fix 13043 (#13065)

* Fix https://github.com/dotnet/fsharp/issues/13043

* with debug

* remove labels

* rename

* Remove extra line

* fix 13043

* baselines

* temp

* Disable il test for now

* opt/non-opt

* proper no_opt

* proper optimize+

* merge main

* strip lambdas correctly during codegen

* proper treatment of typed expressions

* update baselines

* baseline

* simplify
Co-authored-by: NKevin Ransom <codecutter@hotmail.com>

src/fsharp/CheckExpressions.fs

@@ -5850,7 +5850,7 @@ and TcNonControlFlowExpr (env: TcEnv) f =
         | NotedSourceConstruct.Combine
         | NotedSourceConstruct.With
         | NotedSourceConstruct.While
-        | NotedSourceConstruct.DelayOrQuoteOrRun -> 
+        | NotedSourceConstruct.DelayOrQuoteOrRun ->
             res, tpenv
         | NotedSourceConstruct.None ->
             // Skip outer debug point for "e1 && e2" and "e1 || e2"
@@ -5929,7 +5929,6 @@ and TcExprUndelayed cenv (overallTy: OverallTy) env tpenv (synExpr: SynExpr) =
 
     // e: ty
     | SynExpr.Typed (synBodyExpr, synType, m) ->
-        TcNonControlFlowExpr env <| fun env ->
         TcExprTypeAnnotated cenv overallTy env tpenv (synBodyExpr, synType, m)
 
     // e :? ty

tests/FSharp.Compiler.ComponentTests/EmittedIL/TestFunctions/TestFunctions.fs

@@ -7,14 +7,23 @@ open FSharp.Test.Compiler
 
 module TestFunctions =
 
-    let verifyCompilation compilation =
+    let verifyCore compilation =
         compilation
-        |> withOptions [ "--test:EmitFeeFeeAs100001" ]
+        |> withOptions [ "--test:EmitFeeFeeAs100001"; "--nowarn:988"; "--nowarn:3370"]
         |> asExe
         |> withNoOptimize
         |> withEmbeddedPdb
         |> withEmbedAllSource
         |> ignoreWarnings
+
+    let verifyCompileAndRun compilation =
+        compilation
+        |> verifyCore
+        |> compileAndRun
+
+    let verifyCompilation compilation =
+        compilation
+        |> verifyCore
         |> verifyILBaseline
 
     //SOURCE=TestFunction01.fs   SCFLAGS="-g --test:EmitFeeFeeAs100001 --optimize-" COMPILE_ONLY=1 POSTCMD="..\\CompareIL.cmd TestFunction01.exe"	# TestFunction01.fs
@@ -245,3 +254,28 @@ module TestFunctions =
         compilation
         |> verifyCompilation
 
+    // Verify IL 13043
+    [<Theory; Directory(__SOURCE_DIRECTORY__, Includes=[|"Verify13043.fs"|])>]
+    let ``Verify13043_il`` compilation =
+        compilation
+        |> withDebug
+        |> verifyCompilation
+
+    // Verify Execution 13043 run it built not optimized with debug
+    [<Theory; Directory(__SOURCE_DIRECTORY__, Includes=[|"Verify13043.fs"|])>]
+    let ``Verify13043_execution_noopt`` compilation =
+        compilation
+        |> withDebug
+        |> verifyCompileAndRun
+        |> shouldSucceed
+
+    // Verify Execution 13043 --- run it built optimized no debug
+    [<Theory; Directory(__SOURCE_DIRECTORY__, Includes=[|"Verify13043.fs"|])>]
+    let ``Verify13043_execution_opt`` compilation =
+        compilation
+        |> asExe
+        |> withOptions [ "--test:EmitFeeFeeAs100001"; "--nowarn:988"; "--nowarn:3370"]
+        |> withOptimize
+        |> withNoDebug
+        |> compileAndRun
+        |> shouldSucceed

tests/FSharp.Compiler.ComponentTests/EmittedIL/TestFunctions/Verify13043.fs

+module Verify13043
+
+let list = [1; 2; 3]
+let condition n = n < 3
+
+let dropWhileWithMatch condition list =
+  let rec f (l : List<int>) : List<int> =
+    match l with
+    | [] -> []
+    | head :: tail ->
+      match condition head with
+      | true -> f tail
+      | false -> head :: tail
+
+  f list
+
+(*
+  This function caused an Unhandled exception at execution time:
+
+  Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
+   at Program.f@14-1.Invoke(FSharpList`1 _arg1) in /workspaces/function-rec-fsharp-dotnet7-bug-demo/Program.fs:line 18
+   at Program.dropWhileWithFunction(FSharpFunc`2 condition, FSharpList`1 list) in /workspaces/function-rec-fsharp-dotnet7-bug-demo/Program.fs:line 21
+   at <StartupCode$function-rec-fsharp-dotnet7-bug-demo>.$Program.main@() in /workspaces/function-rec-fsharp-dotnet7-bug-demo/Program.fs:line 29
+*)
+let dropWhileWithFunction condition list =
+  let rec f : List<int> -> List<int> =
+    function
+    | [] -> []
+    | head :: tail ->
+      match condition head with
+      | true -> f tail
+      | false -> head :: tail
+
+  f list
+
+
+// this runs fine:
+let matchResult = dropWhileWithMatch condition list
+printfn "Match: %A" matchResult
+
+
+// and this results in a null reference exception
+let functionResult = dropWhileWithFunction condition list
+printfn "Function: %A" functionResult

tests/FSharp.Compiler.ComponentTests/FSharp.Compiler.ComponentTests.fsproj

@@ -193,6 +193,7 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(FSharpSourcesRoot)\fsharp\FSharp.Compiler.Service\FSharp.Compiler.Service.fsproj" />
+    <ProjectReference Include="$(FSharpSourcesRoot)\fsharp\FSharp.Compiler.Interactive.Settings\FSharp.Compiler.Interactive.Settings.fsproj" />
     <ProjectReference Include="$(FSharpSourcesRoot)\fsharp\FSharp.Core\FSharp.Core.fsproj" />
     <ProjectReference Include="$(FSharpTestsRoot)\FSharp.Test.Utilities\FSharp.Test.Utilities.fsproj" />
   </ItemGroup>

tests/FSharp.Test.Utilities/Compiler.fs

@@ -342,6 +342,12 @@ module rec Compiler =
         | FS fs -> FS { fs with Options = fs.Options @ options }
         | _ -> failwith message
 
+    let withDebug (cUnit: CompilationUnit) : CompilationUnit =
+        withOptionsHelper [ "--debug+" ] "debug+ is only supported on F#" cUnit
+
+    let withNoDebug (cUnit: CompilationUnit) : CompilationUnit =
+        withOptionsHelper [ "--debug-" ] "debug- is only supported on F#" cUnit
+
     let withOcamlCompat (cUnit: CompilationUnit) : CompilationUnit =
         withOptionsHelper [ "--mlcompatibility" ] "withOcamlCompat is only supported on F#" cUnit
 
@@ -845,8 +851,8 @@ module rec Compiler =
                         // if the environment variable TEST_UPDATE_BSL has been set
                         if snd (Int32.TryParse(Environment.GetEnvironmentVariable("TEST_UPDATE_BSL"))) <> 0 then
                             match baseline with
-                                | Some baseline -> System.IO.File.Copy(baseline.ILBaseline.FilePath, baseline.ILBaseline.BslSource, true)
-                                | None -> ()
+                            | Some baseline -> System.IO.File.Copy(baseline.ILBaseline.FilePath, baseline.ILBaseline.BslSource, true)
+                            | None -> ()
 
                         createBaselineErrors bsl.ILBaseline actualIL
                         Assert.Fail(errorMsg)

tests/FSharp.Test.Utilities/DirectoryAttribute.fs

@@ -66,8 +66,8 @@ type DirectoryAttribute(dir: string) =
 
     let readFileOrDefault (path: string) : string option =
         match FileSystem.FileExistsShim(path) with
-            | true -> Some <| File.ReadAllText path
-            | _ -> None
+        | true -> Some (File.ReadAllText path)
+        | _ -> None
 
     let createCompilationUnit path fs name =
         let outputDirectory =  outputDirectory name