Reimplement IterableDeclContext::getLocalProtocls() using getLocalConformances()

The uncached, rarely-used getLocalProtocols() does not benefit from
having its own distinct implementation. Reimplement it on top of
getLocalConformances() to simplify things and benefit from the
request-evaluator infrastructure.

Author: DougGregor

lib/AST/ConformanceLookupTable.cpp

@@ -955,9 +955,7 @@ bool ConformanceLookupTable::lookupConformance(
 void ConformanceLookupTable::lookupConformances(
        NominalTypeDecl *nominal,
        DeclContext *dc,
-       ConformanceLookupKind lookupKind,
-       SmallVectorImpl<ProtocolDecl *> *protocols,
-       SmallVectorImpl<ProtocolConformance *> *conformances,
+       std::vector<ProtocolConformance *> *conformances,
        SmallVectorImpl<ConformanceDiagnostic> *diagnostics) {
   // We need to expand all implied conformances before we can find
   // those conformances that pertain to this declaration context.
@@ -980,36 +978,6 @@ void ConformanceLookupTable::lookupConformances(
                      if (entry->isSuperseded())
                        return true;
 
-                     // If we are to filter out this result, do so now.
-                     switch (lookupKind) {
-                     case ConformanceLookupKind::OnlyExplicit:
-                       switch (entry->getKind()) {
-                       case ConformanceEntryKind::Explicit:
-                       case ConformanceEntryKind::Synthesized:
-                         break;
-                       case ConformanceEntryKind::Implied:
-                       case ConformanceEntryKind::Inherited:
-                         return false;
-                       }
-                       break;
-                     case ConformanceLookupKind::NonInherited:
-                       switch (entry->getKind()) {
-                       case ConformanceEntryKind::Explicit:
-                       case ConformanceEntryKind::Synthesized:
-                       case ConformanceEntryKind::Implied:
-                         break;
-                       case ConformanceEntryKind::Inherited:
-                         return false;
-                       }
-                       break;
-                     case ConformanceLookupKind::All:
-                       break;
-                     }
-
-                     // Record the protocol.
-                     if (protocols)
-                       protocols->push_back(entry->getProtocol());
-
                      // Record the conformance.
                      if (conformances) {
                        if (auto conformance = getConformance(nominal, entry))

lib/AST/ConformanceLookupTable.h

@@ -437,9 +437,7 @@ class ConformanceLookupTable {
   /// Look for all of the conformances within the given declaration context.
   void lookupConformances(NominalTypeDecl *nominal,
                           DeclContext *dc,
-                          ConformanceLookupKind lookupKind,
-                          SmallVectorImpl<ProtocolDecl *> *protocols,
-                          SmallVectorImpl<ProtocolConformance *> *conformances,
+                          std::vector<ProtocolConformance *> *conformances,
                           SmallVectorImpl<ConformanceDiagnostic> *diagnostics);
 
   /// Retrieve the complete set of protocols to which this nominal

lib/AST/ProtocolConformance.cpp

@@ -1321,24 +1321,8 @@ NominalTypeDecl::getSatisfiedProtocolRequirementsForMember(
 SmallVector<ProtocolDecl *, 2>
 IterableDeclContext::getLocalProtocols(ConformanceLookupKind lookupKind) const {
   SmallVector<ProtocolDecl *, 2> result;
-
-  // Dig out the nominal type.
-  const auto dc = getAsGenericContext();
-  const auto nominal = dc->getSelfNominalTypeDecl();
-  if (!nominal) {
-    return result;
-  }
-
-  // Update to record all potential conformances.
-  nominal->prepareConformanceTable();
-  nominal->ConformanceTable->lookupConformances(
-    nominal,
-    const_cast<GenericContext *>(dc),
-    lookupKind,
-    &result,
-    nullptr,
-    nullptr);
-
+  for (auto conformance : getLocalConformances(lookupKind))
+    result.push_back(conformance->getProtocol());
   return result;
 }
 
@@ -1361,19 +1345,16 @@ LookupAllConformancesInContextRequest::evaluate(
     return { };
   }
 
-  // Update to record all potential conformances.
+  // Record all potential conformances.
   nominal->prepareConformanceTable();
-  SmallVector<ProtocolConformance *, 4> conformances;
+  std::vector<ProtocolConformance *> conformances;
   nominal->ConformanceTable->lookupConformances(
     nominal,
     const_cast<GenericContext *>(dc),
-    ConformanceLookupKind::All,
-    nullptr,
     &conformances,
     nullptr);
 
-  return std::vector<ProtocolConformance *>(
-      conformances.begin(), conformances.end());
+  return conformances;
 }
 
 SmallVector<ProtocolConformance *, 2>
@@ -1442,8 +1423,6 @@ IterableDeclContext::takeConformanceDiagnostics() const {
   nominal->ConformanceTable->lookupConformances(
     nominal,
     const_cast<GenericContext *>(dc),
-    ConformanceLookupKind::All,
-    nullptr,
     nullptr,
     &result);