#
# rmsif - an ifdef cleaner (ReMove Selected IF)
#
# Another Aromatic Productions
#   http://www.aromatic.com/
#
# Copyright (C) 1997-1998 Raffaele Sena (raff@aromatic.com)
# All rights reserved
#
# $Revision: 1.3 $
#   $Author: raff $
#     $Date: 1998/05/25 03:08:14 $

NAME

rmsif - ReMove Selected IF : an ifdef cleaner


SYNOPSYS

rmsif [-i] [-v] [-#] [-k] [-Dsym[=val]] [-Usym] file


DESCRIPTION

rmsif selectively removes if-then-else cpp directives from a file,
according to symbols you define or undefine on the command line.

There are a few other packages around (unifdef, rmifdef, scpp, etc.)
but either they don't support #if statements and expression or they 
have trouble with it. So, I decided to write another one.

rmsif supports all the #if-related cpp directives (#ifdef, #ifndef, 
#if, #elif, #else, #endif) and, according to the command line 
parameters, simplifies #if expressions or removes them (and the source 
code they cover, if that's the case).


OPTIONS

-i: ignore errors on a file and proceed with the other files
	If not defined, the process will stop at the first error.

	Note: the program accepts and processes multiple files, but 
	the current version sends the output of the processed file on 
	standard output. So, it's not very useful to process more than 
	one file at a time.

-v: dump symbols definitions at the beginning of the file
	Symbol are printed according to cpp grammar (#define and 
	#undef).
	If a symbol is multiple-defined, the generated code will 
	not compile.

-#: print all the # directives
	By default fully simplified expression make the directives 
	disappear.
	This version has a limitation that simplified expression 
	will come up as #if 0 or #if 1, because the original 
	expression get lost.  But still the option can be useful to 
	debug the process.

-d:
-D: create a symbol and mark it DEFINED
	The symbol can be simply defined (-DSYM) or defined with a 
	value (-DSYM=value)
	If the symbol has already been created undefined, its state 
	will change into defined.
	A symbol can have multiple definitions (with different values) 
	to allow the inclusion/exclusion of code marked by a subset of 
	the full set of values (for example for a source file with code 
	for three different processors - CPU=R3000, CPU=R4000, 
	CPU=R4400, you can specify '-DCPU=R3000 -DCPU=R4000' and remove 
	the code for CPU=R4400)

-u:
-U: create a symbol and mark it UNDEFINED
	you cannot undefine a symbol already defined.

-k: remove constants
	Remove code under #if 0 and remove the #if 1 directives.
	Can be useful to clean-up the sources and remove debugging 
	or temporary code.

KNOWN BUGS

Allocated memory is not correctly released. 
This is not really a problem on U*ix-like machines, where the
system provides to release all the memory associated to a terminating
proces, but it's not nice programming technique.

Fixed a problem of lines starting with '#' but inside a comment.
But the current code for checking for comments does not check yet
if the open comment ( '/*' ) is inside a quoted string.