Verifier: Check that !dbg attachments have the right type

A WIP patch makes `DIDescriptor` accessors more strict, which in turn
causes the `DebugInfoFinder` to crash on wrongly typed `!dbg`
attachments.  Catch that error up front in
`Verifier::visitInstruction()`.

Also remove a test that we "handle" invalid `!dbg` attachments, added
back in r99938.  We don't want to handle those anymore.

Note: I'm *not* recursing and verifying the debug info graph reachable
from this node; that work is already done by `verifyDebugInfo()`.

llvm-svn: 232834

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index ce765b14420..4f0e3388d58 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2556,6 +2556,13 @@ void Verifier::visitInstruction(Instruction &I) {
            &I);
   }
 
+  // Don't recurse into !dbg attachments (leave that for verifyDebugInfo()),
+  // but at least check that it's a legal type.
+  if (MDNode *N = I.getDebugLoc().getAsMDNode()) {
+    Assert(isa<MDLocation>(N),
+           "invalid !dbg metadata attachment", &I, N);
+  }
+
   InstsInThisBlock.insert(&I);
 }