[analyzer] Fix FP warnings when binding a temporary to a local static variable

Summary:
When binding a temporary object to a static local variable, the analyzer would
complain about a dangling reference even though the temporary's lifetime should
be extended past the end of the function. This commit tries to detect these
cases and construct them in a global memory region instead of a local one.

Reviewers: jordan_rose

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1133

llvm-svn: 187196

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/test/Analysis/stack-addr-ps.cpp b/clang/test/Analysis/stack-addr-ps.cpp
index 65d757154c8..a39f9c7dc72 100644
--- a/clang/test/Analysis/stack-addr-ps.cpp
+++ b/clang/test/Analysis/stack-addr-ps.cpp
@@ -20,6 +20,10 @@ const int& g3() {
   return s3; // expected-warning{{Address of stack memory associated with local variable 's1' returned}} expected-warning {{reference to stack memory associated with local variable 's1' returned}}
 }
 
+void g4() {
+  static const int &x = 3; // no warning
+}
+
 int get_value();
 
 const int &get_reference1() { return get_value(); } // expected-warning{{Address of stack memory associated with temporary object of type 'int' returned}} expected-warning {{returning reference to local temporary}}