Re: PATCH RFC: stdio optimization [take 2]

[Jeffrey A Law <law at cygnus dot com>]

  In message <199912221658.LAA26539@caip.rutgers.edu>you write:
  > Now here are the shortcomings: :-(
  > 
  > 1.  It works for C and Objc, but not for C++.  I don't know why, but
  > C++ won't expand the inline wrapper functions.  It emits them as
  > extern functions (which I thought was impossible if they were declared
  > as extern __inline__) and then calls them explicitely.
Hopefully one of the C++ front-end gurus can help.


  > 2.  IMO, there are too many wrappers in stdio-opt.h.  I needed these
  > to maintain the return value and signature of each function so I
  > wouldn't have to jump through too many hoops to make a replacement.
  > Suggestions (and instructions) for reducing the number would be great.
  > 
  > E.g. I could elimintate those only needed for the return value if I
  > could detect when the return value was not used and punt in those
  > cases.  But I don't know how to detect that.  I could also use some
  > help on how to build arglists with different argument types.  E.g.
  > given a constant string parameter, how do I take string[0] and
  > transform it into a char/int in a function call in a language
  > independent manner?
First I assume you need to detect when the return value is unused at the
tree level?  If so, look and see under what conditions expand_call is called
with the IGNORE as nonzero and trace how that decision is made (probably
in expand_expr).

Presumably the string[0]->char/int transformation is also happening at the
tree level?  If so, extract the relevent char out of the string and
build up a new tree constant.  You might write a hunk of C code which does
something similar and look at the tree nodes that get generated.


  > 3.  The setup forces you to include stdio-opt.h for now.  I'll
  > eventually have stdio.h include stdio-opt.h automatically.
  > (Suggestions for the best way to do this are welcome.)
If fixincludes provided you with a fixed copy of stdio.h, then you can
put the inclusion of stdio-opt.h at the front of the file.

Else make a wrapper which includes stdio-opt.h, then does an #include_next
stdio.h.