Paper over CBackend/2004-08-09-va-end-null.ll

Note that this indicates a serious problem with the way we are emitting varargs,
but this should not be properly fixed until after 1.3.

This patch SHOULD go into 1.3.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15602 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/Writer.cpp b/lib/Target/CBackend/Writer.cpp
index 65a110e..bb1548f 100644
--- a/lib/Target/CBackend/Writer.cpp
+++ b/lib/Target/CBackend/Writer.cpp
@@ -1390,9 +1390,13 @@
         Out << ")";
         return;
       case Intrinsic::vaend:
-        Out << "va_end(*(va_list*)&";
-        writeOperand(I.getOperand(1));
-        Out << ")";
+        if (!isa<ConstantPointerNull>(I.getOperand(1))) {
+          Out << "va_end(*(va_list*)&";
+          writeOperand(I.getOperand(1));
+          Out << ")";
+        } else {
+          Out << "va_end(*(va_list*)0)";
+        }
         return;
       case Intrinsic::vacopy:
         Out << "0;";