[commit: ghc] wip/rae: Fix #11407. (aece78a)

[git at git.haskell.org]

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

On branch  : wip/rae
Link       : http://ghc.haskell.org/trac/ghc/changeset/aece78a4cee28df557c3c69d7be76b77d3f1aa26/ghc

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

commit aece78a4cee28df557c3c69d7be76b77d3f1aa26
Author: Richard Eisenberg <eir at cis.upenn.edu>
Date:   Mon Feb 22 12:54:56 2016 -0500

    Fix #11407.
    
    This removes the `defer_me` check that was in checkTauTvUpdate
    and uses only a type family check instead. The old defer_me check
    repeated work done by fast_check in occurCheckExpand.
    
    There is also some error message improvement, necessitated by
    the terrible error message that the test case produced, even when
    it didn't consume all of memory.
    
    test case: dependent/should_fail/T11407


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

aece78a4cee28df557c3c69d7be76b77d3f1aa26
 compiler/typecheck/TcErrors.hs                     | 15 +++++++-
 compiler/typecheck/TcUnify.hs                      | 45 +++++-----------------
 compiler/types/TyCoRep.hs                          | 25 ++++++------
 compiler/types/Type.hs                             |  9 ++++-
 compiler/types/Type.hs-boot                        |  5 +++
 testsuite/tests/dependent/should_fail/T11407.hs    | 10 +++++
 .../tests/dependent/should_fail/T11407.stderr      |  9 +++++
 testsuite/tests/dependent/should_fail/all.T        |  1 +
 8 files changed, 71 insertions(+), 48 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 aece78a4cee28df557c3c69d7be76b77d3f1aa26