//
// namespace.cs: Tracks namespaces
//
// Author:
// Miguel de Icaza (miguel@ximian.com)
//
// (C) 2001 Ximian, Inc.
//
using System;
using System.Collections;
namespace Mono.CSharp {
///
/// Keeps track of the namespaces defined in the C# code.
///
/// This is an Expression to allow it to be referenced in the
/// compiler parse/intermediate tree during name resolution.
///
public class Namespace : FullNamedExpression, IAlias {
static ArrayList all_namespaces = new ArrayList ();
static Hashtable namespaces_map = new Hashtable ();
Namespace parent;
string fullname;
ArrayList entries;
Hashtable namespaces;
Hashtable defined_names;
///
/// Constructor Takes the current namespace and the
/// name. This is bootstrapped with parent == null
/// and name = ""
///
public Namespace (Namespace parent, string name)
{
// Expression members.
this.eclass = ExprClass.Namespace;
this.Type = null;
this.loc = Location.Null;
this.parent = parent;
string pname = parent != null ? parent.Name : "";
if (pname == "")
fullname = name;
else
fullname = parent.Name + "." + name;
entries = new ArrayList ();
namespaces = new Hashtable ();
defined_names = new Hashtable ();
all_namespaces.Add (this);
if (namespaces_map.Contains (fullname))
return;
namespaces_map [fullname] = true;
}
public override Expression DoResolve (EmitContext ec)
{
return this;
}
public override void Emit (EmitContext ec)
{
throw new InternalErrorException ("Expression tree referenced namespace " + fullname + " during Emit ()");
}
public static bool IsNamespace (string name)
{
return namespaces_map [name] != null;
}
public static Namespace Root = new Namespace (null, "");
public Namespace GetNamespace (string name, bool create)
{
int pos = name.IndexOf ('.');
Namespace ns;
string first;
if (pos >= 0)
first = name.Substring (0, pos);
else
first = name;
ns = (Namespace) namespaces [first];
if (ns == null) {
if (!create)
return null;
ns = new Namespace (this, first);
namespaces.Add (first, ns);
}
if (pos >= 0)
ns = ns.GetNamespace (name.Substring (pos + 1), create);
return ns;
}
public static Namespace LookupNamespace (string name, bool create)
{
return Root.GetNamespace (name, create);
}
public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
{
IAlias o = (IAlias) defined_names [name];
Type t;
DeclSpace tdecl = o as DeclSpace;
if (tdecl != null) {
t = tdecl.DefineType ();
if (t == null)
return null;
if ((ds == null) || ds.CheckAccessLevel (t))
return new TypeExpression (t, Location.Null);
}
Namespace ns = GetNamespace (name, false);
if (ns != null)
return ns;
t = TypeManager.LookupType (DeclSpace.MakeFQN (fullname, name));
if ((t == null) || ((ds != null) && !ds.CheckAccessLevel (t)))
return null;
return new TypeExpression (t, Location.Null);
}
public void AddNamespaceEntry (NamespaceEntry entry)
{
entries.Add (entry);
}
public void DefineName (string name, IAlias o)
{
defined_names.Add (name, o);
}
static public ArrayList UserDefinedNamespaces {
get {
return all_namespaces;
}
}
///
/// The qualified name of the current namespace
///
public string Name {
get {
return fullname;
}
}
public override string FullName {
get {
return fullname;
}
}
///
/// The parent of this namespace, used by the parser to "Pop"
/// the current namespace declaration
///
public Namespace Parent {
get {
return parent;
}
}
public static void DefineNamespaces (SymbolWriter symwriter)
{
foreach (Namespace ns in all_namespaces) {
foreach (NamespaceEntry entry in ns.entries)
entry.DefineNamespace (symwriter);
}
}
///
/// Used to validate that all the using clauses are correct
/// after we are finished parsing all the files.
///
public static void VerifyUsing ()
{
foreach (Namespace ns in all_namespaces) {
foreach (NamespaceEntry entry in ns.entries)
entry.VerifyUsing ();
}
}
public override string ToString ()
{
if (this == Root)
return "Namespace ()";
else
return String.Format ("Namespace ({0})", Name);
}
bool IAlias.IsType {
get { return false; }
}
TypeExpr IAlias.ResolveAsType (EmitContext ec)
{
throw new InvalidOperationException ();
}
}
public class NamespaceEntry
{
Namespace ns;
NamespaceEntry parent, implicit_parent;
SourceFile file;
int symfile_id;
Hashtable aliases;
ArrayList using_clauses;
public bool DeclarationFound = false;
//
// This class holds the location where a using definition is
// done, and whether it has been used by the program or not.
//
// We use this to flag using clauses for namespaces that do not
// exist.
//
public class UsingEntry {
public Expression Name;
public readonly NamespaceEntry NamespaceEntry;
public readonly Location Location;
public UsingEntry (NamespaceEntry entry, Expression name, Location loc)
{
Name = name;
NamespaceEntry = entry;
Location = loc;
}
internal FullNamedExpression resolved;
public Namespace Resolve ()
{
if (resolved != null)
return resolved as Namespace;
DeclSpace root = RootContext.Tree.Types;
root.NamespaceEntry = NamespaceEntry;
resolved = Name.ResolveAsTypeStep (root.EmitContext);
root.NamespaceEntry = null;
return resolved as Namespace;
}
}
public class AliasEntry {
public readonly string Name;
public readonly Expression Alias;
public readonly NamespaceEntry NamespaceEntry;
public readonly Location Location;
public AliasEntry (NamespaceEntry entry, string name, Expression alias, Location loc)
{
Name = name;
Alias = alias;
NamespaceEntry = entry;
Location = loc;
}
FullNamedExpression resolved;
public FullNamedExpression Resolve ()
{
if (resolved != null)
return resolved;
DeclSpace root = RootContext.Tree.Types;
root.NamespaceEntry = NamespaceEntry;
resolved = Alias.ResolveAsTypeStep (root.EmitContext);
root.NamespaceEntry = null;
return resolved;
}
}
public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
{
this.parent = parent;
this.file = file;
this.IsImplicit = false;
this.ID = ++next_id;
if (parent != null)
ns = parent.NS.GetNamespace (name, true);
else if (name != null)
ns = Namespace.LookupNamespace (name, true);
else
ns = Namespace.Root;
ns.AddNamespaceEntry (this);
this.FullName = ns.Name;
}
private NamespaceEntry (NamespaceEntry parent, SourceFile file, Namespace ns)
{
this.parent = parent;
this.file = file;
this.IsImplicit = true;
this.ID = ++next_id;
this.ns = ns;
this.FullName = ns.Name;
}
//
// According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
// resolved as if the immediately containing namespace body has no using-directives.
//
// Section 16.3.2 says that the same rule is applied when resolving the namespace-name
// in the using-namespace-directive.
//
// To implement these rules, the expressions in the using directives are resolved using
// the "doppelganger" (ghostly bodiless duplicate).
//
NamespaceEntry doppelganger;
NamespaceEntry Doppelganger {
get {
if (!IsImplicit && doppelganger == null)
doppelganger = new NamespaceEntry (ImplicitParent, file, ns);
return doppelganger;
}
}
static int next_id = 0;
public readonly string FullName;
public readonly int ID;
public readonly bool IsImplicit;
public Namespace NS {
get {
return ns;
}
}
public NamespaceEntry Parent {
get {
return parent;
}
}
public NamespaceEntry ImplicitParent {
get {
if (parent == null)
return null;
if (implicit_parent == null) {
implicit_parent = (parent.NS == ns.Parent)
? parent
: new NamespaceEntry (parent, file, ns.Parent);
}
return implicit_parent;
}
}
public void DefineName (string name, IAlias o)
{
ns.DefineName (name, o);
}
///
/// Records a new namespace for resolving name references
///
public void Using (Expression ns, Location loc)
{
string name = ns.ToString ();
if (DeclarationFound){
Report.Error (1529, loc, "A using clause must precede all other namespace elements");
return;
}
if (name == FullName)
return;
if (using_clauses == null)
using_clauses = new ArrayList ();
foreach (UsingEntry old_entry in using_clauses) {
if (old_entry.Name.ToString () == name) {
if (RootContext.WarningLevel >= 3)
Report.Warning (105, loc, "The using directive for '{0}' appeared previously in this namespace", name);
return;
}
}
UsingEntry ue = new UsingEntry (Doppelganger, ns, loc);
using_clauses.Add (ue);
}
public void UsingAlias (string name, Expression alias, Location loc)
{
if (DeclarationFound){
Report.Error (1529, loc, "A using clause must precede all other namespace elements");
return;
}
if (aliases == null)
aliases = new Hashtable ();
if (aliases.Contains (name)){
Report.Error (1537, loc, "The using alias `" + name +
"' appeared previously in this namespace");
return;
}
aliases [name] = new AliasEntry (Doppelganger, name, alias, loc);
}
public FullNamedExpression LookupAlias (string alias)
{
AliasEntry entry = null;
if (aliases != null)
entry = (AliasEntry) aliases [alias];
return entry == null ? null : entry.Resolve ();
}
public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc)
{
FullNamedExpression resolved = null;
string rest = null;
// If name is of the form `N.I', first lookup `N', then search a member `I' in it.
int pos = name.IndexOf ('.');
if (pos >= 0) {
rest = name.Substring (pos + 1);
name = name.Substring (0, pos);
}
for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
if ((resolved = curr_ns.Lookup (ds, name, loc)) != null)
break;
}
if (resolved == null || rest == null)
return resolved;
Namespace ns = resolved as Namespace;
if (ns != null)
return ns.Lookup (ds, rest, loc);
Type nested = TypeManager.LookupType (resolved.FullName + "." + rest);
if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
return null;
return new TypeExpression (nested, Location.Null);
}
private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
{
// Precondition: Only simple names (no dots) will be looked up with this function.
//
// Check whether it's in the namespace.
//
FullNamedExpression o = NS.Lookup (ds, name, loc);
if (o != null)
return o;
if (IsImplicit)
return null;
//
// Check aliases.
//
o = LookupAlias (name);
if (o != null)
return o;
//
// Check using entries.
//
FullNamedExpression t = null, match = null;
foreach (Namespace using_ns in GetUsingTable ()) {
match = using_ns.Lookup (ds, name, loc);
if ((match != null) && (match is TypeExpr)) {
if (t != null) {
DeclSpace.Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
return null;
} else {
t = match;
}
}
}
return t;
}
// Our cached computation.
Namespace [] namespace_using_table;
public Namespace[] GetUsingTable ()
{
if (namespace_using_table != null)
return namespace_using_table;
if (using_clauses == null) {
namespace_using_table = new Namespace [0];
return namespace_using_table;
}
ArrayList list = new ArrayList (using_clauses.Count);
foreach (UsingEntry ue in using_clauses) {
Namespace using_ns = ue.Resolve ();
if (using_ns == null)
continue;
list.Add (using_ns);
}
namespace_using_table = new Namespace [list.Count];
list.CopyTo (namespace_using_table, 0);
return namespace_using_table;
}
public void DefineNamespace (SymbolWriter symwriter)
{
if (symfile_id != 0)
return;
if (parent != null)
parent.DefineNamespace (symwriter);
string[] using_list;
if (using_clauses != null) {
using_list = new string [using_clauses.Count];
for (int i = 0; i < using_clauses.Count; i++)
using_list [i] = ((UsingEntry) using_clauses [i]).Name.ToString ();
} else {
using_list = new string [0];
}
int parent_id = parent != null ? parent.symfile_id : 0;
if (file.SourceFileEntry == null)
return;
symfile_id = symwriter.DefineNamespace (
ns.Name, file.SourceFileEntry, using_list, parent_id);
}
public int SymbolFileID {
get {
return symfile_id;
}
}
static void MsgtryRef (string s)
{
Console.WriteLine (" Try using -r:" + s);
}
static void MsgtryPkg (string s)
{
Console.WriteLine (" Try using -pkg:" + s);
}
protected void error246 (Location loc, string name)
{
Report.Error (246, loc, "The namespace `" + name +
"' can not be found (missing assembly reference?)");
switch (name) {
case "Gtk": case "GtkSharp":
MsgtryPkg ("gtk-sharp");
break;
case "Gdk": case "GdkSharp":
MsgtryPkg ("gdk-sharp");
break;
case "Glade": case "GladeSharp":
MsgtryPkg ("glade-sharp");
break;
case "System.Drawing":
case "System.Web.Services":
case "System.Web":
case "System.Data":
case "System.Windows.Forms":
MsgtryRef (name);
break;
}
}
///
/// Used to validate that all the using clauses are correct
/// after we are finished parsing all the files.
///
public void VerifyUsing ()
{
if (using_clauses != null){
foreach (UsingEntry ue in using_clauses){
if (ue.Resolve () != null)
continue;
if (ue.resolved == null)
error246 (ue.Location, ue.Name.ToString ());
else
Report.Error (138, ue.Location, "The using keyword only lets you specify a namespace, " +
"`" + ue.Name + "' is a class not a namespace.");
}
}
if (aliases != null){
foreach (DictionaryEntry de in aliases){
AliasEntry alias = (AliasEntry) de.Value;
if (alias.Resolve () != null)
continue;
error246 (alias.Location, alias.Alias.ToString ());
}
}
}
public override string ToString ()
{
if (NS == Namespace.Root)
return "NamespaceEntry ()";
else
return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
}
}
}