vendor/libc++/libc++-release_70-r339999

35 files changed, 339 insertions, 145 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 66d9bebc592d..acb49565ce97 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -120,6 +120,7 @@ set(LIBCXX_ABI_VERSION ${DEFAULT_ABI_VERSION} CACHE STRING "ABI version of libc+
 option(LIBCXX_ABI_UNSTABLE "Unstable ABI of libc++." OFF)
 option(LIBCXX_ABI_FORCE_ITANIUM "Ignore auto-detection and force use of the Itanium ABI.")
 option(LIBCXX_ABI_FORCE_MICROSOFT "Ignore auto-detection and force use of the Microsoft ABI.")
+option(LIBCXX_HIDE_FROM_ABI_PER_TU_BY_DEFAULT "Enable per TU ABI insulation by default. To be used by vendors." OFF)
 set(LIBCXX_ABI_DEFINES "" CACHE STRING "A semicolon separated list of ABI macros to define in the site config header.")
 option(LIBCXX_USE_COMPILER_RT "Use compiler-rt instead of libgcc" OFF)
 
@@ -175,7 +176,7 @@ cmake_dependent_option(LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY
 
 cmake_dependent_option(LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
   "Statically link the ABI library to shared library" ON
-  "LIBCXX_ENABLE_STATIC_ABI_LIBRARY;LIBCXX_ENABLE_STATIC" OFF)
+  "LIBCXX_ENABLE_STATIC_ABI_LIBRARY;LIBCXX_ENABLE_SHARED" OFF)
 
 # Generate and install a linker script inplace of libc++.so. The linker script
 # will link libc++ to the correct ABI library. This option is on by default
@@ -662,6 +663,7 @@ endif()
 config_define_if(LIBCXX_ABI_UNSTABLE _LIBCPP_ABI_UNSTABLE)
 config_define_if(LIBCXX_ABI_FORCE_ITANIUM _LIBCPP_ABI_FORCE_ITANIUM)
 config_define_if(LIBCXX_ABI_FORCE_MICROSOFT _LIBCPP_ABI_FORCE_MICROSOFT)
+config_define_if(LIBCXX_HIDE_FROM_ABI_PER_TU_BY_DEFAULT _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT)
 
 config_define_if_not(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
 config_define_if_not(LIBCXX_ENABLE_STDIN _LIBCPP_HAS_NO_STDIN)
diff --git a/docs/BuildingLibcxx.rst b/docs/BuildingLibcxx.rst
index d0b03c675c8b..daf9229a0d05 100644
--- a/docs/BuildingLibcxx.rst
+++ b/docs/BuildingLibcxx.rst
@@ -332,6 +332,15 @@ libc++ Feature Options
   Use the specified GCC toolchain and standard library when building the native
   stdlib benchmark tests.
 
+.. option:: LIBCXX_HIDE_FROM_ABI_PER_TU_BY_DEFAULT:BOOL
+
+  **Default**: ``OFF``
+
+  Pick the default for whether to constrain ABI-unstable symbols to
+  each individual translation unit. This setting controls whether
+  `_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT` is defined by default --
+  see the documentation of that macro for details.
+
 
 libc++ ABI Feature Options
 --------------------------
diff --git a/docs/DesignDocs/VisibilityMacros.rst b/docs/DesignDocs/VisibilityMacros.rst
index 878566ea0bc1..ab577df13641 100644
--- a/docs/DesignDocs/VisibilityMacros.rst
+++ b/docs/DesignDocs/VisibilityMacros.rst
@@ -42,9 +42,42 @@ Visibility Macros
 
 **_LIBCPP_HIDE_FROM_ABI**
   Mark a function as not being part of the ABI of any final linked image that
-  uses it, and also as being internal to each TU that uses that function. In
-  other words, the address of a function marked with this attribute is not
-  guaranteed to be the same across translation units.
+  uses it.
+
+**_LIBCPP_HIDE_FROM_ABI_PER_TU**
+  This macro controls whether symbols hidden from the ABI with `_LIBCPP_HIDE_FROM_ABI`
+  are local to each translation unit in addition to being local to each final
+  linked image. This macro is defined to either 0 or 1. When it is defined to
+  1, translation units compiled with different versions of libc++ can be linked
+  together, since all non ABI-facing functions are local to each translation unit.
+  This allows static archives built with different versions of libc++ to be linked
+  together. This also means that functions marked with `_LIBCPP_HIDE_FROM_ABI`
+  are not guaranteed to have the same address across translation unit boundaries.
+
+  When the macro is defined to 0, there is no guarantee that translation units
+  compiled with different versions of libc++ can interoperate. However, this
+  leads to code size improvements, since non ABI-facing functions can be
+  deduplicated across translation unit boundaries.
+
+  This macro can be defined by users to control the behavior they want from
+  libc++. The default value of this macro (0 or 1) is controlled by whether
+  `_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT` is defined, which is intended to
+  be used by vendors only (see below).
+
+**_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT**
+  This macro controls the default value for `_LIBCPP_HIDE_FROM_ABI_PER_TU`.
+  When the macro is defined, per TU ABI insulation is enabled by default, and
+  `_LIBCPP_HIDE_FROM_ABI_PER_TU` is defined to 1 unless overriden by users.
+  Otherwise, per TU ABI insulation is disabled by default, and
+  `_LIBCPP_HIDE_FROM_ABI_PER_TU` is defined to 0 unless overriden by users.
+
+  This macro is intended for vendors to control whether they want to ship
+  libc++ with per TU ABI insulation enabled by default. Users can always
+  control the behavior they want by defining `_LIBCPP_HIDE_FROM_ABI_PER_TU`
+  appropriately.
+
+  By default, this macro is not defined, which means that per TU ABI insulation
+  is not provided unless explicitly overriden by users.
 
 **_LIBCPP_TYPE_VIS**
   Mark a type's typeinfo, vtable and members as having default visibility.
diff --git a/include/__config b/include/__config
index 639d06c9f5d7..738d891e3032 100644
--- a/include/__config
+++ b/include/__config
@@ -328,6 +328,31 @@
 #  define _LIBCPP_NO_CFI
 #endif
 
+#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
+#  if defined(__FreeBSD__)
+#    define _LIBCPP_HAS_QUICK_EXIT
+#    define _LIBCPP_HAS_C11_FEATURES
+#  elif defined(__Fuchsia__)
+#    define _LIBCPP_HAS_QUICK_EXIT
+#    define _LIBCPP_HAS_TIMESPEC_GET
+#    define _LIBCPP_HAS_C11_FEATURES
+#  elif defined(__linux__)
+#    if !defined(_LIBCPP_HAS_MUSL_LIBC)
+#      if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
+#        define _LIBCPP_HAS_QUICK_EXIT
+#      endif
+#      if _LIBCPP_GLIBC_PREREQ(2, 17)
+#        define _LIBCPP_HAS_C11_FEATURES
+#        define _LIBCPP_HAS_TIMESPEC_GET
+#      endif
+#    else // defined(_LIBCPP_HAS_MUSL_LIBC)
+#      define _LIBCPP_HAS_QUICK_EXIT
+#      define _LIBCPP_HAS_TIMESPEC_GET
+#      define _LIBCPP_HAS_C11_FEATURES
+#    endif
+#  endif // __linux__
+#endif
+
 #if defined(_LIBCPP_COMPILER_CLANG)
 
 // _LIBCPP_ALTERNATE_STRING_LAYOUT is an old name for
@@ -430,28 +455,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
 #endif
 
-#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
-#  if defined(__FreeBSD__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__Fuchsia__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__linux__)
-#    if !defined(_LIBCPP_HAS_MUSL_LIBC)
-#      if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
-#        define _LIBCPP_HAS_QUICK_EXIT
-#      endif
-#      if _LIBCPP_GLIBC_PREREQ(2, 17)
-#        define _LIBCPP_HAS_C11_FEATURES
-#      endif
-#    else // defined(_LIBCPP_HAS_MUSL_LIBC)
-#      define _LIBCPP_HAS_QUICK_EXIT
-#      define _LIBCPP_HAS_C11_FEATURES
-#    endif
-#  endif // __linux__
-#endif
-
 #if !(__has_feature(cxx_noexcept))
 #define _LIBCPP_HAS_NO_NOEXCEPT
 #endif
@@ -801,8 +804,20 @@ namespace std {
 #  define _LIBCPP_INTERNAL_LINKAGE _LIBCPP_ALWAYS_INLINE
 #endif
 
+#ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU
+#  ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
+#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 0
+#  else
+#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 1
+#  endif
+#endif
+
 #ifndef _LIBCPP_HIDE_FROM_ABI
-#  define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
+#  if _LIBCPP_HIDE_FROM_ABI_PER_TU
+#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
+#  else
+#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_ALWAYS_INLINE
+#  endif
 #endif
 
 // Just so we can migrate to _LIBCPP_HIDE_FROM_ABI gradually.
@@ -991,6 +1006,11 @@ template <unsigned> struct __static_assert_check {};
 #  endif
 #endif // defined(__APPLE__)
 
+#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) && \
+    !defined(_LIBCPP_BUILDING_LIBRARY) && \
+    (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
+#  define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
+#endif
 
 #if defined(__APPLE__) || defined(__FreeBSD__)
 #define _LIBCPP_HAS_DEFAULTRUNELOCALE
diff --git a/include/__config_site.in b/include/__config_site.in
index 8d980ff57cc8..7c7c226c4922 100644
--- a/include/__config_site.in
+++ b/include/__config_site.in
@@ -14,6 +14,7 @@
 #cmakedefine _LIBCPP_ABI_UNSTABLE
 #cmakedefine _LIBCPP_ABI_FORCE_ITANIUM
 #cmakedefine _LIBCPP_ABI_FORCE_MICROSOFT
+#cmakedefine _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
 #cmakedefine _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
 #cmakedefine _LIBCPP_HAS_NO_STDIN
 #cmakedefine _LIBCPP_HAS_NO_STDOUT
diff --git a/include/cstdlib b/include/cstdlib
index 78c428403c37..00c604e67623 100644
--- a/include/cstdlib
+++ b/include/cstdlib
@@ -151,11 +151,11 @@ using ::mbtowc;
 using ::wctomb;
 using ::mbstowcs;
 using ::wcstombs;
-#ifdef _LIBCPP_HAS_QUICK_EXIT
+#if !defined(_LIBCPP_CXX03_LANG) && defined(_LIBCPP_HAS_QUICK_EXIT)
 using ::at_quick_exit;
 using ::quick_exit;
 #endif
-#ifdef _LIBCPP_HAS_C11_FEATURES
+#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_C11_FEATURES)
 using ::aligned_alloc;
 #endif
 
diff --git a/include/ctime b/include/ctime
index 81cf11a466c2..8264fe33b964 100644
--- a/include/ctime
+++ b/include/ctime
@@ -73,7 +73,7 @@ using ::gmtime;
 using ::localtime;
 #endif
 using ::strftime;
-#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_C11_FEATURES)
+#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_TIMESPEC_GET)
 using ::timespec_get;
 #endif
 
diff --git a/include/new b/include/new
index e70b9c621570..5a658c7a2f24 100644
--- a/include/new
+++ b/include/new
@@ -108,13 +108,6 @@ void  operator delete[](void* ptr, void*) noexcept;
 # define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
 #endif
 
-#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) && \
-    (!(defined(_LIBCPP_BUILDING_LIBRARY) || _LIBCPP_STD_VER > 14 || \
-    (defined(__cpp_aligned_new) && __cpp_aligned_new >= 201606)))
-# define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
-#endif
-
-
 #if !__has_builtin(__builtin_operator_new) || \
    __has_builtin(__builtin_operator_new) < 201802L || \
    defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || \
diff --git a/test/libcxx/language.support/has_c11_features.pass.cpp b/test/libcxx/language.support/has_c11_features.pass.cpp
index cdccc00e21b4..4edec534eb98 100644
--- a/test/libcxx/language.support/has_c11_features.pass.cpp
+++ b/test/libcxx/language.support/has_c11_features.pass.cpp
@@ -14,6 +14,9 @@
 //		_LIBCPP_HAS_C11_FEATURES - which is defined in <__config>
 //	They should always be the same
 
+#include <__config>
+#include "test_macros.h"
+
 #ifdef TEST_HAS_C11_FEATURES
 # ifndef _LIBCPP_HAS_C11_FEATURES
 #  error "TEST_HAS_C11_FEATURES is defined, but _LIBCPP_HAS_C11_FEATURES is not"
diff --git a/test/libcxx/memory/aligned_allocation_macro.pass.cpp b/test/libcxx/memory/aligned_allocation_macro.pass.cpp
new file mode 100644
index 000000000000..c1a4252aa619
--- /dev/null
+++ b/test/libcxx/memory/aligned_allocation_macro.pass.cpp
@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// aligned allocation functions are not provided prior to macosx10.13
+// XFAIL: macosx10.12
+// XFAIL: macosx10.11
+// XFAIL: macosx10.10
+// XFAIL: macosx10.9
+// XFAIL: macosx10.8
+// XFAIL: macosx10.7
+
+#include <new>
+
+
+#ifdef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
+#   error "libc++ should have aligned allocation in C++17 and up when targeting a platform that supports it"
+#endif
+
+int main() { }
diff --git a/test/std/depr/depr.c.headers/float_h.pass.cpp b/test/std/depr/depr.c.headers/float_h.pass.cpp
index 3001c215cd19..84e89c4dbb84 100644
--- a/test/std/depr/depr.c.headers/float_h.pass.cpp
+++ b/test/std/depr/depr.c.headers/float_h.pass.cpp
@@ -11,6 +11,8 @@
 
 #include <float.h>
 
+#include "test_macros.h"
+
 #ifndef FLT_ROUNDS
 #error FLT_ROUNDS not defined
 #endif
@@ -23,7 +25,7 @@
 #error FLT_RADIX not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_HAS_SUBNORM
 #error FLT_HAS_SUBNORM not defined
 #endif
@@ -53,7 +55,7 @@
 #error DECIMAL_DIG not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_DECIMAL_DIG
 #error FLT_DECIMAL_DIG not defined
 #endif
@@ -163,7 +165,7 @@
 #error LDBL_MIN not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_TRUE_MIN
 #error FLT_TRUE_MIN not defined
 #endif
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/delete_align_val_t_replace.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/delete_align_val_t_replace.pass.cpp
index 2175e29a040d..52aeea314dd5 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/delete_align_val_t_replace.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/delete_align_val_t_replace.pass.cpp
@@ -12,17 +12,27 @@
 // UNSUPPORTED: sanitizer-new-delete, c++98, c++03, c++11, c++14
 
 // Older Clang versions do not support this
-// XFAIL: clang-3, apple-clang-7, apple-clang-8
+// UNSUPPORTED: clang-3, apple-clang-7, apple-clang-8
 
 // None of the current GCC compilers support this.
-// XFAIL: gcc-5, gcc-6
-
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: gcc-5, gcc-6
+
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
index 942f5e778b66..1d20b33a0df2 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
@@ -15,13 +15,22 @@
 // FIXME change this to XFAIL.
 // UNSUPPORTED: no-aligned-allocation && !gcc
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
-
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
index f55ad5bcc84e..60ebdd8e9457 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
@@ -15,12 +15,22 @@
 // FIXME turn this into an XFAIL
 // UNSUPPORTED: no-aligned-allocation && !gcc
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
index e1ebf86ee176..b09316487f90 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
@@ -10,12 +10,24 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // UNSUPPORTED: sanitizer-new-delete
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so our
+// custom aligned allocation functions are not called and the test fails
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Our custom aligned allocation functions are not called when deploying to
+// platforms older than macosx10.13, since those platforms don't support
+// aligned allocation.
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // XFAIL: no-aligned-allocation && !gcc
 
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size.sh.cpp
index 0dfef2e56fca..40632a1bd49b 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size.fail.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size.sh.cpp
@@ -15,11 +15,12 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include <new>
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
 
-#include "test_macros.h"
+#include <new>
 
 int main ()
 {
-    ::operator new[](4);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+    ::operator new[](4);  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 }
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.sh.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.sh.cpp
new file mode 100644
index 000000000000..f7921d2f2c12
--- /dev/null
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.sh.cpp
@@ -0,0 +1,26 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <new>
+
+// void* operator new[](std::size_t, std::align_val_t);
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
+
+#include <new>
+
+int main ()
+{
+    ::operator new[](4, std::align_val_t{4});  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.sh.cpp
index 99e4f76b312f..130148786732 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.fail.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.sh.cpp
@@ -15,11 +15,12 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include <new>
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
 
-#include "test_macros.h"
+#include <new>
 
 int main ()
 {
-    ::operator new[](4, std::align_val_t{4}, std::nothrow);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+    ::operator new[](4, std::align_val_t{4}, std::nothrow);  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 }
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_nothrow.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_nothrow.sh.cpp
index 8aae54e83fbe..43295a7e6932 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_nothrow.fail.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_nothrow.sh.cpp
@@ -15,11 +15,12 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include <new>
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
 
-#include "test_macros.h"
+#include <new>
 
 int main ()
 {
-    ::operator new[](4, std::nothrow);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+    ::operator new[](4, std::nothrow);  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 }
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/delete_align_val_t_replace.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/delete_align_val_t_replace.pass.cpp
index 6f1c7511243e..5885218c4661 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/delete_align_val_t_replace.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/delete_align_val_t_replace.pass.cpp
@@ -11,17 +11,27 @@
 
 // UNSUPPORTED: sanitizer-new-delete, c++98, c++03, c++11, c++14
 // Older Clang versions do not support this
-// XFAIL: clang-3, apple-clang-7, apple-clang-8
+// UNSUPPORTED: clang-3, apple-clang-7, apple-clang-8
 
 // None of the current GCC compilers support this.
-// XFAIL: gcc-5, gcc-6
-
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: gcc-5, gcc-6
+
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
index fae5d3676df6..52db4c56ced4 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
@@ -9,12 +9,22 @@
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
index f22c48994355..a5e40a0d28c8 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
@@ -9,12 +9,22 @@
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so that's a link error
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Using aligned allocation functions is a compiler error when deploying to
+// platforms older than macosx10.13
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
index 565ba9b851bb..de1bd8d82052 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
@@ -10,12 +10,24 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // UNSUPPORTED: sanitizer-new-delete
 
-// XFAIL: with_system_cxx_lib=macosx10.12
-// XFAIL: with_system_cxx_lib=macosx10.11
-// XFAIL: with_system_cxx_lib=macosx10.10
-// XFAIL: with_system_cxx_lib=macosx10.9
-// XFAIL: with_system_cxx_lib=macosx10.7
-// XFAIL: with_system_cxx_lib=macosx10.8
+// dylibs shipped before macosx10.13 do not provide aligned allocation, so our
+// custom aligned allocation functions are not called and the test fails
+// UNSUPPORTED: with_system_cxx_lib=macosx10.12
+// UNSUPPORTED: with_system_cxx_lib=macosx10.11
+// UNSUPPORTED: with_system_cxx_lib=macosx10.10
+// UNSUPPORTED: with_system_cxx_lib=macosx10.9
+// UNSUPPORTED: with_system_cxx_lib=macosx10.8
+// UNSUPPORTED: with_system_cxx_lib=macosx10.7
+
+// Our custom aligned allocation functions are not called when deploying to
+// platforms older than macosx10.13, since those platforms don't support
+// aligned allocation.
+// UNSUPPORTED: macosx10.12
+// UNSUPPORTED: macosx10.11
+// UNSUPPORTED: macosx10.10
+// UNSUPPORTED: macosx10.9
+// UNSUPPORTED: macosx10.8
+// UNSUPPORTED: macosx10.7
 
 // NOTE: gcc doesn't provide -faligned-allocation flag to test for
 // XFAIL: no-aligned-allocation && !gcc
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.fail.cpp
deleted file mode 100644
index c3cabbdb79d5..000000000000
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.fail.cpp
+++ /dev/null
@@ -1,25 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// <new>
-
-// void* operator new(std::size_t, std::align_val_t);
-
-// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
-// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
-
-#include <new>
-
-#include "test_macros.h"
-
-int main ()
-{
-    ::operator new(4, std::align_val_t{4});  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
-}
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.sh.cpp
index ea041aea16ee..410c6d7748da 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.fail.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.sh.cpp
@@ -10,16 +10,17 @@
 
 // <new>
 
-// void* operator new[](std::size_t, std::align_val_t);
+// void* operator new(std::size_t, std::align_val_t);
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include <new>
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
 
-#include "test_macros.h"
+#include <new>
 
 int main ()
 {
-    ::operator new[](4, std::align_val_t{4});  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+    ::operator new(4, std::align_val_t{4});  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 }
diff --git a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.fail.cpp b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.sh.cpp
index e987a53478b0..1fe104551e1b 100644
--- a/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.fail.cpp
+++ b/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.sh.cpp
@@ -15,11 +15,12 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
 
-#include <new>
+// REQUIRES: -faligned-allocation
+// RUN: %compile %verify -faligned-allocation
 
-#include "test_macros.h"
+#include <new>
 
 int main ()
 {
-    ::operator new(4, std::align_val_t{4}, std::nothrow);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+    ::operator new(4, std::align_val_t{4}, std::nothrow);  // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 }
diff --git a/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp b/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
index 6e399d0934bf..c1e5be91ef1f 100644
--- a/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
+++ b/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
@@ -11,6 +11,8 @@
 
 #include <cfloat>
 
+#include "test_macros.h"
+
 #ifndef FLT_ROUNDS
 #error FLT_ROUNDS not defined
 #endif
@@ -23,7 +25,7 @@
 #error FLT_RADIX not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_HAS_SUBNORM
 #error FLT_HAS_SUBNORM not defined
 #endif
@@ -53,7 +55,7 @@
 #error DECIMAL_DIG not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_DECIMAL_DIG
 #error FLT_DECIMAL_DIG not defined
 #endif
@@ -163,7 +165,7 @@
 #error LDBL_MIN not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_TRUE_MIN
 #error FLT_TRUE_MIN not defined
 #endif
diff --git a/test/std/language.support/support.runtime/ctime.pass.cpp b/test/std/language.support/support.runtime/ctime.pass.cpp
index 908dc480884c..d80bc198293e 100644
--- a/test/std/language.support/support.runtime/ctime.pass.cpp
+++ b/test/std/language.support/support.runtime/ctime.pass.cpp
@@ -45,7 +45,7 @@ int main()
     static_assert((std::is_same<decltype(std::difftime(t,t)), double>::value), "");
     static_assert((std::is_same<decltype(std::mktime(&tm)), std::time_t>::value), "");
     static_assert((std::is_same<decltype(std::time(&t)), std::time_t>::value), "");
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_TIMESPEC_GET)
     static_assert((std::is_same<decltype(std::timespec_get(nullptr, 0)), int>::value), "");
 #endif
 #ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
diff --git a/test/std/language.support/support.start.term/quick_exit.pass.cpp b/test/std/language.support/support.start.term/quick_exit.pass.cpp
index bcfdbb75402e..2bf2ea790653 100644
--- a/test/std/language.support/support.start.term/quick_exit.pass.cpp
+++ b/test/std/language.support/support.start.term/quick_exit.pass.cpp
@@ -6,7 +6,7 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
+// UNSUPPORTED: c++98, c++03
 
 // test quick_exit and at_quick_exit
 
diff --git a/test/std/language.support/support.start.term/quick_exit_check1.fail.cpp b/test/std/language.support/support.start.term/quick_exit_check1.fail.cpp
index 8b9729379163..f42498e3d7b9 100644
--- a/test/std/language.support/support.start.term/quick_exit_check1.fail.cpp
+++ b/test/std/language.support/support.start.term/quick_exit_check1.fail.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
+// UNSUPPORTED: c++98, c++03
 
 // test that referencing at_quick_exit when _LIBCPP_HAS_QUICK_EXIT is not defined
 // results in a compile error.
diff --git a/test/std/language.support/support.start.term/quick_exit_check2.fail.cpp b/test/std/language.support/support.start.term/quick_exit_check2.fail.cpp
index 395914136820..c49704f99aea 100644
--- a/test/std/language.support/support.start.term/quick_exit_check2.fail.cpp
+++ b/test/std/language.support/support.start.term/quick_exit_check2.fail.cpp
@@ -6,7 +6,7 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
+// UNSUPPORTED: c++98, c++03
 
 // test that referencing quick_exit when _LIBCPP_HAS_QUICK_EXIT is not defined
 // results in a compile error.
diff --git a/test/std/utilities/time/date.time/ctime.pass.cpp b/test/std/utilities/time/date.time/ctime.pass.cpp
index fe9f38daa3ff..cd1f32be2bca 100644
--- a/test/std/utilities/time/date.time/ctime.pass.cpp
+++ b/test/std/utilities/time/date.time/ctime.pass.cpp
@@ -47,7 +47,7 @@ int main()
     static_assert((std::is_same<decltype(std::difftime(t,t)), double>::value), "");
     static_assert((std::is_same<decltype(std::mktime(&tm)), std::time_t>::value), "");
     static_assert((std::is_same<decltype(std::time(&t)), std::time_t>::value), "");
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_TIMESPEC_GET)
     static_assert((std::is_same<decltype(std::timespec_get(nullptr, 0)), int>::value), "");
 #endif
 #ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
diff --git a/test/support/nasty_macros.hpp b/test/support/nasty_macros.hpp
index 76d8ab0e720f..97a17bb689a4 100644
--- a/test/support/nasty_macros.hpp
+++ b/test/support/nasty_macros.hpp
@@ -22,7 +22,11 @@
 #define _J NASTY_MACRO
 #define _K NASTY_MACRO
 #define _L NASTY_MACRO
+// Because FreeBSD uses _M in its <sys/types.h>, and it is hard to avoid
+// including that header, only define _M for other operating systems.
+#ifndef __FreeBSD__
 #define _M NASTY_MACRO
+#endif
 #define _N NASTY_MACRO
 #define _O NASTY_MACRO
 #define _P NASTY_MACRO
diff --git a/test/support/test_macros.h b/test/support/test_macros.h
index ac6ec79b9235..e008b5323003 100644
--- a/test/support/test_macros.h
+++ b/test/support/test_macros.h
@@ -124,22 +124,29 @@
 
 // Sniff out to see if the underling C library has C11 features
 // Note that at this time (July 2018), MacOS X and iOS do NOT.
-#if __ISO_C_VISIBLE >= 2011
+// This is cribbed from __config; but lives here as well because we can't assume libc++
+#if __ISO_C_VISIBLE >= 2011 || TEST_STD_VER >= 11
 #  if defined(__FreeBSD__)
+//  Specifically, FreeBSD does NOT have timespec_get, even though they have all
+//  the rest of C11 - this is PR#38495
 #    define TEST_HAS_C11_FEATURES
 #  elif defined(__Fuchsia__)
 #    define TEST_HAS_C11_FEATURES
+#    define TEST_HAS_TIMESPEC_GET
 #  elif defined(__linux__)
 #    if !defined(_LIBCPP_HAS_MUSL_LIBC)
 #      if _LIBCPP_GLIBC_PREREQ(2, 17)
+#        define TEST_HAS_TIMESPEC_GET
 #        define TEST_HAS_C11_FEATURES
 #      endif
 #    else // defined(_LIBCPP_HAS_MUSL_LIBC)
 #      define TEST_HAS_C11_FEATURES
+#      define TEST_HAS_TIMESPEC_GET
 #    endif
 #  elif defined(_WIN32)
 #    if defined(_MSC_VER) && !defined(__MINGW32__)
 #      define TEST_HAS_C11_FEATURES // Using Microsoft's C Runtime library
+#      define TEST_HAS_TIMESPEC_GET
 #    endif
 #  endif
 #endif
diff --git a/utils/libcxx/test/config.py b/utils/libcxx/test/config.py
index 6542ceb6fb58..186a273a5b51 100644
--- a/utils/libcxx/test/config.py
+++ b/utils/libcxx/test/config.py
@@ -677,7 +677,8 @@ class Configuration(object):
                 if feature_macros[m]:
                     define += '=%s' % (feature_macros[m])
                 self.cxx.compile_flags += [define]
-            if m == '_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS':
+            if m == '_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS' or \
+               m == '_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT':
                 continue
             if m == '_LIBCPP_ABI_VERSION':
                 self.config.available_features.add('libcpp-abi-version-v%s'