New unarise (714bebff) eliminates void binders in patterns already, so no
need to eliminate them here. I leave assertions to make sure this is the
case.

Assertion failure -> bug in unarise

Reviewers: bgamari, simonpj, austin, simonmar, hvr

Reviewed By: simonpj

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2416

Summary:
The external interpreter is launched by calling
'System.Process.createProcess' with a 'CreateProcess' parameter.

The current value for this has the 'std_in', 'std_out' and 'std_err'
fields use the default of 'Inherit', meaning that the remote interpreter
shares the stdio with the original ghc/ghci process.

This patch introduces a new hook to the DynFlags, which has an
opportunity to override the 'CreateProcess' fields, launch the process,
and retrieve the stdio handles actually used.

So if a ghci external interpreter session is launched from the GHC API
the stdio can be redirected if required, which is useful for tooling/IDE
integration.

Test Plan: ./validate

Reviewers: austin, hvr, simonmar, bgamari

Reviewed By: simonmar, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2518

Instead of stg_interp_constr_entry there are now 7 functions (one for
each value of the tag bits) that tag the constructor pointer before
returning. This is consistent with compiled constructors' entry code,
and expectations that compiled code places on compiled constructors. The
iserv protocol is extended with an extra field that explains what
pointer tag the constructor should use.

Test Plan: Added tests for #12523

Reviewers: erikd, bgamari, hvr, austin, simonmar

Reviewed By: simonmar

Subscribers: osa1, thomie, rwbarton

Differential Revision: https://phabricator.haskell.org/D2473

GHC Trac Issues: #12523

Replaced error-prone index manipulation on a pointer array with
a simple fold on the array elements.

Test Plan: Added a test case that triggers the bug

Reviewers: hvr, austin, bgamari

Reviewed By: bgamari

Subscribers: simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D2439

GHC Trac Issues: #12458

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

When loading a large number of modules into GHCi, we collect
CompiledByteCode for every module and then link it all at the end.
Space leaks in the CompiledByteCode linger until we traverse it all for
linking, and possibly longer, if there are bits we don't look at.

This is the nuke-it-from-orbit approach: we deepseq the whole thing
after code generation. It's the only way to be sure.

Test Plan:
Heap profile of GHCi while loading nofib/real/anna into GHCi, this patch
reduces the peak heap usage from ~100M to ~50M.

Reviewers: hvr, austin, bgamari, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2419

Summary:
This patch implements primitive unboxed sum types, as described in
https://ghc.haskell.org/trac/ghc/wiki/UnpackedSumTypes.

Main changes are:

- Add new syntax for unboxed sums types, terms and patterns. Hidden
  behind `-XUnboxedSums`.

- Add unlifted unboxed sum type constructors and data constructors,
  extend type and pattern checkers and desugarer.

- Add new RuntimeRep for unboxed sums.

- Extend unarise pass to translate unboxed sums to unboxed tuples right
  before code generation.

- Add `StgRubbishArg` to `StgArg`, and a new type `CmmArg` for better
  code generation when sum values are involved.

- Add user manual section for unboxed sums.

Some other changes:

- Generalize `UbxTupleRep` to `MultiRep` and `UbxTupAlt` to
  `MultiValAlt` to be able to use those with both sums and tuples.

- Don't use `tyConPrimRep` in `isVoidTy`: `tyConPrimRep` is really
  wrong, given an `Any` `TyCon`, there's no way to tell what its kind
  is, but `kindPrimRep` and in turn `tyConPrimRep` returns `PtrRep`.

- Fix some bugs on the way: #12375.

Not included in this patch:

- Update Haddock for new the new unboxed sum syntax.

- `TemplateHaskell` support is left as future work.

For reviewers:

- Front-end code is mostly trivial and adapted from unboxed tuple code
  for type checking, pattern checking, renaming, desugaring etc.

- Main translation routines are in `RepType` and `UnariseStg`.
  Documentation in `UnariseStg` should be enough for understanding
  what's going on.

Credits:

- Johan Tibell wrote the initial front-end and interface file
  extensions.

- Simon Peyton Jones reviewed this patch many times, wrote some code,
  and helped with debugging.

Reviewers: bgamari, alanz, goldfire, RyanGlScott, simonpj, austin,
           simonmar, hvr, erikd

Reviewed By: simonpj

Subscribers: Iceland_jack, ggreif, ezyang, RyanGlScott, goldfire,
             thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D2259

seraphime authored 8 years ago and Ben Gamari committed 8 years ago

This fixes #12128.

The bug was introduced in 1c9fd3f1.

Test Plan: ./validate

Reviewers: simonmar, austin, hvr, simonpj, bgamari

Reviewed By: bgamari

Subscribers: simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D2374

GHC Trac Issues: #12128

These get annoying when `undefined` is actually used as placeholder in WIP code.
Some of these were also completely redundant (just call `deAnnotate'` instead of
`deAnnotate` etc.).

Summary: Add more Notes and signposts across the codebase to help navigation.

Test Plan: validate

Reviewers: goldfire, simonpj, austin, ezyang, hvr, bgamari, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2358

Like described in the comment, it's OK here.

GHC Trac: #4012

There should be no performance impact of switching to the
deterministic set here.

GHC Trac: #4012

This isn't strictly necessary for deterministic ABIs.
The results of eltsHpt are consumed in two ways:
1) they determine the order of linking
2) if you track the data flow all the family instances get put in
   FamInstEnvs, so the nondeterministic order is forgotten.
3) same for VectInfo stuff
4) same for Annotations

The problem is that I haven't found a nice way to do 2. in
a local way and 1. is nice to have if we went for deterministic
object files. Besides these maps are keyed on ModuleNames so they
should be small relative to other things and the overhead should
be negligible.

As a bonus we also get more specific names.

Test Plan: ./validate

Reviewers: bgamari, austin, hvr, ezyang, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2300

GHC Trac Issues: #4012

This is not necessary for determinism, but it's a choice
between making this deterministic and using `nonDetEltsUFM`
and a comment explaining that it doesn't matter.

Test Plan: ./validate

Reviewers: austin, hvr, bgamari, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2295

GHC Trac Issues: #4012

When faced runtime-rep-polymorphic code from a pattern-synonym
matcher, the bytecode generator was treating the result as lifted,
which it isn't.  The fix is just to treat those rep-polymorphic
continuations like unlifted types, and add a dummy arg.

Trac #12007 is a case in point.

Reviewers: austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2253

Summary:
Import libraries are files ending in `.dll.a` and `.lib` depending on which
compiler creates them (GCC, vs MSVC).

Import Libraries are standard `archive` files that contain object files.
These object files can have two different formats:

1) The normal COFF Object format for object files
    (contains all ascii data and very little program code, so do not
     try to execute.)
2) "short import" format which just contains a symbol name and
   the dll in which the symbol can be found.

Import Libraries are useful for two things:

1) Allowing applications that don't support dynamic linking to
   link against the import lib (non-short format) which then
   makes calls into the DLL by loading it at runtime.

2) Allow linking of mutually recursive dlls. if `A.DLL` requires
   `B.DLL` and vice versa, import libs can be used to break the cycle
   as they can be created from the expected exports of the DLLs.

A side effect of having these two capabilities is that Import libs are often
used to hide specific versions of DLLs behind a non-versioned import lib.

e.g. GCC_S.a (non-conventional import lib) will point to the correct
`libGCC` DLL. With this support Windows Haskell files can now just link
to `-lGCC_S` and not have to worry about what the actual name of libGCC is.

Also third party libraries such as `icuuc` use import libs to forward to
versioned DLLs. e.g. `icuuc.lib` points to `icuuc51.dll` etc.

Test Plan:
./validate

Two new tests added T11072gcc T11072msvc

Two binary files have been added to the test folder because the "short"
import library format doesn't seem to be creatable via `dlltool`
and requires Microsoft's `lib.exe`.

Reviewers: bgamari, RyanGlScott, erikd, goldfire, austin, hvr

Reviewed By: RyanGlScott, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1696

GHC Trac Issues: #11072

It changed from VarSet to DVarSet some time ago.

Ben Gamari authored 8 years ago and Ben Gamari committed 8 years ago

This adds timings and allocation figures to the compiler's output when
run with `-v2` in an effort to ease performance analysis.

Todo:
  * Documentation
  * Where else should we add these?
  * Perhaps we should remove some of the now-arguably-redundant
    `showPass` occurrences where they are
  * Must we force more?
  * Perhaps we should place this behind a `-ftimings` instead of `-v2`

Test Plan: `ghc -v2 Test.hs`, look at the output

Reviewers: hvr, goldfire, simonmar, austin

Reviewed By: simonmar

Subscribers: angerman, michalt, niteria, ezyang, thomie

Differential Revision: https://phabricator.haskell.org/D1959

barrucadu authored 9 years ago and Herbert Valerio Riedel committed 9 years ago

Both gcc and clang tell which warning flag a reported warning can be
controlled with, this patch makes ghc do the same. More generally, this
allows for annotated compiler output, where an optional annotation is
displayed in brackets after the severity.

This also adds a new flag `-f(no-)show-warning-groups` to control
whether to show which warning-group (such as `-Wall` or `-Wcompat`)
a warning belongs to. This flag is on by default.

This implements #10752

Reviewed By: quchen, bgamari, hvr

Differential Revision: https://phabricator.haskell.org/D1943

See Note [TYPE] in TysPrim. There are still some outstanding
pieces in #11471 though, so this doesn't actually nail the bug.

This commit also contains a few performance improvements:

* Short-cut equality checking of nullary type syns

* Compare types before kinds in eqType

* INLINE coreViewOneStarKind

* Store tycon binders separately from kinds.

This resulted in a ~10% performance improvement in compiling
the Cabal package. No change in functionality other than
performance. (This affects the interface file format, though.)

This commit updates the haddock submodule.

GHC.Conc exports Shutdown

Georgios Karachalias authored 9 years ago and Ben Gamari committed 9 years ago

Overhaul the Overhauled Pattern Match Checker

* Changed the representation of Value Set Abstractions. Instead of
using a prefix tree, we now use a list of Value Vector Abstractions.
The set of constraints Delta for every Value Vector Abstraction is the
oracle state so that we solve everything only once.

* Instead of doing everything lazily, we prune at once (and in general
everything is much stricter). Hence, an example written with pattern
guards is checked in almost the same time as the equivalent with
pattern matching.

* Do not store the covered and the divergent sets at all. Since what we
only need is a yes/no (does this clause cover anything? Does it force
any thunk?) We just keep a boolean for each.

* Removed flags `-Wtoo-many-guards` and `-ffull-guard-reasoning`.
Replaced with `fmax-pmcheck-iterations=n`. Still debatable what should
the default `n` be.

* When a guard is for sure not going to contribute anything, we treat
it as such: The oracle is not called and cases `CGuard`, `UGuard` and
`DGuard` from the paper are not happening at all (the generation of a
fresh variable, the unfolding of the pattern list etc.). his combined
with the above seems to be enough to drop the memory increase for test
T783 down to 18.7%.

* Do not export function `dsPmWarn` (it is now called directly from
within `checkSingle` and `checkMatches`).

* Make `PmExprVar` hold a `Name` instead of an `Id`. The term oracle
does not handle type information so using `Id` was a waste of
time/space.

* Added testcases T11195, T11303b (data families) and T11374

The patch addresses at least the following:
Trac #11195, #11276, #11303, #11374, #11162

Test Plan: validate

Reviewers: goldfire, bgamari, hvr, austin

Subscribers: simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D1795

Summary:
Serialization of BCOs is slow, but we can parallelise it when using
ghci -j<n>.  It parallelises nicely, saving multiple seconds off the
link time in a large example I have.

Test Plan:
* validate
* `ghci -fexternal-interpreter` in `nofib/real/anna`

Reviewers: niteria, bgamari, ezyang, austin, hvr, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1877

GHC Trac Issues: #11100

Summary:
This makes a big performance difference especially when loading a
large number of modules and using parallel compilation (ghci -jN).

Test Plan:
* validate
* `ghci -fexternal-interpreter` in `nofib/real/anna`

Reviewers: niteria, bgamari, ezyang, austin, hvr, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1876

GHC Trac Issues: #11100

Summary: This cuts allocations by about a quarter.

Test Plan:
* validate
* `ghci -fexternal-interpreter` in `nofib/real/anna`

Reviewers: niteria, bgamari, ezyang, austin, hvr, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1875

GHC Trac Issues: #11100

Also fix `isLevityTy` (it should use `coreView`) and start using
`dropLevityArgs` in some places.

Reviewers: goldfire, simonpj, austin, hvr, bgamari

Reviewed By: simonpj

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1867

Towards optimising the binary serialisation that
-fexternal-interpreter does, this saves quite a bit of time when using
-fexternal-interpreter with -prof.

The idea here is described in [wiki:Typechecker]. Briefly,
this refactor keeps solid track of "synthesis" mode vs
"checking" in GHC's bidirectional type-checking algorithm.
When in synthesis mode, the expected type is just an IORef
to write to.

In addition, this patch does a significant reworking of
RebindableSyntax, allowing much more freedom in the types
of the rebindable operators. For example, we can now have
`negate :: Int -> Bool` and
`(>>=) :: m a -> (forall x. a x -> m b) -> m b`. The magic
is in tcSyntaxOp.

This addresses tickets #11397, #11452, and #11458.

Tests:
  typecheck/should_compile/{RebindHR,RebindNegate,T11397,T11458}
  th/T11452

This was causing trouble as we had to remember when to use "unLifted"
and when to use "unlifted".

"unlifted" is used instead of "unLifted" as it's a single word.

Reviewers: austin, hvr, goldfire, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1852

Tamar Christina authored 9 years ago and Ben Gamari committed 9 years ago

Makes the needed changes to make RemoteGHCi work on Windows.
The approach passes OS Handles areound instead of the Posix Fd
as on Linux.

The reason is that I could not find any real documentation about
the behaviour of Windows w.r.t inheritance and Posix FDs.

The implementation with Fd did not seem to be able to find the Fd
in the child process. Instead I'm using the much better documented
approach of passing inheriting handles.

This requires a small modification to the `process` library.
https://github.com/haskell/process/pull/52

Test Plan: ./validate On Windows x86_64

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

Reviewed By: simonmar

Subscribers: #ghc_windows_task_force

Differential Revision: https://phabricator.haskell.org/D1836

GHC Trac Issues: #11100

Summary:
In the past the canonical way for constructing an SDoc string literal was the
composition `ptext . sLit`.  But for some time now we have function `text` that
does the same.  Plus it has some rules that optimize its runtime behaviour.
This patch takes all uses of `ptext . sLit` in the compiler and replaces them
with calls to `text`.  The main benefits of this patch are clener (shorter) code
and less dependencies between module, because many modules now do not need to
import `FastString`.  I don't expect any performance benefits - we mostly use
SDocs to report errors and it seems there is little to be gained here.

Test Plan: ./validate

Reviewers: bgamari, austin, goldfire, hvr, alanz

Subscribers: goldfire, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D1784

Peter Trommler authored 9 years ago and Ben Gamari committed 9 years ago

Symbols in libraries specified on the GHCis command line are
not available to compiled modules because shared libraries
are loaded with local scope. So we link all libraries specified
on the command line into each temporary shared library.

Test Plan: validate

Reviewers: simonmar, hvr, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1631

GHC Trac Issues: #10458

Summary: Moves getIdValFromApStack to the server, and removes one use of wormhole.

Test Plan: validate

Reviewers: bgamari, niteria, austin, hvr, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1768

GHC Trac Issues: #11100

Summary:
The main goal here is enable stack traces in GHCi.  After this change,
if you start GHCi like this:

  ghci -fexternal-interpreter -prof

(which requires packages to be built for profiling, but not GHC
itself) then the interpreter manages cost-centre stacks during
execution and can produce a stack trace on request.  Call locations
are available for all interpreted code, and any compiled code that was
built with the `-fprof-auto` familiy of flags.

There are a couple of ways to get a stack trace:

* `error`/`undefined` automatically get one attached
* `Debug.Trace.traceStack` can be used anywhere, and prints the current
  stack

Because the interpreter is running in a separate process, only the
interpreted code is running in profiled mode and the compiler itself
isn't slowed down by profiling.

The GHCi debugger still doesn't work with -fexternal-interpreter,
although this patch gets it a step closer.  Most of the functionality
of breakpoints is implemented, but the runtime value introspection is
still not supported.

Along the way I also did some refactoring and added type arguments to
the various remote pointer types in `GHCi.RemotePtr`, so there's
better type safety and documentation in the bridge code between GHC
and ghc-iserv.

Test Plan: validate

Reviewers: bgamari, ezyang, austin, hvr, goldfire, erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1747

GHC Trac Issues: #11047, #11100

Starting with GHC 7.10 and base-4.8, `Monad` implies `Applicative`,
which allows to simplify some definitions to exploit the superclass
relationship. This a first refactoring to that end.

Since GHC 8.1/8.2 only needs to be bootstrap-able by GHC 7.10 and
GHC 8.0 (and GHC 8.2), we can now finally drop all that pre-AMP
compatibility CPP-mess for good!

Reviewers: austin, goldfire, bgamari

Subscribers: goldfire, thomie, erikd

Differential Revision: https://phabricator.haskell.org/D1724

Georgios Karachalias authored 9 years ago and Ben Gamari committed 9 years ago

Introduction of two new flags, for more precise control over the new
pattern match checker's behaviour when reasoning about guards. This is
supposed to address #11195 (and maybe more performance bugs related to
the NP-Hardness of coverage checking).

Expected behaviour:

  * When `-ffull-guard-reasoning` is on, run the new pattern match
    checker in its full power

  * When `-ffull-guard-reasoning` is off (the default), for every
    match, check a metric to see whether pattern match checking for it
    has high probability of being non performant (at the the moment we
    check whether the number of guards is over 20 but I would like to
    use a more precise measure in the future). If the probability is
    high:

    - Oversimplify the guards (less expressive but more performant)
      and run the checker, and

    - Issue a warning about the simplification that happened.

A new flag `-Wtoo-many-guards/-Wno-too-many-guards` suppresses the
warning about the simplification (useful when combined with -Werror).

Test Plan: validate

Reviewers: goldfire, austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: mpickering, thomie

Differential Revision: https://phabricator.haskell.org/D1676

GHC Trac Issues: #11195