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77acaf5af5
The "flags" utility is useful but painful to maintain up to date. This
commit aims at providing a low-maintenance solution to keep flags up to
date, by proposing some macros that build a string from a set of flags
in a way that requires the least possible verbosity.
The idea will be to add an inline function dedicated to this just after
the flags declaration, and enumerate the flags one is interested in, and
that function will fill a string based on them.
Placing this inside the type files allows both haproxy and external tools
like "flags" to use it, but comes with a few constraints. First, the
files will be slightly less readable if these functions are huge, so they
need to stay as compact as possible. Second, the function will need
anprintf() and we don't want to include stdio.h in type files as it
proved to be particularly heavy and to cause definition headaches in
the past.
As such the file here only contains a macro enclosed in #ifdef EOF (that
is defined in stdio), and provides an alternate empty one when no stdio
is defined. This way it's the caller that has to include stdio first or
it won't get anything back, and in practice the locations relying on
this always have it.
The macro has to be used in 3 steps:
- prologue: dumps 0 and exits if the value is zero
- flags: the macro can be recursively called and it will push the
flag from bottom to top so that they appear in the same order as
today without requiring to be declared the other way around
- epilogue: dump remaining flags that were not identified
The macro was arranged so that a single character can be used with no
other argument to declare all flags at once. Example:
#define _(n, ...) __APPEND_FLAG(buf, len, del, flg, n, #n, __VA_ARGS__)
_(0);
_(X_FLAG1, _(X_FLAG2, _(X_FLAG3, _(X_FLAG4))));
_(~0);
#undef _
Existing files will have to be updated to rely on it, and more files
could come soon.
The HAProxy documentation has been split into a number of different files for ease of use. Please refer to the following files depending on what you're looking for : - INSTALL for instructions on how to build and install HAProxy - BRANCHES to understand the project's life cycle and what version to use - LICENSE for the project's license - CONTRIBUTING for the process to follow to submit contributions The more detailed documentation is located into the doc/ directory : - doc/intro.txt for a quick introduction on HAProxy - doc/configuration.txt for the configuration's reference manual - doc/lua.txt for the Lua's reference manual - doc/SPOE.txt for how to use the SPOE engine - doc/network-namespaces.txt for how to use network namespaces under Linux - doc/management.txt for the management guide - doc/regression-testing.txt for how to use the regression testing suite - doc/peers.txt for the peers protocol reference - doc/coding-style.txt for how to adopt HAProxy's coding style - doc/internals for developer-specific documentation (not all up to date)