LinuxLists.cc - [PATCH] Avoid compiler warning by storing the result of rq_data

2015-08-02 10:37:13

Subject: [PATCH] Avoid compiler warning by storing the result of rq_data_dir() in an int variable

With gcc 5.1 I get:
warning: switch condition has boolean value [-Wswitch-bool]

Signed-off-by: Tomer Barletz <[email protected]>
---
drivers/mtd/mtd_blkdevs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 41acc50..8c3715c 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -79,6 +79,7 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
{
unsigned long block, nsect;
char *buf;
+ int rq;

block = blk_rq_pos(req) << 9 >> tr->blkshift;
nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
@@ -97,7 +98,8 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
if (req->cmd_flags & REQ_DISCARD)
return tr->discard(dev, block, nsect);

- switch(rq_data_dir(req)) {
+ rq = rq_data_dir(req);
+ switch(rq) {
case READ:
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->readsect(dev, block, buf))
--
2.4.3

2015-08-02 13:58:35

by Hagen Paul Pfeifer

[permalink] [raw]

Subject: Re: [PATCH] Avoid compiler warning by storing the result of rq_data_dir() in an int variable

* Tomer Barletz | 2015-08-02 03:36:52 [-0700]:

>With gcc 5.1 I get:
>warning: switch condition has boolean value [-Wswitch-bool]
>
>Signed-off-by: Tomer Barletz <[email protected]>
>---
> drivers/mtd/mtd_blkdevs.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
>index 41acc50..8c3715c 100644
>--- a/drivers/mtd/mtd_blkdevs.c
>+++ b/drivers/mtd/mtd_blkdevs.c
>@@ -79,6 +79,7 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
> {
> unsigned long block, nsect;
> char *buf;
>+ int rq;
>
> block = blk_rq_pos(req) << 9 >> tr->blkshift;
> nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
>@@ -97,7 +98,8 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
> if (req->cmd_flags & REQ_DISCARD)
> return tr->discard(dev, block, nsect);
>
>- switch(rq_data_dir(req)) {
>+ rq = rq_data_dir(req);
>+ switch(rq) {

Gcc warning seems over the top here, but when then the coding guideline should
be meet:

switch (rw) {
[..]

On the other hand, rq_data_dir() *could* be simplified to:

#define rq_data_dir(rq) (((rq)->cmd_flags & 1)

Or just re-code the construct into a if else construct.

if (rw == READ) {
[...]
} else {
[...]
}

The default branch is superfluous anyway here.

Hagen

2015-08-03 05:50:27

by Tomer Barletz

[permalink] [raw]

Subject: [PATCH] Avoid compiler warning by storing the result of rq_data_dir() in an int variable

With gcc 5.1 I get:
warning: switch condition has boolean value [-Wswitch-bool]

Signed-off-by: Tomer Barletz <[email protected]>
---
drivers/mtd/mtd_blkdevs.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 41acc50..8830475 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -97,14 +97,13 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
if (req->cmd_flags & REQ_DISCARD)
return tr->discard(dev, block, nsect);

- switch(rq_data_dir(req)) {
- case READ:
+ if (rq_data_dir(req) == READ) {
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->readsect(dev, block, buf))
return -EIO;
rq_flush_dcache_pages(req);
return 0;
- case WRITE:
+ } else {
if (!tr->writesect)
return -EIO;

@@ -113,9 +112,6 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
if (tr->writesect(dev, block, buf))
return -EIO;
return 0;
- default:
- printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
- return -EIO;
}
}

--
2.4.3

2015-08-05 04:00:51

by Tomer Barletz

[permalink] [raw]

Subject: [PATCH] mtd: Fix switch-bool compilation warning

2015-08-25 20:59:57

by Brian Norris

[permalink] [raw]

Subject: Re: [PATCH] mtd: Fix switch-bool compilation warning

On Tue, Aug 04, 2015 at 09:00:24PM -0700, Tomer Barletz wrote:
> With gcc 5.1 I get:
> warning: switch condition has boolean value [-Wswitch-bool]
>
> Signed-off-by: Tomer Barletz <[email protected]>

Applied to l2-mtd.git