hush: fix two nasty bugs:

hush-bugs/tick2.tests: ok
hush-bugs/tick.tests: ok

function                                             old     new   delta
parse_stream                                        1332    1557    +225
b_addptr                                               -      97     +97
add_till_backquote                                     -      82     +82
b_addstr                                               -      58     +58
b_grow_by                                              -      50     +50
setup_string_in_str                                    -      29     +29
expand_variables                                    1196    1199      +3
expand_on_ifs                                        100      97      -3
b_addqchr                                             57      50      -7
parse_and_run_string                                  48      31     -17
lookup_param                                          27       -     -27
b_addchr                                              75      45     -30
count_ifs                                             44       -     -44
process_command_subs                                 222       -    -222
------------------------------------------------------------------------------
(add/remove: 5/3 grow/shrink: 2/4 up/down: 544/-350)          Total: 194 bytes
   text    data     bss     dec     hex filename
 759354     604    6684  766642   bb2b2 busybox_old
 759534     604    6684  766822   bb366 busybox_unstripped
This commit is contained in:
Denis Vlasenko 2008-06-10 18:04:32 +00:00
parent 76d50418b3
commit 7b4f3f13d3

View File

@ -341,8 +341,9 @@ typedef struct {
int maxlen;
smallint o_quote;
smallint nonnull;
smallint has_empty_slot;
} o_string;
#define NULL_O_STRING {NULL,0,0,0,0}
#define NULL_O_STRING { NULL }
/* used for initialization: o_string foo = NULL_O_STRING; */
/* I can almost use ordinary FILE *. Is open_memstream() universally
@ -464,8 +465,6 @@ enum { run_list_level = 0 };
} while (0)
#define B_CHUNK 100
#define B_NOSPAC 1
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
#if 1
@ -494,11 +493,6 @@ static void syntax_lineno(int line)
#endif
/* Index of subroutines: */
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
static void b_reset(o_string *o);
static int b_addqchr(o_string *o, int ch, int quote);
/* in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
@ -1176,28 +1170,10 @@ static int builtin_unset(char **argv)
// return EXIT_FAILURE;
//}
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
* in here, such as setting a maximum string length */
if (o->length + len > o->maxlen) {
/* assert(data == NULL || o->maxlen != 0); */
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
return o->data == NULL;
}
static int b_addchr(o_string *o, int ch)
{
debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
if (b_check_space(o, 1))
return B_NOSPAC;
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
return 0;
}
/*
* o_string support
*/
#define B_CHUNK (32 * sizeof(char*))
static void b_reset(o_string *o)
{
@ -1213,20 +1189,124 @@ static void b_free(o_string *o)
memset(o, 0, sizeof(*o));
}
static void b_grow_by(o_string *o, int len)
{
if (o->length + len > o->maxlen) {
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
}
static void b_addchr(o_string *o, int ch)
{
debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
b_grow_by(o, 1);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void b_addstr(o_string *o, const char *str, int len)
{
b_grow_by(o, len);
memcpy(&o->data[o->length], str, len);
o->length += len;
o->data[o->length] = '\0';
}
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static int b_addqchr(o_string *o, int ch, int quote)
static void b_addqchr(o_string *o, int ch, int quote)
{
if (quote && strchr("*?[\\", ch)) {
int rc;
rc = b_addchr(o, '\\');
if (rc)
return rc;
b_addchr(o, '\\');
}
return b_addchr(o, ch);
b_addchr(o, ch);
}
/* A special kind of o_string for $VAR and `cmd` expansion.
* It contains char* list[] at the beginning, which is grown in 16 element
* increments. Actual string data starts at the next multiple of 16.
* list[i] contains an INDEX (int!) into this string data.
* It means that if list[] needs to grow, data needs to be moved higher up
* but list[i]'s need not be modified.
* NB: remembering how many list[i]'s you have there is crucial.
* b_finalize_list() operation post-processes this structure - calculates
* and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
*/
static int b_addptr(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int string_len = o->length - string_start;
if (!o->has_empty_slot) {
if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
/* list[n] points to string_start, make space for 16 more pointers */
o->maxlen += 0x10 * sizeof(list[0]);
o->data = xrealloc(o->data, o->maxlen + 1);
list = (char**)o->data;
memmove(list + n + 0x10, list + n, string_len);
o->length += 0x10 * sizeof(list[0]);
}
} else {
/* We have empty slot at list[n], reuse without growth */
o->has_empty_slot = 0;
}
list[n] = (char*)string_len;
return n + 1;
}
static int b_get_last_ptr(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
return ((int)list[n-1]) + string_start;
}
static char **b_finalize_list(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start;
b_addptr(o, n); /* force growth for list[n] if necessary */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]);
list[n] = NULL;
while (n) {
n--;
list[n] = o->data + (int)list[n] + string_start;
}
return list;
}
#ifdef DEBUG_EXPAND
static void b_debug_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
prefix, list, n, string_start, o->length, o->maxlen);
while (i < n) {
fprintf(stderr, " list[%d]=%d '%s'\n", i, (int)list[i],
o->data + (int)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)list[n] + string_start;
fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
}
}
#else
#define b_debug_list(prefix, o, n) ((void)0)
#endif
/*
* in_str support
*/
static int static_get(struct in_str *i)
{
int ch = *i->p++;
@ -2461,106 +2541,25 @@ static int xglob(o_string *dest, char ***pglob)
* followed by strings themself.
* Caller can deallocate entire list by single free(list). */
/* Helpers first:
* count_XXX estimates size of the block we need. It's okay
* to over-estimate sizes a bit, if it makes code simpler */
static int count_ifs(const char *str)
{
int cnt = 0;
debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
while (1) {
str += strcspn(str, ifs);
if (!*str) break;
str++; /* str += strspn(str, ifs); */
cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
}
debug_printf_expand(" return %d\n", cnt);
return cnt;
}
static void count_var_expansion_space(int *countp, int *lenp, char *arg)
{
char first_ch;
int i;
int len = *lenp;
int count = *countp;
const char *val;
char *p;
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
len += p - arg;
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
first_ch = arg[0];
switch (first_ch & 0x7f) {
/* high bit in 1st_ch indicates that var is double-quoted */
case '$': /* pid */
case '!': /* bg pid */
case '?': /* exitcode */
case '#': /* argc */
len += sizeof(int)*3 + 1; /* enough for int */
break;
case '*':
case '@':
for (i = 1; global_argv[i]; i++) {
len += strlen(global_argv[i]) + 1;
count++;
if (!(first_ch & 0x80))
count += count_ifs(global_argv[i]);
}
break;
default:
*p = '\0';
arg[0] = first_ch & 0x7f;
if (isdigit(arg[0])) {
i = xatoi_u(arg);
val = NULL;
if (i < global_argc)
val = global_argv[i];
} else
val = lookup_param(arg);
arg[0] = first_ch;
*p = SPECIAL_VAR_SYMBOL;
if (val) {
len += strlen(val) + 1;
if (!(first_ch & 0x80))
count += count_ifs(val);
}
}
arg = ++p;
}
len += strlen(arg) + 1;
count++;
*lenp = len;
*countp = count;
}
/* Store given string, finalizing the word and starting new one whenever
* we encounter ifs char(s). This is used for expanding variable values.
* End-of-string does NOT finalize word: think about 'echo -$VAR-' */
static int expand_on_ifs(char **list, int n, char **posp, const char *str)
static int expand_on_ifs(o_string *output, int n, const char *str)
{
char *pos = *posp;
while (1) {
int word_len = strcspn(str, ifs);
if (word_len) {
memcpy(pos, str, word_len); /* store non-ifs chars */
pos += word_len;
b_addstr(output, str, word_len); /* store non-ifs chars */
str += word_len;
}
if (!*str) /* EOL - do not finalize word */
break;
*pos++ = '\0';
if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
b_addchr(output, '\0');
b_debug_list("expand_on_ifs", output, n);
n = b_addptr(output, n);
str += strspn(str, ifs); /* skip ifs chars */
}
*posp = pos;
b_debug_list("expand_on_ifs[1]", output, n);
return n;
}
@ -2571,7 +2570,7 @@ static int expand_on_ifs(char **list, int n, char **posp, const char *str)
* 'echo -$*-'. If you play here, you must run testsuite afterwards! */
/* NB: another bug is that we cannot detect empty strings yet:
* "" or $empty"" expands to zero words, has to expand to empty word */
static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
{
/* or_mask is either 0 (normal case) or 0x80
* (expansion of right-hand side of assignment == 1-element expand) */
@ -2580,18 +2579,19 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char
int i;
const char *val;
char *p;
char *pos = *posp;
ored_ch = 0;
if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
b_debug_list("expand_vars_to_list", output, n);
n = b_addptr(output, n);
b_debug_list("expand_vars_to_list[0]", output, n);
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
memcpy(pos, arg, p - arg);
pos += (p - arg);
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
o_string subst_result = NULL_O_STRING;
b_addstr(output, arg, p - arg);
b_debug_list("expand_vars_to_list[1]", output, n);
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
@ -2620,16 +2620,15 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char
break;
if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
while (global_argv[i]) {
n = expand_on_ifs(list, n, &pos, global_argv[i]);
n = expand_on_ifs(output, n, global_argv[i]);
debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
if (global_argv[i++][0] && global_argv[i]) {
/* this argv[] is not empty and not last:
* put terminating NUL, start new word */
*pos++ = '\0';
if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
b_addchr(output, '\0');
b_debug_list("expand_vars_to_list[2]", output, n);
n = b_addptr(output, n);
b_debug_list("expand_vars_to_list[3]", output, n);
}
}
} else
@ -2637,27 +2636,34 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char
* and in this case should treat it like '$*' - see 'else...' below */
if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
while (1) {
strcpy(pos, global_argv[i]);
pos += strlen(global_argv[i]);
b_addstr(output, global_argv[i], strlen(global_argv[i]));
if (++i >= global_argc)
break;
*pos++ = '\0';
if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
b_addchr(output, '\0');
b_debug_list("expand_vars_to_list[4]", output, n);
n = b_addptr(output, n);
}
} else { /* quoted $*: add as one word */
while (1) {
strcpy(pos, global_argv[i]);
pos += strlen(global_argv[i]);
b_addstr(output, global_argv[i], strlen(global_argv[i]));
if (!global_argv[++i])
break;
if (ifs[0])
*pos++ = ifs[0];
b_addchr(output, ifs[0]);
}
}
break;
case '`': {
struct in_str input;
*p = '\0';
arg++;
//bb_error_msg("SUBST '%s' first_ch %x", arg, first_ch);
setup_string_in_str(&input, arg);
process_command_subs(&subst_result, &input, NULL);
//bb_error_msg("RES '%s'", subst_result.data);
val = subst_result.data;
goto store_val;
}
default:
*p = '\0';
arg[0] = first_ch & 0x7f;
@ -2669,66 +2675,52 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char
} else
val = lookup_param(arg);
arg[0] = first_ch;
store_val:
*p = SPECIAL_VAR_SYMBOL;
if (!(first_ch & 0x80)) { /* unquoted $VAR */
if (val) {
n = expand_on_ifs(list, n, &pos, val);
n = expand_on_ifs(output, n, val);
val = NULL;
}
} /* else: quoted $VAR, val will be appended at pos */
}
if (val) {
strcpy(pos, val);
pos += strlen(val);
} /* else: quoted $VAR, val will be appended below */
}
if (val)
b_addstr(output, val, strlen(val));
b_free(&subst_result);
arg = ++p;
}
debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
strcpy(pos, arg);
pos += strlen(arg) + 1;
if (pos == list[n-1] + 1) { /* expansion is empty */
} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
b_debug_list("expand_vars_to_list[a]", output, n);
b_addstr(output, arg, strlen(arg) + 1);
b_debug_list("expand_vars_to_list[b]", output, n);
//TESTME
if (output->length - 1 == b_get_last_ptr(output, n)) { /* expansion is empty */
if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
pos--;
n--;
/* allow to reuse list[n] later without re-growth */
output->has_empty_slot = 1;
}
}
*posp = pos;
return n;
}
static char **expand_variables(char **argv, char or_mask)
{
int n;
int count = 1;
int len = 0;
char *pos, **v, **list;
char **list;
char **v;
o_string output = NULL_O_STRING;
v = argv;
if (!*v) debug_printf_expand("count_var_expansion_space: "
"argv[0]=NULL count=%d len=%d alloc_space=%d\n",
count, len, sizeof(char*) * count + len);
while (*v) {
count_var_expansion_space(&count, &len, *v);
debug_printf_expand("count_var_expansion_space: "
"'%s' count=%d len=%d alloc_space=%d\n",
*v, count, len, sizeof(char*) * count + len);
v++;
}
len += sizeof(char*) * count; /* total to alloc */
list = xmalloc(len);
pos = (char*)(list + count);
debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
n = 0;
v = argv;
while (*v)
n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
n = expand_vars_to_list(&output, n, *v++, or_mask);
b_debug_list("expand_variables", &output, n);
if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n] = NULL;
/* output.data (malloced) gets returned in "list" */
list = b_finalize_list(&output, n);
#ifdef DEBUG_EXPAND
{
@ -2737,12 +2729,8 @@ static char **expand_variables(char **argv, char or_mask)
debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
m++;
}
debug_printf_expand("used_space=%d\n", pos - (char*)list);
}
#endif
if (ENABLE_HUSH_DEBUG)
if (pos - (char*)list > len)
bb_error_msg_and_die("BUG in varexp");
return list;
}
@ -3391,6 +3379,116 @@ static const char *lookup_param(const char *src)
return NULL;
}
#if ENABLE_HUSH_TICK
/* Subroutines for copying $(...) and `...` things */
static void add_till_backquote(o_string *dest, struct in_str *input);
/* '...' */
static void add_till_single_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = b_getch(input);
if (ch == EOF)
break;
if (ch == '\'')
break;
b_addchr(dest, ch);
}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static void add_till_double_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = b_getch(input);
if (ch == '"')
break;
if (ch == '\\') { /* \x. Copy both chars. */
b_addchr(dest, ch);
ch = b_getch(input);
}
if (ch == EOF)
break;
b_addchr(dest, ch);
if (ch == '`') {
add_till_backquote(dest, input);
b_addchr(dest, ch);
continue;
}
// if (ch == '$') ...
}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
* \` quoting.
* "Within the backquoted style of command substitution, backslash
* shall retain its literal meaning, except when followed by: '$', '`', or '\'.
* The search for the matching backquote shall be satisfied by the first
* backquote found without a preceding backslash; during this search,
* if a non-escaped backquote is encountered within a shell comment,
* a here-document, an embedded command substitution of the $(command)
* form, or a quoted string, undefined results occur. A single-quoted
* or double-quoted string that begins, but does not end, within the
* "`...`" sequence produces undefined results."
* Example Output
* echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
*/
static void add_till_backquote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = b_getch(input);
//bb_error_msg("ADD '%c'", ch);
if (ch == '`')
break;
if (ch == '\\') { /* \x. Copy both chars unless it is \` */
int ch2 = b_getch(input);
if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
b_addchr(dest, ch);
ch = ch2;
}
if (ch == EOF)
break;
b_addchr(dest, ch);
}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
* quoting and nested ()s.
* "With the $(command) style of command substitution, all characters
* following the open parenthesis to the matching closing parenthesis
* constitute the command. Any valid shell script can be used for command,
* except a script consisting solely of redirections which produces
* unspecified results."
* Example Output
* echo $(echo '(TEST)' BEST) (TEST) BEST
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*/
static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
{
int count = 0;
while (1) {
int ch = b_getch(input);
if (ch == EOF)
break;
if (ch == '(')
count++;
if (ch == ')')
if (--count < 0)
break;
b_addchr(dest, ch);
if (ch == '\'') {
add_till_single_quote(dest, input);
b_addchr(dest, ch);
continue;
}
if (ch == '"') {
add_till_double_quote(dest, input);
b_addchr(dest, ch);
continue;
}
}
}
#endif /* ENABLE_HUSH_TICK */
//FIXME: remove ctx and sp
/* return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/ struct in_str *input)
{
@ -3450,7 +3548,10 @@ static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/ struct in_st
#if ENABLE_HUSH_TICK
case '(':
b_getch(input);
process_command_subs(dest, /*ctx,*/ input, ")");
b_addchr(dest, SPECIAL_VAR_SYMBOL);
b_addchr(dest, quote_mask | '`');
add_till_closing_curly_brace(dest, input);
b_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
#endif
case '-':
@ -3572,9 +3673,15 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
dest->o_quote ^= 1; /* invert */
break;
#if ENABLE_HUSH_TICK
case '`':
process_command_subs(dest, /*ctx,*/ input, "`");
case '`': {
//int pos = dest->length;
b_addchr(dest, SPECIAL_VAR_SYMBOL);
b_addchr(dest, dest->o_quote ? 0x80 | '`' : '`');
add_till_backquote(dest, input);
b_addchr(dest, SPECIAL_VAR_SYMBOL);
//bb_error_msg("RES '%s'", dest->data + pos);
break;
}
#endif
case '>':
redir_fd = redirect_opt_num(dest);