initial check-in, taken from old libc svn repo with significant additions

1 files changed, 120 insertions, 0 deletions

diff --git a/snprintf.c b/snprintf.c
new file mode 100644
index 0000000..1e563e5
--- /dev/null
+++ b/snprintf.c
@@ -0,0 +1,120 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include <math.h>
+
+#define TEST(r, f, x, m) ( \
+((r) = (f)) == (x) || \
+(printf(__FILE__ ":%d: %s failed (" m ")\n", __LINE__, #f, r, x), err++, 0) )
+
+#define TEST_S(s, x, m) ( \
+!strcmp((s),(x)) || \
+(printf(__FILE__ ":%d: [%s] != [%s] (%s)\n", __LINE__, s, x, m), err++, 0) )
+
+static const struct {
+	const char *fmt;
+	int i;
+	const char *expect;
+} int_tests[] = {
+	/* width, precision, alignment */
+	{ "%04d", 12, "0012" },
+	{ "%.3d", 12, "012" },
+	{ "%3d", 12, " 12" },
+	{ "%-3d", 12, "12 " },
+	{ "%+3d", 12, "+12" },
+	{ "%+-5d", 12, "+12  " },
+	{ "%+- 5d", 12, "+12  " },
+	{ "%- 5d", 12, " 12  " },
+	{ "% d", 12, " 12" },
+	{ "%0-5d", 12, "12   " },
+	{ "%-05d", 12, "12   " },
+
+	/* ...explicit precision of 0 shall be no characters. */
+	{ "%.0d", 0, "" },
+	{ "%.0o", 0, "" },
+	{ "%#.0d", 0, "" },
+	{ "%#.0o", 0, "" },
+	{ "%#.0x", 0, "" },
+
+	/* hex: test alt form and case */
+	{ "%x", 63, "3f" },
+	{ "%#x", 63, "0x3f" },
+	{ "%X", 63, "3F" },
+
+	/* octal: test alt form */
+	{ "%o", 15, "17" },
+	{ "%#o", 15, "017" },
+
+	{ NULL, 0.0, NULL }
+};
+
+static const struct {
+	const char *fmt;
+	double f;
+	const char *expect;
+} fp_tests[] = {
+	/* basic form, handling of exponent/precision for 0 */
+	{ "%e", 0.0, "0.000000e+00" },
+	{ "%f", 0.0, "0.000000" },
+	{ "%g", 0.0, "0" },
+	{ "%#g", 0.0, "0.00000" },
+
+	/* rounding */
+	{ "%f", 1.1, "1.100000" },
+	{ "%f", 1.2, "1.200000" },
+	{ "%f", 1.3, "1.300000" },
+	{ "%f", 1.4, "1.400000" },
+	{ "%f", 1.5, "1.500000" },
+	
+	/* correctness in DBL_DIG places */
+	{ "%.15g", 1.23456789012345, "1.23456789012345" },
+
+	/* correct choice of notation for %g */
+	{ "%g", 0.0001, "0.0001" },
+	{ "%g", 0.00001, "1e-05" },
+	{ "%g", 123456, "123456" },
+	{ "%g", 1234567, "1.23457e+06" },
+	{ "%.7g", 1234567, "1234567" },
+	{ "%.7g", 12345678, "1.234568e+07" },
+
+	/* pi in double precision, printed to a few extra places */
+	{ "%.15f", M_PI, "3.141592653589793" },
+	{ "%.18f", M_PI, "3.141592653589793116" },
+
+	/* exact conversion of large integers */
+	{ "%.0f", 340282366920938463463374607431768211456.0,
+	         "340282366920938463463374607431768211456" },
+
+	{ NULL, 0.0, NULL }
+};
+
+int test_snprintf(void)
+{
+	int i, j;
+	int err=0;
+	char b[500], *s;
+
+	strcpy(b, "xxxxxxxx");
+	TEST(i, snprintf(b, 4, "%d", 123456), 6, "length returned %d != %d");
+	TEST_S(b, "123", "incorrect output");
+	TEST(i, b[5], 'x', "buffer overrun");
+
+#ifndef DISABLE_SLOW_TESTS
+	errno = 0;
+	TEST(i, snprintf(NULL, 0, "%.*u", 2147483647, 0), 2147483647, "cannot print max length %d");
+	TEST(i, snprintf(NULL, 0, "%.*u ", 2147483647, 0), -1, "integer overflow %d");
+	TEST(i, errno, EOVERFLOW, "after overflow: %d != %d");
+#endif
+	for (j=0; int_tests[j].fmt; j++) {
+		TEST(i, snprintf(b, sizeof b, int_tests[j].fmt, int_tests[j].i), strlen(b), "%d != %d");
+		TEST_S(b, int_tests[j].expect, "bad integer conversion");
+	}
+
+	for (j=0; fp_tests[j].fmt; j++) {
+		TEST(i, snprintf(b, sizeof b, fp_tests[j].fmt, fp_tests[j].f), strlen(b), "%d != %d");
+		TEST_S(b, fp_tests[j].expect, "bad floating point conversion");
+	}
+
+	return err;
+}