Commit 785b9ff290 added libusb init into
sr_init() which can generate an error. In this case, the already
allocated struct sr_context would have leaked.
After sr_init() has successfully run, we can be sure that all drivers
define all the API calls, so we don't have to do these checks later
in the individual API functions / wrappers.
If there are one or more drivers with missing API functions (or driver
name / longname, and so on), sr_init() will fail. This helps catch this
kind of developer error early on.
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>.
Bert Vermeulen
Peter Stuge
Uwe Hermann