[llvm-dwarfdump] Avoid possible div-by-zero in debug output

[slydiman]

Summary

We didn't add a test because this bug only affected the debug output.

[djtodoro]

Thanks.

[djtodoro]

llvm/tools/llvm-dwarfdump/Statistics.cpp

1064

can we face the same here?

[slydiman]

llvm/tools/llvm-dwarfdump/Statistics.cpp

1064

Probably yes, but we did not face it yet. I have updated the patch just to be sure.

[djtodoro]

lgtm

[slydiman]

Closed by commit https://github.com/llvm/llvm-project/commit/e5c1a908b36eadb59c2ec7dd1cc784e1e1fa74f8

llvm/tools/llvm-dwarfdump/Statistics.cpp

bool dwarfdump::collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
   // Print the location statistics for local variables.
   printDatum(J, "#local vars processed by location statistics",
              LocStats.NumVar.Value);
   printLocationStats(J, "#local vars", LocStats.LocalVarLocStats);
   printLocationStats(J, "#local vars - entry values",
                      LocStats.LocalVarNonEntryValLocStats);
   J.objectEnd();
   OS << '\n';
-  LLVM_DEBUG(llvm::dbgs() << "Total Availability: "
-                          << (int)std::round((VarParamWithLoc.Value * 100.0) /
+  LLVM_DEBUG(
+      llvm::dbgs() << "Total Availability: "
+                   << (VarParamTotal.Value
+                           ? (int)std::round((VarParamWithLoc.Value * 100.0) /
                                              VarParamTotal.Value)
-                          << "%\n";
-             llvm::dbgs() << "PC Ranges covered: "
-                          << (int)std::round(
+                           : 0)
+                   << (GlobalStats.ScopeBytes.Value
+                           ? (int)std::round(
                                  (GlobalStats.ScopeBytesCovered.Value * 100.0) /
                                  GlobalStats.ScopeBytes.Value)
-                          << "%\n");
+                           : 0)
   return true;
 }