2 // statement.cs: Statement representation for the IL tree.
5 // Miguel de Icaza (miguel@ximian.com)
6 // Martin Baulig (martin@ximian.com)
8 // (C) 2001, 2002, 2003 Ximian, Inc.
9 // (C) 2003, 2004 Novell, Inc.
14 using System.Reflection;
15 using System.Reflection.Emit;
16 using System.Diagnostics;
18 namespace Mono.CSharp {
20 using System.Collections;
22 public abstract class Statement {
26 /// Resolves the statement, true means that all sub-statements
29 public virtual bool Resolve (EmitContext ec)
35 /// We already know that the statement is unreachable, but we still
36 /// need to resolve it to catch errors.
38 public virtual bool ResolveUnreachable (EmitContext ec, bool warn)
41 // This conflicts with csc's way of doing this, but IMHO it's
42 // the right thing to do.
44 // If something is unreachable, we still check whether it's
45 // correct. This means that you cannot use unassigned variables
46 // in unreachable code, for instance.
49 if (warn && (RootContext.WarningLevel >= 2))
50 Report.Warning (162, loc, "Unreachable code detected");
52 ec.StartFlowBranching (FlowBranching.BranchingType.Block, loc);
53 bool ok = Resolve (ec);
54 ec.KillFlowBranching ();
59 protected void CheckObsolete (Type type)
61 ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (type);
62 if (obsolete_attr == null)
65 AttributeTester.Report_ObsoleteMessage (obsolete_attr, type.FullName, loc);
69 /// Return value indicates whether all code paths emitted return.
71 protected abstract void DoEmit (EmitContext ec);
74 /// Utility wrapper routine for Error, just to beautify the code
76 public void Error (int error, string format, params object[] args)
78 Error (error, String.Format (format, args));
81 public void Error (int error, string s)
83 if (!Location.IsNull (loc))
84 Report.Error (error, loc, s);
86 Report.Error (error, s);
90 /// Return value indicates whether all code paths emitted return.
92 public virtual void Emit (EmitContext ec)
99 public sealed class EmptyStatement : Statement {
101 private EmptyStatement () {}
103 public static readonly EmptyStatement Value = new EmptyStatement ();
105 public override bool Resolve (EmitContext ec)
110 protected override void DoEmit (EmitContext ec)
115 public class If : Statement {
117 public Statement TrueStatement;
118 public Statement FalseStatement;
122 public If (Expression expr, Statement trueStatement, Location l)
125 TrueStatement = trueStatement;
129 public If (Expression expr,
130 Statement trueStatement,
131 Statement falseStatement,
135 TrueStatement = trueStatement;
136 FalseStatement = falseStatement;
140 public override bool Resolve (EmitContext ec)
142 Report.Debug (1, "START IF BLOCK", loc);
144 expr = Expression.ResolveBoolean (ec, expr, loc);
149 Assign ass = expr as Assign;
150 if (ass != null && ass.Source is Constant) {
151 Report.Warning (665, 3, loc, "Assignment in conditional expression is always constant; did you mean to use == instead of = ?");
155 // Dead code elimination
157 if (expr is BoolConstant){
158 bool take = ((BoolConstant) expr).Value;
161 if (!TrueStatement.Resolve (ec))
164 if ((FalseStatement != null) &&
165 !FalseStatement.ResolveUnreachable (ec, true))
167 FalseStatement = null;
169 if (!TrueStatement.ResolveUnreachable (ec, true))
171 TrueStatement = null;
173 if ((FalseStatement != null) &&
174 !FalseStatement.Resolve (ec))
181 ec.StartFlowBranching (FlowBranching.BranchingType.Conditional, loc);
183 bool ok = TrueStatement.Resolve (ec);
185 is_true_ret = ec.CurrentBranching.CurrentUsageVector.Reachability.IsUnreachable;
187 ec.CurrentBranching.CreateSibling ();
189 if ((FalseStatement != null) && !FalseStatement.Resolve (ec))
192 ec.EndFlowBranching ();
194 Report.Debug (1, "END IF BLOCK", loc);
199 protected override void DoEmit (EmitContext ec)
201 ILGenerator ig = ec.ig;
202 Label false_target = ig.DefineLabel ();
206 // If we're a boolean expression, Resolve() already
207 // eliminated dead code for us.
209 if (expr is BoolConstant){
210 bool take = ((BoolConstant) expr).Value;
213 TrueStatement.Emit (ec);
214 else if (FalseStatement != null)
215 FalseStatement.Emit (ec);
220 expr.EmitBranchable (ec, false_target, false);
222 TrueStatement.Emit (ec);
224 if (FalseStatement != null){
225 bool branch_emitted = false;
227 end = ig.DefineLabel ();
229 ig.Emit (OpCodes.Br, end);
230 branch_emitted = true;
233 ig.MarkLabel (false_target);
234 FalseStatement.Emit (ec);
239 ig.MarkLabel (false_target);
244 public class Do : Statement {
245 public Expression expr;
246 public readonly Statement EmbeddedStatement;
249 public Do (Statement statement, Expression boolExpr, Location l)
252 EmbeddedStatement = statement;
256 public override bool Resolve (EmitContext ec)
260 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
262 if (!EmbeddedStatement.Resolve (ec))
265 expr = Expression.ResolveBoolean (ec, expr, loc);
268 else if (expr is BoolConstant){
269 bool res = ((BoolConstant) expr).Value;
275 ec.CurrentBranching.Infinite = infinite;
276 ec.EndFlowBranching ();
281 protected override void DoEmit (EmitContext ec)
283 ILGenerator ig = ec.ig;
284 Label loop = ig.DefineLabel ();
285 Label old_begin = ec.LoopBegin;
286 Label old_end = ec.LoopEnd;
288 ec.LoopBegin = ig.DefineLabel ();
289 ec.LoopEnd = ig.DefineLabel ();
292 EmbeddedStatement.Emit (ec);
293 ig.MarkLabel (ec.LoopBegin);
296 // Dead code elimination
298 if (expr is BoolConstant){
299 bool res = ((BoolConstant) expr).Value;
302 ec.ig.Emit (OpCodes.Br, loop);
304 expr.EmitBranchable (ec, loop, true);
306 ig.MarkLabel (ec.LoopEnd);
308 ec.LoopBegin = old_begin;
309 ec.LoopEnd = old_end;
313 public class While : Statement {
314 public Expression expr;
315 public readonly Statement Statement;
316 bool infinite, empty;
318 public While (Expression boolExpr, Statement statement, Location l)
320 this.expr = boolExpr;
321 Statement = statement;
325 public override bool Resolve (EmitContext ec)
329 expr = Expression.ResolveBoolean (ec, expr, loc);
334 // Inform whether we are infinite or not
336 if (expr is BoolConstant){
337 BoolConstant bc = (BoolConstant) expr;
339 if (bc.Value == false){
340 if (!Statement.ResolveUnreachable (ec, true))
348 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
350 if (!Statement.Resolve (ec))
353 ec.CurrentBranching.Infinite = infinite;
354 ec.EndFlowBranching ();
359 protected override void DoEmit (EmitContext ec)
364 ILGenerator ig = ec.ig;
365 Label old_begin = ec.LoopBegin;
366 Label old_end = ec.LoopEnd;
368 ec.LoopBegin = ig.DefineLabel ();
369 ec.LoopEnd = ig.DefineLabel ();
372 // Inform whether we are infinite or not
374 if (expr is BoolConstant){
375 ig.MarkLabel (ec.LoopBegin);
377 ig.Emit (OpCodes.Br, ec.LoopBegin);
380 // Inform that we are infinite (ie, `we return'), only
381 // if we do not `break' inside the code.
383 ig.MarkLabel (ec.LoopEnd);
385 Label while_loop = ig.DefineLabel ();
387 ig.Emit (OpCodes.Br, ec.LoopBegin);
388 ig.MarkLabel (while_loop);
392 ig.MarkLabel (ec.LoopBegin);
394 expr.EmitBranchable (ec, while_loop, true);
396 ig.MarkLabel (ec.LoopEnd);
399 ec.LoopBegin = old_begin;
400 ec.LoopEnd = old_end;
404 public class For : Statement {
406 readonly Statement InitStatement;
407 readonly Statement Increment;
408 readonly Statement Statement;
409 bool infinite, empty;
411 public For (Statement initStatement,
417 InitStatement = initStatement;
419 Increment = increment;
420 Statement = statement;
424 public override bool Resolve (EmitContext ec)
428 if (InitStatement != null){
429 if (!InitStatement.Resolve (ec))
434 Test = Expression.ResolveBoolean (ec, Test, loc);
437 else if (Test is BoolConstant){
438 BoolConstant bc = (BoolConstant) Test;
440 if (bc.Value == false){
441 if (!Statement.ResolveUnreachable (ec, true))
443 if ((Increment != null) &&
444 !Increment.ResolveUnreachable (ec, false))
454 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
456 ec.CurrentBranching.CreateSibling ();
458 if (!Statement.Resolve (ec))
461 if (Increment != null){
462 if (!Increment.Resolve (ec))
466 ec.CurrentBranching.Infinite = infinite;
467 ec.EndFlowBranching ();
472 protected override void DoEmit (EmitContext ec)
477 ILGenerator ig = ec.ig;
478 Label old_begin = ec.LoopBegin;
479 Label old_end = ec.LoopEnd;
480 Label loop = ig.DefineLabel ();
481 Label test = ig.DefineLabel ();
483 if (InitStatement != null && InitStatement != EmptyStatement.Value)
484 InitStatement.Emit (ec);
486 ec.LoopBegin = ig.DefineLabel ();
487 ec.LoopEnd = ig.DefineLabel ();
489 ig.Emit (OpCodes.Br, test);
493 ig.MarkLabel (ec.LoopBegin);
494 if (Increment != EmptyStatement.Value)
499 // If test is null, there is no test, and we are just
504 // The Resolve code already catches the case for
505 // Test == BoolConstant (false) so we know that
508 if (Test is BoolConstant)
509 ig.Emit (OpCodes.Br, loop);
511 Test.EmitBranchable (ec, loop, true);
514 ig.Emit (OpCodes.Br, loop);
515 ig.MarkLabel (ec.LoopEnd);
517 ec.LoopBegin = old_begin;
518 ec.LoopEnd = old_end;
522 public class StatementExpression : Statement {
523 ExpressionStatement expr;
525 public StatementExpression (ExpressionStatement expr, Location l)
531 public override bool Resolve (EmitContext ec)
534 expr = expr.ResolveStatement (ec);
538 protected override void DoEmit (EmitContext ec)
540 expr.EmitStatement (ec);
543 public override string ToString ()
545 return "StatementExpression (" + expr + ")";
550 /// Implements the return statement
552 public class Return : Statement {
553 public Expression Expr;
555 public Return (Expression expr, Location l)
563 public override bool Resolve (EmitContext ec)
565 if (ec.ReturnType == null){
567 if (ec.CurrentAnonymousMethod != null){
568 Report.Error (1662, loc, String.Format (
569 "Anonymous method could not be converted to delegate " +
570 "since the return value does not match the delegate value"));
572 Error (127, "Return with a value not allowed here");
577 Error (126, "An object of type `{0}' is expected " +
578 "for the return statement",
579 TypeManager.CSharpName (ec.ReturnType));
583 Expr = Expr.Resolve (ec);
587 if (Expr.Type != ec.ReturnType) {
588 Expr = Convert.ImplicitConversionRequired (
589 ec, Expr, ec.ReturnType, loc);
596 Error (-206, "Return statement not allowed inside iterators");
600 FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
602 if (ec.CurrentBranching.InTryOrCatch (true)) {
603 ec.CurrentBranching.AddFinallyVector (vector);
605 } else if (ec.CurrentBranching.InFinally (true)) {
606 Error (157, "Control can not leave the body of the finally block");
609 vector.CheckOutParameters (ec.CurrentBranching);
612 ec.NeedReturnLabel ();
614 ec.CurrentBranching.CurrentUsageVector.Return ();
618 protected override void DoEmit (EmitContext ec)
624 ec.ig.Emit (OpCodes.Stloc, ec.TemporaryReturn ());
628 ec.ig.Emit (OpCodes.Leave, ec.ReturnLabel);
630 ec.ig.Emit (OpCodes.Ret);
634 public class Goto : Statement {
637 LabeledStatement label;
639 public override bool Resolve (EmitContext ec)
641 label = ec.CurrentBranching.LookupLabel (target, loc);
645 // If this is a forward goto.
646 if (!label.IsDefined)
647 label.AddUsageVector (ec.CurrentBranching.CurrentUsageVector);
649 ec.CurrentBranching.CurrentUsageVector.Goto ();
650 label.AddReference ();
655 public Goto (Block parent_block, string label, Location l)
657 block = parent_block;
662 public string Target {
668 protected override void DoEmit (EmitContext ec)
670 Label l = label.LabelTarget (ec);
671 ec.ig.Emit (OpCodes.Br, l);
675 public class LabeledStatement : Statement {
676 public readonly Location Location;
682 FlowBranching.UsageVector vectors;
684 public LabeledStatement (string label_name, Location l)
689 public Label LabelTarget (EmitContext ec)
694 label = ec.ig.DefineLabel ();
700 public bool IsDefined {
706 public bool HasBeenReferenced {
712 public void AddUsageVector (FlowBranching.UsageVector vector)
714 vector = vector.Clone ();
715 vector.Next = vectors;
719 public override bool Resolve (EmitContext ec)
721 ec.CurrentBranching.Label (vectors);
726 protected override void DoEmit (EmitContext ec)
728 if (ig != null && ig != ec.ig) {
729 Report.Error (1632, "Control cannot leave body of anonymous method");
733 ec.ig.MarkLabel (label);
736 public void AddReference ()
744 /// `goto default' statement
746 public class GotoDefault : Statement {
748 public GotoDefault (Location l)
753 public override bool Resolve (EmitContext ec)
755 ec.CurrentBranching.CurrentUsageVector.Goto ();
759 protected override void DoEmit (EmitContext ec)
761 if (ec.Switch == null){
762 Report.Error (153, loc, "goto default is only valid in a switch statement");
766 if (!ec.Switch.GotDefault){
767 Report.Error (159, loc, "No default target on switch statement");
770 ec.ig.Emit (OpCodes.Br, ec.Switch.DefaultTarget);
775 /// `goto case' statement
777 public class GotoCase : Statement {
781 public GotoCase (Expression e, Location l)
787 public override bool Resolve (EmitContext ec)
789 if (ec.Switch == null){
790 Report.Error (153, loc, "goto case is only valid in a switch statement");
794 expr = expr.Resolve (ec);
798 if (!(expr is Constant)){
799 Report.Error (159, loc, "Target expression for goto case is not constant");
803 object val = Expression.ConvertIntLiteral (
804 (Constant) expr, ec.Switch.SwitchType, loc);
809 sl = (SwitchLabel) ec.Switch.Elements [val];
814 "No such label 'case " + val + "': for the goto case");
818 ec.CurrentBranching.CurrentUsageVector.Goto ();
822 protected override void DoEmit (EmitContext ec)
824 ec.ig.Emit (OpCodes.Br, sl.GetILLabelCode (ec));
828 public class Throw : Statement {
831 public Throw (Expression expr, Location l)
837 public override bool Resolve (EmitContext ec)
839 ec.CurrentBranching.CurrentUsageVector.Throw ();
842 expr = expr.Resolve (ec);
846 ExprClass eclass = expr.eclass;
848 if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
849 eclass == ExprClass.Value || eclass == ExprClass.IndexerAccess)) {
850 expr.Error_UnexpectedKind ("value, variable, property or indexer access ", loc);
856 if ((t != TypeManager.exception_type) &&
857 !t.IsSubclassOf (TypeManager.exception_type) &&
858 !(expr is NullLiteral)) {
860 "The type caught or thrown must be derived " +
861 "from System.Exception");
867 if (ec.CurrentBranching.InFinally (true)) {
868 Error (724, "A throw statement with no argument is only allowed in a catch clause nested inside of the innermost catch clause");
872 if (!ec.CurrentBranching.InCatch ()) {
873 Error (156, "A throw statement with no argument is only allowed in a catch clause");
879 protected override void DoEmit (EmitContext ec)
882 ec.ig.Emit (OpCodes.Rethrow);
886 ec.ig.Emit (OpCodes.Throw);
891 public class Break : Statement {
893 public Break (Location l)
900 public override bool Resolve (EmitContext ec)
902 if (!ec.CurrentBranching.InLoop () && !ec.CurrentBranching.InSwitch ()){
903 Error (139, "No enclosing loop or switch to continue to");
905 } else if (ec.CurrentBranching.InFinally (false)) {
906 Error (157, "Control can not leave the body of the finally block");
908 } else if (ec.CurrentBranching.InTryOrCatch (false))
909 ec.CurrentBranching.AddFinallyVector (
910 ec.CurrentBranching.CurrentUsageVector);
911 else if (ec.CurrentBranching.InLoop ())
912 ec.CurrentBranching.AddBreakVector (
913 ec.CurrentBranching.CurrentUsageVector);
915 crossing_exc = ec.CurrentBranching.BreakCrossesTryCatchBoundary ();
918 ec.NeedReturnLabel ();
920 ec.CurrentBranching.CurrentUsageVector.Break ();
924 protected override void DoEmit (EmitContext ec)
926 ILGenerator ig = ec.ig;
929 ig.Emit (OpCodes.Leave, ec.LoopEnd);
931 ig.Emit (OpCodes.Br, ec.LoopEnd);
936 public class Continue : Statement {
938 public Continue (Location l)
945 public override bool Resolve (EmitContext ec)
947 if (!ec.CurrentBranching.InLoop () && !ec.CurrentBranching.InSwitch ()){
948 Error (139, "No enclosing loop to continue to");
950 } else if (ec.CurrentBranching.InFinally (false)) {
951 Error (157, "Control can not leave the body of the finally block");
953 } else if (ec.CurrentBranching.InTryOrCatch (false))
954 ec.CurrentBranching.AddFinallyVector (ec.CurrentBranching.CurrentUsageVector);
956 crossing_exc = ec.CurrentBranching.BreakCrossesTryCatchBoundary ();
958 ec.CurrentBranching.CurrentUsageVector.Goto ();
962 protected override void DoEmit (EmitContext ec)
964 Label begin = ec.LoopBegin;
967 ec.ig.Emit (OpCodes.Leave, begin);
969 ec.ig.Emit (OpCodes.Br, begin);
974 // The information about a user-perceived local variable
976 public class LocalInfo {
977 public Expression Type;
980 // Most of the time a variable will be stored in a LocalBuilder
982 // But sometimes, it will be stored in a field (variables that have been
983 // hoisted by iterators or by anonymous methods). The context of the field will
984 // be stored in the EmitContext
987 public LocalBuilder LocalBuilder;
988 public FieldBuilder FieldBuilder;
990 public Type VariableType;
991 public readonly string Name;
992 public readonly Location Location;
993 public readonly Block Block;
995 public VariableInfo VariableInfo;
1008 public LocalInfo (Expression type, string name, Block block, Location l)
1016 public LocalInfo (TypeContainer tc, Block block, Location l)
1018 VariableType = tc.TypeBuilder;
1023 public bool IsThisAssigned (EmitContext ec, Location loc)
1025 if (VariableInfo == null)
1026 throw new Exception ();
1028 if (!ec.DoFlowAnalysis || ec.CurrentBranching.IsAssigned (VariableInfo))
1031 return VariableInfo.TypeInfo.IsFullyInitialized (ec.CurrentBranching, VariableInfo, loc);
1034 public bool IsAssigned (EmitContext ec)
1036 if (VariableInfo == null)
1037 throw new Exception ();
1039 return !ec.DoFlowAnalysis || ec.CurrentBranching.IsAssigned (VariableInfo);
1042 public bool Resolve (EmitContext ec)
1044 if (VariableType == null) {
1045 TypeExpr texpr = Type.ResolveAsTypeTerminal (ec);
1049 VariableType = texpr.Type;
1052 if (VariableType == TypeManager.void_type) {
1053 Report.Error (1547, Location,
1054 "Keyword 'void' cannot be used in this context");
1058 if (VariableType.IsAbstract && VariableType.IsSealed) {
1059 Report.Error (723, Location, "Cannot declare variable of static type '{0}'", TypeManager.CSharpName (VariableType));
1062 // TODO: breaks the build
1063 // if (VariableType.IsPointer && !ec.InUnsafe)
1064 // Expression.UnsafeError (Location);
1070 // Whether the variable is Fixed (because its Pinned or its a value type)
1072 public bool IsFixed {
1074 if (((flags & Flags.Pinned) != 0) || TypeManager.IsValueType (VariableType))
1081 public bool IsCaptured {
1083 return (flags & Flags.Captured) != 0;
1087 flags |= Flags.Captured;
1091 public bool AddressTaken {
1093 return (flags & Flags.AddressTaken) != 0;
1097 flags |= Flags.AddressTaken;
1101 public override string ToString ()
1103 return String.Format ("LocalInfo ({0},{1},{2},{3})",
1104 Name, Type, VariableInfo, Location);
1109 return (flags & Flags.Used) != 0;
1112 flags = value ? (flags | Flags.Used) : (unchecked (flags & ~Flags.Used));
1116 public bool ReadOnly {
1118 return (flags & Flags.ReadOnly) != 0;
1121 flags = value ? (flags | Flags.ReadOnly) : (unchecked (flags & ~Flags.ReadOnly));
1126 // Whether the variable is pinned, if Pinned the variable has been
1127 // allocated in a pinned slot with DeclareLocal.
1129 public bool Pinned {
1131 return (flags & Flags.Pinned) != 0;
1134 flags = value ? (flags | Flags.Pinned) : (flags & ~Flags.Pinned);
1138 public bool IsThis {
1140 return (flags & Flags.IsThis) != 0;
1143 flags = value ? (flags | Flags.IsThis) : (flags & ~Flags.IsThis);
1149 /// Block represents a C# block.
1153 /// This class is used in a number of places: either to represent
1154 /// explicit blocks that the programmer places or implicit blocks.
1156 /// Implicit blocks are used as labels or to introduce variable
1159 /// Top-level blocks derive from Block, and they are called ToplevelBlock
1160 /// they contain extra information that is not necessary on normal blocks.
1162 public class Block : Statement {
1163 public Block Parent;
1164 public readonly Location StartLocation;
1165 public Location EndLocation = Location.Null;
1172 VariablesInitialized = 8,
1181 public bool Implicit {
1183 return (flags & Flags.Implicit) != 0;
1187 public bool Unchecked {
1189 return (flags & Flags.Unchecked) != 0;
1192 flags |= Flags.Unchecked;
1196 public bool Unsafe {
1198 return (flags & Flags.Unsafe) != 0;
1201 flags |= Flags.Unsafe;
1205 public bool HasVarargs {
1208 return Parent.HasVarargs;
1210 return (flags & Flags.HasVarargs) != 0;
1213 flags |= Flags.HasVarargs;
1218 // The statements in this block
1220 ArrayList statements;
1224 // An array of Blocks. We keep track of children just
1225 // to generate the local variable declarations.
1227 // Statements and child statements are handled through the
1233 // Labels. (label, block) pairs.
1238 // Keeps track of (name, type) pairs
1240 Hashtable variables;
1243 // Keeps track of constants
1244 Hashtable constants;
1247 // The parameters for the block, this is only needed on the toplevel block really
1248 // TODO: move `parameters' into ToplevelBlock
1249 Parameters parameters;
1252 // If this is a switch section, the enclosing switch block.
1256 protected static int id;
1260 public Block (Block parent)
1261 : this (parent, (Flags) 0, Location.Null, Location.Null)
1264 public Block (Block parent, Flags flags)
1265 : this (parent, flags, Location.Null, Location.Null)
1268 public Block (Block parent, Flags flags, Parameters parameters)
1269 : this (parent, flags, parameters, Location.Null, Location.Null)
1272 public Block (Block parent, Location start, Location end)
1273 : this (parent, (Flags) 0, start, end)
1276 public Block (Block parent, Parameters parameters, Location start, Location end)
1277 : this (parent, (Flags) 0, parameters, start, end)
1280 public Block (Block parent, Flags flags, Location start, Location end)
1281 : this (parent, flags, Parameters.EmptyReadOnlyParameters, start, end)
1284 public Block (Block parent, Flags flags, Parameters parameters,
1285 Location start, Location end)
1288 parent.AddChild (this);
1290 this.Parent = parent;
1292 this.parameters = parameters;
1293 this.StartLocation = start;
1294 this.EndLocation = end;
1297 statements = new ArrayList ();
1299 if (parent != null && Implicit) {
1300 if (parent.child_variable_names == null)
1301 parent.child_variable_names = new Hashtable();
1302 // share with parent
1303 child_variable_names = parent.child_variable_names;
1308 public Block CreateSwitchBlock (Location start)
1310 Block new_block = new Block (this, start, start);
1311 new_block.switch_block = this;
1321 void AddChild (Block b)
1323 if (children == null)
1324 children = new ArrayList ();
1329 public void SetEndLocation (Location loc)
1335 /// Adds a label to the current block.
1339 /// false if the name already exists in this block. true
1343 public bool AddLabel (string name, LabeledStatement target, Location loc)
1345 if (switch_block != null)
1346 return switch_block.AddLabel (name, target, loc);
1349 while (cur != null) {
1350 if (cur.DoLookupLabel (name) != null) {
1352 140, loc, "The label '{0}' is a duplicate",
1363 while (cur != null) {
1364 if (cur.DoLookupLabel (name) != null) {
1367 "The label '{0}' shadows another label " +
1368 "by the same name in a containing scope.",
1373 if (children != null) {
1374 foreach (Block b in children) {
1375 LabeledStatement s = b.DoLookupLabel (name);
1381 "The label '{0}' shadows another " +
1382 "label by the same name in a " +
1383 "containing scope.",
1394 labels = new Hashtable ();
1396 labels.Add (name, target);
1400 public LabeledStatement LookupLabel (string name)
1402 LabeledStatement s = DoLookupLabel (name);
1406 if (children == null)
1409 foreach (Block child in children) {
1410 if (!child.Implicit)
1413 s = child.LookupLabel (name);
1421 LabeledStatement DoLookupLabel (string name)
1423 if (switch_block != null)
1424 return switch_block.LookupLabel (name);
1427 if (labels.Contains (name))
1428 return ((LabeledStatement) labels [name]);
1433 LocalInfo this_variable = null;
1436 // Returns the "this" instance variable of this block.
1437 // See AddThisVariable() for more information.
1439 public LocalInfo ThisVariable {
1441 for (Block b = this; b != null; b = b.Parent) {
1442 if (b.this_variable != null)
1443 return b.this_variable;
1450 Hashtable child_variable_names;
1453 // Marks a variable with name @name as being used in a child block.
1454 // If a variable name has been used in a child block, it's illegal to
1455 // declare a variable with the same name in the current block.
1457 public void AddChildVariableName (string name)
1459 if (child_variable_names == null)
1460 child_variable_names = new Hashtable ();
1462 child_variable_names [name] = null;
1466 // Checks whether a variable name has already been used in a child block.
1468 public bool IsVariableNameUsedInChildBlock (string name)
1470 if (child_variable_names == null)
1473 return child_variable_names.Contains (name);
1477 // This is used by non-static `struct' constructors which do not have an
1478 // initializer - in this case, the constructor must initialize all of the
1479 // struct's fields. To do this, we add a "this" variable and use the flow
1480 // analysis code to ensure that it's been fully initialized before control
1481 // leaves the constructor.
1483 public LocalInfo AddThisVariable (TypeContainer tc, Location l)
1485 if (this_variable != null)
1486 return this_variable;
1488 if (variables == null)
1489 variables = new Hashtable ();
1491 this_variable = new LocalInfo (tc, this, l);
1492 this_variable.Used = true;
1493 this_variable.IsThis = true;
1495 variables.Add ("this", this_variable);
1497 return this_variable;
1500 public LocalInfo AddVariable (Expression type, string name, Parameters pars, Location l)
1502 if (variables == null)
1503 variables = new Hashtable ();
1505 LocalInfo vi = GetLocalInfo (name);
1507 if (vi.Block != this)
1508 Report.Error (136, l, "A local variable named `" + name + "' " +
1509 "cannot be declared in this scope since it would " +
1510 "give a different meaning to `" + name + "', which " +
1511 "is already used in a `parent or current' scope to " +
1512 "denote something else");
1514 Report.Error (128, l, "A local variable `" + name + "' is already " +
1515 "defined in this scope");
1519 if (IsVariableNameUsedInChildBlock (name)) {
1520 Report.Error (136, l, "A local variable named `" + name + "' " +
1521 "cannot be declared in this scope since it would " +
1522 "give a different meaning to `" + name + "', which " +
1523 "is already used in a `child' scope to denote something " +
1530 Parameter p = pars.GetParameterByName (name, out idx);
1532 Report.Error (136, l, "A local variable named `" + name + "' " +
1533 "cannot be declared in this scope since it would " +
1534 "give a different meaning to `" + name + "', which " +
1535 "is already used in a `parent or current' scope to " +
1536 "denote something else");
1541 vi = new LocalInfo (type, name, this, l);
1543 variables.Add (name, vi);
1545 // Mark 'name' as "used by a child block" in every surrounding block
1547 while (cur != null && cur.Implicit)
1550 for (Block par = cur.Parent; par != null; par = par.Parent)
1551 par.AddChildVariableName (name);
1553 if ((flags & Flags.VariablesInitialized) != 0)
1554 throw new Exception ();
1556 // Console.WriteLine ("Adding {0} to {1}", name, ID);
1560 public bool AddConstant (Expression type, string name, Expression value, Parameters pars, Location l)
1562 if (AddVariable (type, name, pars, l) == null)
1565 if (constants == null)
1566 constants = new Hashtable ();
1568 constants.Add (name, value);
1572 public Hashtable Variables {
1578 public LocalInfo GetLocalInfo (string name)
1580 for (Block b = this; b != null; b = b.Parent) {
1581 if (b.variables != null) {
1582 LocalInfo ret = b.variables [name] as LocalInfo;
1590 public Expression GetVariableType (string name)
1592 LocalInfo vi = GetLocalInfo (name);
1600 public Expression GetConstantExpression (string name)
1602 for (Block b = this; b != null; b = b.Parent) {
1603 if (b.constants != null) {
1604 Expression ret = b.constants [name] as Expression;
1613 /// True if the variable named @name is a constant
1615 public bool IsConstant (string name)
1617 Expression e = null;
1619 e = GetConstantExpression (name);
1625 // Returns a `ParameterReference' for the given name, or null if there
1626 // is no such parameter
1628 public ParameterReference GetParameterReference (string name, Location loc)
1633 Parameters pars = b.parameters;
1639 par = pars.GetParameterByName (name, out idx);
1641 ParameterReference pr;
1643 pr = new ParameterReference (pars, this, idx, name, loc);
1648 } while (b != null);
1653 // Whether the parameter named `name' is local to this block,
1654 // or false, if the parameter belongs to an encompassing block.
1656 public bool IsLocalParameter (string name)
1659 int toplevel_count = 0;
1662 if (this is ToplevelBlock)
1665 Parameters pars = b.parameters;
1667 if (pars.GetParameterByName (name) != null)
1671 if (toplevel_count > 0)
1674 } while (b != null);
1679 // Whether the `name' is a parameter reference
1681 public bool IsParameterReference (string name)
1686 Parameters pars = b.parameters;
1689 if (pars.GetParameterByName (name) != null)
1692 } while (b != null);
1697 /// A list of labels that were not used within this block
1699 public string [] GetUnreferenced ()
1701 // FIXME: Implement me
1705 public void AddStatement (Statement s)
1708 flags |= Flags.BlockUsed;
1713 return (flags & Flags.BlockUsed) != 0;
1719 flags |= Flags.BlockUsed;
1722 public bool HasRet {
1724 return (flags & Flags.HasRet) != 0;
1728 public bool IsDestructor {
1730 return (flags & Flags.IsDestructor) != 0;
1734 public void SetDestructor ()
1736 flags |= Flags.IsDestructor;
1739 VariableMap param_map, local_map;
1741 public VariableMap ParameterMap {
1743 if ((flags & Flags.VariablesInitialized) == 0)
1744 throw new Exception ("Variables have not been initialized yet");
1750 public VariableMap LocalMap {
1752 if ((flags & Flags.VariablesInitialized) == 0)
1753 throw new Exception ("Variables have not been initialized yet");
1760 /// Emits the variable declarations and labels.
1763 /// tc: is our typecontainer (to resolve type references)
1764 /// ig: is the code generator:
1766 public void ResolveMeta (ToplevelBlock toplevel, EmitContext ec, InternalParameters ip)
1768 bool old_unsafe = ec.InUnsafe;
1770 // If some parent block was unsafe, we remain unsafe even if this block
1771 // isn't explicitly marked as such.
1772 ec.InUnsafe |= Unsafe;
1775 // Compute the VariableMap's.
1777 // Unfortunately, we don't know the type when adding variables with
1778 // AddVariable(), so we need to compute this info here.
1782 if (variables != null) {
1783 foreach (LocalInfo li in variables.Values)
1786 locals = new LocalInfo [variables.Count];
1787 variables.Values.CopyTo (locals, 0);
1789 locals = new LocalInfo [0];
1792 local_map = new VariableMap (Parent.LocalMap, locals);
1794 local_map = new VariableMap (locals);
1796 param_map = new VariableMap (ip);
1797 flags |= Flags.VariablesInitialized;
1799 bool old_check_state = ec.ConstantCheckState;
1800 ec.ConstantCheckState = (flags & Flags.Unchecked) == 0;
1803 // Process this block variables
1805 if (variables != null){
1806 foreach (DictionaryEntry de in variables){
1807 string name = (string) de.Key;
1808 LocalInfo vi = (LocalInfo) de.Value;
1810 if (vi.VariableType == null)
1813 Type variable_type = vi.VariableType;
1815 if (variable_type.IsPointer){
1817 // Am not really convinced that this test is required (Microsoft does it)
1818 // but the fact is that you would not be able to use the pointer variable
1821 if (!TypeManager.VerifyUnManaged (TypeManager.GetElementType (variable_type),
1828 vi.FieldBuilder = ec.MapVariable (name, vi.VariableType);
1831 // This is needed to compile on both .NET 1.x and .NET 2.x
1832 // the later introduced `DeclareLocal (Type t, bool pinned)'
1834 vi.LocalBuilder = TypeManager.DeclareLocalPinned (ig, vi.VariableType);
1835 else if (!vi.IsThis)
1836 vi.LocalBuilder = ig.DeclareLocal (vi.VariableType);
1839 if (constants == null)
1842 Expression cv = (Expression) constants [name];
1846 ec.CurrentBlock = this;
1847 Expression e = cv.Resolve (ec);
1851 Constant ce = e as Constant;
1853 Report.Error (133, vi.Location,
1854 "The expression being assigned to `" +
1855 name + "' must be constant (" + e + ")");
1859 if (e.Type != variable_type){
1860 e = Const.ChangeType (vi.Location, ce, variable_type);
1865 constants.Remove (name);
1866 constants.Add (name, e);
1869 ec.ConstantCheckState = old_check_state;
1872 // Now, handle the children
1874 if (children != null){
1875 foreach (Block b in children)
1876 b.ResolveMeta (toplevel, ec, ip);
1878 ec.InUnsafe = old_unsafe;
1882 // Emits the local variable declarations for a block
1884 public void EmitMeta (EmitContext ec)
1886 ILGenerator ig = ec.ig;
1888 if (variables != null){
1889 bool have_captured_vars = ec.HaveCapturedVariables ();
1890 bool remap_locals = ec.RemapToProxy;
1892 foreach (DictionaryEntry de in variables){
1893 LocalInfo vi = (LocalInfo) de.Value;
1895 if (have_captured_vars && ec.IsCaptured (vi))
1899 vi.FieldBuilder = ec.MapVariable (vi.Name, vi.VariableType);
1903 // This is needed to compile on both .NET 1.x and .NET 2.x
1904 // the later introduced `DeclareLocal (Type t, bool pinned)'
1906 vi.LocalBuilder = TypeManager.DeclareLocalPinned (ig, vi.VariableType);
1907 else if (!vi.IsThis)
1908 vi.LocalBuilder = ig.DeclareLocal (vi.VariableType);
1913 if (children != null){
1914 foreach (Block b in children)
1919 void UsageWarning (FlowBranching.UsageVector vector)
1923 if ((variables != null) && (RootContext.WarningLevel >= 3)) {
1924 foreach (DictionaryEntry de in variables){
1925 LocalInfo vi = (LocalInfo) de.Value;
1930 name = (string) de.Key;
1932 if (vector.IsAssigned (vi.VariableInfo)){
1933 Report.Warning (219, vi.Location, "The variable '{0}' is assigned but its value is never used", name);
1935 Report.Warning (168, vi.Location, "The variable '{0}' is declared but never used", name);
1941 bool unreachable_shown;
1943 public override bool Resolve (EmitContext ec)
1945 Block prev_block = ec.CurrentBlock;
1948 int errors = Report.Errors;
1950 ec.CurrentBlock = this;
1951 ec.StartFlowBranching (this);
1953 Report.Debug (4, "RESOLVE BLOCK", StartLocation, ec.CurrentBranching);
1955 bool unreachable = unreachable_shown;
1957 int statement_count = statements.Count;
1958 for (int ix = 0; ix < statement_count; ix++){
1959 Statement s = (Statement) statements [ix];
1961 if (unreachable && !(s is LabeledStatement)) {
1962 if (s == EmptyStatement.Value)
1963 s.loc = EndLocation;
1965 if (!s.ResolveUnreachable (ec, !unreachable_shown))
1968 if (s != EmptyStatement.Value)
1969 unreachable_shown = true;
1971 s.loc = Location.Null;
1973 if (ok && !(s is Block)) {
1974 statements [ix] = EmptyStatement.Value;
1979 if (s.Resolve (ec) == false) {
1981 statements [ix] = EmptyStatement.Value;
1985 num_statements = ix + 1;
1987 if (s is LabeledStatement)
1988 unreachable = false;
1990 unreachable = ec.CurrentBranching.CurrentUsageVector.Reachability.IsUnreachable;
1993 Report.Debug (4, "RESOLVE BLOCK DONE", StartLocation,
1994 ec.CurrentBranching, statement_count, num_statements);
1997 FlowBranching.UsageVector vector = ec.DoEndFlowBranching ();
1999 ec.CurrentBlock = prev_block;
2001 // If we're a non-static `struct' constructor which doesn't have an
2002 // initializer, then we must initialize all of the struct's fields.
2003 if ((this_variable != null) &&
2004 (vector.Reachability.Throws != FlowBranching.FlowReturns.Always) &&
2005 !this_variable.IsThisAssigned (ec, loc))
2008 if ((labels != null) && (RootContext.WarningLevel >= 2)) {
2009 foreach (LabeledStatement label in labels.Values)
2010 if (!label.HasBeenReferenced)
2011 Report.Warning (164, label.Location,
2012 "This label has not been referenced");
2015 Report.Debug (4, "RESOLVE BLOCK DONE #2", StartLocation, vector);
2017 if ((vector.Reachability.Returns == FlowBranching.FlowReturns.Always) ||
2018 (vector.Reachability.Throws == FlowBranching.FlowReturns.Always) ||
2019 (vector.Reachability.Reachable == FlowBranching.FlowReturns.Never))
2020 flags |= Flags.HasRet;
2022 if (ok && (errors == Report.Errors)) {
2023 if (RootContext.WarningLevel >= 3)
2024 UsageWarning (vector);
2030 public override bool ResolveUnreachable (EmitContext ec, bool warn)
2032 unreachable_shown = true;
2034 if (warn && (RootContext.WarningLevel >= 2))
2035 Report.Warning (162, loc, "Unreachable code detected");
2038 return Resolve (ec);
2040 ec.StartFlowBranching (FlowBranching.BranchingType.Block, loc);
2041 bool ok = Resolve (ec);
2042 ec.KillFlowBranching ();
2047 protected override void DoEmit (EmitContext ec)
2049 for (int ix = 0; ix < num_statements; ix++){
2050 Statement s = (Statement) statements [ix];
2052 // Check whether we are the last statement in a
2055 if (((Parent == null) || Implicit) && (ix+1 == num_statements) && !(s is Block))
2056 ec.IsLastStatement = true;
2058 ec.IsLastStatement = false;
2064 public override void Emit (EmitContext ec)
2066 Block prev_block = ec.CurrentBlock;
2068 ec.CurrentBlock = this;
2070 bool emit_debug_info = (CodeGen.SymbolWriter != null);
2071 bool is_lexical_block = !Implicit && (Parent != null);
2073 if (emit_debug_info) {
2074 if (is_lexical_block)
2077 if (variables != null) {
2078 foreach (DictionaryEntry de in variables) {
2079 string name = (string) de.Key;
2080 LocalInfo vi = (LocalInfo) de.Value;
2082 if (vi.LocalBuilder == null)
2085 ec.DefineLocalVariable (name, vi.LocalBuilder);
2090 ec.Mark (StartLocation, true);
2092 ec.Mark (EndLocation, true);
2094 if (emit_debug_info && is_lexical_block)
2097 ec.CurrentBlock = prev_block;
2100 public ToplevelBlock Toplevel {
2103 while (b.Parent != null){
2104 if ((b.flags & Flags.IsToplevel) != 0)
2109 return (ToplevelBlock) b;
2114 // Returns true if we ar ea child of `b'.
2116 public bool IsChildOf (Block b)
2118 Block current = this;
2121 if (current.Parent == b)
2123 current = current.Parent;
2124 } while (current != null);
2130 // A toplevel block contains extra information, the split is done
2131 // only to separate information that would otherwise bloat the more
2132 // lightweight Block.
2134 // In particular, this was introduced when the support for Anonymous
2135 // Methods was implemented.
2137 public class ToplevelBlock : Block {
2139 // Pointer to the host of this anonymous method, or null
2140 // if we are the topmost block
2142 public ToplevelBlock Container;
2143 CaptureContext capture_context;
2145 Hashtable capture_contexts;
2150 public void RegisterCaptureContext (CaptureContext cc)
2152 if (capture_contexts == null)
2153 capture_contexts = new Hashtable ();
2154 capture_contexts [cc] = cc;
2157 public void CompleteContexts ()
2159 if (capture_contexts == null)
2162 foreach (CaptureContext cc in capture_contexts.Keys){
2167 public CaptureContext ToplevelBlockCaptureContext {
2169 return capture_context;
2174 // Parent is only used by anonymous blocks to link back to their
2177 public ToplevelBlock (ToplevelBlock container, Parameters parameters, Location start) :
2178 base (null, Flags.IsToplevel, parameters, start, Location.Null)
2180 Container = container;
2183 public ToplevelBlock (Parameters parameters, Location start) :
2184 base (null, Flags.IsToplevel, parameters, start, Location.Null)
2188 public ToplevelBlock (Flags flags, Parameters parameters, Location start) :
2189 base (null, flags | Flags.IsToplevel, parameters, start, Location.Null)
2193 public ToplevelBlock (Location loc) : base (null, Flags.IsToplevel, loc, loc)
2197 public void SetHaveAnonymousMethods (Location loc, AnonymousMethod host)
2199 if (capture_context == null)
2200 capture_context = new CaptureContext (this, loc, host);
2203 public CaptureContext CaptureContext {
2205 return capture_context;
2210 public class SwitchLabel {
2213 public Location loc;
2217 Label il_label_code;
2218 bool il_label_code_set;
2221 // if expr == null, then it is the default case.
2223 public SwitchLabel (Expression expr, Location l)
2229 public Expression Label {
2235 public object Converted {
2241 public Label GetILLabel (EmitContext ec)
2244 il_label = ec.ig.DefineLabel ();
2245 il_label_set = true;
2250 public Label GetILLabelCode (EmitContext ec)
2252 if (!il_label_code_set){
2253 il_label_code = ec.ig.DefineLabel ();
2254 il_label_code_set = true;
2256 return il_label_code;
2260 // Resolves the expression, reduces it to a literal if possible
2261 // and then converts it to the requested type.
2263 public bool ResolveAndReduce (EmitContext ec, Type required_type)
2268 Expression e = label.Resolve (ec);
2273 if (!(e is Constant)){
2274 Report.Error (150, loc, "A constant value is expected, got: " + e);
2278 if (e is StringConstant || e is NullLiteral){
2279 if (required_type == TypeManager.string_type){
2285 converted = Expression.ConvertIntLiteral ((Constant) e, required_type, loc);
2286 if (converted == null)
2293 public class SwitchSection {
2294 // An array of SwitchLabels.
2295 public readonly ArrayList Labels;
2296 public readonly Block Block;
2298 public SwitchSection (ArrayList labels, Block block)
2305 public class Switch : Statement {
2306 public readonly ArrayList Sections;
2307 public Expression Expr;
2310 /// Maps constants whose type type SwitchType to their SwitchLabels.
2312 public Hashtable Elements;
2315 /// The governing switch type
2317 public Type SwitchType;
2323 Label default_target;
2324 Expression new_expr;
2326 SwitchSection constant_section;
2329 // The types allowed to be implicitly cast from
2330 // on the governing type
2332 static Type [] allowed_types;
2334 public Switch (Expression e, ArrayList sects, Location l)
2341 public bool GotDefault {
2347 public Label DefaultTarget {
2349 return default_target;
2354 // Determines the governing type for a switch. The returned
2355 // expression might be the expression from the switch, or an
2356 // expression that includes any potential conversions to the
2357 // integral types or to string.
2359 Expression SwitchGoverningType (EmitContext ec, Type t)
2361 if (t == TypeManager.int32_type ||
2362 t == TypeManager.uint32_type ||
2363 t == TypeManager.char_type ||
2364 t == TypeManager.byte_type ||
2365 t == TypeManager.sbyte_type ||
2366 t == TypeManager.ushort_type ||
2367 t == TypeManager.short_type ||
2368 t == TypeManager.uint64_type ||
2369 t == TypeManager.int64_type ||
2370 t == TypeManager.string_type ||
2371 t == TypeManager.bool_type ||
2372 t.IsSubclassOf (TypeManager.enum_type))
2375 if (allowed_types == null){
2376 allowed_types = new Type [] {
2377 TypeManager.int32_type,
2378 TypeManager.uint32_type,
2379 TypeManager.sbyte_type,
2380 TypeManager.byte_type,
2381 TypeManager.short_type,
2382 TypeManager.ushort_type,
2383 TypeManager.int64_type,
2384 TypeManager.uint64_type,
2385 TypeManager.char_type,
2386 TypeManager.bool_type,
2387 TypeManager.string_type
2392 // Try to find a *user* defined implicit conversion.
2394 // If there is no implicit conversion, or if there are multiple
2395 // conversions, we have to report an error
2397 Expression converted = null;
2398 foreach (Type tt in allowed_types){
2401 e = Convert.ImplicitUserConversion (ec, Expr, tt, loc);
2406 // Ignore over-worked ImplicitUserConversions that do
2407 // an implicit conversion in addition to the user conversion.
2410 UserCast ue = e as UserCast;
2412 if (ue.Source != Expr)
2416 if (converted != null){
2417 Report.ExtraInformation (
2419 String.Format ("reason: more than one conversion to an integral type exist for type {0}",
2420 TypeManager.CSharpName (Expr.Type)));
2429 static string Error152 {
2431 return "The label '{0}:' already occurs in this switch statement";
2436 // Performs the basic sanity checks on the switch statement
2437 // (looks for duplicate keys and non-constant expressions).
2439 // It also returns a hashtable with the keys that we will later
2440 // use to compute the switch tables
2442 bool CheckSwitch (EmitContext ec)
2446 Elements = new Hashtable ();
2448 got_default = false;
2450 if (TypeManager.IsEnumType (SwitchType)){
2451 compare_type = TypeManager.EnumToUnderlying (SwitchType);
2453 compare_type = SwitchType;
2455 foreach (SwitchSection ss in Sections){
2456 foreach (SwitchLabel sl in ss.Labels){
2457 if (!sl.ResolveAndReduce (ec, SwitchType)){
2462 if (sl.Label == null){
2464 Report.Error (152, sl.loc, Error152, "default");
2471 object key = sl.Converted;
2473 if (key is Constant)
2474 key = ((Constant) key).GetValue ();
2477 key = NullLiteral.Null;
2479 string lname = null;
2480 if (compare_type == TypeManager.uint64_type){
2481 ulong v = (ulong) key;
2483 if (Elements.Contains (v))
2484 lname = v.ToString ();
2486 Elements.Add (v, sl);
2487 } else if (compare_type == TypeManager.int64_type){
2488 long v = (long) key;
2490 if (Elements.Contains (v))
2491 lname = v.ToString ();
2493 Elements.Add (v, sl);
2494 } else if (compare_type == TypeManager.uint32_type){
2495 uint v = (uint) key;
2497 if (Elements.Contains (v))
2498 lname = v.ToString ();
2500 Elements.Add (v, sl);
2501 } else if (compare_type == TypeManager.char_type){
2502 char v = (char) key;
2504 if (Elements.Contains (v))
2505 lname = v.ToString ();
2507 Elements.Add (v, sl);
2508 } else if (compare_type == TypeManager.byte_type){
2509 byte v = (byte) key;
2511 if (Elements.Contains (v))
2512 lname = v.ToString ();
2514 Elements.Add (v, sl);
2515 } else if (compare_type == TypeManager.sbyte_type){
2516 sbyte v = (sbyte) key;
2518 if (Elements.Contains (v))
2519 lname = v.ToString ();
2521 Elements.Add (v, sl);
2522 } else if (compare_type == TypeManager.short_type){
2523 short v = (short) key;
2525 if (Elements.Contains (v))
2526 lname = v.ToString ();
2528 Elements.Add (v, sl);
2529 } else if (compare_type == TypeManager.ushort_type){
2530 ushort v = (ushort) key;
2532 if (Elements.Contains (v))
2533 lname = v.ToString ();
2535 Elements.Add (v, sl);
2536 } else if (compare_type == TypeManager.string_type){
2537 if (key is NullLiteral){
2538 if (Elements.Contains (NullLiteral.Null))
2541 Elements.Add (NullLiteral.Null, null);
2543 string s = (string) key;
2545 if (Elements.Contains (s))
2548 Elements.Add (s, sl);
2550 } else if (compare_type == TypeManager.int32_type) {
2553 if (Elements.Contains (v))
2554 lname = v.ToString ();
2556 Elements.Add (v, sl);
2557 } else if (compare_type == TypeManager.bool_type) {
2558 bool v = (bool) key;
2560 if (Elements.Contains (v))
2561 lname = v.ToString ();
2563 Elements.Add (v, sl);
2567 throw new Exception ("Unknown switch type!" +
2568 SwitchType + " " + compare_type);
2572 Report.Error (152, sl.loc, Error152, "case " + lname);
2583 void EmitObjectInteger (ILGenerator ig, object k)
2586 IntConstant.EmitInt (ig, (int) k);
2587 else if (k is Constant) {
2588 EmitObjectInteger (ig, ((Constant) k).GetValue ());
2591 IntConstant.EmitInt (ig, unchecked ((int) (uint) k));
2594 if ((long) k >= int.MinValue && (long) k <= int.MaxValue)
2596 IntConstant.EmitInt (ig, (int) (long) k);
2597 ig.Emit (OpCodes.Conv_I8);
2600 LongConstant.EmitLong (ig, (long) k);
2602 else if (k is ulong)
2604 if ((ulong) k < (1L<<32))
2606 IntConstant.EmitInt (ig, (int) (long) k);
2607 ig.Emit (OpCodes.Conv_U8);
2611 LongConstant.EmitLong (ig, unchecked ((long) (ulong) k));
2615 IntConstant.EmitInt (ig, (int) ((char) k));
2616 else if (k is sbyte)
2617 IntConstant.EmitInt (ig, (int) ((sbyte) k));
2619 IntConstant.EmitInt (ig, (int) ((byte) k));
2620 else if (k is short)
2621 IntConstant.EmitInt (ig, (int) ((short) k));
2622 else if (k is ushort)
2623 IntConstant.EmitInt (ig, (int) ((ushort) k));
2625 IntConstant.EmitInt (ig, ((bool) k) ? 1 : 0);
2627 throw new Exception ("Unhandled case");
2630 // structure used to hold blocks of keys while calculating table switch
2631 class KeyBlock : IComparable
2633 public KeyBlock (long _nFirst)
2635 nFirst = nLast = _nFirst;
2639 public ArrayList rgKeys = null;
2640 // how many items are in the bucket
2641 public int Size = 1;
2644 get { return (int) (nLast - nFirst + 1); }
2646 public static long TotalLength (KeyBlock kbFirst, KeyBlock kbLast)
2648 return kbLast.nLast - kbFirst.nFirst + 1;
2650 public int CompareTo (object obj)
2652 KeyBlock kb = (KeyBlock) obj;
2653 int nLength = Length;
2654 int nLengthOther = kb.Length;
2655 if (nLengthOther == nLength)
2656 return (int) (kb.nFirst - nFirst);
2657 return nLength - nLengthOther;
2662 /// This method emits code for a lookup-based switch statement (non-string)
2663 /// Basically it groups the cases into blocks that are at least half full,
2664 /// and then spits out individual lookup opcodes for each block.
2665 /// It emits the longest blocks first, and short blocks are just
2666 /// handled with direct compares.
2668 /// <param name="ec"></param>
2669 /// <param name="val"></param>
2670 /// <returns></returns>
2671 void TableSwitchEmit (EmitContext ec, LocalBuilder val)
2673 int cElements = Elements.Count;
2674 object [] rgKeys = new object [cElements];
2675 Elements.Keys.CopyTo (rgKeys, 0);
2676 Array.Sort (rgKeys);
2678 // initialize the block list with one element per key
2679 ArrayList rgKeyBlocks = new ArrayList ();
2680 foreach (object key in rgKeys)
2681 rgKeyBlocks.Add (new KeyBlock (System.Convert.ToInt64 (key)));
2684 // iteratively merge the blocks while they are at least half full
2685 // there's probably a really cool way to do this with a tree...
2686 while (rgKeyBlocks.Count > 1)
2688 ArrayList rgKeyBlocksNew = new ArrayList ();
2689 kbCurr = (KeyBlock) rgKeyBlocks [0];
2690 for (int ikb = 1; ikb < rgKeyBlocks.Count; ikb++)
2692 KeyBlock kb = (KeyBlock) rgKeyBlocks [ikb];
2693 if ((kbCurr.Size + kb.Size) * 2 >= KeyBlock.TotalLength (kbCurr, kb))
2696 kbCurr.nLast = kb.nLast;
2697 kbCurr.Size += kb.Size;
2701 // start a new block
2702 rgKeyBlocksNew.Add (kbCurr);
2706 rgKeyBlocksNew.Add (kbCurr);
2707 if (rgKeyBlocks.Count == rgKeyBlocksNew.Count)
2709 rgKeyBlocks = rgKeyBlocksNew;
2712 // initialize the key lists
2713 foreach (KeyBlock kb in rgKeyBlocks)
2714 kb.rgKeys = new ArrayList ();
2716 // fill the key lists
2718 if (rgKeyBlocks.Count > 0) {
2719 kbCurr = (KeyBlock) rgKeyBlocks [0];
2720 foreach (object key in rgKeys)
2722 bool fNextBlock = (key is UInt64) ? (ulong) key > (ulong) kbCurr.nLast :
2723 System.Convert.ToInt64 (key) > kbCurr.nLast;
2725 kbCurr = (KeyBlock) rgKeyBlocks [++iBlockCurr];
2726 kbCurr.rgKeys.Add (key);
2730 // sort the blocks so we can tackle the largest ones first
2731 rgKeyBlocks.Sort ();
2733 // okay now we can start...
2734 ILGenerator ig = ec.ig;
2735 Label lblEnd = ig.DefineLabel (); // at the end ;-)
2736 Label lblDefault = ig.DefineLabel ();
2738 Type typeKeys = null;
2739 if (rgKeys.Length > 0)
2740 typeKeys = rgKeys [0].GetType (); // used for conversions
2744 if (TypeManager.IsEnumType (SwitchType))
2745 compare_type = TypeManager.EnumToUnderlying (SwitchType);
2747 compare_type = SwitchType;
2749 for (int iBlock = rgKeyBlocks.Count - 1; iBlock >= 0; --iBlock)
2751 KeyBlock kb = ((KeyBlock) rgKeyBlocks [iBlock]);
2752 lblDefault = (iBlock == 0) ? DefaultTarget : ig.DefineLabel ();
2755 foreach (object key in kb.rgKeys)
2757 ig.Emit (OpCodes.Ldloc, val);
2758 EmitObjectInteger (ig, key);
2759 SwitchLabel sl = (SwitchLabel) Elements [key];
2760 ig.Emit (OpCodes.Beq, sl.GetILLabel (ec));
2765 // TODO: if all the keys in the block are the same and there are
2766 // no gaps/defaults then just use a range-check.
2767 if (compare_type == TypeManager.int64_type ||
2768 compare_type == TypeManager.uint64_type)
2770 // TODO: optimize constant/I4 cases
2772 // check block range (could be > 2^31)
2773 ig.Emit (OpCodes.Ldloc, val);
2774 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nFirst, typeKeys));
2775 ig.Emit (OpCodes.Blt, lblDefault);
2776 ig.Emit (OpCodes.Ldloc, val);
2777 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nLast, typeKeys));
2778 ig.Emit (OpCodes.Bgt, lblDefault);
2781 ig.Emit (OpCodes.Ldloc, val);
2784 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nFirst, typeKeys));
2785 ig.Emit (OpCodes.Sub);
2787 ig.Emit (OpCodes.Conv_I4); // assumes < 2^31 labels!
2792 ig.Emit (OpCodes.Ldloc, val);
2793 int nFirst = (int) kb.nFirst;
2796 IntConstant.EmitInt (ig, nFirst);
2797 ig.Emit (OpCodes.Sub);
2799 else if (nFirst < 0)
2801 IntConstant.EmitInt (ig, -nFirst);
2802 ig.Emit (OpCodes.Add);
2806 // first, build the list of labels for the switch
2808 int cJumps = kb.Length;
2809 Label [] rgLabels = new Label [cJumps];
2810 for (int iJump = 0; iJump < cJumps; iJump++)
2812 object key = kb.rgKeys [iKey];
2813 if (System.Convert.ToInt64 (key) == kb.nFirst + iJump)
2815 SwitchLabel sl = (SwitchLabel) Elements [key];
2816 rgLabels [iJump] = sl.GetILLabel (ec);
2820 rgLabels [iJump] = lblDefault;
2822 // emit the switch opcode
2823 ig.Emit (OpCodes.Switch, rgLabels);
2826 // mark the default for this block
2828 ig.MarkLabel (lblDefault);
2831 // TODO: find the default case and emit it here,
2832 // to prevent having to do the following jump.
2833 // make sure to mark other labels in the default section
2835 // the last default just goes to the end
2836 ig.Emit (OpCodes.Br, lblDefault);
2838 // now emit the code for the sections
2839 bool fFoundDefault = false;
2840 foreach (SwitchSection ss in Sections)
2842 foreach (SwitchLabel sl in ss.Labels)
2844 ig.MarkLabel (sl.GetILLabel (ec));
2845 ig.MarkLabel (sl.GetILLabelCode (ec));
2846 if (sl.Label == null)
2848 ig.MarkLabel (lblDefault);
2849 fFoundDefault = true;
2853 //ig.Emit (OpCodes.Br, lblEnd);
2856 if (!fFoundDefault) {
2857 ig.MarkLabel (lblDefault);
2859 ig.MarkLabel (lblEnd);
2862 // This simple emit switch works, but does not take advantage of the
2864 // TODO: remove non-string logic from here
2865 // TODO: binary search strings?
2867 void SimpleSwitchEmit (EmitContext ec, LocalBuilder val)
2869 ILGenerator ig = ec.ig;
2870 Label end_of_switch = ig.DefineLabel ();
2871 Label next_test = ig.DefineLabel ();
2872 Label null_target = ig.DefineLabel ();
2873 bool default_found = false;
2874 bool first_test = true;
2875 bool pending_goto_end = false;
2877 bool default_at_end = false;
2879 ig.Emit (OpCodes.Ldloc, val);
2881 if (Elements.Contains (NullLiteral.Null)){
2882 ig.Emit (OpCodes.Brfalse, null_target);
2884 ig.Emit (OpCodes.Brfalse, default_target);
2886 ig.Emit (OpCodes.Ldloc, val);
2887 ig.Emit (OpCodes.Call, TypeManager.string_isinterneted_string);
2888 ig.Emit (OpCodes.Stloc, val);
2890 int section_count = Sections.Count;
2891 for (int section = 0; section < section_count; section++){
2892 SwitchSection ss = (SwitchSection) Sections [section];
2893 Label sec_begin = ig.DefineLabel ();
2895 if (pending_goto_end)
2896 ig.Emit (OpCodes.Br, end_of_switch);
2898 int label_count = ss.Labels.Count;
2899 bool mark_default = false;
2901 for (int label = 0; label < label_count; label++){
2902 SwitchLabel sl = (SwitchLabel) ss.Labels [label];
2903 ig.MarkLabel (sl.GetILLabel (ec));
2906 ig.MarkLabel (next_test);
2907 next_test = ig.DefineLabel ();
2910 // If we are the default target
2912 if (sl.Label == null){
2913 if (label+1 == label_count)
2914 default_at_end = true;
2915 mark_default = true;
2916 default_found = true;
2918 object lit = sl.Converted;
2920 if (lit is NullLiteral){
2922 if (label_count == 1)
2923 ig.Emit (OpCodes.Br, next_test);
2927 StringConstant str = (StringConstant) lit;
2929 ig.Emit (OpCodes.Ldloc, val);
2930 ig.Emit (OpCodes.Ldstr, str.Value);
2931 if (label_count == 1)
2932 ig.Emit (OpCodes.Bne_Un, next_test);
2934 if (label+1 == label_count)
2935 ig.Emit (OpCodes.Bne_Un, next_test);
2937 ig.Emit (OpCodes.Beq, sec_begin);
2942 ig.MarkLabel (null_target);
2943 ig.MarkLabel (sec_begin);
2944 foreach (SwitchLabel sl in ss.Labels)
2945 ig.MarkLabel (sl.GetILLabelCode (ec));
2948 ig.MarkLabel (default_target);
2950 pending_goto_end = !ss.Block.HasRet;
2953 ig.MarkLabel (next_test);
2955 if (!default_at_end)
2956 ig.Emit (OpCodes.Br, default_target);
2958 ig.MarkLabel (default_target);
2959 ig.MarkLabel (end_of_switch);
2962 SwitchSection FindSection (SwitchLabel label)
2964 foreach (SwitchSection ss in Sections){
2965 foreach (SwitchLabel sl in ss.Labels){
2974 bool ResolveConstantSwitch (EmitContext ec)
2976 object key = ((Constant) new_expr).GetValue ();
2977 SwitchLabel label = (SwitchLabel) Elements [key];
2982 constant_section = FindSection (label);
2983 if (constant_section == null)
2986 if (constant_section.Block.Resolve (ec) != true)
2992 public override bool Resolve (EmitContext ec)
2994 Expr = Expr.Resolve (ec);
2998 new_expr = SwitchGoverningType (ec, Expr.Type);
2999 if (new_expr == null){
3000 Report.Error (151, loc, "An integer type or string was expected for switch");
3005 SwitchType = new_expr.Type;
3007 if (!CheckSwitch (ec))
3010 Switch old_switch = ec.Switch;
3012 ec.Switch.SwitchType = SwitchType;
3014 Report.Debug (1, "START OF SWITCH BLOCK", loc, ec.CurrentBranching);
3015 ec.StartFlowBranching (FlowBranching.BranchingType.Switch, loc);
3017 is_constant = new_expr is Constant;
3019 object key = ((Constant) new_expr).GetValue ();
3020 SwitchLabel label = (SwitchLabel) Elements [key];
3022 constant_section = FindSection (label);
3026 foreach (SwitchSection ss in Sections){
3028 ec.CurrentBranching.CreateSibling (
3029 null, FlowBranching.SiblingType.SwitchSection);
3033 if (is_constant && (ss != constant_section)) {
3034 // If we're a constant switch, we're only emitting
3035 // one single section - mark all the others as
3037 ec.CurrentBranching.CurrentUsageVector.Goto ();
3038 if (!ss.Block.ResolveUnreachable (ec, true))
3041 if (!ss.Block.Resolve (ec))
3047 ec.CurrentBranching.CreateSibling (
3048 null, FlowBranching.SiblingType.SwitchSection);
3050 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3051 ec.Switch = old_switch;
3053 Report.Debug (1, "END OF SWITCH BLOCK", loc, ec.CurrentBranching,
3059 protected override void DoEmit (EmitContext ec)
3061 ILGenerator ig = ec.ig;
3063 // Store variable for comparission purposes
3066 value = ig.DeclareLocal (SwitchType);
3068 ig.Emit (OpCodes.Stloc, value);
3072 default_target = ig.DefineLabel ();
3075 // Setup the codegen context
3077 Label old_end = ec.LoopEnd;
3078 Switch old_switch = ec.Switch;
3080 ec.LoopEnd = ig.DefineLabel ();
3085 if (constant_section != null)
3086 constant_section.Block.Emit (ec);
3087 } else if (SwitchType == TypeManager.string_type)
3088 SimpleSwitchEmit (ec, value);
3090 TableSwitchEmit (ec, value);
3092 // Restore context state.
3093 ig.MarkLabel (ec.LoopEnd);
3096 // Restore the previous context
3098 ec.LoopEnd = old_end;
3099 ec.Switch = old_switch;
3103 public abstract class ExceptionStatement : Statement
3105 public abstract void EmitFinally (EmitContext ec);
3107 protected bool emit_finally = true;
3108 ArrayList parent_vectors;
3110 protected void DoEmitFinally (EmitContext ec)
3113 ec.ig.BeginFinallyBlock ();
3115 ec.CurrentIterator.MarkFinally (ec, parent_vectors);
3119 protected void ResolveFinally (FlowBranchingException branching)
3121 emit_finally = branching.EmitFinally;
3123 branching.Parent.StealFinallyClauses (ref parent_vectors);
3127 public class Lock : ExceptionStatement {
3129 Statement Statement;
3132 public Lock (Expression expr, Statement stmt, Location l)
3139 public override bool Resolve (EmitContext ec)
3141 expr = expr.Resolve (ec);
3145 if (expr.Type.IsValueType){
3146 Error (185, "lock statement requires the expression to be " +
3147 " a reference type (type is: `{0}'",
3148 TypeManager.CSharpName (expr.Type));
3152 FlowBranchingException branching = ec.StartFlowBranching (this);
3153 bool ok = Statement.Resolve (ec);
3155 ec.KillFlowBranching ();
3159 ResolveFinally (branching);
3161 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3162 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
3163 // Unfortunately, System.Reflection.Emit automatically emits
3164 // a leave to the end of the finally block.
3165 // This is a problem if `returns' is true since we may jump
3166 // to a point after the end of the method.
3167 // As a workaround, emit an explicit ret here.
3168 ec.NeedReturnLabel ();
3174 protected override void DoEmit (EmitContext ec)
3176 Type type = expr.Type;
3178 ILGenerator ig = ec.ig;
3179 temp = ig.DeclareLocal (type);
3182 ig.Emit (OpCodes.Dup);
3183 ig.Emit (OpCodes.Stloc, temp);
3184 ig.Emit (OpCodes.Call, TypeManager.void_monitor_enter_object);
3188 ig.BeginExceptionBlock ();
3189 Statement.Emit (ec);
3194 ig.EndExceptionBlock ();
3197 public override void EmitFinally (EmitContext ec)
3199 ILGenerator ig = ec.ig;
3200 ig.Emit (OpCodes.Ldloc, temp);
3201 ig.Emit (OpCodes.Call, TypeManager.void_monitor_exit_object);
3205 public class Unchecked : Statement {
3206 public readonly Block Block;
3208 public Unchecked (Block b)
3214 public override bool Resolve (EmitContext ec)
3216 bool previous_state = ec.CheckState;
3217 bool previous_state_const = ec.ConstantCheckState;
3219 ec.CheckState = false;
3220 ec.ConstantCheckState = false;
3221 bool ret = Block.Resolve (ec);
3222 ec.CheckState = previous_state;
3223 ec.ConstantCheckState = previous_state_const;
3228 protected override void DoEmit (EmitContext ec)
3230 bool previous_state = ec.CheckState;
3231 bool previous_state_const = ec.ConstantCheckState;
3233 ec.CheckState = false;
3234 ec.ConstantCheckState = false;
3236 ec.CheckState = previous_state;
3237 ec.ConstantCheckState = previous_state_const;
3241 public class Checked : Statement {
3242 public readonly Block Block;
3244 public Checked (Block b)
3247 b.Unchecked = false;
3250 public override bool Resolve (EmitContext ec)
3252 bool previous_state = ec.CheckState;
3253 bool previous_state_const = ec.ConstantCheckState;
3255 ec.CheckState = true;
3256 ec.ConstantCheckState = true;
3257 bool ret = Block.Resolve (ec);
3258 ec.CheckState = previous_state;
3259 ec.ConstantCheckState = previous_state_const;
3264 protected override void DoEmit (EmitContext ec)
3266 bool previous_state = ec.CheckState;
3267 bool previous_state_const = ec.ConstantCheckState;
3269 ec.CheckState = true;
3270 ec.ConstantCheckState = true;
3272 ec.CheckState = previous_state;
3273 ec.ConstantCheckState = previous_state_const;
3277 public class Unsafe : Statement {
3278 public readonly Block Block;
3280 public Unsafe (Block b)
3283 Block.Unsafe = true;
3286 public override bool Resolve (EmitContext ec)
3288 bool previous_state = ec.InUnsafe;
3292 val = Block.Resolve (ec);
3293 ec.InUnsafe = previous_state;
3298 protected override void DoEmit (EmitContext ec)
3300 bool previous_state = ec.InUnsafe;
3304 ec.InUnsafe = previous_state;
3311 public class Fixed : Statement {
3313 ArrayList declarators;
3314 Statement statement;
3319 abstract class Emitter
3321 protected LocalInfo vi;
3322 protected Expression converted;
3324 protected Emitter (Expression expr, LocalInfo li)
3330 public abstract void Emit (EmitContext ec);
3331 public abstract void EmitExit (ILGenerator ig);
3334 class ExpressionEmitter: Emitter {
3335 public ExpressionEmitter (Expression converted, LocalInfo li) :
3336 base (converted, li)
3340 public override void Emit (EmitContext ec) {
3342 // Store pointer in pinned location
3344 converted.Emit (ec);
3345 ec.ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3348 public override void EmitExit (ILGenerator ig)
3350 ig.Emit (OpCodes.Ldc_I4_0);
3351 ig.Emit (OpCodes.Conv_U);
3352 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3356 class StringEmitter: Emitter {
3357 LocalBuilder pinned_string;
3360 public StringEmitter (Expression expr, LocalInfo li, Location loc):
3366 public override void Emit (EmitContext ec)
3368 ILGenerator ig = ec.ig;
3369 pinned_string = TypeManager.DeclareLocalPinned (ig, TypeManager.string_type);
3371 converted.Emit (ec);
3372 ig.Emit (OpCodes.Stloc, pinned_string);
3374 Expression sptr = new StringPtr (pinned_string, loc);
3375 converted = Convert.ImplicitConversionRequired (
3376 ec, sptr, vi.VariableType, loc);
3378 if (converted == null)
3381 converted.Emit (ec);
3382 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3385 public override void EmitExit(ILGenerator ig)
3387 ig.Emit (OpCodes.Ldnull);
3388 ig.Emit (OpCodes.Stloc, pinned_string);
3392 public Fixed (Expression type, ArrayList decls, Statement stmt, Location l)
3395 declarators = decls;
3400 public override bool Resolve (EmitContext ec)
3403 Expression.UnsafeError (loc);
3407 TypeExpr texpr = type.ResolveAsTypeTerminal (ec);
3411 expr_type = texpr.Type;
3413 CheckObsolete (expr_type);
3415 if (ec.RemapToProxy){
3416 Report.Error (-210, loc, "Fixed statement not allowed in iterators");
3420 data = new Emitter [declarators.Count];
3422 if (!expr_type.IsPointer){
3423 Report.Error (209, loc, "Variables in a fixed statement must be pointers");
3428 foreach (Pair p in declarators){
3429 LocalInfo vi = (LocalInfo) p.First;
3430 Expression e = (Expression) p.Second;
3432 vi.VariableInfo.SetAssigned (ec);
3436 // The rules for the possible declarators are pretty wise,
3437 // but the production on the grammar is more concise.
3439 // So we have to enforce these rules here.
3441 // We do not resolve before doing the case 1 test,
3442 // because the grammar is explicit in that the token &
3443 // is present, so we need to test for this particular case.
3447 Report.Error (254, loc, "Cast expression not allowed as right hand expression in fixed statement");
3452 // Case 1: & object.
3454 if (e is Unary && ((Unary) e).Oper == Unary.Operator.AddressOf){
3455 Expression child = ((Unary) e).Expr;
3457 if (child is ParameterReference || child is LocalVariableReference){
3460 "No need to use fixed statement for parameters or " +
3461 "local variable declarations (address is already " +
3466 ec.InFixedInitializer = true;
3468 ec.InFixedInitializer = false;
3472 child = ((Unary) e).Expr;
3474 if (!TypeManager.VerifyUnManaged (child.Type, loc))
3477 data [i] = new ExpressionEmitter (e, vi);
3483 ec.InFixedInitializer = true;
3485 ec.InFixedInitializer = false;
3492 if (e.Type.IsArray){
3493 Type array_type = TypeManager.GetElementType (e.Type);
3496 // Provided that array_type is unmanaged,
3498 if (!TypeManager.VerifyUnManaged (array_type, loc))
3502 // and T* is implicitly convertible to the
3503 // pointer type given in the fixed statement.
3505 ArrayPtr array_ptr = new ArrayPtr (e, array_type, loc);
3507 Expression converted = Convert.ImplicitConversionRequired (
3508 ec, array_ptr, vi.VariableType, loc);
3509 if (converted == null)
3512 data [i] = new ExpressionEmitter (converted, vi);
3521 if (e.Type == TypeManager.string_type){
3522 data [i] = new StringEmitter (e, vi, loc);
3527 // Case 4: fixed buffer
3528 FieldExpr fe = e as FieldExpr;
3530 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
3532 Expression fixed_buffer_ptr = new FixedBufferPtr (fe, ff.ElementType, loc);
3534 Expression converted = Convert.ImplicitConversionRequired (
3535 ec, fixed_buffer_ptr, vi.VariableType, loc);
3536 if (converted == null)
3539 data [i] = new ExpressionEmitter (converted, vi);
3547 // For other cases, flag a `this is already fixed expression'
3549 if (e is LocalVariableReference || e is ParameterReference ||
3550 Convert.ImplicitConversionExists (ec, e, vi.VariableType)){
3552 Report.Error (245, loc, "right hand expression is already fixed, no need to use fixed statement ");
3556 Report.Error (245, loc, "Fixed statement only allowed on strings, arrays or address-of expressions");
3560 ec.StartFlowBranching (FlowBranching.BranchingType.Conditional, loc);
3562 if (!statement.Resolve (ec)) {
3563 ec.KillFlowBranching ();
3567 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3568 has_ret = reachability.IsUnreachable;
3573 protected override void DoEmit (EmitContext ec)
3575 for (int i = 0; i < data.Length; i++) {
3579 statement.Emit (ec);
3584 ILGenerator ig = ec.ig;
3587 // Clear the pinned variable
3589 for (int i = 0; i < data.Length; i++) {
3590 data [i].EmitExit (ig);
3595 public class Catch: Statement {
3596 public readonly string Name;
3597 public readonly Block Block;
3599 Expression type_expr;
3602 public Catch (Expression type, string name, Block block, Location l)
3610 public Type CatchType {
3616 public bool IsGeneral {
3618 return type_expr == null;
3622 protected override void DoEmit(EmitContext ec)
3626 public override bool Resolve (EmitContext ec)
3628 if (type_expr != null) {
3629 TypeExpr te = type_expr.ResolveAsTypeTerminal (ec);
3635 CheckObsolete (type);
3637 if (type != TypeManager.exception_type && !type.IsSubclassOf (TypeManager.exception_type)){
3638 Error (155, "The type caught or thrown must be derived from System.Exception");
3644 return Block.Resolve (ec);
3648 public class Try : ExceptionStatement {
3649 public readonly Block Fini, Block;
3650 public readonly ArrayList Specific;
3651 public readonly Catch General;
3653 bool need_exc_block;
3656 // specific, general and fini might all be null.
3658 public Try (Block block, ArrayList specific, Catch general, Block fini, Location l)
3660 if (specific == null && general == null){
3661 Console.WriteLine ("CIR.Try: Either specific or general have to be non-null");
3665 this.Specific = specific;
3666 this.General = general;
3671 public override bool Resolve (EmitContext ec)
3675 FlowBranchingException branching = ec.StartFlowBranching (this);
3677 Report.Debug (1, "START OF TRY BLOCK", Block.StartLocation);
3679 if (!Block.Resolve (ec))
3682 FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
3684 Report.Debug (1, "START OF CATCH BLOCKS", vector);
3686 Type[] prevCatches = new Type [Specific.Count];
3688 foreach (Catch c in Specific){
3689 ec.CurrentBranching.CreateSibling (
3690 c.Block, FlowBranching.SiblingType.Catch);
3692 Report.Debug (1, "STARTED SIBLING FOR CATCH", ec.CurrentBranching);
3694 if (c.Name != null) {
3695 LocalInfo vi = c.Block.GetLocalInfo (c.Name);
3697 throw new Exception ();
3699 vi.VariableInfo = null;
3702 if (!c.Resolve (ec))
3705 Type resolvedType = c.CatchType;
3706 for (int ii = 0; ii < last_index; ++ii) {
3707 if (resolvedType == prevCatches [ii] || resolvedType.IsSubclassOf (prevCatches [ii])) {
3708 Report.Error (160, c.loc, "A previous catch clause already catches all exceptions of this or a super type '{0}'", prevCatches [ii].FullName);
3713 prevCatches [last_index++] = resolvedType;
3714 need_exc_block = true;
3717 Report.Debug (1, "END OF CATCH BLOCKS", ec.CurrentBranching);
3719 if (General != null){
3720 ec.CurrentBranching.CreateSibling (
3721 General.Block, FlowBranching.SiblingType.Catch);
3723 Report.Debug (1, "STARTED SIBLING FOR GENERAL", ec.CurrentBranching);
3725 if (!General.Resolve (ec))
3728 need_exc_block = true;
3731 Report.Debug (1, "END OF GENERAL CATCH BLOCKS", ec.CurrentBranching);
3735 ec.CurrentBranching.CreateSibling (
3736 Fini, FlowBranching.SiblingType.Finally);
3738 Report.Debug (1, "STARTED SIBLING FOR FINALLY", ec.CurrentBranching, vector);
3740 if (!Fini.Resolve (ec))
3744 ResolveFinally (branching);
3745 need_exc_block |= emit_finally;
3747 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3749 FlowBranching.UsageVector f_vector = ec.CurrentBranching.CurrentUsageVector;
3751 Report.Debug (1, "END OF TRY", ec.CurrentBranching, reachability, vector, f_vector);
3753 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
3754 // Unfortunately, System.Reflection.Emit automatically emits
3755 // a leave to the end of the finally block. This is a problem
3756 // if `returns' is true since we may jump to a point after the
3757 // end of the method.
3758 // As a workaround, emit an explicit ret here.
3759 ec.NeedReturnLabel ();
3765 protected override void DoEmit (EmitContext ec)
3767 ILGenerator ig = ec.ig;
3770 ig.BeginExceptionBlock ();
3773 foreach (Catch c in Specific){
3776 ig.BeginCatchBlock (c.CatchType);
3778 if (c.Name != null){
3779 vi = c.Block.GetLocalInfo (c.Name);
3781 throw new Exception ("Variable does not exist in this block");
3783 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3785 ig.Emit (OpCodes.Pop);
3790 if (General != null){
3791 ig.BeginCatchBlock (TypeManager.object_type);
3792 ig.Emit (OpCodes.Pop);
3793 General.Block.Emit (ec);
3798 ig.EndExceptionBlock ();
3801 public override void EmitFinally (EmitContext ec)
3809 public class Using : ExceptionStatement {
3810 object expression_or_block;
3811 Statement Statement;
3816 Expression [] resolved_vars;
3817 Expression [] converted_vars;
3818 ExpressionStatement [] assign;
3819 LocalBuilder local_copy;
3821 public Using (object expression_or_block, Statement stmt, Location l)
3823 this.expression_or_block = expression_or_block;
3829 // Resolves for the case of using using a local variable declaration.
3831 bool ResolveLocalVariableDecls (EmitContext ec)
3835 TypeExpr texpr = expr.ResolveAsTypeTerminal (ec);
3839 expr_type = texpr.Type;
3842 // The type must be an IDisposable or an implicit conversion
3845 converted_vars = new Expression [var_list.Count];
3846 resolved_vars = new Expression [var_list.Count];
3847 assign = new ExpressionStatement [var_list.Count];
3849 bool need_conv = !TypeManager.ImplementsInterface (
3850 expr_type, TypeManager.idisposable_type);
3852 foreach (DictionaryEntry e in var_list){
3853 Expression var = (Expression) e.Key;
3855 var = var.ResolveLValue (ec, new EmptyExpression ());
3859 resolved_vars [i] = var;
3866 converted_vars [i] = Convert.ImplicitConversionRequired (
3867 ec, var, TypeManager.idisposable_type, loc);
3869 if (converted_vars [i] == null)
3876 foreach (DictionaryEntry e in var_list){
3877 Expression var = resolved_vars [i];
3878 Expression new_expr = (Expression) e.Value;
3881 a = new Assign (var, new_expr, loc);
3887 converted_vars [i] = var;
3888 assign [i] = (ExpressionStatement) a;
3895 bool ResolveExpression (EmitContext ec)
3897 if (!TypeManager.ImplementsInterface (expr_type, TypeManager.idisposable_type)){
3898 conv = Convert.ImplicitConversionRequired (
3899 ec, expr, TypeManager.idisposable_type, loc);
3909 // Emits the code for the case of using using a local variable declaration.
3911 void EmitLocalVariableDecls (EmitContext ec)
3913 ILGenerator ig = ec.ig;
3916 for (i = 0; i < assign.Length; i++) {
3917 assign [i].EmitStatement (ec);
3920 ig.BeginExceptionBlock ();
3922 Statement.Emit (ec);
3924 var_list.Reverse ();
3929 void EmitLocalVariableDeclFinally (EmitContext ec)
3931 ILGenerator ig = ec.ig;
3933 int i = assign.Length;
3934 for (int ii = 0; ii < var_list.Count; ++ii){
3935 Expression var = resolved_vars [--i];
3936 Label skip = ig.DefineLabel ();
3938 ig.BeginFinallyBlock ();
3940 if (!var.Type.IsValueType) {
3942 ig.Emit (OpCodes.Brfalse, skip);
3943 converted_vars [i].Emit (ec);
3944 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
3946 Expression ml = Expression.MemberLookup(ec, TypeManager.idisposable_type, var.Type, "Dispose", Mono.CSharp.Location.Null);
3948 if (!(ml is MethodGroupExpr)) {
3950 ig.Emit (OpCodes.Box, var.Type);
3951 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
3953 MethodInfo mi = null;
3955 foreach (MethodInfo mk in ((MethodGroupExpr) ml).Methods) {
3956 if (TypeManager.GetArgumentTypes (mk).Length == 0) {
3963 Report.Error(-100, Mono.CSharp.Location.Null, "Internal error: No Dispose method which takes 0 parameters.");
3967 IMemoryLocation mloc = (IMemoryLocation) var;
3969 mloc.AddressOf (ec, AddressOp.Load);
3970 ig.Emit (OpCodes.Call, mi);
3974 ig.MarkLabel (skip);
3977 ig.EndExceptionBlock ();
3979 ig.BeginFinallyBlock ();
3984 void EmitExpression (EmitContext ec)
3987 // Make a copy of the expression and operate on that.
3989 ILGenerator ig = ec.ig;
3990 local_copy = ig.DeclareLocal (expr_type);
3995 ig.Emit (OpCodes.Stloc, local_copy);
3998 ig.BeginExceptionBlock ();
4000 Statement.Emit (ec);
4004 ig.EndExceptionBlock ();
4007 void EmitExpressionFinally (EmitContext ec)
4009 ILGenerator ig = ec.ig;
4010 if (!local_copy.LocalType.IsValueType) {
4011 Label skip = ig.DefineLabel ();
4012 ig.Emit (OpCodes.Ldloc, local_copy);
4013 ig.Emit (OpCodes.Brfalse, skip);
4014 ig.Emit (OpCodes.Ldloc, local_copy);
4015 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4016 ig.MarkLabel (skip);
4018 Expression ml = Expression.MemberLookup(ec, TypeManager.idisposable_type, local_copy.LocalType, "Dispose", Mono.CSharp.Location.Null);
4020 if (!(ml is MethodGroupExpr)) {
4021 ig.Emit (OpCodes.Ldloc, local_copy);
4022 ig.Emit (OpCodes.Box, local_copy.LocalType);
4023 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4025 MethodInfo mi = null;
4027 foreach (MethodInfo mk in ((MethodGroupExpr) ml).Methods) {
4028 if (TypeManager.GetArgumentTypes (mk).Length == 0) {
4035 Report.Error(-100, Mono.CSharp.Location.Null, "Internal error: No Dispose method which takes 0 parameters.");
4039 ig.Emit (OpCodes.Ldloca, local_copy);
4040 ig.Emit (OpCodes.Call, mi);
4045 public override bool Resolve (EmitContext ec)
4047 if (expression_or_block is DictionaryEntry){
4048 expr = (Expression) ((DictionaryEntry) expression_or_block).Key;
4049 var_list = (ArrayList)((DictionaryEntry)expression_or_block).Value;
4051 if (!ResolveLocalVariableDecls (ec))
4054 } else if (expression_or_block is Expression){
4055 expr = (Expression) expression_or_block;
4057 expr = expr.Resolve (ec);
4061 expr_type = expr.Type;
4063 if (!ResolveExpression (ec))
4067 FlowBranchingException branching = ec.StartFlowBranching (this);
4069 bool ok = Statement.Resolve (ec);
4072 ec.KillFlowBranching ();
4076 ResolveFinally (branching);
4077 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
4079 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
4080 // Unfortunately, System.Reflection.Emit automatically emits a leave
4081 // to the end of the finally block. This is a problem if `returns'
4082 // is true since we may jump to a point after the end of the method.
4083 // As a workaround, emit an explicit ret here.
4084 ec.NeedReturnLabel ();
4090 protected override void DoEmit (EmitContext ec)
4092 if (expression_or_block is DictionaryEntry)
4093 EmitLocalVariableDecls (ec);
4094 else if (expression_or_block is Expression)
4095 EmitExpression (ec);
4098 public override void EmitFinally (EmitContext ec)
4100 if (expression_or_block is DictionaryEntry)
4101 EmitLocalVariableDeclFinally (ec);
4102 else if (expression_or_block is Expression)
4103 EmitExpressionFinally (ec);
4108 /// Implementation of the foreach C# statement
4110 public class Foreach : ExceptionStatement {
4112 Expression variable;
4114 Statement statement;
4115 ForeachHelperMethods hm;
4116 Expression empty, conv;
4117 Type array_type, element_type;
4119 VariableStorage enumerator;
4121 public Foreach (Expression type, LocalVariableReference var, Expression expr,
4122 Statement stmt, Location l)
4125 this.variable = var;
4131 public override bool Resolve (EmitContext ec)
4133 expr = expr.Resolve (ec);
4137 if (expr is NullLiteral) {
4138 Report.Error (186, expr.Location, "Use of null is not valid in this context");
4142 TypeExpr texpr = type.ResolveAsTypeTerminal (ec);
4146 var_type = texpr.Type;
4149 // We need an instance variable. Not sure this is the best
4150 // way of doing this.
4152 // FIXME: When we implement propertyaccess, will those turn
4153 // out to return values in ExprClass? I think they should.
4155 if (!(expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.Value ||
4156 expr.eclass == ExprClass.PropertyAccess || expr.eclass == ExprClass.IndexerAccess)){
4157 error1579 (expr.Type);
4161 if (expr.Type.IsArray) {
4162 array_type = expr.Type;
4163 element_type = TypeManager.GetElementType (array_type);
4165 empty = new EmptyExpression (element_type);
4167 hm = ProbeCollectionType (ec, expr.Type);
4169 error1579 (expr.Type);
4173 array_type = expr.Type;
4174 element_type = hm.element_type;
4176 empty = new EmptyExpression (hm.element_type);
4181 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
4182 ec.CurrentBranching.CreateSibling ();
4186 // FIXME: maybe we can apply the same trick we do in the
4187 // array handling to avoid creating empty and conv in some cases.
4189 // Although it is not as important in this case, as the type
4190 // will not likely be object (what the enumerator will return).
4192 conv = Convert.ExplicitConversion (ec, empty, var_type, loc);
4196 variable = variable.ResolveLValue (ec, empty);
4197 if (variable == null)
4200 bool disposable = (hm != null) && hm.is_disposable;
4201 FlowBranchingException branching = null;
4203 branching = ec.StartFlowBranching (this);
4205 if (!statement.Resolve (ec))
4209 ResolveFinally (branching);
4210 ec.EndFlowBranching ();
4212 emit_finally = true;
4214 ec.EndFlowBranching ();
4220 // Retrieves a `public bool MoveNext ()' method from the Type `t'
4222 static MethodInfo FetchMethodMoveNext (Type t)
4224 MemberList move_next_list;
4226 move_next_list = TypeContainer.FindMembers (
4227 t, MemberTypes.Method,
4228 BindingFlags.Public | BindingFlags.Instance,
4229 Type.FilterName, "MoveNext");
4230 if (move_next_list.Count == 0)
4233 foreach (MemberInfo m in move_next_list){
4234 MethodInfo mi = (MethodInfo) m;
4237 args = TypeManager.GetArgumentTypes (mi);
4238 if (args != null && args.Length == 0){
4239 if (TypeManager.TypeToCoreType (mi.ReturnType) == TypeManager.bool_type)
4247 // Retrieves a `public T get_Current ()' method from the Type `t'
4249 static MethodInfo FetchMethodGetCurrent (Type t)
4251 MemberList get_current_list;
4253 get_current_list = TypeContainer.FindMembers (
4254 t, MemberTypes.Method,
4255 BindingFlags.Public | BindingFlags.Instance,
4256 Type.FilterName, "get_Current");
4257 if (get_current_list.Count == 0)
4260 foreach (MemberInfo m in get_current_list){
4261 MethodInfo mi = (MethodInfo) m;
4264 args = TypeManager.GetArgumentTypes (mi);
4265 if (args != null && args.Length == 0)
4272 // Retrieves a `public void Dispose ()' method from the Type `t'
4274 static MethodInfo FetchMethodDispose (Type t)
4276 MemberList dispose_list;
4278 dispose_list = TypeContainer.FindMembers (
4279 t, MemberTypes.Method,
4280 BindingFlags.Public | BindingFlags.Instance,
4281 Type.FilterName, "Dispose");
4282 if (dispose_list.Count == 0)
4285 foreach (MemberInfo m in dispose_list){
4286 MethodInfo mi = (MethodInfo) m;
4289 args = TypeManager.GetArgumentTypes (mi);
4290 if (args != null && args.Length == 0){
4291 if (mi.ReturnType == TypeManager.void_type)
4299 // This struct records the helper methods used by the Foreach construct
4301 class ForeachHelperMethods {
4302 public EmitContext ec;
4303 public MethodInfo get_enumerator;
4304 public MethodInfo move_next;
4305 public MethodInfo get_current;
4306 public Type element_type;
4307 public Type enumerator_type;
4308 public bool is_disposable;
4310 public ForeachHelperMethods (EmitContext ec)
4313 this.element_type = TypeManager.object_type;
4314 this.enumerator_type = TypeManager.ienumerator_type;
4315 this.is_disposable = true;
4319 static bool GetEnumeratorFilter (MemberInfo m, object criteria)
4324 if (!(m is MethodInfo))
4327 if (m.Name != "GetEnumerator")
4330 MethodInfo mi = (MethodInfo) m;
4331 Type [] args = TypeManager.GetArgumentTypes (mi);
4333 if (args.Length != 0)
4336 ForeachHelperMethods hm = (ForeachHelperMethods) criteria;
4338 // Check whether GetEnumerator is public
4339 if ((mi.Attributes & MethodAttributes.Public) != MethodAttributes.Public)
4342 if ((mi.ReturnType == TypeManager.ienumerator_type) && (mi.DeclaringType == TypeManager.string_type))
4344 // Apply the same optimization as MS: skip the GetEnumerator
4345 // returning an IEnumerator, and use the one returning a
4346 // CharEnumerator instead. This allows us to avoid the
4347 // try-finally block and the boxing.
4352 // Ok, we can access it, now make sure that we can do something
4353 // with this `GetEnumerator'
4356 Type return_type = mi.ReturnType;
4357 if (mi.ReturnType == TypeManager.ienumerator_type ||
4358 TypeManager.ienumerator_type.IsAssignableFrom (return_type) ||
4359 (!RootContext.StdLib && TypeManager.ImplementsInterface (return_type, TypeManager.ienumerator_type))) {
4362 // If it is not an interface, lets try to find the methods ourselves.
4363 // For example, if we have:
4364 // public class Foo : IEnumerator { public bool MoveNext () {} public int Current { get {}}}
4365 // We can avoid the iface call. This is a runtime perf boost.
4366 // even bigger if we have a ValueType, because we avoid the cost
4369 // We have to make sure that both methods exist for us to take
4370 // this path. If one of the methods does not exist, we will just
4371 // use the interface. Sadly, this complex if statement is the only
4372 // way I could do this without a goto
4375 if (return_type.IsInterface ||
4376 (hm.move_next = FetchMethodMoveNext (return_type)) == null ||
4377 (hm.get_current = FetchMethodGetCurrent (return_type)) == null) {
4379 hm.move_next = TypeManager.bool_movenext_void;
4380 hm.get_current = TypeManager.object_getcurrent_void;
4387 // Ok, so they dont return an IEnumerable, we will have to
4388 // find if they support the GetEnumerator pattern.
4391 hm.move_next = FetchMethodMoveNext (return_type);
4392 if (hm.move_next == null)
4395 hm.get_current = FetchMethodGetCurrent (return_type);
4396 if (hm.get_current == null)
4400 hm.element_type = hm.get_current.ReturnType;
4401 hm.enumerator_type = return_type;
4402 hm.is_disposable = !hm.enumerator_type.IsSealed ||
4403 TypeManager.ImplementsInterface (
4404 hm.enumerator_type, TypeManager.idisposable_type);
4410 /// This filter is used to find the GetEnumerator method
4411 /// on which IEnumerator operates
4413 static MemberFilter FilterEnumerator;
4417 FilterEnumerator = new MemberFilter (GetEnumeratorFilter);
4420 void error1579 (Type t)
4422 Report.Error (1579, loc,
4423 "foreach statement cannot operate on variables of type `" +
4424 t.FullName + "' because that class does not provide a " +
4425 " GetEnumerator method or it is inaccessible");
4428 static bool TryType (Type t, ForeachHelperMethods hm)
4432 mi = TypeContainer.FindMembers (t, MemberTypes.Method,
4433 BindingFlags.Public | BindingFlags.NonPublic |
4434 BindingFlags.Instance | BindingFlags.DeclaredOnly,
4435 FilterEnumerator, hm);
4440 hm.get_enumerator = (MethodInfo) mi [0];
4445 // Looks for a usable GetEnumerator in the Type, and if found returns
4446 // the three methods that participate: GetEnumerator, MoveNext and get_Current
4448 ForeachHelperMethods ProbeCollectionType (EmitContext ec, Type t)
4450 ForeachHelperMethods hm = new ForeachHelperMethods (ec);
4452 for (Type tt = t; tt != null && tt != TypeManager.object_type;){
4453 if (TryType (tt, hm))
4459 // Now try to find the method in the interfaces
4462 Type [] ifaces = t.GetInterfaces ();
4464 foreach (Type i in ifaces){
4465 if (TryType (i, hm))
4470 // Since TypeBuilder.GetInterfaces only returns the interface
4471 // types for this type, we have to keep looping, but once
4472 // we hit a non-TypeBuilder (ie, a Type), then we know we are
4473 // done, because it returns all the types
4475 if ((t is TypeBuilder))
4485 // FIXME: possible optimization.
4486 // We might be able to avoid creating `empty' if the type is the sam
4488 bool EmitCollectionForeach (EmitContext ec)
4490 ILGenerator ig = ec.ig;
4492 enumerator = new VariableStorage (ec, hm.enumerator_type);
4493 enumerator.EmitThis (ig);
4495 // Instantiate the enumerator
4497 if (expr.Type.IsValueType){
4498 IMemoryLocation ml = expr as IMemoryLocation;
4499 // Load the address of the value type.
4501 // This happens if, for example, you have a property
4502 // returning a struct which is IEnumerable
4503 LocalBuilder t = ec.GetTemporaryLocal (expr.Type);
4505 ig.Emit (OpCodes.Stloc, t);
4506 ig.Emit (OpCodes.Ldloca, t);
4507 ec.FreeTemporaryLocal (t, expr.Type);
4509 ml.AddressOf (ec, AddressOp.Load);
4513 if (hm.get_enumerator.DeclaringType.IsValueType) {
4514 // the method is declared on the value type
4515 ig.Emit (OpCodes.Call, hm.get_enumerator);
4517 // it is an interface method, so we must box
4518 ig.Emit (OpCodes.Box, expr.Type);
4519 ig.Emit (OpCodes.Callvirt, hm.get_enumerator);
4523 ig.Emit (OpCodes.Callvirt, hm.get_enumerator);
4525 enumerator.EmitStore (ig);
4528 // Protect the code in a try/finalize block, so that
4529 // if the beast implement IDisposable, we get rid of it
4531 if (hm.is_disposable && emit_finally)
4532 ig.BeginExceptionBlock ();
4534 Label end_try = ig.DefineLabel ();
4536 ig.MarkLabel (ec.LoopBegin);
4538 enumerator.EmitCall (ig, hm.move_next);
4540 ig.Emit (OpCodes.Brfalse, end_try);
4543 ig.Emit (OpCodes.Ldarg_0);
4545 enumerator.EmitCall (ig, hm.get_current);
4549 ig.Emit (OpCodes.Stfld, ((LocalVariableReference) variable).local_info.FieldBuilder);
4551 ((IAssignMethod)variable).EmitAssign (ec, conv, false, false);
4553 statement.Emit (ec);
4554 ig.Emit (OpCodes.Br, ec.LoopBegin);
4555 ig.MarkLabel (end_try);
4557 // The runtime provides this for us.
4558 // ig.Emit (OpCodes.Leave, end);
4561 // Now the finally block
4563 if (hm.is_disposable) {
4566 ig.EndExceptionBlock ();
4569 ig.MarkLabel (ec.LoopEnd);
4573 public override void EmitFinally (EmitContext ec)
4575 ILGenerator ig = ec.ig;
4577 if (hm.enumerator_type.IsValueType) {
4578 enumerator.EmitThis (ig);
4580 MethodInfo mi = FetchMethodDispose (hm.enumerator_type);
4582 enumerator.EmitLoadAddress (ig);
4583 ig.Emit (OpCodes.Call, mi);
4585 enumerator.EmitLoad (ig);
4586 ig.Emit (OpCodes.Box, hm.enumerator_type);
4587 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4590 Label call_dispose = ig.DefineLabel ();
4592 enumerator.EmitThis (ig);
4593 enumerator.EmitLoad (ig);
4594 ig.Emit (OpCodes.Isinst, TypeManager.idisposable_type);
4595 ig.Emit (OpCodes.Dup);
4596 ig.Emit (OpCodes.Brtrue_S, call_dispose);
4597 ig.Emit (OpCodes.Pop);
4599 Label end_finally = ig.DefineLabel ();
4600 ig.Emit (OpCodes.Br, end_finally);
4602 ig.MarkLabel (call_dispose);
4603 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4604 ig.MarkLabel (end_finally);
4607 ig.Emit (OpCodes.Endfinally);
4612 // FIXME: possible optimization.
4613 // We might be able to avoid creating `empty' if the type is the sam
4615 bool EmitArrayForeach (EmitContext ec)
4617 int rank = array_type.GetArrayRank ();
4618 ILGenerator ig = ec.ig;
4620 VariableStorage copy = new VariableStorage (ec, array_type);
4623 // Make our copy of the array
4627 copy.EmitStore (ig);
4630 VariableStorage counter = new VariableStorage (ec,TypeManager.int32_type);
4634 counter.EmitThis (ig);
4635 ig.Emit (OpCodes.Ldc_I4_0);
4636 counter.EmitStore (ig);
4637 test = ig.DefineLabel ();
4638 ig.Emit (OpCodes.Br, test);
4640 loop = ig.DefineLabel ();
4641 ig.MarkLabel (loop);
4644 ig.Emit (OpCodes.Ldarg_0);
4648 counter.EmitThis (ig);
4649 counter.EmitLoad (ig);
4652 // Load the value, we load the value using the underlying type,
4653 // then we use the variable.EmitAssign to load using the proper cast.
4655 ArrayAccess.EmitLoadOpcode (ig, element_type);
4658 ig.Emit (OpCodes.Stfld, ((LocalVariableReference) variable).local_info.FieldBuilder);
4660 ((IAssignMethod)variable).EmitAssign (ec, conv, false, false);
4662 statement.Emit (ec);
4664 ig.MarkLabel (ec.LoopBegin);
4665 counter.EmitThis (ig);
4666 counter.EmitThis (ig);
4667 counter.EmitLoad (ig);
4668 ig.Emit (OpCodes.Ldc_I4_1);
4669 ig.Emit (OpCodes.Add);
4670 counter.EmitStore (ig);
4672 ig.MarkLabel (test);
4673 counter.EmitThis (ig);
4674 counter.EmitLoad (ig);
4677 ig.Emit (OpCodes.Ldlen);
4678 ig.Emit (OpCodes.Conv_I4);
4679 ig.Emit (OpCodes.Blt, loop);
4681 VariableStorage [] dim_len = new VariableStorage [rank];
4682 VariableStorage [] dim_count = new VariableStorage [rank];
4683 Label [] loop = new Label [rank];
4684 Label [] test = new Label [rank];
4687 for (dim = 0; dim < rank; dim++){
4688 dim_len [dim] = new VariableStorage (ec, TypeManager.int32_type);
4689 dim_count [dim] = new VariableStorage (ec, TypeManager.int32_type);
4690 test [dim] = ig.DefineLabel ();
4691 loop [dim] = ig.DefineLabel ();
4694 for (dim = 0; dim < rank; dim++){
4695 dim_len [dim].EmitThis (ig);
4698 IntLiteral.EmitInt (ig, dim);
4699 ig.Emit (OpCodes.Callvirt, TypeManager.int_getlength_int);
4700 dim_len [dim].EmitStore (ig);
4704 for (dim = 0; dim < rank; dim++){
4705 dim_count [dim].EmitThis (ig);
4706 ig.Emit (OpCodes.Ldc_I4_0);
4707 dim_count [dim].EmitStore (ig);
4708 ig.Emit (OpCodes.Br, test [dim]);
4709 ig.MarkLabel (loop [dim]);
4713 ig.Emit (OpCodes.Ldarg_0);
4717 for (dim = 0; dim < rank; dim++){
4718 dim_count [dim].EmitThis (ig);
4719 dim_count [dim].EmitLoad (ig);
4723 // FIXME: Maybe we can cache the computation of `get'?
4725 Type [] args = new Type [rank];
4728 for (int i = 0; i < rank; i++)
4729 args [i] = TypeManager.int32_type;
4731 ModuleBuilder mb = CodeGen.Module.Builder;
4732 get = mb.GetArrayMethod (
4734 CallingConventions.HasThis| CallingConventions.Standard,
4736 ig.Emit (OpCodes.Call, get);
4739 ig.Emit (OpCodes.Stfld, ((LocalVariableReference) variable).local_info.FieldBuilder);
4741 ((IAssignMethod)variable).EmitAssign (ec, conv, false, false);
4742 statement.Emit (ec);
4743 ig.MarkLabel (ec.LoopBegin);
4744 for (dim = rank - 1; dim >= 0; dim--){
4745 dim_count [dim].EmitThis (ig);
4746 dim_count [dim].EmitThis (ig);
4747 dim_count [dim].EmitLoad (ig);
4748 ig.Emit (OpCodes.Ldc_I4_1);
4749 ig.Emit (OpCodes.Add);
4750 dim_count [dim].EmitStore (ig);
4752 ig.MarkLabel (test [dim]);
4753 dim_count [dim].EmitThis (ig);
4754 dim_count [dim].EmitLoad (ig);
4755 dim_len [dim].EmitThis (ig);
4756 dim_len [dim].EmitLoad (ig);
4757 ig.Emit (OpCodes.Blt, loop [dim]);
4760 ig.MarkLabel (ec.LoopEnd);
4765 protected override void DoEmit (EmitContext ec)
4767 ILGenerator ig = ec.ig;
4769 Label old_begin = ec.LoopBegin, old_end = ec.LoopEnd;
4770 ec.LoopBegin = ig.DefineLabel ();
4771 ec.LoopEnd = ig.DefineLabel ();
4774 EmitCollectionForeach (ec);
4776 EmitArrayForeach (ec);
4778 ec.LoopBegin = old_begin;
4779 ec.LoopEnd = old_end;