Merge pull request #16506 from dotnet/merges/main-to-release/dev17.9

Merge main to release/dev17.9

Author: vzarytovskii

docs/perf-discussions-archive.md

@@ -0,0 +1,55 @@
+This is just a typed version of [these notes](https://github.com/dotnet/fsharp/issues/16498), generated during perf discussions on summer of 2023. Can be used as a reference point.
+
+---
+
+# Comparisons
+- OCaml
+- Scala
+- C#
+- Rust
+
+# Underlying problems
+- LOH allocations
+- Build does too much for deltas
+- GC Gen 2
+
+# Major problems
+- Script start up CLI
+- Build on Linux & Mac
+- Glitches in test discovery
+- Edit & test workflow
+- Edit & run workflow
+- Edit & check workflow
+- Unnecessary rebuilds
+
+# Hosted compiler problems
+- Stamp overflow
+- Non-deterministic
+- Memory leaks
+- Infinite loops
+- Stay resident compiler
+- Permission elevation
+
+# Minor problems
+- Benchmarking
+- Squigglies
+- Colorization
+- Debug
+- Press dot
+
+# Incremental phases
+- Incremental parsing file
+- Incremental checking file
+- Incremental optimization for deltas
+- Cascading DLL builds
+- Incremental DLL builds
+- Incremental ILxGen for deltas
+- Incremental assembly generation
+- Incremental PDB generation for deltas
+
+# Community guidelines
+- Community leadership
+- Community enablement for tool performance
+- Performance acceptance criteria
+- Performance running
+- Docs for tooling performance

docs/release-notes/.FSharp.Compiler.Service/8.0.200.md

@@ -15,3 +15,7 @@
 * Parser recovers on unfinished record declarations. ([PR #16357](https://github.com/dotnet/fsharp/pull/16357))
 * `MutableKeyword` to [SynFieldTrivia](../reference/fsharp-compiler-syntaxtrivia-synfieldtrivia.html) ([PR #16357](https://github.com/dotnet/fsharp/pull/16357))
 * Added support for a new parameterless constructor for `CustomOperationAttribute`, which, when applied, will use method name as keyword for custom operation in computation expression builder. ([PR #16475](https://github.com/dotnet/fsharp/pull/16475), part of implementation for [fslang-suggestions/1250](https://github.com/fsharp/fslang-suggestions/issues/1250))
+
+### Changed
+
+* Speed up unused opens handling for empty results. ([PR #16502](https://github.com/dotnet/fsharp/pull/16502))

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.1.24053.1">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="9.0.0-alpha.1.24055.1">
       <Uri>https://github.com/dotnet/source-build-reference-packages</Uri>
-      <Sha>5f670e45d060b25d5b07646dfcd94eae31893191</Sha>
+      <Sha>ef691e3c401949dab9986a50d8288a6e489f72bb</Sha>
       <SourceBuild RepoName="source-build-reference-packages" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="Microsoft.SourceBuild.Intermediate.msbuild" Version="17.7.0-preview-23217-02">

src/Compiler/Service/ServiceAnalysis.fs

@@ -297,12 +297,19 @@ module UnusedOpens =
     /// Async to allow cancellation.
     let getUnusedOpens (checkFileResults: FSharpCheckFileResults, getSourceLineStr: int -> string) : Async<range list> =
         async {
-            let! ct = Async.CancellationToken
-            let symbolUses = checkFileResults.GetAllUsesOfAllSymbolsInFile(ct)
-            let symbolUses = filterSymbolUses getSourceLineStr symbolUses
-            let symbolUses = splitSymbolUses symbolUses
-            let openStatements = getOpenStatements checkFileResults.OpenDeclarations
-            return! filterOpenStatements symbolUses openStatements
+            if checkFileResults.OpenDeclarations.Length = 0 then
+                return []
+            else
+                let! ct = Async.CancellationToken
+                let symbolUses = checkFileResults.GetAllUsesOfAllSymbolsInFile(ct)
+                let symbolUses = filterSymbolUses getSourceLineStr symbolUses
+                let symbolUses = splitSymbolUses symbolUses
+                let openStatements = getOpenStatements checkFileResults.OpenDeclarations
+
+                if openStatements.Length = 0 then
+                    return []
+                else
+                    return! filterOpenStatements symbolUses openStatements
         }
 
 module SimplifyNames =

tests/AheadOfTime/Trimming/SelfContained_Trimming_Test/SelfContained_Trimming_Test.fsproj

@@ -5,7 +5,6 @@
     <TargetFrameworks>net8.0</TargetFrameworks>
     <LangVersion>preview</LangVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-    <DotNetBuildOffline>true</DotNetBuildOffline>
   </PropertyGroup>
 
   <PropertyGroup>

tests/AheadOfTime/Trimming/StaticLinkedFSharpCore_Trimming_Test/StaticLinkedFSharpCore_Trimming_Test.fsproj

@@ -5,7 +5,6 @@
     <TargetFrameworks>net8.0</TargetFrameworks>
     <LangVersion>preview</LangVersion>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-    <DotNetBuildOffline>true</DotNetBuildOffline>
     <ProduceReferenceAssembly>false</ProduceReferenceAssembly>
     <OtherFlags>--standalone</OtherFlags>
   </PropertyGroup>

tests/benchmarks/FCSBenchmarks/CompilerServiceBenchmarks/BackgroundCompilerBenchmarks.fs

@@ -152,10 +152,7 @@ type NoFileSystemCheckerBenchmark() =
     let mutable benchmark : ProjectWorkflowBuilder = Unchecked.defaultof<_>
 
     [<ParamsAllValues>]
-    member val UseGetSource = true with get,set
-
-    [<ParamsAllValues>]
-    member val UseChangeNotifications = true with get,set
+    member val UseInMemoryDocuments = true with get,set
 
     [<ParamsAllValues>]
     member val EmptyCache = true with get,set
@@ -165,8 +162,8 @@ type NoFileSystemCheckerBenchmark() =
         benchmark <-
             ProjectWorkflowBuilder(
             project,
-            useGetSource = this.UseGetSource,
-            useChangeNotifications = this.UseChangeNotifications).CreateBenchmarkBuilder()
+            useGetSource = this.UseInMemoryDocuments,
+            useChangeNotifications = this.UseInMemoryDocuments).CreateBenchmarkBuilder()
 
     [<IterationSetup>]
     member this.EditFirstFile_OnlyInternalChange() =
@@ -178,15 +175,14 @@ type NoFileSystemCheckerBenchmark() =
     member this.ExampleWorkflow() =
 
         use _ = Activity.start "Benchmark" [
-            "UseGetSource", this.UseGetSource.ToString()
-            "UseChangeNotifications", this.UseChangeNotifications.ToString()
+            "UseInMemoryDocuments", this.UseInMemoryDocuments.ToString()
         ]
 
         let first = "File001"
         let middle = $"File%03d{size / 2}"
         let last = $"File%03d{size}"
 
-        if this.UseGetSource && this.UseChangeNotifications then
+        if this.UseInMemoryDocuments then
 
             benchmark {
                 updateFile first updatePublicSurface