Fix a couple false positive "uninitialized value" warnings with RegionStore

involving reasoning about unions (which we don't handle yet).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78342 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 32 insertions, 0 deletions

diff --git a/test/Analysis/unions-region.m b/test/Analysis/unions-region.m
new file mode 100644
index 0000000000..d253009d8b
--- /dev/null
+++ b/test/Analysis/unions-region.m
@@ -0,0 +1,32 @@
+// RUN: clang-cc -analyze -checker-cfref -analyzer-store=region -analyzer-constraints=range %s -verify
+
+//===-- unions-region.m ---------------------------------------------------===//
+//
+// This file tests the analyzer's reasoning about unions.
+//
+//===----------------------------------------------------------------------===//
+
+// When using RegionStore, this test case previously had a false positive
+// of a 'pass-by-value argument is uninitialized' warning at the call to
+// 'testA_aux'.
+
+union u_testA {
+  unsigned i;
+  float f;
+};
+ 
+float testA(float f) {
+  int testA_aux(unsigned x);
+  int testA_aux_2(union u_testA z);
+  
+  union u_testA swap;
+  swap.f = f;
+
+  if (testA_aux(swap.i))  // no-warning
+    swap.i = ((swap.i & 0xffff0000) >> 16) | ((swap.i & 0x0000fffff) << 16);
+
+  testA_aux_2(swap); // no-warning
+
+  return swap.f;  
+}
+