[Mono-dev] AOT and generics

[Rodrigo Kumpera]

You need to correctly drive the FullAOT compiler.
Why do you want to use FullAOT anyway?
Do you plan to run it on a target that disables JIT?
Do you hold a license that allows you to do so? Mono is LGPL and FullAOT
doesn't work with it.

On Fri, Jul 6, 2012 at 9:29 AM, Virgile Bello <virgile.bello at gmail.com>wrote:

> During full AOT, It seems that if generics is a ref type, AOT is skipped
> (which makes sense because most of the time it is not necessary, one
> codegen for any ref type is usually enough).
> However, if the class internally uses a struct based on the generic types,
> it will fail at runtime.
> Here is a simple example showcasing the issue:
>
> public class B
> {
>     public void Test<T>()
>     {
>         System.Console.WriteLine(typeof(T));
>     }
> }
>
> public class A<T>
> {
>     public void Test()
>     {
>         new B().Test<System.Collections.Generic.KeyValuePair<T, T>>();
>     }
> }
>
>
> class P
> {
>     static void Main(string[] args)
>     {
>         new A<int>().Test();
>         new A<string>().Test();
>     }
> }
>
> If I run this program with full aot, it will fail.
> new A<int> will work (AOT forced because value type)
> However, new A<string> will generate a JIT exception (because even though
> string is a ref type, A should be AOT for this specific type because
> KeyValuePair inside A<T> needs to be JITed.)
>
> But maybe I misunderstood the problem (or it is just a specific bug),
> because this other case actually work (I was expecting it to have the same
> issue):
>
> public class B
> {
>     public void Test<T>()
>     {
>
> System.Console.WriteLine(typeof(System.Collections.Generic.KeyValuePair<T,
> T>));
>     }
> }
>
> public class A<T>
> {
>     public void Test()
>     {
>         new B().Test<T>();
>     }
> }
>
>
> class P
> {
>     static void Main(string[] args)
>     {
>         new A<int>().Test();
>         new A<string>().Test();
>     }
> }
>
> Just wanted to check if I understood the issue right and if there would be
> nothing preventing from fixing it?
> I wouldn't mind taking a look at the sources by myself if necessary.
>
> Virgile
>
>
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>
>
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