In order for parameter attribute uniquing to make

any sense it is important that ParamAttr::None gets
treated the same as not supplying an attribute at
all.  Rather than stripping ParamAttr::None out of
the list of attributes, assert if ParamAttr::None
is seen.  Fix up the bitcode reader which liked to
insert ParamAttr::None all over the place.  Patch
based on one by Török Edwin.

llvm-svn: 44250

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/VMCore/Function.cpp b/llvm/lib/VMCore/Function.cpp
index 3256d5b9f63..a011aaea338 100644
--- a/llvm/lib/VMCore/Function.cpp
+++ b/llvm/lib/VMCore/Function.cpp
@@ -129,8 +129,12 @@ ParamAttrsList *
 ParamAttrsList::get(const ParamAttrsVector &attrVec) {
   assert(!attrVec.empty() && "Illegal to create empty ParamAttrsList");
 #ifndef NDEBUG
-  for (unsigned i = 1, e = attrVec.size(); i < e; ++i)
-    assert(attrVec[i-1].index < attrVec[i].index && "Misordered ParamAttrsList!");
+  for (unsigned i = 0, e = attrVec.size(); i < e; ++i) {
+    assert(attrVec[i].attrs != ParamAttr::None
+           && "Pointless parameter attribute!");
+    assert((!i || attrVec[i-1].index < attrVec[i].index)
+           && "Misordered ParamAttrsList!");
+  }
 #endif
   ParamAttrsList key(attrVec);
   FoldingSetNodeID ID;