[tip:x86/build] kbuild, x86: Track generated headers with generated-y

[tip-bot for James Hogan <tipbot@zytor.com>]

Commit-ID:  54b880caf15034644b564e378abf67b7f9eaf4dc
Gitweb:     http://git.kernel.org/tip/54b880caf15034644b564e378abf67b7f9eaf4dc
Author:     James Hogan <james.hogan@imgtec.com>
AuthorDate: Fri, 24 Jun 2016 23:42:23 +0100
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 7 Jul 2016 15:58:44 +0200

kbuild, x86: Track generated headers with generated-y

Track generated header files which aren't already in genhdr-y, alongside
generic-y wrappers in the */include/generated/[uapi/]asm/ directories.
Currently only x86 generates extra headers in these directories, for the
purposes of enumerating system calls for different ABIs, and xen
hypercalls.

This will allow the asm-generic wrapper handling code to remove stale
wrappers when files are removed from generic-y, without also removing
these headers which are generated separately.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Link: http://lkml.kernel.org/r/1466808144-23209-2-git-send-email-james.hogan@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 Documentation/kbuild/makefiles.txt | 14 ++++++++++++++
 arch/x86/include/asm/Kbuild        |  6 ++++++
 2 files changed, 20 insertions(+)

diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 13f888a..385a5ef 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -47,6 +47,7 @@ This document describes the Linux kernel Makefiles.
 		--- 7.2 genhdr-y
 		--- 7.3 destination-y
 		--- 7.4 generic-y
+		--- 7.5 generated-y
 
 	=== 8 Kbuild Variables
 	=== 9 Makefile language
@@ -1319,6 +1320,19 @@ See subsequent chapter for the syntax of the Kbuild file.
 		Example: termios.h
 			#include <asm-generic/termios.h>
 
+	--- 7.5 generated-y
+
+	If an architecture generates other header files alongside generic-y
+	wrappers, and not included in genhdr-y, then generated-y specifies
+	them.
+
+	This prevents them being treated as stale asm-generic wrappers and
+	removed.
+
+		Example:
+			#arch/x86/include/asm/Kbuild
+			generated-y += syscalls_32.h
+
 === 8 Kbuild Variables
 
 The top Makefile exports the following variables:
diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild
index aeac434..2cfed17 100644
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -1,5 +1,11 @@
 
 
+generated-y += syscalls_32.h
+generated-y += syscalls_64.h
+generated-y += unistd_32_ia32.h
+generated-y += unistd_64_x32.h
+generated-y += xen-hypercalls.h
+
 genhdr-y += unistd_32.h
 genhdr-y += unistd_64.h
 genhdr-y += unistd_x32.h