[WIP] Use CodeVersioning for EnC by rcj1 · Pull Request #130159 · dotnet/runtime

rcj1 · 2026-07-03T06:35:58Z

Implement existing runtime and cDAC functionality with EnC as a code version. Each subsequent edit corresponds to a single new ILCodeVersion with a single NativeCodeVersion.
EnC remains incompatible with ReJIT.
Added a Source field to ILCodeVersionNode to distinguish the sources.

dotnet-policy-service · 2026-07-03T06:37:34Z

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Pull request overview

This PR extends the existing code-versioning infrastructure so Edit-and-Continue (EnC) edits are represented as explicit IL code versions (distinct from ReJIT), and updates DAC/cDAC and debugger plumbing to treat only true ReJIT versions as ReJIT.

Changes:

Adds a “source” discriminator for IL code versions (ReJIT vs EnC) plus an EnC version counter, and threads this through CoreCLR, data descriptors, and cDAC contracts.
Updates ReJIT enumeration / DAC-facing ReJIT APIs to exclude EnC code versions (and excludes the synthetic default version from ReJIT ID enumeration).
Adjusts IL retrieval paths in legacy cDAC/DAC DBI paths to read IL from the active EnC code version where appropriate; updates/extends unit tests and contract docs.

Show a summary per file

File	Description
src/native/managed/cdac/tests/UnitTests/ReJITTests.cs	Updates expected ReJIT ID enumeration behavior and mocks `ICodeVersions.IsReJIT`.
src/native/managed/cdac/tests/UnitTests/MockDescriptors/MockDescriptors.CodeVersions.cs	Extends mock IL code version node layout with `Source`/`EnCVersion`; updates builder helpers.
src/native/managed/cdac/tests/UnitTests/CodeVersionsTests.cs	Adds coverage asserting EnC/default versions are excluded from ReJIT detection and enumeration.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.cs	Filters ReJIT-related legacy SOS DAC behaviors using `ICodeVersions.IsReJIT`.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.cs	Fetches IL from active EnC code version when available; filters IL code version node APIs to ReJIT only.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataFrame.cs	Uses active EnC IL for local signature parsing when applicable.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/ILCodeVersionNode.cs	Adds `Source` and `EnCVersion` fields to the ILCodeVersionNode contract data type.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/CodeVersions_1.cs	Implements `ICodeVersions.IsReJIT` based on the new `ILCodeVersionNode.Source`.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/ICodeVersions.cs	Introduces `public CodeVersionSource` and new `ICodeVersions.IsReJIT` API.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/Extensions/IReJITExtensions.cs	Filters ReJIT ID enumeration to true ReJIT versions via `cv.IsReJIT`.
src/coreclr/vm/rejit.cpp	Tags configured ReJIT IL code versions with `CodeVersionSource::kReJIT`; filters ReJIT ID queries.
src/coreclr/vm/method.hpp	Makes EnC IL methods versionable via CodeVersionManager; enforces EnC/ReJIT mutual exclusion.
src/coreclr/vm/method.cpp	Returns active EnC IL from CodeVersionManager in `MethodDesc::GetILHeader`.
src/coreclr/vm/encee.cpp	Creates/activates EnC IL code versions via CodeVersionManager; records source and EnC version.
src/coreclr/vm/datadescriptor/datadescriptor.inc	Adds `ILCodeVersionNode.Source` and `ILCodeVersionNode.EnCVersion` to the CDAC descriptor.
src/coreclr/vm/codeversion.h	Adds `CodeVersionSource` enum and stores `Source`/`EnCVersion` on `ILCodeVersionNode`.
src/coreclr/vm/codeversion.cpp	Implements `ILCodeVersion::IsReJIT` / `GetEnCVersion`, plus node accessors/mutators.
src/coreclr/debug/ee/functioninfo.cpp	Treats only ReJIT (not EnC) explicit versions as “rejitted” for boundary mapping behavior.
src/coreclr/debug/ee/debugger.cpp	Updates debugger ReJIT-related checks to ignore EnC versions; tags created versions as ReJIT.
src/coreclr/debug/daccess/request.cpp	Filters DAC ReJIT data paths to only ReJIT IL code versions.
src/coreclr/debug/daccess/dacdbiimpl.cpp	Uses CodeVersionManager to resolve EnC versions and EnC IL in DBI helper paths.
docs/design/datacontracts/CodeVersions.md	Documents the new `CodeVersionSource`/`IsReJIT` concepts (but needs an `EnCVersion` row added).

Copilot's findings

Files reviewed: 22/22 changed files
Comments generated: 4

+    public MockILCodeVersionNode AddILCodeVersionNode(ulong versionId, uint rejitFlags, bool deoptimized = false, uint source = 1 /* CodeVersionSource.ReJIT */, ulong encVersion = 0)
    {


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Copilot's findings

Files reviewed: 23/23 changed files
Comments generated: 6

Copilot

Copilot's findings

Comments suppressed due to low confidence (1)

src/coreclr/debug/daccess/request.cpp:4693

GetPendingReJITID now rejects the active ILCodeVersion unless ilVersion.IsReJIT() is true. However newly-requested ReJIT versions start in kStateRequested with CodeVersionSource still kUnknown (it isn't set until later in ConfigureILCodeVersion), so pending ReJIT queries will incorrectly return E_INVALIDARG. Reorder the checks to treat kStateRequested as a ReJIT-pending version even before Source is populated, and only use IsReJIT() to reject non-requested non-ReJIT (e.g., EnC) versions.

    CodeVersionManager::LockHolder codeVersioningLockHolder;
    ILCodeVersion ilVersion = pCodeVersionManager->GetActiveILCodeVersion(pMD);
    if (ilVersion.IsNull() || !ilVersion.IsReJIT())
    {
        hr = E_INVALIDARG;
    }
    else if (ilVersion.GetRejitState() == RejitFlags::kStateRequested)
    {

Files reviewed: 24/24 changed files
Comments generated: 3

Copilot

Copilot's findings

Files reviewed: 25/25 changed files
Comments generated: 4

+public enum CodeVersionSource : uint
+{
+    Unknown = 0,
+    ReJIT = 1,
+    EnC = 2,
+}


            _codeVersionsAllocator.Allocate((ulong)ILCodeVersioningStateLayout.Size, "ILCodeVersioningState"));

-    public MockILCodeVersionNode AddILCodeVersionNode(ulong versionId, uint rejitFlags, bool deoptimized = false, ulong ilAddress = 0)
+    public MockILCodeVersionNode AddILCodeVersionNode(ulong versionId, uint rejitFlags, bool deoptimized = false, uint source = 1 /* CodeVersionSource.ReJIT */, ulong encVersion = 0, ulong ilAddress = 0)


+| ILCodeVersionNode | Source | a `CodeVersionSource` value indicating what produced this version (ReJIT, EnC, or unknown) |
 | ILCodeVersionNode | InstrumentedILMap | Embedded `InstrumentedILOffsetMapping` describing the instrumented IL offset mapping |


+{
+    if (!ilCodeVersionHandle.IsExplicit)
+        return false;
+    return // node Source is ReJIT


jkotas · 2026-07-05T14:44:47Z

    Module *pModule = GetModule();

+#ifdef FEATURE_CODE_VERSIONING
+    if (InEnCEnabledModule())


Should both EnC and ReJIT be on the same plan? Either keep using dynamic IL to track last IL for both. Or drop dynamic IL for both and use dynamic IL for reflection emit only.

ReJIT already uses the code version to store IL. It looks like we had just never captured ReJIT IL here. We probably should

rcj1 added 2 commits July 2, 2026 22:35

use code versioning for EnC

b7b39ad

cdac updates

7805ced

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github-actions Bot added the area-Diagnostics-coreclr label Jul 3, 2026

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merge

f07a58c

fixes and adjust feature flag

e83c444

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fix ifdef

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rcj1 marked this pull request as ready for review July 4, 2026 16:00

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Comment thread src/coreclr/debug/daccess/dacdbiimpl.cpp

Comment thread ...anaged/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/ICodeVersions.cs

Comment thread src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.cs

rcj1 added 2 commits July 4, 2026 09:16

update eventtrace

573b352

copilot review

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jkotas reviewed Jul 5, 2026

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jkotas requested a review from noahfalk July 5, 2026 14:48

		public MockILCodeVersionNode AddILCodeVersionNode(ulong versionId, uint rejitFlags, bool deoptimized = false, uint source = 1 /* CodeVersionSource.ReJIT */, ulong encVersion = 0)
		{

		\| ILCodeVersionNode \| Source \| a `CodeVersionSource` value indicating what produced this version (ReJIT, EnC, or unknown) \|
		\| ILCodeVersionNode \| InstrumentedILMap \| Embedded `InstrumentedILOffsetMapping` describing the instrumented IL offset mapping \|

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