Make locales (and transitively, std::endl) work reliably with gcc.
libc++ currently relies on undefined initialization order of global
initializers when using gcc:
1. __start_std_streams in iostream.cpp calls locale::id::_init, which assigns
an id to each locale::facet in an initializer
2. Every facet has a static locale::id id, whose constructor sets the facet's
id to 0
If 2 runs after 1, it clobbers the facet's assigned consecutive id, causing
exceptions to be thrown when e.g. running code like "cout << endl".
To fix this, let _LIBCPP_CONSTEXPR evaluate to "constexpr" instead of nothing
with gcc. locale::id's constructor is marked _LIBCPP_CONSTEXPR, which ensures
that it won't get an initializer that could potentially run after the
iostream.cpp initializer. (This remains broken when building with msvc.)
Also switch constexpr-specific code in bitset to use __SIZEOF_SIZE_T__ instead
of __SIZE_WIDTH__, because gcc doesn't define the latter.
Pair-programmed/debugged with Dana Jansens.
llvm-svn: 210188
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 1d1b46cdf71bec1d95ca8a4665990972bd34bfc7
diff --git a/include/__config b/include/__config
index ce39243..f803c9a 100644
--- a/include/__config
+++ b/include/__config
@@ -368,7 +368,14 @@
#endif
#define _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+
+// constexpr was added to GCC in 4.6.
+#if _GNUC_VER < 406
#define _LIBCPP_HAS_NO_CONSTEXPR
+// Can only use constexpr in c++11 mode.
+#elif !defined(__GXX_EXPERIMENTAL_CXX0X__) && __cplusplus < 201103L
+#define _LIBCPP_HAS_NO_CONSTEXPR
+#endif
#define _NOEXCEPT throw()
#define _NOEXCEPT_(x)
diff --git a/include/bitset b/include/bitset
index 4cc7dbd..8c278cc 100644
--- a/include/bitset
+++ b/include/bitset
@@ -249,9 +249,9 @@
_LIBCPP_CONSTEXPR
__bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
#ifndef _LIBCPP_HAS_NO_CONSTEXPR
-#if __SIZE_WIDTH__ == 64
+#if __SIZEOF_SIZE_T__ == 8
: __first_{__v}
-#elif __SIZE_WIDTH__ == 32
+#elif __SIZEOF_SIZE_T__ == 4
: __first_{__v, __v >> __bits_per_word}
#else
#error This constructor has not been ported to this platform