busybox: Avoid race building libbb

When building busybox, an occasional error was observed.
The error is consistently the same:

libbb/appletlib.c:164:13: error: 'NUM_APPLETS' undeclared (first use in this function)
  while (i < NUM_APPLETS) {

The reason is the include file where NUM_APPLETS is defined is not yet generated (or is being modified)
at the time libbb/appletlib.c is compiled.
The attached patchset fixes the problem by assuring libb is compiled as the last directory.

[YOCTO#10116]

(From OE-Core rev: a866a05e2c7d090a77aa6e95339c93e3592703a6)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/meta/recipes-core/busybox/busybox/busybox-kbuild-race-fix-commit-d8e61bb.patch b/meta/recipes-core/busybox/busybox/busybox-kbuild-race-fix-commit-d8e61bb.patch
new file mode 100644
index 0000000000..38302e0b68
--- /dev/null
+++ b/meta/recipes-core/busybox/busybox/busybox-kbuild-race-fix-commit-d8e61bb.patch
@@ -0,0 +1,53 @@
+Upstream-Status: Backport
+
+Patch addressing a parallel make race in Busybox
+
+  http://git.busybox.net/busybox/commit/?id=d8e61bbf13d0cf38d477255cfd5dc71c5d51d575
+
+Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
+
+From d8e61bbf13d0cf38d477255cfd5dc71c5d51d575 Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux@googlemail.com>
+Date: Sun, 21 Aug 2016 22:00:20 +0200
+Subject: build system: different fix for
+ include/applet_tables.h/include/NUM_APPLETS.h
+
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+
+diff --git a/applets/Kbuild.src b/applets/Kbuild.src
+index 5cc1827..3aedbbf 100644
+--- a/applets/Kbuild.src
++++ b/applets/Kbuild.src
+@@ -29,7 +29,7 @@ applets/applets.o: include/usage_compressed.h include/applet_tables.h
+ 
+ applets/applet_tables: .config include/applets.h
+ applets/usage:         .config include/applets.h
+-applets/usage_pod:     .config include/applets.h include/applet_tables.h include/NUM_APPLETS.h
++applets/usage_pod:     .config include/applets.h include/applet_tables.h
+ 
+ quiet_cmd_gen_usage_compressed = GEN     include/usage_compressed.h
+       cmd_gen_usage_compressed = $(srctree_slash)applets/usage_compressed include/usage_compressed.h applets
+@@ -37,8 +37,21 @@ quiet_cmd_gen_usage_compressed = GEN     include/usage_compressed.h
+ include/usage_compressed.h: applets/usage $(srctree_slash)applets/usage_compressed
+        $(call cmd,gen_usage_compressed)
+ 
+-quiet_cmd_gen_applet_tables = GEN     include/applet_tables.h
++quiet_cmd_gen_applet_tables = GEN     include/applet_tables.h include/NUM_APPLETS.h
+       cmd_gen_applet_tables = applets/applet_tables include/applet_tables.h include/NUM_APPLETS.h
+ 
+-include/applet_tables.h include/NUM_APPLETS.h: applets/applet_tables
++include/NUM_APPLETS.h: applets/applet_tables
++       $(call cmd,gen_applet_tables)
++
++# In fact, include/applet_tables.h depends only on applets/applet_tables,
++# and is generated by it. But specifying only it can run
++# applets/applet_tables twice, possibly in parallel.
++# We say that it also needs NUM_APPLETS.h
++#
++# Unfortunately, we need to list the same command,
++# and it can be executed twice (sequentially).
++# The alternative is to not list any command,
++# and then if include/applet_tables.h is deleted, it won't be rebuilt.
++#
++include/applet_tables.h: include/NUM_APPLETS.h applets/applet_tables
+        $(call cmd,gen_applet_tables)