Script debugging in VS

See spec at https://gist.github.com/latkin/cba4187a99db9747d0bf
closes #225

commit b8ea6f617f32e44f29a22afd7aa4f2d09bb1a091
Author: latkin <latkin@microsoft.com>
Date:   Tue Feb 24 17:12:04 2015 -0800

    Touch-ups after rebase

commit 26ff24562bfb49de79c44342105f2946898c2f1e
Author: latkin <latkin@microsoft.com>
Date:   Wed Feb 18 12:54:36 2015 -0800

    Add capability to auto-break on first executable line

commit 675a27298d687cb8c3240af64069cc22accefe02
Author: latkin <latkin@microsoft.com>
Date:   Wed Feb 18 12:53:27 2015 -0800

    Change menu text, use more sensible hotkeys

commit ab73f78ca8bfc4b433152aa3e173fc22b74786a0
Author: latkin <latkin@microsoft.com>
Date:   Wed Feb 18 12:52:39 2015 -0800

    Small whitespace alignment

commit f551344b09fdfb94bfd813100d6065032bd92520
Author: latkin <latkin@microsoft.com>
Date:   Thu Feb 12 19:29:16 2015 -0800

    Output symbol info for locals

commit d6a0faac99bd33fec0c4be24d13009127b8ff420
Author: latkin <latkin@microsoft.com>
Date:   Thu Feb 12 18:00:14 2015 -0800

    Use same whitespace style as existing code

commit a4003c17a006d7eeda1c3920ad05aef788db846e
Author: latkin <latkin@microsoft.com>
Date:   Wed Feb 11 11:06:22 2015 -0800

    Add 'detach' item for tool window, and give 'attach'/'detach' smart visibility

commit c5a64605aca53cdfd742975225c8fa4e665b9f84
Author: latkin <latkin@microsoft.com>
Date:   Wed Feb 11 07:39:34 2015 -0800

    Enable basic script debugging

src/absil/il.fs

@@ -1185,7 +1185,8 @@ and ILFilterBlock =
 [<NoComparison; NoEquality>]
 type ILLocal = 
     { Type: ILType;
-      IsPinned: bool }
+      IsPinned: bool;
+      DebugInfo: (string * int * int) option }
       
 type ILLocals = ILList<ILLocal>
 let emptyILLocals = (ILList.empty : ILLocals)
@@ -3022,9 +3023,10 @@ let mkILReturn ty : ILReturn =
       Type=ty;
       CustomAttrs=emptyILCustomAttrs  }
 
-let mkILLocal ty = 
+let mkILLocal ty dbgInfo = 
     { IsPinned=false;
-      Type=ty; }
+      Type=ty;
+      DebugInfo=dbgInfo }
 
 type ILFieldSpec with
   member fr.ActualType = 

src/absil/il.fsi

@@ -970,7 +970,8 @@ type ILNativeType =
 [<NoComparison; NoEquality>]
 type ILLocal = 
     { Type: ILType;
-      IsPinned: bool }
+      IsPinned: bool;
+      DebugInfo: (string * int * int) option }
      
 
 type ILLocals = ILList<ILLocal>
@@ -1955,7 +1956,7 @@ val mkILParam: string option * ILType -> ILParameter
 val mkILParamAnon: ILType -> ILParameter
 val mkILParamNamed: string * ILType -> ILParameter
 val mkILReturn: ILType -> ILReturn
-val mkILLocal: ILType -> ILLocal
+val mkILLocal: ILType -> (string * int * int) option -> ILLocal
 val mkILLocals : ILLocal list -> ILLocals
 val emptyILLocals : ILLocals
 

src/absil/ilread.fs

@@ -2206,7 +2206,8 @@ and sigptrGetLocal ctxt numtypars bytes sigptr =
             false, sigptr
     let typ, sigptr = sigptrGetTy ctxt numtypars bytes sigptr
     { IsPinned = pinned;
-      Type = typ }, sigptr
+      Type = typ;
+      DebugInfo = None }, sigptr
          
 and readBlobHeapAsMethodSig ctxt numtypars blobIdx  =
     ctxt.readBlobHeapAsMethodSig (BlobAsMethodSigIdx (numtypars,blobIdx))

src/absil/ilreflect.fs

@@ -1252,7 +1252,11 @@ let emitCode cenv modB emEnv (ilG:ILGenerator) code =
 
 let emitLocal cenv emEnv (ilG : ILGenerator) (local: ILLocal) =
     let ty = convType cenv emEnv  local.Type
-    ilG.DeclareLocalAndLog(ty,local.IsPinned)
+    let locBuilder = ilG.DeclareLocalAndLog(ty, local.IsPinned)
+    match local.DebugInfo with
+    | Some(nm, start, finish) -> locBuilder.SetLocalSymInfo(nm, start, finish)
+    | None -> ()
+    locBuilder
 
 let emitILMethodBody cenv modB emEnv (ilG:ILGenerator) ilmbody =
     // XXX - REVIEW:

src/fsharp/fsi/fsi.fs

@@ -733,7 +733,8 @@ type internal FsiDynamicCompilerState =
       tcState   : Build.TcState 
       ilxGenerator : Ilxgen.IlxAssemblyGenerator
       // Why is this not in FsiOptions?
-      timing    : bool }
+      timing    : bool
+      debugBreak : bool }
 
 let internal WithImplicitHome (tcConfigB, dir) f = 
     let old = tcConfigB.implicitIncludeDir 
@@ -986,13 +987,22 @@ type internal FsiDynamicCompiler
         let mkBind pat expr = Binding (None, DoBinding, false, (*mutable*)false, [], PreXmlDoc.Empty, SynInfo.emptySynValData, pat, None, expr, m, NoSequencePointAtInvisibleBinding)
         let bindingA = mkBind (mkSynPatVar None itID) expr (* let it = <expr> *)  // NOTE: the generalizability of 'expr' must not be damaged, e.g. this can't be an application 
         let saverPath  = ["Microsoft";"FSharp";"Compiler";"Interactive";"RuntimeHelpers";"SaveIt"]
-        let dots = List.replicate (saverPath.Length - 1) rangeStdin
-        let bindingB = mkBind (SynPat.Wild m) (SynExpr.App(ExprAtomicFlag.NonAtomic, false, SynExpr.LongIdent(false, LongIdentWithDots(List.map (mkSynId rangeStdin) saverPath,dots),None,m), itExp,m)) (* let _  = saverPath it *)
+        let dots = List.replicate (saverPath.Length - 1) m
+        let bindingB = mkBind (SynPat.Wild m) (SynExpr.App(ExprAtomicFlag.NonAtomic, false, SynExpr.LongIdent(false, LongIdentWithDots(List.map (mkSynId m) saverPath,dots),None,m), itExp,m)) (* let _  = saverPath it *)
         let defA = SynModuleDecl.Let (false, [bindingA], m)
         let defB = SynModuleDecl.Let (false, [bindingB], m)
         
         [defA; defB]
 
+    // construct an invisible call to Debugger.Break(), in the specified range
+    member __.CreateDebuggerBreak (m : range) =
+        let breakPath = ["System";"Diagnostics";"Debugger";"Break"]
+        let dots = List.replicate (breakPath.Length - 1) m
+        let methCall = SynExpr.LongIdent(false, LongIdentWithDots(List.map (mkSynId m) breakPath, dots), None, m)
+        let args = SynExpr.Const(SynConst.Unit, m)
+        let breakStatement = SynExpr.App(ExprAtomicFlag.Atomic, false, methCall, args, m)
+        SynModuleDecl.DoExpr(SequencePointInfoForBinding.NoSequencePointAtDoBinding, breakStatement, m)
+
     member __.EvalRequireReference istate m path = 
         if Path.IsInvalidPath(path) then
             error(Error(FSIstrings.SR.fsiInvalidAssembly(path),m))
@@ -1080,6 +1090,7 @@ type internal FsiDynamicCompiler
          tcState   = tcState;
          ilxGenerator = ilxGenerator;
          timing    = false;
+         debugBreak = false;
         } 
 
 
@@ -1619,7 +1630,10 @@ type internal FsiInteractionProcessor
             | IHash (ParsedHashDirective("silentCd",[path],m),_) ->
                 ChangeDirectory path m;
                 fsiConsolePrompt.SkipNext(); (* "silent" directive *)
-                istate,Completed                  
+                istate,Completed   
+                               
+            | IHash (ParsedHashDirective("dbgbreak",[],_),_) -> 
+                {istate with debugBreak = true},Completed
 
             | IHash (ParsedHashDirective("time",[],_),_) -> 
                 if istate.timing then
@@ -1678,19 +1692,37 @@ type internal FsiInteractionProcessor
     /// #directive comes through with other definitions as a SynModuleDecl.HashDirective.
     /// We split these out for individual processing.
     let rec ExecInteractions (exitViaKillThread, tcConfig, istate, action:ParsedFsiInteraction option) =
-        let action,nextAction = 
+        let action,nextAction,istate = 
             match action with
-            | None                                      -> None  ,None
-            | Some (IHash _)                            -> action,None
-            | Some (IDefns ([],_))                      -> None  ,None
+            | None                                      -> None  ,None,istate
+            | Some (IHash _)                            -> action,None,istate
+            | Some (IDefns ([],_))                      -> None  ,None,istate
             | Some (IDefns (SynModuleDecl.HashDirective(hash,mh)::defs,m)) -> 
-                Some (IHash(hash,mh)),Some (IDefns(defs,m))
+                Some (IHash(hash,mh)),Some (IDefns(defs,m)),istate
 
             | Some (IDefns (defs,m))                    -> 
                 let isDefHash = function SynModuleDecl.HashDirective(_,_) -> true | _ -> false
+                let isBreakable def = 
+                    // only add automatic debugger breaks before 'let' or 'do' expressions with sequence points
+                    match def with
+                    | SynModuleDecl.DoExpr (SequencePointInfoForBinding.SequencePointAtBinding _, _, _)
+                    | SynModuleDecl.Let (_, SynBinding.Binding(_, _, _, _, _, _, _, _ ,_ ,_ ,_ , SequencePointInfoForBinding.SequencePointAtBinding _) :: _, _) -> true
+                    | _ -> false
                 let defsA = Seq.takeWhile (isDefHash >> not) defs |> Seq.toList
                 let defsB = Seq.skipWhile (isDefHash >> not) defs |> Seq.toList
 
+                // If user is debugging their script interactively, inject call
+                // to Debugger.Break() at the first "breakable" line.
+                // Update istate so that more Break() calls aren't injected when recursing
+                let defsA,istate =
+                    if istate.debugBreak then
+                        let preBreak = Seq.takeWhile (isBreakable >> not) defsA |> Seq.toList
+                        let postBreak = Seq.skipWhile (isBreakable >> not) defsA |> Seq.toList
+                        match postBreak with
+                        | h :: _ -> preBreak @ (fsiDynamicCompiler.CreateDebuggerBreak(h.Range) :: postBreak), { istate with debugBreak = false }
+                        | _ -> defsA, istate
+                    else defsA,istate
+
                 // When the last declaration has a shape of DoExp (i.e., non-binding), 
                 // transform it to a shape of "let it = <exp>", so we can refer it.
                 let defsA = if defsA.Length <= 1 || defsB.Length > 0 then  defsA else
@@ -1698,7 +1730,7 @@ type internal FsiInteractionProcessor
                             | SynModuleDecl.DoExpr(_,exp,_), rest -> (rest |> List.rev) @ (fsiDynamicCompiler.BuildItBinding exp)
                             | _ -> defsA
 
-                Some (IDefns(defsA,m)),Some (IDefns(defsB,m))
+                Some (IDefns(defsA,m)),Some (IDefns(defsB,m)),istate
 
         match action with
           | None -> assert(nextAction.IsNone); istate,Completed

src/fsharp/ilxgen.fs

@@ -1534,7 +1534,7 @@ let discardAndReturnVoid = DiscardThen ReturnVoid
 // the bodies of methods in a couple of places
 //------------------------------------------------------------------------- 
  
-let CodeGenThen mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,eenv,alreadyUsedArgs,alreadyUsedLocals,codeGenFunction,m) = 
+let CodeGenThen cenv mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,eenv,alreadyUsedArgs,alreadyUsedLocals,codeGenFunction,m) = 
     let cgbuf = new CodeGenBuffer(m,mgbuf,methodName,alreadyUsedArgs,alreadyUsedLocals,zapFirstSeqPointToStart)
     let start = CG.GenerateMark cgbuf "mstart"
     let innerVals = entryPointInfo |> List.map (fun (v,kind) -> (v,(kind,start))) 
@@ -1554,7 +1554,21 @@ let CodeGenThen mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,eenv,al
             { locRange=(start.CodeLabel, finish.CodeLabel);
               locInfos= [{ LocalIndex=i; LocalName=nm }] })
 
-    (List.map (snd >> mkILLocal) locals, 
+    let ilLocals =
+        locals
+        |> List.map (fun (infos, ty) ->
+            // in interactive environment, attach name and range info to locals to improve debug experience
+            if cenv.opts.isInteractive && cenv.opts.generateDebugSymbols then
+                match infos with
+                | [(nm, (start, finish))] -> mkILLocal ty (Some(nm, start.CodeLabel, finish.CodeLabel))
+                // REVIEW: what do these cases represent?
+                | _ :: _
+                | [] -> mkILLocal ty None 
+            // if not interactive, don't bother adding this info
+            else
+                mkILLocal ty None)
+
+    (ilLocals, 
      maxStack,
      computeCodeLabelToPC,
      code,
@@ -1566,7 +1580,7 @@ let CodeGenMethod cenv mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,
     (* Codegen the method. REVIEW: change this to generate the AbsIL code tree directly... *)
 
     let locals,maxStack,computeCodeLabelToPC,instrs,exns,localDebugSpecs,hasSequencePoints = 
-      CodeGenThen mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,eenv,alreadyUsedArgs,alreadyUsedLocals,codeGenFunction,m)
+      CodeGenThen cenv mgbuf (zapFirstSeqPointToStart,entryPointInfo,methodName,eenv,alreadyUsedArgs,alreadyUsedLocals,codeGenFunction,m)
 
     let dump() = 
        instrs |> Array.iteri (fun i instr -> dprintf "%s: %d: %A\n" methodName i instr);

src/fsharp/vs/ServiceLexing.fs

@@ -733,6 +733,7 @@ type internal LineTokenizer(text:string,
                     | true,"I" 
                     | true,"load" 
                     | true,"time" 
+                    | true,"dbgbreak" 
                     | true,"cd" 
 #if DEBUG
                     | true,"terms" 

src/ilx/cu_erase.fs

@@ -377,7 +377,7 @@ let rec convInstr cenv (tmps: ILLocalsAllocator) inplab outlab instr =
                         InstrMorph [ AI_pop; (AI_ldc (DT_I4, ILConst.I4 0)) ] 
                 | RuntimeTypes -> 
                         let baseTy = baseTyOfUnionSpec cuspec
-                        let locn = tmps.AllocLocal (mkILLocal baseTy)
+                        let locn = tmps.AllocLocal (mkILLocal baseTy None)
 
                         let mkCase last inplab cidx failLab = 
                             let alt = altOfUnionSpec cuspec cidx
@@ -495,7 +495,7 @@ let rec convInstr cenv (tmps: ILLocalsAllocator) inplab outlab instr =
         
             match cuspecRepr.DiscriminationTechnique cuspec with 
             | RuntimeTypes ->  
-                let locn = tmps.AllocLocal (mkILLocal baseTy)
+                let locn = tmps.AllocLocal (mkILLocal baseTy None)
                 let mkCase _last inplab (cidx,tg) failLab = 
                     let alt = altOfUnionSpec cuspec cidx
                     let altTy = tyForAlt cuspec alt

src/ilx/pubclo.fs

@@ -226,7 +226,7 @@ let rec convInstr cenv (tmps: ILLocalsAllocator, thisGenParams: ILGenericParamet
                 | Apps_app (arg,rest) -> 
                     let storers, loaders = unwind rest
                     let argStorers,argLoaders = 
-                          let locn = tmps.AllocLocal (mkILLocal arg)
+                          let locn = tmps.AllocLocal (mkILLocal arg None)
                           [mkStloc locn], [mkLdloc locn]
                     argStorers :: storers, argLoaders :: loaders  
                 | Apps_done _ -> 
@@ -348,7 +348,7 @@ let mkILFreeVarForParam (p : ILParameter) =
     let nm = (match p.Name with Some x -> x | None -> failwith "closure parameters must be given names")
     mkILFreeVar(nm, false,p.Type)
 
-let mkILLocalForFreeVar (p: IlxClosureFreeVar) = mkILLocal p.fvType
+let mkILLocalForFreeVar (p: IlxClosureFreeVar) = mkILLocal p.fvType None
 
 let mkILCloFldSpecs _cenv flds = 
     flds |> Array.map (fun fv -> (fv.fvName,fv.fvType)) |> Array.toList

vsintegration/src/vs/FsPkgs/FSharp.LanguageService/FSharp.LanguageService.Base/ViewFilter.cs

@@ -64,16 +64,20 @@ public class ViewFilter : IVsTextViewFilter, IVsTextViewEvents, IOleCommandTarge
         private IntPtr pvaChar;
         private bool gotEnterKey;
         private bool snippetBound;
-        private VsCommands gotoCmd; 
+        private VsCommands gotoCmd;
+        private readonly Guid guidInteractive = new Guid("8B9BF77B-AF94-4588-8847-2EB2BFFD29EB");
+        private readonly uint cmdIDDebugSelection = 0x01;
 
         /// <include file='doc\ViewFilter.uex' path='docs/doc[@for="ViewFilter.SnippetBound"]/*' />
         protected bool SnippetBound {
             get { return snippetBound; }
             set { snippetBound = value; }
         }
+
         private NativeMethods.ConnectionPointCookie expansionEvents;
-#if FX_ATLEAST_45
+
         private Microsoft.VisualStudio.Shell.Package projectSystemPackage = null;
+
         private Microsoft.VisualStudio.Shell.Package GetProjectSystemPackage()
         {
             // Ideally the FsiToolWindow would be a part of the language service, but right now its code lives in the
@@ -89,7 +93,7 @@ private Microsoft.VisualStudio.Shell.Package GetProjectSystemPackage()
             }
             return this.projectSystemPackage;
         }
-#endif
+
         /// <include file='doc\ViewFilter.uex' path='docs/doc[@for="ViewFilter.ViewFilter"]/*' />
         internal ViewFilter(CodeWindowManager mgr, IVsTextView view) {
             this.pvaChar = IntPtr.Zero;
@@ -204,16 +208,16 @@ private Microsoft.VisualStudio.Shell.Package GetProjectSystemPackage()
             get { return this.textView; }
         }
 
-		/// <include file='doc\ExpansionProvider.uex' path='docs/doc[@for="ViewFilter.IsExpansionUIActive"]/*' />
-		public virtual bool IsExpansionUIActive {
-			get {
-				IVsTextViewEx tve = this.textView as IVsTextViewEx;
-				if (tve != null && tve.IsExpansionUIActive() == VSConstants.S_OK) {
-					return true;
-				}
-				return false;
-			}
-		}
+        /// <include file='doc\ExpansionProvider.uex' path='docs/doc[@for="ViewFilter.IsExpansionUIActive"]/*' />
+        public virtual bool IsExpansionUIActive {
+            get {
+                IVsTextViewEx tve = this.textView as IVsTextViewEx;
+                if (tve != null && tve.IsExpansionUIActive() == VSConstants.S_OK) {
+                    return true;
+                }
+                return false;
+            }
+        }
 
         #region IVsTextViewFilter methods
         /// <include file='doc\ViewFilter.uex' path='docs/doc[@for="ViewFilter.GetWordExtent"]/*' />
@@ -344,79 +348,88 @@ internal void GetDataTipResponse(BackgroundRequest req)
         /// OLECMDF_ENABLED | OLECMDF_SUPPORTED.  
         /// Return E_FAIL if want to delegate to the next command target.
         /// </returns>
-        protected virtual int QueryCommandStatus(ref Guid guidCmdGroup, uint nCmdId) {
+        protected virtual int QueryCommandStatus(ref Guid guidCmdGroup, uint nCmdId)
+        {
             ExpansionProvider ep = GetExpansionProvider();
-            if (ep != null && ep.InTemplateEditingMode) {
+            if (ep != null && ep.InTemplateEditingMode)
+            {
                 int hr = 0;
                 if (ep.HandleQueryStatus(ref guidCmdGroup, nCmdId, out hr))
                     return hr;
             }
-            if (guidCmdGroup == typeof(VsCommands).GUID) {
+            if (guidCmdGroup == typeof(VsCommands).GUID)
+            {
                 VsCommands cmd = (VsCommands)nCmdId;
 
-                switch (cmd) {
-                    case VsCommands.GotoDefn:
-                    case VsCommands.GotoDecl:
-                    case VsCommands.GotoRef:
-                    case VsCommands.Goto:
-                        return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                switch (cmd)
+                {
+                case VsCommands.GotoDefn:
+                case VsCommands.GotoDecl:
+                case VsCommands.GotoRef:
+                case VsCommands.Goto:
+                    return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
                 }
-            } else if (guidCmdGroup == typeof(VsCommands2K).GUID) {
+            }
+            else if (guidCmdGroup == typeof(VsCommands2K).GUID)
+            {
                 VsCommands2K cmd = (VsCommands2K)nCmdId;
 
-                switch (cmd) {
-                    case VsCommands2K.FORMATDOCUMENT:
-                        if (this.CanReformat())
-                            return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        break;
-                    case VsCommands2K.FORMATSELECTION:
-                        if (this.CanReformat())
-                            return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        break;
-
-                    case VsCommands2K.COMMENT_BLOCK:
-                    case VsCommands2K.UNCOMMENT_BLOCK:
-                        if (this.commentSupported)
-                            return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        break;
-
-                    case VsCommands2K.SHOWMEMBERLIST:
-                    case VsCommands2K.COMPLETEWORD:
-                    case VsCommands2K.PARAMINFO:
+                switch (cmd)
+                {
+                case VsCommands2K.FORMATDOCUMENT:
+                    if (this.CanReformat())
+                        return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                    break;
+                case VsCommands2K.FORMATSELECTION:
+                    if (this.CanReformat())
                         return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                    break;
 
-                    case VsCommands2K.QUICKINFO:
-                        if (this.service.Preferences.EnableQuickInfo) {
-                            return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        }
-                        break;
+                case VsCommands2K.COMMENT_BLOCK:
+                case VsCommands2K.UNCOMMENT_BLOCK:
+                    if (this.commentSupported)
+                        return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                    break;
 
-                    //                    case VsCommands2K.HANDLEIMEMESSAGE:
-                    //                        return 0;
-
-                    // Let the core editor handle this.  Stop outlining also removes user
-                    // defined hidden sections so it is handy to keep this enabled.
-                    //                    case VsCommands2K.OUTLN_STOP_HIDING_ALL: 
-                    //                        int rc = (int)OLECMDF.OLECMDF_SUPPORTED;
-                    //                        if (this.source.OutliningEnabled) {
-                    //                            rc |= (int)OLECMDF.OLECMDF_ENABLED;
-                    //                        }
-                    //                        return rc;
+                case VsCommands2K.SHOWMEMBERLIST:
+                case VsCommands2K.COMPLETEWORD:
+                case VsCommands2K.PARAMINFO:
+                    return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
 
-                    case VsCommands2K.OUTLN_START_AUTOHIDING:
-                        if (this.source.OutliningEnabled) {
-                            return (int)OleConstants.OLECMDERR_E_NOTSUPPORTED;
-                        }
+                case VsCommands2K.QUICKINFO:
+                    if (this.service.Preferences.EnableQuickInfo)
+                    {
                         return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        
-                    case VsCommands2K.OUTLN_STOP_HIDING_ALL: //"stop outlining" on context menu
-                        if (this.source.OutliningEnabled) {
-                            return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
-                        }
+                    }
+                    break;
+
+                //                    case VsCommands2K.HANDLEIMEMESSAGE:
+                //                        return 0;
+
+                // Let the core editor handle this.  Stop outlining also removes user
+                // defined hidden sections so it is handy to keep this enabled.
+                //                    case VsCommands2K.OUTLN_STOP_HIDING_ALL: 
+                //                        int rc = (int)OLECMDF.OLECMDF_SUPPORTED;
+                //                        if (this.source.OutliningEnabled) {
+                //                            rc |= (int)OLECMDF.OLECMDF_ENABLED;
+                //                        }
+                //                        return rc;
+
+                case VsCommands2K.OUTLN_START_AUTOHIDING:
+                    if (this.source.OutliningEnabled)
+                    {
                         return (int)OleConstants.OLECMDERR_E_NOTSUPPORTED;
+                    }
+                    return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+
+                case VsCommands2K.OUTLN_STOP_HIDING_ALL: //"stop outlining" on context menu
+                    if (this.source.OutliningEnabled)
+                    {
+                        return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                    }
+                    return (int)OleConstants.OLECMDERR_E_NOTSUPPORTED;
                 }
             }
-#if FX_ATLEAST_45
             else if (guidCmdGroup == Microsoft.VisualStudio.VSConstants.VsStd11)
             {
                 if (nCmdId == (uint)Microsoft.VisualStudio.VSConstants.VSStd11CmdID.ExecuteSelectionInInteractive)
@@ -424,7 +437,19 @@ internal void GetDataTipResponse(BackgroundRequest req)
                     return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
                 }
             }
-#endif
+            else if (guidCmdGroup == guidInteractive)
+            {
+                if (nCmdId == cmdIDDebugSelection)
+                {
+                    var dbgState = Interactive.Hooks.GetDebuggerState(GetProjectSystemPackage());
+
+                    if (dbgState == Interactive.FsiDebuggerState.AttachedNotToFSI)
+                        return (int)OLECMDF.OLECMDF_INVISIBLE;
+                    else
+                        return (int)OLECMDF.OLECMDF_SUPPORTED | (int)OLECMDF.OLECMDF_ENABLED;
+                }
+            }
+
             return (int)NativeMethods.E_FAIL; // delegate to next command target.
         }
 
@@ -541,16 +566,23 @@ internal void GetDataTipResponse(BackgroundRequest req)
 
                 }
             }
-#if FX_ATLEAST_45
             else if (guidCmdGroup == Microsoft.VisualStudio.VSConstants.VsStd11)
             {
                 if (nCmdId == (uint)Microsoft.VisualStudio.VSConstants.VSStd11CmdID.ExecuteSelectionInInteractive)
                 {
-                    Microsoft.VisualStudio.FSharp.Interactive.Hooks.OnMLSend(GetProjectSystemPackage(), null, null);
+                    Interactive.Hooks.OnMLSend(GetProjectSystemPackage(), false, null, null);
                     return true;
                 }
             }
-#endif
+            else if (guidCmdGroup == guidInteractive)
+            {
+                if (nCmdId == cmdIDDebugSelection)
+                {
+                    Interactive.Hooks.OnMLSend(GetProjectSystemPackage(), true, null, null);
+                    return true;
+                }
+            }
+
             return false;
         }
 

vsintegration/src/vs/FsPkgs/FSharp.VS.FSI/fsiBasis.fs

@@ -42,30 +42,22 @@ module internal Guids =
 #endif
     
     // FSI Session command set
-    let cmdIDFsiConsoleContextMenu      = 0x2100 
-    let guidFsiConsoleCmdSet            = Guid("0E455B35-F2EB-431b-A0BE-B268D8A7D17F")
-#if FX_ATLEAST_45
     let guidInteractiveCommands         = Microsoft.VisualStudio.VSConstants.VsStd11 
     let cmdIDSessionInterrupt           = int Microsoft.VisualStudio.VSConstants.VSStd11CmdID.InteractiveSessionInterrupt
     let cmdIDSessionRestart             = int Microsoft.VisualStudio.VSConstants.VSStd11CmdID.InteractiveSessionRestart
-#else
-    let guidInteractiveCommands         = guidFsiConsoleCmdSet
-    let cmdIDSessionInterrupt           = 0x102
-    let cmdIDSessionRestart             = 0x103
-#endif
+
+    let guidFsiConsoleCmdSet            = Guid("0E455B35-F2EB-431b-A0BE-B268D8A7D17F")
+    let cmdIDAttachDebugger             = 0x104
+    let cmdIDDetachDebugger             = 0x105
+    let cmdIDFsiConsoleContextMenu      = 0x2100 
    
     // Command set for SendToInteractive
-#if FX_ATLEAST_45
-    // commands moved to VS Shell
-    let guidInteractive                 = Microsoft.VisualStudio.VSConstants.VsStd11 
+    // some commands moved to VS Shell
+    let guidInteractiveShell            = Microsoft.VisualStudio.VSConstants.VsStd11 
     let cmdIDSendSelection              = int Microsoft.VisualStudio.VSConstants.VSStd11CmdID.ExecuteSelectionInInteractive
-    let guidInteractive2                = Microsoft.VisualStudio.VSConstants.VsStd11
-#else
-    // hybrid still uses own commands
+    // some commands not in VS Shell
     let guidInteractive                 = Guid("8B9BF77B-AF94-4588-8847-2EB2BFFD29EB")
-    let cmdIDSendSelection              = 0x01
-    let guidInteractive2                = Guid("B607E86C-A761-4685-8D98-71A3BB73233A")
-#endif
+    let cmdIDDebugSelection             = 0x01
 
     let guidFsiPackage                  = "eeeeeeee-9342-42f1-8ea9-42f0e8a6be55" // FSI-LINKAGE-POINT: when packaged here
     let guidFSharpProjectPkgString      = "91A04A73-4F2C-4E7C-AD38-C1A68E7DA05C" // FSI-LINKAGE-POINT: when packaged in project system

vsintegration/src/vs/FsPkgs/FSharp.VS.FSI/fsiCommands.vsct

@@ -92,43 +92,37 @@
         </Strings>
       </Button>
 
-      <!-- In Dev11, shell now has 
+      <!-- In Dev11+, shell now has 
       <Button guid ="guidVSStd11" id ="cmdidInteractiveSessionInterrupt" priority ="0x100" type ="Button">
       <Button guid ="guidVSStd11" id ="cmdidInteractiveSessionRestart" priority ="0x105" type ="Button">
       -->
-      <!-- In Dev10 hybrid, we need buttons below -->
-      <Button Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionInterrupt" priority="0x0100" type="Button">
-        <Parent guid="guidFsiConsoleCmdSet" id="IDG_VS_WNDO_OTRWNDWS1"/>
-        <!-- Icon guid="guidImages" id="bmpPic2" /-->
-        <Icon guid="guidCancelEvaluationBmp" id="bmpConsole" />        
+      <Button guid="guidFsiConsoleCmdSet" id="cmdidAttachDebugger" priority="0x0100" type="Button">
         <Strings>
-          <CommandName>FSharp.Interactive.Interrupt</CommandName>
-          <ButtonText>Cancel Evaluation</ButtonText> <!-- This was called "Interrupt Session" -->
+          <CommandName>FSharp.Interactive.AttachDebugger</CommandName>
+          <ButtonText>Start Debugging</ButtonText>
         </Strings>
+        <CommandFlag>DynamicVisibility | DefaultInvisible</CommandFlag>
       </Button>
-      <Button Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionRestart" priority="0x0100" type="Button">
-        <Parent guid="guidFsiConsoleCmdSet" id="IDG_VS_WNDO_OTRWNDWS1"/>
-        <!-- Icon guid="guidImages" id="bmpPic2" /-->
-        <Icon guid="guidResetSessionBmp" id="bmpConsole" /> 
+      
+      <Button guid="guidFsiConsoleCmdSet" id="cmdidDetachDebugger" priority="0x0101" type="Button">
         <Strings>
-          <CommandName>FSharp.Interactive.Restart</CommandName>
-          <ButtonText>Reset Session</ButtonText>
+          <CommandName>FSharp.Interactive.DetachDebugger</CommandName>
+          <ButtonText>Stop Debugging</ButtonText>
         </Strings>
+        <CommandFlag>DynamicVisibility | DefaultInvisible</CommandFlag>
       </Button>
 
       <!-- The following places a button on the F# Editor Context Menu -->
-      <!-- In Dev11, shell now has 
+      <!-- In Dev11+, shell now has 
       <Button guid ="guidVSStd11" id ="cmdidExecuteSelectionInInteractive" priority ="0x100" type ="Button">
       -->
-      <!-- In Dev10 hybrid, we need buttons below -->
-      <Button Condition="!Defined(FX_ATLEAST_45)" guid ="guidInteractive" id ="cmdidSendSelection" priority ="0x100" type ="Button">
-          <Parent guid="guidSHLMainMenu" id="IDG_VS_CODEWIN_LANGUAGE"/>
-        <Icon guid="guidFsiConsoleBmp" id="bmpConsole"/>
+      <Button guid ="guidInteractive" id ="cmdidDebugSelection" priority ="0x106" type ="Button">
+        <Parent guid="guidSHLMainMenu" id="IDG_VS_CODEWIN_LANGUAGE"/>
         <Strings>
-          <ButtonText>Send To Interactive</ButtonText>
-          <CommandName>Interactive.Send.Selection.Context</CommandName>
+          <ButtonText>Debug in F# Interactive</ButtonText>
+          <CommandName>Interactive.Debug.Selection.Context</CommandName>
         </Strings>
-        <CommandFlag>DynamicVisibility | DefaultInvisible</CommandFlag>
+       <CommandFlag>DynamicVisibility | DefaultInvisible</CommandFlag>
       </Button>
 
     </Buttons>
@@ -177,20 +171,21 @@
     <CommandPlacement guid="guidVSStd97" id="cmdidClearPane" priority="0x0200">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleClearGrp"/>
     </CommandPlacement>
-    <!-- Context menu, session group: Hybrid -->  
-    <CommandPlacement Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionInterrupt" priority="0x0100">
+          
+    <!-- Context menu, session group -->
+    <CommandPlacement guid="guidVSStd11" id="cmdidInteractiveSessionInterrupt" priority="0x0100">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleSessionsGrp"/>
     </CommandPlacement>
-    <CommandPlacement Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionRestart" priority="0x0300">
+    <CommandPlacement guid="guidVSStd11" id="cmdidInteractiveSessionRestart" priority="0x0300">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleSessionsGrp"/>
     </CommandPlacement>
-    <!-- Context menu, session group: Dev11 -->
-    <CommandPlacement Condition="Defined(FX_ATLEAST_45)" guid="guidVSStd11" id="cmdidInteractiveSessionInterrupt" priority="0x0100">
+    <CommandPlacement guid="guidFsiConsoleCmdSet" id="cmdidAttachDebugger" priority="0x0700">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleSessionsGrp"/>
     </CommandPlacement>
-    <CommandPlacement Condition="Defined(FX_ATLEAST_45)" guid="guidVSStd11" id="cmdidInteractiveSessionRestart" priority="0x0300">
+    <CommandPlacement guid="guidFsiConsoleCmdSet" id="cmdidDetachDebugger" priority="0x0800">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleSessionsGrp"/>
     </CommandPlacement>
+    
     <!-- Adds MLSend to the context menu:
     <CommandPlacement guid="guidFsiConsoleCmdSet" id="cmdidMLSendSelection" priority="0x0500">
       <Parent guid="guidFsiConsoleCmdSet" id="FsiConsoleSessionsGrp"/>
@@ -226,24 +221,27 @@
          ALT-ENTER is globally bound to Diagram.Property.
          Here we bind it in the Editor context of the standard TextEditor.
          Ideally, we would bind it for F# only editor.
-         Both Hybrid and Dev11 are used here, to build both ways.
     -->
-    <KeyBinding Condition="!Defined(FX_ATLEAST_45)" guid="guidInteractive" id="cmdidSendSelection" editor="GUID_TextEditorFactory" key1="VK_RETURN" mod1="Alt"  />
-    <KeyBinding Condition="Defined(FX_ATLEAST_45)" guid ="guidVSStd11" id ="cmdidExecuteSelectionInInteractive" editor="GUID_TextEditorFactory" key1="VK_RETURN" mod1="Alt"  />
+    <KeyBinding guid ="guidInteractive" id ="cmdidDebugSelection" editor="GUID_TextEditorFactory" key1="D" mod1="Alt" key2="VK_RETURN" mod2="Alt"  />
+    <KeyBinding guid ="guidVSStd11" id ="cmdidExecuteSelectionInInteractive" editor="GUID_TextEditorFactory" key1="VK_RETURN" mod1="Alt"  />
 
     <!-- CRTL-ALT-F for FSI window - following similar bindings for "other windows" -->
     <KeyBinding guid="guidFsiPackageCmdSet" id="cmdidFsiToolWindow"    editor="guidVSStd97" key1="F" mod1="Control Alt"  />
 
-    <!-- CRTL-Break when in FSI ToolWindow is Interrupt -->
-    <KeyBinding Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionInterrupt" editor="guidFsiToolWindow" key1="VK_CANCEL" mod1="Control"  />    
-    <KeyBinding Condition="Defined(FX_ATLEAST_45)" guid="guidVSStd11" id="cmdidInteractiveSessionInterrupt" editor="guidFsiToolWindow" key1="VK_CANCEL" mod1="Control"  />
+    <!-- CRTL-Break when in FSI ToolWindow is Interrupt --> 
+    <KeyBinding guid="guidVSStd11" id="cmdidInteractiveSessionInterrupt" editor="guidFsiToolWindow" key1="VK_CANCEL" mod1="Control"  />
   
-    <!-- CRTL-Alt-R when in FSI ToolWindow is Reset -->
-    <KeyBinding Condition="!Defined(FX_ATLEAST_45)" guid="guidFsiConsoleCmdSet" id="cmdidSessionRestart" editor="guidFsiToolWindow" key1="R" mod1="Control Alt"  />    
-    <KeyBinding Condition="Defined(FX_ATLEAST_45)" guid="guidVSStd11" id="cmdidInteractiveSessionRestart" editor="guidFsiToolWindow" key1="R" mod1="Control Alt"  />
+    <!-- CRTL-Alt-R when in FSI ToolWindow is Reset -->  
+    <KeyBinding guid="guidVSStd11" id="cmdidInteractiveSessionRestart" editor="guidFsiToolWindow" key1="R" mod1="Control Alt"  />
   
      <!-- CRTL-Alt-C when in FSI ToolWindow is Clear All -->
     <KeyBinding guid="guidVSStd97" id="cmdidClearPane" editor="guidFsiToolWindow" key1="C" mod1="Control Alt"  />
+    
+    <!-- CRTL-Alt-D when in FSI ToolWindow is attach debugger -->
+    <KeyBinding guid="guidFsiConsoleCmdSet" id="cmdidAttachDebugger" editor="guidFsiToolWindow" key1="D" mod1="Control Alt"  />
+    
+    <!-- CRTL-Shift-D when in FSI ToolWindow is detach debugger -->
+    <KeyBinding guid="guidFsiConsoleCmdSet" id="cmdidDetachDebugger" editor="guidFsiToolWindow" key1="D" mod1="Control Shift"  /> 
   </KeyBindings>
 
   <Symbols>
@@ -279,9 +277,8 @@
       <IDSymbol name="FsiConsoleClearGrp" value="0x1040" /> 
       <IDSymbol name="FsiConsoleSessionsGrp" value="0x1050" />      
       <IDSymbol name="cmdidFsiConsole" value="0x101" />
-      <!-- below is only used by hybrid   -->
-      <IDSymbol Condition="!Defined(FX_ATLEAST_45)" name="cmdidSessionInterrupt" value="0x102" />
-      <IDSymbol Condition="!Defined(FX_ATLEAST_45)" name="cmdidSessionRestart" value="0x103" />
+      <IDSymbol name="cmdidAttachDebugger" value="0x104" />
+      <IDSymbol name="cmdidDetachDebugger" value="0x105" />
      </GuidSymbol>
 
     <GuidSymbol name="guidFsiConsoleBmp" value="{9074CE8B-8F1E-4c23-8EDC-82C25E0323A8}" >
@@ -301,12 +298,11 @@
       <IDSymbol name="cmdidInteractiveSessionInterrupt" value ="0x01A"/>
       <IDSymbol name="cmdidInteractiveSessionRestart" value ="0x01B"/>
     </GuidSymbol>
-
-<!-- below is only used by hybrid   -->
-    <GuidSymbol Condition="!Defined(FX_ATLEAST_45)" name="guidInteractive" value="{8B9BF77B-AF94-4588-8847-2EB2BFFD29EB}" >
-      <IDSymbol name="cmdidSendSelection" value ="0x01"/>
-    </GuidSymbol>
   
+    <GuidSymbol name="guidInteractive" value="{8B9BF77B-AF94-4588-8847-2EB2BFFD29EB}" >
+      <IDSymbol name="cmdidDebugSelection" value ="0x01"/>
+    </GuidSymbol>
+
   </Symbols>
 
 </CommandTable>

vsintegration/src/vs/FsPkgs/FSharp.VS.FSI/fsiPackageHooks.fs

@@ -56,25 +56,34 @@ module internal Hooks =
         with e2 ->
             (System.Windows.Forms.MessageBox.Show(e2.ToString()) |> ignore)
 
-    let private withFSIToolWindow (this:Package) f =
+    let private queryFSIToolWindow (this:Package) (f : FsiToolWindow -> 't) (dflt : 't) =
         try            
             let window = this.FindToolWindow(typeof<FsiToolWindow>, 0, true)
             let windowFrame = window.Frame :?> IVsWindowFrame
             if windowFrame.IsVisible() <> VSConstants.S_OK then
                 windowFrame.Show() |> throwOnFailure0
             match window with
-            | null -> ()
             | :? FsiToolWindow as window -> f window
-            | _ -> ()
+            | _ -> dflt
         with e2 ->
             (System.Windows.Forms.MessageBox.Show(VFSIstrings.SR.exceptionRaisedWhenRequestingToolWindow(e2.ToString())) |> ignore)
+            dflt
+
+    let private withFSIToolWindow (this:Package) f =
+        queryFSIToolWindow this f ()
 
-    let OnMLSend (this:Package) (sender:obj) (e:EventArgs) =
-        withFSIToolWindow this (fun window -> window.MLSend(sender, e))
+    let OnMLSend (this:Package) (debug : bool) (sender:obj) (e:EventArgs) =
+        withFSIToolWindow this (fun window ->
+            if debug then window.MLDebug(sender, e)
+            else window.MLSend(sender, e)
+        )
 
     let AddReferencesToFSI (this:Package) references =
         withFSIToolWindow this (fun window -> window.AddReferences references)
 
+    let GetDebuggerState (this:Package) =
+        queryFSIToolWindow this (fun window -> window.GetDebuggerState()) FsiDebuggerState.AttachedNotToFSI
+
     // FxCop request this function not be public
     let private supportWhenFSharpDocument (sender:obj) (e:EventArgs) =    
         let command = sender :?> OleMenuCommand       
@@ -124,16 +133,3 @@ module internal Hooks =
                 let id  = new CommandID(Guids.guidFsiPackageCmdSet,int32 Guids.cmdIDLaunchFsiToolWindow)
                 let cmd = new MenuCommand(new EventHandler(ShowToolWindow this), id)
                 commandService.AddCommand(cmd)
-
-#if FX_ATLEAST_45
-                // Dev11 handles FSI commands in LS ViewFilter
-#else
-                // See VS SDK docs on "Command Routing Algorithm".
-                // Add OLECommand to OleCommandTarget at the package level,
-                // for when it is fired from other contexts, e.g. text editor.
-                let id  = new CommandID(Guids.guidInteractive,int32 Guids.cmdIDSendSelection)
-                let cmd = new OleMenuCommand(new EventHandler(OnMLSend this), id)
-                cmd.BeforeQueryStatus.AddHandler(new EventHandler(supportWhenFSharpDocument))
-                commandService.AddCommand(cmd)
-
-#endif

vsintegration/src/vs/FsPkgs/FSharp.VS.FSI/fsiSessionToolWindow.fs

@@ -70,6 +70,12 @@ module internal Locals =
 open Util
 open Locals
 
+// consumed by C#, so enum type used instead of union
+type internal FsiDebuggerState =
+    | NotRunning = 0
+    | AttachedToFSI = 1
+    | AttachedNotToFSI = 2
+
 [<Guid("dee22b65-9761-4a26-8fb2-759b971d6dfc")>] //REVIEW: double check fresh guid! IIRC it is.
 type internal FsiToolWindow() as this = 
     inherit ToolWindowPane(null)
@@ -431,6 +437,63 @@ type internal FsiToolWindow() as this =
     let showNoActivate() = 
         let frame = this.Frame :?> IVsWindowFrame
         frame.ShowNoActivate() |> ignore
+    
+    let getDebuggerState () =
+        let fsiProcId = sessions.ProcessID
+        let dte = provider.GetService(typeof<DTE>) :?> DTE
+
+        if dte.Debugger.DebuggedProcesses = null || dte.Debugger.DebuggedProcesses.Count = 0 then
+            FsiDebuggerState.NotRunning, None
+        else
+            let debuggedFsi =
+                dte.Debugger.DebuggedProcesses
+                |> Seq.cast<Process>
+                |> Seq.tryFind (fun p -> p.ProcessID = fsiProcId)
+            match debuggedFsi with
+            | Some _ -> FsiDebuggerState.AttachedToFSI, debuggedFsi
+            | None -> FsiDebuggerState.AttachedNotToFSI, None
+    
+    let getDebugAttachedFSIProcess () =
+        match getDebuggerState () with
+        | FsiDebuggerState.AttachedToFSI, opt -> opt
+        | _ -> None
+
+    let debuggerIsRunning () =
+        match getDebuggerState () with
+        | FsiDebuggerState.NotRunning, _ -> false
+        | _ -> true
+
+    // noop if debugger isn't attached to FSI
+    let detachDebugger () =
+        try
+            match getDebugAttachedFSIProcess () with
+            | Some(p) -> p.Detach(true)
+            | _ -> ()
+        with _ -> ()
+
+    // noop if debugger is already running
+    let attachDebugger () =
+        if not (debuggerIsRunning ()) then
+            let fsiProcId = sessions.ProcessID
+            let dte = provider.GetService(typeof<DTE>) :?> DTE
+            let fsiProc = 
+                if dte.Debugger.LocalProcesses = null then None else
+                dte.Debugger.LocalProcesses
+                |> Seq.cast<Process>
+                |> Seq.tryFind (fun p -> p.ProcessID = fsiProcId)
+            try
+                match fsiProc with
+                | Some(p) -> p.Attach()
+                | _ -> ()
+            with _ -> ()
+
+    let onAttachDebugger (sender:obj) (args:EventArgs) =
+        attachDebugger()
+        showNoActivate()
+
+    let onDetachDebugger (sender:obj) (args:EventArgs) =
+        detachDebugger()
+        showNoActivate()
 
     let sendTextToFSI text = 
         try
@@ -440,15 +503,20 @@ type internal FsiToolWindow() as this =
             executeTextNoHistory text
         with _ -> ()
 
-    let executeInteraction dir filename topLine text =
+    let executeInteraction dbgBreak dir filename topLine text =
         // Preserving previous functionality, including the #directives...
-        let directiveA  = sprintf "# silentCd @\"%s\" ;; "  dir
-        let directiveB  = sprintf "# %d @\"%s\" "      topLine filename
-        let directiveC  = sprintf "# 1 \"stdin\""    (* stdin line number reset code *)                
-        let interaction = "\n" + directiveA + "\n" + directiveB + "\n" + text + "\n" + directiveC + "\n;;\n"
+        let interaction =
+            "\n"
+          + (sprintf "# silentCd @\"%s\" ;; " dir) + "\n"
+          + (if dbgBreak then "# dbgbreak\n" else "")
+          + (sprintf "# %d @\"%s\" " topLine filename) + "\n"
+          + text + "\n"
+          + "# 1 \"stdin\"" + "\n" (* stdin line number reset code *)
+          + ";;" + "\n"
+
         executeTextNoHistory interaction
 
-    let sendSelectionToFSI() =
+    let sendSelectionToFSI dbgBreak =
         try
             // REVIEW: See supportWhenFSharpDocument for alternative way of obtaining selection, via IVs APIs.
             // Change post CTP.            
@@ -458,13 +526,13 @@ type internal FsiToolWindow() as this =
             | :? TextSelection as selection when selection.Text = "" ->
                 selection.SelectLine()
                 showNoActivate()
-                executeInteraction (System.IO.Path.GetDirectoryName(activeD.FullName)) activeD.FullName selection.TopLine selection.Text 
+                executeInteraction dbgBreak (System.IO.Path.GetDirectoryName(activeD.FullName)) activeD.FullName selection.TopLine selection.Text 
                 // This has the effect of moving the line and de-selecting it.
                 selection.LineDown(false, 0)
                 selection.StartOfLine(vsStartOfLineOptions.vsStartOfLineOptionsFirstColumn, false)
             | :? TextSelection as selection ->
                 showNoActivate()
-                executeInteraction (System.IO.Path.GetDirectoryName(activeD.FullName)) activeD.FullName selection.TopLine selection.Text 
+                executeInteraction dbgBreak (System.IO.Path.GetDirectoryName(activeD.FullName)) activeD.FullName selection.TopLine selection.Text 
             | _ ->
                 ()
         with
@@ -473,22 +541,12 @@ type internal FsiToolWindow() as this =
                  // Example errors include no active document.
 
     let onMLSend (sender:obj) (e:EventArgs) =       
-        sendSelectionToFSI()
-(*
-        // Remove: after next submit (passing through SD)       
-        // The below did not work, so move to use Automatic API via DTE above...        
-        let vsTextManager  = Util.CreateObjectT<VsTextManagerClass,VsTextManager> provider
-        let res,view = vsTextManager.GetActiveView(0(*<--fMustHaveFocus=0/1*),null) // 
-        if res = VSConstants.S_OK then
-            let span = Array.zeroCreate<TextSpan> 1
-            view.GetSelectionSpan(span) |> throwOnFailure0
-            let span = span.[0]
-            let text = view.GetTextStream(span.iStartLine,span.iStartIndex,span.iEndLine,span.iEndIndex) |> throwOnFailure1
-            Windows.Forms.MessageBox.Show("EXEC:\n" + text) |> ignore
-        else        
-            Windows.Forms.MessageBox.Show("Could not find the 'active text view', error code = " + sprintf "0x%x" res) |> ignore
-*)
-        
+        sendSelectionToFSI false
+
+    let onMLDebug (sender:obj) (e:EventArgs) = 
+        attachDebugger ()
+        sendSelectionToFSI true
+
     /// Handle UP and DOWN. Cycle history.    
     let onHistory (sender:obj) (e:EventArgs) =
         let command = sender :?> OleMenuCommand
@@ -526,6 +584,12 @@ type internal FsiToolWindow() as this =
     do  this.Caption          <- VFSIstrings.SR.fsharpInteractive()
    
     member this.MLSend(obj,e) = onMLSend obj e
+    member this.MLDebug(obj,e) = onMLDebug obj e
+
+    member this.GetDebuggerState() =
+        let (state, _) = getDebuggerState ()
+        state
+
     member this.AddReferences(references : string[]) = 
         let text = 
             references
@@ -594,8 +658,11 @@ type internal FsiToolWindow() as this =
             addCommand guidVSStd2KCmdID (int32 VSStd2KCmdID.SHOWCONTEXTMENU)     showContextMenu None
             addCommand Guids.guidInteractiveCommands Guids.cmdIDSessionInterrupt onInterrupt     None
             addCommand Guids.guidInteractiveCommands Guids.cmdIDSessionRestart   onRestart       None
+            addCommand Guids.guidFsiConsoleCmdSet Guids.cmdIDAttachDebugger      onAttachDebugger  None
+            addCommand Guids.guidFsiConsoleCmdSet Guids.cmdIDDetachDebugger      onDetachDebugger  None
             
-            addCommand Guids.guidInteractive Guids.cmdIDSendSelection            onMLSend        None
+            addCommand Guids.guidInteractiveShell Guids.cmdIDSendSelection       onMLSend        None
+            addCommand Guids.guidInteractive Guids.cmdIDDebugSelection           onMLDebug       None
             
             addCommand guidVSStd2KCmdID (int32 VSConstants.VSStd2KCmdID.UP)      onHistory      (Some supportWhenInInputArea)
             addCommand guidVSStd2KCmdID (int32 VSConstants.VSStd2KCmdID.DOWN)    onHistory      (Some supportWhenInInputArea)            
@@ -615,11 +682,23 @@ type internal FsiToolWindow() as this =
                     context.AddAttribute(VSUSERCONTEXTATTRIBUTEUSAGE.VSUC_Usage_LookupF1, "Keyword", "VS.FSharpInteractive") |> ignore
             |   _ -> Debug.Assert(false)
 
+    member __.QueryCommandStatus(guidCmdGroup:Guid, nCmdId:uint32) =
+        match () with
+        | _ when guidCmdGroup = Guids.guidFsiConsoleCmdSet && nCmdId = uint32 Guids.cmdIDAttachDebugger ->
+            if debuggerIsRunning () then Some(OLECMDF.OLECMDF_INVISIBLE)
+            else Some(OLECMDF.OLECMDF_SUPPORTED ||| OLECMDF.OLECMDF_ENABLED)
+
+        | _ when guidCmdGroup = Guids.guidFsiConsoleCmdSet && nCmdId = uint32 Guids.cmdIDDetachDebugger ->
+            if getDebugAttachedFSIProcess () |> Option.isSome then Some(OLECMDF.OLECMDF_SUPPORTED ||| OLECMDF.OLECMDF_ENABLED)
+            else Some(OLECMDF.OLECMDF_INVISIBLE)
+
+        | _ -> None
+                 
     interface ITestVFSI with
         /// Send a string; the ';;' will be added to the end; does not interact with history
         member this.SendTextInteraction(s:string) =
             let dummyLineNum = 1
-            executeInteraction (System.IO.Path.GetTempPath()) "DummyTestFilename.fs" 1 s
+            executeInteraction false (System.IO.Path.GetTempPath()) "DummyTestFilename.fs" 1 s
         /// Returns the n most recent lines in the view.  After SendTextInteraction, can poll for a prompt to know when interaction finished.
         member this.GetMostRecentLines(n:int) : string[] =
             lock textLines (fun () ->
@@ -667,6 +746,15 @@ type internal FsiToolWindow() as this =
             if not (wpfTextView.HasAggregateFocus) || isFocusedElementInterceptsCommandRouting() then
                 (int Microsoft.VisualStudio.OLE.Interop.Constants.OLECMDERR_E_NOTSUPPORTED)
             else
+                let mutable allHandled = true
+                for i = 0 to ((int cCmds) - 1) do
+                    match this.QueryCommandStatus(guid, prgCmds.[i].cmdID) with
+                    | Some(commandStatus) ->
+                        prgCmds.[i].cmdf <- uint32 commandStatus
+                    | None ->
+                        allHandled <- false
+
+                if allHandled then 0 else
                 let target : IOleCommandTarget = upcast commandService
                 target.QueryStatus(&guid, cCmds, prgCmds, pCmdText)