[PATCH] Rely on beneath to do partial xfer from tfile target

Yao Qi yao@codesourcery.com
Fri Mar 22 11:13:00 GMT 2013


On 03/20/2013 07:40 PM, Pedro Alves wrote:
> But the patch has another related change in behavior which
> it didn't look like was considered.  If we load the tfile target,
> but we're not yet looking at any trace frame, we currently get:
> 
>   (gdb) p testglob
>   Cannot access memory at address 0x60131c
> 
> With your patch, we now get:
> 
>   (gdb) p testglob
>   $1 = 31415
> 
> So we're left discussing whether that is a desirable change.
> I can see arguments for error, <unavailable> or printing
> the value of the variable in the executable.  The latter seems
> to me the least desirable, with <unavailable> perhaps being
> the best one?

I agree that <unavailable> is the best choice.  The "non-const-
not-collected data" should be <unavailable> also, right?  If so, I'll
post a patch to change "Cannot access memory at address" to
"<unavailable>".

> 
> Meanwhile, I've applied this testsuite patch that covers
> the behavior that the patch doesn't change, WRT to non-const
> globals, and your disassembly bit.

Thanks.  Inspired by your patch, I also add a new test to cover more,
which checks printing four variables {collected, not collected} x
{const, non-const} in different situations.  It shows the change you
gave above, and it is also easy to be extended to test ctf.

-- 
Yao (齐尧)

gdb/testsuite:

	* gdb.trace/read-memory.c: New.
	* gdb.trace/read-memory.exp: New.
---
 gdb/testsuite/gdb.trace/read-memory.c   |   46 +++++++++
 gdb/testsuite/gdb.trace/read-memory.exp |  163 +++++++++++++++++++++++++++++++
 2 files changed, 209 insertions(+), 0 deletions(-)
 create mode 100644 gdb/testsuite/gdb.trace/read-memory.c
 create mode 100644 gdb/testsuite/gdb.trace/read-memory.exp

diff --git a/gdb/testsuite/gdb.trace/read-memory.c b/gdb/testsuite/gdb.trace/read-memory.c
new file mode 100644
index 0000000..bc423b9
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/read-memory.c
@@ -0,0 +1,46 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int testglob = 0;
+
+int testglob_not_collected = 10;
+
+const int constglob = 10000;
+
+const int constglob_not_collected = 100;
+
+static void
+start (void)
+{}
+
+static void
+end (void)
+{}
+
+int
+main (void)
+{
+  testglob++;
+  testglob_not_collected++;
+
+  start ();
+
+  testglob++;
+  testglob_not_collected++;
+  end ();
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.trace/read-memory.exp b/gdb/testsuite/gdb.trace/read-memory.exp
new file mode 100644
index 0000000..e7c0af3
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/read-memory.exp
@@ -0,0 +1,163 @@
+#   Copyright 2013 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib "trace-support.exp"
+
+standard_testfile
+
+if { [gdb_compile "$srcdir/$subdir/$srcfile" $binfile \
+	  executable {debug nowarnings}] != "" } {
+    untested read-memory.exp
+    return -1
+}
+clean_restart $testfile
+if ![runto_main] {
+    fail "Can't run to main to check for trace support"
+    return -1
+}
+
+if ![gdb_target_supports_trace] {
+    unsupported "target does not support trace"
+    return -1
+}
+
+# Set tracepoints, start tracing and collect data.
+
+proc set_tracepoint_and_collect { } {
+    global testfile srcfile
+
+    # Start with a fresh gdb.
+    clean_restart ${testfile}
+    if ![runto_main] {
+	fail "Can't run to main"
+	return -1
+    }
+    gdb_test "break end" "Breakpoint \[0-9\] at .*"
+    gdb_test "trace start" "Tracepoint \[0-9\] at .*"
+    gdb_trace_setactions "set action for tracepoint"  "" \
+	"collect testglob" "^$" \
+	"collect constglob" "^$"
+
+    gdb_test_no_output "tstart"
+    gdb_test "continue" ".*Breakpoint.* end .*at.*$srcfile.*" \
+	"continue to end"
+    gdb_test_no_output "tstop"
+}
+
+with_test_prefix "live" {
+    set_tracepoint_and_collect
+
+    gdb_test "print testglob" " = 2"
+    gdb_test "print testglob_not_collected" " = 12"
+    gdb_test "print constglob" " = 10000"
+    gdb_test "print constglob_not_collected" " = 100"
+}
+
+with_test_prefix "live target tfind" {
+    gdb_test "tfind 0" "Found trace frame 0, tracepoint \[0-9\]+.*" \
+	"tfind 0"
+    gdb_test "print testglob" " = 1"
+    gdb_test "print testglob_not_collected" " = <unavailable>"
+    gdb_test "print constglob" " = 10000"
+    gdb_test "print constglob_not_collected" " = 100"
+    gdb_test "tfind" "Target failed to find requested trace frame." \
+	"tfind does not find a second frame"
+}
+
+# Save trace frames to trace file.
+set tracefile [standard_output_file ${testfile}]
+gdb_test "tsave ${tracefile}.tfile" \
+    "Trace data saved to file '${tracefile}.tfile'.*" \
+    "save tfile trace"
+
+# Test read memory when changing target from remote to ${target}.
+
+proc test_from_remote { target } {
+    global gdb_prompt testfile
+    global tracefile
+
+    with_test_prefix "remote to ${target}" {
+	set_tracepoint_and_collect
+
+	# Change target to ${target}.
+	set test "change target"
+	gdb_test_multiple "target ${target} ${tracefile}.${target}" "$test" {
+	    -re "A program is being debugged already.  Kill it. .y or n. " {
+		send_gdb "y\n"
+		exp_continue
+	    }
+	    -re "$gdb_prompt $" {
+		pass "$test"
+	    }
+	}
+
+	with_test_prefix "/wo setting traceframe" {
+	    gdb_test "print testglob" "Cannot access memory at address.*"
+	    gdb_test "print testglob_not_collected" \
+		"Cannot access memory at address.*"
+	    gdb_test "print constglob" " = 10000"
+	    gdb_test "print constglob_not_collected" " = 100"
+	}
+	with_test_prefix "/w setting traceframe" {
+	    gdb_test "tfind 0" "Found trace frame 0, tracepoint \[0-9\]+.*" \
+		"tfind 0"
+	    gdb_test "print testglob" " = 1"
+	    gdb_test "print testglob_not_collected" " = <unavailable>"
+	    gdb_test "print constglob" " = 10000"
+	    gdb_test "print constglob_not_collected" " = 100"
+	    gdb_test "tfind" "Target failed to find requested trace frame." \
+		"tfind does not find a second frame"
+	}
+    }
+}
+
+test_from_remote "tfile"
+
+# Test read memory when changing target from exec to ${target}
+
+proc teset_from_exec { target } {
+    global srcdir subdir binfile testfile
+    global tracefile
+
+    # Restart GDB and read the trace data in ${target} target.
+    gdb_exit
+    gdb_start
+    gdb_reinitialize_dir $srcdir/$subdir
+    gdb_file_cmd $binfile
+
+    gdb_test "target ${target} ${tracefile}.${target}" ".*" \
+	"change to ${target} target"
+
+    with_test_prefix "exec to ${target} /wo setting traceframe" {
+	gdb_test "print testglob" "Cannot access memory at address.*"
+	gdb_test "print testglob_not_collected" \
+	    "Cannot access memory at address.*"
+	gdb_test "print constglob" " = 10000"
+	gdb_test "print constglob_not_collected" " = 100"
+    }
+
+    with_test_prefix "exec to ${target} /w setting traceframe" {
+	gdb_test "tfind 0" "Found trace frame 0, tracepoint \[0-9\]+.*" \
+	    "tfind 0"
+	gdb_test "print testglob" " = 1"
+	gdb_test "print testglob_not_collected" " = <unavailable>"
+	gdb_test "print constglob" " = 10000"
+	gdb_test "print constglob_not_collected" " = 100"
+	gdb_test "tfind" "Target failed to find requested trace frame." \
+	    "tfind does not find a second frame"
+    }
+}
+
+teset_from_exec "tfile"
-- 
1.7.7.6



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