--- /dev/null 2017-01-22 10:16:57.869617664 -0800 +++ new/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.code/src/jdk/vm/ci/code/BytecodePosition.java 2017-02-15 16:55:25.686275845 -0800 @@ -0,0 +1,120 @@ +/* + * Copyright (c) 2009, 2011, 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. + * + * 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 jdk.vm.ci.code; + +import java.util.Objects; + +import jdk.vm.ci.meta.ResolvedJavaMethod; + +/** + * Represents a code position, that is, a chain of inlined methods with bytecode locations, that is + * communicated from the compiler to the runtime system. A code position can be used by the runtime + * system to reconstruct a source-level stack trace for exceptions and to create + * {@linkplain BytecodeFrame frames} for deoptimization. + */ +public class BytecodePosition { + + private final BytecodePosition caller; + private final ResolvedJavaMethod method; + private final int bci; + + /** + * Constructs a new object representing a given parent/caller, a given method, and a given BCI. + * + * @param caller the parent position + * @param method the method + * @param bci a BCI within the method + */ + public BytecodePosition(BytecodePosition caller, ResolvedJavaMethod method, int bci) { + assert method != null; + this.caller = caller; + this.method = method; + this.bci = bci; + } + + /** + * Converts this code position to a string representation. + * + * @return a string representation of this code position + */ + @Override + public String toString() { + return CodeUtil.append(new StringBuilder(100), this).toString(); + } + + /** + * Deep equality test. + */ + @Override + public boolean equals(Object obj) { + if (obj == this) { + return true; + } + if (obj != null && getClass() == obj.getClass()) { + BytecodePosition that = (BytecodePosition) obj; + if (this.bci == that.bci && Objects.equals(this.getMethod(), that.getMethod()) && Objects.equals(this.caller, that.caller)) { + return true; + } + } + return false; + } + + @Override + public int hashCode() { + return getBCI(); + } + + /** + * @return The location within the method, as a bytecode index. The constant {@code -1} may be + * used to indicate the location is unknown, for example within code synthesized by the + * compiler. + */ + public int getBCI() { + return bci; + } + + /** + * @return The runtime interface method for this position. + */ + public ResolvedJavaMethod getMethod() { + return method; + } + + /** + * The position where this position has been called, {@code null} if none. + */ + public BytecodePosition getCaller() { + return caller; + } + + /** + * Adds a caller to the current position returning the new position. + */ + public BytecodePosition addCaller(BytecodePosition link) { + if (getCaller() == null) { + return new BytecodePosition(link, getMethod(), getBCI()); + } else { + return new BytecodePosition(getCaller().addCaller(link), getMethod(), getBCI()); + } + } +}