* tracepoint.c (tfile_get_trace_state_variable_value): Look for

	the last matched 'V' blcok in trace frame.

gdb/gdbserver:

	* tracepoint.c (traceframe_read_tsv): Look for the last matched
	'V' block in trace frame.

gdb/testsuite:

	* gdb.trace/tsv.exp (check_tsv): New.
	(top level): Save a tfile on current trace session. Call
	check_tsv on live target.  Load the tfile with target tfile
	and call check_tsv again.

6 files changed, 63 insertions, 10 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 08aee5c..19801d1 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-13  Yao Qi  <yao@codesourcery.com>
+
+	* tracepoint.c (tfile_get_trace_state_variable_value): Look for
+	the last matched 'V' blcok in trace frame.
+
 2013-03-12  Joel Brobecker  <brobecker@adacore.com>
 
 	* NEWS: Create a new section for the next release branch.
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 9a5ae02..a7289fd 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-13  Yao Qi  <yao@codesourcery.com>
+
+	* tracepoint.c (traceframe_read_tsv): Look for the last matched
+	'V' block in trace frame.
+
 2013-03-11  Markus Metzger  <markus.t.metzger@intel.com>
 
 	* target.h (struct target_ops): Add btrace ops.
diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
index dcc2e78..bea6202 100644
--- a/gdb/gdbserver/tracepoint.c
+++ b/gdb/gdbserver/tracepoint.c
@@ -5257,6 +5257,7 @@ traceframe_read_tsv (int tsvnum, LONGEST *val)
   unsigned char *database, *dataptr;
   unsigned int datasize;
   int vnum;
+  int found = 0;
 
   trace_debug ("traceframe_read_tsv");
 
@@ -5279,7 +5280,8 @@ traceframe_read_tsv (int tsvnum, LONGEST *val)
   datasize = tframe->data_size;
   database = dataptr = &tframe->data[0];
 
-  /* Iterate through a traceframe's blocks, looking for the tsv.  */
+  /* Iterate through a traceframe's blocks, looking for the last
+     matched tsv.  */
   while ((dataptr = traceframe_find_block_type (dataptr,
 						datasize
 						- (dataptr - database),
@@ -5294,16 +5296,17 @@ traceframe_read_tsv (int tsvnum, LONGEST *val)
       if (tsvnum == vnum)
 	{
 	  memcpy (val, dataptr, sizeof (*val));
-	  return 0;
+	  found = 1;
 	}
 
       /* Skip over this block.  */
       dataptr += sizeof (LONGEST);
     }
 
-  trace_debug ("traceframe %d has no data for variable %d",
-	       tfnum, tsvnum);
-  return 1;
+  if (!found)
+    trace_debug ("traceframe %d has no data for variable %d",
+		 tfnum, tsvnum);
+  return !found;
 }
 
 /* Read a requested block of static tracepoint data from a trace
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 588b0b3..37eecbb 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,12 @@
 2013-03-13  Yao Qi  <yao@codesourcery.com>
 
+	* gdb.trace/tsv.exp (check_tsv): New.
+	(top level): Save a tfile on current trace session. Call
+	check_tsv on live target.  Load the tfile with target tfile
+	and call check_tsv again.
+
+2013-03-13  Yao Qi  <yao@codesourcery.com>
+
 	* gdb.trace/tsv.exp: Remove code unrelated to testing TSV.
 	Replace some "gdb_test" with "gdb_test_no_output".
 
diff --git a/gdb/testsuite/gdb.trace/tsv.exp b/gdb/testsuite/gdb.trace/tsv.exp
index bab0a10..de523fd 100644
--- a/gdb/testsuite/gdb.trace/tsv.exp
+++ b/gdb/testsuite/gdb.trace/tsv.exp
@@ -142,7 +142,36 @@ gdb_test "print \$tvar5" " = 16" \
 
 gdb_test_no_output "tstop" ""
 
-gdb_test "print \$tvar5" " = 16" \
-    "Print a trace state variable after run"
+# Save trace frames to tfile.
+set tracefile [standard_output_file ${testfile}]
+gdb_test "tsave ${tracefile}.tf" \
+    "Trace data saved to file '${tracefile}.tf'.*" \
+    "save tfile trace file"
+
+proc check_tsv { data_source } {
+    with_test_prefix "${data_source}" {
+	gdb_test "tfind 0"
+	gdb_test "print \$tvar5" " = 16" \
+	    "Print a trace state variable"
+	gdb_test "tfind" \
+	    "Target failed to find requested trace frame.*"
+    }
+}
 
+# Check the tsv from the live inferior.
+check_tsv "live"
+
+# Change target to tfile.
+set test "change to tfile target"
+gdb_test_multiple "target tfile ${tracefile}.tf" "$test" {
+    -re "A program is being debugged already.  Kill it. .y or n. " {
+	send_gdb "y\n"
+	exp_continue
+    }
+    -re "$gdb_prompt $" {
+	pass "$test"
+    }
+}
 
+# Check the tsv from tfile.
+check_tsv "tfile"
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 7f27bc0..513dccc 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -4655,7 +4655,12 @@ static int
 tfile_get_trace_state_variable_value (int tsvnum, LONGEST *val)
 {
   int pos;
+  int found = 0;
 
+  /* Iterate over blocks in current frame and find the last 'V'
+     block in which tsv number is TSVNUM.  In one trace frame, there
+     may be multiple 'V' blocks created for a given trace variable,
+     and the last matched 'V' block contains the updated value.  */
   pos = 0;
   while ((pos = traceframe_find_block_type ('V', pos)) >= 0)
     {
@@ -4671,13 +4676,12 @@ tfile_get_trace_state_variable_value (int tsvnum, LONGEST *val)
 	  *val = extract_signed_integer ((gdb_byte *) val, 8,
 					 gdbarch_byte_order
 					 (target_gdbarch ()));
-	  return 1;
+	  found = 1;
 	}
       pos += (4 + 8);
     }
 
-  /* Didn't find anything.  */
-  return 0;
+  return found;
 }
 
 static int