[commit: ghc] ghc-8.0: Be less picky about reporing inaccessible code (0e4e03a)

[git at git.haskell.org]

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

On branch  : ghc-8.0
Link       : http://ghc.haskell.org/trac/ghc/changeset/0e4e03a2a810ffa8ae16815d2ce4aad11d4b1065/ghc

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

commit 0e4e03a2a810ffa8ae16815d2ce4aad11d4b1065
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri Sep 9 17:42:42 2016 +0100

    Be less picky about reporing inaccessible code
    
    Triggered by the discussion on Trac #12466, this patch
    makes GHC less aggressive about reporting an error when
    there are insoluble Givens.
    
    Being so agressive was making some libraries fail to
    compile, and is arguably wrong in at least some cases.
    See the discussion on the ticket.
    
    Several test now pass when they failed before; see
    the files-modified list for this patch.
    
    (cherry picked from commit 03541cbae50f0d1cdf99120ab88698f29a278159)


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

0e4e03a2a810ffa8ae16815d2ce4aad11d4b1065
 compiler/typecheck/TcErrors.hs                     | 94 +++++++++++++++++-----
 compiler/typecheck/TcSMonad.hs                     | 14 ++--
 compiler/typecheck/TcSimplify.hs                   |  2 +-
 testsuite/tests/ghci/scripts/Defer02.script        |  5 +-
 testsuite/tests/ghci/scripts/Defer02.stderr        | 92 +++++++++------------
 testsuite/tests/typecheck/should_compile/T12466.hs |  9 +++
 .../tests/typecheck/should_compile/T12466a.hs      | 26 ++++++
 testsuite/tests/typecheck/should_compile/all.T     |  2 +
 .../tests/typecheck/should_fail/FDsFromGivens.hs   |  1 +
 .../typecheck/should_fail/FDsFromGivens.stderr     | 19 -----
 testsuite/tests/typecheck/should_fail/T10715.hs    |  6 ++
 .../tests/typecheck/should_fail/T10715.stderr      | 14 ----
 testsuite/tests/typecheck/should_fail/T5236.hs     |  3 +
 testsuite/tests/typecheck/should_fail/T5236.stderr | 15 ----
 testsuite/tests/typecheck/should_fail/T8392a.hs    |  4 +-
 .../tests/typecheck/should_fail/T8392a.stderr      |  9 ---
 testsuite/tests/typecheck/should_fail/all.T        |  8 +-
 testsuite/tests/typecheck/should_run/Defer01.hs    |  1 +
 18 files changed, 179 insertions(+), 145 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 0e4e03a2a810ffa8ae16815d2ce4aad11d4b1065