[yocto-docs] migration-5.2: Add entries for virtual provider and multiconfig changes

Add some information to the migration guide about two important potentially
breaking changes in 5.2.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
---
Notes:
* original patch by Richard Purdie:
  https://lore.kernel.org/r/20250126111850.2609298-1-richard.purdie@linuxfoundation.org
  This patch is just reformatting/typo fixes.
* The BB_CURRENT_MC should ideally be documented, but that will come at
  a later point with
  https://bugzilla.yoctoproject.org/show_bug.cgi?id=15709.
---
 documentation/migration-guides/migration-5.2.rst | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)


---
base-commit: e6745669cc26de8f61d5d1ccdd5a95b552eece97
change-id: 20250129-migration-5-2-updates-cb613b02bd35

Best regards,

Hi Antonin,

On 1/29/25 11:25 AM, Antonin Godard via lists.yoctoproject.org wrote:
> Add some information to the migration guide about two important potentially
> breaking changes in 5.2.
> 
> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
> Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
> ---
> Notes:
> * original patch by Richard Purdie:
>    https://lore.kernel.org/r/20250126111850.2609298-1-richard.purdie@linuxfoundation.org
>    This patch is just reformatting/typo fixes.
> * The BB_CURRENT_MC should ideally be documented, but that will come at
>    a later point with
>    https://bugzilla.yoctoproject.org/show_bug.cgi?id=15709.
> ---
>   documentation/migration-guides/migration-5.2.rst | 23 +++++++++++++++++++++++
>   1 file changed, 23 insertions(+)
> 
> diff --git a/documentation/migration-guides/migration-5.2.rst b/documentation/migration-guides/migration-5.2.rst
> index e9de6910e..245c22f28 100644
> --- a/documentation/migration-guides/migration-5.2.rst
> +++ b/documentation/migration-guides/migration-5.2.rst
> @@ -94,6 +94,29 @@ systemd changes
>      not for socket files).
>      Now all service files must be explicitly added to :term:`FILES`.
>   
> +Multiconfig changes
> +~~~~~~~~~~~~~~~~~~~
> +
> +-  The value of ``BB_CURRENT_MC`` was changed from ``default`` to an empty string
> +   for the default multiconfig configuration to avoid needing to map the values
> +   within BitBake. This was already not happening in some cases so this fixes
> +   some obscure bugs.
> +
> +Virtual toolchain provider changes
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +-  Support was added for virtual providers on a per-recipe basis for specific
> +   key toolchain providers listed in ``BB_VIRTUAL_RECIPE_PROVIDERS``. As part of
> +   that support, the ``cross`` providers were simplified to remove the triplet
> +   prefix and generalise the naming, so for example::
> +
> +      virtual/${TARGET_PREFIX}-binutils -> virtual/cross-bintuils
> +      virtual/${TARGET_PREFIX}-gcc -> virtual/cross-cc
> +      virtual/${TARGET_PREFIX}-g++ -> virtual/cross-c++
> +      virtual/${TARGET_PREFIX}-compilerlibs -> virtual/compilerlibs
> +      virtual/${SDK_PREFIX}-binutils -> virtual/nativesdk-cross-binutils
> +      virtual/${SDK_PREFIX}-gcc -> virtual/nativesdk-cross-cc
> +

This is in the migration manual so we need to explicit what the user 
needs to do.

What needs to be done wrt BB_CURRENT_MC change?

For the removal of TARGET_PREFIX/SDK_PREFIX, I assume a simple tree-wide:

sed 's;virtual/\${TARGET_PREFIX}binutils;virtual/cross-bintuils;'

should do the trick?

Also, all of the above didn't have a dash after ${SDK_PREFIX} or 
${TARGET_PREFIX}.

Cheers,
Quentin

Hi Quentin,

On Thu Jan 30, 2025 at 5:05 PM CET, Quentin Schulz wrote:
> Hi Antonin,
>
> On 1/29/25 11:25 AM, Antonin Godard via lists.yoctoproject.org wrote:
>> Add some information to the migration guide about two important potentially
>> breaking changes in 5.2.
>> 
>> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
>> Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
>> ---
>> Notes:
>> * original patch by Richard Purdie:
>>    https://lore.kernel.org/r/20250126111850.2609298-1-richard.purdie@linuxfoundation.org
>>    This patch is just reformatting/typo fixes.
>> * The BB_CURRENT_MC should ideally be documented, but that will come at
>>    a later point with
>>    https://bugzilla.yoctoproject.org/show_bug.cgi?id=15709.
>> ---
>>   documentation/migration-guides/migration-5.2.rst | 23 +++++++++++++++++++++++
>>   1 file changed, 23 insertions(+)
>> 
>> diff --git a/documentation/migration-guides/migration-5.2.rst b/documentation/migration-guides/migration-5.2.rst
>> index e9de6910e..245c22f28 100644
>> --- a/documentation/migration-guides/migration-5.2.rst
>> +++ b/documentation/migration-guides/migration-5.2.rst
>> @@ -94,6 +94,29 @@ systemd changes
>>      not for socket files).
>>      Now all service files must be explicitly added to :term:`FILES`.
>>   
>> +Multiconfig changes
>> +~~~~~~~~~~~~~~~~~~~
>> +
>> +-  The value of ``BB_CURRENT_MC`` was changed from ``default`` to an empty string
>> +   for the default multiconfig configuration to avoid needing to map the values
>> +   within BitBake. This was already not happening in some cases so this fixes
>> +   some obscure bugs.
>> +
>> +Virtual toolchain provider changes
>> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> +
>> +-  Support was added for virtual providers on a per-recipe basis for specific
>> +   key toolchain providers listed in ``BB_VIRTUAL_RECIPE_PROVIDERS``. As part of
>> +   that support, the ``cross`` providers were simplified to remove the triplet
>> +   prefix and generalise the naming, so for example::
>> +
>> +      virtual/${TARGET_PREFIX}-binutils -> virtual/cross-bintuils
>> +      virtual/${TARGET_PREFIX}-gcc -> virtual/cross-cc
>> +      virtual/${TARGET_PREFIX}-g++ -> virtual/cross-c++
>> +      virtual/${TARGET_PREFIX}-compilerlibs -> virtual/compilerlibs
>> +      virtual/${SDK_PREFIX}-binutils -> virtual/nativesdk-cross-binutils
>> +      virtual/${SDK_PREFIX}-gcc -> virtual/nativesdk-cross-cc
>> +
>
> This is in the migration manual so we need to explicit what the user 
> needs to do.

I don't know if there is a definite rule, but I will try to add more examples
here so hopefully it gives a clear overview of what should be replaced.

> What needs to be done wrt BB_CURRENT_MC change?

I would assume that any logic based on BB_CURRENT_MC == "default" should be
changed, like what's done in ff469ab2e865 ("bitbake.conf: Handle empty
BB_CURRENT_MC") on OE-Core.

I will suggest to do that in the v2.

> For the removal of TARGET_PREFIX/SDK_PREFIX, I assume a simple tree-wide:
>
> sed 's;virtual/\${TARGET_PREFIX}binutils;virtual/cross-bintuils;'
>
> should do the trick?

In the docs, we don't have any reference to virtual/XXX<something> where XXX is
HOST_PREFIX, SDK_PREFIX, or TARGET_PREFIX. So no changes to be done here at
least.

> Also, all of the above didn't have a dash after ${SDK_PREFIX} or 
> ${TARGET_PREFIX}.

Indeed, good catch, will fix in v2.

Thanks,
Antonin