Summary:
This patch completes the work for #14529 by making sure that all API
Annotations end up attached to a SrcSpan that appears in the final
ParsedSource.

Updates Haddock submodule

Test Plan: ./validate

Reviewers: goldfire, bgamari

Subscribers: rwbarton, thomie, mpickering, carter

GHC Trac Issues: #14529

Differential Revision: https://phabricator.haskell.org/D4867

- dataToExpQUnit
- qq005
- qq006
- qq007
- qq008
- qq009
- T13949
- T8025

[skip ci]

When typechecking a type like
   Maybe (a :: <kind-sig>)
with a kind signature, we were using tc_lhs_kind to
typecheck the signature.  But that's utterly wrong; we
need the signature to be fully solid (non unresolved
equalities) before using it.  In the case of Trac #14904
we went on to instantiate the kind signature, when it
still had embedded unsolved constraints.  This tripped
the level-checking assertion when unifying a variable.

The fix looks pretty easy to me: just call tcLHsKind
instead.  I had to add KindSigCtxt to

* Define Type.substTyVarBndrs, and use it

* Rename substTyVarBndrCallback to substTyVarBndrUsing,
  and other analogous higher order functions.  I kept
  stumbling over the name.

Trac #14164 made GHC loop, a pretty serious error. It turned
out that Unify.niFixTCvSubst was looping forever, because we
had a substitution like
    a :-> ....(b :: (c :: d))....
    d :-> ...
We correctly recognised that d was free in the range of the
substitution, but then failed to apply it "deeeply enough"
to the range of the substiuttion, so d was /still/ free in
the range, and we kept on going.

Trac #9106 was caused by a similar problem, but alas my
fix to Trac #9106 was inadequate when the offending type
variable is more deeply buried.  Urk.

This time I think I've fixed it!  It's much more subtle
than I though, and it took most of a long train journey
to figure it out.  I wrote a long note to explain:
Note [Finding the substitution fixpoint]

This was a stderr file for a WIP test in D4728. I ended up removing
the test, but forgot to remove the stderr file.

Vladislav Zavialov authored 6 years ago and Ben Gamari committed 6 years ago

Add a flag `-Werror=compat` to GHC which has the effect of `-Werror=x
-Werror=y ...`, where `x, y, ...` are warnings from the `-Wcompat`
option group.

Test Plan: ./validate

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15278

Differential Revision: https://phabricator.haskell.org/D4860

It seems like we currently support string literals in Cmm, so we can use
__LINE__ CPP macro in assertion macros. This improves error messages
that previously looked like

    ASSERTION FAILED: file (null), line 1302

(null) part now shows the actual file name.

Also inline some single-use string literals in PrimOps.cmm.

Reviewers: bgamari, simonmar, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4862

Sergei Trofimovich authored 6 years ago and Ben Gamari committed 6 years ago

Gabor noticed C warning when building unregisterised
64-bit compiler on GHC.Integer.Types (from integer-simple).

Minimised example with a warning:

```haskell
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -Wall #-}

module M (bug) where

import GHC.Prim (Word#, minusWord#, ltWord#)
import GHC.Types (isTrue#)

-- assume Word = Word64
bug :: Word# -> Word#
bug x = if isTrue# (x `ltWord#` 0x8000000000000000##) then 0##
        else x `minusWord#` 0x8000000000000000##
```

```
$ LANG=C x86_64-UNREG-linux-gnu-ghc -O1 -c M.hs -fforce-recomp
/tmp/ghc30219_0/ghc_1.hc: In function 'M_bug_entry':

/tmp/ghc30219_0/ghc_1.hc:20:14: error:
     warning: integer constant is so large that it is unsigned
```

It's caused by limited handling of integer literals in CmmRegOff.
This change switches to use standard integer literal pretty-printer.

C code before the change:

```c
FN_(M_bug_entry) {
W_ _sAg;
_cAr:
_sAg = *Sp;
switch ((W_)(_sAg < 0x8000000000000000UL)) {
case 0x1UL: goto _cAq;
default: goto _cAp;
}
_cAp:
R1.w = _sAg+-9223372036854775808;
// ...
```

C code after the change:

```c
FN_(M_bug_entry) {
W_ _sAg;
_cAr:
_sAg = *Sp;
switch ((W_)(_sAg < 0x8000000000000000UL)) {
case 0x1UL: goto _cAq;
default: goto _cAp;
}
_cAp:
R1.w = _sAg+(-0x8000000000000000UL);
```

URL: https://mail.haskell.org/pipermail/ghc-devs/2018-June/015875.html


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

Test Plan: test generated code on unregisterised mips64 and amd64

Reviewers: simonmar, ggreif, bgamari

Reviewed By: ggreif, bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4856

Trac #14845 brought to light a corner case where a data
constructor could not be promoted (even with `-XTypeInType`) due to
an unpromotable constraint in its context. However, the error message
was less than helpful, so this patch adds an additional check to
`tcTyVar` catch unpromotable data constructors like these //before//
they're promoted, and to give a sensible error message in such cases.

Test Plan: make test TEST="T13895 T14845"

Reviewers: simonpj, goldfire, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #13895, #14845

Differential Revision: https://phabricator.haskell.org/D4728

Reviewers: sjakobi, dfeuer, bgamari, hvr

Reviewed By: sjakobi, bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15078

Differential Revision: https://phabricator.haskell.org/D4736

If a module cannot be found because it is ignored or from an unusable
package, report this to the user and the reason it is unusable.

Currently, GHC displays the standard "Cannot find module error". For
example:

```
<no location info>: error:
    Could not find module ‘Control.Monad.Random’
    Perhaps you meant
      Control.Monad.Reader (from mtl-2.2.2)
      Control.Monad.Cont (from mtl-2.2.2)
      Control.Monad.Error (from mtl-2.2.2)
```

GHC does, however, indicate unusable/ignored packages with the -v flag:

```
package MonadRandom-0.5.1-1421RgpXdhC8e8UI7D3emA is unusable due to
missing dependencies:
  fail-4.9.0.0-BAHmj60kS5K7NVhhKpm9J5
```

With this change, I took that message and added it to the output of the
"Cannot find module" message.

Reviewers: bgamari, dfeuer

Reviewed By: bgamari

Subscribers: Phyx, dfeuer, rwbarton, thomie, carter

GHC Trac Issues: #4806

Differential Revision: https://phabricator.haskell.org/D4783

Adam Gundry authored 6 years ago and Ben Gamari committed 6 years ago

filterImports needed a small adjustment to correctly handle record field
definitions arising from modules with DuplicateRecordFields enabled.

Previously hiding fields was not possible with DuplicateRecordFields enabled.

Test Plan: new test rename/should_compile/T14487

Reviewers: bgamari

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #14487

Differential Revision: https://phabricator.haskell.org/D4805

Due to #15061.

Due to #15063.

See #15281

This reverts commit 86210b23.

Vladislav Zavialov authored 6 years ago and Ben Gamari committed 6 years ago

According to an accepted proposal
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/002
4-no-kind-vars.rst

    With -Wcompat, warn if a kind variable is brought into scope
    implicitly in a type with an explicit forall. This applies to type
    signatures and to other contexts that allow a forall with the
    forall-or-nothing rule in effect (for example, class instances).

Test Plan: Validate

Reviewers: goldfire, hvr, bgamari, RyanGlScott

Reviewed By: goldfire

Subscribers: RyanGlScott, rwbarton, thomie, carter

GHC Trac Issues: #15264

Differential Revision: https://phabricator.haskell.org/D4834

Ben Gamari authored 6 years ago and Ben Gamari committed 6 years ago

Fixes #12970 and will provide a reasonable migration path for the
eventual remove of this function.

Test Plan: Validate

Reviewers: ekmett, hvr

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #12970

Differential Revision: https://phabricator.haskell.org/D4857

This appears to inexplicably break the OS X build, which fails with:
```
make[1]: *** No rule to make target `utils/unlit/fs.c', needed by
         `utils/unlit/dist/build/.depend.c_asm'.  Stop.
make[1]: *** Waiting for unfinished jobs....
make: *** [all] Error 2
```

This reverts commit 8ee9c574.

Until now GHC only supported basic constant folding (lit op lit, expr op
0, etc.).

This patch uses laws of +/-/* (associativity, commutativity,
distributivity) to support some constant folding into nested
expressions.

Examples of new transformations:

   - simple nesting: (10 + x) + 10 becomes 20 + x
   - deep nesting: 5 + x + (y + (z + (t + 5))) becomes 10 + (x + (y + (z + t)))
   - distribution: (5 + x) * 6 becomes 30 + 6*x
   - simple factorization: 5 + x + (x + (x + (x + 5))) becomes 10 + (4 *x)
   - siblings: (5 + 4*x) - (3*x + 2) becomes 3 + x

Test Plan: validate

Reviewers: simonpj, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

GHC Trac Issues: #9136

Differential Revision: https://phabricator.haskell.org/D2858

(cherry picked from commit fea04def)

As pointed out in #12951, this was a temporary measure to allow GHC to be
bootstrapped on Windows with GHC 7.10. This release is now out of our bootstrap
support window so let's remove it.

Fixes #15134.

Reviewers: dfeuer, hvr, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15134

Differential Revision: https://phabricator.haskell.org/D4737

Preserve HsPars while typechecking

Test Plan: T15242

Reviewers: bgamari, alanz, simonpj

Reviewed By: alanz, simonpj

Subscribers: simonpj, AndreasK, rwbarton, thomie, carter

GHC Trac Issues: #15242

Differential Revision: https://phabricator.haskell.org/D4822

Ben Gamari authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: Validate using LLVM assembler

Reviewers: carter, erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, thomie

GHC Trac Issues: #15207

Differential Revision: https://phabricator.haskell.org/D4781

Ben Gamari authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: Validate on i386

Reviewers: simonmar

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15255

Differential Revision: https://phabricator.haskell.org/D4855

Ben Gamari authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: Validate

Reviewers: hvr

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #15062

Differential Revision: https://phabricator.haskell.org/D4854

Adam Gundry authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: ./validate

Reviewers: bgamari

Subscribers: rwbarton, thomie, erikd, carter

GHC Trac Issues: #15257

Differential Revision: https://phabricator.haskell.org/D4853

This is a small change in user-facing behavior. When we
have a unification variable left over in a CUSK, we previously
would issue an error. But, we can just quantify. This also
teaches kcLHsQTyVars to use quantifyTyVars instead of its own,
ad-hoc quantification scheme.

Fixes #15273.

test case: polykinds/T11648b

Add support for built-in Natural literals in Core.

- Replace MachInt,MachWord, LitInteger, etc. with a single LitNumber
  constructor with a LitNumType field
- Support built-in Natural literals
- Add desugar warning for negative literals
- Move Maybe(..) from GHC.Base to GHC.Maybe for module dependency
  reasons

This patch introduces only a few rules for Natural literals (compared
to Integer's rules). Factorization of the built-in rules for numeric
literals will be done in another patch as this one is already big to
review.

Test Plan:
  validate
  test build with integer-simple

Reviewers: hvr, bgamari, goldfire, Bodigrim, simonmar

Reviewed By: bgamari

Subscribers: phadej, simonpj, RyanGlScott, carter, hsyl20, rwbarton,
thomie

GHC Trac Issues: #14170, #14465

Differential Revision: https://phabricator.haskell.org/D4212

Kirill Zaborsky authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: ./validate

Reviewers: bgamari, simonpj

Reviewed By: bgamari, simonpj

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #13833

Differential Revision: https://phabricator.haskell.org/D4823

Adam Gundry authored 6 years ago and Ben Gamari committed 6 years ago

Test Plan: new tests rename/should_compile/{T14747,T15149}

Reviewers: simonpj, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14747, #15149

Differential Revision: https://phabricator.haskell.org/D4821

Fixes #15040.

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4772