xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.dwarf2/implref-struct.exp (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
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