binutils-gdb/ld/testsuite/lib/ld-lib.exp

# Support routines for LD testsuite.
#   Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
#   Free Software Foundation, Inc.
#
# This file 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.
#
#
# default_ld_version 
#	extract and print the version number of ld
#
proc default_ld_version { ld } {
    global host_triplet

    if { [which $ld] == 0 } then {
	perror "$ld does not exist"
	exit 1
    }
    
    catch "exec $ld --version" tmp
    set tmp [prune_warnings $tmp]
    regexp "\[^\n\]* (cygnus-|)(\[-0-9.a-zA-Z-\]+)\[\r\n\].*" $tmp version cyg number
    if [info exists number] then {
	clone_output "$ld $number\n"
    }
}

#
# default_ld_relocate 
#	link an object using relocation
#
proc default_ld_relocate { ld target objects } {
    global HOSTING_EMU
    global host_triplet
    
    if { [which $ld] == 0 } then {
	perror "$ld does not exist"
	return 0
    }
    
    verbose -log "$ld $HOSTING_EMU -o $target -r $objects"
    
    catch "exec $ld $HOSTING_EMU -o $target -r $objects" exec_output
    set exec_output [prune_warnings $exec_output]
    if [string match "" $exec_output] then {
	return 1
    } else {
	verbose -log "$exec_output"
	return 0
    }
}

# Check to see if ld is being invoked with a non-endian output format

proc is_endian_output_format { object_flags } {

    if {[string match "*-oformat binary*" $object_flags] ||      \
        [string match "*-oformat ieee*" $object_flags] ||        \
	[string match "*-oformat ihex*" $object_flags] ||        \
	[string match "*-oformat netbsd-core*" $object_flags] || \
	[string match "*-oformat srec*" $object_flags] ||        \
	[string match "*-oformat tekhex*" $object_flags] ||      \
	[string match "*-oformat trad-core*" $object_flags] } then {
        return 0
    } else {
	return 1
    }
}

# Look for big-endian or little-endian switches in the multlib
# options and translate these into a -EB or -EL switch.  Note
# we cannot rely upon proc process_multilib_options to do this
# for us because for some targets the compiler does not support
# -EB/-EL but it does support -mbig-endian/-mlittle-endian, and
# the site.exp file will include the switch "-mbig-endian"
# (rather than "big-endian") which is not detected by proc
# process_multilib_options.

proc big_or_little_endian {} {
    
    if [board_info [target_info name] exists multilib_flags] {
	set tmp_flags " [board_info [target_info name] multilib_flags]";

	foreach x $tmp_flags {
	    case $x in {
		{*big*endian eb EB -eb -EB} {
		    set flags " -EB"
		    return $flags
		}
		{*little*endian el EL -el -EL} {
		    set flags " -EL"
		    return $flags
		}
	    }
	}
    }

    set flags ""
    return $flags
}

#
# default_ld_link 
#	link a program using ld
#
proc default_ld_link { ld target objects } {
    global HOSTING_EMU
    global HOSTING_CRT0
    global HOSTING_LIBS
    global LIBS
    global host_triplet
    global link_output
    
    set objs "$HOSTING_CRT0 $objects"
    set libs "$LIBS $HOSTING_LIBS"
    
    if { [which $ld] == 0 } then {
	perror "$ld does not exist"
	return 0
    }

    if [is_endian_output_format $objects] then {
	set flags [big_or_little_endian]
    } else {
	set flags ""
    }
    verbose -log "$ld $HOSTING_EMU $flags -o $target $objs $libs"
    
    catch "exec $ld $HOSTING_EMU $flags -o $target $objs $libs" link_output
    set exec_output [prune_warnings $link_output]
    if [string match "" $link_output] then {
	return 1
    } else {
	verbose -log "$link_output"
	return 0
    }
}

#
# default_ld_simple_link 
#	link a program using ld, without including any libraries
#
proc default_ld_simple_link { ld target objects } {
    global host_triplet
    global link_output

    if { [which $ld] == 0 } then {
	perror "$ld does not exist"
	return 0
    }
    
    if [is_endian_output_format $objects] then {
	set flags [big_or_little_endian]
    } else {
	set flags ""
    }
    
    verbose -log "$ld $flags -o $target $objects"
    
    catch "exec $ld $flags -o $target $objects" link_output
    set exec_output [prune_warnings $link_output]

    # We don't care if we get a warning about a non-existent start
    # symbol, since the default linker script might use ENTRY.
    regsub -all "(^|\n)(\[^\n\]*: warning: cannot find entry symbol\[^\n\]*\n?)" $exec_output "\\1" exec_output

    if [string match "" $exec_output] then {
	return 1
    } else {
	verbose -log "$exec_output"
	return 0
    }
}

#
# default_ld_compile 
#	compile an object using cc
#
proc default_ld_compile { cc source object } {
    global CFLAGS
    global srcdir
    global subdir
    global host_triplet
    global gcc_gas_flag

    set cc_prog $cc
    if {[llength $cc_prog] > 1} then {
	set cc_prog [lindex $cc_prog 0]
    }
    if {[which $cc_prog] == 0} then {
	perror "$cc_prog does not exist"
	return 0
    }

    catch "exec rm -f $object" exec_output

    set flags "-I$srcdir/$subdir $CFLAGS"

    # If we are compiling with gcc, we want to add gcc_gas_flag to
    # flags.  Rather than determine this in some complex way, we guess
    # based on the name of the compiler.
    if {[string match "*gcc*" $cc] || [string match "*++*" $cc]} then {
	set flags "$gcc_gas_flag $flags"
    }

    if [board_info [target_info name] exists multilib_flags] {
	append flags " [board_info [target_info name] multilib_flags]";
    }

    verbose -log "$cc $flags -c $source -o $object"

    catch "exec $cc $flags -c $source -o $object" exec_output
    set exec_output [prune_warnings $exec_output]
    if [string match "" $exec_output] then {
	if {![file exists $object]} then {
	    regexp ".*/(\[^/\]*)$" $source all dobj
	    regsub "\\.c" $dobj ".o" realobj
	    verbose "looking for $realobj"
	    if {[file exists $realobj]} then {
		verbose -log "mv $realobj $object"
		catch "exec mv $realobj $object" exec_output
		set exec_output [prune_warnings $exec_output]
		if {![string match "" $exec_output]} then {
		    verbose -log "$exec_output"
		    perror "could not move $realobj to $object"
		    return 0
		}
	    } else {
		perror "$object not found after compilation"
		return 0
	    }
	}
	return 1
    } else {
	verbose -log "$exec_output"
	perror "$source: compilation failed"
	return 0
    }
}

#
# default_ld_assemble
#	assemble a file
#
proc default_ld_assemble { as source object } {
    global ASFLAGS
    global host_triplet
    
    if {[which $as] == 0} then {
	perror "$as does not exist"
	return 0
    }

    if ![info exists ASFLAGS] { set ASFLAGS "" }

    set flags [big_or_little_endian]

    verbose -log "$as $flags $ASFLAGS -o $object $source"

    catch "exec $as $flags $ASFLAGS -o $object $source" exec_output
    set exec_output [prune_warnings $exec_output]
    if [string match "" $exec_output] then {
	return 1
    } else {
	verbose -log "$exec_output"
	perror "$source: assembly failed"
	return 0
    }
}

#
# default_ld_nm
#	run nm on a file, putting the result in the array nm_output
#
proc default_ld_nm { nm nmflags object } {
    global NMFLAGS
    global nm_output
    global host_triplet

    if {[which $nm] == 0} then {
	perror "$nm does not exist"
	return 0
    }

    if {[info exists nm_output]} {
      unset nm_output
    }

    if ![info exists NMFLAGS] { set NMFLAGS "" }

    verbose -log "$nm $NMFLAGS $nmflags $object >tmpdir/nm.out"

    catch "exec $nm $NMFLAGS $nmflags $object >tmpdir/nm.out" exec_output
    set exec_output [prune_warnings $exec_output]
    if [string match "" $exec_output] then {
	set file [open tmpdir/nm.out r]
	while { [gets $file line] != -1 } {
	    verbose "$line" 2
	    if [regexp "^(\[0-9a-fA-F\]+) \[a-zA-Z0-9\] (.+)$" $line whole value name] {
                set name [string trimleft $name "_"]
		verbose "Setting nm_output($name) to 0x$value" 2
		set nm_output($name) 0x$value
	    }
	}
	close $file
	return 1
    } else {
	verbose -log "$exec_output"
	perror "$object: nm failed"
	return 0
    }
}

#
# simple_diff
#	compares two files line-by-line
#	returns differences if exist
#	returns null if file(s) cannot be opened
#
proc simple_diff { file_1 file_2 } {
    global target
	
    set eof -1
    set differences 0
    
    if [file exists $file_1] then {
	set file_a [open $file_1 r]
    } else {
	warning "$file_1 doesn't exist"
	return
    }
    
    if [file exists $file_2] then {
	set file_b [open $file_2 r]
    } else {
	fail "$file_2 doesn't exist"
	return
    }
    
    verbose "# Diff'ing: $file_1 $file_2\n" 2
    
    while { [gets $file_a line] != $eof } {
	if [regexp "^#.*$" $line] then {
	    continue
	} else {
	    lappend list_a $line
	}
    }
    close $file_a
    
    while { [gets $file_b line] != $eof } {
	if [regexp "^#.*$" $line] then {
	    continue
	} else {
	    lappend list_b $line
	}
    }
    close $file_b

    for { set i 0 } { $i < [llength $list_a] } { incr i } {
	set line_a [lindex $list_a $i]
	set line_b [lindex $list_b $i]

	verbose "\t$file_1: $i: $line_a\n" 3
	verbose "\t$file_2: $i: $line_b\n" 3
	if [string compare $line_a $line_b] then {
	    verbose -log "\t$file_1: $i: $line_a\n"
	    verbose -log "\t$file_2: $i: $line_b\n"

	    fail "Test: $target"
	    return
	}
    }
    
    if { [llength $list_a] != [llength $list_b] } {
	fail "Test: $target"
	return
    }

    if $differences<1 then {
	pass "Test: $target"
    }
}

# run_dump_test FILE 
# Copied from gas testsuite, tweaked and further extended.
#
# Assemble a .s file, then run some utility on it and check the output.
# 
# There should be an assembly language file named FILE.s in the test
# suite directory, and a pattern file called FILE.d.  `run_dump_test'
# will assemble FILE.s, run some tool like `objdump', `objcopy', or
# `nm' on the .o file to produce textual output, and then analyze that
# with regexps.  The FILE.d file specifies what program to run, and
# what to expect in its output.
#
# The FILE.d file begins with zero or more option lines, which specify
# flags to pass to the assembler, the program to run to dump the
# assembler's output, and the options it wants.  The option lines have
# the syntax:
# 
#         # OPTION: VALUE
# 
# OPTION is the name of some option, like "name" or "objdump", and
# VALUE is OPTION's value.  The valid options are described below.
# Whitespace is ignored everywhere, except within VALUE.  The option
# list ends with the first line that doesn't match the above syntax
# (hmm, not great for error detection).
#
# The interesting options are:
# 
#   name: TEST-NAME
#	The name of this test, passed to DejaGNU's `pass' and `fail'
#       commands.  If omitted, this defaults to FILE, the root of the
#       .s and .d files' names.
# 
#   as: FLAGS
#	When assembling, pass FLAGS to the assembler.
#       If assembling several files, you can pass different assembler
#       options in the "source" directives.  See below.
#
#   ld: FLAGS
#       Link assembled files using FLAGS, in the order of the "source"
#       directives, when using multiple files.
#
#   objcopy_linked_file: FLAGS
#	Run objcopy on the linked file with the specified flags.
#	This lets you transform the linked file using objcopy, before the
#	result is analyzed by an analyzer program specified below (which
#	may in turn *also* be objcopy).
#
#   PROG: PROGRAM-NAME
#       The name of the program to run to analyze the .o file produced
#       by the assembler or the linker output.  This can be omitted;
#       run_dump_test will guess which program to run by seeing which of
#       the flags options below is present.
#
#   objdump: FLAGS
#   nm: FLAGS
#   objcopy: FLAGS
#	Use the specified program to analyze the assembler or linker
#       output file, and pass it FLAGS, in addition to the output name.
#
#   source: SOURCE [FLAGS]
#	Assemble the file SOURCE.s using the flags in the "as" directive
#       and the (optional) FLAGS.  If omitted, the source defaults to
#       FILE.s.
#       This is useful if several .d files want to share a .s file.
#       More than one "source" directive can be given, which is useful
#       when testing linking.
#
#   xfail: TARGET
#       The test is expected to fail on TARGET.  This may occur more than
#       once.
#
#   target: TARGET
#       Only run the test for TARGET.  This may occur more than once; the
#       target being tested must match at least one.
#
#   notarget: TARGET
#       Do not run the test for TARGET.  This may occur more than once;
#       the target being tested must not match any of them.
#
#   error: REGEX
#	An error with message matching REGEX must be emitted for the test
#	to pass.  The PROG, objdump, nm and objcopy options have no
#	meaning and need not supplied if this is present.
#
# Each option may occur at most once unless otherwise mentioned.
#
# After the option lines come regexp lines.  `run_dump_test' calls
# `regexp_diff' to compare the output of the dumping tool against the
# regexps in FILE.d.  `regexp_diff' is defined later in this file; see
# further comments there.

proc run_dump_test { name } {
    global subdir srcdir
    global OBJDUMP NM AS OBJCOPY READELF LD
    global OBJDUMPFLAGS NMFLAGS ASFLAGS OBJCOPYFLAGS READELFFLAGS LDFLAGS
    global host_triplet runtests

    if [string match "*/*" $name] {
	set file $name
	set name [file tail $name]
    } else {
	set file "$srcdir/$subdir/$name"
    }

    if ![runtest_file_p $runtests $name] then {
	return
    }

    set opt_array [slurp_options "${file}.d"]
    if { $opt_array == -1 } {
	perror "error reading options from $file.d"
	unresolved $subdir/$name
	return
    }
    set dumpfile tmpdir/dump.out
    set run_ld 0
    set run_objcopy 0
    set opts(as) {}
    set opts(ld) {}
    set opts(xfail) {}
    set opts(target) {}
    set opts(notarget) {}
    set opts(objdump) {}
    set opts(nm) {}
    set opts(objcopy) {}
    set opts(readelf) {}
    set opts(name) {}
    set opts(PROG) {}
    set opts(source) {}
    set opts(error) {}
    set opts(objcopy_linked_file) {}
    set asflags{${file}.s} {}

    foreach i $opt_array {
	set opt_name [lindex $i 0]
	set opt_val [lindex $i 1]
	if ![info exists opts($opt_name)] {
	    perror "unknown option $opt_name in file $file.d"
	    unresolved $subdir/$name
	    return
	}

	switch -- $opt_name {
	    xfail {}
	    target {}
	    notarget {}
	    source {
		# Move any source-specific as-flags to a separate array to
		# simplify processing.
		if { [llength $opt_val] > 1 } {
		    set asflags([lindex $opt_val 0]) [lrange $opt_val 1 end]
		    set opt_val [lindex $opt_val 0]
		} else {
		    set asflags($opt_val) {}
		}
	    }
	    default {
		if [string length $opts($opt_name)] {
		    perror "option $opt_name multiply set in $file.d"
		    unresolved $subdir/$name
		    return
		}

		# A single "# ld:" with no options should do the right thing.
		if { $opt_name == "ld" } {
		    set run_ld 1
		}
		# Likewise objcopy_linked_file.
		if { $opt_name == "objcopy_linked_file" } {
		    set run_objcopy 1
		}
	    }
	}
	set opts($opt_name) [concat $opts($opt_name) $opt_val]
    }

    # Decide early whether we should run the test for this target.
    if { [llength $opts(target)] > 0 } {
	set targmatch 0
	foreach targ $opts(target) {
	    if [istarget $targ] {
		set targmatch 1
		break
	    }
	}
	if { $targmatch == 0 } {
	    return
	}
    }
    foreach targ $opts(notarget) {
	if [istarget $targ] {
	    return
	}
    }

    if {$opts(PROG) != ""} {
	switch -- $opts(PROG) {
	    objdump
		{ set program objdump }
	    nm
		{ set program nm }
	    objcopy
		{ set program objcopy }
	    readelf
		{ set program readelf }
	    default
		{ perror "unrecognized program option $opts(PROG) in $file.d"
		  unresolved $subdir/$name
		  return }
	}
    } elseif { $opts(error) != "" } {
	# It's meaningless to require an output-testing method when we
	# expect an error.  For simplicity, we fake an arbitrary method.
	set program "nm"
    } else {
	# Guess which program to run, by seeing which option was specified.
	set program ""
	foreach p {objdump objcopy nm readelf} {
	    if {$opts($p) != ""} {
		if {$program != ""} {
		    perror "ambiguous dump program in $file.d"
		    unresolved $subdir/$name
		    return
		} else {
		    set program $p
		}
	    }
	}
	if {$program == ""} {
	    perror "dump program unspecified in $file.d"
	    unresolved $subdir/$name
	    return
	}
    }

    set progopts1 $opts($program)
    eval set progopts \$[string toupper $program]FLAGS
    eval set binary \$[string toupper $program]
    if { $opts(name) == "" } {
	set testname "$subdir/$name"
    } else {
	set testname $opts(name)
    }

    if { $opts(source) == "" } {
	set sourcefiles [list ${file}.s]
    } else {
	set sourcefiles {}
	foreach sf $opts(source) {
	    lappend sourcefiles "$srcdir/$subdir/$sf"
	    # Must have asflags indexed on source name.
	    set asflags($srcdir/$subdir/$sf) $asflags($sf)
	}
    }

    # Time to setup xfailures.
    foreach targ $opts(xfail) {
	setup_xfail $targ
    }

    # Assemble each file.
    set objfiles {}
    for { set i 0 } { $i < [llength $sourcefiles] } { incr i } {
	set sourcefile [lindex $sourcefiles $i]

	set objfile "tmpdir/dump$i.o"
	lappend objfiles $objfile
	set cmd "$AS $ASFLAGS $opts(as) $asflags($sourcefile) -o $objfile $sourcefile"

	send_log "$cmd\n"
	set cmdret [catch "exec $cmd" comp_output]
	set comp_output [prune_warnings $comp_output]

	# We accept errors at assembly stage too, unless we're supposed to
	# link something.
	if { $cmdret != 0 || ![string match "" $comp_output] } then {
	    send_log "$comp_output\n"
	    verbose "$comp_output" 3
	    if { $opts(error) != "" && $run_ld == 0 } {
		if [regexp $opts(error) $comp_output] {
		    pass $testname
		    return
		}
	    }
	    fail $testname
	    return
	}
    }

    # Perhaps link the file(s).
    if { $run_ld } {
	set objfile "tmpdir/dump"
	set cmd "$LD $LDFLAGS $opts(ld) -o $objfile $objfiles"

	send_log "$cmd\n"
	set cmdret [catch "exec $cmd" comp_output]
	set comp_output [prune_warnings $comp_output]

	if { $cmdret != 0 || ![string match "" $comp_output] } then {
	    verbose -log "failed with: <$comp_output>, expected: <$opts(error)>"
	    send_log "$comp_output\n"
	    verbose "$comp_output" 3
	    if { $opts(error) != "" && $run_objcopy == 0 } {
		if [regexp $opts(error) $comp_output] {
		    pass $testname
		    return
		}
	    }
	    fail $testname
	    return
	}

	if { $run_objcopy } {
	    set infile $objfile
	    set objfile "tmpdir/dump1"

	    # Note that we don't use OBJCOPYFLAGS here; any flags must be
	    # explicitly specified.
	    set cmd "$OBJCOPY $opts(objcopy_linked_file) $infile $objfile"

	    send_log "$cmd\n"
	    set cmdret [catch "exec $cmd" comp_output]
	    set comp_output [prune_warnings $comp_output]

	    if { $cmdret != 0 || ![string match "" $comp_output] } then {
		verbose -log "failed with: <$comp_output>, expected: <$opts(error)>"
		send_log "$comp_output\n"
		verbose "$comp_output" 3
		if { $opts(error) != "" } {
		    if [regexp $opts(error) $comp_output] {
			pass $testname
			return
		    }
		}
		fail $testname
		return
	    }
	}
    } else {
	set objfile "tmpdir/dump0.o"
    }

    # We must not have expected failure if we get here.
    if { $opts(error) != "" } {
	fail $testname
	return
    }

    if { [which $binary] == 0 } {
	untested $testname
	return
    }

    if { $progopts1 == "" } { set $progopts1 "-r" }
    verbose "running $binary $progopts $progopts1" 3

    # Objcopy, unlike the other two, won't send its output to stdout,
    # so we have to run it specially.
    if { $program == "objcopy" } {
	set cmd "$binary $progopts $progopts1 $objfile $dumpfile"
	send_log "$cmd\n"
	catch "exec $cmd" comp_output
	set comp_output [prune_warnings $comp_output]
	if ![string match "" $comp_output] then {
	    send_log "$comp_output\n"
	    fail $testname
	    return
	}
    } else {
	set cmd "$binary $progopts $progopts1 $objfile > $dumpfile"
	send_log "$cmd\n"
	catch "exec $cmd" comp_output
	set comp_output [prune_warnings $comp_output]
	if ![string match "" $comp_output] then {
	    send_log "$comp_output\n"
	    fail $testname
	    return
	}
    }

    verbose_eval {[file_contents $dumpfile]} 3
    if { [regexp_diff $dumpfile "${file}.d"] } then {
	fail $testname
	verbose "output is [file_contents $dumpfile]" 2
	return
    }

    pass $testname
}

proc slurp_options { file } {
    if [catch { set f [open $file r] } x] {
	#perror "couldn't open `$file': $x"
	perror "$x"
	return -1
    }
    set opt_array {}
    # whitespace expression
    set ws  {[ 	]*}
    set nws {[^ 	]*}
    # whitespace is ignored anywhere except within the options list;
    # option names are alphabetic plus underscore only.
    set pat "^#${ws}(\[a-zA-Z_\]*)$ws:${ws}(.*)$ws\$"
    while { [gets $f line] != -1 } {
	set line [string trim $line]
	# Whitespace here is space-tab.
	if [regexp $pat $line xxx opt_name opt_val] {
	    # match!
	    lappend opt_array [list $opt_name $opt_val]
	} else {
	    break
	}
    }
    close $f
    return $opt_array
}

# regexp_diff, copied from gas, based on simple_diff above.
#	compares two files line-by-line
#	file1 contains strings, file2 contains regexps and #-comments
#	blank lines are ignored in either file
#	returns non-zero if differences exist
#
proc regexp_diff { file_1 file_2 } {

    set eof -1
    set end_1 0
    set end_2 0
    set differences 0
    set diff_pass 0

    if [file exists $file_1] then {
	set file_a [open $file_1 r]
    } else {
	warning "$file_1 doesn't exist"
	return 1
    }

    if [file exists $file_2] then {
	set file_b [open $file_2 r]
    } else {
	fail "$file_2 doesn't exist"
	close $file_a
	return 1
    }

    verbose " Regexp-diff'ing: $file_1 $file_2" 2

    while { 1 } {
	set line_a ""
	set line_b ""
	while { [string length $line_a] == 0 } {
	    if { [gets $file_a line_a] == $eof } {
		set end_1 1
		break
	    }
	}
	while { [string length $line_b] == 0 || [string match "#*" $line_b] } {
	    if [ string match "#pass" $line_b ] {
		set end_2 1
		set diff_pass 1
		break
	    } elseif [ string match "#..." $line_b ] {
		if { [gets $file_b line_b] == $eof } {
		    set end_2 1
		    break
		}
		verbose "looking for \"^$line_b$\"" 3
		while { ![regexp "^$line_b$" "$line_a"] } {
		    verbose "skipping    \"$line_a\"" 3
		    if { [gets $file_a line_a] == $eof } {
			set end_1 1
			break
		    }
		}
		break
	    }
	    if { [gets $file_b line_b] == $eof } {
		set end_2 1
		break
	    }
	}

        if { $diff_pass } { 
            break 
        } elseif { $end_1 && $end_2 } { 
            break
        } elseif { $end_1 } {
            send_log "extra regexps in $file_2 starting with \"^$line_b$\"\nEOF from $file_1\n"
            verbose "extra regexps in $file_2 starting with \"^$line_b$\"\nEOF from $file_1" 3
            set differences 1
            break
        } elseif { $end_2 } {
            send_log "extra lines in $file_1 starting with \"^$line_a$\"\nEOF from $file_2\n"
            verbose "extra lines in $file_1 starting with \"^$line_a$\"\nEOF from $file_2\n" 3
            set differences 1
            break
        } else {
            verbose "regexp \"^$line_b$\"\nline   \"$line_a\"" 3
            if ![regexp "^$line_b$" "$line_a"] {
		send_log "regexp_diff match failure\n"
		send_log "regexp \"^$line_b$\"\nline   \"$line_a\"\n"
		set differences 1
            }
        }
    }

    if { $differences == 0 && !$diff_pass && [eof $file_a] != [eof $file_b] } {
	send_log "$file_1 and $file_2 are different lengths\n"
	verbose "$file_1 and $file_2 are different lengths" 3
	set differences 1
    }

    close $file_a
    close $file_b

    return $differences
}

proc file_contents { filename } {
    set file [open $filename r]
    set contents [read $file]
    close $file
    return $contents
}

proc verbose_eval { expr { level 1 } } {
    global verbose
    if $verbose>$level then { eval verbose "$expr" $level }
}

# This definition is taken from an unreleased version of DejaGnu.  Once
# that version gets released, and has been out in the world for a few
# months at least, it may be safe to delete this copy.
if ![string length [info proc prune_warnings]] {
    #
    # prune_warnings -- delete various system verbosities from TEXT
    #
    # An example is:
    # ld.so: warning: /usr/lib/libc.so.1.8.1 has older revision than expected 9
    #
    # Sites with particular verbose os's may wish to override this in site.exp.
    #
    proc prune_warnings { text } {
	# This is from sun4's.  Do it for all machines for now.
	# The "\\1" is to try to preserve a "\n" but only if necessary.
	regsub -all "(^|\n)(ld.so: warning:\[^\n\]*\n?)+" $text "\\1" text

	# It might be tempting to get carried away and delete blank lines, etc.
	# Just delete *exactly* what we're ask to, and that's it.
	return $text
    }
}