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Duh.  hsc2hs should be in $(GhcBinDistShScripts), not
$(GhcBinDistBins), otherwise it doesn't get the right directories
tacked on the front at installation time.  Strange that nobody
complained that hsc2hs wasn't working from a binary dist *shrug*.

Make it compile again with 5.04.x

Fix compilation breakage with GHC 4.08.x.

win32/Ticker.c:startTicker(),
win32/IOManager.c:NewIOWorkerThread():
  pass in non-NULL pointer to _beginthreadex()'s outgoing thread ID arg.
  Needed to work with Win9x's impl of CreateThread().

A round of space-leak fixing.

  - re-instate zapping of the PersistentCompilerState at various
    points during the compilation cycle in HscMain.  This affects
    one-shot compilation only, since in this mode the information
    collected in the PCS is not required after creating the final
    interface file.

  - Unravel the recursive dependency between MkIface and
    CoreTidy/CoreToStg.  Previously the CafInfo for each binding was
    calculated by CoreToStg, and fed back into the IdInfo of the Ids
    generated by CoreTidy (an earlier pass).  MkIface then took this
    IdInfo and the bindings from CoreTidy to generate the interface;
    but it couldn't do this until *after* CoreToStg, because the CafInfo
    hadn't been calculated yet.  The result was that the CoreTidy
    output lived until after CoreToStg, and at the same time as the
    CorePrep and STG syntax, which is wasted space, not to mention
    the complexity and general ugliness in HscMain.

    So now we calculate CafInfo directly in CoreTidy.  The downside is
    that we have to predict what CorePrep is going to do to the
    bindings so we can tell what will turn into a CAF later, but it's
    no worse than before (it turned out that we were doing this
    prediction before in CoreToStg anyhow).

  - The typechecker lazilly typechecks unfoldings.  It turns out that
    this is a good idea from a performance perspective, but it also
    means that it must hang on to all the information it needs to
    do the typechecking.  Previously this meant holding on to the
    whole of the typechecker's environment, which includes all sorts
    of stuff which isn't necessary to typecheck unfoldings.  By paring
    down the environment captured by the lazy unfoldings, we can
    save quite a bit of space in the phases after typechecking.

Use listArray rather than array in (un)?boxedTupleArr.

Remove unused export.

underscore some variables that aren't used.

Compilation fix after recent addition of environment stuff to System.Posix.

----------------------------------
	Improve higher-rank type inference
	----------------------------------

Yanling Wang pointed out that if we have

	f = \ (x :: forall a. a->a). x

it would be reasonable to expect that type inference would get the "right"
rank-2 type for f.  She also found that the plausible definition

	f :: (forall a. a->a) = \x -> x

acutally failed to type check.

This commit fixes up TcBinds.tcMonoBinds so that it does a better job.
The main idea is that there are three cases to consider in a function binding:

  a) 'f' has a separate type signature
	In this case, we know f's type everywhere

  b) The binding is recursive, and there is no type sig
	In this case we must give f a monotype in its RHS

  c) The binding is non-recursive, and there is no type sig
	Then we do not need to add 'f' to the envt, and can
	simply infer a type for the RHS, which may be higher
	ranked.

Remove mention of man pages, which we don't have, and clarify a couple
of other things while I'm here.

*** My last commit had a bogus commit message **
	*** This is the right one.  I've appended the **
	*** list of files changed as well.

	-------------------------------------
	   Fix up HOST/TARGET_OS ifdefs
	-------------------------------------

Sigbjorn and Simon helped me to understand when it's appropriate to
say 'ifdef mingw32_HOST_OS' and when 'ifdef mingw32_TARGET_OS'.  I've
documented this in the building guide.

I've fixed up the ifdefs I erroneously changed last week, in this
commit.  I'm not certain about all of them.  For examples, in
DriverPhases there's an ifdef that deals with filename suffices.
Should this be the filename suffices for the system on which GHC runs
(HOST), or the system on which the compiled code will run (TARGET)?
Currently it's the latter.

Similarly, there's some path mangling ('/' vs '\') in DriverState:
should this be for the system on which GHC runs (HOST) or the system
on which the compiled code will run (TARGET)?  Currently the former.

I think some of the darwin_TARGET_OS should be darwin_HOST_OS's.

Finally, for the GHCi stuff we require that HOST_OS = TARGET_OS.  Rather than
make an arbitrary choice in (e.g.) Linker.lhs, it's be better to say
'#ifdef mingw32_OS', and arrange that this macro is set only in stage-2.
I have not done this.

I think these are 'right'.  But I'm not sure the filename mangling is
consistent throughout.

[Changes in the original commit, which had a bogus message.]

  Revision  Changes    Path
  1.46      +30 -0     fptools/docs/building/building.sgml
  1.148     +4 -4      fptools/ghc/compiler/ghci/InteractiveUI.hs
  1.114     +2 -2      fptools/ghc/compiler/main/DriverFlags.hs
  1.23      +3 -1      fptools/ghc/compiler/main/DriverPhases.hs
  1.85      +11 -11    fptools/ghc/compiler/main/SysTools.lhs
  1.20      +3 -3      fptools/ghc/compiler/utils/Panic.lhs

Three Template Haskell improvements

a) Add type synonyms to THSyntax (and DsMeta, Convert)

b) Make Q into a newtype instead of a type synonym

c) Eliminate tiresome and error prone argument to DsMeta.wrapGenSyms
   and similarly addTyVarBinds

bring getourtimeofday() proto into scope

Clean up code&interfaces that deals with timers and asynchrony:

- Timer.{c,h} now defines the platform-independent interface
  to the timing services needed by the RTS. Itimer.{c,h} +
  win32/Ticker.{c,h} defines the OS-specific services that
  creates/destroys a timer.
- For win32 plats, drop the long-standing use of the 'multimedia'
  API timers and implement the ticking service ourselves. Simpler
  and more flexible.
- Select.c is now solely for platforms that use select() to handle
  non-blocking I/O & thread delays. win32/AwaitEvent.c provides
  the same API on the Win32 side.
- support threadDelay on win32 platforms via worker threads.

Not yet compiled up on non-win32 platforms; will do once checked in.

Typos

Fix buglets in new unused-binding story

Use old-style foreign import for bkwd compatibility

-------------------------------------
	Improve the "unused binding" warnings
	-------------------------------------

We've had a succession of hacks for reporting warnings for
unused bindings.  Consider

	module M( f ) where

 	f x = x

	g x = g x + h x
	h x = x

Here, g mentions itself and h, but is not itself mentioned. So
really both g and h are dead code.  We've been getting this wrong
for ages, and every hack so far has failed on some simple programs.

This commit does a much better job.  The renamer applied to a bunch
of bindings returns a NameSet.DefUses, which is a dependency-ordered
lists of def/use pairs.  It's documented in NameSet.
Given this, we can work out precisely what is not used, in a nice
tidy way.

It's less convenient in the case of type and class declarations, because
the strongly-connected-component analysis can span module boundaries.
So things are pretty much as they were for these.


As usual, there was a lot of chuffing around tidying things up.
I havn't tested it at all thoroughly yet.

Various unrelated import-decl-pruning has been done too.

Import pruning

Import pruning, use mingw32_TARGET not HOST, use old-style foreign import (for 4.08 compat)

Import pruning

More tidy up

Small fix to a TH bug; this one concerning the constraint-gathering mechanism

Another typo; sigh

Typo

Debugging hook jiggling

Fix a type-error in desugaring TH code

Asynchronous / non-blocking I/O for Win32 platforms.

This commit introduces a Concurrent Haskell friendly view of I/O on
Win32 platforms. Through the use of a pool of worker Win32 threads, CH
threads may issue asynchronous I/O requests without blocking the
progress of other CH threads. The issuing CH thread is blocked until
the request has been serviced though.

GHC.Conc exports the primops that take care of issuing the
asynchronous I/O requests, which the IO implementation now takes
advantage of. By default, all Handles are non-blocking/asynchronous,
but should performance become an issue, having a per-Handle flag for
turning off non-blocking could easily be imagined&introduced.

[Incidentally, this thread pool-based implementation could easily be
extended to also allow Haskell code to delegate the execution of
arbitrary pieces of (potentially blocking) external code to another OS
thread. Given how relatively gnarly the locking story has turned out
to be with the 'threaded' RTS, that may not be such a bad idea.]

deja vu all over again

* Nuked unused --with-glut-api and --with-glut-xlib arguments
* Only check for OpenGL headers and libs when --enable-hopengl is given

typo

-------------------------------------
      Add Core Notes and the {-# CORE #-} pragma
	-------------------------------------

This is an idea of Hal Daume's. The key point is that Notes in Core
are augmented thus:

  data Note
    = SCC CostCentre
    | ...
    | CoreNote String     -- NEW

These notes can be injected via a Haskell-source pragma:

   f x = ({-# CORE "foo" #-} show) ({-# CORE "bar" #-} x)

This wraps a (Note (CoreNote "foo")) around the 'show' variable,
and a similar note around the argument to 'show'.

These notes are basically ignored by GHC, but are emitted into
External Core, where they may convey useful information.

Exactly how code involving these notes is munged by the simplifier
isn't very well defined.  We'll see how it pans out.  Meanwhile
the impact on the rest of the compiler is minimal.

Document {-# CORE #-} pragma (thanks to Hal Daume)

Import pruning

Add comments

Comments and imports only

closureSatisfiesConstraints: check whether the retainer set is valid
before attempting to match it against a constraint.  It might not be
valid if the object is an ex-weak-pointer which was finalized after
the last GC.

MERGE TO STABLE

-------------------------------------
	   Complete an earlier TH commit
	-------------------------------------

In this earlier commit:

  3.  Ensure that a declaration quotation [d| ... |] does not have a
      permanent effect on the instance environment. (A TH fix.)

I had forgotten to do a stage2 compile.  This commit just completes
the earlier work.  I moved some code from TcExpr (long) to TcSplice
(shorter) which had the happy effect of bringing related code together.

-------------------------------------
   Generate correct dependencies when reading External Core
	-------------------------------------

We have to be more careful than I realised when doing strongly-connected
component analysis of type/class decls when reading External Core.

Here's the relevant new comment:

--		Building edges for SCC analysis
--
-- When building the edges, we treat the 'main name' of the declaration as the
-- key for the node, but when dealing with External Core we may come across
-- references to one of the implicit names for the declaration.  For example:
--	class Eq a where ....
--	data :TSig a = :TSig (:TEq a) ....
-- The first decl is sucked in from an interface file; the second
-- is in an External Core file, generated from a class decl for Sig.
-- We have to recognise that the reference to :TEq represents a
-- dependency on the class Eq declaration, else the SCC stuff won't work right.
--
-- This complication can only happen when consuming an External Core file
--
-- Solution: keep an "EdgeMap" (bad name) that maps :TEq -> Eq.
-- Don't worry about data constructors, because we're only building
-- SCCs for type and class declarations here.  So the tiresome mapping
-- is need only to map   [class tycon -> class]