in System:
[mcs.git] / mcs / literal.cs
blobf371812c6268f0a5fba0704f4aed6a06d7d4a44b
1 //
2 // literal.cs: Literal representation for the IL tree.
3 //
4 // Author:
5 // Miguel de Icaza (miguel@ximian.com)
6 // Marek Safar (marek.safar@seznam.cz)
7 //
8 // Copyright 2001 Ximian, Inc.
9 //
11 // Notice that during parsing we create objects of type Literal, but the
12 // types are not loaded (thats why the Resolve method has to assign the
13 // type at that point).
15 // Literals differ from the constants in that we know we encountered them
16 // as a literal in the source code (and some extra rules apply there) and
17 // they have to be resolved (since during parsing we have not loaded the
18 // types yet) while constants are created only after types have been loaded
19 // and are fully resolved when born.
22 using System;
23 using System.Reflection;
24 using System.Reflection.Emit;
26 namespace Mono.CSharp {
29 // The null literal
31 // Note: C# specification null-literal is NullLiteral of NullType type
33 public class NullLiteral : NullConstant
36 // Default type of null is an object
38 public NullLiteral (Location loc)
39 : base (typeof (NullLiteral), loc)
43 public override Expression CreateExpressionTree (ResolveContext ec)
45 // Optimized version, also avoids referencing literal internal type
46 Arguments args = new Arguments (1);
47 args.Add (new Argument (this));
48 return CreateExpressionFactoryCall (ec, "Constant", args);
51 public override void Error_ValueCannotBeConverted (ResolveContext ec, Location loc, Type t, bool expl)
53 if (TypeManager.IsGenericParameter (t)) {
54 ec.Report.Error(403, loc,
55 "Cannot convert null to the type parameter `{0}' because it could be a value " +
56 "type. Consider using `default ({0})' instead", t.Name);
57 return;
60 if (TypeManager.IsValueType (t)) {
61 ec.Report.Error(37, loc, "Cannot convert null to `{0}' because it is a value type",
62 TypeManager.CSharpName(t));
63 return;
66 base.Error_ValueCannotBeConverted (ec, loc, t, expl);
69 public override Constant ConvertImplicitly (ResolveContext rc, Type targetType)
72 // Null literal is of object type
74 if (targetType == TypeManager.object_type)
75 return this;
77 return base.ConvertImplicitly (rc, targetType);
80 public override bool IsLiteral {
81 get { return true; }
84 public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
86 return System.Linq.Expressions.Expression.Constant (null);
91 // A null literal in a pointer context
93 class NullPointer : NullLiteral {
94 public NullPointer (Location loc):
95 base (loc)
97 type = TypeManager.object_type;
100 public override void Emit (EmitContext ec)
102 ILGenerator ig = ec.ig;
105 // Emits null pointer
107 ig.Emit (OpCodes.Ldc_I4_0);
108 ig.Emit (OpCodes.Conv_U);
112 public class BoolLiteral : BoolConstant {
113 public BoolLiteral (bool val, Location loc) : base (val, loc)
117 public override bool IsLiteral {
118 get { return true; }
122 public class CharLiteral : CharConstant {
123 public CharLiteral (char c, Location loc) : base (c, loc)
127 public override bool IsLiteral {
128 get { return true; }
132 public class IntLiteral : IntConstant {
133 public IntLiteral (int l, Location loc) : base (l, loc)
137 public override Constant ConvertImplicitly (ResolveContext rc, Type type)
140 // The 0 literal can be converted to an enum value
142 if (Value == 0 && TypeManager.IsEnumType (type)) {
143 Constant c = ConvertImplicitly (rc, TypeManager.GetEnumUnderlyingType (type));
144 if (c == null)
145 return null;
147 return new EnumConstant (c, type).Resolve (rc);
150 return base.ConvertImplicitly (rc, type);
153 public override bool IsLiteral {
154 get { return true; }
158 public class UIntLiteral : UIntConstant {
159 public UIntLiteral (uint l, Location loc) : base (l, loc)
163 public override bool IsLiteral {
164 get { return true; }
168 public class LongLiteral : LongConstant {
169 public LongLiteral (long l, Location loc) : base (l, loc)
173 public override bool IsLiteral {
174 get { return true; }
178 public class ULongLiteral : ULongConstant {
179 public ULongLiteral (ulong l, Location loc) : base (l, loc)
183 public override bool IsLiteral {
184 get { return true; }
188 public class FloatLiteral : FloatConstant {
190 public FloatLiteral (float f, Location loc) : base (f, loc)
194 public override bool IsLiteral {
195 get { return true; }
200 public class DoubleLiteral : DoubleConstant {
201 public DoubleLiteral (double d, Location loc) : base (d, loc)
205 public override void Error_ValueCannotBeConverted (ResolveContext ec, Location loc, Type target, bool expl)
207 if (target == TypeManager.float_type) {
208 Error_664 (ec, loc, "float", "f");
209 return;
212 if (target == TypeManager.decimal_type) {
213 Error_664 (ec, loc, "decimal", "m");
214 return;
217 base.Error_ValueCannotBeConverted (ec, loc, target, expl);
220 static void Error_664 (ResolveContext ec, Location loc, string type, string suffix)
222 ec.Report.Error (664, loc,
223 "Literal of type double cannot be implicitly converted to type `{0}'. Add suffix `{1}' to create a literal of this type",
224 type, suffix);
227 public override bool IsLiteral {
228 get { return true; }
233 public class DecimalLiteral : DecimalConstant {
234 public DecimalLiteral (decimal d, Location loc) : base (d, loc)
238 public override bool IsLiteral {
239 get { return true; }
243 public class StringLiteral : StringConstant {
244 public StringLiteral (string s, Location loc) : base (s, loc)
248 public override bool IsLiteral {
249 get { return true; }