Fix use distro toolchian

aclocal.m4

@@ -583,6 +583,7 @@ AC_DEFUN([FP_SETTINGS],
     SettingsCCompilerLinkFlags="$CONF_GCC_LINKER_OPTS_STAGE2"
     SettingsCCompilerSupportsNoPie="$CONF_GCC_SUPPORTS_NO_PIE"
     SettingsLdFlags="$CONF_LD_LINKER_OPTS_STAGE2"
+    SettingsUseDistroMINGW="$EnableDistroToolchain"
     AC_SUBST(SettingsCCompilerCommand)
     AC_SUBST(SettingsHaskellCPPCommand)
     AC_SUBST(SettingsHaskellCPPFlags)
@@ -601,6 +602,7 @@ AC_DEFUN([FP_SETTINGS],
     AC_SUBST(SettingsClangCommand)
     AC_SUBST(SettingsLlcCommand)
     AC_SUBST(SettingsOptCommand)
+    AC_SUBST(SettingsUseDistroMINGW)
 ])
 
 # Helper for cloning a shell variable's state

compiler/GHC/SysTools/BaseDir.hs

@@ -79,7 +79,7 @@ $topdir/../../{mingw, perl}/.
 -- | Expand occurrences of the @$tooldir@ interpolation in a string
 -- on Windows, leave the string untouched otherwise.
 expandToolDir :: Maybe FilePath -> String -> String
-#if defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS) && !defined(USE_INPLACE_MINGW_TOOLCHAIN)
 expandToolDir (Just tool_dir) s = expandPathVar "tooldir" tool_dir s
 expandToolDir Nothing         _ = panic "Could not determine $tooldir"
 #else
@@ -117,10 +117,11 @@ tryFindTopDir Nothing
 -- Returns @Nothing@ when not on Windows.
 -- When called on Windows, it either throws an error when the
 -- tooldir can't be located, or returns @Just tooldirpath@.
+-- If the distro toolchain is being used we treat Windows the same as Linux
 findToolDir
   :: FilePath -- ^ topdir
   -> IO (Maybe FilePath)
-#if defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS) && !defined(USE_INPLACE_MINGW_TOOLCHAIN)
 findToolDir top_dir = go 0 (top_dir </> "..")
   where maxDepth = 3
         go :: Int -> FilePath -> IO (Maybe FilePath)

configure.ac

@@ -462,6 +462,7 @@ then
     # so never tried without the prefix.
     AC_PATH_PROG([CC],[gcc], [clang])
     AC_PATH_PROG([NM],[nm])
+    AC_PATH_PROG([LD],[ld])
     AC_PATH_PROG([AR],[ar])
     AC_PATH_PROG([RANLIB],[ranlib])
     AC_PATH_PROG([OBJDUMP],[objdump])

hadrian/cfg/system.config.in

@@ -92,6 +92,8 @@ project-patch-level1  = @ProjectPatchLevel1@
 project-patch-level2  = @ProjectPatchLevel2@
 project-git-commit-id = @ProjectGitCommitId@
 
+system-use-distro-mingw  = @SettingsUseDistroMINGW@
+
 # Compilation and linking flags:
 #===============================
 

hadrian/src/Oracles/Flag.hs

@@ -25,6 +25,7 @@ data Flag = ArSupportsAtFile
           | HaveLibMingwEx
           | UseSystemFfi
           | BootstrapThreadedRts
+          | SystemDistroMINGW
 
 -- 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.
@@ -45,6 +46,7 @@ flag f = do
             HaveLibMingwEx       -> "have-lib-mingw-ex"
             UseSystemFfi         -> "use-system-ffi"
             BootstrapThreadedRts -> "bootstrap-threaded-rts"
+            SystemDistroMINGW    -> "system-use-distro-mingw"
     value <- lookupValueOrError configFile key
     when (value `notElem` ["YES", "NO", ""]) . error $ "Configuration flag "
         ++ quote (key ++ " = " ++ value) ++ " cannot be parsed."

hadrian/src/Rules/Generate.hs

@@ -245,6 +245,7 @@ generateGhcPlatformH = do
     hostOs         <- chooseSetting HostOs        TargetOs
     hostVendor     <- chooseSetting HostVendor    TargetVendor
     ghcUnreg       <- getFlag    GhcUnregisterised
+    inplaceTools   <- getFlag    SystemDistroMINGW
     return . unlines $
         [ "#if !defined(__GHCPLATFORM_H__)"
         , "#define __GHCPLATFORM_H__"
@@ -274,6 +275,8 @@ generateGhcPlatformH = do
         , ""
         ]
         ++
+        [ "#define USE_INPLACE_MINGW_TOOLCHAIN 1" | inplaceTools ]
+        ++
         [ "#define UnregisterisedCompiler 1" | ghcUnreg ]
         ++
         [ ""

includes/ghc.mk

@@ -186,6 +186,9 @@ $$(includes_$1_H_PLATFORM) : includes/ghc.mk includes/Makefile | $$$$(dir $$$$@)
 	@echo "#define BUILD_VENDOR  \"$(BuildVendor_$1_CPP)\""     >> $$@
 	@echo "#define HOST_VENDOR  \"$(HostVendor_$1_CPP)\""       >> $$@
 	@echo                                                       >> $$@
+ifeq "$$(SettingsUseDistroMINGW)" "YES"
+	@echo "#define USE_INPLACE_MINGW_TOOLCHAIN 1"               >> $$@
+endif
 ifeq "$$(GhcUnregisterised)" "YES"
 	@echo "#define UnregisterisedCompiler 1"                    >> $$@
 endif

mk/project.mk.in

@@ -20,8 +20,8 @@
 #
 # The ProjectVersionInt is included in interface files, and GHC
 # checks that it's reading interface generated by the same ProjectVersion
-# as itself. It does this even though interface file syntax may not 
-# change between versions.  Rationale: calling conventions or other 
+# as itself. It does this even though interface file syntax may not
+# change between versions.  Rationale: calling conventions or other
 # random .o-file stuff might change even if the .hi syntax doesn't
 
 ProjectName       = @ProjectName@
@@ -127,6 +127,7 @@ BuildVendor_CPP         = @BuildVendor_CPP@
 # Valid options: YES/NO
 #
 LeadingUnderscore=@LeadingUnderscore@
+SettingsUseDistroMINGW=@SettingsUseDistroMINGW@
 
 # Pin a suffix on executables? If so, what (Windows only).
 exeext0=@exeext_host@