libc: Add assert()

libs/libc/include/assert.h

@@ -0,0 +1,24 @@
+#ifndef _ASSERT_H
+#define _ASSERT_H
+
+#include <bits/macros.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    __lc_noreturn bool __assertion_failed(const char* file, int line, const char* function, const char* expr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef NDEBUG
+#define assert(expr) (void)0
+#else
+#define assert(expr) (bool)(expr) || __assertion_failed(__FILE__, __LINE__, __FUNCTION__, #expr)
+#endif
+
+#endif

libs/libc/src/assert.cpp

@@ -0,0 +1,12 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+extern "C"
+{
+    __lc_noreturn bool __assertion_failed(const char* file, int line, const char* function, const char* expr)
+    {
+        fprintf(stderr, "%s:%d: %s: Assertion '%s' failed.", file, line, function, expr);
+        abort();
+    }
+}