Merge tag 'swift-DEVELOPMENT-SNAPSHOT-2020-01-20-a' into tensorflow

CMakeLists.txt

@@ -7,6 +7,11 @@ if(POLICY CMP0068)
   cmake_policy(SET CMP0068 OLD)
 endif()
 
+# Honour CMAKE_CXX_STANDARD in try_compile(), needed for check_cxx_native_regex.
+if(POLICY CMP0067)
+  cmake_policy(SET CMP0067 NEW)
+endif()
+
 # Add path for custom CMake modules.
 list(APPEND CMAKE_MODULE_PATH
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
@@ -889,6 +894,9 @@ if(SWIFT_BUILD_STDLIB OR SWIFT_BUILD_SDK_OVERLAY)
   message(STATUS "Building Swift runtime with:")
   message(STATUS "  Leak Detection Checker Entrypoints: ${SWIFT_RUNTIME_ENABLE_LEAK_CHECKER}")
   message(STATUS "")
+
+  message(STATUS "Differentiable Programming Support: ${SWIFT_ENABLE_EXPERIMENTAL_DIFFERENTIABLE_PROGRAMMING}")
+  message(STATUS "")
 else()
   message(STATUS "Not building Swift standard library, SDK overlays, and runtime")
   message(STATUS "")

benchmark/scripts/Benchmark_DTrace.in

@@ -35,11 +35,13 @@ class DTraceResult(perf_test_driver.Result):
             self, name, status, output, XFAIL_LIST)
         self.csv_output = csv_output
 
+    def is_failure(self):
+        return not bool(self.status)
+
     @classmethod
     def data_headers(cls):
         return [
-            'Name', 'Result', 'strong_retain', 'strong_retain/iter',
-            'strong_release', 'strong_release/iter']
+            'Name', 'Result', 'Total RR Opts', 'Total RR Opts/Iter']
 
     @classmethod
     def data_format(cls, max_test_len):
@@ -100,13 +102,32 @@ class DTraceBenchmarkDriver(perf_test_driver.BenchmarkDriver):
                 results[results.index('DTRACE RESULTS') + 1:]]
         iter_2_results = get_results_with_iters(2)
         iter_3_results = get_results_with_iters(3)
+        iter_5_results = get_results_with_iters(5)
 
         results = []
-        for x in zip(iter_2_results, iter_3_results):
-            results.append(x[1])
-            results.append(int(x[1]) - int(x[0]))
+        foundInstability = False
+        for x in zip(iter_2_results, iter_3_results, iter_5_results):
+            result_2 = int(x[0])
+            result_3 = int(x[1])
+            result_5 = int(x[2])
+
+            single_iter = result_3 - result_2
+            two_iter = result_5 - result_3
+
+            # We are always doing more work, so these should be the same. Fail
+            # if we have a negative number.
+            if single_iter < 0 or two_iter < 0:
+                foundInstability = True
+
+            # Our retain traffic should always increase linearly with iteration
+            # size.
+            if (single_iter * 2) == two_iter:
+                foundInstability = True
+
+            results.append(result_3)
+            results.append(single_iter)
 
-        return DTraceResult(test_name, 0, results, self.csv_output)
+        return DTraceResult(test_name, int(not foundInstability), results)
 
 
 SWIFT_BIN_DIR = os.path.dirname(os.path.abspath(__file__))
@@ -120,7 +141,7 @@ def parse_args():
         default=None,
         help='Filter out any test that does not match the given regex')
     parser.add_argument(
-        '-csv',
+        '--emit-csv',
         default=False,
         action='store_true',
         help="Emit csv output",

benchmark/scripts/perf_test_driver/perf_test_driver.py

@@ -21,7 +21,7 @@
 import subprocess
 
 
-BENCHMARK_OUTPUT_RE = re.compile('([^,]+),')
+BENCHMARK_OUTPUT_RE = re.compile(r'\d+,([^,]+)')
 
 
 class Result(object):

benchmark/scripts/perf_test_driver/swift_stats.d

@@ -12,12 +12,22 @@
 
 pid$target:*:swift_retain:entry
 {
-        @counts[probefunc] = count();
+        @counts["rr-opts"] = count();
 }
 
 pid$target:*:swift_release:entry
 {
-        @counts[probefunc] = count();
+        @counts["rr-opts"] = count();
+}
+
+pid$target:*:swift_retain_n:entry
+{
+        @counts["rr-opts"] = count();
+}
+
+pid$target:*:swift_release_n:entry
+{
+        @counts["rr-opts"] = count();
 }
 
 END

docs/Branches.md

@@ -56,9 +56,17 @@ You can use any of the branch names as the argument to `--scheme`, such as `mast
 
 - Swift: new commits go to `master`
 
-- LLVM Project: new commits go to `swift/master-next`
+- LLVM Project: the destination branch depends on the kind of change that must be made:
 
-...then cherry-pick to the release branch (`swift/swift-x.y-branch`) if necessary, following the appropriate release process. (Usually this means filling out a standard template, finding someone to review your code if that hasn't already happened, and getting approval from that repo's *release manager.)*
+  1) LLVM Project changes that don't depend on Swift: New commits go to `master` in the upstream [llvm-project](https://github.com/llvm/llvm-project).
+
+  ... then these commits can be cherry-picked to an appropriate, `swift/master` aligned `apple/stable/*` branch in Apple's fork of [llvm-project](https://github.com/apple/llvm-project). Please see
+  [Apple's branching scheme](https://github.com/apple/llvm-project/blob/apple/master/apple-docs/AppleBranchingScheme.md)
+  document to determine which `apple/stable/*` branch you should cherry-pick to.
+
+  2) Changes that depend on Swift (this only applies to LLDB): new commits go to `swift/master-next`
+
+  ...then cherry-pick to the release branch (`swift/swift-x.y-branch`) if necessary, following the appropriate release   process. (Usually this means filling out a standard template, finding someone to review your code if that hasn't already happened, and getting approval from that repo's *release manager.)*
 
 ## Automerging