Revert "[analyzer] Remove constraints on dead symbols as part of removeDeadBindings."

While we definitely want this optimization in the future, we're not
currently handling constraints on symbolic /expressions/ correctly.
These should stay live even if the SymExpr itself is no longer referenced
because could recreate an identical SymExpr later. Only once the SymExpr
can no longer be recreated -- i.e. a component symbol is dead -- can we
safely remove the constraints on it.

This liveness issue is tracked by <rdar://problem/12333297>.

This reverts r163444 / 24c7f98828e039005cff3bd847e7ab404a6a09f8.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164275 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/StaticAnalyzer/Core/SymbolManager.cpp b/lib/StaticAnalyzer/Core/SymbolManager.cpp
index 16fc5408f5..c21df4c318 100644
--- a/lib/StaticAnalyzer/Core/SymbolManager.cpp
+++ b/lib/StaticAnalyzer/Core/SymbolManager.cpp
@@ -117,17 +117,21 @@ bool SymExpr::symbol_iterator::operator!=(const symbol_iterator &X) const {
 
 SymExpr::symbol_iterator::symbol_iterator(const SymExpr *SE) {
   itr.push_back(SE);
+  while (!isa<SymbolData>(itr.back())) expand();
 }
 
 SymExpr::symbol_iterator &SymExpr::symbol_iterator::operator++() {
   assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
-  expand();
+  assert(isa<SymbolData>(itr.back()));
+  itr.pop_back();
+  if (!itr.empty())
+    while (!isa<SymbolData>(itr.back())) expand();
   return *this;
 }
 
 SymbolRef SymExpr::symbol_iterator::operator*() {
   assert(!itr.empty() && "attempting to dereference an 'end' iterator");
-  return itr.back();
+  return cast<SymbolData>(itr.back());
 }
 
 void SymExpr::symbol_iterator::expand() {