mcs/argument.cs

   1 //
   2 // argument.cs: Argument expressions
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximain.com)
   6 //   Marek Safar (marek.safar@gmail.com)
   7 //
   8 // Dual licensed under the terms of the MIT X11 or GNU GPL
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11
  12 using System;
  13 using System.Collections;
  14 using System.Reflection;
  15 using System.Reflection.Emit;
  16
  17 namespace Mono.CSharp
  18 {
  19         //
  20         // Argument expression used for invocation
  21         //
  22         public class Argument
  23         {
  24                 public enum AType : byte
  25                 {
  26                         Ref = 1,                // ref modifier used
  27                         Out = 2,                // out modifier used
  28                         Default = 3             // argument created from default parameter value
  29                 }
  30
  31                 public readonly AType ArgType;
  32                 public Expression Expr;
  33
  34                 public Argument (Expression expr, AType type)
  35                 {
  36                         this.Expr = expr;
  37                         this.ArgType = type;
  38                 }
  39
  40                 public Argument (Expression expr)
  41                 {
  42                         if (expr == null)
  43                                 throw new ArgumentNullException ();
  44
  45                         this.Expr = expr;
  46                 }
  47
  48                 public Type Type {
  49                         get { return Expr.Type; }
  50                 }
  51
  52                 public Parameter.Modifier Modifier {
  53                         get {
  54                                 switch (ArgType) {
  55                                 case AType.Out:
  56                                         return Parameter.Modifier.OUT;
  57
  58                                 case AType.Ref:
  59                                         return Parameter.Modifier.REF;
  60
  61                                 default:
  62                                         return Parameter.Modifier.NONE;
  63                                 }
  64                         }
  65                 }
  66
  67                 public virtual Expression CreateExpressionTree (EmitContext ec)
  68                 {
  69                         if (ArgType == AType.Default)
  70                                 Report.Error (854, Expr.Location, "An expression tree cannot contain an invocation which uses optional parameter");
  71
  72                         return Expr.CreateExpressionTree (ec);
  73                 }
  74
  75                 public string GetSignatureForError ()
  76                 {
  77                         if (Expr.eclass == ExprClass.MethodGroup)
  78                                 return Expr.ExprClassName;
  79
  80                         return TypeManager.CSharpName (Expr.Type);
  81                 }
  82
  83                 public bool IsByRef {
  84                         get { return ArgType == AType.Ref || ArgType == AType.Out; }
  85                 }
  86
  87                 public bool IsDefaultArgument {
  88                         get { return ArgType == AType.Default; }
  89                 }
  90
  91                 public bool ResolveMethodGroup (EmitContext ec)
  92                 {
  93                         SimpleName sn = Expr as SimpleName;
  94                         if (sn != null)
  95                                 Expr = sn.GetMethodGroup ();
  96
  97                         // FIXME: csc doesn't report any error if you try to use `ref' or
  98                         //        `out' in a delegate creation expression.
  99                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 100                         if (Expr == null)
 101                                 return false;
 102
 103                         return true;
 104                 }
 105
 106                 public void Resolve (EmitContext ec)
 107                 {
 108                         if (Expr == EmptyExpression.Null)
 109                                 return;
 110
 111                         using (ec.With (EmitContext.Flags.DoFlowAnalysis, true)) {
 112                                 // Verify that the argument is readable
 113                                 if (ArgType != AType.Out)
 114                                         Expr = Expr.Resolve (ec);
 115
 116                                 // Verify that the argument is writeable
 117                                 if (Expr != null && IsByRef)
 118                                         Expr = Expr.ResolveLValue (ec, EmptyExpression.OutAccess);
 119
 120                                 if (Expr == null)
 121                                         Expr = EmptyExpression.Null;
 122                         }
 123                 }
 124
 125                 public virtual void Emit (EmitContext ec)
 126                 {
 127                         if (!IsByRef) {
 128                                 Expr.Emit (ec);
 129                                 return;
 130                         }
 131
 132                         AddressOp mode = AddressOp.Store;
 133                         if (ArgType == AType.Ref)
 134                                 mode |= AddressOp.Load;
 135
 136                         IMemoryLocation ml = (IMemoryLocation) Expr;
 137                         ParameterReference pr = ml as ParameterReference;
 138
 139                         //
 140                         // ParameterReferences might already be references, so we want
 141                         // to pass just the value
 142                         //
 143                         if (pr != null && pr.IsRef)
 144                                 pr.EmitLoad (ec);
 145                         else
 146                                 ml.AddressOf (ec, mode);
 147                 }
 148
 149                 public Argument Clone (CloneContext clonectx)
 150                 {
 151                         Argument a = (Argument) MemberwiseClone ();
 152                         a.Expr = Expr.Clone (clonectx);
 153                         return a;
 154                 }
 155         }
 156
 157         public class NamedArgument : Argument
 158         {
 159                 public readonly LocatedToken Name;
 160                 LocalTemporary variable;
 161
 162                 public NamedArgument (LocatedToken name, Expression expr)
 163                         : base (expr)
 164                 {
 165                         Name = name;
 166                 }
 167
 168                 public override Expression CreateExpressionTree (EmitContext ec)
 169                 {
 170                         Report.Error (853, Name.Location, "An expression tree cannot contain named argument");
 171                         return base.CreateExpressionTree (ec);
 172                 }
 173
 174                 public override void Emit (EmitContext ec)
 175                 {
 176                         // TODO: Should guard against multiple emits
 177                         base.Emit (ec);
 178
 179                         // Release temporary variable when used
 180                         if (variable != null)
 181                                 variable.Release (ec);
 182                 }
 183
 184                 public void EmitAssign (EmitContext ec)
 185                 {
 186                         Expr.Emit (ec);
 187                         variable = new LocalTemporary (Expr.Type);
 188                         variable.Store (ec);
 189
 190                         Expr = variable;
 191                 }
 192         }
 193
 194         public class Arguments
 195         {
 196                 ArrayList args;                 // TODO: This should really be linked list
 197                 ArrayList reordered;    // TODO: LinkedList
 198
 199                 public Arguments (int capacity)
 200                 {
 201                         args = new ArrayList (capacity);
 202                 }
 203
 204                 public int Add (Argument arg)
 205                 {
 206                         return args.Add (arg);
 207                 }
 208
 209                 public void AddRange (Arguments args)
 210                 {
 211                         this.args.AddRange (args.args);
 212                 }
 213
 214                 public ArrayList CreateDynamicBinderArguments ()
 215                 {
 216                         ArrayList all = new ArrayList (args.Count);
 217                         Location loc = Location.Null;
 218
 219                         MemberAccess binder = DynamicExpressionStatement.GetBinderNamespace (loc);
 220
 221                         foreach (Argument a in args) {
 222                                 Arguments dargs = new Arguments (2);
 223
 224                                 // TODO: Inspect a.Type or a.Expression
 225
 226                                 // CSharpArgumentInfoFlags.None = 0
 227                                 dargs.Add (new Argument (new IntLiteral (0, loc)));
 228
 229                                 // TODO: named
 230                                 dargs.Add (new Argument (new NullLiteral (loc)));
 231                                 all.Add (new New (new MemberAccess (binder, "CSharpArgumentInfo", loc), dargs, loc));
 232                         }
 233
 234                         return all;
 235                 }
 236
 237                 public static Arguments CreateForExpressionTree (EmitContext ec, Arguments args, params Expression[] e)
 238                 {
 239                         Arguments all = new Arguments ((args == null ? 0 : args.Count) + e.Length);
 240                         for (int i = 0; i < e.Length; ++i) {
 241                                 if (e [i] != null)
 242                                         all.Add (new Argument (e[i]));
 243                         }
 244
 245                         if (args != null) {
 246                                 foreach (Argument a in args.args) {
 247                                         Expression tree_arg = a.CreateExpressionTree (ec);
 248                                         if (tree_arg != null)
 249                                                 all.Add (new Argument (tree_arg));
 250                                 }
 251                         }
 252
 253                         return all;
 254                 }
 255
 256                 public void CheckArrayAsAttribute ()
 257                 {
 258                         foreach (Argument arg in args) {
 259                                 // Type is undefined (was error 246)
 260                                 if (arg.Type == null)
 261                                         continue;
 262
 263                                 if (arg.Type.IsArray)
 264                                         Report.Warning (3016, 1, arg.Expr.Location, "Arrays as attribute arguments are not CLS-compliant");
 265                         }
 266                 }
 267
 268                 public Arguments Clone (CloneContext ctx)
 269                 {
 270                         Arguments cloned = new Arguments (args.Count);
 271                         foreach (Argument a in args)
 272                                 cloned.Add (a.Clone (ctx));
 273
 274                         return cloned;
 275                 }
 276
 277                 public int Count {
 278                         get { return args.Count; }
 279                 }
 280
 281                 //
 282                 // Emits a list of resolved Arguments
 283                 //
 284                 public void Emit (EmitContext ec)
 285                 {
 286                         Emit (ec, false, null);
 287                 }
 288
 289                 //
 290                 // if `dup_args' is true, a copy of the arguments will be left
 291                 // on the stack. If `dup_args' is true, you can specify `this_arg'
 292                 // which will be duplicated before any other args. Only EmitCall
 293                 // should be using this interface.
 294                 //
 295                 public void Emit (EmitContext ec, bool dup_args, LocalTemporary this_arg)
 296                 {
 297                         LocalTemporary[] temps = null;
 298
 299                         if (dup_args && Count != 0)
 300                                 temps = new LocalTemporary [Count];
 301
 302                         if (reordered != null && Count > 1) {
 303                                 foreach (NamedArgument na in reordered)
 304                                         na.EmitAssign (ec);
 305                         }
 306
 307                         int i = 0;
 308                         foreach (Argument a in args) {
 309                                 a.Emit (ec);
 310                                 if (dup_args) {
 311                                         ec.ig.Emit (OpCodes.Dup);
 312                                         (temps [i++] = new LocalTemporary (a.Type)).Store (ec);
 313                                 }
 314                         }
 315
 316                         if (dup_args) {
 317                                 if (this_arg != null)
 318                                         this_arg.Emit (ec);
 319
 320                                 for (i = 0; i < temps.Length; i++) {
 321                                         temps[i].Emit (ec);
 322                                         temps[i].Release (ec);
 323                                 }
 324                         }
 325                 }
 326
 327                 public bool GetAttributableValue (EmitContext ec, out object[] values)
 328                 {
 329                         values = new object [args.Count];
 330                         for (int j = 0; j < values.Length; ++j) {
 331                                 Argument a = this [j];
 332                                 if (!a.Expr.GetAttributableValue (ec, a.Type, out values[j]))
 333                                         return false;
 334                         }
 335
 336                         return true;
 337                 }
 338
 339                 public IEnumerator GetEnumerator ()
 340                 {
 341                         return args.GetEnumerator ();
 342                 }
 343
 344                 public void Insert (int index, Argument arg)
 345                 {
 346                         args.Insert (index, arg);
 347                 }
 348
 349                 public void MarkReorderedArgument (NamedArgument a)
 350                 {
 351                         //
 352                         // Constant expression can have no effect on left-to-right execution
 353                         //
 354                         if (a.Expr is Constant)
 355                                 return;
 356
 357                         if (reordered == null)
 358                                 reordered = new ArrayList ();
 359
 360                         reordered.Add (a);
 361                 }
 362
 363                 //
 364                 // Returns dynamic when at least one argument is of dynamic type
 365                 //
 366                 public void Resolve (EmitContext ec, out bool dynamic)
 367                 {
 368                         dynamic = false;
 369                         foreach (Argument a in args) {
 370                                 a.Resolve (ec);
 371                                 dynamic |= TypeManager.IsDynamicType (a.Type);
 372                         }
 373                 }
 374
 375                 public void MutateHoistedGenericType (AnonymousMethodStorey storey)
 376                 {
 377                         foreach (Argument a in args)
 378                                 a.Expr.MutateHoistedGenericType (storey);
 379                 }
 380
 381                 public void RemoveAt (int index)
 382                 {
 383                         args.RemoveAt (index);
 384                 }
 385
 386                 public Argument this [int index] {
 387                         get { return (Argument) args [index]; }
 388                         set { args [index] = value; }
 389                 }
 390         }
 391 }