[mcs] Initial by ref returns and variables support

[mono.git] / mcs / mcs / iterators.cs

diff --git a/mcs/mcs/iterators.cs b/mcs/mcs/iterators.cs
index 5dce0ed1593086082b897df277c32585ca7bd15e..feb10844b8c7f0eac017a4454d3d7bf8a5d426b2 100644 (file)
--- a/mcs/mcs/iterators.cs
+++ b/mcs/mcs/iterators.cs
@@ -30,6 +30,7 @@ namespace Mono.CSharp
                protected T machine_initializer;
                int resume_pc;
                ExceptionStatement inside_try_block;
+               TryCatch inside_catch_block;
 
                protected YieldStatement (Expression expr, Location l)
                {
@@ -69,6 +70,7 @@ namespace Mono.CSharp
 
                        machine_initializer = bc.CurrentAnonymousMethod as T;
                        inside_try_block = bc.CurrentTryBlock;
+                       inside_catch_block = bc.CurrentTryCatch;
                        return true;
                }
 
@@ -80,7 +82,7 @@ namespace Mono.CSharp
                        if (inside_try_block == null) {
                                resume_pc = machine_initializer.AddResumePoint (this);
                        } else {
-                               resume_pc = inside_try_block.AddResumePoint (this, resume_pc, machine_initializer);
+                               resume_pc = inside_try_block.AddResumePoint (this, resume_pc, machine_initializer, inside_catch_block);
                                unwind_protect = true;
                                inside_try_block = null;
                        }
@@ -159,7 +161,6 @@ namespace Mono.CSharp
 
                protected override void CloneTo (CloneContext clonectx, Statement target)
                {
-                       throw new NotSupportedException ();
                }
 
                protected override bool DoResolve (BlockContext bc)
@@ -202,7 +203,6 @@ namespace Mono.CSharp
 
                Field pc_field;
                StateMachineMethod method;
-               int local_name_idx;
 
                protected StateMachine (ParametersBlock block, TypeDefinition parent, MemberBase host, TypeParameters tparams, string name, MemberKind kind)
                        : base (block, parent, host, tparams, name, kind)
@@ -244,12 +244,19 @@ namespace Mono.CSharp
                        return base.DoDefineMembers ();
                }
 
-               protected override string GetVariableMangledName (LocalVariable local_info)
+               protected override string GetVariableMangledName (ResolveContext rc, LocalVariable local_info)
                {
                        if (local_info.IsCompilerGenerated)
-                               return base.GetVariableMangledName (local_info);
+                               return base.GetVariableMangledName (rc, local_info);
 
-                       return "<" + local_info.Name + ">__" + local_name_idx++.ToString ("X");
+                       //
+                       // Special format which encodes original variable name and
+                       // it's scope to support lifted variables debugging. This
+                       // is same what csc does and allows to correctly set fields
+                       // scope information (like ambiguity, out of scope, etc).
+                       //
+                       var id = rc.CurrentBlock.Explicit.GetDebugSymbolScopeIndex ();
+                       return "<" + local_info.Name + ">__" + id;
                }
        }
 
@@ -1059,6 +1066,7 @@ namespace Mono.CSharp
 
                        method.Block = new ToplevelBlock (method.Compiler, method.ParameterInfo, loc,
                                ToplevelBlock.Flags.CompilerGenerated | ToplevelBlock.Flags.NoFlowAnalysis);
+
                        method.Block.AddStatement (new TryFinallyBlockProxyStatement (this, block));
 
                        // Cannot it add to storey because it'd be emitted before nested
@@ -1179,11 +1187,15 @@ namespace Mono.CSharp
                                return;
 
                        if (!CheckType (ret, parent, out iterator_type, out is_enumerable)) {
-                               parent.Compiler.Report.Error (1624, method.Location,
-                                             "The body of `{0}' cannot be an iterator block " +
-                                             "because `{1}' is not an iterator interface type",
-                                             method.GetSignatureForError (),
-                                             ret.GetSignatureForError ());
+                               if (ret.Kind == MemberKind.ByRef) {
+                                       parent.Compiler.Report.Error (8154, method.Location,
+                                                         "The body of `{0}' cannot be an iterator block because the method returns by reference",
+                                                         method.GetSignatureForError ());
+                               } else {
+                                       parent.Compiler.Report.Error (1624, method.Location,
+                                                         "The body of `{0}' cannot be an iterator block because `{1}' is not an iterator interface type",
+                                                         method.GetSignatureForError (), ret.GetSignatureForError ());
+                               }
                                return;
                        }
 
@@ -1211,7 +1223,7 @@ namespace Mono.CSharp
                        }
 
                        if ((modifiers & Modifiers.UNSAFE) != 0) {
-                               parent.Compiler.Report.Error (1629, method.Location, "Unsafe code may not appear in iterators");
+                               Expression.UnsafeInsideIteratorError (parent.Compiler.Report, method.Location);
                        }
 
                        method.Block = method.Block.ConvertToIterator (method, parent, iterator_type, is_enumerable);