[llvm 20.1.2] [unknown-windows-msvc] The [[__gnu__::__init_priority__]]attribute causes the constructor of the global function to be called multiple times

[MacroModel]

The [[__gnu__::__init_priority__]] attribute causes the constructor of the global function to be called multiple times
This phenomenon only exists with target = unknown-windows-msvc.
In contrast unknown-windows-gnu (mingw) has no problems at all!

clang version:

clang version 20.1.2
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: D:\test\20250410\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin

global.cppm:

module;

#include <iostream>

export module global;

export namespace global {

    struct Test
    {
        Test()
        {
            ::std::cout<<"test\n";
        }
    };

    [[__gnu__::__init_priority__(500)]] // This attribute causes a bug, if you remove this attribute everything works fine!
    inline Test test{};
}

 .\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -Isrc -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-output=global.pcm" .\global.cppm

global1.cpp:

import global;

void test() {}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global1.cpp

global2.cpp:

import global;

int main()
{
    void test();
    test();
}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global2.cpp

link

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang++ -o test.exe .\global.o .\global1.o .\global2.o -m64 --target=x86_64-windows-msvc -g -nostdlib -lntdll -lShell32 -fuse-ld=lld --sysroot=D:\tool-chain\windows-msvc-sysroot

run

test
test

[MacroModel]

[llvmbot]

@llvm/issue-subscribers-c-20

Author: None (MacroModel)

The `[[__gnu__::__init_priority__]]` attribute causes the constructor of the global function to be called multiple times This phenomenon only exists with target = `unknown-windows-msvc`. In contrast `unknown-windows-gnu` (mingw) has no problems at all!

clang version:

clang version 20.1.2
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: D:\test\20250410\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin

global.cppm:

module;

#include <iostream>

export module global;

export namespace global {

    struct Test
    {
        Test()
        {
            ::std::cout<<"test\n";
        }
    };

    [[__gnu__::__init_priority__(500)]] // This attribute causes a bug, if you remove this attribute everything works fine!
    inline Test test{};
}

 .\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -Isrc -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-output=global.pcm" .\global.cppm

global1.cpp:

import global;

void test() {}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global1.cpp

global2.cpp:

import global;

int main()
{
    void test();
    test();
}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global2.cpp

link

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang++ -o test.exe .\global.o .\global1.o .\global2.o -m64 --target=x86_64-windows-msvc -g -nostdlib -lntdll -lShell32 -fuse-ld=lld --sysroot=D:\tool-chain\windows-msvc-sysroot

run

test
test

[llvmbot]

@llvm/issue-subscribers-clang-modules

Author: None (MacroModel)

The `[[__gnu__::__init_priority__]]` attribute causes the constructor of the global function to be called multiple times This phenomenon only exists with target = `unknown-windows-msvc`. In contrast `unknown-windows-gnu` (mingw) has no problems at all!

clang version:

clang version 20.1.2
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: D:\test\20250410\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin

global.cppm:

module;

#include <iostream>

export module global;

export namespace global {

    struct Test
    {
        Test()
        {
            ::std::cout<<"test\n";
        }
    };

    [[__gnu__::__init_priority__(500)]] // This attribute causes a bug, if you remove this attribute everything works fine!
    inline Test test{};
}

 .\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -Isrc -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-output=global.pcm" .\global.cppm

global1.cpp:

import global;

void test() {}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global1.cpp

global2.cpp:

import global;

int main()
{
    void test();
    test();
}

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang -c -Qunused-arguments -m64 --target=x86_64-windows-msvc -g -Wall -Wextra -Werror -O0 -std=c++26 -fms-runtime-lib=dll_dbg -DDEBUG -D_DEBUG -fexceptions -fcxx-exceptions -finput-charset=UTF-8 -fexec-charset=UTF-8 -Wno-braced-scalar-init --sysroot=D:\tool-chain\windows-msvc-sysroot -fno-rtti -fno-unwind-tables -march=native "-fmodule-file=global=global.pcm" .\global2.cpp

link

.\clang+llvm-20.1.2-x86_64-pc-windows-msvc\bin\clang++ -o test.exe .\global.o .\global1.o .\global2.o -m64 --target=x86_64-windows-msvc -g -nostdlib -lntdll -lShell32 -fuse-ld=lld --sysroot=D:\tool-chain\windows-msvc-sysroot

run

test
test

[AaronBallman]

I can confirm the issue happens for me on Windows, but only when you build with modules. Simplifying the reproducer to remove need for modules causes the issue to go away. CC @ChuanqiXu9 @Bigcheese