[commit: ghc] master: Improve error messages from functional dependencies (1a88f9a)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/1a88f9a4fb373ce52284996212fc23b06848b1c0/ghc

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

commit 1a88f9a4fb373ce52284996212fc23b06848b1c0
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri Sep 26 10:53:32 2014 +0100

    Improve error messages from functional dependencies
    
    Reponding to Trac #9612:
    
     * Track the CtOrigin of a Derived equality, arising from a
       functional dependency
    
     * And report it clearly in the error stream
    
    This relies on a previous commit, in which I stop dropping Derived
    insolubles on the floor.


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

1a88f9a4fb373ce52284996212fc23b06848b1c0
 compiler/typecheck/FunDeps.lhs                     |  21 +--
 compiler/typecheck/TcErrors.lhs                    |  61 ++++++---
 compiler/typecheck/TcInteract.lhs                  |  32 +++--
 compiler/typecheck/TcRnTypes.lhs                   | 148 +++++++++++++--------
 compiler/typecheck/TcUnify.lhs                     |   4 +-
 .../tests/typecheck/should_compile/FD3.stderr      |  11 +-
 .../typecheck/should_fail/FDsFromGivens.stderr     |  14 +-
 testsuite/tests/typecheck/should_fail/T5236.stderr |  13 +-
 testsuite/tests/typecheck/should_fail/T5978.stderr |   5 +-
 testsuite/tests/typecheck/should_fail/T9612.hs     |  20 +++
 testsuite/tests/typecheck/should_fail/T9612.stderr |  20 +++
 testsuite/tests/typecheck/should_fail/all.T        |   1 +
 .../tests/typecheck/should_fail/tcfail143.stderr   |   5 +-
 13 files changed, 247 insertions(+), 108 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 1a88f9a4fb373ce52284996212fc23b06848b1c0