mcs/class/System.Core/System.Linq.Expressions/BinaryExpression.cs

   1 //
   2 // BinaryExpression.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //   Miguel de Icaza (miguel@novell.com)
   7 //
   8 // Contains code from the Mono C# compiler:
   9 //   Marek Safar (marek.safar@seznam.cz)
  10 //   Martin Baulig (martin@ximian.com)
  11 //   Raja Harinath (harinath@gmail.com)
  12 //
  13 // (C) 2001-2003 Ximian, Inc.
  14 // (C) 2004-2008 Novell, Inc. (http://www.novell.com)
  15 //
  16 // Permission is hereby granted, free of charge, to any person obtaining
  17 // a copy of this software and associated documentation files (the
  18 // "Software"), to deal in the Software without restriction, including
  19 // without limitation the rights to use, copy, modify, merge, publish,
  20 // distribute, sublicense, and/or sell copies of the Software, and to
  21 // permit persons to whom the Software is furnished to do so, subject to
  22 // the following conditions:
  23 //
  24 // The above copyright notice and this permission notice shall be
  25 // included in all copies or substantial portions of the Software.
  26 //
  27 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  28 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  29 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  30 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  31 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  32 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  33 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  34 //
  35
  36 using System;
  37 using System.Reflection;
  38 using System.Reflection.Emit;
  39
  40 namespace System.Linq.Expressions {
  41
  42         public sealed class BinaryExpression : Expression {
  43
  44                 Expression left;
  45                 Expression right;
  46                 LambdaExpression conversion;
  47                 MethodInfo method;
  48                 bool lift_to_null, is_lifted;
  49
  50                 public Expression Left {
  51                         get { return left; }
  52                 }
  53
  54                 public Expression Right {
  55                         get { return right; }
  56                 }
  57
  58                 public MethodInfo Method {
  59                         get { return method; }
  60                 }
  61
  62                 public bool IsLifted {
  63                         get { return is_lifted;  }
  64                 }
  65
  66                 public bool IsLiftedToNull {
  67                         get { return lift_to_null; }
  68                 }
  69
  70                 public LambdaExpression Conversion {
  71                         get { return conversion; }
  72                 }
  73
  74                 internal BinaryExpression (ExpressionType node_type, Type type, Expression left, Expression right)
  75                         : base (node_type, type)
  76                 {
  77                         this.left = left;
  78                         this.right = right;
  79                 }
  80
  81                 internal BinaryExpression (ExpressionType node_type, Type type, Expression left, Expression right, MethodInfo method)
  82                         : base (node_type, type)
  83                 {
  84                         this.left = left;
  85                         this.right = right;
  86                         this.method = method;
  87                 }
  88
  89                 internal BinaryExpression (ExpressionType node_type, Type type, Expression left, Expression right, bool lift_to_null,
  90                                            bool is_lifted, MethodInfo method, LambdaExpression conversion) : base (node_type, type)
  91                 {
  92                         this.left = left;
  93                         this.right = right;
  94                         this.method = method;
  95                         this.conversion = conversion;
  96                         this.lift_to_null = lift_to_null;
  97                         this.is_lifted = is_lifted;
  98                 }
  99
 100                 void EmitMethod (EmitContext ec)
 101                 {
 102                         left.Emit (ec);
 103                         right.Emit (ec);
 104                         ec.EmitCall (method);
 105                 }
 106
 107                 static MethodInfo GetMethodNoPar (Type t, string name)
 108                 {
 109                         var method = t.GetMethod (name, Type.EmptyTypes);
 110                         if (method == null)
 111                                 throw new ArgumentException (
 112                                         string.Format ("Internal error: method {0} with no parameters not found on {1}", name, t));
 113
 114                         return method;
 115                 }
 116
 117                 void EmitArrayAccess (EmitContext ec)
 118                 {
 119                         left.Emit (ec);
 120                         right.Emit (ec);
 121                         ec.ig.Emit (OpCodes.Ldelem, this.Type);
 122                 }
 123
 124                 void EmitLiftedLogical (EmitContext ec, bool and, bool short_circuit)
 125                 {
 126                         var ig = ec.ig;
 127                         LocalBuilder ret = ig.DeclareLocal (Type);
 128                         LocalBuilder vleft = null, vright = null;
 129                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 130                         MethodInfo get_value = GetMethodNoPar (left.Type, "get_Value");
 131
 132                         vleft = ec.EmitStored (left);
 133                         if (!short_circuit)
 134                                 vright = ec.EmitStored (right);
 135
 136                         Label left_is_null = ig.DefineLabel ();
 137                         Label right_is_null = ig.DefineLabel ();
 138                         Label create = ig.DefineLabel ();
 139                         Label exit = ig.DefineLabel ();
 140                         Label both_are_null = ig.DefineLabel ();
 141
 142                         // Check left
 143
 144                         ig.Emit (OpCodes.Ldloca, vleft);
 145                         ig.Emit (OpCodes.Call, has_value);
 146                         ig.Emit (OpCodes.Brfalse, left_is_null);
 147
 148                         ig.Emit (OpCodes.Ldloca, vleft);
 149                         ig.Emit (OpCodes.Call, get_value);
 150                         ig.Emit (OpCodes.Dup);
 151
 152                         ig.Emit (and ? OpCodes.Brfalse : OpCodes.Brtrue, create);
 153
 154                         // Deal with right
 155                         if (short_circuit)
 156                                 vright = ec.EmitStored (right);
 157
 158                         ig.Emit (OpCodes.Ldloca, vright);
 159                         ig.Emit (OpCodes.Call, has_value);
 160                         ig.Emit (OpCodes.Brfalse, right_is_null);
 161
 162                         ig.Emit (OpCodes.Ldloca, vright);
 163                         ig.Emit (OpCodes.Call, get_value);
 164
 165                         ig.Emit (and ? OpCodes.And : OpCodes.Or);
 166                         ig.Emit (OpCodes.Br, create);
 167
 168                         // left_is_null:
 169                         ig.MarkLabel (left_is_null);
 170
 171                         ig.Emit (OpCodes.Ldloca, vright);
 172                         ig.Emit (OpCodes.Call, has_value);
 173                         ig.Emit (OpCodes.Brfalse, both_are_null);
 174                         ig.Emit (OpCodes.Ldloca, vright);
 175                         ig.Emit (OpCodes.Call, get_value);
 176                         ig.Emit (OpCodes.Dup);
 177                         ig.Emit (and ? OpCodes.Brfalse : OpCodes.Brtrue, create);
 178
 179                         // right_is_null:
 180                         ig.MarkLabel (right_is_null);
 181                         ig.Emit (OpCodes.Pop);
 182
 183                         // both_are_null:
 184                         ig.MarkLabel (both_are_null);
 185                         ig.Emit (OpCodes.Ldloca, ret);
 186                         ig.Emit (OpCodes.Initobj, Type);
 187                         ig.Emit (OpCodes.Ldloc, ret);
 188                         ig.Emit (OpCodes.Br, exit);
 189
 190                         // create:
 191                         ig.MarkLabel (create);
 192                         ig.Emit (OpCodes.Newobj, Type.GetConstructors () [0]);
 193
 194                         // exit:
 195                         ig.MarkLabel (exit);
 196                 }
 197
 198                 void EmitLogical (EmitContext ec, bool and, bool short_circuit)
 199                 {
 200                         if (IsLifted) {
 201                                 EmitLiftedLogical (ec, and, short_circuit);
 202                                 return;
 203                         }
 204
 205                         left.Emit (ec);
 206                         right.Emit (ec);
 207                         ec.ig.Emit (and ? OpCodes.And : OpCodes.Or);
 208                 }
 209
 210                 void EmitCoalesce (EmitContext ec)
 211                 {
 212                         ILGenerator ig = ec.ig;
 213
 214                         LocalBuilder vleft;
 215                         LocalBuilder vright;
 216
 217                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 218
 219                         Label exit = ig.DefineLabel ();
 220                         Label try_right = ig.DefineLabel ();
 221                         Label setup_null = ig.DefineLabel ();
 222
 223                         vleft = ec.EmitStored (left);
 224                         if (IsNullable (left.Type)){
 225                                 ig.Emit (OpCodes.Ldloca, vleft);
 226                                 ig.Emit (OpCodes.Call, has_value);
 227                         } else
 228                                 ig.Emit (OpCodes.Ldloc, vleft);
 229
 230                         ig.Emit (OpCodes.Brfalse, try_right);
 231                         ig.Emit (OpCodes.Ldloc, vleft);
 232                         ig.Emit (OpCodes.Br, exit);
 233
 234                 // try_right;
 235                         ig.MarkLabel (try_right);
 236                         vright = ec.EmitStored (right);
 237                         if (IsNullable (right.Type)){
 238                                 ig.Emit (OpCodes.Ldloca, vright);
 239                                 ig.Emit (OpCodes.Call, has_value);
 240                         } else
 241                                 ig.Emit (OpCodes.Ldloc, vright);
 242
 243                         ig.Emit (OpCodes.Brfalse, setup_null);
 244                         ig.Emit (OpCodes.Ldloc, vright);
 245                         ig.Emit (OpCodes.Br, exit);
 246
 247                 // setup_null:
 248                         ig.MarkLabel (setup_null);
 249                         LocalBuilder ret = ig.DeclareLocal (Type);
 250                         ig.Emit (OpCodes.Ldloca, ret);
 251                         ig.Emit (OpCodes.Initobj, Type);
 252                         ig.Emit (OpCodes.Ldloc, ret);
 253
 254                 // exit:
 255                         ig.MarkLabel (exit);
 256                 }
 257
 258                 void EmitBinaryOperator (EmitContext ec)
 259                 {
 260                         OpCode opcode;
 261                         var ig = ec.ig;
 262                         bool is_unsigned = IsUnsigned (left.Type);
 263
 264                         switch (NodeType) {
 265                         case ExpressionType.Add:
 266                                 opcode = OpCodes.Add;
 267                                 break;
 268
 269                         case ExpressionType.AddChecked:
 270                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 271                                         opcode = OpCodes.Add_Ovf;
 272                                 else if (is_unsigned)
 273                                         opcode = OpCodes.Add_Ovf_Un;
 274                                 else
 275                                         opcode = OpCodes.Add;
 276                                 break;
 277
 278                         case ExpressionType.Subtract:
 279                                 opcode = OpCodes.Sub;
 280                                 break;
 281
 282                         case ExpressionType.SubtractChecked:
 283                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 284                                         opcode = OpCodes.Sub_Ovf;
 285                                 else if (is_unsigned)
 286                                         opcode = OpCodes.Sub_Ovf_Un;
 287                                 else
 288                                         opcode = OpCodes.Sub;
 289                                 break;
 290
 291                         case ExpressionType.Multiply:
 292                                 opcode = OpCodes.Mul;
 293                                 break;
 294
 295                         case ExpressionType.MultiplyChecked:
 296                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 297                                         opcode = OpCodes.Mul_Ovf;
 298                                 else if (is_unsigned)
 299                                         opcode = OpCodes.Mul_Ovf_Un;
 300                                 else
 301                                         opcode = OpCodes.Mul;
 302                                 break;
 303
 304                         case ExpressionType.Divide:
 305                                 if (is_unsigned)
 306                                         opcode = OpCodes.Div_Un;
 307                                 else
 308                                         opcode = OpCodes.Div;
 309                                 break;
 310
 311                         case ExpressionType.Modulo:
 312                                 if (is_unsigned)
 313                                         opcode = OpCodes.Rem_Un;
 314                                 else
 315                                         opcode = OpCodes.Rem;
 316                                 break;
 317
 318                         case ExpressionType.RightShift:
 319                                 if (is_unsigned)
 320                                         opcode = OpCodes.Shr_Un;
 321                                 else
 322                                         opcode = OpCodes.Shr;
 323                                 break;
 324
 325                         case ExpressionType.LeftShift:
 326                                 opcode = OpCodes.Shl;
 327                                 break;
 328
 329                         case ExpressionType.And:
 330                                 opcode = OpCodes.And;
 331                                 break;
 332
 333                         case ExpressionType.Or:
 334                                 opcode = OpCodes.Or;
 335                                 break;
 336
 337                         case ExpressionType.ExclusiveOr:
 338                                 opcode = OpCodes.Xor;
 339                                 break;
 340
 341                         case ExpressionType.GreaterThan:
 342                                 if (is_unsigned)
 343                                         opcode = OpCodes.Cgt_Un;
 344                                 else
 345                                         opcode = OpCodes.Cgt;
 346                                 break;
 347
 348                         case ExpressionType.GreaterThanOrEqual:
 349                                 Type le = left.Type;
 350
 351                                 if (is_unsigned || (le == typeof (double) || le == typeof (float)))
 352                                         ig.Emit (OpCodes.Clt_Un);
 353                                 else
 354                                         ig.Emit (OpCodes.Clt);
 355
 356                                 ig.Emit (OpCodes.Ldc_I4_0);
 357
 358                                 opcode = OpCodes.Ceq;
 359                                 break;
 360
 361                         case ExpressionType.LessThan:
 362                                 if (is_unsigned)
 363                                         opcode = OpCodes.Clt_Un;
 364                                 else
 365                                         opcode = OpCodes.Clt;
 366                                 break;
 367
 368                         case ExpressionType.LessThanOrEqual:
 369                                 Type lt = left.Type;
 370
 371                                 if (is_unsigned || (lt == typeof (double) || lt == typeof (float)))
 372                                         ig.Emit (OpCodes.Cgt_Un);
 373                                 else
 374                                         ig.Emit (OpCodes.Cgt);
 375                                 ig.Emit (OpCodes.Ldc_I4_0);
 376
 377                                 opcode = OpCodes.Ceq;
 378                                 break;
 379
 380                         case ExpressionType.Equal:
 381                                 opcode = OpCodes.Ceq;
 382                                 break;
 383
 384                         case ExpressionType.NotEqual:
 385                                 ig.Emit (OpCodes.Ceq);
 386                                 ig.Emit (OpCodes.Ldc_I4_0);
 387
 388                                 opcode = OpCodes.Ceq;
 389                                 break;
 390
 391                         default:
 392                                 throw new InvalidOperationException (string.Format ("Internal error: BinaryExpression contains non-Binary nodetype {0}", NodeType));
 393                         }
 394
 395                         ig.Emit (opcode);
 396                 }
 397
 398                 void EmitLiftedArithmeticBinary (EmitContext ec)
 399                 {
 400                         EmitLiftedToNullBinary (ec);
 401                 }
 402
 403                 void EmitLiftedToNullBinary (EmitContext ec)
 404                 {
 405                         var ig = ec.ig;
 406                         var left = ec.EmitStored (this.left);
 407                         var right = ec.EmitStored (this.right);
 408                         var result = ig.DeclareLocal (Type);
 409
 410                         var has_value = ig.DefineLabel ();
 411                         var done = ig.DefineLabel ();
 412
 413                         ec.EmitNullableHasValue (left);
 414                         ec.EmitNullableHasValue (right);
 415                         ig.Emit (OpCodes.And);
 416                         ig.Emit (OpCodes.Brtrue, has_value);
 417
 418                         ig.Emit (OpCodes.Ldloca, result);
 419                         ig.Emit (OpCodes.Initobj, result.LocalType);
 420                         ig.Emit (OpCodes.Ldloc, result);
 421
 422                         ig.Emit (OpCodes.Br, done);
 423
 424                         ig.MarkLabel (has_value);
 425
 426                         ec.EmitNullableGetValueOrDefault (left);
 427                         ec.EmitNullableGetValueOrDefault (right);
 428
 429                         EmitBinaryOperator (ec);
 430
 431                         ec.EmitNullableNew (result.LocalType);
 432
 433                         ig.MarkLabel (done);
 434                 }
 435
 436                 void EmitLiftedRelationalBinary (EmitContext ec)
 437                 {
 438                         var ig = ec.ig;
 439                         var left = ec.EmitStored (this.left);
 440                         var right = ec.EmitStored (this.right);
 441
 442                         var ret = ig.DefineLabel ();
 443                         var done = ig.DefineLabel ();
 444
 445                         ec.EmitNullableGetValueOrDefault (left);
 446                         ec.EmitNullableGetValueOrDefault (right);
 447
 448                         switch (NodeType) {
 449                         case ExpressionType.Equal:
 450                         case ExpressionType.NotEqual:
 451                                 ig.Emit (OpCodes.Bne_Un, ret);
 452                                 break;
 453                         default:
 454                                 EmitBinaryOperator (ec);
 455                                 ig.Emit (OpCodes.Brfalse, ret);
 456                                 break;
 457                         }
 458
 459                         ec.EmitNullableHasValue (left);
 460                         ec.EmitNullableHasValue (right);
 461
 462                         switch (NodeType) {
 463                         case ExpressionType.Equal:
 464                                 ig.Emit (OpCodes.Ceq);
 465                                 break;
 466                         case ExpressionType.NotEqual:
 467                                 ig.Emit (OpCodes.Ceq);
 468                                 ig.Emit (OpCodes.Ldc_I4_0);
 469                                 ig.Emit (OpCodes.Ceq);
 470                                 break;
 471                         default:
 472                                 ig.Emit (OpCodes.And);
 473                                 break;
 474                         }
 475
 476                         ig.Emit (OpCodes.Br, done);
 477
 478                         ig.MarkLabel (ret);
 479
 480                         ig.Emit (NodeType == ExpressionType.NotEqual ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0);
 481
 482                         ig.MarkLabel (done);
 483                 }
 484
 485                 void EmitArithmeticBinary (EmitContext ec)
 486                 {
 487                         if (!IsLifted) {
 488                                 left.Emit (ec);
 489                                 right.Emit (ec);
 490                                 EmitBinaryOperator (ec);
 491                         } else
 492                                 EmitLiftedArithmeticBinary (ec);
 493                 }
 494
 495                 void EmitRelationalBinary (EmitContext ec)
 496                 {
 497                         if (!IsLifted) {
 498                                 left.Emit (ec);
 499                                 right.Emit (ec);
 500                                 EmitBinaryOperator (ec);
 501                         } else if (IsLiftedToNull)
 502                                 EmitLiftedToNullBinary (ec);
 503                         else
 504                                 EmitLiftedRelationalBinary (ec);
 505                 }
 506
 507                 internal override void Emit (EmitContext ec)
 508                 {
 509                         if (method != null){
 510                                 EmitMethod (ec);
 511                                 return;
 512                         }
 513
 514                         switch (NodeType){
 515                         case ExpressionType.ArrayIndex:
 516                                 EmitArrayAccess (ec);
 517                                 return;
 518
 519                         case ExpressionType.And:
 520                                 EmitLogical (ec, true, false);
 521                                 return;
 522
 523                         case ExpressionType.Or:
 524                                 EmitLogical (ec, false, false);
 525                                 return;
 526
 527                         case ExpressionType.AndAlso:
 528                                 EmitLogical (ec, true, true);
 529                                 return;
 530
 531                         case ExpressionType.OrElse:
 532                                 EmitLogical (ec, false, true);
 533                                 return;
 534
 535                         case ExpressionType.Coalesce:
 536                                 EmitCoalesce (ec);
 537                                 return;
 538
 539                         case ExpressionType.Power:
 540                                 // likely broken if lifted
 541                                 left.Emit (ec);
 542                                 right.Emit (ec);
 543                                 ec.EmitCall (typeof (Math).GetMethod ("Pow"));
 544                                 return;
 545
 546                         case ExpressionType.Add:
 547                         case ExpressionType.AddChecked:
 548                         case ExpressionType.Divide:
 549                         case ExpressionType.ExclusiveOr:
 550                         case ExpressionType.LeftShift:
 551                         case ExpressionType.Modulo:
 552                         case ExpressionType.Multiply:
 553                         case ExpressionType.MultiplyChecked:
 554                         case ExpressionType.RightShift:
 555                         case ExpressionType.Subtract:
 556                         case ExpressionType.SubtractChecked:
 557                                 EmitArithmeticBinary (ec);
 558                                 return;
 559                         case ExpressionType.Equal:
 560                         case ExpressionType.GreaterThan:
 561                         case ExpressionType.GreaterThanOrEqual:
 562                         case ExpressionType.LessThan:
 563                         case ExpressionType.LessThanOrEqual:
 564                         case ExpressionType.NotEqual:
 565                                 EmitRelationalBinary (ec);
 566                                 return;
 567                         default:
 568                                 throw new NotSupportedException (this.NodeType.ToString ());
 569                         }
 570                 }
 571         }
 572 }