Linker needs to do deep-copy of function-local metadata to update references to function arguments

llvm-svn: 94632

1 files changed, 13 insertions, 1 deletions

diff --git a/llvm/lib/Linker/LinkModules.cpp b/llvm/lib/Linker/LinkModules.cpp
index e2cd47a21b3..ac11450dc34 100644
--- a/llvm/lib/Linker/LinkModules.cpp
+++ b/llvm/lib/Linker/LinkModules.cpp
@@ -392,7 +392,19 @@ static Value *RemapOperand(const Value *In,
       assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
       llvm_unreachable("Unknown type of derived type constant value!");
     }
-  } else if (isa<MDNode>(In) ||  isa<MDString>(In)) {
+  } else if (const MDNode *MD = dyn_cast<MDNode>(In)) {
+    if (MD->isFunctionLocal()) {
+      SmallVector<Value*, 4> Elts;
+      for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
+        Value *Op = MD->getOperand(i);
+        // LinkFunctionBody() already handled non-argument values.
+        Elts.push_back(isa<Argument>(Op) ? RemapOperand(Op, ValueMap) : Op);
+      }
+      Result = MDNode::get(In->getContext(), Elts.data(), MD->getNumOperands());
+    } else {
+      Result = const_cast<Value*>(In);
+    }
+  } else if (isa<MDString>(In)) {
     Result = const_cast<Value*>(In);
   } else if (isa<InlineAsm>(In)) {
     Result = const_cast<Value*>(In);