| /* |
| * Copyright (c) 2001, 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 sun.jvm.hotspot.interpreter; |
| |
| import sun.jvm.hotspot.oops.*; |
| import sun.jvm.hotspot.runtime.*; |
| import sun.jvm.hotspot.utilities.*; |
| |
| public class BytecodeStream { |
| private Method _method; |
| |
| // reading position |
| private int _bci; // bci if current bytecode |
| private int _next_bci; // bci of next bytecode |
| private int _end_bci; // bci after the current iteration interval |
| |
| // last bytecode read |
| private int _code; |
| private boolean _is_wide; |
| |
| // Construction |
| public BytecodeStream(Method method) { |
| _method = method; |
| setInterval(0, (int) method.getCodeSize()); |
| } |
| |
| // Iteration control |
| public void setInterval(int beg_bci, int end_bci) { |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(0 <= beg_bci && beg_bci <= _method.getCodeSize(), "illegal beg_bci"); |
| Assert.that(0 <= end_bci && end_bci <= _method.getCodeSize(), "illegal end_bci"); |
| } |
| // setup of iteration pointers |
| _bci = beg_bci; |
| _next_bci = beg_bci; |
| _end_bci = end_bci; |
| } |
| |
| public void setStart(int beg_bci) { |
| setInterval(beg_bci, (int) _method.getCodeSize()); |
| } |
| |
| // Iteration |
| public int next() { |
| int code; |
| // set reading position |
| _bci = _next_bci; |
| if (isLastBytecode()) { |
| // indicate end of bytecode stream |
| code = Bytecodes._illegal; |
| } else { |
| // get bytecode |
| int rawCode = Bytecodes.codeAt(_method, _bci); |
| code = 0; // Make javac happy |
| try { |
| code = Bytecodes.javaCode(rawCode); |
| } catch (AssertionFailure e) { |
| e.printStackTrace(); |
| Assert.that(false, "Failure occurred at bci " + _bci + " in method " + _method.externalNameAndSignature()); |
| } |
| |
| // set next bytecode position |
| // |
| int l = Bytecodes.lengthFor(code); |
| if (l == 0) l = Bytecodes.lengthAt(_method, _bci); |
| _next_bci += l; |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(_bci < _next_bci, "length must be > 0"); |
| } |
| // set attributes |
| _is_wide = false; |
| // check for special (uncommon) cases |
| if (code == Bytecodes._wide) { |
| code = _method.getBytecodeOrBPAt(_bci + 1); |
| _is_wide = true; |
| } |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(Bytecodes.isJavaCode(code), "sanity check"); |
| } |
| } |
| _code = code; |
| return _code; |
| } |
| |
| // Stream attributes |
| public Method method() { return _method; } |
| public int bci() { return _bci; } |
| public int nextBCI() { return _next_bci; } |
| public int endBCI() { return _end_bci; } |
| public int code() { return _code; } |
| public boolean isWide() { return _is_wide; } |
| public boolean isActiveBreakpoint() { return Bytecodes.isActiveBreakpointAt(_method, _bci); } |
| public boolean isLastBytecode() { return _next_bci >= _end_bci; } |
| |
| // State changes |
| public void setNextBCI(int bci) { |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(0 <= bci && bci <= _method.getCodeSize(), "illegal bci"); |
| } |
| _next_bci = bci; |
| } |
| |
| // Bytecode-specific attributes |
| public int dest() { return bci() + _method.getBytecodeShortArg(bci() + 1); } |
| public int dest_w() { return bci() + _method.getBytecodeIntArg(bci() + 1); } |
| |
| // Unsigned indices, widening |
| public int getIndex() { return (isWide()) |
| ? (_method.getBytecodeShortArg(bci() + 2) & 0xFFFF) |
| : (_method.getBytecodeOrBPAt(bci() + 1) & 0xFF); } |
| public int getIndexU1() { return _method.getBytecodeOrBPAt(bci() + 1) & 0xFF; } |
| public int getIndexU2() { return _method.getBytecodeShortArg(bci() + 1) & 0xFFFF; } |
| public int getIndexU4() { return _method.getNativeIntArg(bci() + 1); } |
| public boolean hasIndexU4() { return code() == Bytecodes._invokedynamic; } |
| |
| public int getIndexU1Cpcache() { return _method.getBytecodeOrBPAt(bci() + 1) & 0xFF; } |
| public int getIndexU2Cpcache() { return _method.getNativeShortArg(bci() + 1) & 0xFFFF; } |
| |
| // Fetch at absolute BCI (for manual parsing of certain bytecodes) |
| public int codeAt(int bci) { |
| return _method.getBytecodeOrBPAt(bci); |
| } |
| } |