--package-name and --package-version flags

Used for --hoogle amongst other things. Now we need to teach cabal to
use it. The situation is still a bit sub-par because if the flags aren't
passed in, the crash will occur. Closes #353.

(cherry picked from commit 8e06728afb0784128ab2df0be7a5d7a191d30ff4)

3 files changed, 53 insertions, 25 deletions

diff --git a/haddock-api/src/Haddock.hs b/haddock-api/src/Haddock.hs
index 915ad47a..72c544e1 100644
--- a/haddock-api/src/Haddock.hs
+++ b/haddock-api/src/Haddock.hs
@@ -25,6 +25,7 @@ module Haddock (
   withGhc
 ) where
 
+import Data.Version
 import Haddock.Backends.Xhtml
 import Haddock.Backends.Xhtml.Themes (getThemes)
 import Haddock.Backends.LaTeX
@@ -36,7 +37,6 @@ import Haddock.Version
 import Haddock.InterfaceFile
 import Haddock.Options
 import Haddock.Utils
-import Haddock.GhcUtils hiding (pretty)
 
 import Control.Monad hiding (forM_)
 import Data.Foldable (forM_)
@@ -66,9 +66,9 @@ import GHC hiding (verbosity)
 import Config
 import DynFlags hiding (projectVersion, verbosity)
 import StaticFlags (discardStaticFlags)
+import Packages
 import Panic (handleGhcException)
 import Module
-import PackageConfig
 import FastString
 
 --------------------------------------------------------------------------------
@@ -252,7 +252,7 @@ render dflags flags qual ifaces installedIfaces srcMap = do
     pkgMod           = ifaceMod (head ifaces)
     pkgKey            = modulePackageKey pkgMod
     pkgStr           = Just (packageKeyString pkgKey)
-    (pkgName,pkgVer) = modulePackageInfo dflags pkgMod
+    (pkgName,pkgVer) = modulePackageInfo dflags flags pkgMod
 
     (srcBase, srcModule, srcEntity, srcLEntity) = sourceUrls flags
     srcMap' = maybe srcMap (\path -> Map.insert pkgKey path srcMap) srcEntity
@@ -299,6 +299,27 @@ render dflags flags qual ifaces installedIfaces srcMap = do
     ppLaTeX title pkgStr visibleIfaces odir (fmap _doc prologue) opt_latex_style
                   libDir
 
+-- | From GHC 7.10, this function has a potential to crash with a
+-- nasty message such as @expectJust getPackageDetails@ because
+-- package name and versions can no longer reliably be extracted in
+-- all cases: if the package is not installed yet then this info is no
+-- longer available. The @--package-name@ and @--package-version@
+-- Haddock flags allow the user to specify this information and it is
+-- returned here if present: if it is not present, the error will
+-- occur. Nasty but that's how it is for now. Potential TODO.
+modulePackageInfo :: DynFlags
+                  -> [Flag] -- ^ Haddock flags are checked as they may
+                            -- contain the package name or version
+                            -- provided by the user which we
+                            -- prioritise
+                  -> Module -> (PackageName, Data.Version.Version)
+modulePackageInfo dflags flags modu =
+  (fromMaybe (packageName pkg) (optPackageName flags),
+   fromMaybe (packageVersion pkg) (optPackageVersion flags))
+  where
+    pkg = getPackageDetails dflags (modulePackageKey modu)
+
+
 -------------------------------------------------------------------------------
 -- * Reading and dumping interface files
 -------------------------------------------------------------------------------
diff --git a/haddock-api/src/Haddock/GhcUtils.hs b/haddock-api/src/Haddock/GhcUtils.hs
index b0ea1730..5caefa77 100644
--- a/haddock-api/src/Haddock/GhcUtils.hs
+++ b/haddock-api/src/Haddock/GhcUtils.hs
@@ -16,18 +16,14 @@
 module Haddock.GhcUtils where
 
 
-import Data.Version
 import Control.Applicative  ( (<$>) )
 import Control.Arrow
-import Data.Foldable hiding (concatMap)
 import Data.Function
-import Data.Traversable
 
 import Exception
 import Outputable
 import Name
 import Lexeme
-import Packages
 import Module
 import RdrName (GlobalRdrEnv)
 import GhcMonad (withSession)
@@ -40,15 +36,6 @@ import Class
 moduleString :: Module -> String
 moduleString = moduleNameString . moduleName
 
-
--- return the (name,version) of the package
-modulePackageInfo :: DynFlags -> Module -> (PackageName, Version)
-modulePackageInfo dflags modu =
-    (packageName pkg, packageVersion pkg)
-  where
-    pkg = getPackageDetails dflags (modulePackageKey modu)
-
-
 lookupLoadedHomeModuleGRE  :: GhcMonad m => ModuleName -> m (Maybe GlobalRdrEnv)
 lookupLoadedHomeModuleGRE mod_name = withSession $ \hsc_env ->
   case lookupUFM (hsc_HPT hsc_env) mod_name of
@@ -280,4 +267,3 @@ setStubDir    f d = d{ stubDir    = Just f, includePaths = f : includePaths d }
   -- -stubdir D adds an implicit -I D, so that gcc can find the _stub.h file
   -- \#included from the .hc file when compiling with -fvia-C.
 setOutputDir  f = setObjectDir f . setHiDir f . setStubDir f
-
diff --git a/haddock-api/src/Haddock/Options.hs b/haddock-api/src/Haddock/Options.hs
index 3fa6397f..e847333e 100644
--- a/haddock-api/src/Haddock/Options.hs
+++ b/haddock-api/src/Haddock/Options.hs
@@ -28,15 +28,21 @@ module Haddock.Options (
   qualification,
   verbosity,
   ghcFlags,
-  readIfaceArgs
+  readIfaceArgs,
+  optPackageName,
+  optPackageVersion
 ) where
 
 
-import Distribution.Verbosity
-import Haddock.Utils
-import Haddock.Types
-import System.Console.GetOpt
 import qualified Data.Char as Char
+import           Data.Version
+import           Distribution.Verbosity
+import           FastString
+import           Haddock.Types
+import           Haddock.Utils
+import           Packages
+import           System.Console.GetOpt
+import qualified Text.ParserCombinators.ReadP as RP
 
 
 data Flag
@@ -83,7 +89,9 @@ data Flag
   | Flag_Qualification String
   | Flag_PrettyHtml
   | Flag_NoPrintMissingDocs
-  deriving (Eq)
+  | Flag_PackageName String
+  | Flag_PackageVersion String
+  deriving (Eq, Show)
 
 
 options :: Bool -> [OptDescr Flag]
@@ -107,7 +115,7 @@ options backwardsCompat =
     Option []  ["latex-style"]  (ReqArg Flag_LaTeXStyle "FILE") "provide your own LaTeX style in FILE",
     Option ['U'] ["use-unicode"] (NoArg Flag_UseUnicode) "use Unicode in HTML output",
     Option []  ["hoogle"]     (NoArg Flag_Hoogle)
-      "output for Hoogle",
+      "output for Hoogle; you may want --package-name and --package-version too",
     Option []  ["source-base"]   (ReqArg Flag_SourceBaseURL "URL")
       "URL for a source code link on the contents\nand index pages",
     Option ['s'] (if backwardsCompat then ["source", "source-module"] else ["source-module"])
@@ -171,7 +179,11 @@ options backwardsCompat =
     Option [] ["pretty-html"] (NoArg Flag_PrettyHtml)
       "generate html with newlines and indenting (for use with --html)",
     Option [] ["no-print-missing-docs"] (NoArg Flag_NoPrintMissingDocs)
-      "don't print information about any undocumented entities"
+      "don't print information about any undocumented entities",
+    Option [] ["package-name"] (ReqArg Flag_PackageName "NAME")
+      "name of the package being documented",
+    Option [] ["package-version"] (ReqArg Flag_PackageVersion "VERSION")
+      "version of the package being documented in usual x.y.z.w format"
   ]
 
 
@@ -192,6 +204,15 @@ parseHaddockOpts params =
       usage <- getUsage
       throwE (concat errors ++ usage)
 
+optPackageVersion :: [Flag] -> Maybe Data.Version.Version
+optPackageVersion flags =
+  let ver = optLast [ v | Flag_PackageVersion v <- flags ]
+  in ver >>= fmap fst . optLast . RP.readP_to_S parseVersion
+
+optPackageName :: [Flag] -> Maybe PackageName
+optPackageName flags =
+  optLast [ PackageName $ mkFastString n | Flag_PackageName n <- flags ]
+
 
 optTitle :: [Flag] -> Maybe String
 optTitle flags =