GitLab

* (+++)                    -->  andUDs
* combineAltsUsageDetails  -->  orUDs
* combineUsageDetailsList  -->  andUDsList
* Change some andUDsList to a fold for efficiency

No change in behaviour

Matthew Pickering uncovered a bad performance hole in the way
that single-method dictionaries work, described in Trac #14955.

See Note [Do not unpack class dictionaries] in WwLib.

I tried to fix this 6 years ago, but got it slightly wrong.  This patch
fixes it, which makes a dramatic improvement in the test case.

Nofib highlights: not much happening:

  Program           Size    Allocs   Runtime   Elapsed  TotalMem
-----------------------------------------------------------------
      VSM          -0.3%     +2.7%     -7.4%     -7.4%      0.0%
cacheprof          -0.0%     +0.1%     +0.3%     +0.7%      0.0%
  integer          -0.0%     +1.1%     +7.5%     +7.5%      0.0%
      tak          -0.1%     -0.2%     0.024     0.024      0.0%
-----------------------------------------------------------------
      Min          -4.4%     -0.2%     -7.4%     -7.4%     -8.0%
      Max          +0.6%     +2.7%     +7.5%     +7.5%      0.0%
Geom Mean          -0.1%     +0.0%     +0.1%     +0.1%     -0.2%

I investigated VSM.  The patch unpacks class dictionaries a bit more
than before (i.e. does so if there is no INLINABLE pragma). And that
gives better code in VSM (less dictionary selection etc), but one closure
gets one word bigger.

I'll accept these changes in exchange for more robust performance.

Some ghci.debugger output wobbled around (order of bindings
being displayed). I have no idea why; but I accepted the changes.

  * Link to Quick Start guide
  * Update README.md (hadrian/578)
  * Fix AppVeyor (hadrian/577)
  * Fix CircleCI
  * Generic library rules (hadrian/571)
  * Fix lint error (hadrian/575)
  * Fix missing libHSghc-8.5-0.a (hadrian/574)
  * Fix the path to touchy (hadrian/572)
  * Fix integer-gmp build (hadrian/568)
  * Undo fs*.h workaround
  * Fix copying of fs*.h files during RTS registration (hadrian/566)
  * Fix Windows build, improve error reporting (hadrian/565)
  * Fix Windows build (hadrian/563)
  * Fix boot and configure on AppVeyor (hadrian/561)
  * Preliminary bindist (hadrian/558, hadrian/555)
  * Unregister stage0 package first if it needs to be
    cloned (hadrian/552)
  * Fix Circle CI (hadrian/553)
  * Fix warnings (hadrian/547)
  * Merge pull request hadrian/542 from Mistuke/fix-specific-file
  * Use Cabal directly in place of ghc-cabal + make build root
    configurable (hadrian/531)
  * Add user-defined flavour example for turning off dynamic
    linking (hadrian/535)
  * Add clean routines for fs (hadrian/533)
  * Add 'git' to nativeBuildInputs in shell.nix (hadrian/530)
  * Add extra include paths when invoking ghc-cabal (hadrian/526)
  * Merge pull request hadrian/528 from snowleopard/bump-cabal
  * Merge pull request hadrian/521 from snowleopard/drop-chmod
  * Change permission bits for build.cabal.sh,
    fixes hadrian/517 (hadrian/520)
  * Pin nixpkgs and all-cabal-hashes in shell.nix (hadrian/511)
  * Add troubleshooting section

Test Plan: Passes validate

Reviewers: simonmar, bgamari, erikd

Subscribers: thomie, carter

GHC Trac Issues: #10296

Differential Revision: https://phabricator.haskell.org/D4627

This relied on Int# being 64-bits. This is nothing a bit of CPP can't
fix, but I think the right solution would be to make out treatment of
word-size dependent types more consistent, as suggested by #11953.

Test Plan: Validate on i386

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4614

We simply truncate the result to 32-bits to ensure that the test passed
under both environments.

Test Plan: Validate on 32-bit

Subscribers: thomie, carter

GHC Trac Issues: #13623

Differential Revision: https://phabricator.haskell.org/D4615

ed6f9fb9 reduced the scope of this hack
to only include Clangs which actually lack __sync_fetch_and_nand.
However, this causes GHC to fail to build with -Werror on Clang due to
the lack of the -Wsync-nand warning flag. As it turns out a flag
controlling the warning is available under a different name, however.

Test Plan: Validate with Clang, GCC

Subscribers: thomie, carter

GHC Trac Issues: #9678

Differential Revision: https://phabricator.haskell.org/D4613

so that we notice if someone accidentially implements this...

* Improve assertion-failure message
* Add HasDebugCallStack to decomposeFunCo

Reviewers: goldfire, bgamari

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4570

[skip ci]

The coercion optimizer will take care of it anyway, and the check is
prohibitively expensive.

See Trac #14737.

Reviewers: bgamari

Subscribers: simonpj, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4568

Expects the current behavior, will be updated by D4593 to reflect
desired behavior.

Reviewers: hvr

Subscribers: thomie, carter

GHC Trac Issues: #10412

Differential Revision: https://phabricator.haskell.org/D4610

Reviewers: ezyang, bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

GHC Trac Issues: #15041

Differential Revision: https://phabricator.haskell.org/D4600

There is a maintained shell.nix file in the hadrian submodule. This
has long since been broken anyway.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

GHC Trac Issues: #15045

Differential Revision: https://phabricator.haskell.org/D4599

This patch has a single significant change:

  strictness wrapper functions are inlined earlier,
  in phase 2 rather than phase 0.

As shown by Trac #15056, this gives a better chance for RULEs to fire.
Before this change, a function that would have inlined early without
strictness analyss was instead inlining late. Result: applying
"optimisation" made the program worse.

This does not make too much difference in nofib, but I've stumbled
over the problem more than once, so even a "no-change" result would be
quite acceptable.  Here are the headlines:

--------------------------------------------------------------------------------
        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
      cacheprof          -0.5%     -0.5%     +2.5%     +2.5%      0.0%
         fulsom          -1.0%     +2.6%     -0.1%     -0.1%      0.0%
           mate          -0.6%     +2.4%     -0.9%     -0.9%      0.0%
        veritas          -0.7%    -23.2%     0.002     0.002      0.0%
--------------------------------------------------------------------------------
            Min          -1.4%    -23.2%    -12.5%    -15.3%      0.0%
            Max          +0.6%     +2.6%     +4.4%     +4.3%    +19.0%
 Geometric Mean          -0.7%     -0.2%     -1.4%     -1.7%     +0.2%

* A worthwhile reduction in binary size.

* Runtimes are not to be trusted much but look as if they
  are moving the right way.

* A really big win in veritas, described in comment:1 of
  Trac #15056; more fusion rules fired.

* I investigated the losses in 'mate' and 'fulsom'; see #15056.

While addressing nonlinear behavior related to coercion roles,
particularly `NthCo`, we noticed that coercion roles are recalculated
often even though they should be readily at hand already in most cases.
This patch adds a `Role` to the `NthCo` constructor so that we can cache
them rather than having to recalculate them on the fly.
https://ghc.haskell.org/trac/ghc/ticket/11735#comment:23 explains the
approach.

Performance improvement over GHC HEAD, when compiling Grammar.hs (see below):

GHC 8.2.1:
```
ghc Grammar.hs  176.27s user 0.23s system 99% cpu 2:56.81 total
```

before patch (but with other optimizations applied):
```
ghc Grammar.hs -fforce-recomp  175.77s user 0.19s system 100% cpu 2:55.78 total
```

after:
```
../../ghc/inplace/bin/ghc-stage2 Grammar.hs  10.32s user 0.17s system 98% cpu 10.678 total
```

Introduces the following regressions:

- perf/compiler/parsing001 (possibly false positive)
- perf/compiler/T9872
- perf/compiler/haddock.base

Reviewers: goldfire, bgamari, simonpj

Reviewed By: simonpj

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #11735

Differential Revision: https://phabricator.haskell.org/D4394

This brings in a commit which migrates Contravariant instances from
base to transformers.

Corrects the inconsistency between Data.Char.isAlphaNum,
Data.Char.isAlpha and Data.Char.isNumber. Indeed, isAlphaNum was
returning True not only when isAlpha or isNumber returned True but
also when isMark did. The selectors for the Mn, Mc and Me general
categories where removed from the macro generating u_iswalnum in
ubconfc.

Also, Data.Char.isAlphaNum's documentation was changed to state that
isAlphaNum returns true not only for Unicode number digits but for
Unicode numbers in general in Unicode.hs.
Signed-off-by: ARJANEN Loïc Jean David <arjanen.loic@gmail.com>

Reviewers: hvr, ekmett, lelf, bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

GHC Trac Issues: #10412

Differential Revision: https://phabricator.haskell.org/D4593

We weren't linting the types used in `newFamInst`, which
might have been why #15012 went undiscovered for so long. Let's fix
that.

One has to be surprisingly careful with expanding type synonyms in
`lintType`, since in the offending program (simplified):

```lang=haskell
type FakeOut a = Int

type family TF a
type instance TF Int = FakeOut a
```

If one expands type synonyms, then `FakeOut a` will expand to
`Int`, which masks the issue (that `a` is unbound). I added an
extra Lint flag to configure whether type synonyms should be
expanded or not in Lint, and disabled this when calling `lintTypes`
from `newFamInst`.

As evidence that this works, I ran it on the offending program
from #15012, and voilà:

```
$ ghc3/inplace/bin/ghc-stage2 Bug.hs -dcore-lint
[1 of 1] Compiling Foo              ( Bug.hs, Bug.o )
ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 8.5.20180417 for x86_64-unknown-linux):
        Core Lint error
  <no location info>: warning:
      In the type ‘... (Rec0 (FakeOut b_a1Qt))))’
      @ b_a1Qt is out of scope
```

Test Plan: make test TEST=T15057

Reviewers: simonpj, goldfire, bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

GHC Trac Issues: #15057

Differential Revision: https://phabricator.haskell.org/D4611

Test Plan: Run `./boot`, check to make sure that
`libraries/ghc-prim/GNUmakefile` is sane

Subscribers: thomie, carter, sjakobi

Differential Revision: https://phabricator.haskell.org/D4580

Clang throws a warning instead of an error when it is passed -no-pie,

    clang: warning: argument unused during compilation: '-nopie'
    [-Wunused-command-line-argument]

Consequently configure concludes that it supports -no-pie. However, this
will fail when used with -Werror. The solution is to simply use -Werror
in the configure check.

Thanks to @goldfire for reporting this.

Reviewers: hvr

Subscribers: thomie, carter, goldfire

Differential Revision: https://phabricator.haskell.org/D4557

Fixes D4609 on Windows by bumping parsec submodule.

This fixes all unexpected passes and unexpected failures from a
`./validate --slow` run I did last week. I commented on many
tickets and created a few more as I was going through the failing
tests. A summary of the entire process is available at:

  https://gist.github.com/alpmestan/c371840968f086c8dc5b56af8325f0a9

This is part of an attempt to have `./validate --slow` pass,
tracked in #14890. Another patch will be necessary for the unexpected
stats failures.

Test Plan: ./validate --slow (not green yet)

Reviewers: bgamari, simonmar

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4546

Summary: Bumps several submodules.

Test Plan: ./validate

Reviewers: hvr, bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

GHC Trac Issues: #15018

Differential Revision: https://phabricator.haskell.org/D4609

Previously, derived `Generic1` instances could have associated `Rep1`
type family instances with unbound variables, such as in the following
example:

```lang=haskell
data T a = MkT (FakeOut a) deriving Generic1
type FakeOut a = Int

==>

instance Generic1 T where
  type Rep1 T = ... (Rec0 (FakeOut a))
```

Yikes! To avoid this, we simply map the last type variable in a
derived `Generic1` instance to `Any`.

Test Plan: make test TEST=T15012

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: simonpj, thomie, carter

GHC Trac Issues: #15012

Differential Revision: https://phabricator.haskell.org/D4602

For empty character literal, the `''`, report error message properly
rather than just throw a "parser error" with wrong error location.

Test Plan: make test TEST="T13450 T13450TH"

Reviewers: goldfire, bgamari

Reviewed By: bgamari

Subscribers: thomie, mpickering, carter

GHC Trac Issues: #13450

Differential Revision: https://phabricator.haskell.org/D4594

Because the program doesn't have any binders that -XStrict can make
strict, the desugarer output should be identical when it's compiled with
and without -XStrict. This wasn't the case with GHC 8.2.2, but
apparently it was fixed some time between 8.2.2 and 8.4.1. We now add a
test case to make sure it stays fixed.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #14815

Differential Revision: https://phabricator.haskell.org/D4531

This change fixes build failure like this:
```
  rts/Stats.c:1467:14: error:
     error: format '%u' expects argument of type 'unsigned int',
         but argument 4 has type 'long unsigned int' [-Werror=format=]
       debugBelch("%51s%9" FMT_Word " %9" FMT_Word "\n",
                  ^~~~~~~~
                  "",tot_live*sizeof(W_),tot_slop*sizeof(W_));
                                         ~~~~~~~~~~~~~~~~~~~
```

The fix is to cast sizeof() result to Word (W_).
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

Test Plan: build for 32-bit target

Reviewers: bgamari, erikd, simonmar

Reviewed By: simonmar

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4608

The Mathjax CDN no longer exists. Use CDNJS instead.

See #15006.

Test Plan: Build HTML users guide, see whether math is rendered.

Reviewers: alpmestan

Reviewed By: alpmestan

Subscribers: thomie, carter

GHC Trac Issues: #15006

Differential Revision: https://phabricator.haskell.org/D4603

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4565

Summary: Requires bumping several submodules.

Test Plan: ./validate

Reviewers: hvr, bgamari

Subscribers: thomie, carter

GHC Trac Issues: #15042

Differential Revision: https://phabricator.haskell.org/D4604

Summary:
#14710 revealed two unfortunate regressions related to kind
polymorphism that had crept in in recent GHC releases:

1. While GHC was able to catch illegal uses of kind polymorphism
   (i.e., if `PolyKinds` wasn't enabled) in limited situations, it
   wasn't able to catch kind polymorphism of the following form:

```lang=haskell
f :: forall a. a -> a
f x = const x g
  where
    g :: Proxy (x :: a)
    g = Proxy
```

Note that the variable `a` is being used as a kind variable in the
type signature of `g`, but GHC happily accepts it, even without
the use of `PolyKinds`.

2. If you have `PolyKinds` (but not `TypeInType`) enabled, then GHC
   incorrectly accepts the following definition:

```lang=haskell
f :: forall k (a :: k). Proxy a
f = Proxy
```

Even though `k` is explicitly bound and then later used as a kind
variable within the same telescope.

This patch fixes these two bugs as follows:

1. Whenever we rename any `HsTyVar`, we check if the following three
   criteria are met:

   (a) It's a type variable
   (b) It's used at the kind level
   (c) `PolyKinds` is not enabled

   If so, then we have found an illegal use of kind polymorphism, so
   throw an error.

   This check replaces the `checkBadKindBndrs` function, which could
   only catch illegal uses of kind polymorphism in very limited
   situations (when the bad kind variable happened to be implicitly
   quantified in the same type signature).

2. In `extract_hs_tv_bndrs`, we must error if `TypeInType` is not
   enabled and either of the following criteria are met:

   (a) An explicitly bound type variable is used in kind position
       in the body of a `forall` type.
   (b) An explicitly bound type variable is used in kind position
       in the kind of a bound type variable in a `forall` type.

   `extract_hs_tv_bndrs` was checking (a), but not (b). Easily fixed.

Test Plan: ./validate

Reviewers: goldfire, simonpj, bgamari, hvr

Reviewed By: simonpj

Subscribers: thomie, carter

GHC Trac Issues: #14710

Differential Revision: https://phabricator.haskell.org/D4554

Summary:
This patch affects several files that affect how we detect mingw and perl
on Windows. The initial motivation is:

    https://github.com/snowleopard/hadrian/issues/564

where, with Hadrian building relocatable (non-inplace) GHCs, the current
detection mechanism falls short by e.g only trying $topdir/../mingw. But
in Hadrian, for reasons given in that issue, we would need to store e.g mingw
under $topdir/../../mingw except for binary distributions, where we want
to follow the existing structure, in which case $topdir/../mingw is correct. So
we need to support both, which is what this patch hopefully implements.

Test Plan: ./validate

Reviewers: Phyx, hvr, bgamari, erikd

Reviewed By: Phyx

Subscribers: snowleopard, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4598