//
// generic.cs: Generics support
//
// Authors: Martin Baulig (martin@ximian.com)
// Miguel de Icaza (miguel@ximian.com)
// Marek Safar (marek.safar@gmail.com)
//
// Licensed under the terms of the GNU GPL
//
// (C) 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
// (C) 2004 Novell, Inc
//
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Globalization;
using System.Collections;
using System.Text;
using System.Text.RegularExpressions;
namespace Mono.CSharp {
///
/// Abstract base class for type parameter constraints.
/// The type parameter can come from a generic type definition or from reflection.
///
public abstract class GenericConstraints {
public abstract string TypeParameter {
get;
}
public abstract GenericParameterAttributes Attributes {
get;
}
public bool HasConstructorConstraint {
get { return (Attributes & GenericParameterAttributes.DefaultConstructorConstraint) != 0; }
}
public bool HasReferenceTypeConstraint {
get { return (Attributes & GenericParameterAttributes.ReferenceTypeConstraint) != 0; }
}
public bool HasValueTypeConstraint {
get { return (Attributes & GenericParameterAttributes.NotNullableValueTypeConstraint) != 0; }
}
public virtual bool HasClassConstraint {
get { return ClassConstraint != null; }
}
public abstract Type ClassConstraint {
get;
}
public abstract Type[] InterfaceConstraints {
get;
}
public abstract Type EffectiveBaseClass {
get;
}
//
// Returns whether the type parameter is "known to be a reference type".
//
public virtual bool IsReferenceType {
get {
if (HasReferenceTypeConstraint)
return true;
if (HasValueTypeConstraint)
return false;
if (ClassConstraint != null) {
if (ClassConstraint.IsValueType)
return false;
if (ClassConstraint != TypeManager.object_type)
return true;
}
foreach (Type t in InterfaceConstraints) {
if (!t.IsGenericParameter)
continue;
GenericConstraints gc = TypeManager.GetTypeParameterConstraints (t);
if ((gc != null) && gc.IsReferenceType)
return true;
}
return false;
}
}
//
// Returns whether the type parameter is "known to be a value type".
//
public virtual bool IsValueType {
get {
if (HasValueTypeConstraint)
return true;
if (HasReferenceTypeConstraint)
return false;
if (ClassConstraint != null) {
if (!ClassConstraint.IsValueType)
return false;
if (ClassConstraint != TypeManager.value_type)
return true;
}
foreach (Type t in InterfaceConstraints) {
if (!t.IsGenericParameter)
continue;
GenericConstraints gc = TypeManager.GetTypeParameterConstraints (t);
if ((gc != null) && gc.IsValueType)
return true;
}
return false;
}
}
}
public enum SpecialConstraint
{
Constructor,
ReferenceType,
ValueType
}
///
/// Tracks the constraints for a type parameter from a generic type definition.
///
public class Constraints : GenericConstraints {
string name;
ArrayList constraints;
Location loc;
//
// name is the identifier, constraints is an arraylist of
// Expressions (with types) or `true' for the constructor constraint.
//
public Constraints (string name, ArrayList constraints,
Location loc)
{
this.name = name;
this.constraints = constraints;
this.loc = loc;
}
public override string TypeParameter {
get {
return name;
}
}
public Constraints Clone ()
{
return new Constraints (name, constraints, loc);
}
GenericParameterAttributes attrs;
TypeExpr class_constraint;
ArrayList iface_constraints;
ArrayList type_param_constraints;
int num_constraints;
Type class_constraint_type;
Type[] iface_constraint_types;
Type effective_base_type;
bool resolved;
bool resolved_types;
///
/// Resolve the constraints - but only resolve things into Expression's, not
/// into actual types.
///
public bool Resolve (IResolveContext ec)
{
if (resolved)
return true;
iface_constraints = new ArrayList ();
type_param_constraints = new ArrayList ();
foreach (object obj in constraints) {
if (HasConstructorConstraint) {
Report.Error (401, loc,
"The new() constraint must be the last constraint specified");
return false;
}
if (obj is SpecialConstraint) {
SpecialConstraint sc = (SpecialConstraint) obj;
if (sc == SpecialConstraint.Constructor) {
if (!HasValueTypeConstraint) {
attrs |= GenericParameterAttributes.DefaultConstructorConstraint;
continue;
}
Report.Error (451, loc, "The `new()' constraint " +
"cannot be used with the `struct' constraint");
return false;
}
if ((num_constraints > 0) || HasReferenceTypeConstraint || HasValueTypeConstraint) {
Report.Error (449, loc, "The `class' or `struct' " +
"constraint must be the first constraint specified");
return false;
}
if (sc == SpecialConstraint.ReferenceType)
attrs |= GenericParameterAttributes.ReferenceTypeConstraint;
else
attrs |= GenericParameterAttributes.NotNullableValueTypeConstraint;
continue;
}
int errors = Report.Errors;
FullNamedExpression fn = ((Expression) obj).ResolveAsTypeStep (ec, false);
if (fn == null) {
if (errors != Report.Errors)
return false;
NamespaceEntry.Error_NamespaceNotFound (loc, ((Expression)obj).GetSignatureForError ());
return false;
}
TypeExpr expr;
ConstructedType cexpr = fn as ConstructedType;
if (cexpr != null) {
if (!cexpr.ResolveConstructedType (ec))
return false;
expr = cexpr;
} else
expr = ((Expression) obj).ResolveAsTypeTerminal (ec, false);
if ((expr == null) || (expr.Type == null))
return false;
// TODO: It's aleady done in ResolveAsBaseTerminal
if (!ec.GenericDeclContainer.AsAccessible (fn.Type, ec.GenericDeclContainer.ModFlags)) {
Report.SymbolRelatedToPreviousError (fn.Type);
Report.Error (703, loc,
"Inconsistent accessibility: constraint type `{0}' is less accessible than `{1}'",
fn.GetSignatureForError (), ec.GenericDeclContainer.GetSignatureForError ());
return false;
}
TypeParameterExpr texpr = expr as TypeParameterExpr;
if (texpr != null)
type_param_constraints.Add (expr);
else if (expr.IsInterface)
iface_constraints.Add (expr);
else if (class_constraint != null) {
Report.Error (406, loc,
"`{0}': the class constraint for `{1}' " +
"must come before any other constraints.",
expr.Name, name);
return false;
} else if (HasReferenceTypeConstraint || HasValueTypeConstraint) {
Report.Error (450, loc, "`{0}': cannot specify both " +
"a constraint class and the `class' " +
"or `struct' constraint", expr.GetSignatureForError ());
return false;
} else
class_constraint = expr;
num_constraints++;
}
ArrayList list = new ArrayList ();
foreach (TypeExpr iface_constraint in iface_constraints) {
foreach (Type type in list) {
if (!type.Equals (iface_constraint.Type))
continue;
Report.Error (405, loc,
"Duplicate constraint `{0}' for type " +
"parameter `{1}'.", iface_constraint.GetSignatureForError (),
name);
return false;
}
list.Add (iface_constraint.Type);
}
foreach (TypeParameterExpr expr in type_param_constraints) {
foreach (Type type in list) {
if (!type.Equals (expr.Type))
continue;
Report.Error (405, loc,
"Duplicate constraint `{0}' for type " +
"parameter `{1}'.", expr.GetSignatureForError (), name);
return false;
}
list.Add (expr.Type);
}
iface_constraint_types = new Type [list.Count];
list.CopyTo (iface_constraint_types, 0);
if (class_constraint != null) {
class_constraint_type = class_constraint.Type;
if (class_constraint_type == null)
return false;
if (class_constraint_type.IsSealed) {
if (class_constraint_type.IsAbstract)
{
Report.Error (717, loc, "`{0}' is not a valid constraint. Static classes cannot be used as constraints",
TypeManager.CSharpName (class_constraint_type));
}
else
{
Report.Error (701, loc, "`{0}' is not a valid constraint. A constraint must be an interface, " +
"a non-sealed class or a type parameter", TypeManager.CSharpName(class_constraint_type));
}
return false;
}
if ((class_constraint_type == TypeManager.array_type) ||
(class_constraint_type == TypeManager.delegate_type) ||
(class_constraint_type == TypeManager.enum_type) ||
(class_constraint_type == TypeManager.value_type) ||
(class_constraint_type == TypeManager.object_type)) {
Report.Error (702, loc,
"Bound cannot be special class `{0}'",
TypeManager.CSharpName (class_constraint_type));
return false;
}
}
if (class_constraint_type != null)
effective_base_type = class_constraint_type;
else if (HasValueTypeConstraint)
effective_base_type = TypeManager.value_type;
else
effective_base_type = TypeManager.object_type;
resolved = true;
return true;
}
bool CheckTypeParameterConstraints (TypeParameter tparam, Hashtable seen)
{
seen.Add (tparam, true);
Constraints constraints = tparam.Constraints;
if (constraints == null)
return true;
if (constraints.HasValueTypeConstraint) {
Report.Error (456, loc, "Type parameter `{0}' has " +
"the `struct' constraint, so it cannot " +
"be used as a constraint for `{1}'",
tparam.Name, name);
return false;
}
if (constraints.type_param_constraints == null)
return true;
foreach (TypeParameterExpr expr in constraints.type_param_constraints) {
if (seen.Contains (expr.TypeParameter)) {
Report.Error (454, loc, "Circular constraint " +
"dependency involving `{0}' and `{1}'",
tparam.Name, expr.Name);
return false;
}
if (!CheckTypeParameterConstraints (expr.TypeParameter, seen))
return false;
}
return true;
}
///
/// Resolve the constraints into actual types.
///
public bool ResolveTypes (IResolveContext ec)
{
if (resolved_types)
return true;
resolved_types = true;
foreach (object obj in constraints) {
ConstructedType cexpr = obj as ConstructedType;
if (cexpr == null)
continue;
if (!cexpr.CheckConstraints (ec))
return false;
}
foreach (TypeParameterExpr expr in type_param_constraints) {
Hashtable seen = new Hashtable ();
if (!CheckTypeParameterConstraints (expr.TypeParameter, seen))
return false;
}
for (int i = 0; i < iface_constraints.Count; ++i) {
TypeExpr iface_constraint = (TypeExpr) iface_constraints [i];
iface_constraint = iface_constraint.ResolveAsTypeTerminal (ec, false);
if (iface_constraint == null)
return false;
iface_constraints [i] = iface_constraint;
}
if (class_constraint != null) {
class_constraint = class_constraint.ResolveAsTypeTerminal (ec, false);
if (class_constraint == null)
return false;
}
return true;
}
///
/// Check whether there are no conflicts in our type parameter constraints.
///
/// This is an example:
///
/// class Foo
/// where T : class
/// where U : T, struct
///
public bool CheckDependencies ()
{
foreach (TypeParameterExpr expr in type_param_constraints) {
if (!CheckDependencies (expr.TypeParameter))
return false;
}
return true;
}
bool CheckDependencies (TypeParameter tparam)
{
Constraints constraints = tparam.Constraints;
if (constraints == null)
return true;
if (HasValueTypeConstraint && constraints.HasClassConstraint) {
Report.Error (455, loc, "Type parameter `{0}' inherits " +
"conflicting constraints `{1}' and `{2}'",
name, TypeManager.CSharpName (constraints.ClassConstraint),
"System.ValueType");
return false;
}
if (HasClassConstraint && constraints.HasClassConstraint) {
Type t1 = ClassConstraint;
TypeExpr e1 = class_constraint;
Type t2 = constraints.ClassConstraint;
TypeExpr e2 = constraints.class_constraint;
if (!Convert.ImplicitReferenceConversionExists (e1, t2) &&
!Convert.ImplicitReferenceConversionExists (e2, t1)) {
Report.Error (455, loc,
"Type parameter `{0}' inherits " +
"conflicting constraints `{1}' and `{2}'",
name, TypeManager.CSharpName (t1), TypeManager.CSharpName (t2));
return false;
}
}
if (constraints.type_param_constraints == null)
return true;
foreach (TypeParameterExpr expr in constraints.type_param_constraints) {
if (!CheckDependencies (expr.TypeParameter))
return false;
}
return true;
}
public override GenericParameterAttributes Attributes {
get { return attrs; }
}
public override bool HasClassConstraint {
get { return class_constraint != null; }
}
public override Type ClassConstraint {
get { return class_constraint_type; }
}
public override Type[] InterfaceConstraints {
get { return iface_constraint_types; }
}
public override Type EffectiveBaseClass {
get { return effective_base_type; }
}
public bool IsSubclassOf (Type t)
{
if ((class_constraint_type != null) &&
class_constraint_type.IsSubclassOf (t))
return true;
if (iface_constraint_types == null)
return false;
foreach (Type iface in iface_constraint_types) {
if (TypeManager.IsSubclassOf (iface, t))
return true;
}
return false;
}
public Location Location {
get {
return loc;
}
}
///
/// This is used when we're implementing a generic interface method.
/// Each method type parameter in implementing method must have the same
/// constraints than the corresponding type parameter in the interface
/// method. To do that, we're called on each of the implementing method's
/// type parameters.
///
public bool CheckInterfaceMethod (GenericConstraints gc)
{
if (gc.Attributes != attrs)
return false;
if (HasClassConstraint != gc.HasClassConstraint)
return false;
if (HasClassConstraint && !TypeManager.IsEqual (gc.ClassConstraint, ClassConstraint))
return false;
int gc_icount = gc.InterfaceConstraints != null ?
gc.InterfaceConstraints.Length : 0;
int icount = InterfaceConstraints != null ?
InterfaceConstraints.Length : 0;
if (gc_icount != icount)
return false;
for (int i = 0; i < gc.InterfaceConstraints.Length; ++i) {
Type iface = gc.InterfaceConstraints [i];
if (iface.IsGenericType)
iface = iface.GetGenericTypeDefinition ();
bool ok = false;
for (int ii = 0; i < InterfaceConstraints.Length; ++ii) {
Type check = InterfaceConstraints [ii];
if (check.IsGenericType)
check = check.GetGenericTypeDefinition ();
if (TypeManager.IsEqual (iface, check)) {
ok = true;
break;
}
}
if (!ok)
return false;
}
return true;
}
public void VerifyClsCompliance ()
{
if (class_constraint_type != null && !AttributeTester.IsClsCompliant (class_constraint_type))
Warning_ConstrainIsNotClsCompliant (class_constraint_type, class_constraint.Location);
if (iface_constraint_types != null) {
for (int i = 0; i < iface_constraint_types.Length; ++i) {
if (!AttributeTester.IsClsCompliant (iface_constraint_types [i]))
Warning_ConstrainIsNotClsCompliant (iface_constraint_types [i],
((TypeExpr)iface_constraints [i]).Location);
}
}
}
void Warning_ConstrainIsNotClsCompliant (Type t, Location loc)
{
Report.SymbolRelatedToPreviousError (t);
Report.Warning (3024, 1, loc, "Constraint type `{0}' is not CLS-compliant",
TypeManager.CSharpName (t));
}
}
///
/// A type parameter from a generic type definition.
///
public class TypeParameter : MemberCore, IMemberContainer
{
string name;
DeclSpace decl;
GenericConstraints gc;
Constraints constraints;
Location loc;
GenericTypeParameterBuilder type;
MemberCache member_cache;
public TypeParameter (DeclSpace parent, DeclSpace decl, string name,
Constraints constraints, Attributes attrs, Location loc)
: base (parent, new MemberName (name, loc), attrs)
{
this.name = name;
this.decl = decl;
this.constraints = constraints;
this.loc = loc;
}
public GenericConstraints GenericConstraints {
get { return gc != null ? gc : constraints; }
}
public Constraints Constraints {
get { return constraints; }
}
public DeclSpace DeclSpace {
get { return decl; }
}
public Type Type {
get { return type; }
}
///
/// This is the first method which is called during the resolving
/// process; we're called immediately after creating the type parameters
/// with SRE (by calling `DefineGenericParameters()' on the TypeBuilder /
/// MethodBuilder).
///
/// We're either called from TypeContainer.DefineType() or from
/// GenericMethod.Define() (called from Method.Define()).
///
public void Define (GenericTypeParameterBuilder type)
{
if (this.type != null)
throw new InvalidOperationException ();
this.type = type;
TypeManager.AddTypeParameter (type, this);
}
///
/// This is the second method which is called during the resolving
/// process - in case of class type parameters, we're called from
/// TypeContainer.ResolveType() - after it resolved the class'es
/// base class and interfaces. For method type parameters, we're
/// called immediately after Define().
///
/// We're just resolving the constraints into expressions here, we
/// don't resolve them into actual types.
///
/// Note that in the special case of partial generic classes, we may be
/// called _before_ Define() and we may also be called multiple types.
///
public bool Resolve (DeclSpace ds)
{
if (constraints != null) {
if (!constraints.Resolve (ds)) {
constraints = null;
return false;
}
}
return true;
}
///
/// This is the third method which is called during the resolving
/// process. We're called immediately after calling DefineConstraints()
/// on all of the current class'es type parameters.
///
/// Our job is to resolve the constraints to actual types.
///
/// Note that we may have circular dependencies on type parameters - this
/// is why Resolve() and ResolveType() are separate.
///
public bool ResolveType (IResolveContext ec)
{
if (constraints != null) {
if (!constraints.ResolveTypes (ec)) {
constraints = null;
return false;
}
}
return true;
}
///
/// This is the fourth and last method which is called during the resolving
/// process. We're called after everything is fully resolved and actually
/// register the constraints with SRE and the TypeManager.
///
public bool DefineType (IResolveContext ec)
{
return DefineType (ec, null, null, false);
}
///
/// This is the fith and last method which is called during the resolving
/// process. We're called after everything is fully resolved and actually
/// register the constraints with SRE and the TypeManager.
///
/// The `builder', `implementing' and `is_override' arguments are only
/// applicable to method type parameters.
///
public bool DefineType (IResolveContext ec, MethodBuilder builder,
MethodInfo implementing, bool is_override)
{
if (!ResolveType (ec))
return false;
if (implementing != null) {
if (is_override && (constraints != null)) {
Report.Error (460, loc,
"`{0}': Cannot specify constraints for overrides or explicit interface implementation methods",
TypeManager.CSharpSignature (builder));
return false;
}
MethodBase mb = TypeManager.DropGenericMethodArguments (implementing);
int pos = type.GenericParameterPosition;
Type mparam = mb.GetGenericArguments () [pos];
GenericConstraints temp_gc = ReflectionConstraints.GetConstraints (mparam);
if (temp_gc != null)
gc = new InflatedConstraints (temp_gc, implementing.DeclaringType);
else if (constraints != null)
gc = new InflatedConstraints (constraints, implementing.DeclaringType);
bool ok = true;
if (constraints != null) {
if (temp_gc == null)
ok = false;
else if (!constraints.CheckInterfaceMethod (gc))
ok = false;
} else {
if (!is_override && (temp_gc != null))
ok = false;
}
if (!ok) {
Report.SymbolRelatedToPreviousError (implementing);
Report.Error (
425, loc, "The constraints for type " +
"parameter `{0}' of method `{1}' must match " +
"the constraints for type parameter `{2}' " +
"of interface method `{3}'. Consider using " +
"an explicit interface implementation instead",
Name, TypeManager.CSharpSignature (builder),
TypeManager.CSharpName (mparam), TypeManager.CSharpSignature (mb));
return false;
}
} else if (DeclSpace is CompilerGeneratedClass) {
TypeParameter[] tparams = DeclSpace.TypeParameters;
Type[] types = new Type [tparams.Length];
for (int i = 0; i < tparams.Length; i++)
types [i] = tparams [i].Type;
if (constraints != null)
gc = new InflatedConstraints (constraints, types);
} else {
gc = (GenericConstraints) constraints;
}
if (gc == null)
return true;
if (gc.HasClassConstraint)
type.SetBaseTypeConstraint (gc.ClassConstraint);
type.SetInterfaceConstraints (gc.InterfaceConstraints);
type.SetGenericParameterAttributes (gc.Attributes);
TypeManager.RegisterBuilder (type, gc.InterfaceConstraints);
return true;
}
///
/// Check whether there are no conflicts in our type parameter constraints.
///
/// This is an example:
///
/// class Foo
/// where T : class
/// where U : T, struct
///
public bool CheckDependencies ()
{
if (constraints != null)
return constraints.CheckDependencies ();
return true;
}
///
/// This is called for each part of a partial generic type definition.
///
/// If `new_constraints' is not null and we don't already have constraints,
/// they become our constraints. If we already have constraints, we must
/// check that they're the same.
/// con
///
public bool UpdateConstraints (IResolveContext ec, Constraints new_constraints)
{
if (type == null)
throw new InvalidOperationException ();
if (new_constraints == null)
return true;
if (!new_constraints.Resolve (ec))
return false;
if (!new_constraints.ResolveTypes (ec))
return false;
if (constraints != null)
return constraints.CheckInterfaceMethod (new_constraints);
constraints = new_constraints;
return true;
}
public override void Emit ()
{
if (OptAttributes != null)
OptAttributes.Emit ();
base.Emit ();
}
public override string DocCommentHeader {
get {
throw new InvalidOperationException (
"Unexpected attempt to get doc comment from " + this.GetType () + ".");
}
}
//
// MemberContainer
//
public override bool Define ()
{
return true;
}
public override void ApplyAttributeBuilder (Attribute a,
CustomAttributeBuilder cb)
{
type.SetCustomAttribute (cb);
}
public override AttributeTargets AttributeTargets {
get {
return (AttributeTargets) AttributeTargets.GenericParameter;
}
}
public override string[] ValidAttributeTargets {
get {
return new string [] { "type parameter" };
}
}
//
// IMemberContainer
//
string IMemberContainer.Name {
get { return Name; }
}
MemberCache IMemberContainer.BaseCache {
get {
if (gc == null)
return null;
if (gc.EffectiveBaseClass.BaseType == null)
return null;
return TypeManager.LookupMemberCache (gc.EffectiveBaseClass.BaseType);
}
}
bool IMemberContainer.IsInterface {
get { return false; }
}
MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
{
return FindMembers (mt, bf, null, null);
}
public MemberCache MemberCache {
get {
if (member_cache != null)
return member_cache;
if (gc == null)
return null;
Type[] ifaces = TypeManager.ExpandInterfaces (gc.InterfaceConstraints);
member_cache = new MemberCache (this, gc.EffectiveBaseClass, ifaces);
return member_cache;
}
}
public MemberList FindMembers (MemberTypes mt, BindingFlags bf,
MemberFilter filter, object criteria)
{
if (gc == null)
return MemberList.Empty;
ArrayList members = new ArrayList ();
if (gc.HasClassConstraint) {
MemberList list = TypeManager.FindMembers (
gc.ClassConstraint, mt, bf, filter, criteria);
members.AddRange (list);
}
Type[] ifaces = TypeManager.ExpandInterfaces (gc.InterfaceConstraints);
foreach (Type t in ifaces) {
MemberList list = TypeManager.FindMembers (
t, mt, bf, filter, criteria);
members.AddRange (list);
}
return new MemberList (members);
}
public bool IsSubclassOf (Type t)
{
if (type.Equals (t))
return true;
if (constraints != null)
return constraints.IsSubclassOf (t);
return false;
}
public override string ToString ()
{
return "TypeParameter[" + name + "]";
}
public static string GetSignatureForError (TypeParameter[] tp)
{
if (tp == null || tp.Length == 0)
return "";
StringBuilder sb = new StringBuilder ("<");
for (int i = 0; i < tp.Length; ++i) {
if (i > 0)
sb.Append (",");
sb.Append (tp[i].GetSignatureForError ());
}
sb.Append ('>');
return sb.ToString ();
}
public void InflateConstraints (Type declaring)
{
if (constraints != null)
gc = new InflatedConstraints (constraints, declaring);
}
public override bool IsClsComplianceRequired ()
{
return false;
}
protected class InflatedConstraints : GenericConstraints
{
GenericConstraints gc;
Type base_type;
Type class_constraint;
Type[] iface_constraints;
Type[] dargs;
public InflatedConstraints (GenericConstraints gc, Type declaring)
: this (gc, TypeManager.GetTypeArguments (declaring))
{ }
public InflatedConstraints (GenericConstraints gc, Type[] dargs)
{
this.gc = gc;
this.dargs = dargs;
ArrayList list = new ArrayList ();
if (gc.HasClassConstraint)
list.Add (inflate (gc.ClassConstraint));
foreach (Type iface in gc.InterfaceConstraints)
list.Add (inflate (iface));
bool has_class_constr = false;
if (list.Count > 0) {
Type first = (Type) list [0];
has_class_constr = !first.IsGenericParameter && !first.IsInterface;
}
if ((list.Count > 0) && has_class_constr) {
class_constraint = (Type) list [0];
iface_constraints = new Type [list.Count - 1];
list.CopyTo (1, iface_constraints, 0, list.Count - 1);
} else {
iface_constraints = new Type [list.Count];
list.CopyTo (iface_constraints, 0);
}
if (HasValueTypeConstraint)
base_type = TypeManager.value_type;
else if (class_constraint != null)
base_type = class_constraint;
else
base_type = TypeManager.object_type;
}
Type inflate (Type t)
{
if (t == null)
return null;
if (t.IsGenericParameter)
return dargs [t.GenericParameterPosition];
if (t.IsGenericType) {
Type[] args = t.GetGenericArguments ();
Type[] inflated = new Type [args.Length];
for (int i = 0; i < args.Length; i++)
inflated [i] = inflate (args [i]);
t = t.GetGenericTypeDefinition ();
t = t.MakeGenericType (inflated);
}
return t;
}
public override string TypeParameter {
get { return gc.TypeParameter; }
}
public override GenericParameterAttributes Attributes {
get { return gc.Attributes; }
}
public override Type ClassConstraint {
get { return class_constraint; }
}
public override Type EffectiveBaseClass {
get { return base_type; }
}
public override Type[] InterfaceConstraints {
get { return iface_constraints; }
}
}
}
///
/// A TypeExpr which already resolved to a type parameter.
///
public class TypeParameterExpr : TypeExpr {
TypeParameter type_parameter;
public override string Name {
get {
return type_parameter.Name;
}
}
public override string FullName {
get {
return type_parameter.Name;
}
}
public TypeParameter TypeParameter {
get {
return type_parameter;
}
}
public TypeParameterExpr (TypeParameter type_parameter, Location loc)
{
this.type_parameter = type_parameter;
this.loc = loc;
}
protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
{
type = type_parameter.Type;
return this;
}
public override bool IsInterface {
get { return false; }
}
public override bool CheckAccessLevel (DeclSpace ds)
{
return true;
}
public void Error_CannotUseAsUnmanagedType (Location loc)
{
Report.Error (-203, loc, "Can not use type parameter as unmanaged type");
}
}
///
/// Tracks the type arguments when instantiating a generic type. We're used in
/// ConstructedType.
///
public class TypeArguments {
public readonly Location Location;
ArrayList args;
Type[] atypes;
int dimension;
bool has_type_args;
bool created;
public TypeArguments (Location loc)
{
args = new ArrayList ();
this.Location = loc;
}
public TypeArguments (Location loc, params Expression[] types)
{
this.Location = loc;
this.args = new ArrayList (types);
}
public TypeArguments (int dimension, Location loc)
{
this.dimension = dimension;
this.Location = loc;
}
public void Add (Expression type)
{
if (created)
throw new InvalidOperationException ();
args.Add (type);
}
public void Add (TypeArguments new_args)
{
if (created)
throw new InvalidOperationException ();
args.AddRange (new_args.args);
}
///
/// We're used during the parsing process: the parser can't distinguish
/// between type parameters and type arguments. Because of that, the
/// parser creates a `MemberName' with `TypeArguments' for both cases and
/// in case of a generic type definition, we call GetDeclarations().
///
public TypeParameterName[] GetDeclarations ()
{
TypeParameterName[] ret = new TypeParameterName [args.Count];
for (int i = 0; i < args.Count; i++) {
TypeParameterName name = args [i] as TypeParameterName;
if (name != null) {
ret [i] = name;
continue;
}
SimpleName sn = args [i] as SimpleName;
if (sn != null) {
ret [i] = new TypeParameterName (sn.Name, null, sn.Location);
continue;
}
Report.Error (81, Location, "Type parameter declaration " +
"must be an identifier not a type");
return null;
}
return ret;
}
///
/// We may only be used after Resolve() is called and return the fully
/// resolved types.
///
public Type[] Arguments {
get {
return atypes;
}
}
public bool HasTypeArguments {
get {
return has_type_args;
}
}
public int Count {
get {
if (dimension > 0)
return dimension;
else
return args.Count;
}
}
public bool IsUnbound {
get {
return dimension > 0;
}
}
public override string ToString ()
{
StringBuilder s = new StringBuilder ();
int count = Count;
for (int i = 0; i < count; i++){
//
// FIXME: Use TypeManager.CSharpname once we have the type
//
if (args != null)
s.Append (args [i].ToString ());
if (i+1 < count)
s.Append (",");
}
return s.ToString ();
}
public string GetSignatureForError()
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < Count; ++i)
{
Expression expr = (Expression)args [i];
sb.Append(expr.GetSignatureForError());
if (i + 1 < Count)
sb.Append(',');
}
return sb.ToString();
}
///
/// Resolve the type arguments.
///
public bool Resolve (IResolveContext ec)
{
int count = args.Count;
bool ok = true;
atypes = new Type [count];
for (int i = 0; i < count; i++){
TypeExpr te = ((Expression) args [i]).ResolveAsTypeTerminal (ec, false);
if (te == null) {
ok = false;
continue;
}
atypes[i] = te.Type;
if (te.Type.IsGenericParameter) {
if (te is TypeParameterExpr)
has_type_args = true;
continue;
}
if (te.Type.IsSealed && te.Type.IsAbstract) {
Report.Error (718, Location, "`{0}': static classes cannot be used as generic arguments",
te.GetSignatureForError ());
return false;
}
if (te.Type.IsPointer) {
Report.Error (306, Location, "The type `{0}' may not be used " +
"as a type argument", TypeManager.CSharpName (te.Type));
return false;
}
if (te.Type == TypeManager.void_type) {
Expression.Error_VoidInvalidInTheContext (Location);
return false;
}
}
return ok;
}
public TypeArguments Clone ()
{
TypeArguments copy = new TypeArguments (Location);
foreach (Expression ta in args)
copy.args.Add (ta);
return copy;
}
}
public class TypeParameterName : SimpleName
{
Attributes attributes;
public TypeParameterName (string name, Attributes attrs, Location loc)
: base (name, loc)
{
attributes = attrs;
}
public Attributes OptAttributes {
get {
return attributes;
}
}
}
///
/// An instantiation of a generic type.
///
public class ConstructedType : TypeExpr {
string full_name;
FullNamedExpression name;
TypeArguments args;
Type[] gen_params, atypes;
Type gt;
///
/// Instantiate the generic type `fname' with the type arguments `args'.
///
public ConstructedType (FullNamedExpression fname, TypeArguments args, Location l)
{
loc = l;
this.name = fname;
this.args = args;
eclass = ExprClass.Type;
full_name = name + "<" + args.ToString () + ">";
}
protected ConstructedType (TypeArguments args, Location l)
{
loc = l;
this.args = args;
eclass = ExprClass.Type;
}
protected ConstructedType (TypeParameter[] type_params, Location l)
{
loc = l;
args = new TypeArguments (l);
foreach (TypeParameter type_param in type_params)
args.Add (new TypeParameterExpr (type_param, l));
eclass = ExprClass.Type;
}
///
/// This is used to construct the `this' type inside a generic type definition.
///
public ConstructedType (Type t, TypeParameter[] type_params, Location l)
: this (type_params, l)
{
gt = t.GetGenericTypeDefinition ();
this.name = new TypeExpression (gt, l);
full_name = gt.FullName + "<" + args.ToString () + ">";
}
///
/// Instantiate the generic type `t' with the type arguments `args'.
/// Use this constructor if you already know the fully resolved
/// generic type.
///
public ConstructedType (Type t, TypeArguments args, Location l)
: this (args, l)
{
gt = t.GetGenericTypeDefinition ();
this.name = new TypeExpression (gt, l);
full_name = gt.FullName + "<" + args.ToString () + ">";
}
public TypeArguments TypeArguments {
get { return args; }
}
public override string GetSignatureForError ()
{
return TypeManager.RemoveGenericArity (gt.FullName) + "<" + args.GetSignatureForError () + ">";
}
protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
{
if (!ResolveConstructedType (ec))
return null;
return this;
}
///
/// Check the constraints; we're called from ResolveAsTypeTerminal()
/// after fully resolving the constructed type.
///
public bool CheckConstraints (IResolveContext ec)
{
return ConstraintChecker.CheckConstraints (ec, gt, gen_params, atypes, loc);
}
///
/// Resolve the constructed type, but don't check the constraints.
///
public bool ResolveConstructedType (IResolveContext ec)
{
if (type != null)
return true;
// If we already know the fully resolved generic type.
if (gt != null)
return DoResolveType (ec);
int num_args;
Type t = name.Type;
if (t == null) {
Report.Error (246, loc, "Cannot find type `{0}'<...>", Name);
return false;
}
num_args = TypeManager.GetNumberOfTypeArguments (t);
if (num_args == 0) {
Report.Error (308, loc,
"The non-generic type `{0}' cannot " +
"be used with type arguments.",
TypeManager.CSharpName (t));
return false;
}
gt = t.GetGenericTypeDefinition ();
return DoResolveType (ec);
}
bool DoResolveType (IResolveContext ec)
{
//
// Resolve the arguments.
//
if (args.Resolve (ec) == false)
return false;
gen_params = gt.GetGenericArguments ();
atypes = args.Arguments;
if (atypes.Length != gen_params.Length) {
Report.Error (305, loc,
"Using the generic type `{0}' " +
"requires {1} type arguments",
TypeManager.CSharpName (gt),
gen_params.Length.ToString ());
return false;
}
//
// Now bind the parameters.
//
type = gt.MakeGenericType (atypes);
return true;
}
public Expression GetSimpleName (EmitContext ec)
{
return this;
}
public override bool CheckAccessLevel (DeclSpace ds)
{
return ds.CheckAccessLevel (gt);
}
public override bool AsAccessible (DeclSpace ds, int flags)
{
foreach (Type t in atypes) {
if (!ds.AsAccessible (t, flags))
return false;
}
return ds.AsAccessible (gt, flags);
}
public override bool IsClass {
get { return gt.IsClass; }
}
public override bool IsValueType {
get { return gt.IsValueType; }
}
public override bool IsInterface {
get { return gt.IsInterface; }
}
public override bool IsSealed {
get { return gt.IsSealed; }
}
public override bool Equals (object obj)
{
ConstructedType cobj = obj as ConstructedType;
if (cobj == null)
return false;
if ((type == null) || (cobj.type == null))
return false;
return type == cobj.type;
}
public override int GetHashCode ()
{
return base.GetHashCode ();
}
public override string Name {
get {
return full_name;
}
}
public override string FullName {
get {
return full_name;
}
}
}
public abstract class ConstraintChecker
{
protected readonly Type[] gen_params;
protected readonly Type[] atypes;
protected readonly Location loc;
protected ConstraintChecker (Type[] gen_params, Type[] atypes, Location loc)
{
this.gen_params = gen_params;
this.atypes = atypes;
this.loc = loc;
}
///
/// Check the constraints; we're called from ResolveAsTypeTerminal()
/// after fully resolving the constructed type.
///
public bool CheckConstraints (IResolveContext ec)
{
for (int i = 0; i < gen_params.Length; i++) {
if (!CheckConstraints (ec, i))
return false;
}
return true;
}
protected bool CheckConstraints (IResolveContext ec, int index)
{
Type atype = atypes [index];
Type ptype = gen_params [index];
if (atype == ptype)
return true;
Expression aexpr = new EmptyExpression (atype);
GenericConstraints gc = TypeManager.GetTypeParameterConstraints (ptype);
if (gc == null)
return true;
bool is_class, is_struct;
if (atype.IsGenericParameter) {
GenericConstraints agc = TypeManager.GetTypeParameterConstraints (atype);
if (agc != null) {
if (agc is Constraints)
((Constraints) agc).Resolve (ec);
is_class = agc.IsReferenceType;
is_struct = agc.IsValueType;
} else {
is_class = is_struct = false;
}
} else {
#if MS_COMPATIBLE
is_class = false;
if (!atype.IsGenericType)
#endif
is_class = atype.IsClass || atype.IsInterface;
is_struct = atype.IsValueType && !TypeManager.IsNullableType (atype);
}
//
// First, check the `class' and `struct' constraints.
//
if (gc.HasReferenceTypeConstraint && !is_class) {
Report.Error (452, loc, "The type `{0}' must be " +
"a reference type in order to use it " +
"as type parameter `{1}' in the " +
"generic type or method `{2}'.",
TypeManager.CSharpName (atype),
TypeManager.CSharpName (ptype),
GetSignatureForError ());
return false;
} else if (gc.HasValueTypeConstraint && !is_struct) {
Report.Error (453, loc, "The type `{0}' must be a " +
"non-nullable value type in order to use it " +
"as type parameter `{1}' in the " +
"generic type or method `{2}'.",
TypeManager.CSharpName (atype),
TypeManager.CSharpName (ptype),
GetSignatureForError ());
return false;
}
//
// The class constraint comes next.
//
if (gc.HasClassConstraint) {
if (!CheckConstraint (ec, ptype, aexpr, gc.ClassConstraint))
return false;
}
//
// Now, check the interface constraints.
//
if (gc.InterfaceConstraints != null) {
foreach (Type it in gc.InterfaceConstraints) {
if (!CheckConstraint (ec, ptype, aexpr, it))
return false;
}
}
//
// Finally, check the constructor constraint.
//
if (!gc.HasConstructorConstraint)
return true;
if (TypeManager.IsBuiltinType (atype) || atype.IsValueType)
return true;
if (HasDefaultConstructor (atype))
return true;
Report_SymbolRelatedToPreviousError ();
Report.SymbolRelatedToPreviousError (atype);
Report.Error (310, loc, "The type `{0}' must have a public " +
"parameterless constructor in order to use it " +
"as parameter `{1}' in the generic type or " +
"method `{2}'",
TypeManager.CSharpName (atype),
TypeManager.CSharpName (ptype),
GetSignatureForError ());
return false;
}
protected bool CheckConstraint (IResolveContext ec, Type ptype, Expression expr,
Type ctype)
{
if (TypeManager.HasGenericArguments (ctype)) {
Type[] types = TypeManager.GetTypeArguments (ctype);
TypeArguments new_args = new TypeArguments (loc);
for (int i = 0; i < types.Length; i++) {
Type t = types [i];
if (t.IsGenericParameter) {
int pos = t.GenericParameterPosition;
t = atypes [pos];
}
new_args.Add (new TypeExpression (t, loc));
}
TypeExpr ct = new ConstructedType (ctype, new_args, loc);
if (ct.ResolveAsTypeStep (ec, false) == null)
return false;
ctype = ct.Type;
} else if (ctype.IsGenericParameter) {
int pos = ctype.GenericParameterPosition;
ctype = atypes [pos];
}
if (Convert.ImplicitStandardConversionExists (expr, ctype))
return true;
Error_TypeMustBeConvertible (expr.Type, ctype, ptype);
return false;
}
bool HasDefaultConstructor (Type atype)
{
if (atype.IsAbstract)
return false;
again:
atype = TypeManager.DropGenericTypeArguments (atype);
if (atype is TypeBuilder) {
TypeContainer tc = TypeManager.LookupTypeContainer (atype);
if (tc.InstanceConstructors == null) {
atype = atype.BaseType;
goto again;
}
foreach (Constructor c in tc.InstanceConstructors) {
if ((c.ModFlags & Modifiers.PUBLIC) == 0)
continue;
if ((c.Parameters.FixedParameters != null) &&
(c.Parameters.FixedParameters.Length != 0))
continue;
if (c.Parameters.HasArglist || c.Parameters.HasParams)
continue;
return true;
}
}
TypeParameter tparam = TypeManager.LookupTypeParameter (atype);
if (tparam != null) {
if (tparam.GenericConstraints == null)
return false;
else
return tparam.GenericConstraints.HasConstructorConstraint;
}
MemberList list = TypeManager.FindMembers (
atype, MemberTypes.Constructor,
BindingFlags.Public | BindingFlags.Instance |
BindingFlags.DeclaredOnly, null, null);
if (atype.IsAbstract || (list == null))
return false;
foreach (MethodBase mb in list) {
ParameterData pd = TypeManager.GetParameterData (mb);
if ((pd.Count == 0) && mb.IsPublic && !mb.IsStatic)
return true;
}
return false;
}
protected abstract string GetSignatureForError ();
protected abstract void Report_SymbolRelatedToPreviousError ();
void Error_TypeMustBeConvertible (Type atype, Type gc, Type ptype)
{
Report_SymbolRelatedToPreviousError ();
Report.SymbolRelatedToPreviousError (atype);
Report.Error (309, loc,
"The type `{0}' must be convertible to `{1}' in order to " +
"use it as parameter `{2}' in the generic type or method `{3}'",
TypeManager.CSharpName (atype), TypeManager.CSharpName (gc),
TypeManager.CSharpName (ptype), GetSignatureForError ());
}
public static bool CheckConstraints (EmitContext ec, MethodBase definition,
MethodBase instantiated, Location loc)
{
MethodConstraintChecker checker = new MethodConstraintChecker (
definition, definition.GetGenericArguments (),
instantiated.GetGenericArguments (), loc);
return checker.CheckConstraints (ec);
}
public static bool CheckConstraints (IResolveContext ec, Type gt, Type[] gen_params,
Type[] atypes, Location loc)
{
TypeConstraintChecker checker = new TypeConstraintChecker (
gt, gen_params, atypes, loc);
return checker.CheckConstraints (ec);
}
protected class MethodConstraintChecker : ConstraintChecker
{
MethodBase definition;
public MethodConstraintChecker (MethodBase definition, Type[] gen_params,
Type[] atypes, Location loc)
: base (gen_params, atypes, loc)
{
this.definition = definition;
}
protected override string GetSignatureForError ()
{
return TypeManager.CSharpSignature (definition);
}
protected override void Report_SymbolRelatedToPreviousError ()
{
Report.SymbolRelatedToPreviousError (definition);
}
}
protected class TypeConstraintChecker : ConstraintChecker
{
Type gt;
public TypeConstraintChecker (Type gt, Type[] gen_params, Type[] atypes,
Location loc)
: base (gen_params, atypes, loc)
{
this.gt = gt;
}
protected override string GetSignatureForError ()
{
return TypeManager.CSharpName (gt);
}
protected override void Report_SymbolRelatedToPreviousError ()
{
Report.SymbolRelatedToPreviousError (gt);
}
}
}
///
/// A generic method definition.
///
public class GenericMethod : DeclSpace
{
Expression return_type;
Parameters parameters;
public GenericMethod (NamespaceEntry ns, DeclSpace parent, MemberName name,
Expression return_type, Parameters parameters)
: base (ns, parent, name, null)
{
this.return_type = return_type;
this.parameters = parameters;
}
public override TypeBuilder DefineType ()
{
throw new Exception ();
}
public override bool Define ()
{
for (int i = 0; i < TypeParameters.Length; i++)
if (!TypeParameters [i].Resolve (this))
return false;
return true;
}
///
/// Define and resolve the type parameters.
/// We're called from Method.Define().
///
public bool Define (MethodBuilder mb, ToplevelBlock block)
{
TypeParameterName[] names = MemberName.TypeArguments.GetDeclarations ();
string[] snames = new string [names.Length];
for (int i = 0; i < names.Length; i++) {
string type_argument_name = names[i].Name;
Parameter p = parameters.GetParameterByName (type_argument_name);
if (p != null) {
Error_ParameterNameCollision (p.Location, type_argument_name, "method parameter");
return false;
}
snames[i] = type_argument_name;
}
GenericTypeParameterBuilder[] gen_params = mb.DefineGenericParameters (snames);
for (int i = 0; i < TypeParameters.Length; i++)
TypeParameters [i].Define (gen_params [i]);
if (!Define ())
return false;
for (int i = 0; i < TypeParameters.Length; i++) {
if (!TypeParameters [i].ResolveType (this))
return false;
}
return true;
}
internal static void Error_ParameterNameCollision (Location loc, string name, string collisionWith)
{
Report.Error (412, loc, "The type parameter name `{0}' is the same as `{1}'",
name, collisionWith);
}
///
/// We're called from MethodData.Define() after creating the MethodBuilder.
///
public bool DefineType (EmitContext ec, MethodBuilder mb,
MethodInfo implementing, bool is_override)
{
for (int i = 0; i < TypeParameters.Length; i++)
if (!TypeParameters [i].DefineType (
ec, mb, implementing, is_override))
return false;
bool ok = true;
foreach (Parameter p in parameters.FixedParameters){
if (!p.Resolve (ec))
ok = false;
}
if ((return_type != null) && (return_type.ResolveAsTypeTerminal (ec, false) == null))
ok = false;
return ok;
}
public void EmitAttributes ()
{
for (int i = 0; i < TypeParameters.Length; i++)
TypeParameters [i].Emit ();
if (OptAttributes != null)
OptAttributes.Emit ();
}
public override bool DefineMembers ()
{
return true;
}
public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
MemberFilter filter, object criteria)
{
throw new Exception ();
}
public override MemberCache MemberCache {
get {
return null;
}
}
public override AttributeTargets AttributeTargets {
get {
return AttributeTargets.Method | AttributeTargets.ReturnValue;
}
}
public override string DocCommentHeader {
get { return "M:"; }
}
public new void VerifyClsCompliance ()
{
foreach (TypeParameter tp in TypeParameters) {
if (tp.Constraints == null)
continue;
tp.Constraints.VerifyClsCompliance ();
}
}
}
public class DefaultValueExpression : Expression
{
Expression expr;
public DefaultValueExpression (Expression expr, Location loc)
{
this.expr = expr;
this.loc = loc;
}
public override Expression DoResolve (EmitContext ec)
{
TypeExpr texpr = expr.ResolveAsTypeTerminal (ec, false);
if (texpr == null)
return null;
type = texpr.Type;
if (type == TypeManager.void_type) {
Error_VoidInvalidInTheContext (loc);
return null;
}
if (type.IsGenericParameter)
{
GenericConstraints constraints = TypeManager.GetTypeParameterConstraints(type);
if (constraints != null && constraints.IsReferenceType)
return new NullDefault (new NullLiteral (Location), type);
}
else
{
Constant c = New.Constantify(type);
if (c != null)
return new NullDefault (c, type);
if (!TypeManager.IsValueType (type))
return new NullDefault (new NullLiteral (Location), type);
}
eclass = ExprClass.Variable;
return this;
}
public override void Emit (EmitContext ec)
{
LocalTemporary temp_storage = new LocalTemporary(type);
temp_storage.AddressOf(ec, AddressOp.LoadStore);
ec.ig.Emit(OpCodes.Initobj, type);
temp_storage.Emit(ec);
}
protected override void CloneTo (CloneContext clonectx, Expression t)
{
DefaultValueExpression target = (DefaultValueExpression) t;
target.expr = expr.Clone (clonectx);
}
}
public class NullableType : TypeExpr
{
Expression underlying;
public NullableType (Expression underlying, Location l)
{
this.underlying = underlying;
loc = l;
eclass = ExprClass.Type;
}
public NullableType (Type type, Location loc)
: this (new TypeExpression (type, loc), loc)
{ }
public override string Name {
get { return underlying.ToString () + "?"; }
}
public override string FullName {
get { return underlying.ToString () + "?"; }
}
protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
{
TypeArguments args = new TypeArguments (loc);
args.Add (underlying);
ConstructedType ctype = new ConstructedType (TypeManager.generic_nullable_type, args, loc);
return ctype.ResolveAsTypeTerminal (ec, false);
}
}
public partial class TypeManager
{
//
// A list of core types that the compiler requires or uses
//
static public Type activator_type;
static public Type generic_ilist_type;
static public Type generic_icollection_type;
static public Type generic_ienumerator_type;
static public Type generic_ienumerable_type;
static public Type generic_nullable_type;
//
// These methods are called by code generated by the compiler
//
static public MethodInfo activator_create_instance;
static void InitGenericCoreTypes ()
{
activator_type = CoreLookupType ("System", "Activator");
generic_ilist_type = CoreLookupType (
"System.Collections.Generic", "IList", 1);
generic_icollection_type = CoreLookupType (
"System.Collections.Generic", "ICollection", 1);
generic_ienumerator_type = CoreLookupType (
"System.Collections.Generic", "IEnumerator", 1);
generic_ienumerable_type = CoreLookupType (
"System.Collections.Generic", "IEnumerable", 1);
generic_nullable_type = CoreLookupType (
"System", "Nullable", 1);
}
static void InitGenericCodeHelpers ()
{
// Activator
activator_create_instance = GetMethod (
activator_type, "CreateInstance", Type.EmptyTypes);
}
static Type CoreLookupType (string ns, string name, int arity)
{
return CoreLookupType (ns, MemberName.MakeName (name, arity));
}
public static TypeContainer LookupGenericTypeContainer (Type t)
{
t = DropGenericTypeArguments (t);
return LookupTypeContainer (t);
}
public static GenericConstraints GetTypeParameterConstraints (Type t)
{
if (!t.IsGenericParameter)
throw new InvalidOperationException ();
TypeParameter tparam = LookupTypeParameter (t);
if (tparam != null)
return tparam.GenericConstraints;
return ReflectionConstraints.GetConstraints (t);
}
///
/// Check whether `a' and `b' may become equal generic types.
/// The algorithm to do that is a little bit complicated.
///
public static bool MayBecomeEqualGenericTypes (Type a, Type b, Type[] class_inferred,
Type[] method_inferred)
{
if (a.IsGenericParameter) {
//
// If a is an array of a's type, they may never
// become equal.
//
while (b.IsArray) {
b = b.GetElementType ();
if (a.Equals (b))
return false;
}
//
// If b is a generic parameter or an actual type,
// they may become equal:
//
// class X : I, I
// class X : I, I
//
if (b.IsGenericParameter || !b.IsGenericType) {
int pos = a.GenericParameterPosition;
Type[] args = a.DeclaringMethod != null ? method_inferred : class_inferred;
if (args [pos] == null) {
args [pos] = b;
return true;
}
return args [pos] == a;
}
//
// We're now comparing a type parameter with a
// generic instance. They may become equal unless
// the type parameter appears anywhere in the
// generic instance:
//
// class X : I, I>
// -> error because you could instanciate it as
// X,int>
//
// class X : I, I> -> ok
//
Type[] bargs = GetTypeArguments (b);
for (int i = 0; i < bargs.Length; i++) {
if (a.Equals (bargs [i]))
return false;
}
return true;
}
if (b.IsGenericParameter)
return MayBecomeEqualGenericTypes (b, a, class_inferred, method_inferred);
//
// At this point, neither a nor b are a type parameter.
//
// If one of them is a generic instance, let
// MayBecomeEqualGenericInstances() compare them (if the
// other one is not a generic instance, they can never
// become equal).
//
if (a.IsGenericType || b.IsGenericType)
return MayBecomeEqualGenericInstances (a, b, class_inferred, method_inferred);
//
// If both of them are arrays.
//
if (a.IsArray && b.IsArray) {
if (a.GetArrayRank () != b.GetArrayRank ())
return false;
a = a.GetElementType ();
b = b.GetElementType ();
return MayBecomeEqualGenericTypes (a, b, class_inferred, method_inferred);
}
//
// Ok, two ordinary types.
//
return a.Equals (b);
}
//
// Checks whether two generic instances may become equal for some
// particular instantiation (26.3.1).
//
public static bool MayBecomeEqualGenericInstances (Type a, Type b,
Type[] class_inferred,
Type[] method_inferred)
{
if (!a.IsGenericType || !b.IsGenericType)
return false;
if (a.GetGenericTypeDefinition () != b.GetGenericTypeDefinition ())
return false;
return MayBecomeEqualGenericInstances (
GetTypeArguments (a), GetTypeArguments (b), class_inferred, method_inferred);
}
public static bool MayBecomeEqualGenericInstances (Type[] aargs, Type[] bargs,
Type[] class_inferred,
Type[] method_inferred)
{
if (aargs.Length != bargs.Length)
return false;
for (int i = 0; i < aargs.Length; i++) {
if (!MayBecomeEqualGenericTypes (aargs [i], bargs [i], class_inferred, method_inferred))
return false;
}
return true;
}
///
/// Type inference. Try to infer the type arguments from the params method
/// `method', which is invoked with the arguments `arguments'. This is used
/// when resolving an Invocation or a DelegateInvocation and the user
/// did not explicitly specify type arguments.
///
public static bool InferParamsTypeArguments (EmitContext ec, ArrayList arguments,
ref MethodBase method)
{
if (!TypeManager.IsGenericMethod (method))
return true;
// if there are no arguments, there's no way to infer the type-arguments
if (arguments == null || arguments.Count == 0)
return false;
ParameterData pd = TypeManager.GetParameterData (method);
int pd_count = pd.Count;
int arg_count = arguments.Count;
if (pd_count == 0)
return false;
if (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS)
return false;
if (pd_count - 1 > arg_count)
return false;
Type[] method_args = method.GetGenericArguments ();
Type[] inferred_types = new Type [method_args.Length];
//
// If we have come this far, the case which
// remains is when the number of parameters is
// less than or equal to the argument count.
//
for (int i = 0; i < pd_count - 1; ++i) {
Argument a = (Argument) arguments [i];
if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
continue;
Type pt = pd.ParameterType (i);
Type at = a.Type;
if (!TypeInferenceV2.UnifyType (pt, at, inferred_types))
return false;
}
Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
for (int i = pd_count - 1; i < arg_count; i++) {
Argument a = (Argument) arguments [i];
if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
continue;
if (!TypeInferenceV2.UnifyType (element_type, a.Type, inferred_types))
return false;
}
for (int i = 0; i < inferred_types.Length; i++)
if (inferred_types [i] == null)
return false;
method = ((MethodInfo)method).MakeGenericMethod (inferred_types);
return true;
}
///
/// Type inference. Try to infer the type arguments from `method',
/// which is invoked with the arguments `arguments'. This is used
/// when resolving an Invocation or a DelegateInvocation and the user
/// did not explicitly specify type arguments.
///
public static int InferTypeArguments (EmitContext ec,
ArrayList arguments,
ref MethodBase method)
{
ATypeInference ti = ATypeInference.CreateInstance (arguments);
Type[] i_args = ti.InferMethodArguments (ec, method);
if (i_args == null)
return ti.InferenceScore;
if (i_args.Length == 0)
return 0;
method = ((MethodInfo) method).MakeGenericMethod (i_args);
return 0;
}
///
/// Type inference.
///
public static bool InferTypeArguments (ParameterData apd,
ref MethodBase method)
{
if (!TypeManager.IsGenericMethod (method))
return true;
ATypeInference ti = ATypeInference.CreateInstance (ArrayList.Adapter (apd.Types));
Type[] i_args = ti.InferDelegateArguments (method);
if (i_args == null)
return false;
method = ((MethodInfo) method).MakeGenericMethod (i_args);
return true;
}
}
abstract class ATypeInference
{
protected readonly ArrayList arguments;
protected readonly int arg_count;
protected ATypeInference (ArrayList arguments)
{
this.arguments = arguments;
if (arguments != null)
arg_count = arguments.Count;
}
public static ATypeInference CreateInstance (ArrayList arguments)
{
if (RootContext.Version == LanguageVersion.ISO_2)
return new TypeInferenceV2 (arguments);
return new TypeInferenceV3 (arguments);
}
public virtual int InferenceScore {
get {
return int.MaxValue;
}
}
public abstract Type[] InferMethodArguments (EmitContext ec, MethodBase method);
public abstract Type[] InferDelegateArguments (MethodBase method);
}
//
// Implements C# 2.0 type inference
//
class TypeInferenceV2 : ATypeInference
{
public TypeInferenceV2 (ArrayList arguments)
: base (arguments)
{
}
public override Type[] InferDelegateArguments (MethodBase method)
{
ParameterData pd = TypeManager.GetParameterData (method);
if (arg_count != pd.Count)
return null;
Type[] method_args = method.GetGenericArguments ();
Type[] inferred_types = new Type[method_args.Length];
Type[] param_types = new Type[pd.Count];
Type[] arg_types = (Type[])arguments.ToArray (typeof (Type));
for (int i = 0; i < arg_count; i++) {
param_types[i] = pd.ParameterType (i);
}
if (!InferTypeArguments (param_types, arg_types, inferred_types))
return null;
return inferred_types;
}
public override Type[] InferMethodArguments (EmitContext ec, MethodBase method)
{
ParameterData pd = TypeManager.GetParameterData (method);
if (arg_count != pd.Count)
return null;
Type[] method_generic_args = method.GetGenericArguments ();
Type[] arg_types = new Type[pd.Count];
for (int i = 0; i < arg_count; i++) {
Argument a = (Argument) arguments[i];
if (a.Expr is NullLiteral || a.Expr is MethodGroupExpr || a.Expr is AnonymousMethodExpression)
continue;
arg_types[i] = a.Type;
}
Type[] inferred_types = new Type [method_generic_args.Length];
if (!InferTypeArguments (pd.Types, arg_types, inferred_types))
return null;
return inferred_types;
}
static bool InferTypeArguments (Type[] param_types, Type[] arg_types,
Type[] inferred_types)
{
for (int i = 0; i < arg_types.Length; i++) {
if (arg_types[i] == null)
continue;
if (!UnifyType (param_types[i], arg_types[i], inferred_types))
return false;
}
for (int i = 0; i < inferred_types.Length; ++i)
if (inferred_types[i] == null)
return false;
return true;
}
public static bool UnifyType (Type pt, Type at, Type[] inferred)
{
if (pt.IsGenericParameter) {
if (pt.DeclaringMethod == null)
return pt == at;
int pos = pt.GenericParameterPosition;
if (inferred [pos] == null)
inferred [pos] = at;
return inferred [pos] == at;
}
if (!pt.ContainsGenericParameters) {
if (at.ContainsGenericParameters)
return UnifyType (at, pt, inferred);
else
return true;
}
if (at.IsArray) {
if (pt.IsArray) {
if (at.GetArrayRank () != pt.GetArrayRank ())
return false;
return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
}
if (!pt.IsGenericType)
return false;
Type gt = pt.GetGenericTypeDefinition ();
if ((gt != TypeManager.generic_ilist_type) && (gt != TypeManager.generic_icollection_type) &&
(gt != TypeManager.generic_ienumerable_type))
return false;
Type[] args = TypeManager.GetTypeArguments (pt);
return UnifyType (args[0], at.GetElementType (), inferred);
}
if (pt.IsArray) {
if (!at.IsArray ||
(pt.GetArrayRank () != at.GetArrayRank ()))
return false;
return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
}
if (pt.IsByRef && at.IsByRef)
return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
ArrayList list = new ArrayList ();
if (at.IsGenericType)
list.Add (at);
for (Type bt = at.BaseType; bt != null; bt = bt.BaseType)
list.Add (bt);
list.AddRange (TypeManager.GetInterfaces (at));
foreach (Type type in list) {
if (!type.IsGenericType)
continue;
if (TypeManager.DropGenericTypeArguments (pt) != TypeManager.DropGenericTypeArguments (type))
continue;
if (!UnifyTypes (pt.GetGenericArguments (), type.GetGenericArguments (), inferred))
return false;
}
return true;
}
static bool UnifyTypes (Type[] pts, Type[] ats, Type[] inferred)
{
for (int i = 0; i < ats.Length; i++) {
if (!UnifyType (pts [i], ats [i], inferred))
return false;
}
return true;
}
}
//
// Implements C# 3.0 type inference
//
class TypeInferenceV3 : ATypeInference
{
//
// Tracks successful rate of type inference
//
int score = int.MaxValue;
public TypeInferenceV3 (ArrayList arguments)
: base (arguments)
{
}
public override int InferenceScore {
get {
return score;
}
}
public override Type[] InferDelegateArguments (MethodBase method)
{
ParameterData pd = TypeManager.GetParameterData (method);
if (arg_count != pd.Count)
return null;
Type[] d_gargs = method.GetGenericArguments ();
TypeInferenceContext context = new TypeInferenceContext (d_gargs);
// A lower-bound inference is made from each argument type Uj of D
// to the corresponding parameter type Tj of M
for (int i = 0; i < arg_count; ++i) {
Type t = pd.Types [i];
if (!t.IsGenericParameter)
continue;
context.LowerBoundInference ((Type)arguments[i], t);
}
if (!context.FixAllTypes ())
return null;
return context.InferredTypeArguments;
}
public override Type[] InferMethodArguments (EmitContext ec, MethodBase method)
{
Type[] method_generic_args = method.GetGenericArguments ();
TypeInferenceContext context = new TypeInferenceContext (method_generic_args);
if (!context.UnfixedVariableExists)
return Type.EmptyTypes;
ParameterData pd = TypeManager.GetParameterData (method);
if (!InferInPhases (ec, context, pd))
return null;
return context.InferredTypeArguments;
}
//
// Implements method type arguments inference
//
bool InferInPhases (EmitContext ec, TypeInferenceContext tic, ParameterData methodParameters)
{
//
// The first inference phase
//
for (int i = 0; i < arg_count; i++) {
Type method_parameter = methodParameters.ParameterType (i);
Argument a = (Argument) arguments[i];
//
// When a lambda expression, an anonymous method
// is used an explicit argument type inference takes a place
//
AnonymousMethodExpression am = a.Expr as AnonymousMethodExpression;
if (am != null) {
if (am.ExplicitTypeInference (tic, method_parameter))
--score;
continue;
}
if (a.Expr.Type == TypeManager.null_type)
continue;
//
// Otherwise an output type inference is made
//
score -= tic.OutputTypeInference (ec, a.Expr, method_parameter);
}
//
// Part of the second phase but because it happens only once
// we don't need to call it in cycle
//
bool fixed_any = false;
if (!tic.FixIndependentTypeArguments (methodParameters, ref fixed_any))
return false;
return DoSecondPhase (ec, tic, methodParameters, !fixed_any);
}
bool DoSecondPhase (EmitContext ec, TypeInferenceContext tic, ParameterData methodParameters, bool fixDependent)
{
bool fixed_any = false;
if (fixDependent && !tic.FixDependentTypes (methodParameters, ref fixed_any))
return false;
// If no further unfixed type variables exist, type inference succeeds
if (!tic.UnfixedVariableExists)
return true;
if (!fixed_any && fixDependent)
return false;
// For all arguments where the corresponding argument output types
// contain unfixed type variables but the input types do not,
// an output type inference is made
for (int i = 0; i < arg_count; i++) {
Type t_i = methodParameters.ParameterType (i);
if (!TypeManager.IsDelegateType (t_i))
continue;
MethodInfo mi = Delegate.GetInvokeMethod (t_i, t_i);
Type rtype = mi.ReturnType;
#if MS_COMPATIBLE
// Blablabla, because reflection does not work with dynamic types
Type[] g_args = t_i.GetGenericArguments ();
rtype = g_args[rtype.GenericParameterPosition];
#endif
if (tic.IsReturnTypeNonDependent (mi, rtype))
score -= tic.OutputTypeInference (ec, ((Argument) arguments [i]).Expr, t_i);
}
return DoSecondPhase (ec, tic, methodParameters, true);
}
}
public class TypeInferenceContext
{
readonly Type[] unfixed_types;
readonly Type[] fixed_types;
readonly ArrayList[] bounds;
public TypeInferenceContext (Type[] typeArguments)
{
if (typeArguments.Length == 0)
throw new ArgumentException ("Empty generic arguments");
fixed_types = new Type [typeArguments.Length];
for (int i = 0; i < typeArguments.Length; ++i) {
if (typeArguments [i].IsGenericParameter) {
if (bounds == null) {
bounds = new ArrayList [typeArguments.Length];
unfixed_types = new Type [typeArguments.Length];
}
unfixed_types [i] = typeArguments [i];
} else {
fixed_types [i] = typeArguments [i];
}
}
}
public Type[] InferredTypeArguments {
get {
return fixed_types;
}
}
void AddToBounds (Type t, int index)
{
ArrayList a = bounds[index];
if (a == null) {
a = new ArrayList ();
a.Add (t);
bounds[index] = a;
return;
}
if (a.Contains (t))
return;
a.Add (t);
}
bool AllTypesAreFixed (Type[] types)
{
foreach (Type t in types) {
if (t.IsGenericParameter) {
if (!IsFixed (t))
return false;
continue;
}
if (t.IsGenericType)
return AllTypesAreFixed (t.GetGenericArguments ());
}
return true;
}
//
// 26.3.3.8 Exact Inference
//
public int ExactInference (Type u, Type v)
{
// If V is an array type
if (v.IsArray) {
if (!u.IsArray)
return 0;
if (u.GetArrayRank () != v.GetArrayRank ())
return 0;
return ExactInference (TypeManager.GetElementType (u), TypeManager.GetElementType (v));
}
// If V is constructed type and U is constructed type
if (v.IsGenericType && !v.IsGenericTypeDefinition) {
if (!u.IsGenericType)
return 0;
Type [] ga_u = u.GetGenericArguments ();
Type [] ga_v = v.GetGenericArguments ();
if (ga_u.Length != ga_v.Length)
return 0;
int score = 0;
for (int i = 0; i < ga_u.Length; ++i)
score += ExactInference (ga_u [i], ga_v [i]);
return score > 0 ? 1 : 0;
}
// If V is one of the unfixed type arguments
int pos = IsUnfixed (v);
if (pos == -1)
return 0;
AddToBounds (u, pos);
return 1;
}
public bool FixAllTypes ()
{
for (int i = 0; i < unfixed_types.Length; ++i) {
if (!FixType (i))
return false;
}
return true;
}
//
// All unfixed type variables Xi are fixed for which all of the following hold:
// a, There is at least one type variable Xj that depends on Xi
// b, Xi has a non-empty set of bounds
//
public bool FixDependentTypes (ParameterData methodParameters, ref bool fixed_any)
{
for (int i = 0; i < unfixed_types.Length; ++i) {
if (unfixed_types[i] == null)
continue;
if (bounds[i] == null)
continue;
if (!FixType (i))
return false;
fixed_any = true;
}
return true;
}
//
// All unfixed type variables Xi which depend on no Xj are fixed
//
public bool FixIndependentTypeArguments (ParameterData methodParameters, ref bool fixed_any)
{
ArrayList types_to_fix = new ArrayList (unfixed_types);
foreach (Type t in methodParameters.Types) {
if (t.IsGenericParameter)
continue;
if (!TypeManager.IsDelegateType (t))
continue;
MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
Type rtype = invoke.ReturnType;
if (!rtype.IsGenericParameter && !rtype.IsGenericType)
continue;
#if MS_COMPATIBLE
// Blablabla, because reflection does not work with dynamic types
if (rtype.IsGenericParameter) {
Type [] g_args = t.GetGenericArguments ();
rtype = g_args [rtype.GenericParameterPosition];
}
#endif
// Remove dependent types, they cannot be fixed yet
RemoveDependentTypes (types_to_fix, rtype);
}
foreach (Type t in types_to_fix) {
if (t == null)
continue;
int idx = IsUnfixed (t);
if (idx >= 0 && !FixType (idx)) {
return false;
}
}
fixed_any = types_to_fix.Count > 0;
return true;
}
//
// 26.3.3.10 Fixing
//
public bool FixType (int i)
{
// It's already fixed
if (unfixed_types[i] == null)
throw new InternalErrorException ("Type argument has been already fixed");
ArrayList candidates = (ArrayList)bounds [i];
if (candidates == null)
return false;
if (candidates.Count == 1) {
unfixed_types[i] = null;
fixed_types[i] = (Type)candidates[0];
return true;
}
// TODO: Review, I think it is still wrong
Type best_candidate = null;
for (int ci = 0; ci < candidates.Count; ++ci) {
TypeExpr candidate = new TypeExpression ((Type)candidates[ci], Location.Null);
bool failed = false;
for (int cii = 0; cii < candidates.Count; ++cii) {
if (cii == ci)
continue;
if (!Convert.ImplicitStandardConversionExists (candidate, (Type)candidates[cii])) {
failed = true;
}
}
if (failed)
continue;
if (best_candidate != null)
return false;
best_candidate = candidate.Type;
}
if (best_candidate == null)
return false;
unfixed_types[i] = null;
fixed_types[i] = best_candidate;
return true;
}
//
// Uses inferred types to inflate delegate type argument
//
public Type InflateGenericArgument (Type parameter)
{
if (parameter.IsGenericParameter)
return fixed_types [parameter.GenericParameterPosition];
if (parameter.IsGenericType) {
Type [] parameter_targs = parameter.GetGenericArguments ();
for (int ii = 0; ii < parameter_targs.Length; ++ii) {
parameter_targs [ii] = InflateGenericArgument (parameter_targs [ii]);
}
return parameter.GetGenericTypeDefinition ().MakeGenericType (parameter_targs);
}
return parameter;
}
//
// Tests whether all delegate input arguments are fixed and generic output type
// requires output type inference
//
public bool IsReturnTypeNonDependent (MethodInfo invoke, Type returnType)
{
if (returnType.IsGenericParameter) {
if (IsFixed (returnType))
return false;
} else if (returnType.IsGenericType) {
if (TypeManager.IsDelegateType (returnType)) {
invoke = Delegate.GetInvokeMethod (returnType, returnType);
return IsReturnTypeNonDependent (invoke, invoke.ReturnType);
}
Type[] g_args = returnType.GetGenericArguments ();
// At least one unfixed return type has to exist
if (AllTypesAreFixed (g_args))
return false;
} else {
return false;
}
// All generic input arguments have to be fixed
ParameterData d_parameters = TypeManager.GetParameterData (invoke);
return AllTypesAreFixed (d_parameters.Types);
}
bool IsFixed (Type type)
{
return IsUnfixed (type) == -1;
}
int IsUnfixed (Type type)
{
if (!type.IsGenericParameter)
return -1;
//return unfixed_types[type.GenericParameterPosition] != null;
for (int i = 0; i < unfixed_types.Length; ++i) {
if (unfixed_types [i] == type)
return i;
}
return -1;
}
//
// 26.3.3.9 Lower-bound Inference
//
public int LowerBoundInference (Type u, Type v)
{
// Remove ref, out modifiers
if (v.IsByRef)
v = v.GetElementType ();
// If U is an array type
if (u.IsArray) {
int u_dim = u.GetArrayRank ();
Type v_e;
Type u_e = TypeManager.GetElementType (u);
if (v.IsArray) {
if (u_dim != v.GetArrayRank ())
return 0;
v_e = TypeManager.GetElementType (v);
if (u.IsByRef) {
return LowerBoundInference (u_e, v_e);
}
return ExactInference (u_e, v_e);
}
if (u_dim != 1)
return 0;
if (v.IsGenericType) {
Type g_v = v.GetGenericTypeDefinition ();
if ((g_v != TypeManager.generic_ilist_type) && (g_v != TypeManager.generic_icollection_type) &&
(g_v != TypeManager.generic_ienumerable_type))
return 0;
v_e = TypeManager.GetTypeArguments (v)[0];
if (u.IsByRef) {
return LowerBoundInference (u_e, v_e);
}
return ExactInference (u_e, v_e);
}
} else if (v.IsGenericType && !v.IsGenericTypeDefinition) {
//
// if V is a constructed type C and there is a unique set of types U1..Uk
// such that a standard implicit conversion exists from U to C then an exact
// inference is made from each Ui for the corresponding Vi
//
ArrayList u_candidates = new ArrayList ();
if (u.IsGenericType)
u_candidates.Add (u);
for (Type t = u.BaseType; t != null; t = t.BaseType) {
if (t.IsGenericType && !t.IsGenericTypeDefinition)
u_candidates.Add (t);
}
// TODO: Implement GetGenericInterfaces only and remove
// the if from foreach
u_candidates.AddRange (TypeManager.GetInterfaces (u));
Type open_v = v.GetGenericTypeDefinition ();
foreach (Type u_candidate in u_candidates) {
if (!u_candidate.IsGenericType || u_candidate.IsGenericTypeDefinition)
continue;
if (TypeManager.DropGenericTypeArguments (u_candidate) != open_v)
continue;
Type [] ga_u = u_candidate.GetGenericArguments ();
Type [] ga_v = v.GetGenericArguments ();
int score = 0;
for (int i = 0; i < ga_u.Length; ++i)
score += ExactInference (ga_u [i], ga_v [i]);
return score > 0 ? 1 : 0;
}
return 0;
}
// If V is one of the unfixed type arguments
int pos = IsUnfixed (v);
if (pos == -1)
return 0;
AddToBounds (u, pos);
return 1;
}
//
// 26.3.3.6 Output Type Inference
//
public int OutputTypeInference (EmitContext ec, Expression e, Type t)
{
// If e is a lambda or anonymous method with inferred return type
AnonymousMethodExpression ame = e as AnonymousMethodExpression;
if (ame != null) {
Type rt = ame.InferReturnType (ec, this, t);
MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
if (rt == null) {
ParameterData pd = TypeManager.GetParameterData (invoke);
return ame.Parameters.Count == pd.Count ? 1 : 0;
}
Type rtype = invoke.ReturnType;
#if MS_COMPATIBLE
// Blablabla, because reflection does not work with dynamic types
Type [] g_args = t.GetGenericArguments ();
rtype = g_args [rtype.GenericParameterPosition];
#endif
return LowerBoundInference (rt, rtype) + 1;
}
if (e is MethodGroupExpr) {
MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
Type rtype = invoke.ReturnType;
if (!TypeManager.IsGenericType (rtype))
return 0;
throw new NotImplementedException ();
}
//
// if e is an expression with type U, then
// a lower-bound inference is made from U for T
//
return LowerBoundInference (e.Type, t) * 2;
}
static void RemoveDependentTypes (ArrayList types, Type returnType)
{
if (returnType.IsGenericParameter) {
types [returnType.GenericParameterPosition] = null;
return;
}
if (returnType.IsGenericType) {
foreach (Type t in returnType.GetGenericArguments ()) {
RemoveDependentTypes (types, t);
}
}
}
public bool UnfixedVariableExists {
get {
if (unfixed_types == null)
return false;
foreach (Type ut in unfixed_types)
if (ut != null)
return true;
return false;
}
}
}
public abstract class Nullable
{
public sealed class NullableInfo
{
public readonly Type Type;
public readonly Type UnderlyingType;
public readonly MethodInfo HasValue;
public readonly MethodInfo Value;
public readonly ConstructorInfo Constructor;
public NullableInfo (Type type)
{
Type = type;
UnderlyingType = TypeManager.GetTypeArguments (type) [0];
PropertyInfo has_value_pi = TypeManager.GetProperty (type, "HasValue");
PropertyInfo value_pi = TypeManager.GetProperty (type, "Value");
HasValue = has_value_pi.GetGetMethod (false);
Value = value_pi.GetGetMethod (false);
Constructor = type.GetConstructor (new Type[] { UnderlyingType });
}
}
public class Unwrap : Expression, IMemoryLocation, IAssignMethod
{
Expression expr;
NullableInfo info;
LocalTemporary temp;
bool has_temp;
protected Unwrap (Expression expr)
{
this.expr = expr;
this.loc = expr.Location;
}
public static Unwrap Create (Expression expr, EmitContext ec)
{
return new Unwrap (expr).Resolve (ec) as Unwrap;
}
public override Expression DoResolve (EmitContext ec)
{
expr = expr.Resolve (ec);
if (expr == null)
return null;
temp = new LocalTemporary (expr.Type);
info = new NullableInfo (expr.Type);
type = info.UnderlyingType;
eclass = expr.eclass;
return this;
}
public override void Emit (EmitContext ec)
{
AddressOf (ec, AddressOp.LoadStore);
ec.ig.EmitCall (OpCodes.Call, info.Value, null);
}
public void EmitCheck (EmitContext ec)
{
AddressOf (ec, AddressOp.LoadStore);
ec.ig.EmitCall (OpCodes.Call, info.HasValue, null);
}
public void Store (EmitContext ec)
{
create_temp (ec);
}
void create_temp (EmitContext ec)
{
if ((temp != null) && !has_temp) {
expr.Emit (ec);
temp.Store (ec);
has_temp = true;
}
}
public void AddressOf (EmitContext ec, AddressOp mode)
{
create_temp (ec);
if (temp != null)
temp.AddressOf (ec, AddressOp.LoadStore);
else
((IMemoryLocation) expr).AddressOf (ec, AddressOp.LoadStore);
}
public void Emit (EmitContext ec, bool leave_copy)
{
create_temp (ec);
if (leave_copy) {
if (temp != null)
temp.Emit (ec);
else
expr.Emit (ec);
}
Emit (ec);
}
public void EmitAssign (EmitContext ec, Expression source,
bool leave_copy, bool prepare_for_load)
{
InternalWrap wrap = new InternalWrap (source, info, loc);
((IAssignMethod) expr).EmitAssign (ec, wrap, leave_copy, false);
}
protected class InternalWrap : Expression
{
public Expression expr;
public NullableInfo info;
public InternalWrap (Expression expr, NullableInfo info, Location loc)
{
this.expr = expr;
this.info = info;
this.loc = loc;
type = info.Type;
eclass = ExprClass.Value;
}
public override Expression DoResolve (EmitContext ec)
{
return this;
}
public override void Emit (EmitContext ec)
{
expr.Emit (ec);
ec.ig.Emit (OpCodes.Newobj, info.Constructor);
}
}
}
public class Wrap : Expression
{
Expression expr;
NullableInfo info;
protected Wrap (Expression expr)
{
this.expr = expr;
this.loc = expr.Location;
}
public static Wrap Create (Expression expr, EmitContext ec)
{
return new Wrap (expr).Resolve (ec) as Wrap;
}
public override Expression DoResolve (EmitContext ec)
{
expr = expr.Resolve (ec);
if (expr == null)
return null;
TypeExpr target_type = new NullableType (expr.Type, loc);
target_type = target_type.ResolveAsTypeTerminal (ec, false);
if (target_type == null)
return null;
type = target_type.Type;
info = new NullableInfo (type);
eclass = ExprClass.Value;
return this;
}
public override void Emit (EmitContext ec)
{
expr.Emit (ec);
ec.ig.Emit (OpCodes.Newobj, info.Constructor);
}
}
public class NullableLiteral : NullLiteral, IMemoryLocation {
public NullableLiteral (Type target_type, Location loc)
: base (loc)
{
this.type = target_type;
eclass = ExprClass.Value;
}
public override Expression DoResolve (EmitContext ec)
{
return this;
}
public override void Emit (EmitContext ec)
{
LocalTemporary value_target = new LocalTemporary (type);
value_target.AddressOf (ec, AddressOp.Store);
ec.ig.Emit (OpCodes.Initobj, type);
value_target.Emit (ec);
}
public void AddressOf (EmitContext ec, AddressOp Mode)
{
LocalTemporary value_target = new LocalTemporary (type);
value_target.AddressOf (ec, AddressOp.Store);
ec.ig.Emit (OpCodes.Initobj, type);
((IMemoryLocation) value_target).AddressOf (ec, Mode);
}
}
public abstract class Lifted : Expression, IMemoryLocation
{
Expression expr, underlying, wrap, null_value;
Unwrap unwrap;
protected Lifted (Expression expr, Location loc)
{
this.expr = expr;
this.loc = loc;
}
public override Expression DoResolve (EmitContext ec)
{
expr = expr.Resolve (ec);
if (expr == null)
return null;
unwrap = Unwrap.Create (expr, ec);
if (unwrap == null)
return null;
underlying = ResolveUnderlying (unwrap, ec);
if (underlying == null)
return null;
wrap = Wrap.Create (underlying, ec);
if (wrap == null)
return null;
null_value = new NullableLiteral (wrap.Type, loc).Resolve (ec);
if (null_value == null)
return null;
type = wrap.Type;
eclass = ExprClass.Value;
return this;
}
protected abstract Expression ResolveUnderlying (Expression unwrap, EmitContext ec);
public override void Emit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
wrap.Emit (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
null_value.Emit (ec);
ig.MarkLabel (end_label);
}
public void AddressOf (EmitContext ec, AddressOp mode)
{
unwrap.AddressOf (ec, mode);
}
}
public class LiftedConversion : Lifted
{
public readonly bool IsUser;
public readonly bool IsExplicit;
public readonly Type TargetType;
public LiftedConversion (Expression expr, Type target_type, bool is_user,
bool is_explicit, Location loc)
: base (expr, loc)
{
this.IsUser = is_user;
this.IsExplicit = is_explicit;
this.TargetType = target_type;
}
protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
{
Type type = TypeManager.GetTypeArguments (TargetType) [0];
if (IsUser) {
return Convert.UserDefinedConversion (ec, unwrap, type, loc, IsExplicit);
} else {
if (IsExplicit)
return Convert.ExplicitConversion (ec, unwrap, type, loc);
else
return Convert.ImplicitConversion (ec, unwrap, type, loc);
}
}
}
public class LiftedUnaryOperator : Lifted
{
public readonly Unary.Operator Oper;
public LiftedUnaryOperator (Unary.Operator op, Expression expr, Location loc)
: base (expr, loc)
{
this.Oper = op;
}
protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
{
return new Unary (Oper, unwrap, loc);
}
}
public class LiftedConditional : Lifted
{
Expression true_expr, false_expr;
public LiftedConditional (Expression expr, Expression true_expr, Expression false_expr,
Location loc)
: base (expr, loc)
{
this.true_expr = true_expr;
this.false_expr = false_expr;
}
protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
{
return new Conditional (unwrap, true_expr, false_expr);
}
}
public class LiftedBinaryOperator : Binary
{
Expression underlying, null_value, bool_wrap;
Unwrap left_unwrap, right_unwrap;
bool is_equality, is_comparision, is_boolean;
public LiftedBinaryOperator (Binary.Operator op, Expression left, Expression right,
Location loc)
: base (op, left, right)
{
this.loc = loc;
}
public override Expression DoResolve (EmitContext ec)
{
if ((Oper == Binary.Operator.LogicalAnd) ||
(Oper == Binary.Operator.LogicalOr)) {
Error_OperatorCannotBeApplied ();
return null;
}
if (TypeManager.IsNullableType (left.Type)) {
left = left_unwrap = Unwrap.Create (left, ec);
if (left == null)
return null;
}
if (TypeManager.IsNullableType (right.Type)) {
right = right_unwrap = Unwrap.Create (right, ec);
if (right == null)
return null;
}
if (((Oper == Binary.Operator.BitwiseAnd) || (Oper == Binary.Operator.BitwiseOr)) &&
((left.Type == TypeManager.bool_type) && (right.Type == TypeManager.bool_type))) {
Expression empty = new EmptyExpression (TypeManager.bool_type);
bool_wrap = Wrap.Create (empty, ec);
null_value = new NullableLiteral (bool_wrap.Type, loc).Resolve (ec);
type = bool_wrap.Type;
is_boolean = true;
} else if ((Oper == Binary.Operator.Equality) || (Oper == Binary.Operator.Inequality)) {
if (!(left is NullLiteral) && !(right is NullLiteral)) {
underlying = new Binary (Oper, left, right).Resolve (ec);
if (underlying == null)
return null;
}
type = TypeManager.bool_type;
is_equality = true;
} else if ((Oper == Binary.Operator.LessThan) ||
(Oper == Binary.Operator.GreaterThan) ||
(Oper == Binary.Operator.LessThanOrEqual) ||
(Oper == Binary.Operator.GreaterThanOrEqual)) {
underlying = new Binary (Oper, left, right).Resolve (ec);
if (underlying == null)
return null;
type = TypeManager.bool_type;
is_comparision = true;
} else {
underlying = new Binary (Oper, left, right).Resolve (ec);
if (underlying == null)
return null;
underlying = Wrap.Create (underlying, ec);
if (underlying == null)
return null;
type = underlying.Type;
null_value = new NullableLiteral (type, loc).Resolve (ec);
}
eclass = ExprClass.Value;
return this;
}
void EmitBoolean (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label left_is_null_label = ig.DefineLabel ();
Label right_is_null_label = ig.DefineLabel ();
Label is_null_label = ig.DefineLabel ();
Label wrap_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
if (left_unwrap != null) {
left_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, left_is_null_label);
}
left.Emit (ec);
ig.Emit (OpCodes.Dup);
if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
ig.Emit (OpCodes.Brtrue, wrap_label);
else
ig.Emit (OpCodes.Brfalse, wrap_label);
if (right_unwrap != null) {
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, right_is_null_label);
}
if ((Oper == Binary.Operator.LogicalAnd) || (Oper == Binary.Operator.LogicalOr))
ig.Emit (OpCodes.Pop);
right.Emit (ec);
if (Oper == Binary.Operator.BitwiseOr)
ig.Emit (OpCodes.Or);
else if (Oper == Binary.Operator.BitwiseAnd)
ig.Emit (OpCodes.And);
ig.Emit (OpCodes.Br, wrap_label);
ig.MarkLabel (left_is_null_label);
if (right_unwrap != null) {
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
}
right.Emit (ec);
ig.Emit (OpCodes.Dup);
if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
ig.Emit (OpCodes.Brtrue, wrap_label);
else
ig.Emit (OpCodes.Brfalse, wrap_label);
ig.MarkLabel (right_is_null_label);
ig.Emit (OpCodes.Pop);
ig.MarkLabel (is_null_label);
null_value.Emit (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (wrap_label);
ig.Emit (OpCodes.Nop);
bool_wrap.Emit (ec);
ig.Emit (OpCodes.Nop);
ig.MarkLabel (end_label);
}
void EmitEquality (EmitContext ec)
{
ILGenerator ig = ec.ig;
// Given 'X? x;' for any value type X: 'x != null' is the same as 'x.HasValue'
if (left is NullLiteral) {
if (right_unwrap == null)
throw new InternalErrorException ();
right_unwrap.EmitCheck (ec);
if (Oper == Binary.Operator.Equality) {
ig.Emit (OpCodes.Ldc_I4_0);
ig.Emit (OpCodes.Ceq);
}
return;
}
if (right is NullLiteral) {
if (left_unwrap == null)
throw new InternalErrorException ();
left_unwrap.EmitCheck (ec);
if (Oper == Binary.Operator.Equality) {
ig.Emit (OpCodes.Ldc_I4_0);
ig.Emit (OpCodes.Ceq);
}
return;
}
Label both_have_value_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
if (left_unwrap != null && right_unwrap != null) {
Label dissimilar_label = ig.DefineLabel ();
left_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Dup);
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Bne_Un, dissimilar_label);
ig.Emit (OpCodes.Brtrue, both_have_value_label);
// both are null
if (Oper == Binary.Operator.Equality)
ig.Emit (OpCodes.Ldc_I4_1);
else
ig.Emit (OpCodes.Ldc_I4_0);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (dissimilar_label);
ig.Emit (OpCodes.Pop);
} else if (left_unwrap != null) {
left_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brtrue, both_have_value_label);
} else if (right_unwrap != null) {
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brtrue, both_have_value_label);
} else {
throw new InternalErrorException ("shouldn't get here");
}
// one is null while the other isn't
if (Oper == Binary.Operator.Equality)
ig.Emit (OpCodes.Ldc_I4_0);
else
ig.Emit (OpCodes.Ldc_I4_1);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (both_have_value_label);
underlying.Emit (ec);
ig.MarkLabel (end_label);
}
void EmitComparision (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
if (left_unwrap != null) {
left_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
}
if (right_unwrap != null) {
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
}
underlying.Emit (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
ig.Emit (OpCodes.Ldc_I4_0);
ig.MarkLabel (end_label);
}
public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
{
Emit (ec);
ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
}
public override void Emit (EmitContext ec)
{
if (left_unwrap != null)
left_unwrap.Store (ec);
if (right_unwrap != null)
right_unwrap.Store (ec);
if (is_boolean) {
EmitBoolean (ec);
return;
} else if (is_equality) {
EmitEquality (ec);
return;
} else if (is_comparision) {
EmitComparision (ec);
return;
}
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
if (left_unwrap != null) {
left_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
}
if (right_unwrap != null) {
right_unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
}
underlying.Emit (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
null_value.Emit (ec);
ig.MarkLabel (end_label);
}
}
public class OperatorTrueOrFalse : Expression
{
public readonly bool IsTrue;
Expression expr;
Unwrap unwrap;
public OperatorTrueOrFalse (Expression expr, bool is_true, Location loc)
{
this.IsTrue = is_true;
this.expr = expr;
this.loc = loc;
}
public override Expression DoResolve (EmitContext ec)
{
unwrap = Unwrap.Create (expr, ec);
if (unwrap == null)
return null;
if (unwrap.Type != TypeManager.bool_type)
return null;
type = TypeManager.bool_type;
eclass = ExprClass.Value;
return this;
}
public override void Emit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
unwrap.Emit (ec);
if (!IsTrue) {
ig.Emit (OpCodes.Ldc_I4_0);
ig.Emit (OpCodes.Ceq);
}
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
ig.Emit (OpCodes.Ldc_I4_0);
ig.MarkLabel (end_label);
}
}
public class NullCoalescingOperator : Expression
{
Expression left, right;
Expression expr;
Unwrap unwrap;
public NullCoalescingOperator (Expression left, Expression right, Location loc)
{
this.left = left;
this.right = right;
this.loc = loc;
eclass = ExprClass.Value;
}
public override Expression DoResolve (EmitContext ec)
{
if (type != null)
return this;
left = left.Resolve (ec);
if (left == null)
return null;
right = right.Resolve (ec);
if (right == null)
return null;
Type ltype = left.Type, rtype = right.Type;
if (!TypeManager.IsNullableType (ltype) && ltype.IsValueType) {
Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
return null;
}
if (TypeManager.IsNullableType (ltype)) {
NullableInfo info = new NullableInfo (ltype);
unwrap = Unwrap.Create (left, ec);
if (unwrap == null)
return null;
expr = Convert.ImplicitConversion (ec, right, info.UnderlyingType, loc);
if (expr != null) {
left = unwrap;
type = expr.Type;
return this;
}
}
expr = Convert.ImplicitConversion (ec, right, ltype, loc);
if (expr != null) {
type = expr.Type;
return this;
}
Expression left_null = unwrap != null ? unwrap : left;
expr = Convert.ImplicitConversion (ec, left_null, rtype, loc);
if (expr != null) {
left = expr;
expr = right;
type = rtype;
return this;
}
Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
return null;
}
public override void Emit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
if (unwrap != null) {
unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
left.Emit (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
expr.Emit (ec);
ig.MarkLabel (end_label);
} else {
left.Emit (ec);
ig.Emit (OpCodes.Dup);
ig.Emit (OpCodes.Brtrue, end_label);
ig.MarkLabel (is_null_label);
ig.Emit (OpCodes.Pop);
expr.Emit (ec);
ig.MarkLabel (end_label);
}
}
}
public class LiftedUnaryMutator : ExpressionStatement
{
public readonly UnaryMutator.Mode Mode;
Expression expr, null_value;
UnaryMutator underlying;
Unwrap unwrap;
public LiftedUnaryMutator (UnaryMutator.Mode mode, Expression expr, Location loc)
{
this.expr = expr;
this.Mode = mode;
this.loc = loc;
eclass = ExprClass.Value;
}
public override Expression DoResolve (EmitContext ec)
{
expr = expr.Resolve (ec);
if (expr == null)
return null;
unwrap = Unwrap.Create (expr, ec);
if (unwrap == null)
return null;
underlying = (UnaryMutator) new UnaryMutator (Mode, unwrap, loc).Resolve (ec);
if (underlying == null)
return null;
null_value = new NullableLiteral (expr.Type, loc).Resolve (ec);
if (null_value == null)
return null;
type = expr.Type;
return this;
}
void DoEmit (EmitContext ec, bool is_expr)
{
ILGenerator ig = ec.ig;
Label is_null_label = ig.DefineLabel ();
Label end_label = ig.DefineLabel ();
unwrap.EmitCheck (ec);
ig.Emit (OpCodes.Brfalse, is_null_label);
if (is_expr)
underlying.Emit (ec);
else
underlying.EmitStatement (ec);
ig.Emit (OpCodes.Br, end_label);
ig.MarkLabel (is_null_label);
if (is_expr)
null_value.Emit (ec);
ig.MarkLabel (end_label);
}
public override void Emit (EmitContext ec)
{
DoEmit (ec, true);
}
public override void EmitStatement (EmitContext ec)
{
DoEmit (ec, false);
}
}
}
}