Reimplement xAsnprintf and xSnprintf as type-safe functions

XAlloc.c

@@ -5,6 +5,8 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -39,6 +41,32 @@ void* xRealloc(void* ptr, size_t size) {
    return data;
 }
 
+int xAsprintf(char** strp, const char* fmt, ...) {
+   va_list vl;
+   va_start(vl, fmt);
+   int _r = vasprintf(strp, fmt, vl);
+   va_end(vl);
+
+   if (_r < 0) {
+      fail();
+   }
+
+   return _r;
+}
+
+int xSnprintf(char* buf, int len, const char* fmt, ...) {
+   va_list vl;
+   va_start(vl, fmt);
+   int _n=vsnprintf(buf, len, fmt, vl);
+   va_end(vl);
+
+   if (!(_n > -1 && _n < len)) {
+      fail();
+   }
+
+   return _n;
+}
+
 char* xStrdup_(const char* str) {
    char* data = strdup(str);
    if (!data) {