7.4.2 ParameterTable Attribute

The ParameterTable attribute represents the BML related information about the method parameters. The structure of the attribute is the following:

     ParameterTable_attribute {
       u2 attribute_name_index;
       u4 attribute_length;
       u2 parameters_count;
       {
         u2 name_index;
         u2 BML_flags;
         u2 index;
       } parameters[parameters_count];
     }

The meaning of the fields is the following:

• attribute_name_index - index in the constant pool of the attribute name (org.bmlspecs.ParameterTable)
• attribute_length - length in bytes of the whole structure (8+6*parameters_count)
• parameters_count - the number of parameters of the method. It must be equal to the number of parameters in the method's type description.
• parameters - the table of parameter descriptions, where each element is a structure containing one field:
  • name_index - the index in the second constant pool where the parameter's name is stored as a CONSTANT_Utf8_info element
  • BML_flags - the flags that are set for the method. The allowed flags are BML_NON_NULL, BML_NULLABLE, BML_FINAL. JCh: anything else? All other flags should be cleared.
  • index - the index by which the parameter is referenced in the BML expressions of this method

Note that for methods with The Code attribute containing The LocalVariableTable attribute the parameter's names can already be stored there. In this case the two names must be equal. For methods without the Code attribute (e.g. abstract or native) however, the parameter's name is only stored in this attribute.

The index field in each parameter description must correspond to the index by which this parameter is referenced in the code (if it is present) and BML expressions in the method specification and other formulas in the method's code.

The order of parameters is not specified, but the description of all paramters must be present.