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                                 EmitNonLiftedBinary (ec);
 202                         else
 203                                 EmitLiftedLogical (ec, and, short_circuit);
 204                 }
 205
 206                 void EmitCoalesce (EmitContext ec)
 207                 {
 208                         ILGenerator ig = ec.ig;
 209
 210                         LocalBuilder vleft;
 211                         LocalBuilder vright;
 212
 213                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 214
 215                         Label exit = ig.DefineLabel ();
 216                         Label try_right = ig.DefineLabel ();
 217                         Label setup_null = ig.DefineLabel ();
 218
 219                         vleft = ec.EmitStored (left);
 220                         if (IsNullable (left.Type)){
 221                                 ig.Emit (OpCodes.Ldloca, vleft);
 222                                 ig.Emit (OpCodes.Call, has_value);
 223                         } else
 224                                 ig.Emit (OpCodes.Ldloc, vleft);
 225
 226                         ig.Emit (OpCodes.Brfalse, try_right);
 227                         ig.Emit (OpCodes.Ldloc, vleft);
 228                         ig.Emit (OpCodes.Br, exit);
 229
 230                 // try_right;
 231                         ig.MarkLabel (try_right);
 232                         vright = ec.EmitStored (right);
 233                         if (IsNullable (right.Type)){
 234                                 ig.Emit (OpCodes.Ldloca, vright);
 235                                 ig.Emit (OpCodes.Call, has_value);
 236                         } else
 237                                 ig.Emit (OpCodes.Ldloc, vright);
 238
 239                         ig.Emit (OpCodes.Brfalse, setup_null);
 240                         ig.Emit (OpCodes.Ldloc, vright);
 241                         ig.Emit (OpCodes.Br, exit);
 242
 243                 // setup_null:
 244                         ig.MarkLabel (setup_null);
 245                         LocalBuilder ret = ig.DeclareLocal (Type);
 246                         ig.Emit (OpCodes.Ldloca, ret);
 247                         ig.Emit (OpCodes.Initobj, Type);
 248                         ig.Emit (OpCodes.Ldloc, ret);
 249
 250                 // exit:
 251                         ig.MarkLabel (exit);
 252                 }
 253
 254                 void EmitBinaryOperator (EmitContext ec)
 255                 {
 256                         OpCode opcode;
 257                         var ig = ec.ig;
 258                         bool is_unsigned = IsUnsigned (left.Type);
 259
 260                         switch (NodeType) {
 261                         case ExpressionType.Add:
 262                                 opcode = OpCodes.Add;
 263                                 break;
 264                         case ExpressionType.AddChecked:
 265                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 266                                         opcode = OpCodes.Add_Ovf;
 267                                 else
 268                                         opcode = is_unsigned ? OpCodes.Add_Ovf_Un : OpCodes.Add;
 269                                 break;
 270                         case ExpressionType.Subtract:
 271                                 opcode = OpCodes.Sub;
 272                                 break;
 273                         case ExpressionType.SubtractChecked:
 274                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 275                                         opcode = OpCodes.Sub_Ovf;
 276                                 else
 277                                         opcode = is_unsigned ? OpCodes.Sub_Ovf_Un : OpCodes.Sub;
 278                                 break;
 279                         case ExpressionType.Multiply:
 280                                 opcode = OpCodes.Mul;
 281                                 break;
 282                         case ExpressionType.MultiplyChecked:
 283                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 284                                         opcode = OpCodes.Mul_Ovf;
 285                                 else
 286                                         opcode = is_unsigned ? OpCodes.Mul_Ovf_Un : OpCodes.Mul;
 287                                 break;
 288                         case ExpressionType.Divide:
 289                                 opcode = is_unsigned ? OpCodes.Div_Un : OpCodes.Div;
 290                                 break;
 291                         case ExpressionType.Modulo:
 292                                 opcode = is_unsigned ? OpCodes.Rem_Un : OpCodes.Rem;
 293                                 break;
 294                         case ExpressionType.RightShift:
 295                                 opcode = is_unsigned ? OpCodes.Shr_Un : OpCodes.Shr;
 296                                 break;
 297                         case ExpressionType.LeftShift:
 298                                 opcode = OpCodes.Shl;
 299                                 break;
 300                         case ExpressionType.And:
 301                         case ExpressionType.AndAlso:
 302                                 opcode = OpCodes.And;
 303                                 break;
 304                         case ExpressionType.Or:
 305                         case ExpressionType.OrElse:
 306                                 opcode = OpCodes.Or;
 307                                 break;
 308                         case ExpressionType.ExclusiveOr:
 309                                 opcode = OpCodes.Xor;
 310                                 break;
 311                         case ExpressionType.GreaterThan:
 312                                 opcode = is_unsigned ? OpCodes.Cgt_Un : OpCodes.Cgt;
 313                                 break;
 314                         case ExpressionType.GreaterThanOrEqual:
 315                                 Type le = left.Type;
 316
 317                                 if (is_unsigned || (le == typeof (double) || le == typeof (float)))
 318                                         ig.Emit (OpCodes.Clt_Un);
 319                                 else
 320                                         ig.Emit (OpCodes.Clt);
 321
 322                                 ig.Emit (OpCodes.Ldc_I4_0);
 323
 324                                 opcode = OpCodes.Ceq;
 325                                 break;
 326                         case ExpressionType.LessThan:
 327                                 opcode = is_unsigned ? OpCodes.Clt_Un : OpCodes.Clt;
 328                                 break;
 329                         case ExpressionType.LessThanOrEqual:
 330                                 Type lt = left.Type;
 331
 332                                 if (is_unsigned || (lt == typeof (double) || lt == typeof (float)))
 333                                         ig.Emit (OpCodes.Cgt_Un);
 334                                 else
 335                                         ig.Emit (OpCodes.Cgt);
 336
 337                                 ig.Emit (OpCodes.Ldc_I4_0);
 338
 339                                 opcode = OpCodes.Ceq;
 340                                 break;
 341                         case ExpressionType.Equal:
 342                                 opcode = OpCodes.Ceq;
 343                                 break;
 344                         case ExpressionType.NotEqual:
 345                                 ig.Emit (OpCodes.Ceq);
 346                                 ig.Emit (OpCodes.Ldc_I4_0);
 347                                 opcode = OpCodes.Ceq;
 348                                 break;
 349                         default:
 350                                 throw new InvalidOperationException (string.Format ("Internal error: BinaryExpression contains non-Binary nodetype {0}", NodeType));
 351                         }
 352
 353                         ig.Emit (opcode);
 354                 }
 355
 356                 void EmitLiftedArithmeticBinary (EmitContext ec)
 357                 {
 358                         EmitLiftedToNullBinary (ec);
 359                 }
 360
 361                 void EmitLiftedToNullBinary (EmitContext ec)
 362                 {
 363                         var ig = ec.ig;
 364                         var left = ec.EmitStored (this.left);
 365                         var right = ec.EmitStored (this.right);
 366                         var result = ig.DeclareLocal (Type);
 367
 368                         var has_value = ig.DefineLabel ();
 369                         var done = ig.DefineLabel ();
 370
 371                         ec.EmitNullableHasValue (left);
 372                         ec.EmitNullableHasValue (right);
 373                         ig.Emit (OpCodes.And);
 374                         ig.Emit (OpCodes.Brtrue, has_value);
 375
 376                         ec.EmitNullableInitialize (result);
 377
 378                         ig.Emit (OpCodes.Br, done);
 379
 380                         ig.MarkLabel (has_value);
 381
 382                         ec.EmitNullableGetValueOrDefault (left);
 383                         ec.EmitNullableGetValueOrDefault (right);
 384
 385                         EmitBinaryOperator (ec);
 386
 387                         ec.EmitNullableNew (result.LocalType);
 388
 389                         ig.MarkLabel (done);
 390                 }
 391
 392                 void EmitLiftedRelationalBinary (EmitContext ec)
 393                 {
 394                         var ig = ec.ig;
 395                         var left = ec.EmitStored (this.left);
 396                         var right = ec.EmitStored (this.right);
 397
 398                         var ret = ig.DefineLabel ();
 399                         var done = ig.DefineLabel ();
 400
 401                         ec.EmitNullableGetValueOrDefault (left);
 402                         ec.EmitNullableGetValueOrDefault (right);
 403
 404                         switch (NodeType) {
 405                         case ExpressionType.Equal:
 406                         case ExpressionType.NotEqual:
 407                                 ig.Emit (OpCodes.Bne_Un, ret);
 408                                 break;
 409                         default:
 410                                 EmitBinaryOperator (ec);
 411                                 ig.Emit (OpCodes.Brfalse, ret);
 412                                 break;
 413                         }
 414
 415                         ec.EmitNullableHasValue (left);
 416                         ec.EmitNullableHasValue (right);
 417
 418                         switch (NodeType) {
 419                         case ExpressionType.Equal:
 420                                 ig.Emit (OpCodes.Ceq);
 421                                 break;
 422                         case ExpressionType.NotEqual:
 423                                 ig.Emit (OpCodes.Ceq);
 424                                 ig.Emit (OpCodes.Ldc_I4_0);
 425                                 ig.Emit (OpCodes.Ceq);
 426                                 break;
 427                         default:
 428                                 ig.Emit (OpCodes.And);
 429                                 break;
 430                         }
 431
 432                         ig.Emit (OpCodes.Br, done);
 433
 434                         ig.MarkLabel (ret);
 435
 436                         ig.Emit (NodeType == ExpressionType.NotEqual ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0);
 437
 438                         ig.MarkLabel (done);
 439                 }
 440
 441                 void EmitArithmeticBinary (EmitContext ec)
 442                 {
 443                         if (!IsLifted)
 444                                 EmitNonLiftedBinary (ec);
 445                         else
 446                                 EmitLiftedArithmeticBinary (ec);
 447                 }
 448
 449                 void EmitNonLiftedBinary (EmitContext ec)
 450                 {
 451                         ec.Emit (left);
 452                         ec.Emit (right);
 453                         EmitBinaryOperator (ec);
 454                 }
 455
 456                 void EmitRelationalBinary (EmitContext ec)
 457                 {
 458                         if (!IsLifted)
 459                                 EmitNonLiftedBinary (ec);
 460                         else if (IsLiftedToNull)
 461                                 EmitLiftedToNullBinary (ec);
 462                         else
 463                                 EmitLiftedRelationalBinary (ec);
 464                 }
 465
 466                 internal override void Emit (EmitContext ec)
 467                 {
 468                         if (method != null){
 469                                 EmitMethod (ec);
 470                                 return;
 471                         }
 472
 473                         switch (NodeType){
 474                         case ExpressionType.ArrayIndex:
 475                                 EmitArrayAccess (ec);
 476                                 return;
 477                         case ExpressionType.And:
 478                                 EmitLogical (ec, true, false);
 479                                 return;
 480                         case ExpressionType.Or:
 481                                 EmitLogical (ec, false, false);
 482                                 return;
 483                         case ExpressionType.AndAlso:
 484                                 EmitLogical (ec, true, true);
 485                                 return;
 486                         case ExpressionType.OrElse:
 487                                 EmitLogical (ec, false, true);
 488                                 return;
 489                         case ExpressionType.Coalesce:
 490                                 EmitCoalesce (ec);
 491                                 return;
 492                         case ExpressionType.Power:
 493                                 // likely broken if lifted
 494                                 left.Emit (ec);
 495                                 right.Emit (ec);
 496                                 ec.EmitCall (typeof (Math).GetMethod ("Pow"));
 497                                 return;
 498                         case ExpressionType.Add:
 499                         case ExpressionType.AddChecked:
 500                         case ExpressionType.Divide:
 501                         case ExpressionType.ExclusiveOr:
 502                         case ExpressionType.LeftShift:
 503                         case ExpressionType.Modulo:
 504                         case ExpressionType.Multiply:
 505                         case ExpressionType.MultiplyChecked:
 506                         case ExpressionType.RightShift:
 507                         case ExpressionType.Subtract:
 508                         case ExpressionType.SubtractChecked:
 509                                 EmitArithmeticBinary (ec);
 510                                 return;
 511                         case ExpressionType.Equal:
 512                         case ExpressionType.GreaterThan:
 513                         case ExpressionType.GreaterThanOrEqual:
 514                         case ExpressionType.LessThan:
 515                         case ExpressionType.LessThanOrEqual:
 516                         case ExpressionType.NotEqual:
 517                                 EmitRelationalBinary (ec);
 518                                 return;
 519                         default:
 520                                 throw new NotSupportedException (this.NodeType.ToString ());
 521                         }
 522                 }
 523         }
 524 }