1 files changed, 34 insertions, 0 deletions
diff --git a/test/CodeGenCXX/tail-padding.cpp b/test/CodeGenCXX/tail-padding.cpp
new file mode 100644
index 000000000000..b8b9e4ccf9a7
--- /dev/null
+++ b/test/CodeGenCXX/tail-padding.cpp
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck %s
+
+// PR36992
+namespace Implicit {
+  struct A { char c; A(const A&); };
+  struct B { int n; char c[3]; ~B(); };
+  struct C : B, virtual A {};
+  static_assert(sizeof(C) == sizeof(void*) + 8);
+  C f(C c) { return c; }
+
+  // CHECK: define {{.*}} @_ZN8Implicit1CC1EOS0_
+  // CHECK: call {{.*}} @_ZN8Implicit1AC2ERKS0_(
+  // Note: this must memcpy 7 bytes, not 8, to avoid trampling over the virtual base class.
+  // CHECK: call void @llvm.memcpy.p0i8.p0i8.i{{32|64}}(i8* {{.*}}, i8* {{.*}}, i{{32|64}} 7, i1 false)
+  // CHECK: store i32 {{.*}} @_ZTVN8Implicit1CE
+}
+
+namespace InitWithinNVSize {
+  // This is the same as the previous test, except that the A base lies
+  // entirely within the nvsize of C. This makes it valid to copy at the
+  // full width.
+  struct A { char c; A(const A&); };
+  struct B { int n; char c[3]; ~B(); };
+  struct C : B, virtual A { char x; };
+  static_assert(sizeof(C) > sizeof(void*) + 8);
+  C f(C c) { return c; }
+
+  // CHECK: define {{.*}} @_ZN16InitWithinNVSize1CC1EOS0_
+  // CHECK: call {{.*}} @_ZN16InitWithinNVSize1AC2ERKS0_(
+  // This copies over the 'C::x' member, but that's OK because we've not initialized it yet.
+  // CHECK: call void @llvm.memcpy.p0i8.p0i8.i{{32|64}}(i8* {{.*}}, i8* {{.*}}, i{{32|64}} 8, i1 false)
+  // CHECK: store i32 {{.*}} @_ZTVN16InitWithinNVSize1CE
+  // CHECK: store i8
+}