mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-27 04:52:05 +08:00
2ddeaf8a7d
This changes dwarf2read to understand DW_TAG_variant_part and DW_TAG_variant. Note that DW_AT_discr_list is not handled. I did not need this for Rust. I imagine this should not be too hard to add later, should someone need it. Meanwhile I have gdb emit a complaint if it is seen. There is a lurking issue concerning the placement of the discriminant in the DWARF. For Rust, I ended up following the letter of the standard and having the discriminant be a child of the DW_TAG_variant_part. However, GCC's Ada support does not do this. Pierre-Marie filed this with the DWARF committee: http://dwarfstd.org/ShowIssue.php?issue=180123.1 However as that is read-only, if you have comments you might consider adding them to the GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83935 Finally, there is a DWARF extension lurking in here. In Rust, a univariant enum will not have a discriminant. However, in order to unify the representation of all data-carrying enums, I've made LLVM (and my forthcoming rustc patch) emit a univariant enum using a DW_TAG_variant with a single variant part and without DW_AT_discr. The lack of this DW_AT_discr is the extension. I will submit an issue on dwarfstd.org about this. 2018-02-26 Tom Tromey <tom@tromey.com> * dwarf2read.c (struct variant_field): New. (struct nextfield) <variant>: New field. (dwarf2_add_field): Handle DW_TAG_variant_part. (dwarf2_attach_fields_to_type): Attach a discriminant_info to a discriminated union. (read_structure_type): Handle DW_TAG_variant_part. (handle_struct_member_die): New function, extracted from process_structure_scope. Handle DW_TAG_variant. (process_structure_scope): Handle discriminated unions. Call handle_struct_member_die. 2018-02-26 Tom Tromey <tom@tromey.com> * gdb.dwarf2/variant.c: New file. * gdb.dwarf2/variant.exp: New file.
225 lines
4.9 KiB
Plaintext
225 lines
4.9 KiB
Plaintext
# Copyright 2018 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 DW_TAG_variant_part and DW_TAG_variant.
|
|
|
|
load_lib dwarf.exp
|
|
|
|
# This test can only be run on targets which support DWARF-2 and use
|
|
# gas.
|
|
if {![dwarf2_support]} {
|
|
return 0
|
|
}
|
|
|
|
standard_testfile .c variant.S
|
|
|
|
# Make some DWARF for the test.
|
|
set asm_file [standard_output_file $srcfile2]
|
|
Dwarf::assemble $asm_file {
|
|
upvar cu_lang cu_lang
|
|
|
|
declare_labels uinteger_label float_label int8_label
|
|
declare_labels discr_1_label discr_2_label discr_3_label
|
|
declare_labels one_label two_label
|
|
|
|
# Creating a CU with 4-byte addresses lets this test link on
|
|
# both 32- and 64-bit machines.
|
|
cu { addr_size 4 } {
|
|
compile_unit {
|
|
{name file1.txt}
|
|
{language @DW_LANG_Rust}
|
|
} {
|
|
uinteger_label: DW_TAG_base_type {
|
|
{DW_AT_byte_size 4 DW_FORM_sdata}
|
|
{DW_AT_encoding @DW_ATE_unsigned}
|
|
{DW_AT_name {unsigned integer}}
|
|
}
|
|
|
|
int8_label: DW_TAG_base_type {
|
|
{DW_AT_byte_size 1 DW_FORM_sdata}
|
|
{DW_AT_encoding @DW_ATE_signed}
|
|
{DW_AT_name i8}
|
|
}
|
|
|
|
float_label: base_type {
|
|
{name float}
|
|
{encoding @DW_ATE_float}
|
|
{byte_size 4 DW_FORM_sdata}
|
|
}
|
|
|
|
one_label: structure_type {
|
|
{name One}
|
|
{byte_size 4 DW_FORM_sdata}
|
|
} {
|
|
member {
|
|
{name __0}
|
|
{type :$uinteger_label}
|
|
{data_member_location 0 data1}
|
|
}
|
|
}
|
|
|
|
two_label: structure_type {
|
|
{name Two}
|
|
{byte_size 4 DW_FORM_sdata}
|
|
} {
|
|
member {
|
|
{name __0}
|
|
{type :$float_label}
|
|
{data_member_location 0 data1}
|
|
}
|
|
}
|
|
|
|
structure_type {
|
|
{name Simple}
|
|
{byte_size 8 DW_FORM_sdata}
|
|
} {
|
|
variant_part {
|
|
{discr :$discr_1_label DW_FORM_ref4}
|
|
} {
|
|
discr_1_label: member {
|
|
{type :$uinteger_label}
|
|
{data_member_location 0 data1}
|
|
}
|
|
|
|
variant {
|
|
{discr_value 23 udata}
|
|
} {
|
|
member {
|
|
{type :$one_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
|
|
variant {
|
|
{discr_value 1 udata}
|
|
} {
|
|
member {
|
|
{type :$two_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
structure_type {
|
|
{name Defaulted}
|
|
{byte_size 8 DW_FORM_sdata}
|
|
} {
|
|
variant_part {
|
|
{discr :$discr_2_label DW_FORM_ref4}
|
|
} {
|
|
discr_2_label: member {
|
|
{type :$uinteger_label}
|
|
{data_member_location 0 data1}
|
|
}
|
|
|
|
variant {
|
|
} {
|
|
member {
|
|
{type :$one_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
|
|
variant {
|
|
{discr_value 1 udata}
|
|
} {
|
|
member {
|
|
{type :$two_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
structure_type {
|
|
{name Univariant}
|
|
{byte_size 8 DW_FORM_sdata}
|
|
} {
|
|
variant_part {
|
|
} {
|
|
variant {
|
|
} {
|
|
member {
|
|
{type :$one_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
# Rust won't emit a negative discriminant like this, but
|
|
# we want to test the code path anyway.
|
|
structure_type {
|
|
{name Negative}
|
|
{byte_size 8 DW_FORM_sdata}
|
|
} {
|
|
variant_part {
|
|
{discr :$discr_3_label DW_FORM_ref4}
|
|
} {
|
|
discr_3_label: member {
|
|
{type :$int8_label}
|
|
{data_member_location 0 data1}
|
|
}
|
|
|
|
variant {
|
|
{discr_value -1 sdata}
|
|
} {
|
|
member {
|
|
{type :$one_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
|
|
# Make this the default value so we'll see an
|
|
# incorrect result if we mishandle signed
|
|
# discriminants.
|
|
variant {
|
|
} {
|
|
member {
|
|
{type :$two_label}
|
|
{data_member_location 4 data1}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if { [prepare_for_testing "failed to prepare" ${testfile} \
|
|
[list $srcfile $asm_file] debug] } {
|
|
return -1
|
|
}
|
|
|
|
if ![runto func] {
|
|
return -1
|
|
}
|
|
|
|
# Get the values into history so we can use it from Rust.
|
|
gdb_test "print (void *) buffer" "\\\$1 = .void .. $hex .buffer."
|
|
gdb_test "print (void *) buffer2" "\\\$2 = .void .. $hex .buffer2."
|
|
|
|
gdb_test "set language rust"
|
|
gdb_test "print *(\$1 as *mut Simple)" " = One\\(23\\)" \
|
|
"print as Simple"
|
|
gdb_test "print *(\$1 as *mut Defaulted)" " = One\\(23\\)" \
|
|
"print as Defaulted"
|
|
gdb_test "print *(\$1 as *mut Univariant)" " = One\\(23\\)" \
|
|
"print as Univariant"
|
|
|
|
gdb_test "print *(\$2 as *mut Negative)" " = One\\(23\\)" \
|
|
"print as Negative"
|