[release/10.0] Fix RoslynAnalyzer crash on indexer property parameters#121861
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agocke merged 2 commits intorelease/10.0from Dec 5, 2025
Merged
[release/10.0] Fix RoslynAnalyzer crash on indexer property parameters#121861agocke merged 2 commits intorelease/10.0from
agocke merged 2 commits intorelease/10.0from
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Co-authored-by: sbomer <787361+sbomer@users.noreply.github.com>
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[WIP] Backport runtime fix from PR 121603 to release/10.0
Backport PR #121603: Fix RoslynAnalyzer crash on indexer property parameters
Nov 20, 2025
sbomer
approved these changes
Dec 1, 2025
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Pull request overview
This is a backport that fixes a crash in the RoslynAnalyzer when analyzing indexer property parameters. The analyzer previously assumed all parameters belong to methods, but Roslyn provides operation blocks for property indexer parameters which don't have a direct method equivalent in IL.
- Adds null guard in
GetParameterTargetValueto handle parameters not owned by methods - Returns
TopValuefor indexer parameters in their initializer context, preventing crashes - Adds comprehensive test coverage for annotated indexer parameters and default arguments
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/TrimAnalysisVisitor.cs | Adds null guard for parameterMethod in GetParameterTargetValue to prevent crash when analyzing indexer parameter initializers by returning TopValue for non-method parameters |
| src/tools/illink/test/Mono.Linker.Tests.Cases/DataFlow/PropertyDataFlow.cs | Adds test classes AnnotatedIndexerParameter and IndexerDefaultArgument to verify analyzer handles indexer parameters with DAM annotations and default arguments without crashing, with appropriate warning expectations |
jtschuster
approved these changes
Dec 1, 2025
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|
/ba-g failures are wasm workload build |
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Backport of #121603 to release/10.0
Customer Impact
Reported by customer in #121546
Regression
Regressed in .NET 10 by analyzer changes that touched related code.
Testing
Verified on the provided repro.
Risk
Low. Adds an early return to the analysis in a place that doesn't have downstream effects.
Backports #121603 to release/10.0. Fixes #121546.
The RoslynAnalyzer crashes when analyzing indexer property parameter initializers because it assumes all parameters belong to methods, but Roslyn provides operation blocks for property indexer parameters that don't have a direct IL equivalent.
Changes
TrimAnalysisVisitor.cs: Guard against null
parameterMethodinGetParameterTargetValue. ReturnsTopValuefor parameters not owned by methods (e.g., indexer parameter initializers), preventing crashes while preserving correct analysis for method parameters.PropertyDataFlow.cs: Add test coverage for annotated indexer parameters and indexers with default arguments to verify the analyzer handles these cases without crashing.
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