LTO: Don't verify modules twice in verifyMergedModuleOnce

[aprantl]

Summary

There's a logic bug that causes the function to run the verifier twice if LTOStripInvalidDebugInfo is true.

[mehdi_amini]

LGTM

[davide]

This is trivially correct, but I wonder whether we can fix this (i.e. feed a broken module, make sure we verify it and find it broken only once).

[davide]

s/fix/test/
Something similar to what we do in http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=295537

[aprantl]

I don't think that is going to work, because of the report_fatal_error that also exits.

[davide]

LGTM

lib/LTO/LTOCodeGenerator.cpp

 }
 
 void LTOCodeGenerator::verifyMergedModuleOnce() {
   // Only run on the first call.
   if (HasVerifiedInput)
     return;
   HasVerifiedInput = true;
 
-  if (LTOStripInvalidDebugInfo) {
-    bool BrokenDebugInfo = false;
-    if (verifyModule(*MergedModule, &dbgs(), &BrokenDebugInfo))
-      report_fatal_error("Broken module found, compilation aborted!");
-    if (BrokenDebugInfo) {
-      emitWarning("Invalid debug info found, debug info will be stripped");
-      StripDebugInfo(*MergedModule);
-    }
-  }
-  if (verifyModule(*MergedModule, &dbgs()))
-    report_fatal_error("Broken module found, compilation aborted!");
-}
+  if (verifyModule(*MergedModule, &dbgs(),
+                   LTOStripInvalidDebugInfo ? &BrokenDebugInfo : nullptr))
 
 void LTOCodeGenerator::finishOptimizationRemarks() {
   if (DiagnosticOutputFile) {
     DiagnosticOutputFile->keep();
     // FIXME: LTOCodeGenerator dtor is not invoked on Darwin
     DiagnosticOutputFile->os().flush();
   }
 }