Add @since tags to some (not all yet) public API functions, to document
in which release they were added (and/or in which release there were
API changes).
Document the @since usage in HACKING.
Also, add Doxygen docs for the functions in version.c.
All frontends will have to include <libsigrok/libsigrok.h> from now on.
This header includes proto.h and version.h, both installed from the
distribution into $INCLUDE/libsigrok/ as well.
The only dynamically changed header is now version.h, which has both
libsigrok and libtool compile-time versions in it.
Use SR_API to mark public API symbols, and SR_PRIV for private symbols.
Variables and functions marked 'static' are private already and don't
need SR_PRIV. However, functions which are not static (because they need
to be used in other libsigrok-internal files) but are also not meant to
be part of the public libsigrok API, must use SR_PRIV.
This uses the 'visibility' feature of gcc (requires gcc >= 4.0).
Details: http://gcc.gnu.org/wiki/Visibility
In the lib, we should only #include "sigrok.h" or "sigrok-internal.h",
but not the (possibly installed and thus different/older versions) via
<sigrok.h> or <sigrok-internal.h>.
Frontends should of course use <sigrok.h> and <sigrok-internal.h>.
libsigrok can now be told at which loglevel to work, i.e., how many
debug/error/warning output to generate. You can also query the current
loglevel.
In sigrok-cli it is now possible to set the loglevel via -l. For example:
- Disable all output: sigrok-cli -l 0
- Only show errors: sigrok-cli -l 1
- Show errors, warnings, info, and debug messages: sigrok-cli -l 4
We should use these (internal) functions in libsigrok exclusively from
now on, i.e. no more use of glib's g_debug() etc.
These functions are only for libsigrok, the frontends use whatever
logging mechanism is suitable there.