Extract shared invocation cache storage from ILLink by sbomer · Pull Request #135886 · dotnet/runtime

sbomer · 2026-10-15T19:08:00Z

Extracts ILLink's experimental invocation cache into shared sources, compiled into each consumer without adding a shared DLL. Tasks provide invocation descriptions and prepare their outputs before executing; the shared engine handles content hashing, lookup, restoration, storage, and purge. This intentionally goes beyond a mechanical extraction: the common output contract supports owned directories and file sets, records absent outputs, and uses checksummed manifests. That changes the experimental v1 entry format: existing entries are not reused, but remain purgable. #135446 builds on this infrastructure to add crossgen2 caching.

Replaces the ILLink-specific maintenance package and command with dotnet-build-cache, shared by both caches. Existing users should install that package instead of dotnet-illink-cache and replace dotnet illink-cache purge ... with dotnet build-cache purge --cache illink .... Commands already selecting an explicit directory can use dotnet build-cache purge --cache-directory <path> ... without a cache name. The cache-enablement environment variables are unchanged.

Validated independently on this branch: 287 ILLink/shared-cache tests and 65 maintenance-tool tests passed. Modern .NET and net472 task builds passed; net472 was built but not executed on Linux.

Note

This content was created with assistance from AI.

Keep ILLink configuration and input identity in the task while sharing entry validation, publication, directory restoration, and usage metadata. Preserve v1 serialization, mutex names, diagnostics, and purge semantics. Compile shared sources into consumers without adding a runtime assembly. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

azure-pipelines · 2026-10-15T19:08:54Z

Azure Pipelines: Successfully started running 4 pipeline(s). 12 pipeline(s) were filtered out due to trigger conditions. There may be pipelines that require an authorized user to comment /azp run to run.

dotnet-policy-service · 2026-10-15T19:09:14Z

Tagging subscribers to this area: @agocke, @dotnet/illink
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Reference the shared invocation cache entry metadata directly from the purge tool and tests. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Keep ILLink configuration and task tests in ILLink, and exercise storage with a tool-independent fixture. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Share opt-in parsing, cache-directory resolution, diagnostics, and construction while keeping ILLink eligibility and input identity in its task. Move configuration tests alongside the shared storage tests and preserve ILLink configuration behavior. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Share entry enumeration, last-used handling, deletion, diagnostics, and summary reporting with explicit layout and tool labels. Keep the ILLink CLI and idle-cache requirement unchanged. Move engine tests into shared sources and cover independent layouts while retaining CLI tests in the tool project. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Move restore-or-execute orchestration and successful-result storage into the shared cache sources. Keep ILLink eligibility, key computation and output preparation in task callbacks, preserving the existing directory-only v1 storage contract. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Describe inputs, context, and outputs independently of cache policy and compute content identities in the shared layer. Resolve cache configuration lazily and keep output preparation in normal tool execution, with cache-owned restoration on hits. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Preserve runtime library ExtraArgs input discovery in DescribeInvocation, including readable XML inputs and assembly search-directory inventories. Adapt bypass returns and diagnostic assertions to the extracted invocation-description contract. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Move the ILLink cache CLI into a standalone dotnet-build-cache tool. Support named ILLink and crossgen2 caches with explicit-directory, environment, and shared platform-default resolution, independently of task enablement. Update build, test, CI, and usage wiring and align tool-file identity coverage with explicit absence markers. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Use only the explicit cache directory in CI commands and the matching example. Explain that a cache name does not validate directory ownership when an explicit directory is supplied. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Copilot

🟡 Changes recommended

Invalid output declarations can trigger cleanup that deletes the configured cache.

3 open issues

What changed in this PR

Extracts ILLink caching into shared sources for reuse by crossgen2, without adding a shared DLL.

Changes:

Shares cache configuration, identity, execution, storage, and purge logic.
Adds file-set output contracts and manifest checksums.
Replaces the ILLink maintenance tool with BuildCache and updates tests, build integration, and documentation.

Builds and tests were not run during this review.

File	Description
src/tools/illink/test/ILLink.Tasks.Tests/Mock.cs	Uses shared key computation.
src/tools/illink/test/ILLink.Tasks.Tests/ILLink.Tasks.Tests.csproj	Includes shared cache tests.
src/tools/illink/test/ILLink.Tasks.Tests/ILLink.Tasks.Tests.cs	Updates task-specific cache coverage.
src/tools/illink/test/ILLink.CacheTool.Tests/ILLink.CacheTool.Tests.csproj	Removes old test project.
src/tools/illink/test/ILLink.CacheTool.Tests/CachePurgeTests.cs	Relocates purge tests.
src/tools/illink/src/ILLink.Tasks/LinkTask.cs	Delegates cache lifecycle to shared helpers.
src/tools/illink/src/ILLink.Tasks/ILLinkCache.cs	Removes task-specific storage implementation.
src/tools/illink/src/ILLink.Tasks/ILLink.Tasks.csproj	Compiles shared cache sources.
src/tools/illink/src/ILLink.CacheTool/README.md	Removes old tool documentation.
src/tools/illink/src/ILLink.CacheTool/Program.cs	Removes old command implementation.
src/tools/illink/src/ILLink.CacheTool/ILLink.CacheTool.csproj	Removes old tool project.
src/tools/illink/illink.slnx	References BuildCache projects.
src/tools/BuildCache/tests/CachePurgeTests.cs	Tests command parsing and cache selection.
src/tools/BuildCache/tests/BuildCache.Tests.csproj	Configures relocated tool tests.
src/tools/BuildCache/src/Program.cs	Implements shared maintenance command.
src/tools/BuildCache/src/BuildCache.csproj	Packages `dotnet-build-cache`.
src/tools/BuildCache/README.md	Documents maintenance and installation.
src/tasks/Common/InvocationCache/InvocationOutputs.cs	Defines output declarations.
src/tasks/Common/InvocationCache/InvocationInputs.cs	Defines input declarations.
src/tasks/Common/InvocationCache/InvocationDescription.cs	Groups invocation identity and outputs.
src/tasks/Common/InvocationCache/InvocationCachePurge.cs	Shares purge implementation.
src/tasks/Common/InvocationCache/InvocationCacheEntry.cs	Shares entry metadata.
src/tasks/Common/InvocationCache/InvocationCacheConfiguration.cs	Defines configuration and default paths.
src/tasks/Common/InvocationCache/InvocationCache.Outputs.cs	Validates and maps outputs.
src/tasks/Common/InvocationCache/InvocationCache.Identity.cs	Computes invocation fingerprints.
src/tasks/Common/InvocationCache/InvocationCache.cs	Implements shared lifecycle and storage.
src/tasks/Common/InvocationCache/InvocationCache.Configuration.cs	Reads cache environment settings.
src/tasks/Common/InvocationCache.Tests/InvocationCacheTests.cs	Tests shared storage and lifecycle.
src/tasks/Common/InvocationCache.Tests/InvocationCachePurgeTests.cs	Tests shared purge behavior.
eng/Subsets.props	Registers BuildCache build subsets.
eng/pipelines/coreclr/templates/purge-illink-cache.yml	Locates renamed maintenance tool.
docs/tools/illink/illink-tasks.md	Updates maintenance instructions.
docs/design/tools/illink/task-cache.md	Describes shared cache architecture.

_{Review effort: Balanced}

Let output validation exceptions propagate instead of falling back to normal execution, preserving the existing protection against overlapping cache and output directories. Cover rejected declarations and ILLink output cleanup with regression tests. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: da7cf090-9a92-453d-beb2-f672a9a7b541

Copilot

🔵 Needs a closer look

Expanded filesystem restoration and incompatible cache encoding warrant maintainer validation across supported platforms; builds and tests were not rerun in this review.

No open issues 🎉

1 previously missed issue

In code that hasn't changed since last review

Update API sketch and lifecycle docs for current cache contract

docs/design/tools/illink/task-cache.md:36

The API sketch and lifecycle paragraph describe an integration that the shared cache no longer exposes. TryCreateFromEnvironment takes InvocationCacheConfiguration; ILLink calls ExecuteCached with an InvocationDescription callback and a parameterless execution callback; restore/store take InvocationOutputs. The shared engine now computes the key from the task's input inventory and context. Update the signatures and ownership explanation together so additional consumers do not follow the obsolete callback contract.

3 resolved since last review

_{Review effort: Balanced}

Copilot

🔵 Needs a closer look

The expanded cache format and destructive output-restoration contract warrant cross-platform maintainer review; builds and tests were not run in this review.

1 open issue

Align API sketch and lifecycle explanation with implementation · New

_{Review effort: Balanced}

+    internal static int Execute(InvocationCache? cache, DateTime outputTimestampUtc,
+        Func<InvocationCacheRequest?> getInvocation, Func<string?, int> execute,
+        Action? onRestored = null);


github-actions Bot added the area-Tools-ILLink .NET linker development as well as trimming analyzers label Oct 15, 2026

dotnet-policy-service Bot added the linkable-framework Issues associated with delivering a linker friendly framework label Oct 15, 2026

dotnet-policy-service Bot assigned sbomer Oct 15, 2026

github-project-automation Bot added this to AppModel Oct 15, 2026

sbomer mentioned this pull request Oct 15, 2026

[Experimental] Add MSBuild task-level cache for crossgen2 invocations #135446

Draft

sbomer added this pull request to stack #135895 October 15, 2026 20:58

sbomer and others added 2 commits October 15, 2026 14:24

sbomer and others added 2 commits October 16, 2026 09:57

build-analysis Bot mentioned this pull request Oct 20, 2026

Test failure: BeginReceiveFrom_RemoteEpIsReturnedWhenCompletedSynchronously #134885

Open

sbomer and others added 4 commits October 21, 2026 11:57

sbomer requested a balanced review from Copilot October 21, 2026 20:28

Copilot started reviewing on behalf of sbomer October 21, 2026 20:29

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Copilot AI reviewed Oct 21, 2026

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Comment thread src/tasks/Common/InvocationCache/InvocationCache.cs Outdated

Comment thread src/tasks/Common/InvocationCache/InvocationCache.cs

Comment thread src/tools/BuildCache/src/BuildCache.csproj

This was referenced Oct 22, 2026

Crash: access violation in coreclr!PgoManager::getPgoInstrumentationResults during tier-1 background JIT (Windows x86) #134695

Open

SOS.Tests.DiagnosticCommandTests.DumpGcData tests failures #136190

Closed

sbomer requested a balanced review from Copilot October 22, 2026 17:51

Copilot started reviewing on behalf of sbomer October 22, 2026 17:52

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Copilot AI reviewed Oct 22, 2026

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sbomer requested a balanced review from Copilot October 22, 2026 19:51

Copilot started reviewing on behalf of sbomer October 22, 2026 19:51

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Copilot AI reviewed Oct 22, 2026

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Comment thread docs/design/tools/illink/task-cache.md

Comment on lines +34 to +36

internal static int Execute(InvocationCache? cache, DateTime outputTimestampUtc,

Func<InvocationCacheRequest?> getInvocation, Func<string?, int> execute,

Action? onRestored = null);

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Extract shared invocation cache storage from ILLink - #135886

Extract shared invocation cache storage from ILLink#135886
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sbomer commented Oct 15, 2026 •

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