| /* |
| * 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 |
| * 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. |
| */ |
| 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>"); |
| } |
| } |
| } |
