Merge branch 'main' into problem/63678072

Author: al45tair

CHANGELOG.md

@@ -6,9 +6,47 @@ _**Note:** This is in reverse chronological order, so newer entries are added to
 Swift 5.5
 ---------
 
+* [SE-0316][]:
+
+	A type can be defined as a global actor. Global actors extend the notion
+	of actor isolation outside of a single actor type, so that global state
+	(and the functions that access it) can benefit from actor isolation,
+	even if the state and functions are scattered across many different
+	types, functions and modules. Global actors make it possible to safely
+	work with global variables in a concurrent program, as well as modeling
+	other global program constraints such as code that must only execute on
+  the "main thread" or "UI thread". A new global actor can be defined with
+  the `globalActor` attribute:
+
+  ```swift
+  @globalActor
+  struct DatabaseActor {
+    actor ActorType { }
+
+    static let shared: ActorType = ActorType()
+  }
+  ```
+
+  Global actor types can be used as custom attributes on various declarations,
+  which ensures that those declarations are only accessed on the actor described
+  by the global actor's `shared` instance. For example:
+
+  ```swift
+  @DatabaseActor func queryDB(query: Query) throws -> QueryResult
+
+  func runQuery(queryString: String) async throws -> QueryResult {
+    let query = try Query(parsing: queryString)
+    return try await queryDB(query: query) // 'await' because this implicitly hops to DatabaseActor.shared
+  }
+  ```
+
+  The concurrency library defines one global actor, `MainActor`, which
+  represents the main thread of execution. It should be used for any code that
+  must execute on the main thread, e.g., for updating UI.
+
 * [SE-0313][]:
 
-  Declarations inside an actor that would normally by actor-isolated can
+  Declarations inside an actor that would normally be actor-isolated can
   explicitly become non-isolated using the `nonisolated` keyword. Non-isolated
   declarations can be used to conform to synchronous protocol requirements:
 
@@ -8525,6 +8563,7 @@ Swift 1.0
 [SE-0306]: <https://github.com/apple/swift-evolution/blob/main/proposals/0306-actors.md>
 [SE-0310]: <https://github.com/apple/swift-evolution/blob/main/proposals/0310-effectful-readonly-properties.md>
 [SE-0313]: <https://github.com/apple/swift-evolution/blob/main/proposals/0313-actor-isolation-control.md>
+[SE-0316]: <https://github.com/apple/swift-evolution/blob/main/proposals/0316-global-actors.md>
 
 [SR-75]: <https://bugs.swift.org/browse/SR-75>
 [SR-106]: <https://bugs.swift.org/browse/SR-106>

CMakeLists.txt

@@ -191,9 +191,10 @@ set(SWIFT_TOOLS_ENABLE_LTO OFF CACHE STRING "Build Swift tools with LTO. One
     option only affects the tools that run on the host (the compiler), and has
     no effect on the target libraries (the standard library and the runtime).")
 
-option(SWIFT_TOOLS_ENABLE_LIBSWIFT
-  "Enable building libswift and linking libswift into the compiler itself."
-  FALSE)
+# NOTE: We do not currently support building libswift with the Xcode generator.
+cmake_dependent_option(SWIFT_TOOLS_ENABLE_LIBSWIFT
+  "Enable building libswift and linking libswift into the compiler itself." FALSE
+  "NOT CMAKE_GENERATOR STREQUAL \"Xcode\"" FALSE)
 
 # The following only works with the Ninja generator in CMake >= 3.0.
 set(SWIFT_PARALLEL_LINK_JOBS "" CACHE STRING
@@ -374,7 +375,7 @@ option(SWIFT_RUNTIME_CLOBBER_FREED_OBJECTS
     "${SWIFT_RUNTIME_CLOBBER_FREED_OBJECTS_default}")
 
 option(SWIFT_STDLIB_SIL_DEBUGGING
-    "Compile the Swift standard library with -gsil to enable debugging and profiling on SIL level"
+    "Compile the Swift standard library with -sil-based-debuginfo to enable debugging and profiling on SIL level"
     FALSE)
 
 option(SWIFT_CHECK_INCREMENTAL_COMPILATION
@@ -480,7 +481,9 @@ endif()
 
 set(SWIFT_BUILD_HOST_DISPATCH FALSE)
 if(SWIFT_ENABLE_DISPATCH AND NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
-  if(SWIFT_BUILD_SYNTAXPARSERLIB OR SWIFT_BUILD_SOURCEKIT)
+  # Only build libdispatch for the host if the host tools are being built and
+  # specifically if these two libraries that depend on it are built.
+  if(SWIFT_INCLUDE_TOOLS AND (SWIFT_BUILD_SYNTAXPARSERLIB OR SWIFT_BUILD_SOURCEKIT))
     set(SWIFT_BUILD_HOST_DISPATCH TRUE)
   endif()
 
@@ -507,6 +510,11 @@ execute_process(COMMAND ${CMAKE_MAKE_PROGRAM} --version
 message(STATUS "CMake Make Program (${CMAKE_MAKE_PROGRAM}) Version: ${_CMAKE_MAKE_PROGRAM_VERSION}")
 message(STATUS "C Compiler (${CMAKE_C_COMPILER}) Version: ${CMAKE_C_COMPILER_VERSION}")
 message(STATUS "C++ Compiler (${CMAKE_CXX_COMPILER}) Version: ${CMAKE_CXX_COMPILER_VERSION}")
+if (CMAKE_Swift_COMPILER)
+  message(STATUS "Swift Compiler (${CMAKE_Swift_COMPILER}) Version: ${CMAKE_Swift_COMPILER_VERSION}")
+else()
+  message(STATUS "Swift Compiler (None).")
+endif()
 if(SWIFT_PATH_TO_CMARK_BUILD)
   execute_process(COMMAND ${SWIFT_PATH_TO_CMARK_BUILD}/src/cmark --version
     OUTPUT_VARIABLE _CMARK_VERSION
@@ -523,6 +531,13 @@ else()
   set(SWIFT_PREBUILT_CLANG TRUE)
 endif()
 
+# Also mark if we have a prebuilt swift before we do anything.
+if("${SWIFT_NATIVE_SWIFT_TOOLS_PATH}" STREQUAL "")
+  set(SWIFT_PREBUILT_SWIFT FALSE)
+else()
+  set(SWIFT_PREBUILT_SWIFT TRUE)
+endif()
+
 include(SwiftSharedCMakeConfig)
 
 # NOTE: We include this before SwiftComponents as it relies on some LLVM CMake
@@ -1044,9 +1059,7 @@ if(SWIFT_INCLUDE_TOOLS)
   # which is used in add_swift_host_tool for the lldb workaround.
   #
   # NOTE: We do not currently support libswift with the Xcode generator.
-  if (NOT CMAKE_GENERATOR STREQUAL "Xcode")
-    add_subdirectory(libswift)
-  endif()
+  add_subdirectory(libswift)
 
   # Always include this after including stdlib/!
   # Refer to the large comment above the add_subdirectory(stdlib) call.

benchmark/scripts/test_Benchmark_Driver.py

@@ -264,6 +264,7 @@ def test_filters_benchmarks_by_pattern(self):
         self.assertEqual(driver.tests, ["Benchmark3"])
         self.assertEqual(driver.all_tests, ["Benchmark1", "Benchmark2", "Benchmark3"])
 
+    @unittest.skip("comparing against localtime() is flaky. rdar://79701124")
     def test_log_file(self):
         """When swift-repo is set, log is tied to Git branch and revision."""
         self.assertIsNone(

benchmark/single-source/ChaCha.swift

@@ -361,6 +361,7 @@ func checkResult(_ plaintext: [UInt8]) {
 }
 
 @inline(never)
+@_assemblyVision
 public func run_ChaCha(_ N: Int) {
   let key = Array(repeating: UInt8(1), count: 32)
   let nonce = Array(repeating: UInt8(2), count: 12)

cmake/modules/AddSwift.cmake

@@ -600,13 +600,22 @@ function(add_swift_host_library name)
     # find all of the necessary swift libraries on Darwin.
     if (NOT ASHL_PURE_SWIFT)
       if (CMAKE_Swift_COMPILER)
-        # Add in the SDK directory for the host platform and add an rpath.
-        target_link_directories(${name} PRIVATE
-          ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_ARCH_${SWIFT_HOST_VARIANT_ARCH}_PATH}/usr/lib/swift)
         # Add in the toolchain directory so we can grab compatibility libraries
         get_filename_component(TOOLCHAIN_BIN_DIR ${CMAKE_Swift_COMPILER} DIRECTORY)
         get_filename_component(TOOLCHAIN_LIB_DIR "${TOOLCHAIN_BIN_DIR}/../lib/swift/macosx" ABSOLUTE)
         target_link_directories(${name} PUBLIC ${TOOLCHAIN_LIB_DIR})
+
+        # Add in the SDK directory for the host platform.
+        #
+        # NOTE: We do this /after/ target_link_directorying TOOLCHAIN_LIB_DIR to
+        # ensure that we first find libraries from the toolchain, rather than
+        # from the SDK. The reason why this is important is that when we perform
+        # a stage2 build, this path is into the stage1 build. This is not a pure
+        # SDK and also contains compatibility libraries. We need to make sure
+        # that the compiler sees the actual toolchain's compatibility libraries
+        # first before the just built compability libraries or build errors occur.
+        target_link_directories(${name} PRIVATE
+          ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_ARCH_${SWIFT_HOST_VARIANT_ARCH}_PATH}/usr/lib/swift)
       endif()
     endif()
 
@@ -808,14 +817,23 @@ function(add_swift_host_tool executable)
     # host side tools but link with clang, add the appropriate -L paths so we
     # find all of the necessary swift libraries on Darwin.
     if (CMAKE_Swift_COMPILER)
-      # Add in the SDK directory for the host platform and add an rpath.
-      target_link_directories(${executable} PRIVATE
-        ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_ARCH_${SWIFT_HOST_VARIANT_ARCH}_PATH}/usr/lib/swift)
       # Add in the toolchain directory so we can grab compatibility libraries
       get_filename_component(TOOLCHAIN_BIN_DIR ${CMAKE_Swift_COMPILER} DIRECTORY)
       get_filename_component(TOOLCHAIN_LIB_DIR "${TOOLCHAIN_BIN_DIR}/../lib/swift/macosx" ABSOLUTE)
       target_link_directories(${executable} PUBLIC ${TOOLCHAIN_LIB_DIR})
 
+      # Add in the SDK directory for the host platform and add an rpath.
+      #
+      # NOTE: We do this /after/ target_link_directorying TOOLCHAIN_LIB_DIR to
+      # ensure that we first find libraries from the toolchain, rather than from
+      # the SDK. The reason why this is important is that when we perform a
+      # stage2 build, this path is into the stage1 build. This is not a pure SDK
+      # and also contains compatibility libraries. We need to make sure that the
+      # compiler sees the actual toolchain's compatibility libraries first
+      # before the just built compability libraries or build errors occur.
+      target_link_directories(${executable} PRIVATE
+        ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_ARCH_${SWIFT_HOST_VARIANT_ARCH}_PATH}/usr/lib/swift)
+
       if (ASHT_HAS_LIBSWIFT AND SWIFT_TOOLS_ENABLE_LIBSWIFT)
         # Workaround to make lldb happy: we have to explicitly add all libswift modules
         # to the linker command line.
@@ -917,7 +935,9 @@ function(add_swift_fuzzer_host_tool executable)
 
   # Then make sure that we pass the -fsanitize=fuzzer flag both on the cflags
   # and cxx flags line.
-  target_compile_options(${executable} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:"-fsanitize=fuzzer">)
+  target_compile_options(${executable} PRIVATE
+    $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:-fsanitize=fuzzer>
+    $<$<COMPILE_LANGUAGE:Swift>:-sanitize=fuzzer>)
   target_link_libraries(${executable} PRIVATE "-fsanitize=fuzzer")
 endfunction()
 

docs/DebuggingTheCompiler.md

@@ -25,7 +25,7 @@ benefit of all Swift developers.
         - [Getting CommandLine for swift stdlib from Ninja to enable dumping stdlib SIL](#getting-commandline-for-swift-stdlib-from-ninja-to-enable-dumping-stdlib-sil)
         - [Dumping the SIL and other Data in LLDB](#dumping-the-sil-and-other-data-in-lldb)
     - [Debugging and Profiling on SIL level](#debugging-and-profiling-on-sil-level)
-        - [SIL source level profiling using -gsil](#sil-source-level-profiling-using--gsil)
+        - [SIL source level profiling using -sil-based-debuginfo](#sil-source-level-profiling)
         - [ViewCFG: Regex based CFG Printer for SIL/LLVM-IR](#viewcfg-regex-based-cfg-printer-for-silllvm-ir)
         - [Debugging the Compiler using advanced LLDB Breakpoints](#debugging-the-compiler-using-advanced-lldb-breakpoints)
         - [Debugging the Compiler using LLDB Scripts](#debugging-the-compiler-using-lldb-scripts)
@@ -101,6 +101,12 @@ swiftc -emit-sil -Onone file.swift
 swiftc -emit-sil -O file.swift
 ```
 
+* **Debug info in SIL** To print debug info from `file.swift` in SIL:
+
+```sh
+swiftc -g -emit-sil -O file.swift
+```
+
 * **IRGen** To print the LLVM IR after IR generation:
 
 ```sh
@@ -299,12 +305,13 @@ has a `dump()` method you can call.
 
 ## Debugging and Profiling on SIL level
 
-### SIL source level profiling using -gsil
+### SIL source level profiling
 
 The compiler provides a way to debug and profile on SIL level. To enable SIL
-debugging add the front-end option -gsil together with -g. Example:
+debugging add the front-end option -sil-based-debuginfo together with -g.
+Example:
 
-    swiftc -g -Xfrontend -gsil -O test.swift -o a.out
+    swiftc -g -Xfrontend -sil-based-debuginfo -O test.swift -o a.out
 
 This writes the SIL after optimizations into a file and generates debug info
 for it. In the debugger and profiler you can then see the SIL code instead of
@@ -915,7 +922,7 @@ One of the first steps is an invocation of the driver's
 In order to create a Swift compiler installation (`--install-swift`), the
 standalone driver must be built as a separate build product using the
 *just-built* Swift compiler and toolchain (the ones built in the same
-`build-script` invocation, preceeding the SwiftDriver build product). The
+`build-script` invocation, preceding the SwiftDriver build product). The
 additional build product is added to the build by specifying the
 `--swift-driver` option of the `build-script`. The driver product is istalled
 into the resulting toolchain installation by specifying the

docs/HowToGuides/GettingStarted.md

@@ -151,35 +151,18 @@ Double-check that running `pwd` prints a path ending with `swift`.
 [Homebrew]: https://brew.sh/
 [Homebrew Bundle]: https://github.com/Homebrew/homebrew-bundle
 
-### Ubuntu Linux
-
-1. For Ubuntu 16.04 LTS and 18.04 LTS, run the following:
-
-   ```sh
-   sudo apt-get install    \
-     clang                 \
-     cmake                 \
-     git                   \
-     icu-devtools          \
-     libcurl4-openssl-dev  \
-     libedit-dev           \
-     libicu-dev            \
-     libncurses5-dev       \
-     libpython3-dev        \
-     libsqlite3-dev        \
-     libxml2-dev           \
-     ninja-build           \
-     pkg-config            \
-     python                \
-     python-six            \
-     rsync                 \
-     swig                  \
-     systemtap-sdt-dev     \
-     tzdata                \
-     uuid-dev
+### Linux
+
+1. The latest Linux dependencies are listed in the respective Dockerfiles:
+   * [Ubuntu 20.04](https://github.com/apple/swift-docker/blob/main/swift-ci/master/ubuntu/20.04/Dockerfile)
+   * [CentOS 7](https://github.com/apple/swift-docker/blob/main/swift-ci/master/centos/7/Dockerfile)
+   * [CentOS 8](https://github.com/apple/swift-docker/blob/main/swift-ci/master/centos/8/Dockerfile)
+   * [Amazon Linux 2](https://github.com/apple/swift-docker/blob/main/swift-ci/master/amazon-linux/2/Dockerfile)
+   
+2. To install sccache (optional):
+   ```
    sudo snap install sccache --candidate --classic
    ```
-
    **Note:** LLDB currently requires at least `swig-1.3.40` but will
    successfully build with version 2 shipped with Ubuntu.
 

include/swift/ABI/ObjectFile.h

@@ -31,7 +31,7 @@ class SwiftObjectFileFormat {
 };
 
 /// Responsible for providing the Mach-O reflection section identifiers.
-class SwiftObjectFileFormatMachO : SwiftObjectFileFormat {
+class SwiftObjectFileFormatMachO : public SwiftObjectFileFormat {
 public:
   llvm::StringRef getSectionName(ReflectionSectionKind section) override {
     switch (section) {
@@ -53,7 +53,7 @@ class SwiftObjectFileFormatMachO : SwiftObjectFileFormat {
 };
 
 /// Responsible for providing the ELF reflection section identifiers.
-class SwiftObjectFileFormatELF : SwiftObjectFileFormat {
+class SwiftObjectFileFormatELF : public SwiftObjectFileFormat {
 public:
   llvm::StringRef getSectionName(ReflectionSectionKind section) override {
     switch (section) {
@@ -75,7 +75,7 @@ class SwiftObjectFileFormatELF : SwiftObjectFileFormat {
 };
 
 /// Responsible for providing the COFF reflection section identifiers
-class SwiftObjectFileFormatCOFF : SwiftObjectFileFormat {
+class SwiftObjectFileFormatCOFF : public SwiftObjectFileFormat {
 public:
   llvm::StringRef getSectionName(ReflectionSectionKind section) override {
     switch (section) {

include/swift/ABI/TaskLocal.h

@@ -69,6 +69,15 @@ class TaskLocal {
     // Trailing storage for the value itself. The storage will be
     // uninitialized or contain an instance of \c valueType.
 
+    /// Returns true if this item is a 'parent pointer'.
+    ///
+    /// A parent pointer is special kind of `Item` is created when pointing at
+    /// the parent storage, forming a chain of task local items spanning multiple
+    /// tasks.
+    bool isParentPointer() const {
+      return !valueType;
+    }
+
   protected:
     explicit Item()
       : next(0),
@@ -174,7 +183,7 @@ class TaskLocal {
     /// returns, as such, any child tasks potentially accessing the value stack
     /// are guaranteed to be completed by the time we pop values off the stack
     /// (after the body has completed).
-    TaskLocal::Item *head;
+    TaskLocal::Item *head = nullptr;
 
   public:
 

include/swift/AST/ASTContext.h

@@ -744,6 +744,10 @@ class ASTContext final {
   /// Get the runtime availability of support for differentiation.
   AvailabilityContext getDifferentiationAvailability();
 
+  /// Get the runtime availability of getters and setters of multi payload enum
+  /// tag single payloads.
+  AvailabilityContext getMultiPayloadEnumTagSinglePayload();
+
   /// Get the runtime availability of features introduced in the Swift 5.2
   /// compiler for the target platform.
   AvailabilityContext getSwift52Availability();
@@ -760,6 +764,10 @@ class ASTContext final {
   /// compiler for the target platform.
   AvailabilityContext getSwift55Availability();
 
+  /// Get the runtime availability of features introduced in the Swift 5.6
+  /// compiler for the target platform.
+  AvailabilityContext getSwift56Availability();
+
   /// Get the runtime availability of features that have been introduced in the
   /// Swift compiler for future versions of the target platform.
   AvailabilityContext getSwiftFutureAvailability();

include/swift/AST/Attr.def

@@ -581,7 +581,7 @@ CONTEXTUAL_SIMPLE_DECL_ATTR(isolated, Isolated,
   103)
 
 SIMPLE_DECL_ATTR(globalActor, GlobalActor,
-  OnClass | OnStruct | OnEnum | ConcurrencyOnly |
+  OnClass | OnStruct | OnEnum |
   ABIStableToAdd | ABIBreakingToRemove |
   APIStableToAdd | APIBreakingToRemove,
   104)