gdb/testsuite/gdb.dwarf2/dw2-bad-elf.exp

# Copyright 2019-2021 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/>.

# Checks for a bug where a baddly formed ELF would cause GDB to crash.
# A section containing executable code, for which there was DWARF is
# accidentally marked as non-alloctable, GDB becomes unhappy.
#
# This test creates some fake DWARF pointing at some symbols in a
# non-allocatable section that is still marked as executable.  We then
# start GDB and try to place a breakpoint on the symbol in the
# non-allocatable section.
#
# It is not expected that the final debug experience really makes
# sense, the symbol is in a non-allocatable section after all, but GDB
# absolutely shouldn't crash.  All we try to do after placing the
# breakpoint is check that GDB is still alive.

load_lib dwarf.exp

# This test can only be run on targets which support DWARF-2 and use gas.
if {![dwarf2_support]} {
    return 0
}

standard_testfile main.c -other.S -dwarf.S

if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
    untested "failed to compile"
    return -1
}

set int_size [get_sizeof "int" 4]

# Make some DWARF for the test.
set asm_file [standard_output_file $srcfile3]
Dwarf::assemble $asm_file {
    global srcdir subdir srcfile srcfile2 int_size

    declare_labels ranges_label_1 ranges_label_2 L1 L2

    set main_result [function_range main ${srcdir}/${subdir}/${srcfile}]
    set main_start [lindex $main_result 0]
    set main_length [lindex $main_result 1]

    cu {} {
	DW_TAG_compile_unit {
	    {DW_AT_language @DW_LANG_C}
	    {DW_AT_name     $srcfile}
	    {DW_AT_comp_dir ${srcdir}/${subdir}}
	    {stmt_list $L1 DW_FORM_sec_offset}
	    {ranges ${ranges_label_1} DW_FORM_sec_offset}
	    {DW_AT_low_pc   0 addr}
	} {
	    declare_labels integer_label

	    DW_TAG_subprogram {
		{name main}
		{low_pc $main_start addr}
		{high_pc $main_length data8}
		{DW_AT_type :$integer_label}
		{DW_AT_decl_file 1 data1}
		{DW_AT_decl_line 10 data1}
	    }

	    integer_label: DW_TAG_base_type {
		{DW_AT_byte_size $int_size DW_FORM_sdata}
		{DW_AT_encoding  @DW_ATE_signed}
		{DW_AT_name      integer}
	    }
	}
    }

    cu {} {
	DW_TAG_compile_unit {
	    {DW_AT_language @DW_LANG_C}
	    {DW_AT_name     $srcfile2}
	    {DW_AT_comp_dir ${srcdir}/${subdir}}
	    {stmt_list $L2 DW_FORM_sec_offset}
	    {ranges ${ranges_label_2} DW_FORM_sec_offset}
	    {DW_AT_low_pc   0 addr}
	} {
	    declare_labels integer_label

	    DW_TAG_subprogram {
		{name some_func}
		{low_pc some_func addr}
		{high_pc some_func_end addr}
		{DW_AT_type :$integer_label}
		{DW_AT_decl_file 2 data1}
		{DW_AT_decl_line 5 data1}
	    }

	    integer_label: DW_TAG_base_type {
		{DW_AT_byte_size $int_size DW_FORM_sdata}
		{DW_AT_encoding  @DW_ATE_signed}
		{DW_AT_name      integer}
	    }
	}
    }

    ranges {is_64 [is_64_target]} {
	ranges_label_1: sequence {
	    base [lindex $main_result 0]
	    range 0 [lindex $main_result 1]
	}
	ranges_label_2: sequence {
	    base some_func
	    range 0 64
	}
    }

    lines {version 2} L1 {
	include_dir "${srcdir}/${subdir}"
	file_name "$srcfile" 1

	# Line data doens't need to be correct, just present.
	program {
	    {DW_LNE_set_address [lindex $main_result 0]}
	    {DW_LNS_advance_line 10}
	    {DW_LNS_copy}
	    {DW_LNS_advance_pc [lindex $main_result 1]}
	    {DW_LNS_advance_line 19}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}
	}
    }

    lines {version 2} L2 {
	include_dir "${srcdir}/${subdir}"
	file_name "dw2-bad-elf-other.c" 1

	# Line data doens't need to be correct, just present.
	program {
	    {DW_LNE_set_address some_func}
	    {DW_LNS_advance_line 5}
	    {DW_LNS_copy}
	    {DW_LNS_advance_pc 64}
	    {DW_LNS_advance_line 8}
	    {DW_LNS_copy}
	    {DW_LNE_end_sequence}
	}
    }
}

if { [build_executable ${testfile}.exp ${testfile} \
	  [list $srcfile $srcfile2 $asm_file] {nodebug}] } {
    return -1
}

# Attempt to place a breakpoint on 'some_func', then check GDB is
# still alive.  This test can optionally set a breakpoint on 'main'
# first (based on GOTO_MAIN), the original bug behaved differently
# when there was already a breakpoint set.
proc run_test { goto_main } {
    global binfile decimal hex

    clean_restart ${binfile}

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

    # Place a breakpoint.
    gdb_test "break some_func" \
	"Breakpoint $decimal at $hex: file .*dw2-bad-elf-other\\.c, line 6\\."

    # Check GDB is still alive.
    gdb_test "echo hello\\n" "hello"
}

# Run the tests.
foreach_with_prefix goto_main { 0 1 } {
    run_test $goto_main
}