diff mbox series

[RFC,v1] checkpatch: Handle FILE pointer type

Message ID 20220901145948.1456353-1-mic@digikod.net (mailing list archive)
State New
Headers show
Series [RFC,v1] checkpatch: Handle FILE pointer type | expand

Commit Message

Mickaël Salaün Sept. 1, 2022, 2:59 p.m. UTC 
When using a "FILE *" type, checkpatch considers this an error.  Fix
this by explicitly defining "FILE" as a common type.

This is useful for user space patches.

With this patch, we now get:
 static void a(FILE *const b)

 <E> <E> <_>WS( )
 <E> <E> <_>IDENT(static)
 <E> <V> <_>WS( )
 <E> <V> <_>DECLARE(void )
 <E> <T> <_>FUNC(a)
 <E> <V> <V>PAREN('(')
 <EV> <N> <_>DECLARE(FILE *const )
 <EV> <T> <_>IDENT(b)
 <EV> <V> <_>PAREN(')') -> V
 <E> <V> <_>WS(
)
32 > . static void a(FILE *const b)
32 > EEVVVVVVVTTTTTVNTTTTTTTTTTTTVVV
32 >  ______________________________

Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
as defined in kselftest_harness.h .  The commented
$typeKselftestHarnessTypedefs should fix it but such definition is
considered as a function instead, because of the closing parenthesis.
I'd like some help to fix this as well.

With $typeKselftestHarnessTypedefs added to $typeTypedefs, we get:
 static void c(const FIXTURE_VARIANT(d) *const e)

 <E> <E> <_>WS( )
 <E> <E> <_>IDENT(static)
 <E> <V> <_>WS( )
 <E> <V> <_>DECLARE(void )
 <E> <T> <_>FUNC(c)
 <E> <V> <V>PAREN('(')
 <EV> <N> <_>MODIFIER(const)
 <EV> <T> <_>WS( )
 <EV> <T> <_>FUNC(FIXTURE_VARIANT)
 <EV> <V> <V>PAREN('(')
 <EVV> <N> <_>IDENT(d)
 <EVV> <V> <_>PAREN(')') -> V
 <EV> <V> <_>WS( )
 <EV> <V> <_>OPV(*)
 <EV> <N> <_>MODIFIER(const)
 <EV> <T> <_>WS( )
 <EV> <T> <_>IDENT(e)
 <EV> <V> <_>PAREN(')') -> V
 <E> <V> <_>WS(
)
30 > . static void c(const FIXTURE_VARIANT(d) *const e)
30 > EEVVVVVVVTTTTTVNTTTTTTVVVVVVVVVVVVVVVNVVVNTTTTTTVVV
30 >  ________________________________________B_________

Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20220901145948.1456353-1-mic@digikod.net
---
 scripts/checkpatch.pl | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)


base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5

Comments

Joe Perches Sept. 1, 2022, 3:49 p.m. UTC | #1 
On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:
> When using a "FILE *" type, checkpatch considers this an error.  Fix
> this by explicitly defining "FILE" as a common type.
[]
> Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
> as defined in kselftest_harness.h .
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
>  	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
>  	atomic_t
>  )};
> +our $typeStdioTypedefs = qr{(?x:
> +	FILE
> +)};

I'm fine with this.

> +# our $typeKselftestHarnessTypedefs = qr{(?x:
> +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
> +# )};

But not this.  Random userspace typedefs should likely
be kept in some local version of checkpatch.

Or maybe add a command line option like --additional_typedefs=<file>.

>  our $typeTypedefs = qr{(?x:
>  	$typeC99Typedefs\b|
>  	$typeOtherOSTypedefs\b|
> -	$typeKernelTypedefs\b
> +	$typeKernelTypedefs\b|
> +	$typeStdioTypedefs\b
>  )};
Mickaël Salaün Sept. 1, 2022, 3:53 p.m. UTC | #2 
On 01/09/2022 17:49, Joe Perches wrote:
> On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:

[...]

>> +# our $typeKselftestHarnessTypedefs = qr{(?x:
>> +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
>> +# )};
> 
> But not this.  Random userspace typedefs should likely
> be kept in some local version of checkpatch.
> 
> Or maybe add a command line option like --additional_typedefs=<file>.

This is part of the kselftest harness API. Could we take this into 
account for files under tools/testing/selftests ?

> 
>>   our $typeTypedefs = qr{(?x:
>>   	$typeC99Typedefs\b|
>>   	$typeOtherOSTypedefs\b|
>> -	$typeKernelTypedefs\b
>> +	$typeKernelTypedefs\b|
>> +	$typeStdioTypedefs\b
>>   )};
>
Joe Perches Sept. 1, 2022, 6:22 p.m. UTC | #3 
On Thu, 2022-09-01 at 11:49 -0400, Joe Perches wrote:
> On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:
> > When using a "FILE *" type, checkpatch considers this an error.  Fix
> > this by explicitly defining "FILE" as a common type.
> []
> > Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
> > as defined in kselftest_harness.h .
> []
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > @@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
> >  	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
> >  	atomic_t
> >  )};
> > +our $typeStdioTypedefs = qr{(?x:
> > +	FILE
> > +)};
> 
> I'm fine with this.
> 
> > +# our $typeKselftestHarnessTypedefs = qr{(?x:
> > +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
> > +# )};
> 
> But not this.  Random userspace typedefs should likely
> be kept in some local version of checkpatch.
> 
> Or maybe add a command line option like --additional_typedefs=<file>.

Oops.  I forgot it already exists:

  --typedefsfile             Read additional types from this file

commit 75ad8c575a5ad105e2afc2051c68abceb9c65431
Author: Jerome Forissier <jerome.forissier@linaro.org>
Date:   Mon May 8 15:56:00 2017 -0700

    checkpatch: add --typedefsfile
    
    When using checkpatch on out-of-tree code, it may occur that some
    project-specific types are used, which will cause spurious warnings.
    Add the --typedefsfile option as a way to extend the known types and
    deal with this issue.
Mickaël Salaün Sept. 2, 2022, 9:04 a.m. UTC | #4 
On 01/09/2022 20:22, Joe Perches wrote:
> On Thu, 2022-09-01 at 11:49 -0400, Joe Perches wrote:
>> On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:
>>> When using a "FILE *" type, checkpatch considers this an error.  Fix
>>> this by explicitly defining "FILE" as a common type.
>> []
>>> Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
>>> as defined in kselftest_harness.h .
>> []
>>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>> []
>>> @@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
>>>   	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
>>>   	atomic_t
>>>   )};
>>> +our $typeStdioTypedefs = qr{(?x:
>>> +	FILE
>>> +)};
>>
>> I'm fine with this.
>>
>>> +# our $typeKselftestHarnessTypedefs = qr{(?x:
>>> +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
>>> +# )};
>>
>> But not this.  Random userspace typedefs should likely
>> be kept in some local version of checkpatch.
>>
>> Or maybe add a command line option like --additional_typedefs=<file>.
> 
> Oops.  I forgot it already exists:
> 
>    --typedefsfile             Read additional types from this file
> 
> commit 75ad8c575a5ad105e2afc2051c68abceb9c65431
> Author: Jerome Forissier <jerome.forissier@linaro.org>
> Date:   Mon May 8 15:56:00 2017 -0700
> 
>      checkpatch: add --typedefsfile
>      
>      When using checkpatch on out-of-tree code, it may occur that some
>      project-specific types are used, which will cause spurious warnings.
>      Add the --typedefsfile option as a way to extend the known types and
>      deal with this issue.
> 

This doesn't work for the FIXTURE_DATA() case. And I'm not sure how 
contributors would know that they need to use this option with a 
specific file.
Joe Perches Sept. 2, 2022, 10:39 a.m. UTC | #5 
On Fri, 2022-09-02 at 11:04 +0200, Mickaël Salaün wrote:
> On 01/09/2022 20:22, Joe Perches wrote:
> > On Thu, 2022-09-01 at 11:49 -0400, Joe Perches wrote:
> > > On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:
> > > > When using a "FILE *" type, checkpatch considers this an error.  Fix
> > > > this by explicitly defining "FILE" as a common type.
> > > []
> > > > Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
> > > > as defined in kselftest_harness.h .
> > > []
> > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> > > []
> > > > @@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
> > > >   	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
> > > >   	atomic_t
> > > >   )};
> > > > +our $typeStdioTypedefs = qr{(?x:
> > > > +	FILE
> > > > +)};
> > > 
> > > I'm fine with this.
> > > 
> > > > +# our $typeKselftestHarnessTypedefs = qr{(?x:
> > > > +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
> > > > +# )};
> > > 
> > > But not this.  Random userspace typedefs should likely
> > > be kept in some local version of checkpatch.
> > > 
> > > Or maybe add a command line option like --additional_typedefs=<file>.
> > 
> > Oops.  I forgot it already exists:
> > 
> >    --typedefsfile             Read additional types from this file
> > 
> > commit 75ad8c575a5ad105e2afc2051c68abceb9c65431
> > Author: Jerome Forissier <jerome.forissier@linaro.org>
> > Date:   Mon May 8 15:56:00 2017 -0700
> > 
> >      checkpatch: add --typedefsfile
> >      
> >      When using checkpatch on out-of-tree code, it may occur that some
> >      project-specific types are used, which will cause spurious warnings.
> >      Add the --typedefsfile option as a way to extend the known types and
> >      deal with this issue.
> 
> This doesn't work for the FIXTURE_DATA() case.

checkpatch is a stupid little script.
It's not a c preprocessor nor a syntax complete compiler.
It's really easy for macros to make its output invalid.
If you feed obfuscated c to checkpatch, it'd be confused.
(Same is true for tools like coccinelle btw, though cocci is far better)
checkpatch will never be comprehensive nor perfect.
It's expected its users will use their common sense about its
output message validity.

> And I'm not sure how 
> contributors would know that they need to use this option with a 
> specific file.

--help exists

Maybe Documentation/dev-tools/checkpatch.rst could be expanded for
--verbose mode.
Mickaël Salaün Sept. 2, 2022, 11:04 a.m. UTC | #6 
On 02/09/2022 12:39, Joe Perches wrote:
> On Fri, 2022-09-02 at 11:04 +0200, Mickaël Salaün wrote:
>> On 01/09/2022 20:22, Joe Perches wrote:
>>> On Thu, 2022-09-01 at 11:49 -0400, Joe Perches wrote:
>>>> On Thu, 2022-09-01 at 16:59 +0200, Mickaël Salaün wrote:
>>>>> When using a "FILE *" type, checkpatch considers this an error.  Fix
>>>>> this by explicitly defining "FILE" as a common type.
>>>> []
>>>>> Another error may be throw when we use FIXTURE_{DATA,VARIANT}() structs,
>>>>> as defined in kselftest_harness.h .
>>>> []
>>>>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>>>> []
>>>>> @@ -576,10 +576,17 @@ our $typeKernelTypedefs = qr{(?x:
>>>>>    	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
>>>>>    	atomic_t
>>>>>    )};
>>>>> +our $typeStdioTypedefs = qr{(?x:
>>>>> +	FILE
>>>>> +)};
>>>>
>>>> I'm fine with this.
>>>>
>>>>> +# our $typeKselftestHarnessTypedefs = qr{(?x:
>>>>> +# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
>>>>> +# )};
>>>>
>>>> But not this.  Random userspace typedefs should likely
>>>> be kept in some local version of checkpatch.
>>>>
>>>> Or maybe add a command line option like --additional_typedefs=<file>.
>>>
>>> Oops.  I forgot it already exists:
>>>
>>>     --typedefsfile             Read additional types from this file
>>>
>>> commit 75ad8c575a5ad105e2afc2051c68abceb9c65431
>>> Author: Jerome Forissier <jerome.forissier@linaro.org>
>>> Date:   Mon May 8 15:56:00 2017 -0700
>>>
>>>       checkpatch: add --typedefsfile
>>>       
>>>       When using checkpatch on out-of-tree code, it may occur that some
>>>       project-specific types are used, which will cause spurious warnings.
>>>       Add the --typedefsfile option as a way to extend the known types and
>>>       deal with this issue.
>>
>> This doesn't work for the FIXTURE_DATA() case.
> 
> checkpatch is a stupid little script.
> It's not a c preprocessor nor a syntax complete compiler.
> It's really easy for macros to make its output invalid.
> If you feed obfuscated c to checkpatch, it'd be confused.
> (Same is true for tools like coccinelle btw, though cocci is far better)
> checkpatch will never be comprehensive nor perfect.
> It's expected its users will use their common sense about its
> output message validity.
> 
>> And I'm not sure how
>> contributors would know that they need to use this option with a
>> specific file.
> 
> --help exists
> 
> Maybe Documentation/dev-tools/checkpatch.rst could be expanded for
> --verbose mode.

I was thinking about which file to use, but I understand your point. 
I'll send a v2 with only the "FILE" addition.
FIXTURE_{DATA,VARIANT}() will just not be handled but that's OK.
diff mbox series

Patch

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 79e759aac543..016b47c35742 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -576,10 +576,17 @@  our $typeKernelTypedefs = qr{(?x:
 	(?:__)?(?:u|s|be|le)(?:8|16|32|64)|
 	atomic_t
 )};
+our $typeStdioTypedefs = qr{(?x:
+	FILE
+)};
+# our $typeKselftestHarnessTypedefs = qr{(?x:
+# 	FIXTURE_(?:DATA|VARIANT)\($Ident\)
+# )};
 our $typeTypedefs = qr{(?x:
 	$typeC99Typedefs\b|
 	$typeOtherOSTypedefs\b|
-	$typeKernelTypedefs\b
+	$typeKernelTypedefs\b|
+	$typeStdioTypedefs\b
 )};
 
 our $zero_initializer = qr{(?:(?:0[xX])?0+$Int_type?|NULL|false)\b};