make-windows-release: support cross-compiling for ARM64 in MSYS2

Cross-compiling for ARM64 is not possible with MSYS2 CLANGARM64 out of
the box, but it is possible to do by downloading and using a prebuilt
toolchain from https://github.com/mstorsjo/llvm-mingw.  Make the
'make-windows-release' script support doing this.

Suggested at https://wimlib.net/forums/viewtopic.php?p=1488#p1488

diff --git a/README.WINDOWS b/README.WINDOWS
index 14fc0d284e05e0de52ae92a3534de72c2e060892..200271869b259456016a6d1cb104a9d19e69bbd3 100644 (file)
--- a/README.WINDOWS
+++ b/README.WINDOWS
@@ -121,16 +121,16 @@ one of the following from the Start menu:
   * "MSYS2 CLANG64" - for x86_64 binaries, built with clang
   * "MSYS2 MINGW32" - for i686 binaries, built with gcc
   * "MSYS2 CLANG32" - for i686 binaries, built with clang
-  * "MSYS2 CLANGARM64" - for ARM64 binaries (EXPERIMENTAL, needs Windows ARM64)
+  * "MSYS2 CLANGARM64" - for ARM64 binaries (EXPERIMENTAL)
 
 (If unsure, use "MSYS2 MINGW64".)  Then run the following commands:
 
     cd wimlib
-    tools/make-windows-release --install-msys2-packages
+    tools/make-windows-release --install-prerequisites
 
-The script will automatically download and install the MSYS2 packages needed to
-build wimlib in the chosen MSYS2 environment, then build wimlib.  The output
-will be in a folder named similarly to "wimlib-1.14.0-windows-x86_64-bin".  Note
-that your "home" folder within MSYS2 is C:\msys64\home\%USERNAME% by default.
+The script will automatically download and install the packages needed to build
+wimlib in the chosen MSYS2 environment, then build wimlib.  The output will be
+in a folder named similarly to "wimlib-1.14.0-windows-x86_64-bin".  Note that
+your "home" folder within MSYS2 is C:\msys64\home\%USERNAME% by default.
 Therefore, the full path to the output folder will be similar to
 C:\msys64\home\%USERNAME%\wimlib\wimlib-1.14.0-windows-x86_64-bin.

diff --git a/tools/make-windows-release b/tools/make-windows-release
index 501d2eef62a5eacaf4d085751097b34daeee8d14..72f7608b8daf33469b89d73ca65b4209e55913e4 100755 (executable)
--- a/tools/make-windows-release
+++ b/tools/make-windows-release
@@ -13,7 +13,7 @@ ARCH=
 DESTDIR=
 EXTRA_CONFIGURE_ARGS=
 INCLUDE_DOCS=false
-INSTALL_MSYS2_PACKAGES=false
+INSTALL_PREREQUISITES=false
 MAKE="make -j$(getconf _NPROCESSORS_ONLN)"
 MSYSTEM=${MSYSTEM:-}
 SKIP_CONFIGURE=false
@@ -21,6 +21,12 @@ VERSION=$(tools/get-version-number)
 ZIP=false
 ZIPFILE=
 
+PREBUILT_LLVM_MINGW_ENABLED=false
+PREBUILT_LLVM_MINGW_URL=https://github.com/mstorsjo/llvm-mingw/releases/download/20230320/llvm-mingw-20230320-msvcrt-x86_64.zip
+PREBUILT_LLVM_MINGW_ZIP=$(basename "$PREBUILT_LLVM_MINGW_URL")
+PREBUILT_LLVM_MINGW=${PREBUILT_LLVM_MINGW_ZIP%.zip}
+PREBUILT_LLVM_MINGW_BIN="/$PREBUILT_LLVM_MINGW/bin"
+
 usage()
 {
        cat << EOF
@@ -31,9 +37,12 @@ Options:
 
   --include-docs            Build and install the PDF manual pages.
 
-  --install-msys2-packages  Install the MSYS2 packages needed to build wimlib.
-                            You can omit this if you have already done this for
-                            the same MSYS2 environment.
+  --install-prerequisites   Install the prerequisite packages needed to build
+                            wimlib.  This is only supported in MSYS2.  You can
+                            omit this if you have already done this for the same
+                            MSYS2 environment.  This option normally only
+                            installs MSYS2 packages, but for ARM64 cross-builds
+                            it also installs a separate prebuilt toolchain.
 
   --skip-configure          Skip running the configure script again.  You can
                             use this to save time in incremental builds if you
@@ -67,7 +76,14 @@ parse_options()
                        ;;
                CLANGARM64)
                        ARCH=aarch64
-                       CC_PKG=mingw-w64-clang-aarch64-clang
+                       # MSYS2 doesn't yet support cross-compiling for ARM64,
+                       # so use a separate prebuilt toolchain for that case.
+                       if [ "$(uname -m)" = x86_64 ]; then
+                               PREBUILT_LLVM_MINGW_ENABLED=true
+                               export PATH="$PREBUILT_LLVM_MINGW_BIN:$PATH"
+                       else
+                               CC_PKG=mingw-w64-clang-aarch64-clang
+                       fi
                        ;;
                *)
                        echo 1>&2 "Unsupported MSYS2 environment: $MSYSTEM.  This script supports"
@@ -80,7 +96,7 @@ parse_options()
        local longopts="help"
        longopts+=",arch:"
        longopts+=",include-docs"
-       longopts+=",install-msys2-packages"
+       longopts+=",install-prerequisites"
        longopts+=",skip-configure"
        longopts+=",zip"
 
@@ -103,12 +119,12 @@ parse_options()
                --include-docs)
                        INCLUDE_DOCS=true
                        ;;
-               --install-msys2-packages)
+               --install-prerequisites)
                        if [ -z "$MSYSTEM" ]; then
-                               echo 1>&2 "--install-msys2-packages is not allowed outside MSYS2."
+                               echo 1>&2 "--install-prerequisites is only supported in MSYS2."
                                exit 1
                        fi
-                       INSTALL_MSYS2_PACKAGES=true
+                       INSTALL_PREREQUISITES=true
                        ;;
                --skip-configure)
                        SKIP_CONFIGURE=true
@@ -141,18 +157,39 @@ parse_options()
        EXTRA_CONFIGURE_ARGS=("$@")
 }
 
-install_msys2_packages()
+install_prebuilt_llvm_mingw()
+{
+       if [ -e "$PREBUILT_LLVM_MINGW_BIN" ]; then
+               echo "Prebuilt $PREBUILT_LLVM_MINGW is already installed"
+               return
+       fi
+       echo "Downloading $PREBUILT_LLVM_MINGW_ZIP..."
+       wget "$PREBUILT_LLVM_MINGW_URL" -O "/$PREBUILT_LLVM_MINGW_ZIP"
+       echo "Unzipping $PREBUILT_LLVM_MINGW_ZIP..."
+       unzip "/$PREBUILT_LLVM_MINGW_ZIP" -d /
+       if [ ! -e "$PREBUILT_LLVM_MINGW_BIN" ]; then
+               echo 1>&2 "$PREBUILT_LLVM_MINGW_BIN not found after unzip"
+               exit 1
+       fi
+       echo "Done installing prebuilt toolchain $PREBUILT_LLVM_MINGW"
+}
+
+install_prerequisites()
 {
        echo "Installing the MSYS2 $MSYSTEM packages needed to build wimlib..."
-       pacman -Syu --noconfirm --needed \
-               autoconf \
-               automake \
-               git \
-               libtool \
-               make \
-               "$CC_PKG" \
-               pkgconf
+       local packages=(autoconf automake git libtool make pkgconf)
+       if "$PREBUILT_LLVM_MINGW_ENABLED"; then
+               echo "Will use prebuilt toolchain instead of MSYS2 one"
+               packages+=(wget unzip)
+       else
+               packages+=("$CC_PKG")
+       fi
+       pacman -Syu --noconfirm --needed "${packages[@]}"
        echo "Done installing the MSYS2 $MSYSTEM packages needed to build wimlib."
+
+       if $PREBUILT_LLVM_MINGW_ENABLED; then
+               install_prebuilt_llvm_mingw
+       fi
 }
 
 bootstrap_repository()
@@ -169,8 +206,12 @@ configure_wimlib()
        # -static-libgcc is needed with gcc.  It should go in the CFLAGS, but
        # libtool strips it, so it must go directly in CC instead.  See
        # http://www.gnu.org/software/libtool/manual/libtool.html#Stripped-link-flags
-       if "${ARCH}-w64-mingw32-cc" --version | grep -q '(GCC)'; then
-               configure_args+=("CC=${ARCH}-w64-mingw32-cc -static-libgcc")
+       local cc="${ARCH}-w64-mingw32-cc"
+       if ! type -P "$cc" &>/dev/null; then
+               cc="${ARCH}-w64-mingw32-gcc"
+       fi
+       if "$cc" --version | grep -q '(GCC)'; then
+               configure_args+=("CC=$cc -static-libgcc")
        fi
        configure_args+=("${EXTRA_CONFIGURE_ARGS[@]}")
        ./configure "${configure_args[@]}"
@@ -272,8 +313,8 @@ create_zip_file()
 parse_options "$@"
 rm -rf -- "$DESTDIR" "$ZIPFILE"
 mkdir -- "$DESTDIR"
-if $INSTALL_MSYS2_PACKAGES; then
-       install_msys2_packages
+if $INSTALL_PREREQUISITES; then
+       install_prerequisites
 fi
 if [ ! -e configure ]; then
        bootstrap_repository