cl -E/-EP, variable declaration behavior -fix?

[Peter Tanski]

Hello Simon,

While building $(TOP)/libraries I found that MS CL strictly conforms  
to the C standard (C99) preprocessor behavior (ISO/IEC 9899:1999,  
Sec. 6.10, para. 2): the '#' token is recognised as a preprocessing  
directive if it follows a newline and whitespace.  In other words,  
unlike the GCC preprocessor '#' does not have to be in column 0.   
This is a problem because people have a habit of block-quoting the  
GHC pragmas like this:

{-# directive
       <one or more directives>
  #-}

and of prefixing some titles with '#', such as this line in Control/ 
Concurrent.hs:

{- $boundthreads
    #boundthreads#

There are two solutions: either I could find some non-whitespace  
character to fit in before the '#' or I could go through and move  
every offending '#' back a line where it won't have whitespace in  
front of it.  For the above examples:

{-# directive
       <one or more directives> #-}

{- $boundthreads   #boundthreads#

If you don't mind I would like to do just that.  It is a larger  
change than I would like but it would not require an odd-looking (and  
apparently inexplicable) non-whitespace character.

On another stylistic note, CL errored out in many cases when people  
did not hold to the recommended GHC style convention and instead of  
declaring all variables first in a function instead declared them  
inside a separate block.  For example:

Instead of:

int fun( StgOtherStruct param ) {
	StgStructTypedef q;

	if ( blah ) {
	  q = param->member;
           ...
	}
}

They did this:

int fun( StgOtherStruct param ) {

	if ( blah ) {
	  StgStructTypedef *q = param->member;
           ...
	}
}

This causes CL to give one of several horrid and very unhelpful  
errors, all based on the fact that 'StgStructTypedef', above is an  
invalid symbol.  My fix was to pull the variable declarations out  
conditionally:

int fun( StgOtherStruct param ) {
#ifdef _MSC_VER
	StgStructTypedef q;
#endif

	if ( blah ) {
#ifdef _MSC_VER
	  q = param->member;
#else
	  StgStructTypedef *q = param->member;
#endif
           ...
	}
}

Which certainly doesn't change any non-CL behavior (it shouldn't, in  
any case).  It is ugly and awful.  Would it be o.k. for me to go  
through and change the variable declarations to be first in each  
function?

Cheers,
Pete