Merge pull request #7702 from KevinRansom/cp_it

Cherry pick fix for eval not returning a value for multi-line submissions.

Author: brettfo

src/fsharp/fsi/fsi.fs

@@ -1139,44 +1139,50 @@ type internal FsiDynamicCompiler
         let newState = { istate with tcState = tcState.NextStateAfterIncrementalFragment(tcEnvAtEndOfLastInput) }
 
         // Find all new declarations the EvaluationListener
+        let mutable itValue = None
         try
             let contents = FSharpAssemblyContents(tcGlobals, tcState.Ccu, Some tcState.CcuSig, tcImports, declaredImpls)
             let contentFile = contents.ImplementationFiles.[0]
+
             // Skip the "FSI_NNNN"
-            match contentFile.Declarations with 
-            | [FSharpImplementationFileDeclaration.Entity (_eFakeModule,modDecls) ] -> 
+            match contentFile.Declarations with
+            | [FSharpImplementationFileDeclaration.Entity (_eFakeModule,modDecls) ] ->
                 let cenv = SymbolEnv(newState.tcGlobals, newState.tcState.Ccu, Some newState.tcState.CcuSig, newState.tcImports)
-                for decl in modDecls do 
-                    match decl with 
+                for decl in modDecls do
+                    match decl with
                     | FSharpImplementationFileDeclaration.MemberOrFunctionOrValue (v,_,_) ->
                         // Report a top-level function or value definition
-                      if v.IsModuleValueOrMember && not v.IsMember then 
-                        let fsiValueOpt = 
-                            match v.Item with 
-                            | Item.Value vref ->
-                                let optValue = newState.ilxGenerator.LookupGeneratedValue(valuePrinter.GetEvaluationContext(newState.emEnv), vref.Deref)
-                                match optValue with
-                                | Some (res, ty) -> Some(FsiValue(res, ty, FSharpType(cenv, vref.Type)))
-                                | None -> None 
-                            | _ -> None
-
-                        let symbol = FSharpSymbol.Create(cenv, v.Item)
-                        let symbolUse = FSharpSymbolUse(tcGlobals, newState.tcState.TcEnvFromImpls.DisplayEnv, symbol, ItemOccurence.Binding, v.DeclarationLocation)
-                        fsi.TriggerEvaluation (fsiValueOpt, symbolUse, decl)
+                        if v.IsModuleValueOrMember && not v.IsMember then
+                            let fsiValueOpt =
+                                match v.Item with
+                                | Item.Value vref ->
+                                    let optValue = newState.ilxGenerator.LookupGeneratedValue(valuePrinter.GetEvaluationContext(newState.emEnv), vref.Deref)
+                                    match optValue with
+                                    | Some (res, ty) -> Some(FsiValue(res, ty, FSharpType(cenv, vref.Type)))
+                                    | None -> None 
+                                | _ -> None
+
+                            if v.CompiledName = "it" then
+                                itValue <- fsiValueOpt
+
+                            let symbol = FSharpSymbol.Create(cenv, v.Item)
+                            let symbolUse = FSharpSymbolUse(tcGlobals, newState.tcState.TcEnvFromImpls.DisplayEnv, symbol, ItemOccurence.Binding, v.DeclarationLocation)
+                            fsi.TriggerEvaluation (fsiValueOpt, symbolUse, decl)
+
                     | FSharpImplementationFileDeclaration.Entity (e,_) ->
                         // Report a top-level module or namespace definition
                         let symbol = FSharpSymbol.Create(cenv, e.Item)
                         let symbolUse = FSharpSymbolUse(tcGlobals, newState.tcState.TcEnvFromImpls.DisplayEnv, symbol, ItemOccurence.Binding, e.DeclarationLocation)
                         fsi.TriggerEvaluation (None, symbolUse, decl)
+
                     | FSharpImplementationFileDeclaration.InitAction _ ->
                         // Top level 'do' bindings are not reported as incremental declarations
                         ()
             | _ -> ()
         with _ -> ()
 
-        newState
-      
-     
+        newState, Completed itValue
+
     /// Evaluate the given expression and produce a new interactive state.
     member fsiDynamicCompiler.EvalParsedExpression (ctok, errorLogger: ErrorLogger, istate, expr: SynExpr) =
         let tcConfig = TcConfig.Create (tcConfigB, validate=false)
@@ -1186,13 +1192,13 @@ type internal FsiDynamicCompiler
         let defs = fsiDynamicCompiler.BuildItBinding expr
 
         // Evaluate the overall definitions.
-        let istate = fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, false, true, defs)
+        let istate = fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, false, true, defs) |> fst
         // Snarf the type for 'it' via the binding
         match istate.tcState.TcEnvFromImpls.NameEnv.FindUnqualifiedItem itName with 
         | NameResolution.Item.Value vref -> 
              if not tcConfig.noFeedback then 
                  valuePrinter.InvokeExprPrinter (istate.tcState.TcEnvFromImpls.DisplayEnv, istate.emEnv, istate.ilxGenerator, vref.Deref)
-             
+
              /// Clear the value held in the previous "it" binding, if any, as long as it has never been referenced.
              match prevIt with
              | Some prevVal when not prevVal.Deref.HasBeenReferenced -> 
@@ -1787,7 +1793,7 @@ type internal FsiInteractionProcessor
             | IDefns ([  SynModuleDecl.DoExpr(_,expr,_)],_) ->
                 fsiDynamicCompiler.EvalParsedExpression(ctok, errorLogger, istate, expr)
             | IDefns (defs,_) -> 
-                fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, true, false, defs),Completed None
+                fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, true, false, defs)
 
             | IHash (ParsedHashDirective("load",sourceFiles,m),_) -> 
                 fsiDynamicCompiler.EvalSourceFiles (ctok, istate, m, sourceFiles, lexResourceManager, errorLogger),Completed None
@@ -2085,7 +2091,7 @@ type internal FsiInteractionProcessor
     /// Send a dummy interaction through F# Interactive, to ensure all the most common code generation paths are 
     /// JIT'ed and ready for use.
     member __.LoadDummyInteraction(ctok, errorLogger) =
-        setCurrState (currState |> InteractiveCatch errorLogger (fun istate ->  fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, true, false, []), Completed None) |> fst)
+        setCurrState (currState |> InteractiveCatch errorLogger (fun istate ->  fsiDynamicCompiler.EvalParsedDefinitions (ctok, errorLogger, istate, true, false, []) |> fst, Completed None) |> fst)
 
     member __.EvalInteraction(ctok, sourceText, scriptFileName, errorLogger) =
         use _unwind1 = ErrorLogger.PushThreadBuildPhaseUntilUnwind(ErrorLogger.BuildPhase.Interactive)