=========================== Including uAPI header files =========================== Sometimes, it is useful to include header files and C example codes in order to describe the userspace API and to generate cross-references between the code and the documentation. Adding cross-references for userspace API files has an additional vantage: Sphinx will generate warnings if a symbol is not found at the documentation. That helps to keep the uAPI documentation in sync with the Kernel changes. The :ref:`parse_headers.pl <parse_headers>` provide a way to generate such cross-references. It has to be called via Makefile, while building the documentation. Please see ``Documentation/media/Makefile`` for an example about how to use it inside the Kernel tree. .. _parse_headers: parse_headers.pl ^^^^^^^^^^^^^^^^ NAME **** parse_headers.pl - parse a C file, in order to identify functions, structs, enums and defines and create cross-references to a Sphinx book. SYNOPSIS ******** \ **parse_headers.pl**\ [<options>] <C_FILE> <OUT_FILE> [<EXCEPTIONS_FILE>] Where <options> can be: --debug, --help or --usage. OPTIONS ******* \ **--debug**\ Put the script in verbose mode, useful for debugging. \ **--usage**\ Prints a brief help message and exits. \ **--help**\ Prints a more detailed help message and exits. DESCRIPTION *********** Convert a C header or source file (C_FILE), into a ReStructured Text included via ..parsed-literal block with cross-references for the documentation files that describe the API. It accepts an optional EXCEPTIONS_FILE with describes what elements will be either ignored or be pointed to a non-default reference. The output is written at the (OUT_FILE). It is capable of identifying defines, functions, structs, typedefs, enums and enum symbols and create cross-references for all of them. It is also capable of distinguish #define used for specifying a Linux ioctl. The EXCEPTIONS_FILE contain two types of statements: \ **ignore**\ or \ **replace**\ . The syntax for the ignore tag is: ignore \ **type**\ \ **name**\ The \ **ignore**\ means that it won't generate cross references for a \ **name**\ symbol of type \ **type**\ . The syntax for the replace tag is: replace \ **type**\ \ **name**\ \ **new_value**\ The \ **replace**\ means that it will generate cross references for a \ **name**\ symbol of type \ **type**\ , but, instead of using the default replacement rule, it will use \ **new_value**\ . For both statements, \ **type**\ can be either one of the following: \ **ioctl**\ The ignore or replace statement will apply to ioctl definitions like: #define VIDIOC_DBG_S_REGISTER _IOW('V', 79, struct v4l2_dbg_register) \ **define**\ The ignore or replace statement will apply to any other #define found at C_FILE. \ **typedef**\ The ignore or replace statement will apply to typedef statements at C_FILE. \ **struct**\ The ignore or replace statement will apply to the name of struct statements at C_FILE. \ **enum**\ The ignore or replace statement will apply to the name of enum statements at C_FILE. \ **symbol**\ The ignore or replace statement will apply to the name of enum value at C_FILE. For replace statements, \ **new_value**\ will automatically use :c:type: references for \ **typedef**\ , \ **enum**\ and \ **struct**\ types. It will use :ref: for \ **ioctl**\ , \ **define**\ and \ **symbol**\ types. The type of reference can also be explicitly defined at the replace statement. EXAMPLES ******** ignore define _VIDEODEV2_H Ignore a #define _VIDEODEV2_H at the C_FILE. ignore symbol PRIVATE On a struct like: enum foo { BAR1, BAR2, PRIVATE }; It won't generate cross-references for \ **PRIVATE**\ . replace symbol BAR1 :c:type:\`foo\` replace symbol BAR2 :c:type:\`foo\` On a struct like: enum foo { BAR1, BAR2, PRIVATE }; It will make the BAR1 and BAR2 enum symbols to cross reference the foo symbol at the C domain. BUGS **** Report bugs to Mauro Carvalho Chehab <mchehab@kernel.org> COPYRIGHT ********* Copyright (c) 2016 by Mauro Carvalho Chehab <mchehab+samsung@kernel.org>. License GPLv2: GNU GPL version 2 <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.