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/* You don't really want to know what this hack is for.
Copyright (C) 1996-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static void *funcall (char **stringp) __attribute_noinline__;
static void *eval (char **stringp);
long int weak_function
__strtol_internal (const char *nptr, char **endptr, int base, int group)
{
unsigned long int result = 0;
long int sign = 1;
while (*nptr == ' ' || *nptr == '\t')
++nptr;
if (*nptr == '-')
{
sign = -1;
++nptr;
}
else if (*nptr == '+')
++nptr;
if (*nptr < '0' || *nptr > '9')
{
if (endptr != NULL)
*endptr = (char *) nptr;
return 0L;
}
assert (base == 0);
base = 10;
if (*nptr == '0')
{
if (nptr[1] == 'x' || nptr[1] == 'X')
{
base = 16;
nptr += 2;
}
else
base = 8;
}
while (*nptr >= '0' && *nptr <= '9')
{
unsigned long int digval = *nptr - '0';
if (result > LONG_MAX / 10
|| (sign > 0 ? result == LONG_MAX / 10 && digval > LONG_MAX % 10
: (result == ((unsigned long int) LONG_MAX + 1) / 10
&& digval > ((unsigned long int) LONG_MAX + 1) % 10)))
{
errno = ERANGE;
return sign > 0 ? LONG_MAX : LONG_MIN;
}
result *= base;
result += digval;
++nptr;
}
return (long int) result * sign;
}
static void *
funcall (char **stringp)
{
void *args[strlen (*stringp)], **ap = args;
void *argcookie = &args[1];
do
{
/* Evaluate the next token. */
*ap++ = eval (stringp);
/* Whitespace is irrelevant. */
while (isspace (**stringp))
++*stringp;
/* Terminate at closing paren or end of line. */
} while (**stringp != '\0' && **stringp != ')');
if (**stringp != '\0')
/* Swallow closing paren. */
++*stringp;
if (args[0] == NULL)
{
static const char unknown[] = "Unknown function\n";
write (1, unknown, sizeof unknown - 1);
return NULL;
}
/* Do it to it. */
__builtin_return (__builtin_apply (args[0],
&argcookie,
(char *) ap - (char *) &args[1]));
}
static void *
eval (char **stringp)
{
void *value;
char *p = *stringp, c;
/* Whitespace is irrelevant. */
while (isspace (*p))
++p;
switch (*p)
{
case '"':
/* String constant. */
value = ++p;
do
if (*p == '\\')
{
switch (*strcpy (p, p + 1))
{
case 't':
*p = '\t';
break;
case 'n':
*p = '\n';
break;
}
++p;
}
while (*p != '\0' && *p++ != '"');
if (p[-1] == '"')
p[-1] = '\0';
break;
case '(':
*stringp = ++p;
return funcall (stringp);
default:
/* Try to parse it as a number. */
value = (void *) __strtol_internal (p, stringp, 0, 0);
if (*stringp != p)
return value;
/* Anything else is a symbol that produces its address. */
value = p;
do
++p;
while (*p != '\0' && !isspace (*p) && (!ispunct (*p) || *p == '_'));
c = *p;
*p = '\0';
value = dlsym (NULL, value);
*p = c;
break;
}
*stringp = p;
return value;
}
extern void _start (void) __attribute__ ((noreturn));
void
__attribute__ ((noreturn))
_start (void)
{
char *buf = NULL;
size_t bufsz = 0;
while (__getdelim (&buf, &bufsz, '\n', stdin) > 0)
{
char *p = buf;
eval (&p);
}
exit (0);
}
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