Set -Wno-unused-but-set-variable globally

As of gcc-4.6 the option -Wunused-but-set-variable is enabled by
default.  While this is a useful warning there are numerous places
in the ZFS code when a variable is set and then only checked in an
ASSERT().  To avoid having to update every instance of this in the
code we now set -Wno-unused-but-set-variable to suppress the warning.

Additionally, when building with --enable-debug and -Werror set these
warning also become fatal.  We can reevaluate the suppression of these
error at a later time if it becomes an issue.  For now we are basically
just reverting to the previous gcc behavior.

8 files changed, 33 insertions, 25 deletions

diff --git a/cmd/mount_zfs/Makefile.in b/cmd/mount_zfs/Makefile.in
index eb30f84aa..27afbebdd 100644
--- a/cmd/mount_zfs/Makefile.in
+++ b/cmd/mount_zfs/Makefile.in
@@ -304,9 +304,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 mount_zfs_SOURCES = \
 	$(top_srcdir)/cmd/mount_zfs/mount_zfs.c
 
diff --git a/cmd/zdb/Makefile.in b/cmd/zdb/Makefile.in
index 092b6b08f..bce8a786e 100644
--- a/cmd/zdb/Makefile.in
+++ b/cmd/zdb/Makefile.in
@@ -300,9 +300,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zdb_SOURCES = \
 	$(top_srcdir)/cmd/zdb/zdb.c \
 	$(top_srcdir)/cmd/zdb/zdb_il.c
diff --git a/cmd/zfs/Makefile.in b/cmd/zfs/Makefile.in
index f9e3c84b6..8df35a2c9 100644
--- a/cmd/zfs/Makefile.in
+++ b/cmd/zfs/Makefile.in
@@ -300,9 +300,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zfs_SOURCES = \
 	$(top_srcdir)/cmd/zfs/zfs_iter.c \
 	$(top_srcdir)/cmd/zfs/zfs_iter.h \
diff --git a/cmd/zinject/Makefile.in b/cmd/zinject/Makefile.in
index 7f3c041da..47ee6d74a 100644
--- a/cmd/zinject/Makefile.in
+++ b/cmd/zinject/Makefile.in
@@ -300,9 +300,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zinject_SOURCES = \
 	$(top_srcdir)/cmd/zinject/translate.c \
 	$(top_srcdir)/cmd/zinject/zinject.c \
diff --git a/cmd/zpios/Makefile.in b/cmd/zpios/Makefile.in
index 70b84e238..9f42e2d6f 100644
--- a/cmd/zpios/Makefile.in
+++ b/cmd/zpios/Makefile.in
@@ -290,9 +290,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zpios_SOURCES = \
 	$(top_srcdir)/cmd/zpios/zpios_main.c \
 	$(top_srcdir)/cmd/zpios/zpios_util.c \
diff --git a/cmd/zpool/Makefile.in b/cmd/zpool/Makefile.in
index 39b1d3bb4..f3e4bc73e 100644
--- a/cmd/zpool/Makefile.in
+++ b/cmd/zpool/Makefile.in
@@ -301,9 +301,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zpool_SOURCES = \
 	$(top_srcdir)/cmd/zpool/zpool_iter.c \
 	$(top_srcdir)/cmd/zpool/zpool_main.c \
diff --git a/cmd/ztest/Makefile.in b/cmd/ztest/Makefile.in
index c929bf0cc..65e36a0c9 100644
--- a/cmd/ztest/Makefile.in
+++ b/cmd/ztest/Makefile.in
@@ -300,10 +300,11 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\" \
-	$(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\" $(DEBUG_STACKFLAGS) \
+	$(FRAME_LARGER_THAN)
 ztest_SOURCES = \
 	$(top_srcdir)/cmd/ztest/ztest.c
 
diff --git a/cmd/zvol_id/Makefile.in b/cmd/zvol_id/Makefile.in
index 7698158b0..3e8a34be0 100644
--- a/cmd/zvol_id/Makefile.in
+++ b/cmd/zvol_id/Makefile.in
@@ -290,9 +290,10 @@ DEFAULT_INCLUDES = -include ${top_builddir}/zfs_config.h \
 	-I$(top_srcdir)/include -I$(top_srcdir)/lib/libspl/include
 AM_LIBTOOLFLAGS = --silent
 AM_CFLAGS = -Wall -Wstrict-prototypes -fno-strict-aliasing \
-	${DEBUG_CFLAGS} -D_GNU_SOURCE -D__EXTENSIONS__ -D_REENTRANT \
-	-D_POSIX_PTHREAD_SEMANTICS -D_FILE_OFFSET_BITS=64 \
-	-D_LARGEFILE64_SOURCE -DTEXT_DOMAIN=\"zfs-linux-user\"
+	-Wno-unused-but-set-variable ${DEBUG_CFLAGS} -D_GNU_SOURCE \
+	-D__EXTENSIONS__ -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS \
+	-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE \
+	-DTEXT_DOMAIN=\"zfs-linux-user\"
 zvol_id_SOURCES = \
 	$(top_srcdir)/cmd/zvol_id/zvol_id_main.c