How to implement gcc __attribute__((constructor)) when compiling dynamic libraries under Linux

[aadog]

Description

How to implement gcc attribute((constructor)) when compiling dynamic libraries under Linux

Reproduction Steps

1.create classlib

2.dotnet publish -r linux-bionic-arm64 -p:DisableUnsupportedError=true -p:PublishAotUsingRuntimePack=true -p:RemoveSections=true

Expected behavior

gcc attribute((constructor))

Actual behavior

no init

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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[am11]

You can use module initializer for this purpose.

Publish a project with module initializer:

$ dotnet new classlib -n ModInitLib
$ cd ModInitLib
$ cat > Class1.cs <<EOF
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

public static class LibraryInitializer
{
    [ModuleInitializer]
    public static void Initialize()
    {
        Console.WriteLine("Library has been initialized (ModuleInitializer)!");
    }

    [UnmanagedCallersOnly(EntryPoint = "say_hello")]
    public static void SayHello()
    {
        Console.WriteLine("Hello from ModInitLib!");
    }
}
EOF

$ dotnet publish -p:PublishAot=true -p:TargetName=libModInitLib -o dist --ucr

Link with some executable code:

$ cat > glue.c <<EOF
#include <stdio.h>

void say_hello();

int main(void)
{
    say_hello();
    return 0;
}
EOF

$ cc -o glue glue.c -L./dist -lModInitLib
$ ./glue
Library has been initialized (ModuleInitializer)!
Hello from ModInitLib!