[analyzer] Treat LValueBitCasts like regular pointer bit casts.

These casts only appear in very well-defined circumstances, in which the
target of a reinterpret_cast or a function formal parameter is an lvalue
reference. According to the C++ standard, the following are equivalent:

 reinterpret_cast<T&>( x)
*reinterpret_cast<T*>(&x)

[expr.reinterpret.cast]p11

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158338 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/test/Analysis/casts.cpp b/test/Analysis/casts.cpp
new file mode 100644
index 0000000000..046ffb53c8
--- /dev/null
+++ b/test/Analysis/casts.cpp
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,experimental.core -analyzer-store=region -verify %s
+
+void fill_r (int * const &x);
+
+char testPointer () {
+  int x[8];
+  int *xp = x;
+  fill_r(xp);
+
+  return x[0]; // no-warning
+}
+
+char testArray () {
+  int x[8];
+  fill_r(x);
+
+  return x[0]; // no-warning
+}
+
+char testReferenceCast () {
+  int x[8];
+  int *xp = x;
+  fill_r(reinterpret_cast<int * const &>(xp));
+  
+  return x[0]; // no-warning
+}
+
+
+void fill (int *x);
+char testReferenceCastRValue () {
+  int x[8];
+  int *xp = x;
+  fill(reinterpret_cast<int * const &>(xp));
+
+  return x[0]; // no-warning
+}