libc: move the strto* functions to stdlib.h, where they "belong"

1 files changed, 68 insertions, 1 deletions

diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
index 2d1f224..994521f 100644
--- a/src/user/lib/stdlib.c
+++ b/src/user/lib/stdlib.c
@@ -1,9 +1,10 @@
 #include <_proc.h>
+#include <bits/panic.h>
 #include <camellia.h>
 #include <camellia/syscalls.h>
+#include <ctype.h>
 #include <errno.h>
 #include <string.h>
-#include <bits/panic.h>
 
 _Noreturn void abort(void) {
 	_sys_exit(1);
@@ -66,3 +67,69 @@ double atof(const char *s) {
 	(void)s;
 	__libc_panic("unimplemented");
 }
+
+static unsigned long long
+strton(const char *restrict s, char **restrict end, int base, int *sign)
+{
+	long res = 0;
+
+	while (isspace(*s)) s++;
+
+	if (sign) *sign = 1;
+	if (*s == '+') {
+		s++;
+	} else if (*s == '-') {
+		s++;
+		if (sign) *sign = -1;
+	}
+
+	if (base == 0) {
+		if (*s == '0') {
+			s++;
+			if (*s == 'x' || *s == 'X') {
+				s++;
+				base = 16;
+			} else {
+				base = 8;
+			}
+		} else {
+			base = 10;
+		}
+	}
+
+	for (;;) {
+		unsigned char digit = *s;
+		if      ('0' <= digit && digit <= '9') digit -= '0';
+		else if ('a' <= digit && digit <= 'z') digit -= 'a' - 10;
+		else if ('A' <= digit && digit <= 'Z') digit -= 'A' - 10;
+		else break;
+
+		if (digit >= base) break;
+		// TODO overflow check
+		res *= base;
+		res += digit;
+
+		s++;
+	}
+	if (end) *end = (void*)s;
+	return res;
+}
+
+long strtol(const char *restrict s, char **restrict end, int base) {
+	int sign;
+	long n = strton(s, end, base, &sign);
+	return n * sign;
+}
+
+unsigned long strtoul(const char *restrict s, char **restrict end, int base) {
+	return strton(s, end, base, NULL);
+}
+
+unsigned long long strtoull(const char *restrict s, char **restrict end, int base) {
+	return strton(s, end, base, NULL);
+}
+
+double strtod(const char *restrict s, char **restrict end) {
+	(void)s; (void)end;
+	__libc_panic("unimplemented");
+}