GitLab

Only the debugging page contains interesting stuff. Some of this stuff
looks old (e.g. recommending "cabal install")...

as well as `-split-objs`, since that is related to
`--print-object-splitting-supported`.
See #18641

The fix to #17962 ended up regressing on Windows as it failed to
replicate the logic responsible for overriding the toolchain paths on
Windows. This resulted in a hard-coded path to a directory that likely
doesn't exist on the user's system (#18550).

The code that converts promoted tuple data constructors to
`IfaceType`s in `GHC.CoreToIface` was using `isTupleDataCon`, which
conflates boxed and unboxed tuple data constructors. To avoid this,
this patch introduces `isBoxedTupleDataCon`, which is like
`isTupleDataCon` but only works for _boxed_ tuple data constructors.

While I was in town, I was horribly confused by the fact that there
were separate functions named `isUnboxedTupleCon` and
`isUnboxedTupleTyCon` (similarly, `isUnboxedSumCon` and
`isUnboxedSumTyCon`). It turns out that the former only works for
data constructors, despite its very general name! I opted to rename
`isUnboxedTupleCon` to `isUnboxedTupleDataCon` (similarly, I renamed
`isUnboxedSumCon` to `isUnboxedSumDataCon`) to avoid this potential
confusion, as well as to be more consistent with
the naming convention I used for `isBoxedTupleDataCon`.

Fixes #18644.

This is in preparation of the removal of sdocWithDynFlags (#10143),
hence of the refactoring of CLabel's Outputable instance.

It looks like the flags were removed in ghc/ghc@3e27205a
and can safely be removed here

See #17856.

Previously, `transpose` produced a list of heads
and a list of tails independently. This meant that
a function using only some heads, and only some tails,
could potentially leak space. Use `unzip` to work
around the problem by producing pairs and selector
thunks instead. Time and allocation behavior will
be worse, but there should be no more leak potential.

And fix the resulting type errors.
Co-authored-by: Krzysztof Gogolewski <krz.gogolewski@gmail.com>

Metric Decrease:
    parsing001

FastStrings can be compared in 2 ways: by Unique or lexically. We don't
want to bless one particular way with an "Ord" instance because it leads
to bugs (#18562) or to suboptimal code (e.g. using lexical comparison
while a Unique comparison would suffice).

UTF-8 encoding has the advantage that sorting strings by their encoded
bytes also sorts them by their Unicode code points, without having to
decode the actual code points. BUT GHC uses Modified UTF-8 which
diverges from UTF-8 by encoding \0 as 0xC080 instead of 0x00 (to avoid
null bytes in the middle of a String so that the string can still be
null-terminated). This patch adds a new `utf8CompareShortByteString`
function that performs sorting by bytes but that also takes Modified
UTF-8 into account. It is much more performant than decoding the strings
into [Char] to perform comparisons (which we did in the previous patch).

Bump haddock submodule

This patch adds the upper bound of a happy version for ghc-9.2.

Currently, We can use happy-1.19 or happy-1.20 for ghc-9.2.

See #18620.

This patch adds the upper bound of a happy version for ghc-9.0
and earlier.

Currently, we can't use happy-1.20.0 for ghc-9.0.

See #18620.

Ignore files from "new style" cabal builds (dist-newstyle folders) and
from clangd (C language server).

This flag should be user controllable, hence Manual: True.

Allow the creation of a UnitConfig (hence of a UnitState) without having
a HomeUnit. It's required for #14335.

The commit in dff1cb3d incorrectly left
the `debugBelch` function without a comment or IF_DEBUG(linker,)
decoration. This rectifies it.

Needs at least a 8.10 backport, as it was backported in 6471cc6a

Two bugs turned out in the package that have been fixed since.
This MR includes this fixes in the GHC port of the code.

There was still one active discussion [thread](ghc/ghc!3543 (comment 284325)) when MR !3543 got merged.

This MR adds the requested tests exercising the changes in
`compiler/GHC/HsToCore/Match/Literal.hs:warnAboutEmptyEnumerations` and its sub-functions.

Avoid a similar regression in the future.

Previously we would produce a rather unhelpful pattern match failure
error in the case where the user called `getSystemTimerManager` in a
program which isn't built with `-threaded`. This understandably confused
the user in #15616.

Fixes #15616.

- Add three pseudoops to primops.txt.pp, so that Haddock renders
  the documentation
- Update comments
- Remove special case for "->" - it's no longer exported from GHC.Prim
- Remove reference to Note [Compiling GHC.Prim] - the ad-hoc fix is no
  longer there after updates to levity polymorphism.
- Document GHC.Prim
- Remove the comment that lazy is levity-polymorphic.
  As far as I can tell, it never was: in 80e39963,
  only the unfolding was given an open type variable.
- Remove haddock hack in GHC.Magic - no longer neccessary after
  adding realWorld# to primops.txt.pp.

`hsExprNeedsParens`, `hsTypeNeedsParens`, and `patNeedsParens`
previously assumed that all uses of explicit tuples in the source
syntax never need to be parenthesized. This is true save for one
exception: boxed one-tuples, which use the `Solo` data type from
`GHC.Tuple` instead of special tuple syntax. This patch adds the
necessary logic to the three `*NeedsParens` functions to handle
`Solo` correctly.

Fixes #18612.

There were four categories of primops: Monadic, Dyadic, Compare, GenPrimOp.

The compiler does not treat Monadic and Dyadic in any special way,
we can just replace them with GenPrimOp.

Compare is still used in isComparisonPrimOp.

GNU as and the AIX assembler support floating point literals.
SPARC seems to have support too but I cannot test on SPARC.
Curiously, `doubleToBytes` is also used in the LLVM backend.

To avoid endianness issues when cross-compiling float and double literals
are printed as C-style floating point values. The assembler then takes
care of memory layout and endianness.

This was brought up in #18431 by @hsyl20.

There was a confusion between the boolean expected by
withNewWordArrayTrimedMaybe and the boolean returned by subtracting
functions.

When we pretty-print a UnitId for the user, we try to map it back to its
origin package name, version and component to print
"package-version:component" instead of some hash.

The UnitId type doesn't carry these information, so we have to look into
a UnitState to find them. This is why the Outputable instance of
UnitId used `sdocWithDynFlags` in order to access the `unitState` field
of DynFlags.

This is wrong for several reasons:

1. The DynFlags are accessed when the message is printed, not when it is
   generated. So we could imagine that the unitState may have changed
   in-between. Especially if we want to allow unit unloading.

2. We want GHC to support several independent sessions at once, hence
   several UnitState. The current approach supposes there is a unique
   UnitState as a UnitId doesn't indicate which UnitState to use.

See the Note [Pretty-printing UnitId] in GHC.Unit for the new approach
implemented by this patch.

One step closer to remove `sdocDynFlags` field from `SDocContext`
(#10143).

Fix #18124.

Also fix some Backpack code to use SDoc instead of String.