From 99d679e7b30ea9a0b6ffcd64e9ba35e43166151b Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Sat, 17 Sep 2022 08:22:32 +0200 Subject: [gdb/symtab] Fix "file index out of range" complaint With the test-case included in this commit, we run into this FAIL: ... (gdb) p var^M During symbol reading: file index out of range^M $1 = 0^M (gdb) FAIL: gdb.dwarf2/dw2-no-code-cu.exp: p var with no complaints ... This is a regression since commit 6d263fe46e0 ("Avoid bad breakpoints with --gc-sections"), which contains this change in read_file_scope: ... - handle_DW_AT_stmt_list (die, cu, fnd, lowpc); + if (lowpc != highpc) + handle_DW_AT_stmt_list (die, cu, fnd, lowpc); ... The change intends to avoid a problem with a check in lnp_state_machine::check_line_address, but also prevents the file and dir tables from being read, which causes the complaint. Fix the FAIL by reducing the scope of the "lowpc != highpc" condition to the call to dwarf_decode_lines in handle_DW_AT_stmt_list. Tested on x86_64-linux. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29561 --- gdb/dwarf2/read.c | 20 +++++++++---------- gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.c | 18 +++++++++++++++++ gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.exp | 31 +++++++++++++++++++++++++++++ 3 files changed, 59 insertions(+), 10 deletions(-) create mode 100644 gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.c create mode 100644 gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.exp diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 0a3c292..ceb1451 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -9498,8 +9498,8 @@ find_file_and_directory (struct die_info *die, struct dwarf2_cu *cu) static void handle_DW_AT_stmt_list (struct die_info *die, struct dwarf2_cu *cu, - const file_and_directory &fnd, - CORE_ADDR lowpc) /* ARI: editCase function */ + const file_and_directory &fnd, CORE_ADDR lowpc, + bool have_code) /* ARI: editCase function */ { dwarf2_per_objfile *per_objfile = cu->per_objfile; struct attribute *attr; @@ -9586,7 +9586,12 @@ handle_DW_AT_stmt_list (struct die_info *die, struct dwarf2_cu *cu, gdb_assert (die->tag != DW_TAG_partial_unit); } decode_mapping = (die->tag != DW_TAG_partial_unit); - dwarf_decode_lines (cu->line_header, cu, lowpc, decode_mapping); + /* The have_code check is here because, if LOWPC and HIGHPC are both 0x0, + then there won't be any interesting code in the CU, but a check later on + (in lnp_state_machine::check_line_address) will fail to properly exclude + an entry that was removed via --gc-sections. */ + if (have_code) + dwarf_decode_lines (cu->line_header, cu, lowpc, decode_mapping); } /* Process DW_TAG_compile_unit or DW_TAG_partial_unit. */ @@ -9625,13 +9630,8 @@ read_file_scope (struct die_info *die, struct dwarf2_cu *cu) /* Decode line number information if present. We do this before processing child DIEs, so that the line header table is available - for DW_AT_decl_file. The PC check is here because, if LOWPC and - HIGHPC are both 0x0, then there won't be any interesting code in - the CU, but a check later on (in - lnp_state_machine::check_line_address) will fail to properly - exclude an entry that was removed via --gc-sections. */ - if (lowpc != highpc) - handle_DW_AT_stmt_list (die, cu, fnd, lowpc); + for DW_AT_decl_file. */ + handle_DW_AT_stmt_list (die, cu, fnd, lowpc, lowpc != highpc); /* Process all dies in compilation unit. */ if (die->child != NULL) diff --git a/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.c b/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.c new file mode 100644 index 0000000..576b1a2 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.c @@ -0,0 +1,18 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2022 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 var; diff --git a/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.exp b/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.exp new file mode 100644 index 0000000..911bb7e --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-no-code-cu.exp @@ -0,0 +1,31 @@ +# Copyright 2022 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 . + +standard_testfile .c main.c + +if [prepare_for_testing "failed to prepare" $testfile "$srcfile $srcfile2"] { + return -1 +} + +set cmd "p var" + +set re \ + [multi_line \ + "$cmd" \ + "\\\$1 = 0"] + +with_complaints 5 { + gdb_test $cmd $re "$cmd with no complaints" +} -- cgit v1.1