[Bug libstdc++/112263] New: [C++23] std::stacktrace does not identify symbols in shared library

[Bug libstdc++/112263] New: [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

            Bug ID: 112263
           Summary: [C++23] std::stacktrace does not identify symbols in
                    shared library
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vincenzo.innocente at cern dot ch
  Target Milestone: ---

using 
gcc version 14.0.0 20231028 (experimental) [master r14-4988-g5d2a360f0a5] (GCC)
that contains the fix for #111936

This simple example  [1]
when run as a single executable prints all symbols in the stacktrace
when the nested functions are in a shared library their names are missing
c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -DINLIB ; ./a.out
   0# nested_func2(int) at
/afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:13
   1# nested_func(int) at
/afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:18
   2# func(int) at
/afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:26
   3# main at /afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:31
   4#      at :0
   5# _start at :0
   6#


c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINLIB -fpic -shared -o
liba.so ; c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -L. -la
-Wl,-rpath=. ; ./a.out
   0#      at :0
   1#      at :0
   2# func(int) at
/afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:26
   3# main at /afs/cern.ch/user/i/innocent/public/ctest/testStacktrace.cpp:31
   4#      at :0
   5# _start at :0
   6#



[1]
cat testStacktrace.cpp
//compile and run with either
// c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -DINLIB; ./a.out
// or
// c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINLIB -fpic -shared -o
liba.so;c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -L. -la
-Wl,-rpath=.; ./a.out
//
#include <iostream>
#include <stacktrace>


#ifdef INLIB
int nested_func2(int c)
{
    std::cout << std::stacktrace::current() << '\n';
    return c + 1;
}
int nested_func(int c)
{
    return nested_func2(c + 1);
}
#else
int nested_func(int c);
#endif
#ifdef INMAIN
int func(int b)
{
    return nested_func(b + 1);
}

int main()
{
    std::cout << func(777);
   return 0;
}
#endif

[Bug libstdc++/112263] [C++23] std::stacktrace does not identify symbols in shared library

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I'm not sure if this is a libstdc++ problem or should be component=libbacktrace

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

vincenzo Innocente <vincenzo.innocente at cern dot ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at gcc dot gnu.org
          Component|libstdc++                   |libbacktrace

--- Comment #2 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
I suspect libbacktrace even if I do not have ways to test it outside
std::stacktrace

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at airs dot com

--- Comment #3 from Ian Lance Taylor <ian at airs dot com> ---
What OS and processor?  Is this x86 GNU/Linux?

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #4 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
intel x86_64 
uname -a
Linux patatrack01 4.18.0-477.13.1.el8_8.x86_64 #1 SMP Thu May 18 10:27:05 EDT
2023 x86_64 x86_64 x86_64 GNU/Linux

boost::backtrace works
can provide example

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #5 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
so if I add to
    std::cout << std::stacktrace::current() << '\n';
I get what needed
   Dl_info dlinfo;
   for (auto & entry : std::stacktrace::current() ) {
     dladdr((const void*)(entry.native_handle()),&dlinfo);
     std::cout << dlinfo.dli_sname << ' ' << dlinfo.dli_fname <<'\n';
   }

 c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINLIB -fpic -shared -o
liba.so -ldl ; c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -L.
-la -Wl,-rpath=. ; ./a.out
   0#      at :0
   1#      at :0
   2# func(int) at
/data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:44
   3# main at /data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:49
   4#      at :0
   5# _start at :0
   6#

_Z12nested_func2i ./liba.so
_Z11nested_funci ./liba.so

of course not de-mangled....

so is it a feature or a defect?

I'm not sure how the implementation works (did not look to the code)
dladdr can be slow and may "hang" in some situations.
so it would be useful to have an option that the "name" is not immediately
resolved
and have a function that returns the name from the native_handle
"asynchronously"

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #6 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
Sorry, made the (almost) full exercise:
read the doc in 
https://en.cppreference.com/w/cpp/utility/stacktrace_entry
and the code in stacktrace header file and in
libstdc++-v3/src/c++23/stacktrace.cc
(have not read the specs in the C++23 standard)
indeed the entry implementation has just the handle as data member
and the details are retrieved when the "Query" methods are called.
This appears to happen in
stacktrace_entry::_Info::_M_populate(native_handle_type pc)
which in turn calls
::__glibcxx_backtrace_pcinfo
if this fails it calls
::__glibcxx_backtrace_syminfo

so most probably the issue is in this last function unless there is a problem
with the logic in _M_populate that I failed to identify.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #7 from Ian Lance Taylor <ian at airs dot com> ---
https://gcc.gnu.org/pipermail/gcc-patches/2023-November/635073.html

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #8 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
Thanks Ian for the patch.
For testing I will need the full git diff (including the makefile itself as my 
autoconf is not compatible with gcc14).

Backports down to gcc12 will be appreciated.
Could you please notify here when the patch enters the various main branches?

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rimvydas.jas at gmail dot com

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
*** Bug 111315 has been marked as a duplicate of this bug. ***

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-11-04
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think we can mark this as confirmed since there is a patch submitted and the
duplicated bug confirmed that patch fixes the issue.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #11 from Ian Lance Taylor <ian at airs dot com> ---
vincenzo: the patch in the linked e-mail is the complete diff.  There are no
changes to generated Makefile.in files.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[vincenzo.innocente at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #12 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
confirm that the patch solves the issue

c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINLIB -fpic -shared -o
liba.so -ldl;c++ -std=c++23 testStacktrace.cpp -lstdc++exp -g -DINMAIN -L. -la
-Wl,-rpath=.; ./a.out
   0# nested_func2(int) at
/data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:63
   1# nested_func(int) at
/data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:93
   2# func(int) at
/data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:101
   3# main at /data/user/innocent/MallocProfiler/tests/testStacktrace.cpp:106
   4# __libc_start_main at :0
   5# _start at :0
   6#

what is the last empty entry is a different story I suppose (not an issue at
the moment).

Thanks again for the fast action

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Ian Lance Taylor <ian@gcc.gnu.org>:

https://gcc.gnu.org/g:2b64e4a54042fb8f75f1c1429eb1c13afb9fa118

commit r14-5173-g2b64e4a54042fb8f75f1c1429eb1c13afb9fa118
Author: Ian Lance Taylor <iant@golang.org>
Date:   Mon Nov 6 15:09:18 2023 -0800

    libstdc++: use -D_GNU_SOURCE when building libbacktrace

            PR libbacktrace/111315
            PR libbacktrace/112263
            * acinclude.m4: Set -D_GNU_SOURCE in BACKTRACE_CPPFLAGS and when
            grepping link.h for dl_iterate_phdr.
            * configure: Regenerate.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #14 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Ian Lance Taylor
<ian@gcc.gnu.org>:

https://gcc.gnu.org/g:8484e3479fe80aebdc4a2406473aef906055b4f8

commit r13-8006-g8484e3479fe80aebdc4a2406473aef906055b4f8
Author: Ian Lance Taylor <iant@golang.org>
Date:   Mon Nov 6 15:12:05 2023 -0800

    libstdc++: use -D_GNU_SOURCE when building libbacktrace

            PR libbacktrace/111315
            PR libbacktrace/112263
            * acinclude.m4: Set -D_GNU_SOURCE in BACKTRACE_CPPFLAGS and when
            grepping link.h for dl_iterate_phdr.
            * configure: Regenerate.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #15 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Ian Lance Taylor
<ian@gcc.gnu.org>:

https://gcc.gnu.org/g:56909c9d4842925749cd9e061ef4afa0501f85e9

commit r12-9961-g56909c9d4842925749cd9e061ef4afa0501f85e9
Author: Ian Lance Taylor <iant@golang.org>
Date:   Mon Nov 6 15:12:41 2023 -0800

    libstdc++: use -D_GNU_SOURCE when building libbacktrace

            PR libbacktrace/111315
            PR libbacktrace/112263
            * acinclude.m4: Set -D_GNU_SOURCE in BACKTRACE_CPPFLAGS and when
            grepping link.h for dl_iterate_phdr.
            * configure: Regenerate.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #16 from Ian Lance Taylor <ian at airs dot com> ---
Fix committed.

[Bug libbacktrace/112263] [C++23] std::stacktrace does not identify symbols in shared library

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112263

--- Comment #17 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Thanks, Ian!