Index: lld/trunk/ELF/SymbolTable.cpp
===================================================================
--- lld/trunk/ELF/SymbolTable.cpp
+++ lld/trunk/ELF/SymbolTable.cpp
@@ -71,6 +71,8 @@
   Symbol *sym = reinterpret_cast<Symbol *>(make<SymbolUnion>());
   symVector.push_back(sym);
 
+  // *sym was not initialized by a constructor. Fields that may get referenced
+  // when it is a placeholder must be initialized here.
   sym->setName(name);
   sym->symbolKind = Symbol::PlaceholderKind;
   sym->versionId = VER_NDX_GLOBAL;
@@ -79,6 +81,8 @@
   sym->exportDynamic = false;
   sym->inDynamicList = false;
   sym->canInline = true;
+  sym->referenced = false;
+  sym->traced = false;
   sym->scriptDefined = false;
   sym->partition = 1;
   return sym;
Index: lld/trunk/ELF/Symbols.h
===================================================================
--- lld/trunk/ELF/Symbols.h
+++ lld/trunk/ELF/Symbols.h
@@ -537,6 +537,8 @@
   Symbol old = *this;
   memcpy(this, &newSym, newSym.getSymbolSize());
 
+  // old may be a placeholder. The referenced fields must be initialized in
+  // SymbolTable::insert.
   versionId = old.versionId;
   visibility = old.visibility;
   isUsedInRegularObj = old.isUsedInRegularObj;