.SH "DEPENDENCY ANALYSER TOOL OPTIONS"
.PP
A number of options are available to control exactly which of the interfaces and
modules (units) found on the search path are compiled. By default, those
units in the current directory are compiled, plus any interfaces
from other directories that are imported by the units in the current
directory. Usually this is exactly what you want. 
However, it is
posssible to expand the set of units that are compiled. 
Two useful points in the spectrum
are "all the units that make up my program" and "all the units on
the search path". 
.TP
.B \-CompileInDirs [dir1  dir2 ...]
With no directory arguments, this is interpreted as "compile
the units in all directories on the search path", otherwise it means
"compile the units in the current directory and in dir1, dir2,...".
Note that the actual set of units that are compiled is still
subject to filtering, see below.
.TP
.B \-NOFilterUnits
By default
compilations are restricted to those that are \fIneeded\fP by the units in the 
current working directory. 
The definition of \fIneeded\fP is straightforward for
interfaces but, since Modula-3 allows any module to export any
interface, requires a heuristic for modules, as follows. 
For any required interface 'Foo', any module whose filename is
of the form 'Foo*' or '*Foo', where '*' denotes a possibly empty
sequence of characters, is considered to be needed. When this
option is enabled, compilation starts with all the units in the current
directory and iterates until no new units are needed.

So, for example, modulo the constraints implied by the heuristic, 
option \fB-CompileInDirs\fP, with no arguments, will cause all the units 
that make up a program
to be compiled (assuming that the sources can be found on the
search path). If \fBNOFilterUnits\fP is also set, then every unit
in every directory will be compiled.
.TP
.B \-FilterUnitsExact
This option has a similar effect to \fPFilterUnits\fP, except that the
export heuristic is altered so that only a module with the same name
as an interface is considered as a possible exporter. 
.TP
.B \-HeadersOnly
By default, the tool compiles an entire interface or module.
This option restricts the compilation to the module header and
\fBIMPORT\fP statements. This provides enough information for
dependency analysis , but not enough for
general browsing or pre-linking. The advantage is that compilations
are much faster and memory usage is kept to a minimum.
.TP
.B \-Verbose
This option provides output on the standard error stream about
the actions of the tool. It is useful to observe the effects of
the filter options on the set of units discovered from the
search path..