Nested function in drivers/of/of_mdio.c

Nested function in drivers/of/of_mdio.c

[Jérôme Pouiller]

Dear,

I have a problem with commit 8bc487d150b939e69830c39322df4ee486efe381 
in file drivers/of/of_mdio.c in function of_phy_find_device.

As you see, this function define match() as a nested function. My 
compiler (powerpc-e500-linux-gnu-gcc-3.4.1) raise an error during link 
due to this nested definition:
  drivers/built-in.o(.text+0x5e2a4): In function `of_phy_find_device': /home/jezz/linux-next/drivers/of/of_mdio.c:107: 
undefined reference to `__trampoline_setup'

I am sure I could solve problem by rebuilding my toolchain. 
Nevertheless, I think nested function definition is not perfectly 
supported by all compilers. Also, I suggest to place function match() 
outside of scope of of_phy_find_device as in following patch.

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index bacaa53..c7b2e26 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -97,6 +97,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 }
 EXPORT_SYMBOL(of_mdiobus_register);

+static int match(struct device *dev, void *phy_np)
+{
+       return dev_archdata_get_node(&dev->archdata) == phy_np;
+}
 /**
  * of_phy_find_device - Give a PHY node, find the phy_device
  * @phy_np: Pointer to the phy's device tree node
@@ -106,11 +110,6 @@ EXPORT_SYMBOL(of_mdiobus_register);
 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 {
        struct device *d;
-       int match(struct device *dev, void *phy_np)
-       {
-               return dev_archdata_get_node(&dev->archdata) == phy_np;
-       }
-
        if (!phy_np)
                return NULL;


What do you think about it?

Best regards,

-- 
Jérôme Pouiller (jezz AT sysmic DOT org)

Re: Nested function in drivers/of/of_mdio.c

[Grant Likely]

On Wed, Oct 7, 2009 at 9:15 AM, Jérôme Pouiller <jezz@sysmic.org> wrote:
> Dear,
>
> I have a problem with commit 8bc487d150b939e69830c39322df4ee486efe381
> in file drivers/of/of_mdio.c in function of_phy_find_device.
>
> As you see, this function define match() as a nested function. My
> compiler (powerpc-e500-linux-gnu-gcc-3.4.1) raise an error during link
> due to this nested definition:
>  drivers/built-in.o(.text+0x5e2a4): In function `of_phy_find_device': /home/jezz/linux-next/drivers/of/of_mdio.c:107:
> undefined reference to `__trampoline_setup'
>
> I am sure I could solve problem by rebuilding my toolchain.
> Nevertheless, I think nested function definition is not perfectly
> supported by all compilers. Also, I suggest to place function match()
> outside of scope of of_phy_find_device as in following patch.

I'm okay with that, but if you're moving code out of the file scope,
then please rename the function to of_phy_match() to avoid global
namespace conflicts.

g.

>
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index bacaa53..c7b2e26 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -97,6 +97,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>  }
>  EXPORT_SYMBOL(of_mdiobus_register);
>
> +static int match(struct device *dev, void *phy_np)
> +{
> +       return dev_archdata_get_node(&dev->archdata) == phy_np;
> +}
>  /**
>  * of_phy_find_device - Give a PHY node, find the phy_device
>  * @phy_np: Pointer to the phy's device tree node
> @@ -106,11 +110,6 @@ EXPORT_SYMBOL(of_mdiobus_register);
>  struct phy_device *of_phy_find_device(struct device_node *phy_np)
>  {
>        struct device *d;
> -       int match(struct device *dev, void *phy_np)
> -       {
> -               return dev_archdata_get_node(&dev->archdata) == phy_np;
> -       }
> -
>        if (!phy_np)
>                return NULL;
>
>
> What do you think about it?
>
> Best regards,
>
> --
> Jérôme Pouiller (jezz AT sysmic DOT org)
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: Nested function in drivers/of/of_mdio.c

[vb]

Guys, are there other instances of nested C functions in the codebase
or was this the first attempt?


On Wed, Oct 7, 2009 at 9:11 AM, Grant Likely <grant.likely@secretlab.ca> wrote:
> On Wed, Oct 7, 2009 at 9:15 AM, Jérôme Pouiller <jezz@sysmic.org> wrote:
>> Dear,
>>
>> I have a problem with commit 8bc487d150b939e69830c39322df4ee486efe381
>> in file drivers/of/of_mdio.c in function of_phy_find_device.
>>
>> As you see, this function define match() as a nested function. My
>> compiler (powerpc-e500-linux-gnu-gcc-3.4.1) raise an error during link
>> due to this nested definition:
>>  drivers/built-in.o(.text+0x5e2a4): In function `of_phy_find_device': /home/jezz/linux-next/drivers/of/of_mdio.c:107:
>> undefined reference to `__trampoline_setup'
>>
>> I am sure I could solve problem by rebuilding my toolchain.
>> Nevertheless, I think nested function definition is not perfectly
>> supported by all compilers. Also, I suggest to place function match()
>> outside of scope of of_phy_find_device as in following patch.
>
> I'm okay with that, but if you're moving code out of the file scope,
> then please rename the function to of_phy_match() to avoid global
> namespace conflicts.
>
> g.
>
>>
>> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
>> index bacaa53..c7b2e26 100644
>> --- a/drivers/of/of_mdio.c
>> +++ b/drivers/of/of_mdio.c
>> @@ -97,6 +97,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>>  }
>>  EXPORT_SYMBOL(of_mdiobus_register);
>>
>> +static int match(struct device *dev, void *phy_np)
>> +{
>> +       return dev_archdata_get_node(&dev->archdata) == phy_np;
>> +}
>>  /**
>>  * of_phy_find_device - Give a PHY node, find the phy_device
>>  * @phy_np: Pointer to the phy's device tree node
>> @@ -106,11 +110,6 @@ EXPORT_SYMBOL(of_mdiobus_register);
>>  struct phy_device *of_phy_find_device(struct device_node *phy_np)
>>  {
>>        struct device *d;
>> -       int match(struct device *dev, void *phy_np)
>> -       {
>> -               return dev_archdata_get_node(&dev->archdata) == phy_np;
>> -       }
>> -
>>        if (!phy_np)
>>                return NULL;
>>
>>
>> What do you think about it?
>>
>> Best regards,
>>
>> --
>> Jérôme Pouiller (jezz AT sysmic DOT org)
>>
>
>
>
> --
> Grant Likely, B.Sc., P.Eng.
> Secret Lab Technologies Ltd.
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>

Re: Nested function in drivers/of/of_mdio.c

[Jérôme Pouiller]

I did some grep on codebase. I have not found any other instances of 
nested functions, but my regexps are not enough to be 100% sure.

On Wednesday 07 October 2009 18:23:04 vb@vsbe.com wrote:
> Guys, are there other instances of nested C functions in the codebase
> or was this the first attempt?
> 
> On Wed, Oct 7, 2009 at 9:11 AM, Grant Likely 
<grant.likely@secretlab.ca> wrote:
> > On Wed, Oct 7, 2009 at 9:15 AM, Jérôme Pouiller <jezz@sysmic.org> 
wrote:
> >> Dear,
> >>
> >> I have a problem with commit
> >> 8bc487d150b939e69830c39322df4ee486efe381 in file
> >> drivers/of/of_mdio.c in function of_phy_find_device.
> >>
> >> As you see, this function define match() as a nested function. My
> >> compiler (powerpc-e500-linux-gnu-gcc-3.4.1) raise an error during
> >> link due to this nested definition:
> >>  drivers/built-in.o(.text+0x5e2a4): In function
> >> `of_phy_find_device':
> >> /home/jezz/linux-next/drivers/of/of_mdio.c:107: undefined
> >> reference to `__trampoline_setup'
> >>
> >> I am sure I could solve problem by rebuilding my toolchain.
> >> Nevertheless, I think nested function definition is not perfectly
> >> supported by all compilers. Also, I suggest to place function
> >> match() outside of scope of of_phy_find_device as in following
> >> patch.
> >
> > I'm okay with that, but if you're moving code out of the file
> > scope, then please rename the function to of_phy_match() to avoid
> > global namespace conflicts.
> >
> > g.
> >
> >> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> >> index bacaa53..c7b2e26 100644
> >> --- a/drivers/of/of_mdio.c
> >> +++ b/drivers/of/of_mdio.c
> >> @@ -97,6 +97,10 @@ int of_mdiobus_register(struct mii_bus *mdio,
> >> struct device_node *np) }
> >>  EXPORT_SYMBOL(of_mdiobus_register);
> >>
> >> +static int match(struct device *dev, void *phy_np)
> >> +{
> >> +       return dev_archdata_get_node(&dev->archdata) == phy_np;
> >> +}
> >>  /**
> >>  * of_phy_find_device - Give a PHY node, find the phy_device
> >>  * @phy_np: Pointer to the phy's device tree node
> >> @@ -106,11 +110,6 @@ EXPORT_SYMBOL(of_mdiobus_register);
> >>  struct phy_device *of_phy_find_device(struct device_node *phy_np)
> >>  {
> >>        struct device *d;
> >> -       int match(struct device *dev, void *phy_np)
> >> -       {
> >> -               return dev_archdata_get_node(&dev->archdata) ==
> >> phy_np; -       }
> >> -
> >>        if (!phy_np)
> >>                return NULL;
> >>
> >>
> >> What do you think about it?
> >>
> >> Best regards,
> >>
> >> --
> >> Jérôme Pouiller (jezz AT sysmic DOT org)
> >
> > --
> > Grant Likely, B.Sc., P.Eng.
> > Secret Lab Technologies Ltd.
> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev@lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/linuxppc-dev
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
> 

-- 
Jérôme Pouiller (jerome AT sysmic DOT org)
Expert Linux Embarqué

Re: Nested function in drivers/of/of_mdio.c

[Gabriel Paubert]

On Thu, Oct 08, 2009 at 10:45:12AM +0200, Jérôme Pouiller wrote:
> I did some grep on codebase. I have not found any other instances of 
> nested functions, but my regexps are not enough to be 100% sure.

>From Documentation/CodingStyle, written by the Head Penguin himself:

"Heretic people all over the world have claimed that this inconsistency
is ...  well ...  inconsistent, but all right-thinking people know that
(a) K&R are _right_ and (b) K&R are right.  Besides, functions are
special anyway (you can't nest them in C)."
                ^^^^^^^^^^^^^^^^^^^^^^^^

I interpret it as a clear prohibition of using nested functions
in the kernel.  

	Regards,
	Gabriel

[PATCH] Remove nested function

[Jérôme Pouiller]

Some toolchains dislike nested function definition, so we define function match
outside of of_phy_find_device.

Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
---
 drivers/of/of_mdio.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index bacaa53..4b22ba5 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -97,6 +97,12 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 }
 EXPORT_SYMBOL(of_mdiobus_register);
 
+/* Helper function for of_phy_find_device */
+static int of_phy_match(struct device *dev, void *phy_np)
+{
+	return dev_archdata_get_node(&dev->archdata) == phy_np;
+}
+
 /**
  * of_phy_find_device - Give a PHY node, find the phy_device
  * @phy_np: Pointer to the phy's device tree node
@@ -106,15 +112,10 @@ EXPORT_SYMBOL(of_mdiobus_register);
 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 {
 	struct device *d;
-	int match(struct device *dev, void *phy_np)
-	{
-		return dev_archdata_get_node(&dev->archdata) == phy_np;
-	}
-
 	if (!phy_np)
 		return NULL;
 
-	d = bus_find_device(&mdio_bus_type, NULL, phy_np, match);
+	d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 	return d ? to_phy_device(d) : NULL;
 }
 EXPORT_SYMBOL(of_phy_find_device);
-- 
1.6.0.4

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [PATCH] Remove nested function

[David Miller]

From: Jérôme Pouiller <jezz@sysmic.org>
Date: Thu,  8 Oct 2009 10:34:23 +0200

> Some toolchains dislike nested function definition, so we define function match
> outside of of_phy_find_device.
> 
> Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>

Acked-by: David S. Miller <davem@davemloft.net>

Re: Nested function in drivers/of/of_mdio.c

[Grant Likely]

Please resend your question with both linuxppc-dev@lists.ozlabs.org
and netdev@vger.kernel.org added to the cc: list.

g.

On Wed, Oct 7, 2009 at 8:29 AM, Jérôme Pouiller <jezz@sysmic.org> wrote:
> Dear,
>
> I have a problem with commit 8bc487d150b939e69830c39322df4ee486efe381
> in file drivers/of/of_mdio.c in function of_phy_find_device.
>
> As you see, this function define match() as a nested function. My
> compiler (powerpc-e500-linux-gnu-gcc-3.4.1) raise an error during link
> due to this nested definition:
>  drivers/built-in.o(.text+0x5e2a4): In function `of_phy_find_device': /home/jezz/linux-next/drivers/of/of_mdio.c:107:
> undefined reference to `__trampoline_setup'
>
> I am sure I could solve problem by rebuilding my toolchain.
> Nevertheless, I think nested function definition is not perfectly
> supported by all compilers. Also, I suggest to place function match()
> outside of scope of of_phy_find_device as in following patch.
>
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index bacaa53..c7b2e26 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -97,6 +97,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>  }
>  EXPORT_SYMBOL(of_mdiobus_register);
>
> +static int match(struct device *dev, void *phy_np)
> +{
> +       return dev_archdata_get_node(&dev->archdata) == phy_np;
> +}
>  /**
>  * of_phy_find_device - Give a PHY node, find the phy_device
>  * @phy_np: Pointer to the phy's device tree node
> @@ -106,11 +110,6 @@ EXPORT_SYMBOL(of_mdiobus_register);
>  struct phy_device *of_phy_find_device(struct device_node *phy_np)
>  {
>        struct device *d;
> -       int match(struct device *dev, void *phy_np)
> -       {
> -               return dev_archdata_get_node(&dev->archdata) == phy_np;
> -       }
> -
>        if (!phy_np)
>                return NULL;
>
>
> What do you think about it?
>
> Best regards,
>
> --
> Jérôme Pouiller (jezz AT sysmic DOT org)
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.