From f4c4456eb4d826f39abb2575ce5c2c4640bb16f3 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Fri, 21 Jul 2023 08:25:25 +0200 Subject: [gdb/symtab] Add optimized out static var to cooked index Consider the test-case: ... $ cat main.c int main (void) { return 0; } $ cat static-optimized-out.c static int aaa; ... compiled like this: ... $ gcc-12 static-optimized-out.c main.c -g -O2 -flto ... There's a difference in behaviour depending on symtab expansion state: ... $ gdb -q -batch a.out -ex "print aaa" No symbol "aaa" in current context. $ gdb -q -batch a.out -ex "maint expand-symtab" -ex "print aaa" $1 = ... The reason for the difference is that the optimized out variable aaa: ... <1><104>: Abbrev Number: 2 (DW_TAG_variable) <105> DW_AT_name : aaa <109> DW_AT_decl_file : 1 <10a> DW_AT_decl_line : 18 <10b> DW_AT_decl_column : 12 <10c> DW_AT_type : <0x110> ... is not added to the cooked index because of this clause in abbrev_table::read: ... else if (!has_location && !has_specification_or_origin && !has_external && cur_abbrev->tag == DW_TAG_variable) cur_abbrev->interesting = false; ... Fix this inconsistency by making sure that the optimized out variable is added to the cooked index. Regression tested on x86_64-linux. Add two test-cases, a C test-case gdb.opt/static-optimized-out.exp and a dwarf assembly test-case gdb.dwarf2/static-optimized-out.exp. Tested gdb.opt/static-optimized-out.exp with gcc-8 to gcc-12, for which we now consistently get: ... (gdb) print aaa^M $1 = ^M ... and with gcc 7.5.0 and clang 13.0.1, for which we still consistently get: ... (gdb) print aaa^M No symbol "aaa" in current context.^M ... due to missing debug info for the variable. PR symtab/30656 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30656 Approved-By: Tom Tromey --- gdb/testsuite/gdb.opt/main.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 gdb/testsuite/gdb.opt/main.c (limited to 'gdb/testsuite/gdb.opt/main.c') diff --git a/gdb/testsuite/gdb.opt/main.c b/gdb/testsuite/gdb.opt/main.c new file mode 100644 index 0000000..c6beff7 --- /dev/null +++ b/gdb/testsuite/gdb.opt/main.c @@ -0,0 +1,22 @@ +/* This testcase is part of GDB, the GNU debugger. + + 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 . */ + +int +main (void) +{ + return 0; +} -- cgit v1.1