[PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Sumitra Sharma]

Convert to_nvec_led from a macro to a static inline function, to make the
relevant types apparent in the definition and to benefit from the type
checking performed by the compiler at call sites.

Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
---

v2: Change patch subject and description, noted by 
Julia Lawall <julia.lawall@inria.fr> 

 drivers/staging/nvec/nvec_paz00.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/nvec/nvec_paz00.c b/drivers/staging/nvec/nvec_paz00.c
index 8b4da95081c8..9573ba762cdd 100644
--- a/drivers/staging/nvec/nvec_paz00.c
+++ b/drivers/staging/nvec/nvec_paz00.c
@@ -14,8 +14,10 @@
 #include <linux/platform_device.h>
 #include "nvec.h"
 
-#define to_nvec_led(led_cdev) \
-	container_of(led_cdev, struct nvec_led, cdev)
+static inline struct nvec_led *to_nvec_led(struct led_classdev *led_cdev)
+{
+	return container_of(led_cdev, struct nvec_led, cdev);
+}
 
 #define NVEC_LED_REQ {'\x0d', '\x10', '\x45', '\x10', '\x00'}
 
-- 
2.25.1

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Dan Carpenter]

On Sat, Mar 18, 2023 at 10:52:50AM -0700, Sumitra Sharma wrote:
> Convert to_nvec_led from a macro to a static inline function, to make the
> relevant types apparent in the definition and to benefit from the type
> checking performed by the compiler at call sites.
> 
> Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
> ---

You need to compile test your changes.

regards,
dan carpenter

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Sumitra Sharma]

On Mon, Mar 20, 2023 at 08:39:49AM +0300, Dan Carpenter wrote:
> On Sat, Mar 18, 2023 at 10:52:50AM -0700, Sumitra Sharma wrote:
> > Convert to_nvec_led from a macro to a static inline function, to make the
> > relevant types apparent in the definition and to benefit from the type
> > checking performed by the compiler at call sites.
> > 
> > Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
> > ---
> 
> You need to compile test your changes.
>

Hi dan,

I am facing problems in creating modules and in compiling them.

Any help in this would be appreciated. Here is the link to the thread https://lore.kernel.org/outreachy/alpine.DEB.2.22.394.2303191336090.2867@hadrien/T/#t

Regards,

Sumitra

> regards,
> dan carpenter
> 

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Dan Carpenter]

On Mon, Mar 20, 2023 at 01:44:22AM -0700, Sumitra Sharma wrote:
> On Mon, Mar 20, 2023 at 08:39:49AM +0300, Dan Carpenter wrote:
> > On Sat, Mar 18, 2023 at 10:52:50AM -0700, Sumitra Sharma wrote:
> > > Convert to_nvec_led from a macro to a static inline function, to make the
> > > relevant types apparent in the definition and to benefit from the type
> > > checking performed by the compiler at call sites.
> > > 
> > > Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
> > > ---
> > 
> > You need to compile test your changes.
> >
> 
> Hi dan,
> 
> I am facing problems in creating modules and in compiling them.
> 
> Any help in this would be appreciated. Here is the link to the thread
> https://lore.kernel.org/outreachy/alpine.DEB.2.22.394.2303191336090.2867@hadrien/T/#t

If you're editing a .h file then you need to compile all the stuff which
includes it.  It's slightly complicated.  But if you're just editing a
.c file like here then what I do is I have use my Smatch script to try
compile it.

In Debian run:
apt-get install gcc make sqlite3 libsqlite3-dev libdbd-sqlite3-perl libssl-dev libtry-tiny-perl
Or in Fedora run:
yum install gcc make sqlite3 sqlite-devel sqlite perl-DBD-SQLite openssl-devel perl-Try-Tiny

git clone https://github.com/error27/smatch.git
cd smatch
make

cd /path/to/kernel_src/
~/smatch/smatch_scripts/kchecker drivers/staging/nvec/nvec_paz00.c

Also I run Sparse on the file.
~/smatch/smatch_scripts/kchecker --sparse drivers/staging/nvec/nvec_paz00.c

When I'm patching a file, then I like to look at any other issues I
might want to fix and deal with that as well.

regards,
dan carpenter

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Julia Lawall]

On Mon, 20 Mar 2023, Sumitra Sharma wrote:

> On Mon, Mar 20, 2023 at 08:39:49AM +0300, Dan Carpenter wrote:
> > On Sat, Mar 18, 2023 at 10:52:50AM -0700, Sumitra Sharma wrote:
> > > Convert to_nvec_led from a macro to a static inline function, to make the
> > > relevant types apparent in the definition and to benefit from the type
> > > checking performed by the compiler at call sites.
> > >
> > > Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
> > > ---
> >
> > You need to compile test your changes.
> >
>
> Hi dan,
>
> I am facing problems in creating modules and in compiling them.

Note that unless the code is under an ifdef for a module, you don't
specifically need the driver to be configured as for a module either.
Since you don't have the device, you aren't going to be able to test it
anyway.  So 'y' is fine.

julia

>
> Any help in this would be appreciated. Here is the link to the thread https://lore.kernel.org/outreachy/alpine.DEB.2.22.394.2303191336090.2867@hadrien/T/#t
>
> Regards,
>
> Sumitra
>
> > regards,
> > dan carpenter
> >
>
>

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[kernel test robot]

Hi Sumitra,

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/Sumitra-Sharma/Staging-nvec-Convert-to_nvec_led-from-a-macro-to-an-inline-function/20230319-015434
patch link:    https://lore.kernel.org/r/20230318175250.GA49618%40sumitra.com
patch subject: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function
config: arm-allyesconfig (https://download.01.org/0day-ci/archive/20230320/202303202327.ojGuSQqT-lkp@intel.com/config)
compiler: arm-linux-gnueabi-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/5bb6b930cab3ac631310d3bbf40c9decf91dfd38
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Sumitra-Sharma/Staging-nvec-Convert-to_nvec_led-from-a-macro-to-an-inline-function/20230319-015434
        git checkout 5bb6b930cab3ac631310d3bbf40c9decf91dfd38
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/staging/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303202327.ojGuSQqT-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/linux/container_of.h:5,
                    from include/linux/list.h:5,
                    from include/linux/module.h:12,
                    from drivers/staging/nvec/nvec_paz00.c:10:
   drivers/staging/nvec/nvec_paz00.c: In function 'to_nvec_led':
>> include/linux/container_of.h:20:54: error: invalid use of undefined type 'struct nvec_led'
      20 |         static_assert(__same_type(*(ptr), ((type *)0)->member) ||       \
         |                                                      ^~
   include/linux/build_bug.h:78:56: note: in definition of macro '__static_assert'
      78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
         |                                                        ^~~~
   include/linux/container_of.h:20:9: note: in expansion of macro 'static_assert'
      20 |         static_assert(__same_type(*(ptr), ((type *)0)->member) ||       \
         |         ^~~~~~~~~~~~~
   include/linux/container_of.h:20:23: note: in expansion of macro '__same_type'
      20 |         static_assert(__same_type(*(ptr), ((type *)0)->member) ||       \
         |                       ^~~~~~~~~~~
   drivers/staging/nvec/nvec_paz00.c:19:16: note: in expansion of macro 'container_of'
      19 |         return container_of(led_cdev, struct nvec_led, cdev);
         |                ^~~~~~~~~~~~
   include/linux/compiler_types.h:338:27: error: expression in static assertion is not an integer
     338 | #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
         |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:78:56: note: in definition of macro '__static_assert'
      78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
         |                                                        ^~~~
   include/linux/container_of.h:20:9: note: in expansion of macro 'static_assert'
      20 |         static_assert(__same_type(*(ptr), ((type *)0)->member) ||       \
         |         ^~~~~~~~~~~~~
   include/linux/container_of.h:20:23: note: in expansion of macro '__same_type'
      20 |         static_assert(__same_type(*(ptr), ((type *)0)->member) ||       \
         |                       ^~~~~~~~~~~
   drivers/staging/nvec/nvec_paz00.c:19:16: note: in expansion of macro 'container_of'
      19 |         return container_of(led_cdev, struct nvec_led, cdev);
         |                ^~~~~~~~~~~~
   In file included from include/uapi/linux/posix_types.h:5,
                    from include/uapi/linux/types.h:14,
                    from include/linux/types.h:6,
                    from include/linux/kasan-checks.h:5,
                    from include/asm-generic/rwonce.h:26,
                    from ./arch/arm/include/generated/asm/rwonce.h:1,
                    from include/linux/compiler.h:247,
                    from include/linux/build_bug.h:5:
>> include/linux/stddef.h:16:33: error: invalid use of undefined type 'struct nvec_led'
      16 | #define offsetof(TYPE, MEMBER)  __builtin_offsetof(TYPE, MEMBER)
         |                                 ^~~~~~~~~~~~~~~~~~
   include/linux/container_of.h:23:28: note: in expansion of macro 'offsetof'
      23 |         ((type *)(__mptr - offsetof(type, member))); })
         |                            ^~~~~~~~
   drivers/staging/nvec/nvec_paz00.c:19:16: note: in expansion of macro 'container_of'
      19 |         return container_of(led_cdev, struct nvec_led, cdev);
         |                ^~~~~~~~~~~~
   drivers/staging/nvec/nvec_paz00.c:20:1: error: control reaches end of non-void function [-Werror=return-type]
      20 | }
         | ^
   cc1: some warnings being treated as errors


vim +20 include/linux/container_of.h

d2a8ebbf8192b8 Andy Shevchenko  2021-11-08   9  
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  10  /**
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  11   * container_of - cast a member of a structure out to the containing structure
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  12   * @ptr:	the pointer to the member.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  13   * @type:	the type of the container struct this is embedded in.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  14   * @member:	the name of the member within the struct.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  15   *
7376e561fd2e01 Sakari Ailus     2022-10-24  16   * WARNING: any const qualifier of @ptr is lost.
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  17   */
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  18  #define container_of(ptr, type, member) ({				\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  19  	void *__mptr = (void *)(ptr);					\
e1edc277e6f6df Rasmus Villemoes 2021-11-08 @20  	static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\
e1edc277e6f6df Rasmus Villemoes 2021-11-08  21  		      __same_type(*(ptr), void),			\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  22  		      "pointer type mismatch in container_of()");	\
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  23  	((type *)(__mptr - offsetof(type, member))); })
d2a8ebbf8192b8 Andy Shevchenko  2021-11-08  24  

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

Re: [PATCH v2] Staging: nvec: Convert to_nvec_led from a macro to an inline function

[Greg Kroah-Hartman]

On Sat, Mar 18, 2023 at 10:52:50AM -0700, Sumitra Sharma wrote:
> Convert to_nvec_led from a macro to a static inline function, to make the
> relevant types apparent in the definition and to benefit from the type
> checking performed by the compiler at call sites.
> 
> Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
> ---
> 
> v2: Change patch subject and description, noted by 
> Julia Lawall <julia.lawall@inria.fr> 
> 
>  drivers/staging/nvec/nvec_paz00.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/nvec/nvec_paz00.c b/drivers/staging/nvec/nvec_paz00.c
> index 8b4da95081c8..9573ba762cdd 100644
> --- a/drivers/staging/nvec/nvec_paz00.c
> +++ b/drivers/staging/nvec/nvec_paz00.c
> @@ -14,8 +14,10 @@
>  #include <linux/platform_device.h>
>  #include "nvec.h"
>  
> -#define to_nvec_led(led_cdev) \
> -	container_of(led_cdev, struct nvec_led, cdev)
> +static inline struct nvec_led *to_nvec_led(struct led_classdev *led_cdev)
> +{
> +	return container_of(led_cdev, struct nvec_led, cdev);
> +}

There is no need for a function, or a macro, for this, as it is only
used once.  Please just open-code it in the one place it is used
instead.

thanks,

greg k-h