Teach -data-list-register-values to not include unavailable registers

This patch adds an option --skip-unavailable to MI command
-data-list-register-values, so that unavailable registers are not
displayed (on the context of traceframes).

The old -data-list-register-values command behaves like

  -data-list-register-values x 0 8
  ^done,register-values=[{number="0",value="<unavailable>"},{number="8",value="0x80483de"}]

With this patch, an option --skip-unavailable is added,

  -data-list-register-values --skip-unavailable x 0 8
  ^done,register-values=[{number="8",value="0x80483de"}]

gdb:

2013-06-20  Pedro Alves  <pedro@codesourcery.com>
	    Yao Qi  <yao@codesourcery.com>

	* NEWS: Mention the new option '--skip-unavailable' of command
	-data-list-register-values.
	* mi/mi-main.c (mi_cmd_data_list_register_values): Accept the
	--skip-unavailable option.  Adjust to use output_register.
	(output_register): Add new 'skip_unavailable' parameter.
	Handle it.

gdb/doc:

2013-06-20  Pedro Alves  <pedro@codesourcery.com>

	* gdb.texinfo (GDB/MI Data Manipulation)
	<-data-list-register-values>: Document the --skip-unavailable
	option.

gdb/testsuite:

2013-06-20  Yao Qi  <yao@codesourcery.com>

	* gdb.trace/mi-trace-unavailable.exp: Set tracepoint on 'foo'
	and set an action.
	(test_trace_unavailable): Test command -data-list-register-values
	in the context of traceframe and with option --skip-unavailable.
	* gdb.trace/trace-unavailable.c (foo): New.
	(main): Call it.
	* gdb.mi/gdb2549.exp: Update matching pattern.

1 files changed, 36 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
index 3098f9aa5fc..42f6e326c2e 100644
--- a/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
+++ b/gdb/testsuite/gdb.trace/mi-trace-unavailable.exp
@@ -52,6 +52,14 @@ mi_gdb_test "-break-insert -a bar" \
 mi_gdb_test "-break-commands 3 \"collect array\" \"collect j\" \"end\" " \
     {\^done} "set action"
 
+mi_gdb_test "-break-insert -a foo" \
+    "\\^done,bkpt=\{number=\"${decimal}\",type=\"tracepoint\".*\"\}" \
+    "insert tracepoint on foo"
+
+# Collect 'main' to make sure no registers are collected except PC.
+mi_gdb_test "-break-commands 4 \"collect main\" \"end\" " \
+    {\^done} "set action on tracepoint 4"
+
 mi_gdb_test "-trace-start" {.*\^done} "trace start"
 mi_send_resuming_command "exec-continue" "continuing to marker"
 mi_expect_stop \
@@ -96,6 +104,34 @@ proc test_trace_unavailable { data_source } {
 	    ".*\\^done,variables=\\\[\{name=\"j\",arg=\"1\",type=\"int\",value=\"4\"\},\{name=\"s\",arg=\"1\",type=\"char \\\*\",value=\"<unavailable>\"\},\{name=\"array\",type=\"unsigned char \\\[2\\\]\"\},\{name=\"i\",type=\"int\",value=\"<unavailable>\"\}\\\]" \
 	    "-stack-list-variables --simple-values"
 
+	mi_gdb_test "-trace-find frame-number 1" \
+	    ".*\\^done,found=\"1\",tracepoint=\"${decimal}\",traceframe=\"1\",frame=\{.*" \
+	    "-trace-find frame-number 1"
+
+	set pcnum 0
+	if [is_amd64_regs_target] {
+	    set pcnum 16
+	} elseif [is_x86_like_target] {
+	    set pcnum 8
+	} else {
+	    # Other ports support tracepoint should define the number
+	    # of its own pc register.
+	}
+
+	if { $pcnum != 0 } {
+	    global hex
+	    # Test that register 0 and PC are displayed, and register
+	    # 0 is unavailable.
+	    mi_gdb_test "-data-list-register-values x 0 ${pcnum}" \
+		".*\\^done,register-values=\\\[\{number=\"0\",value=\"<unavailable>\"\},\{number=\"${pcnum}\",value=\"${hex}\"\}\\\]" \
+		"-data-list-register-values x"
+
+	    # Test that only available register PC is displayed.
+	    mi_gdb_test "-data-list-register-values --skip-unavailable x 0 ${pcnum}" \
+		".*\\^done,register-values=\\\[\{number=\"${pcnum}\",value=\"${hex}\"\}\\\]" \
+		"-data-list-register-values --skip-unavailable x"
+	}
+
 	# Don't issue command '-trace-find none' to return from
 	# tfind mode (examining trace frames) on purpose, in order
 	# to test that GDB is able to clear its tracing-related local state