9091373ab7
The whole struct/function declarations in this header are surrounded
by #ifdef.
As far as I understood, the motivation of this is probably to break
the build earlier if a driver misses to select or depend on correct
CONFIG options in Kconfig.
Since commit 94bed2a9c4ae ("Add -Werror-implicit-function-declaration")
no one cannot call functions that have not been declared.
So, I see some benefit in doing this in the cost of uglier headers.
In reality, it would not be so easy to catch missed 'select' or
'depends on' because GPIOLIB, GPIOLIB_IRQCHIP etc. are already selected
by someone else eventually. So, this kind of error, if any, will be
caught by randconfig bots.
In summary, I am not a big fan of cluttered #ifdef nesting, and this
does not matter for normal developers. The code readability wins.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.