util: Add xa{v}sprintf_append functions

Add variadic and va_list functions, xa{v}sprintf, which appends a
formatted string to an existing string and re-allocate the string buffer
if necessary. xasprintf becomes just a special case of xasprintf_append
with a NULL starting string.

Rather than looping to get a big enough buffer, simply the implementation
by assuming we have a C99 compliant vsnprintf implementation to return the
necessary size. A side effect is glibc 2.0 support is dropped which seems
unnecessary.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Rob Herring 2018-11-24 14:47:54 -06:00 committed by David Gibson
parent 82a52ce457
commit a1eff70c02
2 changed files with 41 additions and 21 deletions

2
util.h
View file

@ -72,6 +72,8 @@ static inline void *xrealloc(void *p, size_t len)
extern char *xstrdup(const char *s);
extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
extern int PRINTF(2, 3) xasprintf_append(char **strp, const char *fmt, ...);
extern int xavsprintf_append(char **strp, const char *fmt, va_list ap);
extern char *join_path(const char *path, const char *name);
/**