[Bug c++/107452] New: Failed to catch C++ exception thrown from multiarch-function (x64 CPUs)

[kim.walisch at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107452

            Bug ID: 107452
           Summary: Failed to catch C++ exception thrown from
                    multiarch-function (x64 CPUs)
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kim.walisch at gmail dot com
  Target Milestone: ---

Hi,

Tested using: GCC 11.2.0, Ubuntu 22.10 x64
Tested using: GCC 9.4.0, Ubuntu 18.04 x64

I am using the GCC multiarch feature (also known as function multiversioning:
https://gcc.gnu.org/onlinedocs/gcc/Function-Multiversioning.html) in my
primesieve C++ project to take advantage of the latest supported CPU
instruction set e.g. AVX, AVX2, AVX512 (on x64 CPUs).

Today I found out that if I throw a C++ exception from a multiarch-function and
I try to catch that exception outside of the originating multiarch-function but
within the same translation unit, then catching the exception fails and my
program simply aborts.

My exception is thrown from here:
https://github.com/kimwalisch/primesieve/blob/776c102f92905401613a83508d60744d41df7c73/src/PrimeGenerator.cpp#L332
It should be caught here:
https://github.com/kimwalisch/primesieve/blob/776c102f92905401613a83508d60744d41df7c73/src/iterator-c.cpp#L151



My bug can be reproduced using these steps:

git clone https://github.com/kimwalisch/primesieve.git
cd primesieve && mkdir build && cd build
git checkout 776c102f92905401613a83508d60744d41df7c73
CXXFLAGS="-O2 -Wall -Wextra -pedantic" cmake ..  -DBUILD_TESTS=ON
-DCMAKE_BUILD_TYPE=Debug -DWITH_MULTIARCH=ON  && make -j8
test/next_prime2

The test/next_prime2 will fail with the following error message:

terminate called after throwing an instance of 'primesieve::primesieve_error'
  what():  cannot generate primes > 2^64
Aborted



If I recompile without function multiversioning (-DWITH_MULTIARCH=OFF) the same
exception is caught successfully:

rm -rf *
CXXFLAGS="-O2 -Wall -Wextra -pedantic" cmake ..  -DBUILD_TESTS=ON
-DCMAKE_BUILD_TYPE=Debug -DWITH_MULTIARCH=OFF && make -j8
test/next_prime2

The test/next_prime2 completes successfully:

...
primesieve_iterator: cannot generate primes > 2^64
next_prime(18446744073709551615) = PRIMESIEVE_ERROR:   OK
primesieve_iterator: cannot generate primes > 2^64
next_prime(18446744073709551615) = PRIMESIEVE_ERROR:   OK

All tests passed successfully!



Clang also supports function multiversioning on Linux & x64 CPUs. And with
Clang this issue is not present, with Clang catching C++ exceptions thrown from
a multiarch-function works flawlessly (tested using Clang 14.0.0 on Ubuntu
22.10 x64):

rm -rf *
CXX=clang++ CC=clang CXXFLAGS="-O2 -Wall -Wextra -pedantic" cmake .. 
-DBUILD_TESTS=ON -DCMAKE_BUILD_TYPE=Debug -DWITH_MULTIARCH=ON && make -j8
test/next_prime2

The test/next_prime2 completes successfully:

...
primesieve_iterator: cannot generate primes > 2^64
next_prime(18446744073709551615) = PRIMESIEVE_ERROR:   OK
primesieve_iterator: cannot generate primes > 2^64
next_prime(18446744073709551615) = PRIMESIEVE_ERROR:   OK

All tests passed successfully!



Is this a known GCC issue? If needed I could also try to write a minimal test
that reproduces this issue.