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.
