GitLab

	Just pre-CUP-publication version
	--------------------------------

Includes all the changes that are in the CUP published version,
but still as two separate reports.  Next thing to do is to merge them.

* Added hs_free_stable_ptr and hs_free_fun_ptr.

hs_free_stable_ptr is.

consistent with hs_perform_gc and hs_set_argv. Furthermore, it's the
name Hugs already uses.

Rambles a bit - feel free to edit.

was stronger in presence of concurrency.  IMHO, SimonPJ's example
didn't demonstrate the claim because it was an argument to be able to
finalize _Haskell_ objects which contain C objects using Haskell
finalizers and so didn't actually involve ForeignPtrs at all.

Minor cleanups - e.g., changing back-references to forward references,
clarifying that 'finalizer' meant 'Haskell finalizer', etc.

Alastair, I'm afraid I removed one or two of your comments that were
simply out of place or duplicated points made elsewhere.  We don't
want to make the document any more hard to read than the email thread
that it is supposed to be summarising.

The structure of the document isn't quite ideal (too many forward
references) but didn't want to mess with it too much.

There were conflicts with the previous commit which I did my best to
resolve.  I don't think I broke anything but I couldn't always
identify what had been changed in the previous commit so I may not
have been successful.

* Added hs_perform_gc().

type class.  Reverse the meaning of the sign of the second argument
for `rotate' and `shift' (this makes it the same as GHC used all
the time).  `bitSize' on `Integer' etc is now undefined.

Allowing multiple calls to hs_init() and clarified the constraints
on the relative timing between hs_set_argv() and
getProgName/getArgs.

* 4.1.4: clarified that header files
         do not impact the semantics of foreign calls, but may be required
         for correct code generation by some systems
* 5.5:   Finalisers must be external functions to facilitate the
         implementation on Haskell systems that do not support pre-emptive
         concurrency

received some support and no dissent.

  Changes since RC5:
  * Author list: changed Alastair Reid's institution
  * 4.1.1: Removed [lib] from impent syntax and discussion
  * 4.1.3: Added parentheses round FunPtr ft to make it easier to
           understand a tolerably complex type.
  * 4.1.4: Removed all mention of library objects
  * 6:     Specified that HsBool==int in table2
           Relabelled column 1 in table 3 (C symbol -> CPP symbol)
           Replaced 0 and 1 with HS_BOOL_FALSE/TRUE

You will need this file:

  http://www.cse.unsw.edu.au/~chak/haskell/grammar.sty

to build it.  (I came close to adding this file to the repo but
figured that Manuel must have a reason for not having done so
himself.)

Changes not applied:

- I really, really want to resolve the ForeignPtr issues soon.

    http://www.mail-archive.com/ffi@haskell.org/msg00655.html
    http://www.mail-archive.com/ffi@haskell.org/msg00544.html
    http://www.mail-archive.com/ffi@haskell.org/msg00545.html

- I'd like to see a standard way to call the GC from C

    http://www.mail-archive.com/ffi@haskell.org/msg00565.html

  Note that Hugs and GHC have had this for ages except that we call the
  function 'performGC' and there's no way to control how many generations
  are collected.

- I see the question of Function prototypes as a portability problem
  waiting to happen.  Either Hugs and GHC are right (you should use the
  user-supplied header file or NHC is right (you should ignore the
  header file).  They can't both be right if we want portable code
  so the report should be clear about which one is right.

  (Given my druthers, I'd drop header files from the foreign import syntax
  and say that you have to specify it on the command line or propose that
  we standardize some variant of the GHCism {-# -include "foo.h" #-}.  But
  I'm not excited enough about it to push hard for this.)

- Changes to hs_init

    http://www.mail-archive.com/ffi@haskell.org/msg00539.html

* Added threadsafe

* Replaced `entity' by `impent' and `expent'

* 5.8: Added `MarshalAlloc.realloc'.
* 3.2: Clarified the description of foreign types; so far, `IO ()' was
  strictly speaking not included as a valid return type.  Currently,
  functions of type `a -> ()' are included.  Do we want this?  Their use
  might not be portable if they include side effects.
* 4.1.5: New section discussing the traps & pitfalls of type promotion with
  C bindings.

a function name in the Prelude.

- corrected special ids