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

24 files changed, 72 insertions, 24 deletions

diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_valarray.pass.cpp
index 3e0951b6e2d..3f3ede056ee 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_value.pass.cpp
index 75bce73a249..de5808e5710 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -42,4 +42,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_value_valarray.pass.cpp
index a6cd5e836d6..c73ec1e54cb 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/and_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -42,4 +42,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_valarray.pass.cpp
index 3b43c109740..187126fc8ed 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_value.pass.cpp
index 1bd1fa0e81b..01c04a62c80 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_value_valarray.pass.cpp
index 5fb05f60ae4..b0db6a0d18e 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/equal_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_valarray.pass.cpp
index 6f7678fc7f5..c8de6208aae 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_value.pass.cpp
index f26e946942a..cf568b5307b 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_value_valarray.pass.cpp
index 2c795aae311..c66a60e062c 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_equal_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_valarray.pass.cpp
index 03468763f13..351b662be07 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_value.pass.cpp
index 970f8d8d567..f895b0783b7 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_value_valarray.pass.cpp
index ad30ae42541..a54b770256b 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/greater_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_valarray.pass.cpp
index 86e5553a8cd..c8812f3fd89 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_value.pass.cpp
index d520a21b965..03caf34a60a 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_value_valarray.pass.cpp
index 2055f7554a1..5026b73d4e2 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_equal_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_valarray.pass.cpp
index 0eb137ca07a..59943f912e3 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_value.pass.cpp
index d7d6b7d8b44..9ced4757139 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_value_valarray.pass.cpp
index 34419bdece0..770d5a96f7d 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/less_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_valarray.pass.cpp
index 4daca5332a8..1892a707176 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_value.pass.cpp
index add76d16c00..3cdb8973958 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_value_valarray.pass.cpp
index a3503805140..49ffeda05ae 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/not_equal_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -31,4 +31,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_valarray.pass.cpp
index ef2b1650980..f62cb4f8cc2 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -34,4 +34,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_value.pass.cpp
index 60f14f2bb56..df73f85e398 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_valarray_value.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -42,4 +42,6 @@ int main()
         for (std::size_t i = 0; i < v1.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_value_valarray.pass.cpp
index 0d9a3124e6c..3798acc67d9 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.comparison/or_value_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef int T;
@@ -42,4 +42,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(v3[i] == a3[i]);
     }
+
+  return 0;
 }