[analyzer] Mark symbol values as dead in the environment.

This allows us to properly remove dead bindings at the end of the top-level
stack frame, using the ReturnStmt, if there is one, to keep the return value
live. This in turn removes the need for a check::EndPath callback in leak
checkers.

This does cause some changes in the path notes for leak checkers. Previously,
a leak would be reported at the location of the closing brace in a function.
Now, it gets reported at the last statement. This matches the way leaks are
currently reported for inlined functions, but is less than ideal for both.

llvm-svn: 168066

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/Environment.cpp b/clang/lib/StaticAnalyzer/Core/Environment.cpp
index bab89c545c3..7dcd12c5bdf 100644
--- a/clang/lib/StaticAnalyzer/Core/Environment.cpp
+++ b/clang/lib/StaticAnalyzer/Core/Environment.cpp
@@ -241,6 +241,10 @@ EnvironmentManager::removeDeadBindings(Environment Env,
       // Mark all symbols in the block expr's value live.
       RSScaner.scan(X);
       continue;
+    } else {
+      SymExpr::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
+      for (; SI != SE; ++SI)
+        SymReaper.maybeDead(*SI);
     }
   }