Fix new warnings emitted by GCC 7

llvm-svn: 302280

diff --git a/libcxx/include/__config b/libcxx/include/__config
index 05622a4..a9f9d0f 100644 (file)
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1089,6 +1089,13 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 # define _LIBCPP_DIAGNOSE_ERROR(...)
 #endif
 
+#if __has_attribute(fallthough) || defined(_LIBCPP_COMPILER_GCC)
+// Use a function like macro to imply that it must be followed by a semicolon
+#define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
+#else
+#define _LIBCPP_FALLTHROUGH() ((void)0)
+#endif
+
 #if defined(_LIBCPP_ABI_MICROSOFT) && \
    (defined(_LIBCPP_COMPILER_MSVC) || __has_declspec_attribute(empty_bases))
 # define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)

diff --git a/libcxx/include/locale b/libcxx/include/locale
index 6bce16e..d0909d5 100644 (file)
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -2825,7 +2825,7 @@ money_get<_CharT, _InputIterator>::__do_get(iter_type& __b, iter_type __e,
                     return false;
                 }
             }
-            // drop through
+            _LIBCPP_FALLTHROUGH();
         case money_base::none:
             if (__p != 3)
             {

diff --git a/libcxx/src/locale.cpp b/libcxx/src/locale.cpp
index 1460f96..1ed9b41 100644 (file)
--- a/libcxx/src/locale.cpp
+++ b/libcxx/src/locale.cpp
@@ -68,8 +68,8 @@ T&
 make(A0 a0)
 {
     static typename aligned_storage<sizeof(T)>::type buf;
-    ::new (&buf) T(a0);
-    return *reinterpret_cast<T*>(&buf);
+    auto *obj = ::new (&buf) T(a0);
+    return *obj;
 }
 
 template <class T, class A0, class A1>
@@ -88,8 +88,8 @@ T&
 make(A0 a0, A1 a1, A2 a2)
 {
     static typename aligned_storage<sizeof(T)>::type buf;
-    ::new (&buf) T(a0, a1, a2);
-    return *reinterpret_cast<T*>(&buf);
+    auto *obj = ::new (&buf) T(a0, a1, a2);
+    return *obj;
 }
 
 template <typename T, size_t N>
@@ -480,8 +480,8 @@ locale::__imp::make_global()
 {
     // only one thread can get in here and it only gets in once
     static aligned_storage<sizeof(locale)>::type buf;
-    ::new (&buf) locale(locale::classic());
-    return *reinterpret_cast<locale*>(&buf);
+    auto *obj = ::new (&buf) locale(locale::classic());
+    return *obj;
 }
 
 locale&