[Ocfs2-devel] [PATCH 04/30] ocfs2: Handle macro uninitialized_var

[Sunil Mushran]

Commit 9490991482a2091a828d997adbc088e24c310a4d in mainline introduced
macro uninitialized_var(). This patch allows one to build ocfs2 with
kernels having/not having that change.

Signed-off-by: Sunil Mushran <sunil.mushran at oracle.com>
---
 Makefile                       |    3 ++-
 configure.in                   |    5 +++++
 kapi-compat/include/compiler.h |   10 ++++++++++
 3 files changed, 17 insertions(+), 1 deletions(-)
 create mode 100644 kapi-compat/include/compiler.h

diff --git a/Makefile b/Makefile
index 4752593..21ff590 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,8 @@ SUBDIRS = fs vendor
 LINUX_INCLUDE_FILES =
 
 KAPI_COMPAT_FILES = \
-	kapi-compat/include/workqueue.h
+	kapi-compat/include/workqueue.h \
+	kapi-compat/include/compiler.h
 
 PATCH_FILES =
 
diff --git a/configure.in b/configure.in
index 72567b5..7faf363 100644
--- a/configure.in
+++ b/configure.in
@@ -162,6 +162,11 @@ OCFS2_CHECK_KERNEL([struct delayed_work in workqueue.h], workqueue.h,
 AC_SUBST(DELAYED_WORK_DEFINED)
 KAPI_COMPAT_HEADERS="$KAPI_COMPAT_HEADERS workqueue.h"
 
+compiler_compat_header=""
+OCFS2_CHECK_KERNEL([uninitialized_var() in compiler-gcc4.h], compiler-gcc4.h,
+  , compiler_compat_header="compiler.h", [uninitialized_var])
+KAPI_COMPAT_HEADERS="$KAPI_COMPAT_HEADERS $compiler_compat_header"
+
 # using -include has two advantages:
 #  the source doesn't need to know to include compat headers
 #  the compat header file names don't go through the search path
diff --git a/kapi-compat/include/compiler.h b/kapi-compat/include/compiler.h
new file mode 100644
index 0000000..c104ed1
--- /dev/null
+++ b/kapi-compat/include/compiler.h
@@ -0,0 +1,10 @@
+#ifndef KAPI_COMPILER_H
+#define KAPI_COMPILER_H
+
+/*
+ * A trick to suppress uninitialized variable warning without generating any
+ * code
+ */
+#define uninitialized_var(x) x = x
+
+#endif
-- 
1.5.2.5