Merge pull request #17643 from dotnet/merges/main-to-release/dev17.12

Merge main to release/dev17.12

docs/release-notes/.FSharp.Compiler.Service/9.0.100.md

@@ -1,5 +1,6 @@
 ### Fixed
 
+* Fix wrong TailCall warning ([Issue #17604](/~https://github.com/dotnet/fsharp/issues/17604), [PR #17637](/~https://github.com/dotnet/fsharp/pull/17637))
 * Compiler hangs when compiling inline recursive invocation ([Issue #17376](/~https://github.com/dotnet/fsharp/issues/17376), [PR #17394](/~https://github.com/dotnet/fsharp/pull/17394))
 * Fix reporting IsFromComputationExpression only for CE builder type constructors and let bindings. ([PR #17375](/~https://github.com/dotnet/fsharp/pull/17375))
 * Optimize simple mappings in comprehensions when the body of the mapping has `let`-bindings and/or sequential expressions before a single yield. ([PR #17419](/~https://github.com/dotnet/fsharp/pull/17419))
@@ -13,6 +14,7 @@
 * Fixed checking failure when `global` namespace is involved with enabled GraphBasedChecking ([PR #17553](/~https://github.com/dotnet/fsharp/pull/17553))
 * Add missing byte chars notations, enforce limits in decimal notation in byte char & string (Issues [#15867](/~https://github.com/dotnet/fsharp/issues/15867), [#15868](/~https://github.com/dotnet/fsharp/issues/15868), [#15869](/~https://github.com/dotnet/fsharp/issues/15869), [PR #15898](/~https://github.com/dotnet/fsharp/pull/15898))
 * Parentheses analysis: keep extra parentheses around unit & tuples in method definitions. ([PR #17618](/~https://github.com/dotnet/fsharp/pull/17618))
+* Consider `open type` used when the type is an enum and any of the enum cases is used unqualified. ([PR #17628](/~https://github.com/dotnet/fsharp/pull/17628))
 
 ### Added
 

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="10.0.0-alpha.1.24426.2">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="10.0.0-alpha.1.24428.1">
       <Uri>/~https://github.com/dotnet/source-build-reference-packages</Uri>
-      <Sha>6c26545ca7999a4192df6899ea9ed4eaa950d367</Sha>
+      <Sha>6bcf90f99d13da86c5e9753a6f34b6484673d0a0</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.24426.3">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.24429.3">
       <Uri>/~https://github.com/dotnet/arcade</Uri>
-      <Sha>e3bdd9a0f2a65fe037ba1adb2261eea48a840fa4</Sha>
+      <Sha>b3f0996b03bfab02a8d9e1669ddb6f12b35634a5</Sha>
     </Dependency>
     <!-- Intermediate is necessary for source build. -->
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.24426.3">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.arcade" Version="9.0.0-beta.24429.3">
       <Uri>/~https://github.com/dotnet/arcade</Uri>
-      <Sha>e3bdd9a0f2a65fe037ba1adb2261eea48a840fa4</Sha>
+      <Sha>b3f0996b03bfab02a8d9e1669ddb6f12b35634a5</Sha>
       <SourceBuild RepoName="arcade" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="optimization.windows_nt-x64.MIBC.Runtime" Version="1.0.0-prerelease.23614.4">

global.json

@@ -17,7 +17,7 @@
     "perl": "5.38.2.2"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.24426.3",
+    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.24429.3",
     "Microsoft.DotNet.Helix.Sdk": "8.0.0-beta.23255.2"
   }
 }

src/Compiler/Checking/TailCallChecks.fs

@@ -47,8 +47,16 @@ type TailCall =
     static member YesFromVal (g: TcGlobals) (v: Val) = TailCall.Yes(TailCall.IsVoidRet g v)
 
     static member YesFromExpr (g: TcGlobals) (expr: Expr) =
+        let yesFromTType (t: TType) =
+            if isUnitTy g t then
+                TailCall.Yes TailCallReturnType.MustReturnVoid
+            else
+                TailCall.Yes TailCallReturnType.NonVoid
+
         match expr with
         | ValUseAtApp(valRef, _) -> TailCall.Yes(TailCall.IsVoidRet g valRef.Deref)
+        | Expr.Const(constType = constType) -> yesFromTType constType
+        | Expr.Match(exprType = exprType) -> yesFromTType exprType
         | _ -> TailCall.Yes TailCallReturnType.NonVoid
 
     member x.AtExprLambda =

src/Compiler/Service/ServiceAnalysis.fs

@@ -51,6 +51,11 @@ module UnusedOpens =
                         if not entity.IsNamespace && not entity.IsFSharpModule then
                             for fv in entity.MembersFunctionsAndValues do
                                 fv
+
+                            if entity.IsEnum then
+                                for field in entity.FSharpFields do
+                                    if field.IsStatic && field.IsLiteral then
+                                        field
                     |]
 
                 HashSet<_>(symbols, symbolHash)

tests/FSharp.Compiler.ComponentTests/ErrorMessages/TailCallAttribute.fs

@@ -1722,3 +1722,22 @@ module M =
         |> withLangVersion80
         |> compile
         |> shouldSucceed
+
+    [<FSharp.Test.FactForNETCOREAPP>]
+    let ``Don't warn for tail rec call returning unit`` () =
+        """
+namespace N
+
+module M =
+
+    [<TailCall>]
+    let rec go (args: string list) =
+        match args with
+        | [] -> ()
+        | "--" :: _ -> ()
+        | arg :: args -> go args
+        """
+        |> FSharp
+        |> withLangVersion80
+        |> compile
+        |> shouldSucceed

tests/FSharp.Compiler.Service.Tests/ProjectAnalysisTests.fs

@@ -5603,13 +5603,25 @@ open SomeUsedModuleContainingFunction
 open SomeUsedModuleContainingExtensionMember
 open SomeUsedModuleContainingActivePattern
 open SomeUsedModuleContainingUnion
+open type System.DayOfWeek // Used, should not appear.
+open type System.DateTimeKind // Unused, should appear.
+
+type FSharpEnum1 = X = 1 | Y = (1 <<< 1) | Z = (1 <<< 2)
+type FSharpEnum2 = H = 1 | I = (1 <<< 1) | J = (1 <<< 2)
+
+open type FSharpEnum1 // Used, should not appear.
+open type FSharpEnum2 // Unused, should appear.
 
 type UseTheThings(i:int) =
     member x.Value = Dictionary<int,int>() // use something from System.Collections.Generic, as a constructor
     member x.UseSomeUsedModuleContainingFunction() = g 3
     member x.UseSomeUsedModuleContainingActivePattern(ActivePattern g) = g
     member x.UseSomeUsedModuleContainingExtensionMember() = (3).Q
     member x.UseSomeUsedModuleContainingUnion() = A
+    member x.UseEnumCase = Monday // Use an enum case from System.DayOfWeek.
+    member x.UseEnumCaseQualified = System.DateTimeKind.Utc // Use a qualified enum case.
+    member x.UseFSharpEnumCase = Y // Use an enum case from FSharpEnum1.
+    member x.UseFSharpEnumCaseQualified = FSharpEnum2.J // Use a qualified enum case.
 """
     let fileSource1 = SourceText.ofString fileSource1Text
     FileSystem.OpenFileForWriteShim(fileName1).Write(fileSource1Text)
@@ -5637,7 +5649,9 @@ type UseTheThings(i:int) =
            (((6, 5), (6, 19)), "open FSharp.Control // unused");
            (((7, 5), (7, 16)), "open FSharp.Data // unused");
            (((8, 5), (8, 25)), "open System.Globalization // unused");
-           (((25, 5), (25, 21)), "open SomeUnusedModule")]
+           (((25, 5), (25, 21)), "open SomeUnusedModule");
+           (((31, 10), (31, 29)), "open type System.DateTimeKind // Unused, should appear.")
+           (((37, 10), (37, 21)), "open type FSharpEnum2 // Unused, should appear.")]
     unusedOpensData |> shouldEqual expected
 
 [<Theory>]