building DTrace support (currently broken) View as Markdown

Hello php internals list,

My name is Mike Harsch. I'm new here, so please set me straight on
matters of etiquette and protocol.

I've recently been spending a lot of time using the DTrace feature in
the 5.3.99-dev code base (--enable-dtrace). I was disappointed to find
out that Revision 305329 broke this feature severely. I have a patch
(http://pastebin.com/SZnvz3L0) that fixes the problem by re-inserting
some of the necessary functionality that was removed in 305329. This
patch should be applied to Rev 305455 (very recent).

I believe the primary confusion here is the platform-specific way in
which DTrace USDT probes are compiled on the various platforms that have
DTrace. Specifically, Solaris requires an intermediate compilation
step, while Mac OS X does not. For details on how this is done on
Solaris, see:

http://dtrace.org/blogs/ahl/2006/05/08/user-land-tracing-gets-better-and-better/
and
http://blogs.sun.com/dap/entry/writing_a_dtrace_usdt_provider

For the Mac OS X way of doing this (much simpler), see the section
"Building code containing USDT Probes" in the dtrace(1M) man page for
Darwin:

http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man1/dtrace.1.html

I've heard that FreeBSD has DTrace also, but I don't have any experience
on that platform, so I can't comment on the procedure for building USDT
probes there.

I'm happy to help however I can to get this feature working again. I
don't have much experience with autoconf, so it's likely that my patch
is sub-optimal, but I've tested it on Solaris and Mac OS X and I know it
works (conversely, I can assure you that --enable-dtrace is completely
broken on both platforms as of 305329).

Cheers,

Mike