vmwcc-mos 0.1.5

Short:        c-subset compiler
Author:       Vince Weaver <vince@deater.net>, Morphos port by Fabrizio "Lanch" Bartoloni
Uploader:     lanch tiscali it (Fabrizio Bartoloni)
Type:         dev/c
Version:      0.1.5
Architecture: ppc-morphos

vmwcc version 0.1.5

  a c-subset compiler by Vince Weaver <vince@deater.net>
            originally based off of code by Martin Burtscher (@cornell.edu)
		  
		  
Current Status:
   Output:         32 bit PPC assembly
   Optimizations:  _OFF_
   Known Bugs:     Few
   Unknown bugs:   Many
   
Eventual Goal:
   Output:        PPC, Alpha, RiSC, more?
   Optimizations: Strength Reduction, Common sub-expression elimination
                  Dead code removal
		  
		  		  
The C-Subset
~~~~~~~~~~~~

   feature          working        will it ever
   
   if/else          yes
   while            yes
   for loops        yes
   structs          yes
   arrays           yes
   integer math     yes
   long type        yes
   int type         yes
   non-void funcs   yes
   
   link to libc     partially
   sizeof  	    partially
   
   floating-point   no             unlikely
   ternary (?:)     no             unlikely   
   typedef 	    no		   unlikely
   bitwise ops      no             maybe
   pointers         no             maybe
   pre/post inc/dec no             maybe
   +=,-=,*=,etc     no             maybe
   in-line assembly no		   maybe
   chars            no             hopefully
   c pre-processor  no             hopefully a subset
   goto             no             unlikely
   switch()/case    no		   unlikely
   self-hosting     no             when pigs fly
     
   
  Non-standard functions supported:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   WriteLine();    -- write a blank line
   WriteLong(x);   -- write out a long (x) to stdout
   ReadLong(x);    -- read a long into x
   

Technology:
~~~~~~~~~~~

 Uses a parser created directly from EBNF.
 Uses SSA (Static Single Assignment) as an intermediate language.

Background:
~~~~~~~~~~~

 This began as my ECE495 project.  Unfortunately it wasn't done at
 the end of the semester.  I've worked on it since then and it has
 made progress.


Running:
~~~~~~~~

  The options are designed to be as compatible as possible with gcc.
  	       
  Please note.  Optimizations are not debugged yet, so use -O2 at your
     own risk.  Also, while many tests are made before release
     (see the ./samples directory) there are undoubtedly many
     bugs lurking.  So please be patient and always use gcc
     if you absolutely need your code working perfectly.
	       
	       
  Usage:
    ./vmwcc [-Ox] [-S] [-W] [-c] [-dom] [-h] [-m arch] [-o filename]
	    [-ssa] [-v] filename.c
				 
    -Ox             : Use optimization level x (0 means none)
    -S              : Output assembly language file only
    -W              : Enable warnings
    -c              : Output object file only
    -dom            : Output dominator tree in .dot format
    -g              : Ignored.  For compatibility with gcc only
    -h              : Help.  This help message
    -m arch         : Output target.  Defaults to ppc-linux for now
    -o filename     : Output object or executable to this filename
    -pg             : Ignored.  For compatibility with gcc only
    -ssa            : Output internal SSA information to file
    -v              : Output version information
	
	
Compatability:
~~~~~~~~~~~~~~

  To make programs compile in both gcc and vmwcc add the following
  lines to the top of the file:
  
  #include <stdio.h>
  #define WriteLine() printf("n");
  #define WriteLong(x) printf(" %ld", x);
  #define ReadLong(a) if (fscanf(stdin, "%ld", &a) != 1) a = 0;
  
  vmwcc will ignore them but gcc will do the right thing.

Why:
~~~~

 Why create such an obviously broken compiler when gcc works fine?
 
 Because it is fun.  Also I am seeing if I can have the compiler 
 optimize for size, rather than speed.
 
 And also, gcc is a mess if you ever look at the code.  vmwcc is too
 but there's a lot less of it to sort through.
 
~~~

Vince Weaver, vince@deater.net  http://www.deater.net/weave/
16 June 2004