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.Reflection;
  14 using System.Reflection.Emit;
  15 using System.Collections.Generic;
  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                         None = 0,
  27                         Ref = 1,                        // ref modifier used
  28                         Out = 2,                        // out modifier used
  29                         Default = 3,            // argument created from default parameter value
  30                         DynamicTypeName = 4     // System.Type argument for dynamic binding
  31                 }
  32
  33                 public readonly AType ArgType;
  34                 public Expression Expr;
  35
  36                 public Argument (Expression expr, AType type)
  37                 {
  38                         this.Expr = expr;
  39                         this.ArgType = type;
  40                 }
  41
  42                 public Argument (Expression expr)
  43                 {
  44                         if (expr == null)
  45                                 throw new ArgumentNullException ();
  46
  47                         this.Expr = expr;
  48                 }
  49
  50                 public Type Type {
  51                         get { return Expr.Type; }
  52                 }
  53
  54                 public Parameter.Modifier Modifier {
  55                         get {
  56                                 switch (ArgType) {
  57                                 case AType.Out:
  58                                         return Parameter.Modifier.OUT;
  59
  60                                 case AType.Ref:
  61                                         return Parameter.Modifier.REF;
  62
  63                                 default:
  64                                         return Parameter.Modifier.NONE;
  65                                 }
  66                         }
  67                 }
  68
  69                 public virtual Expression CreateExpressionTree (ResolveContext ec)
  70                 {
  71                         if (ArgType == AType.Default)
  72                                 ec.Report.Error (854, Expr.Location, "An expression tree cannot contain an invocation which uses optional parameter");
  73
  74                         return Expr.CreateExpressionTree (ec);
  75                 }
  76
  77                 public string GetSignatureForError ()
  78                 {
  79                         if (Expr.eclass == ExprClass.MethodGroup)
  80                                 return Expr.ExprClassName;
  81
  82                         return TypeManager.CSharpName (Expr.Type);
  83                 }
  84
  85                 public bool IsByRef {
  86                         get { return ArgType == AType.Ref || ArgType == AType.Out; }
  87                 }
  88
  89                 public bool IsDefaultArgument {
  90                         get { return ArgType == AType.Default; }
  91                 }
  92
  93                 public bool ResolveMethodGroup (ResolveContext ec)
  94                 {
  95                         SimpleName sn = Expr as SimpleName;
  96                         if (sn != null)
  97                                 Expr = sn.GetMethodGroup ();
  98
  99                         // FIXME: csc doesn't report any error if you try to use `ref' or
 100                         //        `out' in a delegate creation expression.
 101                         Expr = Expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
 102                         if (Expr == null)
 103                                 return false;
 104
 105                         return true;
 106                 }
 107
 108                 public void Resolve (ResolveContext ec)
 109                 {
 110                         if (Expr == EmptyExpression.Null)
 111                                 return;
 112
 113                         using (ec.With (ResolveContext.Options.DoFlowAnalysis, true)) {
 114                                 // Verify that the argument is readable
 115                                 if (ArgType != AType.Out)
 116                                         Expr = Expr.Resolve (ec);
 117
 118                                 // Verify that the argument is writeable
 119                                 if (Expr != null && IsByRef)
 120                                         Expr = Expr.ResolveLValue (ec, EmptyExpression.OutAccess.Instance);
 121
 122                                 if (Expr == null)
 123                                         Expr = EmptyExpression.Null;
 124                         }
 125                 }
 126
 127                 public virtual void Emit (EmitContext ec)
 128                 {
 129                         if (!IsByRef) {
 130                                 Expr.Emit (ec);
 131                                 return;
 132                         }
 133
 134                         AddressOp mode = AddressOp.Store;
 135                         if (ArgType == AType.Ref)
 136                                 mode |= AddressOp.Load;
 137
 138                         IMemoryLocation ml = (IMemoryLocation) Expr;
 139                         ml.AddressOf (ec, mode);
 140                 }
 141
 142                 public Argument Clone (CloneContext clonectx)
 143                 {
 144                         Argument a = (Argument) MemberwiseClone ();
 145                         a.Expr = Expr.Clone (clonectx);
 146                         return a;
 147                 }
 148         }
 149
 150         public class NamedArgument : Argument
 151         {
 152                 public readonly string Name;
 153                 readonly Location loc;
 154                 LocalTemporary variable;
 155
 156                 public NamedArgument (string name, Location loc, Expression expr)
 157                         : this (name, loc, expr, AType.None)
 158                 {
 159                 }
 160
 161                 public NamedArgument (string name, Location loc, Expression expr, AType modifier)
 162                         : base (expr, modifier)
 163                 {
 164                         this.Name = name;
 165                         this.loc = loc;
 166                 }
 167
 168                 public override Expression CreateExpressionTree (ResolveContext ec)
 169                 {
 170                         ec.Report.Error (853, loc, "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                         var type = Expr.Type;
 187                         if (IsByRef) {
 188                                 var ml = (IMemoryLocation) Expr;
 189                                 ml.AddressOf (ec, AddressOp.Load);
 190                                 type = TypeManager.GetReferenceType (type);
 191                         } else {
 192                                 Expr.Emit (ec);
 193                         }
 194
 195                         variable = new LocalTemporary (type);
 196                         variable.Store (ec);
 197
 198                         Expr = variable;
 199                 }
 200
 201                 public Location Location {
 202                         get { return loc; }
 203                 }
 204         }
 205
 206         public class Arguments
 207         {
 208                 List<Argument> args;
 209                 List<NamedArgument> reordered;
 210
 211                 public Arguments (int capacity)
 212                 {
 213                         args = new List<Argument> (capacity);
 214                 }
 215
 216                 public void Add (Argument arg)
 217                 {
 218                         args.Add (arg);
 219                 }
 220
 221                 public void AddRange (Arguments args)
 222                 {
 223                         this.args.AddRange (args.args);
 224                 }
 225
 226                 public ArrayInitializer CreateDynamicBinderArguments (ResolveContext rc)
 227                 {
 228                         Location loc = Location.Null;
 229                         var all = new ArrayInitializer (args.Count, loc);
 230
 231                         MemberAccess binder = DynamicExpressionStatement.GetBinderNamespace (loc);
 232
 233                         foreach (Argument a in args) {
 234                                 Arguments dargs = new Arguments (2);
 235
 236                                 // CSharpArgumentInfoFlags.None = 0
 237                                 const string info_flags_enum = "CSharpArgumentInfoFlags";
 238                                 Expression info_flags = new IntLiteral (0, loc);
 239
 240                                 var constant = a.Expr as Constant;
 241                                 if (constant != null && constant.IsLiteral) {
 242                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 243                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "Constant", loc), loc);
 244                                 } else if (a.ArgType == Argument.AType.Ref) {
 245                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 246                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "IsRef", loc), loc);
 247                                 } else if (a.ArgType == Argument.AType.Out) {
 248                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 249                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "IsOut", loc), loc);
 250                                 } else if (a.ArgType == Argument.AType.DynamicTypeName) {
 251                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 252                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "IsStaticType", loc), loc);
 253                                 }
 254
 255                                 var arg_type = a.Expr.Type;
 256
 257                                 if (!TypeManager.IsDynamicType (arg_type)) {
 258                                         MethodGroupExpr mg = a.Expr as MethodGroupExpr;
 259                                         if (mg != null) {
 260                                                 rc.Report.Error (1976, a.Expr.Location,
 261                                                         "The method group `{0}' cannot be used as an argument of dynamic operation. Consider using parentheses to invoke the method",
 262                                                         mg.Name);
 263                                         } else if (arg_type == InternalType.AnonymousMethod) {
 264                                                 rc.Report.Error (1977, a.Expr.Location,
 265                                                         "An anonymous method or lambda expression cannot be used as an argument of dynamic operation. Consider using a cast");
 266                                         } else if (arg_type == TypeManager.void_type || arg_type == InternalType.Arglist || arg_type.IsPointer) {
 267                                                 rc.Report.Error (1978, a.Expr.Location,
 268                                                         "An expression of type `{0}' cannot be used as an argument of dynamic operation",
 269                                                         TypeManager.CSharpName (arg_type));
 270                                         }
 271
 272                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 273                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "UseCompileTimeType", loc), loc);
 274                                 }
 275
 276                                 string named_value;
 277                                 NamedArgument na = a as NamedArgument;
 278                                 if (na != null) {
 279                                         info_flags = new Binary (Binary.Operator.BitwiseOr, info_flags,
 280                                                 new MemberAccess (new MemberAccess (binder, info_flags_enum, loc), "NamedArgument", loc), loc);
 281
 282                                         named_value = na.Name;
 283                                 } else {
 284                                         named_value = null;
 285                                 }
 286
 287                                 dargs.Add (new Argument (info_flags));
 288                                 dargs.Add (new Argument (new StringLiteral (named_value, loc)));
 289                                 all.Add (new Invocation (new MemberAccess (new MemberAccess (binder, "CSharpArgumentInfo", loc), "Create", loc), dargs));
 290                         }
 291
 292                         return all;
 293                 }
 294
 295                 public static Arguments CreateForExpressionTree (ResolveContext ec, Arguments args, params Expression[] e)
 296                 {
 297                         Arguments all = new Arguments ((args == null ? 0 : args.Count) + e.Length);
 298                         for (int i = 0; i < e.Length; ++i) {
 299                                 if (e [i] != null)
 300                                         all.Add (new Argument (e[i]));
 301                         }
 302
 303                         if (args != null) {
 304                                 foreach (Argument a in args.args) {
 305                                         Expression tree_arg = a.CreateExpressionTree (ec);
 306                                         if (tree_arg != null)
 307                                                 all.Add (new Argument (tree_arg));
 308                                 }
 309                         }
 310
 311                         return all;
 312                 }
 313
 314                 public void CheckArrayAsAttribute (CompilerContext ctx)
 315                 {
 316                         foreach (Argument arg in args) {
 317                                 // Type is undefined (was error 246)
 318                                 if (arg.Type == null)
 319                                         continue;
 320
 321                                 if (arg.Type.IsArray)
 322                                         ctx.Report.Warning (3016, 1, arg.Expr.Location, "Arrays as attribute arguments are not CLS-compliant");
 323                         }
 324                 }
 325
 326                 public Arguments Clone (CloneContext ctx)
 327                 {
 328                         Arguments cloned = new Arguments (args.Count);
 329                         foreach (Argument a in args)
 330                                 cloned.Add (a.Clone (ctx));
 331
 332                         return cloned;
 333                 }
 334
 335                 public int Count {
 336                         get { return args.Count; }
 337                 }
 338
 339                 //
 340                 // Emits a list of resolved Arguments
 341                 //
 342                 public void Emit (EmitContext ec)
 343                 {
 344                         Emit (ec, false, null);
 345                 }
 346
 347                 //
 348                 // if `dup_args' is true, a copy of the arguments will be left
 349                 // on the stack. If `dup_args' is true, you can specify `this_arg'
 350                 // which will be duplicated before any other args. Only EmitCall
 351                 // should be using this interface.
 352                 //
 353                 public void Emit (EmitContext ec, bool dup_args, LocalTemporary this_arg)
 354                 {
 355                         LocalTemporary[] temps = null;
 356
 357                         if (dup_args && Count != 0)
 358                                 temps = new LocalTemporary [Count];
 359
 360                         if (reordered != null && Count > 1) {
 361                                 foreach (NamedArgument na in reordered)
 362                                         na.EmitAssign (ec);
 363                         }
 364
 365                         int i = 0;
 366                         foreach (Argument a in args) {
 367                                 a.Emit (ec);
 368                                 if (dup_args) {
 369                                         ec.ig.Emit (OpCodes.Dup);
 370                                         (temps [i++] = new LocalTemporary (a.Type)).Store (ec);
 371                                 }
 372                         }
 373
 374                         if (dup_args) {
 375                                 if (this_arg != null)
 376                                         this_arg.Emit (ec);
 377
 378                                 for (i = 0; i < temps.Length; i++) {
 379                                         temps[i].Emit (ec);
 380                                         temps[i].Release (ec);
 381                                 }
 382                         }
 383                 }
 384
 385                 public bool GetAttributableValue (ResolveContext ec, out object[] values)
 386                 {
 387                         values = new object [args.Count];
 388                         for (int j = 0; j < values.Length; ++j) {
 389                                 Argument a = this [j];
 390                                 if (!a.Expr.GetAttributableValue (ec, a.Type, out values[j]))
 391                                         return false;
 392                         }
 393
 394                         return true;
 395                 }
 396
 397                 public IEnumerator<Argument> GetEnumerator ()
 398                 {
 399                         return args.GetEnumerator ();
 400                 }
 401
 402                 //
 403                 // At least one argument is of dynamic type
 404                 //
 405                 public bool HasDynamic {
 406                         get {
 407                                 foreach (Argument a in args) {
 408                                         if (TypeManager.IsDynamicType (a.Type))
 409                                                 return true;
 410                                 }
 411
 412                                 return false;
 413                         }
 414                 }
 415
 416                 public void Insert (int index, Argument arg)
 417                 {
 418                         args.Insert (index, arg);
 419                 }
 420
 421                 public static System.Linq.Expressions.Expression[] MakeExpression (Arguments args, BuilderContext ctx)
 422                 {
 423                         if (args == null || args.Count == 0)
 424                                 return null;
 425
 426                         var exprs = new System.Linq.Expressions.Expression [args.Count];
 427                         for (int i = 0; i < exprs.Length; ++i) {
 428                                 Argument a = (Argument) args.args [i];
 429                                 exprs[i] = a.Expr.MakeExpression (ctx);
 430                         }
 431
 432                         return exprs;
 433                 }
 434
 435                 public void MarkReorderedArgument (NamedArgument a)
 436                 {
 437                         //
 438                         // Constant expression can have no effect on left-to-right execution
 439                         //
 440                         if (a.Expr is Constant)
 441                                 return;
 442
 443                         if (reordered == null)
 444                                 reordered = new List<NamedArgument> ();
 445
 446                         reordered.Add (a);
 447                 }
 448
 449                 //
 450                 // Returns dynamic when at least one argument is of dynamic type
 451                 //
 452                 public void Resolve (ResolveContext ec, out bool dynamic)
 453                 {
 454                         dynamic = false;
 455                         foreach (Argument a in args) {
 456                                 a.Resolve (ec);
 457                                 dynamic |= TypeManager.IsDynamicType (a.Type);
 458                         }
 459                 }
 460
 461                 public void MutateHoistedGenericType (AnonymousMethodStorey storey)
 462                 {
 463                         foreach (Argument a in args)
 464                                 a.Expr.MutateHoistedGenericType (storey);
 465                 }
 466
 467                 public void RemoveAt (int index)
 468                 {
 469                         args.RemoveAt (index);
 470                 }
 471
 472                 public Argument this [int index] {
 473                         get { return (Argument) args [index]; }
 474                         set { args [index] = value; }
 475                 }
 476         }
 477 }