1# Copyright 2016 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 a C++ reference marked with DW_OP_GNU_implicit_pointer. 17# The referenced value is a global struct whose location is a DW_OP_addr. 18 19if [skip_cplus_tests] { 20 continue 21} 22 23load_lib dwarf.exp 24 25# This test can only be run on targets which support DWARF-2 and use gas. 26if ![dwarf2_support] { 27 return 0 28} 29 30# We'll place the output of Dwarf::assemble in implref-struct.S. 31standard_testfile .c .S 32 33# ${testfile} is now "implref-struct". srcfile2 is "implref-struct.S". 34set executable ${testfile} 35set asm_file [standard_output_file ${srcfile2}] 36 37# We need to know the size of integer and address types in order 38# to write some of the debugging info we'd like to generate. 39# 40# For that, we ask GDB by debugging our implref-struct program. 41# Any program would do, but since we already have implref-struct 42# specifically for this testcase, might as well use that. 43if [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {debug c++}] { 44 untested ${testfile}.exp 45 return -1 46} 47 48# Create the DWARF. We need a regular variable for the struct and a reference 49# to it that'll be marked with DW_OP_GNU_implicit_pointer. The variable must be 50# global so that its name is an exported symbol that can we can reference from 51# the DWARF using gdb_target_symbol. 52Dwarf::assemble ${asm_file} { 53 global srcdir subdir srcfile 54 55 cu {} { 56 DW_TAG_compile_unit { 57 {DW_AT_language @DW_LANG_C_plus_plus} 58 } { 59 declare_labels int_label struct_label variable_label ref_label 60 set int_size [get_sizeof "int" -1] 61 62 # gdb always assumes references are implemented as pointers. 63 set addr_size [get_sizeof "void *" -1] 64 set S_size [get_sizeof "S" -1] 65 66 # The compiler shouldn't introduce structure padding here. 67 set b_offset 4 68 set c_offset 8 69 70 int_label: DW_TAG_base_type { 71 {DW_AT_byte_size ${int_size} DW_FORM_udata} 72 {DW_AT_encoding @DW_ATE_signed} 73 {DW_AT_name "int"} 74 } 75 76 struct_label: DW_TAG_structure_type { 77 {DW_AT_name "S"} 78 {DW_AT_byte_size ${S_size} DW_FORM_udata} 79 } { 80 DW_TAG_member { 81 {DW_AT_name "a"} 82 {DW_AT_type :${int_label}} 83 {DW_AT_data_member_location 0 DW_FORM_udata} 84 } 85 86 DW_TAG_member { 87 {DW_AT_name "b"} 88 {DW_AT_type :${int_label}} 89 {DW_AT_data_member_location ${b_offset} DW_FORM_udata} 90 } 91 92 DW_TAG_member { 93 {DW_AT_name "c"} 94 {DW_AT_type :${int_label}} 95 {DW_AT_data_member_location ${c_offset} DW_FORM_udata} 96 } 97 } 98 99 ref_label: DW_TAG_reference_type { 100 {DW_AT_byte_size ${addr_size} DW_FORM_udata} 101 {DW_AT_type :${struct_label}} 102 } 103 104 variable_label: DW_TAG_variable { 105 {DW_AT_name "s1"} 106 {DW_AT_type :${struct_label}} 107 {DW_AT_external 1 DW_FORM_flag} 108 {DW_AT_location {DW_OP_addr [gdb_target_symbol "s1"]} SPECIAL_expr} 109 } 110 111 DW_TAG_variable { 112 {DW_AT_name "s2"} 113 {DW_AT_type :${struct_label}} 114 {DW_AT_external 1 DW_FORM_flag} 115 {DW_AT_location {DW_OP_addr [gdb_target_symbol "s2"]} SPECIAL_expr} 116 } 117 118 DW_TAG_subprogram { 119 {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }} 120 {DW_AT_type :${int_label}} 121 {DW_AT_external 1 DW_FORM_flag} 122 } { 123 DW_TAG_variable { 124 {DW_AT_name "ref"} 125 {DW_AT_type :${ref_label}} 126 {DW_AT_location {DW_OP_GNU_implicit_pointer ${variable_label} 0} SPECIAL_expr} 127 } 128 } 129 } 130 } 131} 132 133if [prepare_for_testing ${testfile}.exp ${executable} [list ${asm_file} ${srcfile}] {}] { 134 return -1 135} 136 137# DW_OP_GNU_implicit_pointer implementation requires a valid frame. 138if ![runto_main] { 139 return -1 140} 141 142# Returns the struct members, e.g. '{a = 0, b = 1, c = 2}'. 143proc get_members {var} { 144 set members [get_valueof "" ${var} ""] 145 146 # Trim leading/trailing whitespace, '{' and '}' since they confuse TCL to no end. 147 set members [string trim ${members}] 148 set members [string trim ${members} "{}"] 149 150 return ${members} 151} 152 153# Values of the struct members. 154set s1_members [get_members "s1"] 155set s2_members [get_members "s2"] 156 157# Address of the referenced value. 158set address [get_hexadecimal_valueof "&s1" ""] 159 160# Test printing with both 'set print object off' and 'on', just to make sure 161# the output doesn't change. 162foreach_with_prefix print-object {"off" "on"} { 163 gdb_test_no_output "set print object ${print-object}" 164 165 # Doing 'print ref' should show us e.g. 166 # '(S &) @0xdeadbeef: {a = 0, b = 1, c = 2}'. 167 gdb_test "print ref" " = \\(S &\\) @${address}: \\{${s1_members}\\}" 168 169 # Doing 'print &ref' should show us e.g. '(S *) 0xdeadbeef <s1>'. 170 gdb_test "print &ref" " = \\(S \\*\\) ${address} <s1>" 171 172 # gdb assumes C++ references are implemented as pointers, and 173 # print &(&ref) shows us the underlying pointer's address. 174 # Since in this case there's no physical pointer, gdb should tell us so. 175 gdb_test "print &(&ref)" "Attempt to take address of value not located in memory." 176} 177 178# Test assignment through the synthetic reference. 179gdb_test_no_output "set (ref = s2)" 180 181foreach_with_prefix print-object {"off" "on"} { 182 gdb_test_no_output "set print object ${print-object}" 183 184 gdb_test "print ref" " = \\(S &\\) @${address}: \\{${s2_members}\\}" "print ref after assignment" 185 gdb_test "print s1" " = \\{${s2_members}\\}" "print s1 after assignment" 186} 187