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

108 files changed, 324 insertions, 108 deletions

diff --git a/libcxx/test/std/containers/container.adaptors/nothing_to_do.pass.cpp b/libcxx/test/std/containers/container.adaptors/nothing_to_do.pass.cpp
index f77636c8475..1f764da05d6 100644
--- a/libcxx/test/std/containers/container.adaptors/nothing_to_do.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/nothing_to_do.pass.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-int main()
+int main(int, char**)
 {
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_alloc.pass.cpp
index 293356b386a..59547203b49 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_alloc.pass.cpp
@@ -40,9 +40,11 @@ struct test
     using base::c;
 };
 
-int main()
+int main(int, char**)
 {
     test<int> q((test_allocator<int>(3)));
     assert(q.c.get_allocator() == test_allocator<int>(3));
     assert(q.c.size() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_alloc.pass.cpp
index 58d61b70eb2..40f6bc473c7 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_alloc.pass.cpp
@@ -40,9 +40,11 @@ struct test
     using base::c;
 };
 
-int main()
+int main(int, char**)
 {
     test<int> q(std::less<int>(), test_allocator<int>(3));
     assert(q.c.get_allocator() == test_allocator<int>(3));
     assert(q.c.size() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_cont_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_cont_alloc.pass.cpp
index 39c4955659b..1f3dd7fbd16 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_cont_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_cont_alloc.pass.cpp
@@ -51,7 +51,7 @@ struct test
     using base::c;
 };
 
-int main()
+int main(int, char**)
 {
     typedef std::vector<int, test_allocator<int> > C;
     C v = make<C>(5);
@@ -59,4 +59,6 @@ int main()
     assert(q.c.get_allocator() == test_allocator<int>(3));
     assert(q.size() == 5);
     assert(q.top() == 4);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_rcont_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_rcont_alloc.pass.cpp
index 4609064735f..3956f9b974e 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_rcont_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_comp_rcont_alloc.pass.cpp
@@ -51,11 +51,13 @@ struct test
     using base::c;
 };
 
-int main()
+int main(int, char**)
 {
     typedef std::vector<int, test_allocator<int> > C;
     test<int> q(std::less<int>(), make<C>(5), test_allocator<int>(3));
     assert(q.c.get_allocator() == test_allocator<int>(3));
     assert(q.size() == 5);
     assert(q.top() == 4);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_copy_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_copy_alloc.pass.cpp
index 69ed27c073c..c461718430c 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_copy_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_copy_alloc.pass.cpp
@@ -45,7 +45,7 @@ struct test
     using base::c;
 };
 
-int main()
+int main(int, char**)
 {
     test<int> qo(std::less<int>(),
                       make<std::vector<int, test_allocator<int> > >(5),
@@ -54,4 +54,6 @@ int main()
     assert(q.size() == 5);
     assert(q.c.get_allocator() == test_allocator<int>(6));
     assert(q.top() == int(4));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_move_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_move_alloc.pass.cpp
index d1ca38e022b..98dc207c199 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_move_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons.alloc/ctor_move_alloc.pass.cpp
@@ -53,7 +53,7 @@ struct test
 };
 
 
-int main()
+int main(int, char**)
 {
     test<MoveOnly> qo(std::less<MoveOnly>(),
                       make<std::vector<MoveOnly, test_allocator<MoveOnly> > >(5),
@@ -62,4 +62,6 @@ int main()
     assert(q.size() == 5);
     assert(q.c.get_allocator() == test_allocator<MoveOnly>(6));
     assert(q.top() == MoveOnly(4));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_copy.pass.cpp
index 12c64256111..5b7760d0546 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_copy.pass.cpp
@@ -24,7 +24,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::vector<int> v = make<std::vector<int> >(5);
     std::priority_queue<int, std::vector<int>, std::greater<int> > qo(std::greater<int>(), v);
@@ -32,4 +32,6 @@ int main()
     q = qo;
     assert(q.size() == 5);
     assert(q.top() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_move.pass.cpp
index 61499209478..20f62d9bf64 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/assign_move.pass.cpp
@@ -29,11 +29,13 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<MoveOnly> qo(std::less<MoveOnly>(), make<std::vector<MoveOnly> >(5));
     std::priority_queue<MoveOnly> q;
     q = std::move(qo);
     assert(q.size() == 5);
     assert(q.top() == MoveOnly(4));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp.pass.cpp
index a195b10fc50..02f1bcaf059 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp.pass.cpp
@@ -15,7 +15,7 @@
 
 #include "test_allocator.h"
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int, std::vector<int, limited_allocator<int, 10> > > q((std::less<int>()));
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     q.push(2);
     assert(q.size() == 2);
     assert(q.top() == 2);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_container.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_container.pass.cpp
index 561b5d48ded..487b86c5f52 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_container.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_container.pass.cpp
@@ -24,10 +24,12 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::vector<int> v = make<std::vector<int> >(5);
     std::priority_queue<int, std::vector<int>, std::greater<int> > q(std::greater<int>(), v);
     assert(q.size() == 5);
     assert(q.top() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_rcontainer.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_rcontainer.pass.cpp
index cb3b97997fa..47980032c05 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_rcontainer.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_comp_rcontainer.pass.cpp
@@ -29,9 +29,11 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<MoveOnly> q(std::less<MoveOnly>(), make<std::vector<MoveOnly> >(5));
     assert(q.size() == 5);
     assert(q.top() == MoveOnly(4));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_copy.pass.cpp
index 1c63f71520c..fa8bae2b91b 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_copy.pass.cpp
@@ -24,11 +24,13 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::vector<int> v = make<std::vector<int> >(5);
     std::priority_queue<int, std::vector<int>, std::greater<int> > qo(std::greater<int>(), v);
     std::priority_queue<int, std::vector<int>, std::greater<int> > q = qo;
     assert(q.size() == 5);
     assert(q.top() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_default.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_default.pass.cpp
index ae0e7badb6d..4c8dd524aeb 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_default.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_default.pass.cpp
@@ -15,7 +15,7 @@
 
 #include "test_allocator.h"
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int, std::vector<int, limited_allocator<int, 10> > > q;
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     q.push(2);
     assert(q.size() == 2);
     assert(q.top() == 2);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter.pass.cpp
index d1cda2029ca..d2afe72cad5 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter.pass.cpp
@@ -15,11 +15,13 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     int a[] = {3, 5, 2, 0, 6, 8, 1};
     int* an = a + sizeof(a)/sizeof(a[0]);
     std::priority_queue<int> q(a, an);
     assert(q.size() == static_cast<std::size_t>(an - a));
     assert(q.top() == 8);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp.pass.cpp
index c147b5cfd50..caee12f0f5e 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp.pass.cpp
@@ -16,7 +16,7 @@
 #include <functional>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     int a[] = {3, 5, 2, 0, 6, 8, 1};
     int* an = a + sizeof(a)/sizeof(a[0]);
@@ -24,4 +24,6 @@ int main()
         q(a, an, std::greater<int>());
     assert(q.size() == static_cast<std::size_t>(an - a));
     assert(q.top() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_cont.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_cont.pass.cpp
index b5dd515da13..0b076679240 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_cont.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_cont.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     int a[] = {3, 5, 2, 0, 6, 8, 1};
     const int n = sizeof(a)/sizeof(a[0]);
@@ -23,4 +23,6 @@ int main()
     std::priority_queue<int> q(a+n/2, a+n, std::less<int>(), v);
     assert(q.size() == n);
     assert(q.top() == 8);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_rcont.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_rcont.pass.cpp
index f2f78685f24..6bc4417f478 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_rcont.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_iter_iter_comp_rcont.pass.cpp
@@ -19,7 +19,7 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     int a[] = {3, 5, 2, 0, 6, 8, 1};
     const int n = sizeof(a)/sizeof(a[0]);
@@ -28,4 +28,6 @@ int main()
                                     std::vector<MoveOnly>(a, a+n/2));
     assert(q.size() == n);
     assert(q.top() == MoveOnly(8));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_move.pass.cpp
index 445bdb56675..4158012445a 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/ctor_move.pass.cpp
@@ -29,10 +29,12 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<MoveOnly> qo(std::less<MoveOnly>(), make<std::vector<MoveOnly> >(5));
     std::priority_queue<MoveOnly> q = std::move(qo);
     assert(q.size() == 5);
     assert(q.top() == MoveOnly(4));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.fail.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.fail.cpp
index a37e372edc6..a6e579a4456 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.fail.cpp
@@ -17,7 +17,7 @@
 #include <cstddef>
 
 
-int main()
+int main(int, char**)
 {
 //  Test the explicit deduction guides
     {
@@ -54,4 +54,6 @@ int main()
 //      stack<allocator<int>, allocator<allocator<int>>>
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.pass.cpp
index f175c7d1489..45d39ad3ed7 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/deduct.pass.cpp
@@ -38,7 +38,7 @@
 
 struct A {};
 
-int main()
+int main(int, char**)
 {
 
 //  Test the explicit deduction guides
@@ -119,4 +119,6 @@ int main()
     assert(pri.size() == 4);
     assert(pri.top() == 0);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/default_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/default_noexcept.pass.cpp
index fa0e92a1663..d738a553eaf 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/default_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/default_noexcept.pass.cpp
@@ -23,7 +23,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
 #if defined(_LIBCPP_VERSION)
     {
@@ -31,4 +31,6 @@ int main()
         static_assert(std::is_nothrow_default_constructible<C>::value, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/dtor_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/dtor_noexcept.pass.cpp
index a6418a3c77b..af583a9e27a 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/dtor_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/dtor_noexcept.pass.cpp
@@ -17,10 +17,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::priority_queue<MoveOnly> C;
         static_assert(std::is_nothrow_destructible<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_assign_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_assign_noexcept.pass.cpp
index 8c3800ba21e..3fbd53dc43e 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_assign_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_assign_noexcept.pass.cpp
@@ -21,10 +21,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::priority_queue<MoveOnly> C;
         static_assert(std::is_nothrow_move_assignable<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_noexcept.pass.cpp
index ae6eb4b087d..7c6b5f2136f 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.cons/move_noexcept.pass.cpp
@@ -21,10 +21,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::priority_queue<MoveOnly> C;
         static_assert(std::is_nothrow_move_constructible<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/emplace.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/emplace.pass.cpp
index 5e5dd9f126d..928533075d0 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/emplace.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/emplace.pass.cpp
@@ -19,7 +19,7 @@
 
 #include "../../../Emplaceable.h"
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<Emplaceable> q;
     q.emplace(1, 2.5);
@@ -28,4 +28,6 @@ int main()
     assert(q.top() == Emplaceable(3, 4.5));
     q.emplace(2, 3.5);
     assert(q.top() == Emplaceable(3, 4.5));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.fail.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.fail.cpp
index 33b97d53376..698553d33e1 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.fail.cpp
@@ -20,8 +20,10 @@
 
 #include "test_macros.h"
 
-int main ()
+int main(int, char**)
 {
     std::priority_queue<int> c;
     c.empty();  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.pass.cpp
index 60499b853d1..f8f9279d576 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/empty.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q;
     assert(q.empty());
@@ -23,4 +23,6 @@ int main()
     assert(!q.empty());
     q.pop();
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/pop.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/pop.pass.cpp
index b6bcb4a72f8..a6fc9509c8b 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/pop.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/pop.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q;
     q.push(1);
@@ -30,4 +30,6 @@ int main()
     assert(q.top() == 1);
     q.pop();
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push.pass.cpp
index 8edbe1ad127..01c0ab61832 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q;
     q.push(1);
@@ -24,4 +24,6 @@ int main()
     assert(q.top() == 3);
     q.push(2);
     assert(q.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push_rvalue.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push_rvalue.pass.cpp
index 00bdf0c7e4c..cf474dec565 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/push_rvalue.pass.cpp
@@ -19,7 +19,7 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<MoveOnly> q;
     q.push(1);
@@ -28,4 +28,6 @@ int main()
     assert(q.top() == 3);
     q.push(2);
     assert(q.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/size.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/size.pass.cpp
index 51eef9eda27..393a97c28a4 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/size.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/size.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q;
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     assert(q.size() == 1);
     q.pop();
     assert(q.size() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/swap.pass.cpp
index 995e1742a52..bc3f453d886 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/swap.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q1;
     std::priority_queue<int> q2;
@@ -26,4 +26,6 @@ int main()
     assert(q1.empty());
     assert(q2.size() == 3);
     assert(q2.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/top.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/top.pass.cpp
index 22a8174b34f..ea0e489f617 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/top.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.members/top.pass.cpp
@@ -15,7 +15,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q;
     q.push(1);
@@ -24,4 +24,6 @@ int main()
     assert(q.top() == 3);
     q.push(2);
     assert(q.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap.pass.cpp
index 2c9a39f66b0..bc75df0d384 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap.pass.cpp
@@ -17,7 +17,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::priority_queue<int> q1;
     std::priority_queue<int> q2;
@@ -28,4 +28,6 @@ int main()
     assert(q1.empty());
     assert(q2.size() == 3);
     assert(q2.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap_noexcept.pass.cpp
index f2194ccf874..ad4254c2b79 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/priqueue.special/swap_noexcept.pass.cpp
@@ -22,10 +22,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::priority_queue<MoveOnly> C;
         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/types.fail.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/types.fail.cpp
index 431a4d0d502..244028e444d 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/types.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/types.fail.cpp
@@ -27,8 +27,10 @@
 #include <cassert>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
 //  LWG#2566 says that the first template param must match the second one's value type
     std::priority_queue<double, std::deque<int>> t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/priority.queue/types.pass.cpp b/libcxx/test/std/containers/container.adaptors/priority.queue/types.pass.cpp
index 6084e59069e..54712819050 100644
--- a/libcxx/test/std/containers/container.adaptors/priority.queue/types.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/priority.queue/types.pass.cpp
@@ -50,7 +50,7 @@ struct C
     typedef int size_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_same<std::priority_queue<int>::container_type, std::vector<int> >::value), "");
     static_assert(( std::is_same<std::priority_queue<int, std::deque<int> >::container_type, std::deque<int> >::value), "");
@@ -64,4 +64,6 @@ int main()
     static_assert(( std::uses_allocator<std::priority_queue<int>, std::allocator<int> >::value), "");
     static_assert((!std::uses_allocator<std::priority_queue<int, C>, std::allocator<int> >::value), "");
     test t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_alloc.pass.cpp
index d2a85a34847..8d916f76771 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_alloc.pass.cpp
@@ -31,8 +31,10 @@ struct test
     test_allocator<int> get_allocator() {return c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     test q(test_allocator<int>(3));
     assert(q.get_allocator() == test_allocator<int>(3));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_container_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_container_alloc.pass.cpp
index fc3549d2da2..56272064fc2 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_container_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_container_alloc.pass.cpp
@@ -44,7 +44,7 @@ struct test
     test_allocator<int> get_allocator() {return c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     C d = make<C>(5);
     test q(d, test_allocator<int>(4));
@@ -55,4 +55,6 @@ int main()
         assert(q.front() == d[i]);
         q.pop();
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_queue_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_queue_alloc.pass.cpp
index 6c7fbbc8110..8a66c6f12e7 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_queue_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_queue_alloc.pass.cpp
@@ -42,10 +42,12 @@ struct test
     allocator_type get_allocator() {return this->c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     test<int> q(make<C>(5), test_allocator<int>(4));
     test<int> q2(q, test_allocator<int>(5));
     assert(q2.get_allocator() == test_allocator<int>(5));
     assert(q2.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rcontainer_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rcontainer_alloc.pass.cpp
index cc6cb5cdbc9..3af4fb0dacc 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rcontainer_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rcontainer_alloc.pass.cpp
@@ -48,9 +48,11 @@ struct test
 };
 
 
-int main()
+int main(int, char**)
 {
     test<MoveOnly> q(make<C>(5), test_allocator<MoveOnly>(4));
     assert(q.get_allocator() == test_allocator<MoveOnly>(4));
     assert(q.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rqueue_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rqueue_alloc.pass.cpp
index cac8bf3cd1f..29a742df7d4 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rqueue_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons.alloc/ctor_rqueue_alloc.pass.cpp
@@ -48,10 +48,12 @@ struct test
 };
 
 
-int main()
+int main(int, char**)
 {
     test<MoveOnly> q(make<C>(5), test_allocator<MoveOnly>(4));
     test<MoveOnly> q2(std::move(q), test_allocator<MoveOnly>(5));
     assert(q2.get_allocator() == test_allocator<MoveOnly>(5));
     assert(q2.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_container.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_container.pass.cpp
index e9c41a0b612..dad35d2d169 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_container.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_container.pass.cpp
@@ -24,7 +24,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::deque<int> d = make<std::deque<int> >(5);
     std::queue<int> q(d);
@@ -34,4 +34,6 @@ int main()
         assert(q.front() == d[i]);
         q.pop();
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_copy.pass.cpp
index 35c2fa0136e..19e46a23662 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_copy.pass.cpp
@@ -23,9 +23,11 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q(make<std::deque<int> >(5));
     std::queue<int> q2 = q;
     assert(q2 == q);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_default.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_default.pass.cpp
index 0a1d3dd960b..c5c8b17a690 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_default.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_default.pass.cpp
@@ -15,7 +15,7 @@
 
 #include "test_allocator.h"
 
-int main()
+int main(int, char**)
 {
     std::queue<int, std::vector<int, limited_allocator<int, 10> > > q;
     assert(q.size() == 0);
@@ -24,4 +24,6 @@ int main()
     assert(q.size() == 2);
     assert(q.front() == 1);
     assert(q.back() == 2);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_move.pass.cpp
index a9def3e333b..c275d5d602f 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_move.pass.cpp
@@ -29,10 +29,12 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::queue<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     std::queue<MoveOnly> q2 = std::move(q);
     assert(q2.size() == 5);
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_rcontainer.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_rcontainer.pass.cpp
index 00aba51c3c7..3812ce9169b 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_rcontainer.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/ctor_rcontainer.pass.cpp
@@ -29,8 +29,10 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::queue<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     assert(q.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.fail.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.fail.cpp
index eecb0343b4c..00b39c6a95b 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.fail.cpp
@@ -17,7 +17,7 @@
 #include <cstddef>
 
 
-int main()
+int main(int, char**)
 {
 //  Test the explicit deduction guides
     {
@@ -42,4 +42,6 @@ int main()
 //      stack<allocator<int>, allocator<allocator<int>>>
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
index 45a6f2e75a2..247da2a3d98 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
@@ -33,7 +33,7 @@
 
 struct A {};
 
-int main()
+int main(int, char**)
 {
 
 //  Test the explicit deduction guides
@@ -87,4 +87,6 @@ int main()
     assert(que.back() == 3);
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/default_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/default_noexcept.pass.cpp
index a53dd949256..1200f2e2fef 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/default_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/default_noexcept.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
 #if defined(_LIBCPP_VERSION)
     {
@@ -29,4 +29,6 @@ int main()
         static_assert(std::is_nothrow_default_constructible<C>::value, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/dtor_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/dtor_noexcept.pass.cpp
index 4c87d15e047..18e42ea3a7e 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/dtor_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/dtor_noexcept.pass.cpp
@@ -17,10 +17,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::queue<MoveOnly> C;
         static_assert(std::is_nothrow_destructible<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_assign_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_assign_noexcept.pass.cpp
index 93f69059fb3..a82ab8fa41c 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_assign_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_assign_noexcept.pass.cpp
@@ -20,10 +20,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::queue<MoveOnly> C;
         static_assert(std::is_nothrow_move_assignable<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_noexcept.pass.cpp
index 24e96edc5e4..e4c170a8bb9 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/move_noexcept.pass.cpp
@@ -22,7 +22,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
 #if defined(_LIBCPP_VERSION)
     {
@@ -30,4 +30,6 @@ int main()
         static_assert(std::is_nothrow_move_constructible<C>::value, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_copy.pass.cpp
index 5fe6b70c64d..98385a6f7cc 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_copy.pass.cpp
@@ -23,10 +23,12 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q(make<std::deque<int> >(5));
     std::queue<int> q2;
     q2 = q;
     assert(q2 == q);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_move.pass.cpp
index 87c9ad197e6..de30e5cfe2e 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/assign_move.pass.cpp
@@ -29,11 +29,13 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::queue<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     std::queue<MoveOnly> q2;
     q2 = std::move(q);
     assert(q2.size() == 5);
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back.pass.cpp
index 115360e0709..cb115c70222 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
@@ -22,4 +22,6 @@ int main()
     q.push(3);
     int& ir = q.back();
     assert(ir == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back_const.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back_const.pass.cpp
index 158aa83a9f0..3a6e4c89037 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back_const.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/back_const.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     const std::queue<int>& cqr = q;
     const int& cir = cqr.back();
     assert(cir == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/emplace.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/emplace.pass.cpp
index a8e8791ac69..74afcce974f 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/emplace.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/emplace.pass.cpp
@@ -37,7 +37,7 @@ void test_return_type() {
 #endif
 }
 
-int main()
+int main(int, char**)
 {
     test_return_type<std::queue<int> > ();
     test_return_type<std::queue<int, std::list<int> > > ();
@@ -61,4 +61,6 @@ int main()
     assert(q.size() == 3);
     assert(q.front() == Emplaceable(1, 2.5));
     assert(q.back() == Emplaceable(3, 4.5));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.fail.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.fail.cpp
index f53f9a805e0..454bf32bede 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.fail.cpp
@@ -20,8 +20,10 @@
 
 #include "test_macros.h"
 
-int main ()
+int main(int, char**)
 {
     std::queue<int> c;
     c.empty();  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.pass.cpp
index 095512c2124..cc0fc56b7c4 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/empty.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.empty());
@@ -21,4 +21,6 @@ int main()
     assert(!q.empty());
     q.pop();
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front.pass.cpp
index 7ce29976baf..9c8d253fb92 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
@@ -22,4 +22,6 @@ int main()
     q.push(3);
     int& ir = q.front();
     assert(ir == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front_const.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front_const.pass.cpp
index edcb21ea224..5ad1ae97aae 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front_const.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/front_const.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     const std::queue<int>& cqr = q;
     const int& cir = cqr.front();
     assert(cir == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/pop.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/pop.pass.cpp
index 587cf26c3dd..128cda51237 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/pop.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/pop.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
@@ -33,4 +33,6 @@ int main()
     assert(q.back() == 3);
     q.pop();
     assert(q.size() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push.pass.cpp
index a9e962f8afe..b2a784ccfa8 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push.pass.cpp
@@ -13,7 +13,7 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     q.push(1);
@@ -28,4 +28,6 @@ int main()
     assert(q.size() == 3);
     assert(q.front() == 1);
     assert(q.back() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push_rv.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push_rv.pass.cpp
index aafc9563525..17c442b151e 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push_rv.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/push_rv.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     std::queue<MoveOnly> q;
     q.push(MoveOnly(1));
@@ -32,4 +32,6 @@ int main()
     assert(q.size() == 3);
     assert(q.front() == MoveOnly(1));
     assert(q.back() == MoveOnly(3));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/size.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/size.pass.cpp
index f3ecaa5c4f7..fb4fdfcac4d 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/size.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/size.pass.cpp
@@ -13,10 +13,12 @@
 #include <queue>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q;
     assert(q.size() == 0);
     q.push(1);
     assert(q.size() == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/swap.pass.cpp
index 9017d21273d..3635cea4a91 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/swap.pass.cpp
@@ -23,7 +23,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q1 = make<std::queue<int> >(5);
     std::queue<int> q2 = make<std::queue<int> >(10);
@@ -32,4 +32,6 @@ int main()
     q1.swap(q2);
     assert(q1 == q2_save);
     assert(q2 == q1_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.fail.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.fail.cpp
index b9e018ca13a..041008ce6aa 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.fail.cpp
@@ -12,8 +12,10 @@
 #include <cassert>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
 //  LWG#2566 says that the first template param must match the second one's value type
     std::queue<double, std::deque<int>> t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.pass.cpp
index edc41c1a352..8623710eaa2 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.defn/types.pass.cpp
@@ -43,7 +43,7 @@ struct C
     typedef int size_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_same<std::queue<int>::container_type, std::deque<int> >::value), "");
     static_assert(( std::is_same<std::queue<int, std::vector<int> >::container_type, std::vector<int> >::value), "");
@@ -54,4 +54,6 @@ int main()
     static_assert(( std::uses_allocator<std::queue<int>, std::allocator<int> >::value), "");
     static_assert((!std::uses_allocator<std::queue<int, C>, std::allocator<int> >::value), "");
     test t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.ops/eq.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.ops/eq.pass.cpp
index ee36779b5bd..b4a3327d86b 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.ops/eq.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.ops/eq.pass.cpp
@@ -27,7 +27,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q1 = make<std::queue<int> >(5);
     std::queue<int> q2 = make<std::queue<int> >(10);
@@ -36,4 +36,6 @@ int main()
     assert(q1 == q1_save);
     assert(q1 != q2);
     assert(q2 == q2_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.ops/lt.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.ops/lt.pass.cpp
index 66ef66c7bd4..a8eeb1be197 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.ops/lt.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.ops/lt.pass.cpp
@@ -33,7 +33,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q1 = make<std::queue<int> >(5);
     std::queue<int> q2 = make<std::queue<int> >(10);
@@ -41,4 +41,6 @@ int main()
     assert(q2 > q1);
     assert(q1 <= q2);
     assert(q2 >= q1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap.pass.cpp
index fcaec66d755..1adc4f1f474 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap.pass.cpp
@@ -24,7 +24,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::queue<int> q1 = make<std::queue<int> >(5);
     std::queue<int> q2 = make<std::queue<int> >(10);
@@ -33,4 +33,6 @@ int main()
     swap(q1, q2);
     assert(q1 == q2_save);
     assert(q2 == q1_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap_noexcept.pass.cpp
index 81d728a27d6..b8cc387d186 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.special/swap_noexcept.pass.cpp
@@ -21,10 +21,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::queue<MoveOnly> C;
         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_alloc.pass.cpp
index c0023c40138..9fb09b158df 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_alloc.pass.cpp
@@ -31,8 +31,10 @@ struct test
     test_allocator<int> get_allocator() {return c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     test q(test_allocator<int>(3));
     assert(q.get_allocator() == test_allocator<int>(3));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_container_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_container_alloc.pass.cpp
index ef4d25e05e9..b0c6f4fcac7 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_container_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_container_alloc.pass.cpp
@@ -44,7 +44,7 @@ struct test
     test_allocator<int> get_allocator() {return c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     C d = make<C>(5);
     test q(d, test_allocator<int>(4));
@@ -55,4 +55,6 @@ int main()
         assert(q.top() == d[d.size() - i - 1]);
         q.pop();
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_copy_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_copy_alloc.pass.cpp
index f7c0a962021..0d8481228fd 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_copy_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_copy_alloc.pass.cpp
@@ -42,10 +42,12 @@ struct test
     allocator_type get_allocator() {return this->c.get_allocator();}
 };
 
-int main()
+int main(int, char**)
 {
     test<int> q(make<C>(5), test_allocator<int>(4));
     test<int> q2(q, test_allocator<int>(5));
     assert(q2.get_allocator() == test_allocator<int>(5));
     assert(q2.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rcontainer_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rcontainer_alloc.pass.cpp
index f33f638b8e5..5181c673916 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rcontainer_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rcontainer_alloc.pass.cpp
@@ -48,9 +48,11 @@ struct test
 };
 
 
-int main()
+int main(int, char**)
 {
     test<MoveOnly> q(make<C>(5), test_allocator<MoveOnly>(4));
     assert(q.get_allocator() == test_allocator<MoveOnly>(4));
     assert(q.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rqueue_alloc.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rqueue_alloc.pass.cpp
index 2889763ecf0..c5ff35d2d7a 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rqueue_alloc.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons.alloc/ctor_rqueue_alloc.pass.cpp
@@ -48,10 +48,12 @@ struct test
 };
 
 
-int main()
+int main(int, char**)
 {
     test<MoveOnly> q(make<C>(5), test_allocator<MoveOnly>(4));
     test<MoveOnly> q2(std::move(q), test_allocator<MoveOnly>(5));
     assert(q2.get_allocator() == test_allocator<MoveOnly>(5));
     assert(q2.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_container.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_container.pass.cpp
index 7db358b3f0d..c649e238f5b 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_container.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_container.pass.cpp
@@ -24,7 +24,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::deque<int> d = make<std::deque<int> >(5);
     std::stack<int> q(d);
@@ -34,4 +34,6 @@ int main()
         assert(q.top() == d[d.size() - i - 1]);
         q.pop();
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_copy.pass.cpp
index 2bbf7cc93c9..ef3606366ff 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_copy.pass.cpp
@@ -23,9 +23,11 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q(make<std::deque<int> >(5));
     std::stack<int> q2 = q;
     assert(q2 == q);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_default.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_default.pass.cpp
index 731b2fe4ec7..460cf27ec84 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_default.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_default.pass.cpp
@@ -16,7 +16,7 @@
 
 #include "test_allocator.h"
 
-int main()
+int main(int, char**)
 {
     std::stack<int, std::vector<int, limited_allocator<int, 10> > > q;
     assert(q.size() == 0);
@@ -24,4 +24,6 @@ int main()
     q.push(2);
     assert(q.size() == 2);
     assert(q.top() == 2);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_move.pass.cpp
index e5c846df173..86f4414c91e 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_move.pass.cpp
@@ -29,10 +29,12 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::stack<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     std::stack<MoveOnly> q2 = std::move(q);
     assert(q2.size() == 5);
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_rcontainer.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_rcontainer.pass.cpp
index 9ead9152166..28fb5655f94 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_rcontainer.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/ctor_rcontainer.pass.cpp
@@ -29,8 +29,10 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::stack<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     assert(q.size() == 5);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.fail.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.fail.cpp
index bfddd8b598c..894906fc43f 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.fail.cpp
@@ -24,7 +24,7 @@
 #include <cstddef>
 
 
-int main()
+int main(int, char**)
 {
 //  Test the explicit deduction guides
     {
@@ -49,4 +49,6 @@ int main()
 //      stack<allocator<int>, allocator<allocator<int>>>
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
index ec724b063b5..dd5ab91a09c 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
@@ -35,7 +35,7 @@
 
 struct A {};
 
-int main()
+int main(int, char**)
 {
 
 //  Test the explicit deduction guides
@@ -90,4 +90,6 @@ int main()
     assert(stk.top() == 3);
     }
 
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/default_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/default_noexcept.pass.cpp
index 2e901843ef7..d06e2865e8a 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/default_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/default_noexcept.pass.cpp
@@ -22,7 +22,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
 #if defined(_LIBCPP_VERSION)
     {
@@ -30,4 +30,6 @@ int main()
         static_assert(std::is_nothrow_default_constructible<C>::value, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/dtor_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/dtor_noexcept.pass.cpp
index 616f464186e..7c5fd648684 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/dtor_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/dtor_noexcept.pass.cpp
@@ -17,10 +17,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::stack<MoveOnly> C;
         static_assert(std::is_nothrow_destructible<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_assign_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_assign_noexcept.pass.cpp
index 0e97c0ff66d..6ed6b8250aa 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_assign_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_assign_noexcept.pass.cpp
@@ -20,10 +20,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::stack<MoveOnly> C;
         static_assert(std::is_nothrow_move_assignable<C>::value, "");
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_noexcept.pass.cpp
index e7743ad9807..ddf07c42468 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/move_noexcept.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_macros.h"
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
 #if defined(_LIBCPP_VERSION)
     {
@@ -29,4 +29,6 @@ int main()
         static_assert(std::is_nothrow_move_constructible<C>::value, "");
     }
 #endif
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_copy.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_copy.pass.cpp
index 0f8bf035d98..df34e4c63c8 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_copy.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_copy.pass.cpp
@@ -23,10 +23,12 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q(make<std::deque<int> >(5));
     std::stack<int> q2;
     q2 = q;
     assert(q2 == q);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_move.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_move.pass.cpp
index 16609e983be..ad77defe214 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_move.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/assign_move.pass.cpp
@@ -29,11 +29,13 @@ make(int n)
 }
 
 
-int main()
+int main(int, char**)
 {
     std::stack<MoveOnly> q(make<std::deque<MoveOnly> >(5));
     std::stack<MoveOnly> q2;
     q2 = std::move(q);
     assert(q2.size() == 5);
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/emplace.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/emplace.pass.cpp
index 605440bc48f..1aa6b62c7bb 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/emplace.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/emplace.pass.cpp
@@ -36,7 +36,7 @@ void test_return_type() {
 #endif
 }
 
-int main()
+int main(int, char**)
 {
     test_return_type<std::stack<int> > ();
     test_return_type<std::stack<int, std::vector<int> > > ();
@@ -57,4 +57,6 @@ int main()
 #endif
     assert(q.size() == 3);
     assert(q.top() == Emplaceable(3, 4.5));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.fail.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.fail.cpp
index afdd996ad70..54cd986295a 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.fail.cpp
@@ -20,8 +20,10 @@
 
 #include "test_macros.h"
 
-int main ()
+int main(int, char**)
 {
     std::stack<int> c;
     c.empty();  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.pass.cpp
index 37bf18e2d63..a51045e613d 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/empty.pass.cpp
@@ -13,7 +13,7 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     assert(q.empty());
@@ -21,4 +21,6 @@ int main()
     assert(!q.empty());
     q.pop();
     assert(q.empty());
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/pop.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/pop.pass.cpp
index 756eb01c033..95472d7e2c6 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/pop.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/pop.pass.cpp
@@ -13,7 +13,7 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     assert(q.size() == 0);
@@ -30,4 +30,6 @@ int main()
     assert(q.top() == 1);
     q.pop();
     assert(q.size() == 0);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push.pass.cpp
index 19615a031dd..70c085f17dd 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push.pass.cpp
@@ -13,7 +13,7 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     q.push(1);
@@ -25,4 +25,6 @@ int main()
     q.push(3);
     assert(q.size() == 3);
     assert(q.top() == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push_rv.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push_rv.pass.cpp
index f8ad69e99d6..8969d237b54 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push_rv.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/push_rv.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     std::stack<MoveOnly> q;
     q.push(MoveOnly(1));
@@ -29,4 +29,6 @@ int main()
     q.push(MoveOnly(3));
     assert(q.size() == 3);
     assert(q.top() == MoveOnly(3));
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/size.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/size.pass.cpp
index 2e2f945b23d..26f2e22ee8e 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/size.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/size.pass.cpp
@@ -13,10 +13,12 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     assert(q.size() == 0);
     q.push(1);
     assert(q.size() == 1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/swap.pass.cpp
index 10c44c0df3d..88ec3cdfe3d 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/swap.pass.cpp
@@ -23,7 +23,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q1 = make<std::stack<int> >(5);
     std::stack<int> q2 = make<std::stack<int> >(10);
@@ -32,4 +32,6 @@ int main()
     q1.swap(q2);
     assert(q1 == q2_save);
     assert(q2 == q1_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top.pass.cpp
index f58effe196e..6923cc9d27b 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top.pass.cpp
@@ -13,7 +13,7 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     assert(q.size() == 0);
@@ -22,4 +22,6 @@ int main()
     q.push(3);
     int& ir = q.top();
     assert(ir == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top_const.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top_const.pass.cpp
index 348946baa6b..a5e8c49fa20 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top_const.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/top_const.pass.cpp
@@ -13,7 +13,7 @@
 #include <stack>
 #include <cassert>
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q;
     assert(q.size() == 0);
@@ -23,4 +23,6 @@ int main()
     const std::stack<int>& cqr = q;
     const int& cir = cqr.top();
     assert(cir == 3);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.fail.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.fail.cpp
index f343fa109d3..d5fe97fd5d7 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.fail.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.fail.cpp
@@ -27,8 +27,10 @@
 #include <cassert>
 #include <type_traits>
 
-int main()
+int main(int, char**)
 {
 //  LWG#2566 says that the first template param must match the second one's value type
     std::stack<double, std::deque<int>> t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.pass.cpp
index 33308c1adee..55fc27f8430 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.defn/types.pass.cpp
@@ -44,7 +44,7 @@ struct C
     typedef int size_type;
 };
 
-int main()
+int main(int, char**)
 {
     static_assert(( std::is_same<std::stack<int>::container_type, std::deque<int> >::value), "");
     static_assert(( std::is_same<std::stack<int, std::vector<int> >::container_type, std::vector<int> >::value), "");
@@ -55,4 +55,6 @@ int main()
     static_assert(( std::uses_allocator<std::stack<int>, std::allocator<int> >::value), "");
     static_assert((!std::uses_allocator<std::stack<int, C>, std::allocator<int> >::value), "");
     test t;
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.ops/eq.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.ops/eq.pass.cpp
index a6e60f1e0d1..306869f0e9b 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.ops/eq.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.ops/eq.pass.cpp
@@ -27,7 +27,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q1 = make<std::stack<int> >(5);
     std::stack<int> q2 = make<std::stack<int> >(10);
@@ -36,4 +36,6 @@ int main()
     assert(q1 == q1_save);
     assert(q1 != q2);
     assert(q2 == q2_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.ops/lt.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.ops/lt.pass.cpp
index 5494b3dae71..3c8734befda 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.ops/lt.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.ops/lt.pass.cpp
@@ -33,7 +33,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q1 = make<std::stack<int> >(5);
     std::stack<int> q2 = make<std::stack<int> >(10);
@@ -41,4 +41,6 @@ int main()
     assert(q2 > q1);
     assert(q1 <= q2);
     assert(q2 >= q1);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap.pass.cpp
index f8f0ed919b8..cb1323b5873 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap.pass.cpp
@@ -24,7 +24,7 @@ make(int n)
     return c;
 }
 
-int main()
+int main(int, char**)
 {
     std::stack<int> q1 = make<std::stack<int> >(5);
     std::stack<int> q2 = make<std::stack<int> >(10);
@@ -33,4 +33,6 @@ int main()
     swap(q1, q2);
     assert(q1 == q2_save);
     assert(q2 == q1_save);
+
+  return 0;
 }
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap_noexcept.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap_noexcept.pass.cpp
index 43195ecc8b9..415ea607e17 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.special/swap_noexcept.pass.cpp
@@ -21,10 +21,12 @@
 
 #include "MoveOnly.h"
 
-int main()
+int main(int, char**)
 {
     {
         typedef std::stack<MoveOnly> C;
         static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
     }
+
+  return 0;
 }