#   Copyright 1997-2023 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/>.

# Various tests of gdb's ability to follow the parent or child of a
# Unix vfork system call.  A vfork parent is blocked until the child
# either execs or exits --- since those events take somewhat different
# code paths in GDB, both variants are exercised.

# Until "set follow-fork-mode" and "catch vfork" are implemented on
# other targets...
#
if {![istarget "*-linux*"]} {
    continue
}

standard_testfile .c -exit.c vforked-prog.c

set binfile $testfile
set binfile2 ${testfile}-exit
set binfile3 vforked-prog

if {[build_executable "compile $binfile" $binfile $srcfile] == -1} {
    untested "failed to compile first test binary"
    return -1
}

if {[build_executable "compile $binfile2" $binfile2 $srcfile2] == -1} {
    untested "failed to compile second test binary"
    return -1
}

if {[build_executable "compile $binfile3" $binfile3 $srcfile3] == -1} {
    untested "failed to compile third test binary"
    return -1
}

# If required, download the program that we exec after vfork to the
# remote target.
if { [is_remote target] } {
    gdb_remote_download target [standard_output_file $binfile3]
}

# Start with a fresh GDB, with verbosity enabled, and run to main.  On
# error, behave as "return", so we don't try to continue testing with
# a borked session.
proc setup_gdb { binfile srcfile } {
    clean_restart $binfile

    if ![runto_main] {
	return -code return
    }

    gdb_breakpoint [gdb_get_line_number " VFORK " $srcfile] temporary
    gdb_continue_to_breakpoint "at VFORK"
}

proc check_vfork_catchpoints {} {
  # Because setup_gdb uses 'return -code return' which would return to
  # our caller we need to wrap this call, spot when setup_gdb failed
  # (with return code 2), and then issue our own 'return -code return'.
  set code [catch {setup_gdb $::binfile $::srcfile} string]
  if { $code == 2 } {
    unsupported "vfork catchpoints"
    return -code return
  }

  # Verify that the system supports "catch vfork".
  gdb_test "catch vfork" "Catchpoint \[0-9\]* \\(vfork\\)" "insert first vfork catchpoint"
  set has_vfork_catchpoints 0
  gdb_test_multiple "continue" "continue to first vfork catchpoint" {
    -re -wrap ".*Your system does not support this type\r\nof catchpoint.*" {
      unsupported "continue to first vfork catchpoint"
    }
    -re -wrap ".*Catchpoint.*" {
      set has_vfork_catchpoints 1
      pass "continue to first vfork catchpoint"
    }
  }

  if {$has_vfork_catchpoints == 0} {
    unsupported "vfork catchpoints"
    return -code return
  }
}

proc_with_prefix vfork_parent_follow_through_step { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork parent"

    gdb_test_multiple "next" "" {
	-re -wrap "\\\[Detaching after vfork from.*if \\(pid == 0\\).*" {
	    pass $gdb_test_name
	}
    }
}

proc_with_prefix vfork_parent_follow_to_bp { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork parent"

    set bp_location \
	[gdb_get_line_number "I'm the proud parent of child" $srcfile]
    gdb_test "break ${srcfile}:${bp_location}" ".*" "break, vfork to bp"

    gdb_test_multiple "continue" "continue to bp" {
	-re -wrap ".*\\\[Detaching after vfork from child process.*Breakpoint.*${bp_location}.*" {
	    pass $gdb_test_name
	}
    }
}

proc_with_prefix vfork_child_follow_to_exit { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    gdb_test_multiple "continue" "continue to child exit" {
	-re -wrap "Couldn't get registers.*" {
	    kfail $gdb_test_name "gdb/14766"
	}
	-re -wrap "\\\[Attaching after.* vfork to.*\\\[Detaching vfork parent .* after child exit.*" {
	    pass $gdb_test_name
	}
    }
}

proc_with_prefix vfork_and_exec_child_follow_to_main_bp { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    set linenum [gdb_get_line_number "Hello from vforked-prog" ${::srcfile3}]

    gdb_test_multiple "continue" "continue to bp" {
	-re -wrap "\\\[Attaching after.* vfork to.*\\\[Detaching vfork parent.*xecuting new program.*Breakpoint.*vforked-prog.c:${linenum}.*" {
	    pass $gdb_test_name
	}
    }
}

proc_with_prefix vfork_and_exec_child_follow_through_step { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    # The ideal support is to be able to debug the child even
    # before it execs.  Thus, "next" lands on the next line after
    # the vfork.
    gdb_test_multiple "next" "next over vfork" {
	-re -wrap "\\\[Attaching after .* vfork to child.*if \\(pid == 0\\).*" {
	    pass $gdb_test_name
	}
    }
}

proc continue_to_vfork {} {
    # A vfork catchpoint may stop in either "vfork" or "_vfork".
    gdb_test_multiple "continue" "continue to vfork" {
	-re -wrap "vfork \\(\\) at .*" {
	    pass $gdb_test_name
	}
	-re -wrap "0x\[0-9a-fA-F\]*.*(vfork|__kernel_v?syscall).*" {
	    pass $gdb_test_name
	}
    }
}

proc_with_prefix tcatch_vfork_then_parent_follow { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork parent"

    gdb_test "tcatch vfork" "Catchpoint .*(vfork).*"

    continue_to_vfork

    set linenum [gdb_get_line_number "pid = vfork ();" $srcfile]
    gdb_test_multiple "finish" "" {
	-re -wrap "Run till exit from.*vfork.*0x\[0-9a-fA-F\]* in main .* at .*${srcfile}:${linenum}.*" {
	    pass $gdb_test_name
	}
	-re -wrap "Run till exit from.*__kernel_v?syscall.*0x\[0-9a-fA-F\]* in vfork .*" {
	    send_gdb "finish\n"
	    exp_continue
	}
    }
}

proc_with_prefix tcatch_vfork_then_child_follow_exec { binfile srcfile } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    gdb_test "tcatch vfork" "Catchpoint .*(vfork).*"

    continue_to_vfork

    set linenum1 [gdb_get_line_number "pid = vfork ();" $srcfile]
    set linenum2 [gdb_get_line_number "Hello from vforked-prog" ${::srcfile3}]

    gdb_test_multiple "finish" "" {
	-re -wrap "Run till exit from.*vfork.*${srcfile}:${linenum1}.*" {
	  pass $gdb_test_name
	}
	-re -wrap "Run till exit from.*__kernel_v?syscall.*0x\[0-9a-fA-F\]* in vfork .*" {
	    send_gdb "finish\n"
	    exp_continue
	}
	-re -wrap "Run till exit from.*vfork.*${::srcfile3}:${linenum2}.*" {
	    pass "$gdb_test_name (followed exec)"
	}
    }
}

proc tcatch_vfork_then_child_follow_exit { binfile srcfile } {
   setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    gdb_test "tcatch vfork" "Catchpoint .*(vfork).*"

    continue_to_vfork

    gdb_test_multiple "finish" "" {
	-re -wrap "Run till exit from.*vfork.*exited normally.*" {
	    setup_kfail "gdb/14762" *-*-*
	    fail $gdb_test_name
	}
	-re -wrap "Run till exit from.*vfork.*pid = vfork \\(\\).*" {
	  pass $gdb_test_name
	}
	-re -wrap "Run till exit from.*__kernel_v?syscall.*0x\[0-9a-fA-F\]* in vfork .*" {
	    send_gdb "finish\n"
	    exp_continue
	}
    }
}

proc_with_prefix vfork_relations_in_info_inferiors { variant binfile srcfile non_stop } {
    setup_gdb $binfile $srcfile

    gdb_test_no_output "set follow-fork child"

    gdb_test_multiple "next" "next over vfork" {
	-re -wrap "\\\[Attaching after .* vfork to child.*if \\(pid == 0\\).*" {
	    pass $gdb_test_name
	}
    }

    if { $non_stop } {
	gdb_test "inferior 2" ".*"
    }

    gdb_test "info inferiors" \
	".*is vfork parent of inferior 2.*is vfork child of inferior 1" \
	"info inferiors shows vfork parent/child relation"

    if { $variant == "exec" } {
	set linenum [gdb_get_line_number "Hello from vforked-prog" ${::srcfile3}]
	gdb_test_multiple "continue" "continue to bp" {
	    -re -wrap ".*xecuting new program.*Breakpoint.*vforked-prog.c:${linenum}.*" {
		pass $gdb_test_name
	    }
	}
    } else {
	gdb_continue_to_end "continue until exit" "continue" true
    }

    gdb_test_multiple "info inferiors" "vfork relation no longer appears in info inferiors" {
	-re -wrap "is vfork child of inferior 1.*" {
	   fail $gdb_test_name
	}
	-re -wrap "is vfork parent of inferior 2.*" {
	    fail $gdb_test_name
	}
	-re -wrap "" {
	    pass $gdb_test_name
	}
    }
}

proc do_vfork_and_follow_parent_tests { binfile srcfile } {
   # Try following the parent process by stepping through a call to
   # vfork.  Do this without catchpoints.
   vfork_parent_follow_through_step $binfile $srcfile

   # Try following the parent process by setting a breakpoint on the
   # other side of a vfork, and running to that point.  Do this
   # without catchpoints.
   vfork_parent_follow_to_bp $binfile $srcfile

   # Try catching a vfork, and stepping out to the parent.
   #
   tcatch_vfork_then_parent_follow $binfile $srcfile
}

proc do_vfork_and_follow_child_tests_exec { binfile srcfile non_stop } {
   # Try following the child process by just continuing through the
   # vfork, and letting the parent's breakpoint on "main" be auto-
   # magically reset in the child.
   #
   vfork_and_exec_child_follow_to_main_bp $binfile $srcfile

   # Try following the child process by stepping through a call to
   # vfork.  The child also executes an exec.  Since the child cannot
   # be debugged until after it has exec'd, and since there's a bp on
   # "main" in the parent, and since the bp's for the parent are
   # recomputed in the exec'd child, the step through a vfork should
   # land us in the "main" for the exec'd child, too.
   #
   vfork_and_exec_child_follow_through_step $binfile $srcfile

   # Try catching a vfork, and stepping out to the child.
   #
   tcatch_vfork_then_child_follow_exec $binfile $srcfile

   # Test the ability to follow both child and parent of a vfork.  Do
   # this without catchpoints.
   # ??rehrauer: NYI.  Will add testpoints here when implemented.
   #

   # Test the ability to have the debugger ask the user at vfork-time
   # whether to follow the parent, child or both.  Do this without
   # catchpoints.
   # ??rehrauer: NYI.  Will add testpoints here when implemented.
   #

   # Step over a vfork in the child, do "info inferiors" and check the
   # parent/child relation is displayed.  Run the child over the exec,
   # and confirm the relation is no longer displayed in "info
   # inferiors".
   #
   vfork_relations_in_info_inferiors "exec" $binfile $srcfile $non_stop
}

proc do_vfork_and_follow_child_tests_exit { binfile srcfile non_stop } {
   # Try following the child process by just continuing through the
   # vfork, and letting the child exit.
   #
   vfork_child_follow_to_exit $binfile $srcfile

   # Try catching a vfork, and stepping out to the child.
   #
   tcatch_vfork_then_child_follow_exit $binfile $srcfile

   # Step over a vfork in the child, do "info inferiors" and check the
   # parent/child relation is displayed.  Run the child to completion,
   # and confirm the relation is no longer displayed in "info
   # inferiors".
   #
   vfork_relations_in_info_inferiors "exit" $binfile $srcfile $non_stop
}

with_test_prefix "check vfork support" {
    # Check that vfork catchpoints are supported, as an indicator for
    # whether vfork-following is supported.
    check_vfork_catchpoints
}

# Follow parent and follow child vfork tests with a child that execs.
proc_with_prefix exec_tests { binfile srcfile non_stop } {
    # These are tests of gdb's ability to follow the parent of a Unix
    # vfork system call.  The child will subsequently call a variant
    # of the Unix exec system call.
    do_vfork_and_follow_parent_tests $binfile $srcfile

    # These are tests of gdb's ability to follow the child of a Unix
    # vfork system call.  The child will subsequently call a variant
    # of a Unix exec system call.
    #
    do_vfork_and_follow_child_tests_exec $binfile $srcfile $non_stop
}

# Follow parent and follow child vfork tests with a child that exits.
proc_with_prefix exit_tests { binfile srcfile non_stop } {
    # These are tests of gdb's ability to follow the parent of a Unix
    # vfork system call.  The child will subsequently exit.
    do_vfork_and_follow_parent_tests $binfile $srcfile

    # These are tests of gdb's ability to follow the child of a Unix
    # vfork system call.  The child will subsequently exit.
    #
    do_vfork_and_follow_child_tests_exit $binfile $srcfile $non_stop
}

# Using the remote protocol with schedule-multiple turned triggers bug
# gdb/30574, so avoid this for now.
if {[target_info exists gdb_protocol]
    && ([target_info gdb_protocol] == "remote"
	|| [target_info gdb_protocol] == "extended-remote")} {
    set sm_modes { off }
} else {
    set sm_modes { off on }
}

# A few of these tests require a little more time than the standard timeout
# allows.
with_timeout_factor 2 {
    foreach_with_prefix target-non-stop {auto on off} {
	foreach_with_prefix non-stop {off on} {
	    foreach_with_prefix schedule-multiple $sm_modes {
		save_vars { ::GDBFLAGS } {
		    # These flags will be picked up by the call to
		    # clean_restart inside setup_gdb.
		    append ::GDBFLAGS " -ex \"maintenance set target-non-stop ${target-non-stop}\""
		    append ::GDBFLAGS " -ex \"set non-stop ${non-stop}\""
		    append ::GDBFLAGS " -ex \"set schedule-multiple ${schedule-multiple}\""

		    exec_tests $binfile $srcfile ${non-stop}
		    exit_tests $binfile2 $srcfile2 ${non-stop}
		}
	    }
	}
    }
}