how to call gdb_test "" ... ?

how to call gdb_test "" ... ?

[Michael Elizabeth Chastain]

I am reworking gdb.base/list.exp and in the process I'm converting a lot
of send_gdb calls to gdb_test.  (If you want to know why I'm reworking it,
I'm getting rid of the "testcnt" mechanism, which list.exp uses instead
of just issuing a PASS when a test succeeds).

In one place I want to do this:

  gdb_test "list list0.c:10" "..."
  gdb_test "" "..."
  gdb_test "" "..."
  gdb_test "" "..."

That is to say, I want to send a "list" command, and then send some
empty commands and look at the results as usual.

gdb_test does not work with an argument of "".

Is there an easy way to do this, or should I just stick with send_gdb "\n"?
The test script already calls send_gdb "\n" and I don't mind keeping it
that way.  I'm just wondering if someone knows a better idiom.

Michael C

Re: how to call gdb_test "" ... ?

[Daniel Jacobowitz]

On Mon, Feb 18, 2002 at 04:37:17PM -0600, Michael Elizabeth Chastain wrote:
> I am reworking gdb.base/list.exp and in the process I'm converting a lot
> of send_gdb calls to gdb_test.  (If you want to know why I'm reworking it,
> I'm getting rid of the "testcnt" mechanism, which list.exp uses instead
> of just issuing a PASS when a test succeeds).
> 
> In one place I want to do this:
> 
>   gdb_test "list list0.c:10" "..."
>   gdb_test "" "..."
>   gdb_test "" "..."
>   gdb_test "" "..."
> 
> That is to say, I want to send a "list" command, and then send some
> empty commands and look at the results as usual.
> 
> gdb_test does not work with an argument of "".
> 
> Is there an easy way to do this, or should I just stick with send_gdb "\n"?
> The test script already calls send_gdb "\n" and I don't mind keeping it
> that way.  I'm just wondering if someone knows a better idiom.

Does gdb_test work with "\n"?  I think it will.  In fact, it appears to
in casual testing.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: how to call gdb_test "" ... ?

[Keith Seitz]

On Mon, 18 Feb 2002, Michael Elizabeth Chastain wrote:

> That is to say, I want to send a "list" command, and then send some
> empty commands and look at the results as usual.
>
> gdb_test does not work with an argument of "".

I'll go out on a limb here and say offer that gdb_test be modified:

<gripe>
1) To make it legible:

  proc gdb_test { args } {
     # snip
     set command [lindex $args 0]
     set pattern [lindex $args 1]

     # snip
     set result -1
     set string "${command}\n"
     if { $command != "" } {
         while { "$string" != "" } {
           set foo [string first "\n" "$string"]
           set len [string length "$string"]
           if { $foo < [expr $len - 1] } {
              if [send_gdb "$str"] != "" } {
                #snip
              }
              # snip
           }
          set string [string range "$string" [expr $foo + 1] end
     }
     # snip

Why is this done???? Why not just:

     proc gdb_test {command pattern args} {
       # snip
       set cmd "$command\n"
       foreach cmd [split $command \n] {
         if {$cmd != ""} {
           if {[send_gdb $cmd] != ""} {
             #snip
           }
         }
       # snip

I don't know. Whomever wrote it did not understand tcl at all.
</gripe>

2) To allow empty commands, i.e., skip the send, do the expect

Actually, I don't see from reading the code for gdb_test why "" would be
disallowed. Is it giving you some sort of error?

Ok, off my soapbox now.
Keith

Re: how to call gdb_test "" ... ?

[Michael Elizabeth Chastain]

Okay, it is patch submission time, I am submitting this:

  send_gdb "\n"
  gdb_test "" "..."

Michael C

Re: how to call gdb_test "" ... ?

[Daniel Jacobowitz]

On Mon, Feb 18, 2002 at 05:33:12PM -0600, Michael Elizabeth Chastain wrote:
> Daniel Jacobowitz writes:
> > Does gdb_test work with "\n"?  I think it will.  In fact, it appears to
> > in casual testing.
> 
> Alas, gdb_test "\n" sends two carriage returns.

Even worse, it appears to do so "most of the time" :(

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: how to call gdb_test "" ... ?

[Michael Elizabeth Chastain]

Keith Seitz writes:
> Actually, I don't see from reading the code for gdb_test why "" would be
> disallowed. Is it giving you some sort of error?

gdb_test "" hangs and does not return until some 60-second timer
kicks it out.  That's probably related to the special check for "":

  set result -1
  set string "${command}\n";
  if { $command != "" } {
    ...
  }

Hmmm, this is actually documented behavior:

  # COMMAND is the command to execute, send to GDB with send_gdb.  If
      this is the null string no command is sent.

I suppose I could do this:

  send_gdb "\n"
  gdb_test "" "..."

How does that sound, Keith?  Or would you prefer me to stick with
send_gdb/gdb_expect?  Gross choice, eh?

I can't modify gdb_test; that would take me too far afield from fixing
the real problems in list.exp.

Michael C

Re: how to call gdb_test "" ... ?

[Michael Elizabeth Chastain]

Daniel Jacobowitz writes:
> Does gdb_test work with "\n"?  I think it will.  In fact, it appears to
> in casual testing.

Alas, gdb_test "\n" sends two carriage returns.

Michael C