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There's no point splitting objects when we're going to be dynamically
linking. Plus it breaks compilation on OSX x86.

Without it, when linking the split objects for Language.Haskell.TH.Syntax,
the commandline was too long when listing all the files directly.

LLVM supports PIC on ARM from what I can see.
Signed-off-by: Austin Seipp <aseipp@pobox.com>

We were previously enabling Opt_PIC on certain OSes namely Windows,
Darwin and Linux, but it should always be enabled for the dyn way
because it makes no sense to try to generate non-PIC dynamic
libraries, which is usually impossible.

On OpenBSD and NetBSD, we were accidentally passing "-optl-pthread" to
the gcc to build dynamic libraries because of a bitrotted hack for
those OSes, which resulted in a weird situation where every dynamic
library is named "ptl-pthread" and placed at "$(TOP)".

The hack in question were to work around a linkage problem with
libHSffi, but we no longer build it and just use libffi these days so
the hack can safely be removed.

There were some cases where we weren't unsetting it when turning the
Dyn way on.

In particular, this means that GHCi will use DLLs, rather than loading
object files itself.

This is a slightly refined version of a patch by shachaf,
done by Krzysztof Gogolewski <krz.gogolewski@gmail.com>.

I'm not sure why it caused problems before, but it's fine now.

We don't need them, but GHC API users might.

We only use the unicode characters if the locale supports them.

This work was all done by
   Achim Krause <achim.t.krause@gmail.com>
   George Giorgidze <giorgidze@gmail.com>
   Weijers Jeroen <jeroen.weijers@uni-tuebingen.de>

It allows list syntax, such as [a,b], [a..b] and so on, to be
overloaded so that it works for a variety of types.

The design is described here:
    http://hackage.haskell.org/trac/ghc/wiki/OverloadedLists

Eg. you can use it for maps, so that
        [(1,"foo"), (4,"bar")] :: Map Int String

The main changes
 * The ExplicitList constructor of HsExpr gets witness field
 * Ditto ArithSeq constructor
 * Ditto the ListPat constructor of HsPat

Everything else flows from this.

This patch makes the Data.Typeable.Typeable class work with arguments of any
kind. In particular, this removes the Typeable1..7 class hierarchy, greatly
simplyfing the whole Typeable story. Also added is the AutoDeriveTypeable
language extension, which will automatically derive Typeable for all types and
classes declared in that module. Since there is now no good reason to give
handwritten instances of the Typeable class, those are ignored (for backwards
compatibility), and a warning is emitted.

The old, kind-* Typeable class is now called OldTypeable, and lives in the
Data.OldTypeable module. It is deprecated, and should be removed in some future
version of GHC.

* By default '-fvectorisation-avoidance' is enabled at all optimisation levels (but it only matters in combination with '-fvectorise').
* The new vectoriser always uses vectorisation avoidance, but with '-fno-vectorisation-avoidance' it restricts it to simple scalar applications (and dictionary computations)

Function responsible for parsing the static flags, that were spread
across two modules (StaticFlags and StaticFlagParser), are now
in one file. This is analogous to dynamic flags parsing, which is
also contained within a single module.
Signed-off-by: David Terei <davidterei@gmail.com>

We know have a single flag that takes a version number, instead of one
flag per SSE version.

This controls whether or not the compiler warns if we're using an LLVM
version that's too old or too new. It's mostly useful when building the
compiler knowingly with an unsupported version, so you don't get a lot
of warnings in the build process.

There's no documentation for this since it's a flag only a few
developers would care about anyway.
Signed-off-by: Austin Seipp <mad.one@gmail.com>

This will add the following preprocessor defines when Haskell source
files are compiled:

 * __SSE__ - If any version of SSE is enabled
 * __SSE2__ - If SSE2 or greater is enabled
 * __SSE4_2_ - If SSE4.2 is enabled

Note that SSE2 is enabled by default on x86-64.

Two main changes. First, re-engineer the ambiguity test.  Previously
TcMType.checkAmbiguity used a rather syntactic test to detect some
types that are certainly ambiguous.  But a much easier test is available,
and it is used for inferred types in TcBinds. Namely
    <type> is ambiguous
iff
   <type> `TcUnify.isSubType` <type>
fails to hold, where "isSubType" means "is provably more polymorphic than".
Example:
      C a => Int
is ambiguous, because isSubType instantiates the (C a => Int)
to (C alpha => Int) and then tries to deduce (C alpha) from (C a). This is
Martin Sulzmann's definition of ambiguity.  (Defn 10 of "Understanding
functional dependencies via constraint handling rules", JFP.)

This change is neat, reduces code, and correctly rejects more programs.
However is *is* just possible to have a useful program that would be
rejected. For example
          class C a b
          f :: C Int b => Int -> Int
Here 'f' would be rejected as having an ambiguous type. But it is
just possible that, at a *call* site there might be an instance
declaration  instance C Int b, which does not constrain 'b' at all.
This is pretty strange -- why is 'b' overloaded at all? -- but it's
possible, so I also added a flag -XAllowAmbiguousTypes that simply
removes the ambiguity check.  Let's see if anyone cares.  Meanwhile
the earlier error report will be useful for everyone else.

A handful of regression tests had to be adjusted as a result, because
they used ambiguous types, somewhat accidentally.

Second, split TcMType (already too large) into two

  * TcMType: a low-level module dealing with monadic operations like
    zonking, creating new evidence variables, etc

  * TcValidity: a brand-new higher-level module dealing with
    validity checking for types: checkValidType, checkValidInstance,
    checkFamInstPats etc

Apart from the fact that TcMType was too big, this allows TcValidity
to import TcUnify(tcSubType) without causing a loop.

The main changes are:
  * Parser accepts empty case alternatives
  * Renamer checks that -XEmptyCase is on in that case
  * (Typechecker is pretty much unchanged.)
  * Desugarer desugars empty case alternatives, esp:
      - Match.matchWrapper and Match.match now accept empty eqns
      - New function matchEmpty deals with the empty case
      - See Note [Empty case alternatives] in Match

This patch contains most of the work, but it's a bit mixed up
with a refactoring of MatchGroup that I did at the same time
(next commit).

This fixes Trac #7541, and is on by default.
Use -fno-warn-duplicate-constraints to switch it off.

There's only a single compiler backend now, so the 'z' suffix means
nothing. Also, the flags were confusingly named ('cmm-foo' vs
'foo-cmm',) and counter-intuitively, '-ddump-cmm' did not do at all what
you expected since the new backend went live.

Basically, all of the -ddump-cmmz-* flags are now -ddump-cmm-*. Some were
renamed to be more consistent.

This doesn't update the manual; it already mentions '-ddump-cmm' and
that flag implies all the others anyway, which is probably what you
want.
Signed-off-by: Austin Seipp <mad.one@gmail.com>

Nothing big here, just tidying up deetails

I'm not sure if making an entirely new HscEnv is too large a hammer,
but it works for now.

The situation was pretty dire.  The way in which data constructors
were handled, notably the mapping between their *source* argument types
and their *representation* argument types (after seq'ing and unpacking)
was scattered in three different places, and hard to keep in sync.

Now it is all in one place:

 * The dcRep field of a DataCon gives its representation,
   specified by a DataConRep

 * As well as having the wrapper, the DataConRep has a "boxer"
   of type DataConBoxer (defined in MkId for loopy reasons).
   The boxer used at a pattern match to reconstruct the source-level
   arguments from the rep-level bindings in the pattern match.

 * The unboxing in the wrapper and the boxing in the boxer are dual,
   and are now constructed together, by MkId.mkDataConRep. This is
   the key function of this change.

 * All the computeBoxingStrategy code in TcTyClsDcls disappears.

Much nicer.

There is a little bit of refactoring left to do; the strange
deepSplitProductType functions are now called only in WwLib, so
I moved them there, and I think they could be tidied up further.

We don't yet have the slow path, for when we have to fall back to
separate compilation.

We also only currently handle the case qhere we're compiling Haskell
code with the NCG.

We need to have WayDyn in the ways in the DynFlags, or the interface
loader will fail.

-dynamic-too now correctly evaluates whether or not it is possible to
build for the dynamic way too, but doesn't actually do so yet.