debug.exp

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

#   Copyright (C) 2002 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  

# GCC testsuite that uses the `dg.exp' driver.

# Load support procs.
load_lib gcc-dg.exp

# This is the list of debugging options we'll try.  Some of them won't
# be supported, that's OK; they will be quickly eliminated.
# It's probably not a good idea to add more optimisation options.

if ![info exists DEBUG_TORTURE_OPTIONS] {
    set DEBUG_TORTURE_OPTIONS ""
    foreach type {-gdwarf-2 -gstabs -gstabs+ -gxcoff -gxcoff+ -gcoff} {
	set comp_output [gcc_target_compile \
		"$srcdir/$subdir/trivial.c" "trivial.S" assembly \
		"additional_flags=$type"]
	if { ! [string match "*: unknown or unsupported -g option*" \
		$comp_output] } {
	    foreach level {1 "" 3} {
		lappend DEBUG_TORTURE_OPTIONS [list "${type}${level}"]
		foreach opt { -O -O3 } {
		    lappend DEBUG_TORTURE_OPTIONS \
			    [list "${type}${level}" "$opt" ]
		}
	    }
	}
    }
}

verbose -log "Using options $DEBUG_TORTURE_OPTIONS"

# Initialize `dg'.
dg-init

# Main loop.

foreach test [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\]]] {
    global runtests

    # If we're only testing specific files and this isn't one of 
    # them, skip it.
    if ![runtest_file_p $runtests $test] {
	continue
    }

    set nshort [file tail [file dirname $test]]/[file tail $test]

    foreach flags $DEBUG_TORTURE_OPTIONS {
	set doit 1
	if { [string match {*/debug-[126].c} "$nshort"] \
		&& [string match "*1" [lindex "$flags" 0] ] } { 
	    set doit 0
	}
	
	if { $doit } {
	    verbose -log "Testing $nshort, $flags" 1
	    dg-test $test $flags ""
	}
    }
}

# All done.
dg-finish