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Diffstat (limited to 'sysdeps/gnu/eval.c')
-rw-r--r-- | sysdeps/gnu/eval.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/sysdeps/gnu/eval.c b/sysdeps/gnu/eval.c new file mode 100644 index 0000000..ce452b7 --- /dev/null +++ b/sysdeps/gnu/eval.c @@ -0,0 +1,138 @@ +/* You don't really want to know what this hack is for. + Copyright (C) 1996, 1997 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <stdio.h> +#include <ctype.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <dlfcn.h> + +static void *funcall (char **stringp); +static void *eval (char **stringp); + +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 (p, stringp, 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; +} + + +void +_start (void) +{ + char *buf = NULL; + size_t bufsz = 0; + + while (__getdelim (&buf, &bufsz, '\n', stdin) > 0) + { + char *p = buf; + eval (&p); + } + + exit (0); +} |