# Copyright 2018-2020 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 tests GDB's frame selection as used by the 'frame',
# 'select-frame', and 'info frame' commands.

standard_testfile

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

runto_main
gdb_breakpoint frame_2
gdb_continue_to_breakpoint frame_2

gdb_test "bt" "#0  frame_2.*#1  $hex in frame_1.*#2  $hex in main.*" "backtrace at breakpoint"

# Perform "info frame" to extract the frame's address.
proc get_frame_address { {testname ""} } {
    global hex gdb_prompt

    set frame_address "unknown"
    set testname "get_frame_address: ${testname}"
    gdb_test_multiple "info frame" $testname {
	-re ", frame at ($hex):\r\n.*\r\n$gdb_prompt $" {
	    set frame_address $expect_out(1,string)
	    pass $testname
	}
    }

    return $frame_address
}

# Passed a list of addresses.  Return a new address that is not in the
# list by sorting the addresses and adding 0x10 to the highest
# address.
proc get_new_address { {addresses {}} } {
    # Find the highest element in the list.
    set elem [lindex [lsort -integer -decreasing $addresses] 0]

    # Return a new address as a hex formatted string.
    return [format "%#x" [expr $elem + 0x10]]
}


# Check that the current frame is at stack depth LEVEL, at frame
# address ADDRESS, and is in FUNCTION.
proc check_frame { level address function } {
    global hex gdb_prompt

    set re [multi_line \
		"Stack level ${level}, frame at ($address):" \
		".* = $hex in ${function} \(\[^\r\n\]*\); saved .* = $hex" \
		".*\r\n$gdb_prompt $" ]

    set testname "check frame level ${level}"
    gdb_test_multiple "info frame" $testname {
	-re $re {
	    pass $testname
	}
    }
}

# Select frame using level, but relying on this being the default
# action, so "frame 0" performs "frame level 0".
gdb_test "frame 0" "#0  frame_2.*"
set frame_0_address [ get_frame_address "frame 0" ]
gdb_test "frame 1" "#1  $hex in frame_1.*"
set frame_1_address [ get_frame_address "frame 1" ]
gdb_test "frame 2" "#2  $hex in main.*"
set frame_2_address [ get_frame_address "frame 2" ]
gdb_test "frame 3" "No frame at level 3\."

# Find an address that matches no frame.
set no_frame_address [ get_new_address [list $frame_0_address \
					     $frame_1_address \
					     $frame_2_address] ]

# Select frame using 'level' specification.
gdb_test "frame level 0" "#0  frame_2.*"
gdb_test "frame level 1" "#1  $hex in frame_1.*"
gdb_test "frame level 2" "#2  $hex in main.*"
gdb_test "frame level 3" "No frame at level 3\."

# Select frame by address.
gdb_test "frame address ${frame_0_address}" "#0  frame_2.*" \
    "select frame 0 by address"
gdb_test "frame address ${frame_1_address}" "#1  $hex in frame_1.*" \
    "select frame 1 by address"
gdb_test "frame address ${frame_2_address}" "#2  $hex in main.*" \
    "select frame 2 by address"
gdb_test "frame address ${no_frame_address}" \
    "No frame at address ${no_frame_address}\." \
    "attempt to select a frame at an invalid address"

# Select frame by function.
gdb_test "frame function frame_2" "#0  frame_2.*"
gdb_test "frame function frame_1" "#1  $hex in frame_1.*"
gdb_test "frame function main" "#2  $hex in main.*"

# Check for a distinction between a known function not in the stack
# trace, and an unknown function.
gdb_test "frame function recursive" "No frame for function \"recursive\"."
gdb_test "frame function foo" "Function \"foo\" not defined."


with_test_prefix "select-frame, no keyword" {
    gdb_test_no_output "select-frame 0"
    check_frame "0" "${frame_0_address}" "frame_2"
    gdb_test_no_output "select-frame 1"
    check_frame "1" "${frame_1_address}" "frame_1"
    gdb_test_no_output "select-frame 2"
    check_frame "2" "${frame_2_address}" "main"
    gdb_test "select-frame 3" "No frame at level 3\."
}

with_test_prefix "select-frame, keyword=level" {
    gdb_test_no_output "select-frame level 0"
    check_frame "0" "${frame_0_address}" "frame_2"
    gdb_test_no_output "select-frame level 1"
    check_frame "1" "${frame_1_address}" "frame_1"
    gdb_test_no_output "select-frame level 2"
    check_frame "2" "${frame_2_address}" "main"
    gdb_test "select-frame level 3" "No frame at level 3\."
}

with_test_prefix "select-frame, keyword=address" {
    gdb_test_no_output "select-frame address ${frame_0_address}" \
	"select frame 0 by address"
    check_frame "0" "${frame_0_address}" "frame_2"
    gdb_test_no_output "select-frame address ${frame_1_address}" \
	"select frame 1 by address"
    check_frame "1" "${frame_1_address}" "frame_1"
    gdb_test_no_output "select-frame address ${frame_2_address}" \
	"select frame 2 by address"
    check_frame "2" "${frame_2_address}" "main"
    gdb_test "select-frame address ${no_frame_address}" \
	"No frame at address ${no_frame_address}\." \
	"select-frame for an invalid address"
}

with_test_prefix "select-frame, keyword=function" {
    gdb_test_no_output "select-frame function frame_2"
    check_frame "0" "${frame_0_address}" "frame_2"
    gdb_test_no_output "select-frame function frame_1"
    check_frame "1" "${frame_1_address}" "frame_1"
    gdb_test_no_output "select-frame function main"
    check_frame "2" "${frame_2_address}" "main"
}

# Check for a distinction between a known function not in the stack
# trace, and an unknown function.
gdb_test "select-frame function recursive" \
    "No frame for function \"recursive\"."
gdb_test "select-frame function foo" \
    "Function \"foo\" not defined."

# Now continue until we hit the breakpoint again.
with_test_prefix "second frame_2 breakpoint" {
    gdb_continue_to_breakpoint frame_2
    gdb_test "bt" \
	"#0  frame_2.*#1  $hex in recursive.*#2  $hex in recursive.*#3  $hex in recursive.*#4  $hex in main.*" \
 	"backtrace at breakpoint with recursive frames"

    # Check "frame function" when a function name occurs multiple times in
    # the stack.  The inner most (lowest level) should always be selected.
    gdb_test "frame function frame_2" "#0  frame_2.*"
    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
	"select frame for function recursive, first attempt"
    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
		"select frame for function recursive, second attempt"
    gdb_test "frame function main" "#4  $hex in main.*"
    gdb_test "frame function recursive" "#1  $hex in recursive.*" \
	"select frame for function recursive, third attempt"
}