Give the RTS it's own configure script

Currently it doesn't do much anything, we are just trying to introduce
it without breaking the build. Later, we will move functionality from
the top-level configure script over to it.

We need to bump Cabal for https://github.com/haskell/cabal/pull/8649; to
facilitate and existing hack of skipping some configure checks for the
RTS we now need to skip just *part* not *all* of the "post configure"
hook, as running the configure script (which we definitely want to do)
is also implemented as part of the "post configure" hook. But doing this
requires exposing functionality that wasn't exposed before.

11 files changed, 92 insertions, 43 deletions

diff --git a/boot b/boot
index bd6a5debb9..f3c3e53deb 100755
--- a/boot
+++ b/boot
@@ -63,7 +63,7 @@ def autoreconf():
     else:
         reconf_cmd = 'autoreconf'
 
-    for dir_ in ['.'] + glob.glob('libraries/*/'):
+    for dir_ in ['.', 'rts'] + glob.glob('libraries/*/'):
         if os.path.isfile(os.path.join(dir_, 'configure.ac')):
             print("Booting %s" % dir_)
             # Update config.sub in submodules
diff --git a/hadrian/src/Base.hs b/hadrian/src/Base.hs
index 72baba6aaa..623a5bae8b 100644
--- a/hadrian/src/Base.hs
+++ b/hadrian/src/Base.hs
@@ -28,9 +28,6 @@ module Base (
     module Stage,
     module Way,
 
-    -- * Files
-    configH,
-
     -- * Paths
     hadrianPath, configPath, configFile, sourcePath, shakeFilesDir,
     stageBinPath, stageLibPath, templateHscPath,
@@ -87,11 +84,6 @@ configFile = configPath -/- "system.config"
 sourcePath :: FilePath
 sourcePath = hadrianPath -/- "src"
 
--- TODO: Change @mk/config.h@ to @shake-build/cfg/config.h@.
--- | Path to the generated @mk/config.h@ file.
-configH :: FilePath
-configH = "mk/config.h"
-
 -- | The directory in 'buildRoot' containing the Shake database and other
 -- auxiliary files generated by Hadrian.
 shakeFilesDir :: FilePath
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index 2c02407d31..b156c9dfdf 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -147,7 +147,8 @@ generatePackageCode context@(Context stage pkg _ _) = do
         root -/- "**" -/- dir -/- "cmm/AutoApply.cmm" %> \file ->
             build $ target context GenApply [] [file]
         let go gen file = generate file (semiEmptyTarget stage) gen
-        root -/- "**" -/- dir -/- "include/ghcautoconf.h" %> go generateGhcAutoconfH
+        root -/- "**" -/- dir -/- "include/ghcautoconf.h" %> \_ ->
+            need . pure =<< pkgSetupConfigFile context
         root -/- "**" -/- dir -/- "include/ghcplatform.h" %> go generateGhcPlatformH
         root -/- "**" -/- dir -/- "include/DerivedConstants.h" %> genPlatformConstantsHeader context
         root -/- "**" -/- dir -/- "include/rts/EventLogConstants.h" %> genEventTypes "--event-types-defines"
@@ -486,26 +487,6 @@ generateConfigHs = do
     stageString (Stage0 GlobalLibs) = error "stageString: StageBoot"
 
 
--- | Generate @ghcautoconf.h@ header.
-generateGhcAutoconfH :: Expr String
-generateGhcAutoconfH = do
-    trackGenerateHs
-    configHContents  <- expr $ mapMaybe undefinePackage <$> readFileLines configH
-    return . unlines $
-        [ "#if !defined(__GHCAUTOCONF_H__)"
-        , "#define __GHCAUTOCONF_H__" ]
-        ++ configHContents ++
-        [ "#endif /* __GHCAUTOCONF_H__ */" ]
-  where
-    undefinePackage s
-        | "#define PACKAGE_" `isPrefixOf` s
-            = Just $ "/* #undef " ++ takeWhile (/=' ') (drop 8 s) ++ " */"
-        | "#define __GLASGOW_HASKELL" `isPrefixOf` s
-            = Nothing
-        | "/* REMOVE ME */" == s
-            = Nothing
-        | otherwise = Just s
-
 -- | Generate @Version.hs@ files.
 generateVersionHs :: Expr String
 generateVersionHs = do
diff --git a/hadrian/src/Rules/Lint.hs b/hadrian/src/Rules/Lint.hs
index fa279fa836..0928ec02eb 100644
--- a/hadrian/src/Rules/Lint.hs
+++ b/hadrian/src/Rules/Lint.hs
@@ -11,13 +11,15 @@ lintRules :: Rules ()
 lintRules = do
   "lint:base" ~> lint base
   "lint:compiler" ~> lint compiler
+
+  -- Ensure that autoconf scripts, which are usually run by Cabal, are run to
+  -- avoid depending upon Cabal from the stage0 compiler..
   "libraries" -/- "base" -/- "include" -/- "HsBaseConfig.h" %> \_ ->
       -- ./configure is called here manually because we need to generate
       -- HsBaseConfig.h, which is created from HsBaseConfig.h.in. ./configure
-      -- is usually run by Cabal which generates this file but if we do that
-      -- then hadrian thinks it needs to build the stage0 compiler before
-      -- attempting to configure. Therefore we just run it directly here.
       cmd_ (Cwd "libraries/base") "./configure"
+  "rts" -/- "include" -/- "ghcautoconf.h" %> \_ ->
+      cmd_ (Cwd "rts") "./configure"
 
 lint :: Action () -> Action ()
 lint lintAction = do
diff --git a/hadrian/src/Rules/Register.hs b/hadrian/src/Rules/Register.hs
index bfd8538cb0..8543576215 100644
--- a/hadrian/src/Rules/Register.hs
+++ b/hadrian/src/Rules/Register.hs
@@ -48,11 +48,9 @@ configurePackageRules = do
         when (pkg == rts) $ do
           -- Rts.h is a header listed in the cabal file, and configuring
           -- therefore wants to ensure that the header "works" post-configure.
-          -- But it (transitively) includes these, so we must ensure they exist
+          -- But it (transitively) includes this, so we must ensure it exists
           -- for that check to work.
-          need [ buildP -/- "include/ghcautoconf.h"
-               , buildP -/- "include/ghcplatform.h"
-               ]
+          need [buildP -/- "include/ghcplatform.h"]
         Cabal.configurePackage ctx
 
     root -/- "**/autogen/cabal_macros.h" %> \out -> do
diff --git a/hadrian/src/Rules/SourceDist.hs b/hadrian/src/Rules/SourceDist.hs
index 598b6fdcc9..640b06a47d 100644
--- a/hadrian/src/Rules/SourceDist.hs
+++ b/hadrian/src/Rules/SourceDist.hs
@@ -142,7 +142,9 @@ prepareTree dest = do
       moveFile (dest -/- "boot") (dest -/- "boot.source")
 
     bootFiles =
-      [ pkgPath process -/- "include" -/- "HsProcessConfig.h.in"
+      [ pkgPath rts -/- "configure"
+      , pkgPath rts -/- "ghcautoconf.h.autoconf.in"
+      , pkgPath process -/- "include" -/- "HsProcessConfig.h.in"
       , pkgPath process -/- "configure"
       , pkgPath ghcBignum -/- "configure"
       , pkgPath base -/- "configure"
diff --git a/libraries/base/.gitignore b/libraries/base/.gitignore
index 6a6d524a3f..c7521d6fb0 100644
--- a/libraries/base/.gitignore
+++ b/libraries/base/.gitignore
@@ -19,4 +19,3 @@
 /include/EventConfig.h
 /include/HsBaseConfig.h
 /include/HsBaseConfig.h.in
-
diff --git a/m4/fp_find_libdw.m4 b/m4/fp_find_libdw.m4
index ce830c0fa8..29008408d7 100644
--- a/m4/fp_find_libdw.m4
+++ b/m4/fp_find_libdw.m4
@@ -48,9 +48,6 @@ AC_DEFUN([FP_FIND_LIBDW],
   AC_SUBST(UseLibdw)
   if test $UseLibdw = "YES" ; then
     USE_LIBDW=1
-    AC_SUBST([CabalHaveLibdw],[True])
-  else
-    AC_SUBST([CabalHaveLibdw],[False])
   fi
   AC_DEFINE_UNQUOTED([USE_LIBDW], [$USE_LIBDW], [Set to 1 to use libdw])
 ])
diff --git a/rts/.gitignore b/rts/.gitignore
index a0fafa79ab..662c3c974c 100644
--- a/rts/.gitignore
+++ b/rts/.gitignore
@@ -12,7 +12,12 @@
 /package.conf.install.raw
 /fs.*
 
+/aclocal.m4
 /autom4te.cache/
 /config.log
 /config.status
 /configure
+
+/ghcautoconf.h.autoconf.in
+/ghcautoconf.h.autoconf
+/include/ghcautoconf.h
diff --git a/rts/configure.ac b/rts/configure.ac
new file mode 100644
index 0000000000..fa90a0e114
--- /dev/null
+++ b/rts/configure.ac
@@ -0,0 +1,57 @@
+# Configure script template for the Run-time System of GHC
+#
+# Process with 'autoreconf' to get a working configure script.
+#
+# For the generated configure script, do "./configure --help" to
+# see what flags are available. (Better yet, read the documentation!)
+#
+
+AC_INIT([GHC run-time system], [1.0.2], [libraries@haskell.org], [rts])
+
+AC_CONFIG_MACRO_DIRS([../m4])
+
+# Safety check: Ensure that we are in the correct source directory.
+AC_CONFIG_SRCDIR([include/rts/Constants.h])
+
+dnl * We require autoconf version 2.69 due to
+dnl   https://bugs.ruby-lang.org/issues/8179. Also see #14910.
+dnl * We need 2.50 due to the use of AC_SYS_LARGEFILE and AC_MSG_NOTICE.
+dnl * We need 2.52 due to the use of AS_TR_CPP and AS_TR_SH.
+dnl * Using autoconf 2.59 started to give nonsense like this
+dnl     #define SIZEOF_CHAR 0
+dnl   recently.
+AC_PREREQ([2.69])
+
+AC_CONFIG_HEADERS([ghcautoconf.h.autoconf])
+
+# We have to run these unconditionally, but we may discard their
+# results in the following code
+AC_CANONICAL_BUILD
+AC_CANONICAL_HOST
+
+GHC_CONVERT_PLATFORM_PARTS([host], [Host])
+FPTOOLS_SET_PLATFORM_VARS([host], [Host])
+FPTOOLS_SET_HASKELL_PLATFORM_VARS([Host])
+
+AC_OUTPUT
+
+dnl ######################################################################
+dnl Generate ghcautoconf.h
+dnl ######################################################################
+
+[
+mkdir -p include
+touch include/ghcautoconf.h
+> include/ghcautoconf.h
+
+echo "#if !defined(__GHCAUTOCONF_H__)" >> include/ghcautoconf.h
+echo "#define __GHCAUTOCONF_H__" >> include/ghcautoconf.h
+# Copy the contents of $srcdir/../mk/config.h, turning '#define PACKAGE_FOO
+# "blah"' into '/* #undef PACKAGE_FOO */' to avoid clashes.
+cat $srcdir/../mk/config.h ghcautoconf.h.autoconf | sed \
+   -e 's,^\([	 ]*\)#[	 ]*define[	 ][	 ]*\(PACKAGE_[A-Z]*\)[	 ][ 	]*".*".*$,\1/* #undef \2 */,' \
+   -e '/__GLASGOW_HASKELL/d' \
+   -e '/REMOVE ME/d' \
+   >> include/ghcautoconf.h
+echo "#endif /* __GHCAUTOCONF_H__ */" >> include/ghcautoconf.h
+]
diff --git a/rts/rts.cabal.in b/rts/rts.cabal.in
index ba2524d593..be54a086e9 100644
--- a/rts/rts.cabal.in
+++ b/rts/rts.cabal.in
@@ -1,9 +1,24 @@
 cabal-version: 3.0
 name: rts
 version: 1.0.2
+synopsis: The GHC runtime system
+description:
+    The GHC runtime system.
+
+    Code produced by GHC links this library to provide missing functionality
+    that cannot be written in Haskell itself.
 license: BSD-3-Clause
 maintainer: glasgow-haskell-users@haskell.org
-build-type: Simple
+build-type: Configure
+
+extra-source-files:
+    configure
+    configure.ac
+
+extra-tmp-files:
+    autom4te.cache
+    config.log
+    config.status
 
 source-repository head
     type:     git
@@ -206,6 +221,7 @@ library
 
       include-dirs: include
       includes: Rts.h
+      autogen-includes: ghcautoconf.h
       install-includes: Cmm.h HsFFI.h MachDeps.h Rts.h RtsAPI.h Stg.h
                         ghcautoconf.h ghcconfig.h ghcplatform.h ghcversion.h
                         -- ^ from include