[commit: ghc] wip/wildcards-warn: Implement -Wredundant-record-wildcards and -Wunused-record-wildcards (db47e63)

[git at git.haskell.org]

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

On branch  : wip/wildcards-warn
Link       : http://ghc.haskell.org/trac/ghc/changeset/db47e6320b585adb5100c773105c9e861eebab21/ghc

>---------------------------------------------------------------

commit db47e6320b585adb5100c773105c9e861eebab21
Author: Matthew Pickering <matthewtpickering at gmail.com>
Date:   Mon Feb 11 09:24:04 2019 +0000

    Implement -Wredundant-record-wildcards and -Wunused-record-wildcards
    
    -Wredundant-record-wildcards warns when a .. pattern binds no variables.
    
    -Wunused-record-wildcards warns when none of the variables bound by a ..
    pattern are used.
    
    These flags are not enabled by `-Wall` currently. If people think it
    is appropuiate to add them then that is an easy change.


>---------------------------------------------------------------

db47e6320b585adb5100c773105c9e861eebab21
 compiler/main/DynFlags.hs                          |   4 +
 compiler/rename/RnExpr.hs                          |   2 +-
 compiler/rename/RnPat.hs                           | 113 ++++++++++++++++-----
 compiler/rename/RnUtils.hs                         |  15 +++
 docs/users_guide/using-warnings.rst                |  42 ++++++++
 testsuite/tests/rename/should_compile/T15957.hs    |   8 ++
 testsuite/tests/rename/should_compile/all.T        |   1 +
 testsuite/tests/rename/should_fail/T15957_Fail.hs  |  11 ++
 .../tests/rename/should_fail/T15957_Fail.stderr    |   9 ++
 testsuite/tests/rename/should_fail/all.T           |   1 +
 10 files changed, 182 insertions(+), 24 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 db47e6320b585adb5100c773105c9e861eebab21