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

   1 # Copyright 2016-2023 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 -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     global srcfile
  31
  32     cu {} {
  33         compile_unit {
  34             {DW_AT_name $srcfile}
  35         } {
  36             declare_labels int_type_label char_type_label \
  37                 struct_s_label struct_t_label array_a9_label \
  38                 char_ptr_label implicit_a_label stack_b_label
  39
  40             int_type_label: base_type {
  41                 {name "int"}
  42                 {encoding @DW_ATE_signed}
  43                 {byte_size 4 DW_FORM_sdata}
  44             }
  45             char_type_label: base_type {
  46                 {name "char"}
  47                 {encoding @DW_ATE_unsigned}
  48                 {byte_size 1 DW_FORM_sdata}
  49             }
  50             char_ptr_label: pointer_type {
  51                 {type :$char_type_label}
  52             }
  53
  54             struct_s_label: structure_type {
  55                 {name s}
  56                 {byte_size 4 DW_FORM_sdata}
  57             } {
  58                 member {
  59                     {name a}
  60                     {type :$int_type_label}
  61                     {data_member_location 0 DW_FORM_udata}
  62                     {bit_size 8 DW_FORM_udata}
  63                 }
  64                 member {
  65                     {name b}
  66                     {type :$int_type_label}
  67                     {data_bit_offset 8 DW_FORM_udata}
  68                     {bit_size 24 DW_FORM_udata}
  69                 }
  70             }
  71
  72             struct_t_label: structure_type {
  73                 {name t}
  74                 {byte_size 4 DW_FORM_sdata}
  75             } {
  76                 member {
  77                     {name a}
  78                     {type :$int_type_label}
  79                     {data_member_location 0 DW_FORM_udata}
  80                     {bit_size 9 DW_FORM_udata}
  81                 }
  82                 member {
  83                     {name b}
  84                     {type :$int_type_label}
  85                     {data_bit_offset 9 DW_FORM_udata}
  86                     {bit_size 23 DW_FORM_udata}
  87                 }
  88             }
  89
  90             array_a9_label: array_type {
  91                 {type :$char_type_label}
  92             } {
  93                 subrange_type {
  94                     {type :$int_type_label}
  95                     {upper_bound 8 DW_FORM_udata}
  96                 }
  97             }
  98
  99             DW_TAG_subprogram {
 100                 {MACRO_AT_func {main}}
 101                 {DW_AT_external 1 flag}
 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                         const2s -184
 132                         stack_value
 133                         bit_piece 9 0
 134                         const4u 1752286
 135                         stack_value
 136                         bit_piece 23 0
 137                     } SPECIAL_expr}
 138                 }
 139                 # Composite location with some empty pieces.
 140                 DW_TAG_variable {
 141                     {name part_def_a}
 142                     {type :$array_a9_label}
 143                     {location {
 144                         piece 3
 145                         const4u 0xf1927314
 146                         stack_value
 147                         piece 4
 148                         piece 2
 149                     } SPECIAL_expr}
 150                 }
 151                 # Implicit location: immediate value.
 152                 DW_TAG_variable {
 153                     {name def_implicit_s}
 154                     {type :$struct_s_label}
 155                     {location {
 156                         implicit_value 0x12 0x34 0x56 0x78
 157                     } SPECIAL_expr}
 158                 }
 159                 # Implicit location: immediate value for whole array, with
 160                 # excess bytes.
 161                 implicit_a_label: DW_TAG_variable {
 162                     {name def_implicit_a}
 163                     {type :$array_a9_label}
 164                     {location {
 165                         implicit_value 0x1 0x12 0x23 0x34 0x45 \
 166                             0x56 0x67 0x78 0x89 0x9a 0xab
 167                     } SPECIAL_expr}
 168                 }
 169                 # Implicit pointer into immediate value.
 170                 DW_TAG_variable {
 171                     {name implicit_a_ptr}
 172                     {type :$char_ptr_label}
 173                     {location {
 174                         implicit_pointer $implicit_a_label 5
 175                     } SPECIAL_expr}
 176                 }
 177                 # Stack-value location.
 178                 stack_b_label: DW_TAG_variable {
 179                     {name def_stack_b}
 180                     {type :$struct_t_label}
 181                     {location {
 182                         const4u 0x1a2b3c4d
 183                         stack_value
 184                     } SPECIAL_expr}
 185                 }
 186                 # Implicit pointer into stack value.
 187                 DW_TAG_variable {
 188                     {name implicit_b_ptr}
 189                     {type :$char_ptr_label}
 190                     {location {
 191                         implicit_pointer $stack_b_label 1
 192                     } SPECIAL_expr}
 193                 }
 194             }
 195         }
 196     }
 197 }
 198
 199 if { [prepare_for_testing "failed to prepare" ${testfile} \
 200           [list $srcfile $asm_file] {nodebug}] } {
 201     return -1
 202 }
 203
 204 if ![runto_main] {
 205     return -1
 206 }
 207
 208 # Determine byte order.
 209 set endian [get_endianness]
 210
 211 # Byte-aligned objects with simple location descriptions.
 212 switch $endian { big {set val 0x345678} little {set val 0x785634} }
 213 gdb_test "print/x def_implicit_s" " = \\{a = 0x12, b = $val\\}"
 214 gdb_test "print/x def_implicit_s.b" " = $val"
 215 gdb_test "print/x def_implicit_a" \
 216     " = \\{0x1, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x89\\}"
 217 gdb_test "print/x def_implicit_a\[5\]" " = 0x56"
 218 gdb_test "print/x *(char (*)\[5\]) implicit_a_ptr" \
 219     " = \\{0x56, 0x67, 0x78, 0x89, 0x9a\\}"
 220 switch $endian {
 221     big {set val "a = 52, b = 2833485"}
 222     little {set val "a = 77, b = 857502"}
 223 }
 224 gdb_test "print def_stack_b" " = \\{$val\\}"
 225 switch $endian {big {set val 0x2b} little {set val 0x3c}}
 226 gdb_test "print/x *implicit_b_ptr" " = $val"
 227
 228 # Byte-aligned fields, pieced together from DWARF stack values.
 229 gdb_test "print def_s" " = \\{a = 0, b = -1\\}"
 230 switch $endian { big {set val 0x92} little {set val 0x73} }
 231 gdb_test "print/x part_def_a\[4\]" " = $val"
 232 gdb_test "print/x part_def_a\[8\]" " = <optimized out>"
 233
 234 # Non-byte-aligned fields, pieced together from DWARF stack values.
 235 gdb_test "print def_t" " = \\{a = -184, b = 1752286\\}"
 236
 237 # Simple variable without location.
 238 gdb_test "print undef_int" " = <optimized out>"
 239
 240 # Member of a structure without location.
 241 gdb_test "print undef_s.a" " = <optimized out>"