GitLab

----------------------------------------
     New Core invariant: keep case alternatives in sorted order
	----------------------------------------

We now keep the alternatives of a Case in the Core language in sorted
order.  Sorted, that is,
	by constructor tag	for DataAlt
	by literal		for LitAlt

The main reason is that it makes matching and equality testing more robust.
But in fact some lines of code vanished from SimplUtils.mkAlts.


WARNING: no change to interface file formats, but you'll need to recompile
your libraries so that they generate interface files that respect the
invariant.

--------------------------
	Add -fwarn-orphans flag
	--------------------------

This gives a decent report for modules that contain 'orphan' instance and
rule declarations.  These are to be avoided, because GHC has to proactively
read the interface file every single time, just in case the instance/rule is
needed.

The flag just gives a convenient way of identifying the culprits.

---------------------------------
     Template Haskell: dynamically scoped qualified names
	---------------------------------

This commit adds a constructor to TH.Name, so that

	nameBase (mkName "Foo.baz")    == "baz"
	nameModule (MkName "Foo.baz") == "Foo"

We always did parse the module name off the front, but it used to
be done in hsSyn/Convert, but now it's done in TH.Syntax, which is
a better place.

Fix buglet in CSE

An old commit about paths on windows

---------------------------------
     Improve handling of lexically scoped type variables
	---------------------------------

If we have

	f :: T a -> a
	f (x :: T b) = ...

then the lexically scoped variable 'b' should refer to the rigid
type variable 'a', without any intervening wobbliness.  Previously
the in-scope type variables were always mutable TyVars, which were
instantatiated to point to the type they were bound to; but since
the advent of GADTs the intervening mutable type variable is a bad
thing.

Hence
  * In the type environment, ATyVar now carries a type
  * The call to refineTyVars in tc_pat on SigPatIn
    finds the types by matching
  * Then tcExtendTyVarEnv3 extends the type envt appropriately

Rater a lot of huff and puff, but it's quite natural for ATyVar
to contain a type.

Various other small nomenclature changes along the way.

Comments

Remove debug output

Comments

Add missing NoteTy cases to unify_

Comments only

Fix bogon in type comparison

Comment only

Another wibble to the Panic change; this time on Windows

--------------------------------
	Deal properly with dual-renaming
	--------------------------------

When comparing types and terms, and during matching, we are faced
with 
	\x.e1	~   \y.e2

There are many pitfalls here, and GHC has never done the job properly.
Now, at last it does, using a new abstraction VarEnv.RnEnv2.  See
comments there for how it works.

There are lots of consequential changes to use the new stuff, especially
in 
	types/Type (type comparison), 
	types/Unify (matching on types)
	coreSyn/CoreUtils (equality on expressions), 
	specialise/Rules (matching).

I'm not 100% certain of that I've covered all the bases, so let me
know if something unexpected happens after you update.  Maybe wait until
a nightly build has worked ok first!

The documentation breakage continues... >:-( Fixed DocBook. Again: "make html"
(or the faster "make validate" in the case of DocBook XML) is your friend! >:-(

Restore a test; fixes rnfail042

Fix breakage in previous commit re signal handling

Add entry about Ctrl-C on Windows

Add comment about Ctrl-C/Ctrl-Break issue

Support for Ctrl-C on Windows.

This works fine in a cmd.exe shell, but in a Cygwin bash shell you
have to press Ctrl-Break to get an interrupt.  There appears to be a
long thread on the cygwin mailing list back in 2002 about this, but
life is probably too short to investigate further.

  http://www.cygwin.com/ml/cygwin/2002-01/msg00163.html

Sanity check when configuring for mingw32: make sure that $CC is a
mingw gcc before proceeding.

--with-gcc: export the CC environment variable, so the setting gets
picked up by sub-configures.  Perhaps we should be advising people to use

  CC=c:/mingw/bin/gcc ./configure

because that works for all configure scripts, not just the top level one.

Background:

 - We want --with-gcc to do the right thing, because we don't want
   to require Cygwin users to put c:/mingw/bin first on their
   path: that would break their Cygwin environment.

 - The build system should work with *no* gcc on your PATH, as long
   as you use --with-gcc (equivalently, CC=... ./configure).

Darn!  Forgot this commit, which killed the nightly build

Comments only

Make ghc/lib/compat/Compat/Directory.hs use the C function
	__compat_long_path_size, rather than
	__hscore_long_path_size, as the libraries/ version does
And make ghc/lib/compat/cbits/directory.c define it.

In this way we avoid spurious duplicate-symbol errors when we
compile GHC with ghc6.2.1 etc.

Tidy the type of an interactively-bound Id before adding
it to the environment.  Generally speaking, top level
environments are assumed to be in tidied form, so we
don't tidy the types before printing.

comment

Comments only

stg_sel_##offset##_upd_entry: the ENTER() here is unnecessary, because
we know the closure in R1 will evaluate to a constructor, so we can
save some time by just entering it directly.

Undo bogus 1.4 commit

First commit for new Cmm code generation (branch)

Comments and asserts only

Fix bug #1073501: checkProddableBlock: invalid fixup in runtime linker

The bug manifested when trying to load an object with debugging info
(compiled with gcc -g) into GHCi.

The problem was that the object loader was ignoring the sections
containing debugging info, but then it was later trying to do
relocations for those sections, and its own sanity checking code
correctly detected that the relocations were in unknown parts of the
object file.

The fix is to ignore relocations whose target section isn't one of the
sections that we're interested in, using the same test in both cases
(the code to test section kind has been extracted).  The code could
probably benefit from more refactoring: it looks like the list of
sections we build up in the first phase isn't even used in the second
phase, instead we traverse the section table in the image again.  This
looks like cruft leftover from when the GC used to check whether an
address was in text or data space.

deleteThread: don't attempt to delete threads blocked in foreign calls.

Prevent any intermediate file deletion using

  .SECONDARY:

and remove now-unnecessary .PRECIOUS and .SECONDARY targets.
Suggestion from Ashley Yakeley.

---------------------
	Bug in specialisation
	---------------------

Laszlo managed to get a function like this:

	foo :: Enum a => (# a, Int #)

The specialiser specialised it, resulting in an unboxed tuple
binding, which Lint objected to.

This commit adds a dummy argument to the specialised function, 
very like the case for strictness analysis.  For example, at
type Char we'd get

	foo_char :: State# RealWorld -> (# Char, Int #)
 	foo_char = \_ -> ...

We use a State# type because it generates no argument-passing code 
at runtime.  (We should really have some other void type for this 
purpose, because State# is misleading, but this way avoids extra
types.)

------------------------------------
	Bug in loop detection in TcSimplify
	------------------------------------

The type-class context simplifier has been able to 
build recursive dictionaries for some time: co-induction.
That is, you can build a proof for constraint C by assuming
that C holds when proving the preconditions of C.

You need to be in -fallow-undecidable-instances land to 
make use of this: see comments with [RECURSIVE DICTIONARIES]
in TcSimplify.lhs.

Anyway, this is all fine, but I'd implemented it wrong!  You need
to be very careful with superclasses, or you can make a bogus
loop by mistake.  This commit fixes it; tests LoopOfTheDay{1,2,3}
will test it (thanks Ralf Laemmel).

Error message fixup

Moved GTK_CONFIG detection to ghc subdirectory (untested).