[C++20][Modules][Serialization] Delay marking pending incomplete decl chains until the end of finishPendingActions.

Author: mpark

clang/lib/Serialization/ASTReader.cpp

@@ -10186,12 +10186,12 @@ void ASTReader::visitTopLevelModuleMaps(
 }
 
 void ASTReader::finishPendingActions() {
-  while (
-      !PendingIdentifierInfos.empty() || !PendingDeducedFunctionTypes.empty() ||
-      !PendingDeducedVarTypes.empty() || !PendingIncompleteDeclChains.empty() ||
-      !PendingDeclChains.empty() || !PendingMacroIDs.empty() ||
-      !PendingDeclContextInfos.empty() || !PendingUpdateRecords.empty() ||
-      !PendingObjCExtensionIvarRedeclarations.empty()) {
+  while (!PendingIdentifierInfos.empty() ||
+         !PendingDeducedFunctionTypes.empty() ||
+         !PendingDeducedVarTypes.empty() || !PendingDeclChains.empty() ||
+         !PendingMacroIDs.empty() || !PendingDeclContextInfos.empty() ||
+         !PendingUpdateRecords.empty() ||
+         !PendingObjCExtensionIvarRedeclarations.empty()) {
     // If any identifiers with corresponding top-level declarations have
     // been loaded, load those declarations now.
     using TopLevelDeclsMap =
@@ -10239,13 +10239,6 @@ void ASTReader::finishPendingActions() {
     }
     PendingDeducedVarTypes.clear();
 
-    // For each decl chain that we wanted to complete while deserializing, mark
-    // it as "still needs to be completed".
-    for (unsigned I = 0; I != PendingIncompleteDeclChains.size(); ++I) {
-      markIncompleteDeclChain(PendingIncompleteDeclChains[I]);
-    }
-    PendingIncompleteDeclChains.clear();
-
     // Load pending declaration chains.
     for (unsigned I = 0; I != PendingDeclChains.size(); ++I)
       loadPendingDeclChain(PendingDeclChains[I].first,
@@ -10483,6 +10476,13 @@ void ASTReader::finishPendingActions() {
   for (auto *ND : PendingMergedDefinitionsToDeduplicate)
     getContext().deduplicateMergedDefinitonsFor(ND);
   PendingMergedDefinitionsToDeduplicate.clear();
+
+  // For each decl chain that we wanted to complete while deserializing, mark
+  // it as "still needs to be completed".
+  for (unsigned I = 0; I != PendingIncompleteDeclChains.size(); ++I) {
+    markIncompleteDeclChain(PendingIncompleteDeclChains[I]);
+  }
+  PendingIncompleteDeclChains.clear();
 }
 
 void ASTReader::diagnoseOdrViolations() {