Fix PR16508

This patch fixes PR16508, which is about MI "-trace-find frame-number 0"
behaves differently from CLI "tfind 0".  In CLI, we check both
status->running and status->filename, but in MI, we only check
status->running, which looks wrong to me.  This patch moves the code
of checking to a new function check_trace_running, and use it in
both CLI and MI.

This patch also adds a test case pr16508.exp, which fails without this
fix, and passes with the fix applied.

  FAIL: gdb.trace/pr16508.exp: interpreter-exec mi "-trace-find frame-number 0"

gdb:

2014-03-06  Yao Qi  <yao@codesourcery.com>

	PR breakpoints/16508
	* tracepoint.c (check_trace_running): New function.
	(trace_find_command): Move code to check_trace_running and
	call check_trace_running.
	(trace_find_pc_command): Likewise.
	(trace_find_tracepoint_command): Likewise.
	(trace_find_line_command): Likewise.
	(trace_find_range_command): Likewise.
	* tracepoint.h (check_trace_running): Likewise.
	* mi/mi-main.c (mi_cmd_trace_find): Call check_trace_running.

gdb/testsuite:

2014-03-06  Yao Qi  <yao@codesourcery.com>

	* gdb.trace/pr16508.exp: New file.

1 files changed, 14 insertions, 15 deletions

diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 1ff1bda..4153eae 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -2443,6 +2443,15 @@ tfind_1 (enum trace_find_type type, int num,
     }
 }
 
+/* Error on looking at traceframes while trace is running.  */
+
+void
+check_trace_running (struct trace_status *status)
+{
+  if (status->running && status->filename == NULL)
+    error (_("May not look at trace frames while trace is running."));
+}
+
 /* trace_find_command takes a trace frame number n, 
    sends "QTFrame:<n>" to the target, 
    and accepts a reply that may contain several optional pieces
@@ -2463,9 +2472,7 @@ trace_find_command (char *args, int from_tty)
 { /* This should only be called with a numeric argument.  */
   int frameno = -1;
 
-  if (current_trace_status ()->running
-      && current_trace_status ()->filename == NULL)
-    error (_("May not look at trace frames while trace is running."));
+  check_trace_running (current_trace_status ());
   
   if (args == 0 || *args == 0)
     { /* TFIND with no args means find NEXT trace frame.  */
@@ -2515,9 +2522,7 @@ trace_find_pc_command (char *args, int from_tty)
 {
   CORE_ADDR pc;
 
-  if (current_trace_status ()->running
-      && current_trace_status ()->filename == NULL)
-    error (_("May not look at trace frames while trace is running."));
+  check_trace_running (current_trace_status ());
 
   if (args == 0 || *args == 0)
     pc = regcache_read_pc (get_current_regcache ());
@@ -2534,9 +2539,7 @@ trace_find_tracepoint_command (char *args, int from_tty)
   int tdp;
   struct tracepoint *tp;
 
-  if (current_trace_status ()->running
-      && current_trace_status ()->filename == NULL)
-    error (_("May not look at trace frames while trace is running."));
+  check_trace_running (current_trace_status ());
 
   if (args == 0 || *args == 0)
     {
@@ -2574,9 +2577,7 @@ trace_find_line_command (char *args, int from_tty)
   struct symtab_and_line sal;
   struct cleanup *old_chain;
 
-  if (current_trace_status ()->running
-      && current_trace_status ()->filename == NULL)
-    error (_("May not look at trace frames while trace is running."));
+  check_trace_running (current_trace_status ());
 
   if (args == 0 || *args == 0)
     {
@@ -2640,9 +2641,7 @@ trace_find_range_command (char *args, int from_tty)
   static CORE_ADDR start, stop;
   char *tmp;
 
-  if (current_trace_status ()->running
-      && current_trace_status ()->filename == NULL)
-    error (_("May not look at trace frames while trace is running."));
+  check_trace_running (current_trace_status ());
 
   if (args == 0 || *args == 0)
     { /* XXX FIXME: what should default behavior be?  */