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Previously, all kind arguments were being reified, which would cause
something like this:

```
type Id a = a
data Proxy (a :: Id k) = Proxy
```

to output

```
data Proxy (a :: Id * k) = Proxy
```

when `Proxy`'s `Info` is reified. The fix is simple: simply call
`filterOutInvisibleTypes` on the kind arguments of a kind synonym
application.

Fixes #11463.

Test Plan: ./validate

Reviewers: austin, bgamari, goldfire

Reviewed By: goldfire

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2081

GHC Trac Issues: #11463

Now we check whether a closed type family's equation is headed with
the correct type before we kind-check the equation.

Also, instead of "expected only no parameters" we now generate the
message "expected no parameters".

Fixes #11623.

Reviewers: simonpj, austin, bgamari

Reviewed By: simonpj, bgamari

Subscribers: simonpj, goldfire, thomie

Differential Revision: https://phabricator.haskell.org/D2089

GHC Trac Issues: #11623

The Runtime Linker is currently eagerly loading all object files on all
platforms which do not use the system linker for `GHCi`.

The problem with this approach is that it requires all symbols to be
found.  Even those of functions never used/called. This makes the number
of libraries required to link things like `mingwex` quite high.

To work around this the `rts` was relying on a trick. It itself was
compiled with `MingW64-w`'s `GCC`. So it was already linked against
`mingwex`.  As such, it re-exported the symbols from itself.

While this worked it made it impossible to link against `mingwex` in
user libraries. And with this means no `C99` code could ever run in
`GHCi` on Windows without having the required symbols re-exported from
the rts.

Consequently this rules out a large number of packages on Windows.
SDL2, HMatrix etc.

After talking with @rwbarton I have taken the approach of loading entire
object files when a symbol is needed instead of doing the dependency
tracking on a per symbol basis. This is a lot less fragile and a lot
less complicated to implement.

The changes come down to the following steps:

1) modify the linker to and introduce a new state for ObjectCode:
   `Needed`.  A Needed object is one that is required for the linking to
   succeed.  The initial set consists of all Object files passed as
   arguments to the link.

2) Change `ObjectCode`'s to be indexed but not initialized or resolved.
   This means we know where we would load the symbols,
   but haven't actually done so.

3) Mark any `ObjectCode` belonging to `.o` passed as argument
   as required: ObjectState `NEEDED`.

4) During `Resolve` object calls, mark all `ObjectCode`
   containing the required symbols as `NEEDED`

5) During `lookupSymbol` lookups, (which is called from `linkExpr`
   and `linkDecl` in `GHCI.hs`) is the symbol is in a not-yet-loaded
   `ObjectCode` then load the `ObjectCode` on demand and return the
   address of the symbol. Otherwise produce an unresolved symbols error
   as expected.

6) On `unloadObj` we then change the state of the object and remove
   it's symbols from the `reqSymHash` table so it can be reloaded.

This change affects all platforms and OSes which use the runtime linker.
It seems there are no real perf tests for `GHCi`, but performance
shouldn't be impacted much. We gain a lot of time not loading all `obj`
files, and we lose some time in `lookupSymbol` when we're finding
sections that have to be loaded. The actual finding itself is O(1)
(Assuming the hashtnl is perfect)

It also consumes slighly more memory as instead of storing just the
address of a symbol I also store some other information, like if the
symbol is weak or not.

This change will break any packages relying on renamed POSIX functions
that were re-named and re-exported by the rts. Any packages following
the proper naming for functions as found on MSDN will work fine.

Test Plan: ./validate on all platforms which use the Runtime linker.

Reviewers: thomie, rwbarton, simonmar, erikd, bgamari, austin, hvr

Reviewed By: erikd

Subscribers: kgardas, gridaphobe, RyanGlScott, simonmar,
             rwbarton, #ghc_windows_task_force

Differential Revision: https://phabricator.haskell.org/D1805

GHC Trac Issues: #11223

Otherwise we get a const-ness mismatch when we free the buffer, which
for some reason gcc 5.3 didn't notice.

Previously, deriving `Generic(1)` bailed out when attempting to
instantiate visible type parameters (#5939), but this instantiation
check was quite fragile and doesn't interact well with `-XTypeInType`.
It has been decided that `Generic(1)` shouldn't be subjected to this
check anyway, so it has been removed, and `gen_Generic_binds`'s
machinery has been updated to substitute the type variables in a
generated `Rep`/`Rep1` instance with the user-supplied type arguments.

In addition, this also refactors `Condition` in `TcDeriv` a bit. Namely,
since we no longer need `tc_args` to check any conditions, the `[Type]`
component of `Condition` has been removed.

Fixes #11732.

Test Plan: ./validate

Reviewers: goldfire, kosmikus, simonpj, bgamari, austin

Reviewed By: simonpj, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2061

GHC Trac Issues: #5939, #11732

I have no idea where "4.11" came from.

Fixes #11818, where haddock's documentation broke `make install` when
Sphinx is not available.

When the typechecker generates the error message for an out-of-scope
variable, it now uses the GlobalRdrEnv with respect to which the
variable is unbound, not the GlobalRdrEnv which is available at the time
the error is reported.  Doing so ensures we do not provide suggestions
which themselves are out-of-scope (because they are bound in a later
inter-splice group).

Nonetheless, we do note in the error message if an unambiguous, exact
match to the out-of-scope variable is found in a later inter-splice
group, and we specify where that match is not in scope.

Test Plan: ./validate

Reviewers: goldfire, austin, bgamari

Reviewed By: goldfire

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2000

GHC Trac Issues: #11680

Needed for constructing correct constraint-satisfying code
(particularly type class instances) in a Core-to-Core transformation.

Reviewers: simonpj, austin, bgamari

Reviewed By: austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2088

GHC Trac Issues: #11804

The commit 28f951ed introduced the
`-fmax-pmcheck-iterations` flag and set the default limit to 1e7
iterations.

However, this value is still high enough that it can result GHC to
exhibit memory spikes beyond 1 GiB of RAM usage (heap profile showed
several `(:)`s, as well as `THUNK_2_0`, and `PmCon` during the memory
spikes)

A value of 2e6 seems to be a safer upper bound which still manages to
let the checker not run into the limit in most cases.

Test Plan: Validate, try building a few Hackage packages

Reviewers: austin, gkaracha, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2095

Record selectors of data types spliced in with Template Haskell are not
renamer-resolved correctly in GHC HEAD. The culprit is
`newRecordSelector` which violates notes `Note [Binders in Template
Haskell] in Convert.hs` and `Note [Looking up Exact RdrNames] in
RnEnv.hs`. This commit fixes `newRecordSelector` accordingly.

Test Plan: ./validate

Reviewers: thomie, mpickering, bgamari, austin, simonpj, goldfire

Reviewed By: goldfire

Differential Revision: https://phabricator.haskell.org/D2091

GHC Trac Issues: #11809

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2096

The last user of this file was the "-dynload wrapper"
which was removed in 169f5972
for addressing #4275

Reviewers: austin, erikd, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2098

GHC Trac Issues: #4275

This is another documentation addition similar to D1989, this time
comparing the type of the Kleisli composition operator (<=<) to that
of plain function composition (.).

Reviewers: hvr, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2100

In my testing, the worker/wrapper transformation applied here
significantly decreases the number of allocations performed when using
replicateM_. Additionally, this version of the function behaves
correctly for negative numbers (namely, it will behave the same as
replicateM_ 0, which is what previous versions of base have done).

Reviewers: bgamari, simonpj, hvr, austin

Reviewed By: bgamari, simonpj, austin

Subscribers: nomeata, simonpj, mpickering, thomie

Differential Revision: https://phabricator.haskell.org/D2086

GHC Trac Issues: #11795

Someone must have forgotten to change this.

Since recent changes to CSE, the previous definition were no longer CSEd
with thenIO, which resulted in extra steps in the simplifier and hence
slightly larger compile times. See ticket:11781#comment:7.

Differential Revision: https://phabricator.haskell.org/D2092

This reverts commit 06b7ce21.

69822f0c broke this as it held on to a
reference into the `arg` string, which is later freed. Humbug.

Test Plan: Try using filtering

Reviewers: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2090

GHC Trac Issues: #11810

Previously the `_static` and `_sources` directories were installed in
the wrong parents. See #11803

(cherry picked from commit 6d36d8e1)

to what phabricator found; not sure why my local validation yielded
different numbers.

Reviewed By: erikd, austin

Differential Revision: https://phabricator.haskell.org/D2082

GHC Trac Issues: #8594

Summary:
Till now tct_closed determined whether the type of a binding is closed.
With this patch tct_closed indicates whether the binding is closed.

Test Plan: ./validate

Reviewers: simonpj, austin, bgamari

Reviewed By: simonpj

Subscribers: mboes, thomie, simonpj

Differential Revision: https://phabricator.haskell.org/D2016

GHC Trac Issues: #11698

as suggested in ticket:11770#comment:1. This code was buggy
(#11770), and the occurrence analyzer does the same job anyways.

This also elaborates the notes in the occurrence analyzer accordingly.

Previously, the worker/wrapper code would go through lengths to transfer
the oneShot annotations from the original function to both the worker
and the wrapper. We now simply transfer the demand on the worker, and
let the subsequent occurrence analyzer push this onto the lambda
binders.

This also requires the occurrence analyzer to do this more reliably.
Previously, it would not hand out OneShot annotatoins to things that
would not `certainly_inline` (and it might not have mattered, as the
Demand Analysis might have handed out the annotations). Now we hand out
one-shot annotations unconditionally.

Differential Revision: https://phabricator.haskell.org/D2085

Triggered by an observation by Joachim, Simon felt the urge to clean up
the CSE code a bit. This is the result.

(Code by Simon, commit message and other leg-work by Joachim)

Differential Revision: https://phabricator.haskell.org/D2074

as they (especially their id info with absence information) clutter the
output too much. They come back with debug_on.

Differential Revision: https://phabricator.haskell.org/D2072

It's been quite a while since this has happened for some of our tests.

Shifts by amounts greater-than-or-equal-to the word size are undefined.

This fixes a bug where warnings actually controlled by

- `Opt_WarnUnusedMatches`
- `Opt_WarnUnusedTypePatterns`
- `Opt_WarnUnusedTopBinds`

were incorrectly reported as being controlled by
`Opt_WarnUnusedLocalBinds` as well

This bug was introduced in bb5afd3c
while implementing #10752

Test Plan: ./validate still running -- testsuite output wiggles expected

Reviewers: barrucadu, quchen, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2077

Richard suggested this, a good idea

We originally wanted CallStacks to be opt-in, but dealing with let
binders complicated things, forcing us to infer CallStacks. It turns
out that the inference is actually unnecessary though, we can let the
wanted CallStacks bubble up to the outer context by refusing to
quantify over them. Eventually they'll be solved from a given CallStack
or defaulted to the empty CallStack if they reach the top.

So this patch prevents GHC from quantifying over CallStacks, getting us
back to the original plan. There's a small ugliness to do with
PartialTypeSignatures, if the partial theta contains a CallStack
constraint, we *do* want to quantify over the CallStack; the user asked
us to!

Note that this means that

  foo :: _ => CallStack
  foo = getCallStack callStack

will be an *empty* CallStack, since we won't infer a CallStack for the
hole in the theta. I think this is the right move though, since we want
CallStacks to be opt-in. One can always write

  foo :: (HasCallStack, _) => CallStack
  foo = getCallStack callStack

to get the CallStack and still have GHC infer the rest of the theta.

Test Plan: ./validate

Reviewers: goldfire, simonpj, austin, hvr, bgamari

Reviewed By: simonpj, bgamari

Subscribers: bitemyapp, thomie

Projects: #ghc

Differential Revision: https://phabricator.haskell.org/D1912

GHC Trac Issues: #11573

This just adds the Prox stuff from the Description in Trac #11376
to the test case,

The class stuff seems weird becuase the type is ambiguous

Stable pointers can now be safely dereferenced while the stable pointer
table is simultaneously being enlarged.

Test Plan: ./validate

Reviewers: ezyang, austin, bgamari, simonmar

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D2031

GHC Trac Issues: #10296

See Trac #11376 and
 Note [Deeply instantiate in :type] in TcRnDriver

Sadly this showed up one new problem (Trac #11786) and one opportunity
(Trac #11787), so test T11549 is now marked expect-broken on these two.