Efficient use of the dbx debugger on the SUNs
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(contributed by JPH 940919; based on research by CMV)


	For the convenience of programmers who want to use dbx with Newstar
programs, the objects in the Newstar libraries are routinely compiled with the
-g option (Newstar nsh option 'build -d') which creates objects including the
necessary symbolic information. When an executable is built with this same
option, all this information is carried over, resulting in a .exe file in which
all modules are accessible to dbx.

	This is very convenient for a programmer who needs access not only to
modules that he is modifying in his own shadow system but also to other
unmodified modules in the master libraries; indeed, there is no need for him to
copy master files to his shadow system for the mere purpose of recompiling them.
	The disadvantage is that the .exe file carries a huge ballast of
symbolic information (typically several hundred thousands of items) which take
a long time (many minutes) to load at the expense of a more than unmodest
consumption of machine resources.

	CMV found the following simple procedure to load only those symbols
that one actually needs:

	> dbx
	dbx> modules select <object_1>.o, <object_2>.o, ...
	dbx> debug <$n_exe/<program>.exe
	dbx> <set breakpoints or whatever>
	dbx> run

Should one discover in the subsequent debugging session that more modules are
needed, then one may restart the above sequence without leaving dbx.
Breakpoints and the like remain valid, but the modules selected before must
again be spelled out, - this is not nice but usually one needs only a few ...