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package com.sun.org.apache.bcel.internal.generic;

import com.sun.org.apache.bcel.internal.classfile.CodeException;

This class represents an exception handler, i.e., specifies the region where a handler is active and an instruction where the actual handling is done. pool as parameters. Opposed to the JVM specification the end of the handled region is set to be inclusive, i.e. all instructions between start and end are protected including the start and end instructions (handles) themselves. The end of the region is automatically mapped to be exclusive when calling getCodeException(), i.e., there is no difference semantically.
See Also:
Version:$Id: CodeExceptionGen.java 1749603 2016-06-21 20:50:19Z ggregory $
/** * This class represents an exception handler, i.e., specifies the region where * a handler is active and an instruction where the actual handling is done. * pool as parameters. Opposed to the JVM specification the end of the handled * region is set to be inclusive, i.e. all instructions between start and end * are protected including the start and end instructions (handles) themselves. * The end of the region is automatically mapped to be exclusive when calling * getCodeException(), i.e., there is no difference semantically. * * @version $Id: CodeExceptionGen.java 1749603 2016-06-21 20:50:19Z ggregory $ * @see MethodGen * @see CodeException * @see InstructionHandle */
public final class CodeExceptionGen implements InstructionTargeter, Cloneable { private InstructionHandle start_pc; private InstructionHandle end_pc; private InstructionHandle handler_pc; private ObjectType catch_type;
Add an exception handler, i.e., specify region where a handler is active and an instruction where the actual handling is done.
Params:
  • start_pc – Start of handled region (inclusive)
  • end_pc – End of handled region (inclusive)
  • handler_pc – Where handling is done
  • catch_type – which exception is handled, null for ANY
/** * Add an exception handler, i.e., specify region where a handler is active * and an instruction where the actual handling is done. * * @param start_pc Start of handled region (inclusive) * @param end_pc End of handled region (inclusive) * @param handler_pc Where handling is done * @param catch_type which exception is handled, null for ANY */
public CodeExceptionGen(final InstructionHandle start_pc, final InstructionHandle end_pc, final InstructionHandle handler_pc, final ObjectType catch_type) { setStartPC(start_pc); setEndPC(end_pc); setHandlerPC(handler_pc); this.catch_type = catch_type; }
Get CodeException object.
This relies on that the instruction list has already been dumped to byte code or or that the `setPositions' methods has been called for the instruction list.
Params:
  • cp – constant pool
/** * Get CodeException object.<BR> * * This relies on that the instruction list has already been dumped to byte * code or or that the `setPositions' methods has been called for the * instruction list. * * @param cp constant pool */
public CodeException getCodeException(final ConstantPoolGen cp) { return new CodeException(start_pc.getPosition(), end_pc.getPosition() + end_pc.getInstruction().getLength(), handler_pc.getPosition(), (catch_type == null) ? 0 : cp.addClass(catch_type)); } /* Set start of handler * @param start_pc Start of handled region (inclusive) */ public void setStartPC(final InstructionHandle start_pc) { // TODO could be package-protected? BranchInstruction.notifyTarget(this.start_pc, start_pc, this); this.start_pc = start_pc; } /* Set end of handler * @param end_pc End of handled region (inclusive) */ public void setEndPC(final InstructionHandle end_pc) { // TODO could be package-protected? BranchInstruction.notifyTarget(this.end_pc, end_pc, this); this.end_pc = end_pc; } /* Set handler code * @param handler_pc Start of handler */ public void setHandlerPC(final InstructionHandle handler_pc) { // TODO could be package-protected? BranchInstruction.notifyTarget(this.handler_pc, handler_pc, this); this.handler_pc = handler_pc; }
Params:
  • old_ih – old target, either start or end
  • new_ih – new target
/** * @param old_ih old target, either start or end * @param new_ih new target */
@Override public void updateTarget(final InstructionHandle old_ih, final InstructionHandle new_ih) { boolean targeted = false; if (start_pc == old_ih) { targeted = true; setStartPC(new_ih); } if (end_pc == old_ih) { targeted = true; setEndPC(new_ih); } if (handler_pc == old_ih) { targeted = true; setHandlerPC(new_ih); } if (!targeted) { throw new ClassGenException("Not targeting " + old_ih + ", but {" + start_pc + ", " + end_pc + ", " + handler_pc + "}"); } }
Returns:true, if ih is target of this handler
/** * @return true, if ih is target of this handler */
@Override public boolean containsTarget(final InstructionHandle ih) { return (start_pc == ih) || (end_pc == ih) || (handler_pc == ih); }
Sets the type of the Exception to catch. Set 'null' for ANY.
/** * Sets the type of the Exception to catch. Set 'null' for ANY. */
public void setCatchType(final ObjectType catch_type) { this.catch_type = catch_type; }
Gets the type of the Exception to catch, 'null' for ANY.
/** * Gets the type of the Exception to catch, 'null' for ANY. */
public ObjectType getCatchType() { return catch_type; }
Returns:start of handled region (inclusive)
/** * @return start of handled region (inclusive) */
public InstructionHandle getStartPC() { return start_pc; }
Returns:end of handled region (inclusive)
/** * @return end of handled region (inclusive) */
public InstructionHandle getEndPC() { return end_pc; }
Returns:start of handler
/** * @return start of handler */
public InstructionHandle getHandlerPC() { return handler_pc; } @Override public String toString() { return "CodeExceptionGen(" + start_pc + ", " + end_pc + ", " + handler_pc + ")"; } @Override public Object clone() { try { return super.clone(); } catch (final CloneNotSupportedException e) { throw new Error("Clone Not Supported"); // never happens } } }