// Allows SimpleNames to be returned.
// This is used by MemberAccess to construct long names that can not be
// partially resolved (namespace-qualified names for example).
- SimpleName = 8
+ SimpleName = 8,
+
+ // Mask of all the expression class flags.
+ MaskExprClass = 15,
+
+ // Disable control flow analysis while resolving the expression.
+ // This is used when resolving the instance expression of a field expression.
+ DisableFlowAnalysis = 16
}
//
void AddressOf (EmitContext ec, AddressOp mode);
}
+ /// <summary>
+ /// This interface is implemented by variables
+ /// </summary>
+ public interface IVariable {
+ /// <summary>
+ /// Checks whether the variable has already been assigned at
+ /// the current position of the method's control flow and
+ /// reports an appropriate error message if not.
+ ///
+ /// If the variable is a struct, then this call checks whether
+ /// all of its fields (including all private ones) have been
+ /// assigned.
+ /// </summary>
+ bool IsAssigned (EmitContext ec, Location loc);
+
+ /// <summary>
+ /// Checks whether field `name' in this struct has been assigned.
+ /// </summary>
+ bool IsFieldAssigned (EmitContext ec, string name, Location loc);
+
+ /// <summary>
+ /// Tells the flow analysis code that the variable has already
+ /// been assigned at the current code position.
+ ///
+ /// If the variable is a struct, this call marks all its fields
+ /// (including private fields) as being assigned.
+ /// </summary>
+ void SetAssigned (EmitContext ec);
+
+ /// <summary>
+ /// Tells the flow analysis code that field `name' in this struct
+ /// has already been assigned atthe current code position.
+ /// </summary>
+ void SetFieldAssigned (EmitContext ec, string name);
+ }
+
/// <summary>
/// This interface denotes an expression which evaluates to a member
/// of a struct or a class.
}
}
+ /// <summary>
+ /// Expression which resolves to a type.
+ /// </summary>
+ public interface ITypeExpression
+ {
+ /// <summary>
+ /// Resolve the expression, but only lookup types.
+ /// </summary>
+ Expression DoResolveType (EmitContext ec);
+ }
+
/// <remarks>
/// Base class for expressions
/// </remarks>
/// </remarks>
public Expression Resolve (EmitContext ec, ResolveFlags flags)
{
- Expression e;
+ // Are we doing a types-only search ?
+ if ((flags & ResolveFlags.MaskExprClass) == ResolveFlags.Type) {
+ ITypeExpression type_expr = this as ITypeExpression;
+
+ if (type_expr == null)
+ return null;
+
+ return type_expr.DoResolveType (ec);
+ }
+
+ bool old_do_flow_analysis = ec.DoFlowAnalysis;
+ if ((flags & ResolveFlags.DisableFlowAnalysis) != 0)
+ ec.DoFlowAnalysis = false;
+ Expression e;
if (this is SimpleName)
e = ((SimpleName) this).DoResolveAllowStatic (ec);
else
e = DoResolve (ec);
+ ec.DoFlowAnalysis = old_do_flow_analysis;
+
if (e == null)
return null;
public static Expression MemberLookup (EmitContext ec, Type t, string name,
MemberTypes mt, BindingFlags bf, Location loc)
{
- MemberInfo [] mi = TypeManager.MemberLookup (ec.ContainerType, t, mt, bf, name);
+ return MemberLookup (ec, ec.ContainerType, t, name, mt, bf, loc);
+ }
+
+ public static Expression MemberLookup (EmitContext ec, Type invocation_type, Type t,
+ string name, MemberTypes mt, BindingFlags bf,
+ Location loc)
+ {
+ MemberInfo [] mi = TypeManager.MemberLookup (invocation_type, t, mt, bf, name);
if (mi == null)
return null;
public static Expression MemberLookup (EmitContext ec, Type t, string name, Location loc)
{
- return MemberLookup (ec, t, name, AllMemberTypes, AllBindingFlags, loc);
+ return MemberLookup (ec, ec.ContainerType, t, name,
+ AllMemberTypes, AllBindingFlags, loc);
}
public static Expression MethodLookup (EmitContext ec, Type t, string name, Location loc)
{
- return MemberLookup (ec, t, name, MemberTypes.Method, AllBindingFlags, loc);
+ return MemberLookup (ec, ec.ContainerType, t, name,
+ MemberTypes.Method, AllBindingFlags, loc);
}
/// <summary>
int errors = Report.Errors;
- e = MemberLookup (ec, t, name, mt, bf, loc);
+ e = MemberLookup (ec, ec.ContainerType, t, name, mt, bf, loc);
if (e != null)
return e;
/// The downside of this is that we might be hitting `LookupType' too many
/// times with this scheme.
/// </remarks>
- public class SimpleName : Expression {
+ public class SimpleName : Expression, ITypeExpression {
public readonly string Name;
public SimpleName (string name, Location l)
return SimpleNameResolve (ec, null, true);
}
+ public Expression DoResolveType (EmitContext ec)
+ {
+ //
+ // Stage 3: Lookup symbol in the various namespaces.
+ //
+ DeclSpace ds = ec.DeclSpace;
+ Type t;
+ string alias_value;
+
+ if ((t = RootContext.LookupType (ds, Name, true, loc)) != null)
+ return new TypeExpr (t, loc);
+
+ //
+ // Stage 2 part b: Lookup up if we are an alias to a type
+ // or a namespace.
+ //
+ // Since we are cheating: we only do the Alias lookup for
+ // namespaces if the name does not include any dots in it
+ //
+
+ alias_value = ec.DeclSpace.LookupAlias (Name);
+
+ if (Name.IndexOf ('.') == -1 && alias_value != null) {
+ if ((t = RootContext.LookupType (ds, alias_value, true, loc)) != null)
+ return new TypeExpr (t, loc);
+
+ // we have alias value, but it isn't Type, so try if it's namespace
+ return new SimpleName (alias_value, loc);
+ }
+
+ if (ec.ResolvingTypeTree){
+ Type dt = ec.DeclSpace.FindType (Name);
+ if (dt != null)
+ return new TypeExpr (dt, loc);
+ }
+
+ // No match, maybe our parent can compose us
+ // into something meaningful.
+ return this;
+ }
+
/// <remarks>
/// 7.5.2: Simple Names.
///
//
// Stage 1: Performed by the parser (binding to locals or parameters).
//
- if (!ec.OnlyLookupTypes){
- Block current_block = ec.CurrentBlock;
- if (current_block != null && current_block.IsVariableDefined (Name)){
- LocalVariableReference var;
-
- var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
+ Block current_block = ec.CurrentBlock;
+ if (current_block != null && current_block.IsVariableDefined (Name)){
+ LocalVariableReference var;
- if (right_side != null)
- return var.ResolveLValue (ec, right_side);
- else
- return var.Resolve (ec);
- }
+ var = new LocalVariableReference (ec.CurrentBlock, Name, loc);
- if (current_block != null){
- int idx = -1;
- Parameter par = null;
- Parameters pars = current_block.Parameters;
- if (pars != null)
- par = pars.GetParameterByName (Name, out idx);
+ if (right_side != null)
+ return var.ResolveLValue (ec, right_side);
+ else
+ return var.Resolve (ec);
+ }
- if (par != null) {
- ParameterReference param;
+ if (current_block != null){
+ int idx = -1;
+ Parameter par = null;
+ Parameters pars = current_block.Parameters;
+ if (pars != null)
+ par = pars.GetParameterByName (Name, out idx);
+
+ if (par != null) {
+ ParameterReference param;
- param = new ParameterReference (pars, idx, Name, loc);
+ param = new ParameterReference (pars, idx, Name, loc);
- if (right_side != null)
- return param.ResolveLValue (ec, right_side);
- else
- return param.Resolve (ec);
- }
+ if (right_side != null)
+ return param.ResolveLValue (ec, right_side);
+ else
+ return param.Resolve (ec);
}
+ }
- //
- // Stage 2: Lookup members
- //
-
- //
- // For enums, the TypeBuilder is not ec.DeclSpace.TypeBuilder
- // Hence we have two different cases
- //
+ //
+ // Stage 2: Lookup members
+ //
- DeclSpace lookup_ds = ec.DeclSpace;
- do {
- if (lookup_ds.TypeBuilder == null)
- break;
+ //
+ // For enums, the TypeBuilder is not ec.DeclSpace.TypeBuilder
+ // Hence we have two different cases
+ //
- e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
- if (e != null)
- break;
+ DeclSpace lookup_ds = ec.DeclSpace;
+ do {
+ if (lookup_ds.TypeBuilder == null)
+ break;
- //
- // Classes/structs keep looking, enums break
- //
- if (lookup_ds is TypeContainer)
- lookup_ds = ((TypeContainer) lookup_ds).Parent;
- else
- break;
- } while (lookup_ds != null);
-
- if (e == null && ec.ContainerType != null)
- e = MemberLookup (ec, ec.ContainerType, Name, loc);
- }
+ e = MemberLookup (ec, lookup_ds.TypeBuilder, Name, loc);
+ if (e != null)
+ break;
- // Continuation of stage 2
- if (e == null){
//
- // Stage 3: Lookup symbol in the various namespaces.
+ // Classes/structs keep looking, enums break
//
- DeclSpace ds = ec.DeclSpace;
- Type t;
- string alias_value;
-
- if ((t = RootContext.LookupType (ds, Name, true, loc)) != null)
- return new TypeExpr (t, loc);
-
- //
- // Stage 2 part b: Lookup up if we are an alias to a type
- // or a namespace.
- //
- // Since we are cheating: we only do the Alias lookup for
- // namespaces if the name does not include any dots in it
- //
-
- alias_value = ec.DeclSpace.LookupAlias (Name);
-
- if (Name.IndexOf ('.') == -1 && alias_value != null) {
- if ((t = RootContext.LookupType (ds, alias_value, true, loc))
- != null)
- return new TypeExpr (t, loc);
-
- // we have alias value, but it isn't Type, so try if it's namespace
- return new SimpleName (alias_value, loc);
- }
-
- if (ec.ResolvingTypeTree){
- Type dt = ec.DeclSpace.FindType (Name);
- if (dt != null)
- return new TypeExpr (dt, loc);
- }
+ if (lookup_ds is TypeContainer)
+ lookup_ds = ((TypeContainer) lookup_ds).Parent;
+ else
+ break;
+ } while (lookup_ds != null);
- // No match, maybe our parent can compose us
- // into something meaningful.
- return this;
- }
+ if (e == null && ec.ContainerType != null)
+ e = MemberLookup (ec, ec.ContainerType, Name, loc);
+
+ if (e == null)
+ return DoResolveType (ec);
- //
- // Stage 2 continues here.
- //
if (e is TypeExpr)
return e;
- if (ec.OnlyLookupTypes)
- return null;
+ if (e is IMemberExpr) {
+ e = MemberAccess.ResolveMemberAccess (ec, e, null, loc, this);
+ if (e == null)
+ return null;
- if (e is IMemberExpr)
- return MemberAccess.ResolveMemberAccess (ec, e, null, loc, this);
+ IMemberExpr me = e as IMemberExpr;
+ if (me == null)
+ return e;
+
+ // This fails if ResolveMemberAccess() was unable to decide whether
+ // it's a field or a type of the same name.
+ if (!me.IsStatic && (me.InstanceExpression == null))
+ return e;
+
+ if (right_side != null)
+ e = e.DoResolveLValue (ec, right_side);
+ else
+ e = e.DoResolve (ec);
+
+ return e;
+ }
if (ec.IsStatic || ec.IsFieldInitializer){
if (allow_static)
/// <summary>
/// Fully resolved expression that evaluates to a type
/// </summary>
- public class TypeExpr : Expression {
+ public class TypeExpr : Expression, ITypeExpression {
public TypeExpr (Type t, Location l)
{
Type = t;
loc = l;
}
+ public virtual Expression DoResolveType (EmitContext ec)
+ {
+ return this;
+ }
+
override public Expression DoResolve (EmitContext ec)
{
return this;
/// <summary>
/// Used to create types from a fully qualified name. These are just used
- /// by the parser to setup the core types. A TypeExpression is always
+ /// by the parser to setup the core types. A TypeLookupExpression is always
/// classified as a type.
/// </summary>
- public class TypeExpression : TypeExpr {
+ public class TypeLookupExpression : TypeExpr {
string name;
- public TypeExpression (string name) : base (null, Location.Null)
+ public TypeLookupExpression (string name) : base (null, Location.Null)
{
this.name = name;
}
- public override Expression DoResolve (EmitContext ec)
+ public override Expression DoResolveType (EmitContext ec)
{
if (type == null)
type = RootContext.LookupType (ec.DeclSpace, name, false, Location.Null);
return this;
}
+ public override Expression DoResolve (EmitContext ec)
+ {
+ return DoResolveType (ec);
+ }
+
public override void Emit (EmitContext ec)
{
- throw new Exception ("Should never be called");
+ throw new Exception ("Should never be called");
}
public override string ToString ()
"Of the FieldExpr to set this\n");
}
- instance_expr = instance_expr.Resolve (ec);
+ // Resolve the field's instance expression while flow analysis is turned
+ // off: when accessing a field "a.b", we must check whether the field
+ // "a.b" is initialized, not whether the whole struct "a" is initialized.
+ instance_expr = instance_expr.Resolve (ec, ResolveFlags.VariableOrValue |
+ ResolveFlags.DisableFlowAnalysis);
if (instance_expr == null)
return null;
}
+ // If the instance expression is a local variable or parameter.
+ IVariable var = instance_expr as IVariable;
+ if ((var != null) && !var.IsFieldAssigned (ec, FieldInfo.Name, loc))
+ return null;
+
return this;
}
override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
{
+ IVariable var = instance_expr as IVariable;
+ if (var != null)
+ var.SetFieldAssigned (ec, FieldInfo.Name);
+
Expression e = DoResolve (ec);
if (e == null)
{
ILGenerator ig = ec.ig;
bool is_volatile = false;
-
+
if (FieldInfo is FieldBuilder){
FieldBase f = TypeManager.GetField (FieldInfo);
return null;
}
- type = PropertyInfo.PropertyType;
+ return this;
+ }
+
+ override public Expression DoResolveLValue (EmitContext ec, Expression right_side)
+ {
+ if (!PropertyInfo.CanWrite){
+ Report.Error (154, loc,
+ "The property `" + PropertyInfo.Name +
+ "' can not be used in " +
+ "this context because it lacks a set accessor");
+ return null;
+ }
return this;
}
projects / mono.git / blobdiff