[ltt-dev] LTTng-UST public headers reimplemented under MIT (BSD-style) license

[Mathieu Desnoyers]

Hi,

I noticed that having a LGPLv2.1 license for tracepoint instrumentation
headers of lttng-ust might turn away some class of users unwilling to
include LGPLv2.1 headers into their code. Most of the content of these
headers did fall under the "trivial" structure declarations, static
inline/macros of 10 lines of less, etc. of the LGPL, except for the
tracepoint event probe generation header files, but I figured it would
make everyone more comfortable if all public lttng-ust headers were MIT
(BSD-style) licensed.

So what I did is:

- Relicense all public LGPL header files for which I was the sole author to
  MIT BSD-style license,
- Privatize all headers that did not need to be kept public (this was a
  cleanup phase I was about to do anyway),
- Remove all LGPL and LGPL-derived header files left in the lttng-ust
  git tree,
- Implement the missing headers under MIT BSD-style license. Those were:
  ust-tracepoint-event.h, tracepoint-event.h, tracepoint-types.h,
  tracepoint.h, tracepoint-internal.h, ust-tracepoint-event-reset.h.

Please note that the implementation files of LTTng-UST are still
LGPLv2.1. This license change only apply to the publicly exported
headers.

This is accompanied with a minor tracepoint event API change: from now
on, instead of having separate TRACEPOINT_INCLUDE_PATH and
TRACEPOINT_INCLUDE_FILE macros, we simply have, e.g.:

#undef TRACEPOINT_INCLUDE_FILE
#define TRACEPOINT_INCLUDE_FILE ./ust_tests_demo.h

Also, the TRACEPOINT_INCLUDE_FILE macro becomes mandatory (no more
"default" path).

Best regards,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com