[PATCH 3/3] Select the current frame in command tdump.

[Yao Qi <yao@codesourcery.com>]

Command 'tdump' should be run on the current stack frame instead of
the selected stack frame.  This patch is to change to the current
stack trace when executing command 'tdump'.

This patch also adds a test in gdb.trace/backtrace.exp, to test
'tdump' on frame 0 and frame 1 respectively. If only test
part of patch is applied, we'll get a fail:

Data collected at tracepoint 6, trace frame 4:^M
$ebp = (void *) 0xbfffe7c8^M
(*(void **) ($esp)) @ 64 = {0x3, 0x2, 0x3, 0x4, 0x5, 0x5, 0x6,
0x4cf0d152 <handle_intel+146>, 0xbfffe7cf, 0x0, 0x8a18d300,
0xbfffe7a0, 0x8, 0xbfffe7a3, 0x80487c0, 0x80487b4, 0xf0b2ff,
0x8048243, 0xca0000, 0x4d01cff4, 0x0, 0x0, 0xbfffe818, 0x80486c7
<main+62>, 0xbfffe7e4, 0x8049abc, 0x1, 0x80482cd <_init+41>,
0x4d01b1b4, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa,
0x80486e0 <__libc_csu_init>, 0x0, 0x0, 0x4ce896b3
<__libc_start_main+243>, 0x1, 0xbfffe8b4, 0xbfffe8bc, 0x4ce6cfc4,
<unavailable> <unavailable>, <unavailable>, <unavailable>,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
<unavailable>, <unavailable>, <unavailable>, <unavailable>,
<unavailable>, <unavailable>, <unavailable>, <unavailable>,
<unavailable>, <unavailable>, <unavailable>, <unavailable>,
<unavailable>}
^^^^^^^^^^^^^^
(gdb) FAIL: gdb.trace/backtrace.exp: traceframe 4: tdump on frame 1

as we can see, "<unavailable>" is unexpected.  With all the patch
applied, the fail is fixed, and we'll see that no "<unavailable>"
appeared in the output.

Data collected at tracepoint 6, trace frame 4:^M
$ebp = (void *) 0xbfffe768^M
(*(void **) ($esp)) @ 64 = {0xbfffe810, 0x4ce55a39
<_dl_lookup_symbol_x+265>, 0xbfffe7f0, 0x80481cc, 0xbfffe7d8,
0x4ce6da54, 0x0, 0xb7ffeca8, 0x1, 0x0, 0x1, 0x1, 0x0, 0x0, 0xbfffe7c8,
0x80485fc <gdb_c_test+450>, 0x3, 0x2, 0x3, 0x4, 0x5, 0x5, 0x6,
0x4cf0d152 <handle_intel+146>, 0xbfffe7cf, 0x0, 0x96dfd800,
0xbfffe7a0, 0x8, 0xbfffe7a3, 0x80487c0, 0x80487b4, 0xf0b2ff,
0x8048243, 0xca0000, 0x4d01cff4, 0x0, 0x0, 0xbfffe818, 0x80486c7
<main+62>, 0xbfffe7e4, 0x8049abc, 0x1, 0x80482cd <_init+41>,
0x4d01b1b4, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa,
0x80486e0 <__libc_csu_init>, 0x0, 0x0, 0x4ce896b3
<__libc_start_main+243>, 0x1, 0xbfffe8b4, 0xbfffe8bc, 0x4ce6cfc4}^M
(gdb) PASS: gdb.trace/backtrace.exp: traceframe 4: tdump on frame 1

gdb:

2013-06-27  Pedro Alves  <pedro@codesourcery.com>
	    Yao Qi  <yao@codesourcery.com>

	* tracepoint.c (trace_dump_command): Select the current frame.

gdb/testsuite:

2013-06-27  Yao Qi  <yao@codesourcery.com>

	* gdb.trace/backtrace.exp (gdb_backtrace_tdp_4): Test command
	'tdump' on stack frame 0 and 1 respectively.
---
 gdb/testsuite/gdb.trace/backtrace.exp |   19 +++++++++++++++++++
 gdb/tracepoint.c                      |    6 ++++++
 2 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/gdb/testsuite/gdb.trace/backtrace.exp b/gdb/testsuite/gdb.trace/backtrace.exp
index e40428f..6f32f2a 100644
--- a/gdb/testsuite/gdb.trace/backtrace.exp
+++ b/gdb/testsuite/gdb.trace/backtrace.exp
@@ -211,6 +211,7 @@ proc gdb_backtrace_tdp_3 { msg } {
 
 proc gdb_backtrace_tdp_4 { msg depth traceframe } {
     global gdb_prompt
+    global decimal hex
 
     with_test_prefix "traceframe $traceframe" {
 	# We are in a trace frame at which we collected all registers,
@@ -230,6 +231,24 @@ proc gdb_backtrace_tdp_4 { msg depth traceframe } {
 		fail "$msg (fewer than $depth stack frames found)"
 	    }
 	}
+
+	# Make sure no output like "0x0 <repeats 2 times>" confuses
+	# the matching below.
+	gdb_test_no_output "set print repeats 64" ""
+
+	# Match the output of command 'tdump' like '0xbfffe810' or
+	# '0x4ce55a39 <_dl_lookup_symbol_x+265>'.
+	gdb_test "tdump" \
+	    "Data collected at tracepoint $decimal, trace frame $decimal:.* = \\{($hex, |$hex <.*>, ){63}($hex|$hex <.*>)\\}" \
+	    "tdump on frame 0"
+
+	gdb_test "up" ".*" ""
+
+	# Test command 'tdump' still work properly when the selected
+	# frame is not the current frame.
+	gdb_test "tdump" \
+	    "Data collected at tracepoint $decimal, trace frame $decimal:.* = \\{($hex, |$hex <.*>, ){63}($hex|$hex <.*>)\\}" \
+	    "tdump on frame 1"
     }
 }
 
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 4277843..eb276e9 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -3071,6 +3071,12 @@ trace_dump_command (char *args, int from_tty)
 		   tracepoint_number, traceframe_number);
 
   old_chain = make_cleanup (null_cleanup, NULL);
+
+  /* This command only makes sense for the current frame, not the
+     selected frame.  */
+  make_cleanup_restore_current_thread ();
+  select_frame (get_current_frame ());
+
   actions = all_tracepoint_actions_and_cleanup (loc->owner);
 
   trace_dump_actions (actions, 0, stepping_frame, from_tty);
-- 
1.7.7.6