Add libxml2 build product

This patch adds the libxml2 build product as a dependency of building
foundation.

Author: etcwilde

Diff for: utils/build-script-impl

@@ -265,6 +265,7 @@ components=(
   libcxx
   libdispatch
   libicu
+  libxml2
   llbuild
   lldb
   llvm
@@ -1263,6 +1264,7 @@ LIBDISPATCH_STATIC_SOURCE_DIR="${WORKSPACE}/swift-corelibs-libdispatch"
 LIBICU_SOURCE_DIR="${WORKSPACE}/icu"
 LIBCXX_SOURCE_DIR="${WORKSPACE}/llvm-project/libcxx"
 EXPERIMENTAL_STRING_PROCESSING_SOURCE_DIR="${WORKSPACE}/swift-experimental-string-processing"
+LIBXML2_SOURCE_DIR="${WORKSPACE}/libxml2"
 
 # We cannot currently apply the normal rules of skipping here for LLVM. Even if
 # we are skipping building LLVM, we still need to at least build a few tools
@@ -2516,6 +2518,30 @@ for host in "${ALL_HOSTS[@]}"; do
                     LIBICU_BUILD_ARGS=()
                 fi
 
+                if [[ ! "${SKIP_BUILD_LIBXML2}" ]]; then
+                    BASE_INSTALL_DIR="$(get_host_install_destdir ${host})"
+                    LIBXML2_HEADERS="${BASE_INSTALL_DIR}/usr/include/libxml2"
+                    LIBXML2_LIBRARY="${BASE_INSTALL_DIR}/usr/lib/libxml2.a"
+
+                    if [[ -z "${DRY_RUN}" && ! -d "${LIBXML2_HEADERS}" ]]; then
+                        echo "Error: '${LIBXML2_HEADERS}' does not exist" 1>&2
+                        exit 1
+                    fi
+
+                    if [[ -z "${DRY_RUN}" && ! -e "${LIBXML2_LIBRARY}" ]]; then
+                        echo "Error: '${LIBXML2_LIBRARY}' does not exist" 1>&2
+                        exit 1
+                    fi
+
+                    LIBXML2_BUILD_ARGS=(
+                        -DLIBXML2_INCLUDE_DIR:PATH="${LIBXML2_HEADERS}"
+                        -DLIBXML2_LIBRARY:PATH="${LIBXML2_LIBRARY}"
+                        -DLIBXML2_DEFINITIONS="-DLIBXML_STATIC"
+                    )
+                else
+                    LIBXML2_BUILD_ARGS=()
+                fi
+
                 if [[ "${SKIP_CLEAN_FOUNDATION}" == "0" ]]
                 then
                   # The Swift project might have been changed, but CMake might
@@ -2542,6 +2568,8 @@ for host in "${ALL_HOSTS[@]}"; do
 
                   ${LIBICU_BUILD_ARGS[@]}
 
+                  ${LIBXML2_BUILD_ARGS[@]}
+
                   -DFOUNDATION_PATH_TO_LIBDISPATCH_SOURCE=${LIBDISPATCH_SOURCE_DIR}
                   -DFOUNDATION_PATH_TO_LIBDISPATCH_BUILD=$(build_directory ${host} libdispatch)
                   -Ddispatch_DIR=$(build_directory ${host} libdispatch)/cmake/modules

Diff for: utils/build_swift/build_swift/driver_arguments.py

@@ -90,6 +90,9 @@ def _apply_default_arguments(args):
     if args.libicu_build_variant is None:
         args.libicu_build_variant = args.build_variant
 
+    if args.libxml2_build_variant is None:
+        args.libxml2_build_variant = args.build_variant
+
     # Assertions are enabled by default.
     if args.assertions is None:
         args.assertions = True
@@ -709,6 +712,9 @@ def create_argument_parser():
     option('--libicu', toggle_true('build_libicu'),
            help='build libicu')
 
+    option('--static-libxml2', toggle_true('build_libxml2'), default=False,
+           help='build static libxml2')
+
     option('--playgroundsupport', toggle_true('build_playgroundsupport'),
            help='build PlaygroundSupport')
     option('--install-playgroundsupport',
@@ -820,6 +826,11 @@ def create_argument_parser():
            const='Debug',
            help='build the Debug variant of libicu')
 
+    option('--debug-libxml2', store('libxml2_build_variant'),
+           const='Debug',
+           help='build the Debug variant of libxml2')
+
+
     # -------------------------------------------------------------------------
     # Assertions group
 
@@ -1252,6 +1263,8 @@ def create_argument_parser():
            help='skip building llvm')
     option('--skip-build-swift', toggle_false('build_swift'),
            help='skip building swift')
+    option('--skip-build-libxml2', toggle_false('build_libxml2'),
+           help='skip building libxml2')
 
     # We need to list --skip-test-swift explicitly because otherwise argparse
     # will auto-expand arguments like --skip-test-swift to the only known
@@ -1330,6 +1343,7 @@ def create_argument_parser():
                      /swift-corelibs-foundation  (optional)
                      /swift-corelibs-libdispatch (optional)
                      /icu                        (optional)
+                     /libxml2                    (optional)
 
 SWIFT_BUILD_ROOT: a directory in which to create out-of-tree builds.
                   Defaults to "$SWIFT_SOURCE_ROOT/build/".

Diff for: utils/build_swift/tests/expected_options.py

@@ -66,6 +66,7 @@
     'build_jobs': multiprocessing.cpu_count(),
     'build_libdispatch': False,
     'build_libicu': False,
+    'build_libxml2': False,
     'build_linux': True,
     'build_llbuild': False,
     'build_lldb': False,
@@ -181,6 +182,7 @@
     'legacy_impl': False,
     'libdispatch_build_variant': 'Debug',
     'libicu_build_variant': 'Debug',
+    'libxml2_build_variant': 'Debug',
     'bootstrapping_mode': None,
     'lit_args': '-sv',
     'llbuild_assertions': True,
@@ -429,6 +431,7 @@ class BuildScriptImplOption(_BaseOption):
     SetOption('--debug-libdispatch',
               dest='libdispatch_build_variant', value='Debug'),
     SetOption('--debug-libicu', dest='libicu_build_variant', value='Debug'),
+    SetOption('--debug-libxml2', dest='libxml2_build_variant', value='Debug'),
     SetOption('--debug-lldb', dest='lldb_build_variant', value='Debug'),
     SetOption('--lldb-build-with-xcode', dest='lldb_build_with_xcode',
               value='1'),
@@ -560,6 +563,7 @@ class BuildScriptImplOption(_BaseOption):
     EnableOption('--only-non-executable-test'),
     EnableOption('--libdispatch', dest='build_libdispatch'),
     EnableOption('--libicu', dest='build_libicu'),
+    EnableOption('--static-libxml2', dest='build_libxml2'),
     EnableOption('--indexstore-db', dest='build_indexstoredb'),
     EnableOption('--test-indexstore-db-sanitize-all',
                  dest='test_indexstoredb_sanitize_all'),
@@ -663,6 +667,7 @@ class BuildScriptImplOption(_BaseOption):
                   dest='test_swift_inspect'),
     DisableOption('--skip-build-clang-tools-extra',
                   dest='build_clang_tools_extra'),
+    DisableOption('--skip-build-libxml2', dest='build_libxml2'),
 
     ChoicesOption('--compiler-vendor',
                   choices=['none', 'apple']),

Diff for: utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -254,7 +254,8 @@ def convert_to_impl_arguments(self):
             (args.build_llbuild, "llbuild"),
             (args.build_libcxx, "libcxx"),
             (args.build_libdispatch, "libdispatch"),
-            (args.build_libicu, "libicu")
+            (args.build_libicu, "libicu"),
+            (args.build_libxml2, 'libxml2')
         ]
         for (should_build, string_name) in conditional_subproject_configs:
             if not should_build and not self.args.infer_dependencies:
@@ -541,6 +542,9 @@ def compute_product_pipelines(self):
         builder.add_product(products.CMark,
                             is_enabled=self.args.build_cmark)
 
+        builder.add_product(products.LibXML2,
+                            is_enabled=self.args.build_libxml2)
+
         # Begin a build-script-impl pipeline for handling the compiler toolchain
         # and a subset of the tools that we build. We build these in this manner
         # to preserve current build-script-impl run behavior as we transition

Diff for: utils/swift_build_support/swift_build_support/products/__init__.py

@@ -19,6 +19,7 @@
 from .libcxx import LibCXX
 from .libdispatch import LibDispatch
 from .libicu import LibICU
+from .libxml2 import LibXML2
 from .llbuild import LLBuild
 from .lldb import LLDB
 from .llvm import LLVM
@@ -46,6 +47,7 @@
     'LibCXX',
     'LibDispatch',
     'LibICU',
+    'LibXML2',
     'LLBuild',
     'LLDB',
     'LLVM',

Diff for: utils/swift_build_support/swift_build_support/products/foundation.py

@@ -14,6 +14,7 @@
 from . import libcxx
 from . import libdispatch
 from . import libicu
+from . import libxml2
 from . import llvm
 from . import product
 from . import swift
@@ -51,7 +52,8 @@ def get_dependencies(cls):
                 libcxx.LibCXX,
                 libicu.LibICU,
                 swift.Swift,
-                libdispatch.LibDispatch]
+                libdispatch.LibDispatch,
+                libxml2.LibXML2]
 
     @classmethod
     def is_nondarwin_only_build_product(cls):

Diff for: utils/swift_build_support/swift_build_support/products/libxml2.py

@@ -0,0 +1,102 @@
+# swift_build_support/products/libxml2.py ------------------------------------
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https://swift.org/LICENSE.txt for license information
+# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ----------------------------------------------------------------------------
+
+from . import cmake_product
+from . import earlyswiftdriver
+
+
+class LibXML2(cmake_product.CMakeProduct):
+    @classmethod
+    def is_build_script_impl_product(cls):
+        """is_build_script_impl_product -> bool
+
+        Whether this product is produced by build-script-impl
+        """
+        return False
+
+    @classmethod
+    def is_before_build_script_impl_product(cls):
+        """is_before_build_script_impl_product -> bool
+
+        Whether this product is built before any build-script-impl products
+        """
+        return True
+
+    @classmethod
+    def is_nondarwin_only_build_product(cls):
+        return True
+
+    @classmethod
+    def get_dependencies(cls):
+        return [earlyswiftdriver.EarlySwiftDriver]
+
+    def should_build(self, host_target):
+        """should_build() -> Bool
+
+        Return True if libxml2 should be built
+        """
+        return self.args.build_libxml2
+
+    def should_test(self, host_target):
+        """should_test() -> Bool
+
+        Returns True if libxml2 should be tested.
+        Currently is set to false
+        """
+        return False
+
+    def should_install(self, host_target):
+        """should_install() -> Bool
+
+        Returns True if we're building libxml2
+        """
+        return self.args.build_libxml2
+
+    def install(self, host_target):
+        """
+        Install libxml2 to the target location
+        """
+        path = self.host_install_destdir(host_target)
+        self.install_with_cmake(['install'], path)
+
+    def build(self, host_target):
+        self.cmake_options.define('BUILD_SHARED_LIBS', 'NO')
+        self.cmake_options.define('CMAKE_POSITION_INDEPENDENT_CODE', 'YES')
+
+        if self.args.libxml2_build_variant is None:
+            self.args.libxml2_build_variant = "Release"
+        self.cmake_options.define('CMAKE_BUILD_TYPE:STRING',
+                                  self.args.libxml2_build_variant)
+        self.cmake_options.define('CMAKE_INSTALL_PREFIX', '/usr')
+        self.cmake_options.define('LIBXML2_WITH_THREADS', 'YES')
+        self.cmake_options.define('LIBXML2_WITH_ICONV', 'NO')
+        self.cmake_options.define('LIBXML2_WITH_ICU', 'NO')
+        self.cmake_options.define('LIBXML2_WITH_LZMA', 'NO')
+        self.cmake_options.define('LIBXML2_WITH_PYTHON', 'NO')
+        self.cmake_options.define('LIBXML2_WITH_TESTS', 'NO')
+        self.cmake_options.define('LIBXML2_WITH_ZLIB', 'NO')
+
+        (platform, arch) = host_target.split('-')
+        common_c_flags = ' '.join(self.common_cross_c_flags(platform, arch))
+        self.cmake_options.define('CMAKE_C_FLAGS', common_c_flags)
+        self.cmake_options.define('CMAKE_CXX_FLAGS', common_c_flags)
+
+        if host_target.startswith("macosx") or \
+           host_target.startswith("iphone") or \
+           host_target.startswith("appletv") or \
+           host_target.startswith("watch"):
+            toolchain_file = self.generate_darwin_toolchain_file(platform, arch)
+            self.cmake_options.define('CMAKE_TOOLCHAIN_FILE:PATH', toolchain_file)
+        elif platform == "linux":
+            toolchain_file = self.generate_linux_toolchain_file(platform, arch)
+            self.cmake_options.define('CMAKE_TOOLCHAIN_FILE:PATH', toolchain_file)
+        self.build_with_cmake(["LibXml2"], self.args.libxml2_build_variant, [])