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Andrew Burgess 53e8a631a0 Add a TRY_CATCH to get_prev_frame_always to better manage errors during unwind.
https://sourceware.org/ml/gdb-patches/2014-05/msg00737.html

Currently a MEMORY_ERROR raised during unwinding a frame will cause the
unwind to stop with an error message, for example:

  (gdb) bt
  #0  breakpt () at amd64-invalid-stack-middle.c:27
  #1  0x00000000004008f0 in func5 () at amd64-invalid-stack-middle.c:32
  #2  0x0000000000400900 in func4 () at amd64-invalid-stack-middle.c:38
  #3  0x0000000000400910 in func3 () at amd64-invalid-stack-middle.c:44
  #4  0x0000000000400928 in func2 () at amd64-invalid-stack-middle.c:50
  Cannot access memory at address 0x2aaaaaab0000

However, frame #4 is marked as being the end of the stack unwind, so a
subsequent request for the backtrace looses the error message, such as:

  (gdb) bt
  #0  breakpt () at amd64-invalid-stack-middle.c:27
  #1  0x00000000004008f0 in func5 () at amd64-invalid-stack-middle.c:32
  #2  0x0000000000400900 in func4 () at amd64-invalid-stack-middle.c:38
  #3  0x0000000000400910 in func3 () at amd64-invalid-stack-middle.c:44
  #4  0x0000000000400928 in func2 () at amd64-invalid-stack-middle.c:50

When fetching the backtrace, or requesting the stack depth using the MI
interface the situation is even worse, the first time a request is made
we encounter the memory error and so the MI returns an error instead of
the correct result, for example:

  (gdb) -stack-info-depth
  ^error,msg="Cannot access memory at address 0x2aaaaaab0000"

Or,

  (gdb) -stack-list-frames
  ^error,msg="Cannot access memory at address 0x2aaaaaab0000"

However, once one of these commands has been used gdb has, internally,
walked the stack and figured that out that frame #4 is the bottom of the
stack, so the second time an MI command is tried you'll get the "expected"
result:

  (gdb) -stack-info-depth
  ^done,depth="5"

Or,

  (gdb) -stack-list-frames
  ^done,stack=[frame={level="0", .. snip lots .. }]

After this patch the MEMORY_ERROR encountered during the frame unwind is
attached to frame #4 as the stop reason, and is displayed in the CLI each
time the backtrace is requested.  In the MI, catching the error means that
the "expected" result is returned the first time the MI command is issued.
So, from the CLI the results of the backtrace will be:

  (gdb) bt
  #0  breakpt () at amd64-invalid-stack-middle.c:27
  #1  0x00000000004008f0 in func5 () at amd64-invalid-stack-middle.c:32
  #2  0x0000000000400900 in func4 () at amd64-invalid-stack-middle.c:38
  #3  0x0000000000400910 in func3 () at amd64-invalid-stack-middle.c:44
  #4  0x0000000000400928 in func2 () at amd64-invalid-stack-middle.c:50
  Backtrace stopped: Cannot access memory at address 0x2aaaaaab0000

Each and every time that the backtrace is requested, while the MI output
will similarly be consistently:

  (gdb) -stack-info-depth
  ^done,depth="5"

Or,

  (gdb) -stack-list-frames
  ^done,stack=[frame={level="0", .. snip lots .. }]

gdb/ChangeLog:

	* frame.c (struct frame_info): Add stop_string field.
	(get_prev_frame_always_1): Renamed from get_prev_frame_always.
	(get_prev_frame_always): Old content moved into
	get_prev_frame_always_1.  Call get_prev_frame_always_1 inside
	TRY_CATCH, handle MEMORY_ERROR exceptions.
	(frame_stop_reason_string): New function definition.
	* frame.h (unwind_stop_reason_to_string): Extend comment to
	mention frame_stop_reason_string.
	(frame_stop_reason_string): New function declaration.
	* stack.c (frame_info): Switch to frame_stop_reason_string.
	(backtrace_command_1): Switch to frame_stop_reason_string.
	* unwind_stop_reason.def: Add UNWIND_MEMORY_ERROR.
	(LAST_ENTRY): Changed to UNWIND_MEMORY_ERROR.
	* guile/lib/gdb.scm: Add FRAME_UNWIND_MEMORY_ERROR to export list.

gdb/doc/ChangeLog:

	* guile.texi (Frames In Guile): Mention FRAME_UNWIND_MEMORY_ERROR.
	* python.texi (Frames In Python): Mention
	gdb.FRAME_UNWIND_MEMORY_ERROR.

gdb/testsuite/ChangeLog:

	* gdb.arch/amd64-invalid-stack-middle.exp: Update expected results.
	* gdb.arch/amd64-invalid-stack-top.exp: Likewise.
2014-05-30 22:44:36 +01:00
bfd daily update 2014-05-30 09:30:44 +09:30
binutils This fixes a few issues with pe/coff build-ids that were discovered since the 2014-05-16 15:34:13 +01:00
config Sync nios2 configure changes from GCC mainline. 2014-05-14 16:27:14 -07:00
cpu or1k: add support for l.swa/l.lwa atomic instructions 2014-05-08 09:02:50 +03:00
elfcpp Remove support for the (deprecated) openrisc and or32 configurations and replace 2014-04-22 15:57:47 +01:00
etc
gas Fix whitespace in gas listing errors and warnings 2014-05-22 18:53:22 +09:30
gdb Add a TRY_CATCH to get_prev_frame_always to better manage errors during unwind. 2014-05-30 22:44:36 +01:00
gold Fix testsuite to use newly-built linker for ehdr_start_test_4, and fix 2014-05-30 10:21:27 -07:00
gprof autoreconf 2014-03-12 15:02:00 +10:30
include Fix MSP430 assembler to support #hi(<symbol>). 2014-05-20 10:28:42 +01:00
intl
ld ld: Split GENSCRIPTS rule from dependencies to fix tdir_'s. 2014-05-28 18:20:16 +02:00
libdecnumber PR c/59871 c/ * c-typeck.c (build_compound_expr): Warn even for right-hand operand of a comma expression. (emit_side_effect_warnings): Likewise. libdecnumber/ * decNumberLocal.h (UBFROMUS, UBFROMUI): Remove last argument. testsuite/ * gcc.dg/20020220-2.c: Adjust dg-warning message. * gcc.dg/pr59871.c: New test. 2014-05-08 10:18:28 -06:00
libiberty Fix demangler testsuite crashes with CP_DEMANGLE_DEBUG defined 2014-05-28 23:06:44 +01:00
opcodes Remove unnecessary header from m68k-dis.c 2014-05-20 13:15:18 +09:30
readline * readline.c (bind_arrow_keys_internal): 2013-09-24 14:49:48 +00:00
sim Support 32->64 sign extension in msp430's sign_ext 2014-05-12 19:05:19 -04:00
texinfo
.cvsignore
.gitignore Sync the root .gitignore file with GCC's. 2013-01-11 15:17:35 +00:00
ChangeLog Sync nios2 configure changes from GCC mainline. 2014-05-14 16:27:14 -07:00
compile
config-ml.in
config.guess * config.sub, config.guess: Import from upstream. 2014-05-01 21:49:01 +01:00
config.rpath
config.sub * config.sub, config.guess: Import from upstream. 2014-05-01 21:49:01 +01:00
configure Sync nios2 configure changes from GCC mainline. 2014-05-14 16:27:14 -07:00
configure.ac Sync nios2 configure changes from GCC mainline. 2014-05-14 16:27:14 -07:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS 2013-01-07 Jeff Johnston <jjohnstn@redhat.com> 2013-01-07 21:39:26 +00:00
COPYING.NEWLIB 2013-10-01 Jeff Johnston <jjohnstn@redhat.com> 2013-10-01 18:14:04 +00:00
depcomp
djunpack.bat
install-sh
libtool.m4 * libtool.m4 (_LT_ENABLE_LOCK <ld -m flags>): Remove non-canonical 2013-09-20 09:51:25 +00:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh PR target/59788 2014-02-06 11:01:57 +01:00
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def PR sanitizer/56781 * Makefile.def: Set bootstrap=true; for host fixincludes. * configure.ac: Don't bootstrap host fixincludes unless --with-build-config=bootstrap-{a,ub}san. * Makefile.in: Regenerated. * configure: Regenerated. 2014-05-08 10:18:30 -06:00
Makefile.in PR sanitizer/56781 * Makefile.def: Set bootstrap=true; for host fixincludes. * configure.ac: Don't bootstrap host fixincludes unless --with-build-config=bootstrap-{a,ub}san. * Makefile.in: Regenerated. * configure: Regenerated. 2014-05-08 10:18:30 -06:00
Makefile.tpl PR bootstrap/58572 * Makefile.tpl (POSTSTAGE1_CXX_EXPORT): Use -isystem instead of -I for libstdc++-v3 includes if $(LEAN). * Makefile.in: Regenerated. 2014-05-08 10:18:29 -06:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
README
README-maintainer-mode
setup.com
src-release * src-release (do-proto-toplevel): Support subdir-path-prefixed 2013-10-15 20:45:52 +00:00
symlink-tree
ylwrap

		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.