[NFC] Gate Cross-Module Dependency Sinks on Incremental Info

This has the net effect of only recording cross-module dependency information in the current module if the module under scrutiny can possibly provide dependency information of its own.

For now, because none of this is turned on, this does not actually record additional dependencies from extant modules.

Author: CodaFi

lib/AST/NameLookupRequests.cpp

@@ -300,16 +300,15 @@ void DirectLookupRequest::writeDependencySink(
 
 void LookupInModuleRequest::writeDependencySink(
     evaluator::DependencyCollector &reqTracker, QualifiedLookupResult l) const {
-  auto *module = std::get<0>(getStorage());
+  auto *DC = std::get<0>(getStorage());
   auto member = std::get<1>(getStorage());
-  auto *DC = std::get<4>(getStorage());
 
-  // Decline to record lookups outside our module.
-  if (!DC->getParentSourceFile() ||
-      module->getParentModule() != DC->getParentModule()) {
-    return;
+  // Decline to record lookups if the module in question has no incremental
+  // dependency information available.
+  auto *module = DC->getParentModule();
+  if (module->isMainModule() || module->hasIncrementalInfo()) {
+    reqTracker.addTopLevelName(member.getBaseName());
   }
-  reqTracker.addTopLevelName(member.getBaseName());
 }
 
 //----------------------------------------------------------------------------//
@@ -343,16 +342,14 @@ swift::extractNearestSourceLoc(const LookupConformanceDescriptor &desc) {
 
 void ModuleQualifiedLookupRequest::writeDependencySink(
     evaluator::DependencyCollector &reqTracker, QualifiedLookupResult l) const {
-  auto *DC = std::get<0>(getStorage());
   auto *module = std::get<1>(getStorage());
   auto member = std::get<2>(getStorage());
 
-  // Decline to record lookups outside our module.
-  if (!DC->getParentSourceFile() ||
-      module != DC->getModuleScopeContext()->getParentModule()) {
-    return;
+  // Decline to record lookups if the module in question has no incremental
+  // dependency information available.
+  if (module->isMainModule() || module->hasIncrementalInfo()) {
+    reqTracker.addTopLevelName(member.getBaseName());
   }
-  reqTracker.addTopLevelName(member.getBaseName());
 }
 
 //----------------------------------------------------------------------------//
@@ -370,16 +367,13 @@ void LookupConformanceInModuleRequest::writeDependencySink(
   if (!Adoptee)
     return;
 
-  auto source = reqTracker.getRecorder().getActiveDependencySourceOrNull();
-  if (source.isNull())
-    return;
-
-  // Decline to record conformances defined outside of the active module.
+  // Decline to record lookups if the module in question has no incremental
+  // dependency information available.
   auto *conformance = lookupResult.getConcrete();
-  if (source.get()->getParentModule() !=
-      conformance->getDeclContext()->getParentModule())
-    return;
-  reqTracker.addPotentialMember(Adoptee);
+  auto *module = conformance->getDeclContext()->getParentModule();
+  if (module->isMainModule() || module->hasIncrementalInfo()) {
+    reqTracker.addPotentialMember(Adoptee);
+  }
 }
 
 //----------------------------------------------------------------------------//