In ilasm/codegen:

[mcs.git] / mcs / parameter.cs

//
// parameter.cs: Parameter definition.
//
// Author: Miguel de Icaza (miguel@gnu.org)
//         Marek Safar (marek.safar@seznam.cz)
//
// Licensed under the terms of the GNU GPL
//
// (C) 2001 Ximian, Inc (http://www.ximian.com)
//
//
//
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Collections;
using System.Text;

namespace Mono.CSharp {

        /// <summary>
        ///   Abstract Base class for parameters of a method.
        /// </summary>
        public abstract class ParameterBase : Attributable {

                protected ParameterBuilder builder;
                public readonly Location Location;

                protected ParameterBase (Attributes attrs, Location loc)
                        : base (attrs)
                {
                        Location = loc;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
                {
                        if (a.Type == TypeManager.marshal_as_attr_type) {
                                UnmanagedMarshal marshal = a.GetMarshal (this);
                                if (marshal != null) {
                                        builder.SetMarshal (marshal);
                                }
                                return;
                        }

                        if (a.Type.IsSubclassOf (TypeManager.security_attr_type)) {
                                a.Error_InvalidSecurityParent ();
                                return;
                        }

                        builder.SetCustomAttribute (cb);
                }

                public override bool IsClsComplianceRequired(DeclSpace ds)
                {
                        return false;
                }
        }

        /// <summary>
        /// Class for applying custom attributes on the return type
        /// </summary>
        public class ReturnParameter : ParameterBase {
                public ReturnParameter (MethodBuilder mb, Location location):
                        base (null, location)
                {
                        try {
                                builder = mb.DefineParameter (0, ParameterAttributes.None, "");                 
                        }
                        catch (ArgumentOutOfRangeException) {
                                Report.RuntimeMissingSupport (Location, "custom attributes on the return type");
                        }
                }

                public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
                {
                        if (a.Type == TypeManager.cls_compliant_attribute_type) {
                                Report.Warning (3023, 1, a.Location, "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
                        }

                        // This occurs after Warning -28
                        if (builder == null)
                                return;

                        base.ApplyAttributeBuilder (a, cb);
                }

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

                /// <summary>
                /// Is never called
                /// </summary>
                public override string[] ValidAttributeTargets {
                        get {
                                return null;
                        }
                }
        }

        /// <summary>
        /// Class for applying custom attributes on the implicit parameter type
        /// of the 'set' method in properties, and the 'add' and 'remove' methods in events.
        /// </summary>
        /// 
        // TODO: should use more code from Parameter.ApplyAttributeBuilder
        public class ImplicitParameter : ParameterBase {
                public ImplicitParameter (MethodBuilder mb, Location loc):
                        base (null, loc)
                {
                        builder = mb.DefineParameter (1, ParameterAttributes.None, "");                 
                }

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

                /// <summary>
                /// Is never called
                /// </summary>
                public override string[] ValidAttributeTargets {
                        get {
                                return null;
                        }
                }
        }

        public class ParamsParameter : Parameter {
                public ParamsParameter (Expression type, string name, Attributes attrs, Location loc):
                        base (type, name, Parameter.Modifier.PARAMS, attrs, loc)
                {
                }

                public override bool Resolve (EmitContext ec)
                {
                        if (!base.Resolve (ec))
                                return false;

                        if (!parameter_type.IsArray || parameter_type.GetArrayRank () != 1) {
                                Report.Error (225, Location, "The params parameter must be a single dimensional array");
                                return false;
                        }
                        return true;
                }

                public override void ApplyAttributes (EmitContext ec, MethodBuilder mb, ConstructorBuilder cb, int index)
                {
                        base.ApplyAttributes (ec, mb, cb, index);

                        CustomAttributeBuilder a = new CustomAttributeBuilder (
                                TypeManager.cons_param_array_attribute, new object [0]);
                                
                        builder.SetCustomAttribute (a);
                }
        }

        public class ArglistParameter : Parameter {
                // Doesn't have proper type because it's never choosed for better conversion
                public ArglistParameter () :
                        base (typeof (ArglistParameter), "", Parameter.Modifier.ARGLIST, null, Location.Null)
                {
                }

                public override bool Resolve (EmitContext ec)
                {
                        return true;
                }

                public override string GetSignatureForError ()
                {
                        return "__arglist";
                }
        }

        /// <summary>
        ///   Represents a single method parameter
        /// </summary>
        public class Parameter : ParameterBase {
                [Flags]
                public enum Modifier : byte {
                        NONE    = 0,
                        REF     = REFMASK | ISBYREF,
                        OUT     = OUTMASK | ISBYREF,
                        PARAMS  = 4,
                        // This is a flag which says that it's either REF or OUT.
                        ISBYREF = 8,
                        ARGLIST = 16,
                        REFMASK = 32,
                        OUTMASK = 64
                }

                static string[] attribute_targets = new string [] { "param" };

                public Expression TypeName;
                public readonly Modifier ModFlags;
                public readonly string Name;
                protected Type parameter_type;

                EmitContext ec;  // because ApplyAtrribute doesn't have ec
                
                public Parameter (Expression type, string name, Modifier mod, Attributes attrs, Location loc)
                        : base (attrs, loc)
                {
                        Name = name;
                        ModFlags = mod;
                        TypeName = type;
                }

                public Parameter (Type type, string name, Modifier mod, Attributes attrs, Location loc)
                        : base (attrs, loc)
                {
                        Name = name;
                        ModFlags = mod;
                        parameter_type = type;
                }

                public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
                {
                        if (a.Type == TypeManager.in_attribute_type && ModFlags == Modifier.OUT) {
                                Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
                                return;
                        }

                        if (a.Type == TypeManager.param_array_type) {
                                Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
                                return;
                        }

                        if (a.Type == TypeManager.out_attribute_type && (ModFlags & Modifier.REF) == Modifier.REF &&
                            !OptAttributes.Contains (TypeManager.in_attribute_type, ec)) {
                                Report.Error (662, a.Location,
                                        "Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
                                return;
                        }

                        if (a.Type == TypeManager.cls_compliant_attribute_type) {
                                Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
                        }

                        base.ApplyAttributeBuilder (a, cb);
                }

                // <summary>
                //   Resolve is used in method definitions
                // </summary>
                public virtual bool Resolve (EmitContext ec)
                {
                        if (parameter_type != null)
                                return true;

                        this.ec = ec;

                        TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
                        if (texpr == null)
                                return false;

                        parameter_type = texpr.ResolveType (ec);
                        
                        if (parameter_type.IsAbstract && parameter_type.IsSealed) {
                                Report.Error (721, Location, "`{0}': static types cannot be used as parameters", GetSignatureForError ());
                                return false;
                        }

                        if (parameter_type == TypeManager.void_type){
                                Report.Error (1536, Location, "Invalid parameter type 'void'");
                                return false;
                        }

                        if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
                                if (parameter_type == TypeManager.typed_reference_type ||
                                    parameter_type == TypeManager.arg_iterator_type){
                                        Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
                                                GetSignatureForError ());
                                        return false;
                                }
                        }
                        
                        return true;
                }

                public Type ExternalType ()
                {
                        if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
                                return TypeManager.GetReferenceType (parameter_type);
                        
                        return parameter_type;
                }

                public Type ParameterType {
                        get {
                                return parameter_type;
                        }
                }
                
                public ParameterAttributes Attributes {
                        get {
                                switch (ModFlags) {
                                case Modifier.NONE:
                                        return ParameterAttributes.None;
                                case Modifier.REF:
                                        return ParameterAttributes.None;
                                case Modifier.OUT:
                                        return ParameterAttributes.Out;
                                case Modifier.PARAMS:
                                        return 0;
                                }
                                
                                return ParameterAttributes.None;
                        }
                }
                
                public override AttributeTargets AttributeTargets {
                        get {
                                return AttributeTargets.Parameter;
                        }
                }

                public virtual string GetSignatureForError ()
                {
                        string type_name;
                        if (parameter_type != null)
                                type_name = TypeManager.CSharpName (parameter_type);
                        else
                                type_name = TypeName.GetSignatureForError ();

                        string mod = GetModifierSignature (ModFlags);
                        if (mod.Length > 0)
                                return String.Concat (mod, ' ', type_name);

                        return type_name;
                }

                public static string GetModifierSignature (Modifier mod)
                {
                        switch (mod) {
                                case Modifier.OUT:
                                        return "out";
                                case Modifier.PARAMS:
                                        return "params";
                                case Modifier.REF:
                                        return "ref";
                                case Modifier.ARGLIST:
                                        return "__arglist";
                                default:
                                        return "";
                        }
                }

                public void IsClsCompliant ()
                {
                        if (AttributeTester.IsClsCompliant (ExternalType ()))
                                return;

                        Report.Error (3001, Location, "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
                }

                public virtual void ApplyAttributes (EmitContext ec, MethodBuilder mb, ConstructorBuilder cb, int index)
                {
                        if (mb == null)
                                builder = cb.DefineParameter (index, Attributes, Name);
                        else 
                                builder = mb.DefineParameter (index, Attributes, Name);
                
                        if (OptAttributes != null)
                                OptAttributes.Emit (ec, this);
                }

                public override string[] ValidAttributeTargets {
                        get {
                                return attribute_targets;
                        }
                }
        }

        /// <summary>
        ///   Represents the methods parameters
        /// </summary>
        public class Parameters : ParameterData {
                // Null object pattern
                public Parameter [] FixedParameters;
                public readonly bool HasArglist;
                Type [] types;
                int count;

                public static readonly Parameters EmptyReadOnlyParameters = new Parameters ();
                static readonly Parameter ArgList = new ArglistParameter ();

                private Parameters ()
                {
                        FixedParameters = new Parameter[0];
                        types = new Type [0];
                }
                
                public Parameters (Parameter [] parameters)
                {
                        if (parameters == null)
                                throw new ArgumentException ("Use EmptyReadOnlyPatameters");

                        FixedParameters = parameters;
                        count = parameters.Length;
                }

                public Parameters (Parameter[] parameters, bool has_arglist):
                        this (parameters)
                {
                        HasArglist = has_arglist;
                }

                public bool Empty {
                        get {
                                return count == 0;
                        }
                }

                public int Count {
                        get {
                                return HasArglist ? count + 1 : count;
                        }
                }

                bool VerifyArgs ()
                {
                        if (count < 2)
                                return true;

                        for (int i = 0; i < count; i++){
                                string base_name = FixedParameters [i].Name;
                                for (int j = i + 1; j < count; j++){
                                        if (base_name != FixedParameters [j].Name)
                                                continue;

                                        Report.Error (100, FixedParameters [i].Location,
                                                "The parameter name `{0}' is a duplicate", base_name);
                                        return false;
                                }
                        }
                        return true;
                }
                
                
                /// <summary>
                ///    Returns the paramenter information based on the name
                /// </summary>
                public Parameter GetParameterByName (string name, out int idx)
                {
                        idx = 0;

                        if (count == 0)
                                return null;

                        int i = 0;

                        foreach (Parameter par in FixedParameters){
                                if (par.Name == name){
                                        idx = i;
                                        return par;
                                }
                                i++;
                        }
                        return null;
                }

                public Parameter GetParameterByName (string name)
                {
                        int idx;

                        return GetParameterByName (name, out idx);
                }
                
                public bool Resolve (EmitContext ec)
                {
                        if (types != null)
                                return true;

                        types = new Type [count];
                        
                        if (ec != null && !VerifyArgs ()){
                                return false;
                        }

                        bool ok = true;
                        Parameter p;
                        for (int i = 0; i < FixedParameters.Length; ++i) {
                                p = FixedParameters [i];
                                if (!p.Resolve (ec)) {
                                        ok = false;
                                        continue;
                                }
                                types [i] = p.ExternalType ();
                        }

                        return ok;
                }

                public CallingConventions CallingConvention
                {
                        get {
                                if (HasArglist)
                                        return CallingConventions.VarArgs;
                                else
                                        return CallingConventions.Standard;
                        }
                }

                // Define each type attribute (in/out/ref) and
                // the argument names.
                public void ApplyAttributes (EmitContext ec, MethodBase builder)
                {
                        if (count == 0)
                                return;

                        MethodBuilder mb = builder as MethodBuilder;
                        ConstructorBuilder cb = builder as ConstructorBuilder;

                        for (int i = 0; i < FixedParameters.Length; i++) {
                                FixedParameters [i].ApplyAttributes (ec, mb, cb, i + 1);
                        }
                }

                public void VerifyClsCompliance ()
                {
                        foreach (Parameter p in FixedParameters)
                                p.IsClsCompliant ();
                }

                public string GetSignatureForError ()
                {
                        StringBuilder sb = new StringBuilder ("(");
                        if (count > 0) {
                                for (int i = 0; i < FixedParameters.Length; ++i) {
                                        sb.Append (FixedParameters[i].GetSignatureForError ());
                                        if (i < FixedParameters.Length - 1)
                                                sb.Append (", ");
                                }
                        }

                        if (HasArglist) {
                                if (HasArglist) {
                                        if (sb.Length > 1)
                                                sb.Append (", ");
                                        sb.Append ("__arglist");
                                }
                        }

                        sb.Append (')');
                        return sb.ToString ();
                }

                public Type[] Types {
                        get {
                                return types;
                        }
                }

                Parameter this [int pos]
                {
                        get {
                                if (pos >= count && (HasArglist || HasParams)) {
                                        if (HasArglist && (pos == 0 || pos >= count))
                                                return ArgList;
                                        pos = count - 1;
                                }

                                return FixedParameters [pos];
                        }
                }

                #region ParameterData Members

                public Type ParameterType (int pos)
                {
                        return this [pos].ExternalType ();
                }

                public bool HasParams {
                        get {
                                if (count == 0)
                                        return false;

                                return FixedParameters [count - 1] is ParamsParameter;
                        }
                }

                public string ParameterName (int pos)
                {
                        return this [pos].Name;
                }

                public string ParameterDesc (int pos)
                {
                        return this [pos].GetSignatureForError ();
                }

                public Parameter.Modifier ParameterModifier (int pos)
                {
                        return this [pos].ModFlags;
                }

                #endregion
        }
}