Support tests in freestanding

Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".

Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:

In utils/libcxx/test/config.py add:

  self.cxx.compile_flags += ['-ffreestanding']

Run the tests and they all fail.

Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).

Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.

The former was done with The Magic Of Sed.

The later was done with a (not quite correct but decent) clang tool:

  https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed

This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.

Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.

<rdar://problem/47754795>

Reviewers: ldionne, mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits

Differential Revision: https://reviews.llvm.org/D57624

llvm-svn: 353086

164 files changed, 493 insertions, 165 deletions

diff --git a/libcxx/test/std/utilities/memory/allocator.tag/allocator_arg.pass.cpp b/libcxx/test/std/utilities/memory/allocator.tag/allocator_arg.pass.cpp
index b095dbfaf16..1a58726a854 100644
--- a/libcxx/test/std/utilities/memory/allocator.tag/allocator_arg.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.tag/allocator_arg.pass.cpp
@@ -15,7 +15,9 @@
 
 void test(std::allocator_arg_t) {}
 
-int main()
+int main(int, char**)
 {
     test(std::allocator_arg);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.fail.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.fail.cpp
index 60f267fa5e3..47cfbb0494b 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.fail.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.fail.cpp
@@ -42,9 +42,11 @@ struct A
     }
 };
 
-int main()
+int main(int, char**)
 {
     A<int> a;
     std::allocator_traits<A<int> >::allocate(a, 10);          // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
     std::allocator_traits<A<int> >::allocate(a, 10, nullptr); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.pass.cpp
index a892be03d9d..0ac2f266e81 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate.pass.cpp
@@ -33,7 +33,7 @@ struct A
     }
 };
 
-int main()
+int main(int, char**)
 {
   {
     A<int> a;
@@ -45,4 +45,6 @@ int main()
     Alloc a;
     assert(std::allocator_traits<Alloc >::allocate(a, 10) == reinterpret_cast<VT*>(static_cast<std::uintptr_t>(0xDEADBEEF)));
   }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate_hint.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate_hint.pass.cpp
index 9d4631740b0..e9524716398 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate_hint.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/allocate_hint.pass.cpp
@@ -53,7 +53,7 @@ struct B
 };
 
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 11
   {
@@ -77,4 +77,6 @@ int main()
     Alloc b;
     assert(std::allocator_traits<Alloc >::allocate(b, 11, nullptr) == reinterpret_cast<VT*>(static_cast<std::uintptr_t>(0xFEADBEEF)));
   }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/construct.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/construct.pass.cpp
index 252d99a7a74..67a2e8f4ac8 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/construct.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/construct.pass.cpp
@@ -81,7 +81,7 @@ struct A2
 
 int A2::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A0::count = 0;
@@ -149,4 +149,6 @@ int main()
         assert(b_construct == 1);
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/deallocate.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/deallocate.pass.cpp
index 94f10b64dba..c738416e01d 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/deallocate.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/deallocate.pass.cpp
@@ -36,7 +36,7 @@ struct A
     }
 };
 
-int main()
+int main(int, char**)
 {
   {
     A<int> a;
@@ -51,4 +51,6 @@ int main()
     std::allocator_traits<Alloc >::deallocate(a, reinterpret_cast<VT*>(static_cast<std::uintptr_t>(0xDEADBEEF)), 10);
     assert(called == 1);
   }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
index 677c647a27d..70890d8512f 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
@@ -54,7 +54,7 @@ struct A0
 
 int A0::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A0::count = 0;
@@ -86,4 +86,6 @@ int main()
         assert(b_destroy == 1);
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/max_size.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/max_size.pass.cpp
index a51ec6e95ac..b758c9add8c 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/max_size.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/max_size.pass.cpp
@@ -42,7 +42,7 @@ struct B
     }
 };
 
-int main()
+int main(int, char**)
 {
     {
         B<int> b;
@@ -74,4 +74,6 @@ int main()
         static_assert(noexcept(std::allocator_traits<std::allocator<int>>::max_size(a)) == true, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/select_on_container_copy_construction.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/select_on_container_copy_construction.pass.cpp
index 9594531dad9..be837670dd3 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/select_on_container_copy_construction.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/select_on_container_copy_construction.pass.cpp
@@ -47,7 +47,7 @@ struct B
     }
 };
 
-int main()
+int main(int, char**)
 {
     {
         A<int> a;
@@ -73,4 +73,6 @@ int main()
         assert(std::allocator_traits<B<int> >::select_on_container_copy_construction(b).id == 100);
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_pointer.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_pointer.pass.cpp
index f153d95b4aa..756958b584f 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_pointer.pass.cpp
@@ -55,7 +55,7 @@ private:
   typedef void const_pointer;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::const_pointer, Ptr<const char> >::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::const_pointer, const char*>::value), "");
@@ -63,4 +63,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<D<char> >::const_pointer, const char*>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_void_pointer.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_void_pointer.pass.cpp
index 3acedde6544..4fcc2fb7c15 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_void_pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/const_void_pointer.pass.cpp
@@ -57,7 +57,7 @@ private:
     typedef int const_void_pointer;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::const_void_pointer, Ptr<const void> >::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::const_void_pointer, const void*>::value), "");
@@ -65,4 +65,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<D<char> >::const_void_pointer, const void*>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/difference_type.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/difference_type.pass.cpp
index b0ee1635083..35721f1cbba 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/difference_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/difference_type.pass.cpp
@@ -66,7 +66,7 @@ struct pointer_traits<C<char>::pointer>
 
 }
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::difference_type, short>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::difference_type, std::ptrdiff_t>::value), "");
@@ -74,4 +74,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<D<char> >::difference_type, std::ptrdiff_t>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/is_always_equal.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/is_always_equal.pass.cpp
index fae61849331..42b0fbab19c 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/is_always_equal.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/is_always_equal.pass.cpp
@@ -39,7 +39,7 @@ struct C
     int not_empty_;  // some random member variable
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::is_always_equal, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::is_always_equal, std::true_type>::value), "");
@@ -48,4 +48,6 @@ int main()
     static_assert((std::is_same<std::allocator_traits<A<const char> >::is_always_equal, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<const char> >::is_always_equal, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<C<const char> >::is_always_equal, std::false_type>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/pointer.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/pointer.pass.cpp
index 60f3d257afd..58b306660a8 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/pointer.pass.cpp
@@ -43,11 +43,13 @@ private:
     typedef void pointer;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::pointer, Ptr<char> >::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::pointer, char*>::value), "");
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<C<char> >::pointer, char*>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_copy_assignment.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_copy_assignment.pass.cpp
index c8451b2a975..b049159e2d1 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_copy_assignment.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_copy_assignment.pass.cpp
@@ -43,11 +43,13 @@ private:
     typedef std::true_type propagate_on_container_copy_assignment;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::propagate_on_container_copy_assignment, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::propagate_on_container_copy_assignment, std::false_type>::value), "");
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<C<char> >::propagate_on_container_copy_assignment, std::false_type>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_move_assignment.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_move_assignment.pass.cpp
index 7c58ac8811b..602ba96d5c1 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_move_assignment.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_move_assignment.pass.cpp
@@ -44,11 +44,13 @@ private:
 };
 
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::propagate_on_container_move_assignment, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::propagate_on_container_move_assignment, std::false_type>::value), "");
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<C<char> >::propagate_on_container_move_assignment, std::false_type>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_swap.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_swap.pass.cpp
index 7a6bcd460a6..5ae53015fa3 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_swap.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/propagate_on_container_swap.pass.cpp
@@ -42,11 +42,13 @@ private:
     typedef std::true_type propagate_on_container_swap;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::propagate_on_container_swap, std::true_type>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::propagate_on_container_swap, std::false_type>::value), "");
  #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<C<char> >::propagate_on_container_swap, std::false_type>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/rebind_alloc.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/rebind_alloc.pass.cpp
index eaadeb17048..d0d8476a89a 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/rebind_alloc.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/rebind_alloc.pass.cpp
@@ -80,7 +80,7 @@ struct G {
     };
 };
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_alloc<double>, ReboundA<double> >::value), "");
@@ -97,4 +97,6 @@ int main()
     static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_alloc<double>::other, D<double, char> >::value), "");
     static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_alloc<double>::other, E<double> >::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/size_type.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/size_type.pass.cpp
index 42b29a39c7b..cd74671390e 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/size_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/size_type.pass.cpp
@@ -62,7 +62,7 @@ struct pointer_traits<C<char>::pointer>
 
 }
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::size_type, unsigned short>::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::size_type,
@@ -72,4 +72,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<D<char> >::size_type, unsigned short>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/void_pointer.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/void_pointer.pass.cpp
index 687d892f0cf..55954dc7091 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/void_pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.types/void_pointer.pass.cpp
@@ -56,7 +56,7 @@ private:
     typedef void void_pointer;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::void_pointer, Ptr<void> >::value), "");
     static_assert((std::is_same<std::allocator_traits<B<char> >::void_pointer, void*>::value), "");
@@ -64,4 +64,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<D<char> >::void_pointer, void*>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator_type.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator_type.pass.cpp
index d5977f0a28f..840ad820e1f 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator_type.pass.cpp
@@ -24,7 +24,9 @@ struct A
     typedef T value_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::allocator_type, A<char> >::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/rebind_traits.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/rebind_traits.pass.cpp
index 475ab04b839..01aac9445c8 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/rebind_traits.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/rebind_traits.pass.cpp
@@ -62,7 +62,7 @@ struct E
     template <class U> struct rebind {typedef ReboundA<U> otter;};
 };
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::allocator_traits<A<char> >::rebind_traits<double>, std::allocator_traits<ReboundA<double> > >::value), "");
@@ -77,4 +77,6 @@ int main()
     static_assert((std::is_same<std::allocator_traits<D<int, char> >::rebind_traits<double>::other, std::allocator_traits<D<double, char> > >::value), "");
     static_assert((std::is_same<std::allocator_traits<E<char> >::rebind_traits<double>::other, std::allocator_traits<E<double> > >::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/value_type.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/value_type.pass.cpp
index dec3a41e374..047d40d5c89 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/value_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/value_type.pass.cpp
@@ -24,7 +24,9 @@ struct A
     typedef T value_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator_traits<A<char> >::value_type, char>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.construction/tested_elsewhere.pass.cpp b/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.construction/tested_elsewhere.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.construction/tested_elsewhere.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.construction/tested_elsewhere.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.trait/uses_allocator.pass.cpp b/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.trait/uses_allocator.pass.cpp
index 5b7f710eab0..d9d4fc3d837 100644
--- a/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.trait/uses_allocator.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.uses/allocator.uses.trait/uses_allocator.pass.cpp
@@ -47,7 +47,7 @@ test()
 #endif
 }
 
-int main()
+int main(int, char**)
 {
     test<false, int, std::allocator<int> >();
     test<true, std::vector<int>, std::allocator<int> >();
@@ -71,4 +71,6 @@ int main()
 // #if TEST_STD_VER >= 11
 //     static_assert((!std::uses_allocator<E, int>::value), "");
 // #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/allocator.uses/nothing_to_do.pass.cpp b/libcxx/test/std/utilities/memory/allocator.uses/nothing_to_do.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/allocator.uses/nothing_to_do.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.uses/nothing_to_do.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/c.malloc/nothing_to_do.pass.cpp b/libcxx/test/std/utilities/memory/c.malloc/nothing_to_do.pass.cpp
index a8d90b1ce6f..7e6c6780070 100644
--- a/libcxx/test/std/utilities/memory/c.malloc/nothing_to_do.pass.cpp
+++ b/libcxx/test/std/utilities/memory/c.malloc/nothing_to_do.pass.cpp
@@ -8,6 +8,8 @@
 
 // <cstdlib> and <cstring> are already tested elsewhere
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.ctor.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.ctor.pass.cpp
index 7aa2dbfeb03..57946be085a 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.ctor.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.ctor.pass.cpp
@@ -25,7 +25,7 @@
 #include "test_macros.h"
 
 
-int main()
+int main(int, char**)
 {
     {
     typedef std::allocator<char> AC;
@@ -46,4 +46,6 @@ int main()
     (void) a3;
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.globals/eq.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.globals/eq.pass.cpp
index b38daf8e912..63412bce1f4 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.globals/eq.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.globals/eq.pass.cpp
@@ -21,10 +21,12 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::allocator<int> a1;
     std::allocator<int> a2;
     assert(a1 == a2);
     assert(!(a1 != a2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/address.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/address.pass.cpp
index bb1bb4f11ee..c4ff55d0eab 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/address.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/address.pass.cpp
@@ -31,8 +31,10 @@ struct A
     void operator&() const {}
 };
 
-int main()
+int main(int, char**)
 {
     test_address<int>();
     test_address<A>();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.fail.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.fail.cpp
index df4124f51ed..889804f3b71 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.fail.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.fail.cpp
@@ -19,9 +19,11 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     std::allocator<int> a;
     a.allocate(3);          // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
     a.allocate(3, nullptr); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
index 14e5a8a3c79..8392cbdb709 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.pass.cpp
@@ -99,7 +99,7 @@ void test_aligned() {
   }
 }
 
-int main() {
+int main(int, char**) {
     test_aligned<1>();
     test_aligned<2>();
     test_aligned<4>();
@@ -108,4 +108,6 @@ int main() {
     test_aligned<MaxAligned>();
     test_aligned<OverAligned>();
     test_aligned<OverAligned * 2>();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.size.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.size.pass.cpp
index 09a9bd912d0..685e02ef393 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.size.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/allocate.size.pass.cpp
@@ -39,8 +39,10 @@ void test()
     test_max<T> ((size_t) -1);                     // way too large
 }
 
-int main()
+int main(int, char**)
 {
     test<double>();
     LIBCPP_ONLY(test<const double>());
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
index 322881b1536..96954e04b08 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/construct.pass.cpp
@@ -53,7 +53,7 @@ public:
 };
 #endif // TEST_STD_VER >= 11
 
-int main()
+int main(int, char**)
 {
     {
     std::allocator<A> a;
@@ -139,4 +139,6 @@ int main()
     assert(move_only_constructed == 0);
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
index 50076ce02f4..c2094bc044a 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator.members/max_size.pass.cpp
@@ -18,9 +18,11 @@
 
 int new_called = 0;
 
-int main()
+int main(int, char**)
 {
     const std::allocator<int> a;
     std::size_t M = a.max_size();
     assert(M > 0xFFFF && M <= (std::numeric_limits<std::size_t>::max() / sizeof(int)));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_pointers.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_pointers.pass.cpp
index 375b96f831b..bc89c62a847 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator_pointers.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_pointers.pass.cpp
@@ -108,7 +108,7 @@ void test_void_pointer()
 
 struct Foo { int x; };
 
-int main()
+int main(int, char**)
 {
     test_pointer<std::allocator<char>> ();
     test_pointer<std::allocator<int>> ();
@@ -117,7 +117,9 @@ int main()
     test_void_pointer<std::allocator<char>> ();
     test_void_pointer<std::allocator<int>> ();
     test_void_pointer<std::allocator<Foo>> ();
+
+  return 0;
 }
 #else
-int main() {}
+int main(int, char**) { return 0; }
 #endif
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
index 9cd5815645d..0bff67efbd9 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
@@ -33,7 +33,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator<char>::size_type, std::size_t>::value), "");
     static_assert((std::is_same<std::allocator<char>::difference_type, std::ptrdiff_t>::value), "");
@@ -53,4 +53,6 @@ int main()
     a2 = a;
     std::allocator<int> a3 = a2;
     ((void)a3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_void.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_void.pass.cpp
index 1f13c8be6ca..528902d2112 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator_void.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_void.pass.cpp
@@ -22,7 +22,7 @@
 #include <memory>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::allocator<void>::pointer, void*>::value), "");
     static_assert((std::is_same<std::allocator<void>::const_pointer, const void*>::value), "");
@@ -32,4 +32,6 @@ int main()
     std::allocator<void> a;
     std::allocator<void> a2 = a;
     a2 = a;
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.conversion/to_address.pass.cpp b/libcxx/test/std/utilities/memory/pointer.conversion/to_address.pass.cpp
index 0fd45fd913c..7d55974dd93 100644
--- a/libcxx/test/std/utilities/memory/pointer.conversion/to_address.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.conversion/to_address.pass.cpp
@@ -99,7 +99,7 @@ struct pointer_traits<::P4>
 int n = 0;
 static_assert(std::to_address(&n) == &n);
 
-int main()
+int main(int, char**)
 {
     int i = 0;
     ASSERT_NOEXCEPT(std::to_address(&i));
@@ -116,4 +116,6 @@ int main()
     P4 p4(&i);
     ASSERT_NOEXCEPT(std::to_address(p4));
     assert(std::to_address(p4) == &i);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/difference_type.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/difference_type.pass.cpp
index 867bd46cd29..3eaedab1670 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/difference_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/difference_type.pass.cpp
@@ -18,7 +18,9 @@
 #include <memory>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::pointer_traits<double*>::difference_type, std::ptrdiff_t>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/element_type.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/element_type.pass.cpp
index 42db90ff6ef..505881ddeea 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/element_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/element_type.pass.cpp
@@ -18,7 +18,9 @@
 #include <memory>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::pointer_traits<const short*>::element_type, const short>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer.pass.cpp
index 4a74b5d5894..110a993dc66 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer.pass.cpp
@@ -24,8 +24,10 @@ struct A
     typedef char difference_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::pointer_traits<A>::pointer, A>::value), "");
     static_assert((std::is_same<std::pointer_traits<int*>::pointer, int*>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp
index 0b412dac463..9e6a48930e2 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp
@@ -34,7 +34,7 @@ public:
         {return A(&et);}
 };
 
-int main()
+int main(int, char**)
 {
     {
         int i = 0;
@@ -45,4 +45,6 @@ int main()
     {
         (std::pointer_traits<A<void> >::element_type)0;
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/difference_type.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/difference_type.pass.cpp
index 7e08235399e..d4d763c69ea 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/difference_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/difference_type.pass.cpp
@@ -52,7 +52,7 @@ private:
   typedef int difference_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::pointer_traits<A>::difference_type, char>::value), "");
     static_assert((std::is_same<std::pointer_traits<B>::difference_type, std::ptrdiff_t>::value), "");
@@ -62,4 +62,6 @@ int main()
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::pointer_traits<F<int>>::difference_type, std::ptrdiff_t>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/element_type.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/element_type.pass.cpp
index 8184d2d0027..c0efdeab0b3 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/element_type.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/element_type.pass.cpp
@@ -53,7 +53,7 @@ private:
   typedef int element_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::pointer_traits<A>::element_type, char>::value), "");
     static_assert((std::is_same<std::pointer_traits<B<int> >::element_type, char>::value), "");
@@ -64,4 +64,6 @@ int main()
     static_assert((std::is_same<std::pointer_traits<F<double>>::element_type, double>::value), "");
 #endif
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/rebind.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/rebind.pass.cpp
index 407f4bcfb9f..a79f3391664 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/rebind.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.types/rebind.pass.cpp
@@ -81,7 +81,7 @@ struct G
 #endif
 
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::pointer_traits<A<int*> >::rebind<double*>, A<double*> >::value), "");
@@ -101,4 +101,6 @@ int main()
     static_assert((std::is_same<std::pointer_traits<D<char, int> >::rebind<double>::other, D1<double, int> >::value), "");
     static_assert((std::is_same<std::pointer_traits<E<char, int> >::rebind<double>::other, E<double, int> >::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/pointer_to.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/pointer_to.pass.cpp
index 968d3ee1e72..e9b858c7fd9 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/pointer_to.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/pointer_to.pass.cpp
@@ -35,9 +35,11 @@ bool check() {
     return true;
 }
 
-int main() {
+int main(int, char**) {
     check();
 #if TEST_STD_VER > 17
     static_assert(check(), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/pointer.traits/rebind.pass.cpp b/libcxx/test/std/utilities/memory/pointer.traits/rebind.pass.cpp
index 823d4f11f23..f64213c9b88 100644
--- a/libcxx/test/std/utilities/memory/pointer.traits/rebind.pass.cpp
+++ b/libcxx/test/std/utilities/memory/pointer.traits/rebind.pass.cpp
@@ -20,11 +20,13 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 11
     static_assert((std::is_same<std::pointer_traits<int*>::rebind<double>, double*>::value), "");
 #else
     static_assert((std::is_same<std::pointer_traits<int*>::rebind<double>::other, double*>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/ptr.align/align.pass.cpp b/libcxx/test/std/utilities/memory/ptr.align/align.pass.cpp
index c7a181eb79e..3d0216cce53 100644
--- a/libcxx/test/std/utilities/memory/ptr.align/align.pass.cpp
+++ b/libcxx/test/std/utilities/memory/ptr.align/align.pass.cpp
@@ -13,7 +13,7 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     const unsigned N = 20;
     char buf[N];
@@ -80,4 +80,6 @@ int main()
     assert(p == &buf[0]);
     assert(r == nullptr);
     assert(s == N);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/nothing_to_do.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/nothing_to_do.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/nothing_to_do.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/nothing_to_do.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.pass.cpp
index 956e6b1187c..f6310c7bc91 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.pass.cpp
@@ -26,7 +26,7 @@ struct nothing {
     }
 };
 
-int main()
+int main(int, char**)
 {
     {
     int i;
@@ -47,4 +47,6 @@ int main()
     };
     assert(std::addressof(n) == (void*)std::addressof(i));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.temp.fail.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.temp.fail.cpp
index c12bf41e8ea..f7033014d37 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.temp.fail.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/addressof.temp.fail.cpp
@@ -15,11 +15,13 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER > 14
     const int *p = std::addressof<const int>(0);
 #else
 #error
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/constexpr_addressof.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/constexpr_addressof.pass.cpp
index c042dd5c37b..f14a0e7fc89 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/constexpr_addressof.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.addressof/constexpr_addressof.pass.cpp
@@ -32,10 +32,12 @@ constexpr int i = 0;
 constexpr double d = 0.0;
 constexpr A a{};
 
-int main()
+int main(int, char**)
 {
     static_assert(std::addressof(i) == &i, "");
     static_assert(std::addressof(d) == &d, "");
     constexpr const A* ap = std::addressof(a);
     static_assert(&ap->n == &a.n, "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy.pass.cpp
index f812bb85a62..4dbc20aba39 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy.pass.cpp
@@ -30,7 +30,7 @@ struct Counted {
 };
 int Counted::count = 0;
 
-int main()
+int main(int, char**)
 {
     using It = forward_iterator<Counted*>;
     const int N = 5;
@@ -43,4 +43,6 @@ int main()
     assert(Counted::count == 4);
     std::destroy(It(p), It(p + 4));
     assert(Counted::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_at.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_at.pass.cpp
index 28450faa10f..d505222b02d 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_at.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_at.pass.cpp
@@ -41,7 +41,7 @@ struct DCounted : VCounted {
     friend void operator&(DCounted) = delete;
 };
 
-int main()
+int main(int, char**)
 {
     {
     void* mem1 = std::malloc(sizeof(Counted));
@@ -74,4 +74,6 @@ int main()
     std::free(mem1);
     std::free(mem2);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_n.pass.cpp
index 90836b23355..0dcc8e5a657 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_n.pass.cpp
@@ -30,7 +30,7 @@ struct Counted {
 };
 int Counted::count = 0;
 
-int main()
+int main(int, char**)
 {
     using It = forward_iterator<Counted*>;
     const int N = 5;
@@ -45,4 +45,6 @@ int main()
     It it = std::destroy_n(It(p), 4);
     assert(it == It(p+4));
     assert(Counted::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct.pass.cpp
index bd9ef7b403f..67dd6fbd298 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct.pass.cpp
@@ -103,9 +103,11 @@ void test_value_initialized()
     assert(pool[4] == -1);
 }
 
-int main()
+int main(int, char**)
 {
     test_counted();
     test_value_initialized();
     test_ctor_throws();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct_n.pass.cpp
index d2f6e094a85..1052355a4f2 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.default/uninitialized_default_construct_n.pass.cpp
@@ -107,9 +107,11 @@ void test_value_initialized()
 }
 
 
-int main()
+int main(int, char**)
 {
     test_counted();
     test_value_initialized();
     test_ctor_throws();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct.pass.cpp
index 50ce1224848..5dfcd83fe9b 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct.pass.cpp
@@ -102,9 +102,11 @@ void test_value_initialized()
     assert(pool[4] == 0);
 }
 
-int main()
+int main(int, char**)
 {
     test_counted();
     test_value_initialized();
     test_ctor_throws();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct_n.pass.cpp
index 4d89f9cac4c..e43102ba4aa 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.construct.value/uninitialized_value_construct_n.pass.cpp
@@ -107,8 +107,10 @@ void test_value_initialized()
     assert(pool[4] == 0);
 }
 
-int main()
+int main(int, char**)
 {
     test_counted();
     test_value_initialized();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy.pass.cpp
index b81d561e089..2618bd5339c 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy.pass.cpp
@@ -47,7 +47,7 @@ struct Nasty
 
 int Nasty::counter_ = 0;
 
-int main()
+int main(int, char**)
 {
     {
     const int N = 5;
@@ -85,4 +85,6 @@ int main()
         }
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy_n.pass.cpp
index c3f46bebe67..1a237a7929d 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.copy/uninitialized_copy_n.pass.cpp
@@ -47,7 +47,7 @@ struct Nasty
 
 int Nasty::counter_ = 0;
 
-int main()
+int main(int, char**)
 {
     {
     const int N = 5;
@@ -84,4 +84,6 @@ int main()
         assert(  p[i].i_ == i);
     }
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill.n/uninitialized_fill_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill.n/uninitialized_fill_n.pass.cpp
index 5c177663e40..4dfde4f6e87 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill.n/uninitialized_fill_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill.n/uninitialized_fill_n.pass.cpp
@@ -46,7 +46,7 @@ struct Nasty
 
 int Nasty::counter_ = 0;
 
-int main()
+int main(int, char**)
 {
     {
     const int N = 5;
@@ -84,4 +84,6 @@ int main()
     }
 
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill/uninitialized_fill.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill/uninitialized_fill.pass.cpp
index f7790fc4519..1996ec6c6ff 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill/uninitialized_fill.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.fill/uninitialized_fill.pass.cpp
@@ -47,7 +47,7 @@ struct Nasty
 
 int Nasty::counter_ = 0;
 
-int main()
+int main(int, char**)
 {
     {
     const int N = 5;
@@ -81,4 +81,6 @@ int main()
     for (int i = 0; i < N; ++i)
         assert(bp[i].i_ == 23);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move.pass.cpp
index a0717e61b2c..e17f5734bb2 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move.pass.cpp
@@ -107,7 +107,9 @@ void test_counted()
     assert(Counted::count == 0);
 }
 
-int main() {
+int main(int, char**) {
     test_counted();
     test_ctor_throws();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move_n.pass.cpp b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move_n.pass.cpp
index 75538407421..ee364aaf5b9 100644
--- a/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move_n.pass.cpp
+++ b/libcxx/test/std/utilities/memory/specialized.algorithms/uninitialized.move/uninitialized_move_n.pass.cpp
@@ -109,8 +109,10 @@ void test_counted()
     assert(Counted::count == 0);
 }
 
-int main()
+int main(int, char**)
 {
     test_counted();
     test_ctor_throws();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.base.pass.cpp b/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.base.pass.cpp
index 531158ba158..5355d09ac26 100644
--- a/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.base.pass.cpp
+++ b/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.base.pass.cpp
@@ -36,7 +36,7 @@ public:
     A* operator& () DELETE_FUNCTION;
 };
 
-int main()
+int main(int, char**)
 {
 #if TEST_STD_VER >= 14
     typedef std::aligned_storage<3*sizeof(A), std::alignment_of<A>::value>::type
@@ -54,4 +54,6 @@ int main()
         assert(it.base() == ap + 1);  // next place to write
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.pass.cpp b/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.pass.cpp
index 90bb956fc03..2b9b33fd9b9 100644
--- a/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.pass.cpp
+++ b/libcxx/test/std/utilities/memory/storage.iterator/raw_storage_iterator.pass.cpp
@@ -36,7 +36,7 @@ public:
     A* operator& () DELETE_FUNCTION;
 };
 
-int main()
+int main(int, char**)
 {
     {
     typedef A S;
@@ -67,4 +67,6 @@ int main()
     assert(ap->get() == 1); // original value
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/temporary.buffer/overaligned.pass.cpp b/libcxx/test/std/utilities/memory/temporary.buffer/overaligned.pass.cpp
index fd818577b06..db71c69bf26 100644
--- a/libcxx/test/std/utilities/memory/temporary.buffer/overaligned.pass.cpp
+++ b/libcxx/test/std/utilities/memory/temporary.buffer/overaligned.pass.cpp
@@ -25,10 +25,12 @@ struct alignas(32) A {
     int field;
 };
 
-int main()
+int main(int, char**)
 {
     std::pair<A*, std::ptrdiff_t> ip = std::get_temporary_buffer<A>(5);
     assert(!(ip.first == nullptr) ^ (ip.second == 0));
     assert(reinterpret_cast<uintptr_t>(ip.first) % alignof(A) == 0);
     std::return_temporary_buffer(ip.first);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/temporary.buffer/temporary_buffer.pass.cpp b/libcxx/test/std/utilities/memory/temporary.buffer/temporary_buffer.pass.cpp
index 22efde4af8f..32a58e5a657 100644
--- a/libcxx/test/std/utilities/memory/temporary.buffer/temporary_buffer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/temporary.buffer/temporary_buffer.pass.cpp
@@ -19,10 +19,12 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::pair<int*, std::ptrdiff_t> ip = std::get_temporary_buffer<int>(5);
     assert(ip.first);
     assert(ip.second == 5);
     std::return_temporary_buffer(ip.first);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.fail.cpp b/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.fail.cpp
index c9d1c8b4697..bc6846fe7f5 100644
--- a/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.fail.cpp
+++ b/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.fail.cpp
@@ -26,9 +26,11 @@
 #include "min_allocator.h"
 #include "deleter_types.h"
 
-int main()
+int main(int, char**)
 {
     std::unique_ptr<int, PointerDeleter<int>> p;
     std::ostringstream os;
     os << p; // expected-error {{invalid operands to binary expression}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.pass.cpp b/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.pass.cpp
index e350a0385d6..b9b158a9d2b 100644
--- a/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.pass.cpp
+++ b/libcxx/test/std/utilities/memory/unique.ptr/unique.ptr.special/io.pass.cpp
@@ -21,11 +21,13 @@
 #include <sstream>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::unique_ptr<int> p(new int(3));
     std::ostringstream os;
     assert(os.str().empty());
     os << p;
     assert(!os.str().empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_no_pointers.pass.cpp b/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_no_pointers.pass.cpp
index 5c99a9721a0..a2b6cf22ed8 100644
--- a/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_no_pointers.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_no_pointers.pass.cpp
@@ -13,10 +13,12 @@
 
 #include <memory>
 
-int main()
+int main(int, char**)
 {
     char* p = new char[10];
     std::declare_no_pointers(p, 10);
     std::undeclare_no_pointers(p, 10);
     delete [] p;
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_reachable.pass.cpp b/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_reachable.pass.cpp
index 4a71817d403..c923089fa97 100644
--- a/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_reachable.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.dynamic.safety/declare_reachable.pass.cpp
@@ -14,10 +14,12 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     int* p = new int;
     std::declare_reachable(p);
     assert(std::undeclare_reachable(p) == p);
     delete p;
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.dynamic.safety/get_pointer_safety.pass.cpp b/libcxx/test/std/utilities/memory/util.dynamic.safety/get_pointer_safety.pass.cpp
index 4fc2e010f79..2fea98364b4 100644
--- a/libcxx/test/std/utilities/memory/util.dynamic.safety/get_pointer_safety.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.dynamic.safety/get_pointer_safety.pass.cpp
@@ -22,7 +22,7 @@ void test_pr26961() {
   assert(d == std::get_pointer_safety());
 }
 
-int main()
+int main(int, char**)
 {
   {
     std::pointer_safety r = std::get_pointer_safety();
@@ -33,4 +33,6 @@ int main()
   {
     test_pr26961();
   }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/nothing_to_do.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/nothing_to_do.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/nothing_to_do.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/nothing_to_do.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
index 0f7c44fd8fd..fe7567eebc1 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.enab/enable_shared_from_this.pass.cpp
@@ -52,7 +52,7 @@ struct PrivateBase : private std::enable_shared_from_this<PrivateBase> {
 };
 
 
-int main()
+int main(int, char**)
 {
     {  // https://bugs.llvm.org/show_bug.cgi?id=18843
     std::shared_ptr<T const> t1(new T);
@@ -167,4 +167,6 @@ int main()
         assert(my_weak.lock().get() == ptr);
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
index bd7f644c3ec..440fa8ac480 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/enabled_hash.pass.cpp
@@ -17,6 +17,8 @@
 
 #include "poisoned_hash_helper.hpp"
 
-int main() {
+int main(int, char**) {
   test_library_hash_specializations_available();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
index 8db542c0794..34717ad4256 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_shared_ptr.pass.cpp
@@ -25,7 +25,7 @@
 struct A {};
 #endif
 
-int main()
+int main(int, char**)
 {
   {
     int* ptr = new int;
@@ -40,4 +40,6 @@ int main()
     test_hash_enabled_for_type<std::shared_ptr<A>>();
   }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
index 4f942f6c2d9..5cae6ca7d45 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.hash/hash_unique_ptr.pass.cpp
@@ -60,7 +60,7 @@ struct A {};
 
 #endif // TEST_STD_VER >= 11
 
-int main()
+int main(int, char**)
 {
   {
     int* ptr = new int;
@@ -99,4 +99,6 @@ int main()
 #endif
   }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong.pass.cpp
index 45c82c4bafa..7737cfd4da0 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong.pass.cpp
@@ -29,7 +29,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -51,4 +51,6 @@ int main()
         assert(*v == 4);
         assert(*w == 2);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong_explicit.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong_explicit.pass.cpp
index d1589aaddba..9198ca68cd8 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong_explicit.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_strong_explicit.pass.cpp
@@ -30,7 +30,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -56,4 +56,6 @@ int main()
         assert(*v == 4);
         assert(*w == 2);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak.pass.cpp
index fb09a19fd05..da52811c9c0 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak.pass.cpp
@@ -29,7 +29,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -51,4 +51,6 @@ int main()
         assert(*v == 4);
         assert(*w == 2);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak_explicit.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak_explicit.pass.cpp
index 2a9b6ce1244..703bf008f4f 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak_explicit.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_compare_exchange_weak_explicit.pass.cpp
@@ -30,7 +30,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -56,4 +56,6 @@ int main()
         assert(*v == 4);
         assert(*w == 2);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange.pass.cpp
index cf6ad5b0037..b51a24aefb9 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange.pass.cpp
@@ -28,7 +28,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -37,4 +37,6 @@ int main()
         assert(*p == 3);
         assert(*r == 4);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange_explicit.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange_explicit.pass.cpp
index f177420fe94..b59b515a5c2 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange_explicit.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange_explicit.pass.cpp
@@ -28,7 +28,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(4));
@@ -37,4 +37,6 @@ int main()
         assert(*p == 3);
         assert(*r == 4);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_is_lock_free.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_is_lock_free.pass.cpp
index 3b267f99d09..e8bb64dccb6 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_is_lock_free.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_is_lock_free.pass.cpp
@@ -23,10 +23,12 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<int> p(new int(3));
         assert(std::atomic_is_lock_free(&p) == false);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load.pass.cpp
index b36580ef217..63416faf329 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load.pass.cpp
@@ -28,11 +28,13 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p(new int(3));
         std::shared_ptr<int> q = std::atomic_load(&p);
         assert(*q == *p);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load_explicit.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load_explicit.pass.cpp
index 40f6b49d6c6..0708f874b26 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load_explicit.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_load_explicit.pass.cpp
@@ -28,11 +28,13 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<int> p(new int(3));
         std::shared_ptr<int> q = std::atomic_load_explicit(&p, std::memory_order_relaxed);
         assert(*q == *p);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store.pass.cpp
index 3c6de40f117..42d7099a9df 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store.pass.cpp
@@ -28,7 +28,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p;
@@ -36,4 +36,6 @@ int main()
         std::atomic_store(&p, r);
         assert(*p == *r);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store_explicit.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store_explicit.pass.cpp
index dd4001a82ff..7da4de3fa47 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store_explicit.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_store_explicit.pass.cpp
@@ -28,7 +28,7 @@
 
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<int> p;
@@ -36,4 +36,6 @@ int main()
         std::atomic_store_explicit(&p, r, std::memory_order_seq_cst);
         assert(*p == *r);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/types.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/types.pass.cpp
index 4a96f8181b2..c3aedd5b1ad 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/types.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/types.pass.cpp
@@ -22,10 +22,12 @@
 
 struct A;  // purposefully incomplete
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::shared_ptr<A>::element_type, A>::value), "");
 #if TEST_STD_VER > 14
     static_assert((std::is_same<std::shared_ptr<A>::weak_type, std::weak_ptr<A>>::value), "");
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.getdeleter/get_deleter.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.getdeleter/get_deleter.pass.cpp
index babf1c6ee5b..209e3fe71af 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.getdeleter/get_deleter.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.getdeleter/get_deleter.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         {
@@ -63,4 +63,6 @@ int main()
         std::default_delete<A>* d = std::get_deleter<std::default_delete<A> >(p);
         assert(d == 0);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/auto_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/auto_ptr_Y.pass.cpp
index 69ad9513b6c..a154a121c7f 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/auto_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/auto_ptr_Y.pass.cpp
@@ -40,7 +40,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::auto_ptr<A> pA(new A);
@@ -110,4 +110,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr.pass.cpp
index 6d2000c1375..e362f4d8d4e 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> pA(new A);
@@ -117,4 +117,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y.pass.cpp
index 23b587d0b7d..2b666315ef2 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> pA(new A);
@@ -117,4 +117,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y_rv.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y_rv.pass.cpp
index a3ba5877f49..6787c33c297 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y_rv.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_Y_rv.pass.cpp
@@ -41,7 +41,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> pA(new A);
@@ -119,4 +119,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_rv.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_rv.pass.cpp
index 8c63b14b27d..e921a099189 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_rv.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/shared_ptr_rv.pass.cpp
@@ -41,7 +41,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> pA(new A);
@@ -119,4 +119,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/unique_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/unique_ptr_Y.pass.cpp
index b7fc447b057..4abe371bc07 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/unique_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.assign/unique_ptr_Y.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::unique_ptr<A> pA(new A);
@@ -109,4 +109,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/const_pointer_cast.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/const_pointer_cast.pass.cpp
index 53955aaa218..51e2949b6c6 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/const_pointer_cast.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/const_pointer_cast.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<const A> pA(new A);
@@ -53,4 +53,6 @@ int main()
         assert(pB.get() == pA.get());
         assert(!pB.owner_before(pA) && !pA.owner_before(pB));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/dynamic_pointer_cast.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/dynamic_pointer_cast.pass.cpp
index c27f9503b62..76009b96abd 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/dynamic_pointer_cast.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/dynamic_pointer_cast.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<B> pB(new A);
@@ -53,4 +53,6 @@ int main()
         assert(pA.get() == 0);
         assert(pA.use_count() == 0);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/static_pointer_cast.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/static_pointer_cast.pass.cpp
index ec72834d5cd..9ea544fee01 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/static_pointer_cast.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cast/static_pointer_cast.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> pA(new A);
@@ -65,4 +65,6 @@ int main()
         assert(pB.get() == pA.get());
         assert(!pB.owner_before(pA) && !pA.owner_before(pB));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/cmp_nullptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/cmp_nullptr.pass.cpp
index 6936744c1ab..98b5bbf0d67 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/cmp_nullptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/cmp_nullptr.pass.cpp
@@ -40,7 +40,7 @@
 
 void do_nothing(int*) {}
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int(1));
     assert(!(p1 == nullptr));
@@ -65,4 +65,6 @@ int main()
     assert(!(nullptr > p2));
     assert( (p2 >= nullptr));
     assert( (nullptr >= p2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/eq.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/eq.pass.cpp
index 1257ea65fd8..e25ba611744 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/eq.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/eq.pass.cpp
@@ -18,7 +18,7 @@
 
 void do_nothing(int*) {}
 
-int main()
+int main(int, char**)
 {
     int* ptr1(new int);
     int* ptr2(new int);
@@ -27,4 +27,6 @@ int main()
     const std::shared_ptr<int> p3(ptr2, do_nothing);
     assert(p1 != p2);
     assert(p2 == p3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/lt.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/lt.pass.cpp
index 15e13688b4d..fdef32d518a 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/lt.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.cmp/lt.pass.cpp
@@ -17,7 +17,7 @@
 
 void do_nothing(int*) {}
 
-int main()
+int main(int, char**)
 {
     int* ptr1(new int);
     int* ptr2(new int);
@@ -26,4 +26,6 @@ int main()
     const std::shared_ptr<int> p3(ptr2, do_nothing);
     assert((p1 < p2) == (ptr1 < ptr2));
     assert(!(p2 < p3) && !(p3 < p2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
index 6558e230dff..282ddd0e0ea 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/auto_ptr.pass.cpp
@@ -43,7 +43,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::auto_ptr<A> ptr(new A);
@@ -94,4 +94,6 @@ int main()
     assert(A::count == 0);
     assert(globalMemCounter.checkOutstandingNewEq(0));
 #endif // !defined(TEST_HAS_NO_EXCEPTIONS) && !defined(DISABLE_NEW_COUNT)
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/default.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/default.pass.cpp
index c70e537a9af..247ca0fa924 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/default.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/default.pass.cpp
@@ -13,9 +13,11 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::shared_ptr<int> p;
     assert(p.use_count() == 0);
     assert(p.get() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t.pass.cpp
index a46b31aa5a9..f29dd1cf7ea 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t.pass.cpp
@@ -13,9 +13,11 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::shared_ptr<int> p(nullptr);
     assert(p.use_count() == 0);
     assert(p.get() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter.pass.cpp
index 9644e4f0f99..ee5861122bf 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
     std::shared_ptr<A> p(nullptr, test_deleter<A>(3));
@@ -43,4 +43,6 @@ int main()
     assert(A::count == 0);
     assert(test_deleter<A>::count == 0);
     assert(test_deleter<A>::dealloc_count == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator.pass.cpp
index bc1d3584e1e..0881e8cf42d 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
     std::shared_ptr<A> p(nullptr, test_deleter<A>(3), test_allocator<A>(5));
@@ -81,4 +81,6 @@ int main()
     assert(test_deleter<A>::count == 0);
     assert(test_deleter<A>::dealloc_count == 1);
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator_throw.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator_throw.pass.cpp
index 1948c6860ab..4700df0085c 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator_throw.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_allocator_throw.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     try
     {
@@ -43,4 +43,6 @@ int main()
         assert(test_allocator<A>::count == 0);
         assert(test_allocator<A>::alloc_count == 0);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
index 075cadf43d6..7d2628d60dc 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/nullptr_t_deleter_throw.pass.cpp
@@ -37,7 +37,7 @@ struct A
 int A::count = 0;
 
 
-int main()
+int main(int, char**)
 {
     globalMemCounter.throw_after = 0;
     try
@@ -51,4 +51,6 @@ int main()
         assert(test_deleter<A>::count == 0);
         assert(test_deleter<A>::dealloc_count == 1);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer.pass.cpp
index 67f0ffd2a80..b55d764a6c4 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer.pass.cpp
@@ -24,7 +24,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
     A* ptr = new A;
@@ -42,4 +42,6 @@ int main()
     assert(p.get() == ptr);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter.pass.cpp
index 120171456be..fd98193826e 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
     A* ptr = new A;
@@ -44,4 +44,6 @@ int main()
     assert(A::count == 0);
     assert(test_deleter<A>::count == 0);
     assert(test_deleter<A>::dealloc_count == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator.pass.cpp
index 79a0bc84a39..0ec18a7aebd 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator.pass.cpp
@@ -28,7 +28,7 @@ struct A
 int A::count = 0;
 
 
-int main()
+int main(int, char**)
 {
     {
     A* ptr = new A;
@@ -85,4 +85,6 @@ int main()
     assert(test_deleter<A>::count == 0);
     assert(test_deleter<A>::dealloc_count == 1);
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator_throw.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator_throw.pass.cpp
index ad020f89fd3..5f2984c7e22 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator_throw.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator_throw.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     A* ptr = new A;
     try
@@ -44,4 +44,6 @@ int main()
         assert(test_allocator<A>::count == 0);
         assert(test_allocator<A>::alloc_count == 0);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
index 6af99aaf55e..da12e42ca0b 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_throw.pass.cpp
@@ -34,7 +34,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     A* ptr = new A;
     globalMemCounter.throw_after = 0;
@@ -50,4 +50,6 @@ int main()
         assert(test_deleter<A>::dealloc_count == 1);
     }
     assert(globalMemCounter.checkOutstandingNewEq(0));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
index 95da6f69106..15e776003d9 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_throw.pass.cpp
@@ -33,7 +33,7 @@ struct A
 int A::count = 0;
 
 
-int main()
+int main(int, char**)
 {
     A* ptr = new A;
     assert(A::count == 1);
@@ -48,4 +48,6 @@ int main()
         assert(A::count == 0);
     }
     assert(globalMemCounter.checkOutstandingNewEq(0));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr.pass.cpp
index 44a5be4714b..091782f02f3 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> pA(new A);
@@ -58,4 +58,6 @@ int main()
         assert(A::count == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y.pass.cpp
index 3b7279087ff..01a74898f9c 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y.pass.cpp
@@ -50,7 +50,7 @@ struct C
 
 int C::count = 0;
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_convertible<std::shared_ptr<A>, std::shared_ptr<B> >::value), "");
     static_assert((!std::is_convertible<std::shared_ptr<B>, std::shared_ptr<A> >::value), "");
@@ -93,4 +93,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y_rv.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y_rv.pass.cpp
index 8d3af186e50..cc86d12dfcf 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y_rv.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_Y_rv.pass.cpp
@@ -54,7 +54,7 @@ struct C
 
 int C::count = 0;
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_convertible<std::shared_ptr<A>, std::shared_ptr<B> >::value), "");
     static_assert((!std::is_convertible<std::shared_ptr<B>, std::shared_ptr<A> >::value), "");
@@ -109,4 +109,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_pointer.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_pointer.pass.cpp
index 06a285cd2ce..83a9a9720dc 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_pointer.pass.cpp
@@ -37,7 +37,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> pA(new A);
@@ -57,4 +57,6 @@ int main()
     }
     assert(A::count == 0);
     assert(B::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_rv.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_rv.pass.cpp
index d9eef4a2388..86797a047e8 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_rv.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/shared_ptr_rv.pass.cpp
@@ -30,7 +30,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> pA(new A);
@@ -73,4 +73,6 @@ int main()
         assert(A::count == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
index d235a50b9a1..6fd812fca0a 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/unique_ptr.pass.cpp
@@ -49,7 +49,7 @@ void fn ( const std::shared_ptr<B> &) { assert (false); }
 template <typename T>
 void assert_deleter ( T * ) { assert(false); }
 
-int main()
+int main(int, char**)
 {
     {
         std::unique_ptr<A> ptr(new A);
@@ -97,4 +97,6 @@ int main()
         std::shared_ptr<int> p2(std::move(p)); // should not call deleter when going out of scope
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/weak_ptr.pass.cpp
index 117a74aaa57..9174f39be37 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/weak_ptr.pass.cpp
@@ -40,7 +40,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
 #ifndef TEST_HAS_NO_EXCEPTIONS
     {
@@ -81,4 +81,6 @@ int main()
     }
     assert(A::count == 0);
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.pass.cpp
index 354a23e7015..06c2bba6705 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared.pass.cpp
@@ -51,7 +51,7 @@ private:
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
     int i = 67;
@@ -82,4 +82,6 @@ int main()
     assert(p->get_char() == 'f');
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared_cxx03.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared_cxx03.pass.cpp
index 0783b6e7f1c..00f79cc19d2 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared_cxx03.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared_cxx03.pass.cpp
@@ -97,7 +97,7 @@ void test()
     assert(Three::count == 0);
 }
 
-int main()
+int main(int, char**)
 {
     {
     int i = 67;
@@ -114,4 +114,6 @@ int main()
 #if TEST_STD_VER >= 11
     test<min_allocator<void> >();
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
index 2535519b9e7..aed060e5790 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp
@@ -73,7 +73,7 @@ void test_pointer_to_function() {
 void test_pointer_to_function() {}
 #endif // _LIBCPP_VERSION
 
-int main()
+int main(int, char**)
 {
     int nc = globalMemCounter.outstanding_new;
     {
@@ -107,4 +107,6 @@ int main()
     }
 #endif
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.private.fail.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.private.fail.cpp
index fd5ebdccab3..e17d7424be4 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.private.fail.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.private.fail.cpp
@@ -22,7 +22,9 @@ private:
    S () {};  // ctor is private
 };
 
-int main()
+int main(int, char**)
 {
     std::shared_ptr<S> p = std::make_shared<S>();
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.fail.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.fail.cpp
index 8ba4a69c3c4..d4d8fb630c9 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.fail.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.protected.fail.cpp
@@ -22,7 +22,9 @@ protected:
    S () {};  // ctor is protected
 };
 
-int main()
+int main(int, char**)
 {
     std::shared_ptr<S> p = std::make_shared<S>();  // expected-error-re@memory:* {{static_assert failed{{.*}} "Can't construct object in make_shared"}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.volatile.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.volatile.pass.cpp
index c50b68f7097..aa038f7475f 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.volatile.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.volatile.pass.cpp
@@ -52,9 +52,11 @@ void test(const T &t0)
 
 }
 
-int main()
+int main(int, char**)
 {
     test<bool>(true);
     test<int>(3);
     test<double>(5.0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.dest/tested_elsewhere.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.dest/tested_elsewhere.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.dest/tested_elsewhere.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.dest/tested_elsewhere.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.io/io.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.io/io.pass.cpp
index cf3aac86aec..b09550a6eab 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.io/io.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.io/io.pass.cpp
@@ -18,11 +18,13 @@
 #include <sstream>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::shared_ptr<int> p(new int(3));
     std::ostringstream os;
     assert(os.str().empty());
     os << p;
     assert(!os.str().empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset.pass.cpp
index 3943b5892ba..c9df003192b 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset.pass.cpp
@@ -38,7 +38,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<B> p(new B);
@@ -58,4 +58,6 @@ int main()
         assert(p.get() == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer.pass.cpp
index 3e91fa3de56..c3582416584 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer.pass.cpp
@@ -38,7 +38,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<B> p(new B);
@@ -60,4 +60,6 @@ int main()
         assert(p.get() == ptr);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter.pass.cpp
index 70a2024cce2..e7d457fa139 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<B> p(new B);
@@ -75,4 +75,6 @@ int main()
     assert(A::count == 0);
     assert(test_deleter<A>::count == 0);
     assert(test_deleter<A>::dealloc_count == 2);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter_allocator.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter_allocator.pass.cpp
index d4db96826e3..9e2bd101290 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter_allocator.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/reset_pointer_deleter_allocator.pass.cpp
@@ -40,7 +40,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<B> p(new B);
@@ -84,4 +84,6 @@ int main()
     assert(test_deleter<A>::dealloc_count == 2);
     assert(test_allocator<A>::count == 0);
     assert(test_allocator<A>::alloc_count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/swap.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/swap.pass.cpp
index a47e67f04a9..a27949ebb80 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/swap.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.mod/swap.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A* ptr1 = new A;
@@ -100,4 +100,6 @@ int main()
         assert(A::count == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/arrow.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/arrow.pass.cpp
index 5f7d6582b6f..77bf3a22e08 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/arrow.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/arrow.pass.cpp
@@ -16,7 +16,7 @@
 #include <utility>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<std::pair<int, int> > p(new std::pair<int, int>(3, 4));
     assert(p->first == 3);
@@ -25,4 +25,6 @@ int main()
     p->second = 6;
     assert(p->first == 5);
     assert(p->second == 6);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/dereference.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/dereference.pass.cpp
index 4b2a495a89b..a6f75533acb 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/dereference.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/dereference.pass.cpp
@@ -15,10 +15,12 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p(new int(32));
     assert(*p == 32);
     *p = 3;
     assert(*p == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/op_bool.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/op_bool.pass.cpp
index 4c6790f867c..247deb07bb9 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/op_bool.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/op_bool.pass.cpp
@@ -15,7 +15,7 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     {
     const std::shared_ptr<int> p(new int(32));
@@ -25,4 +25,6 @@ int main()
     const std::shared_ptr<int> p;
     assert(!p);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_shared_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_shared_ptr.pass.cpp
index c6ae19911c3..497a53b2144 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_shared_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_shared_ptr.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2 = p1;
@@ -26,4 +26,6 @@ int main()
     assert(p1.owner_before(p3) || p3.owner_before(p1));
     assert(p3.owner_before(p1) == p3.owner_before(p2));
     ASSERT_NOEXCEPT(p1.owner_before(p2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_weak_ptr.pass.cpp
index e857aa6a83d..07c7a064420 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/owner_before_weak_ptr.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2 = p1;
@@ -29,4 +29,6 @@ int main()
     assert(p1.owner_before(w3) || p3.owner_before(w1));
     assert(p3.owner_before(w1) == p3.owner_before(w2));
     ASSERT_NOEXCEPT(p1.owner_before(w2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/unique.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/unique.pass.cpp
index 14a2fe992f1..dfad3138517 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/unique.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.obs/unique.pass.cpp
@@ -15,7 +15,7 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p(new int(32));
     assert(p.unique());
@@ -24,4 +24,6 @@ int main()
     assert(!p.unique());
     }
     assert(p.unique());
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.spec/swap.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.spec/swap.pass.cpp
index b40e4705acf..b0bfcae9ae4 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.spec/swap.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.spec/swap.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A* ptr1 = new A;
@@ -101,4 +101,6 @@ int main()
         assert(A::count == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/types.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/types.pass.cpp
index 2263eb810cb..f5bdb876b46 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/types.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/types.pass.cpp
@@ -19,7 +19,9 @@
 
 struct A;  // purposefully incomplete
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_same<std::weak_ptr<A>::element_type, A>::value), "");
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
index c65755d8ea4..b3cc13d72a8 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
@@ -52,7 +52,7 @@
 
 struct X {};
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2 = p1;
@@ -128,4 +128,6 @@ int main()
     assert(s.find(vp) == s.end());
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/shared_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/shared_ptr_Y.pass.cpp
index 1362537e030..02f180d3d64 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/shared_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/shared_ptr_Y.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> pA(new A);
@@ -57,4 +57,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr.pass.cpp
index 739165c3cab..f41c391c4c2 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> ps(new A);
@@ -74,4 +74,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr_Y.pass.cpp
index f763dc46395..33b2ddd422a 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.assign/weak_ptr_Y.pass.cpp
@@ -39,7 +39,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> ps(new A);
@@ -74,4 +74,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/default.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/default.pass.cpp
index b29623f296a..e5a70abe417 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/default.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/default.pass.cpp
@@ -17,8 +17,10 @@
 
 struct A;
 
-int main()
+int main(int, char**)
 {
     std::weak_ptr<A> p;
     assert(p.use_count() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/shared_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/shared_ptr_Y.pass.cpp
index 8aaeab0c904..45be55e66f8 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/shared_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/shared_ptr_Y.pass.cpp
@@ -50,7 +50,7 @@ struct C
 
 int C::count = 0;
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_convertible<std::shared_ptr<A>, std::weak_ptr<B> >::value), "");
     static_assert((!std::is_convertible<std::weak_ptr<B>, std::shared_ptr<A> >::value), "");
@@ -91,4 +91,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr.pass.cpp
index 351b66323db..658b233c41c 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr.pass.cpp
@@ -61,7 +61,7 @@ template <class T>
 void sink (std::weak_ptr<T> &&) {}
 #endif
 
-int main()
+int main(int, char**)
 {
     {
         const std::shared_ptr<A> ps(new A);
@@ -112,4 +112,6 @@ int main()
     assert(B::count == 0);
     assert(A::count == 0);
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr_Y.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr_Y.pass.cpp
index e155e4faa13..4268fda3aba 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr_Y.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.const/weak_ptr_Y.pass.cpp
@@ -54,7 +54,7 @@ int C::count = 0;
 template <class T>
 std::weak_ptr<T> source (std::shared_ptr<T> p) { return std::weak_ptr<T>(p); }
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_convertible<std::weak_ptr<A>, std::weak_ptr<B> >::value), "");
     static_assert((!std::is_convertible<std::weak_ptr<B>, std::weak_ptr<A> >::value), "");
@@ -104,4 +104,6 @@ int main()
     }
     assert(B::count == 0);
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.dest/tested_elsewhere.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.dest/tested_elsewhere.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.dest/tested_elsewhere.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.dest/tested_elsewhere.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/reset.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/reset.pass.cpp
index 7c3bcb6c641..eae249ca1a5 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/reset.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/reset.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::shared_ptr<A> p1(new A);
@@ -37,4 +37,6 @@ int main()
         assert(p1.use_count() == 1);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/swap.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/swap.pass.cpp
index 38b1dee093a..76703d0ddd7 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/swap.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.mod/swap.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A* ptr1 = new A;
@@ -45,4 +45,6 @@ int main()
         }
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/expired.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/expired.pass.cpp
index f2fccb5589d..5fb2dd4f95b 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/expired.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/expired.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::weak_ptr<A> wp;
@@ -42,4 +42,6 @@ int main()
         assert(wp.use_count() == 0);
         assert(wp.expired() == (wp.use_count() == 0));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/lock.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/lock.pass.cpp
index 883de740cce..50ff84318ef 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/lock.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/lock.pass.cpp
@@ -26,7 +26,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         std::weak_ptr<A> wp;
@@ -54,4 +54,6 @@ int main()
         assert(A::count == 0);
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/not_less_than.fail.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/not_less_than.fail.cpp
index c916a890740..2df6d6a0e32 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/not_less_than.fail.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/not_less_than.fail.cpp
@@ -15,7 +15,7 @@
 #include <memory>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2(new int);
@@ -23,4 +23,6 @@ int main()
     const std::weak_ptr<int> w2(p2);
 
     bool b = w1 < w2;
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_shared_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_shared_ptr.pass.cpp
index d8483d9b65e..4d26f5f2b33 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_shared_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_shared_ptr.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2 = p1;
@@ -29,4 +29,6 @@ int main()
     assert(w1.owner_before(p3) || w3.owner_before(p1));
     assert(w3.owner_before(p1) == w3.owner_before(p2));
     ASSERT_NOEXCEPT(w1.owner_before(p2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_weak_ptr.pass.cpp
index b323da7d503..39993cd8f6a 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/owner_before_weak_ptr.pass.cpp
@@ -16,7 +16,7 @@
 #include <cassert>
 #include "test_macros.h"
 
-int main()
+int main(int, char**)
 {
     const std::shared_ptr<int> p1(new int);
     const std::shared_ptr<int> p2 = p1;
@@ -29,4 +29,6 @@ int main()
     assert(w1.owner_before(w3) || w3.owner_before(w1));
     assert(w3.owner_before(w1) == w3.owner_before(w2));
     ASSERT_NOEXCEPT(w1.owner_before(w2));
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.spec/swap.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.spec/swap.pass.cpp
index e13d5aeaf63..53bc3eb9cd8 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.spec/swap.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.spec/swap.pass.cpp
@@ -27,7 +27,7 @@ struct A
 
 int A::count = 0;
 
-int main()
+int main(int, char**)
 {
     {
         A* ptr1 = new A;
@@ -46,4 +46,6 @@ int main()
         }
     }
     assert(A::count == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weakptr/bad_weak_ptr.pass.cpp b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weakptr/bad_weak_ptr.pass.cpp
index a85120ae05f..f3e26dee54e 100644
--- a/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weakptr/bad_weak_ptr.pass.cpp
+++ b/libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.weakptr/bad_weak_ptr.pass.cpp
@@ -20,11 +20,13 @@
 #include <cassert>
 #include <cstring>
 
-int main()
+int main(int, char**)
 {
     static_assert((std::is_base_of<std::exception, std::bad_weak_ptr>::value), "");
     std::bad_weak_ptr e;
     std::bad_weak_ptr e2 = e;
     e2 = e;
     assert(std::strcmp(e.what(), "bad_weak_ptr") == 0);
+
+  return 0;
 }