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.

3 files changed, 79 insertions, 1 deletions

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