[Crash-utility] Miscellaneous fixes/enhancements to crash 4.0-2.10 (fwd)

[Castor Fu]

On Thu, 10 Nov 2005, Dave Anderson wrote:

>> I also did not feel comfortable accepting the extension-keyword
>> stuff.  While I do recognize that it would be useful to be
>> able to dynamically determine what extension modules to load,
>> I don't feel the extend command should be encumbered with the
>> job, but rather such an implementation-specific chore should
>> be handled by an instance of extension library code.
>> 
>> For that reason I exported both the load_extension() and
>> unload_extension() functions so that extension library code
>> could use them to in turn load other extension libraries.
>> 
>> The call to load_extension() could be made from either the
>> _init() function or from an extension command.  At those
>> points in time, the "first" extension library will have all
>> the information (kernel version, crash version, dumpfile,
>> etc.) at its disposal, and then can make the decision as to
>> what additional libraries to load.

Implementing this, I realized that the for this scheme to work,
if I want to access things like the crash version, the 'pc'
structure will have to remain the same.  Perhaps a small
set of these functions can be exported to reduce  the dependencies
of such a loader on defs.h?

The minimal expectation would be something which would export

     pc->program_version

If pc->curcmd were exported, that would also remove dependencies
on calling cmd_usage.

     -castor