From: Tom de Vries <tdevries@suse.de>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PATCH v2 4/5] [gdb/symtab] Trust epilogue unwind info for unknown producer (-g0 case)
Date: Mon, 13 Feb 2023 15:23:08 +0100 [thread overview]
Message-ID: <20230213142309.24366-5-tdevries@suse.de> (raw)
In-Reply-To: <20230213142309.24366-1-tdevries@suse.de>
For a -g0 -fasynchronous-unwind-tables exec (without .debug_info but with
.eh_frame section), start using the dwarf2 unwinder instead of the
"amd64 epilogue override" unwinder, by returning true in
compunit_epilogue_unwind_valid for cust == nullptr.
This has effect both on the amd64 and i386 targets, but only add amd64
test-case gdb.base/unwind-on-each-insn-amd64-2.exp.
---
gdb/symtab.h | 4 +-
.../gdb.base/unwind-on-each-insn-amd64-2.exp | 52 ++++++++++++++++++
.../gdb.base/unwind-on-each-insn-amd64-2.s | 54 +++++++++++++++++++
3 files changed, 108 insertions(+), 2 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.exp
create mode 100644 gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.s
diff --git a/gdb/symtab.h b/gdb/symtab.h
index cd6b5f722fd..17d2746fd48 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1924,9 +1924,9 @@ static inline bool
compunit_epilogue_unwind_valid (struct compunit_symtab *cust)
{
/* In absence of producer information, assume epilogue unwind info is
- invalid. */
+ valid. */
if (cust == nullptr)
- return false;
+ return true;
return cust->epilogue_unwind_valid ();
}
diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.exp b/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.exp
new file mode 100644
index 00000000000..c8a94ccef4f
--- /dev/null
+++ b/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.exp
@@ -0,0 +1,52 @@
+# 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 <http://www.gnu.org/licenses/>. */
+
+# Check that epilogue unwind info is used, even if no debug info is available.
+
+require is_x86_64_m64_target
+
+set srcfile_flags {debug}
+set srcfile2_flags {nodebug}
+
+if [info exists COMPILE] {
+ # Make sure that we use .eh_frame info, by generating it
+ # using -fasynchronous-unwind-tables.
+ if { [gdb_can_simple_compile fasynchronous-unwind-tables \
+ { void foo () { } } object -fasynchronous-unwind-tables] } {
+ lappend srcfile2_flags additional_flags=-fasynchronous-unwind-tables
+ } else {
+ unsupported "required: .eh_frame"
+ return
+ }
+ standard_testfile unwind-on-each-insn.c unwind-on-each-insn-foo.c
+ # When updating the .s file, use these flags to generate the file:
+ #lappend srcfile2_flags additional_flags=-save-temps
+ #lappend srcfile2_flags additional_flags=-dA
+ # and do the following:
+ # - copy it in place, run the test-case and verify that all tests pass.
+ # - confuse the amd64 epilogue unwinder by inserting the following
+ # in foo:
+ # nop
+ # + pushq $.L1
+ # + ret
+ # + .L1:
+ # + nop
+ # popq %rbp
+ # - verify that the test-case passes.
+} else {
+ standard_testfile unwind-on-each-insn.c .s
+}
+
+source $srcdir/$subdir/unwind-on-each-insn.exp.tcl
diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.s b/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.s
new file mode 100644
index 00000000000..c141f71817c
--- /dev/null
+++ b/gdb/testsuite/gdb.base/unwind-on-each-insn-amd64-2.s
@@ -0,0 +1,54 @@
+ .file "unwind-on-each-insn-foo.c"
+ .text
+ .globl foo
+ .type foo, @function
+foo:
+.LFB0:
+ .cfi_startproc
+# BLOCK 2 seq:0
+# PRED: ENTRY (FALLTHRU)
+ pushq %rbp
+ .cfi_def_cfa_offset 16
+ .cfi_offset 6, -16
+ movq %rsp, %rbp
+ .cfi_def_cfa_register 6
+ movq %rdi, -8(%rbp)
+ nop
+ pushq $.L1
+ ret
+.L1:
+ nop
+ popq %rbp
+ .cfi_def_cfa 7, 8
+# SUCC: EXIT [100.0%]
+ ret
+ .cfi_endproc
+.LFE0:
+ .size foo, .-foo
+ .globl bar
+ .type bar, @function
+bar:
+.LFB1:
+ .cfi_startproc
+# BLOCK 2 seq:0
+# PRED: ENTRY (FALLTHRU)
+ pushq %rbp
+ .cfi_def_cfa_offset 16
+ .cfi_offset 6, -16
+ movq %rsp, %rbp
+ .cfi_def_cfa_register 6
+ subq $8, %rsp
+ movq %rdi, -8(%rbp)
+ movq -8(%rbp), %rax
+ movq %rax, %rdi
+ call foo
+ nop
+ leave
+ .cfi_def_cfa 7, 8
+# SUCC: EXIT [100.0%]
+ ret
+ .cfi_endproc
+.LFE1:
+ .size bar, .-bar
+ .ident "GCC: (SUSE Linux) 7.5.0"
+ .section .note.GNU-stack,"",@progbits
--
2.35.3
next prev parent reply other threads:[~2023-02-13 14:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-13 14:23 [PATCH v2 0/5] [gdb/symtab] Assume epilogue unwind info is valid unless gcc < 4.5.0 Tom de Vries
2023-02-13 14:23 ` [PATCH v2 1/5] [gdb/symtab] Factor out compunit_epilogue_unwind_valid Tom de Vries
2023-02-14 15:56 ` Tom Tromey
2023-02-14 22:36 ` Tom de Vries
2023-02-20 10:27 ` Tom de Vries
2023-02-13 14:23 ` [PATCH v2 2/5] [gdb/tdep] Fix amd64/i386_stack_frame_destroyed_p Tom de Vries
2023-02-13 14:23 ` [PATCH v2 3/5] [gdb/tdep] Add amd64/i386 epilogue override unwinders Tom de Vries
2023-02-13 14:23 ` Tom de Vries [this message]
2023-02-13 14:23 ` [PATCH v2 5/5] [gdb/symtab] Trust epilogue unwind info for unknown or non-gcc producer Tom de Vries
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