source: trunk/sources/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Parser/mcs/field.cs @ 11807

//
// field.cs: All field handlers
//
// Authors: Miguel de Icaza (miguel@gnu.org)
//          Martin Baulig (martin@ximian.com)
//          Marek Safar (marek.safar@seznam.cz)
//
// Dual licensed under the terms of the MIT X11 or GNU GPL
//
// Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
// Copyright 2004-2008 Novell, Inc
// Copyright 2011 Xamarin Inc
//

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;

#if STATIC
using MetaType = IKVM.Reflection.Type;
using IKVM.Reflection;
using IKVM.Reflection.Emit;
#else
using MetaType = System.Type;
using System.Reflection;
using System.Reflection.Emit;
#endif

namespace Mono.CSharp
{
  public class FieldDeclarator
  {
    public FieldDeclarator (SimpleMemberName name, Expression initializer)
    {
      this.Name = name;
      this.Initializer = initializer;
    }

    #region Properties

    public SimpleMemberName Name { get; private set; }
    public Expression Initializer { get; private set; }

    #endregion

    public virtual FullNamedExpression GetFieldTypeExpression (FieldBase field)
    {
      return new TypeExpression (field.MemberType, Name.Location); 
    }
  }

  //
  // Abstract class for all fields
  //
  abstract public class FieldBase : MemberBase
  {
    protected FieldBuilder FieldBuilder;
    protected FieldSpec spec;
    public Status status;
    protected Expression initializer;
    protected List<FieldDeclarator> declarators;

    [Flags]
    public enum Status : byte {
      HAS_OFFSET = 4    // Used by FieldMember.
    }

    static readonly string[] attribute_targets = new string [] { "field" };

    protected FieldBase (TypeDefinition parent, FullNamedExpression type, Modifiers mod, Modifiers allowed_mod, MemberName name, Attributes attrs)
      : base (parent, type, mod, allowed_mod | Modifiers.ABSTRACT, Modifiers.PRIVATE, name, attrs)
    {
      if ((mod & Modifiers.ABSTRACT) != 0)
        Report.Error (681, Location, "The modifier 'abstract' is not valid on fields. Try using a property instead");
    }

    #region Properties

    public override AttributeTargets AttributeTargets {
      get {
        return AttributeTargets.Field;
      }
    }

    public Expression Initializer {
      get {
        return initializer;
      }
      set {
        this.initializer = value;
      }
    }

    public string Name {
      get {
        return MemberName.Name;
      }
    }

    public FieldSpec Spec {
      get {
        return spec;
      }
    }

    public override string[] ValidAttributeTargets  {
      get {
        return attribute_targets;
      }
    }
    
    public List<FieldDeclarator> Declarators {
      get {
        return this.declarators;
      }
    }
    #endregion

    public void AddDeclarator (FieldDeclarator declarator)
    {
      if (declarators == null)
        declarators = new List<FieldDeclarator> (2);

      declarators.Add (declarator);

      Parent.AddNameToContainer (this, declarator.Name.Value);
    }

    public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
    {
      if (a.Type == pa.FieldOffset) {
        status |= Status.HAS_OFFSET;

        if (!Parent.PartialContainer.HasExplicitLayout) {
          Report.Error (636, Location, "The FieldOffset attribute can only be placed on members of types marked with the StructLayout(LayoutKind.Explicit)");
          return;
        }

        if ((ModFlags & Modifiers.STATIC) != 0 || this is Const) {
          Report.Error (637, Location, "The FieldOffset attribute is not allowed on static or const fields");
          return;
        }
      }

      if (a.Type == pa.FixedBuffer) {
        Report.Error (1716, Location, "Do not use 'System.Runtime.CompilerServices.FixedBuffer' attribute. Use the 'fixed' field modifier instead");
        return;
      }

#if false
      if (a.Type == pa.MarshalAs) {
        UnmanagedMarshal marshal = a.GetMarshal (this);
        if (marshal != null) {
          FieldBuilder.SetMarshal (marshal);
        }
        return;
      }
#endif
      if ((a.HasSecurityAttribute)) {
        a.Error_InvalidSecurityParent ();
        return;
      }

      if (a.Type == pa.Dynamic) {
        a.Error_MisusedDynamicAttribute ();
        return;
      }

      FieldBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
    }

    public void SetCustomAttribute (MethodSpec ctor, byte[] data)
    {
      FieldBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), data);
    }

    protected override bool CheckBase ()
    {
      if (!base.CheckBase ())
        return false;

      MemberSpec candidate;
      bool overrides = false;
      var conflict_symbol = MemberCache.FindBaseMember (this, out candidate, ref overrides);
      if (conflict_symbol == null)
        conflict_symbol = candidate;

      if (conflict_symbol == null) {
        if ((ModFlags & Modifiers.NEW) != 0) {
          Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required",
            GetSignatureForError ());
        }
      } else {
        if ((ModFlags & (Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.BACKING_FIELD)) == 0) {
          Report.SymbolRelatedToPreviousError (conflict_symbol);
          Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
            GetSignatureForError (), conflict_symbol.GetSignatureForError ());
        }

        if (conflict_symbol.IsAbstract) {
          Report.SymbolRelatedToPreviousError (conflict_symbol);
          Report.Error (533, Location, "`{0}' hides inherited abstract member `{1}'",
            GetSignatureForError (), conflict_symbol.GetSignatureForError ());
        }
      }
 
      return true;
    }

    public virtual Constant ConvertInitializer (ResolveContext rc, Constant expr)
    {
      return expr.ConvertImplicitly (MemberType);
    }

    protected override void DoMemberTypeDependentChecks ()
    {
      base.DoMemberTypeDependentChecks ();

      if (MemberType.IsGenericParameter)
        return;

      if (MemberType.IsStatic)
        Error_VariableOfStaticClass (Location, GetSignatureForError (), MemberType, Report);

      if (!IsCompilerGenerated)
        CheckBase ();

      IsTypePermitted ();
    }

    //
    //   Represents header string for documentation comment.
    //
    public override string DocCommentHeader {
      get { return "F:"; }
    }

    public override void Emit ()
    {
      if (member_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
        Module.PredefinedAttributes.Dynamic.EmitAttribute (FieldBuilder);
      } else if (!Parent.IsCompilerGenerated && member_type.HasDynamicElement) {
        Module.PredefinedAttributes.Dynamic.EmitAttribute (FieldBuilder, member_type, Location);
      }

      if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
        Module.PredefinedAttributes.CompilerGenerated.EmitAttribute (FieldBuilder);
      if ((ModFlags & Modifiers.DEBUGGER_HIDDEN) != 0)
        Module.PredefinedAttributes.DebuggerBrowsable.EmitAttribute (FieldBuilder, System.Diagnostics.DebuggerBrowsableState.Never);

      if (OptAttributes != null) {
        OptAttributes.Emit ();
      }

      if (((status & Status.HAS_OFFSET) == 0) && (ModFlags & (Modifiers.STATIC | Modifiers.BACKING_FIELD)) == 0 && Parent.PartialContainer.HasExplicitLayout) {
        Report.Error (625, Location, "`{0}': Instance field types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute", GetSignatureForError ());
      }

      ConstraintChecker.Check (this, member_type, type_expr.Location);

      base.Emit ();
    }

    public static void Error_VariableOfStaticClass (Location loc, string variable_name, TypeSpec static_class, Report Report)
    {
      Report.SymbolRelatedToPreviousError (static_class);
      Report.Error (723, loc, "`{0}': cannot declare variables of static types",
        variable_name);
    }

    protected override bool VerifyClsCompliance ()
    {
      if (!base.VerifyClsCompliance ())
        return false;

      if (!MemberType.IsCLSCompliant () || this is FixedField) {
        Report.Warning (3003, 1, Location, "Type of `{0}' is not CLS-compliant",
          GetSignatureForError ());
      }
      return true;
    }
  }

  //
  // Field specification
  //
  public class FieldSpec : MemberSpec, IInterfaceMemberSpec
  {
    FieldInfo metaInfo;
    TypeSpec memberType;

    public FieldSpec (TypeSpec declaringType, IMemberDefinition definition, TypeSpec memberType, FieldInfo info, Modifiers modifiers)
      : base (MemberKind.Field, declaringType, definition, modifiers)
    {
      this.metaInfo = info;
      this.memberType = memberType;
    }

    #region Properties

    public bool IsReadOnly {
      get {
        return (Modifiers & Modifiers.READONLY) != 0;
      }
    }

    public TypeSpec MemberType {
      get {
        return memberType;
      }
    }

#endregion

    public FieldInfo GetMetaInfo ()
    {
      if ((state & StateFlags.PendingMetaInflate) != 0) {
        var decl_meta = DeclaringType.GetMetaInfo ();
        if (DeclaringType.IsTypeBuilder) {
          metaInfo = TypeBuilder.GetField (decl_meta, metaInfo);
        } else {
          var orig_token = metaInfo.MetadataToken;
          metaInfo = decl_meta.GetField (Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static);
          if (metaInfo.MetadataToken != orig_token)
            throw new NotImplementedException ("Resolved to wrong meta token");

          // What a stupid API, does not work because field handle is imported
          // metaInfo = FieldInfo.GetFieldFromHandle (metaInfo.FieldHandle, DeclaringType.MetaInfo.TypeHandle);
        }

        state &= ~StateFlags.PendingMetaInflate;
      }

      return metaInfo;
    }

    public override MemberSpec InflateMember (TypeParameterInflator inflator)
    {
      var fs = (FieldSpec) base.InflateMember (inflator);
      fs.memberType = inflator.Inflate (memberType);
      return fs;
    }

    public FieldSpec Mutate (TypeParameterMutator mutator)
    {
      var decl = DeclaringType;
      if (DeclaringType.IsGenericOrParentIsGeneric)
        decl = mutator.Mutate (decl);

      if (decl == DeclaringType)
        return this;

      var fs = (FieldSpec) MemberwiseClone ();
      fs.declaringType = decl;
      fs.state |= StateFlags.PendingMetaInflate;

      // Gets back FieldInfo in case of metaInfo was inflated
      fs.metaInfo = MemberCache.GetMember (TypeParameterMutator.GetMemberDeclaringType (DeclaringType), this).metaInfo;
      return fs;
    }

    public override List<MissingTypeSpecReference> ResolveMissingDependencies (MemberSpec caller)
    {
      return memberType.ResolveMissingDependencies (this);
    }
  }

  /// <summary>
  /// Fixed buffer implementation
  /// </summary>
  public class FixedField : FieldBase
  {
    public const string FixedElementName = "FixedElementField";
    static int GlobalCounter;

    TypeBuilder fixed_buffer_type;

    const Modifiers AllowedModifiers =
      Modifiers.NEW |
      Modifiers.PUBLIC |
      Modifiers.PROTECTED |
      Modifiers.INTERNAL |
      Modifiers.PRIVATE |
      Modifiers.UNSAFE;

    public FixedField (TypeDefinition parent, FullNamedExpression type, Modifiers mod, MemberName name, Attributes attrs)
      : base (parent, type, mod, AllowedModifiers, name, attrs)
    {
    }

    #region Properties

    //
    // Explicit struct layout set by parent
    //
    public CharSet? CharSet {
      get; set;
    }   

    #endregion

    public override Constant ConvertInitializer (ResolveContext rc, Constant expr)
    {
      return expr.ImplicitConversionRequired (rc, rc.BuiltinTypes.Int);
    }

    public override bool Define ()
    {
      if (!base.Define ())
        return false;

      if (!BuiltinTypeSpec.IsPrimitiveType (MemberType)) {
        Report.Error (1663, Location,
          "`{0}': Fixed size buffers type must be one of the following: bool, byte, short, int, long, char, sbyte, ushort, uint, ulong, float or double",
          GetSignatureForError ());
      } else if (declarators != null) {
        foreach (var d in declarators) {
          var f = new FixedField (Parent, d.GetFieldTypeExpression (this), ModFlags, new MemberName (d.Name.Value, d.Name.Location), OptAttributes);
          f.initializer = d.Initializer;
          ((ConstInitializer) f.initializer).Name = d.Name.Value;
          f.Define ();
          Parent.PartialContainer.Members.Add (f);
        }
      }
      
      // Create nested fixed buffer container
      string name = String.Format ("<{0}>__FixedBuffer{1}", Name, GlobalCounter++);
      fixed_buffer_type = Parent.TypeBuilder.DefineNestedType (name,
        TypeAttributes.NestedPublic | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit,
        Compiler.BuiltinTypes.ValueType.GetMetaInfo ());

      var ffield = fixed_buffer_type.DefineField (FixedElementName, MemberType.GetMetaInfo (), FieldAttributes.Public);
      
      FieldBuilder = Parent.TypeBuilder.DefineField (Name, fixed_buffer_type, ModifiersExtensions.FieldAttr (ModFlags));

      var element_spec = new FieldSpec (null, this, MemberType, ffield, ModFlags);
      spec = new FixedFieldSpec (Module, Parent.Definition, this, FieldBuilder, element_spec, ModFlags);

      Parent.MemberCache.AddMember (spec);
      return true;
    }

    protected override void DoMemberTypeIndependentChecks ()
    {
      base.DoMemberTypeIndependentChecks ();

      if (!IsUnsafe)
        Expression.UnsafeError (Report, Location);

      if (Parent.PartialContainer.Kind != MemberKind.Struct) {
        Report.Error (1642, Location, "`{0}': Fixed size buffer fields may only be members of structs",
          GetSignatureForError ());
      }
    }
    
    public override void Accept (StructuralVisitor visitor)
    {
      visitor.Visit (this);
    }

    public override void Emit()
    {
      ResolveContext rc = new ResolveContext (this);
      IntConstant buffer_size_const = initializer.Resolve (rc) as IntConstant;
      if (buffer_size_const == null)
        return;

      int buffer_size = buffer_size_const.Value;

      if (buffer_size <= 0) {
        Report.Error (1665, Location, "`{0}': Fixed size buffers must have a length greater than zero", GetSignatureForError ());
        return;
      }

      EmitFieldSize (buffer_size);

#if STATIC
      if (Module.HasDefaultCharSet)
        fixed_buffer_type.__SetAttributes (fixed_buffer_type.Attributes | Module.DefaultCharSetType);
#endif

      Module.PredefinedAttributes.UnsafeValueType.EmitAttribute (fixed_buffer_type);
      Module.PredefinedAttributes.CompilerGenerated.EmitAttribute (fixed_buffer_type);
      fixed_buffer_type.CreateType ();

      base.Emit ();
    }

    void EmitFieldSize (int buffer_size)
    {
      int type_size = BuiltinTypeSpec.GetSize (MemberType);

      if (buffer_size > int.MaxValue / type_size) {
        Report.Error (1664, Location, "Fixed size buffer `{0}' of length `{1}' and type `{2}' exceeded 2^31 limit",
          GetSignatureForError (), buffer_size.ToString (), MemberType.GetSignatureForError ());
        return;
      }

      AttributeEncoder encoder;

      var ctor = Module.PredefinedMembers.StructLayoutAttributeCtor.Resolve (Location);
      if (ctor == null)
        return;

      var field_size = Module.PredefinedMembers.StructLayoutSize.Resolve (Location);
      var field_charset = Module.PredefinedMembers.StructLayoutCharSet.Resolve (Location);
      if (field_size == null || field_charset == null)
        return;

      var char_set = CharSet ?? Module.DefaultCharSet ?? 0;

      encoder = new AttributeEncoder ();
      encoder.Encode ((short)LayoutKind.Sequential);
      encoder.EncodeNamedArguments (
        new [] { field_size, field_charset },
        new Constant [] { 
          new IntConstant (Compiler.BuiltinTypes, buffer_size * type_size, Location),
          new IntConstant (Compiler.BuiltinTypes, (int) char_set, Location)
        }
      );

      fixed_buffer_type.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), encoder.ToArray ());

      //
      // Don't emit FixedBufferAttribute attribute for private types
      //
      if ((ModFlags & Modifiers.PRIVATE) != 0)
        return;

      ctor = Module.PredefinedMembers.FixedBufferAttributeCtor.Resolve (Location);
      if (ctor == null)
        return;

      encoder = new AttributeEncoder ();
      encoder.EncodeTypeName (MemberType);
      encoder.Encode (buffer_size);
      encoder.EncodeEmptyNamedArguments ();

      FieldBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), encoder.ToArray ());
    }
  }

  class FixedFieldSpec : FieldSpec
  {
    readonly FieldSpec element;

    public FixedFieldSpec (ModuleContainer module, TypeSpec declaringType, IMemberDefinition definition, FieldInfo info, FieldSpec element, Modifiers modifiers)
      : base (declaringType, definition, PointerContainer.MakeType (module, element.MemberType), info, modifiers)
    {
      this.element = element;

      // It's never CLS-Compliant
      state &= ~StateFlags.CLSCompliant_Undetected;
    }

    public FieldSpec Element {
      get {
        return element;
      }
    }
    
    public TypeSpec ElementType {
      get {
        return element.MemberType;
      }
    }
  }

  //
  // The Field class is used to represents class/struct fields during parsing.
  //
  public class Field : FieldBase {
    // <summary>
    //   Modifiers allowed in a class declaration
    // </summary>
    const Modifiers AllowedModifiers =
      Modifiers.NEW |
      Modifiers.PUBLIC |
      Modifiers.PROTECTED |
      Modifiers.INTERNAL |
      Modifiers.PRIVATE |
      Modifiers.STATIC |
      Modifiers.VOLATILE |
      Modifiers.UNSAFE |
      Modifiers.READONLY;

    public Field (TypeDefinition parent, FullNamedExpression type, Modifiers mod, MemberName name, Attributes attrs)
      : base (parent, type, mod, AllowedModifiers, name, attrs)
    {
    }

    bool CanBeVolatile ()
    {
      switch (MemberType.BuiltinType) {
      case BuiltinTypeSpec.Type.Bool:
      case BuiltinTypeSpec.Type.Char:
      case BuiltinTypeSpec.Type.SByte:
      case BuiltinTypeSpec.Type.Byte:
      case BuiltinTypeSpec.Type.Short:
      case BuiltinTypeSpec.Type.UShort:
      case BuiltinTypeSpec.Type.Int:
      case BuiltinTypeSpec.Type.UInt:
      case BuiltinTypeSpec.Type.Float:
      case BuiltinTypeSpec.Type.UIntPtr:
      case BuiltinTypeSpec.Type.IntPtr:
        return true;
      }

      if (TypeSpec.IsReferenceType (MemberType))
        return true;

      if (MemberType.IsEnum)
        return true;

      return false;
    }

    public override void Accept (StructuralVisitor visitor)
    {
      visitor.Visit (this);
    }
    
    public override bool Define ()
    {
      if (!base.Define ())
        return false;

      MetaType[] required_modifier = null;
      if ((ModFlags & Modifiers.VOLATILE) != 0) {
        var mod = Module.PredefinedTypes.IsVolatile.Resolve ();
        if (mod != null)
          required_modifier = new MetaType[] { mod.GetMetaInfo () };
      }

      FieldBuilder = Parent.TypeBuilder.DefineField (
        Name, member_type.GetMetaInfo (), required_modifier, null, ModifiersExtensions.FieldAttr (ModFlags));

      spec = new FieldSpec (Parent.Definition, this, MemberType, FieldBuilder, ModFlags);

      //
      // Don't cache inaccessible fields except for struct where we
      // need them for definitive assignment checks
      //
      if ((ModFlags & Modifiers.BACKING_FIELD) == 0 || Parent.Kind == MemberKind.Struct) {
        Parent.MemberCache.AddMember (spec);
      }

      if (initializer != null) {
        Parent.RegisterFieldForInitialization (this, new FieldInitializer (this, initializer, TypeExpression.Location));
      }

      if (declarators != null) {
        foreach (var d in declarators) {
          var f = new Field (Parent, d.GetFieldTypeExpression (this), ModFlags, new MemberName (d.Name.Value, d.Name.Location), OptAttributes);
          if (d.Initializer != null)
            f.initializer = d.Initializer;

          f.Define ();
          Parent.PartialContainer.Members.Add (f);
        }
      }

      return true;
    }

    protected override void DoMemberTypeDependentChecks ()
    {
      if ((ModFlags & Modifiers.BACKING_FIELD) != 0)
        return;

      base.DoMemberTypeDependentChecks ();

      if ((ModFlags & Modifiers.VOLATILE) != 0) {
        if (!CanBeVolatile ()) {
          Report.Error (677, Location, "`{0}': A volatile field cannot be of the type `{1}'",
            GetSignatureForError (), MemberType.GetSignatureForError ());
        }

        if ((ModFlags & Modifiers.READONLY) != 0) {
          Report.Error (678, Location, "`{0}': A field cannot be both volatile and readonly",
            GetSignatureForError ());
        }
      }
    }

    protected override bool VerifyClsCompliance ()
    {
      if (!base.VerifyClsCompliance ())
        return false;

      if ((ModFlags & Modifiers.VOLATILE) != 0) {
        Report.Warning (3026, 1, Location, "CLS-compliant field `{0}' cannot be volatile", GetSignatureForError ());
      }

      return true;
    }
  }

  class PrimaryConstructorField : Field
  {
    //
    // Proxy resolved parameter type expression to avoid type double resolve
    // and problems with correct resolve context on partial classes
    //
    sealed class TypeExpressionFromParameter : TypeExpr
    {
      Parameter parameter;

      public TypeExpressionFromParameter (Parameter parameter)
      {
        this.parameter = parameter;
        eclass = ExprClass.Type;
        loc = parameter.Location;
      }

      public override TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments)
      {
        return parameter.Type;
      }
    }

    public PrimaryConstructorField (TypeDefinition parent, Parameter parameter)
      : base (parent, new TypeExpressionFromParameter (parameter), Modifiers.PRIVATE, new MemberName (parameter.Name, parameter.Location), null)
    {
      caching_flags |= Flags.IsUsed | Flags.IsAssigned;
    }

    public override string GetSignatureForError ()
    {
      return MemberName.Name;
    }
  }
}