Windows/Clang: Build system adaptation

* Bump win32-tarballs to 0.7
* Move Windows toolchain autoconf logic into separate file
* Use clang and LLVM utilities as described in #21019
* Disable object merging as lld doesn't support -r
* Drop --oformat=pe-bigobj-x86-64 arguments from ld flags as LLD detects
  that the output is large on its own.
* Drop gcc wrapper since Clang finds its root fine on its own.

1 files changed, 21 insertions, 122 deletions

diff --git a/configure.ac b/configure.ac
index 95d0043f59..7f2fb42bc6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -354,111 +354,10 @@ AC_SUBST(TargetHasRTSLinker)
 # Requires FPTOOLS_SET_PLATFORMS_VARS to be run first.
 FP_FIND_ROOT
 
-
-if test "$HostOS" = "mingw32"
-then
-    # Find the mingw-w64 7z file to extract.
-    # NB. If you update the tarballs to a new version of gcc, don't
-    # forget to tweak the paths in driver/gcc/gcc.c.
-    if test "$HostArch" = "i386"
-    then
-        mingw_arch="i686"
-        tarball_dest_dir="mingw-w64/i686"
-        tarball_mingw_dir="mingw32"
-    else
-        mingw_arch="x86_64"
-        tarball_dest_dir="mingw-w64/x86_64"
-        tarball_mingw_dir="mingw64"
-    fi
-fi
-
-set_up_tarballs() {
-    AC_MSG_NOTICE([Checking for Windows toolchain tarballs...])
-    local action
-    if test "$TarballsAutodownload" = "NO"
-    then
-        action="verify"
-    else
-        action="download"
-    fi
-    $PYTHON mk/get-win32-tarballs.py $action $mingw_arch > missing-win32-tarballs
-    case $? in
-        0)
-           rm missing-win32-tarballs
-           ;;
-        2)
-           echo
-           echo "Error:"
-           echo "Needed msys2 tarballs are missing. You have a few options to get them,"
-           echo
-           echo "  * run configure with the --enable-tarballs-autodownload option"
-           echo
-           echo "  * run mk/get-win32-tarballs.py download $mingw_arch"
-           echo
-           echo "  * manually download the files listed in ./missing-win32-tarballs and place"
-           echo "    them in the ghc-tarballs directory."
-           echo
-           exit 1
-           ;;
-        *)
-           echo
-           echo "Error fetching msys2 tarballs; see errors above."
-           exit 1
-           ;;
-    esac
-
-    # Extract all the tarballs in one go
-    if ! test -d inplace/mingw
-    then
-        AC_MSG_NOTICE([Extracting Windows toolchain from archives (may take a while)...])
-        rm -rf inplace/mingw
-        local base_dir="../ghc-tarballs/${tarball_dest_dir}"
-        ( cd inplace &&
-        find "${base_dir}" -name "*.tar.xz" -exec tar --xz -xf {} \; &&
-        find "${base_dir}" -name "*.tar.zst" -exec tar --zstd -xf {} \; &&
-        rm ".MTREE" &&
-        rm ".PKGINFO" &&
-        cd .. ) || AC_MSG_ERROR([Could not extract Windows toolchains.])
-
-        mv "inplace/${tarball_mingw_dir}" inplace/mingw &&
-        touch inplace/mingw
-
-        # NB. Now since the GCC is hardcoded to use /mingw32 we need to
-        # make a wrapper around it to give it the proper paths
-        mv inplace/mingw/bin/gcc.exe inplace/mingw/bin/realgcc.exe
-        PATH=`pwd`/inplace/mingw/bin:$PATH
-        inplace/mingw/bin/realgcc.exe driver/gcc/gcc.c driver/utils/cwrapper.c driver/utils/getLocation.c -Idriver/utils -o inplace/mingw/bin/gcc.exe
-
-        AC_MSG_NOTICE([In-tree MingW-w64 tree created])
-    fi
-}
-
-# See Note [tooldir: How GHC finds mingw on Windows]
-if test "$HostOS" = "mingw32" -a "$EnableDistroToolchain" = "NO"
-then
-    test -d inplace || mkdir inplace
-
-    # NB. Download and extract the MingW-w64 distribution if required
-    set_up_tarballs
-
-    mingwbin="$hardtop/inplace/mingw/bin/"
-    CC="${mingwbin}gcc.exe"
-    LD="${mingwbin}ld.exe"
-    NM="${mingwbin}nm.exe"
-    RANLIB="${mingwbin}ranlib.exe"
-    OBJDUMP="${mingwbin}objdump.exe"
-    MergeObjsCmd="$LD"
-    MergeObjsArgs="-r --oformat=pe-bigobj-x86-64"
-    fp_prog_ar="${mingwbin}ar.exe"
-
-    AC_PATH_PROG([Genlib],[genlib])
-fi
-
-# We don't want to bundle a MinGW-w64 toolchain
-# So we have to find these individual tools.
-# See Note [tooldir: How GHC finds mingw on Windows]
-if test "$EnableDistroToolchain" = "YES"
-then
+# Extract and configure the Windows toolchain
+if test "$HostOS" = "mingw32" -a "$EnableDistroToolchain" = "NO"; then
+    FP_SETUP_WINDOWS_TOOLCHAIN
+else
     # 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.
@@ -471,28 +370,28 @@ then
     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
+        AC_CHECK_TARGET_TOOL([Windres],[windres])
+        AC_CHECK_TARGET_TOOL([DllWrap],[dllwrap])
+        AC_CHECK_TARGET_TOOL([OBJDUMP],[objdump])
 
-HAVE_GENLIB=False
-if test "$HostOS" = "mingw32"
-then
-    if test "$Genlib" != ""; then
-        GenlibCmd="$(cygpath -m $Genlib)"
-        HAVE_GENLIB=True
+        if test "$Genlib" != ""; then
+            GenlibCmd="$(cygpath -m $Genlib)"
+            HAVE_GENLIB=True
+        fi
     fi
 fi
 
-AC_SUBST([DllWrapCmd])
-AC_SUBST([WindresCmd])
-AC_SUBST([GenlibCmd])
-AC_SUBST([HAVE_GENLIB])
+if test "$HostOS" = "mingw32"; then
+    DllWrapCmd="$DllWrap"
+    WindresCmd="$Windres"
+    AC_SUBST([DllWrapCmd])
+    AC_SUBST([WindresCmd])
+    AC_SUBST([GenlibCmd])
+    AC_SUBST([HAVE_GENLIB])
+fi
 
 FP_ICONV
 FP_GMP