oracle.toplink.libraries.asm.attrs

Class SourceDebugExtensionAttribute

java.lang.Object

oracle.toplink.libraries.asm.Attribute

oracle.toplink.libraries.asm.attrs.SourceDebugExtensionAttribute

Direct Known Subclasses:

ASMSourceDebugExtensionAttribute

public class SourceDebugExtensionAttribute
extends Attribute

The SourceDebugExtension attribute is an optional attribute defined in JSR-045 in the attributes table of the ClassFile structure. There can be no more than one SourceDebugExtension attribute in the attributes table of a given ClassFile structure. The SourceDebugExtension attribute has the following format:

   SourceDebugExtension_attribute {
     u2 attribute_name_index;
     u4 attribute_length;
     u1 debug_extension[attribute_length];
   }
 

The items of the SourceDebugExtension_attribute structure are as follows:

attribute_name_index

The value of the attribute_name_index item must be a valid index into the constant_pool table. The constant_pool entry at that index must be a CONSTANT_Utf8_info structure representing the string "SourceDebugExtension".

attribute_length

The value of the attribute_length item indicates the length of the attribute, excluding the initial six bytes. The value of the attribute_length item is thus the number of bytes in the debug_extension[] item.

debug_extension[]

The debug_extension array holds a string, which must be in UTF-8 format. There is no terminating zero byte. The string in the debug_extension item will be interpreted as extended debugging information. The content of this string has no semantic effect on the Java Virtual Machine.

Author:

Eugene Kuleshov

See Also:

JSR-045: Debugging Support for Other Languages

Field Summary

Fields

Modifier and Type	Field and Description
java.lang.String	debugExtension

Fields inherited from class oracle.toplink.libraries.asm.Attribute

next, type

Constructor Summary

Constructors

Constructor and Description
SourceDebugExtensionAttribute()
SourceDebugExtensionAttribute(java.lang.String debugExtension)

Method Summary

Modifier and Type	Method and Description
protected Attribute	read(ClassReader cr, int off, int len, char[] buf, int codeOff, Label[] labels) Reads a type attribute.
java.lang.String	toString()
protected ByteVector	write(ClassWriter cw, byte[] code, int len, int maxStack, int maxLocals) Returns the byte array form of this attribute.

Methods inherited from class oracle.toplink.libraries.asm.Attribute

getLabels, isUnknown

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

debugExtension

public java.lang.String debugExtension

Constructor Detail

SourceDebugExtensionAttribute

public SourceDebugExtensionAttribute()

SourceDebugExtensionAttribute

public SourceDebugExtensionAttribute(java.lang.String debugExtension)

Method Detail

read

protected Attribute read(ClassReader cr,
                         int off,
                         int len,
                         char[] buf,
                         int codeOff,
                         Label[] labels)

Description copied from class: Attribute

Reads a type attribute. This method must return a new Attribute object, of type type, corresponding to the len bytes starting at the given offset, in the given class reader.

Overrides:

read in class Attribute

Parameters:

cr - the class that contains the attribute to be read.

off - index of the first byte of the attribute's content in cr.b. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.

len - the length of the attribute's content.

buf - buffer to be used to call readUTF8, readClass or readConst.

codeOff - index of the first byte of code's attribute content in cr.b, or -1 if the attribute to be read is not a code attribute. The 6 attribute header bytes, containing the type and the length of the attribute, are not taken into account here.

labels - the labels of the method's code, or null if the attribute to be read is not a code attribute.

Returns:

a new Attribute object corresponding to the given bytes.

write

protected ByteVector write(ClassWriter cw,
                           byte[] code,
                           int len,
                           int maxStack,
                           int maxLocals)

Description copied from class: Attribute

Returns the byte array form of this attribute.

Overrides:

write in class Attribute

Parameters:

cw - the class to which this attribute must be added. This parameter can be used to add to the constant pool of this class the items that corresponds to this attribute.

code - the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attributes.

len - the length of the bytecode of the method corresponding to this code attribute, or null if this attribute is not a code attribute.

maxStack - the maximum stack size of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.

maxLocals - the maximum number of local variables of the method corresponding to this code attribute, or -1 if this attribute is not a code attribute.

Returns:

the byte array form of this attribute.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object