From 2c9ad13b14de9fcc98f868d301950f0f386f2545 Mon Sep 17 00:00:00 2001
From: Victor Hernandez <vhernandez@apple.com>
Date: Wed, 27 Jan 2010 00:30:42 +0000
Subject: [PATCH] Linker needs to do deep-copy of function-local metadata to
 update references to function arguments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94632 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Linker/LinkModules.cpp | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index e2cd47a21b3..ac11450dc34 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/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);