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| author | David Lamparter <equinox@diac24.net> | 2019-08-13 16:02:51 +0200 |
|---|---|---|
| committer | David Lamparter <equinox@diac24.net> | 2019-09-03 17:18:35 +0200 |
| commit | 81047bc5b7f8c28037084adda318fdd68c1a5776 (patch) | |
| tree | bb59211f6c73ff8a468914b3fb7f8381667fd20c | |
| parent | *: frr_elevate_privs -> frr_with_privs (diff) | |
| download | frr-81047bc5b7f8c28037084adda318fdd68c1a5776.tar.xz frr-81047bc5b7f8c28037084adda318fdd68c1a5776.zip | |
doc: add frr_{each,with} to coding style
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
| -rw-r--r-- | doc/developer/workflow.rst | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/doc/developer/workflow.rst b/doc/developer/workflow.rst index 07c43ac2d..3c6887fba 100644 --- a/doc/developer/workflow.rst +++ b/doc/developer/workflow.rst @@ -767,6 +767,28 @@ ways that can be unexpected for the original implementor. As such debugs ability to turn on/off debugs from the CLI and it is expected that the developer will use this convention to allow control of their debugs. +Custom syntax-like block macros +------------------------------- + +FRR uses some macros that behave like the ``for`` or ``if`` C keywords. These +macros follow these patterns: + +- loop-style macros are named ``frr_each_*`` (and ``frr_each``) +- single run macros are named ``frr_with_*`` +- to avoid confusion, ``frr_with_*`` macros must always use a ``{ ... }`` + block even if the block only contains one statement. The ``frr_each`` + constructs are assumed to be well-known enough to use normal ``for`` rules. +- ``break``, ``return`` and ``goto`` all work correctly. For loop-style + macros, ``continue`` works correctly too. + +Both the ``each`` and ``with`` keywords are inspired by other (more +higher-level) programming languages that provide these constructs. + +There are also some older iteration macros, e.g. ``ALL_LIST_ELEMENTS`` and +``FOREACH_AFI_SAFI``. These macros in some cases do **not** fulfill the above +pattern (e.g. ``break`` does not work in ``FOREACH_AFI_SAFI`` because it +expands to 2 nested loops.) + Static Analysis and Sanitizers ------------------------------ Clang/LLVM and GCC come with a variety of tools that can be used to help find |