Build a static library version of xctest

libXCTest.a can optionally be installed with
 --static-library-install-path

- Put the static libXCTest.a into a static/ subdir when building

- This simplifies linking in static libraries over shared libraries
  when using -static-stdlib during build testing.

Author: spevans

build_script.py

@@ -152,6 +152,7 @@ def build(args):
         """
         swiftc = os.path.abspath(args.swiftc)
         build_dir = os.path.abspath(args.build_dir)
+        static_lib_build_dir = GenericUnixStrategy.static_lib_build_dir(build_dir)
         foundation_build_dir = os.path.abspath(args.foundation_build_dir)
         core_foundation_build_dir = GenericUnixStrategy.core_foundation_build_dir(
             foundation_build_dir, args.foundation_install_prefix)
@@ -206,6 +207,12 @@ def build(args):
                 build_dir=build_dir,
                 foundation_build_dir=foundation_build_dir))
 
+        # Build the static library.
+        run("mkdir -p {static_lib_build_dir}".format(static_lib_build_dir=static_lib_build_dir))
+        run("ar rcs {static_lib_build_dir}/libXCTest.a {build_dir}/XCTest.o".format(
+            static_lib_build_dir=static_lib_build_dir,
+            build_dir=build_dir))
+
         if args.test:
             # Execute main() using the arguments necessary to run the tests.
             main(args=["test",
@@ -217,9 +224,13 @@ def build(args):
         # we also install the built XCTest products.
         if args.module_path is not None and args.lib_path is not None:
             # Execute main() using the arguments necessary for installation.
-            main(args=["install", build_dir,
+            install_args = ["install", build_dir,
                        "--module-install-path", args.module_path,
-                       "--library-install-path", args.lib_path])
+                       "--library-install-path", args.lib_path]
+            if args.static_lib_path:
+                       install_args += ["--static-library-install-path",
+                           args.static_lib_path]
+            main(args=install_args)
 
         note('Done.')
 
@@ -286,6 +297,7 @@ def install(args):
         products into the given module and library paths.
         """
         build_dir = os.path.abspath(args.build_dir)
+        static_lib_build_dir = GenericUnixStrategy.static_lib_build_dir(build_dir)
         module_install_path = os.path.abspath(args.module_install_path)
         library_install_path = os.path.abspath(args.library_install_path)
 
@@ -307,6 +319,14 @@ def install(args):
             os.path.join(build_dir, xctest_swiftdoc),
             os.path.join(module_install_path, xctest_swiftdoc)))
 
+        if args.static_library_install_path:
+               static_library_install_path = os.path.abspath(args.static_library_install_path)
+               _mkdirp(static_library_install_path)
+               xctest_a = "libXCTest.a"
+               run("cp {} {}".format(
+                   os.path.join(static_lib_build_dir, xctest_a),
+                   os.path.join(static_library_install_path, xctest_a)))
+
     @staticmethod
     def core_foundation_build_dir(foundation_build_dir, foundation_install_prefix):
         """
@@ -322,6 +342,16 @@ def core_foundation_build_dir(foundation_build_dir, foundation_install_prefix):
         return os.path.join(foundation_build_dir,
                             foundation_install_prefix.strip("/"), 'lib', 'swift')
 
+    @staticmethod
+    def static_lib_build_dir(build_dir):
+        """
+        Given the path to the build directory, return the path to be used for
+        the static library libXCTest.a. Putting it in a separate directory to
+        libXCTest.so simplifies static linking when building a static test
+        foundation.
+        """
+        return os.path.join(build_dir, "static")
+
 
 def main(args=sys.argv[1:]):
     """
@@ -352,6 +382,7 @@ def main(args=sys.argv[1:]):
                 --build-dir="/tmp/XCTest_build" \\
                 --foundation-build-dir "/swift/usr/lib/swift/linux" \\
                 --library-install-path="/swift/usr/lib/swift/linux" \\
+                --static-library-install-path="/swift/usr/lib/swift_static/linux" \\
                 --module-install-path="/swift/usr/lib/swift/linux/x86_64"
 
             Note that installation is not supported on Darwin as this library
@@ -416,6 +447,11 @@ def main(args=sys.argv[1:]):
         help="Location at which to install XCTest.so. This directory will be "
              "created if it doesn't already exist.",
         dest="lib_path")
+    build_parser.add_argument(
+        "--static-library-install-path",
+        help="Location at which to install XCTest.a. This directory will be "
+             "created if it doesn't already exist.",
+        dest="static_lib_path")
     build_parser.add_argument(
         "--release",
         help="builds for release",
@@ -508,6 +544,10 @@ def main(args=sys.argv[1:]):
         "-l", "--library-install-path",
         help="Location at which to install XCTest.so. This directory will be "
              "created if it doesn't already exist.")
+    install_parser.add_argument(
+        "-s", "--static-library-install-path",
+        help="Location at which to install XCTest.a. This directory will be "
+             "created if it doesn't already exist.")
 
     # Many versions of Python require a subcommand must be specified.
     # We handle this here: if no known subcommand (or none of the help options)