[analyzer] Only adjust the type of 'this' when we devirtualize a method call.

With reinterpret_cast, we can get completely unrelated types in a region
hierarchy together; this was resulting in CXXBaseObjectRegions being layered
directly on an (untyped) SymbolicRegion, whose symbol was from a completely
different type hierarchy. This was what was causing the internal buildbot to
fail.

Reverts r161911, which merely masked the problem.

llvm-svn: 161960

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/Analysis/reinterpret-cast.cpp b/clang/test/Analysis/reinterpret-cast.cpp
new file mode 100644
index 00000000000..73f2e2de738
--- /dev/null
+++ b/clang/test/Analysis/reinterpret-cast.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.ExprInspection -analyzer-ipa=inlining -verify %s
+
+void clang_analyzer_eval(bool);
+
+typedef struct Opaque *Data;
+struct IntWrapper {
+  int x;
+};
+
+struct Child : public IntWrapper {
+  void set() { x = 42; }
+};
+
+void test(Data data) {
+  Child *wrapper = reinterpret_cast<Child*>(data);
+  // Don't crash when upcasting here.
+  // We don't actually know if 'data' is a Child.
+  wrapper->set();
+  clang_analyzer_eval(wrapper->x == 42); // expected-warning{{TRUE}}
+}