[Openmcl-devel] modified GDB for Darwin

Gary Byers gb at clozure.com
Thu Oct 4 17:43:39 UTC 2012

If you ever need to debug CCL (the current trunk or future releases)
with GDB on Darwin, you'll find that GDB's use of a "task level Mach
exception handler" (whatever that is ...) gets in the way of that.
CCL used to try to get around this by using a "thread level Mach
exception handler" (whatever that is ...), but that ran into problems
on Mountain Lion and it seems possible that future OSX releases will
break other things in the Mach layer.  (Apple calls this
"deprecation".  I always thought that that word meant something
slightly different ...)

Until Apple resolves the GDB issues (and there may be reason to think
that they're moving in the right direction), you can use one of the
following versions of GDB:

<ftp://clozure.com/pub/gdb-1820-limited-mach-exceptions.tar.gz> for 10.6-10.8

<ftp://clozure.com/pub/gdb-768-limited-mach-exceptions.tar.gz> for 10.5

Each archive contains a modified GDB executable (the one in the v1820 archive
is signed by Clozure, thanks to rme), diffs to the sources that Apple distributes,
and a README file that tries to explain installation issues (and explains how
to build from source if you'd rather do that than use the provided executable.)

(If you've never used GDB to debug CCL, don't worry: you aren't missing much ...)

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