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

   1 # Copyright 2020-2021 Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # Test for issue PR gdb/27059.  The problem was that when resolving a
  17 # dynamic type that was not-allocated GDB would still try to execute
  18 # the DWARF expressions for the upper, lower, and byte-stride values.
  19 #
  20 # The problem is that, at least in some gfortran compiled programs,
  21 # these values are undefined until the array is allocated.
  22 #
  23 # As a result, executing the dwarf expressions was triggering integer
  24 # overflow in some cases.
  25 #
  26 # This test aims to make the sometimes occurring integer overflow a
  27 # more noticeable error by creating an array that is always marked as
  28 # not-allocated.
  29 #
  30 # The dwarf expressions for the various attributes then contains an
  31 # infinite loop.  If GDB ever tries to execute these expressions we
  32 # will get a test timeout.  With this issue fixed the expressions are
  33 # never executed and the test completes as we'd expect.
  34
  35 load_lib dwarf.exp
  36
  37 if {![dwarf2_support]} {
  38     return 0
  39 }
  40
  41 standard_testfile .c -dw.S
  42
  43 if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
  44     return -1
  45 }
  46
  47 set asm_file [standard_output_file $srcfile2]
  48 Dwarf::assemble $asm_file {
  49     cu {} {
  50         global srcfile
  51
  52         compile_unit {
  53             {producer "gcc" }
  54             {language @DW_LANG_Fortran90}
  55             {name ${srcfile}}
  56             {low_pc 0 addr}
  57         } {
  58             declare_labels array_type_label integer_type_label
  59
  60             set int_size [get_sizeof "int" "UNKNOWN"]
  61             set voidp_size [get_sizeof "void *" "UNKNOWN"]
  62
  63             integer_type_label: DW_TAG_base_type {
  64                 {DW_AT_byte_size $int_size DW_FORM_sdata}
  65                 {DW_AT_encoding  @DW_ATE_signed}
  66                 {DW_AT_name      integer}
  67             }
  68
  69             array_type_label: DW_TAG_array_type {
  70                 {DW_AT_type :$integer_type_label}
  71                 {DW_AT_data_location {
  72                     DW_OP_push_object_address
  73                     DW_OP_deref
  74                 } SPECIAL_expr}
  75                 {DW_AT_allocated {
  76                     DW_OP_lit0
  77                 } SPECIAL_expr}
  78             } {
  79                 DW_TAG_subrange_type {
  80                     {DW_AT_type        :$integer_type_label}
  81                     {DW_AT_lower_bound {
  82                         DW_OP_skip -3
  83                     } SPECIAL_expr}
  84                     {DW_AT_upper_bound {
  85                         DW_OP_skip -3
  86                     } SPECIAL_expr}
  87                     {DW_AT_byte_stride {
  88                         DW_OP_skip -3
  89                     } SPECIAL_expr}
  90                 }
  91             }
  92
  93             DW_TAG_variable {
  94                 {DW_AT_location {
  95                     DW_OP_addr [gdb_target_symbol dyn_object]
  96                 } SPECIAL_expr}
  97                 {name "dyn_object"}
  98                 {type :$array_type_label}
  99             }
 100             subprogram {
 101                 {external 1 flag}
 102                 {MACRO_AT_func {main}}
 103             }
 104         }
 105     }
 106 }
 107
 108 if { [prepare_for_testing "failed to prepare" "${testfile}" \
 109           [list $srcfile $asm_file] {nodebug}] } {
 110     return -1
 111 }
 112
 113 if ![runto_main] {
 114     return -1
 115 }
 116
 117 gdb_breakpoint "marker_label"
 118 gdb_continue_to_breakpoint "stop at marker_label"
 119 gdb_test "ptype dyn_object" "type = integer, allocatable \\(:\\)"