[PING][gdb/testsuite] Add gdb-caching-proc.exp testcase

[Tom de Vries <tdevries@suse.de>]

On 10/9/18 3:47 PM, Tom de Vries wrote:
> On Tue, Oct 09, 2018 at 01:58:26PM +0100, Pedro Alves wrote:
>> Can you please
>> submit the gdb-caching-proc.exp separately, with its own rationale?
>>
> 
> Hi,
> 
> When caching a proc using gdb_caching_proc, it will become less likely to
> be executed, and consequently it's going to be harder to detect that the
> proc is racy.  OTOH, in general the proc is easy to rerun.  So, add a
> test-case to run all uncached gdb_caching_procs a number of times and detect
> inconsistent results.
> 
> The purpose of caching is to reduce runtime, so rerunning is somewhat
> counter-productive in that aspect, but it's better than uncached, because the
> number of reruns is constant-bounded, and the increase in runtime is bound to
> this test-case, and can be disabled on slow targets.
> 
> Tested on x86_64-linux.
> 
> OK for trunk?
> 

Ping.

Thanks,
- Tom

> [gdb/testsuite] Add gdb-caching-proc.exp testcase
> 
> 2018-10-09  Tom de Vries  <tdevries@suse.de>
> 
> 	* gdb.base/gdb-caching-proc.exp: New file.
> 
> ---
>  gdb/testsuite/gdb.base/gdb-caching-proc.exp | 111 ++++++++++++++++++++++++++++
>  1 file changed, 111 insertions(+)
> 
> diff --git a/gdb/testsuite/gdb.base/gdb-caching-proc.exp b/gdb/testsuite/gdb.base/gdb-caching-proc.exp
> new file mode 100644
> index 0000000000..87c20fc574
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/gdb-caching-proc.exp
> @@ -0,0 +1,111 @@
> +#   Copyright 2018 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/>.
> +
> +# When caching a proc using gdb_caching_proc, it will become less likely to
> +# be executed, and consequently it's going to be harder to detect that the
> +# proc is racy.  OTOH, in general the proc is easy to rerun.  So, run all
> +# uncached gdb_caching_procs a number of times and detect inconsistent results.
> +# The purpose of caching is to reduce runtime, so rerunning is somewhat
> +# counter-productive in that aspect, but it's better than uncached, because the
> +# number of reruns is constant-bounded, and the increase in runtime is bound to
> +# this test-case, and could be disabled on slow targets.
> +
> +# Test gdb_caching_proc NAME
> +proc test_proc { name } {
> +    set real_name gdb_real__$name
> +
> +    set first [$real_name]
> +    lappend resultlist $first
> +
> +    # Ten repetitions was enough to trigger target_supports_scheduler_locking,
> +    # and costs about 20 seconds on an i7-6600U.
> +    set repeat 10
> +
> +    set resultlist [list]
> +    set racy 0
> +    for {set i 0} {$i < $repeat} {incr i} {
> +	set rerun [$real_name]
> +	lappend resultlist $rerun
> +	if { $rerun != $first } {
> +	    set racy 1
> +	}
> +    }
> +
> +    if { $racy  == 0 } {
> +	pass "$name consistency"
> +    } else {
> +	fail "$name consistency"
> +	verbose -log "$name: $resultlist"
> +    }
> +}
> +
> +# Test gdb_caching_procs in FILE
> +proc test_file { file } {
> +    upvar obj obj
> +    set procnames [list]
> +
> +    set fp [open $file]
> +    while { [gets $fp line] >= 0 } {
> +	if [regexp -- "^gdb_caching_proc \[ \t\]*(\[^ \t\]*)" $line \
> +		match procname] {
> +	    lappend procnames $procname
> +	}
> +    }
> +    close $fp
> +
> +    if { [llength $procnames] == 0 } {
> +	return
> +    }
> +
> +    if { [file tail $file] == "gdb.exp" } {
> +	# Already loaded
> +    } else {
> +	load_lib [file tail $file]
> +    }
> +
> +    foreach procname $procnames {
> +	switch $procname {
> +	    "is_address_zero_readable" { set setup_gdb 1 }
> +	    "target_is_gdbserver" { set setup_gdb 1 }
> +	    default {set setup_gdb 0 }
> +	}
> +
> +	if { $setup_gdb } {
> +	    clean_restart $obj
> +	}
> +
> +	test_proc $procname
> +
> +	if { $setup_gdb } {
> +	    gdb_exit
> +	}
> +    }
> +}
> +
> +# Init
> +set me "gdb_caching_proc"
> +set src { int main() { return 0; } }
> +if { ![gdb_simple_compile $me $src executable] } {
> +    return 0
> +}
> +
> +# Test gdb_caching_procs in gdb/testsuite/lib/*.exp
> +set files [eval glob -types f $srcdir/lib/*.exp]
> +foreach file $files {
> +    test_file $file
> +}
> +
> +# Cleanup
> +remote_file build delete $obj
>