mcs/mcs/codegen.cs

   1 //
   2 // codegen.cs: The code generator
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001, 2002, 2003 Ximian, Inc.
   8 // (C) 2004 Novell, Inc.
   9 //
  10
  11 #if !DEBUG
  12         #define PRODUCTION
  13 #endif
  14
  15 using System;
  16 using System.IO;
  17 using System.Collections;
  18 using System.Collections.Specialized;
  19 using System.Reflection;
  20 using System.Reflection.Emit;
  21 using System.Runtime.InteropServices;
  22 using System.Security;
  23 using System.Security.Cryptography;
  24 using System.Security.Permissions;
  25
  26 using Mono.Security.Cryptography;
  27
  28 namespace Mono.CSharp {
  29
  30         /// <summary>
  31         ///    Code generator class.
  32         /// </summary>
  33         public class CodeGen {
  34                 static AppDomain current_domain;
  35                 static public SymbolWriter SymbolWriter;
  36
  37                 public static AssemblyClass Assembly;
  38                 public static ModuleClass Module;
  39
  40                 static CodeGen ()
  41                 {
  42                         Reset ();
  43                 }
  44
  45                 public static void Reset ()
  46                 {
  47                         Assembly = new AssemblyClass ();
  48                         Module = new ModuleClass (RootContext.Unsafe);
  49                 }
  50
  51                 public static string Basename (string name)
  52                 {
  53                         int pos = name.LastIndexOf ('/');
  54
  55                         if (pos != -1)
  56                                 return name.Substring (pos + 1);
  57
  58                         pos = name.LastIndexOf ('\\');
  59                         if (pos != -1)
  60                                 return name.Substring (pos + 1);
  61
  62                         return name;
  63                 }
  64
  65                 public static string Dirname (string name)
  66                 {
  67                         int pos = name.LastIndexOf ('/');
  68
  69                         if (pos != -1)
  70                                 return name.Substring (0, pos);
  71
  72                         pos = name.LastIndexOf ('\\');
  73                         if (pos != -1)
  74                                 return name.Substring (0, pos);
  75
  76                         return ".";
  77                 }
  78
  79                 static public string FileName;
  80
  81                 //
  82                 // Initializes the symbol writer
  83                 //
  84                 static void InitializeSymbolWriter (string filename)
  85                 {
  86                         SymbolWriter = SymbolWriter.GetSymbolWriter (Module.Builder, filename);
  87
  88                         //
  89                         // If we got an ISymbolWriter instance, initialize it.
  90                         //
  91                         if (SymbolWriter == null) {
  92                                 Report.Warning (
  93                                         -18, 1, "Could not find the symbol writer assembly (Mono.CompilerServices.SymbolWriter.dll). This is normally an installation problem. Please make sure to compile and install the mcs/class/Mono.CompilerServices.SymbolWriter directory.");
  94                                 return;
  95                         }
  96                 }
  97
  98                 //
  99                 // Initializes the code generator variables
 100                 //
 101                 static public bool Init (string name, string output, bool want_debugging_support)
 102                 {
 103                         FileName = output;
 104                         AssemblyName an = Assembly.GetAssemblyName (name, output);
 105                         if (an == null)
 106                                 return false;
 107
 108                         if (an.KeyPair != null) {
 109                                 // If we are going to strong name our assembly make
 110                                 // sure all its refs are strong named
 111                                 foreach (Assembly a in RootNamespace.Global.Assemblies) {
 112                                         AssemblyName ref_name = a.GetName ();
 113                                         byte [] b = ref_name.GetPublicKeyToken ();
 114                                         if (b == null || b.Length == 0) {
 115                                                 Report.Error (1577, "Assembly generation failed " +
 116                                                                 "-- Referenced assembly '" +
 117                                                                 ref_name.Name +
 118                                                                 "' does not have a strong name.");
 119                                                 //Environment.Exit (1);
 120                                         }
 121                                 }
 122                         }
 123
 124                         current_domain = AppDomain.CurrentDomain;
 125
 126                         try {
 127                                 Assembly.Builder = current_domain.DefineDynamicAssembly (an,
 128                                         AssemblyBuilderAccess.Save, Dirname (name));
 129                         }
 130                         catch (ArgumentException) {
 131                                 // specified key may not be exportable outside it's container
 132                                 if (RootContext.StrongNameKeyContainer != null) {
 133                                         Report.Error (1548, "Could not access the key inside the container `" +
 134                                                 RootContext.StrongNameKeyContainer + "'.");
 135                                         Environment.Exit (1);
 136                                 }
 137                                 return false;
 138                         }
 139                         catch (CryptographicException) {
 140                                 if ((RootContext.StrongNameKeyContainer != null) || (RootContext.StrongNameKeyFile != null)) {
 141                                         Report.Error (1548, "Could not use the specified key to strongname the assembly.");
 142                                         Environment.Exit (1);
 143                                 }
 144                                 return false;
 145                         }
 146
 147                         //
 148                         // Pass a path-less name to DefineDynamicModule.  Wonder how
 149                         // this copes with output in different directories then.
 150                         // FIXME: figure out how this copes with --output /tmp/blah
 151                         //
 152                         // If the third argument is true, the ModuleBuilder will dynamically
 153                         // load the default symbol writer.
 154                         //
 155                         Module.Builder = Assembly.Builder.DefineDynamicModule (
 156                                 Basename (name), Basename (output), false);
 157
 158                         if (want_debugging_support)
 159                                 InitializeSymbolWriter (output);
 160
 161                         return true;
 162                 }
 163
 164                 static public void Save (string name)
 165                 {
 166                         try {
 167                                 Assembly.Builder.Save (Basename (name));
 168                         }
 169                         catch (COMException) {
 170                                 if ((RootContext.StrongNameKeyFile == null) || (!RootContext.StrongNameDelaySign))
 171                                         throw;
 172
 173                                 // FIXME: it seems Microsoft AssemblyBuilder doesn't like to delay sign assemblies
 174                                 Report.Error (1548, "Couldn't delay-sign the assembly with the '" +
 175                                         RootContext.StrongNameKeyFile +
 176                                         "', Use MCS with the Mono runtime or CSC to compile this assembly.");
 177                         }
 178                         catch (System.IO.IOException io) {
 179                                 Report.Error (16, "Could not write to file `"+name+"', cause: " + io.Message);
 180                         }
 181                         catch (System.UnauthorizedAccessException ua) {
 182                                 Report.Error (16, "Could not write to file `"+name+"', cause: " + ua.Message);
 183                         }
 184
 185                         if (SymbolWriter != null)
 186                                 SymbolWriter.WriteSymbolFile ();
 187                 }
 188         }
 189
 190
 191         public interface IResolveContext
 192         {
 193                 DeclSpace DeclContainer { get; }
 194                 bool IsInObsoleteScope { get; }
 195                 bool IsInUnsafeScope { get; }
 196         }
 197
 198         /// <summary>
 199         ///   An Emit Context is created for each body of code (from methods,
 200         ///   properties bodies, indexer bodies or constructor bodies)
 201         /// </summary>
 202         public class EmitContext : IResolveContext {
 203
 204                 DeclSpace declSpace;
 205                 public DeclSpace TypeContainer;
 206                 public ILGenerator   ig;
 207
 208                 /// <summary>
 209                 ///   This variable tracks the `checked' state of the compilation,
 210                 ///   it controls whether we should generate code that does overflow
 211                 ///   checking, or if we generate code that ignores overflows.
 212                 ///
 213                 ///   The default setting comes from the command line option to generate
 214                 ///   checked or unchecked code plus any source code changes using the
 215                 ///   checked/unchecked statements or expressions.   Contrast this with
 216                 ///   the ConstantCheckState flag.
 217                 /// </summary>
 218
 219                 public bool CheckState;
 220
 221                 /// <summary>
 222                 ///   The constant check state is always set to `true' and cant be changed
 223                 ///   from the command line.  The source code can change this setting with
 224                 ///   the `checked' and `unchecked' statements and expressions.
 225                 /// </summary>
 226                 public bool ConstantCheckState;
 227
 228                 /// <summary>
 229                 ///   Whether we are emitting code inside a static or instance method
 230                 /// </summary>
 231                 public bool IsStatic;
 232
 233                 /// <summary>
 234                 ///   Whether the actual created method is static or instance method.
 235                 ///   Althoug the method might be declared as `static', if an anonymous
 236                 ///   method is involved, we might turn this into an instance method.
 237                 ///
 238                 ///   So this reflects the low-level staticness of the method, while
 239                 ///   IsStatic represents the semantic, high-level staticness.
 240                 /// </summary>
 241                 public bool MethodIsStatic;
 242
 243                 /// <summary>
 244                 ///   Whether we are emitting a field initializer
 245                 /// </summary>
 246                 public bool IsFieldInitializer;
 247
 248                 /// <summary>
 249                 ///   The value that is allowed to be returned or NULL if there is no
 250                 ///   return type.
 251                 /// </summary>
 252                 public Type ReturnType;
 253
 254                 /// <summary>
 255                 ///   Points to the Type (extracted from the TypeContainer) that
 256                 ///   declares this body of code
 257                 /// </summary>
 258                 public Type ContainerType;
 259
 260                 /// <summary>
 261                 ///   Whether this is generating code for a constructor
 262                 /// </summary>
 263                 public bool IsConstructor;
 264
 265                 /// <summary>
 266                 ///   Whether we're control flow analysis enabled
 267                 /// </summary>
 268                 public bool DoFlowAnalysis;
 269
 270                 /// <summary>
 271                 ///   Whether we're control flow analysis disabled on struct
 272                 /// </summary>
 273                 public bool OmitStructFlowAnalysis;
 274
 275                 /// <summary>
 276                 ///   Keeps track of the Type to LocalBuilder temporary storage created
 277                 ///   to store structures (used to compute the address of the structure
 278                 ///   value on structure method invocations)
 279                 /// </summary>
 280                 public Hashtable temporary_storage;
 281
 282                 public Block CurrentBlock;
 283
 284                 public int CurrentFile;
 285
 286                 /// <summary>
 287                 ///   The location where we store the return value.
 288                 /// </summary>
 289                 LocalBuilder return_value;
 290
 291                 /// <summary>
 292                 ///   The location where return has to jump to return the
 293                 ///   value
 294                 /// </summary>
 295                 public Label ReturnLabel;
 296
 297                 /// <summary>
 298                 ///   If we already defined the ReturnLabel
 299                 /// </summary>
 300                 public bool HasReturnLabel;
 301
 302                 /// <summary>
 303                 ///   Whether we are inside an iterator block.
 304                 /// </summary>
 305                 public bool InIterator;
 306
 307                 public bool IsLastStatement;
 308
 309                 /// <summary>
 310                 ///  Whether we are inside an unsafe block
 311                 /// </summary>
 312                 public bool InUnsafe;
 313
 314                 /// <summary>
 315                 ///  Whether we are in a `fixed' initialization
 316                 /// </summary>
 317                 public bool InFixedInitializer;
 318
 319                 public bool InRefOutArgumentResolving;
 320
 321                 public bool InCatch;
 322                 public bool InFinally;
 323
 324                 /// <summary>
 325                 ///  Whether we are inside an anonymous method.
 326                 /// </summary>
 327                 public AnonymousContainer CurrentAnonymousMethod;
 328
 329                 /// <summary>
 330                 ///   Location for this EmitContext
 331                 /// </summary>
 332                 public Location loc;
 333
 334                 /// <summary>
 335                 ///   Inside an enum definition, we do not resolve enumeration values
 336                 ///   to their enumerations, but rather to the underlying type/value
 337                 ///   This is so EnumVal + EnumValB can be evaluated.
 338                 ///
 339                 ///   There is no "E operator + (E x, E y)", so during an enum evaluation
 340                 ///   we relax the rules
 341                 /// </summary>
 342                 public bool InEnumContext;
 343
 344                 /// <summary>
 345                 ///   Anonymous methods can capture local variables and fields,
 346                 ///   this object tracks it.  It is copied from the TopLevelBlock
 347                 ///   field.
 348                 /// </summary>
 349                 public CaptureContext capture_context;
 350
 351                 public readonly IResolveContext ResolveContext;
 352
 353                 /// <summary>
 354                 ///    The current iterator
 355                 /// </summary>
 356                 public Iterator CurrentIterator;
 357
 358                 /// <summary>
 359                 ///    Whether we are in the resolving stage or not
 360                 /// </summary>
 361                 enum Phase {
 362                         Created,
 363                         Resolving,
 364                         Emitting
 365                 }
 366
 367                 Phase current_phase;
 368                 FlowBranching current_flow_branching;
 369
 370                 static int next_id = 0;
 371                 int id = ++next_id;
 372
 373                 public override string ToString ()
 374                 {
 375                         return String.Format ("EmitContext ({0}:{1}:{2})", id,
 376                                               CurrentIterator, capture_context, loc);
 377                 }
 378
 379                 public EmitContext (IResolveContext rc, DeclSpace parent, DeclSpace ds, Location l, ILGenerator ig,
 380                                     Type return_type, int code_flags, bool is_constructor)
 381                 {
 382                         this.ResolveContext = rc;
 383                         this.ig = ig;
 384
 385                         TypeContainer = parent;
 386                         this.declSpace = ds;
 387                         CheckState = RootContext.Checked;
 388                         ConstantCheckState = true;
 389
 390                         IsStatic = (code_flags & Modifiers.STATIC) != 0;
 391                         MethodIsStatic = IsStatic;
 392                         InIterator = (code_flags & Modifiers.METHOD_YIELDS) != 0;
 393                         ReturnType = return_type;
 394                         IsConstructor = is_constructor;
 395                         CurrentBlock = null;
 396                         CurrentFile = 0;
 397                         current_phase = Phase.Created;
 398
 399                         if (parent != null){
 400                                 // Can only be null for the ResolveType contexts.
 401                                 ContainerType = parent.TypeBuilder;
 402                                 InUnsafe = rc.IsInUnsafeScope;
 403                         }
 404                         loc = l;
 405
 406                         if (ReturnType == TypeManager.void_type)
 407                                 ReturnType = null;
 408                 }
 409
 410                 public EmitContext (IResolveContext rc, DeclSpace ds, Location l, ILGenerator ig,
 411                                     Type return_type, int code_flags, bool is_constructor)
 412                         : this (rc, ds, ds, l, ig, return_type, code_flags, is_constructor)
 413                 {
 414                 }
 415
 416                 public EmitContext (IResolveContext rc, DeclSpace ds, Location l, ILGenerator ig,
 417                                     Type return_type, int code_flags)
 418                         : this (rc, ds, ds, l, ig, return_type, code_flags, false)
 419                 {
 420                 }
 421
 422                 public DeclSpace DeclContainer {
 423                         get { return declSpace; }
 424                         set { declSpace = value; }
 425                 }
 426
 427                 public bool IsInObsoleteScope {
 428                         get { return ResolveContext.IsInObsoleteScope; }
 429                 }
 430
 431                 public bool IsInUnsafeScope {
 432                         get { return InUnsafe || ResolveContext.IsInUnsafeScope; }
 433                 }
 434
 435
 436                 public FlowBranching CurrentBranching {
 437                         get { return current_flow_branching; }
 438                 }
 439
 440                 public bool HaveCaptureInfo {
 441                         get { return capture_context != null; }
 442                 }
 443
 444                 public void EmitScopeInitFromBlock (Block b)
 445                 {
 446                         if (capture_context != null)
 447                                 capture_context.EmitScopeInitFromBlock (this, b);
 448                 }
 449
 450                 // <summary>
 451                 //   Starts a new code branching.  This inherits the state of all local
 452                 //   variables and parameters from the current branching.
 453                 // </summary>
 454                 public FlowBranching StartFlowBranching (FlowBranching.BranchingType type, Location loc)
 455                 {
 456                         current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, null, loc);
 457                         return current_flow_branching;
 458                 }
 459
 460                 // <summary>
 461                 //   Starts a new code branching for block `block'.
 462                 // </summary>
 463                 public FlowBranching StartFlowBranching (Block block)
 464                 {
 465                         FlowBranching.BranchingType type;
 466
 467                         if ((CurrentBranching != null) &&
 468                             (CurrentBranching.Type == FlowBranching.BranchingType.Switch))
 469                                 type = FlowBranching.BranchingType.SwitchSection;
 470                         else
 471                                 type = FlowBranching.BranchingType.Block;
 472
 473                         DoFlowAnalysis = true;
 474
 475                         current_flow_branching = FlowBranching.CreateBranching (
 476                                 CurrentBranching, type, block, block.StartLocation);
 477                         return current_flow_branching;
 478                 }
 479
 480                 public FlowBranchingException StartFlowBranching (ExceptionStatement stmt)
 481                 {
 482                         FlowBranchingException branching = new FlowBranchingException (
 483                                 CurrentBranching, stmt);
 484                         current_flow_branching = branching;
 485                         return branching;
 486                 }
 487
 488                 // <summary>
 489                 //   Ends a code branching.  Merges the state of locals and parameters
 490                 //   from all the children of the ending branching.
 491                 // </summary>
 492                 public FlowBranching.UsageVector DoEndFlowBranching ()
 493                 {
 494                         FlowBranching old = current_flow_branching;
 495                         current_flow_branching = current_flow_branching.Parent;
 496
 497                         return current_flow_branching.MergeChild (old);
 498                 }
 499
 500                 // <summary>
 501                 //   Ends a code branching.  Merges the state of locals and parameters
 502                 //   from all the children of the ending branching.
 503                 // </summary>
 504                 public FlowBranching.Reachability EndFlowBranching ()
 505                 {
 506                         FlowBranching.UsageVector vector = DoEndFlowBranching ();
 507
 508                         return vector.Reachability;
 509                 }
 510
 511                 // <summary>
 512                 //   Kills the current code branching.  This throws away any changed state
 513                 //   information and should only be used in case of an error.
 514                 // </summary>
 515                 public void KillFlowBranching ()
 516                 {
 517                         current_flow_branching = current_flow_branching.Parent;
 518                 }
 519
 520                 public void CaptureVariable (LocalInfo li)
 521                 {
 522                         capture_context.AddLocal (CurrentAnonymousMethod, li);
 523                         li.IsCaptured = true;
 524                 }
 525
 526                 public void CaptureParameter (string name, Type t, int idx)
 527                 {
 528                         capture_context.AddParameter (this, CurrentAnonymousMethod, name, t, idx);
 529                 }
 530
 531                 public void CaptureThis ()
 532                 {
 533                         capture_context.CaptureThis (CurrentAnonymousMethod);
 534                 }
 535
 536
 537                 //
 538                 // Use to register a field as captured
 539                 //
 540                 public void CaptureField (FieldExpr fe)
 541                 {
 542                         capture_context.AddField (this, CurrentAnonymousMethod, fe);
 543                 }
 544
 545                 //
 546                 // Whether anonymous methods have captured variables
 547                 //
 548                 public bool HaveCapturedVariables ()
 549                 {
 550                         if (capture_context != null)
 551                                 return capture_context.HaveCapturedVariables;
 552                         return false;
 553                 }
 554
 555                 //
 556                 // Whether anonymous methods have captured fields or this.
 557                 //
 558                 public bool HaveCapturedFields ()
 559                 {
 560                         if (capture_context != null)
 561                                 return capture_context.HaveCapturedFields;
 562                         return false;
 563                 }
 564
 565                 //
 566                 // Emits the instance pointer for the host method
 567                 //
 568                 public void EmitMethodHostInstance (EmitContext target, AnonymousMethod am)
 569                 {
 570                         if (capture_context != null)
 571                                 capture_context.EmitMethodHostInstance (target, am);
 572                         else if (IsStatic)
 573                                 target.ig.Emit (OpCodes.Ldnull);
 574                         else
 575                                 target.ig.Emit (OpCodes.Ldarg_0);
 576                 }
 577
 578                 //
 579                 // Returns whether the `local' variable has been captured by an anonymous
 580                 // method
 581                 //
 582                 public bool IsCaptured (LocalInfo local)
 583                 {
 584                         return capture_context.IsCaptured (local);
 585                 }
 586
 587                 public bool IsParameterCaptured (string name)
 588                 {
 589                         if (capture_context != null)
 590                                 return capture_context.IsParameterCaptured (name);
 591                         return false;
 592                 }
 593
 594                 public void EmitMeta (ToplevelBlock b)
 595                 {
 596                         if (capture_context != null)
 597                                 capture_context.EmitAnonymousHelperClasses (this);
 598                         b.EmitMeta (this);
 599
 600                         if (HasReturnLabel)
 601                                 ReturnLabel = ig.DefineLabel ();
 602                 }
 603
 604                 //
 605                 // Here until we can fix the problem with Mono.CSharp.Switch, which
 606                 // currently can not cope with ig == null during resolve (which must
 607                 // be fixed for switch statements to work on anonymous methods).
 608                 //
 609                 public void EmitTopBlock (IMethodData md, ToplevelBlock block)
 610                 {
 611                         if (block == null)
 612                                 return;
 613
 614                         bool unreachable;
 615
 616                         if (ResolveTopBlock (null, block, md.ParameterInfo, md, out unreachable)){
 617                                 EmitMeta (block);
 618
 619                                 current_phase = Phase.Emitting;
 620                                 EmitResolvedTopBlock (block, unreachable);
 621                         }
 622                 }
 623
 624                 bool resolved;
 625
 626                 public bool ResolveTopBlock (EmitContext anonymous_method_host, ToplevelBlock block,
 627                                              Parameters ip, IMethodData md, out bool unreachable)
 628                 {
 629                         current_phase = Phase.Resolving;
 630
 631                         unreachable = false;
 632
 633                         if (resolved)
 634                                 return true;
 635
 636                         capture_context = block.CaptureContext;
 637
 638                         if (!loc.IsNull)
 639                                 CurrentFile = loc.File;
 640
 641 #if PRODUCTION
 642                         try {
 643 #endif
 644                                 if (!block.ResolveMeta (this, ip))
 645                                         return false;
 646
 647                                 bool old_do_flow_analysis = DoFlowAnalysis;
 648                                 DoFlowAnalysis = true;
 649
 650                                 if (anonymous_method_host != null)
 651                                         current_flow_branching = FlowBranching.CreateBranching (
 652                                                 anonymous_method_host.CurrentBranching,
 653                                                 FlowBranching.BranchingType.Block, block, loc);
 654                                 else
 655                                         current_flow_branching = block.TopLevelBranching;
 656
 657                                 if (!block.Resolve (this)) {
 658                                         current_flow_branching = null;
 659                                         DoFlowAnalysis = old_do_flow_analysis;
 660                                         return false;
 661                                 }
 662
 663                                 FlowBranching.Reachability reachability = current_flow_branching.MergeTopBlock ();
 664                                 current_flow_branching = null;
 665
 666                                 DoFlowAnalysis = old_do_flow_analysis;
 667
 668                                 if (reachability.AlwaysReturns ||
 669                                     reachability.AlwaysThrows ||
 670                                     reachability.IsUnreachable)
 671                                         unreachable = true;
 672 #if PRODUCTION
 673                         } catch (Exception e) {
 674                                         Console.WriteLine ("Exception caught by the compiler while compiling:");
 675                                         Console.WriteLine ("   Block that caused the problem begin at: " + loc);
 676
 677                                         if (CurrentBlock != null){
 678                                                 Console.WriteLine ("                     Block being compiled: [{0},{1}]",
 679                                                                    CurrentBlock.StartLocation, CurrentBlock.EndLocation);
 680                                         }
 681                                         Console.WriteLine (e.GetType ().FullName + ": " + e.Message);
 682                                         throw;
 683                         }
 684 #endif
 685
 686                         if (ReturnType != null && !unreachable) {
 687                                 if (CurrentAnonymousMethod == null) {
 688                                         Report.Error (161, md.Location, "`{0}': not all code paths return a value", md.GetSignatureForError ());
 689                                         return false;
 690                                 } else if (!CurrentAnonymousMethod.IsIterator) {
 691                                         Report.Error (1643, CurrentAnonymousMethod.Location, "Not all code paths return a value in anonymous method of type `{0}'",
 692                                                 CurrentAnonymousMethod.GetSignatureForError ());
 693                                         return false;
 694                                 }
 695                         }
 696
 697                         block.CompleteContexts ();
 698                         resolved = true;
 699                         return true;
 700                 }
 701
 702                 public void EmitResolvedTopBlock (ToplevelBlock block, bool unreachable)
 703                 {
 704                         if (block != null)
 705                                 block.Emit (this);
 706
 707                         if (HasReturnLabel)
 708                                 ig.MarkLabel (ReturnLabel);
 709
 710                         if (return_value != null){
 711                                 ig.Emit (OpCodes.Ldloc, return_value);
 712                                 ig.Emit (OpCodes.Ret);
 713                         } else {
 714                                 //
 715                                 // If `HasReturnLabel' is set, then we already emitted a
 716                                 // jump to the end of the method, so we must emit a `ret'
 717                                 // there.
 718                                 //
 719                                 // Unfortunately, System.Reflection.Emit automatically emits
 720                                 // a leave to the end of a finally block.  This is a problem
 721                                 // if no code is following the try/finally block since we may
 722                                 // jump to a point after the end of the method.
 723                                 // As a workaround, we're always creating a return label in
 724                                 // this case.
 725                                 //
 726
 727                                 bool in_iterator = (CurrentAnonymousMethod != null) &&
 728                                         CurrentAnonymousMethod.IsIterator && InIterator;
 729
 730                                 if ((block != null) && block.IsDestructor) {
 731                                         // Nothing to do; S.R.E automatically emits a leave.
 732                                 } else if (HasReturnLabel || (!unreachable && !in_iterator)) {
 733                                         if (ReturnType != null)
 734                                                 ig.Emit (OpCodes.Ldloc, TemporaryReturn ());
 735                                         ig.Emit (OpCodes.Ret);
 736                                 }
 737                         }
 738
 739                         //
 740                         // Close pending helper classes if we are the toplevel
 741                         //
 742                         if (capture_context != null && capture_context.ParentToplevel == null)
 743                                 capture_context.CloseAnonymousHelperClasses ();
 744                 }
 745
 746                 /// <summary>
 747                 ///   This is called immediately before emitting an IL opcode to tell the symbol
 748                 ///   writer to which source line this opcode belongs.
 749                 /// </summary>
 750                 public void Mark (Location loc, bool check_file)
 751                 {
 752                         if ((CodeGen.SymbolWriter == null) || loc.IsNull)
 753                                 return;
 754
 755                         if (check_file && (CurrentFile != loc.File))
 756                                 return;
 757
 758                         CodeGen.SymbolWriter.MarkSequencePoint (ig, loc.Row, loc.Column);
 759                 }
 760
 761                 public void DefineLocalVariable (string name, LocalBuilder builder)
 762                 {
 763                         if (CodeGen.SymbolWriter == null)
 764                                 return;
 765
 766                         CodeGen.SymbolWriter.DefineLocalVariable (name, builder);
 767                 }
 768
 769                 public void BeginScope ()
 770                 {
 771                         ig.BeginScope();
 772
 773                         if (CodeGen.SymbolWriter != null)
 774                                 CodeGen.SymbolWriter.OpenScope(ig);
 775                 }
 776
 777                 public void EndScope ()
 778                 {
 779                         ig.EndScope();
 780
 781                         if (CodeGen.SymbolWriter != null)
 782                                 CodeGen.SymbolWriter.CloseScope(ig);
 783                 }
 784
 785                 /// <summary>
 786                 ///   Returns a temporary storage for a variable of type t as
 787                 ///   a local variable in the current body.
 788                 /// </summary>
 789                 public LocalBuilder GetTemporaryLocal (Type t)
 790                 {
 791                         LocalBuilder location = null;
 792
 793                         if (temporary_storage != null){
 794                                 object o = temporary_storage [t];
 795                                 if (o != null){
 796                                         if (o is ArrayList){
 797                                                 ArrayList al = (ArrayList) o;
 798
 799                                                 for (int i = 0; i < al.Count; i++){
 800                                                         if (al [i] != null){
 801                                                                 location = (LocalBuilder) al [i];
 802                                                                 al [i] = null;
 803                                                                 break;
 804                                                         }
 805                                                 }
 806                                         } else
 807                                                 location = (LocalBuilder) o;
 808                                         if (location != null)
 809                                                 return location;
 810                                 }
 811                         }
 812
 813                         return ig.DeclareLocal (t);
 814                 }
 815
 816                 public void FreeTemporaryLocal (LocalBuilder b, Type t)
 817                 {
 818                         if (temporary_storage == null){
 819                                 temporary_storage = new Hashtable ();
 820                                 temporary_storage [t] = b;
 821                                 return;
 822                         }
 823                         object o = temporary_storage [t];
 824                         if (o == null){
 825                                 temporary_storage [t] = b;
 826                                 return;
 827                         }
 828                         if (o is ArrayList){
 829                                 ArrayList al = (ArrayList) o;
 830                                 for (int i = 0; i < al.Count; i++){
 831                                         if (al [i] == null){
 832                                                 al [i] = b;
 833                                                 return;
 834                                         }
 835                                 }
 836                                 al.Add (b);
 837                                 return;
 838                         }
 839                         ArrayList replacement = new ArrayList ();
 840                         replacement.Add (o);
 841                         temporary_storage.Remove (t);
 842                         temporary_storage [t] = replacement;
 843                 }
 844
 845                 /// <summary>
 846                 ///   Current loop begin and end labels.
 847                 /// </summary>
 848                 public Label LoopBegin, LoopEnd;
 849
 850                 /// <summary>
 851                 ///   Default target in a switch statement.   Only valid if
 852                 ///   InSwitch is true
 853                 /// </summary>
 854                 public Label DefaultTarget;
 855
 856                 /// <summary>
 857                 ///   If this is non-null, points to the current switch statement
 858                 /// </summary>
 859                 public Switch Switch;
 860
 861                 /// <summary>
 862                 ///   ReturnValue creates on demand the LocalBuilder for the
 863                 ///   return value from the function.  By default this is not
 864                 ///   used.  This is only required when returns are found inside
 865                 ///   Try or Catch statements.
 866                 ///
 867                 ///   This method is typically invoked from the Emit phase, so
 868                 ///   we allow the creation of a return label if it was not
 869                 ///   requested during the resolution phase.   Could be cleaned
 870                 ///   up, but it would replicate a lot of logic in the Emit phase
 871                 ///   of the code that uses it.
 872                 /// </summary>
 873                 public LocalBuilder TemporaryReturn ()
 874                 {
 875                         if (return_value == null){
 876                                 return_value = ig.DeclareLocal (ReturnType);
 877                                 if (!HasReturnLabel){
 878                                         ReturnLabel = ig.DefineLabel ();
 879                                         HasReturnLabel = true;
 880                                 }
 881                         }
 882
 883                         return return_value;
 884                 }
 885
 886                 /// <summary>
 887                 ///   This method is used during the Resolution phase to flag the
 888                 ///   need to define the ReturnLabel
 889                 /// </summary>
 890                 public void NeedReturnLabel ()
 891                 {
 892                         if (current_phase != Phase.Resolving){
 893                                 //
 894                                 // The reason is that the `ReturnLabel' is declared between
 895                                 // resolution and emission
 896                                 //
 897                                 throw new Exception ("NeedReturnLabel called from Emit phase, should only be called during Resolve");
 898                         }
 899
 900                         if (!InIterator && !HasReturnLabel)
 901                                 HasReturnLabel = true;
 902                 }
 903
 904                 //
 905                 // Emits the proper object to address fields on a remapped
 906                 // variable/parameter to field in anonymous-method/iterator proxy classes.
 907                 //
 908                 public void EmitThis (bool need_address)
 909                 {
 910                         ig.Emit (OpCodes.Ldarg_0);
 911                         if (capture_context != null && CurrentAnonymousMethod != null){
 912                                 ScopeInfo si = CurrentAnonymousMethod.Scope;
 913                                 while (si != null){
 914                                         if (si.ParentLink != null)
 915                                                 ig.Emit (OpCodes.Ldfld, si.ParentLink);
 916                                         if (si.THIS != null){
 917                                                 if (need_address && TypeManager.IsValueType (si.THIS.FieldType))
 918                                                         ig.Emit (OpCodes.Ldflda, si.THIS);
 919                                                 else
 920                                                         ig.Emit (OpCodes.Ldfld, si.THIS);
 921                                                 break;
 922                                         }
 923                                         si = si.ParentScope;
 924                                 }
 925                         }
 926                 }
 927
 928                 //
 929                 // Emits the code necessary to load the instance required
 930                 // to access the captured LocalInfo
 931                 //
 932                 public void EmitCapturedVariableInstance (LocalInfo li)
 933                 {
 934                         if (capture_context == null)
 935                                 throw new Exception ("Calling EmitCapturedContext when there is no capture_context");
 936
 937                         capture_context.EmitCapturedVariableInstance (this, li, CurrentAnonymousMethod);
 938                 }
 939
 940                 public void EmitParameter (string name, bool leave_copy, bool prepared, ref LocalTemporary temp)
 941                 {
 942                         capture_context.EmitParameter (this, name, leave_copy, prepared, ref temp);
 943                 }
 944
 945                 public void EmitAssignParameter (string name, Expression source, bool leave_copy, bool prepare_for_load, ref LocalTemporary  temp)
 946                 {
 947                         capture_context.EmitAssignParameter (this, name, source, leave_copy, prepare_for_load, ref temp);
 948                 }
 949
 950                 public void EmitAddressOfParameter (string name)
 951                 {
 952                         capture_context.EmitAddressOfParameter (this, name);
 953                 }
 954
 955                 public Expression GetThis (Location loc)
 956                 {
 957                         This my_this;
 958                         if (CurrentBlock != null)
 959                                 my_this = new This (CurrentBlock, loc);
 960                         else
 961                                 my_this = new This (loc);
 962
 963                         if (!my_this.ResolveBase (this))
 964                                 my_this = null;
 965
 966                         return my_this;
 967                 }
 968         }
 969
 970
 971         public abstract class CommonAssemblyModulClass : Attributable, IResolveContext {
 972
 973                 protected CommonAssemblyModulClass ():
 974                         base (null)
 975                 {
 976                 }
 977
 978                 public void AddAttributes (ArrayList attrs)
 979                 {
 980                         foreach (Attribute a in attrs)
 981                                 a.AttachTo (this);
 982
 983                         if (attributes == null) {
 984                                 attributes = new Attributes (attrs);
 985                                 return;
 986                         }
 987                         attributes.AddAttributes (attrs);
 988                 }
 989
 990                 public virtual void Emit (TypeContainer tc)
 991                 {
 992                         if (OptAttributes == null)
 993                                 return;
 994
 995                         OptAttributes.Emit ();
 996                 }
 997
 998                 protected Attribute ResolveAttribute (Type a_type)
 999                 {
1000                         if (OptAttributes == null)
1001                                 return null;
1002
1003                         // Ensure that we only have GlobalAttributes, since the Search below isn't safe with other types.
1004                         if (!OptAttributes.CheckTargets ())
1005                                 return null;
1006
1007                         Attribute a = OptAttributes.Search (a_type);
1008                         if (a != null) {
1009                                 a.Resolve ();
1010                         }
1011                         return a;
1012                 }
1013
1014                 public override IResolveContext ResolveContext {
1015                         get {
1016                                 return this;
1017                         }
1018                 }
1019
1020                 #region IResolveContext Members
1021
1022                 public DeclSpace DeclContainer {
1023                         get {
1024                                 return RootContext.Tree.Types;
1025                         }
1026                 }
1027
1028                 public bool IsInObsoleteScope {
1029                         get {
1030                                 return false;
1031                         }
1032                 }
1033
1034                 public bool IsInUnsafeScope {
1035                         get {
1036                                 return false;
1037                         }
1038                 }
1039
1040                 #endregion
1041         }
1042
1043         public class AssemblyClass : CommonAssemblyModulClass {
1044                 // TODO: make it private and move all builder based methods here
1045                 public AssemblyBuilder Builder;
1046                 bool is_cls_compliant;
1047                 bool wrap_non_exception_throws;
1048
1049                 public Attribute ClsCompliantAttribute;
1050
1051                 ListDictionary declarative_security;
1052
1053                 // Module is here just because of error messages
1054                 static string[] attribute_targets = new string [] { "assembly", "module" };
1055
1056                 public AssemblyClass (): base ()
1057                 {
1058                         wrap_non_exception_throws = true;
1059                 }
1060
1061                 public bool IsClsCompliant {
1062                         get {
1063                                 return is_cls_compliant;
1064                         }
1065                 }
1066
1067                 public bool WrapNonExceptionThrows {
1068                         get {
1069                                 return wrap_non_exception_throws;
1070                         }
1071                 }
1072
1073                 public override AttributeTargets AttributeTargets {
1074                         get {
1075                                 return AttributeTargets.Assembly;
1076                         }
1077                 }
1078
1079                 public override bool IsClsComplianceRequired ()
1080                 {
1081                         return is_cls_compliant;
1082                 }
1083
1084                 public void Resolve ()
1085                 {
1086                         ClsCompliantAttribute = ResolveAttribute (TypeManager.cls_compliant_attribute_type);
1087                         if (ClsCompliantAttribute != null) {
1088                                 is_cls_compliant = ClsCompliantAttribute.GetClsCompliantAttributeValue ();
1089                         }
1090
1091 #if NET_2_0
1092                         Attribute a = ResolveAttribute (TypeManager.runtime_compatibility_attr_type);
1093                         if (a != null) {
1094                                 object val = a.GetPropertyValue ("WrapNonExceptionThrows");
1095                                 if (val != null)
1096                                         wrap_non_exception_throws = (bool)val;
1097                         }
1098 #endif
1099                 }
1100
1101                 // fix bug #56621
1102                 private void SetPublicKey (AssemblyName an, byte[] strongNameBlob)
1103                 {
1104                         try {
1105                                 // check for possible ECMA key
1106                                 if (strongNameBlob.Length == 16) {
1107                                         // will be rejected if not "the" ECMA key
1108                                         an.SetPublicKey (strongNameBlob);
1109                                 }
1110                                 else {
1111                                         // take it, with or without, a private key
1112                                         RSA rsa = CryptoConvert.FromCapiKeyBlob (strongNameBlob);
1113                                         // and make sure we only feed the public part to Sys.Ref
1114                                         byte[] publickey = CryptoConvert.ToCapiPublicKeyBlob (rsa);
1115
1116                                         // AssemblyName.SetPublicKey requires an additional header
1117                                         byte[] publicKeyHeader = new byte [12] { 0x00, 0x24, 0x00, 0x00, 0x04, 0x80, 0x00, 0x00, 0x94, 0x00, 0x00, 0x00 };
1118
1119                                         byte[] encodedPublicKey = new byte [12 + publickey.Length];
1120                                         Buffer.BlockCopy (publicKeyHeader, 0, encodedPublicKey, 0, 12);
1121                                         Buffer.BlockCopy (publickey, 0, encodedPublicKey, 12, publickey.Length);
1122                                         an.SetPublicKey (encodedPublicKey);
1123                                 }
1124                         }
1125                         catch (Exception) {
1126                                 Error_AssemblySigning ("The specified file `" + RootContext.StrongNameKeyFile + "' is incorrectly encoded");
1127                                 Environment.Exit (1);
1128                         }
1129                 }
1130
1131                 // TODO: rewrite this code (to kill N bugs and make it faster) and use standard ApplyAttribute way.
1132                 public AssemblyName GetAssemblyName (string name, string output)
1133                 {
1134                         if (OptAttributes != null) {
1135                                 foreach (Attribute a in OptAttributes.Attrs) {
1136                                         // cannot rely on any resolve-based members before you call Resolve
1137                                         if (a.ExplicitTarget == null || a.ExplicitTarget != "assembly")
1138                                                 continue;
1139
1140                                         // TODO: This code is buggy: comparing Attribute name without resolving is wrong.
1141                                         //       However, this is invoked by CodeGen.Init, when none of the namespaces
1142                                         //       are loaded yet.
1143                                         // TODO: Does not handle quoted attributes properly
1144                                         switch (a.Name) {
1145                                                 case "AssemblyKeyFile":
1146                                                 case "AssemblyKeyFileAttribute":
1147                                                 case "System.Reflection.AssemblyKeyFileAttribute":
1148                                                         if (RootContext.StrongNameKeyFile != null) {
1149                                                                 Report.SymbolRelatedToPreviousError (a.Location, a.Name);
1150                                                                 Report.Warning (1616, 1, "Option `{0}' overrides attribute `{1}' given in a source file or added module",
1151                                     "keyfile", "System.Reflection.AssemblyKeyFileAttribute");
1152                                                         }
1153                                                         else {
1154                                                                 string value = a.GetString ();
1155                                                                 if (value.Length != 0)
1156                                                                         RootContext.StrongNameKeyFile = value;
1157                                                         }
1158                                                         break;
1159                                                 case "AssemblyKeyName":
1160                                                 case "AssemblyKeyNameAttribute":
1161                                                 case "System.Reflection.AssemblyKeyNameAttribute":
1162                                                         if (RootContext.StrongNameKeyContainer != null) {
1163                                                                 Report.SymbolRelatedToPreviousError (a.Location, a.Name);
1164                                                                 Report.Warning (1616, 1, "Option `{0}' overrides attribute `{1}' given in a source file or added module",
1165                                                                         "keycontainer", "System.Reflection.AssemblyKeyNameAttribute");
1166                                                         }
1167                                                         else {
1168                                                                 string value = a.GetString ();
1169                                                                 if (value.Length != 0)
1170                                                                         RootContext.StrongNameKeyContainer = value;
1171                                                         }
1172                                                         break;
1173                                                 case "AssemblyDelaySign":
1174                                                 case "AssemblyDelaySignAttribute":
1175                                                 case "System.Reflection.AssemblyDelaySignAttribute":
1176                                                         RootContext.StrongNameDelaySign = a.GetBoolean ();
1177                                                         break;
1178                                         }
1179                                 }
1180                         }
1181
1182                         AssemblyName an = new AssemblyName ();
1183                         an.Name = Path.GetFileNameWithoutExtension (name);
1184
1185                         // note: delay doesn't apply when using a key container
1186                         if (RootContext.StrongNameKeyContainer != null) {
1187                                 an.KeyPair = new StrongNameKeyPair (RootContext.StrongNameKeyContainer);
1188                                 return an;
1189                         }
1190
1191                         // strongname is optional
1192                         if (RootContext.StrongNameKeyFile == null)
1193                                 return an;
1194
1195                         string AssemblyDir = Path.GetDirectoryName (output);
1196
1197                         // the StrongName key file may be relative to (a) the compiled
1198                         // file or (b) to the output assembly. See bugzilla #55320
1199                         // http://bugzilla.ximian.com/show_bug.cgi?id=55320
1200
1201                         // (a) relative to the compiled file
1202                         string filename = Path.GetFullPath (RootContext.StrongNameKeyFile);
1203                         bool exist = File.Exists (filename);
1204                         if ((!exist) && (AssemblyDir != null) && (AssemblyDir != String.Empty)) {
1205                                 // (b) relative to the outputed assembly
1206                                 filename = Path.GetFullPath (Path.Combine (AssemblyDir, RootContext.StrongNameKeyFile));
1207                                 exist = File.Exists (filename);
1208                         }
1209
1210                         if (exist) {
1211                                 using (FileStream fs = new FileStream (filename, FileMode.Open, FileAccess.Read)) {
1212                                         byte[] snkeypair = new byte [fs.Length];
1213                                         fs.Read (snkeypair, 0, snkeypair.Length);
1214
1215                                         if (RootContext.StrongNameDelaySign) {
1216                                                 // delayed signing - DO NOT include private key
1217                                                 SetPublicKey (an, snkeypair);
1218                                         }
1219                                         else {
1220                                                 // no delay so we make sure we have the private key
1221                                                 try {
1222                                                         CryptoConvert.FromCapiPrivateKeyBlob (snkeypair);
1223                                                         an.KeyPair = new StrongNameKeyPair (snkeypair);
1224                                                 }
1225                                                 catch (CryptographicException) {
1226                                                         if (snkeypair.Length == 16) {
1227                                                                 // error # is different for ECMA key
1228                                                                 Report.Error (1606, "Could not sign the assembly. " +
1229                                                                         "ECMA key can only be used to delay-sign assemblies");
1230                                                         }
1231                                                         else {
1232                                                                 Error_AssemblySigning ("The specified file `" + RootContext.StrongNameKeyFile + "' does not have a private key");
1233                                                         }
1234                                                         return null;
1235                                                 }
1236                                         }
1237                                 }
1238                         }
1239                         else {
1240                                 Error_AssemblySigning ("The specified file `" + RootContext.StrongNameKeyFile + "' does not exist");
1241                                 return null;
1242                         }
1243                         return an;
1244                 }
1245
1246                 void Error_AssemblySigning (string text)
1247                 {
1248                         Report.Error (1548, "Error during assembly signing. " + text);
1249                 }
1250
1251                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
1252                 {
1253                         if (a.Type.IsSubclassOf (TypeManager.security_attr_type) && a.CheckSecurityActionValidity (true)) {
1254                                 if (declarative_security == null)
1255                                         declarative_security = new ListDictionary ();
1256
1257                                 a.ExtractSecurityPermissionSet (declarative_security);
1258                                 return;
1259                         }
1260
1261                         if (a.Type == TypeManager.assembly_culture_attribute_type) {
1262                                 string value = a.GetString ();
1263                                 if (value == null || value.Length == 0)
1264                                         return;
1265
1266                                 if (RootContext.Target == Target.Exe) {
1267                                         a.Error_AttributeEmitError ("The executables cannot be satelite assemblies, remove the attribute or keep it empty");
1268                                         return;
1269                                 }
1270                         }
1271
1272                         Builder.SetCustomAttribute (customBuilder);
1273                 }
1274
1275                 public override void Emit (TypeContainer tc)
1276                 {
1277                         base.Emit (tc);
1278
1279                         if (declarative_security != null) {
1280
1281                                 MethodInfo add_permission = typeof (AssemblyBuilder).GetMethod ("AddPermissionRequests", BindingFlags.Instance | BindingFlags.NonPublic);
1282                                 object builder_instance = Builder;
1283
1284                                 try {
1285                                         // Microsoft runtime hacking
1286                                         if (add_permission == null) {
1287                                                 Type assembly_builder = typeof (AssemblyBuilder).Assembly.GetType ("System.Reflection.Emit.AssemblyBuilderData");
1288                                                 add_permission = assembly_builder.GetMethod ("AddPermissionRequests", BindingFlags.Instance | BindingFlags.NonPublic);
1289
1290                                                 FieldInfo fi = typeof (AssemblyBuilder).GetField ("m_assemblyData", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.GetField);
1291                                                 builder_instance = fi.GetValue (Builder);
1292                                         }
1293
1294                                         object[] args = new object [] { declarative_security [SecurityAction.RequestMinimum],
1295                                                                                                   declarative_security [SecurityAction.RequestOptional],
1296                                                                                                   declarative_security [SecurityAction.RequestRefuse] };
1297                                         add_permission.Invoke (builder_instance, args);
1298                                 }
1299                                 catch {
1300                                         Report.RuntimeMissingSupport (Location.Null, "assembly permission setting");
1301                                 }
1302                         }
1303                 }
1304
1305                 public override string[] ValidAttributeTargets {
1306                         get {
1307                                 return attribute_targets;
1308                         }
1309                 }
1310         }
1311
1312         public class ModuleClass : CommonAssemblyModulClass {
1313                 // TODO: make it private and move all builder based methods here
1314                 public ModuleBuilder Builder;
1315                 bool m_module_is_unsafe;
1316
1317                 public CharSet DefaultCharSet = CharSet.Ansi;
1318                 public TypeAttributes DefaultCharSetType = TypeAttributes.AnsiClass;
1319
1320                 static string[] attribute_targets = new string [] { "module" };
1321
1322                 public ModuleClass (bool is_unsafe)
1323                 {
1324                         m_module_is_unsafe = is_unsafe;
1325                 }
1326
1327                 public override AttributeTargets AttributeTargets {
1328                         get {
1329                                 return AttributeTargets.Module;
1330                         }
1331                 }
1332
1333                 public override bool IsClsComplianceRequired ()
1334                 {
1335                         return CodeGen.Assembly.IsClsCompliant;
1336                 }
1337
1338                 public override void Emit (TypeContainer tc)
1339                 {
1340                         base.Emit (tc);
1341
1342                         if (!m_module_is_unsafe)
1343                                 return;
1344
1345                         if (TypeManager.unverifiable_code_ctor == null) {
1346                                 Console.WriteLine ("Internal error ! Cannot set unverifiable code attribute.");
1347                                 return;
1348                         }
1349
1350                         Builder.SetCustomAttribute (new CustomAttributeBuilder (TypeManager.unverifiable_code_ctor, new object [0]));
1351                 }
1352
1353                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
1354                 {
1355                         if (a.Type == TypeManager.cls_compliant_attribute_type) {
1356                                 if (CodeGen.Assembly.ClsCompliantAttribute == null) {
1357                                         Report.Warning (3012, 1, a.Location, "You must specify the CLSCompliant attribute on the assembly, not the module, to enable CLS compliance checking");
1358                                 }
1359                                 else if (CodeGen.Assembly.IsClsCompliant != a.GetBoolean ()) {
1360                                         Report.SymbolRelatedToPreviousError (CodeGen.Assembly.ClsCompliantAttribute.Location, CodeGen.Assembly.ClsCompliantAttribute.GetSignatureForError ());
1361                                         Report.Error (3017, a.Location, "You cannot specify the CLSCompliant attribute on a module that differs from the CLSCompliant attribute on the assembly");
1362                                         return;
1363                                 }
1364                         }
1365
1366                         Builder.SetCustomAttribute (customBuilder);
1367                 }
1368
1369                 /// <summary>
1370                 /// It is called very early therefore can resolve only predefined attributes
1371                 /// </summary>
1372                 public void ResolveAttributes ()
1373                 {
1374 #if NET_2_0
1375                         Attribute a = ResolveAttribute (TypeManager.default_charset_type);
1376                         if (a != null) {
1377                                 DefaultCharSet = a.GetCharSetValue ();
1378                                 switch (DefaultCharSet) {
1379                                         case CharSet.Ansi:
1380                                         case CharSet.None:
1381                                                 break;
1382                                         case CharSet.Auto:
1383                                                 DefaultCharSetType = TypeAttributes.AutoClass;
1384                                                 break;
1385                                         case CharSet.Unicode:
1386                                                 DefaultCharSetType = TypeAttributes.UnicodeClass;
1387                                                 break;
1388                                         default:
1389                                                 Report.Error (1724, a.Location, "Value specified for the argument to 'System.Runtime.InteropServices.DefaultCharSetAttribute' is not valid");
1390                                                 break;
1391                                 }
1392                         }
1393 #endif
1394                 }
1395
1396                 public override string[] ValidAttributeTargets {
1397                         get {
1398                                 return attribute_targets;
1399                         }
1400                 }
1401         }
1402 }