Don't run compiled condition expressions in gdbserver

[Pedro Alves <pedro at codesourcery dot com>]

As explained in the patch.  Committed.

-- 
Pedro Alves

2010-06-20  Pedro Alves  <pedro@codesourcery.com>

	* tracepoint.c (condition_true_at_tracepoint): Don't run compiled
	conditions in gdbserver.

---
 gdb/gdbserver/tracepoint.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Index: src/gdb/gdbserver/tracepoint.c
===================================================================
--- src.orig/gdb/gdbserver/tracepoint.c	2010-06-20 22:53:32.000000000 +0100
+++ src/gdb/gdbserver/tracepoint.c	2010-06-20 23:12:00.000000000 +0100
@@ -3923,9 +3923,25 @@ condition_true_at_tracepoint (struct tra
   ULONGEST value = 0;
   enum eval_result_type err;
 
+  /* Presently, gdbserver doesn't run compiled conditions, only the
+     IPA does.  If the program stops at a fast tracepoint's address
+     (e.g., due to a breakpoint, trap tracepoint, or stepping),
+     gdbserver preemptively collect the fast tracepoint.  Later, on
+     resume, gdbserver steps over the fast tracepoint like it steps
+     over breakpoints, so that the IPA doesn't see that fast
+     tracepoint.  This avoids double collects of fast tracepoints in
+     that stopping scenario.  Having gdbserver itself handle the fast
+     tracepoint gives the user a consistent view of when fast or trap
+     tracepoints are collected, compared to an alternative where only
+     trap tracepoints are collected on stop, and fast tracepoints on
+     resume.  When a fast tracepoint is being processed by gdbserver,
+     it is always the non-compiled condition expression that is
+     used.  */
+#ifdef IN_PROCESS_AGENT
   if (tpoint->compiled_cond)
     err = ((condfn) (uintptr_t) (tpoint->compiled_cond)) (ctx, &value);
   else
+#endif
     err = eval_agent_expr (ctx, NULL, tpoint->cond, &value);
 
   if (err != expr_eval_no_error)