dotnet · 0101 · Feb 6, 2025 · Oct 8, 2024 · Oct 8, 2024 · Oct 8, 2024
diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
@@ -44,19 +44,19 @@
       ],
       "rollForward": true
     },
-    "dotnet-ilverify": {
-      "version": "9.0.0-rc.2.24473.5",
-      "commands": [
-        "ilverify"
-      ],
-      "rollForward": true
-    },
     "fantomas": {
       "version": "6.2.3",
       "commands": [
         "fantomas"
       ],
       "rollForward": true
+    },
+    "dotnet-ilverify": {
+      "version": "9.0.0",
+      "commands": [
+        "ilverify"
+      ],
+      "rollForward": false
     }
   }
-}
+}
diff --git a/.config/feature-lsp-branch-merge.json b/.config/feature-lsp-branch-merge.json
@@ -0,0 +1,8 @@
+{
+    "merge-flow-configurations": {
+        "main": {
+            "MergeToBranch": "feature/lsp",
+            "ExtraSwitches": "-QuietComments"
+        }
+    }
+}
diff --git a/.config/service-branch-merge.json b/.config/service-branch-merge.json
@@ -0,0 +1,13 @@
+{
+    "merge-flow-configurations": {
+        // regular branch flow
+        "release/dev17.13": {
+            "MergeToBranch": "main",
+            "ExtraSwitches": "-QuietComments"
+        },
+        "main": {
+            "MergeToBranch": "release/dev17.14",
+            "ExtraSwitches": "-QuietComments"
+        }
+    }
+}
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
@@ -1,12 +1,12 @@
 // For format details, see https://aka.ms/vscode-remote/devcontainer.json or this file's README at:
 {
     "name": "F#",
-    "image": "mcr.microsoft.com/dotnet/sdk:9.0.100",
+    "image": "mcr.microsoft.com/dotnet/sdk:9.0.102",
     "features": {
-        "ghcr.io/devcontainers/features/common-utils:2.5.1": {},
+        "ghcr.io/devcontainers/features/common-utils:2.5.2": {},
         "ghcr.io/devcontainers/features/git:1.3.2": {},
         "ghcr.io/devcontainers/features/github-cli:1.0.13": {},
-        "ghcr.io/devcontainers/features/dotnet:2.1.3": {}
+        "ghcr.io/devcontainers/features/dotnet:2.2.0": {}
     },
     "hostRequirements": {
         "cpus": 2,

diff --git a/.fantomasignore b/.fantomasignore
@@ -40,6 +40,9 @@ src/Compiler/Checking/SignatureConformance.fs
 src/Compiler/Checking/TypeHierarchy.fs
 src/Compiler/Checking/TypeRelations.fs
 
+# nullness-related problems
+src/Compiler/DependencyManager/DependencyProvider.fs
+
 # Incorrectly formatted: https://github.com/dotnet/fsharp/pull/14645/commits/49443a67ea8a17670c8a7c80c8bdf91f82231e91 or https://github.com/fsprojects/fantomas/issues/2733
 # This CompilerImports.fs behavior is not fixed yet, following up in  https://github.com/fsprojects/fantomas/issues/2733
 src/Compiler/Driver/CompilerImports.fs

diff --git a/.github/workflows/branch-merge.yml b/.github/workflows/branch-merge.yml
@@ -0,0 +1,22 @@
+# Merges any changes from servicing branches forward.
+
+name: Flow servicing changes to main
+on:
+  push:
+   branches:
+     - 'release/*'
+     - 'main'
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  servicing-flow:
+    uses: dotnet/arcade/.github/workflows/inter-branch-merge-base.yml@main
+    with:
+      configuration_file_path: '.config/service-branch-merge.json'
+  feature-lsp-flow:
+    uses: dotnet/arcade/.github/workflows/inter-branch-merge-base.yml@main
+    with:
+      configuration_file_path: '.config/feature-lsp-branch-merge.json'
diff --git a/.gitignore b/.gitignore
@@ -129,4 +129,9 @@ tests/FSharp.Compiler.Service.Tests/FSharp.CompilerService.SurfaceArea.netstanda
 /tests/AheadOfTime/Trimming/output.txt
 *.svclog
 micro.exe
-positive.exe
+positive.exe
+/tests/FSharp.Compiler.ComponentTests/FSharpChecker/StandardError.txt
+/tests/FSharp.Compiler.ComponentTests/FSharpChecker/StandardOutput.txt
+
+# ilverify baseline result files
+*.bsl.actual
diff --git a/DEVGUIDE.md b/DEVGUIDE.md
@@ -204,6 +204,33 @@ Linux/macOS:
 export TEST_UPDATE_BSL=1
 ```
 
+## Retain Test run built artifacts
+
+When investigating tests issues it is sometimes useful to examine the artifacts built when running tests.  Those built using the newer test framework are usually,
+built in the %TEMP%\FSharp.Test.Utilities subdirectory.
+
+To tell the test framework to not cleanup these files use the: FSHARP_RETAIN_TESTBUILDS environment variable
+
+Windows:
+
+CMD:
+
+```shell
+set FSHARP_RETAIN_TESTBUILDS=1
+```
+
+PowerShell:
+
+```shell
+$env:FSHARP_RETAIN_TESTBUILDS=1
+```
+
+Linux/macOS:
+
+```shell
+export FSHARP_RETAIN_TESTBUILDS=1
+```
+
 Next, run a build script build (debug or release, desktop or coreclr, depending which baselines you need to update), and test as described [above](#Testing-from-the-command-line). For example:
 
 `./Build.cmd -c Release -testCoreClr` to update Release CoreCLR baselines.
@@ -216,6 +243,16 @@ or
 > Please note, that by default, **Release** version of IL baseline tests will be running in CI, so when updating baseline (.bsl) files, make sure to add `-c Release` flag to the build command.
 
 
+### Parallel execution of tests
+
+Tests utilizing xUnit framework by default run in parallel. If your tests depend on some shared state or are time-critical, you can add the module to predefined `NotThreadSafeResourceCollection` to prevent parallel execution.
+For example:
+```fsharp
+[<Collection(nameof NotThreadSafeResourceCollection)>]
+module TimeCritical =
+```
+
+
 ### Updating FCS surface area baselines
 
 ```bash

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
@@ -29,7 +29,7 @@ variables:
   # Should be 'current' release branch name, i.e. 'release/dev17.10' in dotnet/fsharp/refs/heads/main, 'release/dev17.10' in dotnet/fsharp/refs/heads/release/dev17.10 and 'release/dev17.9' in dotnet/fsharp/refs/heads/release/dev17.9
   # Should **never** be 'main' in dotnet/fsharp/refs/heads/main, since it will start inserting to VS twice.
   - name: FSharpReleaseBranchName
-    value: release/dev17.13
+    value: release/dev17.14
   # VS Insertion branch name (NOT the same as F# branch)
   # Should be previous release branch or 'main' in 'main' and 'main' in release branch
   # (since for all *new* release branches we insert into VS main and for all *previous* releases we insert into corresponding VS release),
@@ -88,7 +88,7 @@ extends:
       #                                                  Signed build                                                     #
       #-------------------------------------------------------------------------------------------------------------------#
       # Localization: we only run it for specific release branches
-      - ${{ if eq(variables['Build.SourceBranch'], 'refs/heads/release/dev17.13') }}:
+      - ${{ if eq(variables['Build.SourceBranch'], 'refs/heads/release/dev17.14') }}:
         - template: /eng/common/templates-official/job/onelocbuild.yml@self
           parameters:
             MirrorRepo: fsharp

diff --git a/docs/release-notes/.FSharp.Compiler.Service/9.0.200.md b/docs/release-notes/.FSharp.Compiler.Service/9.0.200.md
@@ -1,5 +1,6 @@
 ### Fixed
 
+* Fix Realsig+ generates nested closures with incorrect Generic  ([Issue #17797](https://github.com/dotnet/fsharp/issues/17797), [PR #17877](https://github.com/dotnet/fsharp/pull/17877))
 * Fix missing TailCall warning in Sequential in use scope ([PR #17927](https://github.com/dotnet/fsharp/pull/17927))
 * Fix false negatives for passing null to "obj" arguments. Only "obj | null" can now subsume any type ([PR #17757](https://github.com/dotnet/fsharp/pull/17757))
 * Fix internal error when calling 'AddSingleton' and other overloads only differing in generic arity ([PR #17804](https://github.com/dotnet/fsharp/pull/17804))
@@ -21,6 +22,8 @@
 * Completion: fix qualified completion in sequence expressions [PR #18111](https://github.com/dotnet/fsharp/pull/18111)
 * Symbols: try to use ValReprInfoForDisplay in Mfv.CurriedParameterGroups ([PR #18124](https://github.com/dotnet/fsharp/pull/18124))
 * Shim/file system: fix leaks of the shim [PR #18144](https://github.com/dotnet/fsharp/pull/18144)
+* fsi: fix auto-loading of script file inside NuGet package ([PR #18177](https://github.com/dotnet/fsharp/pull/18177))
+* Fix for `Obsolete` attribute warning/error not taken into account when used with a unit of measure [PR #18182](https://github.com/dotnet/fsharp/pull/18182)
 
 ### Added
 
@@ -52,8 +55,8 @@
 * Better ranges for #nowarn error reporting; bring back #nowarn warnings for --langVersion:80; add warnings under feature flag ([PR #17871](https://github.com/dotnet/fsharp/pull/17871))
 * CheckAndThrow can be invoked only from within Cancellable context ([PR #18037](https://github.com/dotnet/fsharp/pull/18037))
 * Make ILTypeDef base type calculation lazy. ([PR #18005](https://github.com/dotnet/fsharp/pull/18005))
-* "#if" directive around nullness removed from src/Compiler/TypedTree/TypedTreePickle.fs and refactored. ([PR #18203](https://github.com/dotnet/fsharp/pull/18203))
+* Removed redundant hash directives around nullness syntax ([Issue #18601](https://github.com/dotnet/fsharp/issues/18061), [PR #18203](https://github.com/dotnet/fsharp/pull/18203), [PR #18207](https://github.com/dotnet/fsharp/pull/18207))
 
 ### Breaking Changes
 
-* Aliasing `StructAttribute` will now produce a warning (part of [Language suggestion #1136](https://github.com/fsharp/fslang-suggestions/issues/1136), [PR #18098](https://github.com/dotnet/fsharp/pull/18098))
+* Aliasing `StructAttribute` will now produce a warning (part of [Language suggestion #1136](https://github.com/fsharp/fslang-suggestions/issues/1136), [PR #18098](https://github.com/dotnet/fsharp/pull/18098))
diff --git a/docs/release-notes/.FSharp.Compiler.Service/9.0.300.md b/docs/release-notes/.FSharp.Compiler.Service/9.0.300.md
@@ -0,0 +1,23 @@
+### Fixed
+* Fix Realsig+ generates nested closures with incorrect Generic  ([Issue #17797](https://github.com/dotnet/fsharp/issues/17797), [PR #17877](https://github.com/dotnet/fsharp/pull/17877))
+* Fix optimizer internal error for records with static fields  ([Issue #18165](https://github.com/dotnet/fsharp/issues/18165), [PR #18280](https://github.com/dotnet/fsharp/pull/18280))
+* Fix nullness warning with flexible types  ([Issue #18056](https://github.com/dotnet/fsharp/issues/18056), [PR #18266](https://github.com/dotnet/fsharp/pull/18266))
+* Fix internal error when missing measure attribute in an unsolved measure typar. ([Issue #7491](https://github.com/dotnet/fsharp/issues/7491), [PR #18234](https://github.com/dotnet/fsharp/pull/18234)==
+* Set `Cancellable.token` from async computation ([Issue #18235](https://github.com/dotnet/fsharp/issues/18235), [PR #18238](https://github.com/dotnet/fsharp/pull/18238))
+* Fix missing nullness warning when static upcast dropped nullness ([Issue #18232](https://github.com/dotnet/fsharp/issues/18232), [PR #18261](https://github.com/dotnet/fsharp/pull/18261))
+* Cancellable: only cancel on OCE with own token ([PR #18277](https://github.com/dotnet/fsharp/pull/18277))
+* Cancellable: set token in more places ([PR #18283](https://github.com/dotnet/fsharp/pull/18283))
+
+### Added
+* Added missing type constraints in FCS. ([PR #18241](https://github.com/dotnet/fsharp/pull/18241))
+* The 'use' keyword can be used on IDisposable|null without nullness warnings ([PR #18262](https://github.com/dotnet/fsharp/pull/18262))
+* Symbols: Add FSharpAssembly.IsFSharp ([PR #18290](https://github.com/dotnet/fsharp/pull/18290))
+
+### Changed
+
+* FSharpCheckFileResults.ProjectContext.ProjectOptions will not be available when using the experimental Transparent Compiler feature. ([PR #18205](https://github.com/dotnet/fsharp/pull/18205))
+* Update `Obsolete` attribute checking to account for `DiagnosticId` and `UrlFormat` properties. ([PR #18224](https://github.com/dotnet/fsharp/pull/18224))
+* Remove `Cancellable.UsingToken` from tests ([PR #18276](https://github.com/dotnet/fsharp/pull/18276))
+
+### Breaking Changes
+* Struct unions with overlapping fields now generate mappings needed for reading via reflection ([Issue #18121](https://github.com/dotnet/fsharp/issues/17797), [PR #18274](https://github.com/dotnet/fsharp/pull/17877))
diff --git a/docs/release-notes/.FSharp.Core/9.0.300.md b/docs/release-notes/.FSharp.Core/9.0.300.md
@@ -0,0 +1,8 @@
+### Fixed
+
+### Added
+
+### Changed
+
+### Breaking Changes
+* Struct unions with overlapping fields now generate mappings needed for reading via reflection ([Issue #18121](https://github.com/dotnet/fsharp/issues/17797), [PR #18274](https://github.com/dotnet/fsharp/pull/17877)). Previous versions of FSharp.Core returned incomplete mapping between fields and cases, these older fslib versions will now report an exception.
diff --git a/eng/DotNetBuild.props b/eng/DotNetBuild.props
@@ -31,6 +31,7 @@
     <PropertyGroup>
       <SourceBuildBootstrapTfmArg Condition="$(SourceBuildBootstrapTfm) != ''">--tfm $(SourceBuildBootstrapTfm)</SourceBuildBootstrapTfmArg>
       <DotNetBuildUseMonoRuntime Condition="'$(DotNetBuildUseMonoRuntime)' == ''">false</DotNetBuildUseMonoRuntime>
+      <SourceBuildBootstrapRestoreConfigFileArg Condition="'$(RestoreConfigFile)' != ''" >/p:RestoreConfigFile=$(RestoreConfigFile)</SourceBuildBootstrapRestoreConfigFileArg>
     </PropertyGroup>
 
     <!-- this runs the source-build bootstrap path as described in https://github.com/dotnet/fsharp/blob/95df49e380ea8dbf33653fa4209f89dba29413f5/eng/build.sh#L247
@@ -41,7 +42,7 @@
          -bl enables the binlogs for the tools and Proto builds, which make debugging failures here easier
     -->
     <Exec
-      Command="./build.sh --bootstrap --skipBuild -bl $(SourceBuildBootstrapTfmArg) /p:DotNetBuildUseMonoRuntime=$(DotNetBuildUseMonoRuntime) /p:DotNetBuildSourceOnly=true /p:DotNetBuildInnerRepo=true /p:DotNetBuildRepo=true /p:DotNetBuildOrchestrator=$(DotNetBuildOrchestrator)"
+      Command="./build.sh --bootstrap --skipBuild -bl $(SourceBuildBootstrapTfmArg) $(SourceBuildBootstrapRestoreConfigFileArg) /p:DotNetBuildUseMonoRuntime=$(DotNetBuildUseMonoRuntime) /p:DotNetBuildSourceOnly=true /p:DotNetBuildInnerRepo=true /p:DotNetBuildRepo=true /p:DotNetBuildOrchestrator=$(DotNetBuildOrchestrator)"
       WorkingDirectory="$(InnerSourceBuildRepoRoot)"
       EnvironmentVariables="@(InnerBuildEnv)" />
   </Target>

diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Dependencies>
   <ProductDependencies>
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="9.0.0-alpha.1.24619.1">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="9.0.0-alpha.1.25081.6">
       <Uri>https://github.com/dotnet/source-build-reference-packages</Uri>
-      <Sha>e2b1d16fd66540b3a5813ec0ac1fd166688c3e0a</Sha>
+      <Sha>1cec3b4a8fb07138136a1ca1e04763bfcf7841db</Sha>
       <SourceBuild RepoName="source-build-reference-packages" ManagedOnly="true" />
     </Dependency>
     <!-- Intermediate is necessary for source build. -->
@@ -42,14 +42,14 @@
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.24623.3">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.25077.4">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>e0e05154656254a735ebf19ffa5a37a8b915039b</Sha>
+      <Sha>bac7e1caea791275b7c3ccb4cb75fd6a04a26618</Sha>
     </Dependency>
     <!-- Intermediate is necessary for source build. -->
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.24623.3">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.25077.4">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>e0e05154656254a735ebf19ffa5a37a8b915039b</Sha>
+      <Sha>bac7e1caea791275b7c3ccb4cb75fd6a04a26618</Sha>
       <SourceBuild RepoName="arcade" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="optimization.windows_nt-x64.MIBC.Runtime" Version="1.0.0-prerelease.24462.2">

diff --git a/eng/Versions.props b/eng/Versions.props
@@ -14,7 +14,7 @@
     <!-- F# Version components -->
     <FSMajorVersion>9</FSMajorVersion>
     <FSMinorVersion>0</FSMinorVersion>
-    <FSBuildVersion>200</FSBuildVersion>
+    <FSBuildVersion>300</FSBuildVersion>
     <FSRevisionVersion>0</FSRevisionVersion>
     <!-- -->
     <!-- F# Language version -->
@@ -37,7 +37,7 @@
     <FSharpLibrariesChangelogVersion>$(FSMajorVersion).$(FSMinorVersion).$(FSBuildVersion)</FSharpLibrariesChangelogVersion>
     <!-- -->
     <!-- The current published nuget package -->
-    <FSharpCoreShippedPackageVersionValue>9.0.100</FSharpCoreShippedPackageVersionValue>
+    <FSharpCoreShippedPackageVersionValue>9.0.101</FSharpCoreShippedPackageVersionValue>
     <!-- -->
     <!-- The pattern for specifying the preview package -->
     <FSharpCorePreviewPackageVersionValue>$(FSCorePackageVersionValue)-$(PreReleaseVersionLabel).*</FSharpCorePreviewPackageVersionValue>
@@ -53,7 +53,7 @@
   <PropertyGroup>
     <!-- These have to be in sync with latest release branch -->
     <VSMajorVersion>17</VSMajorVersion>
-    <VSMinorVersion>13</VSMinorVersion>
+    <VSMinorVersion>14</VSMinorVersion>
     <VSGeneralVersion>$(VSMajorVersion).0</VSGeneralVersion>
     <VSAssemblyVersionPrefix>$(VSMajorVersion).$(VSMinorVersion).0</VSAssemblyVersionPrefix>
     <VSAssemblyVersion>$(VSAssemblyVersionPrefix).0</VSAssemblyVersion>
@@ -193,7 +193,6 @@
     <XUnitVersion>2.9.0</XUnitVersion>
     <XUnitRunnerVersion>2.8.2</XUnitRunnerVersion>
     <XunitXmlTestLoggerVersion>3.1.17</XunitXmlTestLoggerVersion>
-    <FluentAssertionsVersion>5.10.3</FluentAssertionsVersion>
     <HumanizerCoreVersion>2.2.0</HumanizerCoreVersion>
     <!-- -->
     <!-- MIBC profile packages -->

diff --git a/eng/common/internal/Tools.csproj b/eng/common/internal/Tools.csproj
@@ -15,16 +15,6 @@
     <PackageReference Include="Microsoft.DotNet.IBCMerge" Version="$(MicrosoftDotNetIBCMergeVersion)" Condition="'$(UsingToolIbcOptimization)' == 'true'" />
     <PackageReference Include="Drop.App" Version="$(DropAppVersion)" ExcludeAssets="all" Condition="'$(UsingToolVisualStudioIbcTraining)' == 'true'"/>
   </ItemGroup>
-  <PropertyGroup>
-    <RestoreSources></RestoreSources>
-    <RestoreSources Condition="'$(UsingToolIbcOptimization)' == 'true'">
-      https://devdiv.pkgs.visualstudio.com/_packaging/dotnet-core-internal-tooling/nuget/v3/index.json;
-    </RestoreSources>
-    <RestoreSources Condition="'$(UsingToolVisualStudioIbcTraining)' == 'true'">
-      $(RestoreSources);
-      https://devdiv.pkgs.visualstudio.com/_packaging/VS/nuget/v3/index.json;
-    </RestoreSources>
-  </PropertyGroup>
 
   <!-- Repository extensibility point -->
   <Import Project="$(RepositoryEngineeringDir)InternalTools.props" Condition="Exists('$(RepositoryEngineeringDir)InternalTools.props')" />

diff --git a/eng/common/template-guidance.md b/eng/common/template-guidance.md
@@ -57,7 +57,7 @@ extends:
 
 Note: Multiple outputs are ONLY applicable to 1ES PT publishing (only usable when referencing `templates-official`).
 
-# Development notes
+## Development notes
 
 **Folder / file structure**
 

diff --git a/global.json b/global.json
@@ -1,10 +1,10 @@
 {
   "sdk": {
-    "version": "9.0.100",
+    "version": "9.0.102",
     "allowPrerelease": true
   },
   "tools": {
-    "dotnet": "9.0.100",
+    "dotnet": "9.0.102",
     "vs": {
       "version": "17.8",
       "components": [
@@ -17,7 +17,7 @@
     "perl": "5.38.2.2"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.24623.3",
+    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.25077.4",
     "Microsoft.DotNet.Helix.Sdk": "8.0.0-beta.23255.2"
   }
 }
diff --git a/src/Compiler/AbstractIL/ilx.fsi b/src/Compiler/AbstractIL/ilx.fsi
@@ -162,6 +162,8 @@ val mkILFormalCloRef: ILGenericParameterDefs -> IlxClosureRef -> useStaticField:
 // MS-ILX: Unions
 // --------------------------------------------------------------------
 
+val mkLowerName: nm: string -> string
+
 val actualTypOfIlxUnionField: IlxUnionSpec -> int -> int -> ILType
 
 val mkILFreeVar: string * bool * ILType -> IlxClosureFreeVar