util: add safe_atou64 for 64-bit values

Copy/paste from safe_atou

Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1226>

src/util-strings.h

@@ -33,6 +33,7 @@
 #include <math.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -232,6 +233,39 @@ safe_atou(const char *str, unsigned int *val)
 	return safe_atou_base(str, val, 10);
 }
 
+static inline bool
+safe_atou64_base(const char *str, uint64_t *val, int base)
+{
+	assert(str != NULL);
+
+	char *endptr;
+	unsigned long long v;
+
+	assert(base == 10 || base == 16 || base == 8);
+
+	errno = 0;
+	v = strtoull(str, &endptr, base);
+	if (errno > 0)
+		return false;
+	if (str == endptr)
+		return false;
+	if (*str != '\0' && *endptr != '\0')
+		return false;
+
+	if ((long long)v < 0)
+		return false;
+
+	*val = v;
+	return true;
+}
+
+static inline bool
+safe_atou64(const char *str, uint64_t *val)
+{
+	assert(str != NULL);
+	return safe_atou64_base(str, val, 10);
+}
+
 static inline bool
 safe_atod(const char *str, double *val)
 {

test/test-utils.c

@@ -1209,6 +1209,47 @@ START_TEST(safe_atou_base_8_test)
 }
 END_TEST
 
+struct atou64_test {
+	char *str;
+	bool success;
+	unsigned long val;
+};
+
+START_TEST(safe_atou64_test)
+{
+	struct atou64_test tests[] = {
+		{ "10", true, 10 },
+		{ "20", true, 20 },
+		{ "-1", false, 0 },
+		{ "9999999999", true, 9999999999 },
+		{ "2147483647", true, 2147483647 },
+		{ "-2147483648", false, 0},
+		{ "0x0", false, 0 },
+		{ "-10x10", false, 0 },
+		{ "1x-99", false, 0 },
+		{ "", false, 0 },
+		{ "abd", false, 0 },
+		{ "xabd", false, 0 },
+		{ "0xaf", false, 0 },
+		{ "0x0x", false, 0 },
+		{ "x10", false, 0 },
+		{ NULL, false, 0 }
+	};
+	uint64_t v;
+	bool success;
+
+	for (int i = 0; tests[i].str != NULL; i++) {
+		v = 0xad;
+		success = safe_atou64(tests[i].str, &v);
+		litest_assert(success == tests[i].success);
+		if (success)
+			litest_assert_int_eq(v, tests[i].val);
+		else
+			litest_assert_int_eq(v, 0xadU);
+	}
+}
+END_TEST
+
 START_TEST(safe_atod_test)
 {
 	struct atod_test {
@@ -2697,6 +2738,7 @@ int main(void)
 	ADD_TEST(safe_atou_test);
 	ADD_TEST(safe_atou_base_16_test);
 	ADD_TEST(safe_atou_base_8_test);
+	ADD_TEST(safe_atou64_test);
 	ADD_TEST(safe_atod_test);
 	ADD_TEST(strsplit_test);
 	ADD_TEST(strv_for_each_test);