[build] Add flags to allow skipping rebuilding the corelibs

Add three new flags, '--skip-clean-libdispatch', '--skip-clean-foundation', and
'--skip-clean-xctest', that leave the previous builds of those products in place.

Author: finagolfin

utils/build-script-impl

@@ -152,6 +152,11 @@ KNOWN_SETTINGS=(
     build-swift-stdlib-unittest-extra             "0"               "set to 1 to build optional StdlibUnittest components"
     build-swift-tools                             "1"               "set to 1 to build Swift host tools"
 
+    ## Skip cleaning build directories ...
+    skip-clean-libdispatch                        "0"               "skip cleaning the libdispatch build"
+    skip-clean-foundation                         "0"               "skip cleaning the foundation build"
+    skip-clean-xctest                             "0"               "skip cleaning the xctest build"
+
     ## Test Options
     llvm-include-tests                            "1"               "Set to true to generate testing targets for LLVM. Set to true by default."
     long-test                                     "0"               "set to run the long test suite"
@@ -2309,6 +2314,14 @@ for host in "${ALL_HOSTS[@]}"; do
                 FOUNDATION_BUILD_DIR=$(build_directory ${host} foundation)
                 SWIFT_BUILD_DIR=$(build_directory ${host} swift)
 
+                if [[ "${SKIP_CLEAN_XCTEST}" == "0" ]]
+                then
+                  # The Swift project might have been changed, but CMake might
+                  # not be aware and will not rebuild.
+                  echo "Cleaning the XCTest build directory"
+                  call rm -rf "${XCTEST_BUILD_DIR}"
+                fi
+
                 case "${host}" in
                 macosx-*)
                   # Staging: require opt-in for building with dispatch
@@ -2336,12 +2349,6 @@ for host in "${ALL_HOSTS[@]}"; do
                   continue
                 ;;
                 *)
-                  # FIXME: Always re-build XCTest on non-darwin platforms.
-                  # The Swift project might have been changed, but CMake might
-                  # not be aware and will not rebuild.
-                  echo "Cleaning the XCTest build directory"
-                  call rm -rf "${XCTEST_BUILD_DIR}"
-
                   cmake_options=(
                     ${cmake_options[@]}
                     -DCMAKE_BUILD_TYPE:STRING="${XCTEST_BUILD_TYPE}"
@@ -2401,11 +2408,13 @@ for host in "${ALL_HOSTS[@]}"; do
                     LIBICU_BUILD_ARGS=()
                 fi
 
-                # FIXME: Always re-build XCTest on non-darwin platforms.
-                # The Swift project might have been changed, but CMake might
-                # not be aware and will not rebuild.
-                echo "Cleaning the Foundation build directory"
-                call rm -rf "${build_dir}"
+                if [[ "${SKIP_CLEAN_FOUNDATION}" == "0" ]]
+                then
+                  # The Swift project might have been changed, but CMake might
+                  # not be aware and will not rebuild.
+                  echo "Cleaning the Foundation build directory"
+                  call rm -rf "${build_dir}"
+                fi
 
                 # Set the PKG_CONFIG_PATH so that core-foundation can find the libraries and
                 # header files
@@ -2466,11 +2475,13 @@ for host in "${ALL_HOSTS[@]}"; do
                   exit 1
                 ;;
                 *)
-                  # FIXME: Always re-build XCTest on non-darwin platforms.
-                  # The Swift project might have been changed, but CMake might
-                  # not be aware and will not rebuild.
-                  echo "Cleaning the libdispatch build directory"
-                  call rm -rf "${LIBDISPATCH_BUILD_DIR}"
+                  if [[ "${SKIP_CLEAN_LIBDISPATCH}" == "0" ]]
+                  then
+                    # The Swift project might have been changed, but CMake might
+                    # not be aware and will not rebuild.
+                    echo "Cleaning the libdispatch build directory"
+                    call rm -rf "${LIBDISPATCH_BUILD_DIR}"
+                  fi
 
                   cmake_options=(
                     -DENABLE_SWIFT=YES

utils/build_swift/build_swift/driver_arguments.py

@@ -1059,6 +1059,12 @@ def create_argument_parser():
            toggle_false('test_android_host'),
            help='skip testing Android device targets on the host machine (the '
                 'phone itself)')
+    option('--skip-clean-libdispatch', toggle_false('clean_libdispatch'),
+           help='skip cleaning up libdispatch')
+    option('--skip-clean-foundation', toggle_false('clean_foundation'),
+           help='skip cleaning up foundation')
+    option('--skip-clean-xctest', toggle_false('clean_xctest'),
+           help='skip cleaning up xctest')
     option('--skip-clean-llbuild', toggle_false('clean_llbuild'),
            help='skip cleaning up llbuild')
     option('--clean-early-swift-driver', toggle_true('clean_early_swift_driver'),

utils/build_swift/tests/expected_options.py

@@ -218,6 +218,9 @@
         defaults.SWIFT_MAX_PARALLEL_LTO_LINK_JOBS,
     'swift_user_visible_version': defaults.SWIFT_USER_VISIBLE_VERSION,
     'symbols_package': None,
+    'clean_libdispatch': True,
+    'clean_foundation': True,
+    'clean_xctest': True,
     'clean_llbuild': True,
     'clean_swiftpm': True,
     'clean_swift_driver': True,
@@ -594,6 +597,9 @@ class BuildScriptImplOption(_BaseOption):
                   dest='build_watchos_device'),
     DisableOption('--skip-build-watchos-simulator',
                   dest='build_watchos_simulator'),
+    DisableOption('--skip-clean-libdispatch', dest='clean_libdispatch'),
+    DisableOption('--skip-clean-foundation', dest='clean_foundation'),
+    DisableOption('--skip-clean-xctest', dest='clean_xctest'),
     DisableOption('--skip-clean-llbuild', dest='clean_llbuild'),
     DisableOption('--skip-early-swift-driver', dest='build_early_swift_driver'),
     DisableOption('--skip-clean-swiftpm', dest='clean_swiftpm'),

utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -420,6 +420,21 @@ def convert_to_impl_arguments(self):
                 "--llvm-install-components=%s" % args.llvm_install_components
             ]
 
+        if not args.clean_libdispatch:
+            impl_args += [
+                "--skip-clean-libdispatch"
+            ]
+
+        if not args.clean_foundation:
+            impl_args += [
+                "--skip-clean-foundation"
+            ]
+
+        if not args.clean_xctest:
+            impl_args += [
+                "--skip-clean-xctest"
+            ]
+
         if not args.clean_llbuild:
             impl_args += [
                 "--skip-clean-llbuild"

validation-test/BuildSystem/skip_clean_corelibs.test

@@ -0,0 +1,23 @@
+# REQUIRES: standalone_build
+# UNSUPPORTED: OS=macosx
+# UNSUPPORTED: OS=ios
+# UNSUPPORTED: OS=tvos
+# UNSUPPORTED: OS=watchos
+
+# RUN: %empty-directory(%t)
+# RUN: mkdir -p %t
+# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --foundation --cmake %cmake  2>&1 | %FileCheck --check-prefix=CLEAN-CORELIBS-CHECK %s
+
+# RUN: %empty-directory(%t)
+# RUN: mkdir -p %t
+# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --foundation --skip-clean-libdispatch --skip-clean-foundation --cmake %cmake  2>&1 | %FileCheck --check-prefix=SKIP-CLEAN-CORELIBS-CHECK %s
+
+# CLEAN-CORELIBS-CHECK: Cleaning the libdispatch build directory
+# CLEAN-CORELIBS-CHECK-NEXT: rm -rf
+# CLEAN-CORELIBS-CHECK: Cleaning the Foundation build directory
+# CLEAN-CORELIBS-CHECK-NEXT: rm -rf
+
+# SKIP-CLEAN-CORELIBS-CHECK-NOT: Cleaning the libdispatch build directory
+# SKIP-CLEAN-CORELIBS-CHECK-NOT: rm -rf {{.*/libdispatch-[^/]*}}
+# SKIP-CLEAN-CORELIBS-CHECK-NOT: Cleaning the Foundation build directory
+# SKIP-CLEAN-CORELIBS-CHECK-NOT: rm -rf {{.*/foundation-[^/]*}}

validation-test/BuildSystem/skip_clean_llbuild.test renamed to validation-test/BuildSystem/skip_clean_xctest_llbuild.test

@@ -2,14 +2,18 @@
 
 # RUN: %empty-directory(%t)
 # RUN: mkdir -p %t
-# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --llbuild --cmake %cmake  2>&1 | %FileCheck --check-prefix=CLEAN-LLBUILD-CHECK %s
+# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --xctest --llbuild --cmake %cmake  2>&1 | %FileCheck --check-prefix=CLEAN-LLBUILD-CHECK %s
 
 # RUN: %empty-directory(%t)
 # RUN: mkdir -p %t
-# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --llbuild --skip-clean-llbuild --cmake %cmake  2>&1 | %FileCheck --check-prefix=SKIP-CLEAN-LLBUILD-CHECK %s
+# RUN: SWIFT_BUILD_ROOT=%t %swift_src_root/utils/build-script --dry-run --xctest --llbuild --skip-clean-xctest --skip-clean-llbuild --cmake %cmake  2>&1 | %FileCheck --check-prefix=SKIP-CLEAN-LLBUILD-CHECK %s
 
+# CLEAN-LLBUILD-CHECK: Cleaning the XCTest build directory
+# CLEAN-LLBUILD-CHECK-NEXT: rm -rf
 # CLEAN-LLBUILD-CHECK: Cleaning the llbuild build directory
 # CLEAN-LLBUILD-CHECK-NEXT: rm -rf
 
+# SKIP-CLEAN-LLBUILD-CHECK-NOT: Cleaning the XCTest build directory
+# SKIP-CLEAN-LLBUILD-CHECK-NOT: rm -rf {{.*/xctest-[^/]*}}
 # SKIP-CLEAN-LLBUILD-CHECK-NOT: Cleaning the llbuild build directory
 # SKIP-CLEAN-LLBUILD-CHECK-NOT: rm -rf {{.*/llbuild-[^/]*}}