[commit: ghc] master: Export more Packages functions (3793d3b)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/3793d3b2b0199e50f6066f948a7c94df0c9f3580/ghc

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

commit 3793d3b2b0199e50f6066f948a7c94df0c9f3580
Author: Luite Stegeman <stegeman at gmail.com>
Date:   Fri Nov 21 11:33:00 2014 -0600

    Export more Packages functions
    
    Summary:
    This patch exports functions for finding the active package
    databases and their locations from the Packages module. This
    allows GHC API clients to use other tools, like Cabal, to gather
    package information that's not directly available from the
    binary package db.
    
    Reviewers: duncan, austin
    
    Reviewed By: austin
    
    Subscribers: thomie, carter
    
    Differential Revision: https://phabricator.haskell.org/D514


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

3793d3b2b0199e50f6066f948a7c94df0c9f3580
 compiler/main/Packages.lhs | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/compiler/main/Packages.lhs b/compiler/main/Packages.lhs
index 40b5e24..2151902 100644
--- a/compiler/main/Packages.lhs
+++ b/compiler/main/Packages.lhs
@@ -11,6 +11,10 @@ module Packages (
         -- * Reading the package config, and processing cmdline args
         PackageState(preloadPackages),
         initPackages,
+        readPackageConfigs,
+        getPackageConfRefs,
+        resolvePackageConfig,
+        readPackageConfig,
 
         -- * Querying the package config
         lookupPackage,
@@ -328,6 +332,12 @@ initPackages dflags = do
 
 readPackageConfigs :: DynFlags -> IO [PackageConfig]
 readPackageConfigs dflags = do
+  conf_refs <- getPackageConfRefs dflags
+  confs     <- liftM catMaybes $ mapM (resolvePackageConfig dflags) conf_refs
+  liftM concat $ mapM (readPackageConfig dflags) confs
+
+getPackageConfRefs :: DynFlags -> IO [PkgConfRef]
+getPackageConfRefs dflags = do
   let system_conf_refs = [UserPkgConf, GlobalPkgConf]
 
   e_pkg_path <- tryIO (getEnv "GHC_PACKAGE_PATH")
@@ -339,13 +349,10 @@ readPackageConfigs dflags = do
          | otherwise
          -> map PkgConfFile (splitSearchPath path)
 
-  let conf_refs = reverse (extraPkgConfs dflags base_conf_refs)
+  return $ reverse (extraPkgConfs dflags base_conf_refs)
   -- later packages shadow earlier ones.  extraPkgConfs
   -- is in the opposite order to the flags on the
   -- command line.
-  confs <- liftM catMaybes $ mapM (resolvePackageConfig dflags) conf_refs
-
-  liftM concat $ mapM (readPackageConfig dflags) confs
 
 resolvePackageConfig :: DynFlags -> PkgConfRef -> IO (Maybe FilePath)
 resolvePackageConfig dflags GlobalPkgConf = return $ Just (systemPackageConfig dflags)