Add new 'autogen-modules' field

Modules that are built automatically at setup, like Paths_PACKAGENAME or others created with a build-type custom, appear on 'other-modules' for the Library, Executable, Test-Suite or Benchmark stanzas or also on 'exposed-modules' for libraries but are not really on the package when distributed. This makes commands like sdist fail because the file is not found, so with this new field modules that appear there are treated the same way as Paths_PACKAGENAME was and there is no need to create complex build hooks.
Just add the module names on 'other-modules' and 'exposed-modules' as always and on the new 'autogen-modules' besides.

Cabal/Cabal.cabal

@@ -38,6 +38,20 @@ extra-source-files:
   tests/PackageTests/AllowOlder/benchmarks/Bench.hs
   tests/PackageTests/AllowOlder/src/Foo.hs
   tests/PackageTests/AllowOlder/tests/Test.hs
+  tests/PackageTests/AutogenModules/Package/Dummy.hs
+  tests/PackageTests/AutogenModules/Package/MyBenchModule.hs
+  tests/PackageTests/AutogenModules/Package/MyExeModule.hs
+  tests/PackageTests/AutogenModules/Package/MyLibModule.hs
+  tests/PackageTests/AutogenModules/Package/MyLibrary.hs
+  tests/PackageTests/AutogenModules/Package/MyTestModule.hs
+  tests/PackageTests/AutogenModules/Package/my.cabal
+  tests/PackageTests/AutogenModules/SrcDist/Dummy.hs
+  tests/PackageTests/AutogenModules/SrcDist/MyBenchModule.hs
+  tests/PackageTests/AutogenModules/SrcDist/MyExeModule.hs
+  tests/PackageTests/AutogenModules/SrcDist/MyLibModule.hs
+  tests/PackageTests/AutogenModules/SrcDist/MyLibrary.hs
+  tests/PackageTests/AutogenModules/SrcDist/MyTestModule.hs
+  tests/PackageTests/AutogenModules/SrcDist/my.cabal
   tests/PackageTests/BenchmarkExeV10/Foo.hs
   tests/PackageTests/BenchmarkExeV10/benchmarks/bench-Foo.hs
   tests/PackageTests/BenchmarkExeV10/my.cabal
@@ -435,6 +449,8 @@ test-suite package-tests
   type: exitcode-stdio-1.0
   main-is: PackageTests.hs
   other-modules:
+    PackageTests.AutogenModules.Package.Check
+    PackageTests.AutogenModules.SrcDist.Check
     PackageTests.BenchmarkStanza.Check
     PackageTests.TestStanza.Check
     PackageTests.DeterministicAr.Check

Cabal/Distribution/PackageDescription.hs

@@ -36,13 +36,15 @@ module Distribution.PackageDescription (
         hasPublicLib,
         hasLibs,
         libModules,
+        libModulesAutogen,
 
         -- ** Executables
         Executable(..),
         emptyExecutable,
         withExe,
         hasExes,
         exeModules,
+        exeModulesAutogen,
 
         -- * Tests
         TestSuite(..),
@@ -54,6 +56,7 @@ module Distribution.PackageDescription (
         hasTests,
         withTest,
         testModules,
+        testModulesAutogen,
 
         -- * Benchmarks
         Benchmark(..),
@@ -65,6 +68,7 @@ module Distribution.PackageDescription (
         hasBenchmarks,
         withBenchmark,
         benchmarkModules,
+        benchmarkModulesAutogen,
 
         -- * Build information
         BuildInfo(..),

Cabal/Distribution/PackageDescription/Check.hs

@@ -41,6 +41,7 @@ import Distribution.PackageDescription.Configuration
 import Distribution.Compiler
 import Distribution.System
 import Distribution.License
+import Distribution.Simple.BuildPaths (autogenPathsModuleName)
 import Distribution.Simple.CCompiler
 import Distribution.Simple.Utils hiding (findPackageDesc, notice)
 import Distribution.Version
@@ -245,6 +246,14 @@ checkLibrary pkg lib =
       PackageDistInexcusable $
            "To use the 'required-signatures' field the package needs to specify "
         ++ "at least 'cabal-version: >= 1.21'."
+
+    -- check that all autogen-modules appear on other-modules or exposed-modules
+  , check
+      (not $ and $ map (flip elem (libModules lib)) (libModulesAutogen lib)) $
+      PackageBuildImpossible $
+           "An 'autogen-module' is neither on 'exposed-modules' or "
+        ++ "'other-modules'."
+
   ]
 
   where
@@ -282,6 +291,14 @@ checkExecutable pkg exe =
        PackageBuildImpossible $
             "Duplicate modules in executable '" ++ exeName exe ++ "': "
          ++ commaSep (map display moduleDuplicates)
+
+    -- check that all autogen-modules appear on other-modules
+  , check
+      (not $ and $ map (flip elem (exeModules exe)) (exeModulesAutogen exe)) $
+      PackageBuildImpossible $
+           "On executable '" ++ exeName exe ++ "' an 'autogen-module' is not "
+        ++ "on 'other-modules'"
+
   ]
   where
     moduleDuplicates = dups (exeModules exe)
@@ -319,6 +336,16 @@ checkTestSuite pkg test =
       PackageDistInexcusable $
            "The package uses a C/C++/obj-C source file for the 'main-is' field. "
         ++ "To use this feature you must specify 'cabal-version: >= 1.18'."
+
+    -- check that all autogen-modules appear on other-modules
+  , check
+      (not $ and $ map
+        (flip elem (testModules test))
+        (testModulesAutogen test)
+      ) $
+      PackageBuildImpossible $
+           "On test suite '" ++ testName test ++ "' an 'autogen-module' is not "
+        ++ "on 'other-modules'"
   ]
   where
     moduleDuplicates = dups $ testModules test
@@ -358,6 +385,16 @@ checkBenchmark _pkg bm =
       PackageBuildImpossible $
            "The 'main-is' field must specify a '.hs' or '.lhs' file "
         ++ "(even if it is generated by a preprocessor)."
+
+    -- check that all autogen-modules appear on other-modules
+  , check
+      (not $ and $ map
+        (flip elem (benchmarkModules bm))
+        (benchmarkModulesAutogen bm)
+      ) $
+      PackageBuildImpossible $
+             "On benchmark '" ++ benchmarkName bm ++ "' an 'autogen-module' is "
+          ++ "not on 'other-modules'"
   ]
   where
     moduleDuplicates = dups $ benchmarkModules bm
@@ -1110,6 +1147,18 @@ checkCabalVersion pkg =
         ++ "that specifies the dependencies of the Setup.hs script itself. "
         ++ "The 'setup-depends' field uses the same syntax as 'build-depends', "
         ++ "so a simple example would be 'setup-depends: base, Cabal'."
+
+  , check (specVersion pkg >= Version [1,25] []
+           && elem (autogenPathsModuleName pkg) allModuleNames
+           && not (elem (autogenPathsModuleName pkg) allModuleNamesAutogen) ) $
+      PackageDistInexcusable $
+           "Packages using 'cabal-version: >= 1.25' and the autogenerated "
+        ++ "module Paths_* must include it also on the 'autogen-modules' field "
+        ++ "besides 'exposed-modules' and 'other-modules'. This specifies that "
+        ++ "the module does not come with the package and is generated on "
+        ++ "setup. Modules built with a custom Setup.hs script also go here "
+        ++ "to ensure that commands like sdist don't fail."
+
   ]
   where
     -- Perform a check on packages that use a version of the spec less than
@@ -1244,6 +1293,15 @@ checkCabalVersion pkg =
       map DisableExtension
       [MonoPatBinds]
 
+    allModuleNames =
+         (case library pkg of
+           Nothing -> []
+           (Just lib) -> libModules lib
+         )
+      ++ concatMap otherModules (allBuildInfo pkg)
+
+    allModuleNamesAutogen = concatMap autogenModules (allBuildInfo pkg)
+
 -- | A variation on the normal 'Text' instance, shows any ()'s in the original
 -- textual syntax. We need to show these otherwise it's confusing to users when
 -- we complain of their presence but do not pretty print them!

Cabal/Distribution/PackageDescription/Parse.hs

@@ -443,6 +443,9 @@ binfoFieldDescrs =
  , listFieldWithSep vcat "other-modules"
            disp               parseModuleNameQ
            otherModules       (\val binfo -> binfo{otherModules=val})
+ , listFieldWithSep vcat "autogen-modules"
+           disp               parseModuleNameQ
+           autogenModules       (\val binfo -> binfo{autogenModules=val})
  , optsField   "ghc-prof-options" GHC
            profOptions        (\val binfo -> binfo{profOptions=val})
  , optsField   "ghcjs-prof-options" GHCJS

Cabal/Distribution/ParseUtils.hs

@@ -288,6 +288,7 @@ ppField name fielddoc
          , "includes"
          , "install-includes"
          , "other-modules"
+         , "autogen-modules"
          , "depends"
          ]
 

Cabal/Distribution/Simple/Build.hs

@@ -583,7 +583,7 @@ writeAutogenFiles verbosity pkg lbi clbi = do
   createDirectoryIfMissingVerbose verbosity True (autogenComponentModulesDir lbi clbi)
 
   let pathsModulePath = autogenComponentModulesDir lbi clbi
-                    </> ModuleName.toFilePath (autogenModuleName pkg) <.> "hs"
+                 </> ModuleName.toFilePath (autogenPathsModuleName pkg) <.> "hs"
   rewriteFile pathsModulePath (Build.PathsModule.generate pkg lbi clbi)
 
   let cppHeaderPath = autogenComponentModulesDir lbi clbi </> cppHeaderName

Cabal/Distribution/Simple/Build/PathsModule.hs

@@ -226,7 +226,7 @@ generate pkg_descr lbi clbi =
                            _         -> False
         supportsRelocatableProgs _    = False
 
-        paths_modulename = autogenModuleName pkg_descr
+        paths_modulename = autogenPathsModuleName pkg_descr
 
         get_prefix_stuff = get_prefix_win32 buildArch
 

Cabal/Distribution/Simple/BuildPaths.hs

@@ -19,6 +19,7 @@ module Distribution.Simple.BuildPaths (
     autogenComponentModulesDir,
 
     autogenModuleName,
+    autogenPathsModuleName,
     cppHeaderName,
     haddockName,
 
@@ -87,9 +88,14 @@ autogenComponentModulesDir lbi clbi = componentBuildDir lbi clbi </> "autogen"
 cppHeaderName :: String
 cppHeaderName = "cabal_macros.h"
 
+{-# DEPRECATED autogenModuleName "Use autogenPathsModuleName instead" #-}
 -- |The name of the auto-generated module associated with a package
 autogenModuleName :: PackageDescription -> ModuleName
-autogenModuleName pkg_descr =
+autogenModuleName = autogenPathsModuleName
+
+-- | The name of the auto-generated Paths_* module associated with a package
+autogenPathsModuleName :: PackageDescription -> ModuleName
+autogenPathsModuleName pkg_descr =
   ModuleName.fromString $
     "Paths_" ++ map fixchar (display (packageName pkg_descr))
   where fixchar '-' = '_'

Cabal/Distribution/Simple/SrcDist.hs

@@ -136,7 +136,7 @@ listPackageSources verbosity pkg_descr0 pps = do
   maybeExecutable <- listPackageSourcesMaybeExecutable pkg_descr
   return (ordinary, maybeExecutable)
   where
-    pkg_descr = filterAutogenModule pkg_descr0
+    pkg_descr = filterAutogenModules pkg_descr0
 
 -- | List those source files that may be executable (e.g. the configure script).
 listPackageSourcesMaybeExecutable :: PackageDescription -> IO [FilePath]
@@ -259,7 +259,7 @@ prepareTree verbosity pkg_descr0 mb_lbi targetDir pps = do
   maybeCreateDefaultSetupScript targetDir
 
   where
-    pkg_descr = filterAutogenModule pkg_descr0
+    pkg_descr = filterAutogenModules pkg_descr0
 
 -- | Find the setup script file, if it exists.
 findSetupFile :: FilePath -> IO (Maybe FilePath)
@@ -305,21 +305,24 @@ findIncludeFile (d:ds) f = do
   b <- doesFileExist path
   if b then return (f,path) else findIncludeFile ds f
 
--- | Remove the auto-generated module ('Paths_*') from 'exposed-modules' and
--- 'other-modules'.
-filterAutogenModule :: PackageDescription -> PackageDescription
-filterAutogenModule pkg_descr0 = mapLib filterAutogenModuleLib $
+-- | Remove the auto-generated modules (like 'Paths_*') from 'exposed-modules' 
+-- and 'other-modules'.
+filterAutogenModules :: PackageDescription -> PackageDescription
+filterAutogenModules pkg_descr0 = mapLib filterAutogenModuleLib $
                                  mapAllBuildInfo filterAutogenModuleBI pkg_descr0
   where
     mapLib f pkg = pkg { library      = fmap f (library pkg)
                        , subLibraries = map f (subLibraries pkg) }
     filterAutogenModuleLib lib = lib {
-      exposedModules = filter (/=autogenModule) (exposedModules lib)
+      exposedModules = filter (filterFunction (libBuildInfo lib)) (exposedModules lib)
     }
     filterAutogenModuleBI bi = bi {
-      otherModules   = filter (/=autogenModule) (otherModules bi)
+      otherModules   = filter (filterFunction bi) (otherModules bi)
     }
-    autogenModule = autogenModuleName pkg_descr0
+    pathsModule = autogenPathsModuleName pkg_descr0
+    filterFunction bi = \mn ->
+                                   mn /= pathsModule
+                                && not (elem mn (autogenModules bi))
 
 -- | Prepare a directory tree of source files for a snapshot version.
 -- It is expected that the appropriate snapshot version has already been set
@@ -437,7 +440,8 @@ allSourcesBuildInfo bi pps modules = do
     nonEmpty _ f xs = f xs
     suffixes = ppSuffixes pps ++ ["hs", "lhs"]
     notFound m = die $ "Error: Could not find module: " ++ display m
-                 ++ " with any suffix: " ++ show suffixes
+                 ++ " with any suffix: " ++ show suffixes ++ ". If the module "
+                 ++ "is autogenerated it should be added to 'autogen-modules'."
 
 
 printPackageProblems :: Verbosity -> PackageDescription -> IO ()

Cabal/Distribution/Types/Benchmark.hs

@@ -6,6 +6,7 @@ module Distribution.Types.Benchmark (
     emptyBenchmark,
     benchmarkType,
     benchmarkModules,
+    benchmarkModulesAutogen
 ) where
 
 import Prelude ()
@@ -60,3 +61,8 @@ benchmarkType benchmark = case benchmarkInterface benchmark of
 -- | Get all the module names from a benchmark.
 benchmarkModules :: Benchmark -> [ModuleName]
 benchmarkModules benchmark = otherModules (benchmarkBuildInfo benchmark)
+
+-- | Get all the auto generated module names from a benchmark.
+-- This are a subset of 'benchmarkModules'.
+benchmarkModulesAutogen :: Benchmark -> [ModuleName]
+benchmarkModulesAutogen benchmark = autogenModules (benchmarkBuildInfo benchmark)

Cabal/Distribution/Types/BuildInfo.hs

@@ -40,6 +40,7 @@ data BuildInfo = BuildInfo {
         jsSources         :: [FilePath],
         hsSourceDirs      :: [FilePath], -- ^ where to look for the Haskell module hierarchy
         otherModules      :: [ModuleName], -- ^ non-exposed or non-main modules
+        autogenModules    :: [ModuleName], -- ^ not present on sdist, Paths_* or user-generated with a custom Setup.hs
 
         defaultLanguage   :: Maybe Language,-- ^ language used when not explicitly specified
         otherLanguages    :: [Language],    -- ^ other languages used within the package
@@ -80,6 +81,7 @@ instance Monoid BuildInfo where
     jsSources           = [],
     hsSourceDirs        = [],
     otherModules        = [],
+    autogenModules      = [],
     defaultLanguage     = Nothing,
     otherLanguages      = [],
     defaultExtensions   = [],
@@ -114,6 +116,7 @@ instance Semigroup BuildInfo where
     jsSources           = combineNub jsSources,
     hsSourceDirs        = combineNub hsSourceDirs,
     otherModules        = combineNub otherModules,
+    autogenModules      = combineNub autogenModules,
     defaultLanguage     = combineMby defaultLanguage,
     otherLanguages      = combineNub otherLanguages,
     defaultExtensions   = combineNub defaultExtensions,

Cabal/Distribution/Types/Executable.hs

@@ -5,6 +5,7 @@ module Distribution.Types.Executable (
     Executable(..),
     emptyExecutable,
     exeModules,
+    exeModulesAutogen
 ) where
 
 import Prelude ()
@@ -46,3 +47,8 @@ emptyExecutable = mempty
 -- | Get all the module names from an exe
 exeModules :: Executable -> [ModuleName]
 exeModules exe = otherModules (buildInfo exe)
+
+-- | Get all the auto generated module names from an exe
+-- This are a subset of 'exeModules'.
+exeModulesAutogen :: Executable -> [ModuleName]
+exeModulesAutogen exe = autogenModules (buildInfo exe)

Cabal/Distribution/Types/Library.hs

@@ -5,6 +5,7 @@ module Distribution.Types.Library (
     Library(..),
     emptyLibrary,
     libModules,
+    libModulesAutogen
 ) where
 
 import Prelude ()
@@ -58,3 +59,8 @@ libModules :: Library -> [ModuleName]
 libModules lib = exposedModules lib
               ++ otherModules (libBuildInfo lib)
               ++ requiredSignatures lib
+
+-- | Get all the auto generated module names from the library, exposed or not.
+-- This are a subset of 'libModules'.
+libModulesAutogen :: Library -> [ModuleName]
+libModulesAutogen lib = autogenModules (libBuildInfo lib)

Cabal/Distribution/Types/TestSuite.hs

@@ -6,6 +6,7 @@ module Distribution.Types.TestSuite (
     emptyTestSuite,
     testType,
     testModules,
+    testModulesAutogen
 ) where
 
 import Prelude ()
@@ -65,3 +66,8 @@ testModules test = (case testInterface test of
                      TestSuiteLibV09 _ m -> [m]
                      _                   -> [])
                 ++ otherModules (testBuildInfo test)
+
+-- | Get all the auto generated module names from a test suite.
+-- This are a subset of 'testModules'.
+testModulesAutogen :: TestSuite -> [ModuleName]
+testModulesAutogen test = autogenModules (testBuildInfo test)

Cabal/changelog

@@ -50,6 +50,17 @@
 	* 'getComponentLocalBuildInfo', 'withComponentsInBuildOrder'
 	  and 'componentsInBuildOrder' are deprecated in favor of a
 	  new interface in "Distribution.Types.LocalBuildInfo".
+	* New 'autogen-modules' field. Modules that are built automatically at
+	  setup, like Paths_PACKAGENAME or others created with a build-type
+	  custom, appear on 'other-modules' for the Library, Executable,
+	  Test-Suite or Benchmark stanzas or also on 'exposed-modules' for
+	  libraries but are not really on the package when distributed. This
+	  makes commands like sdist fail because the file is not found, so with
+	  this new field modules that appear there are treated the same way as
+	  Paths_PACKAGENAME was and there is no need to create complex build
+	  hooks. Just add the module names on 'other-modules' and
+	  'exposed-modules' as always and on the new 'autogen-modules' besides.
+	(#3656).
 
 1.24.0.0 Ryan Thomas <ryan@ryant.org> March 2016
 	* Support GHC 8.