Examples of org.apache.bcel.util.InstructionFinder.search()

org.apache.bcel.util.InstructionFinder.search()

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.

Example pattern:

 search("BranchInstruction NOP ((IfInstruction|GOTO)+ ISTORE Instruction)*");

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 ofinstruction handles describing the matched area

            }
        }
                
        // ALOAD_N ALOAD_N => ALOAD_N DUP
  pattern = "ALOAD ALOAD";
        for (Iterator iter = find.search(pattern); iter.hasNext();) {
            InstructionHandle[] match = (InstructionHandle[])iter.next();
            try {
                if (!match[1].hasTargeters()) {
                    org.apache.bcel.generic.ALOAD aload1 = 
                        (org.apache.bcel.generic.ALOAD) match[0].getInstruction();

        InstructionList il = mg.getInstructionList();
        InstructionFinder f   = new InstructionFinder(il);
        String            pat = "ALOAD_0 ALOAD_1 PUTFIELD ALOAD_0 INVOKESPECIAL";


        boolean changed = false;
        for(Iterator j = f.search(pat, new IsInnerConstructor()); j.hasNext(); )
        {
            InstructionHandle[] match = (InstructionHandle[]) j.next();


            // replace
            //    ALOAD_0       [0]

        InstructionList il = mg.getInstructionList();
        InstructionFinder f   = new InstructionFinder(il);
        String            pat = "[LDC_W|LDC] INVOKEVIRTUAL IFNE ICONST_1 GOTO ICONST_0";


        boolean changed = false;
        for(Iterator j = f.search(pat, new IsLdcClass()); j.hasNext(); )
        {
            InstructionHandle[] match = (InstructionHandle[]) j.next();


            // replace
            //    LDC_W <class>

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.