Index: compiler-rt/test/asan/TestCases/pass-object-byval.cc
===================================================================
--- /dev/null
+++ compiler-rt/test/asan/TestCases/pass-object-byval.cc
@@ -0,0 +1,36 @@
+// Verify that objects passed by value get red zones and that the copy
+// constructor is called.
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s --implicit-check-not \
+// RUN:     Assertion{{.*}}failed
+#include <cassert>
+
+class A {
+ public:
+  A() : me(this) {}
+  A(const A &other) : me(this) {
+    for (int i = 0; i < 8; ++i) a[i] = other.a[i];
+  }
+
+  int a[8];
+  A *me;
+};
+
+int bar(A *a) {
+  int *volatile ptr = &a->a[0];
+  return *(ptr - 1);
+}
+
+void foo(A a) {
+  assert(a.me == &a);
+  bar(&a);
+}
+
+int main() {
+  A a;
+  foo(a);
+}
+
+// CHECK: ERROR: AddressSanitizer: stack-buffer-overflow
+// CHECK: READ of size 4 at
+// CHECK: is located in stack of thread
Index: compiler-rt/test/asan/TestCases/pass-struct-byval-uar.cc
===================================================================
--- /dev/null
+++ compiler-rt/test/asan/TestCases/pass-struct-byval-uar.cc
@@ -0,0 +1,38 @@
+// Test that use-after-return works with arguments passed by value.
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: %env_asan_opts=detect_stack_use_after_return=0 %run %t 2>&1 | \
+// RUN:     FileCheck --check-prefix=CHECK-NO-UAR %s
+// RUN: not %env_asan_opts=detect_stack_use_after_return=1 %run %t 2>&1 | \
+// RUN:     FileCheck --check-prefix=CHECK-UAR %s
+//
+// On several architectures, the IR does not use byval arguments for foo() and
+// instead creates a copy in main() and gives foo() a pointer to the copy.  In
+// that case, ASAN has nothing to poison on return from foo() and will not
+// detect the UAR.
+// REQUIRES: x86_64-target-arch, linux, not-android
+
+#include <cstdio>
+
+struct A {
+  int a[8];
+};
+
+A *foo(A a) {
+  return &a;
+}
+
+int main() {
+  A *a = foo(A());
+  a->a[0] = 7;
+  std::fprintf(stderr, "\n");  // Ensures some output is generated for FileCheck
+                               // to verify in the case where UAR is not
+                               // detected.
+}
+
+// CHECK-NO-UAR-NOT: ERROR: AddressSanitizer: stack-use-after-return
+// CHECK-NO-UAR-NOT: WRITE of size 4 at
+// CHECK-NO-UAR-NOT: Memory access at offset {{[0-9]+}} is inside this variable
+//
+// CHECK-UAR: ERROR: AddressSanitizer: stack-use-after-return
+// CHECK-UAR: WRITE of size 4 at
+// CHECK-UAR: Memory access at offset {{[0-9]+}} is inside this variable
Index: compiler-rt/test/asan/TestCases/pass-struct-byval.cc
===================================================================
--- /dev/null
+++ compiler-rt/test/asan/TestCases/pass-struct-byval.cc
@@ -0,0 +1,23 @@
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s
+
+struct A {
+  int a[8];
+};
+
+int bar(A *a) {
+  int *volatile ptr = &a->a[0];
+  return *(ptr - 1);
+}
+
+void foo(A a) {
+  bar(&a);
+}
+
+int main() {
+  foo(A());
+}
+
+// CHECK: ERROR: AddressSanitizer: stack-buffer-underflow
+// CHECK: READ of size 4 at
+// CHECK: is located in stack of thread