Fix bugs with attribute weak emission


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index e32987c..0fd3046 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -653,6 +653,7 @@
       if ((I->hasInternalLinkage() || !MangledGlobals.count(I)) &&
           !I->getIntrinsicID()) {
         printFunctionSignature(I, true);
+        if (I->hasWeakLinkage()) Out << " __attribute__((weak))";
         Out << ";\n";
       }
     }
@@ -671,7 +672,11 @@
       if (!I->isExternal()) {
         Out << "extern ";
         printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
-      
+
+        if (I->hasLinkOnceLinkage())
+          Out << " __attribute__((common))";
+        else if (I->hasWeakLinkage())
+          Out << " __attribute__((weak))";
         Out << ";\n";
       }
   }
@@ -903,8 +908,6 @@
   FunctionInnards << ")";
   // Print out the return type and the entire signature for that matter
   printType(Out, F->getReturnType(), FunctionInnards.str());
-
-  if (F->hasWeakLinkage()) Out << " __attribute((weak))";
 }
 
 void CWriter::printFunction(Function *F) {