Verifier: Function metadata attachments require a body

Add a verifier check that only functions with bodies have metadata
attachments.  This should help catch bugs in frontends and
transformation passes.  Part of PR23340.

llvm-svn: 235784

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 099cbd9e0fe..afce3e2bf56 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1669,11 +1669,20 @@ void Verifier::visitFunction(const Function &F) {
              "Function takes metadata but isn't an intrinsic", I, &F);
   }
 
+  // Get the function metadata attachments.
+  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
+  F.getAllMetadata(MDs);
+  assert(F.hasMetadata() != MDs.empty() && "Bit out-of-sync");
+
   if (F.isMaterializable()) {
     // Function has a body somewhere we can't see.
+    Assert(MDs.empty(), "unmaterialized function cannot have metadata", &F,
+           MDs.empty() ? nullptr : MDs.front().second);
   } else if (F.isDeclaration()) {
     Assert(F.hasExternalLinkage() || F.hasExternalWeakLinkage(),
            "invalid linkage type for function declaration", &F);
+    Assert(MDs.empty(), "function without a body cannot have metadata", &F,
+           MDs.empty() ? nullptr : MDs.front().second);
   } else {
     // Verify that this function (which has a body) is not named "llvm.*".  It
     // is not legal to define intrinsics.
@@ -1689,6 +1698,10 @@ void Verifier::visitFunction(const Function &F) {
       Assert(!BlockAddress::lookup(Entry)->isConstantUsed(),
              "blockaddress may not be used with the entry block!", Entry);
     }
+
+    // Visit metadata attachments.
+    for (const auto &I : MDs)
+      visitMDNode(*I.second);
   }
 
   // If this function is actually an intrinsic, verify that it is only used in