diff options
Diffstat (limited to 'libc/docs/mechanics_of_public_api.rst')
| -rw-r--r-- | libc/docs/mechanics_of_public_api.rst | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/libc/docs/mechanics_of_public_api.rst b/libc/docs/mechanics_of_public_api.rst new file mode 100644 index 00000000000..992c8ac304a --- /dev/null +++ b/libc/docs/mechanics_of_public_api.rst @@ -0,0 +1,29 @@ +The mechanics of the ``public_api`` command +=========================================== + +The build system, in combination with the header generation mechanism, +facilitates the fine grained ability to pick and choose the public API one wants +to expose on their platform. The public header files are always generated from +the corresponding ``.h.def`` files. A header generation command ``%%public_api`` +is listed in these files. In the generated header file, the header generator +replaces this command with the public API relevant for the target platform. + +Under the hood +-------------- + +When the header generator sees the ``%%public_api`` command, it looks up the +API config file for the platform in the path ``config/<platform>/api.td``. +The API config file lists two kinds of items: + +1. The list of standards from which the public entities available on the platform + are derived from. +2. For each header file exposed on the platfrom, the list of public members + provided in that header file. + +Note that, the header generator only learns the names of the public entities +from the header config file (the 2nd item from above.) The exact manner in which +the entities are to be declared is got from the standards (the 1st item from +above.) + +See the ground truth document for more information on how the standards are +formally listed in LLVM libc using LLVM table-gen files. |
