binutils-gdb/gdb/testsuite/gdb.base/step-over-exit.exp

#   Copyright 2016-2017 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/>.

standard_testfile

# Test a thread is doing step-over a syscall instruction which is exit,
# and GDBserver should cleanup its state of step-over properly.

set syscall_insn ""

# Define the syscall instruction for each target.

if { [istarget "i\[34567\]86-*-linux*"] || [istarget "x86_64-*-linux*"] } {
    set syscall_insn "\[ \t\](int|syscall|sysenter)\[ \t\]"
} elseif { [istarget "aarch64*-*-linux*"] || [istarget "arm*-*-linux*"] } {
    set syscall_insn "\[ \t\](swi|svc)\[ \t\]"
} else {
    unsupported "unknown syscall instruction"
    return -1
}

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

# Start with a fresh gdb.
clean_restart ${testfile}
if ![runto_main] {
    fail "can't run to main"
    return -1
}

gdb_test "set follow-fork-mode child"
gdb_test "set detach-on-fork off"

# Step 1, find the syscall instruction address.

gdb_test "break _exit" "Breakpoint $decimal at .*"

# Hit the breakpoint on _exit.  The address of syscall insn is recorded.

gdb_test "continue" \
    "Continuing\\..*Breakpoint $decimal.*_exit \\(.*\\).*" \
    "continue to exit"

gdb_test "display/i \$pc" ".*"

# Single step until we see a syscall insn or we reach the
# upper bound of loop iterations.
set msg "find syscall insn in exit"
set steps 0
set max_steps 1000
gdb_test_multiple "stepi" $msg {
    -re ".*$syscall_insn.*$gdb_prompt $" {
	pass $msg
    }
    -re "x/i .*=>.*\r\n$gdb_prompt $" {
	incr steps
	if {$steps == $max_steps} {
	    fail $msg
	} else {
	    send_gdb "stepi\n"
	    exp_continue
	}
    }
}

if {$steps == $max_steps} {
    return
}

# Remove the display
gdb_test_no_output "delete display 1"

set syscall_insn_addr [get_hexadecimal_valueof "\$pc" "0"]

gdb_test "continue" "exited normally.*" "continue to end, first time"
gdb_test "inferior 1" ".*Switching to inferior 1.*" \
    "switch back to inferior 1, first time"

delete_breakpoints

gdb_test "break marker"

gdb_test "continue" "Continuing\\..*Breakpoint $decimal, .*" \
    "continue to marker, first time"

# Step 2, create a breakpoint which evaluates false, and force it
# evaluated on the target side.

set test "set breakpoint condition-evaluation target"
gdb_test_multiple $test $test {
    -re "warning: Target does not support breakpoint condition evaluation.\r\nUsing host evaluation mode instead.\r\n$gdb_prompt $" {
	# Target doesn't support breakpoint condition evaluation
	# on its side, but it is no harm to run the test.
    }
    -re "^$test\r\n$gdb_prompt $" {
    }
}

gdb_test "break \*$syscall_insn_addr if main == 0" \
    "Breakpoint \[0-9\]* at .*" \
    "set conditional break at syscall address"

# Resume the child process, and the step-over is being done.

gdb_test "continue" "exited normally.*" "continue to end, second time"
gdb_test "inferior 1" ".*Switching to inferior 1.*" \
    "switch back to inferior 1, second time"

# Switch back to the parent process, continue to the marker to
# test GDBserver's state is still correct.

gdb_test "continue" "Continuing\\..*Breakpoint $decimal, .*" \
    "continue to marker, second time"