Fix extern declaration accessibility

src/fsharp/pars.fsy

@@ -2643,7 +2643,7 @@ cPrototype:
                                   SynExpr.Ident (ident("failwith", rhs parseState 6)),
                                   SynExpr.Const (SynConst.String("extern was not given a DllImport attribute", rhs parseState 8), rhs parseState 8),
                                   mRhs)
-        (fun attrs vis -> 
+        (fun attrs _ -> 
             let bindingId = SynPat.LongIdent (LongIdentWithDots([nm], []), None, Some noInferredTypars, SynArgPats.Pats [SynPat.Tuple(false, args, argsm)], vis, nmm)
             let binding = mkSynBinding 
                               (xmlDoc, bindingId) 

tests/fsharp/typeProviders/helloWorld/provided.fs

@@ -196,5 +196,5 @@ module TheOuterType =
 
 module DllImportSmokeTest = 
     [<System.Runtime.InteropServices.DllImport("kernel32.dll")>]
-    extern System.UInt32 private GetLastError()
+    extern System.UInt32 GetLastError()
 

tests/service/Common.fs

@@ -228,10 +228,15 @@ let matchBraces (name: string, code: string) =
     let braces = checker.MatchBraces(filePath, FSharp.Compiler.Text.SourceText.ofString code, options) |> Async.RunSynchronously
     braces
 
-let parseSourceCodeAndGetModule (source: string) =
-    match parseSourceCode ("test", source) with
-    | Some (ParsedInput.ImplFile (ParsedImplFileInput (_, _, _, _, _, [ moduleOrNamespace ], _))) -> moduleOrNamespace
+
+let getSingleModuleLikeDecl (input: ParsedInput option) =
+    match input with
+    | Some (ParsedInput.ImplFile (ParsedImplFileInput (modules = [ decl ]))) -> decl
     | _ -> failwith "Could not get module decls"
+
+let parseSourceCodeAndGetModule (source: string) =
+    parseSourceCode ("test", source) |> getSingleModuleLikeDecl
+
 
 /// Extract range info 
 let tups (m:Range.range) = (m.StartLine, m.StartColumn), (m.EndLine, m.EndColumn)

tests/service/Symbols.fs

@@ -8,9 +8,10 @@ module Tests.Service.Symbols
 #endif
 
 open FSharp.Compiler.Service.Tests.Common
+open FSharp.Compiler.SourceCodeServices
+open FSharp.Compiler.SyntaxTree
 open FsUnit
 open NUnit.Framework
-open FSharp.Compiler.SourceCodeServices
 
 module ActivePatterns =
 
@@ -57,6 +58,37 @@ match "foo" with
         getCaseUsages partialPatternInput 7 |> Array.head |> getGroupName |> shouldEqual "|String|_|"
 
 
+module ExternDeclarations =
+    [<Test>]
+    let ``Access modifier`` () =
+        let parseResults, checkResults = getParseAndCheckResults """
+extern int a()
+extern int public b()
+extern int private c()
+"""
+        let (SynModuleOrNamespace (decls = decls)) = getSingleModuleLikeDecl parseResults.ParseTree
+
+        [ None
+          Some SynAccess.Public
+          Some SynAccess.Private ]
+        |> List.zip decls
+        |> List.iter (fun (actual, expected) ->
+            match actual with
+            | SynModuleDecl.Let (_, [Binding (accessibility = access)], _) -> access |> should equal expected
+            | decl -> failwithf "unexpected decl: %O" decl)
+
+        [ "a", (true, false, false, false)
+          "b", (true, false, false, false)
+          "c", (false, false, false, true) ]
+        |> List.iter (fun (name, expected) ->
+            match findSymbolByName name checkResults with
+            | :? FSharpMemberOrFunctionOrValue as mfv ->
+                let access = mfv.Accessibility
+                (access.IsPublic, access.IsProtected, access.IsInternal, access.IsPrivate)
+                |> should equal expected
+            | _ -> failwithf "Couldn't get mfv: %s" name)
+
+
 module XmlDocSig =
 
     [<Test>]