Resubmit an earlier patch of mine:

reduce the size of relevant "ghostly" sentinels
by a pointer.

This attempt now makes the compactification dependent
on the configure variable LLVM_COMPACT_SENTINELS
and should not cause any bootstrap failures for
llvm-gcc any more.

Please note that this is not yet the final version,
and (as settled with Chris) I shall take out the
autofoo/cmake portions in the next days.

This will also lose the assertability on sentinel
dereferencing and operator++, but that seems
an acceptable price to pay for the simplified
build logic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79938 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 3 deletions

diff --git a/include/llvm/ADT/ilist.h b/include/llvm/ADT/ilist.h
index 1db648b0ff..1a3571dea5 100644
--- a/include/llvm/ADT/ilist.h
+++ b/include/llvm/ADT/ilist.h
@@ -39,8 +39,15 @@
 #define LLVM_ADT_ILIST_H
 
 #include "llvm/ADT/iterator.h"
+#include "llvm/Config/config.h"
 #include <cassert>
 
+#if defined(LLVM_COMPACT_SENTINELS) && LLVM_COMPACT_SENTINELS
+#   define sentinel_tail_assert(COND)
+#else
+#   define sentinel_tail_assert(COND) assert(COND)
+#endif
+
 namespace llvm {
 
 template<typename NodeTy, typename Traits> class iplist;
@@ -189,12 +196,12 @@ public:
 
   // Accessors...
   operator pointer() const {
-    assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
+    sentinel_tail_assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
     return NodePtr;
   }
 
   reference operator*() const {
-    assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
+    sentinel_tail_assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
     return *NodePtr;
   }
   pointer operator->() const { return &operator*(); }
@@ -215,7 +222,7 @@ public:
   }
   ilist_iterator &operator++() {      // preincrement - Advance
     NodePtr = Traits::getNext(NodePtr);
-    assert(NodePtr && "++'d off the end of an ilist!");
+    sentinel_tail_assert(NodePtr && "++'d off the end of an ilist!");
     return *this;
   }
   ilist_iterator operator--(int) {    // postdecrement operators...