* Get rid of the RCS Header stuff.  They're meaningless in git.
 * Add public domain comment to some of the files if the only comment
   was the RCS header.

o Generate values for REAL_LRA_SLOT, KNOWN_RETURN_P_SLOT, and
  BOGUS_LRA_CONSTANTS from the actual Lisp values.

breakpoint.c:
o Use the generated values above, if available.  We leave suitable
  defaults for now, but they should probably be removed.

disable GC before calling HANDLE-BREAKPOINT.  We save the real LRA
object to the Lisp stack, before calling HANDLE-BREAKPOINT.
Afterwards, we load the LRA from the stack.  Thus, if GC happened, the
stack value will have changed appropriately, and we return to the
correct place.

compiler/ppc/parms.lisp:
compiler/sparc/parms.lisp:
o Don't need lisp::*gc-inhibit* to be a static symbol anymore so
  remove it.

lisp/breakpoint.c:
o Implement above idea in handle_function_end_breakpoint.
o Add comments on the values of REAL_LRA_SLOT and friends.
o Clean up compute_offsets for the x86 case which doesn't handle ppc
  or sparc anymore.

compiler/sparc/parms.lisp:
o Add lisp::*gc-inhibit* to list of static symbols.  (No cross-compile
  needed because we used one of the spare static symbols.  Full cycle
  of builds needed to progate the changes.)

lisp/breakpoint.c:
o Disable GC when calling HANDLE-BREAKPOINT.  This is a temporary
  workaround to the issue where a GC occurring during
  HANDLE-BREAKPOINT can cause a segfault during tracing.  GC moves the
  code object and/or bogus lra such that we don't know where we should
  return to.

at offset 0 error that happens on sparc.  Still has the same segfault
problem that sparc has.

about an unknown breakpoint at offset 0 when handling a function-end
breakpoint.

See the comment for compute_offset for an explanation.

Note that this seems to fix that issue, but there is still the issue
where a segfault will happen during tracing.  It seems to happen if a
GC occurs after the function end breakpoint has happened
(compute_offset has already been called before GC happens), and trace
has printed out the return value.  Then a segfault happens.

Due to some issues, this fix only works when compiled with gcc.
Compiling with Sun c produces some segfaults somewhere such that we
can't build cmucl at all.  The bizarre part is that compute_offset is
never called during a build because there are no breakpoints enabled
during a normal build.

.indent.pro.

as well.

lisp/breakpoint.c:
o Enable function-end stuff in compute_offset for DARWIN too.
o Lots of printf's so we can see what's happening on ppc since gdb is
  majorly broken there.

lisp/ppc-assem.S:
o Actually implement the function-end breakpoint template.  Basically
  copied the sparc version, with appropriate mods.

lisp/ppc-arch.c:
o Add TWLLEI_R0 macro to create the appropriate trap instructions that
  we need, and use as appropriate.
o arch_install_breakpoint was actually broken and installed a twllgei
  instruction instead of twllei.
o arch_do_displaced_inst was also broken.  It didn't install the
  after-break-point trap after the breakpoint trap.  And it also
  didn't continue running the code and returned instead.  That's
  wrong.
o The trap_AfterBreakpoint case in sigill_handler was inserting the
  wrong instruction back.  (Probably too much copying of the sparc
  port.)

Helmut Eller's patch sent to cmucl-imp on 2005-03-08.  This basically
means tracing recursive functions will show all recursions during the
trace and not just the final call.

code/debug-int.lisp:
o Apply Helmut's patch.  Tweak it so when the known-return convention
  is being used, we tell MAKE-BOGUS-LRA that we're using the
  known-return so we can handle it properly.

lisp/breakpoint.c:
o Add an extra parameter to compute_offset so we know we're handling a
  function-end breakpoint or not.  Needed because reg_CODE isn't
  pointing to the bogus lra in this case, so the offsets are all
  wrong.  We compute the right offset for the known return and return
  the offset as negative so we can tell.
o Adjust all callers of compute_offset.
o Adjust handle_function_end_breakpoint to handle negative offsets
  from compute_offset so we can get the right code component for the
  bogus lra.

by the commit of the NetBSD support, and needed by the upcoming merge of
the OS X/Darwin port.

via the POSIX_SIGS conditional. Change the way SA_SIGINFO gets passed
to sigaction. It is turned off for FreeBSD and Linux.

ports; fake_foreign_function_call must be called before sap_alloc on
the non-x86 port so that current_dynamic_space_free_pointer is setup
from reg_ALLOC.

bogus LRA code objects rather than a SAP to avoid lossage if the real
code object is moved while the real return address has been moved off
the stack.

tested in the experimental code and works on both FreeBSD and Linux.
Plus a few improvements to the interrupt safety for the x86 port.

under hpux.