//
// enum.cs: Enum handling.
//
// Author: Miguel de Icaza (miguel@gnu.org)
// Ravi Pratap (ravi@ximian.com)
//
// Licensed under the terms of the GNU GPL
//
// (C) 2001 Ximian, Inc (http://www.ximian.com)
//
using System;
using System.Collections;
using System.Reflection;
using System.Reflection.Emit;
namespace Mono.MonoBASIC {
///
/// Enumeration container
///
public class Enum : DeclSpace {
ArrayList ordered_enums;
public Expression BaseType;
public Attributes OptAttributes;
public Type UnderlyingType;
Hashtable member_to_location;
Hashtable member_to_attributes;
//
// This is for members that have been defined
//
Hashtable member_to_value;
//
// This is used to mark members we're currently defining
//
Hashtable in_transit;
ArrayList field_builders;
public const int AllowedModifiers =
Modifiers.NEW |
Modifiers.PUBLIC |
Modifiers.PROTECTED |
Modifiers.INTERNAL |
Modifiers.PRIVATE;
public Enum (TypeContainer parent, Expression type, int mod_flags, string name, Attributes attrs, Location l)
: base (parent, name, l)
{
this.BaseType = type;
ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
IsTopLevel ? Modifiers.INTERNAL : Modifiers.PUBLIC, l);
OptAttributes = attrs;
ordered_enums = new ArrayList ();
member_to_location = new Hashtable ();
member_to_value = new Hashtable ();
in_transit = new Hashtable ();
field_builders = new ArrayList ();
}
///
/// Adds @name to the enumeration space, with @expr
/// being its definition.
///
public AdditionResult AddEnumMember (string name, Expression expr, Location loc,
Attributes opt_attrs)
{
if (defined_names.Contains (name))
return AdditionResult.NameExists;
DefineName (name, expr);
ordered_enums.Add (name);
member_to_location.Add (name, loc);
if (member_to_attributes == null)
member_to_attributes = new Hashtable ();
member_to_attributes.Add (name, opt_attrs);
return AdditionResult.Success;
}
//
// This is used by corlib compilation: we map from our
// type to a type that is consumable by the DefineField
//
Type MapToInternalType (Type t)
{
if (t == TypeManager.int32_type)
return typeof (int);
if (t == TypeManager.int64_type)
return typeof (long);
if (t == TypeManager.uint32_type)
return typeof (uint);
if (t == TypeManager.uint64_type)
return typeof (ulong);
if (t == TypeManager.float_type)
return typeof (float);
if (t == TypeManager.double_type)
return typeof (double);
if (t == TypeManager.byte_type)
return typeof (byte);
if (t == TypeManager.sbyte_type)
return typeof (sbyte);
if (t == TypeManager.char_type)
return typeof (char);
if (t == TypeManager.short_type)
return typeof (short);
if (t == TypeManager.ushort_type)
return typeof (ushort);
throw new Exception ();
}
public override TypeBuilder DefineType ()
{
if (TypeBuilder != null)
return TypeBuilder;
TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel);
attr |= TypeAttributes.Class | TypeAttributes.Sealed;
UnderlyingType = ResolveType (BaseType, false, Location);
if (UnderlyingType != TypeManager.int32_type &&
UnderlyingType != TypeManager.uint32_type &&
UnderlyingType != TypeManager.int64_type &&
UnderlyingType != TypeManager.uint64_type &&
UnderlyingType != TypeManager.short_type &&
UnderlyingType != TypeManager.ushort_type &&
UnderlyingType != TypeManager.byte_type &&
UnderlyingType != TypeManager.sbyte_type) {
Report.Error (30650, Location,
"Type byte, sbyte, short, ushort, int, uint, " +
"long, or ulong expected (got: " +
TypeManager.MonoBASIC_Name (UnderlyingType) + ")");
return null;
}
if (IsTopLevel) {
ModuleBuilder builder = CodeGen.ModuleBuilder;
TypeBuilder = builder.DefineType (Name, attr, TypeManager.enum_type);
} else {
TypeBuilder builder = Parent.TypeBuilder;
TypeBuilder = builder.DefineNestedType (
Basename, attr, TypeManager.enum_type);
}
//
// Call MapToInternalType for corlib
//
TypeBuilder.DefineField ("value__", UnderlyingType,
FieldAttributes.Public | FieldAttributes.SpecialName
| FieldAttributes.RTSpecialName);
TypeManager.AddEnumType (Name, TypeBuilder, this);
return TypeBuilder;
}
bool IsValidEnumConstant (Expression e)
{
if (!(e is Constant))
return false;
if (e is IntConstant || e is UIntConstant || e is LongConstant ||
e is ByteConstant || e is SByteConstant || e is ShortConstant ||
e is UShortConstant || e is ULongConstant || e is EnumConstant)
return true;
else
return false;
}
object GetNextDefaultValue (object default_value)
{
if (UnderlyingType == TypeManager.int32_type) {
int i = (int) default_value;
if (i < System.Int32.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.uint32_type) {
uint i = (uint) default_value;
if (i < System.UInt32.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.int64_type) {
long i = (long) default_value;
if (i < System.Int64.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.uint64_type) {
ulong i = (ulong) default_value;
if (i < System.UInt64.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.short_type) {
short i = (short) default_value;
if (i < System.Int16.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.ushort_type) {
ushort i = (ushort) default_value;
if (i < System.UInt16.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.byte_type) {
byte i = (byte) default_value;
if (i < System.Byte.MaxValue)
return ++i;
else
return null;
} else if (UnderlyingType == TypeManager.sbyte_type) {
sbyte i = (sbyte) default_value;
if (i < System.SByte.MaxValue)
return ++i;
else
return null;
}
return null;
}
void Error_ConstantValueCannotBeConverted (object val, Location loc)
{
if (val is Constant)
Report.Error (30439, loc, "Constant value '" + ((Constant) val).AsString () +
"' cannot be converted" +
" to a " + TypeManager.MonoBASIC_Name (UnderlyingType));
else
Report.Error (30439, loc, "Constant value '" + val +
"' cannot be converted" +
" to a " + TypeManager.MonoBASIC_Name (UnderlyingType));
return;
}
///
/// Determines if a standard implicit conversion exists from
/// expr_type to target_type
///
public static bool ImplicitConversionExists (Type expr_type, Type target_type)
{
expr_type = TypeManager.TypeToCoreType (expr_type);
if (expr_type == TypeManager.void_type)
return false;
if (expr_type == target_type)
return true;
// First numeric conversions
if (expr_type == TypeManager.sbyte_type){
//
// From sbyte to short, int, long, float, double.
//
if ((target_type == TypeManager.int32_type) ||
(target_type == TypeManager.int64_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.short_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.byte_type){
//
// From byte to short, ushort, int, uint, long, ulong, float, double
//
if ((target_type == TypeManager.short_type) ||
(target_type == TypeManager.ushort_type) ||
(target_type == TypeManager.int32_type) ||
(target_type == TypeManager.uint32_type) ||
(target_type == TypeManager.uint64_type) ||
(target_type == TypeManager.int64_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.short_type){
//
// From short to int, long, float, double
//
if ((target_type == TypeManager.int32_type) ||
(target_type == TypeManager.int64_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.ushort_type){
//
// From ushort to int, uint, long, ulong, float, double
//
if ((target_type == TypeManager.uint32_type) ||
(target_type == TypeManager.uint64_type) ||
(target_type == TypeManager.int32_type) ||
(target_type == TypeManager.int64_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.int32_type){
//
// From int to long, float, double
//
if ((target_type == TypeManager.int64_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.uint32_type){
//
// From uint to long, ulong, float, double
//
if ((target_type == TypeManager.int64_type) ||
(target_type == TypeManager.uint64_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if ((expr_type == TypeManager.uint64_type) ||
(expr_type == TypeManager.int64_type)) {
//
// From long/ulong to float, double
//
if ((target_type == TypeManager.double_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.char_type){
//
// From char to ushort, int, uint, long, ulong, float, double
//
if ((target_type == TypeManager.ushort_type) ||
(target_type == TypeManager.int32_type) ||
(target_type == TypeManager.uint32_type) ||
(target_type == TypeManager.uint64_type) ||
(target_type == TypeManager.int64_type) ||
(target_type == TypeManager.float_type) ||
(target_type == TypeManager.double_type) ||
(target_type == TypeManager.decimal_type))
return true;
} else if (expr_type == TypeManager.float_type){
//
// float to double
//
if (target_type == TypeManager.double_type)
return true;
}
return false;
}
///
/// This is used to lookup the value of an enum member. If the member is undefined,
/// it attempts to define it and return its value
///
public object LookupEnumValue (EmitContext ec, string name, Location loc)
{
object default_value = null;
Constant c = null;
TypeContainer parent = ec.TypeContainer;
// first check whether the requested name is there
// in the member list of enum
if (!(ordered_enums.Contains(name)))
Report.Error (30456, loc,
name + " is not found in member list of enum " + this.Name);
default_value = member_to_value [name];
if (default_value != null)
return default_value;
//
// This may happen if we're calling a method in System.Enum, for instance
// Enum.IsDefined().
//
if (!defined_names.Contains (name))
return null;
if (in_transit.Contains (name)) {
Report.Error (110, loc, "The evaluation of the constant value for `" +
Name + "." + name + "' involves a circular definition.");
return null;
}
//
// So if the above doesn't happen, we have a member that is undefined
// We now proceed to define it
//
Expression val = this [name];
int idx = ordered_enums.IndexOf (name);
if (val == null) {
//int idx = ordered_enums.IndexOf (name);
if (idx == 0)
default_value = 0;
else {
for (int i = 0; i < idx; ++i) {
string n = (string) ordered_enums [i];
Location m_loc = (Mono.MonoBASIC.Location)
member_to_location [n];
in_transit.Add (name, true);
default_value = LookupEnumValue (ec, n, m_loc);
in_transit.Remove (name);
if (default_value == null)
return null;
}
default_value = GetNextDefaultValue (default_value);
}
} else {
// check for any cyclic dependency
if (val is Mono.MonoBASIC.SimpleName) {
int var_idx = ordered_enums.IndexOf (val.ToString());
if (idx <= var_idx)
Report.Error(30500, loc,
"The evaluation of the constant value for `" +
Name + "." + name + "' involves a circular definition");
else
default_value = member_to_value [val.ToString()];
}
else {
bool old = ec.InEnumContext;
ec.InEnumContext = true;
in_transit.Add (name, true);
val = val.Resolve (ec);
in_transit.Remove (name);
ec.InEnumContext = old;
if (val == null)
return null;
if (!IsValidEnumConstant (val)) {
Report.Error (
30650, loc,
"Type byte, sbyte, short, ushort, int, uint, long, or " +
"ulong expected (have: " + val + ")");
return null;
}
c = (Constant) val;
default_value = c.GetValue ();
}
if (default_value == null) {
Error_ConstantValueCannotBeConverted (c, loc);
return null;
}
if (val is EnumConstant) {
Type etype = TypeManager.EnumToUnderlying (c.Type);
if ( (!ImplicitConversionExists (etype, UnderlyingType)) &&
(!Expression.RuntimeConversionExists (ec, val, UnderlyingType)) ){
Expression.Error_CannotConvertImplicit (
loc, c.Type, UnderlyingType);
return null;
}
}
}
/*FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
| FieldAttributes.Literal;
*/
FieldBuilder fb = TypeBuilder.DefineField (name, UnderlyingType,
/*attr*/ Modifiers.FieldAttr (ModFlags));
try {
default_value = TypeManager.ChangeType (default_value, UnderlyingType);
} catch {
Error_ConstantValueCannotBeConverted (c, loc);
return null;
}
fb.SetConstant (default_value);
field_builders.Add (fb);
member_to_value [name] = default_value;
if (!TypeManager.RegisterFieldValue (fb, default_value))
return null;
//
// Now apply attributes
//
Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
return default_value;
}
public override bool DefineMembers (TypeContainer parent)
{
return true;
}
public override bool Define (TypeContainer parent)
{
//
// If there was an error during DefineEnum, return
//
if (TypeBuilder == null)
return false;
EmitContext ec = new EmitContext (parent, this, Location, null,
UnderlyingType, ModFlags, false);
object default_value = 0;
/*FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
| FieldAttributes.Literal;
*/
foreach (string name in ordered_enums) {
//
// Have we already been defined, thanks to some cross-referencing ?
//
if (member_to_value.Contains (name))
continue;
Location loc = (Mono.MonoBASIC.Location) member_to_location [name];
if (this [name] != null) {
default_value = LookupEnumValue (ec, name, loc);
if (default_value == null)
return true;
} else {
FieldBuilder fb = TypeBuilder.DefineField (
name, UnderlyingType,
/*attr*/ Modifiers.FieldAttr (ModFlags));
if (default_value == null) {
Report.Error (30439, loc, "Enumerator value for '" + name + "' is too large to " +
"fit in its type");
return false;
}
try {
default_value = TypeManager.ChangeType (default_value, UnderlyingType);
} catch {
Error_ConstantValueCannotBeConverted (default_value, loc);
return false;
}
fb.SetConstant (default_value);
field_builders.Add (fb);
member_to_value [name] = default_value;
if (!TypeManager.RegisterFieldValue (fb, default_value))
return false;
//
// Apply attributes on the enum member
//
Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
}
default_value = GetNextDefaultValue (default_value);
}
Attribute.ApplyAttributes (ec, TypeBuilder, this, OptAttributes, Location);
return true;
}
//
// IMemberFinder
//
public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
MemberFilter filter, object criteria)
{
ArrayList members = new ArrayList ();
if ((mt & MemberTypes.Field) != 0) {
foreach (FieldBuilder fb in field_builders)
if (filter (fb, criteria) == true)
members.Add (fb);
}
return new MemberList (members);
}
public override MemberCache MemberCache {
get {
return null;
}
}
public ArrayList ValueNames {
get {
return ordered_enums;
}
}
// indexer
public Expression this [string name] {
get {
return (Expression) defined_names [name];
}
}
}
}