Clean up.

Author: dan-zheng

include/swift/AST/DiagnosticsParse.def

@@ -686,7 +686,7 @@ ERROR(sil_witness_assoc_conf_not_found,none,
 ERROR(sil_witness_protocol_conformance_not_found,none,
       "sil protocol conformance not found", ())
 
-// [differentiable ...] (sil-decl attr)
+// SIL differentiability witnesses
 ERROR(sil_diff_witness_expected_keyword,PointsToFirstBadToken,
       "expected '%0' in differentiability witness", (StringRef))
 ERROR(sil_diff_witness_expected_parameter_list,PointsToFirstBadToken,
@@ -698,8 +698,6 @@ ERROR(sil_diff_witness_expected_parameter_index,PointsToFirstBadToken,
 ERROR(sil_diff_witness_expected_source_index,PointsToFirstBadToken,
       "expected the index of a result to differentiate from", ())
 
-// SIL differentiability witnesses
-
 // SIL Coverage Map
 ERROR(sil_coverage_func_not_found, none,
       "sil function not found %0", (Identifier))

lib/Serialization/DeserializeSIL.cpp

@@ -148,9 +148,7 @@ SILDeserializer::SILDeserializer(
   // SIL_DEFAULT_WITNESS_TABLE_NAMES. But each one can be
   // omitted if no entries exist in the module file.
   unsigned kind = 0;
-// SWIFT_ENABLE_TENSORFLOW
   while (kind != sil_index_block::SIL_PROPERTY_OFFSETS) {
-// SWIFT_ENABLE_TENSORFLOW END
     auto next = cursor.advance();
     if (next.Kind == llvm::BitstreamEntry::EndBlock)
       return;
@@ -225,12 +223,14 @@ SILDeserializer::SILDeserializer(
               offKind == sil_index_block::SIL_DEFAULT_WITNESS_TABLE_OFFSETS) &&
              "Expect a SIL_DEFAULT_WITNESS_TABLE_OFFSETS record.");
       MF->allocateBuffer(DefaultWitnessTables, scratch);
+    // SWIFT_ENABLE_TENSORFLOW
     } else if (kind == sil_index_block::SIL_DIFFERENTIABILITY_WITNESS_NAMES) {
       assert((next.Kind == llvm::BitstreamEntry::Record &&
               offKind ==
                   sil_index_block::SIL_DIFFERENTIABILITY_WITNESS_OFFSETS) &&
              "Expect a SIL_DIFFERENTIABILITY_WITNESS_OFFSETS record.");
       MF->allocateBuffer(DifferentiabilityWitnesses, scratch);
+    // SWIFT_ENABLE_TENSORFLOW END
     }
   }
 }

lib/Serialization/SerializeSIL.cpp

@@ -2666,7 +2666,7 @@ void SILSerializer::writeSILBlock(const SILModule *SILMod) {
   // SWIFT_ENABLE_TENSORFLOW
   // Write out differentiability witnesses.
   for (const auto &diffWitness : SILMod->getDifferentiabilityWitnessList()) {
-    // TODO: Consider checking
+    // TODO(TF-893): Consider checking
     // `SILMod->shouldSerializeEntitiesAssociatedWithDeclContext` on the JVP/VJP
     // functions.
     if ((ShouldSerializeAll || diffWitness.isSerialized()))