Avoid desugaring bug in HEAD (see test ds057).

Fix up to compile with GHC 5.04.x again.

Also includes a fix for a memory error I discovered along the way:
should fix the "scavenge_one" crash in the stage2 build of recent
HEADs.

ord# and chr# should be no-ops, not conversions between wordRep and I32.

Add support for UTF-8 source files

GHC finally has support for full Unicode in source files.  Source
files are now assumed to be UTF-8 encoded, and the full range of
Unicode characters can be used, with classifications recognised using
the implementation from Data.Char.  This incedentally means that only
the stage2 compiler will recognise Unicode in source files, because I
was too lazy to port the unicode classifier code into libcompat.

Additionally, the following synonyms for keywords are now recognised:

  forall symbol 	(U+2200)	forall
  right arrow   	(U+2192)	->
  left arrow   		(U+2190)	<-
  horizontal ellipsis 	(U+22EF)	..

there are probably more things we could add here.

This will break some source files if Latin-1 characters are being used.
In most cases this should result in a UTF-8 decoding error.  Later on
if we want to support more encodings (perhaps with a pragma to specify
the encoding), I plan to do it by recoding into UTF-8 before parsing.

Internally, there were some pretty big changes:

  - FastStrings are now stored in UTF-8

  - Z-encoding has been moved right to the back end.  Previously we
    used to Z-encode every identifier on the way in for simplicity,
    and only decode when we needed to show something to the user.
    Instead, we now keep every string in its UTF-8 encoding, and
    Z-encode right before printing it out.  To avoid Z-encoding the
    same string multiple times, the Z-encoding is cached inside the
    FastString the first time it is requested.

    This speeds up the compiler - I've measured some definite
    improvement in parsing at least, and I expect compilations overall
    to be faster too.  It also cleans up a lot of cruft from the
    OccName interface.  Z-encoding is nicely hidden inside the
    Outputable instance for Names & OccNames now.

  - StringBuffers are UTF-8 too, and are now represented as
    ForeignPtrs.

  - I've put together some test cases, not by any means exhaustive,
    but there are some interesting UTF-8 decoding error cases that
    aren't obvious.  Also, take a look at unicode001.hs for a demo.

Document -Rghc-timing

MERGE TO STABLE

This commit fixes a nasty problem discovered by Volker Stolz.
The problem is described in Note [Multiple instantiation] in
TcExpr, which is reproduced below.

(Core Lint identifies the problem, incidentally.)

tc200 is a test case.


Note [Multiple instantiation]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We are careful never to make a MethodInst that has, as its meth_id, another MethodInst.
For example, consider
	f :: forall a. Eq a => forall b. Ord b => a -> b
At a call to f, at say [Int, Bool], it's tempting to translate the call to

	f_m1
  where
	f_m1 :: forall b. Ord b => Int -> b
	f_m1 = f Int dEqInt

	f_m2 :: Int -> Bool
	f_m2 = f_m1 Bool dOrdBool

But notice that f_m2 has f_m1 as its meth_id.  Now the danger is that if we do
a tcSimplCheck with a Given f_mx :: f Int dEqInt, we may make a binding
	f_m1 = f_mx
But it's entirely possible that f_m2 will continue to float out, because it
mentions no type variables.  Result, f_m1 isn't in scope.

Here's a concrete example that does this (test tc200):

    class C a where
      f :: Eq b => b -> a -> Int
      baz :: Eq a => Int -> a -> Int

    instance C Int where
      baz = f

Current solution: only do the "method sharing" thing for the first type/dict
application, not for the iterated ones.  A horribly subtle point.

'newtype' declarations are now parsed exactly like data type declarations,
so that you can declare newtypes using GADT syntax.  But that means we
must check all the newtype restrictions separately, and I mised one.
This commit checks that there is no existential context on the newtype.

Test is tcfail156

This file is not quite POSIX compliant; hopefully fix build on MacOS X
(Tiger)

remove duplicate definition

make 3.79.1 is ok

Resolve ticket 644; crash when data con returns wrong type

setContextAfterLoad: try to load a target if possible, otherwise load
the topmost module in the graph.  Previously we were loading the first
module in the list, which happened to be right a lot of the time, but
not always.

Fixes ticket #642

export ModLocation(..)

sanity bugfix: use TSO_OFFSET_stack instead of OFFSET_stack

two fixes for the case when a (synchronous) exception is propagated to
the top of a thread's stack, i.e. it is unhandled.

  1. store the exception in the right place (we were using the
     OFFSET_StgTSO_stack macro and not accounting for the TSO's
     header size)

  2. put an stg_enter_info on the stack so that the GC can understand
     this thread's stack.

for TSO fields, define a Cmm macro TSO_OFFSET_xxx to get the actual
offset including the header and variable parts (we were misusing the
headerless OFFSET_xxx macros in a couple of places).

wibble in panic message

emit an error message if GNU make 3.7x is found (3.80 is required).

mention that GNU make 3.80 is required.

Trim imports

Document SPECIALISE INLNE

Missing Show instance for FreeRegs on PowerPC

Wibble to printing FunTyCon in GHCi that makes :b GHC.Base work

Marginally improve the error message on a failure in DsMeta

Tiny fix to patterns with type sigs

Allow trailing parens in GADT signatures

** Wibble to Friday's commit (fixes HEAD build) **

	-----------------------------------------
	Make deriving work for infix constructors
	-----------------------------------------

	Merge to stable branch

Back quotes were not being done correctly in deriving Read and Show.
Now they are.  I think.

Test is drvrun018

-----------------------------------------
	Make deriving work for infix constructors
	-----------------------------------------

	Merge to stable branch

Back quotes were not being done correctly in deriving Read and Show.
Now they are.  I think.

Test is drvrun018

Document that type variables in instance context must be distinct; merge to stable

-----------------------------------------
	Test for repated type variables in an instance decl context;
	this should require -fallow-undecidable-instances'
	-----------------------------------------

	Merge to stable branch

Avoid building the GHCi version of this lib

Use standard calloc rather than rolling our own.

As a small bonus, the standard libc version is more effecient about zeroing
the memory.

From: Duncan Coutts <duncan.coutts@worc.ox.ac.uk>

(( PLEASE MERGE TO STABLE ))

Linker.c: linux/ppc: We call mmap() to allocate additional pages to
                     create jump islands.  In the case where no
                     additional memory was needed the mmap call was
                     being made with a size of 0 which would fail.
                     The call is now conditionalised and documentation
                     has been added to the code.  Closes trac #439.

ignore _darcs

fix missing symbol

Raise the (new) exception NestedAtomically when atomically is nested
(using unsafePerformIO).  This is a small improvement over crashing.

fix FAQ links

the FAQ is now in the Wiki

while I'm here, bring various other bits of this page up to date