rts configure scriptwip/rts-configure-2

Need to use CPP not `if` in rts.buildinfo

Bump cabal submodule to include
https://github.com/haskell/cabal/pull/8565

31 files changed, 289 insertions, 412 deletions

diff --git a/compiler/GHC/Linker/Dynamic.hs b/compiler/GHC/Linker/Dynamic.hs
index 171503d4d6..646eab59d4 100644
--- a/compiler/GHC/Linker/Dynamic.hs
+++ b/compiler/GHC/Linker/Dynamic.hs
@@ -3,8 +3,6 @@
 -- | Dynamic linker
 module GHC.Linker.Dynamic
    ( linkDynLib
-   -- * Platform-specifics
-   , libmLinkOpts
    )
 where
 
@@ -214,7 +212,6 @@ linkDynLib logger tmpfs dflags0 unit_env o_files dep_packages
 
             runLink logger tmpfs dflags (
                     map Option verbFlags
-                 ++ libmLinkOpts platform
                  ++ [ Option "-o"
                     , FileOption "" output_fn
                     ]
@@ -230,13 +227,6 @@ linkDynLib logger tmpfs dflags0 unit_env o_files dep_packages
                  ++ map Option pkg_link_opts
               )
 
--- | Some platforms require that we explicitly link against @libm@ if any
--- math-y things are used (which we assume to include all programs). See #14022.
-libmLinkOpts :: Platform -> [Option]
-libmLinkOpts platform
-  | platformHasLibm platform = [Option "-lm"]
-  | otherwise                = []
-
 {-
 Note [-Bsymbolic assumptions by GHC]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/compiler/GHC/Linker/Static.hs b/compiler/GHC/Linker/Static.hs
index 99495d33fb..d251832694 100644
--- a/compiler/GHC/Linker/Static.hs
+++ b/compiler/GHC/Linker/Static.hs
@@ -24,7 +24,6 @@ import GHC.Utils.TmpFs
 
 import GHC.Linker.MacOS
 import GHC.Linker.Unit
-import GHC.Linker.Dynamic
 import GHC.Linker.ExtraObj
 import GHC.Linker.Windows
 import GHC.Linker.Static.Utils
@@ -195,7 +194,6 @@ linkBinary' staticLink logger tmpfs dflags unit_env o_files dep_units = do
                       ++ [ GHC.SysTools.Option "-o"
                          , GHC.SysTools.FileOption "" output_fn
                          ]
-                      ++ libmLinkOpts platform
                       ++ map GHC.SysTools.Option (
                          []
 
diff --git a/compiler/GHC/Platform.hs b/compiler/GHC/Platform.hs
index a630e0c1d3..2faef1599f 100644
--- a/compiler/GHC/Platform.hs
+++ b/compiler/GHC/Platform.hs
@@ -79,10 +79,6 @@ data Platform = Platform
       -- ^ Determines whether we will be compiling info tables that reside just
       --   before the entry code, or with an indirection to the entry code. See
       --   TABLES_NEXT_TO_CODE in rts/include/rts/storage/InfoTables.h.
-   , platformHasLibm                  :: !Bool
-      -- ^ Some platforms require that we explicitly link against @libm@ if any
-      -- math-y things are used (which we assume to include all programs). See
-      -- #14022.
 
    , platform_constants               :: !(Maybe PlatformConstants)
       -- ^ Constants such as structure offsets, type sizes, etc.
@@ -136,7 +132,6 @@ genericPlatform = Platform
    , platformHasGnuNonexecStack      = False
    , platformHasIdentDirective       = False
    , platformHasSubsectionsViaSymbols= False
-   , platformHasLibm                 = False
    , platformIsCrossCompiling        = False
    , platformLeadingUnderscore       = False
    , platformTablesNextToCode        = True
diff --git a/compiler/GHC/Settings/IO.hs b/compiler/GHC/Settings/IO.hs
index 06952774fd..7a971af036 100644
--- a/compiler/GHC/Settings/IO.hs
+++ b/compiler/GHC/Settings/IO.hs
@@ -234,7 +234,6 @@ getTargetPlatform settingsFile settings = do
   targetHasGnuNonexecStack <- getBooleanSetting "target has GNU nonexec stack"
   targetHasIdentDirective <- getBooleanSetting "target has .ident directive"
   targetHasSubsectionsViaSymbols <- getBooleanSetting "target has subsections via symbols"
-  targetHasLibm <- getBooleanSetting "target has libm"
   crossCompiling <- getBooleanSetting "cross compiling"
   tablesNextToCode <- getBooleanSetting "Tables next to code"
 
@@ -249,6 +248,5 @@ getTargetPlatform settingsFile settings = do
     , platformIsCrossCompiling = crossCompiling
     , platformLeadingUnderscore = targetLeadingUnderscore
     , platformTablesNextToCode  = tablesNextToCode
-    , platformHasLibm = targetHasLibm
     , platform_constants = Nothing -- will be filled later when loading (or building) the RTS unit
     }
diff --git a/configure.ac b/configure.ac
index 4a39a9a314..cf3508ce81 100644
--- a/configure.ac
+++ b/configure.ac
@@ -844,72 +844,19 @@ dnl    off_t, because it will affect the result of that test.
 AC_SYS_LARGEFILE
 
 dnl ** check for specific header (.h) files that we are interested in
-AC_CHECK_HEADERS([ctype.h dirent.h dlfcn.h errno.h fcntl.h grp.h limits.h locale.h nlist.h pthread.h pwd.h signal.h sys/param.h sys/mman.h sys/resource.h sys/select.h sys/time.h sys/timeb.h sys/timerfd.h sys/timers.h sys/times.h sys/utsname.h sys/wait.h termios.h utime.h windows.h winsock.h sched.h])
-
-dnl sys/cpuset.h needs sys/param.h to be included first on FreeBSD 9.1; #7708
-AC_CHECK_HEADERS([sys/cpuset.h], [], [],
-[[#if HAVE_SYS_PARAM_H
-# include <sys/param.h>
-#endif
-]])
-
-dnl ** check whether a declaration for `environ` is provided by libc.
-FP_CHECK_ENVIRON
 
 dnl ** do we have long longs?
 AC_CHECK_TYPES([long long])
 
 dnl ** what are the sizes of various types
-FP_CHECK_SIZEOF_AND_ALIGNMENT(char)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(double)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(float)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(int)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(long)
-if test "$ac_cv_type_long_long" = yes; then
-FP_CHECK_SIZEOF_AND_ALIGNMENT(long long)
-fi
-FP_CHECK_SIZEOF_AND_ALIGNMENT(short)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned char)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned int)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned long)
-if test "$ac_cv_type_long_long" = yes; then
-FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned long long)
-fi
-FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned short)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(void *)
-
-FP_CHECK_SIZEOF_AND_ALIGNMENT(int8_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(uint8_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(int16_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(uint16_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(int32_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(uint32_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(int64_t)
-FP_CHECK_SIZEOF_AND_ALIGNMENT(uint64_t)
-
-
 dnl for use in settings file
+FP_CHECK_SIZEOF_AND_ALIGNMENT(void *)
 TargetWordSize=$ac_cv_sizeof_void_p
-if test "x$TargetWordSize" = x8; then
-  AC_SUBST([Cabal64bit],[True])
-else
-  AC_SUBST([Cabal64bit],[False])
-fi
 AC_SUBST(TargetWordSize)
 
 AC_C_BIGENDIAN([TargetWordBigEndian=YES],[TargetWordBigEndian=NO])
 AC_SUBST(TargetWordBigEndian)
 
-FP_CHECK_FUNC([WinExec],
-  [@%:@include <windows.h>], [WinExec("",0)])
-
-FP_CHECK_FUNC([GetModuleFileName],
-  [@%:@include <windows.h>], [GetModuleFileName((HMODULE)0,(LPTSTR)0,0)])
-
-dnl ** check for more functions
-dnl ** The following have been verified to be used in ghc/, but might be used somewhere else, too.
-AC_CHECK_FUNCS([getclock getrusage gettimeofday setitimer siginterrupt sysconf times ctime_r sched_setaffinity sched_getaffinity setlocale uselocale])
-
 dnl ** On OS X 10.4 (at least), time.h doesn't declare ctime_r if
 dnl ** _POSIX_C_SOURCE is defined
 AC_CHECK_DECLS([ctime_r], , ,
@@ -917,40 +864,6 @@ AC_CHECK_DECLS([ctime_r], , ,
 #define _POSIX_C_SOURCE 199506L
 #include <time.h>])
 
-dnl On Linux we should have program_invocation_short_name
-AC_CHECK_DECLS([program_invocation_short_name], , ,
-[#define _GNU_SOURCE 1
-#include <errno.h>])
-
-dnl ** check for mingwex library
-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.])
-fi
-
-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 https://gitlab.haskell.org/ghc/ghc/issues/3730)
-AC_CHECK_LIB(m, atan, HaveLibM=YES, HaveLibM=NO)
-if test $HaveLibM = YES
-then
-  AC_DEFINE([HAVE_LIBM], [1], [Define to 1 if you need to link with libm])
-  AC_SUBST([UseLibm],[YES])
-else
-  AC_SUBST([UseLibm],[NO])
-fi
-TargetHasLibm=$HaveLibM
-AC_SUBST(TargetHasLibm)
-
-FP_BFD_SUPPORT
-
 dnl ################################################################
 dnl Check for libraries
 dnl ################################################################
@@ -958,12 +871,16 @@ dnl ################################################################
 FP_FIND_LIBFFI
 AC_SUBST(UseSystemLibFFI)
 
-dnl ** check whether we need -ldl to get dlopen()
-AC_CHECK_LIB([dl], [dlopen])
-AC_CHECK_LIB([dl], [dlopen], HaveLibdl=YES, HaveLibdl=NO)
-AC_SUBST([UseLibdl],[$HaveLibdl])
-dnl ** check whether we have dlinfo
-AC_CHECK_FUNCS([dlinfo])
+AC_ARG_ENABLE(libffi-adjustors,
+  [AS_HELP_STRING(
+      [--enable-libffi-adjustors],
+      [Force use of libffi for adjustors, even on platforms which have support for more efficient, native adjustors.])],
+  UseLibffiForAdjustors=$enableval,
+  dnl do nothing
+)
+UseLibffiForAdjustors=NO dnl TODO
+
+AC_SUBST([UseLibffiForAdjustors])
 
 dnl --------------------------------------------------
 dnl * Miscellaneous feature tests
@@ -986,27 +903,8 @@ dnl ** check for leading underscores in symbol names
 FP_LEADING_UNDERSCORE
 AC_SUBST([LeadingUnderscore], [`echo $fptools_cv_leading_underscore | sed 'y/yesno/YESNO/'`])
 if test x"$fptools_cv_leading_underscore" = xyes; then
-   AC_SUBST([CabalLeadingUnderscore],[True])
    AC_DEFINE([LEADING_UNDERSCORE], [1], [Define to 1 if C symbols have a leading underscore added by the compiler.])
-else
-   AC_SUBST([CabalLeadingUnderscore],[False])
-fi
-
-FP_VISIBILITY_HIDDEN
-
-FP_MUSTTAIL
-
-dnl ** check for librt
-AC_CHECK_LIB([rt], [clock_gettime])
-AC_CHECK_LIB([rt], [clock_gettime], HaveLibrt=YES, HaveLibrt=NO)
-if test $HaveLibrt = YES
-then
-  AC_SUBST([UseLibrt],[YES])
-else
-  AC_SUBST([UseLibrt],[NO])
 fi
-AC_CHECK_FUNCS(clock_gettime timer_settime)
-FP_CHECK_TIMER_CREATE
 
 dnl ** check for Apple's "interesting" long double compatibility scheme
 AC_MSG_CHECKING(for printf\$LDBLStub)
@@ -1022,116 +920,10 @@ AC_LINK_IFELSE([AC_LANG_CALL([], [printf\$LDBLStub])],
             [Define to 1 if we have printf$LDBLStub (Apple Mac OS >= 10.4, PPC).])
     ])
 
-FP_CHECK_PTHREADS
-
 dnl ** check for eventfd which is needed by the I/O manager
 AC_CHECK_HEADERS([sys/eventfd.h])
 AC_CHECK_FUNCS([eventfd])
 
-AC_CHECK_FUNCS([getpid getuid raise])
-
-dnl ** Check for __thread support in the compiler
-AC_MSG_CHECKING(for __thread support)
-AC_COMPILE_IFELSE(
-  [ AC_LANG_SOURCE([[__thread int tester = 0;]]) ],
-  [
-   AC_MSG_RESULT(yes)
-   AC_DEFINE([CC_SUPPORTS_TLS],[1],[Define to 1 if __thread is supported])
-  ],
-  [
-   AC_MSG_RESULT(no)
-   AC_DEFINE([CC_SUPPORTS_TLS],[0],[Define to 1 if __thread is supported])
-  ])
-
-dnl large address space support (see rts/include/rts/storage/MBlock.h)
-dnl
-dnl Darwin has vm_allocate/vm_protect
-dnl Linux has mmap(MAP_NORESERVE)/madv(MADV_DONTNEED)
-dnl FreeBSD, Solaris and maybe other have MAP_NORESERVE/MADV_FREE
-dnl (They also have MADV_DONTNEED, but it means something else!)
-dnl
-dnl Windows has VirtualAlloc MEM_RESERVE/MEM_COMMIT, however
-dnl it counts page-table space as committed memory, and so quickly
-dnl runs out of paging file when we have multiple processes reserving
-dnl 1TB of address space, we get the following error:
-dnl    VirtualAlloc MEM_RESERVE 1099512676352 bytes failed: The paging file is too small for this operation to complete.
-dnl
-
-AC_ARG_ENABLE(large-address-space,
-    [AS_HELP_STRING([--enable-large-address-space],
-        [Use a single large address space on 64 bit systems (enabled by default on 64 bit platforms)])],
-    EnableLargeAddressSpace=$enableval,
-    EnableLargeAddressSpace=yes
-)
-
-use_large_address_space=no
-if test "$ac_cv_sizeof_void_p" -eq 8 ; then
-    if test "x$EnableLargeAddressSpace" = "xyes" ; then
-        if test "$ghc_host_os" = "darwin" ; then
-            use_large_address_space=yes
-        elif test "$ghc_host_os" = "openbsd" ; then
-            # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE.
-            # The flag MAP_NORESERVE is supported for source compatibility reasons,
-            # but is completely ignored by OS mmap
-                  use_large_address_space=no
-        elif test "$ghc_host_os" = "mingw32" ; then
-            # as of Windows 8.1/Server 2012 windows does no longer allocate the page
-            # tabe for reserved memory eagerly. So we are now free to use LAS there too.
-                  use_large_address_space=yes
-        else
-            AC_CHECK_DECLS([MAP_NORESERVE, MADV_FREE, MADV_DONTNEED],[],[],
-                [
-                #include <unistd.h>
-                #include <sys/types.h>
-                #include <sys/mman.h>
-                #include <fcntl.h>
-            ])
-            if test "$ac_cv_have_decl_MAP_NORESERVE" = "yes" &&
-                test "$ac_cv_have_decl_MADV_FREE" = "yes" ||
-                test "$ac_cv_have_decl_MADV_DONTNEED" = "yes" ; then
-                    use_large_address_space=yes
-            fi
-        fi
-    fi
-fi
-if test "$use_large_address_space" = "yes" ; then
-   AC_DEFINE([USE_LARGE_ADDRESS_SPACE], [1], [Enable single heap address space support])
-fi
-
-dnl ** Use MMAP in the runtime linker?
-dnl --------------------------------------------------------------
-
-case ${TargetOS} in
-    linux|linux-android|freebsd|dragonfly|netbsd|openbsd|kfreebsdgnu|gnu|solaris2)
-        RtsLinkerUseMmap=1
-        ;;
-    darwin|ios|watchos|tvos)
-        RtsLinkerUseMmap=1
-        ;;
-    *)
-        # Windows (which doesn't have mmap) and everything else.
-        RtsLinkerUseMmap=0
-        ;;
-    esac
-
-AC_DEFINE_UNQUOTED([RTS_LINKER_USE_MMAP], [$RtsLinkerUseMmap],
-                   [Use mmap in the runtime linker])
-
-
-GHC_ADJUSTORS_METHOD([Target])
-AC_SUBST([UseLibffiForAdjustors])
-
-dnl ** Other RTS features
-dnl --------------------------------------------------------------
-FP_FIND_LIBDW
-AC_SUBST(UseLibdw)
-AC_SUBST(LibdwLibDir)
-AC_SUBST(LibdwIncludeDir)
-
-FP_FIND_LIBNUMA
-AC_SUBST(UseLibNuma)
-AC_SUBST(LibNumaLibDir)
-AC_SUBST(LibNumaIncludeDir)
 
 dnl ** Documentation
 dnl --------------------------------------------------------------
diff --git a/distrib/configure.ac.in b/distrib/configure.ac.in
index 8b203be35d..81200c247b 100644
--- a/distrib/configure.ac.in
+++ b/distrib/configure.ac.in
@@ -21,19 +21,11 @@ bootstrap_target=@TargetPlatform@
 TargetHasRTSLinker=@TargetHasRTSLinker@
 AC_SUBST(TargetHasRTSLinker)
 
-TargetHasLibm=@TargetHasLibm@
-AC_SUBST(TargetHasLibm)
-
 FFIIncludeDir=@FFIIncludeDir@
 FFILibDir=@FFILibDir@
 AC_SUBST(FFILibDir)
 AC_SUBST(FFIIncludeDir)
 
-LibdwIncludeDir=@LibdwIncludeDir@
-LibdwLibDir=@LibdwLibDir@
-AC_SUBST(LibdwLibDir)
-AC_SUBST(LibdwIncludeDir)
-
 UseLibffiForAdjustors=@UseLibffiForAdjustors@
 AC_SUBST(UseLibffiForAdjustors)
 
diff --git a/hadrian/bindist/Makefile b/hadrian/bindist/Makefile
index 2b0903796e..92defdf68a 100644
--- a/hadrian/bindist/Makefile
+++ b/hadrian/bindist/Makefile
@@ -116,7 +116,6 @@ lib/settings :
 	@echo ',("target has .ident directive", "$(TargetHasIdentDirective)")' >> $@
 	@echo ',("target has subsections via symbols", "$(TargetHasSubsectionsViaSymbols)")' >> $@
 	@echo ',("target has RTS linker", "$(TargetHasRTSLinker)")' >> $@
-	@echo ',("target has libm", "$(TargetHasLibm)")' >> $@
 	@echo ',("Unregisterised", "$(GhcUnregisterised)")' >> $@
 	@echo ',("LLVM target", "$(LLVMTarget_CPP)")' >> $@
 	@echo ',("LLVM llc command", "$(SettingsLlcCommand)")' >> $@
diff --git a/hadrian/bindist/config.mk.in b/hadrian/bindist/config.mk.in
index ee8366a26f..5ede1acb3f 100644
--- a/hadrian/bindist/config.mk.in
+++ b/hadrian/bindist/config.mk.in
@@ -253,7 +253,6 @@ TargetHasGnuNonexecStack = @TargetHasGnuNonexecStack@
 TargetHasIdentDirective = @TargetHasIdentDirective@
 TargetHasSubsectionsViaSymbols = @TargetHasSubsectionsViaSymbols@
 TargetHasRTSLinker = @TargetHasRTSLinker@
-TargetHasLibm = @TargetHasLibm@
 TablesNextToCode = @TablesNextToCode@
 
 SettingsCCompilerCommand = @SettingsCCompilerCommand@
diff --git a/hadrian/cfg/system.config.in b/hadrian/cfg/system.config.in
index 78f66df02f..9d05a9a670 100644
--- a/hadrian/cfg/system.config.in
+++ b/hadrian/cfg/system.config.in
@@ -172,7 +172,6 @@ target-has-gnu-nonexec-stack = @TargetHasGnuNonexecStack@
 target-has-ident-directive = @TargetHasIdentDirective@
 target-has-subsections-via-symbols = @TargetHasSubsectionsViaSymbols@
 target-has-rts-linker = @TargetHasRTSLinker@
-target-has-libm = @TargetHasLibm@
 target-arm-version    = @ARM_ISA@
 
 # Include and library directories:
@@ -193,21 +192,7 @@ use-system-ffi    = @UseSystemLibFFI@
 ffi-include-dir   = @FFIIncludeDir@
 ffi-lib-dir       = @FFILibDir@
 
-libdw-include-dir   = @LibdwIncludeDir@
-libdw-lib-dir       = @LibdwLibDir@
-
-libnuma-include-dir   = @LibNumaIncludeDir@
-libnuma-lib-dir       = @LibNumaLibDir@
-
 # Optional Dependencies:
 #=======================
 
 use-lib-dw        = @UseLibdw@
-use-lib-numa      = @UseLibNuma@
-use-lib-mingw-ex  = @HaveLibMingwEx@
-use-lib-m         = @UseLibm@
-use-lib-rt        = @UseLibrt@
-use-lib-dl        = @UseLibdl@
-use-lib-bfd       = @UseLibbfd@
-use-lib-pthread   = @UseLibpthread@
-need-libatomic    = @NeedLibatomic@
diff --git a/hadrian/src/Oracles/Flag.hs b/hadrian/src/Oracles/Flag.hs
index 836834cbfc..76a7a6c431 100644
--- a/hadrian/src/Oracles/Flag.hs
+++ b/hadrian/src/Oracles/Flag.hs
@@ -32,14 +32,6 @@ data Flag = ArSupportsAtFile
           | BootstrapEventLoggingRts
           | UseLibffiForAdjustors
           | UseLibdw
-          | UseLibnuma
-          | UseLibmingwex
-          | UseLibm
-          | UseLibrt
-          | UseLibdl
-          | UseLibbfd
-          | UseLibpthread
-          | NeedLibatomic
 
 -- Note, if a flag is set to empty string we treat it as set to NO. This seems
 -- fragile, but some flags do behave like this.
@@ -62,14 +54,6 @@ flag f = do
             BootstrapEventLoggingRts -> "bootstrap-event-logging-rts"
             UseLibffiForAdjustors -> "use-libffi-for-adjustors"
             UseLibdw             -> "use-lib-dw"
-            UseLibnuma           -> "use-lib-numa"
-            UseLibmingwex        -> "use-lib-mingw-ex"
-            UseLibm              -> "use-lib-m"
-            UseLibrt             -> "use-lib-rt"
-            UseLibdl             -> "use-lib-dl"
-            UseLibbfd            -> "use-lib-bfd"
-            UseLibpthread        -> "use-lib-pthread"
-            NeedLibatomic        -> "need-libatomic"
     value <- lookupSystemConfig key
     when (value `notElem` ["YES", "NO", ""]) . error $ "Configuration flag "
         ++ quote (key ++ " = " ++ value) ++ " cannot be parsed."
diff --git a/hadrian/src/Oracles/Setting.hs b/hadrian/src/Oracles/Setting.hs
index e064d7a5c1..aa2eb0f851 100644
--- a/hadrian/src/Oracles/Setting.hs
+++ b/hadrian/src/Oracles/Setting.hs
@@ -56,10 +56,6 @@ data Setting = BuildArch
              | HostOsHaskell
              | IconvIncludeDir
              | IconvLibDir
-             | LibdwIncludeDir
-             | LibdwLibDir
-             | LibnumaIncludeDir
-             | LibnumaLibDir
              | LlvmTarget
              | ProjectGitCommitId
              | ProjectName
@@ -158,10 +154,6 @@ setting key = lookupSystemConfig $ case key of
     HostOsHaskell      -> "host-os-haskell"
     IconvIncludeDir    -> "iconv-include-dir"
     IconvLibDir        -> "iconv-lib-dir"
-    LibdwIncludeDir    -> "libdw-include-dir"
-    LibdwLibDir        -> "libdw-lib-dir"
-    LibnumaIncludeDir  -> "libnuma-include-dir"
-    LibnumaLibDir      -> "libnuma-lib-dir"
     LlvmTarget         -> "llvm-target"
     ProjectGitCommitId -> "project-git-commit-id"
     ProjectName        -> "project-name"
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index b156c9dfdf..6eb0edde75 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -264,38 +264,12 @@ templateRules = do
 
     project_version        <- setting ProjectVersion
     project_version_munged <- setting ProjectVersionMunged
-    target_word_size       <- settingWord TargetWordSize
-    lib_dw                 <- flag UseLibdw
-    lib_numa               <- flag UseLibnuma
-    lib_mingwex            <- flag UseLibmingwex
-    lib_m                  <- flag UseLibm
-    lib_rt                 <- flag UseLibrt
-    lib_dl                 <- flag UseLibdl
-    lib_ffi                <- flag UseSystemFfi
-    lib_ffi_adjustors      <- flag UseLibffiForAdjustors
-    lib_bfd                <- flag UseLibbfd
-    lib_pthread            <- flag UseLibpthread
-    leading_underscore     <- flag LeadingUnderscore
-    need_libatomic         <- flag NeedLibatomic
 
     let cabal_bool True  = "True"
         cabal_bool False = "False"
 
         subst = replace "@ProjectVersion@" project_version
                 . replace "@ProjectVersionMunged@" project_version_munged
-                . replace "@Cabal64bit@" (cabal_bool (target_word_size == 8))
-                . replace "@CabalMingwex@" (cabal_bool lib_mingwex)
-                . replace "@CabalHaveLibdw@" (cabal_bool lib_dw)
-                . replace "@CabalHaveLibm@" (cabal_bool lib_m)
-                . replace "@CabalHaveLibrt@" (cabal_bool lib_rt)
-                . replace "@CabalHaveLibdl@" (cabal_bool lib_dl)
-                . replace "@CabalUseSystemLibFFI@" (cabal_bool lib_ffi)
-                . replace "@CabalLibffiAdjustors@" (cabal_bool lib_ffi_adjustors)
-                . replace "@CabalNeedLibpthread@" (cabal_bool lib_pthread)
-                . replace "@CabalHaveLibbfd@" (cabal_bool lib_bfd)
-                . replace "@CabalHaveLibNuma@" (cabal_bool lib_numa)
-                . replace "@CabalLeadingUnderscore@" (cabal_bool leading_underscore)
-                . replace "@CabalNeedLibatomic@" (cabal_bool need_libatomic)
 
     s <- readFile' (out <.> "in")
     writeFile' out (subst s)
@@ -415,7 +389,6 @@ generateSettings = do
         , ("target has .ident directive", expr $ lookupSystemConfig "target-has-ident-directive")
         , ("target has subsections via symbols", expr $ lookupSystemConfig "target-has-subsections-via-symbols")
         , ("target has RTS linker", expr $ lookupSystemConfig "target-has-rts-linker")
-        , ("target has libm", expr $  lookupSystemConfig "target-has-libm")
         , ("Unregisterised", expr $ yesNo <$> flag GhcUnregisterised)
         , ("LLVM target", getSetting LlvmTarget)
         , ("LLVM llc command", expr $ settingsFileSetting SettingsFileSetting_LlcCommand)
diff --git a/hadrian/src/Settings/Packages.hs b/hadrian/src/Settings/Packages.hs
index 128262a0ab..7268a7a041 100644
--- a/hadrian/src/Settings/Packages.hs
+++ b/hadrian/src/Settings/Packages.hs
@@ -283,10 +283,6 @@ rtsPackageArgs = package rts ? do
     useSystemFfi   <- expr $ flag UseSystemFfi
     ffiIncludeDir  <- getSetting FfiIncludeDir
     ffiLibraryDir  <- getSetting FfiLibDir
-    libdwIncludeDir   <- getSetting LibdwIncludeDir
-    libdwLibraryDir   <- getSetting LibdwLibDir
-    libnumaIncludeDir <- getSetting LibnumaIncludeDir
-    libnumaLibraryDir <- getSetting LibnumaLibDir
 
     -- Arguments passed to GHC when compiling C and .cmm sources.
     let ghcArgs = mconcat
@@ -391,9 +387,7 @@ rtsPackageArgs = package rts ? do
           , Debug `wayUnit` way             `cabalFlag` "find-ptr"
           ]
         , builder (Cabal Setup) ? mconcat
-              [ cabalExtraDirs libdwIncludeDir libdwLibraryDir
-              , cabalExtraDirs libnumaIncludeDir libnumaLibraryDir
-              , useSystemFfi ? cabalExtraDirs ffiIncludeDir ffiLibraryDir
+              [ useSystemFfi ? cabalExtraDirs ffiIncludeDir ffiLibraryDir
               ]
         , builder (Cc (FindCDependencies CDep)) ? cArgs
         , builder (Cc (FindCDependencies  CxxDep)) ? cArgs
@@ -405,7 +399,7 @@ rtsPackageArgs = package rts ? do
           [ "-DTOP="             ++ show top ]
 
         , builder HsCpp ? flag UseLibdw ? arg "-DUSE_LIBDW"
-        , builder HsCpp ? flag UseLibmingwex ? arg "-DHAVE_LIBMINGWEX" ]
+        ]
 
 -- Compile various performance-critical pieces *without* -fPIC -dynamic
 -- even when building a shared library.  If we don't do this, then the
diff --git a/libraries/Cabal b/libraries/Cabal
-Subproject 5abfa5032cb6f011c9a7e02d14c9f10dcb2d660
+Subproject 30f8a46008d164b5c4c6ce0b4453eb93eb5ef46
diff --git a/rts/configure.ac b/rts/configure.ac
index 81c702d3c4..a9d08b179d 100644
--- a/rts/configure.ac
+++ b/rts/configure.ac
@@ -8,7 +8,7 @@
 
 AC_INIT([GHC run-time system], [1.0.2], [libraries@haskell.org], [rts])
 
-AC_CONFIG_MACRO_DIRS([../m4])
+AC_CONFIG_MACRO_DIRS([m4 ../m4])
 
 # Safety check: Ensure that we are in the correct source directory.
 AC_CONFIG_SRCDIR([include/rts/Constants.h])
@@ -29,19 +29,143 @@ AC_CONFIG_HEADERS([ghcautoconf.h.autoconf])
 AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
 
+GHC_CONVERT_PLATFORM_PARTS([build], [Build])
 GHC_CONVERT_PLATFORM_PARTS([host], [Host])
+FPTOOLS_SET_PLATFORM_VARS([build], [Build])
 FPTOOLS_SET_PLATFORM_VARS([host], [Host])
 FPTOOLS_SET_HASKELL_PLATFORM_VARS([Host])
 
+AC_CHECK_HEADERS([ctype.h dirent.h dlfcn.h errno.h fcntl.h grp.h limits.h locale.h nlist.h pthread.h pwd.h signal.h sys/param.h sys/mman.h sys/resource.h sys/select.h sys/time.h sys/timeb.h sys/timerfd.h sys/timers.h sys/times.h sys/utsname.h sys/wait.h termios.h utime.h windows.h winsock.h sched.h])
+
+AC_CHECK_FUNCS([getclock getrusage gettimeofday setitimer siginterrupt sysconf times ctime_r sched_setaffinity sched_getaffinity setlocale uselocale])
+
+dnl sys/cpuset.h needs sys/param.h to be included first on FreeBSD 9.1; #7708
+AC_CHECK_HEADERS([sys/cpuset.h], [], [],
+[[#if HAVE_SYS_PARAM_H
+# include <sys/param.h>
+#endif
+]])
+
+dnl ** check whether a declaration for `environ` is provided by libc.
+FP_CHECK_ENVIRON
+
 dnl ** Other RTS features
 dnl --------------------------------------------------------------
-AC_DEFINE_UNQUOTED([USE_LIBDW], [$CABAL_FLAG_libdw], [Set to 1 to use libdw])
 
-AC_DEFINE_UNQUOTED([HAVE_LIBNUMA], [$CABAL_FLAG_libnuma], [Define to 1 if you have libnuma])
+FP_FIND_LIBDW
+
+FP_FIND_LIBNUMA
 
-dnl ** Write config files
+FP_LEADING_UNDERSCORE
+FP_MUSTTAIL
+
+dnl ** Check for __thread support in the compiler
+AC_MSG_CHECKING(for __thread support)
+AC_COMPILE_IFELSE(
+  [ AC_LANG_SOURCE([[__thread int tester = 0;]]) ],
+  [
+   AC_MSG_RESULT(yes)
+   AC_DEFINE([CC_SUPPORTS_TLS],[1],[Define to 1 if __thread is supported])
+  ],
+  [
+   AC_MSG_RESULT(no)
+   AC_DEFINE([CC_SUPPORTS_TLS],[0],[Define to 1 if __thread is supported])
+  ])
+
+dnl ** Use MMAP in the runtime linker?
 dnl --------------------------------------------------------------
 
+case ${TargetOS} in
+    linux|linux-android|freebsd|dragonfly|netbsd|openbsd|kfreebsdgnu|gnu|solaris2)
+        RtsLinkerUseMmap=1
+        ;;
+    darwin|ios|watchos|tvos)
+        RtsLinkerUseMmap=1
+        ;;
+    *)
+        # Windows (which doesn't have mmap) and everything else.
+        RtsLinkerUseMmap=0
+        ;;
+    esac
+
+AC_DEFINE_UNQUOTED([RTS_LINKER_USE_MMAP], [$RtsLinkerUseMmap],
+                   [Use mmap in the runtime linker])
+
+
+GHC_ADJUSTORS_METHOD([Target])
+AC_SUBST([UseLibffiForAdjustors])
+AS_IF(
+  [test x"${UseLibffiForAdjustors}" = x"YES"],
+  [AC_DEFINE([GHC_LIBFFI_ADJUSTORS],[1],[Should libffi be used for adjustors?])],
+  [AC_DEFINE([GHC_LIBFFI_ADJUSTORS],[0],[Should libffi be used for adjustors?])]
+)
+
+dnl ** do we have long longs?
+AC_CHECK_TYPES([long long])
+
+dnl ** what are the sizes of various types
+FP_CHECK_SIZEOF_AND_ALIGNMENT(char)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(double)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(float)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(int)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(long)
+if test "$ac_cv_type_long_long" = yes; then
+FP_CHECK_SIZEOF_AND_ALIGNMENT(long long)
+fi
+FP_CHECK_SIZEOF_AND_ALIGNMENT(short)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned char)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned int)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned long)
+if test "$ac_cv_type_long_long" = yes; then
+FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned long long)
+fi
+FP_CHECK_SIZEOF_AND_ALIGNMENT(unsigned short)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(void *)
+
+FP_CHECK_SIZEOF_AND_ALIGNMENT(int8_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(uint8_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(int16_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(uint16_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(int32_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(uint32_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(int64_t)
+FP_CHECK_SIZEOF_AND_ALIGNMENT(uint64_t)
+
+dnl ** check for pthreads
+FP_CHECK_PTHREADS
+
+dnl ** check for math library
+dnl    Keep that check as early as possible.
+dnl    as we need to know whether we need libm
+dnl    for math functions or not
+dnl    (see https://gitlab.haskell.org/ghc/ghc/issues/3730)
+AC_CHECK_LIB([m], [atan], [need_libm=1], [need_libm=0])
+AC_DEFINE_UNQUOTED([GHC_NEED_LIBM], [$need_libm], [Define to 1 if you need to link with libm])
+
+dnl ** check for librt
+AC_CHECK_LIB([rt], [clock_gettime], [need_librt=1], [need_librt=1])
+AC_DEFINE_UNQUOTED([GHC_NEED_LIBRT], [$need_librt], [Define to 1 if you need to link with librt])
+AC_CHECK_FUNCS(clock_gettime timer_settime)
+FP_CHECK_TIMER_CREATE
+
+dnl ** check whether we need -ldl to get dlopen()
+AC_CHECK_LIB([dl], [dlopen], [need_libdl=1], [need_libdl=0])
+AC_DEFINE_UNQUOTED([GHC_NEED_LIBDL], [$need_libdl], [Define to 1 if you need to link with libdl to get dlopen])
+dnl ** check whether we have dlinfo
+AC_CHECK_FUNCS([dlinfo])
+
+dnl ** On Linux we should have program_invocation_short_name
+AC_CHECK_DECLS([program_invocation_short_name], , ,
+[#define _GNU_SOURCE 1
+#include <errno.h>])
+
+dnl ** check whether we should use the two-step allocator
+FP_LARGE_ADDRESS_SPACE
+
+FP_BFD_SUPPORT
+
+AC_CONFIG_FILES([rts.buildinfo])
+
 AC_OUTPUT
 
 dnl ######################################################################
@@ -55,9 +179,9 @@ touch 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
+# Copy the contents of ghcautoconf.h.autoconf, turning '#define PACKAGE_FOO
 # "blah"' into '/* #undef PACKAGE_FOO */' to avoid clashes.
-cat $srcdir/../mk/config.h ghcautoconf.h.autoconf | sed \
+sed ghcautoconf.h.autoconf \
    -e 's,^\([	 ]*\)#[	 ]*define[	 ][	 ]*\(PACKAGE_[A-Z]*\)[	 ][ 	]*".*".*$,\1/* #undef \2 */,' \
    -e '/__GLASGOW_HASKELL/d' \
    -e '/REMOVE ME/d' \
@@ -92,4 +216,6 @@ cat $srcdir/rts.buildinfo.in | \
     "$CC" -E -P -traditional - -o - \
     > rts.buildinfo
 echo "" >> rts.buildinfo
+echo "cc-options: ${CFLAGS}" >> rts.buildinfo
+echo "ld-options: ${LDFLAGS}" >> rts.buildinfo
 rm -f external-symbols.list
diff --git a/rts/include/rts/PosixSource.h b/rts/include/rts/PosixSource.h
index be6c8ecca1..bc1be83d87 100644
--- a/rts/include/rts/PosixSource.h
+++ b/rts/include/rts/PosixSource.h
@@ -37,6 +37,8 @@
 #define _XOPEN_SOURCE   700
 #endif
 
+#define _GNU_SOURCE 1
+
 #if defined(mingw32_HOST_OS)
 #  if defined(__USE_MINGW_ANSI_STDIO)
 #    if __USE_MINGW_ANSI_STDIO != 1
diff --git a/rts/linker/Elf.c b/rts/linker/Elf.c
index 3595a4c3d4..ff242e835a 100644
--- a/rts/linker/Elf.c
+++ b/rts/linker/Elf.c
@@ -28,10 +28,10 @@
 #include "linker/util.h"
 #include "linker/elf_util.h"
 
-#include <link.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <link.h>
 #if defined(HAVE_DLFCN_H)
 #include <dlfcn.h>
 #endif
diff --git a/rts/linker/elf_got.c b/rts/linker/elf_got.c
index 4d0c97871e..9c9f07e7fa 100644
--- a/rts/linker/elf_got.c
+++ b/rts/linker/elf_got.c
@@ -1,6 +1,7 @@
 #include "Rts.h"
 #include "elf_got.h"
 #include "linker/MMap.h"
+#include "sys/mman.h"
 
 #include <string.h>
 
diff --git a/m4/fp_bfd_support.m4 b/rts/m4/fp_bfd_support.m4
index 2f357820f7..2f357820f7 100644
--- a/m4/fp_bfd_support.m4
+++ b/rts/m4/fp_bfd_support.m4
diff --git a/m4/fp_cc_supports__atomics.m4 b/rts/m4/fp_cc_supports__atomics.m4
index bd3750e972..9c15ef6a1f 100644
--- a/m4/fp_cc_supports__atomics.m4
+++ b/rts/m4/fp_cc_supports__atomics.m4
@@ -62,11 +62,6 @@ AC_DEFUN([FP_CC_SUPPORTS__ATOMICS],
         AC_MSG_ERROR([C compiler needs to support __atomic primitives.])
     ])
     AC_DEFINE([HAVE_C11_ATOMICS], [1], [Does C compiler support __atomic primitives?])
-    if test "$need_latomic" = 1; then
-        AC_SUBST([NeedLibatomic],[YES])
-    else
-        AC_SUBST([NeedLibatomic],[NO])
-    fi
-    AC_DEFINE_UNQUOTED([NEED_ATOMIC_LIB], [$need_latomic],
+    AC_DEFINE_UNQUOTED([GHC_NEED_LIBATOMIC], [$need_latomic],
         [Define to 1 if we need -latomic.])
 ])
diff --git a/m4/fp_check_pthreads.m4 b/rts/m4/fp_check_pthreads.m4
index 5713e7c743..5c63cac2a5 100644
--- a/m4/fp_check_pthreads.m4
+++ b/rts/m4/fp_check_pthreads.m4
@@ -12,23 +12,20 @@ AC_DEFUN([FP_CHECK_PTHREADS],
   AC_CHECK_FUNC(pthread_create,
       [
           AC_MSG_RESULT(no)
-          AC_SUBST([UseLibpthread],[NO])
           need_lpthread=0
       ],
       [
           AC_CHECK_LIB(pthread, pthread_create,
               [
                   AC_MSG_RESULT(yes)
-                  AC_SUBST([UseLibpthread],[YES])
                   need_lpthread=1
               ],
               [
-                  AC_SUBST([UseLibpthread],[NO])
                   AC_MSG_RESULT([no pthreads support found.])
                   need_lpthread=0
               ])
       ])
-  AC_DEFINE_UNQUOTED([NEED_PTHREAD_LIB], [$need_lpthread],
+  AC_DEFINE_UNQUOTED([GHC_NEED_LIBPTHREAD], [$need_lpthread],
       [Define 1 if we need to link code using pthreads with -lpthread])
 
   dnl Setting thread names
diff --git a/m4/fp_find_libdw.m4 b/rts/m4/fp_find_libdw.m4
index fa5bf807cb..70305c78fe 100644
--- a/m4/fp_find_libdw.m4
+++ b/rts/m4/fp_find_libdw.m4
@@ -45,5 +45,12 @@ AC_DEFUN([FP_FIND_LIBDW],
     CFLAGS="$CFLAGS2"
     LDFLAGS="$LDFLAGS2"
   fi
+
+  AC_SUBST(UseLibdw)
+  USE_LIBDW=0
+  if test $UseLibdw = "YES" ; then
+    USE_LIBDW=1
+  fi
+  AC_DEFINE_UNQUOTED([USE_LIBDW], [$USE_LIBDW], [Set to 1 to use libdw]
 ])
 
diff --git a/m4/fp_find_libnuma.m4 b/rts/m4/fp_find_libnuma.m4
index 1563ca4e89..eadd7d86fd 100644
--- a/m4/fp_find_libnuma.m4
+++ b/rts/m4/fp_find_libnuma.m4
@@ -27,7 +27,7 @@ AC_DEFUN([FP_FIND_LIBNUMA],
     [],
     [enable_numa=auto])
 
-  UseLibNuma=NO
+  HaveLibNuma=0
   if test "$enable_numa" != "no" ; then
     CFLAGS2="$CFLAGS"
     CFLAGS="$LIBNUMA_CFLAGS $CFLAGS"
@@ -37,13 +37,15 @@ AC_DEFUN([FP_FIND_LIBNUMA],
     AC_CHECK_HEADERS([numa.h numaif.h])
 
     if test "x:$ac_cv_header_numa_h:$ac_cv_header_numaif_h" = "x:yes:yes" ; then
-      AC_CHECK_LIB([numa], [numa_available], [UseLibNuma=YES])
+      AC_CHECK_LIB([numa], [numa_available], [HaveLibNuma=1])
     fi
-    if test "x:$enable_numa:$UseLibNuma" = "x:yes:NO" ; then
+    if test "x:$enable_numa:$HaveLibNuma" = "x:yes:0" ; then
       AC_MSG_ERROR([Cannot find system libnuma (required by --enable-numa)])
     fi
 
     CFLAGS="$CFLAGS2"
     LDFLAGS="$LDFLAGS2"
   fi
+
+  AC_DEFINE_UNQUOTED([HAVE_LIBNUMA], [$HaveLibNuma], [Define to 1 if you have libnuma])
 ])
diff --git a/rts/m4/fp_large_address_space.m4 b/rts/m4/fp_large_address_space.m4
new file mode 100644
index 0000000000..fd8a352a57
--- /dev/null
+++ b/rts/m4/fp_large_address_space.m4
@@ -0,0 +1,57 @@
+dnl large address space support (see rts/include/rts/storage/MBlock.h)
+dnl
+dnl Darwin has vm_allocate/vm_protect
+dnl Linux has mmap(MAP_NORESERVE)/madv(MADV_DONTNEED)
+dnl FreeBSD, Solaris and maybe other have MAP_NORESERVE/MADV_FREE
+dnl (They also have MADV_DONTNEED, but it means something else!)
+dnl
+dnl Windows has VirtualAlloc MEM_RESERVE/MEM_COMMIT, however
+dnl it counts page-table space as committed memory, and so quickly
+dnl runs out of paging file when we have multiple processes reserving
+dnl 1TB of address space, we get the following error:
+dnl    VirtualAlloc MEM_RESERVE 1099512676352 bytes failed: The paging file is too small for this operation to complete.
+dnl
+
+AC_DEFUN([FP_LARGE_ADDRESS_SPACE],
+[
+    AC_ARG_ENABLE(large-address-space,
+        [AS_HELP_STRING([--enable-large-address-space],
+            [Use a single large address space on 64 bit systems (enabled by default on 64 bit platforms)])],
+        EnableLargeAddressSpace=$enableval,
+        EnableLargeAddressSpace=yes
+    )
+
+    use_large_address_space=no
+    if test "$ac_cv_sizeof_void_p" -eq 8 ; then
+        if test "x$EnableLargeAddressSpace" = "xyes" ; then
+            if test "$ghc_host_os" = "darwin" ; then
+                use_large_address_space=yes
+            elif test "$ghc_host_os" = "openbsd" ; then
+                # as of OpenBSD 5.8 (2015), OpenBSD does not support mmap with MAP_NORESERVE.
+                # The flag MAP_NORESERVE is supported for source compatibility reasons,
+                # but is completely ignored by OS mmap
+                      use_large_address_space=no
+            elif test "$ghc_host_os" = "mingw32" ; then
+                # as of Windows 8.1/Server 2012 windows does no longer allocate the page
+                # tabe for reserved memory eagerly. So we are now free to use LAS there too.
+                      use_large_address_space=yes
+            else
+                AC_CHECK_DECLS([MAP_NORESERVE, MADV_FREE, MADV_DONTNEED],[],[],
+                    [
+                    #include <unistd.h>
+                    #include <sys/types.h>
+                    #include <sys/mman.h>
+                    #include <fcntl.h>
+                ])
+                if test "$ac_cv_have_decl_MAP_NORESERVE" = "yes" &&
+                    test "$ac_cv_have_decl_MADV_FREE" = "yes" ||
+                    test "$ac_cv_have_decl_MADV_DONTNEED" = "yes" ; then
+                        use_large_address_space=yes
+                fi
+            fi
+        fi
+    fi
+    if test "$use_large_address_space" = "yes" ; then
+       AC_DEFINE([USE_LARGE_ADDRESS_SPACE], [1], [Enable single heap address space support])
+    fi
+])
diff --git a/m4/fp_musttail.m4 b/rts/m4/fp_musttail.m4
index 0c61c2ad4c..0c61c2ad4c 100644
--- a/m4/fp_musttail.m4
+++ b/rts/m4/fp_musttail.m4
diff --git a/m4/fp_visibility_hidden.m4 b/rts/m4/fp_visibility_hidden.m4
index 5f5cebeeec..5f5cebeeec 100644
--- a/m4/fp_visibility_hidden.m4
+++ b/rts/m4/fp_visibility_hidden.m4
diff --git a/m4/ghc_adjustors_method.m4 b/rts/m4/ghc_adjustors_method.m4
index cae941a20e..cae941a20e 100644
--- a/m4/ghc_adjustors_method.m4
+++ b/rts/m4/ghc_adjustors_method.m4
diff --git a/rts/posix/OSThreads.c b/rts/posix/OSThreads.c
index 44cda2626d..5b5b736703 100644
--- a/rts/posix/OSThreads.c
+++ b/rts/posix/OSThreads.c
@@ -32,6 +32,9 @@
 #if defined(netbsd_HOST_OS)
 #define _NETBSD_SOURCE 1
 #endif
+#if defined(linux_HOST_OS)
+#define _GNU_SOURCE 1
+#endif
 
 #include "Rts.h"
 
diff --git a/rts/posix/ticker/Pthread.c b/rts/posix/ticker/Pthread.c
index a4c7af588f..9200ff8318 100644
--- a/rts/posix/ticker/Pthread.c
+++ b/rts/posix/ticker/Pthread.c
@@ -55,6 +55,9 @@
 
 #include <string.h>
 
+#if defined(linux_HOST_OS)
+#define _GNU_SOURCE 1
+#endif
 #include <pthread.h>
 #if defined(HAVE_PTHREAD_NP_H)
 #include <pthread_np.h>
diff --git a/rts/rts.buildinfo.in b/rts/rts.buildinfo.in
index 07540357c8..ac68fdc861 100644
--- a/rts/rts.buildinfo.in
+++ b/rts/rts.buildinfo.in
@@ -1,3 +1,63 @@
 -- External symbols referenced by the RTS
 ld-options:
 #include "external-symbols.list"
+
+#if GHC_LIBFFI_ADJUSTORS
+  -- Adjustors via libffi
+  c-sources: adjustor/LibffiAdjustor.c
+#else
+  -- Use GHC's native adjustors
+# if defined(i386_HOST_ARCH)
+    asm-sources: adjustor/Nativei386Asm.S
+    c-sources: adjustor/Nativei386.c
+# elif defined(x86_64_HOST_ARCH)
+#   if defined(mingw32_HOST_OS)
+      asm-sources: adjustor/NativeAmd64MingwAsm.S
+      c-sources: adjustor/NativeAmd64Mingw.c
+#   else
+      asm-sources: adjustor/NativeAmd64Asm.S
+      c-sources: adjustor/NativeAmd64.c
+#   endif
+# elif defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH)
+    asm-sources: AdjustorAsm.S
+    c-sources: adjustor/NativePowerPC.c
+# elif defined(ia64_HOST_ARCH)
+    c-sources: adjustor/NativeIA64.c
+# endif
+#endif
+
+#if GHC_NEED_LIBRT
+  extra-libraries: rt
+#endif
+
+#if GHC_NEED_LIBM
+  extra-libraries: m
+#endif
+
+#if GHC_NEED_LIBDL
+  extra-libraries: dl
+#endif
+
+#if GHC_NEED_LIBATOMIC
+  -- for sub-word-sized atomic operations (#19119)
+  extra-libraries: atomic
+#endif
+
+#if GHC_NEED_LIBPTHREAD
+  -- for pthread_getthreadid_np, pthread_create, ...
+  extra-libraries: pthread
+#endif
+
+#if USE_LIBBFD
+  -- for debugging
+  extra-libraries: bfd iberty
+#endif
+
+#if USE_LIBDW
+  -- for backtraces
+  extra-libraries: elf dw
+#endif
+
+#if USE_LIBNUMA
+  extra-libraries: numa
+#endif
diff --git a/rts/rts.cabal.in b/rts/rts.cabal.in
index 98ca808917..52b8311027 100644
--- a/rts/rts.cabal.in
+++ b/rts/rts.cabal.in
@@ -28,32 +28,9 @@ source-repository head
     location: https://gitlab.haskell.org/ghc/ghc.git
     subdir:   rts
 
-flag libm
-  default: @CabalHaveLibm@
-flag librt
-  default: @CabalHaveLibrt@
-flag libdl
-  default: @CabalHaveLibdl@
+-- Configuration
 flag use-system-libffi
-  default: @CabalUseSystemLibFFI@
-flag libffi-adjustors
-  default: @CabalLibffiAdjustors@
-flag need-pthread
-  default: @CabalNeedLibpthread@
-flag libbfd
-  default: @CabalHaveLibbfd@
-flag mingwex
-  default: @CabalMingwex@
-flag need-atomic
-  default: @CabalNeedLibatomic@
-flag libdw
-  default: @CabalHaveLibdw@
-flag libnuma
-  default: @CabalHaveLibNuma@
-flag 64bit
-  default: @Cabal64bit@
-flag leading-underscore
-  default: @CabalLeadingUnderscore@
+  description: Use the system's libffi library rather than GHC's internally built library.
 flag smp
   default: True
 flag find-ptr
@@ -177,13 +154,6 @@ library
          -- that it is ordered correctly with libpthread, since ghc-prim.cabal
          -- also explicitly lists libc. See #19029.
          extra-libraries: c
-      if flag(libm)
-         -- for ldexp()
-         extra-libraries: m
-      if flag(librt)
-         extra-libraries: rt
-      if flag(libdl)
-         extra-libraries: dl
       if flag(use-system-libffi)
          extra-libraries: ffi
       if os(windows)
@@ -203,22 +173,8 @@ library
          -- and also centralizes the versioning.
          cpp-options: -D_WIN32_WINNT=0x06010000
          cc-options: -D_WIN32_WINNT=0x06010000
-      if flag(need-pthread)
-         -- for pthread_getthreadid_np, pthread_create, ...
-         extra-libraries: pthread
-      if flag(need-atomic)
-         -- for sub-word-sized atomic operations (#19119)
-         extra-libraries: atomic
-      if flag(libbfd)
-         -- for debugging
-         extra-libraries: bfd iberty
-      if flag(mingwex)
+      if os(windows)
          extra-libraries: mingwex
-      if flag(libdw)
-         -- for backtraces
-         extra-libraries: elf dw
-      if flag(libnuma)
-         extra-libraries: numa
       if !flag(smp)
          cpp-options: -DNOSMP
 
@@ -297,8 +253,6 @@ library
 
       if os(osx)
         ld-options: "-Wl,-search_paths_first"
-                    -- See Note [fd_set_overflow]
-                    "-Wl,-U,___darwin_check_fd_set_overflow"
         if !arch(x86_64) && !arch(aarch64)
            ld-options: -read_only_relocs warning
 
@@ -315,27 +269,6 @@ library
                    -- AutoApply is generated
                    AutoApply.cmm
 
-      -- Adjustor stuff
-      if flag(libffi-adjustors)
-        c-sources: adjustor/LibffiAdjustor.c
-      else
-        -- Use GHC's native adjustors
-        if arch(i386)
-          asm-sources: adjustor/Nativei386Asm.S
-          c-sources: adjustor/Nativei386.c
-        if arch(x86_64)
-          if os(mingw32)
-            asm-sources: adjustor/NativeAmd64MingwAsm.S
-            c-sources: adjustor/NativeAmd64Mingw.c
-          else
-            asm-sources: adjustor/NativeAmd64Asm.S
-            c-sources: adjustor/NativeAmd64.c
-        if arch(ppc) || arch(ppc64)
-          asm-sources: AdjustorAsm.S
-          c-sources: adjustor/NativePowerPC.c
-        if arch(ia64)
-          c-sources: adjustor/NativeIA64.c
-
       -- Use assembler STG entrypoint on architectures where it is used
       if arch(ppc) || arch(ppc64) || arch(s390x) || arch(riscv64) || arch(loongarch64)
         asm-sources: StgCRunAsm.S