1 files changed, 11 insertions, 2 deletions
diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index 65e1245624933..3b68d6365872e 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -267,6 +267,9 @@ class Verifier : public InstVisitor<Verifier>, VerifierSupport {
   /// \brief Keep track of the metadata nodes that have been checked already.
   SmallPtrSet<const Metadata *, 32> MDNodes;
 
+  /// Keep track which DISubprogram is attached to which function.
+  DenseMap<const DISubprogram *, const Function *> DISubprogramAttachments;
+
   /// Track all DICompileUnits visited.
   SmallPtrSet<const Metadata *, 2> CUVisited;
 
@@ -386,7 +389,7 @@ public:
     verifyCompileUnits();
 
     verifyDeoptimizeCallingConvs();
-
+    DISubprogramAttachments.clear();
     return !Broken;
   }
 
@@ -2085,13 +2088,19 @@ void Verifier::visitFunction(const Function &F) {
       switch (I.first) {
       default:
         break;
-      case LLVMContext::MD_dbg:
+      case LLVMContext::MD_dbg: {
         ++NumDebugAttachments;
         AssertDI(NumDebugAttachments == 1,
                  "function must have a single !dbg attachment", &F, I.second);
         AssertDI(isa<DISubprogram>(I.second),
                  "function !dbg attachment must be a subprogram", &F, I.second);
+        auto *SP = cast<DISubprogram>(I.second);
+        const Function *&AttachedTo = DISubprogramAttachments[SP];
+        AssertDI(!AttachedTo || AttachedTo == &F,
+                 "DISubprogram attached to more than one function", SP, &F);
+        AttachedTo = &F;
         break;
+      }
       case LLVMContext::MD_prof:
         ++NumProfAttachments;
         Assert(NumProfAttachments == 1,