[commit: ghc] master: New handling of overlapping inst in Safe Haskell (4fffbc3)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/4fffbc34c024231c3c9fac7a2134896cc09c7fb7/ghc

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

commit 4fffbc34c024231c3c9fac7a2134896cc09c7fb7
Author: David Terei <code at davidterei.com>
Date:   Mon May 11 16:05:37 2015 -0700

    New handling of overlapping inst in Safe Haskell
    
    We do much better now due to the newish per-instance flags. Rather than
    mark any module that uses `-XOverlappingInstances`,
    `-XIncoherentInstances` or the new `OVERLAP*` pragmas as unsafe, we
    regard them all as safe and defer the check until an overlap occurs.
    
    An type-class method call that involves overlapping instances is
    considered _unsafe_ when:
    
    1) The most specific instance, Ix, is from a module marked `-XSafe`
    2) Ix is an orphan instance or a MPTC
    3) At least one instance that Ix overlaps, Iy, is:
       a) from a different module than Ix
       AND
       b) Iy is not marked `OVERLAPPABLE`
    
    This check is only enforced in modules compiled with `-XSafe` or
    `-XTrustworthy`.
    
    This fixes Safe Haskell to work with the latest overlapping instance
    pragmas, and also brings consistent behavior. Previously, Safe Inferred
    modules behaved differently than `-XSafe` modules.


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

4fffbc34c024231c3c9fac7a2134896cc09c7fb7
 compiler/main/DynFlags.hs                          |  13 +-
 compiler/main/HscMain.hs                           |  14 +-
 compiler/typecheck/Inst.hs                         |   2 +-
 compiler/typecheck/TcErrors.hs                     |  61 ++++---
 compiler/typecheck/TcForeign.hs                    |   2 +-
 compiler/typecheck/TcInstDcls.hs                   |  10 +-
 compiler/typecheck/TcInteract.hs                   |  75 +++++---
 compiler/typecheck/TcRnMonad.hs                    |  11 +-
 compiler/typecheck/TcRnTypes.hs                    |  34 ++--
 compiler/typecheck/TcSMonad.hs                     |  57 +++++-
 compiler/typecheck/TcSimplify.hs                   | 198 +++++++++++++++++----
 compiler/typecheck/TcSplice.hs                     |   2 +-
 compiler/types/InstEnv.hs                          |  56 +++---
 testsuite/tests/safeHaskell/ghci/P13_A.hs          |   2 +-
 testsuite/tests/safeHaskell/ghci/p13.stderr        |   7 +-
 .../overlapping}/Makefile                          |   0
 .../tests/safeHaskell/overlapping/SH_Overlap1.hs   |  16 ++
 .../safeHaskell/overlapping/SH_Overlap1.stderr     |  15 ++
 .../tests/safeHaskell/overlapping/SH_Overlap10.hs  |  17 ++
 .../safeHaskell/overlapping/SH_Overlap10.stderr    |   3 +
 .../safeHaskell/overlapping/SH_Overlap10_A.hs      |  13 ++
 .../safeHaskell/overlapping/SH_Overlap10_B.hs      |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap11.hs  |  18 ++
 .../safeHaskell/overlapping/SH_Overlap11.stderr    |  18 ++
 .../safeHaskell/overlapping/SH_Overlap11_A.hs      |  13 ++
 .../safeHaskell/overlapping/SH_Overlap11_B.hs      |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap1_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap1_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap2.hs   |  19 ++
 .../safeHaskell/overlapping/SH_Overlap2.stderr     |  15 ++
 .../tests/safeHaskell/overlapping/SH_Overlap2_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap2_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap3.hs   |  16 ++
 .../safeHaskell/overlapping/SH_Overlap3.stderr     |   3 +
 .../tests/safeHaskell/overlapping/SH_Overlap3_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap3_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap4.hs   |  23 +++
 .../safeHaskell/overlapping/SH_Overlap4.stderr     |   3 +
 .../tests/safeHaskell/overlapping/SH_Overlap4_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap4_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap5.hs   |  16 ++
 .../safeHaskell/overlapping/SH_Overlap5.stderr     |  15 ++
 .../tests/safeHaskell/overlapping/SH_Overlap5_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap5_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap6.hs   |  15 ++
 .../safeHaskell/overlapping/SH_Overlap6.stderr     |  15 ++
 .../tests/safeHaskell/overlapping/SH_Overlap6_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap6_B.hs |   8 +
 .../tests/safeHaskell/overlapping/SH_Overlap7.hs   |  15 ++
 .../safeHaskell/overlapping/SH_Overlap7.stderr     |  21 +++
 .../tests/safeHaskell/overlapping/SH_Overlap7_A.hs |  14 ++
 .../tests/safeHaskell/overlapping/SH_Overlap7_B.hs |   9 +
 .../tests/safeHaskell/overlapping/SH_Overlap8.hs   |  18 ++
 .../safeHaskell/overlapping/SH_Overlap8.stderr     |   2 +
 .../tests/safeHaskell/overlapping/SH_Overlap8_A.hs |  14 ++
 .../tests/safeHaskell/overlapping/SH_Overlap9.hs   |  16 ++
 .../safeHaskell/overlapping/SH_Overlap9.stderr     |   3 +
 .../tests/safeHaskell/overlapping/SH_Overlap9_A.hs |  13 ++
 .../tests/safeHaskell/overlapping/SH_Overlap9_B.hs |   8 +
 testsuite/tests/safeHaskell/overlapping/all.T      |  62 +++++++
 .../tests/safeHaskell/safeInfered/SafeInfered05.hs |  20 +--
 .../safeHaskell/safeInfered/SafeInfered05.stderr   |  15 +-
 .../safeHaskell/safeInfered/UnsafeInfered08.stderr |   4 -
 .../safeHaskell/safeInfered/UnsafeInfered08_A.hs   |   4 +-
 .../safeHaskell/safeInfered/UnsafeInfered13.stderr |   9 -
 .../safeHaskell/safeInfered/UnsafeInfered14.stderr |   9 -
 .../safeHaskell/safeInfered/UnsafeInfered15.stderr |   9 -
 .../safeHaskell/safeInfered/UnsafeInfered16.stderr |  13 --
 .../safeHaskell/safeInfered/UnsafeInfered17.stderr |   9 -
 .../safeHaskell/safeInfered/UnsafeInfered18.stderr |  10 +-
 .../safeHaskell/safeInfered/UnsafeInfered19.stderr |  11 --
 testsuite/tests/safeHaskell/safeInfered/all.T      |  24 +--
 72 files changed, 992 insertions(+), 279 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 4fffbc34c024231c3c9fac7a2134896cc09c7fb7