[commit: ghc] master: Add a pointer to the relevant paper for InScopeSet (47ccf4d)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/47ccf4d2a0df33f26e66f340e89ca516b4597ed0/ghc

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

commit 47ccf4d2a0df33f26e66f340e89ca516b4597ed0
Author: Bartosz Nitka <niteria at gmail.com>
Date:   Fri Jan 8 15:26:49 2016 +0100

    Add a pointer to the relevant paper for InScopeSet
    
    This was non-obvious to me when reading the sources and the
    paper provides the motivation and explores the design space.
    
    Test Plan: just a comment
    
    Reviewers: simonpj, austin, ezyang, bgamari
    
    Reviewed By: bgamari
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1749


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47ccf4d2a0df33f26e66f340e89ca516b4597ed0
 compiler/basicTypes/VarEnv.hs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/basicTypes/VarEnv.hs b/compiler/basicTypes/VarEnv.hs
index bdc451a..08c7965 100644
--- a/compiler/basicTypes/VarEnv.hs
+++ b/compiler/basicTypes/VarEnv.hs
@@ -80,6 +80,8 @@ import FastString
 -}
 
 -- | A set of variables that are in scope at some point
+-- "Secrets of the Glasgow Haskell Compiler inliner" Section 3. provides
+-- the motivation for this abstraction.
 data InScopeSet = InScope (VarEnv Var) {-# UNPACK #-} !Int
         -- The (VarEnv Var) is just a VarSet.  But we write it like
         -- this to remind ourselves that you can look up a Var in