Add build system scaffolding and libc headers

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/libc/stdlib/calloc.c b/lib/libc/stdlib/calloc.c
new file mode 100644
index 00000000..408eef5e
--- /dev/null
+++ b/lib/libc/stdlib/calloc.c
@@ -0,0 +1,25 @@
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+void *calloc(size_t nelem, size_t elsize)
+{
+	void *ptr;
+	size_t total;
+
+	if (nelem == 0 || elsize == 0) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	if (__builtin_mul_overflow(nelem, elsize, &total)) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	if ((ptr = malloc(total)) != NULL) {
+		memset(ptr, 0, total);
+	}
+
+	return ptr;
+}