libbb: make xrealloc_vector zero out the realloc'ed tail

function                                             old     new   delta
xrealloc_vector_helper                                51      76     +25
man_main                                             712     705      -7
act                                                  250     234     -16
create_list                                           91      70     -21
getopt_main                                          695     664     -31
load_dep_bb                                          281     248     -33
fileAction                                           744     709     -35
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/6 up/down: 25/-143)          Total: -118 bytes
This commit is contained in:
Denis Vlasenko 2008-08-04 13:20:36 +00:00
parent 2b576b8e76
commit 27842288b3
9 changed files with 30 additions and 20 deletions

View File

@ -1169,10 +1169,9 @@ static char **create_list(const char *filename)
file_list = NULL;
count = 0;
while ((line = xmalloc_fgetline(list_stream)) != NULL) {
//TODO: zeroing xrealloc_vector?
file_list = xrealloc_vector(file_list, 2, count);
file_list[count++] = line;
file_list[count] = NULL;
/*file_list[count] = NULL; - xrealloc_vector did it */
}
fclose(list_stream);

View File

@ -92,7 +92,7 @@ static int FAST_FUNC act(const char *file, struct stat *statbuf, void *args UNUS
names = xrealloc_vector(names, 4, cur);
names[cur++] = xstrdup(file);
names[cur] = NULL;
/*names[cur] = NULL; - xrealloc_vector did it */
return TRUE;
}

View File

@ -570,6 +570,10 @@ void *malloc_or_warn(size_t size) FAST_FUNC;
void *xmalloc(size_t size) FAST_FUNC;
void *xzalloc(size_t size) FAST_FUNC;
void *xrealloc(void *old, size_t size) FAST_FUNC;
/* After xrealloc_vector(v, 4, idx) it's ok to use
* at least v[idx] and v[idx+1], for all idx values.
* shift specifies how many new elements are added (1: 2, 2: 4... 8: 256...)
* when all elements are used up. New elements are zeroed out. */
#define xrealloc_vector(vector, shift, idx) \
xrealloc_vector_helper((vector), (sizeof((vector)[0]) << 8) + (shift), (idx))
void* xrealloc_vector_helper(void *vector, unsigned sizeof_and_shift, int idx) FAST_FUNC;

View File

@ -45,8 +45,8 @@ static int get_cached(cache_t *cp, unsigned id)
for (i = 0; i < cp->size; i++)
if (cp->cache[i].id == id)
return i;
i = cp->size;
cp->cache = xrealloc_vector(cp->cache, 2, cp->size++);
i = cp->size++;
cp->cache = xrealloc_vector(cp->cache, 2, i);
cp->cache[i++].id = id;
return -i;
}
@ -59,8 +59,8 @@ static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
for (i = 0; i < cp->size; i++)
if (cp->cache[i].id == id)
return cp->cache[i].name;
i = cp->size;
cp->cache = xrealloc_vector(cp->cache, 2, cp->size++);
i = cp->size++;
cp->cache = xrealloc_vector(cp->cache, 2, i);
cp->cache[i].id = id;
/* Never fails. Generates numeric string if name isn't found */
fp(cp->cache[i].name, sizeof(cp->cache[i].name), id);

View File

@ -14,7 +14,6 @@
* #define magic packed two parameters into one:
* sizeof = sizeof_and_shift >> 8
* shift = (sizeof_and_shift) & 0xff
* (TODO: encode "I want it zeroed" in lowest bit?)
*
* Lets say shift = 4. 1 << 4 == 0x10.
* If idx == 0, 0x10, 0x20 etc, vector[] is resized to next higher
@ -23,14 +22,25 @@
*
* In other words: after xrealloc_vector(v, 4, idx) it's ok to use
* at least v[idx] and v[idx+1], for all idx values.
*
* New elements are zeroed out, but only if realloc was done
* (not on every call). You can depend on v[idx] and v[idx+1] being
* zeroed out if you use it like this:
* v = xrealloc_vector(v, 4, idx);
* v[idx].some_fields = ...; - the rest stays 0/NULL
* idx++;
* If you do not advance idx like above, you should be more careful.
* Next call to xrealloc_vector(v, 4, idx) may or may not zero out v[idx].
*/
void* FAST_FUNC xrealloc_vector_helper(void *vector, unsigned sizeof_and_shift, int idx)
{
int mask = 1 << (uint8_t)sizeof_and_shift;
if (!(idx & (mask - 1))) {
sizeof_and_shift >>= 8;
sizeof_and_shift >>= 8; /* sizeof(vector[0]) */
vector = xrealloc(vector, sizeof_and_shift * (idx + mask + 1));
vector += idx;
memset(vector, 0, sizeof_and_shift * (mask + 1));
}
return vector;
}

View File

@ -112,7 +112,7 @@ int man_main(int argc UNUSED_PARAM, char **argv)
man_path_list[count_mp] = xstrdup(token[1]);
count_mp++;
/* man_path_list is NULL terminated */
man_path_list[count_mp] = NULL;
/*man_path_list[count_mp] = NULL; - xrealloc_vector did it */
}
if (strcmp("MANSECT", token[0]) == 0) {
free(sec_list);

View File

@ -270,10 +270,9 @@ static FAST_FUNC int fileAction(const char *pathname,
cur = module_count++;
modinfo = xrealloc_vector(modinfo, 12, cur);
//TODO: use zeroing version of xrealloc_vector?
modinfo[cur].pathname = xstrdup(pathname);
modinfo[cur].aliases = NULL;
modinfo[cur+1].pathname = NULL;
/*modinfo[cur].aliases = NULL; - xrealloc_vector did it */
/*modinfo[cur+1].pathname = NULL;*/
if (!pathname_matches_modname(fname, modname_to_match)) {
dbg1_error_msg("'%s' module name doesn't match", pathname);
@ -330,8 +329,7 @@ static int load_dep_bb(void)
space = strchrnul(line, ' ');
cur = module_count++;
modinfo = xrealloc_vector(modinfo, 12, cur);
//TODO: use zeroing version of xrealloc_vector?
modinfo[cur+1].pathname = NULL;
/*modinfo[cur+1].pathname = NULL; - xrealloc_vector did it */
modinfo[cur].pathname = line; /* we take ownership of malloced block here */
if (*space)
*space++ = '\0';

View File

@ -814,7 +814,7 @@ int top_main(int argc UNUSED_PARAM, char **argv)
int n;
if (scan_mask == TOP_MASK) {
n = ntop;
top = xrealloc_vector(top, 2, ntop++);
top = xrealloc_vector(top, 6, ntop++);
top[n].pid = p->pid;
top[n].ppid = p->ppid;
top[n].vsz = p->vsz;
@ -830,7 +830,7 @@ int top_main(int argc UNUSED_PARAM, char **argv)
continue; /* kernel threads are ignored */
n = ntop;
/* No bug here - top and topmem are the same */
top = xrealloc_vector(topmem, 2, ntop++);
top = xrealloc_vector(topmem, 6, ntop++);
strcpy(topmem[n].comm, p->comm);
topmem[n].pid = p->pid;
topmem[n].vsz = p->mapped_rw + p->mapped_ro;

View File

@ -238,14 +238,13 @@ static struct option *add_long_options(struct option *long_options, char *option
if (tlen == 0)
bb_error_msg_and_die("empty long option specified");
}
//TODO: zeroing version of xrealloc_vector!
long_options = xrealloc_vector(long_options, 4, long_nr);
long_options[long_nr].has_arg = arg_opt;
long_options[long_nr].flag = NULL;
/*long_options[long_nr].flag = NULL; - xrealloc_vector did it */
long_options[long_nr].val = LONG_OPT;
long_options[long_nr].name = xstrdup(tokptr);
long_nr++;
memset(&long_options[long_nr], 0, sizeof(long_options[0]));
/*memset(&long_options[long_nr], 0, sizeof(long_options[0])); - xrealloc_vector did it */
}
tokptr = strtok(NULL, ", \t\n");
}