Enable root-relative ILLink task cache sharing by sbomer · Pull Request #135320 · dotnet/runtime

sbomer · 2026-10-07T00:43:17Z

Builds on #135886 to share eligible ILLink task cache entries across worktrees with equivalent layouts. Map declared source roots into stable cache identities while retaining full content hashing, and run single-root invocations from that root with structured relative arguments rather than rewriting raw command strings. Use the shared invocation cache for storage and restoration.

Caching remains opt-in, with compiler and symbol-preservation defaults unchanged. Unsupported inputs run uncached with their original arguments and working directory. This branch retains the already-merged resolver fix from #136249 because the current base predates it.

Validated both task targets, 355 task/shared-cache tests, 1,307 linker tests (30 existing skips), and 65 cache-maintenance tests on Linux. Real enclosing-root and disjoint-root cache hits matched uncached DLL/PDB bytes, including concurrent writers and SDK mapping probes. Windows/macOS execution and full runtime builds were not run.

Note

This pull request description was created with assistance from GitHub Copilot.

azure-pipelines · 2026-10-07T00:44:06Z

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.

Copilot

Copilot review overview

🟡 Changes recommended

Untracked assembly-resolution paths and Windows drive-root rewriting can produce unsound cache keys.

Review effort: Balanced
Findings: 2

Open (2)

Re-quoting drive roots changes Windows directory semantics · New
Cache misses path-shaped assembly dependencies from input metadata · New

What changed in this PR

Adds root-relative ILLink cache identities so equivalent worktrees can share eligible cached outputs.

Changes:

Maps source-root paths into stable cache keys and relative invocations.
Expands cache eligibility checks and input hashing.
Adds target wiring, documentation, and extensive tests.

File	Description
`LinkTask.cs`	Implements path mapping and cache validation.
`Microsoft.NET.ILLink.targets`	Forwards SDK source roots.
`Mock.cs`	Captures cache invocation details.
`ILLink.Tasks.Tests.cs`	Tests sharing, eligibility, and fallback behavior.
`eng/illink.targets`	Defines the runtime repository source root.
`sfx-finish.proj`	Forwards source roots for framework trimming.
`oob-trim.proj`	Forwards source roots for OOB trimming.
`illink-tasks.md`	Documents task behavior and configuration.
`task-cache.md`	Updates cache design decisions.

dotnet-policy-service · 2026-10-07T01:09:22Z

Tagging subscribers to this area: @agocke, @dotnet/illink
See info in area-owners.md if you want to be subscribed.

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

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

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

Map declared source roots into structured cache identity and use relative execution arguments for eligible single-root invocations. Retain full content hashing, conservative symbol and resolution checks, and original execution for uncached requests. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

Bypass unsupported escaped quotes, account for Unix ToolTask normalization, and strengthen disjoint-root coverage. Clarify the SDK mapping prerequisites without changing compilation defaults. Assisted-by: GitHub Copilot CLI:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

Retain the stricter ILLink identity diagnostics when exercising eligibility tests from the shared-cache extraction. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

) Treat path-shaped assembly-name strings as unresolved before constructing assembly-name references or consulting the loaded cache. This prevents name-based lookup from probing parent directories or other paths while preserving each caller's existing unresolved diagnostics and tolerant reflection probing. Explicit reference file paths and already-created assembly-name references retain their current behavior. Linux validation passed: 1,317 ILLink tests (including 175 focused resolver cases), 212 task tests, 33 cache-tool tests, and 1,135 analyzer tests, with 39 existing skips and no failures. ILTrim also builds successfully. Windows/macOS and the ILC/ILTrim test suites were not run. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 58eb5972-179d-44fb-8b71-3632cb35ab0c (cherry picked from commit 598d884)

Use analyzer-compliant path checks on both task targets and dispose the Cecil reader before rewriting the path-shaped-reference fixture. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

Copilot

🔵 Needs a closer look

Cross-worktree cache identity and platform-specific subprocess argument handling warrant maintainer review, especially with Windows and macOS execution unvalidated.

No open issues 🎉

_{Review effort: Balanced}

Copilot

🔵 Needs a closer look

Cross-worktree cache correctness relies on platform-specific path and symbol behavior that still warrants maintainer review and Windows/macOS validation.

No open issues 🎉

_{Review effort: Balanced}

Preserve root-aware cache identity while integrating the shared invocation cache changes. Assisted-by: GitHub Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Assisted-by: GitHub Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Keep cache orchestration in the shared adapter and let ILLink handle root and XML assembly-name validation. Retain metadata-reference and working-directory safeguards, and remove the redundant key version suffix. Assisted-by: GitHub Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Prepare the same root-relative invocation regardless of cache eligibility and reuse initialized SourceRoot items. Describe logical path identities for the shared key builder instead of duplicating serialization and hashing in ILLink. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Rely on full-content hashes to distinguish embedded checkout paths instead of rejecting those inputs. Remove scan-only machinery while retaining root mapping, input readability checks, and symbol eligibility checks. Cover identical-byte sharing and embedded-path invalidation. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Record input roles while generating execution arguments and logical cache context. Capture normalized file identities in InvocationDescription and extract source-root mapping from LinkTask. Remove override detection and assembly-name/module preflight restrictions; defer hashless linked-resource tracking. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

Resolve physical input and output locations through a reversible path map instead of retaining parallel path and identity inventories. Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

dotnet-policy-service Bot added the linkable-framework Issues associated with delivering a linker friendly framework label Oct 7, 2026

dotnet-policy-service Bot assigned sbomer Oct 7, 2026

github-project-automation Bot added this to AppModel Oct 7, 2026

sbomer requested a balanced review from Copilot October 7, 2026 00:45

Copilot started reviewing on behalf of sbomer October 7, 2026 00:46

View session

Copilot AI reviewed Oct 7, 2026

View reviewed changes

Comment thread src/tools/illink/src/ILLink.Tasks/LinkTask.cs Resolved

Comment thread src/tools/illink/src/ILLink.Tasks/LinkTask.cs Resolved

github-actions Bot added the area-Tools-ILLink .NET linker development as well as trimming analyzers label Oct 7, 2026

sbomer mentioned this pull request Oct 13, 2026

Add experimental ILLink task caching and cache maintenance #135065

Merged

Base automatically changed from sbomer/illink-task-cache to main October 14, 2026 17:01

sbomer and others added 11 commits October 15, 2026 11:52

sbomer changed the base branch from main to sbomer/illink-reject-path-shaped-resolution October 21, 2026 21:48

sbomer added this pull request to stack #136310 October 22, 2026 17:49

Base automatically changed from sbomer/illink-reject-path-shaped-resolution to main October 22, 2026 20:57

sbomer and others added 5 commits October 23, 2026 15:10

Preserve trailing backslashes in quoted ILLink arguments

c01c1c3

Assisted-by: Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: cf203c67-3550-4744-a063-3f1230546d53

sbomer force-pushed the sbomer/illink-cache-worktree-sharing branch from 78eb283 to 1dd380b Compare October 23, 2026 22:28

sbomer removed this pull request from stack #136310 October 23, 2026 22:29

sbomer changed the base branch from main to sbomer/shared-invocation-cache October 23, 2026 22:29

sbomer requested a balanced review from Copilot October 26, 2026 20:02

Copilot started reviewing on behalf of sbomer October 26, 2026 20:02

View session

Copilot AI reviewed Oct 26, 2026

View reviewed changes

This was referenced Oct 27, 2026

SendAsync_ConnectionFailure_RecordsActivitiesWithCorrectErrorInfo failed on macOS #133126

Open

Http3 tests failing with "An error occurred while sending the request." #136162

Closed

sbomer requested a balanced review from Copilot October 27, 2026 15:53

Copilot started reviewing on behalf of sbomer October 27, 2026 15:53

View session

Copilot AI reviewed Oct 27, 2026

View reviewed changes

Base automatically changed from sbomer/shared-invocation-cache to main October 29, 2026 17:34

sbomer and others added 4 commits October 29, 2026 10:55

Merge latest origin/main into illink-cache-worktree-sharing

f367a2f

Assisted-by: GitHub Copilot:gpt-6.1-sol Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: af970add-1797-4965-9c32-5230b3bf3400

This was referenced Nov 11, 2026

"We stopped hearing from agent Azure Pipelines 32. Verify the agent machine is running and has a healthy network connection" dotnet/dnceng#1886

Open

TensorExtensionsSpanInSpanOut<Single> test failure #135718

Open

sbomer and others added 3 commits November 11, 2026 11:53

This was referenced Nov 12, 2026

Checkout failure: "Git fetch failed with exit code 128" dotnet/arcade#9009

Open

Unable to checkout dotnet/dnceng#4115

Open

Runtime_133587 SIGSEGV in mono #133910

Open

Navigation Menu

Repository navigation

Enable root-relative ILLink task cache sharing - #135320

Enable root-relative ILLink task cache sharing#135320
sbomer wants to merge 26 commits into
mainfrom
sbomer/illink-cache-worktree-sharing

sbomer commented Oct 7, 2026 •

edited

Loading

Uh oh!

azure-pipelines Bot commented Oct 7, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

dotnet-policy-service Bot commented Oct 7, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI left a comment

Uh oh!

This branch has not been deployed

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

sbomer commented Oct 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

azure-pipelines Bot commented Oct 7, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🟡 Changes recommended

Uh oh!

Uh oh!

Uh oh!

dotnet-policy-service Bot commented Oct 7, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🔵 Needs a closer look

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🔵 Needs a closer look

Uh oh!

This branch has not been deployed

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

sbomer commented Oct 7, 2026 •

edited

Loading