From 703adbb1f97db52ed63b2a6a074195b1cee0f132 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Mon, 27 Nov 2023 16:44:22 -0700 Subject: Fix dynamic type resolution for LOC_CONST and LOC_CONST_BYTES symbols PR rust/31005 points out that dynamic type resolution of a LOC_CONST or LOC_CONST_BYTES symbol will fail, leading to output like: from_index= This patch fixes the problem by using the constant value or bytes when performing type resolution. Thanks to tpzker@thepuzzlemaker.info for a first version of this patch. I also tested this on a big-endian PPC system (cfarm203). Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31005 --- gdb/findvar.c | 19 ++++-- gdb/testsuite/gdb.dwarf2/rust-enum.exp | 120 +++++++++++++++++++++++++++++++++ 2 files changed, 135 insertions(+), 4 deletions(-) create mode 100644 gdb/testsuite/gdb.dwarf2/rust-enum.exp (limited to 'gdb') diff --git a/gdb/findvar.c b/gdb/findvar.c index 952ec20..02b4a12 100644 --- a/gdb/findvar.c +++ b/gdb/findvar.c @@ -534,8 +534,16 @@ language_defn::read_var_value (struct symbol *var, case LOC_CONST: if (is_dynamic_type (type)) { - /* Value is a constant byte-sequence and needs no memory access. */ - type = resolve_dynamic_type (type, {}, /* Unused address. */ 0); + gdb_byte bytes[sizeof (LONGEST)]; + + size_t len = std::min (sizeof (LONGEST), (size_t) type->length ()); + store_unsigned_integer (bytes, len, + type_byte_order (type), + var->value_longest ()); + gdb::array_view view (bytes, len); + + /* Value is a constant byte-sequence. */ + type = resolve_dynamic_type (type, view, /* Unused address. */ 0); } /* Put the constant back in target format. */ v = value::allocate (type); @@ -575,8 +583,11 @@ language_defn::read_var_value (struct symbol *var, case LOC_CONST_BYTES: if (is_dynamic_type (type)) { - /* Value is a constant byte-sequence and needs no memory access. */ - type = resolve_dynamic_type (type, {}, /* Unused address. */ 0); + gdb::array_view view (var->value_bytes (), + type->length ()); + + /* Value is a constant byte-sequence. */ + type = resolve_dynamic_type (type, view, /* Unused address. */ 0); } v = value::allocate (type); memcpy (v->contents_raw ().data (), var->value_bytes (), diff --git a/gdb/testsuite/gdb.dwarf2/rust-enum.exp b/gdb/testsuite/gdb.dwarf2/rust-enum.exp new file mode 100644 index 0000000..a052c11 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/rust-enum.exp @@ -0,0 +1,120 @@ +# Copyright 2023 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 . + +load_lib dwarf.exp + +# This test can only be run on targets which support DWARF-2 and use gas. +require dwarf2_support + +standard_testfile main.c -dw.S + +# Make some DWARF for the test. +set asm_file [standard_output_file $srcfile2] +Dwarf::assemble $asm_file { + upvar cu_lang cu_lang + + declare_labels uinteger_label discr_1_label + declare_labels one_label two_label simple_label + + cu { addr_size 4 } { + compile_unit { + {name file1.txt} + {language @DW_LANG_Rust} + } { + uinteger_label: DW_TAG_base_type { + {DW_AT_byte_size 1 DW_FORM_sdata} + {DW_AT_encoding @DW_ATE_unsigned} + {DW_AT_name {unsigned integer}} + } + + one_label: structure_type { + {name One} + {byte_size 1 DW_FORM_sdata} + } { + member { + {name __0} + {type :$uinteger_label} + {data_member_location 0 data1} + } + } + + two_label: structure_type { + {name Two} + {byte_size 1 DW_FORM_sdata} + } { + member { + {name __0} + {type :$uinteger_label} + {data_member_location 0 data1} + } + } + + simple_label: structure_type { + {name Simple} + {byte_size 2 DW_FORM_sdata} + } { + variant_part { + {discr :$discr_1_label DW_FORM_ref4} + } { + discr_1_label: member { + {type :$uinteger_label} + {data_member_location 0 data1} + {artificial 1 DW_FORM_flag_present} + } + + variant { + {discr_value 65 udata} + } { + member { + {type :$one_label} + {data_member_location 1 data1} + } + } + + variant { + } { + member { + {type :$two_label} + {data_member_location 1 data1} + } + } + } + } + + # In PR rust/31005, a constant Rust enum value could not + # be correctly resolved. + DW_TAG_variable { + {name constant_variable} + {const_value 0x4141 udata} + {type :$simple_label} + } + DW_TAG_variable { + {name constant_variable2} + {const_value "AA" DW_FORM_block1} + {type :$simple_label} + } + } + } +} + +if { [prepare_for_testing "failed to prepare" ${testfile} \ + [list $srcfile $asm_file] {nodebug}] } { + return -1 +} + +gdb_test_no_output "set language rust" + +gdb_test "print constant_variable" [string_to_regexp "One(65)"] +gdb_test "print constant_variable2" [string_to_regexp "One(65)"] -- cgit v1.1