@@ -2055,6 +2055,66 @@ get_frame_address_in_block_wrapper (void *baton)
return get_frame_address_in_block ((struct frame_info *) baton);
}
+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 at 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)
+{
+ struct value *result = NULL;
+
+ /* 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)
+ result = dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
+ baton.data, baton.size,
+ baton.per_cu, byte_offset);
+ else
+ result = fetch_const_value_from_synthetic_pointer (die, byte_offset, per_cu,
+ type);
+
+ return result;
+}
+
/* An implementation of an lval_funcs method to indirect through a
pointer. This handles the synthetic pointer case when needed. */
@@ -2109,6 +2169,7 @@ indirect_pieced_value (struct value *value)
break;
}
+ gdb_assert (piece);
frame = get_selected_frame (_("No frame selected."));
/* This is an offset requested by GDB, such as value subscripts.
@@ -2126,44 +2187,36 @@ indirect_pieced_value (struct value *value)
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);
+static struct value *coerce_pieced_ref (const struct value *value)
+{
+ struct value *result = NULL;
+ struct type *type = check_typedef (value_type (value));
+ if (value_bits_synthetic_pointer (value, value_embedded_offset (value),
+ TARGET_CHAR_BIT * TYPE_LENGTH (type)))
{
- struct obstack temp_obstack;
- struct cleanup *cleanup;
- const gdb_byte *bytes;
- LONGEST len;
- struct value *result;
+ const struct piece_closure *closure
+ = (struct piece_closure *) value_computed_closure (value);
- obstack_init (&temp_obstack);
- cleanup = make_cleanup_obstack_free (&temp_obstack);
+ /* gdb represents synthetic pointers as pieced values with a single
+ piece. */
+ gdb_assert (closure != NULL);
+ gdb_assert (closure->n_pieces == 1);
- 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);
+ struct frame_info *frame = get_selected_frame (_("No frame selected."));
+
+ result = indirect_synthetic_pointer (closure->pieces->v.ptr.die,
+ closure->pieces->v.ptr.offset,
+ closure->per_cu, frame, type);
}
+ /* Else: not a synthetic reference; do nothing. */
- do_cleanups (cleanup);
return result;
}
-}
static void *
copy_pieced_value_closure (const struct value *v)
@@ -2200,7 +2253,7 @@ static const struct lval_funcs pieced_value_funcs = {
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
new file mode 100644
@@ -0,0 +1,27 @@
+/* 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;
+}
new file mode 100644
@@ -0,0 +1,168 @@
+# 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\[0\])" 5]
+
+# 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" 4]
+ set upper_bound [expr ${array_length} - 1]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" 4]
+
+ 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" "\{0, 1, 2, 3, 4\}"]
+set contents [string trim ${contents}]
+set contents [string trim ${contents} "{}"]
+
+# Doing 'print ref' should show us e.g. '(int (&)[5]) <synthetic pointer>: {0, 1, 2, 3, 4}'.
+gdb_test "print ref" " = ${ref_type} <synthetic pointer>: \\{${contents}\\}" "print ref"
+
+# Doing 'print &ref' should show us e.g. '(int (*)[5]) 0xdeadbeef <array>'.
+gdb_test "print &ref" " = ${ptr_type} \[\[:xdigit:\]x\]+ <array>" "print &ref"
+
+# 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)"
+
+# Test assignment through the synthetic reference.
+set first_value 10
+gdb_test_no_output "set (ref\[0\] = ${first_value})" "set (ref\[0\] = ${first_value})"
+
+# This matches e.g. '{10, 1, 2, 3, 4}'
+set new_contents [format {\{%d[\d,\s]+\}} ${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} <synthetic pointer>: ${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[\d,\s]+\}} ${first_value} ${second_value}]
+
+gdb_test "print *ref" " = ${first_value}" "print *ref"
+gdb_test_no_output "set (*(ref + 1) = ${second_value})" "set (*(ref + 1) = ${second_value})"
+gdb_test "print ref\[1\]" " = ${second_value}" "print ref\[1\]"
+gdb_test "print array" " = ${new_contents}" "print array (after second assignment)"
new file mode 100644
@@ -0,0 +1,120 @@
+# 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 DW_AT_const_value.
+
+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-const.S.
+standard_testfile main.c .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} {
+ global srcdir subdir srcfile
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_language @DW_LANG_C_plus_plus}
+ } {
+ declare_labels int_label const_label variable_label ref_label
+ set int_size [get_sizeof "int" 4]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" 4]
+ set var_value 42
+
+ 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}}
+ }
+
+ const_label: DW_TAG_const_type {
+ {DW_AT_type :${ref_label}}
+ }
+
+ DW_TAG_subprogram {
+ {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }}
+ {DW_AT_type :${int_label}}
+ {DW_AT_external 1 DW_FORM_flag}
+ } {
+ variable_label: DW_TAG_variable {
+ {DW_AT_name "var"}
+ {DW_AT_type :${int_label}}
+ {DW_AT_const_value ${var_value} DW_FORM_udata}
+ }
+
+ DW_TAG_variable {
+ {DW_AT_name "ref"}
+ {DW_AT_type :${const_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
+}
+
+# Doing 'print ref' should show us e.g. '(int &) <synthetic pointer>: 42'.
+set value_output {\(int &\) <synthetic pointer>: \d+}
+gdb_test "print ref" " = ${value_output}" "print ref"
+
+# 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." "print &var"
+gdb_test "print &ref" "Attempt to take address of value not located in memory." "print &ref"
+
+# 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)"
new file mode 100644
@@ -0,0 +1,27 @@
+/* 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;
+}
new file mode 100644
@@ -0,0 +1,124 @@
+# 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" 4]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" 4]
+
+ 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
+}
+
+# Doing 'print ref' should show us e.g. '(int &) <synthetic pointer>: 42'.
+set value_output {\(int &\) <synthetic pointer>: \d+}
+gdb_test "print ref" " = ${value_output}" "print ref"
+
+# Doing 'print &ref' should show us e.g. '(int *) 0xdeadbeef <global_var>'.
+set addr_output {\(int \*\) [[:xdigit:]x]+ <global_var>}
+gdb_test "print &ref" " = ${addr_output}" "print &ref"
+
+# 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)"
+
+# Test assignment through the synthetic reference.
+set new_value 10
+gdb_test_no_output "set (ref = ${new_value})" "set (ref = ${new_value})"
+gdb_test "print ref" " = \\(int &\\) <synthetic pointer>: ${new_value}" "print ref (after assignment)"
+gdb_test "print global_var" " = ${new_value}" "print global_var (after assignment)"
new file mode 100644
@@ -0,0 +1,43 @@
+/* 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 = {
+ .a = 0,
+ .b = 1,
+ .c = 2
+};
+
+struct S s2 = {
+ .a = 10,
+ .b = 11,
+ .c = 12
+};
+
+int
+main (void)
+{
+ asm ("main_label: .globl main_label");
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,173 @@
+# 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" 4]
+
+ # gdb always assumes references are implemented as pointers.
+ set addr_size [get_sizeof "void *" 4]
+ set S_size [get_sizeof "S" 12]
+
+ # 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.
+proc get_members {var default} {
+ set members [get_valueof "" ${var} ${default}]
+
+ # Trim leading/trailing whitespace, '{' and '}' since they confuse TCL
+ # to no end.
+ set members [string trim ${members}]
+ set members [string trim ${members} "{}"]
+
+ return ${members}
+}
+
+# Values of the struct members.
+set s1_members [get_members "s1" "\{a = 0, b = 1, c = 2\}"]
+set s2_members [get_members "s2" "\{a = 10, b = 11, c = 12\}"]
+
+# Doing 'print ref' should show us e.g. '(S &) <synthetic pointer>: {a = 0, b = 1, c = 2}'.
+gdb_test "print ref" " = \\(S &\\) <synthetic pointer>: \\{${s1_members}\\}" "print ref"
+
+# Doing 'print &ref' should show us e.g. '(S *) 0xdeadbeef <s1>'.
+set addr_output {\(S \*\) [[:xdigit:]x]+ <s1>}
+gdb_test "print &ref" " = ${addr_output}" "print &ref"
+
+# gdb assumes C++ references are implemented as pointers, and print &(&ref)
+# shows us the underlying pointer's address. Since in this case there's no
+# physical pointer, gdb should tell us so.
+gdb_test "print &(&ref)" "Attempt to take address of value not located in memory." "print &(&ref)"
+
+# Test assignment through the synthetic reference.
+gdb_test_no_output "set (ref = s2)" "set (ref = s2)"
+gdb_test "print ref" " = \\(S &\\) <synthetic pointer>: \\{${s2_members}\\}" "print ref (after assignment)"
+gdb_test "print s1" " = \\{${s2_members}\\}" "print s1 (after assignment)"
deleted file mode 100644
@@ -1,98 +0,0 @@
-# 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 C++ references marked with DW_OP_GNU_implicit_pointer.
-
-# TODO: Add more test statements after fixing bug #19893:
-# https://sourceware.org/bugzilla/show_bug.cgi?id=19893.
-
-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.S.
-standard_testfile main.c .S
-
-# ${testfile} is now "implref". srcfile2 is "implref.S".
-set executable ${testfile}
-set asm_file [standard_output_file ${srcfile2}]
-
-# 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 $asm_file {
- global srcdir subdir srcfile
-
- cu { version 3 addr_size 4 } {
- DW_TAG_compile_unit {
- {DW_AT_producer "GNU C++ 4.8.4"}
- {DW_AT_language @DW_LANG_C_plus_plus}
- } {
- declare_labels int_label const_label variable_label ref_label
-
- int_label: DW_TAG_base_type {
- {DW_AT_byte_size 4 DW_FORM_udata}
- {DW_AT_encoding @DW_ATE_signed}
- {DW_AT_name "int"}
- }
-
- ref_label: DW_TAG_reference_type {
- {DW_AT_byte_size 4 DW_FORM_udata}
- {DW_AT_type :${int_label}}
- }
-
- const_label: DW_TAG_const_type {
- {DW_AT_type :${ref_label}}
- }
-
- DW_TAG_subprogram {
- {MACRO_AT_func { "main" "${srcdir}/${subdir}/${srcfile}" }}
- {DW_AT_type :${int_label}}
- {DW_AT_external 1 DW_FORM_flag}
- } {
- variable_label: DW_TAG_variable {
- {DW_AT_name "var"}
- {DW_AT_type :${int_label}}
- {DW_AT_const_value 42 DW_FORM_udata}
- }
-
- DW_TAG_variable {
- {DW_AT_name "ref"}
- {DW_AT_type :${const_label}}
- {DW_AT_location {DW_OP_GNU_implicit_pointer ${variable_label} 0} SPECIAL_expr}
- }
- }
- }
- }
-}
-
-if [prepare_for_testing ${testfile}.exp ${executable} "${asm_file} ${srcfile}" {}] {
- return -1
-}
-
-# DW_OP_GNU_implicit_pointer implementation requires a valid frame.
-if ![runto_main] {
- return -1
-}
-
-gdb_test "print ref" " = \\(int &\\) <synthetic pointer>" "print ref"
-gdb_test "print &ref" " = \\(int \\*\\) <synthetic pointer>" "print &ref"
-
-# 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)"
@@ -1465,16 +1465,21 @@ value_addr (struct value *arg1)
if (TYPE_CODE (type) == TYPE_CODE_REF)
{
+ 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));
+ 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);
@@ -1482,6 +1487,7 @@ value_addr (struct value *arg1)
return arg2;
}
+ }
if (TYPE_CODE (type) == TYPE_CODE_FUNC)
return value_coerce_function (arg1);
@@ -336,7 +336,9 @@ valprint_check_validity (struct ui_file *stream,
TARGET_CHAR_BIT * TYPE_LENGTH (type)))
{
fputs_filtered (_("<synthetic pointer>"), stream);
- return 0;
+
+ /* C++ references should be valid even if they're synthetic. */
+ return TYPE_CODE (type) == TYPE_CODE_REF;
}
if (!value_bytes_available (val, embedded_offset, TYPE_LENGTH (type)))
@@ -495,11 +497,27 @@ generic_val_print_ref (struct type *type, const gdb_byte *valaddr,
if (options->addressprint)
{
+ const int is_synthetic =
+ value_bits_synthetic_pointer (original_value,
+ TARGET_CHAR_BIT * embedded_offset,
+ TARGET_CHAR_BIT * TYPE_LENGTH (type));
+ if (!is_synthetic)
+ {
CORE_ADDR addr
= extract_typed_address (valaddr + embedded_offset, type);
fprintf_filtered (stream, "@");
fputs_filtered (paddress (gdbarch, addr), stream);
+ }
+ /* Else, we have a synthetic reference. Don't print '@address'; we'll
+ show '<synthetic pointer>' instead through valprint_check_validity.
+ Notice however that 'set print object on' will still show '@address'.
+ This happens because value_bits_synthetic_pointer returns false if
+ original value is not 'lval_computed'. While that's usually the case,
+ if options->objectprint is true, c_value_print will call value_addr
+ on the reference, which coerces synthetic references and returns a
+ 'not_lval'. */
+
if (options->deref_ref)
fputs_filtered (": ", stream);
}