.TH FM2 1
.SH NAME
fm2 \- fast CC compatible Modula-2 compiler
.SH SYNOPSIS
.B fm2
[
.B \-c
]
[
.B \-O
]
[
.B \-v
]
[
.B \-vn
]
[ \fB\-D\fIname\fR ]
[ \fB\-D\fIname\fB=\fIdef\fR ]
[
.BI \-I pathname
]
[
.BI \-w classes
]
[
.BI \-W classes
]
[
.B \-L
]
[
.B \-o 
.I outfile
]
[
.B \-R
]
[
.B \-A
]
[
.B \-3
]
[
.B \-U
]
[
.B \-e
]
[
.BI \-U name
]
[
.BI -M compiler
]
.I sourcefile ...
.SH DESCRIPTION
.LP
.I fm2
is a fast
.B Modula-2
compiler. It translates 
.B Modula-2
programs
into cc(1)-compatible relocatable object modules, and does so in one pass.
Then, if the \fB\-c\fP flag is not given,
.I fm2
offers the object modules to a link-editor,
to create an executable binary.
.LP
.I Fm2
accepts several types of filename arguments.  Files with 
names ending in
.B .mod
are taken to be 
.B Modula-2
source programs. 
They are compiled, and the resulting object module is placed in the current
directory.
The object module is named after its source file, the suffix
.B .o
replacing 
.BR .mod
in the name of the object.
A file with suffix
.B .mod
is passed through the C preprocessor if it begins with a '#'.
.PP
Definition modules are not separately compiled. The compiler reads them when
it needs them.
Definition modules are expected to reside in files with names ending
in
.BR .def .
The name of the file in which a definition module is stored must be the same as
the module-name, apart from the extension.
Also, in most Unix systems filenames are only 14 characters long.
So, given an IMPORT declaration for a module called "LongModulName",
the compiler will try to open a file called "LongModulN.def".
The requirement does not hold for implementation or program modules,
but is certainly recommended.
.LP
Other arguments refer to loader options,
object modules, or object libraries.
Unless the
.B \-c
flag is given, these modules and libraries, together with the results of any
specified compilations, are passed (in the order given) to the
link-editor to produce
an output file named
.IR a.out .
You can specify a name for the executable by using the
.B \-o 
option.
.LP
If a single 
.B Modula-2
program is compiled and loaded all at once, the object module
file is deleted.
.SH OPTIONS
.LP
The \fB\-l\fIlib\fR, \fB\-d\fP, \fB\-n\fP, \fB\-N\fP,
\fB\-r\fP, \fB\-s\fP, \fB\-S\fP, \fB\-i\fP, and \fB\-u\fP options are
passed to the link-editor program.
The \fB\-u\fP option takes an extra argument.
.IP \fB\-c\fP
.br
Suppress the loading phase of the compilation, and force an object module to
be produced, even if only one program is compiled.
A single object module can be named explicitly using the
.B \-o
option.
.IP \fB\-D\fIname\fR\fB=\fIdef\fR
Define a symbol
.I name
to the 
preprocessor, as if by "#define".
.IP \fB\-D\fIname\fR
.br
same as \fB\-D\fIname\fB=1\fR.
.IP \fB\-I\fIpathname\fR
.br
Add
.I pathname
to the list of directories in which to search for
.B #include
files with filenames not beginning with slash.
The preprocessor first searches for
.B #include
files in the directory containing
.I sourcefile,
then in directories in
.B \-I
options, and finally, in
.I /usr/include.
This flag is also passed to the compiler. When the compiler needs a definition
module, it is first searched for in the current directory, then in the
directories given to it by the \fB\-I\fP flag, and then in a default directory,
.I CHANGE_ME.
.I fm2
This default directory contains all definition modules of
the runtime system.
.IP "\fB\-o \fIoutput\fR"
Name the final output file
.I output.
.IP \fB\-O\fP
.br
Use a version of the compiler that is just a bit slower, but produces
better code.
.IP \fB\-U\fIname\fR
.br
Remove any initial definition of
.I name.
.IP \fB\-v\fP
.br
Verbose. Print the commands as they are executed.
.IP \fB\-vn\fP
.br
Verbose, no execute. Only print the commands, do not execute them.
.IP \fB\-L\fR
do not generate code to keep track of
the current location in the source code.
.IP \fB\-w\fR\fIclasses\fR
suppress warning messages whose class is a member of \fIclasses\fR.
Currently, there are three classes: \fBO\fR, indicating old-flashioned use,
\fBW\fR, indicating "ordinary" warnings, and \fBR\fR, indicating
restricted Modula-2.
If no \fIclasses\fR are given, all warnings are suppressed.
By default, warnings in class \fBO\fR and \fBW\fR are given.
.IP \fB\-W\fR\fIclasses\fR
allow for warning messages whose class is a member of \fIclasses\fR.
.IP \fB\-R\fP
.br
disable all range-checks.
.IP \fB\-A\fP
.br
enable extra array bound checks. Unfortunately, the back-end used for this
compiler is a bit sloppy, so extra array bound checks are needed if you want
detection of array bound errors.
.IP \fB\-3\fP
.br
Only accept Modula-2 programs that strictly conform to the 3rd Edition of
[1].
.IP \fB\-U\fP
.br
allow for underscores within identifiers. Identifiers may not start or end
with an underscore, even if this flag is given.
.IP \fB\-e\fP
.br
allow for local extensions. Currently, the only local extensions are
procedure constants.
.IP \fB\-M\fIcompiler\fR
.br
use \fIcompiler\fR as Modula-2 compiler instead of the default.
.PP
The compiler does not do any version-control. Instead, a makefile
generator,
.IR m2mm ,
is included.
.SH "SEE ALSO"
.IP [1]
N. Wirth, \fIProgramming in Modula-2\fP, 3rd edition, Springer Verlag.
.IP [2]
C.J.H. Jacobs, \fIThe ACK Modula-2 Compiler\fP.
.IP [3]
cc(1) unix manual page.
.IP [4]
m2mm(1) manual page.
.SH DIAGNOSTICS
Diagnostics are intended to be self-explanatory.