Deduplicate "unique subdir" code between GHC and Cabal

The code, including the generated module with the version, is now in
ghc-boot. Config.hs reexports stuff as needed, ghc-pkg doesn't need any
tricks at all.

11 files changed, 143 insertions, 69 deletions

diff --git a/.gitignore b/.gitignore
index 27709cb449..08485567fb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -142,7 +142,6 @@ _darcs/
 /libraries/frames.html
 /libraries/ghc-boot/GNUmakefile
 /libraries/ghc-boot/ghc-boot.cabal
-/libraries/ghc-boot/ghc.mk
 /libraries/ghc-boot-th/GNUmakefile
 /libraries/ghc-boot-th/ghc-boot-th.cabal
 /libraries/ghc-boot-th/ghc.mk
diff --git a/boot b/boot
index fc5dd29336..04dec14314 100755
--- a/boot
+++ b/boot
@@ -126,6 +126,9 @@ def boot_pkgs():
                 top = os.path.join(*['..'] * len(os.path.normpath(package).split(os.path.sep)))
 
                 ghc_mk = os.path.join(package, 'ghc.mk')
+                if os.path.exists(ghc_mk):
+                    print('Skipping %s which already exists' % ghc_mk)
+                    continue
                 print('Creating %s' % ghc_mk)
                 with open(ghc_mk, 'w') as f:
                     f.write(dedent(
diff --git a/compiler/ghc.mk b/compiler/ghc.mk
index 1cd82d1635..4e0fb9095b 100644
--- a/compiler/ghc.mk
+++ b/compiler/ghc.mk
@@ -49,33 +49,33 @@ compiler/stage%/build/Config.hs : mk/config.mk mk/project.mk | $$(dir $$@)/.
 	$(call removeFiles,$@)
 	@echo 'Creating $@ ... '
 	@echo '{-# LANGUAGE CPP #-}'                                        >> $@
-	@echo 'module Config where'                                         >> $@
+	@echo 'module Config'                                               >> $@
+	@echo '  ( module GHC.Version'                                      >> $@
+	@echo '  , cBuildPlatformString'                                    >> $@
+	@echo '  , cHostPlatformString'                                     >> $@
+	@echo '  , cProjectName'                                            >> $@
+	@echo '  , cBooterVersion'                                          >> $@
+	@echo '  , cStage'                                                  >> $@
+	@echo '  ) where'                                                   >> $@
 	@echo                                                               >> $@
 	@echo 'import GhcPrelude'                                           >> $@
 	@echo                                                               >> $@
+	@echo 'import GHC.Version'                                          >> $@
+	@echo                                                               >> $@
 	@echo '#include "ghc_boot_platform.h"'                              >> $@
 	@echo                                                               >> $@
 	@echo 'cBuildPlatformString :: String'                              >> $@
 	@echo 'cBuildPlatformString = BuildPlatform_NAME'                   >> $@
+	@echo                                                               >> $@
 	@echo 'cHostPlatformString :: String'                               >> $@
 	@echo 'cHostPlatformString = HostPlatform_NAME'                     >> $@
 	@echo                                                               >> $@
 	@echo 'cProjectName          :: String'                             >> $@
 	@echo 'cProjectName          = "$(ProjectName)"'                    >> $@
-	@echo 'cProjectGitCommitId   :: String'				    >> $@
-	@echo 'cProjectGitCommitId   = "$(ProjectGitCommitId)"'		    >> $@
-	@echo 'cProjectVersion       :: String'                             >> $@
-	@echo 'cProjectVersion       = "$(ProjectVersion)"'                 >> $@
-	@echo 'cProjectVersionInt    :: String'                             >> $@
-	@echo 'cProjectVersionInt    = "$(ProjectVersionInt)"'              >> $@
-	@echo 'cProjectPatchLevel    :: String'                             >> $@
-	@echo 'cProjectPatchLevel    = "$(ProjectPatchLevel)"'              >> $@
-	@echo 'cProjectPatchLevel1   :: String'                             >> $@
-	@echo 'cProjectPatchLevel1   = "$(ProjectPatchLevel1)"'             >> $@
-	@echo 'cProjectPatchLevel2   :: String'                             >> $@
-	@echo 'cProjectPatchLevel2   = "$(ProjectPatchLevel2)"'             >> $@
+	@echo                                                               >> $@
 	@echo 'cBooterVersion        :: String'                             >> $@
 	@echo 'cBooterVersion        = "$(GhcVersion)"'                     >> $@
+	@echo                                                               >> $@
 	@echo 'cStage                :: String'                             >> $@
 	@echo 'cStage                = show (STAGE :: Int)'                 >> $@
 	@echo done.
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 2379f484e9..7009771aa4 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -250,6 +250,7 @@ module DynFlags (
 import GhcPrelude
 
 import GHC.Platform
+import GHC.UniqueSubdir (uniqueSubdir)
 import PlatformConstants
 import Module
 import PackageConfig
@@ -1499,17 +1500,8 @@ versionedAppDir dflags = do
   appdir <- tryMaybeT $ getAppUserDataDirectory (programName dflags)
   return $ appdir </> versionedFilePath dflags
 
--- | A filepath like @x86_64-linux-7.6.3@ with the platform string to use when
--- constructing platform-version-dependent files that need to co-exist.
---
 versionedFilePath :: DynFlags -> FilePath
-versionedFilePath dflags = intercalate "-"
-  [ stringEncodeArch $ platformArch $ targetPlatform dflags
-  , stringEncodeOS $ platformOS $ targetPlatform dflags
-  , projectVersion dflags
-  ]
-  -- NB: This functionality is reimplemented in Cabal, so if you
-  -- change it, be sure to update Cabal.
+versionedFilePath dflags = uniqueSubdir $ targetPlatform dflags
 
 -- | The target code type of the compilation (if any).
 --
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index edf6783055..1949c3bfe2 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -116,8 +116,8 @@ generatePackageCode context@(Context stage pkg _) = do
         when (pkg == ghcPrim) $ do
             root <//> dir -/- "GHC/Prim.hs" %> genPrimopCode context
             root <//> dir -/- "GHC/PrimopWrappers.hs" %> genPrimopCode context
-        when (pkg == ghcPkg) $
-            root <//> dir -/- "Version.hs" %> go generateVersionHs
+        when (pkg == ghcBoot) $
+            root <//> dir -/- "GHC/Version.hs" %> go generateVersionHs
 
     when (pkg == compiler) $ do
         root -/- primopsTxt stage %> \file -> do
@@ -337,42 +337,36 @@ generateConfigHs :: Expr String
 generateConfigHs = do
     trackGenerateHs
     cProjectName        <- getSetting ProjectName
-    cProjectGitCommitId <- getSetting ProjectGitCommitId
-    cProjectVersion     <- getSetting ProjectVersion
-    cProjectVersionInt  <- getSetting ProjectVersionInt
-    cProjectPatchLevel  <- getSetting ProjectPatchLevel
-    cProjectPatchLevel1 <- getSetting ProjectPatchLevel1
-    cProjectPatchLevel2 <- getSetting ProjectPatchLevel2
     cBooterVersion      <- getSetting GhcVersion
     return $ unlines
         [ "{-# LANGUAGE CPP #-}"
-        , "module Config where"
+        , "module Config"
+        , "  ( module GHC.Version"
+        , "  , cBuildPlatformString"
+        , "  , cHostPlatformString"
+        , "  , cProjectName"
+        , "  , cBooterVersion"
+        , "  , cStage"
+        , "  ) where"
         , ""
         , "import GhcPrelude"
         , ""
+        , "import GHC.Version"
+        , ""
         , "#include \"ghc_boot_platform.h\""
         , ""
         , "cBuildPlatformString :: String"
         , "cBuildPlatformString = BuildPlatform_NAME"
+        , ""
         , "cHostPlatformString :: String"
         , "cHostPlatformString = HostPlatform_NAME"
         , ""
         , "cProjectName          :: String"
         , "cProjectName          = " ++ show cProjectName
-        , "cProjectGitCommitId   :: String"
-        , "cProjectGitCommitId   = " ++ show cProjectGitCommitId
-        , "cProjectVersion       :: String"
-        , "cProjectVersion       = " ++ show cProjectVersion
-        , "cProjectVersionInt    :: String"
-        , "cProjectVersionInt    = " ++ show cProjectVersionInt
-        , "cProjectPatchLevel    :: String"
-        , "cProjectPatchLevel    = " ++ show cProjectPatchLevel
-        , "cProjectPatchLevel1   :: String"
-        , "cProjectPatchLevel1   = " ++ show cProjectPatchLevel1
-        , "cProjectPatchLevel2   :: String"
-        , "cProjectPatchLevel2   = " ++ show cProjectPatchLevel2
+        , ""
         , "cBooterVersion        :: String"
         , "cBooterVersion        = " ++ show cBooterVersion
+        , ""
         , "cStage                :: String"
         , "cStage                = show (STAGE :: Int)"
         ]
@@ -492,9 +486,32 @@ generateGhcVersionH = do
 generateVersionHs :: Expr String
 generateVersionHs = do
     trackGenerateHs
-    projectVersion <- getSetting ProjectVersion
+    cProjectGitCommitId <- getSetting ProjectGitCommitId
+    cProjectVersion     <- getSetting ProjectVersion
+    cProjectVersionInt  <- getSetting ProjectVersionInt
+    cProjectPatchLevel  <- getSetting ProjectPatchLevel
+    cProjectPatchLevel1 <- getSetting ProjectPatchLevel1
+    cProjectPatchLevel2 <- getSetting ProjectPatchLevel2
     return $ unlines
-        [ "module Version where"
-        , "version :: String"
-        , "version    = " ++ show projectVersion
+        [ "module GHC.Version where"
+        , ""
+        , "import Prelude -- See Note [Why do we import Prelude here?]"
+        , ""
+        , "cProjectGitCommitId   :: String"
+        , "cProjectGitCommitId   = " ++ show cProjectGitCommitId
+        , ""
+        , "cProjectVersion       :: String"
+        , "cProjectVersion       = " ++ show cProjectVersion
+        , ""
+        , "cProjectVersionInt    :: String"
+        , "cProjectVersionInt    = " ++ show cProjectVersionInt
+        , ""
+        , "cProjectPatchLevel    :: String"
+        , "cProjectPatchLevel    = " ++ show cProjectPatchLevel
+        , ""
+        , "cProjectPatchLevel1   :: String"
+        , "cProjectPatchLevel1   = " ++ show cProjectPatchLevel1
+        , ""
+        , "cProjectPatchLevel2   :: String"
+        , "cProjectPatchLevel2   = " ++ show cProjectPatchLevel2
         ]
diff --git a/libraries/ghc-boot/GHC/UniqueSubdir.hs b/libraries/ghc-boot/GHC/UniqueSubdir.hs
new file mode 100644
index 0000000000..49ae05e526
--- /dev/null
+++ b/libraries/ghc-boot/GHC/UniqueSubdir.hs
@@ -0,0 +1,32 @@
+module GHC.UniqueSubdir
+  ( uniqueSubdir
+  , uniqueSubdir0
+  ) where
+
+import Prelude -- See Note [Why do we import Prelude here?]
+
+import Data.List (intercalate)
+
+import GHC.Platform
+import GHC.Version (cProjectVersion)
+
+-- | A filepath like @x86_64-linux-7.6.3@ with the platform string to use when
+-- constructing platform-version-dependent files that need to co-exist.
+--
+uniqueSubdir :: Platform -> FilePath
+uniqueSubdir platform = uniqueSubdir0
+  (stringEncodeArch $ platformArch platform)
+  (stringEncodeOS $ platformOS platform)
+
+-- | 'ghc-pkg' falls back on the host platform if the settings file is missing,
+-- and so needs this since we don't have information about the host platform in
+-- as much detail as 'Platform'.
+uniqueSubdir0 :: String -> String -> FilePath
+uniqueSubdir0 arch os = intercalate "-"
+  [ arch
+  , os
+  , cProjectVersion
+  ]
+  -- NB: This functionality is reimplemented in Cabal, so if you
+  -- change it, be sure to update Cabal.
+  -- TODO make Cabal use this now that it is in ghc-boot.
diff --git a/libraries/ghc-boot/ghc-boot.cabal.in b/libraries/ghc-boot/ghc-boot.cabal.in
index 650f7518dc..aed75b0c8a 100644
--- a/libraries/ghc-boot/ghc-boot.cabal.in
+++ b/libraries/ghc-boot/ghc-boot.cabal.in
@@ -45,6 +45,12 @@ Library
             GHC.HandleEncoding
             GHC.Platform
             GHC.Settings
+            GHC.UniqueSubdir
+            GHC.Version
+
+    -- but done by Hadrian
+    -- autogen-modules:
+    --         GHC.Version
 
     build-depends: base       >= 4.7 && < 4.14,
                    binary     == 0.8.*,
diff --git a/libraries/ghc-boot/ghc.mk b/libraries/ghc-boot/ghc.mk
new file mode 100644
index 0000000000..29c5376560
--- /dev/null
+++ b/libraries/ghc-boot/ghc.mk
@@ -0,0 +1,36 @@
+libraries/ghc-boot_PACKAGE = ghc-boot
+libraries/ghc-boot_dist-install_GROUP = libraries
+$(if $(filter ghc-boot,$(PACKAGES_STAGE0)),$(eval $(call build-package,libraries/ghc-boot,dist-boot,0)))
+$(if $(filter ghc-boot,$(PACKAGES_STAGE1)),$(eval $(call build-package,libraries/ghc-boot,dist-install,1)))
+$(if $(filter ghc-boot,$(PACKAGES_STAGE2)),$(eval $(call build-package,libraries/ghc-boot,dist-install,2)))
+
+libraries/ghc-boot/dist-boot/build/GHC/Version.hs \
+libraries/ghc-boot/dist-install/build/GHC/Version.hs: mk/project.mk | $$(dir $$@)/.
+	$(call removeFiles,$@)
+	@echo "module GHC.Version where"                                    >> $@
+	@echo                                                               >> $@
+	@echo 'import Prelude -- See Note [Why do we import Prelude here?]' >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectGitCommitId   :: String'                             >> $@
+	@echo 'cProjectGitCommitId   = "$(ProjectGitCommitId)"'             >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectVersion       :: String'                             >> $@
+	@echo 'cProjectVersion       = "$(ProjectVersion)"'                 >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectVersionInt    :: String'                             >> $@
+	@echo 'cProjectVersionInt    = "$(ProjectVersionInt)"'              >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectPatchLevel    :: String'                             >> $@
+	@echo 'cProjectPatchLevel    = "$(ProjectPatchLevel)"'              >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectPatchLevel1   :: String'                             >> $@
+	@echo 'cProjectPatchLevel1   = "$(ProjectPatchLevel1)"'             >> $@
+	@echo                                                               >> $@
+	@echo 'cProjectPatchLevel2   :: String'                             >> $@
+	@echo 'cProjectPatchLevel2   = "$(ProjectPatchLevel2)"'             >> $@
+	@echo done.
+
+libraries/ghc-boot/dist-boot/package-data.mk: \
+	libraries/ghc-boot/dist-boot/build/GHC/Version.hs
+libraries/ghc-boot/dist-install/package-data.mk: \
+	libraries/ghc-boot/dist-install/build/GHC/Version.hs
diff --git a/utils/ghc-pkg/Main.hs b/utils/ghc-pkg/Main.hs
index 0e28ce9353..bace7356cd 100644
--- a/utils/ghc-pkg/Main.hs
+++ b/utils/ghc-pkg/Main.hs
@@ -30,7 +30,6 @@
 
 module Main (main) where
 
-import Version ( version )
 import qualified GHC.PackageDb as GhcPkg
 import GHC.PackageDb (BinaryStringRep(..))
 import GHC.HandleEncoding
@@ -40,6 +39,10 @@ import GHC.Platform
   ( platformArch, platformOS
   , stringEncodeArch, stringEncodeOS
   )
+import GHC.UniqueSubdir
+  ( uniqueSubdir0
+  )
+import GHC.Version ( cProjectVersion )
 import qualified Distribution.Simple.PackageIndex as PackageIndex
 import qualified Data.Graph as Graph
 import qualified Distribution.ModuleName as ModuleName
@@ -229,7 +232,7 @@ deprecFlags = [
   ]
 
 ourCopyright :: String
-ourCopyright = "GHC package manager version " ++ Version.version ++ "\n"
+ourCopyright = "GHC package manager version " ++ GHC.Version.cProjectVersion ++ "\n"
 
 shortUsage :: String -> String
 shortUsage prog = "For usage information see '" ++ prog ++ " --help'."
@@ -654,7 +657,7 @@ getPkgDatabases verbosity mode use_user use_cache expand_vars my_flags = do
               case getTargetPlatform settingsFile mySettings of
                 Right platform -> pure (stringEncodeArch $ platformArch platform, stringEncodeOS $ platformOS platform)
                 Left e -> die e
-          let subdir = arch ++ '-':os ++ '-':Version.version
+          let subdir = uniqueSubdir0 arch os
               dir = appdir </> subdir
           r <- lookForPackageDBIn dir
           case r of
@@ -2016,9 +2019,9 @@ checkHSLib :: Verbosity -> [String] -> String -> Validate ()
 checkHSLib _verbosity dirs lib = do
   let filenames = ["lib" ++ lib ++ ".a",
                    "lib" ++ lib ++ "_p.a",
-                   "lib" ++ lib ++ "-ghc" ++ Version.version ++ ".so",
-                   "lib" ++ lib ++ "-ghc" ++ Version.version ++ ".dylib",
-                            lib ++ "-ghc" ++ Version.version ++ ".dll"]
+                   "lib" ++ lib ++ "-ghc" ++ GHC.Version.cProjectVersion ++ ".so",
+                   "lib" ++ lib ++ "-ghc" ++ GHC.Version.cProjectVersion ++ ".dylib",
+                            lib ++ "-ghc" ++ GHC.Version.cProjectVersion ++ ".dll"]
   b <- liftIO $ doesFileExistOnPath filenames dirs
   when (not b) $
     verror ForceFiles ("cannot find any of " ++ show filenames ++
diff --git a/utils/ghc-pkg/ghc-pkg.cabal b/utils/ghc-pkg/ghc-pkg.cabal
index 4b1aae7631..13f47c0c3e 100644
--- a/utils/ghc-pkg/ghc-pkg.cabal
+++ b/utils/ghc-pkg/ghc-pkg.cabal
@@ -23,7 +23,6 @@ Flag terminfo
 Executable ghc-pkg
     Default-Language: Haskell2010
     Main-Is: Main.hs
-    Other-Modules: Version
     Other-Extensions: CPP
 
     Build-Depends: base       >= 4   && < 5,
diff --git a/utils/ghc-pkg/ghc.mk b/utils/ghc-pkg/ghc.mk
index 32e18f490d..1ba38329d2 100644
--- a/utils/ghc-pkg/ghc.mk
+++ b/utils/ghc-pkg/ghc.mk
@@ -13,13 +13,6 @@
 # -----------------------------------------------------------------------------
 # Bootstrapping ghc-pkg
 
-utils/ghc-pkg/dist/build/Version.hs \
-utils/ghc-pkg/dist-install/build/Version.hs: mk/project.mk | $$(dir $$@)/.
-	$(call removeFiles,$@)
-	echo "module Version where"                    >> $@
-	echo "version :: String" >> $@
-	echo "version    = \"$(ProjectVersion)\""      >> $@
-
 utils/ghc-pkg_PACKAGE = ghc-pkg
 
 # Note [Why build certain utils twice?]
@@ -72,9 +65,6 @@ $(eval $(call build-prog,utils/ghc-pkg,dist,0))
 # is to specify global package db only.
 $(ghc-pkg_INPLACE) : | $(INPLACE_PACKAGE_CONF)/. $(INPLACE_LIB)/settings
 
-utils/ghc-pkg/dist/package-data.mk: \
-    utils/ghc-pkg/dist/build/Version.hs
-
 # -----------------------------------------------------------------------------
 # Build another copy of ghc-pkg with the stage1 compiler in the dist-install
 # directory. Don't install it inplace (we use the dist copy there), but do
@@ -92,9 +82,6 @@ utils/ghc-pkg_dist-install_INSTALL = YES
 utils/ghc-pkg_dist-install_INSTALL_SHELL_WRAPPER_NAME = ghc-pkg-$(ProjectVersion)
 
 $(eval $(call build-prog,utils/ghc-pkg,dist-install,1))
-
-utils/ghc-pkg/dist-install/package-data.mk: \
-    utils/ghc-pkg/dist-install/build/Version.hs
 endif
 
 # -----------------------------------------------------------------------------