Second half of fix for https://github.com/Microsoft/visualfsharp/issues/106

src/fsharp/CompileOps.fs

@@ -3846,11 +3846,20 @@ type TcImports(tcConfigP:TcConfigProvider, initialResolutions:TcAssemblyResoluti
                    referencedAssemblies   = [| for r in resolutions.GetAssemblyResolutions() -> r.resolvedPath |]
                    temporaryFolder        = Path.GetTempPath() }
 
+            // The type provider should not hold strong references to disposed
+            // TcImport objects.  So the callbacks provided in the type provider config
+            // dispatch via a thunk which gets set to a non-resource-capturing 
+            // failing function when the object is disposed. 
+            let systemRuntimeContainsType =  
+                let systemRuntimeContainsTypeRef = ref tcImports.SystemRuntimeContainsType  
+                tcImports.AttachDisposeAction(fun () -> systemRuntimeContainsTypeRef := (fun _ -> raise (System.ObjectDisposedException("The type provider has been disposed"))))  
+                fun arg -> systemRuntimeContainsTypeRef.Value arg  
+
             let providers = 
                 [ for assemblyName in providerAssemblies do
                       yield ExtensionTyping.GetTypeProvidersOfAssembly(displayPSTypeProviderSecurityDialogBlockingUI, tcConfig.validateTypeProviders, tpApprovals, 
                                                                        fileNameOfRuntimeAssembly, ilScopeRefOfRuntimeAssembly, assemblyName, typeProviderEnvironment, 
-                                                                       tcConfig.isInvalidationSupported, tcConfig.isInteractive, tcImports.SystemRuntimeContainsType, systemRuntimeAssemblyVersion, m) ]
+                                                                       tcConfig.isInvalidationSupported, tcConfig.isInteractive, systemRuntimeContainsType, systemRuntimeAssemblyVersion, m) ]
             let wasApproved = providers |> List.forall (fun (ok,_) -> ok)
             let providers = providers |> List.map snd |> List.concat
 

vsintegration/src/unittests/Resources.MockTypeProviders/DummyProviderForLanguageServiceTesting/DummyProviderForLanguageServiceTesting.fs

@@ -115,15 +115,25 @@ module internal TPModule =
 module GlobalCounters = 
     let mutable creations = 0
     let mutable disposals = 0
+    let mutable configs = ([]: TypeProviderConfig list)
     let GetTotalCreations() = creations
     let GetTotalDisposals() = disposals
+    let CheckAllConfigsDisposed() = 
+        for c in configs do 
+            try 
+                c.SystemRuntimeContainsType("System.Object") |> ignore
+                failwith "expected configuration object to be disposed"
+            with :? System.ObjectDisposedException -> 
+                ()
+
 
 
 [<TypeProvider>]
-type HelloWorldProvider() = 
+type HelloWorldProvider(config: TypeProviderConfig) = 
     inherit TypeProviderForNamespaces(TPModule.namespaceName,TPModule.types)
     do GlobalCounters.creations <- GlobalCounters.creations + 1                         
     let mutable disposed = false
+    do GlobalCounters.configs <- config :: GlobalCounters.configs
     interface System.IDisposable with 
         member x.Dispose() = 
             System.Diagnostics.Debug.Assert(not disposed)

vsintegration/src/unittests/Tests.LanguageService.Script.fs

@@ -1628,6 +1628,8 @@ type ScriptTests() as this =
         Assert.IsNotNull(totalCreationsMeth, "totalCreationsMeth should not be null")
         let totalDisposalsMeth = providerCounters.GetMethod("GetTotalDisposals")
         Assert.IsNotNull(totalDisposalsMeth, "totalDisposalsMeth should not be null")
+        let checkConfigsMeth = providerCounters.GetMethod("CheckAllConfigsDisposed")
+        Assert.IsNotNull(checkConfigsMeth, "checkConfigsMeth should not be null")
 
         let providerCounters2 = providerAssembly.GetType("Microsoft.FSharp.TypeProvider.Emit.GlobalCountersForInvalidation")
         Assert.IsNotNull(providerCounters2, "provider counters #2 module should not be null")
@@ -1638,6 +1640,7 @@ type ScriptTests() as this =
 
         let totalCreations() = totalCreationsMeth.Invoke(null, [| |]) :?> int
         let totalDisposals() = totalDisposalsMeth.Invoke(null, [| |]) :?> int
+        let checkConfigsDisposed() = checkConfigsMeth.Invoke(null, [| |]) |> ignore
         let totalInvaldiationHandlersAdded() = totalInvaldiationHandlersAddedMeth.Invoke(null, [| |]) :?> int
         let totalInvaldiationHandlersRemoved() = totalInvaldiationHandlersRemovedMeth.Invoke(null, [| |]) :?> int
 
@@ -1693,6 +1696,7 @@ type ScriptTests() as this =
         ClearLanguageServiceRootCachesAndCollectAndFinalizeAllTransients(this.VS)
         Assert.IsTrue(countDisposals() = 50, "Check6b, at end, countDisposals() = 50 after explicit clearing")
         Assert.IsTrue(countInvaldiationHandlersAdded() - countInvaldiationHandlersRemoved() = 0, "Check6b2, at end, all invalidation handlers removed after explicit cleraring")
+        checkConfigsDisposed()
 
     [<Test>]
     [<Category("TypeProvider")>]