src/jdk.compiler/share/classes/com/sun/tools/javac/comp/MemberEnter.java
changeset 47216 71c04702a3d5
parent 45504 ea7475564d07
child 47268 48ec75306997
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/MemberEnter.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,447 @@
+/*
+ * Copyright (c) 2003, 2017, Oracle and/or its affiliates. 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.tools.javac.comp;
+
+import java.util.EnumSet;
+import java.util.Set;
+
+import com.sun.tools.javac.code.*;
+import com.sun.tools.javac.code.Scope.WriteableScope;
+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.code.Symbol.*;
+import com.sun.tools.javac.code.Type.*;
+import com.sun.tools.javac.resources.CompilerProperties.Errors;
+import com.sun.tools.javac.tree.JCTree.*;
+
+import static com.sun.tools.javac.code.Flags.*;
+import static com.sun.tools.javac.code.Kinds.*;
+import static com.sun.tools.javac.code.Kinds.Kind.*;
+import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
+
+/** Resolves field, method and constructor header, and constructs corresponding Symbols.
+ *
+ *  <p><b>This is NOT part of any supported API.
+ *  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 MemberEnter extends JCTree.Visitor {
+    protected static final Context.Key<MemberEnter> memberEnterKey = new Context.Key<>();
+
+    private final Enter enter;
+    private final Log log;
+    private final Check chk;
+    private final Attr attr;
+    private final Symtab syms;
+    private final Annotate annotate;
+    private final Types types;
+    private final DeferredLintHandler deferredLintHandler;
+
+    public static MemberEnter instance(Context context) {
+        MemberEnter instance = context.get(memberEnterKey);
+        if (instance == null)
+            instance = new MemberEnter(context);
+        return instance;
+    }
+
+    protected MemberEnter(Context context) {
+        context.put(memberEnterKey, this);
+        enter = Enter.instance(context);
+        log = Log.instance(context);
+        chk = Check.instance(context);
+        attr = Attr.instance(context);
+        syms = Symtab.instance(context);
+        annotate = Annotate.instance(context);
+        types = Types.instance(context);
+        deferredLintHandler = DeferredLintHandler.instance(context);
+    }
+
+    /** Construct method type from method signature.
+     *  @param typarams    The method's type parameters.
+     *  @param params      The method's value parameters.
+     *  @param res             The method's result type,
+     *                 null if it is a constructor.
+     *  @param recvparam       The method's receiver parameter,
+     *                 null if none given; TODO: or already set here?
+     *  @param thrown      The method's thrown exceptions.
+     *  @param env             The method's (local) environment.
+     */
+    Type signature(MethodSymbol msym,
+                   List<JCTypeParameter> typarams,
+                   List<JCVariableDecl> params,
+                   JCTree res,
+                   JCVariableDecl recvparam,
+                   List<JCExpression> thrown,
+                   Env<AttrContext> env) {
+
+        // Enter and attribute type parameters.
+        List<Type> tvars = enter.classEnter(typarams, env);
+        attr.attribTypeVariables(typarams, env);
+
+        // Enter and attribute value parameters.
+        ListBuffer<Type> argbuf = new ListBuffer<>();
+        for (List<JCVariableDecl> l = params; l.nonEmpty(); l = l.tail) {
+            memberEnter(l.head, env);
+            argbuf.append(l.head.vartype.type);
+        }
+
+        // Attribute result type, if one is given.
+        Type restype = res == null ? syms.voidType : attr.attribType(res, env);
+
+        // Attribute receiver type, if one is given.
+        Type recvtype;
+        if (recvparam!=null) {
+            memberEnter(recvparam, env);
+            recvtype = recvparam.vartype.type;
+        } else {
+            recvtype = null;
+        }
+
+        // Attribute thrown exceptions.
+        ListBuffer<Type> thrownbuf = new ListBuffer<>();
+        for (List<JCExpression> l = thrown; l.nonEmpty(); l = l.tail) {
+            Type exc = attr.attribType(l.head, env);
+            if (!exc.hasTag(TYPEVAR)) {
+                exc = chk.checkClassType(l.head.pos(), exc);
+            } else if (exc.tsym.owner == msym) {
+                //mark inference variables in 'throws' clause
+                exc.tsym.flags_field |= THROWS;
+            }
+            thrownbuf.append(exc);
+        }
+        MethodType mtype = new MethodType(argbuf.toList(),
+                                    restype,
+                                    thrownbuf.toList(),
+                                    syms.methodClass);
+        mtype.recvtype = recvtype;
+
+        return tvars.isEmpty() ? mtype : new ForAll(tvars, mtype);
+    }
+
+/* ********************************************************************
+ * Visitor methods for member enter
+ *********************************************************************/
+
+    /** Visitor argument: the current environment
+     */
+    protected Env<AttrContext> env;
+
+    /** Enter field and method definitions and process import
+     *  clauses, catching any completion failure exceptions.
+     */
+    protected void memberEnter(JCTree tree, Env<AttrContext> env) {
+        Env<AttrContext> prevEnv = this.env;
+        try {
+            this.env = env;
+            tree.accept(this);
+        }  catch (CompletionFailure ex) {
+            chk.completionError(tree.pos(), ex);
+        } finally {
+            this.env = prevEnv;
+        }
+    }
+
+    /** Enter members from a list of trees.
+     */
+    void memberEnter(List<? extends JCTree> trees, Env<AttrContext> env) {
+        for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
+            memberEnter(l.head, env);
+    }
+
+    public void visitMethodDef(JCMethodDecl tree) {
+        WriteableScope enclScope = enter.enterScope(env);
+        MethodSymbol m = new MethodSymbol(0, tree.name, null, enclScope.owner);
+        m.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, m, tree);
+        tree.sym = m;
+
+        //if this is a default method, add the DEFAULT flag to the enclosing interface
+        if ((tree.mods.flags & DEFAULT) != 0) {
+            m.enclClass().flags_field |= DEFAULT;
+        }
+
+        Env<AttrContext> localEnv = methodEnv(tree, env);
+        DiagnosticPosition prevLintPos = deferredLintHandler.setPos(tree.pos());
+        try {
+            // Compute the method type
+            m.type = signature(m, tree.typarams, tree.params,
+                               tree.restype, tree.recvparam,
+                               tree.thrown,
+                               localEnv);
+        } finally {
+            deferredLintHandler.setPos(prevLintPos);
+        }
+
+        if (types.isSignaturePolymorphic(m)) {
+            m.flags_field |= SIGNATURE_POLYMORPHIC;
+        }
+
+        // Set m.params
+        ListBuffer<VarSymbol> params = new ListBuffer<>();
+        JCVariableDecl lastParam = null;
+        for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
+            JCVariableDecl param = lastParam = l.head;
+            params.append(Assert.checkNonNull(param.sym));
+        }
+        m.params = params.toList();
+
+        // mark the method varargs, if necessary
+        if (lastParam != null && (lastParam.mods.flags & Flags.VARARGS) != 0)
+            m.flags_field |= Flags.VARARGS;
+
+        localEnv.info.scope.leave();
+        if (chk.checkUnique(tree.pos(), m, enclScope)) {
+        enclScope.enter(m);
+        }
+
+        annotate.annotateLater(tree.mods.annotations, localEnv, m, tree.pos());
+        // Visit the signature of the method. Note that
+        // TypeAnnotate doesn't descend into the body.
+        annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, m, tree.pos());
+
+        if (tree.defaultValue != null) {
+            m.defaultValue = annotate.unfinishedDefaultValue(); // set it to temporary sentinel for now
+            annotate.annotateDefaultValueLater(tree.defaultValue, localEnv, m, tree.pos());
+        }
+    }
+
+    /** Create a fresh environment for method bodies.
+     *  @param tree     The method definition.
+     *  @param env      The environment current outside of the method definition.
+     */
+    Env<AttrContext> methodEnv(JCMethodDecl tree, Env<AttrContext> env) {
+        Env<AttrContext> localEnv =
+            env.dup(tree, env.info.dup(env.info.scope.dupUnshared(tree.sym)));
+        localEnv.enclMethod = tree;
+        if (tree.sym.type != null) {
+            //when this is called in the enter stage, there's no type to be set
+            localEnv.info.returnResult = attr.new ResultInfo(KindSelector.VAL,
+                                                             tree.sym.type.getReturnType());
+        }
+        if ((tree.mods.flags & STATIC) != 0) localEnv.info.staticLevel++;
+        return localEnv;
+    }
+
+    public void visitVarDef(JCVariableDecl tree) {
+        Env<AttrContext> localEnv = env;
+        if ((tree.mods.flags & STATIC) != 0 ||
+            (env.info.scope.owner.flags() & INTERFACE) != 0) {
+            localEnv = env.dup(tree, env.info.dup());
+            localEnv.info.staticLevel++;
+        }
+        DiagnosticPosition prevLintPos = deferredLintHandler.setPos(tree.pos());
+
+        try {
+            if (TreeInfo.isEnumInit(tree)) {
+                attr.attribIdentAsEnumType(localEnv, (JCIdent)tree.vartype);
+            } else {
+                attr.attribType(tree.vartype, localEnv);
+                if (TreeInfo.isReceiverParam(tree))
+                    checkReceiver(tree, localEnv);
+            }
+        } finally {
+            deferredLintHandler.setPos(prevLintPos);
+        }
+
+        if ((tree.mods.flags & VARARGS) != 0) {
+            //if we are entering a varargs parameter, we need to
+            //replace its type (a plain array type) with the more
+            //precise VarargsType --- we need to do it this way
+            //because varargs is represented in the tree as a
+            //modifier on the parameter declaration, and not as a
+            //distinct type of array node.
+            ArrayType atype = (ArrayType)tree.vartype.type;
+            tree.vartype.type = atype.makeVarargs();
+        }
+        WriteableScope enclScope = enter.enterScope(env);
+        VarSymbol v =
+            new VarSymbol(0, tree.name, tree.vartype.type, enclScope.owner);
+        v.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, v, tree);
+        tree.sym = v;
+        if (tree.init != null) {
+            v.flags_field |= HASINIT;
+            if ((v.flags_field & FINAL) != 0 &&
+                needsLazyConstValue(tree.init)) {
+                Env<AttrContext> initEnv = getInitEnv(tree, env);
+                initEnv.info.enclVar = v;
+                v.setLazyConstValue(initEnv(tree, initEnv), attr, tree);
+            }
+        }
+        if (chk.checkUnique(tree.pos(), v, enclScope)) {
+            chk.checkTransparentVar(tree.pos(), v, enclScope);
+            enclScope.enter(v);
+        }
+
+        annotate.annotateLater(tree.mods.annotations, localEnv, v, tree.pos());
+        annotate.queueScanTreeAndTypeAnnotate(tree.vartype, localEnv, v, tree.pos());
+
+        v.pos = tree.pos;
+    }
+    // where
+    void checkType(JCTree tree, Type type, String diag) {
+        if (!tree.type.isErroneous() && !types.isSameType(tree.type, type)) {
+            log.error(tree, diag, type, tree.type);
+        }
+    }
+    void checkReceiver(JCVariableDecl tree, Env<AttrContext> localEnv) {
+        attr.attribExpr(tree.nameexpr, localEnv);
+        MethodSymbol m = localEnv.enclMethod.sym;
+        if (m.isConstructor()) {
+            Type outertype = m.owner.owner.type;
+            if (outertype.hasTag(TypeTag.METHOD)) {
+                // we have a local inner class
+                outertype = m.owner.owner.owner.type;
+            }
+            if (outertype.hasTag(TypeTag.CLASS)) {
+                checkType(tree.vartype, outertype, "incorrect.constructor.receiver.type");
+                checkType(tree.nameexpr, outertype, "incorrect.constructor.receiver.name");
+            } else {
+                log.error(tree, Errors.ReceiverParameterNotApplicableConstructorToplevelClass);
+            }
+        } else {
+            checkType(tree.vartype, m.owner.type, "incorrect.receiver.type");
+            checkType(tree.nameexpr, m.owner.type, "incorrect.receiver.name");
+        }
+    }
+
+    public boolean needsLazyConstValue(JCTree tree) {
+        InitTreeVisitor initTreeVisitor = new InitTreeVisitor();
+        tree.accept(initTreeVisitor);
+        return initTreeVisitor.result;
+    }
+
+    /** Visitor class for expressions which might be constant expressions,
+     *  as per JLS 15.28 (Constant Expressions).
+     */
+    static class InitTreeVisitor extends JCTree.Visitor {
+
+        private static final Set<Tag> ALLOWED_OPERATORS =
+                EnumSet.of(Tag.POS, Tag.NEG, Tag.NOT, Tag.COMPL, Tag.PLUS, Tag.MINUS,
+                           Tag.MUL, Tag.DIV, Tag.MOD, Tag.SL, Tag.SR, Tag.USR,
+                           Tag.LT, Tag.LE, Tag.GT, Tag.GE, Tag.EQ, Tag.NE,
+                           Tag.BITAND, Tag.BITXOR, Tag.BITOR, Tag.AND, Tag.OR);
+
+        boolean result = true;
+
+        @Override
+        public void visitTree(JCTree tree) {
+            result = false;
+        }
+
+        @Override
+        public void visitLiteral(JCLiteral that) {}
+
+        @Override
+        public void visitTypeCast(JCTypeCast tree) {
+            tree.expr.accept(this);
+        }
+
+        @Override
+        public void visitUnary(JCUnary that) {
+            if (!ALLOWED_OPERATORS.contains(that.getTag())) {
+                result = false;
+                return ;
+            }
+            that.arg.accept(this);
+        }
+
+        @Override
+        public void visitBinary(JCBinary that) {
+            if (!ALLOWED_OPERATORS.contains(that.getTag())) {
+                result = false;
+                return ;
+            }
+            that.lhs.accept(this);
+            that.rhs.accept(this);
+        }
+
+        @Override
+        public void visitConditional(JCConditional tree) {
+            tree.cond.accept(this);
+            tree.truepart.accept(this);
+            tree.falsepart.accept(this);
+        }
+
+        @Override
+        public void visitParens(JCParens tree) {
+            tree.expr.accept(this);
+        }
+
+        @Override
+        public void visitIdent(JCIdent that) {}
+
+        @Override
+        public void visitSelect(JCFieldAccess tree) {
+            tree.selected.accept(this);
+        }
+    }
+
+    /** Create a fresh environment for a variable's initializer.
+     *  If the variable is a field, the owner of the environment's scope
+     *  is be the variable itself, otherwise the owner is the method
+     *  enclosing the variable definition.
+     *
+     *  @param tree     The variable definition.
+     *  @param env      The environment current outside of the variable definition.
+     */
+    Env<AttrContext> initEnv(JCVariableDecl tree, Env<AttrContext> env) {
+        Env<AttrContext> localEnv = env.dupto(new AttrContextEnv(tree, env.info.dup()));
+        if (tree.sym.owner.kind == TYP) {
+            localEnv.info.scope = env.info.scope.dupUnshared(tree.sym);
+        }
+        if ((tree.mods.flags & STATIC) != 0 ||
+                ((env.enclClass.sym.flags() & INTERFACE) != 0 && env.enclMethod == null))
+            localEnv.info.staticLevel++;
+        return localEnv;
+    }
+
+    /** Default member enter visitor method: do nothing
+     */
+    public void visitTree(JCTree tree) {
+    }
+
+    public void visitErroneous(JCErroneous tree) {
+        if (tree.errs != null)
+            memberEnter(tree.errs, env);
+    }
+
+    public Env<AttrContext> getMethodEnv(JCMethodDecl tree, Env<AttrContext> env) {
+        Env<AttrContext> mEnv = methodEnv(tree, env);
+        mEnv.info.lint = mEnv.info.lint.augment(tree.sym);
+        for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
+            mEnv.info.scope.enterIfAbsent(l.head.type.tsym);
+        for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail)
+            mEnv.info.scope.enterIfAbsent(l.head.sym);
+        return mEnv;
+    }
+
+    public Env<AttrContext> getInitEnv(JCVariableDecl tree, Env<AttrContext> env) {
+        Env<AttrContext> iEnv = initEnv(tree, env);
+        return iEnv;
+    }
+}