Summary: Escape `\` in paths on Windows in `cwapper.c` when we re-output the paths.

Test Plan: ./validate

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #13666

Differential Revision: https://phabricator.haskell.org/D3628

This patch fixes a bad bug in the specialiser, which showed up as
Trac #13429.  When specialising an imported DFun, the specialiser could
generate a recusive loop where none existed in the original program.

It's all rather tricky, and I've documented it at some length in
   Note [Avoiding loops]

We'd encoutered exactly this before (Trac #3591) but I had failed
to realise that the very same thing could happen for /imported/
DFuns.

I did quite a bit of refactoring.

The compiler seems to get a tiny bit faster on
   deriving/perf/T10858
but almost all the gain had occurred before now; this
patch just pushed it over the line.

The output is not being checked in the test suite.
However other tools may check it for obtaining the status
of the remote slave.

So I'd suggest to merge this to 8.2 branch, in order to not
fragment the tooling's checks.

Summary:
See https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow

This commit prepares the ground for a full extensible AST, by replacing the type
parameter for the hsSyn data types with a set of indices into type families,

    data GhcPs -- ^ Index for GHC parser output
    data GhcRn -- ^ Index for GHC renamer output
    data GhcTc -- ^ Index for GHC typechecker output

These are now used instead of `RdrName`, `Name` and `Id`/`TcId`/`Var`

Where the original name type is required in a polymorphic context, this is
accessible via the IdP type family, defined as

    type family IdP p
    type instance IdP GhcPs = RdrName
    type instance IdP GhcRn = Name
    type instance IdP GhcTc = Id

These types are declared in the new 'hsSyn/HsExtension.hs' module.

To gain a better understanding of the extension mechanism, it has been applied
to `HsLit` only, also replacing the `SourceText` fields in them with extension
types.

To preserve extension generality, a type class is introduced to capture the
`SourceText` interface, which must be honoured by all of the extension points
which originally had a `SourceText`.  The class is defined as

    class HasSourceText a where
      -- Provide setters to mimic existing constructors
      noSourceText  :: a
      sourceText    :: String -> a

      setSourceText :: SourceText -> a
      getSourceText :: a -> SourceText

And the constraint is captured in `SourceTextX`, which is a constraint type
listing all the extension points that make use of the class.

Updating Haddock submodule to match.

Test Plan: ./validate

Reviewers: simonpj, shayan-najd, goldfire, austin, bgamari

Subscribers: rwbarton, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D3609

Previously modules with hscTarget == HscNothing were not desugared.
This patch changes behavior so that all modules HsSrcFile Modules except GHC.Prim
are desugared. Modules with hscTarget == HscNothing are not simplified.

Warnings and errors produced by the desugarer will now be produced when
compiling with -fno-code.

HscMain.finishTypecheckingOnly is removed, HscMain.hscIncrementalCompile is
simplified a bit, and HscMain.finish takes in the removed logic. I think this
is easier to follow.

Updates haddock submodule.

Tests T8101, T8101b, T10600 are no longer expect_broken.

Reviewers: ezyang, austin, bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #10600

Differential Revision: https://phabricator.haskell.org/D3542

Trac #13785 showed that we were emitting monomorphism warnings
when we shouldn't.  The fix turned out to be simple.

In fact test T10935 then turned out to be another example of
the over-noisy warning so I changed the test slightly.

Ben Gamari authored 7 years ago and Ben Gamari committed 7 years ago

Otherwise this will fail if the prefix path contains spaces. Thanks to
marinelli for pointing this out.

Test Plan: Validate

Reviewers: austin

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3604

While investigating #12545, I discovered several places in the code
that performed length-checks like so:

```
length ts == 4
```

This is not ideal, since the length of `ts` could be much longer than 4,
and we'd be doing way more work than necessary! There are already a slew
of helper functions in `Util` such as `lengthIs` that are designed to do
this efficiently, so I found every place where they ought to be used and
did just that. I also defined a couple more utility functions for list
length that were common patterns (e.g., `ltLength`).

Test Plan: ./validate

Reviewers: austin, hvr, goldfire, bgamari, simonmar

Reviewed By: bgamari, simonmar

Subscribers: goldfire, rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3622

This does two things:

* The `RtsTime` type wasn't exported, but it is used as the type of
  several record fields. Let's export it and give it some documentation.
* Neither `RTSStats` nor `GCDetails` have `Read` or `Show` instances,
  but `GCStats` does! Let's fix this discrepancy.

Reviewers: austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: goldfire, rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3625

Previously, we were running some blocks of code at the start of every
GHCi sessions which use do-notation, something which doesn't work well
if you start GHCi with the `-XRebindableSyntax` flag on. This tweaks the
code to avoid the use of do-notation so that `-XRebindableSyntax` won't
reject it.

Test Plan: make test TEST=T13385

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #13385

Differential Revision: https://phabricator.haskell.org/D3621

A follow-up to #8440 (Ditch static flags). There are still some
lingering references to static flags in the flag reference, so let's
modify those references accordingly.

Test Plan: Build the documentation

Reviewers: bgamari, austin

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3615

Test Plan: Read it

Reviewers: bgamari, austin

Reviewed By: bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #13762

Differential Revision: https://phabricator.haskell.org/D3614

Tamar Christina authored 7 years ago and Ben Gamari committed 7 years ago

The import library support added for 7.10.3 was only a partial one.
This support was predicated on using file extensions to determine
whether or not a library was an import library. It also couldn't handle
libraries with multiple dll pointers.

This is a rewrite of that patch and fully integrating it into the normal
archive parsing and loading routines. This solves a host of issues,
among others allowing us to finally use `-lgcc_s`.

This also fixes a problem with our previous implementation, where we
just loaded the DLL and moved on. Doing this had the potential of using
the wrong symbol at resolve time. Say a DLL already loaded (A.dll) has
symbol a exported (dependency of another dll perhaps).

We find an import library `B.lib` explicitly defining an export of `a`.
we load `B.dll` but this gets put after `A.dll`, at resolve time we
would use the value from `A` instead of `B` which is what we wanted.

Test Plan: ./valide and make test TEST=13606

Reviewers: austin, bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, RyanGlScott, thomie, #ghc_windows_task_force

GHC Trac Issues: #13606, #12499, #12498

Differential Revision: https://phabricator.haskell.org/D3513

5ddb307e regressed autoconf's ability to
find the linker due to a silly variable interpolation issue, causing
segmentation faults on AArch64.

Moritz Angermann authored 7 years ago and Ben Gamari committed 7 years ago

This moves the forkIO into the `startSlave` function from the
`startSlave'` function, such that this allows consumers to call
`forkSlave'` if they want the blocking behaviour.

Reviewers: bgamari, austin

Reviewed By: bgamari

Subscribers: Ericson2314, ryantrinkle, rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3601

The change adds support for 'darwin*' OS:
    $ ./configure --target=aarch64-apple-darwin14

Reported-by: jp_rider
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

This implements the idea from
https://ghc.haskell.org/trac/ghc/ticket/13092#comment:14.

It's explained in Note [Checking family instance optimization]
in more detail.

This improves the test case T13719 tenfold and
cuts down the compile time on `:load` in `ghci` on our
internal code base by half.

Test Plan: ./validate

Reviewers: simonpj, simonmar, rwbarton, austin, bgamari

Reviewed By: simonpj

Subscribers: thomie

GHC Trac Issues: #13719

Differential Revision: https://phabricator.haskell.org/D3603

With a large number of modules in a home package
(in my case 5000) the costs of linear lookups becomes significant.
This changes them to efficient IntMap lookups.

It reduces the cost of `:reload` on unchanged source
from 5.77s to 1.62s on my test case.

I could go further and make `Linker.unload` also take a set,
but I prefer to concentrate on one thing at a time.

Test Plan: harbormaster

Reviewers: simonmar, austin, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3611

This is a cleanup after Trac #13238, as the context was no longer being used.

Most are cosmetic. There's an interesting change in T7861,
but the error is still accurate.

Reviewers: hvr, bgamari, austin

Reviewed By: hvr

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3612

Commit ce97b729 (the fix for #12175) also
fixed #12648. Let's add a regression test so that it stays fixed.

This reverts commit 0440af6a.
Unfortunately this breaks on Windows for tiresome reasons. I'll need to
reevaluate this.

Triggered by the changes in #13677, I ended up doing a bit of
refactoring in type pretty-printing.

* We were using TyOpPrec and FunPrec rather inconsitently, so
  I made it consisent.

* That exposed the fact that we were a bit undecided about whether
  to print
     a + b -> c + d   vs   (a+b) -> (c+d)
  and similarly
     a ~ [b] => blah  vs   (a ~ [b]) => blah

  I decided to make TyOpPrec and FunPrec compare equal
  (in BasicTypes), so (->) is treated as equal precedence with
  other type operators, so you get the unambiguous forms above,
  even though they have more parens.

  We could readily reverse this decision.
  See Note [Type operator precedence] in BasicTypes

* I fixed a bug in pretty-printing of HsType where some
  parens were omitted by mistake.

IfaceType.hs-boot and ToIface.hs-boot were bigger than they
needed to be, so I'm shrinking them.

The big change here is to fix an outright bug in flattening of Givens,
albeit one that is very hard to exhibit.  Suppose we have the constraint
    forall a. (a ~ F b) => ..., (forall c. ....(F b)...) ...

Then
 - we'll flatten the (F) b to a fsk, say  (F b ~ fsk1)
 - we'll rewrite the (F b) inside the inner implication to 'fsk1'
 - when we leave the outer constraint we are suppose to unflatten;
   but that fsk1 will still be there
 - if we re-simplify the entire outer implication, we'll re-flatten
   the Given (F b) to, say, (F b ~ fsk2)
Now we have two fsks standing for the same thing, and that is very
wrong.

Solution: make fsks behave more like fmvs:
 - A flatten-skolem is now a MetaTyVar, whose MetaInfo is FlatSkolTv
 - We "fill in" that meta-tyvar when leaving the implication
 - The old FlatSkol form of TcTyVarDetails is gone completely
 - We track the flatten-skolems for the current implication in
   a new field of InertSet, inert_fsks.

See Note [The flattening story] in TcFlatten.

In doing this I found various other things to fix:

* I removed the zonkSimples from TcFlatten.unflattenWanteds; it wasn't
  needed.   But I added one in TcSimplify.floatEqualities, which does
  the zonk precisely when it is needed.

* Trac #13674 showed up a case where we had
     - an insoluble Given,   e.g.  a ~ [a]
     - the same insoluble Wanted   a ~ [a]
  We don't use the Given to rewwrite the Wanted (obviously), but
  we therefore ended up reporting
      Can't deduce (a ~ [a]) from (a ~ [a])
  which is silly.

  Conclusion: when reporting errors, make the occurs check "win"
  See Note [Occurs check wins] in TcErrors

Consider
  type family F a :: * -> *

Then (a ~ F Int a) is an insoluble occurs check, and can be reported
as such.  Previous to this patch, TcType.isInsolubleOccursCheck was
treating any type-family application (including an over-saturated one)
as unconditionally not-insoluble.

This really only affects error messages, and then only slightly. I
tripped over this when investigating  Trac #13674.

Sometimes it's handy to change a compiler flag
for a library in stage{0,1,2}.

Usage example:

    libraries/binary_EXTRA_HC_OPTS += -O1
    libraries/containers_EXTRA_HC_OPTS += -O1
    libraries/bytestring_EXTRA_HC_OPTS += -O1

Here override default -O2 defined in .cabal files
for these libraries to speed build up.

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

This patch fixes two separate bugs which contributed to making
Trac #13752 go wrong

1.  We need to use tcSubType, not tcUnify,
    in tcCheckPatSynDecl.tc_arg.

    Reason: Note [Pattern synonyms and higher rank types]

2.  TcUnify.tc_sub_type had a special case designed to improve error
    messages; see Note [Don't skolemise unnecessarily].  But the
    special case was too liberal, and ended up using unification
    (which led to rejecting the program) when it should instead taken
    the normal path (which accepts the program).

    I fixed this by making the test more conservative.