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.ig.Emit (OpCodes.Call, 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 EmitLiftedLogical (EmitContext ec, bool and, bool short_circuit)
 118                 {
 119                         var ig = ec.ig;
 120                         LocalBuilder ret = ig.DeclareLocal (Type);
 121                         LocalBuilder vleft = null, vright = null;
 122                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 123                         MethodInfo get_value = GetMethodNoPar (left.Type, "get_Value");
 124
 125                         vleft = EmitStored (ec, left);
 126                         if (!short_circuit)
 127                                 vright = EmitStored (ec, right);
 128
 129                         Label left_is_null = ig.DefineLabel ();
 130                         Label left_is_false = ig.DefineLabel ();
 131                         Label right_is_null = ig.DefineLabel ();
 132                         Label create = ig.DefineLabel ();
 133                         Label exit = ig.DefineLabel ();
 134                         Label both_are_null = ig.DefineLabel ();
 135
 136                         // Check left
 137
 138                         ig.Emit (OpCodes.Ldloca, vleft);
 139                         ig.Emit (OpCodes.Call, has_value);
 140                         ig.Emit (OpCodes.Brfalse, left_is_null);
 141
 142                         ig.Emit (OpCodes.Ldloca, vleft);
 143                         ig.Emit (OpCodes.Call, get_value);
 144                         ig.Emit (OpCodes.Dup);
 145
 146                         ig.Emit (and ? OpCodes.Brfalse : OpCodes.Brtrue, create);
 147
 148                         // Deal with right
 149                         if (short_circuit)
 150                                 vright = EmitStored (ec, right);
 151
 152                         ig.Emit (OpCodes.Ldloca, vright);
 153                         ig.Emit (OpCodes.Call, has_value);
 154                         ig.Emit (OpCodes.Brfalse, right_is_null);
 155
 156                         ig.Emit (OpCodes.Ldloca, vright);
 157                         ig.Emit (OpCodes.Call, get_value);
 158
 159                         ig.Emit (and ? OpCodes.And : OpCodes.Or);
 160                         ig.Emit (OpCodes.Br, create);
 161
 162                         // left_is_null:
 163                         ig.MarkLabel (left_is_null);
 164
 165                         ig.Emit (OpCodes.Ldloca, vright);
 166                         ig.Emit (OpCodes.Call, has_value);
 167                         ig.Emit (OpCodes.Brfalse, both_are_null);
 168                         ig.Emit (OpCodes.Ldloca, vright);
 169                         ig.Emit (OpCodes.Call, get_value);
 170                         ig.Emit (OpCodes.Dup);
 171                         ig.Emit (and ? OpCodes.Brfalse : OpCodes.Brtrue, create);
 172
 173                         // right_is_null:
 174                         ig.MarkLabel (right_is_null);
 175                         ig.Emit (OpCodes.Pop);
 176
 177                         // both_are_null:
 178                         ig.MarkLabel (both_are_null);
 179                         ig.Emit (OpCodes.Ldloca, ret);
 180                         ig.Emit (OpCodes.Initobj, Type);
 181                         ig.Emit (OpCodes.Ldloc, ret);
 182                         ig.Emit (OpCodes.Br, exit);
 183
 184                         // create:
 185                         ig.MarkLabel (create);
 186                         ig.Emit (OpCodes.Newobj, Type.GetConstructors () [0]);
 187
 188                         // exit:
 189                         ig.MarkLabel (exit);
 190                 }
 191
 192                 void EmitLogical (EmitContext ec, bool and, bool short_circuit)
 193                 {
 194                         ILGenerator ig = ec.ig;
 195                         if (IsLifted) {
 196                                 EmitLiftedLogical (ec, and, short_circuit);
 197                                 return;
 198                         }
 199
 200                         left.Emit (ec);
 201                         right.Emit (ec);
 202                         ig.Emit (and ? OpCodes.And : OpCodes.Or);
 203                 }
 204
 205                 void EmitCoalesce (EmitContext ec)
 206                 {
 207                         ILGenerator ig = ec.ig;
 208
 209                         LocalBuilder vleft;
 210                         LocalBuilder vright;
 211
 212                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 213
 214                         Label exit = ig.DefineLabel ();
 215                         Label try_right = ig.DefineLabel ();
 216                         Label setup_null = ig.DefineLabel ();
 217
 218                         vleft = EmitStored (ec, left);
 219                         if (IsNullable (left.Type)){
 220                                 ig.Emit (OpCodes.Ldloca, vleft);
 221                                 ig.Emit (OpCodes.Call, has_value);
 222                         } else
 223                                 ig.Emit (OpCodes.Ldloc, vleft);
 224
 225                         ig.Emit (OpCodes.Brfalse, try_right);
 226                         ig.Emit (OpCodes.Ldloc, vleft);
 227                         ig.Emit (OpCodes.Br, exit);
 228
 229                 // try_right;
 230                         ig.MarkLabel (try_right);
 231                         vright = EmitStored (ec, right);
 232                         if (IsNullable (right.Type)){
 233                                 ig.Emit (OpCodes.Ldloca, vright);
 234                                 ig.Emit (OpCodes.Call, has_value);
 235                         } else
 236                                 ig.Emit (OpCodes.Ldloc, vright);
 237
 238                         ig.Emit (OpCodes.Brfalse, setup_null);
 239                         ig.Emit (OpCodes.Ldloc, vright);
 240                         ig.Emit (OpCodes.Br, exit);
 241
 242                 // setup_null:
 243                         ig.MarkLabel (setup_null);
 244                         LocalBuilder ret = ig.DeclareLocal (Type);
 245                         ig.Emit (OpCodes.Ldloca, ret);
 246                         ig.Emit (OpCodes.Initobj, Type);
 247                         ig.Emit (OpCodes.Ldloc, ret);
 248
 249                 // exit:
 250                         ig.MarkLabel (exit);
 251                 }
 252
 253                 void EmitBinaryOperator (EmitContext ec)
 254                 {
 255                         OpCode opcode;
 256                         var ig = ec.ig;
 257                         bool is_unsigned = IsUnsigned (left.Type);
 258
 259                         switch (NodeType) {
 260                         case ExpressionType.Add:
 261                                 opcode = OpCodes.Add;
 262                                 break;
 263
 264                         case ExpressionType.AddChecked:
 265                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 266                                         opcode = OpCodes.Add_Ovf;
 267                                 else if (is_unsigned)
 268                                         opcode = OpCodes.Add_Ovf_Un;
 269                                 else
 270                                         opcode = OpCodes.Add;
 271                                 break;
 272
 273                         case ExpressionType.Subtract:
 274                                 opcode = OpCodes.Sub;
 275                                 break;
 276
 277                         case ExpressionType.SubtractChecked:
 278                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 279                                         opcode = OpCodes.Sub_Ovf;
 280                                 else if (is_unsigned)
 281                                         opcode = OpCodes.Sub_Ovf_Un;
 282                                 else
 283                                         opcode = OpCodes.Sub;
 284                                 break;
 285
 286                         case ExpressionType.Multiply:
 287                                 opcode = OpCodes.Mul;
 288                                 break;
 289
 290                         case ExpressionType.MultiplyChecked:
 291                                 if (left.Type == typeof (int) || left.Type == typeof (long))
 292                                         opcode = OpCodes.Mul_Ovf;
 293                                 else if (is_unsigned)
 294                                         opcode = OpCodes.Mul_Ovf_Un;
 295                                 else
 296                                         opcode = OpCodes.Mul;
 297                                 break;
 298
 299                         case ExpressionType.Divide:
 300                                 if (is_unsigned)
 301                                         opcode = OpCodes.Div_Un;
 302                                 else
 303                                         opcode = OpCodes.Div;
 304                                 break;
 305
 306                         case ExpressionType.Modulo:
 307                                 if (is_unsigned)
 308                                         opcode = OpCodes.Rem_Un;
 309                                 else
 310                                         opcode = OpCodes.Rem;
 311                                 break;
 312
 313                         case ExpressionType.RightShift:
 314                                 if (is_unsigned)
 315                                         opcode = OpCodes.Shr_Un;
 316                                 else
 317                                         opcode = OpCodes.Shr;
 318                                 break;
 319
 320                         case ExpressionType.LeftShift:
 321                                 opcode = OpCodes.Shl;
 322                                 break;
 323
 324                         case ExpressionType.And:
 325                                 opcode = OpCodes.And;
 326                                 break;
 327
 328                         case ExpressionType.Or:
 329                                 opcode = OpCodes.Or;
 330                                 break;
 331
 332                         case ExpressionType.ExclusiveOr:
 333                                 opcode = OpCodes.Xor;
 334                                 break;
 335
 336                         case ExpressionType.GreaterThan:
 337                                 if (is_unsigned)
 338                                         opcode = OpCodes.Cgt_Un;
 339                                 else
 340                                         opcode = OpCodes.Cgt;
 341                                 break;
 342
 343                         case ExpressionType.GreaterThanOrEqual:
 344                                 Type le = left.Type;
 345
 346                                 if (is_unsigned || (le == typeof (double) || le == typeof (float)))
 347                                         ig.Emit (OpCodes.Clt_Un);
 348                                 else
 349                                         ig.Emit (OpCodes.Clt);
 350
 351                                 ig.Emit (OpCodes.Ldc_I4_0);
 352
 353                                 opcode = OpCodes.Ceq;
 354                                 break;
 355
 356                         case ExpressionType.LessThan:
 357                                 if (is_unsigned)
 358                                         opcode = OpCodes.Clt_Un;
 359                                 else
 360                                         opcode = OpCodes.Clt;
 361                                 break;
 362
 363                         case ExpressionType.LessThanOrEqual:
 364                                 Type lt = left.Type;
 365
 366                                 if (is_unsigned || (lt == typeof (double) || lt == typeof (float)))
 367                                         ig.Emit (OpCodes.Cgt_Un);
 368                                 else
 369                                         ig.Emit (OpCodes.Cgt);
 370                                 ig.Emit (OpCodes.Ldc_I4_0);
 371
 372                                 opcode = OpCodes.Ceq;
 373                                 break;
 374
 375                         case ExpressionType.Equal:
 376                                 opcode = OpCodes.Ceq;
 377                                 break;
 378
 379                         case ExpressionType.NotEqual:
 380                                 ig.Emit (OpCodes.Ceq);
 381                                 ig.Emit (OpCodes.Ldc_I4_0);
 382
 383                                 opcode = OpCodes.Ceq;
 384                                 break;
 385
 386                         default:
 387                                 throw new InvalidOperationException (string.Format ("Internal error: BinaryExpression contains non-Binary nodetype {0}", NodeType));
 388                         }
 389
 390                         ig.Emit (opcode);
 391                 }
 392
 393                 void EmitLiftedSimpleBinary (EmitContext ec)
 394                 {
 395                         Label empty_value;
 396                         LocalBuilder ret = null;
 397
 398                         LocalBuilder vleft, vright;
 399
 400                         var ig = ec.ig;
 401                         empty_value = ig.DefineLabel ();
 402                         ret = ig.DeclareLocal (Type);
 403
 404                         vleft = EmitStored (ec, left);
 405                         vright = EmitStored (ec, right);
 406
 407                         MethodInfo has_value = left.Type.GetMethod ("get_HasValue");
 408                         MethodInfo get_value = GetMethodNoPar (left.Type, "get_Value");
 409
 410                         ig.Emit (OpCodes.Ldloca, vleft);
 411                         ig.Emit (OpCodes.Call, has_value);
 412                         ig.Emit (OpCodes.Brfalse, empty_value);
 413                         ig.Emit (OpCodes.Ldloca, vright);
 414                         ig.Emit (OpCodes.Call, has_value);
 415                         ig.Emit (OpCodes.Brfalse, empty_value);
 416                         ig.Emit (OpCodes.Ldloca, vleft);
 417                         ig.Emit (OpCodes.Call, get_value);
 418                         ig.Emit (OpCodes.Ldloca, vright);
 419                         ig.Emit (OpCodes.Call, get_value);
 420
 421                         EmitBinaryOperator (ec);
 422
 423                         ig.Emit (OpCodes.Newobj, left.Type.GetConstructors () [0]);
 424
 425                         Label skip = ig.DefineLabel ();
 426                         ig.Emit (OpCodes.Br_S, skip);
 427                         ig.MarkLabel (empty_value);
 428                         ig.Emit (OpCodes.Ldloc, ret);
 429                         ig.Emit (OpCodes.Ldloca, ret);
 430                         ig.Emit (OpCodes.Initobj, Type);
 431
 432                         ig.MarkLabel (skip);
 433                 }
 434
 435                 void EmitSimpleBinary (EmitContext ec)
 436                 {
 437                         if (IsLifted) {
 438                                 EmitLiftedSimpleBinary (ec);
 439                                 return;
 440                         }
 441
 442                         left.Emit (ec);
 443                         right.Emit (ec);
 444                         EmitBinaryOperator (ec);
 445                 }
 446
 447                 internal override void Emit (EmitContext ec)
 448                 {
 449                         ILGenerator ig = ec.ig;
 450                         OpCode opcode;
 451
 452                         if (method != null){
 453                                 EmitMethod (ec);
 454                                 return;
 455                         }
 456
 457                         switch (NodeType){
 458                         case ExpressionType.And:
 459                                 EmitLogical (ec, true, false);
 460                                 return;
 461
 462                         case ExpressionType.Or:
 463                                 EmitLogical (ec, false, false);
 464                                 return;
 465
 466                         case ExpressionType.AndAlso:
 467                                 EmitLogical (ec, true, true);
 468                                 return;
 469
 470                         case ExpressionType.OrElse:
 471                                 EmitLogical (ec, false, true);
 472                                 return;
 473
 474                         case ExpressionType.Coalesce:
 475                                 EmitCoalesce (ec);
 476                                 return;
 477
 478                         case ExpressionType.Power:
 479                                 left.Emit (ec);
 480                                 right.Emit (ec);
 481                                 ig.Emit (OpCodes.Call, typeof (System.Math).GetMethod ("Pow"));
 482                                 return;
 483                         }
 484
 485                         EmitSimpleBinary (ec);
 486                 }
 487         }
 488 }