Index: lld/COFF/InputFiles.cpp
===================================================================
--- lld/COFF/InputFiles.cpp
+++ lld/COFF/InputFiles.cpp
@@ -227,11 +227,17 @@
                                         uint32_t ParentSection) {
   SectionChunk *Parent = SparseChunks[ParentSection];
 
-  // If the parent is pending, it probably means that its section definition
-  // appears after us in the symbol table. Leave the associated section as
-  // pending; we will handle it during the second pass in initializeSymbols().
-  if (Parent == PendingComdat)
+  if (Parent == PendingComdat) {
+    // This can only happen if an associative comdat refers to another
+    // associative comdat that appears after it.
+    StringRef Name, ParentName;
+    COFFObj->getSymbolName(Sym, Name);
+    COFFSymbolRef ParentSym = check(COFFObj->getSymbol(ParentSection));
+    COFFObj->getSymbolName(ParentSym, ParentName);
+    error("associative comdat " + Name +
+          " refers to associative comdat " + ParentName);
     return;
+  }
 
   // Check whether the parent is prevailing. If it is, so are we, and we read
   // the section; otherwise mark it as discarded.
@@ -438,21 +444,15 @@
     return Leader;
   }
 
-  // Read associative section definitions and prepare to handle the comdat
-  // leader symbol by setting the section's ComdatDefs pointer if we encounter a
-  // non-associative comdat.
+  // Prepare to handle the comdat leader symbol by setting the section's
+  // ComdatDefs pointer if we encounter a non-associative comdat.
   if (SparseChunks[SectionNumber] == PendingComdat) {
     if (const coff_aux_section_definition *Def = Sym.getSectionDefinition()) {
-      if (Def->Selection == IMAGE_COMDAT_SELECT_ASSOCIATIVE)
-        readAssociativeDefinition(Sym, Def);
-      else
+      if (Def->Selection != IMAGE_COMDAT_SELECT_ASSOCIATIVE)
         ComdatDefs[SectionNumber] = Def;
     }
-  }
-
-  // readAssociativeDefinition() writes to SparseChunks, so need to check again.
-  if (SparseChunks[SectionNumber] == PendingComdat)
     return None;
+  }
 
   return createRegular(Sym);
 }