Release notes in reaction to hvr's comment:26 on #10079.

Reviewed By: austin

Differential Revision: https://phabricator.haskell.org/D735

Summary:
This implements the new `Typeable` solver: when GHC sees `Typeable` constraints
it solves them on the spot.

The current implementation creates `TyCon` representations on the spot.

Pro: No overhead at all in code that does not use `Typeable`
Cons: Code that uses `Typeable` may create multipe `TyCon` represntations.

We have discussed an implementation where representations of `TyCons` are
computed once, in the module, where a datatype is declared.  This would
lead to more code being generated:  for a promotable datatype we need to
generate `2 + number_of_data_cons` type-constructro representations,
and we have to do that for all programs, even ones that do not intend to
use typeable.

I added code to emit warning whenevar `deriving Typeable` is encountered---
the idea being that this is not needed anymore, and shold be fixed.

Also, we allow `instance Typeable T` in .hs-boot files, but they result
in a warning, and are ignored.  This last one was to avoid breaking exisitng
code, and should become an error, eventually.

Test Plan:
1. GHC can compile itself.
2. I compiled a number of large libraries, including `lens`.
    - I had to make some small changes:
      `unordered-containers` uses internals of `TypeReps`, so I had to do a 1 line fix
    - `lens` needed one instance changed, due to a poly-kinded `Typeble` instance

3. I also run some code that uses `syb` to traverse a largish datastrucutre.
I didn't notice any signifiant performance difference between the 7.8.3 version,
and this implementation.

Reviewers: simonpj, simonmar, austin, hvr

Reviewed By: austin, hvr

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D652

GHC Trac Issues: #9858

(cherry picked from commit b359c886)

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Signed-off-by: Austin Seipp <aseipp@pobox.com>

(cherry picked from commit 8e774ba1)

David Feuer authored 10 years ago and Herbert Valerio Riedel committed 10 years ago

Also remove foldr2/right rule to avoid possibly introducing
bottoms with rules.

This effectively reverts most of 488e95b4

(cherry picked from commit f44bbc83)

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Edsko de Vries authored 10 years ago and thoughtpolice committed 10 years ago

Summary: Package environments are files with package IDs that indicate which packages should be visible; see entry in user guide for details.

Reviewers: duncan, austin

Reviewed By: duncan, austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D558

(cherry picked from commit 099b7676)

GregWeber authored 10 years ago and thoughtpolice committed 10 years ago

Summary:
see Trac #8624

similar functionality is now available
with -ddump-to-file -ddump-splices

However, users are already accustomed to -ddump-splices
having a particular format, and this format is not completely valid code
The goal of -th-file is to dump valid Haskell code

Additionally, the convention of -ddump-to-file is to name the file after
the flag, so the file is .dump-splices
Given that the goal of the new flag is to generate valid Haskell,
The extension should be .hs

Additionally, -ddump-to-file effects all other dump flags

Test Plan:
look at the output of using the -th-file flag
and compare it to the output of using -ddump-to-file and -ddump-splices
I want to add test cases, but just need some pointers on getting started there

Reviewers: thomie, goldfire, simonpj, austin

Reviewed By: simonpj, austin

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D518

GHC Trac Issues: #8624

(cherry picked from commit 07ace5c2)

Conflicts:
	docs/users_guide/7.12.1-notes.xml

Simon Marlow authored 10 years ago and Herbert Valerio Riedel committed 10 years ago

(cherry picked from commit 2a103c7d)

Gergő Érdi authored 10 years ago and Herbert Valerio Riedel committed 10 years ago

(cherry picked from commit 6f818e08)

Gergő Érdi authored 10 years ago and Herbert Valerio Riedel committed 10 years ago

(cherry picked from commit 68a5a784)

Facundo Domínguez authored 10 years ago and thoughtpolice committed 10 years ago

Reviewed By: austin

Differential Revision: https://phabricator.haskell.org/D575

(cherry picked from commit c72f61c6)

thomasw authored 10 years ago and thoughtpolice committed 10 years ago

Summary:
Mind the capital C. As there is already a flag RecordWildCards with a capital
C, we should at least try to be consistent in the spelling of WildCards.

Test Plan: validate

Reviewers: goldfire, simonpj, austin

Reviewed By: simonpj, austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D584

(cherry picked from commit 089222c9)

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

There were two related bugs here

Trac #9426
   We must increment the ic_mod_index field of the InteractiveContext
   if we have new instances, because we maek DFunIds that should be
   distinct from previous ones.  Previously we were only incrementing
   when defining new user-visible Ids.

   The main change is in HscTypes.extendInteractiveContext, which now
   alwyas bumps the ic_mod_index.  I also added a specialised
   extendInteractiveContextWithIds for the case where we are *only*
   adding new user-visible Ids.

Trac #9424
   In HscMain.hscDeclsWithLocations we were failing to use the
   *tidied* ClsInsts; but the un-tidied ones are LocalIds which
   causes a later ASSERT error.

   On the way I realised that, to behave consistently, the tcg_insts
   and tcg_fam_insts field of TcGblEnv should really only contain
   instances from the current GHCi command, not all the ones to date.
   That in turn meant I had to move the code for deleting replacement
   instances from addLocalInst, addLocalFamInst to
   HscTypes.extendInteractiveContext

THe documentation in 7.9.4 of promoted list and tuple types was
misleading, which led to Trac #9882.  This patch makes explicit
that only type-level with two or more elements can have the
quote omitted.

Test Plan: ./validate

Reviewers: goldfire, austin

Reviewed By: austin

Subscribers: mboes, carter, thomie

Differential Revision: https://phabricator.haskell.org/D568

GHC Trac Issues: #7015

Summary:
`splitAt` is stricter than the Report specifies, so we should
say so.

Reviewers: hvr, austin

Reviewed By: austin

Subscribers: carter, thomie

Projects: #ghc

Differential Revision: https://phabricator.haskell.org/D562

GHC Trac Issues: #9870

Summary:
As proposed in [1], this extension introduces a new syntactic form
`static e`, where `e :: a` can be any closed expression. The static form
produces a value of type `StaticPtr a`, which works as a reference that
programs can "dereference" to get the value of `e` back. References are
like `Ptr`s, except that they are stable across invocations of a
program.

The relevant wiki pages are [2, 3], which describe the motivation/ideas
and implementation plan respectively.

[1] Jeff Epstein, Andrew P. Black, and Simon Peyton-Jones. Towards
Haskell in the cloud. SIGPLAN Not., 46(12):118–129, September 2011. ISSN
0362-1340.
[2] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers
[3] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers/ImplementationPlan



Authored-by: Facundo Domínguez <facundo.dominguez@tweag.io>
Authored-by: Mathieu Boespflug <m@tweag.io>
Authored-by: Alexander Vershilov <alexander.vershilov@tweag.io>

Test Plan: `./validate`

Reviewers: hvr, simonmar, simonpj, austin

Reviewed By: simonpj, austin

Subscribers: qnikst, bgamari, mboes, carter, thomie, goldfire

Differential Revision: https://phabricator.haskell.org/D550

GHC Trac Issues: #7015

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

Signed-off-by: Austin Seipp <austin@well-typed.com>

The documentation on what warnings -W/-Wall enable was slightly out of
date, so lets fix that.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Summary: Added flag -fwarn-unticked-promoted-constructors

Test Plan: test T9778 under tests/rename/should_compile

Reviewers: jstolarek, simonpj, austin

Reviewed By: jstolarek, simonpj, austin

Subscribers: simonpj, goldfire, jstolarek, thomie, carter

Differential Revision: https://phabricator.haskell.org/D534

GHC Trac Issues: #9778

Also includes a fix for the segfaults on Windows caused by the original
version of this patch.

This reverts commit 4b51194d.

Summary:
It's not great, but it preserves a nice invariant that every Haskell
source file has an object file (we already have a hack in place ensure
this is the case for hs-boot files) and further ensures every package
has a library associated with it (which would not be the case if
the package had all signatures and we didn't make object files.)

Contains Cabal submodule update.

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

Test Plan: validate

Reviewers: simonpj, austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D548

This reverts commit b5e8b3b1.

I reverted it because one of these two patches
  9e6e4796 Add purgeObj()
  b5e8b3b1 Make the linker API thread-safe

causes a seg-fault on Windows.  The seg-fault happens immediately
the linker is invoked, in ghci or in Template Haskell.

I believe that it is the "linker API thread-safe" commit that causes
the seg-fault; it happens even if the "purgeObj" commit alone is
reverted.  But since the two patches mess with the same code, to
revert the "linker API" patch I had revert both.

This finally solves the issue of instance-method signatures that are
more polymorphic than the instanted class method.

See Note [Instance method signatures] in TcInstDcls.

A very nice fix for the two Trac tickets above.

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

Summary:
Add support for Partial Type Signatures, i.e. holes in types, see:
https://ghc.haskell.org/trac/ghc/wiki/PartialTypeSignatures

This requires an update to the Haddock submodule.

Test Plan: validate

Reviewers: austin, goldfire, simonpj

Reviewed By: simonpj

Subscribers: thomie, Iceland_jack, dominique.devriese, simonmar, carter, goldfire

Differential Revision: https://phabricator.haskell.org/D168

GHC Trac Issues: #9478