Add a __builtin_addressof that performs the same functionality as the built-in
& operator (ignoring any overloaded operator& for the type). The purpose of
this builtin is for use in std::addressof, to allow it to be made constexpr;
the existing implementation technique (reinterpret_cast to some reference type,
take address, reinterpert_cast back) does not permit this because
reinterpret_cast between reference types is not permitted in a constant
expression in C++11 onwards.
llvm-svn: 186053
diff --git a/clang/test/SemaCXX/builtins.cpp b/clang/test/SemaCXX/builtins.cpp
index 5d61690..63aa711 100644
--- a/clang/test/SemaCXX/builtins.cpp
+++ b/clang/test/SemaCXX/builtins.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -fsyntax-only -verify
+// RUN: %clang_cc1 %s -fsyntax-only -verify -std=c++11
typedef const struct __CFString * CFStringRef;
#define CFSTR __builtin___CFStringMakeConstantString
@@ -24,3 +24,17 @@
// pr14895
typedef __typeof(sizeof(int)) size_t;
extern "C" void *__builtin_alloca (size_t);
+
+namespace addressof {
+ struct S {} s;
+ static_assert(__builtin_addressof(s) == &s, "");
+
+ struct T { constexpr T *operator&() const { return nullptr; } int n; } t;
+ constexpr T *pt = __builtin_addressof(t);
+ static_assert(&pt->n == &t.n, "");
+
+ struct U { int n : 5; } u;
+ int *pbf = __builtin_addressof(u.n); // expected-error {{address of bit-field requested}}
+
+ S *ptmp = __builtin_addressof(S{}); // expected-error {{taking the address of a temporary}}
+}