Merge main to release/dev17.10 (#16959)

* PrettyNaming: make DoesIdentifierNeedBackticks public (#16613) * Update dependencies from https://github.com/dotnet/arcade build (#16944) Microsoft.DotNet.Arcade.Sdk From Version 8.0.0-beta.24170.6 -> To Version 8.0.0-beta.24172.5 Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com> * Unskip a few tests (#16946) * Unskip a few tests * another one * Fix [<tailcall>] false positive with yield! (#16933) * add test case showing a false positive with yield! * add missing case in IsAppInLambdaBody that can happen with yield! * add release notes entry * update PR number * only bind to what we are interested in * add test expecting a warning for yield! in a list comprehension * add test case using yield! in a custom CE that overflows the stack * Add regression test for nameof type with generic parameters (#16827) Co-authored-by: Vlad Zarytovskii <vzaritovsky@hotmail.com> * Minor README update about proto (#16945) * Minor README update about proto It's Bootstrap actually. * Update DEVGUIDE.md Co-authored-by: Vlad Zarytovskii <vzaritovsky@hotmail.com> * Update DEVGUIDE.md --------- Co-authored-by: Vlad Zarytovskii <vzaritovsky@hotmail.com> * Compiled code benchmarks: easy benchmarking of `preview` against current (#16942) * Make it easy to bench preview against current * Revert EnableDefaultNoneItems false (#16953) * Exclude compiler service benchmark from VMR build when not building tests (#16955) * Exclude compiler service benchmark from VMR build when not building tests * remove Z --------- Co-authored-by: Petr <psfinaki@users.noreply.github.com> * Update dependencies from https://github.com/dotnet/arcade build 20240326.8 (#16957) Microsoft.DotNet.Arcade.Sdk From Version 8.0.0-beta.24172.5 -> To Version 8.0.0-beta.24176.8 Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com> --------- Co-authored-by: Eugene Auduchinok <eugene.auduchinok@jetbrains.com> Co-authored-by: dotnet-maestro[bot] <42748379+dotnet-maestro[bot]@users.noreply.github.com> Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com> Co-authored-by: Petr <psfinaki@users.noreply.github.com> Co-authored-by: dawe <dawedawe@posteo.de> Co-authored-by: Florian Verdonck <florian.verdonck@outlook.com> Co-authored-by: Vlad Zarytovskii <vzaritovsky@hotmail.com> Co-authored-by: Brian Rourke Boll <brianrourkeboll@users.noreply.github.com> Co-authored-by: Kevin Ransom (msft) <codecutter@hotmail.com> Co-authored-by: Matt Mitchell <mmitche@microsoft.com>
dotnet · Mar 28, 2024 · 20b263a · 20b263a
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Showing 22 changed files with 996 additions and 28 deletions.
diff --git a/DEVGUIDE.md b/DEVGUIDE.md
@@ -124,7 +124,7 @@ Running any of the above will build the latest changes and run tests against the
 
 ## Using your custom compiler to build this repository
 
-By removing all the subfolders called `Proto` under `artifacts` and running the `build` script again, the proto compiler will include your changes.
+By removing all the subfolders called `Bootstrap` or `Proto` under `artifacts` and running the `build` script again, the proto compiler will include your changes.
 
 Once the "proto" compiler is built, it won't be built again, so you may want to perform those steps again to ensure your changes don't break building the compiler itself.
 

diff --git a/VisualFSharp.sln b/VisualFSharp.sln
@@ -191,6 +191,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "FSharp.Editor.IntegrationTe
 EndProject
 Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "FSharp.Benchmarks.Common", "tests\benchmarks\FSharp.Benchmarks.Common\FSharp.Benchmarks.Common.fsproj", "{6734FC6F-B5F3-45E1-9A72-720378BB49C9}"
 EndProject
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "MicroPerf", "tests\benchmarks\CompiledCodeBenchmarks\MicroPerf\MicroPerf.fsproj", "{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MicroPerfCSharp", "tests\benchmarks\CompiledCodeBenchmarks\MicroPerf\CS\MicroPerfCSharp.csproj", "{9F9DD315-37DA-4413-928E-1CFC6924B64F}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1005,6 +1009,30 @@ Global
 		{6734FC6F-B5F3-45E1-9A72-720378BB49C9}.Release|Any CPU.Build.0 = Release|Any CPU
 		{6734FC6F-B5F3-45E1-9A72-720378BB49C9}.Release|x86.ActiveCfg = Release|Any CPU
 		{6734FC6F-B5F3-45E1-9A72-720378BB49C9}.Release|x86.Build.0 = Release|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Debug|x86.Build.0 = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Proto|Any CPU.ActiveCfg = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Proto|Any CPU.Build.0 = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Proto|x86.ActiveCfg = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Proto|x86.Build.0 = Debug|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Release|Any CPU.Build.0 = Release|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Release|x86.ActiveCfg = Release|Any CPU
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213}.Release|x86.Build.0 = Release|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Debug|x86.Build.0 = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Proto|Any CPU.ActiveCfg = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Proto|Any CPU.Build.0 = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Proto|x86.ActiveCfg = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Proto|x86.Build.0 = Debug|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Release|x86.ActiveCfg = Release|Any CPU
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1084,6 +1112,8 @@ Global
 		{CBC96CC7-65AB-46EA-A82E-F6A788DABF80} = {F7876C9B-FB6A-4EFB-B058-D6967DB75FB2}
 		{E31F9B59-FCF1-4D04-8762-C7BB60285A7B} = {F7876C9B-FB6A-4EFB-B058-D6967DB75FB2}
 		{6734FC6F-B5F3-45E1-9A72-720378BB49C9} = {DFB6ADD7-3149-43D9-AFA0-FC4A818B472B}
+		{601CD5C1-EAFA-4AE3-8FB9-F667B5728213} = {DFB6ADD7-3149-43D9-AFA0-FC4A818B472B}
+		{9F9DD315-37DA-4413-928E-1CFC6924B64F} = {DFB6ADD7-3149-43D9-AFA0-FC4A818B472B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {48EDBBBE-C8EE-4E3C-8B19-97184A487B37}

diff --git a/docs/release-notes/.FSharp.Compiler.Service/8.0.300.md b/docs/release-notes/.FSharp.Compiler.Service/8.0.300.md
@@ -1,5 +1,6 @@
 ### Fixed
 
+* Fix a false positive of the `[<TailCall>]` analysis in combination with `yield!`. ([PR #16933](https://github.com/dotnet/fsharp/pull/16933))
 * Don't blow the stack when traversing deeply nested sequential expressions. ([PR #16882](https://github.com/dotnet/fsharp/pull/16882))
 * Fix wrong range start of INTERP_STRING_END. ([PR #16774](https://github.com/dotnet/fsharp/pull/16774), [PR #16785](https://github.com/dotnet/fsharp/pull/16785))
 * Fix missing warning for recursive calls in list comprehensions. ([PR #16652](https://github.com/dotnet/fsharp/pull/16652))
@@ -35,6 +36,7 @@
 * Parser recovers on complex primary constructor patterns, better tree representation for primary constructor patterns. ([PR #16425](https://github.com/dotnet/fsharp/pull/16425))
 * Name resolution: keep type vars in subsequent checks ([PR #16456](https://github.com/dotnet/fsharp/pull/16456))
 * Higher-order-function-based API for working with the untyped abstract syntax tree. ([PR #16462](https://github.com/dotnet/fsharp/pull/16462))
+* PrettyNaming: make `DoesIdentifierNeedBackticks` public ([PR #16613](https://github.com/dotnet/fsharp/pull/16613))
 * Add switch to generate types and members with  IL visibility that accurately represents their F# visibility. ([PR #15484](https://github.com/dotnet/fsharp/pull/15484)
 * Allow returning bool instead of unit option for partial active patterns. ([Language suggestion #1041](https://github.com/fsharp/fslang-suggestions/issues/1041), [PR #16473](https://github.com/dotnet/fsharp/pull/16473))
 * Symbols: Add GenericArguments to FSharpEntity ([PR #16470](https://github.com/dotnet/fsharp/pull/16470))

diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
@@ -30,9 +30,9 @@
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="8.0.0-beta.24170.6">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="8.0.0-beta.24176.8">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>8e3e00a76f467cc262dc14f6466ab884b2c4eb96</Sha>
+      <Sha>48e9e0d2164de0535446809364724da8962123a6</Sha>
       <SourceBuild RepoName="arcade" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="Microsoft.DotNet.XliffTasks" Version="1.0.0-beta.23475.1" CoherentParentDependency="Microsoft.DotNet.Arcade.Sdk">

diff --git a/eng/common/templates-official/job/job.yml b/eng/common/templates-official/job/job.yml
@@ -128,14 +128,15 @@ jobs:
 
   - ${{ if and(eq(parameters.runAsPublic, 'false'), ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
     - ${{ if eq(parameters.enableMicrobuild, 'true') }}:
-      - task: MicroBuildSigningPlugin@3
+      - task: MicroBuildSigningPlugin@4
         displayName: Install MicroBuild plugin
         inputs:
           signType: $(_SignType)
           zipSources: false
           feedSource: https://dnceng.pkgs.visualstudio.com/_packaging/MicroBuildToolset/nuget/v3/index.json
         env:
           TeamName: $(_TeamName)
+          MicroBuildOutputFolderOverride: '$(Agent.TempDirectory)'
         continueOnError: ${{ parameters.continueOnError }}
         condition: and(succeeded(), in(variables['_SignType'], 'real', 'test'), eq(variables['Agent.Os'], 'Windows_NT'))
 

diff --git a/global.json b/global.json
@@ -17,7 +17,7 @@
     "perl": "5.38.0.1"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "8.0.0-beta.24170.6",
+    "Microsoft.DotNet.Arcade.Sdk": "8.0.0-beta.24176.8",
     "Microsoft.DotNet.Helix.Sdk": "8.0.0-beta.23255.2"
   }
 }
diff --git a/src/Compiler/Checking/TailCallChecks.fs b/src/Compiler/Checking/TailCallChecks.fs
@@ -222,6 +222,13 @@ and CheckCall cenv args ctxts (tailCall: TailCall) =
             | Expr.App _ -> Some(TailCall.YesFromExpr cenv.g e)
             | IsAppInLambdaBody t -> Some t
             | _ -> None
+        | Expr.App(args = args) ->
+            args
+            |> List.tryPick (fun a ->
+                match a with
+                | IsAppInLambdaBody t -> Some t
+                | _ -> None)
+
         | _ -> None
 
     // if we haven't already decided this is no tail call, try to detect CPS-like expressions

diff --git a/src/Compiler/SyntaxTree/PrettyNaming.fsi b/src/Compiler/SyntaxTree/PrettyNaming.fsi
@@ -58,7 +58,7 @@ val IsIdentifierName: name: string -> bool
 /// TBD: needs unit testing
 val IsActivePatternName: name: string -> bool
 
-val internal DoesIdentifierNeedBackticks: string -> bool
+val DoesIdentifierNeedBackticks: string -> bool
 
 /// Adds double backticks if necessary to make a valid identifier, e.g.
 ///     op_Addition  -->  op_Addition

diff --git a/src/FSharp.Build/Microsoft.FSharp.NetSdk.props b/src/FSharp.Build/Microsoft.FSharp.NetSdk.props
@@ -30,7 +30,14 @@ WARNING:  DO NOT MODIFY this file unless you are knowledgeable about MSBuild and
   </Choose>
 
   <PropertyGroup>
-    <EnableDefaultCompileItems Condition=" '$(EnableDefaultCompileItems)' == '' ">false</EnableDefaultCompileItems>                                <!-- Do not glob F# source files -->
+    <EnableDefaultCompileItems Condition=" '$(EnableDefaultCompileItems)' == '' ">false</EnableDefaultCompileItems>                                 <!-- Do not glob F# source files -->
+    <!--
+        It turns out that the project system discovers Folders as a consequence of <SomeItem Include="path to files" />
+        ''''EnableDefaultNoneItems true'''' causes folders and .fsi files to be displayed in the wrong order. because
+        Discovers Folders as a consequence of ````<SomeItem Include="path to files" />```` which EnableDefaultNoneItems causes folders and .fsi files to be located in the solution folder
+        prior to the ````<Compile Include="" />```` in the .fsproj which messes with the display order in solution explorer.
+    -->
+    <EnableDefaultNoneItems Condition=" '$(EnableDefaultNoneItems)' == '' ">false</EnableDefaultNoneItems>                                          <!-- Do not glob F# none items-->
   </PropertyGroup>
 
   <PropertyGroup>

diff --git a/tests/FSharp.Compiler.ComponentTests/CompilerOptions/fsc/flaterrors.fs b/tests/FSharp.Compiler.ComponentTests/CompilerOptions/fsc/flaterrors.fs
@@ -59,7 +59,7 @@ module flaterrors =
 
     [<InlineData("--FlatErrors")>]                          //Invalid case
     [<InlineData("--FLATERRORS")>]                          //Even more invalid case
-    [<InlineData("--flaterrors-")>]                         // no + allowed
+    [<InlineData("--flaterrors+")>]                         // no + allowed
     [<InlineData("--flaterrors-")>]                         // no - allowed
     [<Theory>]
     let ``E_MultiLine04_fs`` (option: string) =

diff --git a/tests/FSharp.Compiler.ComponentTests/ErrorMessages/TailCallAttribute.fs b/tests/FSharp.Compiler.ComponentTests/ErrorMessages/TailCallAttribute.fs
@@ -1522,3 +1522,164 @@ namespace N
               Message =
                 "The member or function 'reverse' has the 'TailCallAttribute' attribute, but is not being used in a tail recursive way." }
         ]
+
+    [<FSharp.Test.FactForNETCOREAPP>]
+    let ``Don't warn for yield! call of rec func in seq`` () =
+        """
+namespace N
+
+module M =
+
+    type SynExpr =
+        | Sequential of expr1 : SynExpr * expr2 : SynExpr
+        | NotSequential
+        member _.Range = 99
+
+    type SyntaxNode = SynExpr of SynExpr
+
+    type SyntaxVisitor () = member _.VisitExpr _ = None
+
+    let visitor = SyntaxVisitor ()
+    let dive expr range f = range, fun () -> Some expr
+    let traverseSynExpr _ expr = Some expr
+
+    [<TailCall>]
+    let rec traverseSequentials path expr =
+        seq {
+            match expr with
+            | SynExpr.Sequential(expr1 = expr1; expr2 = SynExpr.Sequential _ as expr2) ->
+                yield dive expr expr.Range (fun expr -> visitor.VisitExpr(path, traverseSynExpr path, (fun _ -> None), expr))
+                let path = SyntaxNode.SynExpr expr :: path
+                yield dive expr1 expr1.Range (traverseSynExpr path)
+                yield! traverseSequentials path expr2   // should not warn
+
+            | _ ->
+                yield dive expr expr.Range (traverseSynExpr path)
+        }
+        """
+        |> FSharp
+        |> withLangVersion80
+        |> compile
+        |> shouldSucceed
+
+    [<FSharp.Test.FactForNETCOREAPP>]
+    let ``Warn for yield! call of rec func in list comprehension`` () =
+        """
+namespace N
+
+module M =
+
+    type SynExpr =
+        | Sequential of expr1 : SynExpr * expr2 : SynExpr
+        | NotSequential
+        member _.Range = 99
+
+    type SyntaxNode = SynExpr of SynExpr
+
+    type SyntaxVisitor () = member _.VisitExpr _ = None
+
+    let visitor = SyntaxVisitor ()
+    let dive expr range f = range, fun () -> Some expr
+    let traverseSynExpr _ expr = Some expr
+
+    [<TailCall>]
+    let rec traverseSequentials path expr =
+        [
+            match expr with
+            | SynExpr.Sequential(expr1 = expr1; expr2 = SynExpr.Sequential _ as expr2) ->
+                // It's a nested sequential expression.
+                // Visit it, but make defaultTraverse do nothing,
+                // since we're going to traverse its descendants ourselves.
+                yield dive expr expr.Range (fun expr -> visitor.VisitExpr(path, traverseSynExpr path, (fun _ -> None), expr))
+
+                // Now traverse its descendants.
+                let path = SyntaxNode.SynExpr expr :: path
+                yield dive expr1 expr1.Range (traverseSynExpr path)
+                yield! traverseSequentials path expr2   // should warn
+
+            | _ ->
+                // It's not a nested sequential expression.
+                // Traverse it normally.
+                yield dive expr expr.Range (traverseSynExpr path)
+        ]
+        """
+        |> FSharp
+        |> withLangVersion80
+        |> compile
+        |> shouldFail
+        |> withResults [
+            { Error = Warning 3569
+              Range = { StartLine = 32
+                        StartColumn = 24
+                        EndLine = 32
+                        EndColumn = 54 }
+              Message =
+                "The member or function 'traverseSequentials' has the 'TailCallAttribute' attribute, but is not being used in a tail recursive way." }
+        ]
+
+    [<FSharp.Test.FactForNETCOREAPP>]
+    let ``Warn for yield! call of rec func in custom CE`` () =
+        """
+namespace N
+
+module M =
+
+    type SynExpr =
+        | Sequential of expr1 : SynExpr * expr2 : SynExpr
+        | NotSequential
+        member _.Range = 99
+
+    type SyntaxNode = SynExpr of SynExpr
+
+    type SyntaxVisitor () = member _.VisitExpr _ = None
+
+    let visitor = SyntaxVisitor ()
+    let dive expr range f = range, fun () -> Some expr
+    let traverseSynExpr _ expr = Some expr
+
+    type ThingsBuilder() =
+
+        member _.Yield(x) = [ x ]
+
+        member _.Combine(currentThings, newThings) = currentThings @ newThings
+
+        member _.Delay(f) = f ()
+
+        member _.YieldFrom(x) = x
+
+    let things = ThingsBuilder()
+
+    [<TailCall>]
+    let rec traverseSequentials path expr =
+        things {
+            match expr with
+            | SynExpr.Sequential(expr1 = expr1; expr2 = SynExpr.Sequential _ as expr2) ->
+                // It's a nested sequential expression.
+                // Visit it, but make defaultTraverse do nothing,
+                // since we're going to traverse its descendants ourselves.
+                yield dive expr expr.Range (fun expr -> visitor.VisitExpr(path, traverseSynExpr path, (fun _ -> None), expr))
+
+                // Now traverse its descendants.
+                let path = SyntaxNode.SynExpr expr :: path
+                yield dive expr1 expr1.Range (traverseSynExpr path)
+                yield! traverseSequentials path expr2   // should warn
+
+            | _ ->
+                // It's not a nested sequential expression.
+                // Traverse it normally.
+                yield dive expr expr.Range (traverseSynExpr path)
+        }
+        """
+        |> FSharp
+        |> withLangVersion80
+        |> compile
+        |> shouldFail
+        |> withResults [
+            { Error = Warning 3569
+              Range = { StartLine = 43
+                        StartColumn = 17
+                        EndLine = 43
+                        EndColumn = 68 }
+              Message =
+                "The member or function 'traverseSequentials' has the 'TailCallAttribute' attribute, but is not being used in a tail recursive way." }
+        ]
diff --git a/tests/FSharp.Compiler.ComponentTests/Language/ComputationExpressionTests.fs b/tests/FSharp.Compiler.ComponentTests/Language/ComputationExpressionTests.fs
@@ -96,7 +96,6 @@ let x = lb {1; 2; if true then 3;}
 
     [<Theory>]
     [<InlineData("preview","BindReturn")>]
-    [<InlineData("preview","BindReturn")>]
     [<InlineData("preview","WithoutBindReturn")>]
     [<InlineData("4.7","BindReturn")>]   
     [<InlineData("4.7","WithoutBindReturn")>]  
@@ -135,4 +134,4 @@ let _pythags = seqbuilder {{
         code
         |> FSharp     
         |> typecheck
-        |> shouldSucceed
+        |> shouldSucceed
diff --git a/tests/FSharp.Compiler.ComponentTests/TypeChecks/Graph/Scenarios.fs b/tests/FSharp.Compiler.ComponentTests/TypeChecks/Graph/Scenarios.fs
@@ -937,6 +937,30 @@ let v = 2
 module B
 
 do ignore (match "" with | nameof X.Y.Z -> () | _ -> ())
+"""
+                    (set [| 0 |])
+            ]
+        scenario
+            "nameof type with generic parameters"
+            [
+                sourceFile
+                    "A.fs"
+                    """
+namespace A
+
+module B =
+    module C =
+        type D = class end
+"""
+                    Set.empty
+                sourceFile
+                    "Z.fs"
+                    """
+module Z
+
+open System.Threading.Tasks
+
+let _ = nameof Task<A.B.C.D>
 """
                     (set [| 0 |])
             ]

diff --git a/...FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl b/...FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl
@@ -6049,6 +6049,7 @@ FSharp.Compiler.Syntax.ParserDetail: Int32 GetHashCode(System.Collections.IEqual
 FSharp.Compiler.Syntax.ParserDetail: Int32 Tag
 FSharp.Compiler.Syntax.ParserDetail: Int32 get_Tag()
 FSharp.Compiler.Syntax.ParserDetail: System.String ToString()
+FSharp.Compiler.Syntax.PrettyNaming: Boolean DoesIdentifierNeedBackticks(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsActivePatternName(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsCompilerGeneratedName(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsIdentifierFirstCharacter(Char)

diff --git a/...harp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl b/...harp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl
@@ -6049,6 +6049,7 @@ FSharp.Compiler.Syntax.ParserDetail: Int32 GetHashCode(System.Collections.IEqual
 FSharp.Compiler.Syntax.ParserDetail: Int32 Tag
 FSharp.Compiler.Syntax.ParserDetail: Int32 get_Tag()
 FSharp.Compiler.Syntax.ParserDetail: System.String ToString()
+FSharp.Compiler.Syntax.PrettyNaming: Boolean DoesIdentifierNeedBackticks(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsActivePatternName(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsCompilerGeneratedName(System.String)
 FSharp.Compiler.Syntax.PrettyNaming: Boolean IsIdentifierFirstCharacter(Char)

diff --git a/tests/benchmarks/CompiledCodeBenchmarks/MicroPerf/Benchmarks.fs b/tests/benchmarks/CompiledCodeBenchmarks/MicroPerf/Benchmarks.fs