XZ package compression

This reduces the size of the package file by about a third.
On a machine with many CPU cores, it reduces the elapsed time to perform
the compression also by about a third.

Author: mplatings

CHANGELOG.md

@@ -13,7 +13,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 - Updated multilib to use LLVM multilib.yaml 1.0 (#250).
 - `*.cfg` files for library variant selection removed in favor of multilib
-- The macOS package is now a .dmg instead of .tar.gz.
+- The macOS package is now a `.dmg` instead of `.tar.gz`.
+- Linux packages are now in `tar.xz` format instead of `tar.gz`.
 
 ### Removed
 

CMakeLists.txt

@@ -313,6 +313,9 @@ set(CPACK_ARCHIVE_COMPONENT_INSTALL TRUE)
 set(CPACK_COMPONENTS_GROUPING ALL_COMPONENTS_IN_ONE)
 # When extracting the files put them in an ArmCompiler-.../ directory.
 set(CPACK_COMPONENT_INCLUDE_TOPLEVEL_DIRECTORY TRUE)
+# Compress package in parallel.
+set(CPACK_THREADS 0 CACHE STRING "")
+
 
 if(CMAKE_OSX_ARCHITECTURES)
     # For universal binaries don't include architecture in the package name.
@@ -1248,8 +1251,8 @@ elseif(CMAKE_OSX_ARCHITECTURES)
     set(cpack_generator DragNDrop)
     set(package_filename_extension ".dmg")
 else()
-    set(cpack_generator TGZ)
-    set(package_filename_extension ".tar.gz")
+    set(cpack_generator TXZ)
+    set(package_filename_extension ".tar.xz")
 endif()
 # CPACK_PACKAGE_FILE_NAME may refer to the source package so use this variable instead.
 set(binary_package_name ${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}-${CPACK_SYSTEM_NAME})

cmake/copy_target_libraries.py

@@ -18,10 +18,10 @@
 def main():
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument(
-        "--distribution-tgz",
+        "--distribution-file",
         required=True,
         help="""Copy from this LLVM Embedded Toolchain for Arm distribution
-        tar.gz file. This is a glob to make things easier on Windows.""",
+        tarfile. This is a glob to make things easier on Windows.""",
     )
     parser.add_argument(
         "--build-dir",
@@ -33,11 +33,11 @@ def main():
     # Find the distribution. This is a glob because scripts may not
     # know the version number and we can't rely on the Windows shell to
     # do it.
-    for distribution_tgz in glob.glob(args.distribution_tgz):
+    for distribution_file in glob.glob(args.distribution_file):
         break
     else:
         raise RuntimeError(
-            f"Distribution glob '{args.distribution_tgz}' not found"
+            f"Distribution glob '{args.distribution_file}' not found"
         )
 
     lib_dir = os.path.join(args.build_dir, "llvm", "lib")
@@ -52,7 +52,7 @@ def main():
         dir=args.build_dir,
     ) as tmp:
         # Extract the distribution package.
-        with tarfile.open(distribution_tgz) as tf:
+        with tarfile.open(distribution_file) as tf:
             tf.extractall(tmp)
 
         # Find the clang-runtimes directory in the extracted package

docs/building-from-source.md

@@ -69,7 +69,7 @@ ninja check-llvm-toolchain
 
 ### Packaging the toolchain
 
-After building, create a zip or tar.gz file as appropriate for the platform:
+After building, create a zip or tar.xz file as appropriate for the platform:
 ```
 ninja package-llvm-toolchain
 ```