http://sourceware.org/ml/archer/2010-q3/msg00028.html

Subject: [delayed-symfile] [commit] Fix a regression on CFI without DIE  [Re:

On Wed, 25 Feb 2009 00:14:29 +0100, Jan Kratochvil wrote:

> commit 6a37c2b9962258ecf9299cc34a650e64a06acaa5

> 

> There was a regression on gdb.base/savedregs.exp.

> 

> quick_addrmap/require_partial_symbols should be used even for the unwind debug

> info checking as its load has been also delayed by this branch.

[...]

> --- a/gdb/dwarf2-frame.c

> +++ b/gdb/dwarf2-frame.c

[...]

> @@ -1499,6 +1500,14 @@ dwarf2_frame_find_fde (CORE_ADDR *pc)

>        struct dwarf2_fde *fde;

>        CORE_ADDR offset;

>  

> +      if (objfile->quick_addrmap)

> +	{

> +	  if (!addrmap_find (objfile->quick_addrmap, *pc))

> +	    continue;

> +	}

> +      /* FIXME: Read-in only .debug_frame/.eh_frame without .debug_info?  */

> +      require_partial_symbols (objfile);

> +

but this has caused a different regression (as discussed in the confcall).

QUICK_ADDRMAP is built only from .debug_aranges.  But we can have existing

built .debug_aranges for CUs in OBJFILE but still some CUs do not need to have

DWARF at all while they can feature CFIs (.eh_frame or .debug_frame).

It has been described by Daniel Jacobowitz at:

	Re: [2/4] RFC: check psymtabs_addrmap before reading FDEs

	http://sourceware.org/ml/gdb-patches/2010-07/msg00012.html

Sorry for this regression by me (in that fix of a different regression).

Fixed it the "slow way" as this branch is now obsoleted by .gdb-index.

No regressions on {x86_64,x86_64-m32,i686}-fedora13-linux-gnu.

Checked-in.

Thanks,

Jan

eb8df8566acc1ed963e3e9b77c13b9c2c3db03fb

Test CFI is parsed even for range (function) not described by any DIE.

https://bugzilla.redhat.com/show_bug.cgi?id=614028

gdb/

	* dwarf2-frame.c (dwarf2_frame_find_fde): Remove the

	OBJFILE->QUICK_ADDRMAP check.  New comment why.

gdb/testsuite/

	* gdb.base/cfi-without-die.exp, gdb.base/cfi-without-die-main.c,

	gdb.base/cfi-without-die-caller.c: New files.

---

 gdb/dwarf2-frame.c                              |    8 +--

 gdb/testsuite/gdb.base/cfi-without-die-caller.c |   28 ++++++++++

 gdb/testsuite/gdb.base/cfi-without-die-main.c   |   32 +++++++++++

 gdb/testsuite/gdb.base/cfi-without-die.exp      |   67 +++++++++++++++++++++++

 4 files changed, 130 insertions(+), 5 deletions(-)

 create mode 100644 gdb/testsuite/gdb.base/cfi-without-die-caller.c

 create mode 100644 gdb/testsuite/gdb.base/cfi-without-die-main.c

 create mode 100644 gdb/testsuite/gdb.base/cfi-without-die.exp

Index: gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die-caller.c

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die-caller.c	2016-01-08 21:10:15.498079587 +0100

@@ -0,0 +1,28 @@

+/* This testcase is part of GDB, the GNU debugger.

+

+   Copyright 2005, 2007, 2008, 2009, 2010 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/>.  */

+

+typedef int (*callback_t) (void);

+

+int

+caller (callback_t callback)

+{

+  /* Ensure some frame content to push away the return address.  */

+  volatile const long one = 1;

+

+  /* Modify the return value to prevent any tail-call optimization.  */

+  return (*callback) () - one;

+}

Index: gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die-main.c

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die-main.c	2016-01-08 21:10:15.498079587 +0100

@@ -0,0 +1,32 @@

+/* This testcase is part of GDB, the GNU debugger.

+

+   Copyright 2005, 2007, 2008, 2009, 2010 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/>.  */

+

+typedef int (*callback_t) (void);

+

+extern int caller (callback_t callback);

+

+int

+callback (void)

+{

+  return 1;

+}

+

+int

+main (void)

+{

+  return caller (callback);

+}

Index: gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die.exp

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.10.50.20160106/gdb/testsuite/gdb.base/cfi-without-die.exp	2016-01-08 21:13:04.529998009 +0100

@@ -0,0 +1,71 @@

+# Copyright 2010 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 CFI is parsed even for range (function) not described by any DIE.

+

+set testfile cfi-without-die

+set srcmainfile ${testfile}-main.c

+set srccallerfile ${testfile}-caller.c

+set executable ${testfile}

+set objmainfile [standard_output_file ${testfile}-main.o]

+set objcallerfile [standard_output_file ${testfile}-caller.o]

+set binfile [standard_output_file ${executable}]

+

+if { [gdb_compile "${srcdir}/${subdir}/${srccallerfile}" ${objcallerfile} \

+      object [list {additional_flags=-fomit-frame-pointer -fno-unwind-tables -fno-asynchronous-unwind-tables}]] != ""

+     || [gdb_compile "${srcdir}/${subdir}/${srcmainfile}" ${objmainfile} object {debug}] != ""

+     || [gdb_compile "${objmainfile} ${objcallerfile}" ${binfile} executable {}] != "" } {

+     untested ${testfile}.exp

+     return -1

+}

+

+clean_restart $executable

+

+if ![runto callback] then {

+   fail "verify unwinding: Can't run to callback"

+   return 0

+}

+set test "verify unwinding breaks without CFI"

+gdb_test_multiple "bt" $test {

+    -re " in \[?\]\[?\] .*\r\n$gdb_prompt $" {

+	# It may backtrace through some random frames even to main().

+	pass $test

+    }

+    -re " in main .*\r\n$gdb_prompt $" {

+	fail $test

+    }

+    -re "\r\n$gdb_prompt $" {

+	pass $test

+    }

+}

+

+if { [gdb_compile "${srcdir}/${subdir}/${srccallerfile}" ${objcallerfile} \

+      object [list {additional_flags=-fomit-frame-pointer -funwind-tables -fasynchronous-unwind-tables}]] != ""

+     || [gdb_compile "${srcdir}/${subdir}/${srcmainfile}" ${objmainfile} object {debug}] != ""

+     || [gdb_compile "${objmainfile} ${objcallerfile}" ${binfile} executable {}] != "" } {

+     untested ${testfile}.exp

+     return -1

+}

+

+clean_restart $executable

+

+if ![runto callback] then {

+   fail "test CFI without DIEs: Can't run to callback"

+   return 0

+}

+# #0  callback () at ...

+# #1  0x00000000004004e9 in caller ()

+# #2  0x00000000004004cd in main () at ...

+gdb_test "bt" "#0 +callback \[^\r\n\]+\r\n#1 \[^\r\n\]+ in caller \[^\r\n\]+\r\n#2 \[^\r\n\]+ in main \[^\r\n\]+" "verify unwindin works for CFI without DIEs"