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 Ximian, Inc.
   8 //
   9
  10 using System;
  11 using System.IO;
  12 using System.Collections;
  13 using System.Reflection;
  14 using System.Reflection.Emit;
  15 using System.Runtime.InteropServices;
  16 using System.Security.Cryptography;
  17
  18 using Mono.Security.Cryptography;
  19
  20 namespace Mono.CSharp {
  21
  22         /// <summary>
  23         ///    Code generator class.
  24         /// </summary>
  25         public class CodeGen {
  26                 static AppDomain current_domain;
  27                 static public SymbolWriter SymbolWriter;
  28
  29                 public static AssemblyClass Assembly;
  30                 public static ModuleClass Module;
  31
  32                 static CodeGen ()
  33                 {
  34                         Assembly = new AssemblyClass ();
  35                         Module = new ModuleClass (RootContext.Unsafe);
  36                 }
  37
  38                 public static string Basename (string name)
  39                 {
  40                         int pos = name.LastIndexOf ('/');
  41
  42                         if (pos != -1)
  43                                 return name.Substring (pos + 1);
  44
  45                         pos = name.LastIndexOf ('\\');
  46                         if (pos != -1)
  47                                 return name.Substring (pos + 1);
  48
  49                         return name;
  50                 }
  51
  52                 public static string Dirname (string name)
  53                 {
  54                         int pos = name.LastIndexOf ('/');
  55
  56                         if (pos != -1)
  57                                 return name.Substring (0, pos);
  58
  59                         pos = name.LastIndexOf ('\\');
  60                         if (pos != -1)
  61                                 return name.Substring (0, pos);
  62
  63                         return ".";
  64                 }
  65
  66                 static string TrimExt (string name)
  67                 {
  68                         int pos = name.LastIndexOf ('.');
  69
  70                         return name.Substring (0, pos);
  71                 }
  72
  73                 static public string FileName;
  74
  75                 //
  76                 // Initializes the symbol writer
  77                 //
  78                 static void InitializeSymbolWriter ()
  79                 {
  80                         SymbolWriter = SymbolWriter.GetSymbolWriter (Module.Builder);
  81
  82                         //
  83                         // If we got an ISymbolWriter instance, initialize it.
  84                         //
  85                         if (SymbolWriter == null) {
  86                                 Report.Warning (
  87                                         -18, "Could not find the symbol writer assembly (Mono.CSharp.Debugger.dll). This is normally an installation problem. Please make sure to compile and install the mcs/class/Mono.CSharp.Debugger directory.");
  88                                 return;
  89                         }
  90                 }
  91
  92                 //
  93                 // Initializes the code generator variables
  94                 //
  95                 static public void Init (string name, string output, bool want_debugging_support)
  96                 {
  97                         FileName = output;
  98                         AssemblyName an = Assembly.GetAssemblyName (name, output);
  99
 100                         if (an.KeyPair != null) {
 101                                 // If we are going to strong name our assembly make
 102                                 // sure all its refs are strong named
 103                                 foreach (Assembly a in TypeManager.GetAssemblies ()) {
 104                                         AssemblyName ref_name = a.GetName ();
 105                                         byte [] b = ref_name.GetPublicKeyToken ();
 106                                         if (b == null || b.Length == 0) {
 107                                                 Report.Warning (1577, "Assembly generation failed " +
 108                                                                 "-- Referenced assembly '" +
 109                                                                 ref_name.Name +
 110                                                                 "' does not have a strong name.");
 111                                                 //Environment.Exit (1);
 112                                         }
 113                                 }
 114                         }
 115
 116                         current_domain = AppDomain.CurrentDomain;
 117
 118                         try {
 119                                 Assembly.Builder = current_domain.DefineDynamicAssembly (an,
 120                                         AssemblyBuilderAccess.Save, Dirname (name));
 121                         }
 122                         catch (ArgumentException) {
 123                                 // specified key may not be exportable outside it's container
 124                                 if (RootContext.StrongNameKeyContainer != null) {
 125                                         Report.Error (1548, "Could not access the key inside the container `" +
 126                                                 RootContext.StrongNameKeyContainer + "'.");
 127                                         Environment.Exit (1);
 128                                 }
 129                                 throw;
 130                         }
 131                         catch (CryptographicException) {
 132                                 if ((RootContext.StrongNameKeyContainer != null) || (RootContext.StrongNameKeyFile != null)) {
 133                                         Report.Error (1548, "Could not use the specified key to strongname the assembly.");
 134                                         Environment.Exit (1);
 135                                 }
 136                                 throw;
 137                         }
 138
 139                         //
 140                         // Pass a path-less name to DefineDynamicModule.  Wonder how
 141                         // this copes with output in different directories then.
 142                         // FIXME: figure out how this copes with --output /tmp/blah
 143                         //
 144                         // If the third argument is true, the ModuleBuilder will dynamically
 145                         // load the default symbol writer.
 146                         //
 147                         Module.Builder = Assembly.Builder.DefineDynamicModule (
 148                                 Basename (name), Basename (output), want_debugging_support);
 149
 150                         if (want_debugging_support)
 151                                 InitializeSymbolWriter ();
 152                 }
 153
 154                 static public void Save (string name)
 155                 {
 156                         try {
 157                                 Assembly.Builder.Save (Basename (name));
 158                         }
 159                         catch (COMException) {
 160                                 if ((RootContext.StrongNameKeyFile == null) || (!RootContext.StrongNameDelaySign))
 161                                         throw;
 162
 163                                 // FIXME: it seems Microsoft AssemblyBuilder doesn't like to delay sign assemblies
 164                                 Report.Error (1548, "Couldn't delay-sign the assembly with the '" +
 165                                         RootContext.StrongNameKeyFile +
 166                                         "', Use MCS with the Mono runtime or CSC to compile this assembly.");
 167                         }
 168                         catch (System.IO.IOException io) {
 169                                 Report.Error (16, "Could not write to file `"+name+"', cause: " + io.Message);
 170                         }
 171                 }
 172         }
 173
 174         //
 175         // Provides "local" store across code that can yield: locals
 176         // or fields, notice that this should not be used by anonymous
 177         // methods to create local storage, those only require
 178         // variable mapping.
 179         //
 180         public class VariableStorage {
 181                 ILGenerator ig;
 182                 FieldBuilder fb;
 183                 LocalBuilder local;
 184
 185                 static int count;
 186
 187                 public VariableStorage (EmitContext ec, Type t)
 188                 {
 189                         count++;
 190                         if (ec.InIterator)
 191                                 fb = IteratorHandler.Current.MapVariable ("s_", count.ToString (), t);
 192                         else
 193                                 local = ec.ig.DeclareLocal (t);
 194                         ig = ec.ig;
 195                 }
 196
 197                 public void EmitThis ()
 198                 {
 199                         if (fb != null)
 200                                 ig.Emit (OpCodes.Ldarg_0);
 201                 }
 202
 203                 public void EmitStore ()
 204                 {
 205                         if (fb == null)
 206                                 ig.Emit (OpCodes.Stloc, local);
 207                         else
 208                                 ig.Emit (OpCodes.Stfld, fb);
 209                 }
 210
 211                 public void EmitLoad ()
 212                 {
 213                         if (fb == null)
 214                                 ig.Emit (OpCodes.Ldloc, local);
 215                         else
 216                                 ig.Emit (OpCodes.Ldfld, fb);
 217                 }
 218
 219                 public void EmitCall (MethodInfo mi)
 220                 {
 221                         // FIXME : we should handle a call like tostring
 222                         // here, where boxing is needed. However, we will
 223                         // never encounter that with the current usage.
 224
 225                         bool value_type_call;
 226                         EmitThis ();
 227                         if (fb == null) {
 228                                 value_type_call = local.LocalType.IsValueType;
 229
 230                                 if (value_type_call)
 231                                         ig.Emit (OpCodes.Ldloca, local);
 232                                 else
 233                                         ig.Emit (OpCodes.Ldloc, local);
 234                         } else {
 235                                 value_type_call = fb.FieldType.IsValueType;
 236
 237                                 if (value_type_call)
 238                                         ig.Emit (OpCodes.Ldflda, fb);
 239                                 else
 240                                         ig.Emit (OpCodes.Ldfld, fb);
 241                         }
 242
 243                         ig.Emit (value_type_call ? OpCodes.Call : OpCodes.Callvirt, mi);
 244                 }
 245         }
 246
 247         /// <summary>
 248         ///   An Emit Context is created for each body of code (from methods,
 249         ///   properties bodies, indexer bodies or constructor bodies)
 250         /// </summary>
 251         public class EmitContext {
 252                 public DeclSpace DeclSpace;
 253                 public DeclSpace TypeContainer;
 254                 public ILGenerator   ig;
 255
 256                 /// <summary>
 257                 ///   This variable tracks the `checked' state of the compilation,
 258                 ///   it controls whether we should generate code that does overflow
 259                 ///   checking, or if we generate code that ignores overflows.
 260                 ///
 261                 ///   The default setting comes from the command line option to generate
 262                 ///   checked or unchecked code plus any source code changes using the
 263                 ///   checked/unchecked statements or expressions.   Contrast this with
 264                 ///   the ConstantCheckState flag.
 265                 /// </summary>
 266
 267                 public bool CheckState;
 268
 269                 /// <summary>
 270                 ///   The constant check state is always set to `true' and cant be changed
 271                 ///   from the command line.  The source code can change this setting with
 272                 ///   the `checked' and `unchecked' statements and expressions.
 273                 /// </summary>
 274                 public bool ConstantCheckState;
 275
 276                 /// <summary>
 277                 ///   Whether we are emitting code inside a static or instance method
 278                 /// </summary>
 279                 public bool IsStatic;
 280
 281                 /// <summary>
 282                 ///   Whether we are emitting a field initializer
 283                 /// </summary>
 284                 public bool IsFieldInitializer;
 285
 286                 /// <summary>
 287                 ///   The value that is allowed to be returned or NULL if there is no
 288                 ///   return type.
 289                 /// </summary>
 290                 public Type ReturnType;
 291
 292                 /// <summary>
 293                 ///   Points to the Type (extracted from the TypeContainer) that
 294                 ///   declares this body of code
 295                 /// </summary>
 296                 public Type ContainerType;
 297
 298                 /// <summary>
 299                 ///   Whether this is generating code for a constructor
 300                 /// </summary>
 301                 public bool IsConstructor;
 302
 303                 /// <summary>
 304                 ///   Whether we're control flow analysis enabled
 305                 /// </summary>
 306                 public bool DoFlowAnalysis;
 307
 308                 /// <summary>
 309                 ///   Keeps track of the Type to LocalBuilder temporary storage created
 310                 ///   to store structures (used to compute the address of the structure
 311                 ///   value on structure method invocations)
 312                 /// </summary>
 313                 public Hashtable temporary_storage;
 314
 315                 public Block CurrentBlock;
 316
 317                 public int CurrentFile;
 318
 319                 /// <summary>
 320                 ///   The location where we store the return value.
 321                 /// </summary>
 322                 LocalBuilder return_value;
 323
 324                 /// <summary>
 325                 ///   The location where return has to jump to return the
 326                 ///   value
 327                 /// </summary>
 328                 public Label ReturnLabel;
 329
 330                 /// <summary>
 331                 ///   If we already defined the ReturnLabel
 332                 /// </summary>
 333                 public bool HasReturnLabel;
 334
 335                 /// <summary>
 336                 ///   Whether we are inside an iterator block.
 337                 /// </summary>
 338                 public bool InIterator;
 339
 340                 public bool IsLastStatement;
 341
 342                 /// <summary>
 343                 ///   Whether remapping of locals, parameters and fields is turned on.
 344                 ///   Used by iterators and anonymous methods.
 345                 /// </summary>
 346                 public bool RemapToProxy;
 347
 348                 /// <summary>
 349                 ///  Whether we are inside an unsafe block
 350                 /// </summary>
 351                 public bool InUnsafe;
 352
 353                 /// <summary>
 354                 ///  Whether we are in a `fixed' initialization
 355                 /// </summary>
 356                 public bool InFixedInitializer;
 357
 358                 /// <summary>
 359                 ///  Whether we are inside an anonymous method.
 360                 /// </summary>
 361                 public bool InAnonymousMethod;
 362
 363                 /// <summary>
 364                 ///   Location for this EmitContext
 365                 /// </summary>
 366                 public Location loc;
 367
 368                 /// <summary>
 369                 ///   Used to flag that it is ok to define types recursively, as the
 370                 ///   expressions are being evaluated as part of the type lookup
 371                 ///   during the type resolution process
 372                 /// </summary>
 373                 public bool ResolvingTypeTree;
 374
 375                 /// <summary>
 376                 ///   Inside an enum definition, we do not resolve enumeration values
 377                 ///   to their enumerations, but rather to the underlying type/value
 378                 ///   This is so EnumVal + EnumValB can be evaluated.
 379                 ///
 380                 ///   There is no "E operator + (E x, E y)", so during an enum evaluation
 381                 ///   we relax the rules
 382                 /// </summary>
 383                 public bool InEnumContext;
 384
 385                 FlowBranching current_flow_branching;
 386
 387                 public EmitContext (DeclSpace parent, DeclSpace ds, Location l, ILGenerator ig,
 388                                     Type return_type, int code_flags, bool is_constructor)
 389                 {
 390                         this.ig = ig;
 391
 392                         TypeContainer = parent;
 393                         DeclSpace = ds;
 394                         CheckState = RootContext.Checked;
 395                         ConstantCheckState = true;
 396
 397                         IsStatic = (code_flags & Modifiers.STATIC) != 0;
 398                         InIterator = (code_flags & Modifiers.METHOD_YIELDS) != 0;
 399                         RemapToProxy = InIterator;
 400                         ReturnType = return_type;
 401                         IsConstructor = is_constructor;
 402                         CurrentBlock = null;
 403                         CurrentFile = 0;
 404
 405                         if (parent != null){
 406                                 // Can only be null for the ResolveType contexts.
 407                                 ContainerType = parent.TypeBuilder;
 408                                 if (parent.UnsafeContext)
 409                                         InUnsafe = true;
 410                                 else
 411                                         InUnsafe = (code_flags & Modifiers.UNSAFE) != 0;
 412                         }
 413                         loc = l;
 414
 415                         if (ReturnType == TypeManager.void_type)
 416                                 ReturnType = null;
 417                 }
 418
 419                 public EmitContext (TypeContainer tc, Location l, ILGenerator ig,
 420                                     Type return_type, int code_flags, bool is_constructor)
 421                         : this (tc, tc, l, ig, return_type, code_flags, is_constructor)
 422                 {
 423                 }
 424
 425                 public EmitContext (TypeContainer tc, Location l, ILGenerator ig,
 426                                     Type return_type, int code_flags)
 427                         : this (tc, tc, l, ig, return_type, code_flags, false)
 428                 {
 429                 }
 430
 431                 public FlowBranching CurrentBranching {
 432                         get {
 433                                 return current_flow_branching;
 434                         }
 435                 }
 436
 437                 // <summary>
 438                 //   Starts a new code branching.  This inherits the state of all local
 439                 //   variables and parameters from the current branching.
 440                 // </summary>
 441                 public FlowBranching StartFlowBranching (FlowBranching.BranchingType type, Location loc)
 442                 {
 443                         current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, null, loc);
 444                         return current_flow_branching;
 445                 }
 446
 447                 // <summary>
 448                 //   Starts a new code branching for block `block'.
 449                 // </summary>
 450                 public FlowBranching StartFlowBranching (Block block)
 451                 {
 452                         FlowBranching.BranchingType type;
 453
 454                         if (CurrentBranching.Type == FlowBranching.BranchingType.Switch)
 455                                 type = FlowBranching.BranchingType.SwitchSection;
 456                         else
 457                                 type = FlowBranching.BranchingType.Block;
 458
 459                         current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, block, block.StartLocation);
 460                         return current_flow_branching;
 461                 }
 462
 463                 // <summary>
 464                 //   Ends a code branching.  Merges the state of locals and parameters
 465                 //   from all the children of the ending branching.
 466                 // </summary>
 467                 public FlowBranching.UsageVector DoEndFlowBranching ()
 468                 {
 469                         FlowBranching old = current_flow_branching;
 470                         current_flow_branching = current_flow_branching.Parent;
 471
 472                         return current_flow_branching.MergeChild (old);
 473                 }
 474
 475                 // <summary>
 476                 //   Ends a code branching.  Merges the state of locals and parameters
 477                 //   from all the children of the ending branching.
 478                 // </summary>
 479                 public FlowBranching.Reachability EndFlowBranching ()
 480                 {
 481                         FlowBranching.UsageVector vector = DoEndFlowBranching ();
 482
 483                         return vector.Reachability;
 484                 }
 485
 486                 // <summary>
 487                 //   Kills the current code branching.  This throws away any changed state
 488                 //   information and should only be used in case of an error.
 489                 // </summary>
 490                 public void KillFlowBranching ()
 491                 {
 492                         current_flow_branching = current_flow_branching.Parent;
 493                 }
 494
 495                 public void EmitTopBlock (Block block, InternalParameters ip, Location loc)
 496                 {
 497                         bool unreachable = false;
 498
 499                         if (!Location.IsNull (loc))
 500                                 CurrentFile = loc.File;
 501
 502                         if (block != null){
 503                             try {
 504                                 int errors = Report.Errors;
 505
 506                                 block.EmitMeta (this, ip);
 507
 508                                 if (Report.Errors == errors){
 509                                         bool old_do_flow_analysis = DoFlowAnalysis;
 510                                         DoFlowAnalysis = true;
 511
 512                                         current_flow_branching = FlowBranching.CreateBranching (
 513                                                 null, FlowBranching.BranchingType.Block, block, loc);
 514
 515                                         if (!block.Resolve (this)) {
 516                                                 current_flow_branching = null;
 517                                                 DoFlowAnalysis = old_do_flow_analysis;
 518                                                 return;
 519                                         }
 520
 521                                         FlowBranching.Reachability reachability = current_flow_branching.MergeTopBlock ();
 522                                         current_flow_branching = null;
 523
 524                                         DoFlowAnalysis = old_do_flow_analysis;
 525
 526                                         block.Emit (this);
 527
 528                                         if (reachability.AlwaysReturns ||
 529                                             reachability.AlwaysThrows ||
 530                                             reachability.IsUnreachable)
 531                                                 unreachable = true;
 532                                 }
 533                             } catch (Exception e) {
 534                                         Console.WriteLine ("Exception caught by the compiler while compiling:");
 535                                         Console.WriteLine ("   Block that caused the problem begin at: " + loc);
 536
 537                                         if (CurrentBlock != null){
 538                                                 Console.WriteLine ("                     Block being compiled: [{0},{1}]",
 539                                                                    CurrentBlock.StartLocation, CurrentBlock.EndLocation);
 540                                         }
 541                                         Console.WriteLine (e.GetType ().FullName + ": " + e.Message);
 542                                         Console.WriteLine (Report.FriendlyStackTrace (e));
 543
 544                                         Environment.Exit (1);
 545                             }
 546                         }
 547
 548                         if (ReturnType != null && !unreachable){
 549                                 if (!InIterator){
 550                                         Report.Error (161, loc, "Not all code paths return a value");
 551                                         return;
 552                                 }
 553                         }
 554
 555                         if (HasReturnLabel)
 556                                 ig.MarkLabel (ReturnLabel);
 557                         if (return_value != null){
 558                                 ig.Emit (OpCodes.Ldloc, return_value);
 559                                 ig.Emit (OpCodes.Ret);
 560                         } else {
 561                                 //
 562                                 // If `HasReturnLabel' is set, then we already emitted a
 563                                 // jump to the end of the method, so we must emit a `ret'
 564                                 // there.
 565                                 //
 566                                 // Unfortunately, System.Reflection.Emit automatically emits
 567                                 // a leave to the end of a finally block.  This is a problem
 568                                 // if no code is following the try/finally block since we may
 569                                 // jump to a point after the end of the method.
 570                                 // As a workaround, we're always creating a return label in
 571                                 // this case.
 572                                 //
 573
 574                                 if ((block != null) && block.IsDestructor) {
 575                                         // Nothing to do; S.R.E automatically emits a leave.
 576                                 } else if (HasReturnLabel || (!unreachable && !InIterator)) {
 577                                         if (ReturnType != null)
 578                                                 ig.Emit (OpCodes.Ldloc, TemporaryReturn ());
 579                                         ig.Emit (OpCodes.Ret);
 580                                 }
 581                         }
 582                 }
 583
 584                 /// <summary>
 585                 ///   This is called immediately before emitting an IL opcode to tell the symbol
 586                 ///   writer to which source line this opcode belongs.
 587                 /// </summary>
 588                 public void Mark (Location loc, bool check_file)
 589                 {
 590                         if ((CodeGen.SymbolWriter == null) || Location.IsNull (loc))
 591                                 return;
 592
 593                         if (check_file && (CurrentFile != loc.File))
 594                                 return;
 595
 596                         ig.MarkSequencePoint (null, loc.Row, 0, 0, 0);
 597                 }
 598
 599                 /// <summary>
 600                 ///   Returns a temporary storage for a variable of type t as
 601                 ///   a local variable in the current body.
 602                 /// </summary>
 603                 public LocalBuilder GetTemporaryLocal (Type t)
 604                 {
 605                         LocalBuilder location = null;
 606
 607                         if (temporary_storage != null){
 608                                 object o = temporary_storage [t];
 609                                 if (o != null){
 610                                         if (o is ArrayList){
 611                                                 ArrayList al = (ArrayList) o;
 612
 613                                                 for (int i = 0; i < al.Count; i++){
 614                                                         if (al [i] != null){
 615                                                                 location = (LocalBuilder) al [i];
 616                                                                 al [i] = null;
 617                                                                 break;
 618                                                         }
 619                                                 }
 620                                         } else
 621                                                 location = (LocalBuilder) o;
 622                                         if (location != null)
 623                                                 return location;
 624                                 }
 625                         }
 626
 627                         return ig.DeclareLocal (t);
 628                 }
 629
 630                 public void FreeTemporaryLocal (LocalBuilder b, Type t)
 631                 {
 632                         if (temporary_storage == null){
 633                                 temporary_storage = new Hashtable ();
 634                                 temporary_storage [t] = b;
 635                                 return;
 636                         }
 637                         object o = temporary_storage [t];
 638                         if (o == null){
 639                                 temporary_storage [t] = b;
 640                                 return;
 641                         }
 642                         if (o is ArrayList){
 643                                 ArrayList al = (ArrayList) o;
 644                                 for (int i = 0; i < al.Count; i++){
 645                                         if (al [i] == null){
 646                                                 al [i] = b;
 647                                                 return;
 648                                         }
 649                                 }
 650                                 al.Add (b);
 651                                 return;
 652                         }
 653                         ArrayList replacement = new ArrayList ();
 654                         replacement.Add (o);
 655                         temporary_storage.Remove (t);
 656                         temporary_storage [t] = replacement;
 657                 }
 658
 659                 /// <summary>
 660                 ///   Current loop begin and end labels.
 661                 /// </summary>
 662                 public Label LoopBegin, LoopEnd;
 663
 664                 /// <summary>
 665                 ///   Default target in a switch statement.   Only valid if
 666                 ///   InSwitch is true
 667                 /// </summary>
 668                 public Label DefaultTarget;
 669
 670                 /// <summary>
 671                 ///   If this is non-null, points to the current switch statement
 672                 /// </summary>
 673                 public Switch Switch;
 674
 675                 /// <summary>
 676                 ///   ReturnValue creates on demand the LocalBuilder for the
 677                 ///   return value from the function.  By default this is not
 678                 ///   used.  This is only required when returns are found inside
 679                 ///   Try or Catch statements.
 680                 /// </summary>
 681                 public LocalBuilder TemporaryReturn ()
 682                 {
 683                         if (return_value == null){
 684                                 return_value = ig.DeclareLocal (ReturnType);
 685                                 ReturnLabel = ig.DefineLabel ();
 686                                 HasReturnLabel = true;
 687                         }
 688
 689                         return return_value;
 690                 }
 691
 692                 public void NeedReturnLabel ()
 693                 {
 694                         if (!HasReturnLabel) {
 695                                 ReturnLabel = ig.DefineLabel ();
 696                                 HasReturnLabel = true;
 697                         }
 698                 }
 699
 700                 //
 701                 // Creates a field `name' with the type `t' on the proxy class
 702                 //
 703                 public FieldBuilder MapVariable (string name, Type t)
 704                 {
 705                         if (InIterator){
 706                                 return IteratorHandler.Current.MapVariable ("v_", name, t);
 707                         }
 708
 709                         throw new Exception ("MapVariable for an unknown state");
 710                 }
 711
 712                 //
 713                 // Invoke this routine to remap a VariableInfo into the
 714                 // proper MemberAccess expression
 715                 //
 716                 public Expression RemapLocal (LocalInfo local_info)
 717                 {
 718                         FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc);
 719                         fe.InstanceExpression = new ProxyInstance ();
 720                         return fe.DoResolve (this);
 721                 }
 722
 723                 public Expression RemapLocalLValue (LocalInfo local_info, Expression right_side)
 724                 {
 725                         FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc);
 726                         fe.InstanceExpression = new ProxyInstance ();
 727                         return fe.DoResolveLValue (this, right_side);
 728                 }
 729
 730                 public Expression RemapParameter (int idx)
 731                 {
 732                         FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc);
 733                         fe.InstanceExpression = new ProxyInstance ();
 734                         return fe.DoResolve (this);
 735                 }
 736
 737                 public Expression RemapParameterLValue (int idx, Expression right_side)
 738                 {
 739                         FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc);
 740                         fe.InstanceExpression = new ProxyInstance ();
 741                         return fe.DoResolveLValue (this, right_side);
 742                 }
 743
 744                 //
 745                 // Emits the proper object to address fields on a remapped
 746                 // variable/parameter to field in anonymous-method/iterator proxy classes.
 747                 //
 748                 public void EmitThis ()
 749                 {
 750                         if (InIterator){
 751                                 ig.Emit (OpCodes.Ldarg_0);
 752                                 if (!IsStatic){
 753                                         FieldBuilder this_field = IteratorHandler.Current.this_field;
 754                                         if (TypeManager.IsValueType (this_field.FieldType))
 755                                                 ig.Emit (OpCodes.Ldflda, this_field);
 756                                         else
 757                                                 ig.Emit (OpCodes.Ldfld, this_field);
 758                                 }
 759                         } else
 760                                 ig.Emit (OpCodes.Ldarg_0);
 761                 }
 762
 763                 public Expression GetThis (Location loc)
 764                 {
 765                         This my_this;
 766                         if (CurrentBlock != null)
 767                                 my_this = new This (CurrentBlock, loc);
 768                         else
 769                                 my_this = new This (loc);
 770
 771                         if (!my_this.ResolveBase (this))
 772                                 my_this = null;
 773
 774                         return my_this;
 775                 }
 776         }
 777
 778
 779         public abstract class CommonAssemblyModulClass: Attributable {
 780                 static string[] attribute_targets = new string [] { "assembly", "module" };
 781
 782                 protected CommonAssemblyModulClass ():
 783                         base (null)
 784                 {
 785                 }
 786
 787                 public void AddAttributes (ArrayList attrs)
 788                 {
 789                         if (OptAttributes == null) {
 790                                 OptAttributes = new Attributes (attrs);
 791                                 return;
 792                         }
 793                         OptAttributes.AddAttributes (attrs);
 794                         OptAttributes.CheckTargets (ValidAttributeTargets);
 795                 }
 796
 797                 public virtual void Emit (TypeContainer tc)
 798                 {
 799                         if (OptAttributes == null)
 800                                 return;
 801
 802                         EmitContext ec = new EmitContext (tc, Mono.CSharp.Location.Null, null, null, 0, false);
 803                         OptAttributes.Emit (ec, this);
 804                 }
 805
 806                 protected Attribute GetClsCompliantAttribute ()
 807                 {
 808                         if (OptAttributes == null)
 809                                 return null;
 810
 811                         EmitContext temp_ec = new EmitContext (new TypeContainer (), Mono.CSharp.Location.Null, null, null, 0, false);
 812                         Attribute a = OptAttributes.Search (TypeManager.cls_compliant_attribute_type, temp_ec);
 813                         if (a != null) {
 814                                 a.Resolve (temp_ec);
 815                         }
 816                         return a;
 817                 }
 818
 819                 protected override string[] ValidAttributeTargets {
 820                         get {
 821                                 return attribute_targets;
 822                         }
 823                 }
 824
 825         }
 826
 827         public class AssemblyClass: CommonAssemblyModulClass {
 828                 // TODO: make it private and move all builder based methods here
 829                 public AssemblyBuilder Builder;
 830                 bool is_cls_compliant;
 831
 832                 public AssemblyClass (): base ()
 833                 {
 834                         is_cls_compliant = false;
 835                 }
 836
 837                 public bool IsClsCompliant {
 838                         get {
 839                                 return is_cls_compliant;
 840                         }
 841                 }
 842
 843                 public override AttributeTargets AttributeTargets {
 844                         get {
 845                                 return AttributeTargets.Assembly;
 846                         }
 847                 }
 848
 849                 public override bool IsClsCompliaceRequired(DeclSpace ds)
 850                 {
 851                         return is_cls_compliant;
 852                 }
 853
 854                 public void ResolveClsCompliance ()
 855                 {
 856                         Attribute a = GetClsCompliantAttribute ();
 857                         if (a == null)
 858                                 return;
 859
 860                         is_cls_compliant = a.GetClsCompliantAttributeValue (null);
 861                 }
 862
 863                 public AssemblyName GetAssemblyName (string name, string output)
 864                 {
 865                         if (OptAttributes != null) {
 866                                 foreach (Attribute a in OptAttributes.Attrs) {
 867                                         if (a.Target != "assembly")
 868                                                 continue;
 869                                         // TODO: This code is buggy: comparing Attribute name without resolving it is wrong.
 870                                         //       However, this is invoked by CodeGen.Init, at which time none of the namespaces
 871                                         //       are loaded yet.
 872                                         switch (a.Name) {
 873                                                 case "AssemblyKeyFile":
 874                                                 case "AssemblyKeyFileAttribute":
 875                                                 case "System.Reflection.AssemblyKeyFileAttribute":
 876                                                         if (RootContext.StrongNameKeyFile != null) {
 877                                                                 Report.Warning (1616, "Compiler option -keyfile overrides " +
 878                                                                         "AssemblyKeyFileAttribute");
 879                                                         }
 880                                                         else {
 881                                                                 string value = a.GetString ();
 882                                                                 if (value != String.Empty)
 883                                                                         RootContext.StrongNameKeyFile = value;
 884                                                         }
 885                                                         break;
 886                                                 case "AssemblyKeyName":
 887                                                 case "AssemblyKeyNameAttribute":
 888                                                 case "System.Reflection.AssemblyKeyNameAttribute":
 889                                                         if (RootContext.StrongNameKeyContainer != null) {
 890                                                                 Report.Warning (1616, "Compiler option -keycontainer overrides " +
 891                                                                         "AssemblyKeyNameAttribute");
 892                                                         }
 893                                                         else {
 894                                                                 string value = a.GetString ();
 895                                                                 if (value != String.Empty)
 896                                                                         RootContext.StrongNameKeyContainer = value;
 897                                                         }
 898                                                         break;
 899                                                 case "AssemblyDelaySign":
 900                                                 case "AssemblyDelaySignAttribute":
 901                                                 case "System.Reflection.AssemblyDelaySignAttribute":
 902                                                         RootContext.StrongNameDelaySign = a.GetBoolean ();
 903                                                         break;
 904                                         }
 905                                 }
 906                         }
 907
 908                         AssemblyName an = new AssemblyName ();
 909                         an.Name = Path.GetFileNameWithoutExtension (name);
 910
 911                         // note: delay doesn't apply when using a key container
 912                         if (RootContext.StrongNameKeyContainer != null) {
 913                                 an.KeyPair = new StrongNameKeyPair (RootContext.StrongNameKeyContainer);
 914                                 return an;
 915                         }
 916
 917                         // strongname is optional
 918                         if (RootContext.StrongNameKeyFile == null)
 919                                 return an;
 920
 921                         string AssemblyDir = Path.GetDirectoryName (output);
 922
 923                         // the StrongName key file may be relative to (a) the compiled
 924                         // file or (b) to the output assembly. See bugzilla #55320
 925                         // http://bugzilla.ximian.com/show_bug.cgi?id=55320
 926
 927                         // (a) relative to the compiled file
 928                         string filename = Path.GetFullPath (RootContext.StrongNameKeyFile);
 929                         bool exist = File.Exists (filename);
 930                         if ((!exist) && (AssemblyDir != null) && (AssemblyDir != String.Empty)) {
 931                                 // (b) relative to the outputed assembly
 932                                 filename = Path.GetFullPath (Path.Combine (AssemblyDir, RootContext.StrongNameKeyFile));
 933                                 exist = File.Exists (filename);
 934                         }
 935
 936                         if (exist) {
 937                                 using (FileStream fs = new FileStream (filename, FileMode.Open, FileAccess.Read)) {
 938                                         byte[] snkeypair = new byte [fs.Length];
 939                                         fs.Read (snkeypair, 0, snkeypair.Length);
 940
 941                                         if (RootContext.StrongNameDelaySign) {
 942                                                 // delayed signing - DO NOT include private key
 943                                                 try {
 944                                                         // check for possible ECMA key
 945                                                         if (snkeypair.Length == 16) {
 946                                                                 // will be rejected if not "the" ECMA key
 947                                                                 an.KeyPair = new StrongNameKeyPair (snkeypair);
 948                                                         }
 949                                                         else {
 950                                                                 // take it, with or without, a private key
 951                                                                 RSA rsa = CryptoConvert.FromCapiKeyBlob (snkeypair);
 952                                                                 // and make sure we only feed the public part to Sys.Ref
 953                                                                 byte[] publickey = CryptoConvert.ToCapiPublicKeyBlob (rsa);
 954                                                                 an.KeyPair = new StrongNameKeyPair (publickey);
 955                                                         }
 956                                                 }
 957                                                 catch (Exception) {
 958                                                         Report.Error (1548, "Could not strongname the assembly. File `" +
 959                                                                 RootContext.StrongNameKeyFile + "' incorrectly encoded.");
 960                                                         Environment.Exit (1);
 961                                                 }
 962                                         }
 963                                         else {
 964                                                 // no delay so we make sure we have the private key
 965                                                 try {
 966                                                         CryptoConvert.FromCapiPrivateKeyBlob (snkeypair);
 967                                                         an.KeyPair = new StrongNameKeyPair (snkeypair);
 968                                                 }
 969                                                 catch (CryptographicException) {
 970                                                         if (snkeypair.Length == 16) {
 971                                                                 // error # is different for ECMA key
 972                                                                 Report.Error (1606, "Could not strongname the assembly. " +
 973                                                                         "ECMA key can only be used to delay-sign assemblies");
 974                                                         }
 975                                                         else {
 976                                                                 Report.Error (1548, "Could not strongname the assembly. File `" +
 977                                                                         RootContext.StrongNameKeyFile +
 978                                                                         "' doesn't have a private key.");
 979                                                         }
 980                                                         Environment.Exit (1);
 981                                                 }
 982                                         }
 983                                 }
 984                         }
 985                         else {
 986                                 Report.Error (1548, "Could not strongname the assembly. File `" +
 987                                         RootContext.StrongNameKeyFile + "' not found.");
 988                                 Environment.Exit (1);
 989                         }
 990                         return an;
 991                 }
 992
 993                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
 994                 {
 995                         Builder.SetCustomAttribute (customBuilder);
 996                 }
 997         }
 998
 999         public class ModuleClass: CommonAssemblyModulClass {
1000                 // TODO: make it private and move all builder based methods here
1001                 public ModuleBuilder Builder;
1002                 bool m_module_is_unsafe;
1003
1004                 public ModuleClass (bool is_unsafe)
1005                 {
1006                         m_module_is_unsafe = is_unsafe;
1007                 }
1008
1009                 public override AttributeTargets AttributeTargets {
1010                         get {
1011                                 return AttributeTargets.Module;
1012                         }
1013                 }
1014
1015                 public override bool IsClsCompliaceRequired(DeclSpace ds)
1016                 {
1017                         return CodeGen.Assembly.IsClsCompliant;
1018                 }
1019
1020                 public override void Emit (TypeContainer tc)
1021                 {
1022                         base.Emit (tc);
1023
1024                         if (!m_module_is_unsafe)
1025                                 return;
1026
1027                         if (TypeManager.unverifiable_code_ctor == null) {
1028                                 Console.WriteLine ("Internal error ! Cannot set unverifiable code attribute.");
1029                                 return;
1030                         }
1031
1032                         ApplyAttributeBuilder (null, new CustomAttributeBuilder (TypeManager.unverifiable_code_ctor, new object [0]));
1033                 }
1034
1035                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder customBuilder)
1036                 {
1037                         if (a != null && a.Type == TypeManager.cls_compliant_attribute_type) {
1038                                 Report.Warning_T (3012, a.Location);
1039                                 return;
1040                         }
1041
1042                         Builder.SetCustomAttribute (customBuilder);
1043                 }
1044         }
1045 }