gdb/testsuite/gdb.base/nostdlib.exp

# Copyright 2010-2025 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/>.

standard_testfile .c

# If we're using a stub, breakpoints at the entry point will not trigger.
# See also the comment in break-entry.exp.

require !use_gdb_stub

# default_target_compile would otherwise add "-lm" making the testcase
# dependent on whether the system libraries are already prelinked.
# prelink: Could not set /lib64/libm-2.11.1.so owner or mode: Operation not permitted
set compile {
    gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable $opts
}

foreach_with_prefix pie { "nopie" "pie" } {
    # OPTS and BINFILE are used by the COMPILE string (defined above)
    # when it is evaluated below.
    set opts [list debug additional_flags=-nostdlib $pie]
    set binfile [standard_output_file $testfile-$pie]

    set board [target_info name]
    if [board_info $board exists mathlib] {
	set mathlib [board_info $dest mathlib]
	set_board_info mathlib ""
	set err [eval $compile]
	set_board_info mathlib $mathlib
    } else {
	set_board_info mathlib ""
	set err [eval $compile]
	unset_board_info mathlib
    }
    if {$err != ""} {
	untested "failed to compile"
	return -1
    }

    clean_restart
    gdb_load $binfile

    gdb_breakpoint "*marker"

    # Say we set a permanent breakpoint on *_start.  When setting the
    # breakpoint, it will resolve to _start in the exec.
    # After starting to run, that may stay the same, and consequently
    # execution will stop there.
    # OTOH, after starting to run, that may change to *_start in the dynamic
    # linker, and consequently execution will stop there.
    # There's currently no way to enforce one or the other (PR32748).
    #
    # Say we run into a stop in *_start in the dynamic linker.  Continuing
    # from this situation, the dynamic linker is reported as unloaded, which
    # makes the breakpoint resolve again to *_start in the exec, and
    # consequently execution will stop there as well.
    #
    # However, we cannot rely on this behavior either.  Reporting the dynamic
    # linker as unloaded is a GLIBC bug, which may get fixed eventually.
    #
    # Instead of trying to cater for all these possibilities in a controlled
    # fashion, make the breakpoint temporary, ensuring that there will just be
    # one stop.
    gdb_breakpoint "*_start" temporary

    gdb_run_cmd

    # Breakpoint 2, Stopped due to shared library event
    # _start () at ./gdb.base/nostdlib.c:20
    gdb_test "" {Temporary breakpoint [0-9]+, .*_start .*} "stop at run"

    gdb_test "continue" {Breakpoint [0-9]+, marker .*} "continue to marker"

    # When compiling as PIE the executable will be a dynamic
    # executable, the dynamic linker performs the PIE relocation.
    # Some versions of glibc would (possibly due to a bug) report the
    # dynamic linker as unmapped during startup, which places the
    # 'shlib event' breakpoint(s) into the PENDING state.
    #
    # At one point trying to print these internal breakpoints in a
    # PENDING state would crash GDB, so lets make sure that doesn't
    # happen now.  We don't really care about the exact output,
    # gdb_test will spot if running this command crashes GDB, which is
    # all we're really checking for.
    gdb_test "maint info breakpoints" ".*"
}