binutils-gdb/gdb/testsuite/gdb.threads/infcall-from-bp-cond-simple.exp

# Copyright 2022-2025 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/>.

# Some simple tests of inferior function calls from breakpoint
# conditions, in multi-threaded inferiors.
#
# This test sets up a multi-threaded inferior, and places a breakpoint
# at a location that many of the threads will reach.  We repeat the
# test with different conditions, sometimes a single thread should
# stop at the breakpoint, sometimes multiple threads should stop, and
# sometimes no threads should stop.

standard_testfile

if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
	  {debug pthreads}] == -1 } {
    return
}

set cond_bp_line [gdb_get_line_number "Breakpoint here"]
set stop_bp_line [gdb_get_line_number "Stop marker"]
set nested_bp_line [gdb_get_line_number "Nested breakpoint"]
set segv_line [gdb_get_line_number "Segfault happens here"]

# Start GDB based on TARGET_ASYNC and TARGET_NON_STOP, and then runto main.
proc start_gdb_and_runto_main { target_async target_non_stop } {
    save_vars { ::GDBFLAGS } {
	append ::GDBFLAGS \
	    " -ex \"maint set target-non-stop $target_non_stop\""
	append ::GDBFLAGS \
	    " -ex \"maintenance set target-async ${target_async}\""

	clean_restart ${::binfile}
    }

    if { ![runto_main] } {
	return -1
    }

    return 0
}

# Run a test of GDB's conditional breakpoints, where the conditions include
# inferior function calls.
#
# CONDITION is the expression to be used as the breakpoint condition.
#
# N_EXPECTED_HITS is the number of threads that we expect to stop due to
# CONDITON.
#
# MESSAGE is used as a test name prefix.
proc run_condition_test { message n_expected_hits condition \
			      target_async target_non_stop } {
    with_test_prefix $message {

	if { [start_gdb_and_runto_main $target_async \
		  $target_non_stop] == -1 } {
	    return
	}

	# Use this convenience variable to track how often the
	# breakpoint condition has been evaluated.  This should be
	# once per thread.
	gdb_test "set \$n_cond_eval = 0"

	# Setup the conditional breakpoint.
	gdb_breakpoint \
	    "${::srcfile}:${::cond_bp_line} if ((++\$n_cond_eval) && (${condition}))"

	# Add a breakpoint that we hit when the test is over, this one is
	# not conditional.  Only the main thread gets here once all the
	# other threads have finished.
	gdb_breakpoint "${::srcfile}:${::stop_bp_line}"

	# The number of times we stop at the conditional breakpoint.
	set n_hit_condition 0

	# Now keep 'continue'-ing GDB until all the threads have finished
	# and we reach the stop_marker breakpoint.
	gdb_test_multiple "continue" "spot all breakpoint hits" {
	    -re " worker_func \[^\r\n\]+${::srcfile}:${::cond_bp_line}\r\n${::decimal}\\s+\[^\r\n\]+Breakpoint here\[^\r\n\]+\r\n${::gdb_prompt} $" {
		incr n_hit_condition
		send_gdb "continue\n"
		exp_continue
	    }

	    -re " stop_marker \[^\r\n\]+${::srcfile}:${::stop_bp_line}\r\n${::decimal}\\s+\[^\r\n\]+Stop marker\[^\r\n\]+\r\n${::gdb_prompt} $" {
		pass $gdb_test_name
	    }
	}

	gdb_assert { $n_hit_condition == $n_expected_hits } \
	    "stopped at breakpoint the expected number of times"

	# Ensure the breakpoint condition was evaluated once per thread.
	gdb_test "print \$n_cond_eval" "= 3" \
	    "condition was evaluated in each thread"
    }
}

# Check that after handling a conditional breakpoint (where the condition
# includes an inferior call), it is still possible to kill the running
# inferior, and then restart the inferior.
#
# At one point doing this would result in GDB giving an assertion error.
proc_with_prefix run_kill_and_restart_test { target_async target_non_stop } {
    # This test relies on the 'start' command, which is not possible with
    # the plain 'remote' target.
    if { [target_info gdb_protocol] == "remote" } {
	return
    }

    if { [start_gdb_and_runto_main $target_async \
	      $target_non_stop] == -1 } {
	return
    }

    # Setup the conditional breakpoint.
    gdb_breakpoint \
	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 1))"
    gdb_continue_to_breakpoint "worker_func"

    # Now kill the program being debugged.
    gdb_test "kill" "" "kill process" \
	"Kill the program being debugged.*y or n. $" "y"

    # Check we can restart the inferior.  At one point this would trigger an
    # assertion.
    gdb_start_cmd
}

set re_thread_exited {\[Thread [^\r\n]+ exited\]}

# Create a conditional breakpoint which includes a call to a function that
# segfaults.  Run GDB and check what happens when the inferior segfaults
# during the inferior call.
proc_with_prefix run_bp_cond_segfaults { target_async target_non_stop } {
    if { [start_gdb_and_runto_main $target_async \
	      $target_non_stop] == -1 } {
	return
    }

    # This test relies on the inferior segfaulting when trying to
    # access address zero.
    if { [is_address_zero_readable] } {
	return
    }

    # Setup the conditional breakpoint, include a call to
    # 'function_that_segfaults', which triggers the segfault.
    gdb_breakpoint \
	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 0) && function_that_segfaults ())"
    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		      "get number of conditional breakpoint"]

    gdb_test "continue" \
	[multi_line \
	     "Continuing\\." \
	     ".*" \
	     "Thread ${::decimal} \"infcall-from-bp\" received signal SIGSEGV, Segmentation fault\\." \
	     "${::hex} in function_that_segfaults \\(\\) at \[^\r\n\]+:${::segv_line}" \
	     "${::decimal}\\s+\[^\r\n\]+Segfault happens here\[^\r\n\]+" \
	     "Error in testing condition for breakpoint ${bp_1_num}:" \
	     "The program being debugged was signaled while in a function called from GDB\\." \
	     "GDB remains in the frame where the signal was received\\." \
	     "To change this behavior use \"set unwind-on-signal on\"\\." \
	     "Evaluation of the expression containing the function" \
	     "\\(function_that_segfaults\\) will be abandoned\\." \
	     "When the function is done executing, GDB will silently stop\\.(" \
	     "$::re_thread_exited)?"]
}

# Create a conditional breakpoint which includes a call to a function that
# itself has a breakpoint set within it.  Run GDB and check what happens
# when GDB hits the nested breakpoint.
proc_with_prefix run_bp_cond_hits_breakpoint { target_async target_non_stop } {
    if { [start_gdb_and_runto_main $target_async \
	      $target_non_stop] == -1 } {
	return
    }

    # Setup the conditional breakpoint, include a call to
    # 'function_with_breakpoint' in which we will shortly place a
    # breakpoint.
    gdb_breakpoint \
	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 0) && function_with_breakpoint ())"
    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		      "get number of conditional breakpoint"]

    gdb_breakpoint "${::srcfile}:${::nested_bp_line}"
    set bp_2_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		      "get number of nested breakpoint"]

    gdb_test "continue" \
	[multi_line \
	     "Continuing\\." \
	     ".*" \
	     "Thread ${::decimal} \"infcall-from-bp\" hit Breakpoint ${bp_2_num}, function_with_breakpoint \\(\\) at \[^\r\n\]+:${::nested_bp_line}" \
	     "${::decimal}\\s+\[^\r\n\]+Nested breakpoint\[^\r\n\]+" \
	     "Error in testing condition for breakpoint ${bp_1_num}:" \
	     "The program being debugged stopped while in a function called from GDB\\." \
	     "Evaluation of the expression containing the function" \
	     "\\(function_with_breakpoint\\) will be abandoned\\." \
	     "When the function is done executing, GDB will silently stop\\.(" \
	     "$::re_thread_exited)?"]
}

foreach_with_prefix target_async { "on" "off" } {
    foreach_with_prefix target_non_stop { "on" "off" } {
	run_condition_test "exactly one thread is hit" \
	    1 "is_matching_tid (arg, 1)" \
	    $target_async $target_non_stop
	run_condition_test "exactly two threads are hit" \
	    2 "(is_matching_tid (arg, 0) || is_matching_tid (arg, 2))" \
	    $target_async $target_non_stop
	run_condition_test "all three threads are hit" \
	    3 "return_true ()" \
	    $target_async $target_non_stop
	run_condition_test "no thread is hit" \
	    0 "return_false ()" \
	    $target_async $target_non_stop

	run_kill_and_restart_test $target_async $target_non_stop
	run_bp_cond_segfaults $target_async $target_non_stop
	run_bp_cond_hits_breakpoint $target_async $target_non_stop
    }
}