Add vprintf, (v)sprintf and (v)snprintf to libc + move the non v-printfs to stdio.cpp, since they can now call their v-variants and thus don't depend on internal_printf

libs/libc/include/stdio.h

@@ -29,6 +29,11 @@ extern "C"
     void setbuf(FILE*, char*);
     int vfprintf(FILE*, const char*, va_list);
     int printf(const char*, ...);
+    int vprintf(const char*, va_list);
+    int sprintf(char*, const char*, ...);
+    int snprintf(char*, size_t, const char*, ...);
+    int vsprintf(char*, const char*, va_list);
+    int vsnprintf(char*, size_t, const char*, va_list);
     int puts(const char*);
 
 #ifdef __cplusplus

libs/libc/src/printf.cpp

@@ -247,13 +247,29 @@ static int internal_printf(const char* format, PutString put_string_callback, ss
 
 extern "C"
 {
-    int printf(const char* format, ...)
+    int vprintf(const char* format, va_list ap)
     {
-        va_list ap;
+        return internal_printf(
-        va_start(ap, format);
-        int written = internal_printf(
             format, [](const char* s) { syscall(SYS_write, s, strlen(s)); }, -1, ap);
-        va_end(ap);
+    }
-        return written;
+
+    int vsprintf(char* str, const char* format, va_list ap)
+    {
+        return internal_printf(
+            format,
+            [&](const char* s) {
+                if (str) strcat(str, s);
+            },
+            -1, ap);
+    }
+
+    int vsnprintf(char* str, size_t max, const char* format, va_list ap)
+    {
+        return internal_printf(
+            format,
+            [&](const char* s) {
+                if (str) strcat(str, s);
+            },
+            max == 0 ? 0 : max - 1, ap);
     }
 }

libs/libc/src/stdio.cpp

@@ -53,4 +53,28 @@ extern "C"
         nwritten += syscall(SYS_write, "\n", 1);
         return nwritten;
     }
+    int snprintf(char* str, size_t max, const char* format, ...)
+    {
+        va_list ap;
+        va_start(ap, format);
+        int written = vsnprintf(str, max, format, ap);
+        va_end(ap);
+        return written;
+    }
+    int sprintf(char* str, const char* format, ...)
+    {
+        va_list ap;
+        va_start(ap, format);
+        int written = vsprintf(str, format, ap);
+        va_end(ap);
+        return written;
+    }
+    int printf(const char* format, ...)
+    {
+        va_list ap;
+        va_start(ap, format);
+        int written = vprintf(format, ap);
+        va_end(ap);
+        return written;
+    }
 }