[PATCH v2] GDB/testsuite: Add a way to send multiple init commands

["Maciej W. Rozycki" <macro at codesourcery dot com>]

On Fri, 20 Jun 2014, Pedro Alves wrote:

> > 2014-06-11  Maciej W. Rozycki  <macro@mips.com>
> >             Maciej W. Rozycki  <macro@codesourcery.com>
> > 
> > 	* lib/gdb.exp (gdb_run_cmd): Process `gdb_init_commands'.
> > 	* lib/mi-support.exp (mi_run_cmd): Process `gdb_init_commands'.
> > 	* README (Board Settings): Document `gdb_init_command' and 
> > 	`gdb_init_commands'.
> 
> I don't particularly see much need for this -- I do this in my
> boards instead:
> 
>  set GDBFLAGS ""
>  set GDBFLAGS "${GDBFLAGS} -ex \"set breakpoint always-inserted on\""
>  set GDBFLAGS "${GDBFLAGS} -ex \"set target-async 1\""
> 
> See:
> 
> https://sourceware.org/gdb/wiki/TestingGDB#Passing_an_option_to_GDB_.2BAC8_Running_the_whole_test_suite_in_a_non-default_mode
> 
> But, given gdb_init_command exists and this can be made
> non-intrusive, it's fine with me to add the new option.

 That and I think there are two issues with passing commands as 
command-line arguments:

1. They are always executed, perhaps unnecessarily whereas 
   `gdb_init_command' and consequently `gdb_init_commands' are only 
   interpreted when a target connection is about to be made (this is more 
   of an aesthetic matter, but still).

2. Some environments have a limit, maybe quite low, on the maximum length 
   of a command line or command-line arguments they accept (now that is 
   more real).

 BTW, in updating DejaGNU documentation that refers to `gdb_init_command' 
I've noticed it lists a command that pokes at a CPU register there -- has 
the semantics of the setting changed sometime, perhaps long ago?  Does 
anybody know/remember?

> Thought, I'd much prefer if this code that appears twice:
> 
> > +    set commands ""
> >      if [target_info exists gdb_init_command] {
> > -	send_gdb "[target_info gdb_init_command]\n"
> > +	lappend commands [target_info gdb_init_command]
> > +    }
> > +    if [target_info exists gdb_init_commands] {
> > +	set commands [concat $commands [target_info gdb_init_commands]]
> > +    }
> > +    foreach command $commands {
> 
> was factored out to a procedure that returns the command list.  Like:
> 
> # Comment here
> proc gdb_init_commands {} {
>     set commands {}
>     if [target_info exists gdb_init_command] {
> 	lappend commands [target_info gdb_init_command]
>     }
>     if [target_info exists gdb_init_commands] {
> 	set commands [concat $commands [target_info gdb_init_commands]]
>     }
>     return commands
> }
> 
> And then, both users can do
> 
>     foreach command [gdb_init_commands] {

 Done, as below, and retested.  Any other questions or comments?  
Otherwise OK to apply?

 Here's the original description repeated, for a reference:

--------------------------------------------------------------------------
 Right now we provide a board info entry, `gdb_init_command', that allows 
one to send a single command to GDB before the program to be debugged is 
started.  This is useful e.g. for slow remote targets to change the 
default "remotetimeout" setting.  Occasionally I found a need to send 
multiple commands instead, however this cannot be achieved with 
`gdb_init_command'.

 This change therefore extends the mechanism by adding a TCL list of GDB 
commands to send, via a board info entry called `gdb_init_commands'.  
There is no limit as to the number of commands put there.  The old 
`gdb_init_command' mechanism remains supported for compatibility with 
existing people's environments.  I have a separate change for DejaGNU too, 
being posted right away, that adds an `add_board_info' procedure that 
makes it easy to append entries there; it's not strictly needed here or 
anywhere in our testsuite though.
--------------------------------------------------------------------------

2014-07-10  Maciej W. Rozycki  <macro@mips.com>
            Maciej W. Rozycki  <macro@codesourcery.com>

	* lib/gdb-utils.exp: New file.
	* lib/gdb.exp (gdb_run_cmd): Call gdb_init_commands, replacing
	inline `gdb_init_command' processing.
	* lib/mi-support.exp (mi_run_cmd): Likewise.
	* README: Document `gdb_init_command' and `gdb_init_commands'.

  Maciej

gdb-init-commands.diff
Index: gdb-fsf-trunk-quilt/gdb/testsuite/README
===================================================================
--- gdb-fsf-trunk-quilt.orig/gdb/testsuite/README	2014-06-03 15:23:24.000000000 +0100
+++ gdb-fsf-trunk-quilt/gdb/testsuite/README	2014-06-11 19:29:49.538972371 +0100
@@ -271,6 +271,16 @@ gdb,use_precord
 
   The board supports process record.
 
+gdb_init_command
+gdb_init_commands
+
+  Commands to send to GDB every time a program is about to be run.  The
+  first of these settings defines a single command as a string.  The
+  second defines a TCL list of commands being a string each.  The commands
+  are sent one by one in a sequence, first from `gdb_init_command', if any,
+  followed by individual commands from `gdb_init_command', if any, in this
+  list's order.
+
 gdb_server_prog
 
   The location of GDBserver.  If GDBserver somewhere other than its
Index: gdb-fsf-trunk-quilt/gdb/testsuite/lib/gdb.exp
===================================================================
--- gdb-fsf-trunk-quilt.orig/gdb/testsuite/lib/gdb.exp	2014-06-07 18:27:52.000000000 +0100
+++ gdb-fsf-trunk-quilt/gdb/testsuite/lib/gdb.exp	2014-06-20 23:48:39.868925158 +0100
@@ -27,6 +27,7 @@ if {$tool == ""} {
 
 load_lib libgloss.exp
 load_lib cache.exp
+load_lib gdb-utils.exp
 
 global GDB
 
@@ -209,8 +210,8 @@ proc delete_breakpoints {} {
 proc gdb_run_cmd {args} {
     global gdb_prompt use_gdb_stub
 
-    if [target_info exists gdb_init_command] {
-	send_gdb "[target_info gdb_init_command]\n"
+    foreach command [gdb_init_commands] {
+	send_gdb "$command\n"
 	gdb_expect 30 {
 	    -re "$gdb_prompt $" { }
 	    default {
@@ -311,8 +312,8 @@ proc gdb_run_cmd {args} {
 proc gdb_start_cmd {args} {
     global gdb_prompt use_gdb_stub
 
-    if [target_info exists gdb_init_command] {
-	send_gdb "[target_info gdb_init_command]\n"
+    foreach command [gdb_init_commands] {
+	send_gdb "$command\n"
 	gdb_expect 30 {
 	    -re "$gdb_prompt $" { }
 	    default {
Index: gdb-fsf-trunk-quilt/gdb/testsuite/lib/mi-support.exp
===================================================================
--- gdb-fsf-trunk-quilt.orig/gdb/testsuite/lib/mi-support.exp	2014-06-07 18:27:50.000000000 +0100
+++ gdb-fsf-trunk-quilt/gdb/testsuite/lib/mi-support.exp	2014-06-20 23:47:57.868926864 +0100
@@ -17,6 +17,8 @@
 
 # Test setup routines that work with the MI interpreter.
 
+load_lib gdb-utils.exp
+
 # The variable mi_gdb_prompt is a regexp which matches the gdb mi prompt.
 # Set it if it is not already set.
 global mi_gdb_prompt
@@ -859,8 +861,8 @@ proc mi_run_cmd_full {use_mi_command arg
 	set run_match ""
     }
 
-    if [target_info exists gdb_init_command] {
-	send_gdb "[target_info gdb_init_command]\n"
+    foreach command [gdb_init_commands] {
+	send_gdb "$command\n"
 	gdb_expect 30 {
 	    -re "$mi_gdb_prompt$" { }
 	    default {
Index: gdb-fsf-trunk-quilt/gdb/testsuite/lib/gdb-utils.exp
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb-fsf-trunk-quilt/gdb/testsuite/lib/gdb-utils.exp	2014-06-20 23:47:20.858922875 +0100
@@ -0,0 +1,30 @@
+# Copyright 2014 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/>.
+
+# Utility procedures, shared between test suite domains.
+
+# A helper procedure to retrieve commands to send to GDB before a program
+# is started.
+
+proc gdb_init_commands {} {
+    set commands ""
+    if [target_info exists gdb_init_command] {
+	lappend commands [target_info gdb_init_command]
+    }
+    if [target_info exists gdb_init_commands] {
+	set commands [concat $commands [target_info gdb_init_commands]]
+    }
+    return $commands
+}