Fix exponential typechecking time for large rationals (#15646)
[ghc.git] / configure.ac
index 83e692f..0030446 100644 (file)
@@ -13,7 +13,7 @@ dnl
 # see what flags are available. (Better yet, read the documentation!)
 #
 
-AC_INIT([The Glorious Glasgow Haskell Compilation System], [8.3], [glasgow-haskell-bugs@haskell.org], [ghc-AC_PACKAGE_VERSION])
+AC_INIT([The Glorious Glasgow Haskell Compilation System], [8.9], [glasgow-haskell-bugs@haskell.org], [ghc-AC_PACKAGE_VERSION])
 
 # Set this to YES for a released version, otherwise NO
 : ${RELEASE=NO}
@@ -27,7 +27,7 @@ AC_INIT([The Glorious Glasgow Haskell Compilation System], [8.3], [glasgow-haske
 # when the source distribution was created.
 
 if test ! -f mk/config.h.in; then
-   echo "mk/config.h.in doesn't exist: perhaps you haven't run 'perl boot'?"
+   echo "mk/config.h.in doesn't exist: perhaps you haven't run 'python3 boot'?"
    exit 1
 fi
 
@@ -55,13 +55,14 @@ AC_SUBST([release], [1])
 # First off, a distrib sanity check..
 AC_CONFIG_SRCDIR([mk/config.mk.in])
 
-dnl * We require autoconf version 2.60
-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([2.60])
+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])
 
 # -------------------------------------------------------------------------
 # Prepare to generate the following header files
@@ -86,14 +87,12 @@ dnl use either is considered a Feature.
 dnl ** What command to use to compile compiler sources ?
 dnl --------------------------------------------------------------
 
+AC_ARG_VAR(GHC,[Use as the path to GHC [default=autodetect]])
+AC_PATH_PROG([GHC], [ghc])
 AC_ARG_WITH([ghc],
-[AC_HELP_STRING([--with-ghc=ARG],
-  [Use ARG as the path to GHC  [default=autodetect]])],
-  [WithGhc="$withval"],
-  [if test "$GHC" = ""; then
-    AC_PATH_PROG([GHC], [ghc])
-  fi
-  WithGhc="$GHC"])
+        AS_HELP_STRING([--with-ghc=ARG], [Use ARG as the path to ghc (obsolete, use GHC=ARG instead) [default=autodetect]]),
+        AC_MSG_ERROR([--with-ghc=$withval is obsolete (use './configure GHC=$withval' or 'GHC=$withval ./configure' instead)]))
+AC_SUBST(WithGhc,$GHC)
 
 dnl ** Tell the make system which OS we are using
 dnl $OSTYPE is set by the operating system to "msys" or "cygwin" or something
@@ -113,6 +112,17 @@ AC_ARG_ENABLE(tarballs-autodownload,
         TarballsAutodownload=NO
 )
 
+AC_ARG_ENABLE(distro-toolchain,
+[AC_HELP_STRING([--enable-distro-toolchain],
+                [Do not use bundled Windows toolchain binaries.])],
+        EnableDistroToolchain=YES,
+        EnableDistroToolchain=NO
+)
+
+if test "$EnableDistroToolchain" = "YES"; then
+  TarballsAutodownload=NO
+fi
+
 dnl CC_STAGE0 is like the "previous" variable CC (inherited by CC_STAGE[123])
 dnl but instead used by stage0 for bootstrapping stage1
 AC_ARG_VAR(CC_STAGE0, [C compiler command (bootstrap)])
@@ -147,8 +157,8 @@ if test "$WithGhc" = ""
 then
     AC_MSG_ERROR([GHC is required.])
 fi
-FP_COMPARE_VERSIONS([$GhcVersion],[-lt],[7.10],
-    [AC_MSG_ERROR([GHC version 7.10 or later is required to compile GHC.])])
+FP_COMPARE_VERSIONS([$GhcVersion],[-lt],[8.4],
+    [AC_MSG_ERROR([GHC version 8.4 or later is required to compile GHC.])])
 
 if test `expr $GhcMinVersion % 2` = "1"
 then
@@ -165,11 +175,6 @@ fi
 GHC_PACKAGE_DB_FLAG=package-db
 AC_SUBST(GHC_PACKAGE_DB_FLAG)
 
-FP_COMPARE_VERSIONS([$GhcVersion],[-lt],[7.11],
-                    SUPPORTS_THIS_UNIT_ID=NO,
-                    SUPPORTS_THIS_UNIT_ID=YES)
-AC_SUBST(SUPPORTS_THIS_UNIT_ID)
-
 # GHC is passed to Cabal, so we need a native path
 if test "${WithGhc}" != ""
 then
@@ -177,9 +182,13 @@ then
 
     if test "$ghc_host_os" = "mingw32"
     then
-        # Canonicalise to <drive>:/path/to/ghc
-        WithGhc=`cygpath -m "${WithGhc}"`
-
+        if test "${OSTYPE}" = "msys"
+        then
+            WithGhc=`echo "${WithGhc}" | sed "s#^/\([a-zA-Z]\)/#\1:/#"`
+        else
+            # Canonicalise to <drive>:/path/to/ghc
+            WithGhc=`cygpath -m "${WithGhc}"`
+        fi
         echo "GHC path canonicalised to: ${WithGhc}"
     fi
 fi
@@ -361,7 +370,7 @@ set_up_tarballs() {
     fi
 }
 
-if test "$HostOS" = "mingw32"
+if test "$HostOS" = "mingw32" -a "$EnableDistroToolchain" = "NO"
 then
     test -d inplace || mkdir inplace
 
@@ -374,25 +383,49 @@ then
     NM="${mingwbin}nm.exe"
     RANLIB="${mingwbin}ranlib.exe"
     OBJDUMP="${mingwbin}objdump.exe"
-    Windres="${mingwbin}windres.exe"
-    DllWrap="${mingwbin}dllwrap.exe"
     fp_prog_ar="${mingwbin}ar.exe"
 
-    # NB. Download the perl binaries if required
-    if ! test -d inplace/perl ||
-         test inplace/perl -ot ghc-tarballs/perl/ghc-perl*.tar.gz
-    then
-        AC_MSG_NOTICE([Making in-tree perl tree])
-        rm -rf inplace/perl
-        mkdir inplace/perl
-        (
-            cd inplace/perl &&
-            tar -zxf ../../ghc-tarballs/perl/ghc-perl*.tar.gz
-        )
-        AC_MSG_NOTICE([In-tree perl tree created])
+    AC_PATH_PROG([Genlib],[genlib])
+fi
+
+# We don't want to bundle a MinGW-w64 toolchain
+# So we have to find these individual tools.
+if test "$EnableDistroToolchain" = "YES"
+then
+    # Ideally should use AC_CHECK_TARGET_TOOL but our triples
+    # are screwed up. Configure doesn't think they're ever equal and
+    # so never tried without the prefix.
+    AC_PATH_PROG([CC],[gcc], [clang])
+    AC_PATH_PROG([NM],[nm])
+    AC_PATH_PROG([AR],[ar])
+    AC_PATH_PROG([RANLIB],[ranlib])
+    AC_PATH_PROG([OBJDUMP],[objdump])
+    AC_PATH_PROG([DllWrap],[dllwrap])
+    AC_PATH_PROG([Windres],[windres])
+    AC_PATH_PROG([Genlib],[genlib])
+else
+    AC_CHECK_TARGET_TOOL([Windres],[windres])
+    AC_CHECK_TARGET_TOOL([DllWrap],[dllwrap])
+    AC_CHECK_TARGET_TOOL([OBJDUMP],[objdump])
+fi
+
+DllWrapCmd="$DllWrap"
+WindresCmd="$Windres"
+
+HAVE_GENLIB=False
+if test "$HostOS" = "mingw32"
+then
+    if test "$Genlib" != ""; then
+        GenlibCmd="$(cygpath -m $Genlib)"
+        HAVE_GENLIB=True
     fi
 fi
 
+AC_SUBST([DllWrapCmd])
+AC_SUBST([WindresCmd])
+AC_SUBST([GenlibCmd])
+AC_SUBST([HAVE_GENLIB])
+
 FP_ICONV
 FP_GMP
 FP_CURSES
@@ -459,6 +492,7 @@ fi
 AC_SUBST(CrossCompiling)
 AC_SUBST(CrossCompilePrefix)
 AC_SUBST(TargetPlatformFull)
+AC_SUBST(EnableDistroToolchain)
 
 dnl ** Which gcc to use?
 dnl --------------------------------------------------------------
@@ -493,31 +527,49 @@ FP_SET_CFLAGS_C99([CC_STAGE0],[CONF_CC_OPTS_STAGE0],[CONF_CPP_OPTS_STAGE0])
 FP_SET_CFLAGS_C99([CC],[CONF_CC_OPTS_STAGE1],[CONF_CPP_OPTS_STAGE1])
 FP_SET_CFLAGS_C99([CC],[CONF_CC_OPTS_STAGE2],[CONF_CPP_OPTS_STAGE2])
 
-dnl ** Which ld to use?
+dnl ** Which ld to use
 dnl --------------------------------------------------------------
-FIND_LD([LdCmd])
+FIND_LD([$target],[GccUseLdOpt])
+CONF_GCC_LINKER_OPTS_STAGE1="$CONF_GCC_LINKER_OPTS_STAGE1 $GccUseLdOpt"
+CONF_GCC_LINKER_OPTS_STAGE2="$CONF_GCC_LINKER_OPTS_STAGE2 $GccUseLdOpt"
+LdCmd="$LD"
+LdNoGoldCmd="$LD_NO_GOLD"
+CFLAGS="$CFLAGS $GccUseLdOpt"
 AC_SUBST([LdCmd])
+AC_SUBST([LdNoGoldCmd])
+
+FP_PROG_LD_IS_GNU
+FP_PROG_LD_BUILD_ID
+FP_PROG_LD_NO_COMPACT_UNWIND
+FP_PROG_LD_FILELIST
 
 dnl ** Which nm to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([NM], [nm], [nm])
+if test "$HostOS" != "mingw32"; then
+    AC_CHECK_TARGET_TOOL([NM], [nm])
+    if test "$NM" = ":"; then
+        AC_MSG_ERROR([cannot find nm in your PATH])
+    fi
+fi
+NmCmd="$NM"
+AC_SUBST([NmCmd])
 
 if test "$TargetOS_CPP" = "darwin"
 then
     AC_MSG_CHECKING(whether nm program is broken)
     # Some versions of XCode ship a broken version of `nm`. Detect and work
-    # around this issue. See : https://ghc.haskell.org/trac/ghc/ticket/11744
+    # around this issue. See : https://gitlab.haskell.org/ghc/ghc/issues/11744
     nmver=$(${NM} --version | grep version | sed 's/ //g')
     case "$nmver" in
         LLVMversion7.3.0|LLVMversion7.3.1)
             AC_MSG_RESULT(yes)
             echo "The detected nm program is broken."
             echo
-            echo "See: https://ghc.haskell.org/trac/ghc/ticket/11744"
+            echo "See: https://gitlab.haskell.org/ghc/ghc/issues/11744"
             echo
             echo "Try re-running configure with:"
             echo
-            echo '   ./configure --with-nm=$(xcrun --find nm-classic)'
+            echo '   NM=$(xcrun --find nm-classic) ./configure'
             echo
             exit 1
             ;;
@@ -527,58 +579,77 @@ then
         esac
 fi
 
-NmCmd="$NM"
-AC_SUBST([NmCmd])
-
 dnl ** Which objdump to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG_OPTIONAL([OBJDUMP], [objdump], [objdump])
+dnl Note: we may not have objdump on OS X, and we only need it on
+dnl Windows (for DLL checks), OpenBSD, and AIX
+case $HostOS_CPP in
+  cygwin32|mingw32|openbsd|aix)
+    AC_CHECK_TARGET_TOOL([OBJDUMP], [objdump])
+    ;;
+esac
+
 ObjdumpCmd="$OBJDUMP"
 AC_SUBST([ObjdumpCmd])
 
-dnl ** Which ar to use?
-dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([AR], [ar], [ar])
-ArCmd="$AR"
-fp_prog_ar="$AR"
-AC_SUBST([ArCmd])
-
 dnl ** Which ranlib to use?
 dnl --------------------------------------------------------------
-FP_ARG_WITH_PATH_GNU_PROG([RANLIB], [ranlib], [ranlib])
+AC_PROG_RANLIB
+if test "$RANLIB" = ":"; then
+    AC_MSG_ERROR([cannot find ranlib in your PATH])
+fi
 RanlibCmd="$RANLIB"
-RANLIB="$RanlibCmd"
+AC_SUBST([RanlibCmd])
 
+dnl ** which strip to use?
+dnl --------------------------------------------------------------
+AC_CHECK_TARGET_TOOL([STRIP], [strip])
+StripCmd="$STRIP"
+AC_SUBST([StripCmd])
 
-# Note: we may not have objdump on OS X, and we only need it on Windows (for DLL checks)
-case $HostOS_CPP in
-cygwin32|mingw32)
-    dnl ** Which objdump to use?
-    dnl --------------------------------------------------------------
-    FP_ARG_WITH_PATH_GNU_PROG([OBJDUMP], [objdump], [objdump])
-    ObjdumpCmd="$OBJDUMP"
-    AC_SUBST([ObjdumpCmd])
-    ;;
-esac
+
+dnl ** which libtool to use?
+dnl --------------------------------------------------------------
+# The host normalization on Windows breaks autoconf, it no longer
+# thinks that target == host so it never checks the unqualified
+# tools for Windows. See #14274.
+if test "$HostOS" = "mingw32"
+then
+    AC_PATH_PROG([LIBTOOL],[libtool])
+    LibtoolCmd="$(cygpath -m $LIBTOOL)"
+else
+    AC_CHECK_TARGET_TOOL([LIBTOOL], [libtool])
+    LibtoolCmd="$LIBTOOL"
+fi
+AC_SUBST([LibtoolCmd])
 
 # Here is where we re-target which specific version of the LLVM
 # tools we are looking for. In the past, GHC supported a number of
 # versions of LLVM simultaneously, but that stopped working around
 # 3.5/3.6 release of LLVM.
-LlvmVersion=3.9
+LlvmVersion=7.0
 AC_SUBST([LlvmVersion])
 sUPPORTED_LLVM_VERSION=$(echo \($LlvmVersion\) | sed 's/\./,/')
 AC_DEFINE_UNQUOTED([sUPPORTED_LLVM_VERSION], ${sUPPORTED_LLVM_VERSION}, [The supported LLVM version number])
 
+dnl ** Which LLVM clang to use?
+dnl --------------------------------------------------------------
+AC_ARG_VAR(CLANG,[Use as the path to clang [default=autodetect]])
+AC_CHECK_TARGET_TOOL([CLANG], [clang])
+ClangCmd="$CLANG"
+AC_SUBST([ClangCmd])
+
 dnl ** Which LLVM llc to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([LLC], [llc], [llc], [$LlvmVersion])
+AC_ARG_VAR(LLC,[Use as the path to LLVM's llc [default=autodetect]])
+FIND_LLVM_PROG([LLC], [llc], [$LlvmVersion])
 LlcCmd="$LLC"
 AC_SUBST([LlcCmd])
 
 dnl ** Which LLVM opt to use?
 dnl --------------------------------------------------------------
-FIND_LLVM_PROG([OPT], [opt], [opt], [$LlvmVersion])
+AC_ARG_VAR(OPT,[Use as the path to LLVM's opt [default=autodetect]])
+FIND_LLVM_PROG([OPT], [opt], [$LlvmVersion])
 OptCmd="$OPT"
 AC_SUBST([OptCmd])
 
@@ -586,6 +657,15 @@ dnl --------------------------------------------------------------
 dnl End of configure script option section
 dnl --------------------------------------------------------------
 
+dnl ** Copy the files from the "fs" utility into the right folders.
+dnl --------------------------------------------------------------
+AC_MSG_NOTICE([Creating links for in-tree file handling routines.])
+ln -f utils/fs/fs.* utils/lndir/
+ln -f utils/fs/fs.* utils/unlit/
+ln -f utils/fs/fs.* rts/
+ln -f utils/fs/fs.h libraries/base/include/
+ln -f utils/fs/fs.c libraries/base/cbits/
+AC_MSG_NOTICE([Routines in place. Packages can now be build normally.])
 
 dnl --------------------------------------------------------------
 dnl ** Can the unix package be built?
@@ -602,26 +682,6 @@ AC_SUBST([GhcLibsWithUnix])
 dnl ** does #! work?
 AC_SYS_INTERPRETER()
 
-# Check for split-objs
-SplitObjsBroken=NO
-dnl ** look for `perl'
-case $HostOS_CPP in
-cygwin32|mingw32)
-  PerlCmd=$hardtop/inplace/perl/perl
-  ;;
-*)
-    AC_PATH_PROG([PerlCmd],[perl])
-    if test -z "$PerlCmd"
-    then
-        AC_MSG_WARN([No Perl on PATH, disabling split object support])
-        SplitObjsBroken=YES
-    else
-        FPTOOLS_CHECK_PERL_VERSION
-    fi
-    ;;
-esac
-AC_SUBST([SplitObjsBroken])
-
 dnl ** look for GCC and find out which version
 dnl     Figure out which C compiler to use.  Gcc is preferred.
 dnl     If gcc, make sure it's at least 3.0
@@ -631,24 +691,23 @@ FP_GCC_VERSION
 dnl ** See whether gcc supports -no-pie
 FP_GCC_SUPPORTS_NO_PIE
 
+dnl ** Used to determine how to compile ghc-prim's atomics.c, used by
+dnl    unregisterised, Sparc, and PPC backends.
+FP_GCC_SUPPORTS__ATOMICS
+AC_DEFINE([HAVE_C11_ATOMICS], [$CONF_GCC_SUPPORTS__ATOMICS], [Does GCC support __atomic primitives?])
+
+FP_GCC_EXTRA_FLAGS
+
 dnl ** look to see if we have a C compiler using an llvm back end.
 dnl
 FP_CC_LLVM_BACKEND
 
-FP_PROG_LD_IS_GNU
-FP_PROG_LD_BUILD_ID
-FP_PROG_LD_NO_COMPACT_UNWIND
-FP_PROG_LD_FILELIST
-
-
 FPTOOLS_SET_C_LD_FLAGS([target],[CFLAGS],[LDFLAGS],[IGNORE_LINKER_LD_FLAGS],[CPPFLAGS])
 FPTOOLS_SET_C_LD_FLAGS([build],[CONF_CC_OPTS_STAGE0],[CONF_GCC_LINKER_OPTS_STAGE0],[CONF_LD_LINKER_OPTS_STAGE0],[CONF_CPP_OPTS_STAGE0])
 FPTOOLS_SET_C_LD_FLAGS([target],[CONF_CC_OPTS_STAGE1],[CONF_GCC_LINKER_OPTS_STAGE1],[CONF_LD_LINKER_OPTS_STAGE1],[CONF_CPP_OPTS_STAGE1])
 FPTOOLS_SET_C_LD_FLAGS([target],[CONF_CC_OPTS_STAGE2],[CONF_GCC_LINKER_OPTS_STAGE2],[CONF_LD_LINKER_OPTS_STAGE2],[CONF_CPP_OPTS_STAGE2])
 # Stage 3 won't be supported by cross-compilation
 
-FP_GCC_EXTRA_FLAGS
-
 # See rules/distdir-way-opts.mk for details.
 # Flags passed to the C compiler
 AC_SUBST(CONF_CC_OPTS_STAGE0)
@@ -714,12 +773,27 @@ dnl ** check for patch
 dnl if GNU patch is named gpatch, look for it first
 AC_PATH_PROGS(PatchCmd,gpatch patch, patch)
 
+dnl ** check for autoreconf
+AC_PATH_PROG(AutoreconfCmd, autoreconf, autoreconf)
+
 dnl ** check for dtrace (currently only implemented for Mac OS X)
+AC_ARG_ENABLE(dtrace,
+    [AC_HELP_STRING([--enable-dtrace],
+        [Enable DTrace])],
+    EnableDtrace=$enableval,
+    EnableDtrace=yes
+)
+
 HaveDtrace=NO
+
 AC_PATH_PROG(DtraceCmd,dtrace)
-if test -n "$DtraceCmd"; then
-  if test "x$TargetOS_CPP-$TargetVendor_CPP" = "xdarwin-apple" -o "x$TargetOS_CPP-$TargetVendor_CPP" = "xsolaris2-unknown"; then
-    HaveDtrace=YES
+if test "x$EnableDtrace" = "xyes"; then
+  if test -n "$DtraceCmd"; then
+    if test "x$TargetOS_CPP-$TargetVendor_CPP" = "xdarwin-apple" \
+      -o "x$TargetOS_CPP-$TargetVendor_CPP" = "xfreebsd-portbld" \
+      -o "x$TargetOS_CPP-$TargetVendor_CPP" = "xsolaris2-unknown"; then
+      HaveDtrace=YES
+    fi
   fi
 fi
 AC_SUBST(HaveDtrace)
@@ -727,6 +801,7 @@ AC_SUBST(HaveDtrace)
 AC_PATH_PROG(HSCOLOUR,HsColour)
 # HsColour is passed to Cabal, so we need a native path
 if test "$HostOS"      = "mingw32" && \
+   test "${OSTYPE}"   != "msys"    && \
    test "${HSCOLOUR}" != ""
 then
     # Canonicalise to <drive>:/path/to/gcc
@@ -738,7 +813,7 @@ AC_PATH_PROG(SPHINXBUILD,sphinx-build)
 AC_CACHE_CHECK([for version of sphinx-build], fp_cv_sphinx_version,
 changequote(, )dnl
 [if test -n "$SPHINXBUILD"; then
-  fp_cv_sphinx_version=`"$SPHINXBUILD" --version 2>&1 | sed 's/Sphinx\( (sphinx-build)\)\? v\?\([0-9]\.[0-9]\.[0-9]\)/\2/' | head -n1`;
+  fp_cv_sphinx_version=`"$SPHINXBUILD" --version 2>&1 | sed 's/.* v\?\([0-9]\.[0-9]\.[0-9]\)/\1/' | head -n1`;
 fi;
 changequote([, ])dnl
 ])
@@ -752,9 +827,13 @@ dnl ** check for ghc-pkg command
 FP_PROG_GHC_PKG
 
 dnl ** check for installed happy binary + version
+
+AC_ARG_VAR(HAPPY,[Use as the path to happy [default=autodetect]])
 FPTOOLS_HAPPY
 
 dnl ** check for installed alex binary + version
+
+AC_ARG_VAR(ALEX,[Use as the path to alex [default=autodetect]])
 FPTOOLS_ALEX
 
 dnl --------------------------------------------------
@@ -818,8 +897,13 @@ FP_CHECK_SIZEOF_AND_ALIGNMENT(uint64_t)
 
 
 dnl for use in settings.in
-WordSize=$ac_cv_sizeof_void_p
-AC_SUBST(WordSize)
+TargetWordSize=$ac_cv_sizeof_void_p
+if test "x$TargetWordSize" == 8; then
+  AC_SUBST([Cabal64bit],[True])
+else
+  AC_SUBST([Cabal64bit],[False])
+fi
+AC_SUBST(TargetWordSize)
 FP_CHECK_FUNC([WinExec],
   [@%:@include <windows.h>], [WinExec("",0)])
 
@@ -838,8 +922,11 @@ AC_CHECK_DECLS([ctime_r], , ,
 #include <time.h>])
 
 dnl ** check for mingwex library
-AC_CHECK_LIB(mingwex, closedir, HaveLibMingwEx=YES, HaveLibMingwEx=NO)
-AC_SUBST(HaveLibMingwEx)
+AC_CHECK_LIB(
+  [mingwex],
+  [closedir],
+  [AC_SUBST([HaveLibMingwEx],[YES])] [AC_SUBST([CabalMingwex],[True])],
+  [AC_SUBST([HaveLibMingwEx],[NO])] [AC_SUBST([CabalMingwex],[False])])
 
 if test $HaveLibMingwEx = YES ; then
   AC_DEFINE([HAVE_MINGWEX], [1], [Define to 1 if you have the mingwex library.])
@@ -849,11 +936,14 @@ dnl ** check for math library
 dnl    Keep that check as early as possible.
 dnl    as we need to know whether we need libm
 dnl    for math functions or not
-dnl    (see http://ghc.haskell.org/trac/ghc/ticket/3730)
+dnl    (see https://gitlab.haskell.org/ghc/ghc/issues/3730)
 AC_CHECK_LIB(m, atan, HaveLibM=YES, HaveLibM=NO)
 if test $HaveLibM = YES
 then
   AC_DEFINE([HAVE_LIBM], [1], [Define to 1 if you need to link with libm])
+  AC_SUBST([CabalHaveLibm],[True])
+else
+  AC_SUBST([CabalHaveLibm],[False])
 fi
 
 FP_BFD_SUPPORT
@@ -905,6 +995,7 @@ AC_ARG_WITH([ffi-libraries],
 
 AC_SUBST(FFILibDir)
 
+AC_SUBST([CabalHaveLibffi],[False])
 AS_IF([test "$UseSystemLibFFI" = "YES"], [
  CFLAGS2="$CFLAGS"
  CFLAGS="$LIBFFI_CFLAGS $CFLAGS"
@@ -921,14 +1012,16 @@ AS_IF([test "$UseSystemLibFFI" = "YES"], [
  fi
  AC_CHECK_LIB(ffi, ffi_call,
   [AC_CHECK_HEADERS([ffi.h], [break], [])
-   AC_DEFINE([HAVE_LIBFFI], [1], [Define to 1 if you have libffi.])],
+   AC_DEFINE([HAVE_LIBFFI], [1], [Define to 1 if you have libffi.])]
+   AC_SUBST([CabalHaveLibffi],[True]),
   [AC_MSG_ERROR([Cannot find system libffi])])
  CFLAGS="$CFLAGS2"
  LDFLAGS="$LDFLAGS2"
 ])
 
 dnl ** check whether we need -ldl to get dlopen()
-AC_CHECK_LIB(dl, dlopen)
+AC_CHECK_LIB([dl], [dlopen])
+AC_CHECK_LIB([dl], [dlopen], [AC_SUBST([CabalHaveLibdl], [True])], [AC_SUBST([CabalHaveLibdl], [False])])
 
 dnl --------------------------------------------------
 dnl * Miscellaneous feature tests
@@ -953,7 +1046,8 @@ FP_LEADING_UNDERSCORE
 FP_VISIBILITY_HIDDEN
 
 dnl ** check for librt
-AC_CHECK_LIB(rt, clock_gettime)
+AC_CHECK_LIB([rt], [clock_gettime])
+AC_CHECK_LIB([rt], [clock_gettime], [AC_SUBST([CabalHaveLibrt], [True])], [AC_SUBST([CabalHaveLibrt], [False])])
 AC_CHECK_FUNCS(clock_gettime timer_settime)
 FP_CHECK_TIMER_CREATE
 
@@ -980,15 +1074,18 @@ AC_MSG_CHECKING(whether -lpthread is needed for pthreads)
 AC_CHECK_FUNC(pthread_create,
     [
         AC_MSG_RESULT(no)
+        AC_SUBST([CabalNeedLibpthread],[False])
         need_lpthread=0
     ],
     [
         AC_CHECK_LIB(pthread, pthread_create,
             [
                 AC_MSG_RESULT(yes)
+                AC_SUBST([CabalNeedLibpthread],[True])
                 need_lpthread=1
             ],
             [
+                AC_SUBST([CabalNeedLibpthread],[False])
                 AC_MSG_RESULT([no pthreads support found.])
                 need_lpthread=0
             ])
@@ -1087,17 +1184,8 @@ case ${TargetOS} in
     linux|linux-android|freebsd|dragonfly|netbsd|openbsd|kfreebsdgnu|gnu|solaris2)
         RtsLinkerUseMmap=1
         ;;
-    darwin|ios)
-        # Don't use mmap on powerpc/darwin as the mmap there doesn't support
-        # reallocating. Reallocating is needed to allocate jump islands just
-        # after each object image. Jumps to these jump islands use relative
-        # branches which are limited to offsets that can be represented in
-        # 24-bits.
-        if test "$TargetArch" != "powerpc" ; then
-            RtsLinkerUseMmap=1
-        else
-            RtsLinkerUseMmap=0
-        fi
+    darwin|ios|watchos|tvos)
+        RtsLinkerUseMmap=1
         ;;
     *)
         # Windows (which doesn't have mmap) and everything else.
@@ -1115,12 +1203,17 @@ USE_LIBDW=0
 AC_ARG_ENABLE(dwarf-unwind,
     [AC_HELP_STRING([--enable-dwarf-unwind],
         [Enable DWARF unwinding support in the runtime system via elfutils' libdw [default=no]])],
-    [AC_CHECK_LIB(dw, dwfl_attach_state, [UseLibdw=YES], [UseLibdw=NO])],
+    [AC_CHECK_LIB(dw, dwfl_attach_state,
+      [UseLibdw=YES],
+      [AC_MSG_ERROR([Cannot find system libdw (required by --enable-dwarf-unwind)])])],
     [UseLibdw=NO]
 )
 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])
 
@@ -1133,6 +1226,12 @@ if test "$ac_cv_header_numa_h$ac_cv_header_numaif_h" = "yesyes" ; then
     AC_CHECK_LIB(numa, numa_available,HaveLibNuma=1)
 fi
 AC_DEFINE_UNQUOTED([HAVE_LIBNUMA], [$HaveLibNuma], [Define to 1 if you have libnuma])
+if test $HaveLibNuma = "1" ; then
+  AC_SUBST([CabalHaveLibNuma],[True])
+else
+  AC_SUBST([CabalHaveLibNuma],[False])
+fi
+
 
 dnl ** Documentation
 dnl --------------------------------------------------------------
@@ -1192,7 +1291,7 @@ checkMake380() {
 checkMake380 make
 checkMake380 gmake
 
-AC_CONFIG_FILES([mk/config.mk mk/install.mk mk/project.mk compiler/ghc.cabal ghc/ghc-bin.cabal utils/runghc/runghc.cabal libraries/ghc-boot/ghc-boot.cabal libraries/ghc-boot-th/ghc-boot-th.cabal libraries/ghci/ghci.cabal settings docs/users_guide/ghc_config.py docs/index.html libraries/prologue.txt utils/mkUserGuidePart/mkUserGuidePart.cabal distrib/configure.ac])
+AC_CONFIG_FILES([mk/config.mk mk/install.mk mk/project.mk rts/rts.cabal compiler/ghc.cabal ghc/ghc-bin.cabal utils/iserv/iserv.cabal utils/iserv-proxy/iserv-proxy.cabal utils/remote-iserv/remote-iserv.cabal utils/runghc/runghc.cabal utils/gen-dll/gen-dll.cabal libraries/ghc-boot/ghc-boot.cabal libraries/ghc-boot-th/ghc-boot-th.cabal libraries/ghci/ghci.cabal libraries/ghc-heap/ghc-heap.cabal libraries/libiserv/libiserv.cabal libraries/template-haskell/template-haskell.cabal settings docs/users_guide/ghc_config.py docs/index.html libraries/prologue.txt distrib/configure.ac])
 AC_OUTPUT
 [
 if test "$print_make_warning" = "true"; then
@@ -1240,15 +1339,19 @@ echo "\
    ar           : $ArCmd
    ld           : $LdCmd
    nm           : $NmCmd
+   libtool      : $LibtoolCmd
    objdump      : $ObjdumpCmd
    ranlib       : $RanlibCmd
+   windres      : $WindresCmd
+   dllwrap      : $DllWrapCmd
+   genlib       : $GenlibCmd
    Happy        : $HappyCmd ($HappyVersion)
    Alex         : $AlexCmd ($AlexVersion)
-   Perl         : $PerlCmd
    sphinx-build : $SPHINXBUILD
    xelatex      : $XELATEX
 
    Using LLVM tools
+      clang : $ClangCmd
       llc   : $LlcCmd
       opt   : $OptCmd"