mcs/class/corlib/System.Reflection.Emit/ILGenerator.cs

   1
   2 //
   3 // System.Reflection.Emit/ILGenerator.cs
   4 //
   5 // Author:
   6 //   Paolo Molaro (lupus@ximian.com)
   7 //
   8 // (C) 2001 Ximian, Inc.  http://www.ximian.com
   9 //
  10
  11 using System;
  12 using System.Diagnostics.SymbolStore;
  13
  14 namespace System.Reflection.Emit {
  15
  16         internal struct ILExceptionBlock {
  17                 public const int CATCH = 0;
  18                 public const int FILTER = 1;
  19                 public const int FINALLY = 2;
  20                 public const int FAULT = 4;
  21
  22                 internal Type extype;
  23                 internal int type;
  24                 internal int start;
  25                 internal int len;
  26                 internal int filter_offset;
  27
  28                 internal void Debug () {
  29                         System.Console.Write ("\ttype="+type.ToString()+" start="+start.ToString()+" len="+len.ToString());
  30                         if (extype != null)
  31                                 System.Console.WriteLine (" extype="+extype.ToString());
  32                         else
  33                                 System.Console.WriteLine ("");
  34                 }
  35         }
  36         internal struct ILExceptionInfo {
  37                 ILExceptionBlock[] handlers;
  38                 internal int start;
  39                 int len;
  40                 internal Label end;
  41
  42                 internal void AddCatch (Type extype, int offset) {
  43                         int i;
  44                         End (offset);
  45                         add_block (offset);
  46                         i = handlers.Length - 1;
  47                         handlers [i].type = ILExceptionBlock.CATCH;
  48                         handlers [i].start = offset;
  49                         handlers [i].extype = extype;
  50                 }
  51
  52                 internal void AddFinally (int offset) {
  53                         int i;
  54                         End (offset);
  55                         add_block (offset);
  56                         i = handlers.Length - 1;
  57                         handlers [i].type = ILExceptionBlock.FINALLY;
  58                         handlers [i].start = offset;
  59                         handlers [i].extype = null;
  60                 }
  61
  62                 internal void End (int offset) {
  63                         if (handlers == null)
  64                                 return;
  65                         int i = handlers.Length - 1;
  66                         if (i >= 0)
  67                                 handlers [i].len = offset - handlers [i].start;
  68                 }
  69
  70                 internal int LastClauseType () {
  71                         if (handlers != null)
  72                                 return handlers [handlers.Length-1].type;
  73                         else
  74                                 return ILExceptionBlock.CATCH;
  75                 }
  76
  77                 internal void Debug () {
  78                         if (false) {
  79                         System.Console.WriteLine ("Handler at "+start.ToString()+ " len: "+len.ToString());
  80                         for (int i = 0; i < handlers.Length; ++i)
  81                                 handlers [i].Debug ();
  82                         }
  83                 }
  84
  85                 void add_block (int offset) {
  86                         if (handlers != null) {
  87                                 int i = handlers.Length;
  88                                 ILExceptionBlock[] new_b = new ILExceptionBlock [i + 1];
  89                                 System.Array.Copy (handlers, new_b, i);
  90                                 handlers = new_b;
  91                                 handlers [i].len = offset - handlers [i].start;
  92                         } else {
  93                                 handlers = new ILExceptionBlock [1];
  94                                 len = offset - start;
  95                         }
  96                 }
  97         }
  98
  99         public class ILGenerator: Object {
 100                 private struct LabelFixup {
 101                         public int size;
 102                         public int pos;
 103                         public int label_idx;
 104                 };
 105                 private byte[] code;
 106                 private MethodBase mbuilder; /* a MethodBuilder or ConstructorBuilder */
 107                 private int code_len;
 108                 private int max_stack;
 109                 private int cur_stack;
 110                 private LocalBuilder[] locals;
 111                 private ILExceptionInfo[] ex_handlers;
 112                 private int[] label_to_addr;
 113                 private int num_labels;
 114                 private LabelFixup[] fixups;
 115                 private int num_fixups;
 116                 private AssemblyBuilder abuilder;
 117                 private int cur_block;
 118                 private int open_blocks;
 119
 120                 internal ILGenerator (MethodBase mb, int size) {
 121                         if (size < 0)
 122                                 size = 256;
 123                         code_len = 0;
 124                         code = new byte [size];
 125                         mbuilder = mb;
 126                         cur_stack = max_stack = 0;
 127                         num_fixups = num_labels = 0;
 128                         label_to_addr = new int [16];
 129                         fixups = new LabelFixup [16];
 130                         if (mb is MethodBuilder) {
 131                                 abuilder = (AssemblyBuilder)((MethodBuilder)mb).TypeBuilder.Module.Assembly;
 132                         } else if (mb is ConstructorBuilder) {
 133                                 abuilder = (AssemblyBuilder)((ConstructorBuilder)mb).TypeBuilder.Module.Assembly;
 134                         }
 135                 }
 136
 137                 private void make_room (int nbytes) {
 138                         if (code_len + nbytes < code.Length)
 139                                 return;
 140                         byte[] new_code = new byte [code.Length * 2 + 128];
 141                         System.Array.Copy (code, 0, new_code, 0, code.Length);
 142                         code = new_code;
 143                 }
 144                 private void emit_int (int val) {
 145                         code [code_len++] = (byte) (val & 0xFF);
 146                         code [code_len++] = (byte) ((val >> 8) & 0xFF);
 147                         code [code_len++] = (byte) ((val >> 16) & 0xFF);
 148                         code [code_len++] = (byte) ((val >> 24) & 0xFF);
 149                 }
 150                 /* change to pass by ref to avoid copy */
 151                 private void ll_emit (OpCode opcode) {
 152                         /*
 153                          * there is already enough room allocated in code.
 154                          */
 155                         // access op1 and op2 directly since the Value property is useless
 156                         if (opcode.Size == 2)
 157                                 code [code_len++] = opcode.op1;
 158                         code [code_len++] = opcode.op2;
 159                         /*
 160                          * We should probably keep track of stack needs here.
 161                          * Or we may want to run the verifier on the code before saving it
 162                          * (this may be needed anyway when the ILGenerator is not used...).
 163                          */
 164                         switch (opcode.StackBehaviourPush) {
 165                         case StackBehaviour.Push1:
 166                         case StackBehaviour.Pushi:
 167                         case StackBehaviour.Pushi8:
 168                         case StackBehaviour.Pushr4:
 169                         case StackBehaviour.Pushr8:
 170                         case StackBehaviour.Pushref:
 171                         case StackBehaviour.Varpush: /* again we are conservative and assume it pushes 1 */
 172                                 cur_stack ++;
 173                                 break;
 174                         case StackBehaviour.Push1_push1:
 175                                 cur_stack += 2;
 176                                 break;
 177                         }
 178                         if (max_stack < cur_stack)
 179                                 max_stack = cur_stack;
 180                         /*
 181                          * Note that we adjust for the pop behaviour _after_ setting max_stack.
 182                          */
 183                         switch (opcode.StackBehaviourPop) {
 184                         case StackBehaviour.Varpop:
 185                                 break; /* we are conservative and assume it doesn't decrease the stack needs */
 186                         case StackBehaviour.Pop1:
 187                         case StackBehaviour.Popi:
 188                         case StackBehaviour.Popref:
 189                                 cur_stack --;
 190                                 break;
 191                         case StackBehaviour.Pop1_pop1:
 192                         case StackBehaviour.Popi_pop1:
 193                         case StackBehaviour.Popi_popi:
 194                         case StackBehaviour.Popi_popi8:
 195                         case StackBehaviour.Popi_popr4:
 196                         case StackBehaviour.Popi_popr8:
 197                         case StackBehaviour.Popref_pop1:
 198                         case StackBehaviour.Popref_popi:
 199                                 cur_stack -= 2;
 200                                 break;
 201                         case StackBehaviour.Popi_popi_popi:
 202                         case StackBehaviour.Popref_popi_popi:
 203                         case StackBehaviour.Popref_popi_popi8:
 204                         case StackBehaviour.Popref_popi_popr4:
 205                         case StackBehaviour.Popref_popi_popr8:
 206                         case StackBehaviour.Popref_popi_popref:
 207                                 cur_stack -= 3;
 208                                 break;
 209                         }
 210                 }
 211
 212                 private static int target_len (OpCode opcode) {
 213                         if (opcode.operandType == OperandType.InlineBrTarget)
 214                                 return 4;
 215                         return 1;
 216                 }
 217
 218                 private void InternalEndClause () {
 219                         switch (ex_handlers [cur_block].LastClauseType ()) {
 220                         case ILExceptionBlock.CATCH:
 221                                 // how could we optimize code size here?
 222                                 Emit (OpCodes.Leave, ex_handlers [cur_block].end);
 223                                 break;
 224                         case ILExceptionBlock.FAULT:
 225                         case ILExceptionBlock.FINALLY:
 226                                 Emit (OpCodes.Endfinally);
 227                                 break;
 228                         case ILExceptionBlock.FILTER:
 229                                 Emit (OpCodes.Endfilter);
 230                                 break;
 231                         }
 232                 }
 233
 234                 public virtual void BeginCatchBlock (Type exceptionType) {
 235                         if (open_blocks <= 0)
 236                                 throw new NotSupportedException ("Not in an exception block");
 237                         InternalEndClause ();
 238                         ex_handlers [cur_block].AddCatch (exceptionType, code_len);
 239                         //System.Console.WriteLine ("Begin catch Block: "+exceptionType.ToString());
 240                         //throw new NotImplementedException ();
 241                 }
 242                 public virtual void BeginExceptFilterBlock () {
 243                         throw new NotImplementedException ();
 244                 }
 245                 public virtual Label BeginExceptionBlock () {
 246                         //System.Console.WriteLine ("Begin Block");
 247
 248                         if (ex_handlers != null) {
 249                                 cur_block = ex_handlers.Length;
 250                                 ILExceptionInfo[] new_ex = new ILExceptionInfo [cur_block + 1];
 251                                 System.Array.Copy (ex_handlers, new_ex, cur_block);
 252                                 ex_handlers = new_ex;
 253                         } else {
 254                                 ex_handlers = new ILExceptionInfo [1];
 255                                 cur_block = 0;
 256                         }
 257                         open_blocks++;
 258                         ex_handlers [cur_block].start = code_len;
 259                         return ex_handlers [cur_block].end = DefineLabel ();
 260                 }
 261                 public virtual void BeginFaultBlock() {
 262                         if (open_blocks <= 0)
 263                                 throw new NotSupportedException ("Not in an exception block");
 264                         //System.Console.WriteLine ("Begin fault Block");
 265                         //throw new NotImplementedException ();
 266                 }
 267                 public virtual void BeginFinallyBlock() {
 268                         if (open_blocks <= 0)
 269                                 throw new NotSupportedException ("Not in an exception block");
 270                         //System.Console.WriteLine ("Begin finally Block");
 271                         InternalEndClause ();
 272                         ex_handlers [cur_block].AddFinally (code_len);
 273                         //throw new NotImplementedException ();
 274                 }
 275                 public virtual void BeginScope () {
 276                         throw new NotImplementedException ();
 277                 }
 278                 public virtual LocalBuilder DeclareLocal (Type localType) {
 279                         LocalBuilder res = new LocalBuilder (localType);
 280                         if (locals != null) {
 281                                 LocalBuilder[] new_l = new LocalBuilder [locals.Length + 1];
 282                                 System.Array.Copy (locals, new_l, locals.Length);
 283                                 new_l [locals.Length] = res;
 284                                 locals = new_l;
 285                         } else {
 286                                 locals = new LocalBuilder [1];
 287                                 locals [0] = res;
 288                         }
 289                         res.position = locals.Length - 1;
 290                         return res;
 291                 }
 292                 public virtual Label DefineLabel () {
 293                         if (num_labels >= label_to_addr.Length) {
 294                                 int[] new_l = new int [label_to_addr.Length + 16];
 295                                 System.Array.Copy (label_to_addr, new_l, label_to_addr.Length);
 296                                 label_to_addr = new_l;
 297                         }
 298                         label_to_addr [num_labels] = -1;
 299                         return new Label (num_labels++);
 300                 }
 301                 public virtual void Emit (OpCode opcode) {
 302                         make_room (2);
 303                         ll_emit (opcode);
 304                 }
 305                 public virtual void Emit (OpCode opcode, Byte val) {
 306                         make_room (3);
 307                         ll_emit (opcode);
 308                         code [code_len++] = val;
 309                 }
 310                 public virtual void Emit (OpCode opcode, ConstructorInfo constructor) {
 311                         int token = abuilder.GetToken (constructor);
 312                         make_room (6);
 313                         ll_emit (opcode);
 314                         emit_int (token);
 315                 }
 316                 public virtual void Emit (OpCode opcode, Double val) {
 317                         byte[] s = System.BitConverter.GetBytes (val);
 318                         make_room (10);
 319                         ll_emit (opcode);
 320                         System.Array.Copy (s, 0, code, code_len, 8);
 321                         code_len += 8;
 322                 }
 323                 public virtual void Emit (OpCode opcode, FieldInfo field) {
 324                         int token = abuilder.GetToken (field);
 325                         make_room (6);
 326                         ll_emit (opcode);
 327                         emit_int (token);
 328                 }
 329                 public virtual void Emit (OpCode opcode, Int16 val) {
 330                         make_room (4);
 331                         ll_emit (opcode);
 332                         code [code_len++] = (byte) (val & 0xFF);
 333                         code [code_len++] = (byte) ((val >> 8) & 0xFF);
 334                 }
 335                 public virtual void Emit (OpCode opcode, Int32 val) {
 336                         make_room (6);
 337                         ll_emit (opcode);
 338                         emit_int (val);
 339                 }
 340                 public virtual void Emit (OpCode opcode, Int64 val) {
 341                         make_room (10);
 342                         ll_emit (opcode);
 343                         code [code_len++] = (byte) (val & 0xFF);
 344                         code [code_len++] = (byte) ((val >> 8) & 0xFF);
 345                         code [code_len++] = (byte) ((val >> 16) & 0xFF);
 346                         code [code_len++] = (byte) ((val >> 24) & 0xFF);
 347                         code [code_len++] = (byte) ((val >> 32) & 0xFF);
 348                         code [code_len++] = (byte) ((val >> 40) & 0xFF);
 349                         code [code_len++] = (byte) ((val >> 48) & 0xFF);
 350                         code [code_len++] = (byte) ((val >> 56) & 0xFF);
 351                 }
 352                 public virtual void Emit (OpCode opcode, Label label) {
 353                         int tlen = target_len (opcode);
 354                         make_room (6);
 355                         ll_emit (opcode);
 356                         if (num_fixups >= fixups.Length) {
 357                                 LabelFixup[] newf = new LabelFixup [fixups.Length + 16];
 358                                 System.Array.Copy (fixups, newf, fixups.Length);
 359                                 fixups = newf;
 360                         }
 361                         fixups [num_fixups].size = tlen;
 362                         fixups [num_fixups].pos = code_len;
 363                         fixups [num_fixups].label_idx = label.label;
 364                         num_fixups++;
 365                         code_len += tlen;
 366
 367                 }
 368                 public virtual void Emit (OpCode opcode, Label[] labels) {
 369                         /* opcode needs to be switch. */
 370                         int count = labels.Length;
 371                         make_room (6 + count * 4);
 372                         ll_emit (opcode);
 373                         emit_int (count);
 374                         if (num_fixups + count >= fixups.Length) {
 375                                 LabelFixup[] newf = new LabelFixup [fixups.Length + count + 16];
 376                                 System.Array.Copy (fixups, newf, fixups.Length);
 377                                 fixups = newf;
 378                         }
 379                         for (int i = 0; i < count; ++i) {
 380                                 fixups [num_fixups].size = 4;
 381                                 fixups [num_fixups].pos = code_len;
 382                                 fixups [num_fixups].label_idx = labels [i].label;
 383                                 num_fixups++;
 384                                 code_len += 4;
 385                         }
 386                 }
 387                 public virtual void Emit (OpCode opcode, LocalBuilder lbuilder) {
 388                         make_room (6);
 389                         ll_emit (opcode);
 390                         code [code_len++] = (byte) (lbuilder.position & 0xFF);
 391                         if (opcode.operandType == OperandType.InlineVar) {
 392                                 code [code_len++] = (byte) ((lbuilder.position >> 8) & 0xFF);
 393                         }
 394                 }
 395                 public virtual void Emit (OpCode opcode, MethodInfo method) {
 396                         int token = abuilder.GetToken (method);
 397                         make_room (6);
 398                         ll_emit (opcode);
 399                         emit_int (token);
 400                 }
 401                 [CLSCompliant(false)]
 402                 public virtual void Emit (OpCode opcode, sbyte val) {
 403                         make_room (3);
 404                         ll_emit (opcode);
 405                         code [code_len++] = (byte)val;
 406                 }
 407
 408                 [MonoTODO]
 409                 public virtual void Emit (OpCode opcode, SignatureHelper shelper) {
 410                         int token = 0; // FIXME: request a token from the modulebuilder
 411                         make_room (6);
 412                         ll_emit (opcode);
 413                         emit_int (token);
 414                 }
 415                 public virtual void Emit (OpCode opcode, float val) {
 416                         byte[] s = System.BitConverter.GetBytes (val);
 417                         make_room (6);
 418                         ll_emit (opcode);
 419                         System.Array.Copy (s, 0, code, code_len, 4);
 420                         code_len += 4;
 421                 }
 422                 public virtual void Emit (OpCode opcode, string val) {
 423                         int token = abuilder.GetToken (val);
 424                         make_room (3);
 425                         ll_emit (opcode);
 426                         emit_int (token);
 427                 }
 428                 public virtual void Emit (OpCode opcode, Type type) {
 429                         make_room (6);
 430                         ll_emit (opcode);
 431                         emit_int (abuilder.GetToken (type));
 432                 }
 433
 434                 public void EmitCall (OpCode opcode, MethodInfo methodinfo, Type[] optionalParamTypes) {
 435                         throw new NotImplementedException ();
 436                 }
 437                 public void EmitCalli (OpCode opcode, CallingConventions call_conv, Type returnType, Type[] paramTypes, Type[] optionalParamTypes) {
 438                         throw new NotImplementedException ();
 439                 }
 440
 441                 public virtual void EmitWriteLine (FieldInfo field) {
 442                         throw new NotImplementedException ();
 443                 }
 444                 public virtual void EmitWriteLine (LocalBuilder lbuilder) {
 445                         throw new NotImplementedException ();
 446                 }
 447                 public virtual void EmitWriteLine (string val) {
 448                         throw new NotImplementedException ();
 449                 }
 450
 451                 public virtual void EndExceptionBlock () {
 452                         if (open_blocks <= 0)
 453                                 throw new NotSupportedException ("Not in an exception block");
 454                         InternalEndClause ();
 455                         MarkLabel (ex_handlers [cur_block].end);
 456                         ex_handlers [cur_block].End (code_len);
 457                         ex_handlers [cur_block].Debug ();
 458                         --cur_block;
 459                         --open_blocks;
 460                         //System.Console.WriteLine ("End Block");
 461                         //throw new NotImplementedException ();
 462                 }
 463                 public virtual void EndScope () {
 464                         throw new NotImplementedException ();
 465                 }
 466                 public virtual void MarkLabel (Label loc) {
 467                         if (loc.label < 0 || loc.label >= num_labels)
 468                                 throw new System.ArgumentException ("The label is not valid");
 469                         if (label_to_addr [loc.label] >= 0)
 470                                 throw new System.ArgumentException ("The label was already defined");
 471                         label_to_addr [loc.label] = code_len;
 472                 }
 473                 public virtual void MarkSequencePoint (ISymbolDocumentWriter document, int startLine, int startColumn, int endLine, int EndColumn) {
 474                         throw new NotImplementedException ();
 475                 }
 476                 public virtual void ThrowException (Type exceptionType) {
 477                         throw new NotImplementedException ();
 478                 }
 479                 public virtual void UsingNamespace (String usingNamespace) {
 480                         throw new NotImplementedException ();
 481                 }
 482
 483                 internal void label_fixup () {
 484                         int i;
 485                         for (i = 0; i < num_fixups; ++i) {
 486                                 int diff = label_to_addr [fixups [i].label_idx] - fixups [i].pos;
 487                                 if (fixups [i].size == 1) {
 488                                         code [fixups [i].pos] = (byte)((sbyte) diff - 1);
 489                                 } else {
 490                                         int old_cl = code_len;
 491                                         code_len = fixups [i].pos;
 492                                         emit_int (diff - 4);
 493                                         code_len = old_cl;
 494                                 }
 495                         }
 496                 }
 497         }
 498 }