/* * Copyright (c) 1994, 2004, 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 sun.tools.tree; import sun.tools.java.*;import sun.tools.asm.Assembler;import sun.tools.asm.Label;import sun.tools.asm.TryData;import sun.tools.asm.CatchData;import java.io.PrintStream;import java.util.Hashtable;import java.util.Enumeration; /** * WARNING: The contents of this source file are not part of any * supported API.  Code that depends on them does so at its own risk: * they are subject to change or removal without notice. */publicclass FinallyStatement extends Statement {    Statement body;    Statement finalbody;    boolean finallyCanFinish; // does finalBody never return?    boolean needReturnSlot;   // set by inner return statement    Statement init;           // try object expression  or declaration from parser    LocalMember tryTemp;      // temp holding the try object, if any     /**     * Constructor     */    public FinallyStatement(long where, Statement body, Statement finalbody) {        super(FINALLY, where);        this.body = body;        this.finalbody = finalbody;    } //    /**//     * Constructor for  try (init) {body}//     *///    public FinallyStatement(long where, Statement init, Statement body, int junk) {//      this(where, body, null);//      this.init = init;//    }     /**     * Check statement     */    Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {        vset = reach(env, vset);        Hashtable newexp = new Hashtable();         // Handle the proposed 'try (init) { stmts } finally { stmts }' syntax.        // This feature has not been adopted, and support is presently disabled.        /*-----------------------------------------------------------*        if (init != null) {            ClassDefinition sourceClass = ctx.field.getClassDefinition();            Expression tryExpr = null;            DeclarationStatement tryDecl = null;            long where = init.getWhere();            // find out whether init is a simple expression or a declaration            if (init.getOp() == EXPRESSION) {                tryExpr = ((ExpressionStatement)init).expr;                init = null;    // restore it below                vset = tryExpr.checkValue(env, ctx, vset, exp);            } else if (init.getOp() == DECLARATION) {                tryDecl = (DeclarationStatement) init;                init = null;    // restore it below                vset = tryDecl.checkBlockStatement(env, ctx, vset, exp);                if (tryDecl.args.length != 1) {                    env.error(where, "invalid.decl");                } else {                    LocalMember field =                        ((VarDeclarationStatement) tryDecl.args[0]).field;                    tryExpr = new IdentifierExpression(where, field);                    tryExpr.type = field.getType();                }            } else {                env.error(where, "invalid.expr");                vset = init.check(env, ctx, vset, exp);            }            Type type = (tryExpr == null) ? Type.tError : tryExpr.getType();             MemberDefinition tryEnter = null;            MemberDefinition tryExit = null;            if (!type.isType(TC_CLASS)) {                if (!type.isType(TC_ERROR)) {                    env.error(where, "invalid.method.invoke", type);                }            } else {                Identifier idTryEnter = Identifier.lookup("tryEnter");                Identifier idTryExit = Identifier.lookup("tryExit");                Type tTryMethod = Type.tMethod(Type.tVoid);                try {                    ClassDefinition tryClass = env.getClassDefinition(type);                    tryEnter = tryClass.matchMethod(env, sourceClass, idTryEnter);                    tryExit = tryClass.matchMethod(env, sourceClass, idTryExit);                    if (tryEnter != null && !tryEnter.getType().equals(tTryMethod)) {                        tryEnter = null;                    }                    if (tryExit != null && !tryExit.getType().equals(tTryMethod)) {                        tryExit = null;                    }                } catch (ClassNotFound ee) {                    env.error(where, "class.not.found", ee.name, ctx.field);                } catch (AmbiguousMember ee) {                    Identifier id = ee.field1.getName();                    env.error(where, "ambig.field", id, ee.field1, ee.field2);                }            }            if (tryEnter == null || tryExit == null) {                // Make a better (more didactic) error here!                env.error(where, "invalid.method.invoke", type);            } else {                tryTemp = new LocalMember(where, sourceClass, 0,                                          type, Identifier.lookup("<try_object>"));                ctx = new Context(ctx, this);                ctx.declare(env, tryTemp);                 Expression e;                e = new IdentifierExpression(where, tryTemp);                e = new AssignExpression(where, e, tryExpr);                e = new MethodExpression(where, e, tryEnter, new Expression[0]);                e.type = Type.tVoid;                Statement enterCall = new ExpressionStatement(where, e);                // store it on the init, for code generation                if (tryDecl != null) {                    Statement args2[] = { tryDecl.args[0], enterCall };                    tryDecl.args = args2;                    init = tryDecl;                } else {                    init = enterCall;                }                e = new IdentifierExpression(where, tryTemp);                e = new MethodExpression(where, e, tryExit, new Expression[0]);                e.type = Type.tVoid;                Statement exitCall = new ExpressionStatement(where, e);                finalbody = exitCall;            }        }        *-----------------------------------------------------------*/         // Check the try part. We reach the end of the try part either by        // finishing normally, or doing a break to the label of the try/finally.        // NOTE: I don't think newctx1.vsBreak is ever used -- see TryStatement.        CheckContext newctx1 = new CheckContext(ctx, this);        Vset vset1 = body.check(env, newctx1, vset.copy(), newexp)            .join(newctx1.vsBreak);        // Check the finally part.        CheckContext newctx2 = new CheckContext(ctx, this);        // Should never access this field.  The null indicates the finally part.        newctx2.vsContinue = null;        Vset vset2 = finalbody.check(env, newctx2, vset, exp);        finallyCanFinish = !vset2.isDeadEnd();        vset2 = vset2.join(newctx2.vsBreak);        // If !finallyCanFinish, then the only possible exceptions that can        // occur at this point are the ones preceding the try/finally, or        // the ones generated by the finally.  Anything in the try is        // irrelevant. Otherwise, we have to merge in all the exceptions        // generated by the body into exp.        if (finallyCanFinish) {            // Add newexp's back into exp; cf. ThrowStatement.check().            for (Enumeration e = newexp.keys() ; e.hasMoreElements() ; ) {                Object def = e.nextElement();                exp.put(def, newexp.get(def));            }        }        return ctx.removeAdditionalVars(vset1.addDAandJoinDU(vset2));    }     /**     * Inline     */    public Statement inline(Environment env, Context ctx) {        if (tryTemp != null) {            ctx = new Context(ctx, this);            ctx.declare(env, tryTemp);        }        if (init != null) {            init = init.inline(env, ctx);        }        if (body != null) {            body = body.inline(env, ctx);        }        if (finalbody != null) {            finalbody = finalbody.inline(env, ctx);        }        if (body == null) {            return eliminate(env, finalbody);        }        if (finalbody == null) {            return eliminate(env, body);        }        return this;    }     /**     * Create a copy of the statement for method inlining     */    public Statement copyInline(Context ctx, boolean valNeeded) {        FinallyStatement s = (FinallyStatement)clone();        if (tryTemp != null) {            s.tryTemp = tryTemp.copyInline(ctx);        }        if (init != null) {            s.init = init.copyInline(ctx, valNeeded);        }        if (body != null) {            s.body = body.copyInline(ctx, valNeeded);        }        if (finalbody != null) {            s.finalbody = finalbody.copyInline(ctx, valNeeded);        }        return s;     }     /**     * Compute cost of inlining this statement     */    public int costInline(int thresh, Environment env, Context ctx){        int cost = 4;        if (init != null) {            cost += init.costInline(thresh, env,ctx);            if (cost >= thresh) return cost;        }        if (body != null) {            cost += body.costInline(thresh, env,ctx);            if (cost >= thresh) return cost;        }        if (finalbody != null) {            cost += finalbody.costInline(thresh, env,ctx);        }        return cost;    }     /**     * Code     */    public void code(Environment env, Context ctx, Assembler asm) {        ctx = new Context(ctx);        Integer num1 = null, num2 = null;        Label endLabel = new Label();         if (tryTemp != null) {            ctx.declare(env, tryTemp);        }        if (init != null) {            CodeContext exprctx = new CodeContext(ctx, this);            init.code(env, exprctx, asm);        }         if (finallyCanFinish) {            LocalMember f1, f2;            ClassDefinition thisClass = ctx.field.getClassDefinition();             if (needReturnSlot) {                Type returnType = ctx.field.getType().getReturnType();                LocalMember localfield = new LocalMember(0, thisClass, 0,                                                       returnType,                                                       idFinallyReturnValue);                ctx.declare(env, localfield);                env.debugOutput("Assigning return slot to " + localfield.number);            }             // allocate space for the exception and return address            f1 = new LocalMember(where, thisClass, 0, Type.tObject, null);            f2 = new LocalMember(where, thisClass, 0, Type.tInt, null);            num1 = new Integer(ctx.declare(env, f1));            num2 = new Integer(ctx.declare(env, f2));        }         TryData td = new TryData();        td.add(null);         // Main body        CodeContext bodyctx = new CodeContext(ctx, this);        asm.add(where, opc_try, td); // start of protected code        body.code(env, bodyctx, asm);        asm.add(bodyctx.breakLabel);        asm.add(td.getEndLabel());   // end of protected code         // Cleanup afer body        if (finallyCanFinish) {            asm.add(where, opc_jsr, bodyctx.contLabel);            asm.add(where, opc_goto, endLabel);        } else {            // just goto the cleanup code.  It will never return.            asm.add(where, opc_goto, bodyctx.contLabel);        }         // Catch code        CatchData cd = td.getCatch(0);        asm.add(cd.getLabel());        if (finallyCanFinish) {            asm.add(where, opc_astore, num1); // store exception            asm.add(where, opc_jsr, bodyctx.contLabel);            asm.add(where, opc_aload, num1); // rethrow exception            asm.add(where, opc_athrow);        } else {            // pop exception off stack.  Fall through to finally code            asm.add(where, opc_pop);        }         // The finally part, which is marked by the contLabel.  Update        //    breakLabel: since break's in the finally are different        //    contLabel:  to null to indicate no longer in the protected code.        asm.add(bodyctx.contLabel);        bodyctx.contLabel = null;        bodyctx.breakLabel = endLabel;        if (finallyCanFinish) {            asm.add(where, opc_astore, num2);  // save the return address            finalbody.code(env, bodyctx, asm); // execute the cleanup code            asm.add(where, opc_ret, num2);     // return        } else {            finalbody.code(env, bodyctx, asm); // execute the cleanup code        }        asm.add(endLabel);                     // breaks come here    }     /**     * Print     */    public void print(PrintStream out, int indent) {        super.print(out, indent);        out.print("try ");        if (body != null) {            body.print(out, indent);        } else {            out.print("<empty>");        }        out.print(" finally ");        if (finalbody != null) {            finalbody.print(out, indent);        } else {            out.print("<empty>");        }    }}