4 files changed, 38 insertions, 0 deletions
diff --git a/include/bits/errno.h b/include/bits/errno.h
new file mode 100644
index 00000000..4789fef8
--- /dev/null
+++ b/include/bits/errno.h
@@ -0,0 +1,12 @@
+#ifndef __BITS_ERRNO_H
+#define __BITS_ERRNO_H
+
+#ifndef __BITS_ERRNO_H_
+#error "Internal header — include the public API header instead."
+#else
+#undef __BITS_ERRNO_H_
+#endif
+
+typedef int errno_t;
+
+#endif
diff --git a/include/bits/sigevent.h b/include/bits/sigevent.h
index b36e676c..ddf4c4d7 100644
--- a/include/bits/sigevent.h
+++ b/include/bits/sigevent.h
@@ -3,6 +3,8 @@
 
 #ifndef __BITS_SIGEVENT_H_
 #error "Internal header — include the public API header instead."
+#else
+#undef __BITS_SIGEVENT_H_
 #endif
 
 union sigval {
diff --git a/include/bits/timespec.h b/include/bits/timespec.h
index ebcacf76..646c76f7 100644
--- a/include/bits/timespec.h
+++ b/include/bits/timespec.h
@@ -3,6 +3,8 @@
 
 #ifndef __BITS_TIMESPEC_H_
 #error "Never include <bits/timespec.h> directly; use <time.h> instead."
+#else
+#undef __BITS_TIMESPEC_H_
 #endif
 
 typedef __INT64_TYPE__ time_t;
diff --git a/include/bits/wait.h b/include/bits/wait.h
new file mode 100644
index 00000000..5e346276
--- /dev/null
+++ b/include/bits/wait.h
@@ -0,0 +1,22 @@
+#ifndef __BITS_WAIT_H
+#define __BITS_WAIT_H
+
+#ifndef __BITS_WAIT_H_
+#error "Internal header — include the public API header instead."
+#else
+#undef __BITS_WAIT_H_
+#endif
+
+#define WNOHANG	  0x00000001
+#define WUNTRACED 0x00000002
+
+#define WEXITSTATUS(__status) (((__status) & 0xff00) >> 8)
+#define WCOREDUMP(__status)   ((__status) & 0x80)
+#define WTERMSIG(__status)    ((__status) & 0x7f)
+#define WSTOPSIG(__status)    WEXITSTATUS(__status)
+#define WIFEXITED(__status)   (WTERMSIG(__status) == 0)
+#define WIFSTOPPED(__status)  (((__status) & 0xff) == 0x7f)
+#define WIFSIGNALED(__status) (((__status) & 0xffff) - 1U < 0xffu)
+#define WSTOPSIG(__status)    WEXITSTATUS(__status)
+
+#endif