[commit: ghc] master: Improvements/bugfixes to signature reexport handling. (fd2d5b6)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/fd2d5b6de7493c2ff2ac76401ef296f575c52483/ghc

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

commit fd2d5b6de7493c2ff2ac76401ef296f575c52483
Author: Edward Z. Yang <ezyang at cs.stanford.edu>
Date:   Sun Feb 12 16:02:44 2017 -0800

    Improvements/bugfixes to signature reexport handling.
    
    Summary:
    A number of changes:
    
    - Keep the TcGblEnv from typechecking the local signature
      around when we do merging.  In particular, we setup
      tcg_imports and tcg_rdr_env according to the local
      signature.  This improves our error output (for example,
      see bkpfail04) and also fixes a bug with reexporting
      modules in signatures (see bkpreex07)
    
    - Fix a bug in thinning, where if we had signature A(module A),
      this previously would have *thinned out* all of the inherited
      signatures.  Now we treat every inherited signature as having
      come from an import like "import A", so a module A reexport
      will pick them up.
    
    - Recompilation checking now keeps track of dependent source files
      of the source signature; previously we forgot to retain this
      info.
    
    There's a manual update too.
    
    Signed-off-by: Edward Z. Yang <ezyang at cs.stanford.edu>
    
    Test Plan: validate
    
    Reviewers: bgamari, austin
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D3133


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

fd2d5b6de7493c2ff2ac76401ef296f575c52483
 compiler/main/HscMain.hs                           |  2 +-
 compiler/typecheck/TcBackpack.hs                   | 43 +++++++++---
 docs/users_guide/separate_compilation.rst          | 82 +++++++++++++---------
 .../backpack/cabal/bkpcabal02/bkpcabal02.stderr    |  4 +-
 testsuite/tests/backpack/reexport/all.T            |  4 ++
 testsuite/tests/backpack/reexport/bkpreex07.bkp    |  3 +
 testsuite/tests/backpack/reexport/bkpreex07.stderr |  2 +
 testsuite/tests/backpack/reexport/bkpreex08.bkp    | 17 +++++
 testsuite/tests/backpack/reexport/bkpreex08.stderr |  8 +++
 testsuite/tests/backpack/reexport/bkpreex09.bkp    | 10 +++
 .../bkp07.stderr => reexport/bkpreex09.stderr}     |  2 +-
 testsuite/tests/backpack/reexport/bkpreex10.bkp    | 10 +++
 .../bkp07.stderr => reexport/bkpreex10.stderr}     |  2 +-
 .../tests/backpack/should_fail/bkpfail04.stderr    |  4 +-
 .../tests/backpack/should_fail/bkpfail42.stderr    |  4 +-
 15 files changed, 148 insertions(+), 49 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 fd2d5b6de7493c2ff2ac76401ef296f575c52483