Reenable compiling runtime-async versions of synchronous task-returning methods in crossgen2 by jtschuster · Pull Request #129474 · dotnet/runtime

jtschuster · 2026-06-16T17:18:54Z

Builds off #128384 to add crossgen2 support. I just want to validate the work in CI for now.

jtschuster · 2026-06-16T17:19:20Z

/azp run runtime-coreclr crossgen2-outerloop

azure-pipelines · 2026-06-16T17:19:26Z

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dotnet-policy-service · 2026-06-16T17:20:12Z

Tagging @dotnet/jit-contrib for JIT-EE GUID update

jtschuster · 2026-06-16T17:20:44Z

/azp run runtime-coreclr crossgen2 outerloop

azure-pipelines · 2026-06-16T17:20:56Z

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Copilot

Pull request overview

This PR extends the “runtime async version” work (async calling convention variants of synchronous Task/ValueTask-returning methods) to support crossgen2/ReadyToRun and NativeAOT scenarios by (1) tagging such methods as “async versions” while reusing the original IL, and (2) synthesizing an await/unwrapping call at returns so the async version’s signature matches the original IL behavior.

Changes:

Introduces a new JIT/EE interface query (getAwaitReturnCall) plus a new CORINFO_ASYNC_VERSION option to let the JIT compile async-version methods using the non-async IL and wrap return values appropriately.
Updates JIT importer + interpreter + AOT toolchain (R2R/NativeAOT IL providers and scanners) to recognize async-version compilation and the new await-return wrapper call.
Adds CoreLib helper overloads (AsyncHelpers.TransparentAwaitWithResult*) used by the JIT/EE to implement the return-value unwrap.

Reviewed changes

Copilot reviewed 52 out of 52 changed files in this pull request and generated 4 comments.

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File	Description
src/tests/nativeaot/SmokeTests/UnitTests/UnitTests.csproj	Removes explicit `runtime-async=on` feature flag from NativeAOT smoke test project.
src/tests/async/reflection/reflection.cs	Adds an async test variant for unsafe accessor invocation paths.
src/libraries/Directory.Build.targets	Removes conditional `runtime-async=on` feature injection for libraries builds.
src/coreclr/vm/prestub.cpp	Adjusts async-variant IL header resolution logic for new async-version handling.
src/coreclr/vm/method.inl	Refines `IsDiagnosticsHidden` behavior for async thunk/async-version scenarios.
src/coreclr/vm/method.hpp	Adds `SupportsAsyncVersionCodegen()` and updates IL-header availability rules for async thunks.
src/coreclr/vm/metasig.h	Adds metasig definitions for the new `TransparentAwaitWithResult*` overloads.
src/coreclr/vm/jitinterface.h	Adds helpers for runtime lookup construction and await-call lookup support.
src/coreclr/vm/jitinterface.cpp	Implements `getAwaitReturnCall`, factors runtime lookup finishing, and adjusts IL sourcing for async versions.
src/coreclr/vm/corelib.h	Adds CoreLib binder entries for `TransparentAwaitWithResult*` overloads.
src/coreclr/vm/asyncthunks.cpp	Removes legacy async thunk emitter path; keeps return-dropping thunk generation.
src/coreclr/tools/superpmi/superpmi/icorjitinfo.cpp	Plumbs `getAwaitReturnCall` through SuperPMI replay.
src/coreclr/tools/superpmi/superpmi-shim-simple/icorjitinfo_generated.cpp	Adds shim forwarding for `getAwaitReturnCall`.
src/coreclr/tools/superpmi/superpmi-shim-counter/icorjitinfo_generated.cpp	Adds shim counting + forwarding for `getAwaitReturnCall`.
src/coreclr/tools/superpmi/superpmi-shim-collector/icorjitinfo.cpp	Records/replays `getAwaitReturnCall` in collector shim.
src/coreclr/tools/superpmi/superpmi-shared/spmirecordhelper.h	Makes restore helpers take `const&` and updates lookup restore signatures.
src/coreclr/tools/superpmi/superpmi-shared/methodcontext.h	Adds MethodContext packet + APIs for `getAwaitReturnCall`.
src/coreclr/tools/superpmi/superpmi-shared/methodcontext.cpp	Implements recording/replay plumbing for `getAwaitReturnCall`.
src/coreclr/tools/superpmi/superpmi-shared/lwmlist.h	Adds LWM entry for `GetAwaitReturnCall`.
src/coreclr/tools/superpmi/superpmi-shared/agnostic.h	Adds agnostic representations for `CORINFO_LOOKUP` and await-return results.
src/coreclr/tools/Common/TypeSystem/IL/Stubs/AsyncThunks.cs	Removes managed-side async thunk emitter path now replaced by async-version codegen.
src/coreclr/tools/Common/TypeSystem/IL/NativeAotILProvider.cs	Wraps IL for async variants generically via `AsyncMethodIL` instead of specialized Ecma-only wrapper.
src/coreclr/tools/Common/TypeSystem/IL/EcmaMethodIL.cs	Updates `EcmaMethodILScope` to accept `MethodDesc` to support async variants.
src/coreclr/tools/Common/JitInterface/ThunkGenerator/ThunkInput.txt	Adds `getAwaitReturnCall` to thunk-generator input.
src/coreclr/tools/Common/JitInterface/CorInfoTypes.cs	Adds `CORINFO_ASYNC_VERSION` option bit.
src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs	Implements toolchain-side `getAwaitReturnCall` and sets `CORINFO_ASYNC_VERSION` option when needed.
src/coreclr/tools/Common/JitInterface/CorInfoImpl_generated.cs	Plumbs `getAwaitReturnCall` through generated callback surface.
src/coreclr/tools/Common/Compiler/MethodExtensions.cs	Adds `SupportsAsyncVersionCodegen` extension helper for toolchain decisions.
src/coreclr/tools/Common/Compiler/AsyncMethodVariant.cs	Adds `RequiresSaveRestoreOfAsyncContexts` helper for dependency reporting decisions.
src/coreclr/tools/aot/jitinterface/jitinterface_generated.h	Plumbs `getAwaitReturnCall` into the AOT jitinterface wrapper.
src/coreclr/tools/aot/ILCompiler.RyuJit/JitInterface/CorInfoImpl.RyuJit.cs	Refactors `ComputeLookup` to accept explicit “isInlining” and adjusts behavior accordingly.
src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs	Updates type check to the renamed `AsyncMethodIL`.
src/coreclr/tools/aot/ILCompiler.ReadyToRun/IL/ReadyToRunILProvider.cs	Replaces `AsyncEcmaMethodIL` with `AsyncMethodIL` wrapper delegating to wrapped IL.
src/coreclr/tools/aot/ILCompiler.ReadyToRun/Compiler/ReadyToRunCodegenCompilation.cs	Seeds tokens for `TransparentAwaitWithResult*` overloads used by synthesized calls.
src/coreclr/tools/aot/ILCompiler.ReadyToRun/Compiler/ExternalReferenceTokenManager.cs	Ensures token availability for methods/types with type instantiation.
src/coreclr/tools/aot/ILCompiler.Compiler/IL/ILImporter.Scanner.cs	Tracks tail-await patterns for async-version methods and adds dependencies for return-wrapping await calls.
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/Dataflow/AsyncMaskingILProvider.cs	Adjusts masking logic to apply to async variants regardless of `IsAsync`.
src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj	Removes explicit `runtime-async=on` features injection.
src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.CoreCLR.cs	Adds `TransparentAwaitWithResult*` helper overloads used by the synthesized await-return call.
src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj	Removes `runtime-async=on` features injection (and normalizes leading BOM/whitespace).
src/coreclr/jit/importercalls.cpp	Adjusts async call setup for async-version inlining/tail-await semantics.
src/coreclr/jit/importer.cpp	Adds async-version recognition, tail-await flagging, and return-value await wrapping via `getAwaitReturnCall`.
src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp	Adds wrapper for `getAwaitReturnCall`.
src/coreclr/jit/ICorJitInfo_names_generated.h	Adds API name entry for `getAwaitReturnCall`.
src/coreclr/jit/compiler.h	Adds `PREFIX_IS_ASYNC_VERSION_TAIL_AWAIT`, `impWrapTopOfStackInAwait`, and `compIsAsyncVersion`.
src/coreclr/jit/compiler.cpp	Prints diagnostics when compiling an async-version method.
src/coreclr/interpreter/compiler.h	Adds async-version tracking and await-wrapping helpers to interpreter compiler.
src/coreclr/interpreter/compiler.cpp	Implements async-version return wrapping and related peephole recognition in interpreter path.
src/coreclr/inc/jiteeversionguid.h	Updates JIT/EE interface version GUID for the new interface method.
src/coreclr/inc/icorjitinfoimpl_generated.h	Adds `getAwaitReturnCall` to the EE’s generated `ICorJitInfo` implementation surface.
src/coreclr/inc/corinfo.h	Adds `CORINFO_ASYNC_VERSION` and the `getAwaitReturnCall` interface method.
eng/testing/tests.targets	Removes conditional `runtime-async=on` feature injection for test builds.

Currently crossgen2 skips methods where SupportsAsyncVersionCodegen() is true (IsAsyncVariant() && IsAsyncThunk()), emitting a wrapper thunk instead of compiling the real async body. This enables full R2R compilation of them: - CorInfoImpl.ReadyToRun.cs: remove the SupportsAsyncVersionCodegen() skip in ShouldSkipCompilation. - CorInfoImpl.cs Get_CORINFO_METHOD_INFO: set CORINFO_ASYNC_VERSION for R2R too (was NativeAOT-only) so the JIT runs the async-version import path. - CorInfoImpl.cs getAwaitReturnCall: implement the R2R path (was returning null). For the generic await case, emit a MethodDictionary ReadyToRunHelper const lookup; the runtime-determined case defers to the runtime JIT (TODO-Async). - ExternalReferenceTokenManager / ReadyToRunCodegenCompilation: pre-seed manifest tokens for the AsyncHelpers.TransparentAwaitWithResult overloads, which the JIT synthesizes calls to in getAwaitReturnCall and which therefore have no IL token in the caller. Validated: full async test tree with --runcrossgen2tests (87 passed, 0 failed, 1 pre-existing skip); covariant-returns crossgens to a valid R2R image. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Per review feedback: seed the TransparentAwaitWithResult overloads in the same place the getAsyncInfo references are seeded (AddNecessaryAsyncReferences) instead of a separate ExternalReferenceTokenManager method. They are folded into the single batched EnsureDefTokensAreAvailable call. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…licit signatures Per review feedback: instead of enumerating AsyncHelpers methods by name, add the four TransparentAwaitWithResult overloads to the requiredMethods list using GetKnownMethod with explicit MethodSignatures, mirroring how CorInfoImpl.getAwaitReturnCall constructs them (Task/ValueTask and their generic forms). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

jtschuster · 2026-06-30T17:08:58Z

/azp run runtime-coreclr crossgen2 outerloop

azure-pipelines · 2026-06-30T17:09:08Z

Azure Pipelines successfully started running 1 pipeline(s).

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

jakobbotsch

LGTM! Thanks for helping on this.

…ter/async-crossgen2-codegen-v2

The await-return call synthesized in impWrapTopOfStackInAwait (AsyncHelpers.TransparentAwaitWithResult) never had its Ready-to-Run entry point set, unlike the seven sibling synthesized async calls in async.cpp. As a result IsR2RRelativeIndir() was false for it, so on arm64 fgMorphCall omitted the WellKnownArg::R2RIndirectionCell (x11) argument that the ReadyToRun DelayLoad helpers require. At runtime the arm64 DelayLoad_Helper then read a stale x11 as pCell, tripping the GetDataRva "Data pointer is outside of loaded image" assert. x64 is unaffected because it recovers the indirection cell by disassembling the call site rather than from a register. Fix: give the synthesized await call its R2R entry point explicitly by reusing the existing async.cpp helper SetCallEntrypointForR2R (exposed via a prototype in compiler.h, matching the dumpConvertedVarSet precedent). The helper self-guards on FEATURE_READYTORUN / IsReadyToRun(), so the importer call site needs no extra guard and the change is a no-op on x64. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

jtschuster · 2026-07-02T19:53:58Z

/azp run runtime-coreclr crossgen2 outerloop

azure-pipelines · 2026-07-02T19:54:09Z

Azure Pipelines successfully started running 1 pipeline(s).

jakobbotsch · 2026-07-02T20:03:04Z

This test should also be reenabled:

runtime/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/R2RTestSuites.cs

Lines 1178 to 1185 in 92a20b9

    
           /// <summary> 
        
           /// Composite + runtime-async caller awaiting a NON-runtime-async virtual callee that the JIT 
        
           /// devirtualizes to a sealed receiver. Resolving the callee's async-variant thunk must unwrap it 
        
           /// to the underlying EcmaMethod. 
        
           /// </summary> 
        
           [Fact] 
        
           [ActiveIssue("https://github.com/dotnet/runtime/issues/129524")] 
        
           public void CompositeAsyncDevirtNonAsyncCallee()

The callee virtuals are trivial no-op thunks. Under --optimize the JIT devirtualizes and inlines the async-variant thunk into the caller, so no standalone async-variant callee body is emitted and the test's HasAsyncVariant check fails. Mark both virtuals [MethodImpl(NoInlining)] so crossgen2 emits the callee's async-variant thunk as a standalone method, exercising the devirtualized-method token resolution path this test targets. Remove the [ActiveIssue(129524)] now that it passes. Also apply a whitespace-only jit-format realignment in importer.cpp. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

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Copilot AI review requested due to automatic review settings June 16, 2026 17:18

github-actions Bot added the area-crossgen2-coreclr only use for closed issues label Jun 16, 2026

jtschuster added area-ReadyToRun and removed area-crossgen2-coreclr only use for closed issues labels Jun 16, 2026

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jtschuster mentioned this pull request Jun 17, 2026

Reenable compiling async variants of non-async functions in crossgen2 #129524

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jtschuster force-pushed the jtschuster/async-crossgen2-codegen branch from 19a8732 to e881f61 Compare June 25, 2026 17:51

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Comment thread src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs Outdated

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Comment thread ...ols/aot/ILCompiler.ReadyToRun/Compiler/DependencyAnalysis/ReadyToRun/ILBodyFixupSignature.cs

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Comment thread src/coreclr/tools/Common/Compiler/AsyncMethodVariant.cs Outdated

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings June 30, 2026 17:06

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jtschuster changed the title ~~[No Review] Test crossgen2 compiling runtime async versions of synchronous task-returning methods~~ Reenable compiling runtime-async versions of synchronous task-returning methods in crossgen2 Jun 30, 2026

jtschuster marked this pull request as ready for review June 30, 2026 17:09

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Merge branch 'main' of https://github.com/dotnet/runtime into jtschus…

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…ter/async-crossgen2-codegen-v2

jtschuster linked an issue Jun 30, 2026 that may be closed by this pull request

Reenable compiling async variants of non-async functions in crossgen2 #129524

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build-analysis Bot mentioned this pull request Jul 3, 2026

ILC failing with exit code 139 for risc-v build #130145

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jtschuster merged commit 2c05d04 into dotnet:main Jul 3, 2026
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[main] Source code updates from dotnet/runtime dotnet/dotnet#7544

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