-mungePackagePaths :: String -> [PackageConfig] -> [PackageConfig]
--- Replace the string "$topdir" at the beginning of a path
--- with the current topdir (obtained from the -B option).
-mungePackagePaths top_dir ps = map munge_pkg ps
- where
- munge_pkg p = p{ importDirs = munge_paths (importDirs p),
- includeDirs = munge_paths (includeDirs p),
- libraryDirs = munge_paths (libraryDirs p),
- frameworkDirs = munge_paths (frameworkDirs p),
- haddockInterfaces = munge_paths (haddockInterfaces p),
- haddockHTMLs = munge_paths (haddockHTMLs p)
- }
-
- munge_paths = map munge_path
-
- munge_path p
- | Just p' <- stripPrefix "$topdir" p = top_dir ++ p'
- | Just p' <- stripPrefix "$httptopdir" p = toHttpPath top_dir ++ p'
- | otherwise = p
-
- toHttpPath p = "file:///" ++ p
+mungePackagePaths :: FilePath -> FilePath -> PackageConfig -> PackageConfig
+-- Perform path/URL variable substitution as per the Cabal ${pkgroot} spec
+-- (http://www.haskell.org/pipermail/libraries/2009-May/011772.html)
+-- Paths/URLs can be relative to ${pkgroot} or ${pkgrooturl}.
+-- The "pkgroot" is the directory containing the package database.
+--
+-- Also perform a similar substitution for the older GHC-specific
+-- "$topdir" variable. The "topdir" is the location of the ghc
+-- installation (obtained from the -B option).
+mungePackagePaths top_dir pkgroot pkg =
+ pkg {
+ importDirs = munge_paths (importDirs pkg),
+ includeDirs = munge_paths (includeDirs pkg),
+ libraryDirs = munge_paths (libraryDirs pkg),
+ frameworkDirs = munge_paths (frameworkDirs pkg),
+ haddockInterfaces = munge_paths (haddockInterfaces pkg),
+ haddockHTMLs = munge_urls (haddockHTMLs pkg)
+ }
+ where
+ munge_paths = map munge_path
+ munge_urls = map munge_url
+
+ munge_path p
+ | Just p' <- stripVarPrefix "${pkgroot}" sp = pkgroot </> p'
+ | Just p' <- stripVarPrefix "$topdir" sp = top_dir </> p'
+ | otherwise = p
+ where
+ sp = splitPath p
+
+ munge_url p
+ | Just p' <- stripVarPrefix "${pkgrooturl}" sp = toUrlPath pkgroot p'
+ | Just p' <- stripVarPrefix "$httptopdir" sp = toUrlPath top_dir p'
+ | otherwise = p
+ where
+ sp = splitPath p
+
+ toUrlPath r p = "file:///"
+ -- URLs always use posix style '/' separators:
+ ++ FilePath.Posix.joinPath (r : FilePath.splitDirectories p)
+
+ stripVarPrefix var (root:path')
+ | Just [sep] <- stripPrefix var root
+ , isPathSeparator sep
+ = Just (joinPath path')
+
+ stripVarPrefix _ _ = Nothing