mcs/gmcs/codegen.cs

   1 //
   2 // codegen.cs: The code generator
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001 Ximian, Inc.
   8 //
   9
  10 using System;
  11 using System.IO;
  12 using System.Collections;
  13 using System.Reflection;
  14 using System.Reflection.Emit;
  15 using System.Runtime.InteropServices;
  16 using System.Security.Cryptography;
  17
  18 using Mono.Security.Cryptography;
  19
  20 namespace Mono.CSharp {
  21
  22         /// <summary>
  23         ///    Code generator class.
  24         /// </summary>
  25         public class CodeGen {
  26                 static AppDomain current_domain;
  27                 static public SymbolWriter SymbolWriter;
  28
  29                 public static AssemblyClass Assembly;
  30                 public static ModuleClass Module;
  31
  32                 static CodeGen ()
  33                 {
  34                         Assembly = new AssemblyClass ();
  35                         Module = new ModuleClass (RootContext.Unsafe);
  36                 }
  37
  38                 public static string Basename (string name)
  39                 {
  40                         int pos = name.LastIndexOf ('/');
  41
  42                         if (pos != -1)
  43                                 return name.Substring (pos + 1);
  44
  45                         pos = name.LastIndexOf ('\\');
  46                         if (pos != -1)
  47                                 return name.Substring (pos + 1);
  48
  49                         return name;
  50                 }
  51
  52                 public static string Dirname (string name)
  53                 {
  54                         int pos = name.LastIndexOf ('/');
  55
  56                         if (pos != -1)
  57                                 return name.Substring (0, pos);
  58
  59                         pos = name.LastIndexOf ('\\');
  60                         if (pos != -1)
  61                                 return name.Substring (0, pos);
  62
  63                         return ".";
  64                 }
  65
  66                 static string TrimExt (string name)
  67                 {
  68                         int pos = name.LastIndexOf ('.');
  69
  70                         return name.Substring (0, pos);
  71                 }
  72
  73                 static public string FileName;
  74
  75                 //
  76                 // Initializes the symbol writer
  77                 //
  78                 static void InitializeSymbolWriter ()
  79                 {
  80                         SymbolWriter = SymbolWriter.GetSymbolWriter (Module.Builder);
  81
  82                         //
  83                         // If we got an ISymbolWriter instance, initialize it.
  84                         //
  85                         if (SymbolWriter == null) {
  86                                 Report.Warning (
  87                                         -18, "Could not find the symbol writer assembly (Mono.CSharp.Debugger.dll). This is normally an installation problem. Please make sure to compile and install the mcs/class/Mono.CSharp.Debugger directory.");
  88                                 return;
  89                         }
  90                 }
  91
  92                 //
  93                 // Initializes the code generator variables
  94                 //
  95                 static public void Init (string name, string output, bool want_debugging_support)
  96                 {
  97                         FileName = output;
  98                         AssemblyName an = Assembly.GetAssemblyName (name, output);
  99
 100                         current_domain = AppDomain.CurrentDomain;
 101
 102                         try {
 103                                 Assembly.Builder = current_domain.DefineDynamicAssembly (an,
 104                                         AssemblyBuilderAccess.Save, Dirname (name));
 105                         }
 106                         catch (ArgumentException) {
 107                                 // specified key may not be exportable outside it's container
 108                                 if (RootContext.StrongNameKeyContainer != null) {
 109                                         Report.Error (1548, "Could not access the key inside the container `" +
 110                                                 RootContext.StrongNameKeyContainer + "'.");
 111                                         Environment.Exit (1);
 112                                 }
 113                                 throw;
 114                         }
 115                         catch (CryptographicException) {
 116                                 if ((RootContext.StrongNameKeyContainer != null) || (RootContext.StrongNameKeyFile != null)) {
 117                                         Report.Error (1548, "Could not use the specified key to strongname the assembly.");
 118                                         Environment.Exit (1);
 119                                 }
 120                                 throw;
 121                         }
 122
 123                         //
 124                         // Pass a path-less name to DefineDynamicModule.  Wonder how
 125                         // this copes with output in different directories then.
 126                         // FIXME: figure out how this copes with --output /tmp/blah
 127                         //
 128                         // If the third argument is true, the ModuleBuilder will dynamically
 129                         // load the default symbol writer.
 130                         //
 131                         Module.Builder = Assembly.Builder.DefineDynamicModule (
 132                                 Basename (name), Basename (output), want_debugging_support);
 133
 134                         if (want_debugging_support)
 135                                 InitializeSymbolWriter ();
 136                 }
 137
 138                 static public void Save (string name)
 139                 {
 140                         try {
 141                                 Assembly.Builder.Save (Basename (name));
 142                         }
 143                         catch (COMException) {
 144                                 if ((RootContext.StrongNameKeyFile == null) || (!RootContext.StrongNameDelaySign))
 145                                         throw;
 146
 147                                 // FIXME: it seems Microsoft AssemblyBuilder doesn't like to delay sign assemblies
 148                                 Report.Error (1548, "Couldn't delay-sign the assembly with the '" +
 149                                         RootContext.StrongNameKeyFile +
 150                                         "', Use MCS with the Mono runtime or CSC to compile this assembly.");
 151                         }
 152                         catch (System.IO.IOException io) {
 153                                 Report.Error (16, "Could not write to file `"+name+"', cause: " + io.Message);
 154                         }
 155                 }
 156         }
 157
 158         //
 159         // Provides "local" store across code that can yield: locals
 160         // or fields, notice that this should not be used by anonymous
 161         // methods to create local storage, those only require
 162         // variable mapping.
 163         //
 164         public class VariableStorage {
 165                 ILGenerator ig;
 166                 FieldBuilder fb;
 167                 LocalBuilder local;
 168
 169                 static int count;
 170
 171                 public VariableStorage (EmitContext ec, Type t)
 172                 {
 173                         count++;
 174                         if (ec.InIterator)
 175                                 fb = IteratorHandler.Current.MapVariable ("s_", count.ToString (), t);
 176                         else
 177                                 local = ec.ig.DeclareLocal (t);
 178                         ig = ec.ig;
 179                 }
 180
 181                 public void EmitThis ()
 182                 {
 183                         if (fb != null)
 184                                 ig.Emit (OpCodes.Ldarg_0);
 185                 }
 186
 187                 public void EmitStore ()
 188                 {
 189                         if (fb == null)
 190                                 ig.Emit (OpCodes.Stloc, local);
 191                         else
 192                                 ig.Emit (OpCodes.Stfld, fb);
 193                 }
 194
 195                 public void EmitLoad ()
 196                 {
 197                         if (fb == null)
 198                                 ig.Emit (OpCodes.Ldloc, local);
 199                         else
 200                                 ig.Emit (OpCodes.Ldfld, fb);
 201                 }
 202
 203                 public void EmitCall (MethodInfo mi)
 204                 {
 205                         // FIXME : we should handle a call like tostring
 206                         // here, where boxing is needed. However, we will
 207                         // never encounter that with the current usage.
 208
 209                         bool value_type_call;
 210                         EmitThis ();
 211                         if (fb == null) {
 212                                 value_type_call = local.LocalType.IsValueType;
 213
 214                                 if (value_type_call)
 215                                         ig.Emit (OpCodes.Ldloca, local);
 216                                 else
 217                                         ig.Emit (OpCodes.Ldloc, local);
 218                         } else {
 219                                 value_type_call = fb.FieldType.IsValueType;
 220
 221                                 if (value_type_call)
 222                                         ig.Emit (OpCodes.Ldflda, fb);
 223                                 else
 224                                         ig.Emit (OpCodes.Ldfld, fb);
 225                         }
 226
 227                         ig.Emit (value_type_call ? OpCodes.Call : OpCodes.Callvirt, mi);
 228                 }
 229         }
 230
 231         /// <summary>
 232         ///   An Emit Context is created for each body of code (from methods,
 233         ///   properties bodies, indexer bodies or constructor bodies)
 234         /// </summary>
 235         public class EmitContext {
 236                 public DeclSpace DeclSpace;
 237                 public DeclSpace TypeContainer;
 238                 public ILGenerator   ig;
 239
 240                 /// <summary>
 241                 ///   This variable tracks the `checked' state of the compilation,
 242                 ///   it controls whether we should generate code that does overflow
 243                 ///   checking, or if we generate code that ignores overflows.
 244                 ///
 245                 ///   The default setting comes from the command line option to generate
 246                 ///   checked or unchecked code plus any source code changes using the
 247                 ///   checked/unchecked statements or expressions.   Contrast this with
 248                 ///   the ConstantCheckState flag.
 249                 /// </summary>
 250
 251                 public bool CheckState;
 252
 253                 /// <summary>
 254                 ///   The constant check state is always set to `true' and cant be changed
 255                 ///   from the command line.  The source code can change this setting with
 256                 ///   the `checked' and `unchecked' statements and expressions.
 257                 /// </summary>
 258                 public bool ConstantCheckState;
 259
 260                 /// <summary>
 261                 ///   Whether we are emitting code inside a static or instance method
 262                 /// </summary>
 263                 public bool IsStatic;
 264
 265                 /// <summary>
 266                 ///   Whether we are emitting a field initializer
 267                 /// </summary>
 268                 public bool IsFieldInitializer;
 269
 270                 /// <summary>
 271                 ///   The value that is allowed to be returned or NULL if there is no
 272                 ///   return type.
 273                 /// </summary>
 274                 public Type ReturnType;
 275
 276                 /// <summary>
 277                 ///   Points to the Type (extracted from the TypeContainer) that
 278                 ///   declares this body of code
 279                 /// </summary>
 280                 public Type ContainerType;
 281
 282                 /// <summary>
 283                 ///   Whether this is generating code for a constructor
 284                 /// </summary>
 285                 public bool IsConstructor;
 286
 287                 /// <summary>
 288                 ///   Whether we're control flow analysis enabled
 289                 /// </summary>
 290                 public bool DoFlowAnalysis;
 291
 292                 /// <summary>
 293                 ///   Keeps track of the Type to LocalBuilder temporary storage created
 294                 ///   to store structures (used to compute the address of the structure
 295                 ///   value on structure method invocations)
 296                 /// </summary>
 297                 public Hashtable temporary_storage;
 298
 299                 public Block CurrentBlock;
 300
 301                 public int CurrentFile;
 302
 303                 /// <summary>
 304                 ///   The location where we store the return value.
 305                 /// </summary>
 306                 LocalBuilder return_value;
 307
 308                 /// <summary>
 309                 ///   The location where return has to jump to return the
 310                 ///   value
 311                 /// </summary>
 312                 public Label ReturnLabel;
 313
 314                 /// <summary>
 315                 ///   If we already defined the ReturnLabel
 316                 /// </summary>
 317                 public bool HasReturnLabel;
 318
 319                 /// <summary>
 320                 ///   Whether we are inside an iterator block.
 321                 /// </summary>
 322                 public bool InIterator;
 323
 324                 public bool IsLastStatement;
 325
 326                 /// <summary>
 327                 ///   Whether remapping of locals, parameters and fields is turned on.
 328                 ///   Used by iterators and anonymous methods.
 329                 /// </summary>
 330                 public bool RemapToProxy;
 331
 332                 /// <summary>
 333                 ///  Whether we are inside an unsafe block
 334                 /// </summary>
 335                 public bool InUnsafe;
 336
 337                 /// <summary>
 338                 ///  Whether we are in a `fixed' initialization
 339                 /// </summary>
 340                 public bool InFixedInitializer;
 341
 342                 /// <summary>
 343                 ///  Whether we are inside an anonymous method.
 344                 /// </summary>
 345                 public bool InAnonymousMethod;
 346
 347                 /// <summary>
 348                 ///   Location for this EmitContext
 349                 /// </summary>
 350                 public Location loc;
 351
 352                 /// <summary>
 353                 ///   Used to flag that it is ok to define types recursively, as the
 354                 ///   expressions are being evaluated as part of the type lookup
 355                 ///   during the type resolution process
 356                 /// </summary>
 357                 public bool ResolvingTypeTree;
 358
 359                 /// <summary>
 360                 ///   Inside an enum definition, we do not resolve enumeration values
 361                 ///   to their enumerations, but rather to the underlying type/value
 362                 ///   This is so EnumVal + EnumValB can be evaluated.
 363                 ///
 364                 ///   There is no "E operator + (E x, E y)", so during an enum evaluation
 365                 ///   we relax the rules
 366                 /// </summary>
 367                 public bool InEnumContext;
 368
 369                 FlowBranching current_flow_branching;
 370
 371                 public EmitContext (DeclSpace parent, DeclSpace ds, Location l, ILGenerator ig,
 372                                     Type return_type, int code_flags, bool is_constructor)
 373                 {
 374                         this.ig = ig;
 375
 376                         TypeContainer = parent;
 377                         DeclSpace = ds;
 378                         CheckState = RootContext.Checked;
 379                         ConstantCheckState = true;
 380
 381                         IsStatic = (code_flags & Modifiers.STATIC) != 0;
 382                         InIterator = (code_flags & Modifiers.METHOD_YIELDS) != 0;
 383                         RemapToProxy = InIterator;
 384                         ReturnType = return_type;
 385                         IsConstructor = is_constructor;
 386                         CurrentBlock = null;
 387                         CurrentFile = 0;
 388
 389                         if (parent != null){
 390                                 // Can only be null for the ResolveType contexts.
 391                                 ContainerType = parent.TypeBuilder;
 392                                 if (parent.UnsafeContext)
 393                                         InUnsafe = true;
 394                                 else
 395                                         InUnsafe = (code_flags & Modifiers.UNSAFE) != 0;
 396                         }
 397                         loc = l;
 398
 399                         if (ReturnType == TypeManager.void_type)
 400                                 ReturnType = null;
 401                 }
 402
 403                 public EmitContext (TypeContainer tc, Location l, ILGenerator ig,
 404                                     Type return_type, int code_flags, bool is_constructor)
 405                         : this (tc, tc, l, ig, return_type, code_flags, is_constructor)
 406                 {
 407                 }
 408
 409                 public EmitContext (TypeContainer tc, Location l, ILGenerator ig,
 410                                     Type return_type, int code_flags)
 411                         : this (tc, tc, l, ig, return_type, code_flags, false)
 412                 {
 413                 }
 414
 415                 public FlowBranching CurrentBranching {
 416                         get {
 417                                 return current_flow_branching;
 418                         }
 419                 }
 420
 421                 // <summary>
 422                 //   Starts a new code branching.  This inherits the state of all local
 423                 //   variables and parameters from the current branching.
 424                 // </summary>
 425                 public FlowBranching StartFlowBranching (FlowBranching.BranchingType type, Location loc)
 426                 {
 427                         current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, null, loc);
 428                         return current_flow_branching;
 429                 }
 430
 431                 // <summary>
 432                 //   Starts a new code branching for block `block'.
 433                 // </summary>
 434                 public FlowBranching StartFlowBranching (Block block)
 435                 {
 436                         FlowBranching.BranchingType type;
 437
 438                         if (CurrentBranching.Type == FlowBranching.BranchingType.Switch)
 439                                 type = FlowBranching.BranchingType.SwitchSection;
 440                         else
 441                                 type = FlowBranching.BranchingType.Block;
 442
 443                         current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, block, block.StartLocation);
 444                         return current_flow_branching;
 445                 }
 446
 447                 // <summary>
 448                 //   Ends a code branching.  Merges the state of locals and parameters
 449                 //   from all the children of the ending branching.
 450                 // </summary>
 451                 public FlowBranching.UsageVector DoEndFlowBranching ()
 452                 {
 453                         FlowBranching old = current_flow_branching;
 454                         current_flow_branching = current_flow_branching.Parent;
 455
 456                         return current_flow_branching.MergeChild (old);
 457                 }
 458
 459                 // <summary>
 460                 //   Ends a code branching.  Merges the state of locals and parameters
 461                 //   from all the children of the ending branching.
 462                 // </summary>
 463                 public FlowBranching.Reachability EndFlowBranching ()
 464                 {
 465                         FlowBranching.UsageVector vector = DoEndFlowBranching ();
 466
 467                         return vector.Reachability;
 468                 }
 469
 470                 // <summary>
 471                 //   Kills the current code branching.  This throws away any changed state
 472                 //   information and should only be used in case of an error.
 473                 // </summary>
 474                 public void KillFlowBranching ()
 475                 {
 476                         current_flow_branching = current_flow_branching.Parent;
 477                 }
 478
 479                 public void EmitTopBlock (Block block, InternalParameters ip, Location loc)
 480                 {
 481                         bool unreachable = false;
 482
 483                         if (!Location.IsNull (loc))
 484                                 CurrentFile = loc.File;
 485
 486                         if (block != null){
 487                             try {
 488                                 int errors = Report.Errors;
 489
 490                                 block.EmitMeta (this, ip);
 491
 492                                 if (Report.Errors == errors){
 493                                         bool old_do_flow_analysis = DoFlowAnalysis;
 494                                         DoFlowAnalysis = true;
 495
 496                                         current_flow_branching = FlowBranching.CreateBranching (
 497                                                 null, FlowBranching.BranchingType.Block, block, loc);
 498
 499                                         if (!block.Resolve (this)) {
 500                                                 current_flow_branching = null;
 501                                                 DoFlowAnalysis = old_do_flow_analysis;
 502                                                 return;
 503                                         }
 504
 505                                         FlowBranching.Reachability reachability = current_flow_branching.MergeTopBlock ();
 506                                         current_flow_branching = null;
 507
 508                                         DoFlowAnalysis = old_do_flow_analysis;
 509
 510                                         block.Emit (this);
 511
 512                                         if (reachability.AlwaysReturns ||
 513                                             reachability.AlwaysThrows ||
 514                                             reachability.IsUnreachable)
 515                                                 unreachable = true;
 516                                         }
 517 #if FIXME
 518                             } catch (Exception e) {
 519                                         Console.WriteLine ("Exception caught by the compiler while compiling:");
 520                                         Console.WriteLine ("   Block that caused the problem begin at: " + loc);
 521
 522                                         if (CurrentBlock != null){
 523                                                 Console.WriteLine ("                     Block being compiled: [{0},{1}]",
 524                                                                    CurrentBlock.StartLocation, CurrentBlock.EndLocation);
 525                                         }
 526                                         Console.WriteLine (e.GetType ().FullName + ": " + e.Message);
 527                                         Console.WriteLine (Report.FriendlyStackTrace (e));
 528
 529                                         Environment.Exit (1);
 530 #else
 531                             } finally {
 532 #endif
 533                             }
 534                         }
 535
 536                         if (ReturnType != null && !unreachable){
 537                                 if (!InIterator){
 538                                         Report.Error (161, loc, "Not all code paths return a value");
 539                                         return;
 540                                 }
 541                         }
 542
 543                         if (HasReturnLabel)
 544                                 ig.MarkLabel (ReturnLabel);
 545                         if (return_value != null){
 546                                 ig.Emit (OpCodes.Ldloc, return_value);
 547                                 ig.Emit (OpCodes.Ret);
 548                         } else {
 549                                 //
 550                                 // If `HasReturnLabel' is set, then we already emitted a
 551                                 // jump to the end of the method, so we must emit a `ret'
 552                                 // there.
 553                                 //
 554                                 // Unfortunately, System.Reflection.Emit automatically emits
 555                                 // a leave to the end of a finally block.  This is a problem
 556                                 // if no code is following the try/finally block since we may
 557                                 // jump to a point after the end of the method.
 558                                 // As a workaround, we're always creating a return label in
 559                                 // this case.
 560                                 //
 561
 562                                 if ((block != null) && block.IsDestructor) {
 563                                         // Nothing to do; S.R.E automatically emits a leave.
 564                                 } else if (HasReturnLabel || (!unreachable && !InIterator)) {
 565                                         if (ReturnType != null)
 566                                                 ig.Emit (OpCodes.Ldloc, TemporaryReturn ());
 567                                         ig.Emit (OpCodes.Ret);
 568                                 }
 569                         }
 570                 }
 571
 572                 /// <summary>
 573                 ///   This is called immediately before emitting an IL opcode to tell the symbol
 574                 ///   writer to which source line this opcode belongs.
 575                 /// </summary>
 576                 public void Mark (Location loc, bool check_file)
 577                 {
 578                         if ((CodeGen.SymbolWriter == null) || Location.IsNull (loc))
 579                                 return;
 580
 581                         if (check_file && (CurrentFile != loc.File))
 582                                 return;
 583
 584                         ig.MarkSequencePoint (null, loc.Row, 0, 0, 0);
 585                 }
 586
 587                 /// <summary>
 588                 ///   Returns a temporary storage for a variable of type t as
 589                 ///   a local variable in the current body.
 590                 /// </summary>
 591                 public LocalBuilder GetTemporaryLocal (Type t)
 592                 {
 593                         LocalBuilder location = null;
 594
 595                         if (temporary_storage != null){
 596                                 object o = temporary_storage [t];
 597                                 if (o != null){
 598                                         if (o is ArrayList){
 599                                                 ArrayList al = (ArrayList) o;
 600
 601                                                 for (int i = 0; i < al.Count; i++){
 602                                                         if (al [i] != null){
 603                                                                 location = (LocalBuilder) al [i];
 604                                                                 al [i] = null;
 605                                                                 break;
 606                                                         }
 607                                                 }
 608                                         } else
 609                                                 location = (LocalBuilder) o;
 610                                         if (location != null)
 611                                                 return location;
 612                                 }
 613                         }
 614
 615                         return ig.DeclareLocal (t);
 616                 }
 617
 618                 public void FreeTemporaryLocal (LocalBuilder b, Type t)
 619                 {
 620                         if (temporary_storage == null){
 621                                 temporary_storage = new Hashtable ();
 622                                 temporary_storage [t] = b;
 623                                 return;
 624                         }
 625                         object o = temporary_storage [t];
 626                         if (o == null){
 627                                 temporary_storage [t] = b;
 628                                 return;
 629                         }
 630                         if (o is ArrayList){
 631                                 ArrayList al = (ArrayList) o;
 632                                 for (int i = 0; i < al.Count; i++){
 633                                         if (al [i] == null){
 634                                                 al [i] = b;
 635                                                 return;
 636                                         }
 637                                 }
 638                                 al.Add (b);
 639                                 return;
 640                         }
 641                         ArrayList replacement = new ArrayList ();
 642                         replacement.Add (o);
 643                         temporary_storage.Remove (t);
 644                         temporary_storage [t] = replacement;
 645                 }
 646
 647                 /// <summary>
 648                 ///   Current loop begin and end labels.
 649                 /// </summary>
 650                 public Label LoopBegin, LoopEnd;
 651
 652                 /// <summary>
 653                 ///   Default target in a switch statement.   Only valid if
 654                 ///   InSwitch is true
 655                 /// </summary>
 656                 public Label DefaultTarget;
 657
 658                 /// <summary>
 659                 ///   If this is non-null, points to the current switch statement
 660                 /// </summary>
 661                 public Switch Switch;
 662
 663                 /// <summary>
 664                 ///   ReturnValue creates on demand the LocalBuilder for the
 665                 ///   return value from the function.  By default this is not
 666                 ///   used.  This is only required when returns are found inside
 667                 ///   Try or Catch statements.
 668                 /// </summary>
 669                 public LocalBuilder TemporaryReturn ()
 670                 {
 671                         if (return_value == null){
 672                                 return_value = ig.DeclareLocal (ReturnType);
 673                                 ReturnLabel = ig.DefineLabel ();
 674                                 HasReturnLabel = true;
 675                         }
 676
 677                         return return_value;
 678                 }
 679
 680                 public void NeedReturnLabel ()
 681                 {
 682                         if (!HasReturnLabel) {
 683                                 ReturnLabel = ig.DefineLabel ();
 684                                 HasReturnLabel = true;
 685                         }
 686                 }
 687
 688                 //
 689                 // Creates a field `name' with the type `t' on the proxy class
 690                 //
 691                 public FieldBuilder MapVariable (string name, Type t)
 692                 {
 693                         if (InIterator){
 694                                 return IteratorHandler.Current.MapVariable ("v_", name, t);
 695                         }
 696
 697                         throw new Exception ("MapVariable for an unknown state");
 698                 }
 699
 700                 //
 701                 // Invoke this routine to remap a VariableInfo into the
 702                 // proper MemberAccess expression
 703                 //
 704                 public Expression RemapLocal (LocalInfo local_info)
 705                 {
 706                         FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc);
 707                         fe.InstanceExpression = new ProxyInstance ();
 708                         return fe.DoResolve (this);
 709                 }
 710
 711                 public Expression RemapLocalLValue (LocalInfo local_info, Expression right_side)
 712                 {
 713                         FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc);
 714                         fe.InstanceExpression = new ProxyInstance ();
 715                         return fe.DoResolveLValue (this, right_side);
 716                 }
 717
 718                 public Expression RemapParameter (int idx)
 719                 {
 720                         FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc);
 721                         fe.InstanceExpression = new ProxyInstance ();
 722                         return fe.DoResolve (this);
 723                 }
 724
 725                 public Expression RemapParameterLValue (int idx, Expression right_side)
 726                 {
 727                         FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc);
 728                         fe.InstanceExpression = new ProxyInstance ();
 729                         return fe.DoResolveLValue (this, right_side);
 730                 }
 731
 732                 //
 733                 // Emits the proper object to address fields on a remapped
 734                 // variable/parameter to field in anonymous-method/iterator proxy classes.
 735                 //
 736                 public void EmitThis ()
 737                 {
 738                         if (InIterator){
 739                                 ig.Emit (OpCodes.Ldarg_0);
 740                                 if (!IsStatic){
 741                                         FieldBuilder this_field = IteratorHandler.Current.this_field;
 742                                         if (TypeManager.IsValueType (this_field.FieldType))
 743                                                 ig.Emit (OpCodes.Ldflda, this_field);
 744                                         else
 745                                                 ig.Emit (OpCodes.Ldfld, this_field);
 746                                 }
 747                         } else
 748                                 ig.Emit (OpCodes.Ldarg_0);
 749                 }
 750
 751                 public Expression GetThis (Location loc)
 752                 {
 753                         This my_this;
 754                         if (CurrentBlock != null)
 755                                 my_this = new This (CurrentBlock, loc);
 756                         else
 757                                 my_this = new This (loc);
 758
 759                         if (!my_this.ResolveBase (this))
 760                                 my_this = null;
 761
 762                         return my_this;
 763                 }
 764         }
 765
 766
 767         public abstract class CommonAssemblyModulClass: Attributable {
 768                 static string[] attribute_targets = new string [] { "assembly", "module" };
 769
 770                 protected CommonAssemblyModulClass ():
 771                         base (null)
 772                 {
 773                 }
 774
 775                 public void AddAttributes (ArrayList attrs)
 776                 {
 777                         if (OptAttributes == null) {
 778                                 OptAttributes = new Attributes (attrs);
 779                                 return;
 780                         }
 781                         OptAttributes.AddAttributes (attrs);
 782                         OptAttributes.CheckTargets (ValidAttributeTargets);
 783                 }
 784
 785                 public virtual void Emit (TypeContainer tc)
 786                 {
 787                         if (OptAttributes == null)
 788                                 return;
 789
 790                         EmitContext ec = new EmitContext (tc, Mono.CSharp.Location.Null, null, null, 0, false);
 791                         OptAttributes.Emit (ec, this);
 792                 }
 793
 794                 protected Attribute GetClsCompliantAttribute ()
 795                 {
 796                         if (OptAttributes == null)
 797                                 return null;
 798
 799                         EmitContext temp_ec = new EmitContext (new TypeContainer (), Mono.CSharp.Location.Null, null, null, 0, false);
 800                         Attribute a = OptAttributes.Search (TypeManager.cls_compliant_attribute_type, temp_ec);
 801                         if (a != null) {
 802                                 a.Resolve (temp_ec);
 803                         }
 804                         return a;
 805                 }
 806
 807                 protected override string[] ValidAttributeTargets {
 808                         get {
 809                                 return attribute_targets;
 810                         }
 811                 }
 812         }
 813
 814         public class AssemblyClass: CommonAssemblyModulClass {
 815                 // TODO: make it private and move all builder based methods here
 816                 public AssemblyBuilder Builder;
 817
 818                 bool is_cls_compliant;
 819
 820                 public AssemblyClass (): base ()
 821                 {
 822                         is_cls_compliant = false;
 823                 }
 824
 825                 public bool IsClsCompliant {
 826                         get {
 827                                 return is_cls_compliant;
 828                         }
 829                         }
 830
 831                 public override AttributeTargets AttributeTargets {
 832                         get {
 833                                 return AttributeTargets.Assembly;
 834                         }
 835                 }
 836
 837                 public override bool IsClsCompliaceRequired(DeclSpace ds)
 838                 {
 839                         return is_cls_compliant;
 840                 }
 841
 842                 public void ResolveClsCompliance ()
 843                 {
 844                         Attribute a = GetClsCompliantAttribute ();
 845                         if (a == null)
 846                                 return;
 847
 848                         is_cls_compliant = a.GetClsCompliantAttributeValue (null);
 849                 }
 850
 851                 public AssemblyName GetAssemblyName (string name, string output)
 852                 {
 853                         if (OptAttributes != null) {
 854                                foreach (Attribute a in OptAttributes.Attrs) {
 855                                         if (a.Target != "assembly")
 856                                                 continue;
 857                                        // TODO: This code is buggy: comparing Attribute name without resolving it is wrong.
 858                                        //       However, this is invoked by CodeGen.Init, at which time none of the namespaces
 859                                        //       are loaded yet.
 860                                         switch (a.Name) {
 861                                                 case "AssemblyKeyFile":
 862                                                case "AssemblyKeyFileAttribute":
 863                                                case "System.Reflection.AssemblyKeyFileAttribute":
 864                                                         if (RootContext.StrongNameKeyFile != null) {
 865                                                                 Report.Warning (1616, "Compiler option -keyfile overrides " +
 866                                                                         "AssemblyKeyFileAttribute");
 867                                                         }
 868                                                         else {
 869                                                                 string value = a.GetString ();
 870                                                                 if (value != String.Empty)
 871                                                                         RootContext.StrongNameKeyFile = value;
 872                                                         }
 873                                                         break;
 874                                                 case "AssemblyKeyName":
 875                                                case "AssemblyKeyNameAttribute":
 876                                                case "System.Reflection.AssemblyKeyNameAttribute":
 877                                                         if (RootContext.StrongNameKeyContainer != null) {
 878                                                                 Report.Warning (1616, "Compiler option -keycontainer overrides " +
 879                                                                         "AssemblyKeyNameAttribute");
 880                                                         }
 881                                                         else {
 882                                                                 string value = a.GetString ();
 883                                                                 if (value != String.Empty)
 884                                                                         RootContext.StrongNameKeyContainer = value;
 885                                                         }
 886                                                         break;
 887                                                 case "AssemblyDelaySign":
 888                                                case "AssemblyDelaySignAttribute":
 889                                                case "System.Reflection.AssemblyDelaySignAttribute":
 890                                                         RootContext.StrongNameDelaySign = a.GetBoolean ();
 891                                                         break;
 892                                         }
 893                                 }
 894                         }
 895
 896                         AssemblyName an = new AssemblyName ();
 897                         an.Name = Path.GetFileNameWithoutExtension (name);
 898
 899                         // note: delay doesn't apply when using a key container
 900                         if (RootContext.StrongNameKeyContainer != null) {
 901                                 an.KeyPair = new StrongNameKeyPair (RootContext.StrongNameKeyContainer);
 902                                 return an;
 903                         }
 904
 905                         // strongname is optional
 906                         if (RootContext.StrongNameKeyFile == null)
 907                                 return an;
 908
 909                         string AssemblyDir = Path.GetDirectoryName (output);
 910
 911                         // the StrongName key file may be relative to (a) the compiled
 912                         // file or (b) to the output assembly. See bugzilla #55320
 913                         // http://bugzilla.ximian.com/show_bug.cgi?id=55320
 914
 915                         // (a) relative to the compiled file
 916                         string filename = Path.GetFullPath (RootContext.StrongNameKeyFile);
 917                         bool exist = File.Exists (filename);
 918                         if ((!exist) && (AssemblyDir != null) && (AssemblyDir != String.Empty)) {
 919                                 // (b) relative to the outputed assembly
 920                                 filename = Path.GetFullPath (Path.Combine (AssemblyDir, RootContext.StrongNameKeyFile));
 921                                 exist = File.Exists (filename);
 922                         }
 923
 924                         if (exist) {
 925                                 using (FileStream fs = new FileStream (filename, FileMode.Open, FileAccess.Read)) {
 926                                         byte[] snkeypair = new byte [fs.Length];
 927                                         fs.Read (snkeypair, 0, snkeypair.Length);
 928
 929                                         if (RootContext.StrongNameDelaySign) {
 930                                                 // delayed signing - DO NOT include private key
 931                                                 try {
 932                                                         // check for possible ECMA key
 933                                                         if (snkeypair.Length == 16) {
 934                                                                 // will be rejected if not "the" ECMA key
 935                                                                 an.KeyPair = new StrongNameKeyPair (snkeypair);
 936                                                         }
 937                                                         else {
 938                                                                 // take it, with or without, a private key
 939                                                                 RSA rsa = CryptoConvert.FromCapiKeyBlob (snkeypair);
 940                                                                 // and make sure we only feed the public part to Sys.Ref
 941                                                                 byte[] publickey = CryptoConvert.ToCapiPublicKeyBlob (rsa);
 942                                                                 an.KeyPair = new StrongNameKeyPair (publickey);
 943                                                         }
 944                                                 }
 945                                                 catch (Exception) {
 946                                                         Report.Error (1548, "Could not strongname the assembly. File `" +
 947                                                                 RootContext.StrongNameKeyFile + "' incorrectly encoded.");
 948                                                         Environment.Exit (1);
 949                                                 }
 950                                         }
 951                                         else {
 952                                                 // no delay so we make sure we have the private key
 953                                                 try {
 954                                                         CryptoConvert.FromCapiPrivateKeyBlob (snkeypair);
 955                                                         an.KeyPair = new StrongNameKeyPair (snkeypair);
 956                                                 }
 957                                                 catch (CryptographicException) {
 958                                                         if (snkeypair.Length == 16) {
 959                                                                 // error # is different for ECMA key
 960                                                                 Report.Error (1606, "Could not strongname the assembly. " +
 961                                                                         "ECMA key can only be used to delay-sign assemblies");
 962                                                         }
 963                                                         else {
 964                                                                 Report.Error (1548, "Could not strongname the assembly. File `" +
 965                                                                         RootContext.StrongNameKeyFile +
 966                                                                         "' doesn't have a private key.");
 967                                                         }
 968                                                         Environment.Exit (1);
 969                                                 }
 970                                         }
 971                                 }
 972                         }
 973                         else {
 974                                 Report.Error (1548, "Could not strongname the assembly. File `" +
 975                                         RootContext.StrongNameKeyFile + "' not found.");
 976                                 Environment.Exit (1);
 977                         }
 978                         return an;
 979                 }
 980
 981                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
 982                 {
 983                         Builder.SetCustomAttribute (customBuilder);
 984                 }
 985         }
 986
 987         public class ModuleClass: CommonAssemblyModulClass {
 988                 // TODO: make it private and move all builder based methods here
 989                 public ModuleBuilder Builder;
 990                 bool m_module_is_unsafe;
 991
 992                 public ModuleClass (bool is_unsafe)
 993                 {
 994                         m_module_is_unsafe = is_unsafe;
 995                 }
 996
 997                 public override AttributeTargets AttributeTargets {
 998                         get {
 999                                 return AttributeTargets.Module;
1000                         }
1001                 }
1002
1003                 public override bool IsClsCompliaceRequired(DeclSpace ds)
1004                 {
1005                         return CodeGen.Assembly.IsClsCompliant;
1006                         }
1007
1008                 public override void Emit (TypeContainer tc)
1009                 {
1010                         base.Emit (tc);
1011
1012                         if (!m_module_is_unsafe)
1013                                 return;
1014
1015                         if (TypeManager.unverifiable_code_ctor == null) {
1016                                 Console.WriteLine ("Internal error ! Cannot set unverifiable code attribute.");
1017                                 return;
1018                         }
1019
1020                         ApplyAttributeBuilder (null, new CustomAttributeBuilder (TypeManager.unverifiable_code_ctor, new object [0]));
1021                 }
1022
1023                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
1024                 {
1025                         if (a != null && a.Type == TypeManager.cls_compliant_attribute_type) {
1026                                 Report.Warning_T (3012, a.Location);
1027                                 return;
1028                         }
1029
1030                         Builder.SetCustomAttribute (customBuilder);
1031                 }
1032         }
1033
1034 }