Re: [PATCH] testsuite: expect possible pagination when starting gdb

[Simon Marchi <simon dot marchi at ericsson dot com>]

On 2014-09-26 05:01 PM, Simon Marchi wrote:
> When gdb starts, the lines that appear before the first prompt may get
> paginated if the terminal in which the tests are ran is too small (in
> terms of rows). These lines include the welcome/license message and
> possibly more, such as "Reading symbols from...". Pagination is disabled
> right after gdb is started (with "set height 0"), but this output happens
> before we are able to set height.
> 
> If these lines get paginated, gdb waits for the user to press enter and
> the test harness waits for gdb to print its prompt, resulting in a
> deadlock.
> 
> My first idea was to launch gdb with --quiet. However, some lines are
> still printed ("Reading symbols from...", some more stuff when attaching
> with --pid, etc).
> 
> The proposed solution simply expects that pagination can occur after
> starting gdb. If this is the case, it sends a "\n" and loops.
> 
> gdb/testsuite/Changelog:
> 
> 	* lib/gdb.exp (default_gdb_start): After starting gdb, loop
> 	as long as we get pagination notifications.
> ---
>  gdb/testsuite/lib/gdb.exp | 39 ++++++++++++++++++++++++---------------
>  1 file changed, 24 insertions(+), 15 deletions(-)
> 
> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
> index 47dc27b..820f87f 100644
> --- a/gdb/testsuite/lib/gdb.exp
> +++ b/gdb/testsuite/lib/gdb.exp
> @@ -1451,7 +1451,7 @@ proc default_gdb_spawn { } {
>  # Default gdb_start procedure.
>  
>  proc default_gdb_start { } {
> -    global gdb_prompt
> +    global gdb_prompt pagination_prompt
>      global gdb_spawn_id
>  
>      if [info exists gdb_spawn_id] {
> @@ -1466,20 +1466,29 @@ proc default_gdb_start { } {
>      # When running over NFS, particularly if running many simultaneous
>      # tests on different hosts all using the same server, things can
>      # get really slow.  Give gdb at least 3 minutes to start up.
> -    gdb_expect 360 {
> -	-re "\[\r\n\]$gdb_prompt $" {
> -	    verbose "GDB initialized."
> -	}
> -	-re "$gdb_prompt $"	{
> -	    perror "GDB never initialized."
> -	    unset gdb_spawn_id
> -	    return -1
> -	}
> -	timeout	{
> -	    perror "(timeout) GDB never initialized after 10 seconds."
> -	    remote_close host
> -	    unset gdb_spawn_id
> -	    return -1
> +    set loop_again 1
> +    while { $loop_again } {
> +	set loop_again 0
> +	gdb_expect 360 {
> +	    -re "$pagination_prompt" {
> +		verbose "Hit pagination during startup. Pressing enter to continue."
> +		send_gdb "\n"
> +		set loop_again 1
> +	    }
> +	    -re "\[\r\n\]$gdb_prompt $" {
> +		verbose "GDB initialized."
> +	    }
> +	    -re "$gdb_prompt $"	{
> +		perror "GDB never initialized."
> +		unset gdb_spawn_id
> +		return -1
> +	    }
> +	    timeout	{
> +		perror "(timeout) GDB never initialized after 10 seconds."
> +		remote_close host
> +		unset gdb_spawn_id
> +		return -1
> +	    }
>  	}
>      }
>  
> 

Ping.