| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| package com.sun.org.apache.bcel.internal.util; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache BCEL" must not be used to endorse or promote products |
| * derived from this software without prior written permission. For |
| * written permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * "Apache BCEL", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import java.util.*; |
| import com.sun.org.apache.bcel.internal.Constants; |
| import com.sun.org.apache.bcel.internal.generic.*; |
| import com.sun.org.apache.regexp.internal.*; |
| |
| /** |
| * InstructionFinder is a tool to search for given instructions patterns, |
| * i.e., match sequences of instructions in an instruction list via |
| * regular expressions. This can be used, e.g., in order to implement |
| * a peep hole optimizer that looks for code patterns and replaces |
| * them with faster equivalents. |
| * |
| * <p>This class internally uses the <a href="http://jakarta.apache.org/regexp/"> |
| * Regexp</a> package to search for regular expressions. |
| * |
| * A typical application would look like this: |
| <pre> |
| InstructionFinder f = new InstructionFinder(il); |
| String pat = "IfInstruction ICONST_0 GOTO ICONST_1 NOP (IFEQ|IFNE)"; |
| |
| for(Iterator i = f.search(pat, constraint); i.hasNext(); ) { |
| InstructionHandle[] match = (InstructionHandle[])i.next(); |
| ... |
| il.delete(match[1], match[5]); |
| ... |
| } |
| </pre> |
| * @author <A HREF="http://www.berlin.de/~markus.dahm/">M. Dahm</A> |
| * @see Instruction |
| * @see InstructionList |
| */ |
| public class InstructionFinder { |
| private static final int OFFSET = 32767; // char + OFFSET is outside of LATIN-1 |
| private static final int NO_OPCODES = 256; // Potential number, some are not used |
| |
| private static final HashMap map = new HashMap(); // Map<String,Pattern> |
| |
| private InstructionList il; |
| private String il_string; // instruction list as string |
| private InstructionHandle[] handles; // map instruction list to array |
| |
| /** |
| * @param il instruction list to search for given patterns |
| */ |
| public InstructionFinder(InstructionList il) { |
| this.il = il; |
| reread(); |
| } |
| |
| /** |
| * Reread the instruction list, e.g., after you've altered the list upon a match. |
| */ |
| public final void reread() { |
| int size = il.getLength(); |
| char[] buf = new char[size]; // Create a string with length equal to il length |
| handles = il.getInstructionHandles(); |
| |
| // Map opcodes to characters |
| for(int i=0; i < size; i++) |
| buf[i] = makeChar(handles[i].getInstruction().getOpcode()); |
| |
| il_string = new String(buf); |
| } |
| |
| /** |
| * Map symbolic instruction names like "getfield" to a single character. |
| * |
| * @param pattern instruction pattern in lower case |
| * @return encoded string for a pattern such as "BranchInstruction". |
| */ |
| private static final String mapName(String pattern) { |
| String result = (String)map.get(pattern); |
| |
| if(result != null) |
| return result; |
| |
| for(short i=0; i < NO_OPCODES; i++) |
| if(pattern.equals(Constants.OPCODE_NAMES[i])) |
| return "" + makeChar(i); |
| |
| throw new RuntimeException("Instruction unknown: " + pattern); |
| } |
| |
| /** |
| * Replace symbolic names of instructions with the appropiate character and remove |
| * all white space from string. Meta characters such as +, * are ignored. |
| * |
| * @param pattern The pattern to compile |
| * @return translated regular expression string |
| */ |
| private static final String compilePattern(String pattern) { |
| String lower = pattern.toLowerCase(); |
| StringBuffer buf = new StringBuffer(); |
| int size = pattern.length(); |
| |
| for(int i=0; i < size; i++) { |
| char ch = lower.charAt(i); |
| |
| if(Character.isLetterOrDigit(ch)) { |
| StringBuffer name = new StringBuffer(); |
| |
| while((Character.isLetterOrDigit(ch) || ch == '_') && i < size) { |
| name.append(ch); |
| |
| if(++i < size) |
| ch = lower.charAt(i); |
| else |
| break; |
| } |
| |
| i--; |
| |
| buf.append(mapName(name.toString())); |
| } else if(!Character.isWhitespace(ch)) |
| buf.append(ch); |
| } |
| |
| return buf.toString(); |
| } |
| |
| /** |
| * @return the matched piece of code as an array of instruction (handles) |
| */ |
| private InstructionHandle[] getMatch(int matched_from, int match_length) { |
| InstructionHandle[] match = new InstructionHandle[match_length]; |
| System.arraycopy(handles, matched_from, match, 0, match_length); |
| |
| return match; |
| } |
| |
| /** |
| * Search for the given pattern in the instruction list. You can search for any valid |
| * opcode via its symbolic name, e.g. "istore". You can also use a super class or |
| * an interface name to match a whole set of instructions, e.g. "BranchInstruction" or |
| * "LoadInstruction". "istore" is also an alias for all "istore_x" instructions. Additional |
| * aliases are "if" for "ifxx", "if_icmp" for "if_icmpxx", "if_acmp" for "if_acmpxx". |
| * |
| * Consecutive instruction names must be separated by white space which will be removed |
| * during the compilation of the pattern. |
| * |
| * For the rest the usual pattern matching rules for regular expressions apply.<P> |
| * Example pattern: |
| * <pre> |
| search("BranchInstruction NOP ((IfInstruction|GOTO)+ ISTORE Instruction)*"); |
| * </pre> |
| * |
| * <p>If you alter the instruction list upon a match such that other |
| * matching areas are affected, you should call reread() to update |
| * the finder and call search() again, because the matches are cached. |
| * |
| * @param pattern the instruction pattern to search for, where case is ignored |
| * @param from where to start the search in the instruction list |
| * @param constraint optional CodeConstraint to check the found code pattern for |
| * user-defined constraints |
| * @return iterator of matches where e.nextElement() returns an array of instruction handles |
| * describing the matched area |
| */ |
| public final Iterator search(String pattern, InstructionHandle from, |
| CodeConstraint constraint) |
| { |
| String search = compilePattern(pattern); |
| int start = -1; |
| |
| for(int i=0; i < handles.length; i++) { |
| if(handles[i] == from) { |
| start = i; // Where to start search from (index) |
| break; |
| } |
| } |
| |
| if(start == -1) |
| throw new ClassGenException("Instruction handle " + from + |
| " not found in instruction list."); |
| try { |
| RE regex = new RE(search); |
| ArrayList matches = new ArrayList(); |
| |
| while(start < il_string.length() && regex.match(il_string, start)) { |
| int startExpr = regex.getParenStart(0); |
| int endExpr = regex.getParenEnd(0); |
| int lenExpr = regex.getParenLength(0); |
| |
| InstructionHandle[] match = getMatch(startExpr, lenExpr); |
| |
| if((constraint == null) || constraint.checkCode(match)) |
| matches.add(match); |
| start = endExpr; |
| } |
| |
| return matches.iterator(); |
| } catch(RESyntaxException e) { |
| System.err.println(e); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Start search beginning from the start of the given instruction list. |
| * |
| * @param pattern the instruction pattern to search for, where case is ignored |
| * @return iterator of matches where e.nextElement() |
| * returns an array of instruction handles describing the matched |
| * area |
| */ |
| public final Iterator search(String pattern) { |
| return search(pattern, il.getStart(), null); |
| } |
| |
| /** |
| * Start search beginning from `from'. |
| * |
| * @param pattern the instruction pattern to search for, where case is ignored |
| * @param from where to start the search in the instruction list |
| * @return iterator of matches where e.nextElement() returns an array of instruction handles |
| * describing the matched area |
| */ |
| public final Iterator search(String pattern, InstructionHandle from) { |
| return search(pattern, from, null); |
| } |
| |
| /** |
| * Start search beginning from the start of the given instruction list. |
| * Check found matches with the constraint object. |
| * |
| * @param pattern the instruction pattern to search for, case is ignored |
| * @param constraint constraints to be checked on matching code |
| * @return instruction handle or `null' if the match failed |
| */ |
| public final Iterator search(String pattern, CodeConstraint constraint) { |
| return search(pattern, il.getStart(), constraint); |
| } |
| |
| /** |
| * Convert opcode number to char. |
| */ |
| private static final char makeChar(short opcode) { |
| return (char)(opcode + OFFSET); |
| } |
| |
| /** |
| * @return the inquired instruction list |
| */ |
| public final InstructionList getInstructionList() { return il; } |
| |
| /** |
| * Code patterns found may be checked using an additional |
| * user-defined constraint object whether they really match the needed criterion. |
| * I.e., check constraints that can not expressed with regular expressions. |
| * |
| */ |
| public interface CodeConstraint { |
| /** |
| * @param match array of instructions matching the requested pattern |
| * @return true if the matched area is really useful |
| */ |
| public boolean checkCode(InstructionHandle[] match); |
| } |
| |
| // Initialize pattern map |
| |
| static { |
| map.put("arithmeticinstruction", "(irem|lrem|iand|ior|ineg|isub|lneg|fneg|fmul|ldiv|fadd|lxor|frem|idiv|land|ixor|ishr|fsub|lshl|fdiv|iadd|lor|dmul|lsub|ishl|imul|lmul|lushr|dneg|iushr|lshr|ddiv|drem|dadd|ladd|dsub)"); |
| map.put("invokeinstruction", "(invokevirtual|invokeinterface|invokestatic|invokespecial)"); |
| map.put("arrayinstruction", "(baload|aastore|saload|caload|fastore|lastore|iaload|castore|iastore|aaload|bastore|sastore|faload|laload|daload|dastore)"); |
| map.put("gotoinstruction", "(goto|goto_w)"); |
| map.put("conversioninstruction", "(d2l|l2d|i2s|d2i|l2i|i2b|l2f|d2f|f2i|i2d|i2l|f2d|i2c|f2l|i2f)"); |
| map.put("localvariableinstruction", "(fstore|iinc|lload|dstore|dload|iload|aload|astore|istore|fload|lstore)"); |
| map.put("loadinstruction", "(fload|dload|lload|iload|aload)"); |
| map.put("fieldinstruction", "(getfield|putstatic|getstatic|putfield)"); |
| map.put("cpinstruction", "(ldc2_w|invokeinterface|multianewarray|putstatic|instanceof|getstatic|checkcast|getfield|invokespecial|ldc_w|invokestatic|invokevirtual|putfield|ldc|new|anewarray)"); |
| map.put("stackinstruction", "(dup2|swap|dup2_x2|pop|pop2|dup|dup2_x1|dup_x2|dup_x1)"); |
| map.put("branchinstruction", "(ifle|if_acmpne|if_icmpeq|if_acmpeq|ifnonnull|goto_w|iflt|ifnull|if_icmpne|tableswitch|if_icmple|ifeq|if_icmplt|jsr_w|if_icmpgt|ifgt|jsr|goto|ifne|ifge|lookupswitch|if_icmpge)"); |
| map.put("returninstruction", "(lreturn|ireturn|freturn|dreturn|areturn|return)"); |
| map.put("storeinstruction", "(istore|fstore|dstore|astore|lstore)"); |
| map.put("select", "(tableswitch|lookupswitch)"); |
| map.put("ifinstruction", "(ifeq|ifgt|if_icmpne|if_icmpeq|ifge|ifnull|ifne|if_icmple|if_icmpge|if_acmpeq|if_icmplt|if_acmpne|ifnonnull|iflt|if_icmpgt|ifle)"); |
| map.put("jsrinstruction", "(jsr|jsr_w)"); |
| map.put("variablelengthinstruction", "(tableswitch|jsr|goto|lookupswitch)"); |
| map.put("unconditionalbranch", "(goto|jsr|jsr_w|athrow|goto_w)"); |
| map.put("constantpushinstruction", "(dconst|bipush|sipush|fconst|iconst|lconst)"); |
| map.put("typedinstruction", "(imul|lsub|aload|fload|lor|new|aaload|fcmpg|iand|iaload|lrem|idiv|d2l|isub|dcmpg|dastore|ret|f2d|f2i|drem|iinc|i2c|checkcast|frem|lreturn|astore|lushr|daload|dneg|fastore|istore|lshl|ldiv|lstore|areturn|ishr|ldc_w|invokeinterface|aastore|lxor|ishl|l2d|i2f|return|faload|sipush|iushr|caload|instanceof|invokespecial|putfield|fmul|ireturn|laload|d2f|lneg|ixor|i2l|fdiv|lastore|multianewarray|i2b|getstatic|i2d|putstatic|fcmpl|saload|ladd|irem|dload|jsr_w|dconst|dcmpl|fsub|freturn|ldc|aconst_null|castore|lmul|ldc2_w|dadd|iconst|f2l|ddiv|dstore|land|jsr|anewarray|dmul|bipush|dsub|sastore|d2i|i2s|lshr|iadd|l2i|lload|bastore|fstore|fneg|iload|fadd|baload|fconst|ior|ineg|dreturn|l2f|lconst|getfield|invokevirtual|invokestatic|iastore)"); |
| map.put("popinstruction", "(fstore|dstore|pop|pop2|astore|putstatic|istore|lstore)"); |
| map.put("allocationinstruction", "(multianewarray|new|anewarray|newarray)"); |
| map.put("indexedinstruction", "(lload|lstore|fload|ldc2_w|invokeinterface|multianewarray|astore|dload|putstatic|instanceof|getstatic|checkcast|getfield|invokespecial|dstore|istore|iinc|ldc_w|ret|fstore|invokestatic|iload|putfield|invokevirtual|ldc|new|aload|anewarray)"); |
| map.put("pushinstruction", "(dup|lload|dup2|bipush|fload|ldc2_w|sipush|lconst|fconst|dload|getstatic|ldc_w|aconst_null|dconst|iload|ldc|iconst|aload)"); |
| map.put("stackproducer", "(imul|lsub|aload|fload|lor|new|aaload|fcmpg|iand|iaload|lrem|idiv|d2l|isub|dcmpg|dup|f2d|f2i|drem|i2c|checkcast|frem|lushr|daload|dneg|lshl|ldiv|ishr|ldc_w|invokeinterface|lxor|ishl|l2d|i2f|faload|sipush|iushr|caload|instanceof|invokespecial|fmul|laload|d2f|lneg|ixor|i2l|fdiv|getstatic|i2b|swap|i2d|dup2|fcmpl|saload|ladd|irem|dload|jsr_w|dconst|dcmpl|fsub|ldc|arraylength|aconst_null|tableswitch|lmul|ldc2_w|iconst|dadd|f2l|ddiv|land|jsr|anewarray|dmul|bipush|dsub|d2i|newarray|i2s|lshr|iadd|lload|l2i|fneg|iload|fadd|baload|fconst|lookupswitch|ior|ineg|lconst|l2f|getfield|invokevirtual|invokestatic)"); |
| map.put("stackconsumer", "(imul|lsub|lor|iflt|fcmpg|if_icmpgt|iand|ifeq|if_icmplt|lrem|ifnonnull|idiv|d2l|isub|dcmpg|dastore|if_icmpeq|f2d|f2i|drem|i2c|checkcast|frem|lreturn|astore|lushr|pop2|monitorexit|dneg|fastore|istore|lshl|ldiv|lstore|areturn|if_icmpge|ishr|monitorenter|invokeinterface|aastore|lxor|ishl|l2d|i2f|return|iushr|instanceof|invokespecial|fmul|ireturn|d2f|lneg|ixor|pop|i2l|ifnull|fdiv|lastore|i2b|if_acmpeq|ifge|swap|i2d|putstatic|fcmpl|ladd|irem|dcmpl|fsub|freturn|ifgt|castore|lmul|dadd|f2l|ddiv|dstore|land|if_icmpne|if_acmpne|dmul|dsub|sastore|ifle|d2i|i2s|lshr|iadd|l2i|bastore|fstore|fneg|fadd|ior|ineg|ifne|dreturn|l2f|if_icmple|getfield|invokevirtual|invokestatic|iastore)"); |
| map.put("exceptionthrower", "(irem|lrem|laload|putstatic|baload|dastore|areturn|getstatic|ldiv|anewarray|iastore|castore|idiv|saload|lastore|fastore|putfield|lreturn|caload|getfield|return|aastore|freturn|newarray|instanceof|multianewarray|athrow|faload|iaload|aaload|dreturn|monitorenter|checkcast|bastore|arraylength|new|invokevirtual|sastore|ldc_w|ireturn|invokespecial|monitorexit|invokeinterface|ldc|invokestatic|daload)"); |
| map.put("loadclass", "(multianewarray|invokeinterface|instanceof|invokespecial|putfield|checkcast|putstatic|invokevirtual|new|getstatic|invokestatic|getfield|anewarray)"); |
| map.put("instructiontargeter", "(ifle|if_acmpne|if_icmpeq|if_acmpeq|ifnonnull|goto_w|iflt|ifnull|if_icmpne|tableswitch|if_icmple|ifeq|if_icmplt|jsr_w|if_icmpgt|ifgt|jsr|goto|ifne|ifge|lookupswitch|if_icmpge)"); |
| |
| // Some aliases |
| map.put("if_icmp", "(if_icmpne|if_icmpeq|if_icmple|if_icmpge|if_icmplt|if_icmpgt)"); |
| map.put("if_acmp", "(if_acmpeq|if_acmpne)"); |
| map.put("if", "(ifeq|ifne|iflt|ifge|ifgt|ifle)"); |
| |
| // Precompile some aliases first |
| map.put("iconst", precompile(Constants.ICONST_0, Constants.ICONST_5, Constants.ICONST_M1)); |
| map.put("lconst", new String(new char[] { '(', makeChar(Constants.LCONST_0), '|', |
| makeChar(Constants.LCONST_1), ')' })); |
| map.put("dconst", new String(new char[] { '(', makeChar(Constants.DCONST_0), '|', |
| makeChar(Constants.DCONST_1), ')' })); |
| map.put("fconst", new String(new char[] { '(', makeChar(Constants.FCONST_0), '|', |
| makeChar(Constants.FCONST_1), ')' })); |
| |
| map.put("iload", precompile(Constants.ILOAD_0, Constants.ILOAD_3, Constants.ILOAD)); |
| map.put("dload", precompile(Constants.DLOAD_0, Constants.DLOAD_3, Constants.DLOAD)); |
| map.put("fload", precompile(Constants.FLOAD_0, Constants.FLOAD_3, Constants.FLOAD)); |
| map.put("aload", precompile(Constants.ALOAD_0, Constants.ALOAD_3, Constants.ALOAD)); |
| |
| map.put("istore", precompile(Constants.ISTORE_0, Constants.ISTORE_3, Constants.ISTORE)); |
| map.put("dstore", precompile(Constants.DSTORE_0, Constants.DSTORE_3, Constants.DSTORE)); |
| map.put("fstore", precompile(Constants.FSTORE_0, Constants.FSTORE_3, Constants.FSTORE)); |
| map.put("astore", precompile(Constants.ASTORE_0, Constants.ASTORE_3, Constants.ASTORE)); |
| |
| // Compile strings |
| |
| for(Iterator i = map.keySet().iterator(); i.hasNext(); ) { |
| String key = (String)i.next(); |
| String value = (String)map.get(key); |
| |
| char ch = value.charAt(1); // Omit already precompiled patterns |
| if(ch < OFFSET) { |
| map.put(key, compilePattern(value)); // precompile all patterns |
| } |
| } |
| |
| // Add instruction alias to match anything |
| |
| StringBuffer buf = new StringBuffer("("); |
| |
| for(short i=0; i < NO_OPCODES; i++) { |
| if(Constants.NO_OF_OPERANDS[i] != Constants.UNDEFINED) { // Not an invalid opcode |
| buf.append(makeChar(i)); |
| |
| if(i < NO_OPCODES - 1) |
| buf.append('|'); |
| } |
| } |
| buf.append(')'); |
| |
| map.put("instruction", buf.toString()); |
| } |
| |
| private static String precompile(short from, short to, short extra) { |
| StringBuffer buf = new StringBuffer("("); |
| |
| for(short i=from; i <= to; i++) { |
| buf.append(makeChar(i)); |
| buf.append('|'); |
| } |
| |
| buf.append(makeChar(extra)); |
| buf.append(")"); |
| return buf.toString(); |
| } |
| |
| /* |
| * Internal debugging routines. |
| */ |
| private static final String pattern2string(String pattern) { |
| return pattern2string(pattern, true); |
| } |
| |
| private static final String pattern2string(String pattern, boolean make_string) { |
| StringBuffer buf = new StringBuffer(); |
| |
| for(int i=0; i < pattern.length(); i++) { |
| char ch = pattern.charAt(i); |
| |
| if(ch >= OFFSET) { |
| if(make_string) |
| buf.append(Constants.OPCODE_NAMES[ch - OFFSET]); |
| else |
| buf.append((int)(ch - OFFSET)); |
| } else |
| buf.append(ch); |
| } |
| |
| return buf.toString(); |
| } |
| } |
