[PATCHv4] print stack trace after each syscall

[Luca Clementi]

On Thu, Sep 12, 2013 at 8:49 AM, Dmitry V. Levin <ldv at altlinux.org> wrote:
> On Fri, Aug 16, 2013 at 02:20:09PM +0900, Masatake YAMATO wrote:
>> After rebuilding libunwind with enabling minidebuginfo feature[1], your
>> patch works fine on my Fedora 19.
>>
>> strace maintainer(s), is there any issue for merging the patch to
>> the official source tree?
>
> I've changed the patch a bit and pushed it to branch ldv/unwind,
> please have a look:
> http://sourceforge.net/p/strace/code/ci/5a9cf58a485a97b4fcfd36a7a6e3637368086f4b/
>

Hey Dmitry,
I think the patch looks much nicer now, thanks for polishing it.

Although when I try to configure against the latest libunwind compiled
in a folder (not the distro package), I get an error if I use:

------------------------------------------------
./configure --with-libunwind=/home/clem/projects/libunwind/libunwindinstall
[...]
checking for perl... /usr/bin/perl
checking libunwind-ptrace.h usability... yes
checking libunwind-ptrace.h presence... yes
checking for libunwind-ptrace.h... yes
checking for _UPT_create in -lunwind-ptrace... no
configure: error: in `/home/clem/projects/strace':
configure: error: failed to find _UPT_create in libunwind-ptrace
See `config.log' for more details
------------------------------------------------


In config.log I have:
-----------------------------
configure:7026: gcc -o conftest -g -O2
-I/home/clem/projects/libunwind/libunwindinstall//include
-L/home/clem/projects/libunwind/libunwindinstall//lib conftest.c
-lunwind-ptrace
                >&5
/home/clem/projects/FingerPrint/libunwind/libunwindinstall//lib/libunwind-ptrace.so:
undefined reference to `_Ux86_64_get_elf_image'
/home/clem/projects/FingerPrint/libunwind/libunwindinstall//lib/libunwind-ptrace.so:
undefined reference to `_Ux86_64_dwarf_find_unwind_table'
/home/clem/projects/FingerPrint/libunwind/libunwindinstall//lib/libunwind-ptrace.so:
undefined reference to `_Ux86_64_dwarf_search_unwind_table'
-----------------------------


To properly configure I need to use the following:
./configure --with-libunwind=/home/clem/projects/FingerPrint/libunwind/libunwindinstall/
LIBS="-lunwind -lunwind-generic"
LDFLAGS=-L/home/clem/projects/libunwind/libunwindinstall/lib


AFAIK if you want to avoid the LDFLAG/LIBS variable you need add the test on:
        AC_CHECK_LIB([unwind], [backtrace],
        AC_CHECK_LIB([unwind-generic], [_U${UNWIND_ARCH}_create_addr_space],
I know that it is not the prettiest code ever but that's the only way
I could get to configure with my setup.


If you want I can send you a patch on top of your ldv/unwind branch for that.


The rest works properly.

Thank you,
Clem