apple · rxwei · Oct 2, 2019 · Oct 3, 2019 · Oct 3, 2019 · Oct 3, 2019
diff --git a/.gitignore b/.gitignore
@@ -18,6 +18,7 @@
 # vim swap files
 .*.sw[a-z]
 .sw?
+*.vscode
 
 #==============================================================================#
 # Explicit files to ignore (only matches one).

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -67,6 +67,10 @@ option(SWIFT_BUILD_STDLIB_EXTRA_TOOLCHAIN_CONTENT
     "If not building stdlib, controls whether to build 'stdlib/toolchain' content"
     TRUE)
 
+option(SWIFT_ENABLE_TENSORFLOW
+    "Enable TensorFlow in the compiler and build the Swift TensorFlow library"
+    FALSE)
+
 # In many cases, the CMake build system needs to determine whether to include
 # a directory, or perform other actions, based on whether the stdlib or SDK is
 # being built at all -- statically or dynamically. Please note that these
@@ -348,6 +352,19 @@ option(SWIFT_REPORT_STATISTICS
     "Create json files which contain internal compilation statistics"
     FALSE)
 
+#
+# User-configurable TensorFlow specific options.
+#
+set(SWIFT_TENSORFLOW_HOST_LIB_DIR "" CACHE PATH
+    "If set, directory with TensorFlow host libraries to be linked into swiftc.")
+set(SWIFT_TENSORFLOW_TARGET_LIB_DIR "" CACHE PATH
+    "If set, directory with TensorFlow target libraries to be linked into swift programs.")
+
+set(SWIFT_TENSORFLOW_HOST_INCLUDE_DIR "" CACHE PATH
+    "If set, directory with host TensorFlow headers.")
+set(SWIFT_TENSORFLOW_TARGET_INCLUDE_DIR "" CACHE PATH
+    "If set, directory with target TensorFlow headers.")
+
 #
 # User-configurable experimental options.  Do not use in production builds.
 #
@@ -1083,6 +1100,11 @@ if(SWIFT_NEED_EXPLICIT_LIBDISPATCH)
                         ${SWIFT_PATH_TO_LIBDISPATCH_SOURCE})
 endif()
 
+# Enable TensorFlow in compiler code.
+if(SWIFT_ENABLE_TENSORFLOW)
+  add_definitions(-DSWIFT_ENABLE_TENSORFLOW)
+endif()
+
 # Add all of the subdirectories, where we actually do work.
 
 ###############

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -5,7 +5,23 @@ license](https://swift.org/LICENSE.txt).
 
 ---
 
-Before submitting the pull request, please make sure you have [tested your
-changes](https://github.com/apple/swift/blob/master/docs/ContinuousIntegration.md)
-and that they follow the Swift project [guidelines for contributing
-code](https://swift.org/contributing/#contributing-code).
+Before submitting a pull request, please make sure that your changes follow the
+[Swift project guidelines for contributing code](https://swift.org/contributing/#contributing-code).
+
+We request that code changes unrelated to Swift for TensorFlow be submitted to
+the [upstream Swift repository](https://github.com/apple/swift). For example,
+code formatting changes that do not affect Swift for TensorFlow source code
+should be submitted upstream.
+
+It is a good idea to discuss any non-trivial submissions with the project
+maintainers before submitting a pull request: please join the
+[swift@tensorflow.org](https://groups.google.com/a/tensorflow.org/d/forum/swift)
+mailing list to participate in discussions.
+
+All changes to existing Swift source code should be marked clearly with a
+`SWIFT_ENABLE_TENSORFLOW` comment at the top of every diff hunk. This makes
+it easier to merge from upstream.
+
+Continuous integration (CI) is still being set up, so if you submit a pull
+request with non-trivial changes that require test coverage, please anticipate
+some delay before we can properly review and merge it.
diff --git a/README.md b/README.md
diff --git a/cmake/modules/AddSwift.cmake b/cmake/modules/AddSwift.cmake
@@ -676,6 +676,9 @@ endfunction()
 #     [SWIFT_COMPILE_FLAGS flag1...]
 #     [LINK_FLAGS flag1...]
 #     [FILE_DEPENDS target1 ...]
+# SWIFT_ENABLE_TENSORFLOW
+#     [EXTRA_RPATHS rpath1 ...]
+# END SWIFT_ENABLE_TENSORFLOW
 #     [DONT_EMBED_BITCODE]
 #     [IS_STDLIB]
 #     [FORCE_BUILD_OPTIMIZED]
@@ -732,6 +735,11 @@ endfunction()
 # FILE_DEPENDS
 #   Additional files this library depends on.
 #
+# SWIFT_ENABLE_TENSORFLOW
+# EXTRA_RPATHS
+#   List of directories to add to this library's RPATH.
+# END SWIFT_ENABLE_TENSORFLOW
+#
 # DONT_EMBED_BITCODE
 #   Don't embed LLVM bitcode in this target, even if it is enabled globally.
 #
@@ -776,6 +784,9 @@ function(_add_swift_library_single target name)
         C_COMPILE_FLAGS
         DEPENDS
         FILE_DEPENDS
+        # SWIFT_ENABLE_TENSORFLOW
+        EXTRA_RPATHS
+        # END SWIFT_ENABLE_TENSORFLOW
         FRAMEWORK_DEPENDS
         FRAMEWORK_DEPENDS_WEAK
         GYB_SOURCES
@@ -1118,6 +1129,28 @@ function(_add_swift_library_single target name)
     endif()
   endif()
 
+  # SWIFT_ENABLE_TENSORFLOW
+  # Hande extra RPATHs.
+  set(local_rpath "")
+  if("${SWIFTLIB_SINGLE_SDK}" STREQUAL "LINUX" AND NOT "${SWIFTLIB_SINGLE_SDK}" STREQUAL "ANDROID")
+    set(local_rpath "$ORIGIN:/usr/lib/swift/linux")
+  elseif("${SWIFTLIB_SINGLE_SDK}" STREQUAL "CYGWIN")
+    set(local_rpath "$ORIGIN:/usr/lib/swift/cygwin")
+  endif()
+  foreach(rpath_element ${SWIFTLIB_SINGLE_EXTRA_RPATHS})
+    if("${local_rpath}" STREQUAL "")
+      set(local_rpath "${rpath_element}")
+    else()
+      set(local_rpath "${local_rpath}:${rpath_element}")
+    endif()
+  endforeach()
+  if(NOT "${local_rpath}" STREQUAL "")
+    set_target_properties("${target}"
+      PROPERTIES
+      INSTALL_RPATH "${local_rpath}")
+  endif()
+  # END SWIFT_ENABLE_TENSORFLOW
+
   set_target_properties("${target}" PROPERTIES BUILD_WITH_INSTALL_RPATH YES)
   set_target_properties("${target}" PROPERTIES FOLDER "Swift libraries")
 
@@ -2319,6 +2352,18 @@ function(_add_swift_executable_single name)
         "-Xlinker" "@executable_path/../lib/swift/${SWIFT_SDK_${SWIFTEXE_SINGLE_SDK}_LIB_SUBDIR}")
   endif()
 
+  # SWIFT_ENABLE_TENSORFLOW
+  set(swift_relative_library_path "../lib/swift/${SWIFT_SDK_${SWIFTEXE_SINGLE_SDK}_LIB_SUBDIR}")
+  is_darwin_based_sdk("${SWIFTEXE_SINGLE_SDK}" IS_DARWIN)
+  # NOTE: Adding "${SWIFTLIB_DIR}/.." to the rpath was necessary to fix linker
+  # errors for Syntax/Parser tests on Linux.
+  if("${SWIFTEXE_SINGLE_SDK}" STREQUAL "LINUX" AND NOT "${SWIFTEXE_SINGLE_SDK}" STREQUAL "ANDROID")
+    set(local_rpath "$ORIGIN:$ORIGIN/${swift_relative_library_path}:${SWIFTLIB_DIR}/..:/usr/lib/swift/linux")
+  elseif("${SWIFTEXE_SINGLE_SDK}" STREQUAL "CYGWIN")
+    set(local_rpath "$ORIGIN:$ORIGIN/${swift_relative_library_path}:${SWIFTLIB_DIR}/..:/usr/lib/swift/cygwin")
+  endif()
+  # END SWIFT_ENABLE_TENSORFLOW
+
   _list_add_string_suffix(
       "${SWIFTEXE_SINGLE_LINK_LIBRARIES}"
       "-${SWIFT_SDK_${SWIFTEXE_SINGLE_SDK}_LIB_SUBDIR}-${SWIFTEXE_SINGLE_ARCHITECTURE}"
@@ -2386,6 +2431,13 @@ function(_add_swift_executable_single name)
   endif()
 
   set_target_properties(${name} PROPERTIES FOLDER "Swift executables")
+
+  # SWIFT_ENABLE_TENSORFLOW
+  if(NOT "${local_rpath}" STREQUAL "")
+    set_target_properties("${name}" PROPERTIES INSTALL_RPATH "${local_rpath}")
+  endif()
+  set_target_properties("${name}" PROPERTIES BUILD_WITH_INSTALL_RPATH YES)
+  # END SWIFT_ENABLE_TENSORFLOW
 endfunction()
 
 macro(add_swift_tool_subdirectory name)

diff --git a/cmake/modules/FindTensorFlow.cmake b/cmake/modules/FindTensorFlow.cmake
@@ -0,0 +1,23 @@
+# SWIFT_ENABLE_TENSORFLOW
+# Find TensorFlow.
+
+include(FindPackageHandleStandardArgs)
+
+find_path(TF_INCLUDE_DIR
+  NAMES third_party/tensorflow/c tensorflow/c
+  HINTS ${SWIFT_TENSORFLOW_TARGET_INCLUDE_DIR} /usr/include /usr/local/include)
+if (EXISTS ${TF_INCLUDE_DIR}/third_party/tensorflow/c/c_api.h)
+  # This is experimental and not covered by CI.
+  set(TF_PATH_ADJUSTMENT "third_party")
+else()
+  # Note: This is the normal workflow.
+  set(TF_PATH_ADJUSTMENT "")
+endif()
+
+find_library(TF_LIBRARY
+  NAMES tensorflow
+  HINTS ${SWIFT_TENSORFLOW_TARGET_LIB_DIR} /usr/lib /usr/local/lib)
+set(TF_LIBRARIES ${TF_LIBRARY})
+
+find_package_handle_standard_args(TensorFlow DEFAULT_MSG TF_INCLUDE_DIR TF_LIBRARIES)
+mark_as_advanced(${TF_INCLUDE_DIR} ${TF_LIBRARIES})
diff --git a/cmake/modules/SwiftSource.cmake b/cmake/modules/SwiftSource.cmake
@@ -228,8 +228,21 @@ function(_compile_swift_files
 
   # The standard library and overlays are always built resiliently.
   if(SWIFTFILE_IS_STDLIB)
-    list(APPEND swift_flags "-enable-library-evolution")
-    list(APPEND swift_flags "-Xfrontend" "-enable-ownership-stripping-after-serialization")
+    # SWIFT_ENABLE_TENSORFLOW
+    # FIXME(TF-328): Resilience is currently disabled for the TensorFlow module
+    # because it causes compilation to crash during IRGen.
+    # Also, disable resilience for DifferentiationUnittest because resilience
+    # changes generated AD code, leading to additional leaks.
+    if(NOT "${SWIFTFILE_MODULE_NAME}" STREQUAL "TensorFlow" AND
+       NOT "${SWIFTFILE_MODULE_NAME}" STREQUAL "DifferentiationUnittest")
+      list(APPEND swift_flags "-enable-library-evolution")
+    endif()
+    # FIXME(SR-11336): `-enable-ownership-stripping-after-serialization` for
+    # swiftCore causes test/AutoDiff/array.swift to crash, related to
+    # Array and key paths.
+    # Disabling the flag for swiftCore requires disabling the flag for all
+    # other standard library modules.
+    # list(APPEND swift_flags "-Xfrontend" "-enable-ownership-stripping-after-serialization")
   endif()
 
   if(SWIFT_STDLIB_USE_NONATOMIC_RC)
@@ -334,8 +347,8 @@ function(_compile_swift_files
     endif()
 
     if (NOT SWIFTFILE_IS_STDLIB_CORE)
-      list(APPEND swift_module_flags
-           "-Xfrontend" "-experimental-skip-non-inlinable-function-bodies")
+      #      list(APPEND swift_module_flags
+      #       "-Xfrontend" "-experimental-skip-non-inlinable-function-bodies")
     endif()
 
     # If we have extra regexp flags, check if we match any of the regexps. If so

diff --git a/docs/ABI/Mangling.rst b/docs/ABI/Mangling.rst
@@ -517,6 +517,12 @@ Types
   FUNCTION-KIND ::= 'C'                      // C function pointer type
   FUNCTION-KIND ::= 'A'                      // @auto_closure function type (escaping)
   FUNCTION-KIND ::= 'E'                      // function type (noescape)
+  .. SWIFT_ENABLE_TENSORFLOW
+  FUNCTION-KIND ::= 'F'                      // @differentiable function type
+  FUNCTION-KIND ::= 'G'                      // @differentiable function type (escaping)
+  FUNCTION-KIND ::= 'H'                      // @differentiable(linear) function type
+  FUNCTION-KIND ::= 'I'                      // @differentiable(linear) function type (escaping)
+  .. SWIFT_ENABLE_TENSORFLOW END
 
   function-signature ::= params-type params-type throws? // results and parameters
 
@@ -585,12 +591,19 @@ mangled in to disambiguate.
   impl-function-type ::= type* 'I' FUNC-ATTRIBUTES '_'
   impl-function-type ::= type* generic-signature 'I' PSEUDO-GENERIC? FUNC-ATTRIBUTES '_'
 
-  FUNC-ATTRIBUTES ::= CALLEE-ESCAPE? CALLEE-CONVENTION FUNC-REPRESENTATION? PARAM-CONVENTION* RESULT-CONVENTION* ('z' RESULT-CONVENTION)
+  .. SWIFT_ENABLE_TENSORFLOW
+  FUNC-ATTRIBUTES ::= CALLEE-ESCAPE? DIFFERENTIABILITY-KIND? CALLEE-CONVENTION FUNC-REPRESENTATION? PARAM-CONVENTION* RESULT-CONVENTION* ('z' RESULT-CONVENTION)
 
   PSEUDO-GENERIC ::= 'P'
 
   CALLEE-ESCAPE ::= 'e'                      // @escaping (inverse of SIL @noescape)
 
+  .. SWIFT_ENABLE_TENSORFLOW
+  DIFFERENTIABILITY-KIND ::= DIFFERENTIABLE | LINEAR
+  DIFFERENTIABLE ::= 'd'                     // @differentiable
+  LINEAR ::= 'l'                             // @differentiable(linear)
+  .. SWIFT_ENABLE_TENSORFLOW END
+
   CALLEE-CONVENTION ::= 'y'                  // @callee_unowned
   CALLEE-CONVENTION ::= 'g'                  // @callee_guaranteed
   CALLEE-CONVENTION ::= 'x'                  // @callee_owned

diff --git a/docs/ContinuousIntegration.md b/docs/ContinuousIntegration.md
@@ -27,7 +27,21 @@ This page is designed to assist in the understanding of proper practices for tes
 
 In order for the Swift project to be able to advance quickly, it is important that we maintain a green build [[1]](#footnote-1). In order to help maintain this green build, the Swift project heavily uses pull request (PR) testing. Specifically, an important general rule is that **all** non-trivial checkins to any Swift Project repository should at least perform a [smoke test](#smoke-testing) if simulators will not be impacted *or* a full [validation test](#validation-testing) if simulators may be impacted. If in addition one is attempting to make a source breaking change across multiple repositories, one should follow the cross repo source breaking changes workflow. We now continue by describing the Swift system for Pull Request testing, @swift-ci:
 
-### @swift-ci
+### @swift-ci (Swift for TensorFlow)
+
+
+Platform     | Comment
+------------ | -------
+All supported platforms     | @swift-ci Please test tensorflow
+All supported platforms     | @swift-ci Please clean test tensorflow
+Linux                       | @swift-ci Please test tensorflow Linux
+Linux GPU                   | @swift-ci Please test tensorflow Linux GPU
+macOS                       | @swift-ci Please test tensorflow macOS
+
+Status can be checked at https://ci-external.swift.org/view/Pull%20Request/.
+
+
+### @swift-ci (general Swift)
 
 Users with [commit access](https://swift.org/contributing/#commit-access) can trigger pull request testing by writing a comment on a PR addressed to the GitHub user @swift-ci. Different tests will run depending on the specific comment used. The current test types are: