added efmt to write out error messages + ERROR_ON macro

2 files changed, 17 insertions, 0 deletions

diff --git a/lib/include/common.h b/lib/include/common.h
new file mode 100644
index 0000000..5ea6050
--- /dev/null
+++ b/lib/include/common.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2020 Johannes Stoelp
+
+#pragma once
+
+#include "io.h"
+#include "syscall.h"
+
+#include <asm/unistd.h>
+
+#define ERROR_ON(cond, ...)         \
+    do {                            \
+        if ((cond)) {               \
+            efmt(__VA_ARGS__);      \
+            syscall1(__NR_exit, 1); \
+        }                           \
+    } while (0)
diff --git a/lib/include/io.h b/lib/include/io.h
index 5ca78a3..0f8b900 100644
--- a/lib/include/io.h
+++ b/lib/include/io.h
@@ -3,3 +3,4 @@
 #pragma once
 
 int pfmt(const char* fmt, ...);
+int efmt(const char* fmt, ...);