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)
144 Report.Debug (1, "START IF BLOCK", loc);
146 expr = Expression.ResolveBoolean (ec, expr, loc);
152 Assign ass = expr as Assign;
153 if (ass != null && ass.Source is Constant) {
154 Report.Warning (665, 3, loc, "Assignment in conditional expression is always constant; did you mean to use == instead of = ?");
158 // Dead code elimination
160 if (expr is BoolConstant){
161 bool take = ((BoolConstant) expr).Value;
164 if (!TrueStatement.Resolve (ec))
167 if ((FalseStatement != null) &&
168 !FalseStatement.ResolveUnreachable (ec, true))
170 FalseStatement = null;
172 if (!TrueStatement.ResolveUnreachable (ec, true))
174 TrueStatement = null;
176 if ((FalseStatement != null) &&
177 !FalseStatement.Resolve (ec))
184 ec.StartFlowBranching (FlowBranching.BranchingType.Conditional, loc);
186 ok &= TrueStatement.Resolve (ec);
188 is_true_ret = ec.CurrentBranching.CurrentUsageVector.Reachability.IsUnreachable;
190 ec.CurrentBranching.CreateSibling ();
192 if (FalseStatement != null)
193 ok &= FalseStatement.Resolve (ec);
195 ec.EndFlowBranching ();
197 Report.Debug (1, "END IF BLOCK", loc);
202 protected override void DoEmit (EmitContext ec)
204 ILGenerator ig = ec.ig;
205 Label false_target = ig.DefineLabel ();
209 // If we're a boolean expression, Resolve() already
210 // eliminated dead code for us.
212 if (expr is BoolConstant){
213 bool take = ((BoolConstant) expr).Value;
216 TrueStatement.Emit (ec);
217 else if (FalseStatement != null)
218 FalseStatement.Emit (ec);
223 expr.EmitBranchable (ec, false_target, false);
225 TrueStatement.Emit (ec);
227 if (FalseStatement != null){
228 bool branch_emitted = false;
230 end = ig.DefineLabel ();
232 ig.Emit (OpCodes.Br, end);
233 branch_emitted = true;
236 ig.MarkLabel (false_target);
237 FalseStatement.Emit (ec);
242 ig.MarkLabel (false_target);
247 public class Do : Statement {
248 public Expression expr;
249 public readonly Statement EmbeddedStatement;
252 public Do (Statement statement, Expression boolExpr, Location l)
255 EmbeddedStatement = statement;
259 public override bool Resolve (EmitContext ec)
263 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
265 if (!EmbeddedStatement.Resolve (ec))
268 expr = Expression.ResolveBoolean (ec, expr, loc);
271 else if (expr is BoolConstant){
272 bool res = ((BoolConstant) expr).Value;
278 ec.CurrentBranching.Infinite = infinite;
279 ec.EndFlowBranching ();
284 protected override void DoEmit (EmitContext ec)
286 ILGenerator ig = ec.ig;
287 Label loop = ig.DefineLabel ();
288 Label old_begin = ec.LoopBegin;
289 Label old_end = ec.LoopEnd;
291 ec.LoopBegin = ig.DefineLabel ();
292 ec.LoopEnd = ig.DefineLabel ();
295 EmbeddedStatement.Emit (ec);
296 ig.MarkLabel (ec.LoopBegin);
299 // Dead code elimination
301 if (expr is BoolConstant){
302 bool res = ((BoolConstant) expr).Value;
305 ec.ig.Emit (OpCodes.Br, loop);
307 expr.EmitBranchable (ec, loop, true);
309 ig.MarkLabel (ec.LoopEnd);
311 ec.LoopBegin = old_begin;
312 ec.LoopEnd = old_end;
316 public class While : Statement {
317 public Expression expr;
318 public readonly Statement Statement;
319 bool infinite, empty;
321 public While (Expression boolExpr, Statement statement, Location l)
323 this.expr = boolExpr;
324 Statement = statement;
328 public override bool Resolve (EmitContext ec)
332 expr = Expression.ResolveBoolean (ec, expr, loc);
337 // Inform whether we are infinite or not
339 if (expr is BoolConstant){
340 BoolConstant bc = (BoolConstant) expr;
342 if (bc.Value == false){
343 if (!Statement.ResolveUnreachable (ec, true))
351 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
353 ec.CurrentBranching.CreateSibling ();
355 if (!Statement.Resolve (ec))
358 ec.CurrentBranching.Infinite = infinite;
359 ec.EndFlowBranching ();
364 protected override void DoEmit (EmitContext ec)
369 ILGenerator ig = ec.ig;
370 Label old_begin = ec.LoopBegin;
371 Label old_end = ec.LoopEnd;
373 ec.LoopBegin = ig.DefineLabel ();
374 ec.LoopEnd = ig.DefineLabel ();
377 // Inform whether we are infinite or not
379 if (expr is BoolConstant){
380 ig.MarkLabel (ec.LoopBegin);
382 ig.Emit (OpCodes.Br, ec.LoopBegin);
385 // Inform that we are infinite (ie, `we return'), only
386 // if we do not `break' inside the code.
388 ig.MarkLabel (ec.LoopEnd);
390 Label while_loop = ig.DefineLabel ();
392 ig.Emit (OpCodes.Br, ec.LoopBegin);
393 ig.MarkLabel (while_loop);
397 ig.MarkLabel (ec.LoopBegin);
399 expr.EmitBranchable (ec, while_loop, true);
401 ig.MarkLabel (ec.LoopEnd);
404 ec.LoopBegin = old_begin;
405 ec.LoopEnd = old_end;
409 public class For : Statement {
411 readonly Statement InitStatement;
412 readonly Statement Increment;
413 readonly Statement Statement;
414 bool infinite, empty;
416 public For (Statement initStatement,
422 InitStatement = initStatement;
424 Increment = increment;
425 Statement = statement;
429 public override bool Resolve (EmitContext ec)
433 if (InitStatement != null){
434 if (!InitStatement.Resolve (ec))
439 Test = Expression.ResolveBoolean (ec, Test, loc);
442 else if (Test is BoolConstant){
443 BoolConstant bc = (BoolConstant) Test;
445 if (bc.Value == false){
446 if (!Statement.ResolveUnreachable (ec, true))
448 if ((Increment != null) &&
449 !Increment.ResolveUnreachable (ec, false))
459 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
461 ec.CurrentBranching.CreateSibling ();
463 if (!Statement.Resolve (ec))
466 if (Increment != null){
467 if (!Increment.Resolve (ec))
471 ec.CurrentBranching.Infinite = infinite;
472 ec.EndFlowBranching ();
477 protected override void DoEmit (EmitContext ec)
482 ILGenerator ig = ec.ig;
483 Label old_begin = ec.LoopBegin;
484 Label old_end = ec.LoopEnd;
485 Label loop = ig.DefineLabel ();
486 Label test = ig.DefineLabel ();
488 if (InitStatement != null && InitStatement != EmptyStatement.Value)
489 InitStatement.Emit (ec);
491 ec.LoopBegin = ig.DefineLabel ();
492 ec.LoopEnd = ig.DefineLabel ();
494 ig.Emit (OpCodes.Br, test);
498 ig.MarkLabel (ec.LoopBegin);
499 if (Increment != EmptyStatement.Value)
504 // If test is null, there is no test, and we are just
509 // The Resolve code already catches the case for
510 // Test == BoolConstant (false) so we know that
513 if (Test is BoolConstant)
514 ig.Emit (OpCodes.Br, loop);
516 Test.EmitBranchable (ec, loop, true);
519 ig.Emit (OpCodes.Br, loop);
520 ig.MarkLabel (ec.LoopEnd);
522 ec.LoopBegin = old_begin;
523 ec.LoopEnd = old_end;
527 public class StatementExpression : Statement {
528 ExpressionStatement expr;
530 public StatementExpression (ExpressionStatement expr, Location l)
536 public override bool Resolve (EmitContext ec)
539 expr = expr.ResolveStatement (ec);
543 protected override void DoEmit (EmitContext ec)
545 expr.EmitStatement (ec);
548 public override string ToString ()
550 return "StatementExpression (" + expr + ")";
555 /// Implements the return statement
557 public class Return : Statement {
558 public Expression Expr;
560 public Return (Expression expr, Location l)
568 public override bool Resolve (EmitContext ec)
570 if (ec.ReturnType == null){
572 if (ec.CurrentAnonymousMethod != null){
573 Report.Error (1662, loc, String.Format (
574 "Anonymous method could not be converted to delegate " +
575 "since the return value does not match the delegate value"));
577 Error (127, "Return with a value not allowed here");
582 Error (126, "An object of type `{0}' is expected " +
583 "for the return statement",
584 TypeManager.CSharpName (ec.ReturnType));
589 Report.Error (1622, loc, "Cannot return a value from iterators. Use the yield return " +
590 "statement to return a value, or yield break to end the iteration");
594 Expr = Expr.Resolve (ec);
598 if (Expr.Type != ec.ReturnType) {
599 Expr = Convert.ImplicitConversionRequired (
600 ec, Expr, ec.ReturnType, loc);
607 Error (-206, "Return statement not allowed inside iterators");
611 FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
613 if (ec.CurrentBranching.InTryOrCatch (true)) {
614 ec.CurrentBranching.AddFinallyVector (vector);
616 } else if (ec.InFinally) {
617 Error (157, "Control can not leave the body of the finally block");
620 vector.CheckOutParameters (ec.CurrentBranching);
623 ec.NeedReturnLabel ();
625 ec.CurrentBranching.CurrentUsageVector.Return ();
629 protected override void DoEmit (EmitContext ec)
635 ec.ig.Emit (OpCodes.Stloc, ec.TemporaryReturn ());
639 ec.ig.Emit (OpCodes.Leave, ec.ReturnLabel);
641 ec.ig.Emit (OpCodes.Ret);
645 public class Goto : Statement {
647 LabeledStatement label;
649 public override bool Resolve (EmitContext ec)
651 label = ec.CurrentBranching.LookupLabel (target, loc);
655 // If this is a forward goto.
656 if (!label.IsDefined)
657 label.AddUsageVector (ec.CurrentBranching.CurrentUsageVector);
659 ec.CurrentBranching.CurrentUsageVector.Goto ();
660 label.AddReference ();
665 public Goto (string label, Location l)
671 public string Target {
677 protected override void DoEmit (EmitContext ec)
679 Label l = label.LabelTarget (ec);
680 ec.ig.Emit (OpCodes.Br, l);
684 public class LabeledStatement : Statement {
685 public readonly Location Location;
691 FlowBranching.UsageVector vectors;
693 public LabeledStatement (string label_name, Location l)
698 public Label LabelTarget (EmitContext ec)
703 label = ec.ig.DefineLabel ();
709 public bool IsDefined {
715 public bool HasBeenReferenced {
721 public void AddUsageVector (FlowBranching.UsageVector vector)
723 vector = vector.Clone ();
724 vector.Next = vectors;
728 public override bool Resolve (EmitContext ec)
730 ec.CurrentBranching.Label (vectors);
735 protected override void DoEmit (EmitContext ec)
737 if (ig != null && ig != ec.ig) {
738 Report.Error (1632, "Control cannot leave body of anonymous method");
742 ec.ig.MarkLabel (label);
745 public void AddReference ()
753 /// `goto default' statement
755 public class GotoDefault : Statement {
757 public GotoDefault (Location l)
762 public override bool Resolve (EmitContext ec)
764 ec.CurrentBranching.CurrentUsageVector.Goto ();
768 protected override void DoEmit (EmitContext ec)
770 if (ec.Switch == null){
771 Report.Error (153, loc, "goto default is only valid in a switch statement");
775 if (!ec.Switch.GotDefault){
776 Report.Error (159, loc, "No default target on switch statement");
779 ec.ig.Emit (OpCodes.Br, ec.Switch.DefaultTarget);
784 /// `goto case' statement
786 public class GotoCase : Statement {
790 public GotoCase (Expression e, Location l)
796 public override bool Resolve (EmitContext ec)
798 if (ec.Switch == null){
799 Report.Error (153, loc, "goto case is only valid in a switch statement");
803 expr = expr.Resolve (ec);
807 if (!(expr is Constant)){
808 Report.Error (159, loc, "Target expression for goto case is not constant");
812 object val = Expression.ConvertIntLiteral (
813 (Constant) expr, ec.Switch.SwitchType, loc);
818 sl = (SwitchLabel) ec.Switch.Elements [val];
823 "No such label 'case " + val + "': for the goto case");
827 ec.CurrentBranching.CurrentUsageVector.Goto ();
831 protected override void DoEmit (EmitContext ec)
833 ec.ig.Emit (OpCodes.Br, sl.GetILLabelCode (ec));
837 public class Throw : Statement {
840 public Throw (Expression expr, Location l)
846 public override bool Resolve (EmitContext ec)
848 ec.CurrentBranching.CurrentUsageVector.Throw ();
851 expr = expr.Resolve (ec);
855 ExprClass eclass = expr.eclass;
857 if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
858 eclass == ExprClass.Value || eclass == ExprClass.IndexerAccess)) {
859 expr.Error_UnexpectedKind ("value, variable, property or indexer access ", loc);
865 if ((t != TypeManager.exception_type) &&
866 !t.IsSubclassOf (TypeManager.exception_type) &&
867 !(expr is NullLiteral)) {
869 "The type caught or thrown must be derived " +
870 "from System.Exception");
877 Error (156, "A throw statement with no arguments is not allowed outside of a catch clause");
882 Error (724, "A throw statement with no argument is only allowed in a catch clause nested inside of the innermost catch clause");
888 protected override void DoEmit (EmitContext ec)
891 ec.ig.Emit (OpCodes.Rethrow);
895 ec.ig.Emit (OpCodes.Throw);
900 public class Break : Statement {
902 public Break (Location l)
909 public override bool Resolve (EmitContext ec)
911 if (!ec.CurrentBranching.InLoop () && !ec.CurrentBranching.InSwitch ()){
912 Error (139, "No enclosing loop or switch to continue to");
914 } else if (ec.InFinally && ec.CurrentBranching.BreakCrossesTryCatchBoundary()) {
915 Error (157, "Control can not leave the body of the finally block");
917 } else if (ec.CurrentBranching.InTryOrCatch (false))
918 ec.CurrentBranching.AddFinallyVector (
919 ec.CurrentBranching.CurrentUsageVector);
920 else if (ec.CurrentBranching.InLoop ())
921 ec.CurrentBranching.AddBreakVector (
922 ec.CurrentBranching.CurrentUsageVector);
924 crossing_exc = ec.CurrentBranching.BreakCrossesTryCatchBoundary ();
927 ec.NeedReturnLabel ();
929 ec.CurrentBranching.CurrentUsageVector.Break ();
933 protected override void DoEmit (EmitContext ec)
935 ILGenerator ig = ec.ig;
938 ig.Emit (OpCodes.Leave, ec.LoopEnd);
940 ig.Emit (OpCodes.Br, ec.LoopEnd);
945 public class Continue : Statement {
947 public Continue (Location l)
954 public override bool Resolve (EmitContext ec)
956 if (!ec.CurrentBranching.InLoop () && !ec.CurrentBranching.InSwitch ()){
957 Error (139, "No enclosing loop to continue to");
959 } else if (ec.InFinally) {
960 Error (157, "Control can not leave the body of the finally block");
962 } else if (ec.CurrentBranching.InTryOrCatch (false))
963 ec.CurrentBranching.AddFinallyVector (ec.CurrentBranching.CurrentUsageVector);
965 crossing_exc = ec.CurrentBranching.BreakCrossesTryCatchBoundary ();
967 ec.CurrentBranching.CurrentUsageVector.Goto ();
971 protected override void DoEmit (EmitContext ec)
973 Label begin = ec.LoopBegin;
976 ec.ig.Emit (OpCodes.Leave, begin);
978 ec.ig.Emit (OpCodes.Br, begin);
983 // The information about a user-perceived local variable
985 public class LocalInfo {
986 public Expression Type;
989 // Most of the time a variable will be stored in a LocalBuilder
991 // But sometimes, it will be stored in a field (variables that have been
992 // hoisted by iterators or by anonymous methods). The context of the field will
993 // be stored in the EmitContext
996 public LocalBuilder LocalBuilder;
997 public FieldBuilder FieldBuilder;
999 public Type VariableType;
1000 public readonly string Name;
1001 public readonly Location Location;
1002 public readonly Block Block;
1004 public VariableInfo VariableInfo;
1017 public LocalInfo (Expression type, string name, Block block, Location l)
1025 public LocalInfo (TypeContainer tc, Block block, Location l)
1027 VariableType = tc.TypeBuilder;
1032 public bool IsThisAssigned (EmitContext ec, Location loc)
1034 if (VariableInfo == null)
1035 throw new Exception ();
1037 if (!ec.DoFlowAnalysis || ec.CurrentBranching.IsAssigned (VariableInfo))
1040 return VariableInfo.TypeInfo.IsFullyInitialized (ec.CurrentBranching, VariableInfo, loc);
1043 public bool IsAssigned (EmitContext ec)
1045 if (VariableInfo == null)
1046 throw new Exception ();
1048 return !ec.DoFlowAnalysis || ec.CurrentBranching.IsAssigned (VariableInfo);
1051 public bool Resolve (EmitContext ec)
1053 if (VariableType == null) {
1054 TypeExpr texpr = Type.ResolveAsTypeTerminal (ec);
1058 VariableType = texpr.Type;
1061 if (VariableType == TypeManager.void_type) {
1062 Report.Error (1547, Location,
1063 "Keyword 'void' cannot be used in this context");
1067 if (VariableType.IsAbstract && VariableType.IsSealed) {
1068 Report.Error (723, Location, "Cannot declare variable of static type '{0}'", TypeManager.CSharpName (VariableType));
1071 // TODO: breaks the build
1072 // if (VariableType.IsPointer && !ec.InUnsafe)
1073 // Expression.UnsafeError (Location);
1079 // Whether the variable is Fixed (because its Pinned or its a value type)
1081 public bool IsFixed {
1083 if (((flags & Flags.Pinned) != 0) || TypeManager.IsValueType (VariableType))
1090 public bool IsCaptured {
1092 return (flags & Flags.Captured) != 0;
1096 flags |= Flags.Captured;
1100 public bool AddressTaken {
1102 return (flags & Flags.AddressTaken) != 0;
1106 flags |= Flags.AddressTaken;
1110 public override string ToString ()
1112 return String.Format ("LocalInfo ({0},{1},{2},{3})",
1113 Name, Type, VariableInfo, Location);
1118 return (flags & Flags.Used) != 0;
1121 flags = value ? (flags | Flags.Used) : (unchecked (flags & ~Flags.Used));
1125 public bool ReadOnly {
1127 return (flags & Flags.ReadOnly) != 0;
1130 flags = value ? (flags | Flags.ReadOnly) : (unchecked (flags & ~Flags.ReadOnly));
1135 // Whether the variable is pinned, if Pinned the variable has been
1136 // allocated in a pinned slot with DeclareLocal.
1138 public bool Pinned {
1140 return (flags & Flags.Pinned) != 0;
1143 flags = value ? (flags | Flags.Pinned) : (flags & ~Flags.Pinned);
1147 public bool IsThis {
1149 return (flags & Flags.IsThis) != 0;
1152 flags = value ? (flags | Flags.IsThis) : (flags & ~Flags.IsThis);
1158 /// Block represents a C# block.
1162 /// This class is used in a number of places: either to represent
1163 /// explicit blocks that the programmer places or implicit blocks.
1165 /// Implicit blocks are used as labels or to introduce variable
1168 /// Top-level blocks derive from Block, and they are called ToplevelBlock
1169 /// they contain extra information that is not necessary on normal blocks.
1171 public class Block : Statement {
1172 public Block Parent;
1173 public readonly Location StartLocation;
1174 public Location EndLocation = Location.Null;
1176 public readonly ToplevelBlock Toplevel;
1183 VariablesInitialized = 8,
1192 public bool Implicit {
1194 return (flags & Flags.Implicit) != 0;
1198 public bool Unchecked {
1200 return (flags & Flags.Unchecked) != 0;
1203 flags |= Flags.Unchecked;
1207 public bool Unsafe {
1209 return (flags & Flags.Unsafe) != 0;
1212 flags |= Flags.Unsafe;
1216 public bool HasVarargs {
1219 return Parent.HasVarargs;
1221 return (flags & Flags.HasVarargs) != 0;
1224 flags |= Flags.HasVarargs;
1229 // The statements in this block
1231 ArrayList statements;
1235 // An array of Blocks. We keep track of children just
1236 // to generate the local variable declarations.
1238 // Statements and child statements are handled through the
1244 // Labels. (label, block) pairs.
1249 // Keeps track of (name, type) pairs
1251 Hashtable variables;
1254 // Keeps track of constants
1255 Hashtable constants;
1258 // If this is a switch section, the enclosing switch block.
1262 protected static int id;
1266 public Block (Block parent)
1267 : this (parent, (Flags) 0, Location.Null, Location.Null)
1270 public Block (Block parent, Flags flags)
1271 : this (parent, flags, Location.Null, Location.Null)
1274 public Block (Block parent, Location start, Location end)
1275 : this (parent, (Flags) 0, start, end)
1278 public Block (Block parent, Flags flags, Location start, Location end)
1281 parent.AddChild (this);
1283 this.Parent = parent;
1285 this.StartLocation = start;
1286 this.EndLocation = end;
1289 statements = new ArrayList ();
1291 if ((flags & Flags.IsToplevel) != 0)
1292 Toplevel = (ToplevelBlock) this;
1294 Toplevel = parent.Toplevel;
1296 if (parent != null && Implicit) {
1297 if (parent.known_variables == null)
1298 parent.known_variables = new Hashtable ();
1299 // share with parent
1300 known_variables = parent.known_variables;
1305 public Block CreateSwitchBlock (Location start)
1307 Block new_block = new Block (this, start, start);
1308 new_block.switch_block = this;
1318 void AddChild (Block b)
1320 if (children == null)
1321 children = new ArrayList ();
1326 public void SetEndLocation (Location loc)
1332 /// Adds a label to the current block.
1336 /// false if the name already exists in this block. true
1340 public bool AddLabel (string name, LabeledStatement target, Location loc)
1342 if (switch_block != null)
1343 return switch_block.AddLabel (name, target, loc);
1346 while (cur != null) {
1347 if (cur.DoLookupLabel (name) != null) {
1349 140, loc, "The label '{0}' is a duplicate",
1360 while (cur != null) {
1361 if (cur.DoLookupLabel (name) != null) {
1364 "The label '{0}' shadows another label " +
1365 "by the same name in a containing scope.",
1370 if (children != null) {
1371 foreach (Block b in children) {
1372 LabeledStatement s = b.DoLookupLabel (name);
1378 "The label '{0}' shadows another " +
1379 "label by the same name in a " +
1380 "containing scope.",
1391 labels = new Hashtable ();
1393 labels.Add (name, target);
1397 public LabeledStatement LookupLabel (string name)
1399 LabeledStatement s = DoLookupLabel (name);
1403 if (children == null)
1406 foreach (Block child in children) {
1407 if (!child.Implicit)
1410 s = child.LookupLabel (name);
1418 LabeledStatement DoLookupLabel (string name)
1420 if (switch_block != null)
1421 return switch_block.LookupLabel (name);
1424 if (labels.Contains (name))
1425 return ((LabeledStatement) labels [name]);
1430 LocalInfo this_variable = null;
1433 // Returns the "this" instance variable of this block.
1434 // See AddThisVariable() for more information.
1436 public LocalInfo ThisVariable {
1438 for (Block b = this; b != null; b = b.Parent) {
1439 if (b.this_variable != null)
1440 return b.this_variable;
1447 Hashtable known_variables;
1450 // Marks a variable with name @name as being used in this or a child block.
1451 // If a variable name has been used in a child block, it's illegal to
1452 // declare a variable with the same name in the current block.
1454 void AddKnownVariable (string name, LocalInfo info)
1456 if (known_variables == null)
1457 known_variables = new Hashtable ();
1459 known_variables [name] = info;
1462 LocalInfo GetKnownVariableInfo (string name)
1464 if (known_variables == null)
1466 return (LocalInfo) known_variables [name];
1469 public bool CheckInvariantMeaningInBlock (string name, Expression e, Location loc)
1471 LocalInfo kvi = GetKnownVariableInfo (name);
1472 if (kvi == null || kvi.Block == this)
1475 if (known_variables != kvi.Block.known_variables) {
1476 Report.SymbolRelatedToPreviousError (kvi.Location, name);
1477 Report.Error (135, loc, "'{0}' has a different meaning in a child block", name);
1482 // this block and kvi.Block are the same textual block.
1483 // However, different variables are extant.
1485 // Check if the variable is in scope in both blocks. We use
1486 // an indirect check that depends on AddVariable doing its
1487 // part in maintaining the invariant-meaning-in-block property.
1489 if (e is LocalVariableReference || (e is Constant && GetLocalInfo (name) != null))
1492 Report.SymbolRelatedToPreviousError (kvi.Location, name);
1493 Report.Error (136, loc, "'{0}' has a different meaning later in the block", name);
1498 // This is used by non-static `struct' constructors which do not have an
1499 // initializer - in this case, the constructor must initialize all of the
1500 // struct's fields. To do this, we add a "this" variable and use the flow
1501 // analysis code to ensure that it's been fully initialized before control
1502 // leaves the constructor.
1504 public LocalInfo AddThisVariable (TypeContainer tc, Location l)
1506 if (this_variable != null)
1507 return this_variable;
1509 if (variables == null)
1510 variables = new Hashtable ();
1512 this_variable = new LocalInfo (tc, this, l);
1513 this_variable.Used = true;
1514 this_variable.IsThis = true;
1516 variables.Add ("this", this_variable);
1518 return this_variable;
1521 public LocalInfo AddVariable (Expression type, string name, Location l)
1523 if (variables == null)
1524 variables = new Hashtable ();
1526 LocalInfo vi = GetLocalInfo (name);
1528 Report.SymbolRelatedToPreviousError (vi.Location, name);
1529 if (known_variables == vi.Block.known_variables)
1530 Report.Error (128, l,
1531 "A local variable '{0}' is already declared in this scope", name);
1533 Report.Error (136, l,
1534 "'{0}' hides the declaration of local variable '{0}' in a parent scope", name);
1538 vi = GetKnownVariableInfo (name);
1540 Report.SymbolRelatedToPreviousError (vi.Location, name);
1541 Report.Error (136, l,
1542 "A child block already has a declaration of local variable '{0}':" +
1543 " allowing this declaration would violate 'invariant meaning in a block'",
1549 Parameter p = Toplevel.Parameters.GetParameterByName (name, out idx);
1551 Report.SymbolRelatedToPreviousError (Toplevel.Parameters.Location, name);
1552 Report.Error (136, l, "'{0}' hides a method parameter", name);
1556 vi = new LocalInfo (type, name, this, l);
1558 variables.Add (name, vi);
1560 for (Block b = this; b != null; b = b.Parent)
1561 b.AddKnownVariable (name, vi);
1563 if ((flags & Flags.VariablesInitialized) != 0)
1564 throw new Exception ();
1566 // Console.WriteLine ("Adding {0} to {1}", name, ID);
1570 public bool AddConstant (Expression type, string name, Expression value, Location l)
1572 if (AddVariable (type, name, l) == null)
1575 if (constants == null)
1576 constants = new Hashtable ();
1578 constants.Add (name, value);
1582 public Hashtable Variables {
1588 public LocalInfo GetLocalInfo (string name)
1590 for (Block b = this; b != null; b = b.Parent) {
1591 if (b.variables != null) {
1592 LocalInfo ret = b.variables [name] as LocalInfo;
1600 public Expression GetVariableType (string name)
1602 LocalInfo vi = GetLocalInfo (name);
1610 public Expression GetConstantExpression (string name)
1612 for (Block b = this; b != null; b = b.Parent) {
1613 if (b.constants != null) {
1614 Expression ret = b.constants [name] as Expression;
1623 /// True if the variable named @name is a constant
1625 public bool IsConstant (string name)
1627 Expression e = null;
1629 e = GetConstantExpression (name);
1635 // Returns a `ParameterReference' for the given name, or null if there
1636 // is no such parameter
1638 public ParameterReference GetParameterReference (string name, Location loc)
1643 for (Block b = this; b != null; b = b.Toplevel.Parent) {
1644 Parameters pars = b.Toplevel.Parameters;
1645 par = pars.GetParameterByName (name, out idx);
1647 return new ParameterReference (pars, this, idx, name, loc);
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)
1658 return Toplevel.Parameters.GetParameterByName (name) != null;
1662 // Whether the `name' is a parameter reference
1664 public bool IsParameterReference (string name)
1669 for (Block b = this; b != null; b = b.Toplevel.Parent) {
1670 par = b.Toplevel.Parameters.GetParameterByName (name, out idx);
1678 /// A list of labels that were not used within this block
1680 public string [] GetUnreferenced ()
1682 // FIXME: Implement me
1686 public void AddStatement (Statement s)
1689 flags |= Flags.BlockUsed;
1694 return (flags & Flags.BlockUsed) != 0;
1700 flags |= Flags.BlockUsed;
1703 public bool HasRet {
1705 return (flags & Flags.HasRet) != 0;
1709 public bool IsDestructor {
1711 return (flags & Flags.IsDestructor) != 0;
1715 public void SetDestructor ()
1717 flags |= Flags.IsDestructor;
1720 VariableMap param_map, local_map;
1722 public VariableMap ParameterMap {
1724 if ((flags & Flags.VariablesInitialized) == 0)
1725 throw new Exception ("Variables have not been initialized yet");
1731 public VariableMap LocalMap {
1733 if ((flags & Flags.VariablesInitialized) == 0)
1734 throw new Exception ("Variables have not been initialized yet");
1741 /// Emits the variable declarations and labels.
1744 /// tc: is our typecontainer (to resolve type references)
1745 /// ig: is the code generator:
1747 public void ResolveMeta (ToplevelBlock toplevel, EmitContext ec, InternalParameters ip)
1749 bool old_unsafe = ec.InUnsafe;
1751 // If some parent block was unsafe, we remain unsafe even if this block
1752 // isn't explicitly marked as such.
1753 ec.InUnsafe |= Unsafe;
1756 // Compute the VariableMap's.
1758 // Unfortunately, we don't know the type when adding variables with
1759 // AddVariable(), so we need to compute this info here.
1763 if (variables != null) {
1764 foreach (LocalInfo li in variables.Values)
1767 locals = new LocalInfo [variables.Count];
1768 variables.Values.CopyTo (locals, 0);
1770 locals = new LocalInfo [0];
1773 local_map = new VariableMap (Parent.LocalMap, locals);
1775 local_map = new VariableMap (locals);
1777 param_map = new VariableMap (ip);
1778 flags |= Flags.VariablesInitialized;
1780 bool old_check_state = ec.ConstantCheckState;
1781 ec.ConstantCheckState = (flags & Flags.Unchecked) == 0;
1784 // Process this block variables
1786 if (variables != null){
1787 foreach (DictionaryEntry de in variables){
1788 string name = (string) de.Key;
1789 LocalInfo vi = (LocalInfo) de.Value;
1791 if (vi.VariableType == null)
1794 Type variable_type = vi.VariableType;
1796 if (variable_type.IsPointer){
1798 // Am not really convinced that this test is required (Microsoft does it)
1799 // but the fact is that you would not be able to use the pointer variable
1802 if (!TypeManager.VerifyUnManaged (TypeManager.GetElementType (variable_type),
1809 vi.FieldBuilder = ec.MapVariable (name, vi.VariableType);
1812 // This is needed to compile on both .NET 1.x and .NET 2.x
1813 // the later introduced `DeclareLocal (Type t, bool pinned)'
1815 vi.LocalBuilder = TypeManager.DeclareLocalPinned (ig, vi.VariableType);
1816 else if (!vi.IsThis)
1817 vi.LocalBuilder = ig.DeclareLocal (vi.VariableType);
1820 if (constants == null)
1823 Expression cv = (Expression) constants [name];
1827 ec.CurrentBlock = this;
1828 Expression e = cv.Resolve (ec);
1832 Constant ce = e as Constant;
1834 Report.Error (133, vi.Location,
1835 "The expression being assigned to `" +
1836 name + "' must be constant (" + e + ")");
1840 if (e.Type != variable_type){
1841 e = Const.ChangeType (vi.Location, ce, variable_type);
1846 constants.Remove (name);
1847 constants.Add (name, e);
1850 ec.ConstantCheckState = old_check_state;
1853 // Now, handle the children
1855 if (children != null){
1856 foreach (Block b in children)
1857 b.ResolveMeta (toplevel, ec, ip);
1859 ec.InUnsafe = old_unsafe;
1863 // Emits the local variable declarations for a block
1865 public void EmitMeta (EmitContext ec)
1867 ILGenerator ig = ec.ig;
1869 if (variables != null){
1870 bool have_captured_vars = ec.HaveCapturedVariables ();
1871 bool remap_locals = ec.RemapToProxy;
1873 foreach (DictionaryEntry de in variables){
1874 LocalInfo vi = (LocalInfo) de.Value;
1876 if (have_captured_vars && ec.IsCaptured (vi))
1880 vi.FieldBuilder = ec.MapVariable (vi.Name, vi.VariableType);
1884 // This is needed to compile on both .NET 1.x and .NET 2.x
1885 // the later introduced `DeclareLocal (Type t, bool pinned)'
1887 vi.LocalBuilder = TypeManager.DeclareLocalPinned (ig, vi.VariableType);
1888 else if (!vi.IsThis)
1889 vi.LocalBuilder = ig.DeclareLocal (vi.VariableType);
1894 if (children != null){
1895 foreach (Block b in children)
1900 void UsageWarning (FlowBranching.UsageVector vector)
1904 if ((variables != null) && (RootContext.WarningLevel >= 3)) {
1905 foreach (DictionaryEntry de in variables){
1906 LocalInfo vi = (LocalInfo) de.Value;
1911 name = (string) de.Key;
1913 if (vector.IsAssigned (vi.VariableInfo)){
1914 Report.Warning (219, vi.Location, "The variable '{0}' is assigned but its value is never used", name);
1916 Report.Warning (168, vi.Location, "The variable '{0}' is declared but never used", name);
1922 bool unreachable_shown;
1924 public override bool Resolve (EmitContext ec)
1926 Block prev_block = ec.CurrentBlock;
1929 int errors = Report.Errors;
1931 ec.CurrentBlock = this;
1932 ec.StartFlowBranching (this);
1934 Report.Debug (4, "RESOLVE BLOCK", StartLocation, ec.CurrentBranching);
1937 // This flag is used to notate nested statements as unreachable from the beginning of this block.
1938 // For the purposes of this resolution, it doesn't matter that the whole block is unreachable
1939 // from the beginning of the function. The outer Resolve() that detected the unreachability is
1940 // responsible for handling the situation.
1942 bool unreachable = false;
1944 int statement_count = statements.Count;
1945 for (int ix = 0; ix < statement_count; ix++){
1946 Statement s = (Statement) statements [ix];
1948 if (unreachable && !(s is LabeledStatement)) {
1949 if (s == EmptyStatement.Value)
1950 s.loc = EndLocation;
1952 if (!s.ResolveUnreachable (ec, !unreachable_shown))
1955 if (s != EmptyStatement.Value)
1956 unreachable_shown = true;
1958 s.loc = Location.Null;
1960 if (ok && !(s is Block)) {
1961 statements [ix] = EmptyStatement.Value;
1966 if (s.Resolve (ec) == false) {
1968 statements [ix] = EmptyStatement.Value;
1972 num_statements = ix + 1;
1974 if (s is LabeledStatement)
1975 unreachable = false;
1977 unreachable = ec.CurrentBranching.CurrentUsageVector.Reachability.IsUnreachable;
1980 Report.Debug (4, "RESOLVE BLOCK DONE", StartLocation,
1981 ec.CurrentBranching, statement_count, num_statements);
1984 FlowBranching.UsageVector vector = ec.DoEndFlowBranching ();
1986 ec.CurrentBlock = prev_block;
1988 // If we're a non-static `struct' constructor which doesn't have an
1989 // initializer, then we must initialize all of the struct's fields.
1990 if ((this_variable != null) &&
1991 (vector.Reachability.Throws != FlowBranching.FlowReturns.Always) &&
1992 !this_variable.IsThisAssigned (ec, loc))
1995 if ((labels != null) && (RootContext.WarningLevel >= 2)) {
1996 foreach (LabeledStatement label in labels.Values)
1997 if (!label.HasBeenReferenced)
1998 Report.Warning (164, label.Location,
1999 "This label has not been referenced");
2002 Report.Debug (4, "RESOLVE BLOCK DONE #2", StartLocation, vector);
2004 if ((vector.Reachability.Returns == FlowBranching.FlowReturns.Always) ||
2005 (vector.Reachability.Throws == FlowBranching.FlowReturns.Always) ||
2006 (vector.Reachability.Reachable == FlowBranching.FlowReturns.Never))
2007 flags |= Flags.HasRet;
2009 if (ok && (errors == Report.Errors)) {
2010 if (RootContext.WarningLevel >= 3)
2011 UsageWarning (vector);
2017 public override bool ResolveUnreachable (EmitContext ec, bool warn)
2019 unreachable_shown = true;
2021 if (warn && (RootContext.WarningLevel >= 2))
2022 Report.Warning (162, loc, "Unreachable code detected");
2025 return Resolve (ec);
2027 ec.StartFlowBranching (FlowBranching.BranchingType.Block, loc);
2028 bool ok = Resolve (ec);
2029 ec.KillFlowBranching ();
2034 protected override void DoEmit (EmitContext ec)
2036 for (int ix = 0; ix < num_statements; ix++){
2037 Statement s = (Statement) statements [ix];
2039 // Check whether we are the last statement in a
2042 if (((Parent == null) || Implicit) && (ix+1 == num_statements) && !(s is Block))
2043 ec.IsLastStatement = true;
2045 ec.IsLastStatement = false;
2051 public override void Emit (EmitContext ec)
2053 Block prev_block = ec.CurrentBlock;
2055 ec.CurrentBlock = this;
2057 bool emit_debug_info = (CodeGen.SymbolWriter != null);
2058 bool is_lexical_block = !Implicit && (Parent != null);
2060 if (emit_debug_info) {
2061 if (is_lexical_block)
2064 if (variables != null) {
2065 foreach (DictionaryEntry de in variables) {
2066 string name = (string) de.Key;
2067 LocalInfo vi = (LocalInfo) de.Value;
2069 if (vi.LocalBuilder == null)
2072 ec.DefineLocalVariable (name, vi.LocalBuilder);
2077 ec.Mark (StartLocation, true);
2079 ec.Mark (EndLocation, true);
2081 if (emit_debug_info && is_lexical_block)
2084 ec.CurrentBlock = prev_block;
2088 // Returns true if we ar ea child of `b'.
2090 public bool IsChildOf (Block b)
2092 Block current = this;
2095 if (current.Parent == b)
2097 current = current.Parent;
2098 } while (current != null);
2102 public override string ToString ()
2104 return String.Format ("{0} ({1}:{2})", GetType (),ID, StartLocation);
2109 // A toplevel block contains extra information, the split is done
2110 // only to separate information that would otherwise bloat the more
2111 // lightweight Block.
2113 // In particular, this was introduced when the support for Anonymous
2114 // Methods was implemented.
2116 public class ToplevelBlock : Block {
2118 // Pointer to the host of this anonymous method, or null
2119 // if we are the topmost block
2121 public ToplevelBlock Container;
2122 CaptureContext capture_context;
2123 FlowBranching top_level_branching;
2125 Hashtable capture_contexts;
2128 // The parameters for the block.
2130 public readonly Parameters Parameters;
2132 public void RegisterCaptureContext (CaptureContext cc)
2134 if (capture_contexts == null)
2135 capture_contexts = new Hashtable ();
2136 capture_contexts [cc] = cc;
2139 public void CompleteContexts ()
2141 if (capture_contexts == null)
2144 foreach (CaptureContext cc in capture_contexts.Keys){
2149 public CaptureContext ToplevelBlockCaptureContext {
2151 return capture_context;
2156 // Parent is only used by anonymous blocks to link back to their
2159 public ToplevelBlock (ToplevelBlock container, Parameters parameters, Location start) :
2160 this (container, (Flags) 0, parameters, start)
2164 public ToplevelBlock (Parameters parameters, Location start) :
2165 this (null, (Flags) 0, parameters, start)
2169 public ToplevelBlock (Flags flags, Parameters parameters, Location start) :
2170 this (null, flags, parameters, start)
2174 public ToplevelBlock (ToplevelBlock container, Flags flags, Parameters parameters, Location start) :
2175 base (null, flags | Flags.IsToplevel, start, Location.Null)
2177 Parameters = parameters == null ? Parameters.EmptyReadOnlyParameters : parameters;
2178 Container = container;
2181 public ToplevelBlock (Location loc) : this (null, (Flags) 0, null, loc)
2185 public void SetHaveAnonymousMethods (Location loc, AnonymousMethod host)
2187 if (capture_context == null)
2188 capture_context = new CaptureContext (this, loc, host);
2191 public CaptureContext CaptureContext {
2193 return capture_context;
2197 public FlowBranching TopLevelBranching {
2199 return top_level_branching;
2203 public bool ResolveMeta (EmitContext ec, InternalParameters ip)
2205 int errors = Report.Errors;
2207 if (top_level_branching != null)
2210 ResolveMeta (this, ec, ip);
2212 top_level_branching = ec.StartFlowBranching (this);
2214 return Report.Errors == errors;
2218 public class SwitchLabel {
2221 public Location loc;
2225 Label il_label_code;
2226 bool il_label_code_set;
2229 // if expr == null, then it is the default case.
2231 public SwitchLabel (Expression expr, Location l)
2237 public Expression Label {
2243 public object Converted {
2249 public Label GetILLabel (EmitContext ec)
2252 il_label = ec.ig.DefineLabel ();
2253 il_label_set = true;
2258 public Label GetILLabelCode (EmitContext ec)
2260 if (!il_label_code_set){
2261 il_label_code = ec.ig.DefineLabel ();
2262 il_label_code_set = true;
2264 return il_label_code;
2268 // Resolves the expression, reduces it to a literal if possible
2269 // and then converts it to the requested type.
2271 public bool ResolveAndReduce (EmitContext ec, Type required_type)
2276 Expression e = label.Resolve (ec);
2281 if (!(e is Constant)){
2282 Report.Error (150, loc, "A constant value is expected, got: " + e);
2286 if (e is StringConstant || e is NullLiteral){
2287 if (required_type == TypeManager.string_type){
2293 converted = Expression.ConvertIntLiteral ((Constant) e, required_type, loc);
2294 if (converted == null)
2301 public class SwitchSection {
2302 // An array of SwitchLabels.
2303 public readonly ArrayList Labels;
2304 public readonly Block Block;
2306 public SwitchSection (ArrayList labels, Block block)
2313 public class Switch : Statement {
2314 public readonly ArrayList Sections;
2315 public Expression Expr;
2318 /// Maps constants whose type type SwitchType to their SwitchLabels.
2320 public Hashtable Elements;
2323 /// The governing switch type
2325 public Type SwitchType;
2330 Label default_target;
2331 Expression new_expr;
2333 SwitchSection constant_section;
2334 SwitchSection default_section;
2337 // The types allowed to be implicitly cast from
2338 // on the governing type
2340 static Type [] allowed_types;
2342 public Switch (Expression e, ArrayList sects, Location l)
2349 public bool GotDefault {
2351 return default_section != null;
2355 public Label DefaultTarget {
2357 return default_target;
2362 // Determines the governing type for a switch. The returned
2363 // expression might be the expression from the switch, or an
2364 // expression that includes any potential conversions to the
2365 // integral types or to string.
2367 Expression SwitchGoverningType (EmitContext ec, Type t)
2369 if (t == TypeManager.int32_type ||
2370 t == TypeManager.uint32_type ||
2371 t == TypeManager.char_type ||
2372 t == TypeManager.byte_type ||
2373 t == TypeManager.sbyte_type ||
2374 t == TypeManager.ushort_type ||
2375 t == TypeManager.short_type ||
2376 t == TypeManager.uint64_type ||
2377 t == TypeManager.int64_type ||
2378 t == TypeManager.string_type ||
2379 t == TypeManager.bool_type ||
2380 t.IsSubclassOf (TypeManager.enum_type))
2383 if (allowed_types == null){
2384 allowed_types = new Type [] {
2385 TypeManager.int32_type,
2386 TypeManager.uint32_type,
2387 TypeManager.sbyte_type,
2388 TypeManager.byte_type,
2389 TypeManager.short_type,
2390 TypeManager.ushort_type,
2391 TypeManager.int64_type,
2392 TypeManager.uint64_type,
2393 TypeManager.char_type,
2394 TypeManager.bool_type,
2395 TypeManager.string_type
2400 // Try to find a *user* defined implicit conversion.
2402 // If there is no implicit conversion, or if there are multiple
2403 // conversions, we have to report an error
2405 Expression converted = null;
2406 foreach (Type tt in allowed_types){
2409 e = Convert.ImplicitUserConversion (ec, Expr, tt, loc);
2414 // Ignore over-worked ImplicitUserConversions that do
2415 // an implicit conversion in addition to the user conversion.
2418 UserCast ue = e as UserCast;
2420 if (ue.Source != Expr)
2424 if (converted != null){
2425 Report.ExtraInformation (
2427 String.Format ("reason: more than one conversion to an integral type exist for type {0}",
2428 TypeManager.CSharpName (Expr.Type)));
2437 static string Error152 {
2439 return "The label '{0}:' already occurs in this switch statement";
2444 // Performs the basic sanity checks on the switch statement
2445 // (looks for duplicate keys and non-constant expressions).
2447 // It also returns a hashtable with the keys that we will later
2448 // use to compute the switch tables
2450 bool CheckSwitch (EmitContext ec)
2454 Elements = new Hashtable ();
2456 if (TypeManager.IsEnumType (SwitchType)){
2457 compare_type = TypeManager.EnumToUnderlying (SwitchType);
2459 compare_type = SwitchType;
2461 foreach (SwitchSection ss in Sections){
2462 foreach (SwitchLabel sl in ss.Labels){
2463 if (!sl.ResolveAndReduce (ec, SwitchType)){
2468 if (sl.Label == null){
2469 if (default_section != null){
2470 Report.Error (152, sl.loc, Error152, "default");
2473 default_section = ss;
2477 object key = sl.Converted;
2479 if (key is Constant)
2480 key = ((Constant) key).GetValue ();
2483 key = NullLiteral.Null;
2485 string lname = null;
2486 if (compare_type == TypeManager.uint64_type){
2487 ulong v = (ulong) key;
2489 if (Elements.Contains (v))
2490 lname = v.ToString ();
2492 Elements.Add (v, sl);
2493 } else if (compare_type == TypeManager.int64_type){
2494 long v = (long) key;
2496 if (Elements.Contains (v))
2497 lname = v.ToString ();
2499 Elements.Add (v, sl);
2500 } else if (compare_type == TypeManager.uint32_type){
2501 uint v = (uint) key;
2503 if (Elements.Contains (v))
2504 lname = v.ToString ();
2506 Elements.Add (v, sl);
2507 } else if (compare_type == TypeManager.char_type){
2508 char v = (char) key;
2510 if (Elements.Contains (v))
2511 lname = v.ToString ();
2513 Elements.Add (v, sl);
2514 } else if (compare_type == TypeManager.byte_type){
2515 byte v = (byte) key;
2517 if (Elements.Contains (v))
2518 lname = v.ToString ();
2520 Elements.Add (v, sl);
2521 } else if (compare_type == TypeManager.sbyte_type){
2522 sbyte v = (sbyte) key;
2524 if (Elements.Contains (v))
2525 lname = v.ToString ();
2527 Elements.Add (v, sl);
2528 } else if (compare_type == TypeManager.short_type){
2529 short v = (short) key;
2531 if (Elements.Contains (v))
2532 lname = v.ToString ();
2534 Elements.Add (v, sl);
2535 } else if (compare_type == TypeManager.ushort_type){
2536 ushort v = (ushort) key;
2538 if (Elements.Contains (v))
2539 lname = v.ToString ();
2541 Elements.Add (v, sl);
2542 } else if (compare_type == TypeManager.string_type){
2543 if (key is NullLiteral){
2544 if (Elements.Contains (NullLiteral.Null))
2547 Elements.Add (NullLiteral.Null, null);
2549 string s = (string) key;
2551 if (Elements.Contains (s))
2554 Elements.Add (s, sl);
2556 } else if (compare_type == TypeManager.int32_type) {
2559 if (Elements.Contains (v))
2560 lname = v.ToString ();
2562 Elements.Add (v, sl);
2563 } else if (compare_type == TypeManager.bool_type) {
2564 bool v = (bool) key;
2566 if (Elements.Contains (v))
2567 lname = v.ToString ();
2569 Elements.Add (v, sl);
2573 throw new Exception ("Unknown switch type!" +
2574 SwitchType + " " + compare_type);
2578 Report.Error (152, sl.loc, Error152, "case " + lname);
2589 void EmitObjectInteger (ILGenerator ig, object k)
2592 IntConstant.EmitInt (ig, (int) k);
2593 else if (k is Constant) {
2594 EmitObjectInteger (ig, ((Constant) k).GetValue ());
2597 IntConstant.EmitInt (ig, unchecked ((int) (uint) k));
2600 if ((long) k >= int.MinValue && (long) k <= int.MaxValue)
2602 IntConstant.EmitInt (ig, (int) (long) k);
2603 ig.Emit (OpCodes.Conv_I8);
2606 LongConstant.EmitLong (ig, (long) k);
2608 else if (k is ulong)
2610 if ((ulong) k < (1L<<32))
2612 IntConstant.EmitInt (ig, (int) (long) k);
2613 ig.Emit (OpCodes.Conv_U8);
2617 LongConstant.EmitLong (ig, unchecked ((long) (ulong) k));
2621 IntConstant.EmitInt (ig, (int) ((char) k));
2622 else if (k is sbyte)
2623 IntConstant.EmitInt (ig, (int) ((sbyte) k));
2625 IntConstant.EmitInt (ig, (int) ((byte) k));
2626 else if (k is short)
2627 IntConstant.EmitInt (ig, (int) ((short) k));
2628 else if (k is ushort)
2629 IntConstant.EmitInt (ig, (int) ((ushort) k));
2631 IntConstant.EmitInt (ig, ((bool) k) ? 1 : 0);
2633 throw new Exception ("Unhandled case");
2636 // structure used to hold blocks of keys while calculating table switch
2637 class KeyBlock : IComparable
2639 public KeyBlock (long _nFirst)
2641 nFirst = nLast = _nFirst;
2645 public ArrayList rgKeys = null;
2646 // how many items are in the bucket
2647 public int Size = 1;
2650 get { return (int) (nLast - nFirst + 1); }
2652 public static long TotalLength (KeyBlock kbFirst, KeyBlock kbLast)
2654 return kbLast.nLast - kbFirst.nFirst + 1;
2656 public int CompareTo (object obj)
2658 KeyBlock kb = (KeyBlock) obj;
2659 int nLength = Length;
2660 int nLengthOther = kb.Length;
2661 if (nLengthOther == nLength)
2662 return (int) (kb.nFirst - nFirst);
2663 return nLength - nLengthOther;
2668 /// This method emits code for a lookup-based switch statement (non-string)
2669 /// Basically it groups the cases into blocks that are at least half full,
2670 /// and then spits out individual lookup opcodes for each block.
2671 /// It emits the longest blocks first, and short blocks are just
2672 /// handled with direct compares.
2674 /// <param name="ec"></param>
2675 /// <param name="val"></param>
2676 /// <returns></returns>
2677 void TableSwitchEmit (EmitContext ec, LocalBuilder val)
2679 int cElements = Elements.Count;
2680 object [] rgKeys = new object [cElements];
2681 Elements.Keys.CopyTo (rgKeys, 0);
2682 Array.Sort (rgKeys);
2684 // initialize the block list with one element per key
2685 ArrayList rgKeyBlocks = new ArrayList ();
2686 foreach (object key in rgKeys)
2687 rgKeyBlocks.Add (new KeyBlock (System.Convert.ToInt64 (key)));
2690 // iteratively merge the blocks while they are at least half full
2691 // there's probably a really cool way to do this with a tree...
2692 while (rgKeyBlocks.Count > 1)
2694 ArrayList rgKeyBlocksNew = new ArrayList ();
2695 kbCurr = (KeyBlock) rgKeyBlocks [0];
2696 for (int ikb = 1; ikb < rgKeyBlocks.Count; ikb++)
2698 KeyBlock kb = (KeyBlock) rgKeyBlocks [ikb];
2699 if ((kbCurr.Size + kb.Size) * 2 >= KeyBlock.TotalLength (kbCurr, kb))
2702 kbCurr.nLast = kb.nLast;
2703 kbCurr.Size += kb.Size;
2707 // start a new block
2708 rgKeyBlocksNew.Add (kbCurr);
2712 rgKeyBlocksNew.Add (kbCurr);
2713 if (rgKeyBlocks.Count == rgKeyBlocksNew.Count)
2715 rgKeyBlocks = rgKeyBlocksNew;
2718 // initialize the key lists
2719 foreach (KeyBlock kb in rgKeyBlocks)
2720 kb.rgKeys = new ArrayList ();
2722 // fill the key lists
2724 if (rgKeyBlocks.Count > 0) {
2725 kbCurr = (KeyBlock) rgKeyBlocks [0];
2726 foreach (object key in rgKeys)
2728 bool fNextBlock = (key is UInt64) ? (ulong) key > (ulong) kbCurr.nLast :
2729 System.Convert.ToInt64 (key) > kbCurr.nLast;
2731 kbCurr = (KeyBlock) rgKeyBlocks [++iBlockCurr];
2732 kbCurr.rgKeys.Add (key);
2736 // sort the blocks so we can tackle the largest ones first
2737 rgKeyBlocks.Sort ();
2739 // okay now we can start...
2740 ILGenerator ig = ec.ig;
2741 Label lblEnd = ig.DefineLabel (); // at the end ;-)
2742 Label lblDefault = ig.DefineLabel ();
2744 Type typeKeys = null;
2745 if (rgKeys.Length > 0)
2746 typeKeys = rgKeys [0].GetType (); // used for conversions
2750 if (TypeManager.IsEnumType (SwitchType))
2751 compare_type = TypeManager.EnumToUnderlying (SwitchType);
2753 compare_type = SwitchType;
2755 for (int iBlock = rgKeyBlocks.Count - 1; iBlock >= 0; --iBlock)
2757 KeyBlock kb = ((KeyBlock) rgKeyBlocks [iBlock]);
2758 lblDefault = (iBlock == 0) ? DefaultTarget : ig.DefineLabel ();
2761 foreach (object key in kb.rgKeys)
2763 ig.Emit (OpCodes.Ldloc, val);
2764 EmitObjectInteger (ig, key);
2765 SwitchLabel sl = (SwitchLabel) Elements [key];
2766 ig.Emit (OpCodes.Beq, sl.GetILLabel (ec));
2771 // TODO: if all the keys in the block are the same and there are
2772 // no gaps/defaults then just use a range-check.
2773 if (compare_type == TypeManager.int64_type ||
2774 compare_type == TypeManager.uint64_type)
2776 // TODO: optimize constant/I4 cases
2778 // check block range (could be > 2^31)
2779 ig.Emit (OpCodes.Ldloc, val);
2780 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nFirst, typeKeys));
2781 ig.Emit (OpCodes.Blt, lblDefault);
2782 ig.Emit (OpCodes.Ldloc, val);
2783 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nLast, typeKeys));
2784 ig.Emit (OpCodes.Bgt, lblDefault);
2787 ig.Emit (OpCodes.Ldloc, val);
2790 EmitObjectInteger (ig, System.Convert.ChangeType (kb.nFirst, typeKeys));
2791 ig.Emit (OpCodes.Sub);
2793 ig.Emit (OpCodes.Conv_I4); // assumes < 2^31 labels!
2798 ig.Emit (OpCodes.Ldloc, val);
2799 int nFirst = (int) kb.nFirst;
2802 IntConstant.EmitInt (ig, nFirst);
2803 ig.Emit (OpCodes.Sub);
2805 else if (nFirst < 0)
2807 IntConstant.EmitInt (ig, -nFirst);
2808 ig.Emit (OpCodes.Add);
2812 // first, build the list of labels for the switch
2814 int cJumps = kb.Length;
2815 Label [] rgLabels = new Label [cJumps];
2816 for (int iJump = 0; iJump < cJumps; iJump++)
2818 object key = kb.rgKeys [iKey];
2819 if (System.Convert.ToInt64 (key) == kb.nFirst + iJump)
2821 SwitchLabel sl = (SwitchLabel) Elements [key];
2822 rgLabels [iJump] = sl.GetILLabel (ec);
2826 rgLabels [iJump] = lblDefault;
2828 // emit the switch opcode
2829 ig.Emit (OpCodes.Switch, rgLabels);
2832 // mark the default for this block
2834 ig.MarkLabel (lblDefault);
2837 // TODO: find the default case and emit it here,
2838 // to prevent having to do the following jump.
2839 // make sure to mark other labels in the default section
2841 // the last default just goes to the end
2842 ig.Emit (OpCodes.Br, lblDefault);
2844 // now emit the code for the sections
2845 bool fFoundDefault = false;
2846 foreach (SwitchSection ss in Sections)
2848 foreach (SwitchLabel sl in ss.Labels)
2850 ig.MarkLabel (sl.GetILLabel (ec));
2851 ig.MarkLabel (sl.GetILLabelCode (ec));
2852 if (sl.Label == null)
2854 ig.MarkLabel (lblDefault);
2855 fFoundDefault = true;
2859 //ig.Emit (OpCodes.Br, lblEnd);
2862 if (!fFoundDefault) {
2863 ig.MarkLabel (lblDefault);
2865 ig.MarkLabel (lblEnd);
2868 // This simple emit switch works, but does not take advantage of the
2870 // TODO: remove non-string logic from here
2871 // TODO: binary search strings?
2873 void SimpleSwitchEmit (EmitContext ec, LocalBuilder val)
2875 ILGenerator ig = ec.ig;
2876 Label end_of_switch = ig.DefineLabel ();
2877 Label next_test = ig.DefineLabel ();
2878 Label null_target = ig.DefineLabel ();
2879 bool first_test = true;
2880 bool pending_goto_end = false;
2881 bool null_marked = false;
2884 ig.Emit (OpCodes.Ldloc, val);
2886 if (Elements.Contains (NullLiteral.Null)){
2887 ig.Emit (OpCodes.Brfalse, null_target);
2889 ig.Emit (OpCodes.Brfalse, default_target);
2891 ig.Emit (OpCodes.Ldloc, val);
2892 ig.Emit (OpCodes.Call, TypeManager.string_isinterneted_string);
2893 ig.Emit (OpCodes.Stloc, val);
2895 int section_count = Sections.Count;
2896 for (int section = 0; section < section_count; section++){
2897 SwitchSection ss = (SwitchSection) Sections [section];
2899 if (ss == default_section)
2902 Label sec_begin = ig.DefineLabel ();
2904 ig.Emit (OpCodes.Nop);
2906 if (pending_goto_end)
2907 ig.Emit (OpCodes.Br, end_of_switch);
2909 int label_count = ss.Labels.Count;
2911 for (int label = 0; label < label_count; label++){
2912 SwitchLabel sl = (SwitchLabel) ss.Labels [label];
2913 ig.MarkLabel (sl.GetILLabel (ec));
2916 ig.MarkLabel (next_test);
2917 next_test = ig.DefineLabel ();
2920 // If we are the default target
2922 if (sl.Label != null){
2923 object lit = sl.Converted;
2925 if (lit is NullLiteral){
2927 if (label_count == 1)
2928 ig.Emit (OpCodes.Br, next_test);
2932 StringConstant str = (StringConstant) lit;
2934 ig.Emit (OpCodes.Ldloc, val);
2935 ig.Emit (OpCodes.Ldstr, str.Value);
2936 if (label_count == 1)
2937 ig.Emit (OpCodes.Bne_Un, next_test);
2939 if (label+1 == label_count)
2940 ig.Emit (OpCodes.Bne_Un, next_test);
2942 ig.Emit (OpCodes.Beq, sec_begin);
2947 ig.MarkLabel (null_target);
2950 ig.MarkLabel (sec_begin);
2951 foreach (SwitchLabel sl in ss.Labels)
2952 ig.MarkLabel (sl.GetILLabelCode (ec));
2955 pending_goto_end = !ss.Block.HasRet;
2958 ig.MarkLabel (next_test);
2959 ig.MarkLabel (default_target);
2961 ig.MarkLabel (null_target);
2962 if (default_section != null)
2963 default_section.Block.Emit (ec);
2964 ig.MarkLabel (end_of_switch);
2967 SwitchSection FindSection (SwitchLabel label)
2969 foreach (SwitchSection ss in Sections){
2970 foreach (SwitchLabel sl in ss.Labels){
2979 public override bool Resolve (EmitContext ec)
2981 Expr = Expr.Resolve (ec);
2985 new_expr = SwitchGoverningType (ec, Expr.Type);
2986 if (new_expr == null){
2987 Report.Error (151, loc, "An integer type or string was expected for switch");
2992 SwitchType = new_expr.Type;
2994 if (!CheckSwitch (ec))
2997 Switch old_switch = ec.Switch;
2999 ec.Switch.SwitchType = SwitchType;
3001 Report.Debug (1, "START OF SWITCH BLOCK", loc, ec.CurrentBranching);
3002 ec.StartFlowBranching (FlowBranching.BranchingType.Switch, loc);
3004 is_constant = new_expr is Constant;
3006 object key = ((Constant) new_expr).GetValue ();
3007 SwitchLabel label = (SwitchLabel) Elements [key];
3009 constant_section = FindSection (label);
3010 if (constant_section == null)
3011 constant_section = default_section;
3015 foreach (SwitchSection ss in Sections){
3017 ec.CurrentBranching.CreateSibling (
3018 null, FlowBranching.SiblingType.SwitchSection);
3022 if (is_constant && (ss != constant_section)) {
3023 // If we're a constant switch, we're only emitting
3024 // one single section - mark all the others as
3026 ec.CurrentBranching.CurrentUsageVector.Goto ();
3027 if (!ss.Block.ResolveUnreachable (ec, true))
3030 if (!ss.Block.Resolve (ec))
3035 if (default_section == null)
3036 ec.CurrentBranching.CreateSibling (
3037 null, FlowBranching.SiblingType.SwitchSection);
3039 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3040 ec.Switch = old_switch;
3042 Report.Debug (1, "END OF SWITCH BLOCK", loc, ec.CurrentBranching,
3048 protected override void DoEmit (EmitContext ec)
3050 ILGenerator ig = ec.ig;
3052 // Store variable for comparission purposes
3055 value = ig.DeclareLocal (SwitchType);
3057 ig.Emit (OpCodes.Stloc, value);
3061 default_target = ig.DefineLabel ();
3064 // Setup the codegen context
3066 Label old_end = ec.LoopEnd;
3067 Switch old_switch = ec.Switch;
3069 ec.LoopEnd = ig.DefineLabel ();
3074 if (constant_section != null)
3075 constant_section.Block.Emit (ec);
3076 } else if (SwitchType == TypeManager.string_type)
3077 SimpleSwitchEmit (ec, value);
3079 TableSwitchEmit (ec, value);
3081 // Restore context state.
3082 ig.MarkLabel (ec.LoopEnd);
3085 // Restore the previous context
3087 ec.LoopEnd = old_end;
3088 ec.Switch = old_switch;
3092 public abstract class ExceptionStatement : Statement
3094 public abstract void EmitFinally (EmitContext ec);
3096 protected bool emit_finally = true;
3097 ArrayList parent_vectors;
3099 protected void DoEmitFinally (EmitContext ec)
3102 ec.ig.BeginFinallyBlock ();
3104 ec.CurrentIterator.MarkFinally (ec, parent_vectors);
3108 protected void ResolveFinally (FlowBranchingException branching)
3110 emit_finally = branching.EmitFinally;
3112 branching.Parent.StealFinallyClauses (ref parent_vectors);
3116 public class Lock : ExceptionStatement {
3118 Statement Statement;
3121 public Lock (Expression expr, Statement stmt, Location l)
3128 public override bool Resolve (EmitContext ec)
3130 expr = expr.Resolve (ec);
3134 if (expr.Type.IsValueType){
3135 Error (185, "lock statement requires the expression to be " +
3136 " a reference type (type is: `{0}'",
3137 TypeManager.CSharpName (expr.Type));
3141 FlowBranchingException branching = ec.StartFlowBranching (this);
3142 bool ok = Statement.Resolve (ec);
3144 ec.KillFlowBranching ();
3148 ResolveFinally (branching);
3150 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3151 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
3152 // Unfortunately, System.Reflection.Emit automatically emits
3153 // a leave to the end of the finally block.
3154 // This is a problem if `returns' is true since we may jump
3155 // to a point after the end of the method.
3156 // As a workaround, emit an explicit ret here.
3157 ec.NeedReturnLabel ();
3163 protected override void DoEmit (EmitContext ec)
3165 Type type = expr.Type;
3167 ILGenerator ig = ec.ig;
3168 temp = ig.DeclareLocal (type);
3171 ig.Emit (OpCodes.Dup);
3172 ig.Emit (OpCodes.Stloc, temp);
3173 ig.Emit (OpCodes.Call, TypeManager.void_monitor_enter_object);
3177 ig.BeginExceptionBlock ();
3178 Statement.Emit (ec);
3183 ig.EndExceptionBlock ();
3186 public override void EmitFinally (EmitContext ec)
3188 ILGenerator ig = ec.ig;
3189 ig.Emit (OpCodes.Ldloc, temp);
3190 ig.Emit (OpCodes.Call, TypeManager.void_monitor_exit_object);
3194 public class Unchecked : Statement {
3195 public readonly Block Block;
3197 public Unchecked (Block b)
3203 public override bool Resolve (EmitContext ec)
3205 bool previous_state = ec.CheckState;
3206 bool previous_state_const = ec.ConstantCheckState;
3208 ec.CheckState = false;
3209 ec.ConstantCheckState = false;
3210 bool ret = Block.Resolve (ec);
3211 ec.CheckState = previous_state;
3212 ec.ConstantCheckState = previous_state_const;
3217 protected override void DoEmit (EmitContext ec)
3219 bool previous_state = ec.CheckState;
3220 bool previous_state_const = ec.ConstantCheckState;
3222 ec.CheckState = false;
3223 ec.ConstantCheckState = false;
3225 ec.CheckState = previous_state;
3226 ec.ConstantCheckState = previous_state_const;
3230 public class Checked : Statement {
3231 public readonly Block Block;
3233 public Checked (Block b)
3236 b.Unchecked = false;
3239 public override bool Resolve (EmitContext ec)
3241 bool previous_state = ec.CheckState;
3242 bool previous_state_const = ec.ConstantCheckState;
3244 ec.CheckState = true;
3245 ec.ConstantCheckState = true;
3246 bool ret = Block.Resolve (ec);
3247 ec.CheckState = previous_state;
3248 ec.ConstantCheckState = previous_state_const;
3253 protected override void DoEmit (EmitContext ec)
3255 bool previous_state = ec.CheckState;
3256 bool previous_state_const = ec.ConstantCheckState;
3258 ec.CheckState = true;
3259 ec.ConstantCheckState = true;
3261 ec.CheckState = previous_state;
3262 ec.ConstantCheckState = previous_state_const;
3266 public class Unsafe : Statement {
3267 public readonly Block Block;
3269 public Unsafe (Block b)
3272 Block.Unsafe = true;
3275 public override bool Resolve (EmitContext ec)
3277 bool previous_state = ec.InUnsafe;
3281 val = Block.Resolve (ec);
3282 ec.InUnsafe = previous_state;
3287 protected override void DoEmit (EmitContext ec)
3289 bool previous_state = ec.InUnsafe;
3293 ec.InUnsafe = previous_state;
3300 public class Fixed : Statement {
3302 ArrayList declarators;
3303 Statement statement;
3308 abstract class Emitter
3310 protected LocalInfo vi;
3311 protected Expression converted;
3313 protected Emitter (Expression expr, LocalInfo li)
3319 public abstract void Emit (EmitContext ec);
3320 public abstract void EmitExit (ILGenerator ig);
3323 class ExpressionEmitter: Emitter {
3324 public ExpressionEmitter (Expression converted, LocalInfo li) :
3325 base (converted, li)
3329 public override void Emit (EmitContext ec) {
3331 // Store pointer in pinned location
3333 converted.Emit (ec);
3334 ec.ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3337 public override void EmitExit (ILGenerator ig)
3339 ig.Emit (OpCodes.Ldc_I4_0);
3340 ig.Emit (OpCodes.Conv_U);
3341 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3345 class StringEmitter: Emitter {
3346 LocalBuilder pinned_string;
3349 public StringEmitter (Expression expr, LocalInfo li, Location loc):
3355 public override void Emit (EmitContext ec)
3357 ILGenerator ig = ec.ig;
3358 pinned_string = TypeManager.DeclareLocalPinned (ig, TypeManager.string_type);
3360 converted.Emit (ec);
3361 ig.Emit (OpCodes.Stloc, pinned_string);
3363 Expression sptr = new StringPtr (pinned_string, loc);
3364 converted = Convert.ImplicitConversionRequired (
3365 ec, sptr, vi.VariableType, loc);
3367 if (converted == null)
3370 converted.Emit (ec);
3371 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3374 public override void EmitExit(ILGenerator ig)
3376 ig.Emit (OpCodes.Ldnull);
3377 ig.Emit (OpCodes.Stloc, pinned_string);
3381 public Fixed (Expression type, ArrayList decls, Statement stmt, Location l)
3384 declarators = decls;
3389 public override bool Resolve (EmitContext ec)
3392 Expression.UnsafeError (loc);
3396 TypeExpr texpr = type.ResolveAsTypeTerminal (ec);
3400 expr_type = texpr.Type;
3402 CheckObsolete (expr_type);
3404 if (ec.RemapToProxy){
3405 Report.Error (-210, loc, "Fixed statement not allowed in iterators");
3409 data = new Emitter [declarators.Count];
3411 if (!expr_type.IsPointer){
3412 Report.Error (209, loc, "Variables in a fixed statement must be pointers");
3417 foreach (Pair p in declarators){
3418 LocalInfo vi = (LocalInfo) p.First;
3419 Expression e = (Expression) p.Second;
3421 vi.VariableInfo.SetAssigned (ec);
3425 // The rules for the possible declarators are pretty wise,
3426 // but the production on the grammar is more concise.
3428 // So we have to enforce these rules here.
3430 // We do not resolve before doing the case 1 test,
3431 // because the grammar is explicit in that the token &
3432 // is present, so we need to test for this particular case.
3436 Report.Error (254, loc, "Cast expression not allowed as right hand expression in fixed statement");
3441 // Case 1: & object.
3443 if (e is Unary && ((Unary) e).Oper == Unary.Operator.AddressOf){
3444 Expression child = ((Unary) e).Expr;
3446 if (child is ParameterReference || child is LocalVariableReference){
3449 "No need to use fixed statement for parameters or " +
3450 "local variable declarations (address is already " +
3455 ec.InFixedInitializer = true;
3457 ec.InFixedInitializer = false;
3461 child = ((Unary) e).Expr;
3463 if (!TypeManager.VerifyUnManaged (child.Type, loc))
3466 data [i] = new ExpressionEmitter (e, vi);
3472 ec.InFixedInitializer = true;
3474 ec.InFixedInitializer = false;
3481 if (e.Type.IsArray){
3482 Type array_type = TypeManager.GetElementType (e.Type);
3485 // Provided that array_type is unmanaged,
3487 if (!TypeManager.VerifyUnManaged (array_type, loc))
3491 // and T* is implicitly convertible to the
3492 // pointer type given in the fixed statement.
3494 ArrayPtr array_ptr = new ArrayPtr (e, array_type, loc);
3496 Expression converted = Convert.ImplicitConversionRequired (
3497 ec, array_ptr, vi.VariableType, loc);
3498 if (converted == null)
3501 data [i] = new ExpressionEmitter (converted, vi);
3510 if (e.Type == TypeManager.string_type){
3511 data [i] = new StringEmitter (e, vi, loc);
3516 // Case 4: fixed buffer
3517 FieldExpr fe = e as FieldExpr;
3519 IFixedBuffer ff = AttributeTester.GetFixedBuffer (fe.FieldInfo);
3521 Expression fixed_buffer_ptr = new FixedBufferPtr (fe, ff.ElementType, loc);
3523 Expression converted = Convert.ImplicitConversionRequired (
3524 ec, fixed_buffer_ptr, vi.VariableType, loc);
3525 if (converted == null)
3528 data [i] = new ExpressionEmitter (converted, vi);
3536 // For other cases, flag a `this is already fixed expression'
3538 if (e is LocalVariableReference || e is ParameterReference ||
3539 Convert.ImplicitConversionExists (ec, e, vi.VariableType)){
3541 Report.Error (245, loc, "right hand expression is already fixed, no need to use fixed statement ");
3545 Report.Error (245, loc, "Fixed statement only allowed on strings, arrays or address-of expressions");
3549 ec.StartFlowBranching (FlowBranching.BranchingType.Conditional, loc);
3551 if (!statement.Resolve (ec)) {
3552 ec.KillFlowBranching ();
3556 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3557 has_ret = reachability.IsUnreachable;
3562 protected override void DoEmit (EmitContext ec)
3564 for (int i = 0; i < data.Length; i++) {
3568 statement.Emit (ec);
3573 ILGenerator ig = ec.ig;
3576 // Clear the pinned variable
3578 for (int i = 0; i < data.Length; i++) {
3579 data [i].EmitExit (ig);
3584 public class Catch: Statement {
3585 public readonly string Name;
3586 public readonly Block Block;
3588 Expression type_expr;
3591 public Catch (Expression type, string name, Block block, Location l)
3599 public Type CatchType {
3605 public bool IsGeneral {
3607 return type_expr == null;
3611 protected override void DoEmit(EmitContext ec)
3615 public override bool Resolve (EmitContext ec)
3617 bool was_catch = ec.InCatch;
3620 if (type_expr != null) {
3621 TypeExpr te = type_expr.ResolveAsTypeTerminal (ec);
3625 type = te.ResolveType (ec);
3627 CheckObsolete (type);
3629 if (type != TypeManager.exception_type && !type.IsSubclassOf (TypeManager.exception_type)){
3630 Error (155, "The type caught or thrown must be derived from System.Exception");
3636 return Block.Resolve (ec);
3639 ec.InCatch = was_catch;
3644 public class Try : ExceptionStatement {
3645 public readonly Block Fini, Block;
3646 public readonly ArrayList Specific;
3647 public readonly Catch General;
3649 bool need_exc_block;
3652 // specific, general and fini might all be null.
3654 public Try (Block block, ArrayList specific, Catch general, Block fini, Location l)
3656 if (specific == null && general == null){
3657 Console.WriteLine ("CIR.Try: Either specific or general have to be non-null");
3661 this.Specific = specific;
3662 this.General = general;
3667 public override bool Resolve (EmitContext ec)
3671 FlowBranchingException branching = ec.StartFlowBranching (this);
3673 Report.Debug (1, "START OF TRY BLOCK", Block.StartLocation);
3675 if (!Block.Resolve (ec))
3678 FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
3680 Report.Debug (1, "START OF CATCH BLOCKS", vector);
3682 Type[] prevCatches = new Type [Specific.Count];
3684 foreach (Catch c in Specific){
3685 ec.CurrentBranching.CreateSibling (
3686 c.Block, FlowBranching.SiblingType.Catch);
3688 Report.Debug (1, "STARTED SIBLING FOR CATCH", ec.CurrentBranching);
3690 if (c.Name != null) {
3691 LocalInfo vi = c.Block.GetLocalInfo (c.Name);
3693 throw new Exception ();
3695 vi.VariableInfo = null;
3698 if (!c.Resolve (ec))
3701 Type resolvedType = c.CatchType;
3702 for (int ii = 0; ii < last_index; ++ii) {
3703 if (resolvedType == prevCatches [ii] || resolvedType.IsSubclassOf (prevCatches [ii])) {
3704 Report.Error (160, c.loc, "A previous catch clause already catches all exceptions of this or a super type '{0}'", prevCatches [ii].FullName);
3709 prevCatches [last_index++] = resolvedType;
3710 need_exc_block = true;
3713 Report.Debug (1, "END OF CATCH BLOCKS", ec.CurrentBranching);
3715 if (General != null){
3716 ec.CurrentBranching.CreateSibling (
3717 General.Block, FlowBranching.SiblingType.Catch);
3719 Report.Debug (1, "STARTED SIBLING FOR GENERAL", ec.CurrentBranching);
3721 if (!General.Resolve (ec))
3724 need_exc_block = true;
3727 Report.Debug (1, "END OF GENERAL CATCH BLOCKS", ec.CurrentBranching);
3731 ec.CurrentBranching.CreateSibling (
3732 Fini, FlowBranching.SiblingType.Finally);
3734 Report.Debug (1, "STARTED SIBLING FOR FINALLY", ec.CurrentBranching, vector);
3735 bool was_finally = ec.InFinally;
3736 ec.InFinally = true;
3737 if (!Fini.Resolve (ec))
3739 ec.InFinally = was_finally;
3742 ResolveFinally (branching);
3743 need_exc_block |= emit_finally;
3745 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
3747 FlowBranching.UsageVector f_vector = ec.CurrentBranching.CurrentUsageVector;
3749 Report.Debug (1, "END OF TRY", ec.CurrentBranching, reachability, vector, f_vector);
3751 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
3752 // Unfortunately, System.Reflection.Emit automatically emits
3753 // a leave to the end of the finally block. This is a problem
3754 // if `returns' is true since we may jump to a point after the
3755 // end of the method.
3756 // As a workaround, emit an explicit ret here.
3757 ec.NeedReturnLabel ();
3763 protected override void DoEmit (EmitContext ec)
3765 ILGenerator ig = ec.ig;
3768 ig.BeginExceptionBlock ();
3771 foreach (Catch c in Specific){
3774 ig.BeginCatchBlock (c.CatchType);
3776 if (c.Name != null){
3777 vi = c.Block.GetLocalInfo (c.Name);
3779 throw new Exception ("Variable does not exist in this block");
3781 ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
3783 ig.Emit (OpCodes.Pop);
3788 if (General != null){
3789 ig.BeginCatchBlock (TypeManager.object_type);
3790 ig.Emit (OpCodes.Pop);
3791 General.Block.Emit (ec);
3796 ig.EndExceptionBlock ();
3799 public override void EmitFinally (EmitContext ec)
3806 public bool HasCatch
3809 return General != null || Specific.Count > 0;
3814 public class Using : ExceptionStatement {
3815 object expression_or_block;
3816 Statement Statement;
3821 Expression [] resolved_vars;
3822 Expression [] converted_vars;
3823 ExpressionStatement [] assign;
3824 LocalBuilder local_copy;
3826 public Using (object expression_or_block, Statement stmt, Location l)
3828 this.expression_or_block = expression_or_block;
3834 // Resolves for the case of using using a local variable declaration.
3836 bool ResolveLocalVariableDecls (EmitContext ec)
3840 TypeExpr texpr = expr.ResolveAsTypeTerminal (ec);
3844 expr_type = texpr.Type;
3847 // The type must be an IDisposable or an implicit conversion
3850 converted_vars = new Expression [var_list.Count];
3851 resolved_vars = new Expression [var_list.Count];
3852 assign = new ExpressionStatement [var_list.Count];
3854 bool need_conv = !TypeManager.ImplementsInterface (
3855 expr_type, TypeManager.idisposable_type);
3857 foreach (DictionaryEntry e in var_list){
3858 Expression var = (Expression) e.Key;
3860 var = var.ResolveLValue (ec, new EmptyExpression ());
3864 resolved_vars [i] = var;
3871 converted_vars [i] = Convert.ImplicitConversionRequired (
3872 ec, var, TypeManager.idisposable_type, loc);
3874 if (converted_vars [i] == null)
3881 foreach (DictionaryEntry e in var_list){
3882 Expression var = resolved_vars [i];
3883 Expression new_expr = (Expression) e.Value;
3886 a = new Assign (var, new_expr, loc);
3892 converted_vars [i] = var;
3893 assign [i] = (ExpressionStatement) a;
3900 bool ResolveExpression (EmitContext ec)
3902 if (!TypeManager.ImplementsInterface (expr_type, TypeManager.idisposable_type)){
3903 if (Convert.ImplicitConversion (ec, expr, TypeManager.idisposable_type, loc) == null) {
3904 Report.Error (1674, loc, "'{0}': type used in a using statement must be implicitly convertible to 'System.IDisposable'",
3905 TypeManager.CSharpName (expr_type));
3914 // Emits the code for the case of using using a local variable declaration.
3916 void EmitLocalVariableDecls (EmitContext ec)
3918 ILGenerator ig = ec.ig;
3921 for (i = 0; i < assign.Length; i++) {
3922 assign [i].EmitStatement (ec);
3925 ig.BeginExceptionBlock ();
3927 Statement.Emit (ec);
3929 var_list.Reverse ();
3934 void EmitLocalVariableDeclFinally (EmitContext ec)
3936 ILGenerator ig = ec.ig;
3938 int i = assign.Length;
3939 for (int ii = 0; ii < var_list.Count; ++ii){
3940 Expression var = resolved_vars [--i];
3941 Label skip = ig.DefineLabel ();
3943 ig.BeginFinallyBlock ();
3945 if (!var.Type.IsValueType) {
3947 ig.Emit (OpCodes.Brfalse, skip);
3948 converted_vars [i].Emit (ec);
3949 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
3951 Expression ml = Expression.MemberLookup(ec, TypeManager.idisposable_type, var.Type, "Dispose", Mono.CSharp.Location.Null);
3953 if (!(ml is MethodGroupExpr)) {
3955 ig.Emit (OpCodes.Box, var.Type);
3956 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
3958 MethodInfo mi = null;
3960 foreach (MethodInfo mk in ((MethodGroupExpr) ml).Methods) {
3961 if (TypeManager.GetArgumentTypes (mk).Length == 0) {
3968 Report.Error(-100, Mono.CSharp.Location.Null, "Internal error: No Dispose method which takes 0 parameters.");
3972 IMemoryLocation mloc = (IMemoryLocation) var;
3974 mloc.AddressOf (ec, AddressOp.Load);
3975 ig.Emit (OpCodes.Call, mi);
3979 ig.MarkLabel (skip);
3982 ig.EndExceptionBlock ();
3984 ig.BeginFinallyBlock ();
3989 void EmitExpression (EmitContext ec)
3992 // Make a copy of the expression and operate on that.
3994 ILGenerator ig = ec.ig;
3995 local_copy = ig.DeclareLocal (expr_type);
4000 ig.Emit (OpCodes.Stloc, local_copy);
4003 ig.BeginExceptionBlock ();
4005 Statement.Emit (ec);
4009 ig.EndExceptionBlock ();
4012 void EmitExpressionFinally (EmitContext ec)
4014 ILGenerator ig = ec.ig;
4015 if (!local_copy.LocalType.IsValueType) {
4016 Label skip = ig.DefineLabel ();
4017 ig.Emit (OpCodes.Ldloc, local_copy);
4018 ig.Emit (OpCodes.Brfalse, skip);
4019 ig.Emit (OpCodes.Ldloc, local_copy);
4020 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4021 ig.MarkLabel (skip);
4023 Expression ml = Expression.MemberLookup(ec, TypeManager.idisposable_type, local_copy.LocalType, "Dispose", Mono.CSharp.Location.Null);
4025 if (!(ml is MethodGroupExpr)) {
4026 ig.Emit (OpCodes.Ldloc, local_copy);
4027 ig.Emit (OpCodes.Box, local_copy.LocalType);
4028 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4030 MethodInfo mi = null;
4032 foreach (MethodInfo mk in ((MethodGroupExpr) ml).Methods) {
4033 if (TypeManager.GetArgumentTypes (mk).Length == 0) {
4040 Report.Error(-100, Mono.CSharp.Location.Null, "Internal error: No Dispose method which takes 0 parameters.");
4044 ig.Emit (OpCodes.Ldloca, local_copy);
4045 ig.Emit (OpCodes.Call, mi);
4050 public override bool Resolve (EmitContext ec)
4052 if (expression_or_block is DictionaryEntry){
4053 expr = (Expression) ((DictionaryEntry) expression_or_block).Key;
4054 var_list = (ArrayList)((DictionaryEntry)expression_or_block).Value;
4056 if (!ResolveLocalVariableDecls (ec))
4059 } else if (expression_or_block is Expression){
4060 expr = (Expression) expression_or_block;
4062 expr = expr.Resolve (ec);
4066 expr_type = expr.Type;
4068 if (!ResolveExpression (ec))
4072 FlowBranchingException branching = ec.StartFlowBranching (this);
4074 bool ok = Statement.Resolve (ec);
4077 ec.KillFlowBranching ();
4081 ResolveFinally (branching);
4082 FlowBranching.Reachability reachability = ec.EndFlowBranching ();
4084 if (reachability.Returns != FlowBranching.FlowReturns.Always) {
4085 // Unfortunately, System.Reflection.Emit automatically emits a leave
4086 // to the end of the finally block. This is a problem if `returns'
4087 // is true since we may jump to a point after the end of the method.
4088 // As a workaround, emit an explicit ret here.
4089 ec.NeedReturnLabel ();
4095 protected override void DoEmit (EmitContext ec)
4097 if (expression_or_block is DictionaryEntry)
4098 EmitLocalVariableDecls (ec);
4099 else if (expression_or_block is Expression)
4100 EmitExpression (ec);
4103 public override void EmitFinally (EmitContext ec)
4105 if (expression_or_block is DictionaryEntry)
4106 EmitLocalVariableDeclFinally (ec);
4107 else if (expression_or_block is Expression)
4108 EmitExpressionFinally (ec);
4113 /// Implementation of the foreach C# statement
4115 public class Foreach : ExceptionStatement {
4117 Expression variable;
4119 Statement statement;
4120 ForeachHelperMethods hm;
4121 Expression empty, conv;
4122 Type array_type, element_type;
4124 VariableStorage enumerator;
4127 public Foreach (Expression type, LocalVariableReference var, Expression expr,
4128 Statement stmt, Location l)
4131 this.variable = var;
4137 public override bool Resolve (EmitContext ec)
4139 expr = expr.Resolve (ec);
4143 if (expr is NullLiteral) {
4144 Report.Error (186, expr.Location, "Use of null is not valid in this context");
4148 TypeExpr texpr = type.ResolveAsTypeTerminal (ec);
4152 var_type = texpr.Type;
4155 // We need an instance variable. Not sure this is the best
4156 // way of doing this.
4158 // FIXME: When we implement propertyaccess, will those turn
4159 // out to return values in ExprClass? I think they should.
4161 if (!(expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.Value ||
4162 expr.eclass == ExprClass.PropertyAccess || expr.eclass == ExprClass.IndexerAccess)){
4163 error1579 (expr.Type);
4167 if (expr.Type.IsArray) {
4168 array_type = expr.Type;
4169 element_type = TypeManager.GetElementType (array_type);
4171 empty = new EmptyExpression (element_type);
4173 array = new ArrayForeach (type, variable, expr, statement, loc);
4174 return array.Resolve (ec);
4176 hm = ProbeCollectionType (ec, expr.Type);
4178 error1579 (expr.Type);
4182 array_type = expr.Type;
4183 element_type = hm.element_type;
4185 empty = new EmptyExpression (hm.element_type);
4190 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
4191 ec.CurrentBranching.CreateSibling ();
4195 // FIXME: maybe we can apply the same trick we do in the
4196 // array handling to avoid creating empty and conv in some cases.
4198 // Although it is not as important in this case, as the type
4199 // will not likely be object (what the enumerator will return).
4201 conv = Convert.ExplicitConversion (ec, empty, var_type, loc);
4205 variable = variable.ResolveLValue (ec, empty);
4206 if (variable == null)
4209 bool disposable = (hm != null) && hm.is_disposable;
4210 FlowBranchingException branching = null;
4212 branching = ec.StartFlowBranching (this);
4214 if (!statement.Resolve (ec))
4218 ResolveFinally (branching);
4219 ec.EndFlowBranching ();
4221 emit_finally = true;
4223 ec.EndFlowBranching ();
4229 // Retrieves a `public bool MoveNext ()' method from the Type `t'
4231 static MethodInfo FetchMethodMoveNext (Type t)
4233 MemberList move_next_list;
4235 move_next_list = TypeContainer.FindMembers (
4236 t, MemberTypes.Method,
4237 BindingFlags.Public | BindingFlags.Instance,
4238 Type.FilterName, "MoveNext");
4239 if (move_next_list.Count == 0)
4242 foreach (MemberInfo m in move_next_list){
4243 MethodInfo mi = (MethodInfo) m;
4246 args = TypeManager.GetArgumentTypes (mi);
4247 if (args != null && args.Length == 0){
4248 if (TypeManager.TypeToCoreType (mi.ReturnType) == TypeManager.bool_type)
4256 // Retrieves a `public T get_Current ()' method from the Type `t'
4258 static MethodInfo FetchMethodGetCurrent (Type t)
4260 MemberList get_current_list;
4262 get_current_list = TypeContainer.FindMembers (
4263 t, MemberTypes.Method,
4264 BindingFlags.Public | BindingFlags.Instance,
4265 Type.FilterName, "get_Current");
4266 if (get_current_list.Count == 0)
4269 foreach (MemberInfo m in get_current_list){
4270 MethodInfo mi = (MethodInfo) m;
4273 args = TypeManager.GetArgumentTypes (mi);
4274 if (args != null && args.Length == 0)
4281 // Retrieves a `public void Dispose ()' method from the Type `t'
4283 static MethodInfo FetchMethodDispose (Type t)
4285 MemberList dispose_list;
4287 dispose_list = TypeContainer.FindMembers (
4288 t, MemberTypes.Method,
4289 BindingFlags.Public | BindingFlags.Instance,
4290 Type.FilterName, "Dispose");
4291 if (dispose_list.Count == 0)
4294 foreach (MemberInfo m in dispose_list){
4295 MethodInfo mi = (MethodInfo) m;
4298 args = TypeManager.GetArgumentTypes (mi);
4299 if (args != null && args.Length == 0){
4300 if (mi.ReturnType == TypeManager.void_type)
4308 // This struct records the helper methods used by the Foreach construct
4310 class ForeachHelperMethods {
4311 public EmitContext ec;
4312 public MethodInfo get_enumerator;
4313 public MethodInfo move_next;
4314 public MethodInfo get_current;
4315 public Type element_type;
4316 public Type enumerator_type;
4317 public bool is_disposable;
4319 public ForeachHelperMethods (EmitContext ec)
4322 this.element_type = TypeManager.object_type;
4323 this.enumerator_type = TypeManager.ienumerator_type;
4324 this.is_disposable = true;
4328 static bool GetEnumeratorFilter (MemberInfo m, object criteria)
4333 if (!(m is MethodInfo))
4336 if (m.Name != "GetEnumerator")
4339 MethodInfo mi = (MethodInfo) m;
4340 Type [] args = TypeManager.GetArgumentTypes (mi);
4342 if (args.Length != 0)
4345 ForeachHelperMethods hm = (ForeachHelperMethods) criteria;
4347 // Check whether GetEnumerator is public
4348 if ((mi.Attributes & MethodAttributes.Public) != MethodAttributes.Public)
4351 if ((mi.ReturnType == TypeManager.ienumerator_type) && (mi.DeclaringType == TypeManager.string_type))
4353 // Apply the same optimization as MS: skip the GetEnumerator
4354 // returning an IEnumerator, and use the one returning a
4355 // CharEnumerator instead. This allows us to avoid the
4356 // try-finally block and the boxing.
4361 // Ok, we can access it, now make sure that we can do something
4362 // with this `GetEnumerator'
4365 Type return_type = mi.ReturnType;
4366 if (mi.ReturnType == TypeManager.ienumerator_type ||
4367 TypeManager.ienumerator_type.IsAssignableFrom (return_type) ||
4368 (!RootContext.StdLib && TypeManager.ImplementsInterface (return_type, TypeManager.ienumerator_type))) {
4371 // If it is not an interface, lets try to find the methods ourselves.
4372 // For example, if we have:
4373 // public class Foo : IEnumerator { public bool MoveNext () {} public int Current { get {}}}
4374 // We can avoid the iface call. This is a runtime perf boost.
4375 // even bigger if we have a ValueType, because we avoid the cost
4378 // We have to make sure that both methods exist for us to take
4379 // this path. If one of the methods does not exist, we will just
4380 // use the interface. Sadly, this complex if statement is the only
4381 // way I could do this without a goto
4384 if (return_type.IsInterface ||
4385 (hm.move_next = FetchMethodMoveNext (return_type)) == null ||
4386 (hm.get_current = FetchMethodGetCurrent (return_type)) == null) {
4388 hm.move_next = TypeManager.bool_movenext_void;
4389 hm.get_current = TypeManager.object_getcurrent_void;
4396 // Ok, so they dont return an IEnumerable, we will have to
4397 // find if they support the GetEnumerator pattern.
4400 hm.move_next = FetchMethodMoveNext (return_type);
4401 if (hm.move_next == null)
4404 hm.get_current = FetchMethodGetCurrent (return_type);
4405 if (hm.get_current == null)
4409 hm.element_type = hm.get_current.ReturnType;
4410 hm.enumerator_type = return_type;
4411 hm.is_disposable = !hm.enumerator_type.IsSealed ||
4412 TypeManager.ImplementsInterface (
4413 hm.enumerator_type, TypeManager.idisposable_type);
4419 /// This filter is used to find the GetEnumerator method
4420 /// on which IEnumerator operates
4422 static MemberFilter FilterEnumerator;
4426 FilterEnumerator = new MemberFilter (GetEnumeratorFilter);
4429 void error1579 (Type t)
4431 Report.Error (1579, loc,
4432 "foreach statement cannot operate on variables of type `" +
4433 t.FullName + "' because that class does not provide a " +
4434 " GetEnumerator method or it is inaccessible");
4437 static bool TryType (Type t, ForeachHelperMethods hm)
4441 mi = TypeContainer.FindMembers (t, MemberTypes.Method,
4442 BindingFlags.Public | BindingFlags.NonPublic |
4443 BindingFlags.Instance | BindingFlags.DeclaredOnly,
4444 FilterEnumerator, hm);
4449 hm.get_enumerator = (MethodInfo) mi [0];
4454 // Looks for a usable GetEnumerator in the Type, and if found returns
4455 // the three methods that participate: GetEnumerator, MoveNext and get_Current
4457 ForeachHelperMethods ProbeCollectionType (EmitContext ec, Type t)
4459 ForeachHelperMethods hm = new ForeachHelperMethods (ec);
4461 for (Type tt = t; tt != null && tt != TypeManager.object_type;){
4462 if (TryType (tt, hm))
4468 // Now try to find the method in the interfaces
4471 Type [] ifaces = t.GetInterfaces ();
4473 foreach (Type i in ifaces){
4474 if (TryType (i, hm))
4479 // Since TypeBuilder.GetInterfaces only returns the interface
4480 // types for this type, we have to keep looping, but once
4481 // we hit a non-TypeBuilder (ie, a Type), then we know we are
4482 // done, because it returns all the types
4484 if ((t is TypeBuilder))
4494 // FIXME: possible optimization.
4495 // We might be able to avoid creating `empty' if the type is the sam
4497 bool EmitCollectionForeach (EmitContext ec)
4499 ILGenerator ig = ec.ig;
4501 enumerator = new VariableStorage (ec, hm.enumerator_type);
4502 enumerator.EmitThis (ig);
4504 // Instantiate the enumerator
4506 if (expr.Type.IsValueType){
4507 IMemoryLocation ml = expr as IMemoryLocation;
4508 // Load the address of the value type.
4510 // This happens if, for example, you have a property
4511 // returning a struct which is IEnumerable
4512 LocalBuilder t = ec.GetTemporaryLocal (expr.Type);
4514 ig.Emit (OpCodes.Stloc, t);
4515 ig.Emit (OpCodes.Ldloca, t);
4516 ec.FreeTemporaryLocal (t, expr.Type);
4518 ml.AddressOf (ec, AddressOp.Load);
4522 if (hm.get_enumerator.DeclaringType.IsValueType) {
4523 // the method is declared on the value type
4524 ig.Emit (OpCodes.Call, hm.get_enumerator);
4526 // it is an interface method, so we must box
4527 ig.Emit (OpCodes.Box, expr.Type);
4528 ig.Emit (OpCodes.Callvirt, hm.get_enumerator);
4532 ig.Emit (OpCodes.Callvirt, hm.get_enumerator);
4534 enumerator.EmitStore (ig);
4537 // Protect the code in a try/finalize block, so that
4538 // if the beast implement IDisposable, we get rid of it
4540 if (hm.is_disposable && emit_finally)
4541 ig.BeginExceptionBlock ();
4543 Label end_try = ig.DefineLabel ();
4545 ig.MarkLabel (ec.LoopBegin);
4547 enumerator.EmitCall (ig, hm.move_next);
4549 ig.Emit (OpCodes.Brfalse, end_try);
4552 ig.Emit (OpCodes.Ldarg_0);
4554 enumerator.EmitCall (ig, hm.get_current);
4558 ig.Emit (OpCodes.Stfld, ((LocalVariableReference) variable).local_info.FieldBuilder);
4560 ((IAssignMethod)variable).EmitAssign (ec, conv, false, false);
4562 statement.Emit (ec);
4563 ig.Emit (OpCodes.Br, ec.LoopBegin);
4564 ig.MarkLabel (end_try);
4566 // The runtime provides this for us.
4567 // ig.Emit (OpCodes.Leave, end);
4570 // Now the finally block
4572 if (hm.is_disposable) {
4575 ig.EndExceptionBlock ();
4578 ig.MarkLabel (ec.LoopEnd);
4582 public override void EmitFinally (EmitContext ec)
4584 ILGenerator ig = ec.ig;
4586 if (hm.enumerator_type.IsValueType) {
4587 enumerator.EmitThis (ig);
4589 MethodInfo mi = FetchMethodDispose (hm.enumerator_type);
4591 enumerator.EmitLoadAddress (ig);
4592 ig.Emit (OpCodes.Call, mi);
4594 enumerator.EmitLoad (ig);
4595 ig.Emit (OpCodes.Box, hm.enumerator_type);
4596 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4599 Label call_dispose = ig.DefineLabel ();
4601 enumerator.EmitThis (ig);
4602 enumerator.EmitLoad (ig);
4603 ig.Emit (OpCodes.Isinst, TypeManager.idisposable_type);
4604 ig.Emit (OpCodes.Dup);
4605 ig.Emit (OpCodes.Brtrue_S, call_dispose);
4606 ig.Emit (OpCodes.Pop);
4608 Label end_finally = ig.DefineLabel ();
4609 ig.Emit (OpCodes.Br, end_finally);
4611 ig.MarkLabel (call_dispose);
4612 ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
4613 ig.MarkLabel (end_finally);
4616 ig.Emit (OpCodes.Endfinally);
4620 protected override void DoEmit (EmitContext ec)
4622 ILGenerator ig = ec.ig;
4624 Label old_begin = ec.LoopBegin, old_end = ec.LoopEnd;
4625 ec.LoopBegin = ig.DefineLabel ();
4626 ec.LoopEnd = ig.DefineLabel ();
4629 EmitCollectionForeach (ec);
4633 ec.LoopBegin = old_begin;
4634 ec.LoopEnd = old_end;
4637 protected class TemporaryVariable : Expression
4642 public TemporaryVariable (Type type, Location loc)
4646 eclass = ExprClass.Value;
4651 public override Expression DoResolve (EmitContext ec)
4653 if (ec.InIterator) {
4655 fb = ec.CurrentIterator.MapVariable (
4656 "s_", count.ToString (), type);
4658 local = ec.ig.DeclareLocal (type);
4663 public override void Emit (EmitContext ec)
4665 ILGenerator ig = ec.ig;
4668 ig.Emit (OpCodes.Ldarg_0);
4669 ig.Emit (OpCodes.Ldfld, fb);
4671 ig.Emit (OpCodes.Ldloc, local);
4675 public void Store (EmitContext ec, Expression right_side)
4678 ec.ig.Emit (OpCodes.Ldarg_0);
4679 right_side.Emit (ec);
4681 ec.ig.Emit (OpCodes.Stloc, local);
4683 ec.ig.Emit (OpCodes.Stfld, fb);
4686 public void EmitThis (ILGenerator ig)
4689 ig.Emit (OpCodes.Ldarg_0);
4692 public void EmitStore (ILGenerator ig)
4695 ig.Emit (OpCodes.Stloc, local);
4697 ig.Emit (OpCodes.Stfld, fb);
4701 protected class ArrayCounter : TemporaryVariable
4703 public ArrayCounter (Location loc)
4704 : base (TypeManager.int32_type, loc)
4707 public void Initialize (EmitContext ec)
4710 ec.ig.Emit (OpCodes.Ldc_I4_0);
4714 public void Increment (EmitContext ec)
4718 ec.ig.Emit (OpCodes.Ldc_I4_1);
4719 ec.ig.Emit (OpCodes.Add);
4724 protected class ArrayForeach : Statement
4726 Expression type, variable, expr, conv;
4727 Statement statement;
4728 Type array_type, element_type;
4730 TemporaryVariable[] lengths;
4731 ArrayCounter[] counter;
4734 TemporaryVariable copy;
4737 public ArrayForeach (Expression type, Expression var,
4738 Expression expr, Statement stmt, Location l)
4741 this.variable = var;
4747 public override bool Resolve (EmitContext ec)
4749 TypeExpr texpr = type.ResolveAsTypeTerminal (ec);
4753 var_type = texpr.Type;
4755 array_type = expr.Type;
4756 element_type = TypeManager.GetElementType (array_type);
4757 rank = array_type.GetArrayRank ();
4759 copy = new TemporaryVariable (array_type, loc);
4762 counter = new ArrayCounter [rank];
4763 lengths = new TemporaryVariable [rank];
4765 ArrayList list = new ArrayList ();
4766 for (int i = 0; i < rank; i++) {
4767 counter [i] = new ArrayCounter (loc);
4768 counter [i].Resolve (ec);
4770 lengths [i] = new TemporaryVariable (TypeManager.int32_type, loc);
4771 lengths [i].Resolve (ec);
4773 list.Add (counter [i]);
4776 access = new ElementAccess (copy, list, loc).Resolve (ec);
4780 conv = Convert.ExplicitConversion (ec, access, var_type, loc);
4786 ec.StartFlowBranching (FlowBranching.BranchingType.Loop, loc);
4787 ec.CurrentBranching.CreateSibling ();
4789 variable = variable.ResolveLValue (ec, conv);
4790 if (variable == null)
4793 if (!statement.Resolve (ec))
4796 ec.EndFlowBranching ();
4801 protected override void DoEmit (EmitContext ec)
4803 ILGenerator ig = ec.ig;
4805 copy.Store (ec, expr);
4807 Label[] test = new Label [rank];
4808 Label[] loop = new Label [rank];
4810 for (int i = 0; i < rank; i++) {
4811 test [i] = ig.DefineLabel ();
4812 loop [i] = ig.DefineLabel ();
4814 lengths [i].EmitThis (ig);
4815 ((ArrayAccess) access).EmitGetLength (ec, i);
4816 lengths [i].EmitStore (ig);
4819 for (int i = 0; i < rank; i++) {
4820 counter [i].Initialize (ec);
4822 ig.Emit (OpCodes.Br, test [i]);
4823 ig.MarkLabel (loop [i]);
4826 ((IAssignMethod) variable).EmitAssign (ec, conv, false, false);
4828 statement.Emit (ec);
4830 ig.MarkLabel (ec.LoopBegin);
4832 for (int i = rank - 1; i >= 0; i--){
4833 counter [i].Increment (ec);
4835 ig.MarkLabel (test [i]);
4836 counter [i].Emit (ec);
4837 lengths [i].Emit (ec);
4838 ig.Emit (OpCodes.Blt, loop [i]);
4841 ig.MarkLabel (ec.LoopEnd);