testsuite/gdb.base/sysroot-debug-lookup.exp

# 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/>.

# Test GDB's ability to find debug information by looking within the
# sysroot.
#
# We compile a static binary (to reduce what we need to copy into the
# sysroot), split the debug information from the binary, and setup a
# sysroot.
#
# The debug-file-directory is set to just '/debug', but we're
# expecting GDB to actually look in '$SYSROOT/debug'.
#
# There's a test for using .build-id based lookup, and a test for
# gnu_debuglink based lookup.

require {!is_remote host}

standard_testfile main.c

# Create a copy of BINFILE, split out the debug information, and then
# setup a sysroot.  Hide (by moving) the actual debug information file
# and create a symlink to the hidden debug information from within the
# sysroot.
#
# Start GDB, set the sysroot, and then load the executable, ensure GDB
# finds the debug information, which must have happened by lookin in
# the sysroot.
proc_with_prefix lookup_via_build_id {} {
    set filename ${::binfile}_1
    if { [build_executable "build exec" ${filename} $::srcfile \
	      {additional_flags=-static debug build-id}] } {
	return
    }

    # Split debug information into a .debug file, remove debug
    # information from FILENAME.  Don't add a .gnu_debuglink to
    # FILENAME, we rely on the build-id.
    if {[gdb_gnu_strip_debug $filename { no-debuglink }] != 0} {
	unsupported "cannot split debug information from executable"
	return
    }

    set sysroot [standard_output_file "sysroot1"]
    set debug_dir "/debug"

    set debug_symlink \
	${sysroot}${debug_dir}/[build_id_debug_filename_get $filename]

    set build_id_dir [file dirname $debug_symlink]

    set debug_filename ${filename}_hidden_debug

    remote_exec build "mkdir -p $build_id_dir"
    remote_exec build "mv $filename.debug $debug_filename"
    remote_exec build "ln -sf $debug_filename $debug_symlink"

    foreach_with_prefix sysroot_prefix { "" "target:" } {
	clean_restart

	gdb_test_no_output "set sysroot ${sysroot_prefix}$sysroot" "set sysroot"
	gdb_test_no_output "set debug-file-directory $debug_dir"

	gdb_file_cmd $filename

	gdb_assert { $::gdb_file_cmd_debug_info eq "debug" } \
	    "ensure debug information was found"

	if { $sysroot_prefix eq "target:"
	     && [target_info gdb_protocol] == "extended-remote"} {
	    # Only when using the extended-remote board will we have
	    # started a remote target by this point.  In this case GDB
	    # will see the 'target:' prefix as remote, and so the
	    # reported filename will include the 'target:' prefix.
	    #
	    # In all other cases we will still be using the default,
	    # initial target, in which case GDB considers the
	    # 'target:' prefix to indicate the local filesystem.
	    set lookup_filename $sysroot_prefix$debug_symlink
	} else {
	    set lookup_filename $debug_filename
	}
	set re [string_to_regexp "Reading symbols from $lookup_filename..."]
	gdb_assert {[regexp $re $::gdb_file_cmd_msg]} \
	    "debug symbols read from correct file"
    }
}

# Create a copy of BINFILE, split out the debug information, and then
# setup a sysroot.  Hide (by moving) the actual debug information file
# and create a symlink to the hidden debug information from within the
# sysroot.
#
# Copy the executable into the sysroot and then start GDB, set the
# sysroot, and load the executable.  Check that GDB finds the debug
# information, which must have happened by lookin in the sysroot.
proc_with_prefix lookup_via_debuglink {} {
    set filename ${::binfile}_2
    if { [build_executable "build exec" ${filename} $::srcfile \
	      {additional_flags=-static debug no-build-id}] } {
	return
    }

    # Split debug information into a .debug file, remove debug
    # information from FILENAME.
    if {[gdb_gnu_strip_debug $filename] != 0} {
	unsupported "cannot split debug information from executable"
	return
    }

    # We're going to setup the sysroot like this:
    #
    # sysroot2/
    #    bin/
    #      $FILENAME
    #    debug/
    #      bin/
    #        $FILENAME.debug
    #
    # When looking up debug information via the debuglink, GDB will
    # only search in the sysroot if the original objfile was in the
    # sysroot.  And GDB will resolve symlinks, so if the objfile is
    # symlinked to outside the sysroot, GDB will not search in the
    # sysroot for the debug information.
    #
    # So we have to copy the executable into the sysroot.
    #
    # We are OK to symlink the debug information to a file outside the
    # sysroot though.

    set sysroot [standard_output_file "sysroot2"]

    foreach path { bin debug/bin } {
	remote_exec build "mkdir -p $sysroot/$path"
    }

    # Copy the executable into the sysroot.
    set file_basename [file tail $filename]
    set exec_in_sysroot ${sysroot}/bin/${file_basename}
    remote_exec build "cp $filename $exec_in_sysroot"

    # Rename the debug file outside of the sysroot, this should stop
    # GDB finding this file "by accident".
    set debug_filename ${filename}_hidden_debug
    remote_exec build "mv $filename.debug $debug_filename"

    # Symlink the debug information into the sysroot.
    set debug_symlink \
	${sysroot}/debug/bin/${file_basename}.debug
    remote_exec build "ln -sf $debug_filename $debug_symlink"

    foreach_with_prefix sysroot_prefix { "" "target:" } {
	# Restart GDB and setup the sysroot and debug directory.
	clean_restart
	gdb_test_no_output "set sysroot ${sysroot_prefix}$sysroot" "set sysroot"
	gdb_test_no_output "set debug-file-directory /debug"

	# Load the executable, we expect GDB to find the debug information
	# in the sysroot.
	gdb_file_cmd ${sysroot_prefix}$exec_in_sysroot

	gdb_assert { $::gdb_file_cmd_debug_info eq "debug" } \
	    "ensure debug information was found"

	set re [string_to_regexp "Reading symbols from ${sysroot_prefix}$debug_symlink..."]
	gdb_assert {[regexp $re $::gdb_file_cmd_msg]} \
	    "debug symbols read from correct file"
    }
}

lookup_via_build_id
lookup_via_debuglink