gdb/testsuite/gdb.base/sss-bp-on-user-bp-2.exp

# Copyright (C) 2014-2021 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/>.

# Test that GDB doesn't get confused in the following scenario
# (PR breakpoints/17000).  Say, we have this program:
#
#  =>  0xff000001  INSN1
#      0xff000002  INSN2
#
# The PC currently points at INSN1.
#
# 1 - User sets a breakpoint at 0xff000002 (INSN2).
#
# 2 - User steps.  On software single-step archs, this sets a software
#     single-step breakpoint at 0xff000002 (INSN2) too.
#
# 3 - User deletes breakpoint (INSN2) before the single-step finishes.
#
# 4 - The single-step finishes, and GDB removes the single-step
#     breakpoint.

# Test relies on checking gdb debug output. Do not run if gdb debug is
# enabled as any debug will be redirected to the log.
if [gdb_debug_enabled] {
    untested "debug is enabled"
    return 0
}

standard_testfile

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

if ![runto_main] {
    return 0
}

delete_breakpoints

# With the all-stop RSP, we can't talk to the target while it's
# running, until we get back the stop reply.  If not using single-step
# breakpoints, then the "del" in stepi_del_break below will try to
# delete the user breakpoint from the target, which will fail, with
# "Cannot execute this command while the target is running.".  On
# software single-step targets, that del shouldn't trigger any RSP
# traffic.  Hardware-step targets that can't access memory while the
# target is running, either remote or native, are likewise affected.
# So we just skip the test if not using software single-stepping.  We
# detect that by looking for 'to_resume (..., step)' in "debug
# target" output.

# Probe for software single-step breakpoint use.

gdb_test_no_output "set debug target 1"
set hardware_step 0
set test "probe target hardware step"
gdb_test_multiple "si" $test {
    -re "resume \\(\[^\r\n\]+, step, .*$gdb_prompt $" {
	set hardware_step 1
	pass $test
    }
    -re "$gdb_prompt $" {
	pass $test
    }
}

if { $hardware_step } {
    unsupported "target doesn't use software single-stepping"
    return
}

gdb_test "set debug target 0" "->log_command.*\\)"

set line_re "\[^\r\n\]*"

gdb_test "b test:label" "Breakpoint .*"
gdb_continue_to_breakpoint "run past setup"
delete_breakpoints

# So we can precisely control breakpoint insertion order.
gdb_test_no_output "set breakpoint always-inserted on"

# Capture disassembly output.  PREFIX is used as test prefix.  The
# current instruction indicator (=>) is stripped away.
proc disassemble { prefix } {
    with_test_prefix "$prefix" {
	set output [capture_command_output "disassemble test" ""]
	return [string map {"=>" "  "} $output]
    }
}

# Issue a stepi and immediately delete the user breakpoint that is set
# at the same address as the software single-step breakpoint.  Do this
# in a user defined command, so that the stepi's trap doesn't have a
# chance to be handled before further input is processed.  We then
# compare before/after disassembly.  GDB should be able to handle
# deleting the user breakpoint before deleting the single-step
# breakpoint.  E.g., we shouldn't see breakpoint instructions in the
# disassembly.

set disasm_before [disassemble "before"]

gdb_test "b test:label2" ".*" "set breakpoint where si will land"

set test "define stepi_del_break"
gdb_test_multiple $test $test {
    -re "Type commands for definition of \"stepi_del_break\".\r\nEnd with a line saying just \"end\".\r\n>$" {
	gdb_test "si&\ndel \$bpnum\nend" "" $test
    }
}

set command "stepi_del_break"
set test $command
gdb_test_multiple $command $test {
    -re "^$command\r\n$gdb_prompt " {
	# Note no end anchor, because "si&" finishes and prints the
	# current frame/line after the prompt is printed.
	pass $test
    }
}

# Now consume the output of the finished "si&".
set test "si& finished"
gdb_test_multiple "" $test {
    -re "must be a single line \\\*/\r\n" {
	pass $test
    }
}

set disasm_after [disassemble "after"]

set test "before/after disassembly matches"
if ![string compare $disasm_before $disasm_after]  {
    pass $test
} else {
    fail $test
}