Examples with ClassGenException org.apache.bcel.generic.ClassGenException used on opensource projects

Example 1 with ClassGenException

use of org.apache.bcel.generic.ClassGenException in project jop by jop-devel.

the class InstructionFinder method 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".
     *
     * BUGFIX: wrong length (WP)
     *
     * 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(&quot;BranchInstruction NOP ((IfInstruction|GOTO)+ ISTORE Instruction)*&quot;);
     * </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) {
            // Where to start search from (index)
            start = i;
            break;
        }
    }
    if (start == -1) {
        throw new ClassGenException("Instruction handle " + from + " not found in instruction list.");
    }
    Pattern regex = Pattern.compile(search);
    List matches = new ArrayList();
    Matcher matcher = regex.matcher(il_string);
    while (start < il_string.length() && matcher.find(start)) {
        int startExpr = matcher.start();
        int endExpr = matcher.end();
        // int lenExpr = (endExpr - startExpr) + 1;
        int lenExpr = (endExpr - startExpr);
        InstructionHandle[] match = getMatch(startExpr, lenExpr);
        if ((constraint == null) || constraint.checkCode(match)) {
            matches.add(match);
        }
        start = endExpr;
    }
    return matches.iterator();
}