Implement string formatting into libc :)

Of course, using <luna/Format.h> makes it so simple. No need for duplicate code!

apps/app.c

@@ -10,6 +10,11 @@ int main()
 {
     atexit(bye);
 
+    char buffer[64];
+    snprintf(buffer, sizeof(buffer), "Welcome to %s!\n", "Luna");
+
+    console_print(buffer);
+
     for (int i = 0; i < atoi("8"); i++) { console_print("."); }
 
     console_print("\n");

libc/include/stdio.h

@@ -36,7 +36,18 @@ extern "C"
 
     int fprintf(FILE*, const char*, ...);
     int vfprintf(FILE*, const char*, va_list);
-    int sprintf(char*, const char*, ...);
+
+    /* Write formatted output into a buffer. */
+    int sprintf(char* buf, const char* format, ...);
+
+    /* Write up to max bytes of formatted output into a buffer. */
+    int snprintf(char* buf, size_t max, const char* format, ...);
+
+    /* Write formatted output into a buffer. */
+    int vsprintf(char*, const char*, va_list);
+
+    /* Write up to max bytes of formatted output into a buffer. */
+    int vsnprintf(char*, size_t, const char*, va_list);
 
     /* Output a message to the console. */
     int console_print(const char* msg);

libc/src/stdio.cpp

@@ -1,4 +1,6 @@
+#define _LUNA_SYSTEM_ERROR_EXTENSIONS
 #include <bits/errno-return.h>
+#include <luna/Format.h>
 #include <stdio.h>
 #include <sys/syscall.h>
 #include <unistd.h>
@@ -12,4 +14,38 @@ extern "C"
         long rc = syscall(SYS_console_print, str);
         __errno_return(rc, int);
     }
+
+    int vsnprintf(char* buf, size_t max, const char* format, va_list ap)
+    {
+        return (int)vstring_format(buf, max, format, ap);
+    }
+
+    int snprintf(char* buf, size_t max, const char* format, ...)
+    {
+        va_list ap;
+        va_start(ap, format);
+
+        int rc = vsnprintf(buf, max, format, ap);
+
+        va_end(ap);
+
+        return rc;
+    }
+
+    int vsprintf(char* buf, const char* format, va_list ap)
+    {
+        return vsnprintf(buf, (size_t)-1, format, ap);
+    }
+
+    int sprintf(char* buf, const char* format, ...)
+    {
+        va_list ap;
+        va_start(ap, format);
+
+        int rc = vsnprintf(buf, (size_t)-1, format, ap);
+
+        va_end(ap);
+
+        return rc;
+    }
 }

luna/src/Alloc.cpp

@@ -10,7 +10,9 @@
     char* const rc = new (std::nothrow) char[size];
     return (void*)rc;
 #else
-    return malloc(size);
+    // return malloc(size);
+    (void)size;
+    return NULL;
 #endif
 }
 
@@ -20,11 +22,17 @@ void raw_free(void* ptr)
     char* const arr = (char*)ptr;
     delete[] arr;
 #else
-    return free(ptr);
+    // return free(ptr);
+    (void)ptr;
 #endif
 }
 
 void operator delete(void* ptr, usize size, std::align_val_t) noexcept
 {
+#ifdef USE_FREESTANDING
     operator delete(ptr, size);
+#else
+    (void)ptr;
+    (void)size;
+#endif
 }