A thread can obtain the invocation context of a current
    procedure by using this function.

    Format

      LIB$X86_GET_CURR_INVO_CONTEXT(invo_context)

1  –  Returns

 Zero

    This facilitates use in the implementation of the C language
    unwind setjmp or longjmp function. Check the
    LIBICB$L_ALERT_CODE field of the invocation context block for
    further status indication.

2  –  Argument

 invo_context

    OpenVMS usage: invo_context_blk
    type:          structure
    access:        modify
    mechanism:     by reference

    Address of an invocation context block into which the procedure
    context of the caller will be written.