Merge pull request #5002 from BrzVlad/feature-sgen-modes
[mono.git] / mcs / mcs / statement.cs
index 703e7ba497fef805446a5df389a8fa4f81258816..dd7f737139ea372f64af929377608936fd582120 100644 (file)
@@ -270,10 +270,14 @@ namespace Mono.CSharp {
                        var da_false = new DefiniteAssignmentBitSet (fc.DefiniteAssignmentOnFalse);
 
                        fc.DefiniteAssignment = fc.DefiniteAssignmentOnTrue;
+                       var labels = fc.CopyLabelStack ();
 
                        var res = TrueStatement.FlowAnalysis (fc);
 
+                       fc.SetLabelStack (labels);
+
                        if (FalseStatement == null) {
+
                                var c = expr as Constant;
                                if (c != null && !c.IsDefaultValue)
                                        return true_returns;
@@ -288,14 +292,20 @@ namespace Mono.CSharp {
 
                        if (true_returns) {
                                fc.DefiniteAssignment = da_false;
-                               return FalseStatement.FlowAnalysis (fc);
+
+                               res = FalseStatement.FlowAnalysis (fc);
+                               fc.SetLabelStack (labels);
+                               return res;
                        }
 
                        var da_true = fc.DefiniteAssignment;
 
                        fc.DefiniteAssignment = da_false;
+
                        res &= FalseStatement.FlowAnalysis (fc);
 
+                       fc.SetLabelStack (labels);
+
                        if (!TrueStatement.IsUnreachable) {
                                if (false_returns || FalseStatement.IsUnreachable)
                                        fc.DefiniteAssignment = da_true;
@@ -548,6 +558,8 @@ namespace Mono.CSharp {
                                ec.Emit (OpCodes.Br, ec.LoopBegin);
                                ec.MarkLabel (while_loop);
 
+                               expr.EmitPrepare (ec);
+
                                Statement.Emit (ec);
                        
                                ec.MarkLabel (ec.LoopBegin);
@@ -1104,6 +1116,7 @@ namespace Mono.CSharp {
        public class Return : ExitStatement
        {
                Expression expr;
+               bool expr_returns;
 
                public Return (Expression expr, Location l)
                {
@@ -1291,7 +1304,7 @@ namespace Mono.CSharp {
                                                // Special case hoisted return value (happens in try/finally scenario)
                                                //
                                                if (ec.TryFinallyUnwind != null) {
-                                                       exit_label = TryFinally.EmitRedirectedReturn (ec, async_body);
+                                                       exit_label = TryFinally.EmitRedirectedReturn (ec, async_body, unwind_protect);
                                                }
 
                                                var async_return = (IAssignMethod)storey.HoistedReturnValue;
@@ -1301,7 +1314,7 @@ namespace Mono.CSharp {
                                                expr.Emit (ec);
 
                                                if (ec.TryFinallyUnwind != null)
-                                                       exit_label = TryFinally.EmitRedirectedReturn (ec, async_body);
+                                                       exit_label = TryFinally.EmitRedirectedReturn (ec, async_body, unwind_protect);
                                        }
 
                                        ec.Emit (OpCodes.Leave, exit_label);
@@ -1329,7 +1342,9 @@ namespace Mono.CSharp {
                        if (expr != null)
                                expr.FlowAnalysis (fc);
 
-                       base.DoFlowAnalysis (fc);
+                       if (!expr_returns)
+                               base.DoFlowAnalysis (fc);
+                       
                        return true;
                }
 
@@ -1342,6 +1357,12 @@ namespace Mono.CSharp {
                public override Reachability MarkReachable (Reachability rc)
                {
                        base.MarkReachable (rc);
+
+                       if (Expr != null) {
+                               rc = Expr.MarkReachable (rc);
+                               expr_returns = rc.IsUnreachable;
+                       }
+
                        return Reachability.CreateUnreachable ();
                }
 
@@ -1450,7 +1471,7 @@ namespace Mono.CSharp {
 
                        if (ec.TryFinallyUnwind != null && IsLeavingFinally (label.Block)) {
                                var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
-                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, label.Block);
+                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, label.Block, unwind_protect);
                        }
 
                        ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
@@ -1757,6 +1778,19 @@ namespace Mono.CSharp {
                        }
                }
 
+               public static Expression ConvertType (ResolveContext rc, Expression expr)
+               {
+                       var et = rc.BuiltinTypes.Exception;
+                       if (Convert.ImplicitConversionExists (rc, expr, et))
+                               expr = Convert.ImplicitConversion (rc, expr, et, expr.Location);
+                       else {
+                               rc.Report.Error (155, expr.Location, "The type caught or thrown must be derived from System.Exception");
+                               expr = EmptyCast.Create (expr, et);
+                       }
+
+                       return expr;
+               }
+
                public override bool Resolve (BlockContext ec)
                {
                        if (expr == null) {
@@ -1780,11 +1814,7 @@ namespace Mono.CSharp {
                        if (expr == null)
                                return false;
 
-                       var et = ec.BuiltinTypes.Exception;
-                       if (Convert.ImplicitConversionExists (ec, expr, et))
-                               expr = Convert.ImplicitConversion (ec, expr, et, loc);
-                       else
-                               ec.Report.Error (155, expr.Location, "The type caught or thrown must be derived from System.Exception");
+                       expr = ConvertType (ec, expr);
 
                        return true;
                }
@@ -1857,7 +1887,7 @@ namespace Mono.CSharp {
 
                        if (ec.TryFinallyUnwind != null) {
                                var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
-                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block);
+                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block, unwind_protect);
                        }
 
                        ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
@@ -1905,7 +1935,7 @@ namespace Mono.CSharp {
 
                        if (ec.TryFinallyUnwind != null) {
                                var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
-                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block);
+                               l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block, unwind_protect);
                        }
 
                        ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
@@ -2241,11 +2271,8 @@ namespace Mono.CSharp {
 
                public override Reachability MarkReachable (Reachability rc)
                {
-                       var init = initializer as ExpressionStatement;
-                       if (init != null)
-                               init.MarkReachable (rc);
-
-                       return base.MarkReachable (rc);
+                       base.MarkReachable (rc);
+                       return initializer == null ? rc : initializer.MarkReachable (rc);
                }
 
                protected override void CloneTo (CloneContext clonectx, Statement target)
@@ -2280,6 +2307,9 @@ namespace Mono.CSharp {
 
                public override void Emit (EmitContext ec)
                {
+                       if (!Variable.IsUsed)
+                               ec.Report.Warning (219, 3, loc, "The constant `{0}' is never used", Variable.Name);
+                       
                        // Nothing to emit, not even sequence point
                }
 
@@ -2405,6 +2435,12 @@ namespace Mono.CSharp {
                        }
                }
 
+               public bool Created {
+                       get {
+                               return builder != null;
+                       }
+               }
+
                public bool IsDeclared {
                        get {
                                return type != null;
@@ -2438,6 +2474,12 @@ namespace Mono.CSharp {
                        }
                }
 
+               public bool IsUsed {
+                       get {
+                               return (flags & Flags.Used) != 0;
+                       }
+               }
+
                public bool IsFixed {
                        get {
                                return (flags & Flags.FixedVariable) != 0;
@@ -2527,8 +2569,10 @@ namespace Mono.CSharp {
 
                public Expression CreateReferenceExpression (ResolveContext rc, Location loc)
                {
-                       if (IsConstant && const_value != null)
+                       if (IsConstant && const_value != null) {
+                               SetIsUsed ();
                                return Constant.CreateConstantFromValue (Type, const_value.GetValue (), loc);
+                       }
 
                        return new LocalVariableReference (this, loc);
                }
@@ -2657,6 +2701,7 @@ namespace Mono.CSharp {
                        AwaitBlock = 1 << 13,
                        FinallyBlock = 1 << 14,
                        CatchBlock = 1 << 15,
+                       HasReferenceToStoreyForInstanceLambdas = 1 << 16,
                        Iterator = 1 << 20,
                        NoFlowAnalysis = 1 << 21,
                        InitializationEmitted = 1 << 22
@@ -3223,9 +3268,10 @@ namespace Mono.CSharp {
 
                public override void Emit (EmitContext ec)
                {
-                       if (Parent != null) {
-                               // TODO: It's needed only when scope has variable (normal or lifted)
-                               ec.BeginScope (GetDebugSymbolScopeIndex ());
+                       // TODO: It's needed only when scope has variable (normal or lifted)
+                       var scopeIndex = GetDebugSymbolScopeIndex ();
+                       if (scopeIndex > 0) {
+                               ec.BeginScope (scopeIndex);
                        }
 
                        EmitScopeInitialization (ec);
@@ -3236,7 +3282,7 @@ namespace Mono.CSharp {
 
                        DoEmit (ec);
 
-                       if (Parent != null)
+                       if (scopeIndex > 0)
                                ec.EndScope ();
 
                        if (ec.EmitAccurateDebugInfo && HasReachableClosingBrace && !(this is ParametersBlock) &&
@@ -3257,6 +3303,7 @@ namespace Mono.CSharp {
                        //
                        storey.CreateContainer ();
                        storey.DefineContainer ();
+                       storey.ExpandBaseInterfaces ();
 
                        if (Original.Explicit.HasCapturedThis && Original.ParametersBlock.TopBlock.ThisReferencesFromChildrenBlock != null) {
 
@@ -3281,7 +3328,7 @@ namespace Mono.CSharp {
                                                        break;
                                        }
                                }
-                               
+
                                //
                                // We are the first storey on path and 'this' has to be hoisted
                                //
@@ -3349,7 +3396,7 @@ namespace Mono.CSharp {
 
                                                                //
                                                                // If we are state machine with no parent. We can hook into parent without additional
-                                                               // reference and capture this directly
+                                                               // reference and capture this directly
                                                                //
                                                                ExplicitBlock parent_storey_block = pb;
                                                                while (parent_storey_block.Parent != null) {
@@ -3428,7 +3475,12 @@ namespace Mono.CSharp {
                        storey.Parent.PartialContainer.AddCompilerGeneratedClass (storey);
                }
 
-               public int GetDebugSymbolScopeIndex ()
+               public void DisableDebugScopeIndex ()
+               {
+                       debug_scope_index = -1;
+               }
+
+               public virtual int GetDebugSymbolScopeIndex ()
                {
                        if (debug_scope_index == 0)
                                debug_scope_index = ++ParametersBlock.debug_scope_index;
@@ -3666,6 +3718,15 @@ namespace Mono.CSharp {
 
                #region Properties
 
+               public bool HasReferenceToStoreyForInstanceLambdas {
+                       get {
+                               return (flags & Flags.HasReferenceToStoreyForInstanceLambdas) != 0;
+                       }
+                       set {
+                               flags = value ? flags | Flags.HasReferenceToStoreyForInstanceLambdas : flags & ~Flags.HasReferenceToStoreyForInstanceLambdas;
+                       }
+               }
+
                public bool IsAsync {
                        get {
                                return (flags & Flags.HasAsyncModifier) != 0;
@@ -3827,6 +3888,11 @@ namespace Mono.CSharp {
                        return res;
                }
 
+               public override int GetDebugSymbolScopeIndex ()
+               {
+                       return 0;
+               }
+
                public LabeledStatement GetLabel (string name, Block block)
                {
                        //
@@ -6002,7 +6068,7 @@ namespace Mono.CSharp {
                                ec.EmitInt (first_resume_pc);
                                ec.Emit (OpCodes.Sub);
 
-                               var labels = new Label[resume_points.Count - System.Math.Max (first_catch_resume_pc, 0)];
+                               var labels = new Label [first_catch_resume_pc > 0 ? first_catch_resume_pc : resume_points.Count];
                                for (int i = 0; i < labels.Length; ++i)
                                        labels[i] = resume_points[i].PrepareForEmit (ec);
                                ec.Emit (OpCodes.Switch, labels);
@@ -6314,7 +6380,7 @@ namespace Mono.CSharp {
                public override bool Resolve (BlockContext ec)
                {
                        if (ec.CurrentIterator != null)
-                               ec.Report.Error (1629, loc, "Unsafe code may not appear in iterators");
+                               Expression.UnsafeInsideIteratorError (ec, loc);
 
                        using (ec.Set (ResolveContext.Options.UnsafeScope))
                                return Block.Resolve (ec);
@@ -6954,7 +7020,7 @@ namespace Mono.CSharp {
        {
                ExplicitBlock fini;
                List<DefiniteAssignmentBitSet> try_exit_dat;
-               List<Label> redirected_jumps;
+               List<Tuple<Label, bool>> redirected_jumps;
                Label? start_fin_label;
 
                public TryFinally (Statement stmt, ExplicitBlock fini, Location loc)
@@ -7041,6 +7107,7 @@ namespace Mono.CSharp {
                        ec.Emit (OpCodes.Stloc, temp);
 
                        var exception_field = ec.GetTemporaryField (type);
+                       exception_field.AutomaticallyReuse = false;
                        ec.EmitThis ();
                        ec.Emit (OpCodes.Ldloc, temp);
                        exception_field.EmitAssignFromStack (ec);
@@ -7064,7 +7131,7 @@ namespace Mono.CSharp {
                        ec.Emit (OpCodes.Throw);
                        ec.MarkLabel (skip_throw);
 
-                       exception_field.IsAvailableForReuse = true;
+                       exception_field.PrepareCleanup (ec);
 
                        EmitUnwindFinallyTable (ec);
                }
@@ -7079,7 +7146,7 @@ namespace Mono.CSharp {
                        return false;
                }
 
-               public static Label EmitRedirectedJump (EmitContext ec, AsyncInitializer initializer, Label label, Block labelBlock)
+               public static Label EmitRedirectedJump (EmitContext ec, AsyncInitializer initializer, Label label, Block labelBlock, bool unwindProtect)
                {
                        int idx;
                        if (labelBlock != null) {
@@ -7099,7 +7166,7 @@ namespace Mono.CSharp {
                                if (labelBlock != null && !fin.IsParentBlock (labelBlock))
                                        break;
 
-                               fin.EmitRedirectedExit (ec, label, initializer, set_return_state);
+                               fin.EmitRedirectedExit (ec, label, initializer, set_return_state, unwindProtect);
                                set_return_state = false;
 
                                if (fin.start_fin_label == null) {
@@ -7112,26 +7179,26 @@ namespace Mono.CSharp {
                        return label;
                }
 
-               public static Label EmitRedirectedReturn (EmitContext ec, AsyncInitializer initializer)
+               public static Label EmitRedirectedReturn (EmitContext ec, AsyncInitializer initializer, bool unwindProtect)
                {
-                       return EmitRedirectedJump (ec, initializer, initializer.BodyEnd, null);
+                       return EmitRedirectedJump (ec, initializer, initializer.BodyEnd, null, unwindProtect);
                }
 
-               void EmitRedirectedExit (EmitContext ec, Label label, AsyncInitializer initializer, bool setReturnState)
+               void EmitRedirectedExit (EmitContext ec, Label label, AsyncInitializer initializer, bool setReturnState, bool unwindProtect)
                {
                        if (redirected_jumps == null) {
-                               redirected_jumps = new List<Label> ();
+                               redirected_jumps = new List<Tuple<Label, bool>> ();
 
                                // Add fallthrough label
-                               redirected_jumps.Add (ec.DefineLabel ());
+                               redirected_jumps.Add (Tuple.Create (ec.DefineLabel (), false));
 
                                if (setReturnState)
                                        initializer.HoistedReturnState = ec.GetTemporaryField (ec.Module.Compiler.BuiltinTypes.Int, true);
                        }
 
-                       int index = redirected_jumps.IndexOf (label);
+                       int index = redirected_jumps.FindIndex (l => l.Item1 == label);
                        if (index < 0) {
-                               redirected_jumps.Add (label);
+                               redirected_jumps.Add (Tuple.Create (label, unwindProtect));
                                index = redirected_jumps.Count - 1;
                        }
 
@@ -7155,10 +7222,34 @@ namespace Mono.CSharp {
 
                        var initializer = (AsyncInitializer)ec.CurrentAnonymousMethod;
                        initializer.HoistedReturnState.EmitLoad (ec);
-                       ec.Emit (OpCodes.Switch, redirected_jumps.ToArray ());
+
+                       var jumps_table = new Label [redirected_jumps.Count];
+                       List<Tuple<Label, Label>> leave_redirect = null;
+                       for (int i = 0; i < jumps_table.Length; ++i) {
+                               var val = redirected_jumps [i];
+
+                               if (val.Item2) {
+                                       if (leave_redirect == null)
+                                               leave_redirect = new List<Tuple<Label, Label>> ();
+                                       var label = ec.DefineLabel ();
+                                       leave_redirect.Add (Tuple.Create (label, val.Item1));
+                                       jumps_table [i] = label;
+                               } else {
+                                       jumps_table [i] = val.Item1;
+                               }
+                       }
+
+                       ec.Emit (OpCodes.Switch, jumps_table);
+
+                       if (leave_redirect != null) {
+                               foreach (var entry in leave_redirect) {
+                                       ec.MarkLabel (entry.Item1);
+                                       ec.Emit (OpCodes.Leave, entry.Item2);
+                               }
+                       }
 
                        // Mark fallthrough label
-                       ec.MarkLabel (redirected_jumps [0]);
+                       ec.MarkLabel (jumps_table [0]);
                }
 
                protected override bool DoFlowAnalysis (FlowAnalysisContext fc)
@@ -7391,6 +7482,10 @@ namespace Mono.CSharp {
                                                ec.Emit (OpCodes.Br, end);
 
                                        ec.MarkLabel (labels [i + 1]);
+
+                                       ec.EmitInt (0);
+                                       ec.Emit (OpCodes.Stloc, state_variable);
+
                                        c = catch_sm [i];
                                        ec.AsyncThrowVariable = c.Variable;
                                        c.Block.Emit (ec);
@@ -8305,15 +8400,14 @@ namespace Mono.CSharp {
                        ec.LoopBegin = ec.DefineLabel ();
                        ec.LoopEnd = ec.DefineLabel ();
 
-                       if (!(Statement is Block))
-                               ec.BeginCompilerScope (variable.Block.Explicit.GetDebugSymbolScopeIndex ());
+                       ec.BeginCompilerScope (variable.Block.Explicit.GetDebugSymbolScopeIndex ());
+                       body.Explicit.DisableDebugScopeIndex ();
 
                        variable.CreateBuilder (ec);
 
                        Statement.Emit (ec);
 
-                       if (!(Statement is Block))
-                               ec.EndScope ();
+                       ec.EndScope ();
 
                        ec.LoopBegin = old_begin;
                        ec.LoopEnd = old_end;