bug fix - When TBB_USE_EXCEPTIONS is disabled task_dispatcher fails to link

[fran6co]

Description

When TBB_USE_EXCEPTIONS is disabled task_dispatcher fails to link.

ld.lld: error: undefined symbol: tbb::detail::r1::do_throw_noexcept(void (*)())
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               arena.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<true, tbb::detail::r1::outermost_worker_waiter>(tbb::detail::d1::task*, tbb::detail::r1::outermost_worker_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               arena.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<false, tbb::detail::r1::outermost_worker_waiter>(tbb::detail::d1::task*, tbb::detail::r1::outermost_worker_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               task_dispatcher.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<true, tbb::detail::r1::external_waiter>(tbb::detail::d1::task*, tbb::detail::r1::external_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               task_dispatcher.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<false, tbb::detail::r1::external_waiter>(tbb::detail::d1::task*, tbb::detail::r1::external_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               task_dispatcher.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<true, tbb::detail::r1::coroutine_waiter>(tbb::detail::d1::task*, tbb::detail::r1::coroutine_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
>>> referenced by task_dispatcher.h:358 (/tmp/apg/external/tbb/src/tbb/task_dispatcher.h:358)
>>>               task_dispatcher.cpp.o:(tbb::detail::d1::task* tbb::detail::r1::task_dispatcher::local_wait_for_all<false, tbb::detail::r1::coroutine_waiter>(tbb::detail::d1::task*, tbb::detail::r1::coroutine_waiter&)) in archive ../../gnu_9.3_cxx17_64_debug/libtbb_debug.a
collect2: error: ld returned 1 exit status

Type of change

• [x] bug fix - change that fixes an issue
• [ ] new feature - change that adds functionality
• [ ] tests - change in tests
• [ ] infrastructure - change in infrastructure and CI
• [ ] documentation - documentation update

Tests

• [ ] added - required for new features and some bug fixes
• [x] not needed

Documentation

• [ ] updated in # - add PR number
• [ ] needs to be updated
• [x] not needed

Breaks backward compatibility

• [ ] Yes
• [x] No
• [ ] Unknown

[pavelkumbrasev]

Hi @fran6co, could you provide the steps to reproduce it?

[fran6co]

Just try to compile with TBB_USE_EXCEPTIONS disabled

[pavelkumbrasev]

I successfully built and linked library with TBB_USE_EXCEPTIONS=0 using such command cmake -DCMAKE_BUILD_TYPE=debug -DCMAKE_CXX_COMPILER=g++ -DCMAKE_CXX_FLAGS='-DTBB_USE_EXCEPTIONS=0' .. I built it on both release and debug configurations.

[fran6co]

That wouldn't work because the CMake define will not be translate to a C++ preprocessor define. You need to pass it like this:

-DCMAKE_CXX_FLAGS=-DTBB_USE_EXCEPTIONS=0

[pavelkumbrasev]

I built it with verbose and define was there also I add something like "dsadasd not compile" under macro and it not compiled with enabled macro and compiled with disabled

[pavelkumbrasev]

There is no difference between -DCMAKE_CXX_FLAGS='-DTBB_USE_EXCEPTIONS=0' and -DCMAKE_CXX_FLAGS=-DTBB_USE_EXCEPTIONS=0. I still built it successfully. Could you try to do it on environment?

[isaevil]

@fran6co please share more info about configuration you are facing that issue on (OS, compiler, etc)?

[pavelkumbrasev]

Hi @fran6co, any updates?

[fran6co]

Sorry, I didn't have time to check it out. Over the weekend I should be able to

[fran6co]

So, for some reason it's not enough to pass it to DCMAKE_CXX_FLAGS. I had to add it to cmake itself for it to fail when building:

diff --git a/src/tbb/CMakeLists.txt b/src/tbb/CMakeLists.txt
index 7f8228c0..8207375f 100644
--- a/src/tbb/CMakeLists.txt
+++ b/src/tbb/CMakeLists.txt
@@ -52,6 +52,7 @@ endif()
 
 target_compile_definitions(tbb
                            PUBLIC
+                           TBB_USE_EXCEPTIONS=0
                            $<$<CONFIG:DEBUG>:TBB_USE_DEBUG>
                            PRIVATE
                            __TBB_BUILD
diff --git a/src/tbbmalloc/CMakeLists.txt b/src/tbbmalloc/CMakeLists.txt
index 5a851851..77698d1a 100644
--- a/src/tbbmalloc/CMakeLists.txt
+++ b/src/tbbmalloc/CMakeLists.txt
@@ -24,6 +24,7 @@ add_library(TBB::tbbmalloc ALIAS tbbmalloc)
 
 target_compile_definitions(tbbmalloc
                            PUBLIC
+                           TBB_USE_EXCEPTIONS=0
                            $<$<CONFIG:DEBUG>:TBB_USE_DEBUG>
                            PRIVATE
                            __TBBMALLOC_BUILD

[fran6co]

In my project TBB is part of the build so I just have a add_definitions("-DTBB_USE_EXCEPTIONS=0") and without this fix it fails to build

[fran6co]

For the sake of completeness:

OS: Ubuntu 22.04 Compiler: GCC 11.3.0

[isaevil]

In my project TBB is part of the build so I just have a add_definitions("-DTBB_USE_EXCEPTIONS=0") and without this fix it fails to build

@fran6co do you add oneTBB as subdirectory (add_subdirectory) of your project?

[fran6co]

Yes, but even when I build the TBB project standalone I get the same linking error:

/usr/bin/ld: ../gnu_11.3_cxx11_64_debug/libtbb_debug.so.12.9: undefined reference to `tbb::detail::r1::do_throw_noexcept(void (*)())'

[fran6co]

I'm actually surprised that it builds for you, because do_throw does reference do_throw_noexcept but it's behind the #ifdef

[isaevil]

According to specification https://spec.oneapi.io/versions/latest/elements/oneTBB/source/configuration/feature_macros.html:

The TBB_USE_EXCEPTIONS macro controls whether the library headers use exception-handling constructs such as try, catch, and throw. The headers do not use these constructs when TBB_USE_EXCEPTIONS=0.

Caution The runtime library may still throw an exception when TBB_USE_EXCEPTIONS=0.

Is there some special usecase where you need to compile oneTBB library (not your program using oneTBB) without exceptions?

[fran6co]

TBB_USE_EXCEPTIONS makes it harder for us to deal with crash dumps so we need it disabled library wide so we can debug stuff in an easier way

[yilei]

Should this try/catch block be guarded by TBB_USE_EXCEPTIONS? When exception is disabled, this line with a throw; fails to compile.

[GertyP]

I also ran in to this problem, which I mention in this issue and was directed to this (thanks, @isaevil).

I wonder if others have an explanation for what seems to be needlessly elaborate/complicated existing code, which I hope could be cleaner and simpler and also fix this particular issue.

Since a throw from a noexcept function will (by definition) result in a std::terminate() then any existing call to do_throw_noexcept(...) ultimately becomes std::terminate().

There are only 2 places where do_throw_noexcept(...) is called -

• In 'task_dispatcher.h', near the end of task_dispatcher::local_wait_for_all(...)
• and in 'exception.cpp', within void do_throw(F throw_func) if terminate_on_exception() is enabled

What benefit is there in do_throw_noexcept(...) over std::terminate()? ... The only thing I can see is that it calls a user/custom function before terminating, allowing for some other bit of final work before we exit. However, unless I've overlooked something, all ways that we can reach do_throw_noexcept from do_throw simply use a lambda that does nothing more than throws a particular exception... Which means that the 2 calls to do_throw_noexcept lose nothing if they were simply changed to std::terminate.

I'd also argue that doing so fixes the problem mentioned here with fairly minimal changes, allows us to remove the slightly odd do_throw_noexcept entirely, as well as improves the code readability: Does everyone know what the standard says about a noexcept function that throws? Even if most effortlessly translate this to a terminate, what benefit are we currently getting by going through this potentially jarring function, instead of simply calling std::terminate?