From 25c11acac349bf6e77a233c7604bf8e04b8a1424 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Tue, 7 Apr 2020 17:33:05 +0200 Subject: [PATCH] [gdb/symtab] Add symbol with inherited DW_AT_const_value to psymtabs Consider the test-case added in this patch, with resulting dwarf (related to variable aaa): ... <0>: Abbrev Number: 2 (DW_TAG_partial_unit) <1>: Abbrev Number: 4 (DW_TAG_variable) DW_AT_name : aaa DW_AT_type : <0xe4> DW_AT_const_value : 1 <0><10c>: Abbrev Number: 2 (DW_TAG_compile_unit) <10e> DW_AT_name : <1><11b>: Abbrev Number: 3 (DW_TAG_variable) <11c> DW_AT_abstract_origin: <0xeb> ... When running the test-case, we see: ... (gdb) p aaa^M No symbol "aaa" in current context.^M (gdb) FAIL: gdb.dwarf2/imported-unit-abstract-const-value.exp: p aaa ... while with target board readnow.exp, we have: ... (gdb) p aaa^M $1 = 1^M ... This is due to the fact that there's no aaa symbol in the partial symtabs: ... Partial symtab for source file @0x101 (object 0x351cf40)^M ... Global partial symbols:^M `main', function, 0x4004a7^M ^M ... which is due to the fact that when attempting to add the symbol corresponding to DIE 0x11b in add_partial_symbol: ... (gdb) p /x pdi->sect_off $4 = 0x11b (gdb) p pdi.has_const_value $5 = 0 ... it seems the DW_AT_const_value was not inherited from DIE 0xeb, and consequently we leave without adding a partial symbol. Fix this by making sure that partial_die_info::has_const_value is inherited in partial_die_info::fixup. Build and reg-tested on x86_64-linux. Tested test-case with target boards readnow, cc-with-gdb-index and cc-with-debug-names. The "print aaa" test fails for cc-with-gdb-index, that's PR25791, the test passes when applying the corresponding proposed patch. gdb/ChangeLog: 2020-04-07 Tom de Vries PR symtab/25796 * dwarf2/read.c (can_have_DW_AT_const_value_p): New function. (partial_die_info::fixup): Inherit has_const_value. gdb/testsuite/ChangeLog: 2020-04-07 Tom de Vries PR symtab/25796 * gdb.dwarf2/imported-unit-abstract-const-value.exp: New file. --- gdb/ChangeLog | 6 ++ gdb/dwarf2/read.c | 37 +++++++ gdb/testsuite/ChangeLog | 5 + .../imported-unit-abstract-const-value.exp | 98 +++++++++++++++++++ 4 files changed, 146 insertions(+) create mode 100644 gdb/testsuite/gdb.dwarf2/imported-unit-abstract-const-value.exp diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 16a00898722..e24011dbb09 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2020-04-07 Tom de Vries + + PR symtab/25796 + * dwarf2/read.c (can_have_DW_AT_const_value_p): New function. + (partial_die_info::fixup): Inherit has_const_value. + 2020-04-07 Tom de Vries * psymtab.c (maintenance_check_psymtabs): Skip static LOC_BLOCK diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 749acb3ba26..61e288ab83a 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -18259,6 +18259,25 @@ guess_partial_die_structure_name (struct partial_die_info *struct_pdi, } } +/* Return true if a DIE with TAG may have the DW_AT_const_value + attribute. */ + +static bool +can_have_DW_AT_const_value_p (enum dwarf_tag tag) +{ + switch (tag) + { + case DW_TAG_constant: + case DW_TAG_enumerator: + case DW_TAG_formal_parameter: + case DW_TAG_template_value_param: + case DW_TAG_variable: + return true; + } + + return false; +} + void partial_die_info::fixup (struct dwarf2_cu *cu) { @@ -18291,6 +18310,24 @@ partial_die_info::fixup (struct dwarf2_cu *cu) } } + if (!has_const_value && has_specification + && can_have_DW_AT_const_value_p (tag)) + { + struct partial_die_info *spec_die; + + auto res = find_partial_die (spec_offset, spec_is_dwz, cu); + spec_die = res.pdi; + cu = res.cu; + + spec_die->fixup (cu); + + if (spec_die->has_const_value) + { + /* Copy DW_AT_const_value attribute if it is set. */ + has_const_value = spec_die->has_const_value; + } + } + /* Set default names for some unnamed DIEs. */ if (name == NULL && tag == DW_TAG_namespace) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index bd55a78b211..8c2ace4e538 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-04-07 Tom de Vries + + PR symtab/25796 + * gdb.dwarf2/imported-unit-abstract-const-value.exp: New file. + 2020-04-07 Tom de Vries * gdb.base/check-psymtab.c: New test. diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit-abstract-const-value.exp b/gdb/testsuite/gdb.dwarf2/imported-unit-abstract-const-value.exp new file mode 100644 index 00000000000..f93dc123885 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/imported-unit-abstract-const-value.exp @@ -0,0 +1,98 @@ +# Copyright 2020 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 . + +# Test that a concrete var importing an abstract var using +# DW_AT_abstract_origin inherits the DW_AT_const_value attribute. + +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 main.c .S + +set executable ${testfile} +set asm_file [standard_output_file ${srcfile2}] + +# We need to know the size of integer type in order +# to write some of the debugging info we'd like to generate. +if [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] { + return -1 +} + +# Create the DWARF. +Dwarf::assemble $asm_file { + declare_labels cu_label main_label int_label + declare_labels aaa_label + set int_size [get_sizeof "int" 4] + + global srcdir subdir srcfile + + extern main + + set main_range [function_range main ${srcdir}/${subdir}/${srcfile}] + set main_start [lindex $main_range 0] + set main_length [lindex $main_range 1] + + cu {} { + cu_label: partial_unit { + {language @DW_LANG_C} + {name "imported_unit.c"} + } { + int_label: base_type { + {byte_size $int_size sdata} + {encoding @DW_ATE_signed} + {name int} + } + + aaa_label: DW_TAG_variable { + {name aaa} + {type :$int_label} + {const_value 1 DW_FORM_sdata} + } + + main_label: subprogram { + {name main} + {type :$int_label} + {external 1 flag} + } + } + } + + cu {} { + compile_unit { + {language @DW_LANG_C} + {name ""} + } { + DW_TAG_variable { + {abstract_origin %$aaa_label} + } + subprogram { + {abstract_origin %$main_label} + {low_pc $main_start addr} + {high_pc "$main_start + $main_length" addr} + } + } + } +} + +if { [prepare_for_testing "failed to prepare" ${testfile} \ + [list $srcfile $asm_file] {nodebug}] } { + return -1 +} + +gdb_test "p aaa" "= 1" -- 2.30.2