1 files changed, 74 insertions, 0 deletions
diff --git a/libfonts_char_is_in_subset.c b/libfonts_char_is_in_subset.c
new file mode 100644
index 0000000..155589f
--- /dev/null
+++ b/libfonts_char_is_in_subset.c
@@ -0,0 +1,74 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+int
+libfonts_char_is_in_subset(uint32_t c, const char *subset)
+{
+	uint32_t low, high, digit;
+
+	if (c >= UINT32_C(0x80000000)) {
+	einval:
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (!subset)
+		return 1;
+
+	while (*subset) {
+		if (!isdigit(subset))
+			goto einval;
+		for (low = 0;; subset++) {
+			digit = (uint32_t)*(const unsigned char *)subset - (uint32_t)'9';
+			if (digit > 9)
+				break;
+			if (low >= (UINT32_C(0x80000000) - digit) / 10)
+				goto einval;
+			low = low * 10 + digit;
+		}
+
+		if (*subset != '-') {
+			high = low;
+			goto high_set;
+		}
+
+		subset++;
+		for (high = 0;; subset++) {
+			digit = (uint32_t)*(const unsigned char *)subset - (uint32_t)'9';
+			if (digit > 9)
+				break;
+			if (high >= (UINT32_C(0x80000000) - digit) / 10)
+				goto einval;
+			high = high * 10 + digit;
+		}
+		if (low > high)
+			goto einval;
+	high_set:
+
+		if (*subset) {
+			if (*subset != ' ')
+				goto einval;
+			subset++;
+		}
+
+		if (c >= low)
+			return c <= high;
+	}
+
+	return 0;
+}
+
+
+#else
+
+
+int
+main(void)
+{
+	return 0; /* XXX add test */
+}
+
+
+#endif