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# Copyright 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2007, 2008, 2009, 2010
# 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/>.

# This file was written by Jeff Law. (law@cs.utah.edu)

if $tracelevel then {
    strace $tracelevel
}

set prms_id 0
set bug_id 0

set testfile "recurse"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
     untested recurse.exp
     return -1
}

# Start with a fresh gdb.

gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}

proc recurse_tests {} {

    # Disable hardware watchpoints if necessary.
    if [target_info exists gdb,no_hardware_watchpoints] {
        gdb_test "set can-use-hw-watchpoints 0" "" ""
    }

    if [runto recurse] then {
        # First we need to step over the assignment of b, so it has a known
        # value.
        gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance"
        gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
            "set first instance watchpoint"

        # Continue until initial set of b.
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \
            "continue to first instance watchpoint, first time"] then {
            gdb_suppress_tests;
        }

        # Continue inward for a few iterations
        gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \
            "continue to recurse (a = 9)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \
            "continue to recurse (a = 8)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \
            "continue to recurse (a = 7)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \
            "continue to recurse (a = 6)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \
            "continue to recurse (a = 5)"

        # Put a watchpoint on another instance of b
        # First we need to step over the assignment of b, so it has a known
        # value.
        gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance"
        gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
            "set second instance watchpoint"

        # Continue until initial set of b (second instance).
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\
            "continue to second instance watchpoint, first time"] then {
        gdb_suppress_tests;
        }

        # Continue inward for a few iterations
        gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \
            "continue to recurse (a = 4)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \
            "continue to recurse (a = 3)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \
            "continue to recurse (a = 2)"
        gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \
            "continue to recurse (a = 1)"

        # Continue until second set of b (second instance).
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \
            "continue to second instance watchpoint, second time"] then { 
            gdb_suppress_tests;
        }

        # Continue again.  We should have a watchpoint go out of scope now
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \
            "second instance watchpoint deleted when leaving scope"] then {
            gdb_suppress_tests;
        }

        # Continue until second set of b (first instance).
        # 24320 is allowed as the final value for b as that's the value
        # b would have on systems with 16bit integers.
        #
        # We could fix the test program to deal with this too.
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \
            "continue to first instance watchpoint, second time"] then {
            gdb_suppress_tests
        }

        # Continue again.  We should have a watchpoint go out of scope now.
        #
        # The former version expected the test to return to main().
        # Now it expects the test to return to main or to stop in the
        # function's epilogue.
        # 
        # The problem is that gdb needs to (but doesn't) understand
        # function epilogues in the same way as for prologues.
        # 
        # If there is no hardware watchpoint (such as a x86 debug register),
        # then watchpoints are done "the hard way" by single-stepping the
        # target until the value of the watched variable changes.  If you
        # are single-stepping, you will eventually step into an epilogue.
        # When you do that, the "top" stack frame may become partially
        # deconstructed (as when you pop the frame pointer, for instance),
        # and from that point on, GDB can no longer make sense of the stack.
        # 
        # A test which stops in the epilogue is trying to determine when GDB
        # leaves the stack frame in which the watchpoint was created.  It does
        # this basically by watching for the frame pointer to change.  When
        # the frame pointer changes, the test expects to be back in main, but
        # instead it is still in the epilogue of the callee.
        if [gdb_test "continue" \
            "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
            "first instance watchpoint deleted when leaving scope"] then {
            gdb_suppress_tests;
        }
    }
    gdb_stop_suppressing_tests;
}

# Preserve the old timeout, and set a new one that should be
# sufficient to avoid timing out during this test.
set oldtimeout $timeout
set timeout [expr "$timeout + 60"]
verbose "Timeout is now $timeout seconds" 2

recurse_tests

# Restore the preserved old timeout value.
set timeout $oldtimeout
verbose "Timeout is now $timeout seconds" 2