gdb/testsuite/gdb.btrace/tailcall-only.exp

# This testcase is part of GDB, the GNU debugger.
#
# Copyright 2016-2021 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/>.
#
#
# This is a variant of tailcall.exp where the entire trace contains only tail
# calls.  This used to cause a crash in get_frame_type.
#

if { [skip_btrace_tests] } {
    unsupported "target does not support record-btrace"
    return -1
}

# This test requires the compiler to generate a tail call.  To guarantee that
# we always get one, we use an assembly source file.
#
# We use different assembly sources based on the target architecture.
#
# Luckily, they are similar enough that a single test script can handle
# both.
set opts {}
if [info exists COMPILE] {
    # make check RUNTESTFLAGS="gdb.btrace/tailcall-only.exp COMPILE=1"
    standard_testfile tailcall-only.c
    lappend opts debug optimize=-O2
} elseif {[istarget "i?86-*-*"] || [istarget "x86_64-*-*"]} {
	if {[is_amd64_regs_target]} {
		standard_testfile x86_64-tailcall-only.S
	} else {
		standard_testfile i686-tailcall-only.S
	}
} else {
    unsupported "target architecture not supported"
    return -1
}

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

if ![runto_main] {
    return -1
}

# we want to see the full trace for this test
gdb_test_no_output "set record function-call-history-size 0"

# trace foo
gdb_test "step" ".*" "prepare for recording"
gdb_test_no_output "record btrace"
gdb_test "stepi 4" ".*" "record branch trace"

# for debugging
gdb_test "info record" ".*"

# show the branch trace with calls indented
gdb_test "record function-call-history /c 1" [multi_line \
  "1\tfoo" \
  "2\t  foo_1" \
  "3\t    bar" \
  "4\t      bar_1"
  ] "function-call-history"

# We can step
gdb_test "record goto begin" ".*foo.*"
gdb_test "stepi" ".*foo_1.*" "step into foo_1"
gdb_test "step" ".*bar.*" "step into bar"
gdb_test "stepi" ".*bar_1.*" "step into bar_1"

# We can neither finish nor return.
gdb_test "finish" "Cannot find the caller frame.*"
gdb_test_multiple "return" "return" {
  -re "Make .* return now.*y or n. $" {
    send_gdb "y\n"
    exp_continue
  }
  -re "Cannot find the caller frame.*$gdb_prompt $" {
    pass "return"
  }
}

# But we can reverse-finish
gdb_test "reverse-finish" ".*bar.*"
gdb_test "reverse-step" ".*foo_1.*"

# Info frame isn't useful but doesn't crash as it used to.
gdb_test "up" ".*foo.*"
gdb_test "info frame" ".*"