[mirror_ubuntu-zesty-kernel.git] / tools / lib / str_error_r.c

#undef _GNU_SOURCE
#include <string.h>
#include <stdio.h>
#include <linux/string.h>

/*
 * The tools so far have been using the strerror_r() GNU variant, that returns
 * a string, be it the buffer passed or something else.
 *
 * But that, besides being tricky in cases where we expect that the function
 * using strerror_r() returns the error formatted in a provided buffer (we have
 * to check if it returned something else and copy that instead), breaks the
 * build on systems not using glibc, like Alpine Linux, where musl libc is
 * used.
 *
 * So, introduce yet another wrapper, str_error_r(), that has the GNU
 * interface, but uses the portable XSI variant of strerror_r(), so that users
 * rest asured that the provided buffer is used and it is what is returned.
 */
char *str_error_r(int errnum, char *buf, size_t buflen)
{
	int err = strerror_r(errnum, buf, buflen);
	if (err)
		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
	return buf;
}
Commit	Line	Data
c8b5f2c9 ACM	1	#undef _GNU_SOURCE
	2	#include <string.h>
	3	#include <stdio.h>
	4	#include <linux/string.h>
	5
	6	/*
	7	* The tools so far have been using the strerror_r() GNU variant, that returns
	8	* a string, be it the buffer passed or something else.
	9	*
	10	* But that, besides being tricky in cases where we expect that the function
	11	* using strerror_r() returns the error formatted in a provided buffer (we have
	12	* to check if it returned something else and copy that instead), breaks the
	13	* build on systems not using glibc, like Alpine Linux, where musl libc is
	14	* used.
	15	*
	16	* So, introduce yet another wrapper, str_error_r(), that has the GNU
	17	* interface, but uses the portable XSI variant of strerror_r(), so that users
	18	* rest asured that the provided buffer is used and it is what is returned.
	19	*/
	20	char str_error_r(int errnum, char buf, size_t buflen)
	21	{
	22	int err = strerror_r(errnum, buf, buflen);
	23	if (err)
	24	snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
	25	return buf;
	26	}