mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
46 lines
2.0 KiB
46 lines
2.0 KiB
.. _programming_language: |
|
|
|
Programming Language |
|
==================== |
|
|
|
The kernel is written in the C programming language [c-language]_. |
|
More precisely, the kernel is typically compiled with ``gcc`` [gcc]_ |
|
under ``-std=gnu11`` [gcc-c-dialect-options]_: the GNU dialect of ISO C11. |
|
``clang`` [clang]_ is also supported, see docs on |
|
:ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. |
|
|
|
This dialect contains many extensions to the language [gnu-extensions]_, |
|
and many of them are used within the kernel as a matter of course. |
|
|
|
There is some support for compiling the kernel with ``icc`` [icc]_ for several |
|
of the architectures, although at the time of writing it is not completed, |
|
requiring third-party patches. |
|
|
|
Attributes |
|
---------- |
|
|
|
One of the common extensions used throughout the kernel are attributes |
|
[gcc-attribute-syntax]_. Attributes allow to introduce |
|
implementation-defined semantics to language entities (like variables, |
|
functions or types) without having to make significant syntactic changes |
|
to the language (e.g. adding a new keyword) [n2049]_. |
|
|
|
In some cases, attributes are optional (i.e. a compiler not supporting them |
|
should still produce proper code, even if it is slower or does not perform |
|
as many compile-time checks/diagnostics). |
|
|
|
The kernel defines pseudo-keywords (e.g. ``__pure``) instead of using |
|
directly the GNU attribute syntax (e.g. ``__attribute__((__pure__))``) |
|
in order to feature detect which ones can be used and/or to shorten the code. |
|
|
|
Please refer to ``include/linux/compiler_attributes.h`` for more information. |
|
|
|
.. [c-language] http://www.open-std.org/jtc1/sc22/wg14/www/standards |
|
.. [gcc] https://gcc.gnu.org |
|
.. [clang] https://clang.llvm.org |
|
.. [icc] https://software.intel.com/en-us/c-compilers |
|
.. [gcc-c-dialect-options] https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html |
|
.. [gnu-extensions] https://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html |
|
.. [gcc-attribute-syntax] https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html |
|
.. [n2049] http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2049.pdf |
|
|
|
|