Add way to exclude generated modules from sdists

Cabal/Distribution/Simple/Setup.hs

@@ -113,6 +113,8 @@ import Distribution.Simple.InstallDirs
          ( InstallDirs(..), CopyDest(..),
            PathTemplate, toPathTemplate, fromPathTemplate )
 import Distribution.Verbosity
+import Distribution.ModuleName
+         ( ModuleName )
 
 import Data.List   ( sort )
 import Data.Char   ( isSpace, isAlpha )
@@ -785,7 +787,8 @@ data SDistFlags = SDistFlags {
     sDistSnapshot  :: Flag Bool,
     sDistDirectory :: Flag FilePath,
     sDistDistPref  :: Flag FilePath,
-    sDistVerbosity :: Flag Verbosity
+    sDistVerbosity :: Flag Verbosity,
+    sDistGeneratedModules :: [ModuleName]
   }
   deriving Show
 
@@ -794,7 +797,8 @@ defaultSDistFlags = SDistFlags {
     sDistSnapshot  = Flag False,
     sDistDirectory = mempty,
     sDistDistPref  = Flag defaultDistPref,
-    sDistVerbosity = Flag normal
+    sDistVerbosity = Flag normal,
+    sDistGeneratedModules = mempty
   }
 
 sdistCommand :: CommandUI SDistFlags
@@ -818,6 +822,13 @@ sdistCommand = makeCommand name shortDesc longDesc defaultSDistFlags options
          "Generate a source distribution in the given directory"
          sDistDirectory (\v flags -> flags { sDistDirectory = v })
          (reqArgFlag "DIR")
+
+      ,option "" ["generated-module"]
+         "Name a generated module to exclude from the tarball"
+         sDistGeneratedModules (\v flags -> flags { sDistGeneratedModules = v })
+         (reqArg "MODULE"
+                 (readP_to_E (const "module name expected") ((\x -> [x]) `fmap` parse))
+                 (map (\x -> display x)))
       ]
 
 emptySDistFlags :: SDistFlags
@@ -828,13 +839,15 @@ instance Monoid SDistFlags where
     sDistSnapshot  = mempty,
     sDistDirectory = mempty,
     sDistDistPref  = mempty,
-    sDistVerbosity = mempty
+    sDistVerbosity = mempty,
+    sDistGeneratedModules = mempty
   }
   mappend a b = SDistFlags {
     sDistSnapshot  = combine sDistSnapshot,
     sDistDirectory = combine sDistDirectory,
     sDistDistPref  = combine sDistDistPref,
-    sDistVerbosity = combine sDistVerbosity
+    sDistVerbosity = combine sDistVerbosity,
+    sDistGeneratedModules = combine sDistGeneratedModules
   }
     where combine field = field a `mappend` field b
 

Cabal/Distribution/Simple/SrcDist.hs

@@ -56,11 +56,13 @@ module Distribution.Simple.SrcDist (
 
   -- ** Parts of 'sdist'
   printPackageProblems,
+  prepareTreeWithoutGeneratedModules,
   prepareTree,
   createArchive,
 
   -- ** Snaphots
   prepareSnapshotTree,
+  prepareSnapshotTreeWithoutGeneratedModules,
   snapshotPackage,
   snapshotVersion,
   dateToSnapshotNumber,
@@ -140,18 +142,18 @@ sdist pkg mb_lbi flags mkTmpDir pps = do
     generateSourceDir targetDir pkg' = do
 
       setupMessage verbosity "Building source dist for" (packageId pkg')
-      prepareTree verbosity pkg' mb_lbi distPref targetDir pps
+      prepareTreeWithoutGeneratedModules verbosity pkg' mb_lbi distPref targetDir pps generatedModules
       when snapshot $
         overwriteSnapshotPackageDesc verbosity pkg' targetDir
 
     verbosity = fromFlag (sDistVerbosity flags)
     snapshot  = fromFlag (sDistSnapshot flags)
+    generatedModules = sDistGeneratedModules flags
 
     distPref     = fromFlag $ sDistDistPref flags
     targetPref   = distPref
     tmpTargetDir = mkTmpDir distPref
 
-
 -- |Prepare a directory tree of source files.
 prepareTree :: Verbosity          -- ^verbosity
             -> PackageDescription -- ^info from the cabal file
@@ -160,7 +162,21 @@ prepareTree :: Verbosity          -- ^verbosity
             -> FilePath           -- ^source tree to populate
             -> [PPSuffixHandler]  -- ^extra preprocessors (includes suffixes)
             -> IO ()
-prepareTree verbosity pkg_descr0 mb_lbi distPref targetDir pps = do
+prepareTree verbosity pkg_descr mb_lbi distPref targetDir pps =
+  prepareTreeWithoutGeneratedModules verbosity pkg_descr mb_lbi distPref targetDir pps []
+
+-- |Prepare a directory tree of source files, except for generated modules.
+-- Note that this automatically ignores the Paths_<pkg>.hs module.
+prepareTreeWithoutGeneratedModules 
+    :: Verbosity          -- ^verbosity
+    -> PackageDescription -- ^info from the cabal file
+    -> Maybe LocalBuildInfo
+    -> FilePath           -- ^dist dir
+    -> FilePath           -- ^source tree to populate
+    -> [PPSuffixHandler]  -- ^extra preprocessors (includes suffixes)
+    -> [ModuleName]       -- ^generated modules to ignore
+    -> IO ()
+prepareTreeWithoutGeneratedModules verbosity pkg_descr0 mb_lbi distPref targetDir pps generatedModules0 = do
   createDirectoryIfMissingVerbose verbosity True targetDir
 
   -- maybe move the library files into place
@@ -262,11 +278,19 @@ prepareTree verbosity pkg_descr0 mb_lbi distPref targetDir pps = do
   installOrdinaryFile verbosity descFile (targetDir </> descFile)
 
   where
-    pkg_descr = mapAllBuildInfo filterAutogenModule pkg_descr0
-    filterAutogenModule bi = bi {
-      otherModules = filter (/=autogenModule) (otherModules bi)
+    pkg_descr1 = mapAllBuildInfo filterGeneratedOtherModules pkg_descr0
+    pkg_descr = pkg_descr1 {
+      library = fmap filterGeneratedExposedModules (library pkg_descr1)
+    }
+    filterGeneratedOtherModules bi = bi {
+      otherModules = filterGeneratedModules (otherModules bi)
+    }
+    filterGeneratedExposedModules libr = libr {
+      exposedModules = filterGeneratedModules (exposedModules libr)
     }
-    autogenModule = autogenModuleName pkg_descr0
+    filterGeneratedModules = filter (flip notElem generatedModules)
+    -- Paths_<pkg>.hs, as well as the modules specified by the caller.
+    generatedModules = autogenModuleName pkg_descr0 : generatedModules0
 
     findInc [] f = die ("can't find include file " ++ f)
     findInc (d:ds) f = do
@@ -292,8 +316,24 @@ prepareSnapshotTree :: Verbosity          -- ^verbosity
                     -> FilePath           -- ^source tree to populate
                     -> [PPSuffixHandler]  -- ^extra preprocessors (includes suffixes)
                     -> IO ()
-prepareSnapshotTree verbosity pkg mb_lbi distPref targetDir pps = do
-  prepareTree verbosity pkg mb_lbi distPref targetDir pps
+prepareSnapshotTree verbosity pkg mb_lbi distPref targetDir pps =
+  prepareSnapshotTreeWithoutGeneratedModules verbosity pkg mb_lbi distPref targetDir pps []
+
+-- | Prepare a directory tree of source files for a snapshot version, without
+-- the specified generated modules (as well as Paths_<pkg>.hs).
+-- It is expected that the appropriate snapshot version has already been set
+-- in the package description, eg using 'snapshotPackage' or 'snapshotVersion'.
+prepareSnapshotTreeWithoutGeneratedModules
+    :: Verbosity          -- ^verbosity
+    -> PackageDescription -- ^info from the cabal file
+    -> Maybe LocalBuildInfo
+    -> FilePath           -- ^dist dir
+    -> FilePath           -- ^source tree to populate
+    -> [PPSuffixHandler]  -- ^extra preprocessors (includes suffixes)
+    -> [ModuleName]       -- ^generated modules to ignore
+    -> IO ()
+prepareSnapshotTreeWithoutGeneratedModules verbosity pkg mb_lbi distPref targetDir pps generatedModules = do
+  prepareTreeWithoutGeneratedModules verbosity pkg mb_lbi distPref targetDir pps generatedModules
   overwriteSnapshotPackageDesc verbosity pkg targetDir
 
 overwriteSnapshotPackageDesc :: Verbosity          -- ^verbosity

Cabal/doc/installing-packages.markdown

@@ -785,12 +785,23 @@ the setup script, the sources of the modules named in the package
 description file, and files named in the `license-file`, `main-is`,
 `c-sources`, `data-files` and `extra-source-files` fields.
 
+If the package includes generated Haskell source files, they can be
+excluded from the distribution on the command line.  `Paths_`_pkgname_
+does not need to be so specified; Cabal automatically knows to exclude it.
+All the necessary scripts and data to re-generate the modules should be listed
+in the `extra-source-files` field of the `.cabal` file.
+
 This command takes the following option:
 
 `--snapshot`
 :   Append today's date (in "YYYYMMDD" format) to the version number for
     the generated source package.  The original package is unaffected.
 
+`--generated-module=`_module_
+:   Specify that the named module is machine-generated and not to be included
+    it in the distribution.  Note that this takes a module name, not a
+    path name (that is, `Distribution.GeneratedModule` rather than
+    `Distribution/GeneratedModule.hs`).
 
 [dist-simple]:  ../libraries/Cabal/Distribution-Simple.html
 [dist-make]:    ../libraries/Cabal/Distribution-Make.html