From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Tom Tromey <tromey@adacore.com>
Date: Fri, 23 Apr 2021 11:28:48 -0600
Subject: gdb-gdb27743-psymtab-imported-unit.patch
;; Backport "Fix crash when expanding partial symtabs with DW_TAG_imported_unit"
;; (Tom Tromey, gdb/27743)
From e7d77ce0c408e7019f9885b8be64c9cdb46dd312 Mon Sep 17 00:00:00 2001
Subject: [PATCH] Fix crash when expanding partial symtabs with
DW_TAG_imported_unit
PR gdb/27743 points out a gdb crash when expanding partial symtabs,
where one of the compilation units uses DW_TAG_imported_unit.
The bug is that partial_map_expand_apply expects only to be called for
the outermost psymtab. However, filename searching doesn't (and
probably shouldn't) guarantee this. The fix is to walk upward to find
the outermost CU.
A new test case is included. It is mostly copied from other test
cases, which really sped up the effort.
This bug does not occur on trunk. There,
psym_map_symtabs_matching_filename is gone, replaced by
psymbol_functions::expand_symtabs_matching. When this find a match,
it calls psymtab_to_symtab, which does this same upward walk.
Tested on x86-64 Fedora 32.
I propose checking in this patch on the gdb-10 branch, and just the
new test case on trunk.
gdb/ChangeLog
2021-04-23 Tom Tromey <tromey@adacore.com>
PR gdb/27743:
* psymtab.c (partial_map_expand_apply): Expand outermost psymtab.
gdb/testsuite/ChangeLog
2021-04-23 Tom Tromey <tromey@adacore.com>
PR gdb/27743:
* gdb.dwarf2/imported-unit-bp.exp: New file.
* gdb.dwarf2/imported-unit-bp-main.c: New file.
* gdb.dwarf2/imported-unit-bp-alt.c: New file.
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -127,9 +127,10 @@ static struct compunit_symtab *psymtab_to_symtab (struct objfile *objfile,
{
struct compunit_symtab *last_made = objfile->compunit_symtabs;
- /* Shared psymtabs should never be seen here. Instead they should
- be handled properly by the caller. */
- gdb_assert (pst->user == NULL);
+ /* We may see a shared psymtab here, but we want to expand the
+ outermost symtab. */
+ while (pst->user != nullptr)
+ pst = pst->user;
/* Don't visit already-expanded psymtabs. */
if (pst->readin_p (objfile))
diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit-bp-alt.c b/gdb/testsuite/gdb.dwarf2/imported-unit-bp-alt.c
new file mode 100644
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/imported-unit-bp-alt.c
@@ -0,0 +1,50 @@
+/* Copyright 2020-2021 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/>. */
+
+/* Used to insert labels with which we can build a fake line table. */
+#define LL(N) asm ("line_label_" #N ": .globl line_label_" #N)
+
+volatile int var;
+volatile int bar;
+
+/* Generate some code to take up some space. */
+#define FILLER do { \
+ var = 99; \
+} while (0)
+
+int
+func (void)
+{ /* func prologue */
+ asm ("func_label: .globl func_label");
+ LL (1); // F1, Ln 16
+ FILLER;
+ LL (2); // F1, Ln 17
+ FILLER;
+ LL (3); // F2, Ln 21
+ FILLER;
+ LL (4); // F2, Ln 22 // F1, Ln 18, !S
+ FILLER;
+ LL (5); // F1, Ln 19 !S
+ FILLER;
+ LL (6); // F1, Ln 20
+ FILLER;
+ LL (7);
+ FILLER;
+ return 0; /* func end */
+}
+
+#ifdef WITHMAIN
+int main () { return 0; }
+#endif
diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit-bp-main.c b/gdb/testsuite/gdb.dwarf2/imported-unit-bp-main.c
new file mode 100644
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/imported-unit-bp-main.c
@@ -0,0 +1,24 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2004-2021 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/>. */
+
+extern int func (void);
+
+int
+main()
+{
+ return func ();
+}
diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit-bp.exp b/gdb/testsuite/gdb.dwarf2/imported-unit-bp.exp
new file mode 100644
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/imported-unit-bp.exp
@@ -0,0 +1,128 @@
+# Copyright 2020-2021 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 that "break /absolute/file:line" works ok with imported CUs.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+# The .c files use __attribute__.
+if [get_compiler_info] {
+ return -1
+}
+if !$gcc_compiled {
+ return 0
+}
+
+standard_testfile imported-unit-bp-alt.c .S imported-unit-bp-main.c
+
+set build_options {nodebug optimize=-O1}
+
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcdir subdir srcfile srcfile
+ global build_options
+ declare_labels lines_label callee_subprog_label cu_label
+
+ get_func_info func "$build_options additional_flags=-DWITHMAIN"
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_C}
+ {name "<artificial>"}
+ } {
+ imported_unit {
+ {import %$cu_label}
+ }
+ }
+ }
+
+ cu {} {
+ cu_label: compile_unit {
+ {producer "gcc"}
+ {language @DW_LANG_C}
+ {name ${srcfile}}
+ {comp_dir "/tmp"}
+ {low_pc 0 addr}
+ {stmt_list ${lines_label} DW_FORM_sec_offset}
+ } {
+ callee_subprog_label: subprogram {
+ {external 1 flag}
+ {name callee}
+ {inline 3 data1}
+ }
+ subprogram {
+ {external 1 flag}
+ {name func}
+ {low_pc $func_start addr}
+ {high_pc "$func_start + $func_len" addr}
+ } {
+ }
+ }
+ }
+
+ lines {version 2 default_is_stmt 1} lines_label {
+ include_dir "/tmp"
+ file_name "$srcfile" 1
+
+ program {
+ {DW_LNE_set_address line_label_1}
+ {DW_LNS_advance_line 15}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_2}
+ {DW_LNS_advance_line 1}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_3}
+ {DW_LNS_advance_line 4}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_4}
+ {DW_LNS_advance_line 1}
+ {DW_LNS_copy}
+
+ {DW_LNS_advance_line -4}
+ {DW_LNS_negate_stmt}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_5}
+ {DW_LNS_advance_line 1}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_6}
+ {DW_LNS_advance_line 1}
+ {DW_LNS_negate_stmt}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address line_label_7}
+ {DW_LNE_end_sequence}
+ }
+ }
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file $srcfile3] $build_options] } {
+ return -1
+}
+
+gdb_reinitialize_dir /tmp
+
+# Using an absolute path is important to see the bug.
+gdb_test "break /tmp/${srcfile}:19" "Breakpoint .* file $srcfile, line .*"