# Copyright 2011-2021 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/>.

# x86 and amd64 gdbserver had a bug where a watchpoint triggered by
# the DR3 debug register would trip on a bogus assertion.

# This test relies on being able to set 4 hardware watchpoints.  Since
# that is not a valid assumption across most targets, and we're
# testing a x86 specific bug, skip everywhere else.
if { ![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"] } then {
    return 0
}

standard_testfile

if [prepare_for_testing "failed to prepare" ${binfile} ${srcfile} {debug $additional_flags}] {
    return -1
}

if ![runto_main] then {
    return -1
}

gdb_test_no_output "set breakpoint always-inserted on"

# Test that we handle watchpoints in all of DR0-DR3.

gdb_test "watch i1" "Hardware watchpoint .*: i1"
gdb_test "watch i2" "Hardware watchpoint .*: i2"
gdb_test "watch i3" "Hardware watchpoint .*: i3"
gdb_test "watch i4" "Hardware watchpoint .*: i4"

gdb_test "c" "Hardware watchpoint.*: i1.*" "continue to i1 watchpoint"
gdb_test "c" "Hardware watchpoint.*: i2.*" "continue to i2 watchpoint"
gdb_test "c" "Hardware watchpoint.*: i3.*" "continue to i3 watchpoint"
gdb_test "c" "Hardware watchpoint.*: i4.*" "continue to i4 watchpoint"

delete_breakpoints

# Regression test for a bug where the i386 watchpoints support backend
# would leave some debug registers occupied even if not enough debug
# registers were available to cover a single watchpoint location.

gdb_test "watch i1" \
    "Hardware watchpoint .*: i1" \
    "set watchpoint occuping one debug register"

# gap1 too long to fit the 3 left over debug registers (but would fit
# 4 if all were available).
set test "watchpoint on gap1 does not fit debug registers"
gdb_test_multiple "watch gap1" "$test" {
    -re "Hardware watchpoint .*: gap1.*Warning:.*Could not insert hardware watchpoint.*You may have requested too many.*\r\n$gdb_prompt $" {
	pass $test
    }
    -re "Hardware watchpoint .*: gap1\r\n$gdb_prompt $" {
	pass "$test (target emulates hardware watchpoints)"
	return
    }
    -re "Watchpoint .*: gap1\r\n$gdb_prompt $" {
	pass "$test (gdb figured out itself the watchpoint does not fit)"
	return
    }
}

# Start over.
gdb_test "delete" \
    "" \
    "delete all watchpoints" \
    {Delete all breakpoints\? \(y or n\) $} \
    "y"

# If debug registers were left occupied by mistake, we'll fail to set
# some of these watchpoints.  Each watchpoint should fit in one of the
# 4 debug registers available.
gdb_test "watch i1" "Hardware watchpoint .*: i1" "watch i1 still fits"
gdb_test "watch i2" "Hardware watchpoint .*: i2" "watch i2 still fits"
gdb_test "watch i3" "Hardware watchpoint .*: i3" "watch i3 still fits"
gdb_test "watch i4" "Hardware watchpoint .*: i4" "watch i4 still fits"