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