+2016-05-31 Martin Galvan <martin.galvan@tallertechnologies.com>
+
+ PR c++/19893
+ * dwarf2loc.c (coerce_pieced_ref, indirect_synthetic_pointer,
+ fetch_const_value_from_synthetic_pointer): New functions.
+ (indirect_pieced_value): Move lower half to indirect_synthetic_pointer.
+ (pieced_value_funcs): Implement coerce_ref.
+ * valops.c (value_addr): Call coerce_ref for synthetic references.
+ * valprint.c (valprint_check_validity): Return true for synthetic
+ references. Also, don't show "<synthetic pointer>" if they reference
+ addressable values.
+ (generic_val_print_ref): Handle synthetic references. Also move some
+ code to print_ref_address.
+ (print_ref_address, get_value_addr_contents): New functions.
+
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
return get_frame_address_in_block ((struct frame_info *) baton);
}
+/* Fetch a DW_AT_const_value through a synthetic pointer. */
+
+static struct value *
+fetch_const_value_from_synthetic_pointer (sect_offset die, LONGEST byte_offset,
+ struct dwarf2_per_cu_data *per_cu,
+ struct type *type)
+{
+ struct value *result = NULL;
+ struct obstack temp_obstack;
+ struct cleanup *cleanup;
+ const gdb_byte *bytes;
+ LONGEST len;
+
+ obstack_init (&temp_obstack);
+ cleanup = make_cleanup_obstack_free (&temp_obstack);
+ bytes = dwarf2_fetch_constant_bytes (die, per_cu, &temp_obstack, &len);
+
+ if (bytes != NULL)
+ {
+ if (byte_offset >= 0
+ && byte_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)) <= len)
+ {
+ bytes += byte_offset;
+ result = value_from_contents (TYPE_TARGET_TYPE (type), bytes);
+ }
+ else
+ invalid_synthetic_pointer ();
+ }
+ else
+ result = allocate_optimized_out_value (TYPE_TARGET_TYPE (type));
+
+ do_cleanups (cleanup);
+
+ return result;
+}
+
+/* Fetch the value pointed to by a synthetic pointer. */
+
+static struct value *
+indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset,
+ struct dwarf2_per_cu_data *per_cu,
+ struct frame_info *frame, struct type *type)
+{
+ /* Fetch the location expression of the DIE we're pointing to. */
+ struct dwarf2_locexpr_baton baton
+ = dwarf2_fetch_die_loc_sect_off (die, per_cu,
+ get_frame_address_in_block_wrapper, frame);
+
+ /* If pointed-to DIE has a DW_AT_location, evaluate it and return the
+ resulting value. Otherwise, it may have a DW_AT_const_value instead,
+ or it may've been optimized out. */
+ if (baton.data != NULL)
+ return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
+ baton.data, baton.size, baton.per_cu,
+ byte_offset);
+ else
+ return fetch_const_value_from_synthetic_pointer (die, byte_offset, per_cu,
+ type);
+}
+
/* An implementation of an lval_funcs method to indirect through a
pointer. This handles the synthetic pointer case when needed. */
break;
}
+ gdb_assert (piece != NULL);
frame = get_selected_frame (_("No frame selected."));
/* This is an offset requested by GDB, such as value subscripts.
TYPE_LENGTH (type), byte_order);
byte_offset += piece->v.ptr.offset;
- gdb_assert (piece);
- baton
- = dwarf2_fetch_die_loc_sect_off (piece->v.ptr.die, c->per_cu,
- get_frame_address_in_block_wrapper,
- frame);
+ return indirect_synthetic_pointer (piece->v.ptr.die, byte_offset, c->per_cu,
+ frame, type);
+}
- if (baton.data != NULL)
- return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
- baton.data, baton.size, baton.per_cu,
- byte_offset);
+/* Implementation of the coerce_ref method of lval_funcs for synthetic C++
+ references. */
- {
- struct obstack temp_obstack;
- struct cleanup *cleanup;
- const gdb_byte *bytes;
- LONGEST len;
- struct value *result;
-
- obstack_init (&temp_obstack);
- cleanup = make_cleanup_obstack_free (&temp_obstack);
-
- bytes = dwarf2_fetch_constant_bytes (piece->v.ptr.die, c->per_cu,
- &temp_obstack, &len);
- if (bytes == NULL)
- result = allocate_optimized_out_value (TYPE_TARGET_TYPE (type));
- else
- {
- if (byte_offset < 0
- || byte_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > len)
- invalid_synthetic_pointer ();
- bytes += byte_offset;
- result = value_from_contents (TYPE_TARGET_TYPE (type), bytes);
- }
+static struct value *
+coerce_pieced_ref (const struct value *value)
+{
+ struct type *type = check_typedef (value_type (value));
- do_cleanups (cleanup);
- return result;
- }
+ if (value_bits_synthetic_pointer (value, value_embedded_offset (value),
+ TARGET_CHAR_BIT * TYPE_LENGTH (type)))
+ {
+ const struct piece_closure *closure
+ = (struct piece_closure *) value_computed_closure (value);
+ struct frame_info *frame
+ = get_selected_frame (_("No frame selected."));
+
+ /* gdb represents synthetic pointers as pieced values with a single
+ piece. */
+ gdb_assert (closure != NULL);
+ gdb_assert (closure->n_pieces == 1);
+
+ return indirect_synthetic_pointer (closure->pieces->v.ptr.die,
+ closure->pieces->v.ptr.offset,
+ closure->per_cu, frame, type);
+ }
+ else
+ {
+ /* Else: not a synthetic reference; do nothing. */
+ return NULL;
+ }
}
static void *
read_pieced_value,
write_pieced_value,
indirect_pieced_value,
- NULL, /* coerce_ref */
+ coerce_pieced_ref,
check_pieced_synthetic_pointer,
copy_pieced_value_closure,
free_pieced_value_closure
+2016-05-31 Martin Galvan <martin.galvan@tallertechnologies.com>
+
+ PR c++/19893
+ * gdb.dwarf2/implref.exp: Rename to...
+ * gdb.dwarf2/implref-const.exp: ...this. Also add more test statements.
+ * gdb.dwarf2/implref-array.c: New file.
+ * gdb.dwarf2/implref-array.exp: Likewise.
+ * gdb.dwarf2/implref-global.c: Likewise.
+ * gdb.dwarf2/implref-global.exp: Likewise.
+ * gdb.dwarf2/implref-struct.c: Likewise.
+ * gdb.dwarf2/implref-struct.exp: Likewise.
+
2016-05-30 Antoine Tremblay <antoine.tremblay@ericsson.com>
* gdb.trace/trace-condition.exp: Add 64bit tests.
--- /dev/null
+/* Copyright (C) 2016 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 <http://www.gnu.org/licenses/>. */
+
+/* Test program for synthetic C++ references to arrays. */
+
+int array[5] = {0, 1, 2, 3, 4};
+
+int
+main (void)
+{
+ asm ("main_label: .globl main_label");
+ return 0;
+}
--- /dev/null
+# Copyright 2016 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 <http://www.gnu.org/licenses/>.
+
+# Test a C++ reference marked with DW_OP_GNU_implicit_pointer.
+# The referenced value is a global array whose location is a DW_OP_addr.
+
+if [skip_cplus_tests] {
+ continue
+}
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if ![dwarf2_support] {
+ return 0
+}
+
+# We'll place the output of Dwarf::assemble in implref-array.S.
+standard_testfile .c .S
+
+# ${testfile} is now "implref-array". srcfile2 is "implref-array.S".
+set executable ${testfile}
+set asm_file [standard_output_file ${srcfile2}]
+
+# We need to know the size of integer and address types in order
+# to write some of the debugging info we'd like to generate.
+#
+# For that, we ask GDB by debugging our implref-array program.
+# Any program would do, but since we already have implref-array
+# specifically for this testcase, might as well use that.
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+ untested ${testfile}.exp
+ return -1
+}
+
+set array_length [get_valueof "/u" "sizeof(array) / sizeof(array\[0\])" -1]
+
+# Create the DWARF. We need a regular variable which represents the array, and
+# a reference to it that'll be marked with DW_OP_GNU_implicit_pointer.
+# The variable must be global so that its name is an exported symbol that we
+# can reference from the DWARF using gdb_target_symbol.
+Dwarf::assemble ${asm_file} {
+ global srcdir subdir srcfile array_length
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_language @DW_LANG_C_plus_plus}
+ } {
+ declare_labels int_label sizetype_label array_label variable_label ref_label
+ set int_size [get_sizeof "int" -1]
+ set upper_bound [expr ${array_length} - 1]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" -1]
+
+ int_label: DW_TAG_base_type {
+ {DW_AT_byte_size ${int_size} DW_FORM_udata}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name "int"}
+ }
+
+ sizetype_label: DW_TAG_base_type {
+ {DW_AT_byte_size ${int_size} DW_FORM_udata}
+ {DW_AT_encoding @DW_ATE_unsigned}
+ {DW_AT_name "sizetype"}
+ }
+
+ array_label: DW_TAG_array_type {
+ {DW_AT_type :${int_label}}
+ } {
+ DW_TAG_subrange_type {
+ {DW_AT_type :${sizetype_label}}
+ {DW_AT_lower_bound 0 DW_FORM_udata}
+ {DW_AT_upper_bound ${upper_bound} DW_FORM_udata}
+ }
+ }
+
+ ref_label: DW_TAG_reference_type {
+ {DW_AT_byte_size ${addr_size} DW_FORM_udata}
+ {DW_AT_type :${array_label}}
+ }
+
+ variable_label: DW_TAG_variable {
+ {DW_AT_name "array"}
+ {DW_AT_type :${array_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ {DW_AT_location {DW_OP_addr [gdb_target_symbol "array"]} SPECIAL_expr}
+ }
+
+ DW_TAG_subprogram {
+ {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }}
+ {DW_AT_type :${int_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ } {
+ DW_TAG_variable {
+ {DW_AT_name "ref"}
+ {DW_AT_type :${ref_label}}
+ {DW_AT_location {DW_OP_GNU_implicit_pointer ${variable_label} 0} SPECIAL_expr}
+ }
+ }
+ }
+ }
+}
+
+if [prepare_for_testing ${testfile}.exp ${executable} [list ${asm_file} ${srcfile}] {}] {
+ return -1
+}
+
+# DW_OP_GNU_implicit_pointer implementation requires a valid frame.
+if ![runto_main] {
+ return -1
+}
+
+# This matches e.g. '(int (&)[5])'
+set ref_type [format {\(int \(&\)\[%d\]\)} ${array_length}]
+
+# This matches e.g. '(int (*)[5])'
+set ptr_type [format {\(int \(\*\)\[%d\]\)} ${array_length}]
+
+# Contents of the array. Trim leading/trailing whitespace, '{' and '}'
+# since they confuse TCL to no end.
+set contents [get_valueof "" "array" ""]
+set contents [string trim ${contents}]
+set contents [string trim ${contents} "{}"]
+
+# Address of the referenced value.
+set address [get_hexadecimal_valueof "&array" ""]
+
+# Doing 'print ref' should show us e.g. '(int (&)[5]) 0xdeadbeef: {0, 1, 2, 3, 4}'.
+gdb_test "print ref" " = ${ref_type} @${address}: \\{${contents}\\}"
+
+# Doing 'print &ref' should show us e.g. '(int (*)[5]) 0xdeadbeef <array>'.
+gdb_test "print &ref" " = ${ptr_type} ${address} <array>"
+
+# gdb assumes C++ references are implemented as pointers, and print &(&ref)
+# shows us the underlying pointer's address. Since in this case there's no
+# physical pointer, gdb should tell us so.
+gdb_test "print &(&ref)" "Attempt to take address of value not located in memory."
+
+# Test assignment through the synthetic reference.
+set first_value 10
+gdb_test_no_output "set (ref\[0\] = ${first_value})"
+
+# This matches '{10, 1, 2, 3, 4}'.
+set new_contents [format {\{%d, 1, 2, 3, 4\}} ${first_value}]
+
+# Doing 'print ref' should now show us e.g.
+# '(int (&)[5]) <synthetic pointer>: {10, 1, 2, 3, 4}'.
+gdb_test "print ref" " = ${ref_type} @${address}: ${new_contents}" "print ref after assignment"
+gdb_test "print array" " = ${new_contents}" "print array after assignment"
+
+# Test treating the array as a pointer.
+set second_value 20
+set new_contents [format {\{%d, %d, 2, 3, 4\}} ${first_value} ${second_value}]
+
+gdb_test "print *ref" " = ${first_value}"
+gdb_test_no_output "set (*(ref + 1) = ${second_value})"
+gdb_test "print ref\[1\]" " = ${second_value}"
+gdb_test "print array" " = ${new_contents}" "print array after second assignment"
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-# Test C++ references marked with DW_OP_GNU_implicit_pointer.
+# Test a C++ reference marked with DW_OP_GNU_implicit_pointer.
+# The referenced value is a DW_AT_const_value.
-# TODO: Add more test statements after fixing bug #19893:
-# https://sourceware.org/bugzilla/show_bug.cgi?id=19893.
+if [skip_cplus_tests] {
+ continue
+}
load_lib dwarf.exp
# This test can only be run on targets which support DWARF-2 and use gas.
-if {![dwarf2_support]} {
+if ![dwarf2_support] {
return 0
}
-# We'll place the output of Dwarf::assemble in implref.S.
+# We'll place the output of Dwarf::assemble in implref-const.S.
standard_testfile main.c .S
-# ${testfile} is now "implref". srcfile2 is "implref.S".
+# ${testfile} is now "implref-const". srcfile2 is "implref-const.S".
set executable ${testfile}
set asm_file [standard_output_file ${srcfile2}]
+# We need to know the size of integer and address types in order
+# to write some of the debugging info we'd like to generate.
+#
+# For that, we ask GDB by debugging our implref-const program.
+# Any program would do, but since we already have implref-const
+# specifically for this testcase, might as well use that.
+if [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] {
+ untested ${testfile}.exp
+ return -1
+}
+
# Create the DWARF. We need a regular variable and a reference to it that'll
# be marked with DW_OP_GNU_implicit_pointer.
-Dwarf::assemble $asm_file {
+Dwarf::assemble ${asm_file} {
global srcdir subdir srcfile
- cu { version 3 addr_size 4 } {
+ cu {} {
DW_TAG_compile_unit {
- {DW_AT_producer "GNU C++ 4.8.4"}
{DW_AT_language @DW_LANG_C_plus_plus}
} {
declare_labels int_label const_label variable_label ref_label
+ set int_size [get_sizeof "int" -1]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" -1]
+ set var_value 42
int_label: DW_TAG_base_type {
- {DW_AT_byte_size 4 DW_FORM_udata}
+ {DW_AT_byte_size ${int_size} DW_FORM_udata}
{DW_AT_encoding @DW_ATE_signed}
{DW_AT_name "int"}
}
ref_label: DW_TAG_reference_type {
- {DW_AT_byte_size 4 DW_FORM_udata}
+ {DW_AT_byte_size ${addr_size} DW_FORM_udata}
{DW_AT_type :${int_label}}
}
variable_label: DW_TAG_variable {
{DW_AT_name "var"}
{DW_AT_type :${int_label}}
- {DW_AT_const_value 42 DW_FORM_udata}
+ {DW_AT_const_value ${var_value} DW_FORM_udata}
}
DW_TAG_variable {
}
}
-if [prepare_for_testing ${testfile}.exp ${executable} "${asm_file} ${srcfile}" {}] {
+if [prepare_for_testing ${testfile}.exp ${executable} [list ${asm_file} ${srcfile}] {}] {
return -1
}
return -1
}
-gdb_test "print ref" " = \\(int &\\) <synthetic pointer>" "print ref"
-gdb_test "print &ref" " = \\(int \\*\\) <synthetic pointer>" "print &ref"
+# Doing 'print ref' should show us e.g. '(int &) <synthetic pointer>: 42'.
+gdb_test "print ref" " = \\(int &\\) <synthetic pointer>: \\\d+"
+
+# The variable isn't located in memory, thus we can't take its address.
+gdb_test "print &var" "Can't take address of \"var\" which isn't an lvalue."
+gdb_test "print &ref" "Attempt to take address of value not located in memory."
# gdb assumes C++ references are implemented as pointers, and print &(&ref)
# shows us the underlying pointer's address.
# Since in this case there's no physical pointer, gdb should tell us so.
-gdb_test "print &\(&ref\)" "Attempt to take address of value not located in memory." "print &(&ref)"
+gdb_test "print &(&ref)" "Attempt to take address of value not located in memory."
--- /dev/null
+/* Copyright (C) 2016 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 <http://www.gnu.org/licenses/>. */
+
+/* Test program for synthetic C++ references to global variables. */
+
+int global_var = 42;
+
+int
+main (void)
+{
+ asm ("main_label: .globl main_label");
+ return 0;
+}
--- /dev/null
+# Copyright 2016 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 <http://www.gnu.org/licenses/>.
+
+# Test a C++ reference marked with DW_OP_GNU_implicit_pointer.
+# The referenced value is a global variable whose location is a DW_OP_addr.
+
+if [skip_cplus_tests] {
+ continue
+}
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if ![dwarf2_support] {
+ return 0
+}
+
+# We'll place the output of Dwarf::assemble in implref-global.S.
+standard_testfile .c .S
+
+# ${testfile} is now "implref-global". srcfile2 is "implref-global.S".
+set executable ${testfile}
+set asm_file [standard_output_file ${srcfile2}]
+
+# We need to know the size of integer and address types in order
+# to write some of the debugging info we'd like to generate.
+#
+# For that, we ask GDB by debugging our implref-global program.
+# Any program would do, but since we already have implref-global
+# specifically for this testcase, might as well use that.
+if [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] {
+ untested ${testfile}.exp
+ return -1
+}
+
+# Create the DWARF. We need a regular variable and a reference to it that'll
+# be marked with DW_OP_GNU_implicit_pointer. The variable must be global so
+# that its name is an exported symbol that we can reference from the DWARF
+# using gdb_target_symbol.
+Dwarf::assemble ${asm_file} {
+ global srcdir subdir srcfile
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_language @DW_LANG_C_plus_plus}
+ } {
+ declare_labels int_label variable_label ref_label
+ set int_size [get_sizeof "int" -1]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" -1]
+
+ int_label: DW_TAG_base_type {
+ {DW_AT_byte_size ${int_size} DW_FORM_udata}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name "int"}
+ }
+
+ ref_label: DW_TAG_reference_type {
+ {DW_AT_byte_size ${addr_size} DW_FORM_udata}
+ {DW_AT_type :${int_label}}
+ }
+
+ variable_label: DW_TAG_variable {
+ {DW_AT_name "global_var"}
+ {DW_AT_type :${int_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ {DW_AT_location {DW_OP_addr [gdb_target_symbol "global_var"]} SPECIAL_expr}
+ }
+
+ DW_TAG_subprogram {
+ {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }}
+ {DW_AT_type :${int_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ } {
+ DW_TAG_variable {
+ {DW_AT_name "ref"}
+ {DW_AT_type :${ref_label}}
+ {DW_AT_location {DW_OP_GNU_implicit_pointer ${variable_label} 0} SPECIAL_expr}
+ }
+ }
+ }
+ }
+}
+
+if [prepare_for_testing ${testfile}.exp ${executable} [list ${asm_file} ${srcfile}] {}] {
+ return -1
+}
+
+# DW_OP_GNU_implicit_pointer implementation requires a valid frame.
+if ![runto_main] {
+ return -1
+}
+
+# Address of the referenced value.
+set address [get_hexadecimal_valueof "&global_var" ""]
+
+# Doing 'print ref' should show us e.g. '(int &) @0xdeadbeef: 42'.
+gdb_test "print ref" " = \\(int &\\) @${address}: \\\d+"
+
+# Doing 'print &ref' should show us e.g. '(int *) 0xdeadbeef <global_var>'.
+gdb_test "print &ref" " = \\(int \\*\\) ${address} <global_var>"
+
+# gdb assumes C++ references are implemented as pointers, and print &(&ref)
+# shows us the underlying pointer's address. Since in this case there's no
+# physical pointer, gdb should tell us so.
+gdb_test "print &(&ref)" "Attempt to take address of value not located in memory."
+
+# Test assignment through the synthetic reference.
+set new_value 10
+gdb_test_no_output "set (ref = ${new_value})"
+gdb_test "print ref" " = \\(int &\\) @${address}: ${new_value}" "print ref after assignment"
+gdb_test "print global_var" " = ${new_value}" "print global_var after assignment"
--- /dev/null
+/* Copyright (C) 2016 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 <http://www.gnu.org/licenses/>. */
+
+/* Test program for synthetic C++ references to structs. */
+
+struct S {
+ int a;
+ int b;
+ int c;
+};
+
+struct S s1 = {
+ 0,
+ 1,
+ 2
+};
+
+struct S s2 = {
+ 10,
+ 11,
+ 12
+};
+
+int
+main (void)
+{
+ asm ("main_label: .globl main_label");
+ return 0;
+}
--- /dev/null
+# Copyright 2016 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 <http://www.gnu.org/licenses/>.
+
+# Test a C++ reference marked with DW_OP_GNU_implicit_pointer.
+# The referenced value is a global struct whose location is a DW_OP_addr.
+
+if [skip_cplus_tests] {
+ continue
+}
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if ![dwarf2_support] {
+ return 0
+}
+
+# We'll place the output of Dwarf::assemble in implref-struct.S.
+standard_testfile .c .S
+
+# ${testfile} is now "implref-struct". srcfile2 is "implref-struct.S".
+set executable ${testfile}
+set asm_file [standard_output_file ${srcfile2}]
+
+# We need to know the size of integer and address types in order
+# to write some of the debugging info we'd like to generate.
+#
+# For that, we ask GDB by debugging our implref-struct program.
+# Any program would do, but since we already have implref-struct
+# specifically for this testcase, might as well use that.
+if [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {debug c++}] {
+ untested ${testfile}.exp
+ return -1
+}
+
+# Create the DWARF. We need a regular variable for the struct and a reference
+# to it that'll be marked with DW_OP_GNU_implicit_pointer. The variable must be
+# global so that its name is an exported symbol that can we can reference from
+# the DWARF using gdb_target_symbol.
+Dwarf::assemble ${asm_file} {
+ global srcdir subdir srcfile
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_language @DW_LANG_C_plus_plus}
+ } {
+ declare_labels int_label struct_label variable_label ref_label
+ set int_size [get_sizeof "int" -1]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" -1]
+ set S_size [get_sizeof "S" -1]
+
+ # The compiler shouldn't introduce structure padding here.
+ set b_offset 4
+ set c_offset 8
+
+ int_label: DW_TAG_base_type {
+ {DW_AT_byte_size ${int_size} DW_FORM_udata}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name "int"}
+ }
+
+ struct_label: DW_TAG_structure_type {
+ {DW_AT_name "S"}
+ {DW_AT_byte_size ${S_size} DW_FORM_udata}
+ } {
+ DW_TAG_member {
+ {DW_AT_name "a"}
+ {DW_AT_type :${int_label}}
+ {DW_AT_data_member_location 0 DW_FORM_udata}
+ }
+
+ DW_TAG_member {
+ {DW_AT_name "b"}
+ {DW_AT_type :${int_label}}
+ {DW_AT_data_member_location ${b_offset} DW_FORM_udata}
+ }
+
+ DW_TAG_member {
+ {DW_AT_name "c"}
+ {DW_AT_type :${int_label}}
+ {DW_AT_data_member_location ${c_offset} DW_FORM_udata}
+ }
+ }
+
+ ref_label: DW_TAG_reference_type {
+ {DW_AT_byte_size ${addr_size} DW_FORM_udata}
+ {DW_AT_type :${struct_label}}
+ }
+
+ variable_label: DW_TAG_variable {
+ {DW_AT_name "s1"}
+ {DW_AT_type :${struct_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ {DW_AT_location {DW_OP_addr [gdb_target_symbol "s1"]} SPECIAL_expr}
+ }
+
+ DW_TAG_variable {
+ {DW_AT_name "s2"}
+ {DW_AT_type :${struct_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ {DW_AT_location {DW_OP_addr [gdb_target_symbol "s2"]} SPECIAL_expr}
+ }
+
+ DW_TAG_subprogram {
+ {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }}
+ {DW_AT_type :${int_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ } {
+ DW_TAG_variable {
+ {DW_AT_name "ref"}
+ {DW_AT_type :${ref_label}}
+ {DW_AT_location {DW_OP_GNU_implicit_pointer ${variable_label} 0} SPECIAL_expr}
+ }
+ }
+ }
+ }
+}
+
+if [prepare_for_testing ${testfile}.exp ${executable} [list ${asm_file} ${srcfile}] {}] {
+ return -1
+}
+
+# DW_OP_GNU_implicit_pointer implementation requires a valid frame.
+if ![runto_main] {
+ return -1
+}
+
+# Returns the struct members, e.g. '{a = 0, b = 1, c = 2}'.
+proc get_members {var} {
+ set members [get_valueof "" ${var} ""]
+
+ # Trim leading/trailing whitespace, '{' and '}' since they confuse TCL to no end.
+ set members [string trim ${members}]
+ set members [string trim ${members} "{}"]
+
+ return ${members}
+}
+
+# Values of the struct members.
+set s1_members [get_members "s1"]
+set s2_members [get_members "s2"]
+
+# Address of the referenced value.
+set address [get_hexadecimal_valueof "&s1" ""]
+
+# Test printing with both 'set print object off' and 'on', just to make sure
+# the output doesn't change.
+foreach_with_prefix print-object {"off" "on"} {
+ gdb_test_no_output "set print object ${print-object}"
+
+ # Doing 'print ref' should show us e.g.
+ # '(S &) @0xdeadbeef: {a = 0, b = 1, c = 2}'.
+ gdb_test "print ref" " = \\(S &\\) @${address}: \\{${s1_members}\\}"
+
+ # Doing 'print &ref' should show us e.g. '(S *) 0xdeadbeef <s1>'.
+ gdb_test "print &ref" " = \\(S \\*\\) ${address} <s1>"
+
+ # gdb assumes C++ references are implemented as pointers, and
+ # print &(&ref) shows us the underlying pointer's address.
+ # Since in this case there's no physical pointer, gdb should tell us so.
+ gdb_test "print &(&ref)" "Attempt to take address of value not located in memory."
+}
+
+# Test assignment through the synthetic reference.
+gdb_test_no_output "set (ref = s2)"
+
+foreach_with_prefix print-object {"off" "on"} {
+ gdb_test_no_output "set print object ${print-object}"
+
+ gdb_test "print ref" " = \\(S &\\) @${address}: \\{${s2_members}\\}" "print ref after assignment"
+ gdb_test "print s1" " = \\{${s2_members}\\}" "print s1 after assignment"
+}
if (TYPE_CODE (type) == TYPE_CODE_REF)
{
- /* Copy the value, but change the type from (T&) to (T*). We
- keep the same location information, which is efficient, and
- allows &(&X) to get the location containing the reference.
- Do the same to its enclosing type for consistency. */
- struct type *type_ptr
- = lookup_pointer_type (TYPE_TARGET_TYPE (type));
- struct type *enclosing_type
- = check_typedef (value_enclosing_type (arg1));
- struct type *enclosing_type_ptr
- = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type));
-
- arg2 = value_copy (arg1);
- deprecated_set_value_type (arg2, type_ptr);
- set_value_enclosing_type (arg2, enclosing_type_ptr);
+ if (value_bits_synthetic_pointer (arg1, value_embedded_offset (arg1),
+ TARGET_CHAR_BIT * TYPE_LENGTH (type)))
+ arg1 = coerce_ref (arg1);
+ else
+ {
+ /* Copy the value, but change the type from (T&) to (T*). We
+ keep the same location information, which is efficient, and
+ allows &(&X) to get the location containing the reference.
+ Do the same to its enclosing type for consistency. */
+ struct type *type_ptr
+ = lookup_pointer_type (TYPE_TARGET_TYPE (type));
+ struct type *enclosing_type
+ = check_typedef (value_enclosing_type (arg1));
+ struct type *enclosing_type_ptr
+ = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type));
+
+ arg2 = value_copy (arg1);
+ deprecated_set_value_type (arg2, type_ptr);
+ set_value_enclosing_type (arg2, enclosing_type_ptr);
- return arg2;
+ return arg2;
+ }
}
if (TYPE_CODE (type) == TYPE_CODE_FUNC)
return value_coerce_function (arg1);
if (value_bits_synthetic_pointer (val, TARGET_CHAR_BIT * embedded_offset,
TARGET_CHAR_BIT * TYPE_LENGTH (type)))
{
- fputs_filtered (_("<synthetic pointer>"), stream);
- return 0;
+ const int is_ref = TYPE_CODE (type) == TYPE_CODE_REF;
+ int ref_is_addressable = 0;
+
+ if (is_ref)
+ {
+ const struct value *deref_val = coerce_ref_if_computed (val);
+
+ if (deref_val != NULL)
+ ref_is_addressable = value_lval_const (deref_val) == lval_memory;
+ }
+
+ if (!is_ref || !ref_is_addressable)
+ fputs_filtered (_("<synthetic pointer>"), stream);
+
+ /* C++ references should be valid even if they're synthetic. */
+ return is_ref;
}
if (!value_bytes_available (val, embedded_offset, TYPE_LENGTH (type)))
original_value, options, 0, stream);
}
+/* Print '@' followed by the address contained in ADDRESS_BUFFER. */
+
+static void
+print_ref_address (struct type *type, const gdb_byte *address_buffer,
+ int embedded_offset, struct ui_file *stream)
+{
+ struct gdbarch *gdbarch = get_type_arch (type);
+
+ if (address_buffer != NULL)
+ {
+ CORE_ADDR address
+ = extract_typed_address (address_buffer + embedded_offset, type);
+
+ fprintf_filtered (stream, "@");
+ fputs_filtered (paddress (gdbarch, address), stream);
+ }
+ /* Else: we have a non-addressable value, such as a DW_AT_const_value. */
+}
+
+/* If VAL is addressable, return the value contents buffer of a value that
+ represents a pointer to VAL. Otherwise return NULL. */
+
+static const gdb_byte *
+get_value_addr_contents (struct value *deref_val)
+{
+ gdb_assert (deref_val != NULL);
+
+ if (value_lval_const (deref_val) == lval_memory)
+ return value_contents_for_printing_const (value_addr (deref_val));
+ else
+ {
+ /* We have a non-addressable value, such as a DW_AT_const_value. */
+ return NULL;
+ }
+}
+
/* generic_val_print helper for TYPE_CODE_REF. */
static void
const struct value *original_value,
const struct value_print_options *options)
{
- struct gdbarch *gdbarch = get_type_arch (type);
struct type *elttype = check_typedef (TYPE_TARGET_TYPE (type));
+ struct value *deref_val = NULL;
+ const int value_is_synthetic
+ = value_bits_synthetic_pointer (original_value,
+ TARGET_CHAR_BIT * embedded_offset,
+ TARGET_CHAR_BIT * TYPE_LENGTH (type));
+ const int must_coerce_ref = ((options->addressprint && value_is_synthetic)
+ || options->deref_ref);
+ const int type_is_defined = TYPE_CODE (elttype) != TYPE_CODE_UNDEF;
+
+ if (must_coerce_ref && type_is_defined)
+ {
+ deref_val = coerce_ref_if_computed (original_value);
+
+ if (deref_val != NULL)
+ {
+ /* More complicated computed references are not supported. */
+ gdb_assert (embedded_offset == 0);
+ }
+ else
+ deref_val = value_at (TYPE_TARGET_TYPE (type),
+ unpack_pointer (type, valaddr + embedded_offset));
+ }
+ /* Else, original_value isn't a synthetic reference or we don't have to print
+ the reference's contents.
+
+ Notice that for references to TYPE_CODE_STRUCT, 'set print object on' will
+ cause original_value to be a not_lval instead of an lval_computed,
+ which will make value_bits_synthetic_pointer return false.
+ This happens because if options->objectprint is true, c_value_print will
+ overwrite original_value's contents with the result of coercing
+ the reference through value_addr, and then set its type back to
+ TYPE_CODE_REF. In that case we don't have to coerce the reference again;
+ we can simply treat it as non-synthetic and move on. */
if (options->addressprint)
{
- CORE_ADDR addr
- = extract_typed_address (valaddr + embedded_offset, type);
+ const gdb_byte *address = (value_is_synthetic && type_is_defined
+ ? get_value_addr_contents (deref_val)
+ : valaddr);
+
+ print_ref_address (type, address, embedded_offset, stream);
- fprintf_filtered (stream, "@");
- fputs_filtered (paddress (gdbarch, addr), stream);
if (options->deref_ref)
fputs_filtered (": ", stream);
}
- /* De-reference the reference. */
+
if (options->deref_ref)
{
- if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
- {
- struct value *deref_val;
-
- deref_val = coerce_ref_if_computed (original_value);
- if (deref_val != NULL)
- {
- /* More complicated computed references are not supported. */
- gdb_assert (embedded_offset == 0);
- }
- else
- deref_val = value_at (TYPE_TARGET_TYPE (type),
- unpack_pointer (type,
- (valaddr
- + embedded_offset)));
-
- common_val_print (deref_val, stream, recurse, options,
- current_language);
- }
+ if (type_is_defined)
+ common_val_print (deref_val, stream, recurse, options,
+ current_language);
else
fputs_filtered ("???", stream);
}