stdlib: remove VS injection for Swift development

Inject the necessary module maps and apinotes via the VFS.  This cleans
up the developer build in preparation for a secondary change to remove
this need for deployed scenarios as well.  Injecting the content via the
VFS will enable us restore the ability to work with a pristine
installation of Visual Studio, dropping the custom action for the Swift
installer, and open the pathway to per-user installation of Swift.

Use the development path as a high pass filter to identify issues that
might come from this injection.  This identified a potential issue due
to case sensitivity and areas that would break down under tests.

Author: compnerd

stdlib/CMakeLists.txt

@@ -24,6 +24,18 @@ else()
   set(SWIFT_BUILD_TEST_SUPPORT_MODULES_default FALSE)
 endif()
 
+# TODO(compnerd) use a target to avoid re-creating this file all the time
+function(generate_windows_vfs_overlay)
+  file(TO_CMAKE_PATH ${VCToolsInstallDir} VCToolsInstallDir)
+  file(TO_CMAKE_PATH ${UniversalCRTSdkDir} UniversalCRTSdkDir)
+  configure_file("${PROJECT_SOURCE_DIR}/cmake/WindowsVFS.yaml.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/windows-vfs-overlay.yaml"
+                 @ONLY)
+endfunction()
+generate_windows_vfs_overlay()
+file(TO_CMAKE_PATH "${CMAKE_CURRENT_BINARY_DIR}/windows-vfs-overlay.yaml"
+     SWIFT_WINDOWS_VFS_OVERLAY)
+
 #
 # User-configurable options for the standard library.
 #

stdlib/cmake/WindowsVFS.yaml.in

@@ -0,0 +1,27 @@
+
+version: 0
+case-sensitive: false
+use-external-names: false
+roots:
+  - name: "@UniversalCRTSdkDir@\\Include\\@UCRTVersion@\\um"
+    type: directory
+    contents:
+      - name: module.modulemap
+        type: file
+        external-contents: "@PROJECT_SOURCE_DIR@\\public\\Platform\\winsdk.modulemap"
+  - name: "@UniversalCRTSdkDir@\\Include\\@UCRTVersion@\\ucrt"
+    type: directory
+    contents:
+      - name: module.modulemap
+        type: file
+        external-contents: "@PROJECT_SOURCE_DIR@\\public\\Platform\\ucrt.modulemap"
+  - name: "@VCToolsInstallDir@\\include"
+    type: directory
+    contents:
+      - name: module.modulemap
+        type: file
+        external-contents: "@PROJECT_SOURCE_DIR@\\public\\Platform\\vcruntime.modulemap"
+      - name: vcruntime.apinotes
+        type: file
+        external-contents: "@PROJECT_SOURCE_DIR@\\public\\Platform\\vcruntime.apinotes"
+

stdlib/cmake/modules/AddSwiftStdlib.cmake

@@ -875,6 +875,8 @@ function(add_swift_target_library_single target name)
       list(APPEND SWIFTLIB_SINGLE_SWIFT_COMPILE_FLAGS
         -Xcc;-Xclang;-Xcc;-ivfsoverlay;-Xcc;-Xclang;-Xcc;${SWIFTLIB_SINGLE_VFS_OVERLAY})
     endif()
+    list(APPEND SWIFTLIB_SINGLE_SWIFT_COMPILE_FLAGS
+      -Xcc;-ivfsoverlay;-Xcc;"${SWIFT_WINDOWS_VFS_OVERLAY}")
     swift_windows_include_for_arch(${SWIFTLIB_SINGLE_ARCHITECTURE} SWIFTLIB_INCLUDE)
     foreach(directory ${SWIFTLIB_INCLUDE})
       list(APPEND SWIFTLIB_SINGLE_SWIFT_COMPILE_FLAGS -Xcc;-isystem;-Xcc;${directory})

test/lit.cfg

@@ -364,6 +364,15 @@ if test_resource_dir:
    config.resource_dir_opt = ("-resource-dir %s" % test_resource_dir)
 else:
     test_resource_dir = make_path(config.swift_lib_dir, 'swift')
+config.swift_system_overlay_opt = ""
+config.clang_system_overlay_opt = ""
+if kIsWindows:
+    config.swift_system_overlay_opt = "-vfsoverlay {}".format(
+        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
+    )
+    config.clang_system_overlay_opt = "-Xcc -ivfsoverlay -Xcc {}".format(
+        os.path.join(config.swift_obj_root, "stdlib", "windows-vfs-overlay.yaml")
+    )
 stdlib_resource_dir_opt = config.resource_dir_opt
 sourcekitd_framework_dir = config.swift_lib_dir
 config.substitutions.append( ('%test-resource-dir', test_resource_dir) )
@@ -1355,20 +1364,22 @@ elif run_os in ['windows-msvc']:
     config.target_env_prefix = ''
 
     config.target_build_swift =                                                  \
-            ('%r -target %s %s %s %s %s -libc %s' %                              \
-                    (config.swiftc, config.variant_triple, config.resource_dir_opt,     \
+            ('%r -target %s %s %s %s %s %s -libc %s' %                           \
+                    (config.swiftc, config.variant_triple,                       \
+                     config.resource_dir_opt, config.swift_system_overlay_opt,   \
                      config.swift_test_options, config.swift_driver_test_options,\
                      swift_execution_tests_extra_flags,                          \
                      config.swift_stdlib_msvc_runtime))
 
     config.target_run = ''
 
     config.target_swift_frontend =                                               \
-            ('%r -target %s %s %s %s %s' % (config.swift_frontend,             \
-                                                      config.variant_triple,     \
-                                                      config.resource_dir_opt, mcp_opt, \
-                                                      config.swift_test_options, \
-                                                      config.swift_frontend_test_options))
+            ('%r -target %s %s %s %s %s %s' % (config.swift_frontend,            \
+                                               config.variant_triple,            \
+                                               config.resource_dir_opt, mcp_opt, \
+                                               config.swift_system_overlay_opt,  \
+                                               config.swift_test_options,        \
+                                               config.swift_frontend_test_options))
 
     config.target_codesign = 'echo'
 
@@ -1387,9 +1398,11 @@ elif run_os in ['windows-msvc']:
             ('%r -libpath:%s' % (config.link, os.path.join(test_resource_dir,    \
                                                            config.target_sdk_name)))
     config.target_sil_opt =                                                      \
-            ('%r -target %s %s %s %s' % (config.sil_opt, config.variant_triple,  \
-                                         config.resource_dir_opt, mcp_opt,              \
-                                         config.sil_test_options))
+            ('%r -target %s %s %s %s %s' % (config.sil_opt,                      \
+                                            config.variant_triple,               \
+                                            config.resource_dir_opt, mcp_opt,    \
+                                            config.swift_system_overlay_opt,     \
+                                            config.sil_test_options))
     subst_target_sil_opt_mock_sdk = config.target_sil_opt
     subst_target_sil_opt_mock_sdk_after = ''
     config.target_swift_symbolgraph_extract =                                    \
@@ -1409,9 +1422,10 @@ elif run_os in ['windows-msvc']:
     subst_target_swift_ide_test_mock_sdk_after = ''
 
     config.target_swiftc_driver =                                                \
-            ('%r -target %s %s %s %s' % (config.swiftc, config.variant_triple,   \
-                                      config.resource_dir_opt, mcp_opt,                 \
-                                      config.swift_driver_test_options))
+            ('%r -target %s %s %s %s %s' % (config.swiftc, config.variant_triple,\
+                                            config.resource_dir_opt, mcp_opt,    \
+                                            config.swift_system_overlay_opt,     \
+                                            config.swift_driver_test_options))
     config.target_swift_modulewrap =                                             \
             ('%r -modulewrap -target %s' % (config.swiftc, config.variant_triple))
     config.target_swift_emit_pcm =                                               \
@@ -2416,7 +2430,10 @@ config.substitutions.append(('%target-swift-ide-test\(mock-sdk:([^)]+)\)',
                                  escape_for_substitute_captures(subst_target_swift_ide_test_mock_sdk),
                                  escape_for_substitute_captures(subst_target_swift_ide_test_mock_sdk_after),
                                  escape_for_substitute_captures(swift_version)))))
-config.substitutions.append(('%target-swift-ide-test', "%s -swift-version %s" % (config.target_swift_ide_test, swift_version)))
+config.substitutions.append(('%target-swift-ide-test',
+                             "%s -swift-version %s %s" % (config.target_swift_ide_test,
+                                                          swift_version,
+                                                          config.clang_system_overlay_opt)))
 
 config.substitutions.append(('%target-swift-symbolgraph-extract', config.target_swift_symbolgraph_extract))
 config.substitutions.append(('%target-swift-api-extract', config.target_swift_api_extract))

utils/build-windows-toolchain.bat

@@ -178,12 +178,6 @@ cmake ^
 cmake --build "%BuildRoot%\curl" || (exit /b)
 cmake --build "%BuildRoot%\curl" --target install || (exit /b)
 
-:: Prepare system modules
-copy /y "%SourceRoot%\swift\stdlib\public\Platform\ucrt.modulemap" "%UniversalCRTSdkDir%\Include\%UCRTVersion%\ucrt\module.modulemap" || (exit /b)
-copy /y "%SourceRoot%\swift\stdlib\public\Platform\winsdk.modulemap" "%UniversalCRTSdkDir%\Include\%UCRTVersion%\um\module.modulemap" || (exit /b)
-copy /y "%SourceRoot%\swift\stdlib\public\Platform\vcruntime.modulemap" "%VCToolsInstallDir%\include\module.modulemap" || (exit /b)
-copy /y "%SourceRoot%\swift\stdlib\public\Platform\vcruntime.apinotes" "%VCToolsInstallDir%\include\vcruntime.apinotes" || (exit /b)
-
 :: Build Toolchain
 cmake ^
   -B "%BuildRoot%\1" ^

utils/build-windows.bat

@@ -78,7 +78,6 @@ path %PATH%;%install_directory%\bin
 
 call :build_cmark %exitOnError%
 
-call :prepare_platform_modules %exitOnError%
 call :build_swift %exitOnError%
 
 call :build_lldb %exitOnError%
@@ -160,22 +159,6 @@ curl -L -O "https://www.sqlite.org/2021/%file_name%" %exitOnError%
 goto :eof
 endlocal
 
-
-:prepare_platform_modules
-:: Create files into the right places of the Windows SDK to the files in the
-:: swift repository, in order to consider the headers of the Windows SDK a
-:: module to compile Swift code against them.
-setlocal enableextensions enabledelayedexpansion
-
-copy /y "%source_root%\swift\stdlib\public\Platform\ucrt.modulemap" "%UniversalCRTSdkDir%\Include\%UCRTVersion%\ucrt\module.modulemap" %exitOnError%
-copy /y "%source_root%\swift\stdlib\public\Platform\winsdk.modulemap" "%UniversalCRTSdkDir%\Include\%UCRTVersion%\um\module.modulemap" %exitOnError%
-copy /y "%source_root%\swift\stdlib\public\Platform\vcruntime.modulemap" "%VCToolsInstallDir%\include\module.modulemap" %exitOnError%
-copy /y "%source_root%\swift\stdlib\public\Platform\vcruntime.apinotes" "%VCToolsInstallDir%\include\vcruntime.apinotes" %exitOnError%
-
-goto :eof
-endlocal
-
-
 :build_llvm
 :: Configures, builds, and installs LLVM
 setlocal enableextensions enabledelayedexpansion