Fix header inclusions for standards conformance

musl's sys/errno.h is literally:

/#warning redirecting incorrect #include <sys/errno.h> to <errno.h>
/#include <errno.h>

It does the same for sys/{poll,signal}.h. This is rather noisy when
building ZoL against musl. musl is also correct in pointing out that the
correct headers are outside of sys/ according to the single unix
specification:

http://pubs.opengroup.org/onlinepubs/7908799/xsh/errno.h.html
http://pubs.opengroup.org/onlinepubs/7908799/xsh/poll.h.html
http://pubs.opengroup.org/onlinepubs/7908799/xsh/signal.h.html

Lets implement our own sys/* versions of these headers to redirect to
the proper userland ones when building in userspace. That will silence
the warning.

There are also some instances where we include incorrectly from sys/ or
from outside of sys/ in userspace only code. In these instances, lets
just fix the includes directly.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes #5993

4 files changed, 114 insertions, 0 deletions

diff --git a/lib/libspl/include/sys/Makefile.am b/lib/libspl/include/sys/Makefile.am
index ca2963499c54..a6c274268382 100644
--- a/lib/libspl/include/sys/Makefile.am
+++ b/lib/libspl/include/sys/Makefile.am
@@ -13,6 +13,7 @@ libspl_HEADERS = \
 	$(top_srcdir)/lib/libspl/include/sys/debug.h \
 	$(top_srcdir)/lib/libspl/include/sys/dkio.h \
 	$(top_srcdir)/lib/libspl/include/sys/dklabel.h \
+	$(top_srcdir)/lib/libspl/include/sys/errno.h \
 	$(top_srcdir)/lib/libspl/include/sys/feature_tests.h \
 	$(top_srcdir)/lib/libspl/include/sys/file.h \
 	$(top_srcdir)/lib/libspl/include/sys/frame.h \
@@ -31,8 +32,10 @@ libspl_HEADERS = \
 	$(top_srcdir)/lib/libspl/include/sys/note.h \
 	$(top_srcdir)/lib/libspl/include/sys/param.h \
 	$(top_srcdir)/lib/libspl/include/sys/policy.h \
+	$(top_srcdir)/lib/libspl/include/sys/poll.h \
 	$(top_srcdir)/lib/libspl/include/sys/priv.h \
 	$(top_srcdir)/lib/libspl/include/sys/processor.h \
+	$(top_srcdir)/lib/libspl/include/sys/signal.h \
 	$(top_srcdir)/lib/libspl/include/sys/stack.h \
 	$(top_srcdir)/lib/libspl/include/sys/stat.h \
 	$(top_srcdir)/lib/libspl/include/sys/stropts.h \
diff --git a/lib/libspl/include/sys/errno.h b/lib/libspl/include/sys/errno.h
new file mode 100644
index 000000000000..e8bfbe353842
--- /dev/null
+++ b/lib/libspl/include/sys/errno.h
@@ -0,0 +1,35 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2017 Zettabyte Software, LLC.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * Compiling against musl correctly points out that including sys/errno.h is
+ * disallowed by the Single UNIX Specification when building in userspace, so
+ * we implement a dummy header to redirect the include to the proper header.
+ */
+#ifndef _LIBSPL_SYS_ERRNO_H
+#define	_LIBSPL_SYS_ERRNO_H
+#include <errno.h>
+#endif /* _LIBSPL_SYS_ERRNO_H */
diff --git a/lib/libspl/include/sys/poll.h b/lib/libspl/include/sys/poll.h
new file mode 100644
index 000000000000..6ab0bddc0be5
--- /dev/null
+++ b/lib/libspl/include/sys/poll.h
@@ -0,0 +1,41 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2017 Zettabyte Software, LLC.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * Compiling against musl correctly points out that including sys/poll.h is
+ * disallowed by the Single UNIX Specification when building in userspace. We
+ * implement a dummy header to redirect the include to the proper header.
+ * However, glibc, klibc and uclibc break this shim by including sys/poll.h
+ * from poll.h, so we add explicit exceptions for them.
+ */
+#ifndef _LIBSPL_SYS_POLL_H
+#define	_LIBSPL_SYS_POLL_H
+#if defined(__GLIBC__) || defined(__KLIBC__) || defined(__UCLIBC__)
+#include_next <sys/poll.h>
+#else
+#include <poll.h>
+#endif
+#endif /* _LIBSPL_SYS_POLL_H */
diff --git a/lib/libspl/include/sys/signal.h b/lib/libspl/include/sys/signal.h
new file mode 100644
index 000000000000..df9221a694d0
--- /dev/null
+++ b/lib/libspl/include/sys/signal.h
@@ -0,0 +1,35 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2017 Zettabyte Software, LLC.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*
+ * Compiling against musl correctly points out that including sys/signal.h is
+ * disallowed by the Single UNIX Specification when building in userspace, so
+ * we implement a dummy header to redirect the include to the proper header.
+ */
+#ifndef _LIBSPL_SYS_SIGNAL_H
+#define	_LIBSPL_SYS_SIGNAL_H
+#include <signal.h>
+#endif /* _LIBSPL_SYS_SIGNAL_H */