Add some context to fatal verifier errors

Summary: Add function name when verification fails as an initial breadcrumb for debugging.

Patch by David Callahan.

Reviewers: mehdi_amini, modocache

Reviewed By: modocache

Subscribers: llvm-commits, modocache

Differential Revision: https://reviews.llvm.org/D51386

llvm-svn: 341974

llvm/lib/IR/Verifier.cpp

@@ -4730,9 +4730,10 @@ struct VerifierLegacyPass : public FunctionPass {
   }
 
   bool runOnFunction(Function &F) override {
-    if (!V->verify(F) && FatalErrors)
+    if (!V->verify(F) && FatalErrors) {
+      errs() << "in function " << F.getName() << '\n'; 
       report_fatal_error("Broken function found, compilation aborted!");
-
+    }
     return false;
   }