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Optimization: eliminate all remaining usages of strcat()
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After this change, we don't use strcat() anywhere.

* defs.h: Change sprinttv() return type to char *.
* time.c (sprinttv): Return pointer past last stored char.
* desc.c (decode_select): Change printing logic in order to eliminate
usage of strcat() - use stpcpy(), *outptr++ = ch, sprintf() instead.
Also reduce usage of strlen().
* stream.c (decode_poll): Likewise.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
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@dvlasenk
dvlasenk committed Aug 31, 2011
1 parent 8778bff commit 2fb4db3
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Showing 4 changed files with 86 additions and 86 deletions.
2 changes: 1 addition & 1 deletion defs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -616,7 +616,7 @@ extern void printnum_int(struct tcb *, long, const char *);
extern void printpath(struct tcb *, long);
extern void printpathn(struct tcb *, long, int);
extern void printtv_bitness(struct tcb *, long, enum bitness_t, int);
extern void sprinttv(struct tcb *, long, enum bitness_t, char *);
extern char *sprinttv(struct tcb *, long, enum bitness_t, char *);
extern void print_timespec(struct tcb *, long);
extern void sprint_timespec(char *, struct tcb *, long);
#ifdef HAVE_SIGINFO_T
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58 changes: 30 additions & 28 deletions desc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -493,7 +493,6 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
unsigned int fdsize = ((((args[0] + 7) / 8) + sizeof(long) - 1)
& -sizeof(long));
fd_set *fds;
static char outstr[1024];
const char *sep;
long arg;

Expand Down Expand Up @@ -532,8 +531,10 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
printtv_bitness(tcp, args[4], bitness, 0);
}
else {
unsigned int cumlen = 0;
const char *sep = "";
static char outstr[1024];
char *outptr;
#define end_outstr (outstr + sizeof(outstr))
const char *sep;

if (syserror(tcp))
return 0;
Expand All @@ -544,57 +545,58 @@ decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
return RVAL_STR;
}

fds = (fd_set *) malloc(fdsize);
fds = malloc(fdsize);
if (fds == NULL)
fprintf(stderr, "out of memory\n");

outstr[0] = '\0';
tcp->auxstr = outstr;
outptr = outstr;
sep = "";
for (i = 0; i < 3; i++) {
int first = 1;

tcp->auxstr = outstr;
arg = args[i+1];
if (fds == NULL || !arg ||
umoven(tcp, arg, fdsize, (char *) fds) < 0)
continue;
for (j = 0; j < args[0]; j++) {
if (FD_ISSET(j, fds)) {
char str[11 + 3 * sizeof(int)];

if (first) {
sprintf(str, "%s%s [%u", sep,
i == 0 ? "in" :
i == 1 ? "out" :
"except", j);
first = 0;
sep = ", ";
/* +2 chars needed at the end: ']',NUL */
if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
if (first) {
outptr += sprintf(outptr, "%s%s [%u",
sep,
i == 0 ? "in" : i == 1 ? "out" : "except",
j
);
first = 0;
sep = ", ";
}
else {
outptr += sprintf(outptr, " %u", j);
}
}
else
sprintf(str, " %u", j);
cumlen += strlen(str);
if (cumlen < sizeof(outstr))
strcat(outstr, str);
nfds--;
}
}
if (cumlen)
strcat(outstr, "]");
if (outptr != outstr)
*outptr++ = ']';
if (nfds == 0)
break;
}
free(fds);
#ifdef LINUX
/* This contains no useful information on SunOS. */
if (args[4]) {
char str[128];

sprintf(str, "%sleft ", sep);
sprinttv(tcp, args[4], bitness, str + strlen(str));
if ((cumlen += strlen(str)) < sizeof(outstr))
strcat(outstr, str);
if (outptr < end_outstr - 128) {
outptr += sprintf(outptr, "%sleft ", sep);
outptr = sprinttv(tcp, args[4], bitness, outptr);
}
}
#endif /* LINUX */
*outptr = '\0';
return RVAL_STR;
#undef end_outstr
}
return 0;
}
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56 changes: 25 additions & 31 deletions stream.c
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Original file line number Diff line number Diff line change
Expand Up @@ -341,9 +341,9 @@ decode_poll(struct tcb *tcp, long pts)
return 0;
} else {
static char outstr[1024];
char str[64];
char *outptr;
#define end_outstr (outstr + sizeof(outstr))
const char *flagstr;
unsigned int cumlen;

if (syserror(tcp))
return 0;
Expand All @@ -366,62 +366,56 @@ decode_poll(struct tcb *tcp, long pts)
abbrev_end = end;
}

outstr[0] = '\0';
cumlen = 0;
outptr = outstr;

for (cur = start; cur < end; cur += sizeof(fds)) {
if (umoven(tcp, cur, sizeof fds, (char *) &fds) < 0) {
++cumlen;
if (cumlen < sizeof(outstr))
strcat(outstr, "?");
if (outptr < end_outstr - 2)
*outptr++ = '?';
failed = 1;
break;
}
if (!fds.revents)
continue;
if (!cumlen) {
++cumlen;
strcat(outstr, "[");
if (outptr == outstr) {
*outptr++ = '[';
} else {
cumlen += 2;
if (cumlen < sizeof(outstr))
strcat(outstr, ", ");
if (outptr < end_outstr - 3)
outptr = stpcpy(outptr, ", ");
}
if (cur >= abbrev_end) {
cumlen += 3;
if (cumlen < sizeof(outstr))
strcat(outstr, "...");
if (outptr < end_outstr - 4)
outptr = stpcpy(outptr, "...");
break;
}
sprintf(str, "{fd=%d, revents=", fds.fd);
if (outptr < end_outstr - (sizeof("{fd=%d, revents=") + sizeof(int)*3) + 1)
outptr += sprintf(outptr, "{fd=%d, revents=", fds.fd);
flagstr = sprintflags("", pollflags, fds.revents);
cumlen += strlen(str) + strlen(flagstr) + 1;
if (cumlen < sizeof(outstr)) {
strcat(outstr, str);
strcat(outstr, flagstr);
strcat(outstr, "}");
if (outptr < end_outstr - (strlen(flagstr) + 2)) {
outptr = stpcpy(outptr, flagstr);
*outptr++ = '}';
}
}
if (failed)
return 0;

if (cumlen && ++cumlen < sizeof(outstr))
strcat(outstr, "]");
if (outptr != outstr /* && outptr < end_outstr - 1 (always true)*/)
*outptr++ = ']';

*outptr = '\0';
if (pts) {
char str[128];

sprintf(str, "%sleft ", cumlen ? ", " : "");
sprint_timespec(str + strlen(str), tcp, pts);
if ((cumlen += strlen(str)) < sizeof(outstr))
strcat(outstr, str);
if (outptr < end_outstr - 128) {
outptr = stpcpy(outptr, outptr == outstr ? "left " : ", left ");
sprint_timespec(outptr, tcp, pts);
}
}

if (!outstr[0])
if (outptr == outstr)
return 0;

tcp->auxstr = outstr;
return RVAL_STR;
#undef end_outstr
}
}

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56 changes: 30 additions & 26 deletions time.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -112,40 +112,44 @@ printtv_bitness(struct tcb *tcp, long addr, enum bitness_t bitness, int special)
}
}

void
char *
sprinttv(struct tcb *tcp, long addr, enum bitness_t bitness, char *buf)
{
int rc;

if (addr == 0)
strcpy(buf, "NULL");
else if (!verbose(tcp))
sprintf(buf, "%#lx", addr);
else {
int rc;
return stpcpy(buf, "NULL");

if (bitness == BITNESS_32
if (!verbose(tcp)) {
buf += sprintf(buf, "%#lx", addr);
return buf;
}

if (bitness == BITNESS_32
#if defined(LINUX) && SUPPORTED_PERSONALITIES > 1
|| personality_wordsize[current_personality] == 4
|| personality_wordsize[current_personality] == 4
#endif
)
{
struct timeval32 tv;

rc = umove(tcp, addr, &tv);
if (rc >= 0)
sprintf(buf, "{%u, %u}",
tv.tv_sec, tv.tv_usec);
} else {
struct timeval tv;
)
{
struct timeval32 tv;

rc = umove(tcp, addr, &tv);
if (rc >= 0)
buf += sprintf(buf, "{%u, %u}",
tv.tv_sec, tv.tv_usec);
} else {
struct timeval tv;

rc = umove(tcp, addr, &tv);
if (rc >= 0)
sprintf(buf, "{%lu, %lu}",
(unsigned long) tv.tv_sec,
(unsigned long) tv.tv_usec);
}
if (rc < 0)
strcpy(buf, "{...}");
rc = umove(tcp, addr, &tv);
if (rc >= 0)
buf += sprintf(buf, "{%lu, %lu}",
(unsigned long) tv.tv_sec,
(unsigned long) tv.tv_usec);
}
if (rc < 0)
buf = stpcpy(buf, "{...}");

return buf;
}

void print_timespec(struct tcb *tcp, long addr)
Expand Down

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