mcs/gmcs/codegen.cs

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