[Object] Add symbol attribute flags: ST_ThreadLocal, ST_Common, and ST_Undefined. Implement these completely for ELF.
Rename ST_External to ST_Unknown, and slightly change its semantics. It now only indicates that the symbol's type
is unknown, not that the symbol is undefined. (For that, use ST_Undefined).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151696 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/COFFObjectFile.cpp b/lib/Object/COFFObjectFile.cpp
index bf27878..d55aba5 100644
--- a/lib/Object/COFFObjectFile.cpp
+++ b/lib/Object/COFFObjectFile.cpp
@@ -143,7 +143,7 @@
   Result = SymbolRef::ST_Other;
   if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL &&
       symb->SectionNumber == COFF::IMAGE_SYM_UNDEFINED) {
-    Result = SymbolRef::ST_External;
+    Result = SymbolRef::ST_Unknown;
   } else {
     if (symb->getComplexType() == COFF::IMAGE_SYM_DTYPE_FUNCTION) {
       Result = SymbolRef::ST_Function;
@@ -164,7 +164,11 @@
   const coff_symbol *symb = toSymb(Symb);
   Result = SymbolRef::SF_None;
 
-  // TODO: Set SF_FormatSpecific.
+  // TODO: Correctly set SF_FormatSpecific, SF_ThreadLocal, SF_Common
+
+  if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL &&
+      symb->SectionNumber == COFF::IMAGE_SYM_UNDEFINED)
+    Result |= SymbolRef::SF_Undefined;
 
   // TODO: This are certainly too restrictive.
   if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL)