# Copyright 2016-2023 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 . # This test ensures that with "set print object on", -var-create will # return "" for an optimized out pointer to structure, # rather than attempting to dereference the pointer to determine its # actual type (instead of its declared type). We want to test that GDB # can display such a pointer without throwing an error, while also # ensuring that any attempt to dereference the pointer *will* throw an # error. load_lib dwarf.exp # This test can only be run on targets which support DWARF-2 and use gas. require dwarf2_support standard_testfile .c -dw.S # Generate a test program with dwarf information showing the variable # 'ptr', a pointer-to-struct, as optimized out. The dwarf will also # describe the structure as have a scalar, array, and pointer-to-struct # members. proc build_test_program {} { global testfile srcfile srcfile2 # Make some DWARF for the test. set asm_file [standard_output_file $srcfile2] Dwarf::assemble $asm_file { global srcfile # Creating a CU with 4-byte addresses lets this test link on # both 32- and 64-bit machines. cu { addr_size 4 } { DW_TAG_compile_unit { {DW_AT_language @DW_LANG_C99} {DW_AT_name $srcfile} {DW_AT_comp_dir /tmp} } { declare_labels int_label struct_label pointer_label \ array_label int_label: DW_TAG_base_type { {DW_AT_byte_size 4 DW_FORM_sdata} {DW_AT_encoding @DW_ATE_signed} {DW_AT_name integer} } array_label: DW_TAG_array_type { {DW_AT_name foo__array_type} {DW_AT_type :$int_label} } { DW_TAG_subrange_type { {DW_AT_type :$int_label} {DW_AT_lower_bound 0 DW_FORM_data1} {DW_AT_upper_bound 127 DW_FORM_data1} } } struct_label: DW_TAG_structure_type { {DW_AT_name "foo"} {DW_AT_byte_size 12 DW_FORM_sdata} } { member { {name a} {type :$int_label} {data_member_location 0 data1} } member { {name x} {type :$array_label} {data_member_location 4 data1} } member { {name y} {type :$pointer_label} {data_member_location 8 data1} } } pointer_label: DW_TAG_pointer_type { {DW_AT_byte_size 4 DW_FORM_sdata} {DW_AT_type :$struct_label} } DW_TAG_subprogram { {DW_AT_name func01} {DW_AT_type :$int_label} {external 1 flag} {MACRO_AT_func {func01}} } { DW_TAG_variable { {DW_AT_name ptr} {DW_AT_type :$pointer_label} {DW_AT_location {} DW_FORM_block1} } } DW_TAG_subprogram { {DW_AT_name main} {DW_AT_type :$int_label} {external 1 flag} {MACRO_AT_func {main}} } { } } } } set sources "$srcfile $asm_file" if {[build_executable "failed to compile" $testfile $sources {nodebug}]} { return -1 } } # Test access to an optimized-out pointer-to-struct using the # console interpreter. proc do_console_test {} { global binfile clean_restart $binfile with_test_prefix "console" { gdb_test_no_output "set print object on" if {![runto_main]} { return -1 } if {![runto func01]} { return -1 } gdb_test "info addr ptr" "Symbol \"ptr\" is optimized out." gdb_test "print ptr" "" gdb_test "print *ptr" "value has been optimized out" gdb_test "print ptr->a" "value has been optimized out" gdb_test "print ptr->x" "value has been optimized out" gdb_test "print ptr->y" "value has been optimized out" } } # Test access to an optimized-out pointer-to-struct using the # MI interpreter. proc do_mi_test {} { load_lib mi-support.exp set MIFLAGS "-i=mi" global mi_gdb_prompt global binfile with_test_prefix "mi" { if {[mi_clean_restart $binfile]} { return } # This causes GDB to dereference a pointer-to-structure when doing # -var-create. mi_gdb_test "-gdb-set print object on" ".*" "set print object on" mi_gdb_test "-break-insert main" ".*" "insert breakpoint main" mi_gdb_test "-break-insert func01" ".*" "insert breakpoint func01" # Run to main. Use an explicit expect here since the limited # debug info will result in output that isn't handled by the # MI test utilities. set test "run to main" mi_run_cmd gdb_expect { -re "\\*stopped,reason=\"breakpoint-hit\".*func=\"main\".*$mi_gdb_prompt$" { pass "$test" } timeout { fail "$test (timeout)" } } # Run to func01. Use an explicit expect here as above. set test "continue to func01" mi_send_resuming_command "exec-continue" "$test" gdb_expect { -re "\\*stopped,reason=\"breakpoint-hit\".*func=\"func01\".*$mi_gdb_prompt$" { pass "$test" } timeout { fail "$test (timeout)" } } # Test that -var-create for 'ptr' is successful. mi_create_varobj "var1" "ptr" "create varobj for ptr" # Test that -var-list-children of 'ptr' is successful. mi_list_varobj_children "var1" { \ {var1.a a 0 integer} \ {var1.x x 128 foo__array_type} \ {var1.y y 3 "struct foo \\*"} \ } "get children of var1 (ptr)" # Test that dereferencing 'ptr' will throw an error. mi_gdb_test "-var-create var2 * &((ptr)->a)" \ "\\^error,msg=\"value has been optimized out\"" \ "throw error, dereference ptr to access integer member " # Test that dereferencing 'ptr' will throw an error. mi_gdb_test "-var-create var3 * &((ptr)->x)" \ "\\^error,msg=\"value has been optimized out\"" \ "throw error, dereference ptr to access array member " # Test that dereferencing 'ptr' will throw an error. mi_gdb_test "-var-create var4 * &((ptr)->y)" \ "\\^error,msg=\"value has been optimized out\"" \ "throw error, dereference ptr to access pointer member " } } if { [build_test_program] == -1 } { return -1 } do_console_test do_mi_test