[region-isolation] Add verbose logging to PartitionUtils behind a flag.

One needs to pass in the explicit flag to enable this as well as
-debug-flag=send-non-sendable. This makes it easier to debug the affect of
applying specific partition ops.

Author: gottesmm

include/swift/SILOptimizer/Utils/PartitionUtils.h

@@ -1,6 +1,7 @@
 #ifndef SWIFT_PARTITIONUTILS_H
 #define SWIFT_PARTITIONUTILS_H
 
+#include "swift/Basic/Defer.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/SIL/SILInstruction.h"
 #include "llvm/ADT/SmallVector.h"
@@ -13,6 +14,18 @@ namespace swift {
 
 namespace PartitionPrimitives {
 
+#ifndef NDEBUG
+extern bool REGIONBASEDISOLATION_ENABLE_VERBOSE_LOGGING;
+#define REGIONBASEDISOLATION_VERBOSE_LOG(...)                                  \
+  do {                                                                         \
+    if (REGIONBASEDISOLATION_ENABLE_VERBOSE_LOGGING) {                         \
+      LLVM_DEBUG(__VA_ARGS__);                                                 \
+    }                                                                          \
+  } while (0);
+#else
+#define REGIONBASEDISOLATION_VERBOSE_LOG(...)
+#endif
+
 struct Element {
   unsigned num;
 
@@ -391,11 +404,17 @@ class Partition {
       PartitionOp op,
       llvm::function_ref<void(const PartitionOp &, Element)> handleFailure =
           [](const PartitionOp &, Element) {},
-
       ArrayRef<Element> nonconsumables = {},
-
       llvm::function_ref<void(const PartitionOp &, Element)>
           handleConsumeNonConsumable = [](const PartitionOp &, Element) {}) {
+    REGIONBASEDISOLATION_VERBOSE_LOG(llvm::dbgs() << "Applying: ";
+                                     op.print(llvm::dbgs()));
+    REGIONBASEDISOLATION_VERBOSE_LOG(llvm::dbgs() << "    Before: ";
+                                     print(llvm::dbgs()));
+    SWIFT_DEFER {
+      REGIONBASEDISOLATION_VERBOSE_LOG(llvm::dbgs() << "    After:  ";
+                                       print(llvm::dbgs()));
+    };
     switch (op.OpKind) {
     case PartitionOpKind::Assign:
       assert(op.OpArgs.size() == 2 &&

lib/SILOptimizer/Utils/CMakeLists.txt

@@ -23,6 +23,7 @@ target_sources(swiftSILOptimizer PRIVATE
   LoopUtils.cpp
   OptimizerStatsUtils.cpp
   PartialApplyCombiner.cpp
+  PartitionUtils.cpp
   PerformanceInlinerUtils.cpp
   ShrinkBorrowScope.cpp
   SILInliner.cpp

lib/SILOptimizer/Utils/PartitionUtils.cpp

@@ -0,0 +1,29 @@
+//===--- PartitionUtils.cpp -----------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/SILOptimizer/Utils/PartitionUtils.h"
+#include "llvm/Support/CommandLine.h"
+
+#ifndef NDEBUG
+
+bool swift::PartitionPrimitives::REGIONBASEDISOLATION_ENABLE_VERBOSE_LOGGING;
+
+static llvm::cl::opt<bool, true> // The parser
+    RegionBasedIsolationVerboseLog(
+        "sil-regionbasedisolation-verbose-log",
+        llvm::cl::desc("Enable verbose logging for SIL region based isolation "
+                       "diagnostics"),
+        llvm::cl::Hidden,
+        llvm::cl::location(swift::PartitionPrimitives::
+                               REGIONBASEDISOLATION_ENABLE_VERBOSE_LOGGING));
+
+#endif