Commit 12496aad authored by Thomas Weißschuh's avatar Thomas Weißschuh
Browse files

tools/nolibc: add support for asprintf() 



Add support for dynamically allocating formatted strings through
asprintf() and vasprintf().

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Acked-by: default avatarWilly Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260401-nolibc-asprintf-v1-3-46292313439f@weissschuh.net
parent fd2e9f82

tools/include/nolibc/stdio.h

+50 −0
Original line number Diff line number Diff line
@@ -795,6 +795,56 @@ int sprintf(char *buf, const char *fmt, ...) 
	return ret;

}



static __attribute__((unused, format(printf, 2, 0)))

int __nolibc_vasprintf(char **strp, const char *fmt, va_list args1, va_list args2)

{

	int len1, len2;

	char *buf;



	len1 = vsnprintf(NULL, 0, fmt, args1);

	if (len1 < 0)

		return -1;



	buf = malloc(len1 + 1);

	if (!buf)

		return -1;



	len2 = vsnprintf(buf, len1 + 1, fmt, args2);

	if (len2 < 0) {

		free(buf);

		return -1;

	}



	*strp = buf;

	return len1;

}



static __attribute__((unused, format(printf, 2, 0)))

int vasprintf(char **strp, const char *fmt, va_list args)

{

	va_list args2;

	int ret;



	va_copy(args2, args);

	ret = __nolibc_vasprintf(strp, fmt, args, args2);

	va_end(args2);



	return ret;

}



static __attribute__((unused, format(printf, 2, 3)))

int asprintf(char **strp, const char *fmt, ...)

{

	va_list args;

	int ret;



	va_start(args, fmt);

	ret = vasprintf(strp, fmt, args);

	va_end(args);



	return ret;

}



static __attribute__((unused))

int vsscanf(const char *str, const char *format, va_list args)

{

tools/testing/selftests/nolibc/nolibc-test.c

+24 −0
Original line number Diff line number Diff line
@@ -1841,6 +1841,29 @@ static int test_printf_error(void) 
	return 0;

}



int test_asprintf(void)

{

	char *str;

	int ret;



	ret = asprintf(&str, "foo%s", "bar");

	if (ret == -1)

		return 1;



	if (ret != 6) {

		free(str);

		return 2;

	}



	if (memcmp(str, "foobar", 6) != 0) {

		free(str);

		return 3;

	}



	free(str);

	return 0;

}



static int run_printf(int min, int max)

{

	int test;
@@ -1904,6 +1927,7 @@ static int run_printf(int min, int max) 
		CASE_TEST(errno-neg);    errno = -22; EXPECT_VFPRINTF(is_nolibc, "errno=-22   ", "%-12m"); break;

		CASE_TEST(scanf);        EXPECT_ZR(1, test_scanf()); break;

		CASE_TEST(printf_error); EXPECT_ZR(1, test_printf_error()); break;

		CASE_TEST(asprintf);     EXPECT_ZR(1, test_asprintf()); break;

		case __LINE__:

			return ret; /* must be last */

		/* note: do not set any defaults so as to permit holes above */