[commit: ghc] ghc-8.4: Special-case record fields ending with hash when deriving Read (32e1842)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-8.4
Link       : http://ghc.haskell.org/trac/ghc/changeset/32e18420b328b1f939dd92333d3b7637c26ef3a8/ghc

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commit 32e18420b328b1f939dd92333d3b7637c26ef3a8
Author: Ryan Scott <ryan.gl.scott at gmail.com>
Date:   Fri Mar 23 11:40:02 2018 -0400

    Special-case record fields ending with hash when deriving Read
    
    Summary:
    In commit dbd81f7e86514498218572b9d978373b1699cc5b, a
    regression was inadvertently introduced which caused derived `Read`
    instances for record data types with fields ending in a `#` symbol
    (using `MagicHash`) would no longer parse on valid output. This
    is ultimately due to the same reasons as #5041, as we cannot parse
    a field name like `foo#` as a single identifier. We fix this issue
    by employing the same workaround as in #5041: first parse the
    identifier name `foo`, then then symbol `#`.
    
    This is accomplished by the new `readFieldHash` function in
    `GHC.Read`. This will likely warrant a `base-4.11.1.0` release.
    
    Test Plan: make test TEST=T14918
    
    Reviewers: tdammers, hvr, bgamari
    
    Reviewed By: bgamari
    
    Subscribers: rwbarton, thomie, carter
    
    GHC Trac Issues: #14918
    
    Differential Revision: https://phabricator.haskell.org/D4502
    
    (cherry picked from commit d5577f44eaf3b9dfdfc77828038782bf818c176a)


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32e18420b328b1f939dd92333d3b7637c26ef3a8
 compiler/prelude/PrelNames.hs                     |  3 +-
 compiler/typecheck/TcGenDeriv.hs                  | 16 +++--
 docs/users_guide/8.4.2-notes.rst                  | 88 +++++++++++++++++++++++
 docs/users_guide/index.rst                        |  1 +
 libraries/base/GHC/Read.hs                        | 17 +++++
 libraries/base/changelog.md                       |  4 ++
 testsuite/tests/deriving/should_run/T14918.hs     | 18 +++++
 testsuite/tests/deriving/should_run/T14918.stdout |  2 +
 testsuite/tests/deriving/should_run/all.T         |  1 +
 9 files changed, 143 insertions(+), 7 deletions(-)

Diff suppressed because of size. To see it, use:

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc 32e18420b328b1f939dd92333d3b7637c26ef3a8