Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright 1999-2008 Sun Microsystems, Inc.  All Rights Reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Sun designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Sun in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  */

 package com.sun.tools.javac.comp;

 import java.util.*;

 import javax.tools.JavaFileObject;

 import javax.tools.JavaFileManager;

 import com.sun.tools.javac.code.*;

 import com.sun.tools.javac.jvm.*;

 import com.sun.tools.javac.tree.*;

 import com.sun.tools.javac.util.*;

 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

 import com.sun.tools.javac.util.List;

 import com.sun.tools.javac.code.Type.*;

 import com.sun.tools.javac.code.Symbol.*;

 import com.sun.tools.javac.tree.JCTree.*;

 import static com.sun.tools.javac.code.Flags.*;

 import static com.sun.tools.javac.code.Kinds.*;

 /** This class enters symbols for all encountered definitions into

  *  the symbol table. The pass consists of two phases, organized as

  *  follows:

  *

  *  <p>In the first phase, all class symbols are intered into their

  *  enclosing scope, descending recursively down the tree for classes

  *  which are members of other classes. The class symbols are given a

  *  MemberEnter object as completer.

  *

  *  <p>In the second phase classes are completed using

  *  MemberEnter.complete().  Completion might occur on demand, but

  *  any classes that are not completed that way will be eventually

  *  completed by processing the `uncompleted' queue.  Completion

  *  entails (1) determination of a class's parameters, supertype and

  *  interfaces, as well as (2) entering all symbols defined in the

  *  class into its scope, with the exception of class symbols which

  *  have been entered in phase 1.  (2) depends on (1) having been

  *  completed for a class and all its superclasses and enclosing

  *  classes. That's why, after doing (1), we put classes in a

  *  `halfcompleted' queue. Only when we have performed (1) for a class

  *  and all it's superclasses and enclosing classes, we proceed to

  *  (2).

  *

  *  <p>Whereas the first phase is organized as a sweep through all

  *  compiled syntax trees, the second phase is demand. Members of a

  *  class are entered when the contents of a class are first

  *  accessed. This is accomplished by installing completer objects in

  *  class symbols for compiled classes which invoke the member-enter

  *  phase for the corresponding class tree.

  *

  *  <p>Classes migrate from one phase to the next via queues:

  *

  *  <pre>

  *  class enter -> (Enter.uncompleted)         --> member enter (1)

  *              -> (MemberEnter.halfcompleted) --> member enter (2)

  *              -> (Todo)                      --> attribute

  *                                              (only for toplevel classes)

  *  </pre>

  *

  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If

  *  you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class Enter extends JCTree.Visitor {

     protected static final Context.Key<Enter> enterKey =

         new Context.Key<Enter>();

     Log log;

     Symtab syms;

     Check chk;

     TreeMaker make;

     ClassReader reader;

     Annotate annotate;

     MemberEnter memberEnter;

     Types types;

     Lint lint;

     JavaFileManager fileManager;

     private final Todo todo;

     public static Enter instance(Context context) {

         Enter instance = context.get(enterKey);

         if (instance == null)

             instance = new Enter(context);

         return instance;

     }

     protected Enter(Context context) {

         context.put(enterKey, this);

         log = Log.instance(context);

         reader = ClassReader.instance(context);

         make = TreeMaker.instance(context);

         syms = Symtab.instance(context);

         chk = Check.instance(context);

         memberEnter = MemberEnter.instance(context);

         types = Types.instance(context);

         annotate = Annotate.instance(context);

         lint = Lint.instance(context);

         predefClassDef = make.ClassDef(

             make.Modifiers(PUBLIC),

             syms.predefClass.name, null, null, null, null);

         predefClassDef.sym = syms.predefClass;

         todo = Todo.instance(context);

         fileManager = context.get(JavaFileManager.class);

     }

     /** A hashtable mapping classes and packages to the environments current

      *  at the points of their definitions.

      */

     Map<TypeSymbol,Env<AttrContext>> typeEnvs =

             new HashMap<TypeSymbol,Env<AttrContext>>();

     /** Accessor for typeEnvs

      */

     public Env<AttrContext> getEnv(TypeSymbol sym) {

         return typeEnvs.get(sym);

     }

     public Env<AttrContext> getClassEnv(TypeSymbol sym) {

         Env<AttrContext> localEnv = getEnv(sym);

         Env<AttrContext> lintEnv = localEnv;

         while (lintEnv.info.lint == null)

             lintEnv = lintEnv.next;

         localEnv.info.lint = lintEnv.info.lint.augment(sym.attributes_field, sym.flags());

         return localEnv;

     }

     /** The queue of all classes that might still need to be completed;

      *  saved and initialized by main().

      */

     ListBuffer<ClassSymbol> uncompleted;

     /** A dummy class to serve as enclClass for toplevel environments.

      */

     private JCClassDecl predefClassDef;

 /* ************************************************************************

  * environment construction

  *************************************************************************/

     /** Create a fresh environment for class bodies.

      *  This will create a fresh scope for local symbols of a class, referred

      *  to by the environments info.scope field.

      *  This scope will contain

      *    - symbols for this and super

      *    - symbols for any type parameters

      *  In addition, it serves as an anchor for scopes of methods and initializers

      *  which are nested in this scope via Scope.dup().

      *  This scope should not be confused with the members scope of a class.

      *

      *  @param tree     The class definition.

      *  @param env      The environment current outside of the class definition.

      */

     public Env<AttrContext> classEnv(JCClassDecl tree, Env<AttrContext> env) {

         Env<AttrContext> localEnv =

             env.dup(tree, env.info.dup(new Scope(tree.sym)));

         localEnv.enclClass = tree;

         localEnv.outer = env;

         localEnv.info.isSelfCall = false;

         localEnv.info.lint = null; // leave this to be filled in by Attr,

                                    // when annotations have been processed

         return localEnv;

     }

     /** Create a fresh environment for toplevels.

      *  @param tree     The toplevel tree.

      */

     Env<AttrContext> topLevelEnv(JCCompilationUnit tree) {

         Env<AttrContext> localEnv = new Env<AttrContext>(tree, new AttrContext());

         localEnv.toplevel = tree;

         localEnv.enclClass = predefClassDef;

         tree.namedImportScope = new Scope.ImportScope(tree.packge);

         tree.starImportScope = new Scope.ImportScope(tree.packge);

         localEnv.info.scope = tree.namedImportScope;

         localEnv.info.lint = lint;

         return localEnv;

     }

     public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) {

         Env<AttrContext> localEnv = new Env<AttrContext>(tree, new AttrContext());

         localEnv.toplevel = tree;

         localEnv.enclClass = predefClassDef;

         localEnv.info.scope = tree.namedImportScope;

         localEnv.info.lint = lint;

         return localEnv;

     }

     /** The scope in which a member definition in environment env is to be entered

      *  This is usually the environment's scope, except for class environments,

      *  where the local scope is for type variables, and the this and super symbol

      *  only, and members go into the class member scope.

      */

     Scope enterScope(Env<AttrContext> env) {

         return (env.tree.getTag() == JCTree.CLASSDEF)

             ? ((JCClassDecl) env.tree).sym.members_field

             : env.info.scope;

     }

 /* ************************************************************************

  * Visitor methods for phase 1: class enter

  *************************************************************************/

     /** Visitor argument: the current environment.

      */

     protected Env<AttrContext> env;

     /** Visitor result: the computed type.

      */

     Type result;

     /** Visitor method: enter all classes in given tree, catching any

      *  completion failure exceptions. Return the tree's type.

      *

      *  @param tree    The tree to be visited.

      *  @param env     The environment visitor argument.

      */

     Type classEnter(JCTree tree, Env<AttrContext> env) {

         Env<AttrContext> prevEnv = this.env;

         try {

             this.env = env;

             tree.accept(this);

             return result;

         }  catch (CompletionFailure ex) {

             return chk.completionError(tree.pos(), ex);

         } finally {

             this.env = prevEnv;

         }

     }

     /** Visitor method: enter classes of a list of trees, returning a list of types.

      */

     <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) {

         ListBuffer<Type> ts = new ListBuffer<Type>();

         for (List<T> l = trees; l.nonEmpty(); l = l.tail) {

             Type t = classEnter(l.head, env);

             if (t != null)

                 ts.append(t);

         }

         return ts.toList();

     }

     public void visitTopLevel(JCCompilationUnit tree) {

         JavaFileObject prev = log.useSource(tree.sourcefile);

         boolean addEnv = false;

         boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info",

                                                              JavaFileObject.Kind.SOURCE);

         if (tree.pid != null) {

             tree.packge = reader.enterPackage(TreeInfo.fullName(tree.pid));

             if (tree.packageAnnotations.nonEmpty()) {

                 if (isPkgInfo) {

                     addEnv = true;

                 } else {

                     log.error(tree.packageAnnotations.head.pos(),

                               "pkg.annotations.sb.in.package-info.java");

                 }

             }

         } else {

             tree.packge = syms.unnamedPackage;

         }

         tree.packge.complete(); // Find all classes in package.

         Env<AttrContext> env = topLevelEnv(tree);

         // Save environment of package-info.java file.

         if (isPkgInfo) {

             Env<AttrContext> env0 = typeEnvs.get(tree.packge);

             if (env0 == null) {

                 typeEnvs.put(tree.packge, env);

             } else {

                 JCCompilationUnit tree0 = env0.toplevel;

                 if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) {

                     log.warning(tree.pid != null ? tree.pid.pos()

                                                  : null,

                                 "pkg-info.already.seen",

                                 tree.packge);

                     if (addEnv || (tree0.packageAnnotations.isEmpty() &&

                                    tree.docComments != null &&

                                    tree.docComments.get(tree) != null)) {

                         typeEnvs.put(tree.packge, env);

                     }

                 }

             }

         }

         classEnter(tree.defs, env);

         if (addEnv) {

             todo.append(env);

         }

         log.useSource(prev);

         result = null;

     }

     public void visitClassDef(JCClassDecl tree) {

         Symbol owner = env.info.scope.owner;

         Scope enclScope = enterScope(env);

         ClassSymbol c;

         if (owner.kind == PCK) {

             // We are seeing a toplevel class.

             PackageSymbol packge = (PackageSymbol)owner;

             for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner)

                 q.flags_field |= EXISTS;

             c = reader.enterClass(tree.name, packge);

             packge.members().enterIfAbsent(c);

             if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) {

                 log.error(tree.pos(),

                           "class.public.should.be.in.file", tree.name);

             }

         } else {

             if (!tree.name.isEmpty() &&

                 !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) {

                 result = null;

                 return;

             }

             if (owner.kind == TYP) {

                 // We are seeing a member class.

                 c = reader.enterClass(tree.name, (TypeSymbol)owner);

                 if ((owner.flags_field & INTERFACE) != 0) {

                     tree.mods.flags |= PUBLIC | STATIC;

                 }

             } else {

                 // We are seeing a local class.

                 c = reader.defineClass(tree.name, owner);

                 c.flatname = chk.localClassName(c);

                 if (!c.name.isEmpty())

                     chk.checkTransparentClass(tree.pos(), c, env.info.scope);

             }

         }

         tree.sym = c;

         // Enter class into `compiled' table and enclosing scope.

         if (chk.compiled.get(c.flatname) != null) {

             duplicateClass(tree.pos(), c);

             result = types.createErrorType(tree.name, (TypeSymbol)owner, Type.noType);

             tree.sym = (ClassSymbol)result.tsym;

             return;

         }

         chk.compiled.put(c.flatname, c);

         enclScope.enter(c);

         // Set up an environment for class block and store in `typeEnvs'

         // table, to be retrieved later in memberEnter and attribution.

         Env<AttrContext> localEnv = classEnv(tree, env);

         typeEnvs.put(c, localEnv);

         // Fill out class fields.

         c.completer = memberEnter;

         c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree);

         c.sourcefile = env.toplevel.sourcefile;

         c.members_field = new Scope(c);

         ClassType ct = (ClassType)c.type;

         if (owner.kind != PCK && (c.flags_field & STATIC) == 0) {

             // We are seeing a local or inner class.

             // Set outer_field of this class to closest enclosing class

             // which contains this class in a non-static context

             // (its "enclosing instance class"), provided such a class exists.

             Symbol owner1 = owner;

             while ((owner1.kind & (VAR | MTH)) != 0 &&

                    (owner1.flags_field & STATIC) == 0) {

                 owner1 = owner1.owner;

             }

             if (owner1.kind == TYP) {

                 ct.setEnclosingType(owner1.type);

             }

         }

         // Enter type parameters.

         ct.typarams_field = classEnter(tree.typarams, localEnv);

         // Add non-local class to uncompleted, to make sure it will be

         // completed later.

         if (!c.isLocal() && uncompleted != null) uncompleted.append(c);

 //      System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG

         // Recursively enter all member classes.

         classEnter(tree.defs, localEnv);

         result = c.type;

     }

     //where

         /** Does class have the same name as the file it appears in?

          */

         private static boolean classNameMatchesFileName(ClassSymbol c,

                                                         Env<AttrContext> env) {

             return env.toplevel.sourcefile.isNameCompatible(c.name.toString(),

                                                             JavaFileObject.Kind.SOURCE);

         }

     /** Complain about a duplicate class. */

     protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) {

         log.error(pos, "duplicate.class", c.fullname);

     }

     /** Class enter visitor method for type parameters.

      *  Enter a symbol for type parameter in local scope, after checking that it

      *  is unique.

      */

     public void visitTypeParameter(JCTypeParameter tree) {

         TypeVar a = (tree.type != null)

             ? (TypeVar)tree.type

             : new TypeVar(tree.name, env.info.scope.owner, syms.botType);

         tree.type = a;

         if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) {

             env.info.scope.enter(a.tsym);

         }

         result = a;

     }

     /** Default class enter visitor method: do nothing.

      */

     public void visitTree(JCTree tree) {

         result = null;

     }

     /** Main method: enter all classes in a list of toplevel trees.

      *  @param trees      The list of trees to be processed.

      */

     public void main(List<JCCompilationUnit> trees) {

         complete(trees, null);

     }

     /** Main method: enter one class from a list of toplevel trees and

      *  place the rest on uncompleted for later processing.

      *  @param trees      The list of trees to be processed.

      *  @param c          The class symbol to be processed.

      */

     public void complete(List<JCCompilationUnit> trees, ClassSymbol c) {

         annotate.enterStart();

         ListBuffer<ClassSymbol> prevUncompleted = uncompleted;

         if (memberEnter.completionEnabled) uncompleted = new ListBuffer<ClassSymbol>();

         try {

             // enter all classes, and construct uncompleted list

             classEnter(trees, null);

             // complete all uncompleted classes in memberEnter

             if  (memberEnter.completionEnabled) {

                 while (uncompleted.nonEmpty()) {

                     ClassSymbol clazz = uncompleted.next();

                     if (c == null || c == clazz || prevUncompleted == null)

                         clazz.complete();

                     else

                         // defer

                         prevUncompleted.append(clazz);

                 }

                 // if there remain any unimported toplevels (these must have

                 // no classes at all), process their import statements as well.

                 for (JCCompilationUnit tree : trees) {

                     if (tree.starImportScope.elems == null) {

                         JavaFileObject prev = log.useSource(tree.sourcefile);

                         Env<AttrContext> env = typeEnvs.get(tree);

                         if (env == null)

                             env = topLevelEnv(tree);

                         memberEnter.memberEnter(tree, env);

                         log.useSource(prev);

                     }

                 }

             }

         } finally {

             uncompleted = prevUncompleted;

             annotate.enterDone();

         }

     }

 }