2023-03-11 13:59:32

by Menna Mahmoud

[permalink] [raw]
Subject: [PATCH] staging: greybus: eclose macro in a do - while loop

" ERROR: Macros with multiple statements should be enclosed in a do -
while loop"

Reported by checkpath.

do loop with the conditional expression set to a constant
value of zero (0).This creates a loop that
will execute exactly one time.This is a coding idiom that
allows a multi-line macro to be used anywhere
that a single statement can be used.

So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
fix checkpath error

Signed-off-by: Menna Mahmoud <[email protected]>
---
drivers/staging/greybus/loopback.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index 1a61fce98056..e86d50638cb5 100644
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device *dev, \
} \
static DEVICE_ATTR_RO(name##_avg)

-#define gb_loopback_stats_attrs(field) \
- gb_loopback_ro_stats_attr(field, min, u); \
- gb_loopback_ro_stats_attr(field, max, u); \
- gb_loopback_ro_avg_attr(field)
+#define gb_loopback_stats_attrs(field) \
+ do { \
+ gb_loopback_ro_stats_attr(field, min, u); \
+ gb_loopback_ro_stats_attr(field, max, u); \
+ gb_loopback_ro_avg_attr(field); \
+ } while (0)

#define gb_loopback_attr(field, type) \
static ssize_t field##_show(struct device *dev, \
--
2.34.1



2023-03-11 14:06:31

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop

On Sat, Mar 11, 2023 at 03:59:19PM +0200, Menna Mahmoud wrote:
> " ERROR: Macros with multiple statements should be enclosed in a do -
> while loop"
>
> Reported by checkpath.
>
> do loop with the conditional expression set to a constant
> value of zero (0).This creates a loop that
> will execute exactly one time.This is a coding idiom that
> allows a multi-line macro to be used anywhere
> that a single statement can be used.
>
> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
> fix checkpath error
>
> Signed-off-by: Menna Mahmoud <[email protected]>
> ---

This breaks the build. You need to compile the code before sending a
patch.

regards,
dan carpenter


2023-03-11 14:36:11

by Julia Lawall

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop

Menna,

There is a typo in the subject line.

On Sat, 11 Mar 2023, Menna Mahmoud wrote:

> " ERROR: Macros with multiple statements should be enclosed in a do -
> while loop"
>
> Reported by checkpath.
>
> do loop with the conditional expression set to a constant
> value of zero (0).This creates a loop that
> will execute exactly one time.This is a coding idiom that
> allows a multi-line macro to be used anywhere
> that a single statement can be used.
>
> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
> fix checkpath error

The log message should focus on what is done and why. The checkpatch
warning text and the fact that the problem was detected using checkpatch
is useful, but less, so it should come last, not first.

Here, what is done is to enclose a sequence of statements in a macro
definition in a do-while loop with a test expression 0.

The reason why is to make it safe to use the sequence anywhere a single
statement can be used.

A period at the end of a sentence should be followed by some whitespace
before starting the next sentence.

julia

> Signed-off-by: Menna Mahmoud <[email protected]>
> ---
> drivers/staging/greybus/loopback.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
> index 1a61fce98056..e86d50638cb5 100644
> --- a/drivers/staging/greybus/loopback.c
> +++ b/drivers/staging/greybus/loopback.c
> @@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device *dev, \
> } \
> static DEVICE_ATTR_RO(name##_avg)
>
> -#define gb_loopback_stats_attrs(field) \
> - gb_loopback_ro_stats_attr(field, min, u); \
> - gb_loopback_ro_stats_attr(field, max, u); \
> - gb_loopback_ro_avg_attr(field)
> +#define gb_loopback_stats_attrs(field) \
> + do { \
> + gb_loopback_ro_stats_attr(field, min, u); \
> + gb_loopback_ro_stats_attr(field, max, u); \
> + gb_loopback_ro_avg_attr(field); \
> + } while (0)
>
> #define gb_loopback_attr(field, type) \
> static ssize_t field##_show(struct device *dev, \
> --
> 2.34.1
>
>
>

2023-03-11 14:52:05

by Menna Mahmoud

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop


On ١١‏/٣‏/٢٠٢٣ ١٦:٠٦, Dan Carpenter wrote:
> On Sat, Mar 11, 2023 at 03:59:19PM +0200, Menna Mahmoud wrote:
>> " ERROR: Macros with multiple statements should be enclosed in a do -
>> while loop"
>>
>> Reported by checkpath.
>>
>> do loop with the conditional expression set to a constant
>> value of zero (0).This creates a loop that
>> will execute exactly one time.This is a coding idiom that
>> allows a multi-line macro to be used anywhere
>> that a single statement can be used.
>>
>> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
>> fix checkpath error
>>
>> Signed-off-by: Menna Mahmoud <[email protected]>
>> ---
> This breaks the build. You need to compile the code before sending a
> patch.
>
> regards,
> dan carpenter


I see, I thought building the file only enough. appreciate your feedback.


Thanks,

Menna



2023-03-11 14:54:41

by Menna Mahmoud

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop


On ١١‏/٣‏/٢٠٢٣ ١٦:٣٦, Julia Lawall wrote:
> Menna,
>
> There is a typo in the subject line.
>
> On Sat, 11 Mar 2023, Menna Mahmoud wrote:
>
>> " ERROR: Macros with multiple statements should be enclosed in a do -
>> while loop"
>>
>> Reported by checkpath.
>>
>> do loop with the conditional expression set to a constant
>> value of zero (0).This creates a loop that
>> will execute exactly one time.This is a coding idiom that
>> allows a multi-line macro to be used anywhere
>> that a single statement can be used.
>>
>> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
>> fix checkpath error
> The log message should focus on what is done and why. The checkpatch
> warning text and the fact that the problem was detected using checkpatch
> is useful, but less, so it should come last, not first.
>
> Here, what is done is to enclose a sequence of statements in a macro
> definition in a do-while loop with a test expression 0.
>
> The reason why is to make it safe to use the sequence anywhere a single
> statement can be used.
>
> A period at the end of a sentence should be followed by some whitespace
> before starting the next sentence.
>
> julia


got it, thank you.


Menna

>
>> Signed-off-by: Menna Mahmoud <[email protected]>
>> ---
>> drivers/staging/greybus/loopback.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
>> index 1a61fce98056..e86d50638cb5 100644
>> --- a/drivers/staging/greybus/loopback.c
>> +++ b/drivers/staging/greybus/loopback.c
>> @@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device *dev, \
>> } \
>> static DEVICE_ATTR_RO(name##_avg)
>>
>> -#define gb_loopback_stats_attrs(field) \
>> - gb_loopback_ro_stats_attr(field, min, u); \
>> - gb_loopback_ro_stats_attr(field, max, u); \
>> - gb_loopback_ro_avg_attr(field)
>> +#define gb_loopback_stats_attrs(field) \
>> + do { \
>> + gb_loopback_ro_stats_attr(field, min, u); \
>> + gb_loopback_ro_stats_attr(field, max, u); \
>> + gb_loopback_ro_avg_attr(field); \
>> + } while (0)
>>
>> #define gb_loopback_attr(field, type) \
>> static ssize_t field##_show(struct device *dev, \
>> --
>> 2.34.1
>>
>>
>>

2023-03-11 15:01:10

by Julia Lawall

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop



On Sat, 11 Mar 2023, Menna Mahmoud wrote:

>
> On ١١/٣/٢٠٢٣ ١٦:٠٦, Dan Carpenter wrote:
> > On Sat, Mar 11, 2023 at 03:59:19PM +0200, Menna Mahmoud wrote:
> > > " ERROR: Macros with multiple statements should be enclosed in a do -
> > > while loop"
> > >
> > > Reported by checkpath.
> > >
> > > do loop with the conditional expression set to a constant
> > > value of zero (0).This creates a loop that
> > > will execute exactly one time.This is a coding idiom that
> > > allows a multi-line macro to be used anywhere
> > > that a single statement can be used.
> > >
> > > So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
> > > fix checkpath error
> > >
> > > Signed-off-by: Menna Mahmoud <[email protected]>
> > > ---
> > This breaks the build. You need to compile the code before sending a
> > patch.
> >
> > regards,
> > dan carpenter
>
>
> I see, I thought building the file only enough. appreciate your feedback.

The outreachy tutorial explains how to compile everything in a
subdirectory.

julia

2023-03-11 15:56:32

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop

Hi Menna,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on staging/staging-testing]

url: https://github.com/intel-lab-lkp/linux/commits/Menna-Mahmoud/staging-greybus-eclose-macro-in-a-do-while-loop/20230311-220021
patch link: https://lore.kernel.org/r/20230311135919.9129-1-eng.mennamahmoud.mm%40gmail.com
patch subject: [PATCH] staging: greybus: eclose macro in a do - while loop
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230311/[email protected]/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/a0856cd3d280813cb65e083f5a5c72add1a89f15
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Menna-Mahmoud/staging-greybus-eclose-macro-in-a-do-while-loop/20230311-220021
git checkout a0856cd3d280813cb65e083f5a5c72add1a89f15
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/staging/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
| Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All errors (new ones prefixed by >>):

>> drivers/staging/greybus/loopback.c:166:9: error: expected identifier or '(' before 'do'
166 | do { \
| ^~
drivers/staging/greybus/loopback.c:273:1: note: in expansion of macro 'gb_loopback_stats_attrs'
273 | gb_loopback_stats_attrs(latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:170:11: error: expected identifier or '(' before 'while'
170 | } while (0)
| ^~~~~
drivers/staging/greybus/loopback.c:273:1: note: in expansion of macro 'gb_loopback_stats_attrs'
273 | gb_loopback_stats_attrs(latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:166:9: error: expected identifier or '(' before 'do'
166 | do { \
| ^~
drivers/staging/greybus/loopback.c:275:1: note: in expansion of macro 'gb_loopback_stats_attrs'
275 | gb_loopback_stats_attrs(requests_per_second);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:170:11: error: expected identifier or '(' before 'while'
170 | } while (0)
| ^~~~~
drivers/staging/greybus/loopback.c:275:1: note: in expansion of macro 'gb_loopback_stats_attrs'
275 | gb_loopback_stats_attrs(requests_per_second);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:166:9: error: expected identifier or '(' before 'do'
166 | do { \
| ^~
drivers/staging/greybus/loopback.c:277:1: note: in expansion of macro 'gb_loopback_stats_attrs'
277 | gb_loopback_stats_attrs(throughput);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:170:11: error: expected identifier or '(' before 'while'
170 | } while (0)
| ^~~~~
drivers/staging/greybus/loopback.c:277:1: note: in expansion of macro 'gb_loopback_stats_attrs'
277 | gb_loopback_stats_attrs(throughput);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:166:9: error: expected identifier or '(' before 'do'
166 | do { \
| ^~
drivers/staging/greybus/loopback.c:279:1: note: in expansion of macro 'gb_loopback_stats_attrs'
279 | gb_loopback_stats_attrs(apbridge_unipro_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:170:11: error: expected identifier or '(' before 'while'
170 | } while (0)
| ^~~~~
drivers/staging/greybus/loopback.c:279:1: note: in expansion of macro 'gb_loopback_stats_attrs'
279 | gb_loopback_stats_attrs(apbridge_unipro_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:166:9: error: expected identifier or '(' before 'do'
166 | do { \
| ^~
drivers/staging/greybus/loopback.c:281:1: note: in expansion of macro 'gb_loopback_stats_attrs'
281 | gb_loopback_stats_attrs(gbphy_firmware_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:170:11: error: expected identifier or '(' before 'while'
170 | } while (0)
| ^~~~~
drivers/staging/greybus/loopback.c:281:1: note: in expansion of macro 'gb_loopback_stats_attrs'
281 | gb_loopback_stats_attrs(gbphy_firmware_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:319:10: error: 'dev_attr_latency_min' undeclared here (not in a function); did you mean 'dev_attr_timeout_min'?
319 | &dev_attr_latency_min.attr,
| ^~~~~~~~~~~~~~~~~~~~
| dev_attr_timeout_min
>> drivers/staging/greybus/loopback.c:320:10: error: 'dev_attr_latency_max' undeclared here (not in a function); did you mean 'dev_attr_timeout_max'?
320 | &dev_attr_latency_max.attr,
| ^~~~~~~~~~~~~~~~~~~~
| dev_attr_timeout_max
>> drivers/staging/greybus/loopback.c:321:10: error: 'dev_attr_latency_avg' undeclared here (not in a function)
321 | &dev_attr_latency_avg.attr,
| ^~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:322:10: error: 'dev_attr_requests_per_second_min' undeclared here (not in a function)
322 | &dev_attr_requests_per_second_min.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:323:10: error: 'dev_attr_requests_per_second_max' undeclared here (not in a function)
323 | &dev_attr_requests_per_second_max.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:324:10: error: 'dev_attr_requests_per_second_avg' undeclared here (not in a function)
324 | &dev_attr_requests_per_second_avg.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:325:10: error: 'dev_attr_throughput_min' undeclared here (not in a function); did you mean 'dev_attr_timeout_min'?
325 | &dev_attr_throughput_min.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~
| dev_attr_timeout_min
>> drivers/staging/greybus/loopback.c:326:10: error: 'dev_attr_throughput_max' undeclared here (not in a function); did you mean 'dev_attr_timeout_max'?
326 | &dev_attr_throughput_max.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~
| dev_attr_timeout_max
>> drivers/staging/greybus/loopback.c:327:10: error: 'dev_attr_throughput_avg' undeclared here (not in a function)
327 | &dev_attr_throughput_avg.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~
>> drivers/staging/greybus/loopback.c:328:10: error: 'dev_attr_apbridge_unipro_latency_min' undeclared here (not in a function)
328 | &dev_attr_apbridge_unipro_latency_min.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/greybus/loopback.c:329:10: error: 'dev_attr_apbridge_unipro_latency_max' undeclared here (not in a function)
329 | &dev_attr_apbridge_unipro_latency_max.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/greybus/loopback.c:330:10: error: 'dev_attr_apbridge_unipro_latency_avg' undeclared here (not in a function)
330 | &dev_attr_apbridge_unipro_latency_avg.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/greybus/loopback.c:331:10: error: 'dev_attr_gbphy_firmware_latency_min' undeclared here (not in a function)
331 | &dev_attr_gbphy_firmware_latency_min.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/greybus/loopback.c:332:10: error: 'dev_attr_gbphy_firmware_latency_max' undeclared here (not in a function)
332 | &dev_attr_gbphy_firmware_latency_max.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/greybus/loopback.c:333:10: error: 'dev_attr_gbphy_firmware_latency_avg' undeclared here (not in a function)
333 | &dev_attr_gbphy_firmware_latency_avg.attr,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +166 drivers/staging/greybus/loopback.c

164
165 #define gb_loopback_stats_attrs(field) \
> 166 do { \
167 gb_loopback_ro_stats_attr(field, min, u); \
168 gb_loopback_ro_stats_attr(field, max, u); \
169 gb_loopback_ro_avg_attr(field); \
> 170 } while (0)
171
172 #define gb_loopback_attr(field, type) \
173 static ssize_t field##_show(struct device *dev, \
174 struct device_attribute *attr, \
175 char *buf) \
176 { \
177 struct gb_loopback *gb = dev_get_drvdata(dev); \
178 return sprintf(buf, "%" #type "\n", gb->field); \
179 } \
180 static ssize_t field##_store(struct device *dev, \
181 struct device_attribute *attr, \
182 const char *buf, \
183 size_t len) \
184 { \
185 int ret; \
186 struct gb_loopback *gb = dev_get_drvdata(dev); \
187 mutex_lock(&gb->mutex); \
188 ret = sscanf(buf, "%"#type, &gb->field); \
189 if (ret != 1) \
190 len = -EINVAL; \
191 else \
192 gb_loopback_check_attr(gb, bundle); \
193 mutex_unlock(&gb->mutex); \
194 return len; \
195 } \
196 static DEVICE_ATTR_RW(field)
197
198 #define gb_dev_loopback_ro_attr(field, conn) \
199 static ssize_t field##_show(struct device *dev, \
200 struct device_attribute *attr, \
201 char *buf) \
202 { \
203 struct gb_loopback *gb = dev_get_drvdata(dev); \
204 return sprintf(buf, "%u\n", gb->field); \
205 } \
206 static DEVICE_ATTR_RO(field)
207
208 #define gb_dev_loopback_rw_attr(field, type) \
209 static ssize_t field##_show(struct device *dev, \
210 struct device_attribute *attr, \
211 char *buf) \
212 { \
213 struct gb_loopback *gb = dev_get_drvdata(dev); \
214 return sprintf(buf, "%" #type "\n", gb->field); \
215 } \
216 static ssize_t field##_store(struct device *dev, \
217 struct device_attribute *attr, \
218 const char *buf, \
219 size_t len) \
220 { \
221 int ret; \
222 struct gb_loopback *gb = dev_get_drvdata(dev); \
223 mutex_lock(&gb->mutex); \
224 ret = sscanf(buf, "%"#type, &gb->field); \
225 if (ret != 1) \
226 len = -EINVAL; \
227 else \
228 gb_loopback_check_attr(gb); \
229 mutex_unlock(&gb->mutex); \
230 return len; \
231 } \
232 static DEVICE_ATTR_RW(field)
233
234 static void gb_loopback_reset_stats(struct gb_loopback *gb);
235 static void gb_loopback_check_attr(struct gb_loopback *gb)
236 {
237 if (gb->us_wait > GB_LOOPBACK_US_WAIT_MAX)
238 gb->us_wait = GB_LOOPBACK_US_WAIT_MAX;
239 if (gb->size > gb_dev.size_max)
240 gb->size = gb_dev.size_max;
241 gb->requests_timedout = 0;
242 gb->requests_completed = 0;
243 gb->iteration_count = 0;
244 gb->send_count = 0;
245 gb->error = 0;
246
247 if (kfifo_depth < gb->iteration_max) {
248 dev_warn(gb->dev,
249 "cannot log bytes %u kfifo_depth %u\n",
250 gb->iteration_max, kfifo_depth);
251 }
252 kfifo_reset_out(&gb->kfifo_lat);
253
254 switch (gb->type) {
255 case GB_LOOPBACK_TYPE_PING:
256 case GB_LOOPBACK_TYPE_TRANSFER:
257 case GB_LOOPBACK_TYPE_SINK:
258 gb->jiffy_timeout = usecs_to_jiffies(gb->timeout);
259 if (!gb->jiffy_timeout)
260 gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MIN;
261 else if (gb->jiffy_timeout > GB_LOOPBACK_TIMEOUT_MAX)
262 gb->jiffy_timeout = GB_LOOPBACK_TIMEOUT_MAX;
263 gb_loopback_reset_stats(gb);
264 wake_up(&gb->wq);
265 break;
266 default:
267 gb->type = 0;
268 break;
269 }
270 }
271
272 /* Time to send and receive one message */
273 gb_loopback_stats_attrs(latency);
274 /* Number of requests sent per second on this cport */
275 gb_loopback_stats_attrs(requests_per_second);
276 /* Quantity of data sent and received on this cport */
277 gb_loopback_stats_attrs(throughput);
278 /* Latency across the UniPro link from APBridge's perspective */
279 gb_loopback_stats_attrs(apbridge_unipro_latency);
280 /* Firmware induced overhead in the GPBridge */
281 gb_loopback_stats_attrs(gbphy_firmware_latency);
282
283 /* Number of errors encountered during loop */
284 gb_loopback_ro_attr(error);
285 /* Number of requests successfully completed async */
286 gb_loopback_ro_attr(requests_completed);
287 /* Number of requests timed out async */
288 gb_loopback_ro_attr(requests_timedout);
289 /* Timeout minimum in useconds */
290 gb_loopback_ro_attr(timeout_min);
291 /* Timeout minimum in useconds */
292 gb_loopback_ro_attr(timeout_max);
293
294 /*
295 * Type of loopback message to send based on protocol type definitions
296 * 0 => Don't send message
297 * 2 => Send ping message continuously (message without payload)
298 * 3 => Send transfer message continuously (message with payload,
299 * payload returned in response)
300 * 4 => Send a sink message (message with payload, no payload in response)
301 */
302 gb_dev_loopback_rw_attr(type, d);
303 /* Size of transfer message payload: 0-4096 bytes */
304 gb_dev_loopback_rw_attr(size, u);
305 /* Time to wait between two messages: 0-1000 ms */
306 gb_dev_loopback_rw_attr(us_wait, d);
307 /* Maximum iterations for a given operation: 1-(2^32-1), 0 implies infinite */
308 gb_dev_loopback_rw_attr(iteration_max, u);
309 /* The current index of the for (i = 0; i < iteration_max; i++) loop */
310 gb_dev_loopback_ro_attr(iteration_count, false);
311 /* A flag to indicate synchronous or asynchronous operations */
312 gb_dev_loopback_rw_attr(async, u);
313 /* Timeout of an individual asynchronous request */
314 gb_dev_loopback_rw_attr(timeout, u);
315 /* Maximum number of in-flight operations before back-off */
316 gb_dev_loopback_rw_attr(outstanding_operations_max, u);
317
318 static struct attribute *loopback_attrs[] = {
> 319 &dev_attr_latency_min.attr,
> 320 &dev_attr_latency_max.attr,
> 321 &dev_attr_latency_avg.attr,
> 322 &dev_attr_requests_per_second_min.attr,
> 323 &dev_attr_requests_per_second_max.attr,
> 324 &dev_attr_requests_per_second_avg.attr,
> 325 &dev_attr_throughput_min.attr,
> 326 &dev_attr_throughput_max.attr,
> 327 &dev_attr_throughput_avg.attr,
> 328 &dev_attr_apbridge_unipro_latency_min.attr,
> 329 &dev_attr_apbridge_unipro_latency_max.attr,
> 330 &dev_attr_apbridge_unipro_latency_avg.attr,
> 331 &dev_attr_gbphy_firmware_latency_min.attr,
> 332 &dev_attr_gbphy_firmware_latency_max.attr,
> 333 &dev_attr_gbphy_firmware_latency_avg.attr,
334 &dev_attr_type.attr,
335 &dev_attr_size.attr,
336 &dev_attr_us_wait.attr,
337 &dev_attr_iteration_count.attr,
338 &dev_attr_iteration_max.attr,
339 &dev_attr_async.attr,
340 &dev_attr_error.attr,
341 &dev_attr_requests_completed.attr,
342 &dev_attr_requests_timedout.attr,
343 &dev_attr_timeout.attr,
344 &dev_attr_outstanding_operations_max.attr,
345 &dev_attr_timeout_min.attr,
346 &dev_attr_timeout_max.attr,
347 NULL,
348 };
349 ATTRIBUTE_GROUPS(loopback);
350

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

2023-03-11 19:11:11

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop

On 3/11/23 7:59 AM, Menna Mahmoud wrote:
> " ERROR: Macros with multiple statements should be enclosed in a do -
> while loop"
>
> Reported by checkpath.

This is also not an issue that should be "fixed."

If you look at where that macro is expanded, you see
that its purpose is simply to reduce the possibility
of some errors by enclosing some much-duplicated code
in this macro. The expansion is at the top level of
the source file, so a "do...while" loop ends up being
an error.

When looking at the output of checkpatch, assume it's
giving you clues about problems that one *might* like to
fix. Its suggestions are most often reasonable, but in
some cases (like this one) it's just not smart enough
to recognize the problem that comes from following its
advice.

Make sure you understand exactly what happens when
you make a change. That means understanding the
code, and then it means ensuring that the fix passes
at least a compile test, and if possible an actual
execution test.

-Alex

>
> do loop with the conditional expression set to a constant
> value of zero (0).This creates a loop that
> will execute exactly one time.This is a coding idiom that
> allows a multi-line macro to be used anywhere
> that a single statement can be used.
>
> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
> fix checkpath error
>
> Signed-off-by: Menna Mahmoud <[email protected]>
> ---
> drivers/staging/greybus/loopback.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
> index 1a61fce98056..e86d50638cb5 100644
> --- a/drivers/staging/greybus/loopback.c
> +++ b/drivers/staging/greybus/loopback.c
> @@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device *dev, \
> } \
> static DEVICE_ATTR_RO(name##_avg)
>
> -#define gb_loopback_stats_attrs(field) \
> - gb_loopback_ro_stats_attr(field, min, u); \
> - gb_loopback_ro_stats_attr(field, max, u); \
> - gb_loopback_ro_avg_attr(field)
> +#define gb_loopback_stats_attrs(field) \
> + do { \
> + gb_loopback_ro_stats_attr(field, min, u); \
> + gb_loopback_ro_stats_attr(field, max, u); \
> + gb_loopback_ro_avg_attr(field); \
> + } while (0)
>
> #define gb_loopback_attr(field, type) \
> static ssize_t field##_show(struct device *dev, \


2023-03-12 13:40:04

by Menna Mahmoud

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop


On ١١‏/٣‏/٢٠٢٣ ١٧:٠٠, Julia Lawall wrote:
>
> On Sat, 11 Mar 2023, Menna Mahmoud wrote:
>
>> On ١١/٣/٢٠٢٣ ١٦:٠٦, Dan Carpenter wrote:
>>> On Sat, Mar 11, 2023 at 03:59:19PM +0200, Menna Mahmoud wrote:
>>>> " ERROR: Macros with multiple statements should be enclosed in a do -
>>>> while loop"
>>>>
>>>> Reported by checkpath.
>>>>
>>>> do loop with the conditional expression set to a constant
>>>> value of zero (0).This creates a loop that
>>>> will execute exactly one time.This is a coding idiom that
>>>> allows a multi-line macro to be used anywhere
>>>> that a single statement can be used.
>>>>
>>>> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
>>>> fix checkpath error
>>>>
>>>> Signed-off-by: Menna Mahmoud <[email protected]>
>>>> ---
>>> This breaks the build. You need to compile the code before sending a
>>> patch.
>>>
>>> regards,
>>> dan carpenter
>>
>> I see, I thought building the file only enough. appreciate your feedback.
> The outreachy tutorial explains how to compile everything in a
> subdirectory.
>
> julia


Thanks Julia, I will check it.

Menna


2023-03-12 13:44:16

by Menna Mahmoud

[permalink] [raw]
Subject: Re: [PATCH] staging: greybus: eclose macro in a do - while loop


On ١١‏/٣‏/٢٠٢٣ ٢١:١٠, Alex Elder wrote:
> On 3/11/23 7:59 AM, Menna Mahmoud wrote:
>> " ERROR: Macros with multiple statements should be enclosed in a do -
>> while loop"
>>
>> Reported by checkpath.
>
> This is also not an issue that should be "fixed."
>
> If you look at where that macro is expanded, you see
> that its purpose is simply to reduce the possibility
> of some errors by enclosing some much-duplicated code
> in this macro.  The expansion is at the top level of
> the source file, so a "do...while" loop ends up being
> an error.
>
> When looking at the output of checkpatch, assume it's
> giving you clues about problems that one *might* like to
> fix.  Its suggestions are most often reasonable, but in
> some cases (like this one) it's just not smart enough
> to recognize the problem that comes from following its
> advice.
>
> Make sure you understand exactly what happens when
> you make a change.  That means understanding the
> code, and then it means ensuring that the fix passes
> at least a compile test, and if possible an actual
> execution test.
>
>                     -Alex


I see, Thanks Alex for explaining. I will check the code before making
any change.

Menna


>
>>
>> do loop with the conditional expression set to a constant
>> value of zero (0).This creates a loop that
>> will execute exactly one time.This is a coding idiom that
>> allows a multi-line macro to be used anywhere
>> that a single statement can be used.
>>
>> So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
>> fix checkpath error
>>
>> Signed-off-by: Menna Mahmoud <[email protected]>
>> ---
>>   drivers/staging/greybus/loopback.c | 10 ++++++----
>>   1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/staging/greybus/loopback.c
>> b/drivers/staging/greybus/loopback.c
>> index 1a61fce98056..e86d50638cb5 100644
>> --- a/drivers/staging/greybus/loopback.c
>> +++ b/drivers/staging/greybus/loopback.c
>> @@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device
>> *dev,        \
>>   }                                    \
>>   static DEVICE_ATTR_RO(name##_avg)
>>   -#define gb_loopback_stats_attrs(field)                \
>> -    gb_loopback_ro_stats_attr(field, min, u);        \
>> -    gb_loopback_ro_stats_attr(field, max, u);        \
>> -    gb_loopback_ro_avg_attr(field)
>> +#define gb_loopback_stats_attrs(field)                    \
>> +    do { \
>> +        gb_loopback_ro_stats_attr(field, min, u);        \
>> +        gb_loopback_ro_stats_attr(field, max, u);        \
>> +        gb_loopback_ro_avg_attr(field);                \
>> +    } while (0)
>>     #define gb_loopback_attr(field, type)                    \
>>   static ssize_t field##_show(struct device *dev, \
>