[llvm-commits] CVS: llvm/include/llvm/ADT/SmallVector.h

[Dan Gohman]

Changes in directory llvm/include/llvm/ADT:

SmallVector.h updated: 1.28 -> 1.29
---
Log message:

Fix some sporadic segfaults that are triggered when SmallVector's heap
storage lands near the end of the available address space. In the expression
Begin+N > Capacity, the Begin+N was overflowing. Fix this by replacing it
by with an expression that doesn't involve computation of an address
beyond the end of allocated memory.


---
Diffs of the changes:  (+3 -3)

 SmallVector.h |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)


Index: llvm/include/llvm/ADT/SmallVector.h
diff -u llvm/include/llvm/ADT/SmallVector.h:1.28 llvm/include/llvm/ADT/SmallVector.h:1.29
--- llvm/include/llvm/ADT/SmallVector.h:1.28	Wed Apr 18 21:04:09 2007
+++ llvm/include/llvm/ADT/SmallVector.h	Thu May 17 13:29:01 2007
@@ -147,7 +147,7 @@
       destroy_range(Begin+N, End);
       End = Begin+N;
     } else if (N > size()) {
-      if (Begin+N > Capacity)
+      if (Capacity-Begin < N)
         grow(N);
       construct_range(End, Begin+N, T());
       End = Begin+N;
@@ -159,7 +159,7 @@
       destroy_range(Begin+N, End);
       End = Begin+N;
     } else if (N > size()) {
-      if (Begin+N > Capacity)
+      if (Capacity-Begin < N)
         grow(N);
       construct_range(End, Begin+N, NV);
       End = Begin+N;
@@ -189,7 +189,7 @@
   
   void assign(unsigned NumElts, const T &Elt) {
     clear();
-    if (Begin+NumElts > Capacity)
+    if (Capacity-Begin < NumElts)
       grow(NumElts);
     End = Begin+NumElts;
     construct_range(Begin, End, Elt);