Add build system scaffolding and libc headers

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/libc/stdlib/btowc.c b/lib/libc/stdlib/btowc.c
new file mode 100644
index 00000000..f16865b7
--- /dev/null
+++ b/lib/libc/stdlib/btowc.c
@@ -0,0 +1,18 @@
+#include <wchar.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define CODEUNIT(c) (0xdfff & (signed char)(c))
+
+wint_t btowc(int c)
+{
+	if ((unsigned char)c < 128U) {
+		return c;
+	}
+
+	if (MB_CUR_MAX == 1 && c != EOF) {
+		return CODEUNIT(c);
+	}
+
+	return WEOF;
+}