[commit: ghc] master: Reimplement shadowing on a per database basis. (39b71e8)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/39b71e81ec1044518f065d0055676d713521e483/ghc

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

commit 39b71e81ec1044518f065d0055676d713521e483
Author: Edward Z. Yang <ezyang at cs.stanford.edu>
Date:   Tue Oct 27 14:47:33 2015 -0700

    Reimplement shadowing on a per database basis.
    
    Summary:
    This commit reimplements shadowing on package databases by doing
    the shadowing calculation on a per-database basis: specifically,
    if a later package database shadows a package from the earlier
    databases, we first remove that package (and its transitive
    dependencies) before merging the databases together.
    
    This should also fix bootstrapping GHC HEAD with HEAD.
    
    Signed-off-by: Edward Z. Yang <ezyang at cs.stanford.edu>
    
    Test Plan: validate
    
    Reviewers: ggreif, bgamari, austin
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1385


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39b71e81ec1044518f065d0055676d713521e483
 compiler/main/DynFlags.hs           |   2 +-
 compiler/main/Packages.hs           | 196 ++++++++++++++++++++++--------------
 testsuite/tests/cabal/Makefile      |  14 +--
 testsuite/tests/cabal/shadow.stderr |   8 +-
 testsuite/tests/cabal/shadow.stdout |   2 +-
 5 files changed, 134 insertions(+), 88 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 39b71e81ec1044518f065d0055676d713521e483