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Diffstat (limited to 'Documentation/bpf/libbpf/libbpf_naming_convention.rst')
| -rw-r--r-- | Documentation/bpf/libbpf/libbpf_naming_convention.rst | 63 |
1 files changed, 47 insertions, 16 deletions
diff --git a/Documentation/bpf/libbpf/libbpf_naming_convention.rst b/Documentation/bpf/libbpf/libbpf_naming_convention.rst index 3de1d51e41da..b5b41b61b3c0 100644 --- a/Documentation/bpf/libbpf/libbpf_naming_convention.rst +++ b/Documentation/bpf/libbpf/libbpf_naming_convention.rst @@ -9,8 +9,8 @@ described here. It's recommended to follow these conventions whenever a new function or type is added to keep libbpf API clean and consistent. All types and functions provided by libbpf API should have one of the -following prefixes: ``bpf_``, ``btf_``, ``libbpf_``, ``xsk_``, -``btf_dump_``, ``ring_buffer_``, ``perf_buffer_``. +following prefixes: ``bpf_``, ``btf_``, ``libbpf_``, ``btf_dump_``, +``ring_buffer_``, ``perf_buffer_``. System call wrappers -------------------- @@ -59,17 +59,8 @@ Auxiliary functions and types that don't fit well in any of categories described above should have ``libbpf_`` prefix, e.g. ``libbpf_get_error`` or ``libbpf_prog_type_by_name``. -AF_XDP functions -------------------- - -AF_XDP functions should have an ``xsk_`` prefix, e.g. -``xsk_umem__get_data`` or ``xsk_umem__create``. The interface consists -of both low-level ring access functions and high-level configuration -functions. These can be mixed and matched. Note that these functions -are not reentrant for performance reasons. - ABI -========== +--- libbpf can be both linked statically or used as DSO. To avoid possible conflicts with other libraries an application is linked with, all @@ -92,8 +83,8 @@ This prevents from accidentally exporting a symbol, that is not supposed to be a part of ABI what, in turn, improves both libbpf developer- and user-experiences. -ABI versionning ---------------- +ABI versioning +-------------- To make future ABI extensions possible libbpf ABI is versioned. Versioning is implemented by ``libbpf.map`` version script that is @@ -108,7 +99,7 @@ This bump in ABI version is at most once per kernel development cycle. For example, if current state of ``libbpf.map`` is: -.. code-block:: c +.. code-block:: none LIBBPF_0.0.1 { global: @@ -121,7 +112,7 @@ For example, if current state of ``libbpf.map`` is: , and a new symbol ``bpf_func_c`` is being introduced, then ``libbpf.map`` should be changed like this: -.. code-block:: c +.. code-block:: none LIBBPF_0.0.1 { global: @@ -150,6 +141,46 @@ mirror of the mainline's version of libbpf for a stand-alone build. However, all changes to libbpf's code base must be upstreamed through the mainline kernel tree. + +API documentation convention +============================ + +The libbpf API is documented via comments above definitions in +header files. These comments can be rendered by doxygen and sphinx +for well organized html output. This section describes the +convention in which these comments should be formatted. + +Here is an example from btf.h: + +.. code-block:: c + + /** + * @brief **btf__new()** creates a new instance of a BTF object from the raw + * bytes of an ELF's BTF section + * @param data raw bytes + * @param size number of bytes passed in `data` + * @return new BTF object instance which has to be eventually freed with + * **btf__free()** + * + * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract + * error code from such a pointer `libbpf_get_error()` should be used. If + * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is + * returned on error instead. In both cases thread-local `errno` variable is + * always set to error code as well. + */ + +The comment must start with a block comment of the form '/\*\*'. + +The documentation always starts with a @brief directive. This line is a short +description about this API. It starts with the name of the API, denoted in bold +like so: **api_name**. Please include an open and close parenthesis if this is a +function. Follow with the short description of the API. A longer form description +can be added below the last directive, at the bottom of the comment. + +Parameters are denoted with the @param directive, there should be one for each +parameter. If this is a function with a non-void return, use the @return directive +to document it. + License ------------------- |