class/System.Core/System.Linq.Expressions/UnaryExpression.cs

   1 //
   2 // UnaryExpression.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //
   7 // (C) 2008 Novell, Inc. (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Reflection;
  31 using System.Reflection.Emit;
  32
  33 namespace System.Linq.Expressions {
  34
  35         public sealed class UnaryExpression : Expression {
  36
  37                 Expression operand;
  38                 MethodInfo method;
  39                 bool is_lifted;
  40
  41                 public Expression Operand {
  42                         get { return operand; }
  43                 }
  44
  45                 public MethodInfo Method {
  46                         get { return method; }
  47                 }
  48
  49                 public bool IsLifted {
  50                         get { return is_lifted; }
  51                 }
  52
  53                 public bool IsLiftedToNull {
  54                         get { return is_lifted && this.Type.IsNullable (); }
  55                 }
  56
  57                 internal UnaryExpression (ExpressionType node_type, Expression operand, Type type)
  58                         : base (node_type, type)
  59                 {
  60                         this.operand = operand;
  61                 }
  62
  63                 internal UnaryExpression (ExpressionType node_type, Expression operand, Type type, MethodInfo method, bool is_lifted)
  64                         : base (node_type, type)
  65                 {
  66                         this.operand = operand;
  67                         this.method = method;
  68                         this.is_lifted = is_lifted;
  69                 }
  70
  71                 void EmitArrayLength (EmitContext ec)
  72                 {
  73                         operand.Emit (ec);
  74                         ec.ig.Emit (OpCodes.Ldlen);
  75                 }
  76
  77                 void EmitTypeAs (EmitContext ec)
  78                 {
  79                         var type = this.Type;
  80
  81                         ec.EmitIsInst (operand, type);
  82
  83                         if (type.IsNullable ())
  84                                 ec.ig.Emit (OpCodes.Unbox_Any, type);
  85                 }
  86
  87                 void EmitLiftedUnary (EmitContext ec)
  88                 {
  89                         var ig = ec.ig;
  90
  91                         var from = ec.EmitStored (operand);
  92                         var to = ig.DeclareLocal (Type);
  93
  94                         var has_value = ig.DefineLabel ();
  95                         var done = ig.DefineLabel ();
  96
  97                         ec.EmitNullableHasValue (from);
  98                         ig.Emit (OpCodes.Brtrue, has_value);
  99
 100                         // if not has value
 101                         ec.EmitNullableInitialize (to);
 102
 103                         ig.Emit (OpCodes.Br, done);
 104
 105                         ig.MarkLabel (has_value);
 106                         // if has value
 107                         ec.EmitNullableGetValueOrDefault (from);
 108
 109                         EmitUnaryOperator (ec);
 110
 111                         ec.EmitNullableNew (Type);
 112
 113                         ig.MarkLabel (done);
 114                 }
 115
 116                 void EmitUnaryOperator (EmitContext ec)
 117                 {
 118                         var ig = ec.ig;
 119
 120                         switch (NodeType) {
 121                         case ExpressionType.Not:
 122                                 if (operand.Type.GetNotNullableType () == typeof (bool)) {
 123                                         ig.Emit (OpCodes.Ldc_I4_0);
 124                                         ig.Emit (OpCodes.Ceq);
 125                                 } else
 126                                         ig.Emit (OpCodes.Not);
 127                                 break;
 128                         case ExpressionType.Negate:
 129                                 ig.Emit (OpCodes.Neg);
 130                                 break;
 131                         case ExpressionType.NegateChecked:
 132                                 ig.Emit (OpCodes.Ldc_I4_M1);
 133                                 ig.Emit (IsUnsigned (operand.Type) ? OpCodes.Mul_Ovf_Un : OpCodes.Mul_Ovf);
 134                                 break;
 135                         case ExpressionType.Convert:
 136                         case ExpressionType.ConvertChecked:
 137                                 // Called when converting from nullable from nullable
 138                                 EmitPrimitiveConversion (ec,
 139                                         operand.Type.GetNotNullableType (),
 140                                         Type.GetNotNullableType ());
 141                                 break;
 142                         }
 143                 }
 144
 145                 void EmitConvert (EmitContext ec)
 146                 {
 147                         var from = operand.Type;
 148                         var target = Type;
 149
 150                         if (from == target)
 151                                 operand.Emit (ec);
 152                         else if (from.IsNullable () && !target.IsNullable ())
 153                                 EmitConvertFromNullable (ec);
 154                         else if (!from.IsNullable () && target.IsNullable ())
 155                                 EmitConvertToNullable (ec);
 156                         else if (from.IsNullable () && target.IsNullable ())
 157                                 EmitConvertFromNullableToNullable (ec);
 158                         else if (IsReferenceConversion (from, target))
 159                                 EmitCast (ec);
 160                         else if (IsPrimitiveConversion (from, target))
 161                                 EmitPrimitiveConversion (ec);
 162                         else
 163                                 throw new NotImplementedException ();
 164                 }
 165
 166                 void EmitConvertFromNullableToNullable (EmitContext ec)
 167                 {
 168                         EmitLiftedUnary (ec);
 169                 }
 170
 171                 void EmitConvertToNullable (EmitContext ec)
 172                 {
 173                         ec.Emit (operand);
 174
 175                         if (IsUnBoxing ()) {
 176                                 EmitUnbox (ec);
 177                                 return;
 178                         }
 179
 180                         if (operand.Type != Type.GetNotNullableType ()) {
 181                                 EmitPrimitiveConversion (ec,
 182                                         operand.Type,
 183                                         Type.GetNotNullableType ());
 184                         }
 185
 186                         ec.EmitNullableNew (Type);
 187                 }
 188
 189                 void EmitConvertFromNullable (EmitContext ec)
 190                 {
 191                         if (IsBoxing ()) {
 192                                 ec.Emit (operand);
 193                                 EmitBox (ec);
 194                                 return;
 195                         }
 196
 197                         ec.EmitCall (operand, operand.Type.GetMethod ("get_Value"));
 198
 199                         if (operand.Type.GetNotNullableType () != Type) {
 200                                 EmitPrimitiveConversion (ec,
 201                                         operand.Type.GetNotNullableType (),
 202                                         Type);
 203                         }
 204                 }
 205
 206                 bool IsBoxing ()
 207                 {
 208                         return operand.Type.IsValueType && !Type.IsValueType;
 209                 }
 210
 211                 void EmitBox (EmitContext ec)
 212                 {
 213                         ec.ig.Emit (OpCodes.Box, operand.Type);
 214                 }
 215
 216                 bool IsUnBoxing ()
 217                 {
 218                         return !operand.Type.IsValueType && Type.IsValueType;
 219                 }
 220
 221                 void EmitUnbox (EmitContext ec)
 222                 {
 223                         ec.ig.Emit (OpCodes.Unbox_Any, Type);
 224                 }
 225
 226                 void EmitCast (EmitContext ec)
 227                 {
 228                         operand.Emit (ec);
 229
 230                         if (IsBoxing ()) {
 231                                 EmitBox (ec);
 232                         } else if (IsUnBoxing ()) {
 233                                 EmitUnbox (ec);
 234                         } else
 235                                 ec.ig.Emit (OpCodes.Castclass, Type);
 236                 }
 237
 238                 void EmitPrimitiveConversion (EmitContext ec, bool is_unsigned,
 239                         OpCode signed, OpCode unsigned, OpCode signed_checked, OpCode unsigned_checked)
 240                 {
 241                         if (this.NodeType != ExpressionType.ConvertChecked)
 242                                 ec.ig.Emit (is_unsigned ? unsigned : signed);
 243                         else
 244                                 ec.ig.Emit (is_unsigned ? unsigned_checked : signed_checked);
 245                 }
 246
 247                 void EmitPrimitiveConversion (EmitContext ec)
 248                 {
 249                         operand.Emit (ec);
 250
 251                         EmitPrimitiveConversion (ec, operand.Type, Type);
 252                 }
 253
 254                 void EmitPrimitiveConversion (EmitContext ec, Type from, Type to)
 255                 {
 256                         var is_unsigned = IsUnsigned (from);
 257
 258                         switch (Type.GetTypeCode (to)) {
 259                         case TypeCode.SByte:
 260                                 EmitPrimitiveConversion (ec,
 261                                         is_unsigned,
 262                                         OpCodes.Conv_I1,
 263                                         OpCodes.Conv_U1,
 264                                         OpCodes.Conv_Ovf_I1,
 265                                         OpCodes.Conv_Ovf_I1_Un);
 266                                 return;
 267                         case TypeCode.Byte:
 268                                 EmitPrimitiveConversion (ec,
 269                                         is_unsigned,
 270                                         OpCodes.Conv_I1,
 271                                         OpCodes.Conv_U1,
 272                                         OpCodes.Conv_Ovf_U1,
 273                                         OpCodes.Conv_Ovf_U1_Un);
 274                                 return;
 275                         case TypeCode.Int16:
 276                                 EmitPrimitiveConversion (ec,
 277                                         is_unsigned,
 278                                         OpCodes.Conv_I2,
 279                                         OpCodes.Conv_U2,
 280                                         OpCodes.Conv_Ovf_I2,
 281                                         OpCodes.Conv_Ovf_I2_Un);
 282                                 return;
 283                         case TypeCode.UInt16:
 284                                 EmitPrimitiveConversion (ec,
 285                                         is_unsigned,
 286                                         OpCodes.Conv_I2,
 287                                         OpCodes.Conv_U2,
 288                                         OpCodes.Conv_Ovf_U2,
 289                                         OpCodes.Conv_Ovf_U2_Un);
 290                                 return;
 291                         case TypeCode.Int32:
 292                                 EmitPrimitiveConversion (ec,
 293                                         is_unsigned,
 294                                         OpCodes.Conv_I4,
 295                                         OpCodes.Conv_U4,
 296                                         OpCodes.Conv_Ovf_I4,
 297                                         OpCodes.Conv_Ovf_I4_Un);
 298                                 return;
 299                         case TypeCode.UInt32:
 300                                 EmitPrimitiveConversion (ec,
 301                                         is_unsigned,
 302                                         OpCodes.Conv_I4,
 303                                         OpCodes.Conv_U4,
 304                                         OpCodes.Conv_Ovf_U4,
 305                                         OpCodes.Conv_Ovf_U4_Un);
 306                                 return;
 307                         case TypeCode.Int64:
 308                                 EmitPrimitiveConversion (ec,
 309                                         is_unsigned,
 310                                         OpCodes.Conv_I8,
 311                                         OpCodes.Conv_U8,
 312                                         OpCodes.Conv_Ovf_I8,
 313                                         OpCodes.Conv_Ovf_I8_Un);
 314                                 return;
 315                         case TypeCode.UInt64:
 316                                 EmitPrimitiveConversion (ec,
 317                                         is_unsigned,
 318                                         OpCodes.Conv_I8,
 319                                         OpCodes.Conv_U8,
 320                                         OpCodes.Conv_Ovf_U8,
 321                                         OpCodes.Conv_Ovf_U8_Un);
 322                                 return;
 323                         case TypeCode.Single:
 324                                 if (is_unsigned)
 325                                         ec.ig.Emit (OpCodes.Conv_R_Un);
 326                                 ec.ig.Emit (OpCodes.Conv_R4);
 327                                 return;
 328                         case TypeCode.Double:
 329                                 if (is_unsigned)
 330                                         ec.ig.Emit (OpCodes.Conv_R_Un);
 331                                 ec.ig.Emit (OpCodes.Conv_R8);
 332                                 return;
 333                         default:
 334                                 throw new NotImplementedException (this.Type.ToString ());
 335                         }
 336                 }
 337
 338                 void EmitArithmeticUnary (EmitContext ec)
 339                 {
 340                         if (!IsLifted) {
 341                                 operand.Emit (ec);
 342                                 EmitUnaryOperator (ec);
 343                         } else
 344                                 EmitLiftedUnary (ec);
 345                 }
 346
 347                 void EmitUserDefinedLiftedToNullOperator (EmitContext ec)
 348                 {
 349                         var ig = ec.ig;
 350                         var local = ec.EmitStored (operand);
 351
 352                         var ret = ig.DefineLabel ();
 353                         var done = ig.DefineLabel ();
 354
 355                         ec.EmitNullableHasValue (local);
 356                         ig.Emit (OpCodes.Brfalse, ret);
 357
 358                         ec.EmitNullableGetValueOrDefault (local);
 359                         ec.EmitCall (method);
 360                         ec.EmitNullableNew (Type);
 361                         ig.Emit (OpCodes.Br, done);
 362
 363                         ig.MarkLabel (ret);
 364
 365                         var temp = ig.DeclareLocal (Type);
 366                         ec.EmitNullableInitialize (temp);
 367
 368                         ig.MarkLabel (done);
 369                 }
 370
 371                 void EmitUserDefinedLiftedOperator (EmitContext ec)
 372                 {
 373                         var local = ec.EmitStored (operand);
 374                         ec.EmitNullableGetValue (local);
 375                         ec.EmitCall (method);
 376                 }
 377
 378                 void EmitUserDefinedOperator (EmitContext ec)
 379                 {
 380                         if (!IsLifted) {
 381                                 ec.Emit (operand);
 382                                 ec.EmitCall (method);
 383                         } else if (IsLiftedToNull) {
 384                                 EmitUserDefinedLiftedToNullOperator (ec);
 385                         } else
 386                                 EmitUserDefinedLiftedOperator (ec);
 387                 }
 388
 389                 void EmitQuote (EmitContext ec)
 390                 {
 391                         ec.EmitScope ();
 392
 393                         ec.EmitReadGlobal (operand, typeof (Expression));
 394
 395                         if (ec.HasHoistedLocals)
 396                                 ec.EmitLoadHoistedLocalsStore ();
 397                         else
 398                                 ec.ig.Emit (OpCodes.Ldnull);
 399
 400                         ec.EmitIsolateExpression ();
 401                 }
 402
 403                 internal override void Emit (EmitContext ec)
 404                 {
 405                         if (method != null) {
 406                                 EmitUserDefinedOperator (ec);
 407                                 return;
 408                         }
 409
 410                         switch (this.NodeType) {
 411                         case ExpressionType.ArrayLength:
 412                                 EmitArrayLength (ec);
 413                                 return;
 414                         case ExpressionType.TypeAs:
 415                                 EmitTypeAs (ec);
 416                                 return;
 417                         case ExpressionType.Convert:
 418                         case ExpressionType.ConvertChecked:
 419                                 EmitConvert (ec);
 420                                 return;
 421                         case ExpressionType.Not:
 422                         case ExpressionType.Negate:
 423                         case ExpressionType.NegateChecked:
 424                         case ExpressionType.UnaryPlus:
 425                                 EmitArithmeticUnary (ec);
 426                                 return;
 427                         case ExpressionType.Quote:
 428                                 EmitQuote (ec);
 429                                 return;
 430                         default:
 431                                 throw new NotImplementedException (this.NodeType.ToString ());
 432                         }
 433                 }
 434         }
 435 }