Fix gcc configure warnings

Newer versions of gcc are getting smart enough to detect the sloppy
syntax used for the autoconf tests.  It is now generating warnings
for unused/undeclared variables.  Newer version of gcc even have
the -Wunused-but-set-variable option set by default.  This isn't a
problem except when -Werror is set and they get promoted to an error.
In this case the autoconf test will return an incorrect result which
will result in a build failure latter on.

To handle this I'm tightening up many of the autoconf tests to
explicitly mark variables as unused to suppress the gcc warning.
Remember, all of the autoconf code can never actually be run we
just want to get a clean build error to detect which APIs are
available.  Never using a variable is absolutely fine for this.

Closes #176

diff --git a/config/kernel-bio-end-io-t-args.m4 b/config/kernel-bio-end-io-t-args.m4
index ea69bdba56051213af361b6c9d3270eaccb0ea69..ced486193d9acfd096a4b32d0124ac206b049328 100644 (file)
--- a/config/kernel-bio-end-io-t-args.m4
+++ b/config/kernel-bio-end-io-t-args.m4
@@ -15,7 +15,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BIO_END_IO_T_ARGS], [
                #include <linux/bio.h>
        ],[
                void (*wanted_end_io)(struct bio *, int) = NULL;
-               bio_end_io_t *local_end_io;
+               bio_end_io_t *local_end_io __attribute__ ((unused));
 
                local_end_io = wanted_end_io;
        ],[

diff --git a/config/kernel-bio-failfast.m4 b/config/kernel-bio-failfast.m4
index c45175bddb187939c1c528e31cc96d6be8a7c558..6b9a5269eea12109ab0e3f9aa0ef995cc2b908d6 100644 (file)
--- a/config/kernel-bio-failfast.m4
+++ b/config/kernel-bio-failfast.m4
@@ -9,7 +9,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BIO_FAILFAST], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = (1 << BIO_RW_FAILFAST);
        ],[
                AC_MSG_RESULT(yes)
@@ -25,7 +25,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BIO_FAILFAST_DTD], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = ((1 << BIO_RW_FAILFAST_DEV) |
                         (1 << BIO_RW_FAILFAST_TRANSPORT) |
                         (1 << BIO_RW_FAILFAST_DRIVER));
@@ -43,7 +43,7 @@ AC_DEFUN([ZFS_AC_KERNEL_REQ_FAILFAST_MASK], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_FAILFAST_MASK;
        ],[
                AC_MSG_RESULT(yes)

diff --git a/config/kernel-bio-rw-syncio.m4 b/config/kernel-bio-rw-syncio.m4
index 6f8b5b59157c23eec2d9ec37a2aae4f9d032e01c..4bff80a8f863d057c1b31d8d633be91c2d84f1e9 100644 (file)
--- a/config/kernel-bio-rw-syncio.m4
+++ b/config/kernel-bio-rw-syncio.m4
@@ -9,7 +9,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BIO_RW_SYNC], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNC;
        ],[
                AC_MSG_RESULT(yes)
@@ -24,7 +24,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BIO_RW_SYNCIO], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNCIO;
        ],[
                AC_MSG_RESULT(yes)
@@ -39,7 +39,7 @@ AC_DEFUN([ZFS_AC_KERNEL_REQ_SYNC], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/bio.h>
        ],[
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_SYNC;
        ],[
                AC_MSG_RESULT(yes)

diff --git a/config/kernel-evict-inode.m4 b/config/kernel-evict-inode.m4
index 3cf5a366615959e10a5428f10e338d208acf8113..f748898c3edd1507a78e34cd881b2e9407adc061 100644 (file)
--- a/config/kernel-evict-inode.m4
+++ b/config/kernel-evict-inode.m4
@@ -9,7 +9,7 @@ AC_DEFUN([ZFS_AC_KERNEL_EVICT_INODE], [
                #include <linux/fs.h>
        ],[
                void (*evict_inode) (struct inode *) = NULL;
-               struct super_operations sops;
+               struct super_operations sops __attribute__ ((unused));
 
                sops.evict_inode = evict_inode;
        ],[

diff --git a/config/kernel-fmode-t.m4 b/config/kernel-fmode-t.m4
index cf25d812728fe39dcbbef50da74bb335dcf0aa9d..4a23c391d326d713f03eee4da113863af5903087 100644 (file)
--- a/config/kernel-fmode-t.m4
+++ b/config/kernel-fmode-t.m4
@@ -7,7 +7,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TYPE_FMODE_T],
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/types.h>
        ],[
-               fmode_t *ptr;
+               fmode_t *ptr __attribute__ ((unused));
        ],[
                AC_MSG_RESULT([yes])
                AC_DEFINE(HAVE_FMODE_T, 1,

diff --git a/config/kernel-fsync.m4 b/config/kernel-fsync.m4
index 2733dba33a54b2b31598c02bdf94718a1b29be13..3f938426bda09776f8ee03663aafe356d3253c0b 100644 (file)
--- a/config/kernel-fsync.m4
+++ b/config/kernel-fsync.m4
@@ -8,7 +8,7 @@ AC_DEFUN([ZFS_AC_KERNEL_FSYNC_2ARGS], [
                #include <linux/fs.h>
        ],[
                int (*fsync) (struct file *, int datasync) = NULL;
-               struct file_operations fops;
+               struct file_operations fops __attribute__ ((unused));
 
                fops.fsync = fsync;
        ],[

diff --git a/config/kernel-invalidate-bdev-args.m4 b/config/kernel-invalidate-bdev-args.m4
index c768f6275f00ab40251b62384067962e824e1f15..09c2ebf26e99a4d94ca962faa67aa430180c61b5 100644 (file)
--- a/config/kernel-invalidate-bdev-args.m4
+++ b/config/kernel-invalidate-bdev-args.m4
@@ -7,7 +7,7 @@ AC_DEFUN([ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/buffer_head.h>
        ],[
-               struct block_device *bdev;
+               struct block_device *bdev = NULL;
                invalidate_bdev(bdev);
        ],[
                AC_MSG_RESULT(yes)

diff --git a/config/kernel-kobj-name-len.m4 b/config/kernel-kobj-name-len.m4
index 5363a41ca29606cfadd673172f2f6271d5c6558f..37999fabb81da3155fcf4cfbac515efa54ca4579 100644 (file)
--- a/config/kernel-kobj-name-len.m4
+++ b/config/kernel-kobj-name-len.m4
@@ -9,7 +9,7 @@ AC_DEFUN([ZFS_AC_KERNEL_KOBJ_NAME_LEN], [
        ZFS_LINUX_TRY_COMPILE([
                #include <linux/kobject.h>
        ],[
-               int val;
+               int val __attribute__ ((unused));
                val = KOBJ_NAME_LEN;
        ],[
                AC_MSG_RESULT([yes])

diff --git a/config/kernel-xattr-handler.m4 b/config/kernel-xattr-handler.m4
index 1ebe1f0d966270c6164eee83ce66594c18327f9b..325c960df6e476010cef315ad28651e36b5e0cd4 100644 (file)
--- a/config/kernel-xattr-handler.m4
+++ b/config/kernel-xattr-handler.m4
@@ -19,7 +19,7 @@ AC_DEFUN([ZFS_AC_KERNEL_CONST_XATTR_HANDLER],
                        &xattr_test_handler,
                };
        ],[
-               struct super_block sb;
+               struct super_block sb __attribute__ ((unused));
 
                sb.s_xattr = xattr_handlers;
        ],[
@@ -43,7 +43,7 @@ AC_DEFUN([ZFS_AC_KERNEL_XATTR_HANDLER_GET], [
        ],[
                int (*get)(struct dentry *dentry, const char *name,
                    void *buffer, size_t size, int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.get = get;
        ],[
@@ -68,7 +68,7 @@ AC_DEFUN([ZFS_AC_KERNEL_XATTR_HANDLER_SET], [
                int (*set)(struct dentry *dentry, const char *name,
                    const void *buffer, size_t size, int flags,
                    int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.set = set;
        ],[

diff --git a/configure b/configure
index 88155541bfb9cf92c2cf23718bcedf3fd05b21e5..feffaae4873d2d2164f1f34b8b90fbb850ab682f 100755 (executable)
--- a/configure
+++ b/configure
@@ -12372,7 +12372,7 @@ int
 main (void)
 {
 
-               fmode_t *ptr;
+               fmode_t *ptr __attribute__ ((unused));
 
   ;
   return 0;
@@ -12437,7 +12437,7 @@ int
 main (void)
 {
 
-               int val;
+               int val __attribute__ ((unused));
                val = KOBJ_NAME_LEN;
 
   ;
@@ -12583,7 +12583,7 @@ int
 main (void)
 {
 
-               struct block_device *bdev;
+               struct block_device *bdev = NULL;
                invalidate_bdev(bdev);
 
   ;
@@ -12782,7 +12782,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = (1 << BIO_RW_FAILFAST);
 
   ;
@@ -12848,7 +12848,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = ((1 << BIO_RW_FAILFAST_DEV) |
                         (1 << BIO_RW_FAILFAST_TRANSPORT) |
                         (1 << BIO_RW_FAILFAST_DRIVER));
@@ -12916,7 +12916,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_FAILFAST_MASK;
 
   ;
@@ -12985,7 +12985,7 @@ main (void)
 {
 
                void (*wanted_end_io)(struct bio *, int) = NULL;
-               bio_end_io_t *local_end_io;
+               bio_end_io_t *local_end_io __attribute__ ((unused));
 
                local_end_io = wanted_end_io;
 
@@ -13053,7 +13053,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNC;
 
   ;
@@ -13119,7 +13119,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNCIO;
 
   ;
@@ -13185,7 +13185,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_SYNC;
 
   ;
@@ -13994,7 +13994,7 @@ int
 main (void)
 {
 
-               struct super_block sb;
+               struct super_block sb __attribute__ ((unused));
 
                sb.s_xattr = xattr_handlers;
 
@@ -14063,7 +14063,7 @@ main (void)
 
                int (*get)(struct dentry *dentry, const char *name,
                    void *buffer, size_t size, int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.get = get;
 
@@ -14133,7 +14133,7 @@ main (void)
                int (*set)(struct dentry *dentry, const char *name,
                    const void *buffer, size_t size, int flags,
                    int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.set = set;
 
@@ -14201,7 +14201,7 @@ main (void)
 {
 
                int (*fsync) (struct file *, int datasync) = NULL;
-               struct file_operations fops;
+               struct file_operations fops __attribute__ ((unused));
 
                fops.fsync = fsync;
 
@@ -14269,7 +14269,7 @@ main (void)
 {
 
                void (*evict_inode) (struct inode *) = NULL;
-               struct super_operations sops;
+               struct super_operations sops __attribute__ ((unused));
 
                sops.evict_inode = evict_inode;
 
@@ -16417,7 +16417,7 @@ int
 main (void)
 {
 
-               fmode_t *ptr;
+               fmode_t *ptr __attribute__ ((unused));
 
   ;
   return 0;
@@ -16482,7 +16482,7 @@ int
 main (void)
 {
 
-               int val;
+               int val __attribute__ ((unused));
                val = KOBJ_NAME_LEN;
 
   ;
@@ -16628,7 +16628,7 @@ int
 main (void)
 {
 
-               struct block_device *bdev;
+               struct block_device *bdev = NULL;
                invalidate_bdev(bdev);
 
   ;
@@ -16827,7 +16827,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = (1 << BIO_RW_FAILFAST);
 
   ;
@@ -16893,7 +16893,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = ((1 << BIO_RW_FAILFAST_DEV) |
                         (1 << BIO_RW_FAILFAST_TRANSPORT) |
                         (1 << BIO_RW_FAILFAST_DRIVER));
@@ -16961,7 +16961,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_FAILFAST_MASK;
 
   ;
@@ -17030,7 +17030,7 @@ main (void)
 {
 
                void (*wanted_end_io)(struct bio *, int) = NULL;
-               bio_end_io_t *local_end_io;
+               bio_end_io_t *local_end_io __attribute__ ((unused));
 
                local_end_io = wanted_end_io;
 
@@ -17098,7 +17098,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNC;
 
   ;
@@ -17164,7 +17164,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = BIO_RW_SYNCIO;
 
   ;
@@ -17230,7 +17230,7 @@ int
 main (void)
 {
 
-               int flags;
+               int flags __attribute__ ((unused));
                flags = REQ_SYNC;
 
   ;
@@ -18039,7 +18039,7 @@ int
 main (void)
 {
 
-               struct super_block sb;
+               struct super_block sb __attribute__ ((unused));
 
                sb.s_xattr = xattr_handlers;
 
@@ -18108,7 +18108,7 @@ main (void)
 
                int (*get)(struct dentry *dentry, const char *name,
                    void *buffer, size_t size, int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.get = get;
 
@@ -18178,7 +18178,7 @@ main (void)
                int (*set)(struct dentry *dentry, const char *name,
                    const void *buffer, size_t size, int flags,
                    int handler_flags) = NULL;
-               struct xattr_handler xops;
+               struct xattr_handler xops __attribute__ ((unused));
 
                xops.set = set;
 
@@ -18246,7 +18246,7 @@ main (void)
 {
 
                int (*fsync) (struct file *, int datasync) = NULL;
-               struct file_operations fops;
+               struct file_operations fops __attribute__ ((unused));
 
                fops.fsync = fsync;
 
@@ -18314,7 +18314,7 @@ main (void)
 {
 
                void (*evict_inode) (struct inode *) = NULL;
-               struct super_operations sops;
+               struct super_operations sops __attribute__ ((unused));
 
                sops.evict_inode = evict_inode;