[llvm-commits] [llvm] r128567 - in /llvm/trunk: include/llvm/ADT/StringMap.h lib/Support/StringMap.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Wed Mar 30 13:32:51 2011
New Revision: 128567

URL: http://llvm.org/viewvc/llvm-project?rev=128567&view=rev
Log:
Reset StringMap's NumTombstones on clears and rehashes.

StringMap was not properly updating NumTombstones after a clear or rehash.

This was not fatal until now because the table was growing faster than
NumTombstones could, but with the previous change of preventing infinite
growth of the table the invariant (NumItems + NumTombstones <= NumBuckets)
stopped being observed, causing infinite loops in certain situations.

Patch by José Fonseca!

Modified:
    llvm/trunk/include/llvm/ADT/StringMap.h
    llvm/trunk/lib/Support/StringMap.cpp

Modified: llvm/trunk/include/llvm/ADT/StringMap.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/StringMap.h?rev=128567&r1=128566&r2=128567&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/StringMap.h (original)
+++ llvm/trunk/include/llvm/ADT/StringMap.h Wed Mar 30 13:32:51 2011
@@ -329,6 +329,7 @@
       --NumTombstones;
     Bucket.Item = KeyValue;
     ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
 
     RehashTable();
     return true;
@@ -348,6 +349,7 @@
     }
 
     NumItems = 0;
+    NumTombstones = 0;
   }
 
   /// GetOrCreateValue - Look up the specified key in the table.  If a value
@@ -367,6 +369,7 @@
     if (Bucket.Item == getTombstoneVal())
       --NumTombstones;
     ++NumItems;
+    assert(NumItems + NumTombstones <= NumBuckets);
 
     // Fill in the bucket for the hash table.  The FullHashValue was already
     // filled in by LookupBucketFor.

Modified: llvm/trunk/lib/Support/StringMap.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/StringMap.cpp?rev=128567&r1=128566&r2=128567&view=diff
==============================================================================
--- llvm/trunk/lib/Support/StringMap.cpp (original)
+++ llvm/trunk/lib/Support/StringMap.cpp Wed Mar 30 13:32:51 2011
@@ -169,6 +169,8 @@
   TheTable[Bucket].Item = getTombstoneVal();
   --NumItems;
   ++NumTombstones;
+  assert(NumItems + NumTombstones <= NumBuckets);
+
   return Result;
 }
 
@@ -224,4 +226,5 @@
   
   TheTable = NewTableArray;
   NumBuckets = NewSize;
+  NumTombstones = 0;
 }