[region-isolation] Stub out PartitionOpEvaluator::doesFunctionHaveSendingResult() so that the unittests can override it.

The unittests for PartitionUtils pass in mocked operands and instructions that
cannot be dereferenced. Adding this static CRTP helper allows for the unittest
PartitionOpEvaluator subclass to just return false for it instead of
dereferencing operands or instructions. The rest of the evaluators just get to
use the default "normal" implementation that actually accesses program state.

Author: gottesmm

include/swift/SILOptimizer/Utils/PartitionUtils.h

@@ -1087,6 +1087,14 @@ struct PartitionOpEvaluator {
     return Impl::getIsolationInfo(partitionOp);
   }
 
+  /// Some evaluators do not support accessing fields on their SILInstruction
+  /// since they just pass in "mocked" SILInstruction. We allow for them to just
+  /// return false for this case to prevent dereference issues.
+  static bool
+  doesParentFunctionHaveSendingResult(const PartitionOp &partitionOp) {
+    return Impl::doesFunctionHaveSendingResult(partitionOp);
+  }
+
   std::optional<Element> getElement(SILValue value) const {
     return asImpl().getElement(value);
   }
@@ -1130,10 +1138,7 @@ struct PartitionOpEvaluator {
 
       // See if we are assigning an a non-disconnected value into a 'out
       // sending' parameter. In such a case, we emit a diagnostic.
-      if (op.getSourceInst()
-              ->getFunction()
-              ->getLoweredFunctionType()
-              ->hasSendingResult()) {
+      if (doesParentFunctionHaveSendingResult(op)) {
         if (auto instance = getRepresentativeValue(op.getOpArgs()[0])) {
           if (auto value = instance.maybeGetValue()) {
             if (auto *fArg = dyn_cast<SILFunctionArgument>(value)) {
@@ -1246,10 +1251,7 @@ struct PartitionOpEvaluator {
 
       // See if we are assigning an a non-disconnected value into a 'out
       // sending' parameter. In such a case, we emit a diagnostic.
-      if (op.getSourceInst()
-              ->getFunction()
-              ->getLoweredFunctionType()
-              ->hasSendingResult()) {
+      if (doesParentFunctionHaveSendingResult(op)) {
         if (auto instance = getRepresentativeValue(op.getOpArgs()[0])) {
           if (auto value = instance.maybeGetValue()) {
             if (auto *fArg = dyn_cast<SILFunctionArgument>(value)) {
@@ -1571,6 +1573,12 @@ struct PartitionOpEvaluatorBaseImpl : PartitionOpEvaluator<Subclass> {
   static SILIsolationInfo getIsolationInfo(const PartitionOp &partitionOp) {
     return SILIsolationInfo::get(partitionOp.getSourceInst());
   }
+  static bool doesFunctionHaveSendingResult(const PartitionOp &partitionOp) {
+    return partitionOp.getSourceInst()
+        ->getFunction()
+        ->getLoweredFunctionType()
+        ->hasSendingResult();
+  }
 };
 
 /// A subclass of PartitionOpEvaluatorBaseImpl that doesn't have any special

unittests/SILOptimizer/PartitionUtilsTest.cpp

@@ -61,6 +61,10 @@ struct MockedPartitionOpEvaluator final
   static SILIsolationInfo getIsolationInfo(const PartitionOp &partitionOp) {
     return {};
   }
+
+  static bool doesFunctionHaveSendingResult(const PartitionOp &partitionOp) {
+    return false;
+  }
 };
 
 } // namespace