Add JS backend adapted from the GHCJS project by Luite Stegeman.

Some features haven't been ported or implemented yet. Tests for these
features have been disabled with an associated gitlab ticket.

Bump array submodule

Work funded by IOG.

Co-authored-by: Jeffrey Young <jeffrey.young@iohk.io>
Co-authored-by: Luite Stegeman <stegeman@gmail.com>
Co-authored-by: Josh Meredith <joshmeredith2008@gmail.com>

Matthew Pickering authored 3 years ago and Marge Bot committed 3 years ago

The reqlib modifer was supposed to indicate that a test needed a certain
library in order to work. If the library happened to be installed then
the test would run as normal.

However, CI has never run these tests as the packages have not been
installed and we don't want out tests to depend on things which might
get externally broken by updating the compiler.

The new strategy is to run these tests in head.hackage, where the tests
have been cabalised as well as possible. Some tests couldn't be
transferred into the normal style testsuite but it's better than never
running any of the reqlib tests. head.hackage!169

A few submodules also had reqlib tests and have been updated to remove
it.

Closes #16264 #20032 #17764 #16561

Sylvain Henry authored 4 years ago and Marge Bot committed 4 years ago

Update Haddock submodule

Metric Increase:
   haddock.compiler

omit_ways expects a list but this was broken in several cases.

This eliminates most uses of run_command in the testsuite in favor of the more
structured makefile_test.

This reverts commit 76c8fd67.

Chaitanya Koparkar authored 6 years ago and Ryan Scott committed 6 years ago

Summary:
In some modules we directly dump the debugging output to STDOUT
via 'putLogMsg', 'printInfoForUser' etc. However, if `-ddump-to-file`
is enabled, that output should be written to a file. Easily fixed.

Certain tests (T3017, Roles3, T12763 etc.) expect part of the
output generated by `-ddump-types` to be in 'PprUser' style. However,
generally we want all other debugging output to use 'PprDump'
style. `traceTcRn` and `traceTcRnForUser` help us accomplish this.

This patch also documents some missing flags in the users guide.

Reviewers: RyanGlScott, bgamari, hvr

Reviewed By: RyanGlScott

Subscribers: rwbarton, carter

GHC Trac Issues: #15953

Differential Revision: https://phabricator.haskell.org/D5382

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

Summary:
Reimplement global FastString table using a concurrent hashatable with
fixed size segments and dynamically growing buckets instead of fixed size
buckets.

This addresses the problem that `mkFastString` was not linear when the
total number of entries was large.

Test Plan:
./validate

```
inplace/bin/ghc-stage2 --interactive -dfaststring-stats < /dev/null
GHCi, version 8.7.20181005: http://www.haskell.org/ghc/  :? for help
Prelude> Leaving GHCi.
FastString stats:
    segments:          256
    buckets:           16384
    entries:           7117
    largest segment:   64
    smallest segment:  64
    longest bucket:    5
    has z-encoding:    0%
```

Also comapre the two implementation using

{P187}

The new implementation is on a par with the old version with different
conbination of parameters and perform better when the number of
FastString's are large.

{P188}

Reviewers: simonmar, bgamari, niteria

Reviewed By: simonmar, bgamari

Subscribers: rwbarton, carter

GHC Trac Issues: #14854

Differential Revision: https://phabricator.haskell.org/D5211