[PATCH] abg-dwarf-reader.cc: Avoid division by zero.

[Giuliano Procida]

The DWARF reader could divide by zero when emitting statistics about
late canonicalisation of types. This is undefined behaviour but
typically results in process termination.

	* src/abg-dwarf-reader.cc (perform_late_type_canonicalizing):
	If total is zero, don't try to output percentages using it as
	a divisor.

Signed-off-by: Giuliano Procida <gprocida@google.com>
---
 src/abg-dwarf-reader.cc | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/abg-dwarf-reader.cc b/src/abg-dwarf-reader.cc
index 10ca1232..249e196d 100644
--- a/src/abg-dwarf-reader.cc
+++ b/src/abg-dwarf-reader.cc
@@ -5849,11 +5849,15 @@ public:
 	     << elf_path()
 	     << "\n";
 	cerr << "    # late canonicalized types: "
-	     << num_canonicalized
-	     << " (" << num_canonicalized * 100 / total << "%)\n"
+             << num_canonicalized;
+        if (total)
+          cerr << " (" << num_canonicalized * 100 / total << "%)";
+        cerr << "\n"
 	     << "    # missed canonicalization opportunities: "
-	     << num_missed
-	     << " (" << num_missed * 100 / total << "%)\n";
+             << num_missed;
+        if (total)
+          cerr << " (" << num_missed * 100 / total << "%)";
+        cerr << "\n";
       }
 
   }
-- 
2.26.0.rc2.310.g2932bb562d-goog