gdb/testsuite/gdb.dwarf2/dyn-type-unallocated.exp

# Copyright 2020-2021 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/>.

# Test for issue PR gdb/27059.  The problem was that when resolving a
# dynamic type that was not-allocated GDB would still try to execute
# the DWARF expressions for the upper, lower, and byte-stride values.
#
# The problem is that, at least in some gfortran compiled programs,
# these values are undefined until the array is allocated.
#
# As a result, executing the dwarf expressions was triggering integer
# overflow in some cases.
#
# This test aims to make the sometimes occurring integer overflow a
# more noticeable error by creating an array that is always marked as
# not-allocated.
#
# The dwarf expressions for the various attributes then contains an
# infinite loop.  If GDB ever tries to execute these expressions we
# will get a test timeout.  With this issue fixed the expressions are
# never executed and the test completes as we'd expect.

load_lib dwarf.exp

if {![dwarf2_support]} {
    return 0
}

standard_testfile .c -dw.S

if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
    return -1
}

set asm_file [standard_output_file $srcfile2]
Dwarf::assemble $asm_file {
    cu {} {
	global srcfile

	compile_unit {
	    {producer "gcc" }
            {language @DW_LANG_Fortran90}
            {name ${srcfile}}
            {low_pc 0 addr}
        } {
	    declare_labels array_type_label integer_type_label

	    set int_size [get_sizeof "int" "UNKNOWN"]
	    set voidp_size [get_sizeof "void *" "UNKNOWN"]

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

	    array_type_label: DW_TAG_array_type {
		{DW_AT_type :$integer_type_label}
		{DW_AT_data_location {
		    DW_OP_push_object_address
		    DW_OP_deref
		} SPECIAL_expr}
		{DW_AT_allocated {
		    DW_OP_lit0
		} SPECIAL_expr}
	    } {
		DW_TAG_subrange_type {
		    {DW_AT_type        :$integer_type_label}
		    {DW_AT_lower_bound {
			DW_OP_skip -3
		    } SPECIAL_expr}
		    {DW_AT_upper_bound {
			DW_OP_skip -3
		    } SPECIAL_expr}
		    {DW_AT_byte_stride {
			DW_OP_skip -3
		    } SPECIAL_expr}
		}
	    }

	    DW_TAG_variable {
                {DW_AT_location {
                    DW_OP_addr [gdb_target_symbol dyn_object]
                } SPECIAL_expr}
		{name "dyn_object"}
		{type :$array_type_label}
	    }
            subprogram {
                {external 1 flag}
                {MACRO_AT_func {main}}
            }
        }
    }
}

if { [prepare_for_testing "failed to prepare" "${testfile}" \
	  [list $srcfile $asm_file] {nodebug}] } {
    return -1
}

if ![runto_main] {
    return -1
}

gdb_breakpoint "marker_label"
gdb_continue_to_breakpoint "stop at marker_label"
gdb_test "ptype dyn_object" "type = integer, allocatable \\(:\\)"