[Bug c++/106627] New: Exception from multiversion function cannot be caught

["gcc.gnu at vvalter dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106627

            Bug ID: 106627
           Summary: Exception from multiversion function cannot be caught
           Product: gcc
           Version: 12.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc.gnu at vvalter dot com
  Target Milestone: ---

An exception thrown by a multiversioned function cannot be caught in the called
function. I expect the following program to exit with status code 0, but it
gets terminated because of an uncaught exception. With clang, the program works
as expected. According to godbolt.org it's also broken in gcc trunk and all
other versions that I checked: https://godbolt.org/z/564c6q8xo

__attribute__((target("default")))
void f() {
    throw 1;
}

__attribute__((target("sse4.2,bmi")))
void f() {
    throw 2;
}

int main()
{
    try {
        f();
    }
    catch(... )
    {
        return 0;
    }
    return 1;
}

Output of g++ -v:

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/12/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-gcc-major-version-only --enable-libstdcxx-backtrace
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--with-isl=/builddir/build/BUILD/gcc-12.1.1-20220507/obj-x86_64-redhat-linux/isl-install
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-offload-defaulted --enable-gnu-indirect-function --enable-cet
--with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
--with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.1.1 20220507 (Red Hat 12.1.1-1) (GCC)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' 'a-'
 /usr/libexec/gcc/x86_64-redhat-linux/12/cc1plus -E -quiet -v -D_GNU_SOURCE
bug.cpp -mtune=generic -march=x86-64 -fpch-preprocess -o a-bug.ii
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/12/include-fixed"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/12/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12

/usr/lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12/x86_64-redhat-linux
 /usr/lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12/backward
 /usr/lib/gcc/x86_64-redhat-linux/12/include
 /usr/local/include
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' 'a-'
 /usr/libexec/gcc/x86_64-redhat-linux/12/cc1plus -fpreprocessed a-bug.ii -quiet
-dumpdir a- -dumpbase bug.cpp -dumpbase-ext .cpp -mtune=generic -march=x86-64
-version -o a-bug.s
GNU C++17 (GCC) version 12.1.1 20220507 (Red Hat 12.1.1-1)
(x86_64-redhat-linux)
        compiled by GNU C version 12.1.1 20220507 (Red Hat 12.1.1-1), GMP
version 6.2.1, MPFR version 4.1.0-p13, MPC version 1.2.1, isl version
isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++17 (GCC) version 12.1.1 20220507 (Red Hat 12.1.1-1)
(x86_64-redhat-linux)
        compiled by GNU C version 12.1.1 20220507 (Red Hat 12.1.1-1), GMP
version 6.2.1, MPFR version 4.1.0-p13, MPC version 1.2.1, isl version
isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 2b1c93ff5f3b69a44b0e1b07f6437558
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' 'a-'
 as -v --64 -o a-bug.o a-bug.s
GNU assembler version 2.37 (x86_64-redhat-linux) using BFD version version
2.37-27.fc36
COMPILER_PATH=/usr/libexec/gcc/x86_64-redhat-linux/12/:/usr/libexec/gcc/x86_64-redhat-linux/12/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/12/:/usr/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/lib/gcc/x86_64-redhat-linux/12/:/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-redhat-linux/12/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' 'a.'
 /usr/libexec/gcc/x86_64-redhat-linux/12/collect2 -plugin
/usr/libexec/gcc/x86_64-redhat-linux/12/liblto_plugin.so
-plugin-opt=/usr/libexec/gcc/x86_64-redhat-linux/12/lto-wrapper
-plugin-opt=-fresolution=a.res -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --build-id
--no-add-needed --eh-frame-hdr --hash-style=gnu -m elf_x86_64 -dynamic-linker
/lib64/ld-linux-x86-64.so.2
/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64/crt1.o
/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64/crti.o
/usr/lib/gcc/x86_64-redhat-linux/12/crtbegin.o
-L/usr/lib/gcc/x86_64-redhat-linux/12
-L/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64 -L/lib/../lib64
-L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-redhat-linux/12/../../.. a-bug.o
-lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/lib/gcc/x86_64-redhat-linux/12/crtend.o
/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64/crtn.o
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' 'a.'