[PATCH] _scanf.c: Implement 'm' modifier for 'c' and '[' conversions.
Will Newton
will.newton at gmail.com
Tue Oct 16 11:00:00 UTC 2012
The current code implements the 'm' modifier only for 's'
conversions and would cause a segfault if it was used for 'c'
or '[' conversions. This patch extends the code to cover these
cases too.
Signed-off-by: Will Newton <will.newton at imgtec.com>
---
libc/stdio/_scanf.c | 51 ++++++++++++++++++++++++++++++++-------------------
1 files changed, 32 insertions(+), 19 deletions(-)
diff --git a/libc/stdio/_scanf.c b/libc/stdio/_scanf.c
index 952853c..c862afb 100644
--- a/libc/stdio/_scanf.c
+++ b/libc/stdio/_scanf.c
@@ -1355,7 +1355,21 @@ int VFSCANF (FILE *__restrict fp, const Wchar
*__restrict format, va_list arg)
(psfs.conv_num >= CONV_c)
#endif /* __UCLIBC_HAS_WCHAR__ */
{
+ /* We might have to handle the allocation ourselves */
+ int len;
+ unsigned char **ptr;
+
b = (psfs.store ? ((unsigned char *) psfs.cur_ptr) : buf);
+ /* With 'm', we actually got a pointer to a pointer */
+ ptr = (void *)b;
+
+ i = 0;
+ if (psfs.flags & FLAG_MALLOC) {
+ len = 0;
+ b = NULL;
+ } else
+ len = -1;
+
fail = 1;
if (psfs.conv_num == CONV_c) {
@@ -1363,31 +1377,25 @@ int VFSCANF (FILE *__restrict fp, const Wchar
*__restrict format, va_list arg)
sc.width = 1;
}
+ if (psfs.flags & FLAG_MALLOC)
+ b = malloc(sc.width);
+
while (__scan_getc(&sc) >= 0) {
zero_conversions = 0;
- *b = sc.cc;
- b += psfs.store;
+ b[i] = sc.cc;
+ i += psfs.store;
}
__scan_ungetc(&sc);
if (sc.width > 0) { /* Failed to read all required. */
goto DONE;
}
+ if (psfs.flags & FLAG_MALLOC)
+ *ptr = b;
psfs.cnt += psfs.store;
goto NEXT_FMT;
}
if (psfs.conv_num == CONV_s) {
- /* We might have to handle the allocation ourselves */
- int len;
- /* With 'm', we actually got a pointer to a pointer */
- unsigned char **ptr = (void *)b;
-
- i = 0;
- if (psfs.flags & FLAG_MALLOC) {
- len = 0;
- b = NULL;
- } else
- len = -1;
/* Yes, believe it or not, a %s conversion can store nuls. */
while ((__scan_getc(&sc) >= 0) && !isspace(sc.cc)) {
@@ -1403,10 +1411,6 @@ int VFSCANF (FILE *__restrict fp, const Wchar
*__restrict format, va_list arg)
fail = 0;
}
- if (psfs.flags & FLAG_MALLOC)
- *ptr = b;
- /* The code below takes care of terminating NUL */
- b += i;
} else {
#ifdef __UCLIBC_HAS_WCHAR__
assert((psfs.conv_num == CONV_LEFTBRACKET) || \
@@ -1462,8 +1466,14 @@ int VFSCANF (FILE *__restrict fp, const Wchar
*__restrict format, va_list arg)
if (!scanset[sc.cc]) {
break;
}
- *b = sc.cc;
- b += psfs.store;
+ if (i == len) {
+ /* Pick a size that won't trigger a lot of
+ * mallocs early on ... */
+ len += 256;
+ b = realloc(b, len + 1);
+ }
+ b[i] = sc.cc;
+ i += psfs.store;
fail = 0;
}
}
@@ -1473,6 +1483,9 @@ int VFSCANF (FILE *__restrict fp, const Wchar
*__restrict format, va_list arg)
if (fail) { /* nothing stored! */
goto DONE;
}
+ if (psfs.flags & FLAG_MALLOC)
+ *ptr = b;
+ b += i;
*b = 0; /* Nul-terminate string. */
psfs.cnt += psfs.store;
goto NEXT_FMT;
--
1.7.1
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