libluna+libc: Add strtok_r()

libc/include/string.h

@@ -71,6 +71,9 @@ extern "C"
     /* Separate a string into several tokens. */
     char* strtok(char* str, const char* delim);
 
+    /* Separate a string into several tokens. */
+    char* strtok_r(char* str, const char* delim, char** savep);
+
     /* Return a heap-allocated copy of a fixed-size string. */
     char* strndup(const char* str, size_t max);
 

libluna/include/luna/CString.h

@@ -18,6 +18,7 @@ extern "C"
     usize strcspn(const char* str, const char* reject);
 
     char* strtok(char* str, const char* delim);
+    char* strtok_r(char* str, const char* delim, char** savep);
 
     usize wcslen(const wchar_t* str);
     int wcscmp(const wchar_t* a, const wchar_t* b);

libluna/src/CString.cpp

@@ -219,9 +219,9 @@ extern "C"
         return (usize)(s - str);
     }
 
-    char* strtok(char* str, const char* delim)
+    char* strtok_r(char* str, const char* delim, char** savep)
     {
-        static char* s = nullptr;
+        auto& s = *savep;
         if (str) s = str;
         if (!s) return nullptr;
 
@@ -248,6 +248,12 @@ extern "C"
         return nullptr;
     }
 
+    char* strtok(char* str, const char* delim)
+    {
+        static char* s;
+        return strtok_r(str, delim, &s);
+    }
+
     char* strpbrk(const char* s, const char* accept)
     {
         usize index = strcspn(s, accept);