
(void) mbtowc (NULL_PTR, NULL_PTR, 0);
|
||
if (mbtowc (& wc, token_buffer, num_chars) == num_chars)
|
||
result = wc;
|
||
else
|
||
cpp_pedwarn (pfile,"Ignoring invalid multibyte character");
|
||
}
|
||
#endif
|
||
op.value = result;
|
||
}
|
||
}
|
||
|
||
/* This is always a signed type. */
|
||
op.unsignedp = 0;
|
||
op.op = CHAR;
|
||
|
||
return op;
|
||
|
||
case CPP_NAME:
|
||
if (CPP_WARN_UNDEF (pfile) && !skip_evaluation)
|
||
cpp_warning (pfile, "`%.*s' is not defined",
|
||
(int) (tok_end - tok_start), tok_start);
|
||
return parse_number (pfile, "0", 0);
|
||
|
||
case CPP_OTHER:
|
||
/* See if it is a special token of length 2. */
|
||
if (tok_start + 2 == tok_end)
|
||
{
|
||
for (toktab = tokentab2; toktab->operator != NULL; toktab++)
|
||
if (tok_start[0] == toktab->operator[0]
|
||
&& tok_start[1] == toktab->operator[1])
|
||
break;
|
||
if (toktab->token == ERROR)
|
||
{
|
||
char *buf = (char *) alloca (40);
|
||
sprintf (buf, "`%s' not allowed in operand of `#if'", tok_start);
|
||
cpp_error (pfile, buf);
|
||
}
|
||
op.op = toktab->token;
|
||
return op;
|
||
}
|
||
/* fall through */
|
||
default:
|
||
op.op = *tok_start;
|
||
return op;
|
||
}
|
||
}
|
||
|
||
|
||
/* Parse a C escape sequence. STRING_PTR points to a variable
|
||
containing a pointer to the string to parse. That pointer
|
||
is updated past the characters we use. The value of the
|
||
escape sequence is returned.
|
||
|
||
A negative value means the sequence \ newline was seen,
|
||
which is supposed to be equivalent to nothing at all.
|
||
|
||
If \ is followed by a null character, we return a negative
|
||
value and leave the string pointer pointing at the null character.
|
||
|
||
If \ is followed by 000, we return 0 and leave the string pointer
|
||
after the zeros. A value of 0 does not mean end of string. */
|
||
|
||
int
|
||
cpp_parse_escape (pfile, string_ptr)
|
||
cpp_reader *pfile;
|
||
char **string_ptr;
|
||
{
|
||
register int c = *(*string_ptr)++;
|
||
switch (c)
|
||
{
|
||
case 'a':
|
||
return TARGET_BELL;
|
||
case 'b':
|
||
return TARGET_BS;
|
||
case 'e':
|
||
case 'E':
|
||
if (CPP_PEDANTIC (pfile))
|
||
cpp_pedwarn (pfile, "non-ANSI-standard escape sequence, `\\%c'", c);
|
||
return 033;
|
||
case 'f':
|
||
return TARGET_FF;
|
||
case 'n':
|
||
return TARGET_NEWLINE;
|
||
case 'r':
|
||
return TARGET_CR;
|
||
case 't':
|
||
return TARGET_TAB;
|
||
case 'v':
|
||
return TARGET_VT;
|
||
case '\n':
|
||
return -2;
|
||
case 0:
|
||
(*string_ptr)--;
|
||
return 0;
|
||
|
||
case '0':
|
||
case '1':
|
||
case '2':
|
||
case '3':
|
||
case '4':
|
||
case '5':
|
||
case '6':
|
||
case '7':
|
||
{
|
||
register int i = c - '0';
|
||
register int count = 0;
|
||
while (++count < 3)
|
||
{
|
||
c = *(*string_ptr)++;
|
||
if (c >= '0' && c <= '7')
|
||
i = (i << 3) + c - '0';
|
||
else
|
||
{
|
||
(*string_ptr)--;
|
||
break;
|
||
}
|
||
}
|
||
if ((i & ~((1 << MAX_CHAR_TYPE_SIZE) - 1)) != 0)
|
||
{
|
||
i &= (1 << MAX_CHAR_TYPE_SIZE) - 1;
|
||
cpp_pedwarn (pfile,
|
||
"octal character constant does not fit in a byte");
|
||
}
|
||
return i;
|
||
}
|
||
case 'x':
|
||
{
|
||
register unsigned i = 0, overflow = 0, digits_found = 0, digit;
|
||
for (;;)
|
||
{
|
||
c = *(*string_ptr)++;
|
||
if (c >= '0' && c <= '9')
|
||
digit = c - '0';
|
||
else if (c >= 'a' && c <= 'f')
|
||
digit = c - 'a' + 10;
|
||
else if (c >= 'A' && c <= 'F')
|
||
digit = c - 'A' + 10;
|
||
else
|
||
{
|
||
(*string_ptr)--;
|
||
break;
|
||
}
|
||
overflow |= i ^ (i << 4 >> 4);
|
||
i = (i << 4) + digit;
|
||
digits_found = 1;
|
||
}
|
||
if (!digits_found)
|
||
cpp_error (pfile, "\\x used with no following hex digits");
|
||
if (overflow | (i & ~((1 << BITS_PER_UNIT) - 1)))
|
||
{
|
||
i &= (1 << BITS_PER_UNIT) - 1;
|
||
cpp_pedwarn (pfile,
|
||
"hex character constant does not fit in a byte");
|
||
}
|
||
return i;
|
||
}
|
||
default:
|
||
return c;
|
||
}
|
||
}
|
||
|
||
static void
|
||
integer_overflow (pfile)
|
||
cpp_reader *pfile;
|
||
{
|
||
if (CPP_PEDANTIC (pfile))
|
||
cpp_pedwarn (pfile, "integer overflow in preprocessor expression");
|
||
}
|
||
|
||
static long
|
||
left_shift (pfile, a, unsignedp, b)
|
||
cpp_reader *pfile;
|
||
long a;
|
||
int unsignedp;
|
||
unsigned long b;
|
||
{
|
||
if (b >= HOST_BITS_PER_LONG)
|
||
{
|
||
if (! unsignedp && a != 0)
|
||
integer_overflow (pfile);
|
||
return 0;
|
||
}
|
||
else if (unsignedp)
|
||
return (unsigned long) a << b;
|
||
else
|
||
{
|
||
long l = a << b;
|
||
if (l >> b != a)
|
||
integer_overflow (pfile);
|
||
return l;
|
||
}
|
||
}
|
||
|
||
static long
|
||
right_shift (pfile, a, unsignedp, b)
|
||
cpp_reader *pfile ATTRIBUTE_UNUSED;
|
||
long a;
|
||
int unsignedp;
|
||
unsigned long b;
|
||
{
|
||
if (b >= HOST_BITS_PER_LONG)
|
||
return unsignedp ? 0 : a >> (HOST_BITS_PER_LONG - 1);
|
||
else if (unsignedp)
|
||
return (unsigned long) a >> b;
|
||
else
|
||
return a >> b;
|
||
}
|
||
|
||
/* These priorities are all even, so we can handle associatively. */
|
||
#define PAREN_INNER_PRIO 0
|
||
#define COMMA_PRIO 4
|
||
#define COND_PRIO (COMMA_PRIO+2)
|
||
#define OROR_PRIO (COND_PRIO+2)
|
||
#define ANDAND_PRIO (OROR_PRIO+2)
|
||
#define OR_PRIO (ANDAND_PRIO+2)
|
||
#define XOR_PRIO (OR_PRIO+2)
|
||
#define AND_PRIO (XOR_PRIO+2)
|
||
#define EQUAL_PRIO (AND_PRIO+2)
|
||
#define LESS_PRIO (EQUAL_PRIO+2)
|
||
#define SHIFT_PRIO (LESS_PRIO+2)
|
||
#define PLUS_PRIO (SHIFT_PRIO+2)
|
||
#define MUL_PRIO (PLUS_PRIO+2)
|
||
#define UNARY_PRIO (MUL_PRIO+2)
|
||
#define PAREN_OUTER_PRIO (UNARY_PRIO+2)
|
||
|
||
#define COMPARE(OP) \
|
||
top->unsignedp = 0;\
|
||
top->value = (unsigned1 || unsigned2) ? (unsigned long) v1 OP v2 : (v1 OP v2)
|
||
|
||
/* Parse and evaluate a C expression, reading from PFILE.
|
||
Returns the value of the expression. */
|
||
|
||
HOST_WIDE_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 operation init_stack[INIT_STACK_SIZE];
|
||
struct operation *stack = init_stack;
|
||
struct operation *limit = stack + INIT_STACK_SIZE;
|
||
register struct operation *top = stack;
|
||
int lprio, rprio;
|
||
int skip_evaluation = 0;
|
||
|
||
top->rprio = 0;
|
||
top->flags = 0;
|
||
for (;;)
|
||
{
|
||
struct operation op;
|
||
char flags = 0;
|
||
|
||
/* Read a token */
|
||
op = cpp_lex (pfile, skip_evaluation);
|
||
|
||
/* See if the token is an operand, in which case go to set_value.
|
||
If the token is an operator, figure out its left and right
|
||
priorities, and then goto maybe_reduce. */
|
||
|
||
switch (op.op)
|
||
{
|
||
case NAME:
|
||
abort ();
|
||
case INT: case CHAR:
|
||
top->value = op.value;
|
||
top->unsignedp = op.unsignedp;
|
||
goto set_value;
|
||
case 0:
|
||
lprio = 0; goto maybe_reduce;
|
||
case '+': case '-':
|
||
/* Is this correct if unary ? FIXME */
|
||
flags = RIGHT_OPERAND_REQUIRED;
|
||
lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce;
|
||
case '!': case '~':
|
||
flags = RIGHT_OPERAND_REQUIRED;
|
||
rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce;
|
||
case '*': case '/': case '%':
|
||
lprio = MUL_PRIO; goto binop;
|
||
case '<': case '>': case LEQ: case GEQ:
|
||
lprio = LESS_PRIO; goto binop;
|
||
case EQUAL: case NOTEQUAL:
|
||
lprio = EQUAL_PRIO; goto binop;
|
||
case LSH: case RSH:
|
||
lprio = SHIFT_PRIO; goto binop;
|
||
case '&': lprio = AND_PRIO; goto binop;
|
||
case '^': lprio = XOR_PRIO; goto binop;
|
||
case '|': lprio = OR_PRIO; goto binop;
|
||
case ANDAND: lprio = ANDAND_PRIO; goto binop;
|
||
case OROR: lprio = OROR_PRIO; goto binop;
|
||
case ',':
|
||
lprio = COMMA_PRIO; goto binop;
|
||
case '(':
|
||
lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO;
|
||
goto maybe_reduce;
|
||
case ')':
|
||
lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO;
|
||
goto maybe_reduce;
|
||
case ':':
|
||
lprio = COND_PRIO; rprio = COND_PRIO;
|
||
goto maybe_reduce;
|
||
case '?':
|
||
lprio = COND_PRIO + 1; rprio = COND_PRIO;
|
||
goto maybe_reduce;
|
||
binop:
|
||
flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED;
|
||
rprio = lprio + 1;
|
||
goto maybe_reduce;
|
||
default:
|
||
cpp_error (pfile, "invalid character in #if");
|
||
goto syntax_error;
|
||
}
|
||
|
||
set_value:
|
||
/* Push a value onto the stack. */
|
||
if (top->flags & HAVE_VALUE)
|
||
{
|
||
cpp_error (pfile, "syntax error in #if");
|
||
goto syntax_error;
|
||
}
|
||
top->flags |= HAVE_VALUE;
|
||
continue;
|
||
|
||
maybe_reduce:
|
||
/* Push an operator, and check if we can reduce now. */
|
||
while (top->rprio > lprio)
|
||
{
|
||
long v1 = top[-1].value, v2 = top[0].value;
|
||
int unsigned1 = top[-1].unsignedp, unsigned2 = top[0].unsignedp;
|
||
top--;
|
||
if ((top[1].flags & LEFT_OPERAND_REQUIRED)
|
||
&& ! (top[0].flags & HAVE_VALUE))
|
||
{
|
||
cpp_error (pfile, "syntax error - missing left operand");
|
||
goto syntax_error;
|
||
}
|
||
if ((top[1].flags & RIGHT_OPERAND_REQUIRED)
|
||
&& ! (top[1].flags & HAVE_VALUE))
|
||
{
|
||
cpp_error (pfile, "syntax error - missing right operand");
|
||
goto syntax_error;
|
||
}
|
||
/* top[0].value = (top[1].op)(v1, v2);*/
|
||
switch (top[1].op)
|
||
{
|
||
case '+':
|
||
if (!(top->flags & HAVE_VALUE))
|
||
{ /* Unary '+' */
|
||
top->value = v2;
|
||
top->unsignedp = unsigned2;
|
||
top->flags |= HAVE_VALUE;
|
||
}
|
||
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 '-':
|
||
if (!(top->flags & HAVE_VALUE))
|
||
{ /* Unary '-' */
|
||
top->value = - v2;
|
||
if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2)
|
||
integer_overflow (pfile);
|
||
top->unsignedp = unsigned2;
|
||
top->flags |= HAVE_VALUE;
|
||
}
|
||
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 '*':
|
||
top->unsignedp = unsigned1 || unsigned2;
|
||
if (top->unsignedp)
|
||
top->value = (unsigned long) 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 '/':
|
||
if (skip_evaluation)
|
||
break;
|
||
if (v2 == 0)
|
||
{
|
||
cpp_error (pfile, "division by zero in #if");
|
||
v2 = 1;
|
||
}
|
||
top->unsignedp = unsigned1 || unsigned2;
|
||
if (top->unsignedp)
|
||
top->value = (unsigned long) v1 / v2;
|
||
else
|
||
{
|
||
top->value = v1 / v2;
|
||
if ((top->value & v1 & v2) < 0)
|
||
integer_overflow (pfile);
|
||
}
|
||
break;
|
||
case '%':
|
||
if (skip_evaluation)
|
||
break;
|
||
if (v2 == 0)
|
||
{
|
||
cpp_error (pfile, "division by zero in #if");
|
||
v2 = 1;
|
||
}
|
||
top->unsignedp = unsigned1 || unsigned2;
|
||
if (top->unsignedp)
|
||
top->value = (unsigned long) v1 % v2;
|
||
else
|
||
top->value = v1 % v2;
|
||
break;
|
||
case '!':
|
||
if (top->flags & HAVE_VALUE)
|
||
{
|
||
cpp_error (pfile, "syntax error");
|
||
goto syntax_error;
|
||
}
|
||
top->value = ! v2;
|
||
top->unsignedp = 0;
|
||
top->flags |= HAVE_VALUE;
|
||
break;
|
||
case '~':
|
||
if (top->flags & HAVE_VALUE)
|
||
{
|
||
cpp_error (pfile, "syntax error");
|
||
goto syntax_error;
|
||
}
|
||
top->value = ~ v2;
|
||
top->unsignedp = unsigned2;
|
||
top->flags |= HAVE_VALUE;
|
||
break;
|
||
case '<': COMPARE(<); break;
|
||
case '>': COMPARE(>); break;
|
||
case LEQ: COMPARE(<=); break;
|
||
case GEQ: COMPARE(>=); break;
|
||
case EQUAL:
|
||
top->value = (v1 == v2);
|
||
top->unsignedp = 0;
|
||
break;
|
||
case NOTEQUAL:
|
||
top->value = (v1 != v2);
|
||
top->unsignedp = 0;
|
||
break;
|
||
case LSH:
|
||
if (skip_evaluation)
|
||
break;
|
||
top->unsignedp = unsigned1;
|
||
if (v2 < 0 && ! unsigned2)
|
||
top->value = right_shift (pfile, v1, unsigned1, -v2);
|
||
else
|
||
top->value = left_shift (pfile, v1, unsigned1, v2);
|
||
break;
|
||
case RSH:
|
||
if (skip_evaluation)
|
||
break;
|
||
top->unsignedp = unsigned1;
|
||
if (v2 < 0 && ! unsigned2)
|
||
top->value = left_shift (pfile, v1, unsigned1, -v2);
|
||
else
|
||
top->value = right_shift (pfile, v1, unsigned1, v2);
|
||
break;
|
||
#define LOGICAL(OP) \
|
||
top->value = v1 OP v2;\
|
||
top->unsignedp = unsigned1 || unsigned2;
|
||
case '&': LOGICAL(&); break;
|
||
case '^': LOGICAL(^); break;
|
||
case '|': LOGICAL(|); break;
|
||
case ANDAND:
|
||
top->value = v1 && v2; top->unsignedp = 0;
|
||
if (!v1) skip_evaluation--;
|
||
break;
|
||
case OROR:
|
||
top->value = v1 || v2; top->unsignedp = 0;
|
||
if (v1) skip_evaluation--;
|
||
break;
|
||
case ',':
|
||
if (CPP_PEDANTIC (pfile))
|
||
cpp_pedwarn (pfile, "comma operator in operand of `#if'");
|
||
top->value = v2;
|
||
top->unsignedp = unsigned2;
|
||
break;
|
||
case '(': case '?':
|
||
cpp_error (pfile, "syntax error in #if");
|
||
goto syntax_error;
|
||
case ':':
|
||
if (top[0].op != '?')
|
||
{
|
||
cpp_error (pfile,
|
||
"syntax error ':' without preceding '?'");
|
||
goto syntax_error;
|
||
}
|
||
else if (! (top[1].flags & HAVE_VALUE)
|
||
|| !(top[-1].flags & HAVE_VALUE)
|
||
|| !(top[0].flags & HAVE_VALUE))
|
||
{
|
||
cpp_error (pfile, "bad syntax for ?: operator");
|
||
goto syntax_error;
|
||
}
|
||
else
|
||
{
|
||
top--;
|
||
if (top->value) skip_evaluation--;
|
||
top->value = top->value ? v1 : v2;
|
||
top->unsignedp = unsigned1 || unsigned2;
|
||
}
|
||
break;
|
||
case ')':
|
||
if ((top[1].flags & HAVE_VALUE)
|
||
|| ! (top[0].flags & HAVE_VALUE)
|
||
|| top[0].op != '('
|
||
|| (top[-1].flags & HAVE_VALUE))
|
||
{
|
||
cpp_error (pfile, "mismatched parentheses in #if");
|
||
goto syntax_error;
|
||
}
|
||
else
|
||
{
|
||
top--;
|
||
top->value = v1;
|
||
top->unsignedp = unsigned1;
|
||
top->flags |= HAVE_VALUE;
|
||
}
|
||
break;
|
||
default:
|
||
fprintf (stderr,
|
||
top[1].op >= ' ' && top[1].op <= '~'
|
||
? "unimplemented operator '%c'\n"
|
||
: "unimplemented operator '\\%03o'\n",
|
||
top[1].op);
|
||
}
|
||
}
|
||
if (op.op == 0)
|
||
{
|
||
if (top != stack)
|
||
cpp_error (pfile, "internal error in #if expression");
|
||
if (stack != init_stack)
|
||
free (stack);
|
||
return top->value;
|
||
}
|
||
top++;
|
||
|
||
/* Check for and handle stack overflow. */
|
||
if (top == limit)
|
||
{
|
||
struct operation *new_stack;
|
||
int old_size = (char *) limit - (char *) stack;
|
||
int new_size = 2 * old_size;
|
||
if (stack != init_stack)
|
||
new_stack = (struct operation *) xrealloc (stack, new_size);
|
||
else
|
||
{
|
||
new_stack = (struct operation *) xmalloc (new_size);
|
||
bcopy ((char *) stack, (char *) new_stack, old_size);
|
||
}
|
||
stack = new_stack;
|
||
top = (struct operation *) ((char *) new_stack + old_size);
|
||
limit = (struct operation *) ((char *) new_stack + new_size);
|
||
}
|
||
|
||
top->flags = flags;
|
||
top->rprio = rprio;
|
||
top->op = op.op;
|
||
if ((op.op == OROR && top[-1].value)
|
||
|| (op.op == ANDAND && !top[-1].value)
|
||
|| (op.op == '?' && !top[-1].value))
|
||
{
|
||
skip_evaluation++;
|
||
}
|
||
else if (op.op == ':')
|
||
{
|
||
if (top[-2].value) /* Was condition true? */
|
||
skip_evaluation++;
|
||
else
|
||
skip_evaluation--;
|
||
}
|
||
}
|
||
syntax_error:
|
||
if (stack != init_stack)
|
||
free (stack);
|
||
skip_rest_of_line (pfile);
|
||
return 0;
|
||
}
|