[commit: ghc] master: Fix #13214 by correctly setting up dep_orphs for signatures. (26eaa7e)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/26eaa7ecde288b9dc123f3c120e70b2cf18b4e4a/ghc

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

commit 26eaa7ecde288b9dc123f3c120e70b2cf18b4e4a
Author: Edward Z. Yang <ezyang at cs.stanford.edu>
Date:   Sat Feb 11 19:20:36 2017 -0500

    Fix #13214 by correctly setting up dep_orphs for signatures.
    
    Prior to this, I hadn't thought about orphan handling at all.
    This commit implements the semantics that if a signature
    (transitively) imports an orphan instance, that instance
    is considered in scope no matter what the implementing module
    is.  (As it turns out, this is the semantics that falls out
    when orphans are recorded transitively.)
    
    This patch fixes a few bugs:
    
    1. Put semantic modules in dep_orphs rather than identity
       modules.
    2. Don't put the implementing module in dep_orphs when
       merging signatures (this is a silly bug that happened
       because we were reusing calculateAvails, which is
       designed for imports. It mostly works for signature
       merging, except this case.)
    3. When renaming a signature, blast in the orphans of the
       implementing module inside Dependencies.
    
    Signed-off-by: Edward Z. Yang <ezyang at cs.stanford.edu>
    
    Test Plan: validate
    
    Reviewers: bgamari, austin
    
    Reviewed By: bgamari
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D3095


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

26eaa7ecde288b9dc123f3c120e70b2cf18b4e4a
 compiler/backpack/RnModIface.hs                    | 24 ++++++++++++++-
 compiler/rename/RnNames.hs                         |  9 +++---
 compiler/typecheck/TcBackpack.hs                   |  6 +++-
 docs/users_guide/separate_compilation.rst          |  5 ++++
 testsuite/tests/backpack/should_compile/T13214.bkp | 33 ++++++++++++++++++++
 .../tests/backpack/should_compile/T13214.stderr    | 18 +++++++++++
 testsuite/tests/backpack/should_compile/all.T      |  2 ++
 testsuite/tests/backpack/should_compile/bkp51.bkp  | 35 ++++++++++++++++++++++
 .../tests/backpack/should_compile/bkp51.stderr     | 22 ++++++++++++++
 testsuite/tests/backpack/should_fail/all.T         |  1 +
 testsuite/tests/backpack/should_fail/bkpfail43.bkp | 13 ++++++++
 .../tests/backpack/should_fail/bkpfail43.stderr    | 19 ++++++++++++
 12 files changed, 181 insertions(+), 6 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 26eaa7ecde288b9dc123f3c120e70b2cf18b4e4a