[lld] r288443 - Fix undefined behavior.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Thu Dec  1 18:38:15 2016
New Revision: 288443

URL: http://llvm.org/viewvc/llvm-project?rev=288443&view=rev
Log:
Fix undefined behavior.

New items can be added to Ranges here, and that invalidates
an iterater that previously pointed the end of the vector.

Modified:
    lld/trunk/ELF/ICF.cpp

Modified: lld/trunk/ELF/ICF.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ICF.cpp?rev=288443&r1=288442&r2=288443&view=diff
==============================================================================
--- lld/trunk/ELF/ICF.cpp (original)
+++ lld/trunk/ELF/ICF.cpp Thu Dec  1 18:38:15 2016
@@ -328,19 +328,21 @@ template <class ELFT> void ICF<ELFT>::ru
   };
 
   // Compare static contents and assign unique IDs for each static content.
-  auto End = Ranges.end();
-  foreach(Ranges.begin(), End, [&](Range &R) { segregate(&R, true); });
-  foreach(End, Ranges.end(), Copy);
+  size_t Size = Ranges.size();
+  foreach(Ranges.begin(), Ranges.end(),
+          [&](Range &R) { segregate(&R, true); });
+  foreach(Ranges.begin() + Size, Ranges.end(), Copy);
   ++Cnt;
 
   // Split ranges by comparing relocations until convergence is obtained.
   for (;;) {
-    auto End = Ranges.end();
-    foreach(Ranges.begin(), End, [&](Range &R) { segregate(&R, false); });
-    foreach(End, Ranges.end(), Copy);
+    size_t Size = Ranges.size();
+    foreach(Ranges.begin(), Ranges.end(),
+            [&](Range &R) { segregate(&R, false); });
+    foreach(Ranges.begin() + Size, Ranges.end(), Copy);
     ++Cnt;
 
-    if (End == Ranges.end())
+    if (Size == Ranges.size())
       break;
   }