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hush: fix segfault in ${?:N:M}

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function                                             old     new   delta
expand_vars_to_list                                 2374    2409     +35
builtin_umask                                        132     133      +1
builtin_exit                                          47      48      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 37/0)               Total: 37 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2010-05-22 06:20:26 +02:00
parent 8a33679694
commit e85248afa2
5 changed files with 78 additions and 37 deletions
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81
shell/hush.c
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@ -179,9 +179,13 @@
#define ERR_PTR ((void*)(long)1)
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
#define SPECIAL_VAR_SYMBOL 3
#define _SPECIAL_VARS_STR "_*@$!?#"
#define SPECIAL_VARS_STR ("_*@$!?#" + 1)
#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
#define SPECIAL_VAR_SYMBOL 3
struct variable;
@ -2472,21 +2476,6 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
switch (first_ch & 0x7f) {
/* Highest bit in first_ch indicates that var is double-quoted */
case '$': /* pid */
val = utoa(G.root_pid);
break;
case '!': /* bg pid */
val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
break;
case '?': /* exitcode */
val = utoa(G.last_exitcode);
break;
case '#': /* argc */
if (arg[1] != SPECIAL_VAR_SYMBOL)
/* actually, it's a ${#var} */
goto case_default;
val = utoa(G.global_argc ? G.global_argc-1 : 0);
break;
case '*':
case '@':
i = 1;
@ -2581,27 +2570,35 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
break;
}
#endif
default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
case_default: {
char *var = arg;
char exp_len; /* '#' if it's ${#var} */
default: { /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
char *var;
char first_char;
char exp_op;
char exp_save = exp_save; /* for compiler */
char *exp_saveptr = exp_saveptr; /* points to expansion operator */
char *exp_saveptr; /* points to expansion operator */
char *exp_word = exp_word; /* for compiler */
var = arg;
*p = '\0';
arg[0] = first_ch & 0x7f;
/* prepare for expansions */
exp_saveptr = arg[1] ? strchr("%#:-=+?", arg[1]) : NULL;
first_char = arg[0] = first_ch & 0x7f;
exp_op = 0;
exp_len = var[0];
if (exp_len == '#') {
if (first_char == '#' && arg[1] && !exp_saveptr) {
/* handle length expansion ${#var} */
var++;
exp_op = 'L';
} else {
/* maybe handle parameter expansion */
exp_saveptr = var + strcspn(var, "%#:-=+?");
if (exp_saveptr /* if 2nd char is one of expansion operators */
&& strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
) {
/* ${?:0}, ${#[:]%0} etc */
exp_saveptr = var + 1;
} else {
/* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
exp_saveptr = var+1 + strcspn(var+1, "%#:-=+?");
}
exp_op = exp_save = *exp_saveptr;
if (exp_op) {
exp_word = exp_saveptr + 1;
@ -2616,7 +2613,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
}
}
*exp_saveptr = '\0';
}
} /* else: it's not an expansion op, but bare ${var} */
}
/* lookup the variable in question */
@ -2626,11 +2623,27 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
if (i < G.global_argc)
val = G.global_argv[i];
/* else val remains NULL: $N with too big N */
} else
val = get_local_var_value(var);
} else {
switch (var[0]) {
case '$': /* pid */
val = utoa(G.root_pid);
break;
case '!': /* bg pid */
val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
break;
case '?': /* exitcode */
val = utoa(G.last_exitcode);
break;
case '#': /* argc */
val = utoa(G.global_argc ? G.global_argc-1 : 0);
break;
default:
val = get_local_var_value(var);
}
}
/* handle any expansions */
if (exp_len == '#') {
if (exp_op == 'L') {
debug_printf_expand("expand: length(%s)=", val);
val = utoa(val ? strlen(val) : 0);
debug_printf_expand("%s\n", val);
@ -2761,7 +2774,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
}
}
}
}
} /* one of "-=+?" */
*exp_saveptr = exp_save;
} /* if (exp_op) */
@ -6031,7 +6044,7 @@ static int handle_dollar(o_string *as_string,
* or even ${?+subst} - operator acting on a special variable,
* or the beginning of variable name.
*/
if (!strchr("$!?#*@_", ch) && !isalnum(ch)) { /* not one of those */
if (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) { /* not one of those */
bad_dollar_syntax:
syntax_error_unterm_str("${name}");
debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");