# Copyright 2024 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 test exercises GDB's ability to validate build-ids when loading
# shared libraries for a core file.
#
# The test creates two "versions" of a shared library, sets up a
# symlink to point to one version of the library, and creates a core file.
#
# We then try re-loading the core file and executable and check that
# GDB is able to correctly load the shared library.  To confuse things
# we retarget the library symlink at the other version of the library.
#
# After that we repeat the test, but this time deleting the symlink
# completely.
#
# Then we remove the version of the library completely, at this point
# we do expect GDB to give a warning about being unable to load the library.
#
# And finally, we setup debuginfod and have it serve the missing
# library file, GDB should correctly download the library file.
#
# Despite this test living in the gdb.debuginfod/ directory, only the last
# part of this test actually uses debuginfod, everything up to that point is
# pretty generic.

load_lib debuginfod-support.exp

require allow_shlib_tests
require {istarget "*-linux*"}
require {!is_remote host}
require {!using_fission}

standard_testfile -1.c -2.c

# Build two similar, but slightly different versions of the shared
# library.  Both libraries have DT_SONAME set to the generic
# libfoo.so, we'll create a symlink with that name later.
set library_1_filename [standard_output_file "libfoo_1.so"]
set library_2_filename [standard_output_file "libfoo_2.so"]

# The generic name for the library.
set library_filename [standard_output_file "libfoo.so"]

# When compiling a shared library the -Wl,-soname,NAME option is
# automatically added based on the final name of the library.  We want
# to compile libfoo_1.so, but set the soname to libfoo.so.  To achieve
# this we first compile into libfoo.so, and then rename the library to
# libfoo_1.so.
if {[build_executable "build libfoo_1.so" $library_filename \
	 $srcfile \
	      { debug shlib build-id \
		    additional_flags=-DLIB_VERSION=1 }] == -1} {
    return
}
remote_exec build "mv ${library_filename} ${library_1_filename}"

# See the comment above, but this time we rename to libfoo_2.so.
if {[build_executable "build libfoo_2.so" $library_filename \
	 $srcfile \
	      { debug shlib build-id \
		    additional_flags=-DLIB_VERSION=2 }] == -1} {
    return
}
remote_exec build "mv ${library_filename} ${library_2_filename}"

# Create libfoo.so symlink to the libfoo_1.so library.  If this
# symlink creation fails then we assume we can't create symlinks on
# this host.  If this succeeds then later symlink creation is required
# to succeed, and will trigger an FAIL if it doesn't.
set status \
    [remote_exec build \
	 "ln -sf ${library_1_filename} ${library_filename}"]
if {[lindex $status 0] != 0} {
    unsupported "host does not support symbolic links"
    return
}

# Build the executable.  This links against libfoo.so, which is
# poining at libfoo_1.so.  Just to confuse things even more, this
# executable uses dlopen to load libfoo_2.so.  Weird!
if { [build_executable "build executable" ${binfile} ${srcfile2} \
	  [list debug shlib=${library_filename} shlib_load]] == -1 } {
    return
}

# If the board file is automatically splitting the debug information
# into a separate file (e.g. the cc-with-gnu-debuglink.exp board) then
# this test isn't going to work.
clean_restart
gdb_file_cmd $binfile
if {$gdb_file_cmd_debug_info ne "debug"} {
    unsupported "failed to find debug information"
    return
}
if {[regexp "${testfile}.debug" $gdb_file_cmd_msg]} {
    unsupported "debug information has been split to a separate file"
    return
}

# Run BINFILE which will generate a corefile.
set corefile [core_find $binfile]
if {$corefile eq ""} {
    untested "could not generate core file"
    return
}

# Helper proc to load global BINFILE and then load global COREFILE.
#
# If EXPECT_WARNING is true then we require a warning about being
# unable to load the shared library symbols, otherwise, EXPECT_WARNING
# is false and we require no warning.
#
# If EXPECT_DOWNLOAD is true then we require a line indicating that
# the shared library is being downloaded from debuginfod, otherwise
# the shared library should not be downloaded.
#
# If DEBUGDIR is not the empty string then 'debug-file-directory' is
# set to the value of DEBUGDIR.
proc load_exec_and_core_file { expect_warning expect_download testname \
				   {debugdir ""} } {
    with_test_prefix $testname {
	clean_restart $::binfile

	if { $debugdir ne "" } {
	    gdb_test_no_output "set debug-file-directory $debugdir" \
		"set debug directory"
	}

	set saw_warning false
	set saw_download false
	set saw_generated false
	set saw_terminated false

	gdb_test_multiple "core-file $::corefile" "load core file" {
	    -re "^Core was generated by \[^\r\n\]+\r\n" {
		set saw_generated true
		exp_continue
	    }
	    -re "^Program terminated with signal \[^\r\n\]+\r\n" {
		set saw_terminated true
		exp_continue
	    }
	    -re "^warning: Can't open file \[^\r\n\]+ during file-backed mapping note processing\r\n" {
		# Ignore warnings from the file backed mapping phase.
		exp_continue
	    }
	    -re "^warning: Could not load shared library symbols for \[^\r\n\]+/libfoo\\.so\\.\r\n" {
		set saw_warning true
		exp_continue
	    }
	    -re "^Downloading executable for \[^\r\n\]+/libfoo_1\\.so\\.\\.\\.\r\n" {
		set saw_download true
		exp_continue
	    }
	    -re "^$::gdb_prompt $" {
		gdb_assert { $saw_generated && $saw_terminated \
				 && $saw_warning == $expect_warning \
				 && $saw_download == $expect_download } \
		    $gdb_test_name
	    }
	    -re "^\[^\r\n\]*\r\n" {
		exp_continue
	    }
	}

	# If we don't expect a warning then debug symbols from the
	# shared library should be available.  Confirm we can read a
	# variable from the shared library.  If we do expect a warning
	# then the shared library debug symbols have not loaded, and
	# the library variable should not be available.
	if { !$expect_warning } {
	    gdb_test "print/x library_1_var" " = 0x12345678" \
		"check library_1_var can be read"
	} else {
	    gdb_test "print/x library_1_var" \
		"^No symbol \"library_1_var\" in current context\\." \
		"check library_1_var cannot be read"
	}
    }
}

# Initial test, just load the executable and core file.  At this point
# everything should load fine as everything is where we expect to find
# it.
load_exec_and_core_file false false \
    "load core file, all libraries as expected"

# Update libfoo.so symlink to point at the second library then reload
# the core file.  GDB should spot that the symlink points to the wrong
# file, but should be able to figure out the correct file to load as
# the right file will be in the mapped file list.
set status [remote_exec build \
		"ln -sf ${library_2_filename} ${library_filename}"]
gdb_assert { [lindex $status 0] == 0 } \
    "update library symlink to point to the wrong file"

load_exec_and_core_file false false \
    "load core file, symlink points to wrong file"

# Remove libfoo.so symlink and reload the core file.  As in the
# previous test GDB should be able to figure out the correct file to
# load as the correct file will still appear in the mapped file list.
set status [remote_exec build "rm -f ${library_filename}"]
gdb_assert { [lindex $status 0] == 0 } "remove library symlink"

load_exec_and_core_file false false \
    "load core file, symlink removed"

# Remove LIBRARY_1_FILENAME.  We'll now see a warning that the mapped
# file can't be loaded (we ignore that warning), and we'll see a
# warning that the shared library can't be loaded.
set library_1_backup_filename ${library_1_filename}.backup
set status \
    [remote_exec build \
	 "mv ${library_1_filename} ${library_1_backup_filename}"]
gdb_assert { [lindex $status 0] == 0 } \
    "remove libfoo_1.so"

load_exec_and_core_file true false \
    "load core file, libfoo_1.so removed"

# Symlink the .build-id/xx/xxx...xxx filename within the debug
# directory to LIBRARY_1_BACKUP_FILENAME, now when we restart GDB it
# should find the missing library within the debug directory.
set debugdir [standard_output_file "debugdir"]
set build_id_filename \
    $debugdir/[build_id_debug_filename_get $library_1_backup_filename ""]
set status \
    [remote_exec build \
	 "mkdir -p [file dirname $build_id_filename]"]
gdb_assert { [lindex $status 0] == 0 } \
    "create sub-directory within the debug directory"
set status \
    [remote_exec build \
	 "ln -sf $library_1_backup_filename $build_id_filename"]
gdb_assert { [lindex $status 0] == 0 } \
    "create symlink within the debug directory "

load_exec_and_core_file false false \
    "load core file, find libfoo_1.so through debug-file-directory" \
    $debugdir

# Setup a debuginfod server which can serve the original shared
# library file.
if {![allow_debuginfod_tests]} {
    untested "skippig debuginfod parts of this test"
    return
}

set server_dir [standard_output_file "debuginfod.server"]
file mkdir $server_dir
file rename -force $library_1_backup_filename $server_dir

prepare_for_debuginfod cache db

set url [start_debuginfod $db $server_dir]
if { $url eq "" } {
    unresolved "failed to start debuginfod server"
    return
}

with_debuginfod_env $cache {
    setenv DEBUGINFOD_URLS $url

    save_vars { GDBFLAGS } {
	append GDBFLAGS " -ex \"set debuginfod enabled on\""

	# Reload the executable and core file.  GDB should download
	# the file libfoo_1.so using debuginfod during the mapped file
	# phase, but should then reuse that download during the shared
	# library phase.
	load_exec_and_core_file false true \
	    "load core file, use debuginfod"
    }
}

stop_debuginfod