ARM64EC/ARM64X support for apphost, allowing one apphost to launch either x64 or ARM64 runtime

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#118,184 16 comments 1 reaction 0 assignees View on GitHub

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
25/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
csharp
Domain
build-system

Research direction

Start with dotnet/sdk#26647 and the referenced comment, then trace the dotnet publish path for framework-dependent apphost generation. The issue names no source files or tests; done means producing one AnyCPU executable that launches natively on x64 and ARM64, with validation points identified during investigation.

Written by the indexing model from the issue text.

Description

area-Host
Is your feature request related to a problem? Please describe.

dotnet/sdk#26647 highlights an important shortcoming in .NET: the inability to publish for AnyCPU. With the recent push for Windows on Arm, I think it's important to have an officially supported way of shipping AnyCPU executables. It's silly if .NET Framework can do it just fine, but the supposedly better, more modern version cannot.

There is some discussion there about the technical challenges for 32-bit x86, but I'd like to re-contextualize this issue to x64/ARM64, which is arguably more important for the future of the Windows ecosystem. The original issue has been untriaged for 3 years.

Describe the solution you'd like

Being able to dotnet publish a (framework-dependent) AnyCPU .exe file that runs natively on x64 and ARM64, ideally x86, too. How it's implemented behind the scenes or what PE headers it has is not important.

Additional context

Relying on dotnet myapp.dll doesn't play nice with tools that make decisions based on the .exe, such as Xbox Game Bar, GPU drivers, some application firewalls; the issue highlighted by this comment; and I'm sure many others.

Dominant language
C#
Stars
18.3k
Forks
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PR merge metrics
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