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stephentoub merged 9 commits into from
Jan 7, 2026
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Remove NET9_0_OR_GREATER and NET10_0_OR_GREATER preprocessor constants #122953

stephentoub merged 9 commits into from
Jan 7, 2026

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Copilot AI commented Jan 7, 2026 •
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Cleanup of .NET Version Constants

The repo no longer builds for .NET Core versions older than 10. This PR removes obsolete version-specific preprocessor constants (NET9_0_OR_GREATER, NET10_0_OR_GREATER).

Strategy

For files that only build for .NET 10+ runtime (System.Private.CoreLib):

  • Replace #if NET9_0_OR_GREATER / #if NET10_0_OR_GREATER with #if NET
  • This is needed because these files are also compiled by packages like Microsoft.Bcl.AsyncInterfaces which target netstandard/netframework

For files in netcore directories or ending in netcore.cs:

  • These are .NET Core only, so #if NET checks are removed entirely and code is made unconditional
  • Fixed formatting where lines were awkwardly split due to removed #if directives

For other files that also build for netstandard/netframework:

  • Replaced NET9_0_OR_GREATER / NET10_0_OR_GREATER with just NET
  • This maintains the distinction between .NET Core and netstandard/netframework
  • Conditions use #if NET ... #else ... #endif structure

For test files:

  • Replaced NET9_0_OR_GREATER / NET10_0_OR_GREATER with NET since test projects target both .NET Core and .NET Framework

Files Changed

Source files:

  • System.Private.CoreLib Base64 helpers, IAsyncEnumerable/IAsyncEnumerator, ConfiguredCancelableAsyncEnumerable
  • Common/src crypto helpers (HexConverter uses #if NET ... #else structure)
  • Microsoft.Bcl.Cryptography, Microsoft.Bcl.Memory
  • Microsoft.Extensions.Caching, Configuration.Binder, DependencyInjection, Options
  • System.Collections.Immutable, Diagnostics.DiagnosticSource, DirectoryServices.Protocols
  • System.Formats.Asn1, System.Formats.Nrbf, System.Numerics.Tensors (netcore files updated with clean formatting)
  • System.Security.Cryptography.Pkcs/Xml, System.Text.Json, System.Threading.Channels
  • Reference assemblies
  • Test baseline files for Microsoft.Extensions.Options source generators

Test files:

  • Common/tests/System/Security/Cryptography/ByteUtils.cs
  • Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderPkcs12Tests.cs
  • Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderPkcs12CollectionTests.cs
  • Microsoft.Extensions.Caching.Memory/tests/AltLookupTests.cs
  • System.Formats.Asn1/tests/Writer/*.cs
  • System.Text.Json/tests/Common/MetadataTests.cs
  • System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/Serialization/MetadataTests.cs
  • System.Text.Json/tests/System.Text.Json.SourceGeneration.Unit.Tests/JsonSourceGeneratorDiagnosticsTests.cs

Note: Searched for older version constants (NET8_0_OR_GREATER, NET7_0_OR_GREATER, NET6_0_OR_GREATER, etc.) - none were found in the source files.

Original prompt

This repo no longer builds for .NET Core versions older than 10. As such, search for all occurrences of compilation constants like NET10_0_OR_GREATER, NET9_0_OR_GREATER, etc. If they're in files that also build for netstandard, replace them with just NET. If they're in files that only build for .NET 10+, whatever is protected by those constants can be unconditionally included, and anything po

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Copilot AI and others added 2 commits January 7, 2026 02:02
@stephentoub
Remove NET9_0_OR_GREATER and NET10_0_OR_GREATER from System.Private.C…
75f6e00 
…oreLib

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
@stephentoub
Replace NET9_0_OR_GREATER and NET10_0_OR_GREATER with NET in libraries
91a0aa3 
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
Copilot AI changed the title [WIP] Update compilation constants for .NET Core versioning Remove NET9_0_OR_GREATER and NET10_0_OR_GREATER preprocessor constants Jan 7, 2026
Copilot AI requested a review from stephentoub January 7, 2026 02:20
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stephentoub commented Jan 7, 2026

@copilot, what about NET8_0_OR_GREATER, NET7_0_OR_GREATER, NET6_0_OR_GREATER, etc. Any of those that also need to be cleaned up?

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Copilot AI commented Jan 7, 2026

@copilot, what about NET8_0_OR_GREATER, NET7_0_OR_GREATER, NET6_0_OR_GREATER, etc. Any of those that also need to be cleaned up?

I searched for NET8_0_OR_GREATER, NET7_0_OR_GREATER, NET6_0_OR_GREATER, and other older version constants in src/libraries/ (excluding tests, baselines, and gen folders). No occurrences were found - it appears those were already cleaned up previously or never existed in the source files that needed updating.

Copilot AI requested a review from stephentoub January 7, 2026 02:45
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stephentoub commented Jan 7, 2026

@copilot, there are build failures, e.g.

Build FAILED.

D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Runtime\CompilerServices\ConfiguredCancelableAsyncEnumerable.cs(13,26): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=netstandard2.0]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Collections\Generic\IAsyncEnumerable.cs(11,26): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=netstandard2.0]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Collections\Generic\IAsyncEnumerator.cs(11,27): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=netstandard2.0]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Threading\Tasks\TaskAsyncEnumerableExtensions.cs(26,30): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=netstandard2.0]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Threading\Tasks\TaskAsyncEnumerableExtensions.cs(36,30): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=netstandard2.0]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Runtime\CompilerServices\ConfiguredCancelableAsyncEnumerable.cs(13,26): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=net462]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Collections\Generic\IAsyncEnumerable.cs(11,26): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=net462]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Collections\Generic\IAsyncEnumerator.cs(11,27): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=net462]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Threading\Tasks\TaskAsyncEnumerableExtensions.cs(26,30): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=net462]
D:\a\_work\1\s\src\libraries\System.Private.CoreLib\src\System\Threading\Tasks\TaskAsyncEnumerableExtensions.cs(36,30): error CS9240: Target runtime doesn't support by-ref-like generics. [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.AsyncInterfaces\src\Microsoft.Bcl.AsyncInterfaces.csproj::TargetFramework=net462]
D:\a\_work\1\s\src\libraries\Common\src\System\HexConverter.cs(235,27): error CS9244: The type 'HexConverter.SpanCasingPair' may not be a ref struct or a type parameter allowing ref structs in order to use it as parameter 'TState' in the generic type or method 'string.Create<TState>(int, TState, SpanAction<char, TState>)' [D:\a\_work\1\s\src\libraries\Microsoft.Bcl.Cryptography\src\Microsoft.Bcl.Cryptography.csproj::TargetFramework=netstandard2.1]
    0 Warning(s)
    11 Error(s)

@stephentoub
Remove #if NET from netcore-only files that are always .NET Core
968297f 
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
@stephentoub
Fix build failures: restore #if NET guards for allows ref struct in s…
156bd27 
…hared files

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
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Copilot AI commented Jan 7, 2026

@copilot, there are build failures, e.g.

Build FAILED.

...

Fixed in 156bd27. The issue was that files like IAsyncEnumerable.cs, IAsyncEnumerator.cs, ConfiguredCancelableAsyncEnumerable.cs, and TaskAsyncEnumerableExtensions.cs are shared with Microsoft.Bcl.AsyncInterfaces which targets netstandard2.0 and net462. I incorrectly removed the #if NET9_0_OR_GREATER guards entirely instead of replacing them with #if NET. These files now correctly use #if NET to protect the allows ref struct constraint.

@stephentoub stephentoub marked this pull request as ready for review January 7, 2026 04:27
Copilot AI review requested due to automatic review settings January 7, 2026 04:27
Copilot AI reviewed Jan 7, 2026
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Pull request overview

This PR performs a systematic cleanup of obsolete .NET version-specific preprocessor constants (NET9_0_OR_GREATER and NET10_0_OR_GREATER) since the repository no longer builds for .NET versions older than 10. The changes follow a clear strategy based on file location and target frameworks.

Key changes:

  • System.Private.CoreLib files: Replace version constants with #if NET to maintain compatibility with packages targeting netstandard/netframework
  • Files in netcore directories or ending in netcore.cs: Remove conditionals entirely as they only build for .NET Core
  • Other multi-target files: Replace with #if NET to distinguish between .NET Core and netstandard/netframework

Reviewed changes

Copilot reviewed 89 out of 89 changed files in this pull request and generated no comments.

Show a summary per file
File Description
System.Threading.Channels/AsyncOperation.cs Replaced NET9_0_OR_GREATER with NET for bool/int field type selection
System.Text.Json/EnumConverter.cs Replaced NET9_0_OR_GREATER with NET for alternate lookup APIs
System.Text.Json/JsonHelpers.cs Replaced NET9_0_OR_GREATER with NET for dictionary alternate lookup
System.Security.Cryptography.Xml/SignedXmlDebugLog.cs Replaced NET9_0_OR_GREATER with NET for ToHexStringLower usage
System.Security.Cryptography.Pkcs/SignerInfo.cs Replaced NET9_0_OR_GREATER with NET for AsnWriter.Encode callback
System.Private.CoreLib (IAsyncEnumerable/Enumerator) Replaced NET9_0_OR_GREATER/NET10_0_OR_GREATER with NET for ref struct constraints
System.Private.CoreLib/Base64 helpers Removed NET9_0_OR_GREATER conditionals around CompExactlyDependsOn attributes and ARM intrinsics
System.Numerics.Tensors/netcore files Removed all version conditionals as these only build for .NET Core
System.Numerics.Tensors reference assembly Replaced NET9_0_OR_GREATER with NET for allows ref struct constraints
System.Formats.Nrbf/Asn1 Replaced NET9_0_OR_GREATER/NET10_0_OR_GREATER with NET
System.DirectoryServices.Protocols Replaced NET10_0_OR_GREATER with NET for Obsolete attributes
System.Diagnostics.DiagnosticSource Replaced NET9_0_OR_GREATER with NET for Activity/MeterListener
System.Collections.Immutable Replaced NET9_0_OR_GREATER with NET for allows ref struct constraints
Microsoft.Extensions.* Replaced version constants with NET for various features
Microsoft.Bcl.* Replaced version constants and adjusted type forwards
Common/src/System Replaced NET10_0_OR_GREATER with NET in crypto helpers and HexConverter

All changes appear to be systematic and consistent with the stated strategy. The PR correctly maintains compatibility for packages that target netstandard/netframework while simplifying conditional compilation for .NET Core-only code.

stephentoub
stephentoub reviewed Jan 7, 2026
View reviewed changes
@stephentoub
Fix HexConverter build failure and update test baselines to use NET i…
461104d 
…nstead of NET10_0_OR_GREATER

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
Copilot AI requested a review from stephentoub January 7, 2026 06:24
@stephentoub
Invert HexConverter condition to use #if NET ... #else format
85ad72e 
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
@build-analysis build-analysis bot mentioned this pull request Jan 7, 2026
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@MihaZupan
Fix formatting in netcore files after removing #if directives
bd39db3 
Co-authored-by: MihaZupan <25307628+MihaZupan@users.noreply.github.com>
Copilot AI requested a review from MihaZupan January 7, 2026 14:28
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stephentoub commented Jan 7, 2026

@copilot, please search the repo for any remaining NET9_0_OR_GREATER or NET10_0_OR_GREATER constants in any files.

@stephentoub
Replace NET9_0_OR_GREATER and NET10_0_OR_GREATER in test files
6a4b0e8 
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
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Copilot AI commented Jan 7, 2026

@copilot, please search the repo for any remaining NET9_0_OR_GREATER or NET10_0_OR_GREATER constants in any files.

Found and fixed 18 remaining occurrences in test files (commit 6a4b0e8):

  • Common/tests/System/Security/Cryptography/ByteUtils.cs - 3 occurrences
  • Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderPkcs12Tests.cs - 2 occurrences
  • Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderPkcs12CollectionTests.cs - 2 occurrences
  • Microsoft.Extensions.Caching.Memory/tests/AltLookupTests.cs - 3 occurrences
  • System.Formats.Asn1/tests/Writer/PushPopSetOf.cs - 1 occurrence
  • System.Formats.Asn1/tests/Writer/Asn1WriterTests.cs - 1 occurrence
  • System.Formats.Asn1/tests/Writer/SimpleWriterTests.cs - 2 occurrences
  • System.Text.Json/tests/Common/MetadataTests.cs - 2 occurrences
  • System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/Serialization/MetadataTests.cs - 1 occurrence
  • System.Text.Json/tests/System.Text.Json.SourceGeneration.Unit.Tests/JsonSourceGeneratorDiagnosticsTests.cs - 1 occurrence

All replaced with NET to maintain the .NET Core vs .NET Framework distinction. No remaining occurrences in src/libraries.

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stephentoub commented Jan 7, 2026

No remaining occurrences in src/libraries.

@copilot, are there remaining uses elsewhere than src/libraries?

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Copilot AI commented Jan 7, 2026

No remaining occurrences in src/libraries.

@copilot, are there remaining uses elsewhere than src/libraries?

No, there are no remaining occurrences anywhere in the repo. I searched the entire repository (excluding .git/, .dotnet/, and /docs/) for NET9_0_OR_GREATER and NET10_0_OR_GREATER in .cs, .csproj, .targets, and .props files - the search returned empty results.

@build-analysis build-analysis bot mentioned this pull request Jan 7, 2026
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@stephentoub stephentoub merged commit 313982d into main Jan 7, 2026
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@stephentoub stephentoub deleted the copilot/update-compilation-constants branch January 7, 2026 21:05
This was referenced Jan 9, 2026
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