/*

 * Copyright (c) 1994, 2014, 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

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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.

 */

public

class 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<Object, Object> exp) {

        vset = reach(env, vset);

        Hashtable<Object, Object> 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);

                Environment.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 = ctx.declare(env, f1);

            num2 = 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>");

        }

    }

}