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

Test Plan: ./validate

Reviewers: bgamari, hvr, RyanGlScott

Reviewed By: RyanGlScott

Subscribers: monoidal, rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5114

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

Test Plan: Validate

Reviewers: hvr, alpmestan

Reviewed By: alpmestan

Subscribers: rwbarton, carter

GHC Trac Issues: #15509

Differential Revision: https://phabricator.haskell.org/D5083

Fallout from earlier commit, sorry.

Since the introduction of quantified constraints, GHC has rejected
a quantified constraint with (~) in the head, thus
  f :: (forall a. blah => a ~ ty) => stuff

I am frankly dubious that this is ever useful.  But /is/ necessary for
Coercible (representation equality version of (~)) and it does no harm
to allow it for (~) as well.  Plus, our users are asking for it
(Trac #15359, #15625).

It was really only excluded by accident, so
this patch lifts the restriction. See TcCanonical
Note [Equality superclasses in quantified constraints]

There are a number of wrinkles:

* If the context of the quantified constraint is empty, we
  can get trouble when we get down to unboxed equality (a ~# b)
  or (a ~R# b), as Trac #15625 showed. This is even more of
  a corner case, but it produced an outright crash, so I elaborated
  the superclass machinery in TcCanonical.makeStrictSuperClasses
  to add a void argument in this case.  See
  Note [Equality superclasses in quantified constraints]

* The restriction on (~) was in TcValidity.checkValidInstHead.
  In lifting the restriction I discovered an old special case for
  (~), namely
      | clas_nm `elem` [ heqTyConName, eqTyConName]
      , nameModule clas_nm /= this_mod
  This was (solely) to support the strange instance
      instance a ~~ b => a ~ b
  in Data.Type.Equality. But happily that is no longer
  with us, since
     commit f265008f
     Refactor (~) to reduce the suerpclass stack
  So I removed the special case.

* I found that the Core invariants on when we could have
       co = <expr>
  were entirely not written down. (Getting this wrong ws
  the proximate source of the crash in Trac #15625.  So

  - Documented them better in CoreSyn
      Note [CoreSyn type and coercion invariant],
  - Modified CoreOpt and CoreLint to match
  - Modified CoreUtils.bindNonRec to match
  - Made MkCore.mkCoreLet use bindNonRec, rather
    than duplicate its logic
  - Made Simplify.rebuildCase case-to-let respect
      Note [CoreSyn type and coercion invariant],

Tobias Dammers authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
Fix test for #15578

By allowing 0-arity values to be inlined, we end up changing boringness
annotations, and this gets reflected in the Core output for this
particular test.

Add Notes for #15578

Test Plan: ./validate

Reviewers: simonpj, bgamari

Reviewed By: simonpj

Subscribers: rwbarton, carter

GHC Trac Issues: #15578

Differential Revision: https://phabricator.haskell.org/D5137

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

It was previously only defined (and therefore shipped) when DEBUG is
defined.  This patch defines it regardless of DEBUG. This will help fix
hadrian on OS X [1].

[1]: https://github.com/snowleopard/hadrian/issues/614

Test Plan: The error from hadrian#614 is gone

Reviewers: bgamari, erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5138

While we now support use of StaticPointers in modules loaded via the
REPL (e.g. via `:load`), we currently do not support use of
StaticPointers on the REPL itself.

This reverts commit 9400a5c6.

This patch takes up the missed opportunity described in
Trac #15631, by convering a case into a let slightly
more agressively. See Simplify.hs
Note [Case-to-let for strictly-used binders]

There is no measurable perf impact for good or ill. But
the code is simpler and easier to explain.

We now show address of the entered object in error messages. Example:

    foo: internal error: Evaluated a CAF (0xe4c518) that was GC'd!
        (GHC version 8.6.0.20180907 for x86_64_unknown_linux)
        Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Helpful when debugging.

Test Plan: This validates

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5143

Summary:
This removes the last direct import from simplCore/
to typechecker/.

Test Plan: validate

Reviewers: nomeata, simonpj, bgamari

Reviewed By: simonpj

Subscribers: rwbarton, carter

GHC Trac Issues: #14391

Differential Revision: https://phabricator.haskell.org/D5139

Alp Mestanogullari authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
D5140 makes us build some new profiling ways by default, but since it
is not advertised in rts.cabal, hadrian doesn't know about that. This patch
fixes this and successfully lets hadrian build those flavours of libHSrts.

Test Plan: hadrian/build.sh --flavour=perf

Reviewers: bgamari, erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5142

Ömer Sinan Ağacan authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary: (see the comments)

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5144

For some reason these were disabled. I find these quite useful when
debugging profiling issues, so enable them again.

Reviewers: bgamari, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5140

Only run the test in non-threaded, compiled mode. It hangs with threaded
runtime (which stage 2 compiler uses, so disable it for ghci too).

Reviewers: simonmar, alpmestan, bgamari

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #14912

Differential Revision: https://phabricator.haskell.org/D5136

(use ScopedTypeVariables to remove dummy arguments)

Reviewers: bgamari, RyanGlScott, dfeuer, hvr, monoidal

Reviewed By: monoidal

Subscribers: monoidal, rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5124

Takenobu Tani authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
I disabled syntax highlighting for NumericUnderscores extension.

Because pygments does not yet correspond to syntax rule for NumericUnderscores.
(Sphinx uses pygments as the syntax highlighting.)

I've sent a pull-request to pygments project[1].
But development of pygments has been suspended since 2017 March.

[1]: https://bitbucket.org/birkenfeld/pygments-main/pull-requests/
       745/fix-haskell-lexer-for-numeric-literals/diff

[ci skip]

Test Plan: build

Reviewers: bgamari, monoidal

Reviewed By: monoidal

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5120

Support for StaticPointers was added in #12356 but I apparently
neglected to remove the warning.

Summary:
- Mention static pointers in "stolen syntax"
- Suggest importing Constraint and IsString from Data.* instead of GHC.*
- Remove obsolete SPECIALISE syntax; it was removed in or before 1999
  (d66d409b)
- Fix link in pattern signatures

Test Plan: build

Reviewers: bgamari, takenobu

Reviewed By: takenobu

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5132

- Retainer profiler: init_srt_thunk() should mark the stack entry as SRT
- Retainer profiler: Remove an incorrect assertion about FUN_STATIC.
  FUN_STATIC does not have to have an SRT.
- Fix nptrs of BCO

Test Plan: validate

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5134

While debugging #15285 I realized that free block lists (free_list in
BlockAlloc.c) get corrupted when multiple scavenge threads allocate and
release blocks concurrently. Here's a picture of one such race:

    Thread 2 (Thread 32573.32601):
    #0  check_tail
        (bd=0x940d40 <stg_TSO_info>) at rts/sm/BlockAlloc.c:860
    #1  0x0000000000928ef7 in checkFreeListSanity
        () at rts/sm/BlockAlloc.c:896
    #2  0x0000000000928979 in freeGroup
        (p=0x7e998ce02880) at rts/sm/BlockAlloc.c:721
    #3  0x0000000000928a17 in freeChain
        (bd=0x7e998ce02880) at rts/sm/BlockAlloc.c:738
    #4  0x0000000000926911 in freeChain_sync
        (bd=0x7e998ce02880) at rts/sm/GCUtils.c:80
    #5  0x0000000000934720 in scavenge_capability_mut_lists
        (cap=0x1acae80) at rts/sm/Scav.c:1665
    #6  0x000000000092b411 in gcWorkerThread
        (cap=0x1acae80) at rts/sm/GC.c:1157
    #7  0x000000000090be9a in yieldCapability
        (pCap=0x7f9994e69e20, task=0x7e9984000b70, gcAllowed=true) at rts/Capability.c:861
    #8  0x0000000000906120 in scheduleYield
        (pcap=0x7f9994e69e50, task=0x7e9984000b70) at rts/Schedule.c:673
    #9  0x0000000000905500 in schedule
        (initialCapability=0x1acae80, task=0x7e9984000b70) at rts/Schedule.c:293
    #10 0x0000000000908d4f in scheduleWorker
        (cap=0x1acae80, task=0x7e9984000b70) at rts/Schedule.c:2554
    #11 0x000000000091a30a in workerStart
        (task=0x7e9984000b70) at rts/Task.c:444
    #12 0x00007f99937fa6db in start_thread
        (arg=0x7f9994e6a700) at pthread_create.c:463
    #13 0x000061654d59f88f in clone
        () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

    Thread 1 (Thread 32573.32573):
    #0  checkFreeListSanity
        () at rts/sm/BlockAlloc.c:887
    #1  0x0000000000928979 in freeGroup
        (p=0x7e998d303540) at rts/sm/BlockAlloc.c:721
    #2  0x0000000000926f23 in todo_block_full
        (size=513, ws=0x1aa8ce0) at rts/sm/GCUtils.c:264
    #3  0x00000000009583b9 in alloc_for_copy
        (size=513, gen_no=0) at rts/sm/Evac.c:80
    #4  0x000000000095850d in copy_tag_nolock
        (p=0x7e998c675f28, info=0x421d98 <Main_Large_con_info>, src=0x7e998d075d80, size=513,
        gen_no=0, tag=1) at rts/sm/Evac.c:153
    #5  0x0000000000959177 in evacuate
        (p=0x7e998c675f28) at rts/sm/Evac.c:715
    #6  0x0000000000932388 in scavenge_small_bitmap
        (p=0x7e998c675f28, size=1, bitmap=0) at rts/sm/Scav.c:271
    #7  0x0000000000934aaf in scavenge_stack
        (p=0x7e998c675f28, stack_end=0x7e998c676000) at rts/sm/Scav.c:1908
    #8  0x0000000000934295 in scavenge_one
        (p=0x7e998c66e000) at rts/sm/Scav.c:1466
    #9  0x0000000000934662 in scavenge_mutable_list
        (bd=0x7e998d300440, gen=0x1b1d880) at rts/sm/Scav.c:1643
    #10 0x0000000000934700 in scavenge_capability_mut_lists
        (cap=0x1aaa340) at rts/sm/Scav.c:1664
    #11 0x00000000009299b6 in GarbageCollect
        (collect_gen=0, do_heap_census=false, gc_type=2, cap=0x1aaa340, idle_cap=0x1b38aa0)
        at rts/sm/GC.c:378
    #12 0x0000000000907a4a in scheduleDoGC
        (pcap=0x7ffdec5b5310, task=0x1b36650, force_major=false) at rts/Schedule.c:1798
    #13 0x0000000000905de7 in schedule
        (initialCapability=0x1aaa340, task=0x1b36650) at rts/Schedule.c:546
    #14 0x0000000000908bc4 in scheduleWaitThread
        (tso=0x7e998c0067c8, ret=0x0, pcap=0x7ffdec5b5430) at rts/Schedule.c:2537
    #15 0x000000000091b5a0 in rts_evalLazyIO
        (cap=0x7ffdec5b5430, p=0x9c11f0, ret=0x0) at rts/RtsAPI.c:530
    #16 0x000000000091ca56 in hs_main
        (argc=1, argv=0x7ffdec5b5628, main_closure=0x9c11f0, rts_config=...) at rts/RtsMain.c:72
    #17 0x0000000000421ea0 in main
        ()

In particular, dbl_link_onto() which is used to add a freed block to a
doubly-linked free list is not thread safe and corrupts the list when
called concurrently.

Note that thread 1 is to blame here as thread 2 is properly taking the
spinlock. With this patch we now take the spinlock when freeing a todo
block in GC, avoiding this race.

Test Plan:
- Tried slow validate locally: this patch does not introduce new failures.
- circleci: https://circleci.com/gh/ghc/ghc-diffs/283 The test got killed
  because it took 5 hours but T7919 (which was previously failing on circleci)
  passed.

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #15285

Differential Revision: https://phabricator.haskell.org/D5115

The assertion is triggered when we have a loop in the program (in which case we
see the same update frame multiple times in the stack). See #14915 for more
details.

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #14915

Differential Revision: https://phabricator.haskell.org/D5133

Trac #15445 showed that, as a result of CSE, a function with an
automatically generated specialisation RULE could be inlined
before the RULE had a chance to fire.

This patch attaches a NOINLINE[2] activation to the Id, during
CSE, to stop this happening.

See Note [Delay inlining after CSE]

---- Historical note ---

This patch is simpler and more direct than an earlier
version:

  commit 2110738b
  Author: Simon Peyton Jones <simonpj@microsoft.com>
  Date:   Mon Jul 30 13:43:56 2018 +0100

  Don't inline functions with RULES too early

We had to revert this patch because it made GHC itself slower.

Why? It delayed inlining of /all/ functions with RULES, and that was
very bad in TcFlatten.flatten_ty_con_app

* It delayed inlining of liftM
* That delayed the unravelling of the recursion in some dictionary
  bindings.
* That delayed some eta expansion, leaving
     flatten_ty_con_app = \x y. let <stuff> in \z. blah
* That allowed the float-out pass to put sguff between
  the \y and \z.
* And that permanently stopped eta expasion of the function,
  even once <stuff> was simplified.

-- End of historical note ---

This is pure refactoring, just adding a couple of
definitions to BasicTypes, and using them.

Plus some whitespace stuff.

Alec Theriault authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
Having direct access to this field is going to enable Haddock to
compute in batch which modules to load before looking up instances
of external packages.

Reviewers: bgamari, monoidal

Reviewed By: monoidal

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5100

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

Summary: Just as it says on the tin.

Test Plan: Validate

Reviewers: bgamari, osa1

Reviewed By: osa1

Subscribers: osa1, monoidal, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D5010

Chaitanya Koparkar authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
Modules like GHC.Integer, GHC.Natural etc. are special and sometimes
have to be imported just to resolve build ordering issues. It's useful
to refer to the appropriate Notes at such import sites.

Test Plan: Read it.

Reviewers: RyanGlScott, bgamari, hvr, simonpj

Reviewed By: RyanGlScott, simonpj

Subscribers: simonpj, rwbarton, carter

GHC Trac Issues: #15526

Differential Revision: https://phabricator.haskell.org/D5092

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

Reviewers: bgamari, osa1

Reviewed By: osa1

Subscribers: osa1, monoidal, rwbarton, thomie, carter

GHC Trac Issues: #15368

Differential Revision: https://phabricator.haskell.org/D4958

Ömer Sinan Ağacan authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary: (GHCi doesn't generate event logs)

Test Plan:
These tests were failing in GHCi way, they're now skipped in GHCi way as GHCi
doesn't generate eventlogs

Reviewers: bgamari, simonmar, maoe, alpmestan

Reviewed By: alpmestan

Subscribers: rwbarton, carter

GHC Trac Issues: #15587

Differential Revision: https://phabricator.haskell.org/D5119

Roland Senn authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary: As both tests specify -fno-ghci-leak-check, the GHCi :set
command is not expected to list the -fghci-leak check flag.

Test Plan: WINDOWS: make test TESTS="ghci057 T9293"

Reviewers: bgamari, monoidal

Reviewed By: monoidal

Subscribers: rwbarton, carter

GHC Trac Issues: #15071

Differential Revision: https://phabricator.haskell.org/D5125

Alp Mestanogullari authored 6 years ago and Krzysztof Gogolewski committed 6 years ago

Summary:
Without this patch, boilerplate.mk (which is included by a lot of Makefiles from
our testsuite) just assumes they reside in the usual inplace directory, which is
not friendly to hadrian and this makes a lot of tests (e.g T10255) fail when
building GHC and running the testsuite with hadrian.

With this patch, the said tests pass.

Test Plan: api annotation tests (with hadrian)

Reviewers: bgamari, monoidal

Reviewed By: monoidal

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5127