Mercurial > hg > truffle
diff agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeStream.java @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeStream.java Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,139 @@ +/* + * Copyright 2001-2002 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.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 getIndexBig() { return _method.getBytecodeShortArg(bci() + 1); } + + // Fetch at absolute BCI (for manual parsing of certain bytecodes) + public int codeAt(int bci) { + return _method.getBytecodeOrBPAt(bci); + } +}