gdb/testsuite/gdb.dwarf2/nonvar-access.exp

   1 # Copyright 2016-2017 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 accessing "non-variable" variables, i.e., variables which are
  17 # optimized to a constant DWARF location expression and/or
  18 # partially/fully optimized out.
  19
  20 load_lib dwarf.exp
  21
  22 if {![dwarf2_support]} { return 0 }
  23
  24 standard_testfile main.c nonvar-access-dw.S
  25
  26 # Make some DWARF for the test.
  27 set asm_file [standard_output_file $srcfile2]
  28
  29 Dwarf::assemble $asm_file {
  30     cu {} {
  31         compile_unit {
  32             {DW_AT_name main.c}
  33         } {
  34             declare_labels int_type_label char_type_label \
  35                 struct_s_label struct_t_label array_a9_label \
  36                 char_ptr_label implicit_a_label stack_b_label
  37
  38             int_type_label: base_type {
  39                 {name "int"}
  40                 {encoding @DW_ATE_signed}
  41                 {byte_size 4 DW_FORM_sdata}
  42             }
  43             char_type_label: base_type {
  44                 {name "char"}
  45                 {encoding @DW_ATE_unsigned}
  46                 {byte_size 1 DW_FORM_sdata}
  47             }
  48             char_ptr_label: pointer_type {
  49                 {type :$char_type_label}
  50             }
  51
  52             struct_s_label: structure_type {
  53                 {name s}
  54                 {byte_size 4 DW_FORM_sdata}
  55             } {
  56                 member {
  57                     {name a}
  58                     {type :$int_type_label}
  59                     {data_member_location 0 DW_FORM_udata}
  60                     {bit_size 8 DW_FORM_udata}
  61                 }
  62                 member {
  63                     {name b}
  64                     {type :$int_type_label}
  65                     {data_bit_offset 8 DW_FORM_udata}
  66                     {bit_size 24 DW_FORM_udata}
  67                 }
  68             }
  69
  70             struct_t_label: structure_type {
  71                 {name t}
  72                 {byte_size 4 DW_FORM_sdata}
  73             } {
  74                 member {
  75                     {name a}
  76                     {type :$int_type_label}
  77                     {data_member_location 0 DW_FORM_udata}
  78                     {bit_size 9 DW_FORM_udata}
  79                 }
  80                 member {
  81                     {name b}
  82                     {type :$int_type_label}
  83                     {data_bit_offset 9 DW_FORM_udata}
  84                     {bit_size 23 DW_FORM_udata}
  85                 }
  86             }
  87
  88             array_a9_label: array_type {
  89                 {type :$char_type_label}
  90             } {
  91                 subrange_type {
  92                     {type :$int_type_label}
  93                     {upper_bound 8 DW_FORM_udata}
  94                 }
  95             }
  96
  97             DW_TAG_subprogram {
  98                 {name main}
  99                 {DW_AT_external 1 flag}
 100                 {low_pc [gdb_target_symbol main] DW_FORM_addr}
 101                 {high_pc [gdb_target_symbol main]+0x10000 DW_FORM_addr}
 102             } {
 103                 # Simple variable without location.
 104                 DW_TAG_variable {
 105                     {name undef_int}
 106                     {type :$int_type_label}
 107                 }
 108                 # Struct variable without location.
 109                 DW_TAG_variable {
 110                     {name undef_s}
 111                     {type :$struct_s_label}
 112                 }
 113                 # Composite location: byte-aligned pieces.
 114                 DW_TAG_variable {
 115                     {name def_s}
 116                     {type :$struct_s_label}
 117                     {location {
 118                         const1u 0
 119                         stack_value
 120                         bit_piece 8 0
 121                         const1s -1
 122                         stack_value
 123                         bit_piece 24 0
 124                     } SPECIAL_expr}
 125                 }
 126                 # Composite location: non-byte-aligned pieces.
 127                 DW_TAG_variable {
 128                     {name def_t}
 129                     {type :$struct_t_label}
 130                     {location {
 131                         const1u 0
 132                         stack_value
 133                         bit_piece 9 0
 134                         const1s -1
 135                         stack_value
 136                         bit_piece 23 0
 137                     } SPECIAL_expr}
 138                 }
 139                 # Implicit location: immediate value.
 140                 DW_TAG_variable {
 141                     {name def_implicit_s}
 142                     {type :$struct_s_label}
 143                     {location {
 144                         implicit_value 0x12 0x34 0x56 0x78
 145                     } SPECIAL_expr}
 146                 }
 147                 # Implicit location: immediate value for whole array, with
 148                 # excess bytes.
 149                 implicit_a_label: DW_TAG_variable {
 150                     {name def_implicit_a}
 151                     {type :$array_a9_label}
 152                     {location {
 153                         implicit_value 0x1 0x12 0x23 0x34 0x45 \
 154                             0x56 0x67 0x78 0x89 0x9a 0xab
 155                     } SPECIAL_expr}
 156                 }
 157                 # Implicit pointer into immediate value.
 158                 DW_TAG_variable {
 159                     {name implicit_a_ptr}
 160                     {type :$char_ptr_label}
 161                     {location {
 162                         implicit_pointer $implicit_a_label 5
 163                     } SPECIAL_expr}
 164                 }
 165                 # Stack-value location.
 166                 stack_b_label: DW_TAG_variable {
 167                     {name def_stack_b}
 168                     {type :$struct_t_label}
 169                     {location {
 170                         const4u 0x1a2b3c4d
 171                         stack_value
 172                     } SPECIAL_expr}
 173                 }
 174                 # Implicit pointer into stack value.
 175                 DW_TAG_variable {
 176                     {name implicit_b_ptr}
 177                     {type :$char_ptr_label}
 178                     {location {
 179                         implicit_pointer $stack_b_label 1
 180                     } SPECIAL_expr}
 181                 }
 182             }
 183         }
 184     }
 185 }
 186
 187 if { [prepare_for_testing "failed to prepare" ${testfile} \
 188           [list $srcfile $asm_file] {nodebug}] } {
 189     return -1
 190 }
 191
 192 if ![runto_main] {
 193     return -1
 194 }
 195
 196 # Determine endianness.
 197 set endian "little"
 198 gdb_test_multiple "show endian" "determine endianness" {
 199     -re ".* (big|little) endian.*$gdb_prompt $" {
 200         set endian $expect_out(1,string)
 201         pass "endianness: $endian"
 202     }
 203 }
 204
 205 # Byte-aligned objects with simple location descriptions.
 206 switch $endian { big {set val 0x345678} little {set val 0x785634} }
 207 gdb_test "print/x def_implicit_s" " = \\{a = 0x12, b = $val\\}"
 208 gdb_test "print/x def_implicit_s.b" " = $val"
 209 gdb_test "print/x def_implicit_a" \
 210     " = \\{0x1, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x89\\}"
 211 gdb_test "print/x def_implicit_a\[5\]" " = 0x56"
 212 gdb_test "print/x *(char (*)\[5\]) implicit_a_ptr" \
 213     " = \\{0x56, 0x67, 0x78, 0x89, 0x9a\\}"
 214 switch $endian {
 215     big {set val "a = 52, b = 2833485"}
 216     little {set val "a = 77, b = 857502"}
 217 }
 218 gdb_test "print def_stack_b" " = \\{$val\\}"
 219 switch $endian {big {set val 0x2b} little {set val 0x3c}}
 220 gdb_test "print/x *implicit_b_ptr" " = $val"
 221
 222 # Byte-aligned fields, pieced together from DWARF stack values.
 223 gdb_test "print def_s" " = \\{a = 0, b = -1\\}"
 224
 225 # Non-byte-aligned fields, pieced together from DWARF stack values.
 226 gdb_test "print def_t" " = \\{a = 0, b = -1\\}"
 227
 228 # Simple variable without location.
 229 gdb_test "print undef_int" " = <optimized out>"
 230
 231 # Member of a structure without location.
 232 gdb_test "print undef_s.a" " = <optimized out>"