Fix the build-script --skip-build option.

utils/build-script

@@ -464,9 +464,7 @@ class BuildScriptInvocation(object):
             ]
 
         if args.skip_build:
-            impl_args += ["--skip-build-cmark",
-                          "--skip-build-llvm",
-                          "--skip-build-swift"]
+            impl_args += ["--skip-build"]
         if not args.build_benchmarks:
             impl_args += ["--skip-build-benchmarks"]
         # Currently we do not build external benchmarks by default.

utils/build-script-impl

@@ -30,12 +30,13 @@ umask 0022
 # A default value of "" indicates that the corresponding variable
 # will remain unset unless set explicitly.
 #
-# skip-* parameters do not affect the configuration (CMake parameters).
-# You can turn them on and off in different invocations of the script for the
-# same build directory.
+# The --skip-build parameter, with no product name, does not affect the
+# configuration (CMake parameters). You can turn this option on and
+# off in different invocations of the script for the same build
+# directory without affecting configutation.
 #
-# build-* parameters affect the CMake configuration (enable/disable those
-# components).
+# skip-build-* and build-* parameters affect the CMake configuration
+# (enable/disable those components).
 #
 # Each variable name is re-exported into this script in uppercase, where dashes
 # are substituted by underscores. For example, `swift-install-components` is
@@ -118,6 +119,7 @@ KNOWN_SETTINGS=(
     swift-stdlib-build-type                       "Debug"           "the CMake build variant for Swift"
 
     ## Skip Build ...
+    skip-build                                    ""                "set to configure as usual while skipping the build step"
     skip-build-android                            ""                "set to skip building Swift stdlibs for Android"
     skip-build-benchmarks                         ""                "set to skip building Swift Benchmark Suite"
     skip-build-clang-tools-extra                  ""                "set to skip building clang-tools-extra as part of llvm"
@@ -1041,13 +1043,10 @@ if [[ ! "${SKIP_BUILD_PLAYGROUNDSUPPORT}" && ! -d ${PLAYGROUNDSUPPORT_SOURCE_DIR
     exit 1
 fi
 
-# 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 several tools
-# that swift relies on for building and testing. See the LLVM configure rules.
-PRODUCTS=(llvm)
 [[ "${SKIP_BUILD_CMARK}" ]] || PRODUCTS+=(cmark)
 [[ "${SKIP_BUILD_LIBCXX}" ]] || PRODUCTS+=(libcxx)
 [[ "${SKIP_BUILD_LIBICU}" ]] || PRODUCTS+=(libicu)
+[[ "${SKIP_BUILD_LLVM}" ]] || PRODUCTS+=(llvm)
 [[ "${SKIP_BUILD_SWIFT}" ]] || PRODUCTS+=(swift)
 [[ "${SKIP_BUILD_LLDB}" ]] || PRODUCTS+=(lldb)
 [[ "${SKIP_BUILD_LIBDISPATCH}" ]] || PRODUCTS+=(libdispatch)
@@ -1406,7 +1405,6 @@ for host in "${ALL_HOSTS[@]}"; do
     for product in "${PRODUCTS[@]}"; do
         [[ $(should_execute_action "${host}-${product/_static}-build") ]] || continue
 
-        unset skip_build
         source_dir_var="$(toupper ${product})_SOURCE_DIR"
         source_dir=${!source_dir_var}
         build_dir=$(build_directory ${host} ${product})
@@ -1436,7 +1434,7 @@ for host in "${ALL_HOSTS[@]}"; do
                 if [ "${BUILD_LLVM}" == "0" ] ; then
                     build_targets=(clean)
                 fi
-                if [ "${SKIP_BUILD_LLVM}" ] ; then
+                if [ "${SKIP_BUILD}" ] ; then
                     # We can't skip the build completely because the standalone
                     # build of Swift depend on these for building and testing.
                     build_targets=(llvm-tblgen clang-resource-headers intrinsics_gen clang-tablegen-targets)
@@ -2207,18 +2205,25 @@ for host in "${ALL_HOSTS[@]}"; do
         fi
 
         # Build.
-        if [[ "${CMAKE_GENERATOR}" == "Xcode" ]] ; then
-            # Xcode generator uses "ALL_BUILD" instead of "all".
-            # Also, xcodebuild uses -target instead of bare names.
-            build_targets=("${build_targets[@]/all/ALL_BUILD}")
-            build_targets=("${build_targets[@]/#/${BUILD_TARGET_FLAG} }")
-
-            # Xcode can't restart itself if it turns out we need to reconfigure.
-            # Do an advance build to handle that.
-            call "${CMAKE_BUILD[@]}" "${build_dir}" $(cmake_config_opt ${product})
-        fi
+        #
+        # Even if builds are skipped, Swift configuration relies on
+        # some LLVM tools like TableGen. In the LLVM configure rules
+        # above, a small subset of LLVM build_targets are selected
+        # when SKIP_BUILD is set.
+        if [[ $(not ${SKIP_BUILD}) || "${product}" == "llvm" ]]; then
+            if [[ "${CMAKE_GENERATOR}" == "Xcode" ]] ; then
+                # Xcode generator uses "ALL_BUILD" instead of "all".
+                # Also, xcodebuild uses -target instead of bare names.
+                build_targets=("${build_targets[@]/all/ALL_BUILD}")
+                build_targets=("${build_targets[@]/#/${BUILD_TARGET_FLAG} }")
+
+                # Xcode can't restart itself if it turns out we need to reconfigure.
+                # Do an advance build to handle that.
+                call "${CMAKE_BUILD[@]}" "${build_dir}" $(cmake_config_opt ${product})
+            fi
 
-        call "${CMAKE_BUILD[@]}" "${build_dir}" $(cmake_config_opt ${product}) -- "${BUILD_ARGS[@]}" ${build_targets[@]}
+            call "${CMAKE_BUILD[@]}" "${build_dir}" $(cmake_config_opt ${product}) -- "${BUILD_ARGS[@]}" ${build_targets[@]}
+        fi
 
         # When we are building LLVM copy over the compiler-rt
         # builtins for iOS/tvOS/watchOS to ensure that Swift's

utils/build_swift/build_swift/driver_arguments.py

@@ -131,29 +131,6 @@ def _apply_default_arguments(args):
         raise ValueError('error: --watchos-all is unavailable in open-source '
                          'Swift.\nUse --watchos to skip watchOS device tests.')
 
-    # Propagate global --skip-build
-    if args.skip_build:
-        args.build_linux = False
-        args.build_freebsd = False
-        args.build_cygwin = False
-        args.build_osx = False
-        args.build_ios = False
-        args.build_tvos = False
-        args.build_watchos = False
-        args.build_android = False
-        args.build_benchmarks = False
-        args.build_external_benchmarks = False
-        args.build_lldb = False
-        args.build_llbuild = False
-        args.build_libcxx = False
-        args.build_swiftpm = False
-        args.build_xctest = False
-        args.build_foundation = False
-        args.build_libdispatch = False
-        args.build_libicu = False
-        args.build_playgroundsupport = False
-        args.build_pythonkit = False
-
     # --skip-{ios,tvos,watchos} or --skip-build-{ios,tvos,watchos} are
     # merely shorthands for --skip-build-{**os}-{device,simulator}
     if not args.ios or not args.build_ios:

utils/build_swift/tests/build_swift/test_driver_arguments.py

@@ -540,30 +540,6 @@ def test_implied_defaults_build_variant(self):
         self.assertEqual(namespace.swift_build_variant, 'Debug')
         self.assertEqual(namespace.swift_stdlib_build_variant, 'Debug')
 
-    def test_implied_defaults_skip_build(self):
-        namespace = self.parse_default_args(['--skip-build'])
-
-        self.assertFalse(namespace.build_benchmarks)
-
-        self.assertFalse(namespace.build_linux)
-        self.assertFalse(namespace.build_android)
-        self.assertFalse(namespace.build_freebsd)
-        self.assertFalse(namespace.build_cygwin)
-        self.assertFalse(namespace.build_osx)
-        self.assertFalse(namespace.build_ios)
-        self.assertFalse(namespace.build_tvos)
-        self.assertFalse(namespace.build_watchos)
-
-        self.assertFalse(namespace.build_foundation)
-        self.assertFalse(namespace.build_libdispatch)
-        self.assertFalse(namespace.build_libicu)
-        self.assertFalse(namespace.build_lldb)
-        self.assertFalse(namespace.build_llbuild)
-        self.assertFalse(namespace.build_libcxx)
-        self.assertFalse(namespace.build_playgroundsupport)
-        self.assertFalse(namespace.build_swiftpm)
-        self.assertFalse(namespace.build_xctest)
-
     def test_implied_defaults_skip_build_ios(self):
         namespace = self.parse_default_args(['--skip-build-ios'])
         self.assertFalse(namespace.build_ios_device)