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

20 files changed, 60 insertions, 20 deletions

diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/abs_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/abs_valarray.pass.cpp
index ff5c7d89a7a..d721c844263 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/abs_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/abs_valarray.pass.cpp
@@ -18,7 +18,7 @@
 #include <cassert>
 #include <cstddef>
 
-int main()
+int main(int, char**)
 {
     {
         typedef double 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.transcend/acos_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/acos_valarray.pass.cpp
index bee16abd798..18b5bcb5b6c 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/acos_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/acos_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/asin_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/asin_valarray.pass.cpp
index 4cecd8cace1..9401200e5c7 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/asin_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/asin_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_valarray.pass.cpp
index 7e81821dd44..fcbd63b8317 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -50,4 +50,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_value.pass.cpp
index 3ab73757778..59928d447ea 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_valarray_value.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_value_valarray.pass.cpp
index 07e7894ae14..ed42627d1f9 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan2_value_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan_valarray.pass.cpp
index 567f568a915..7176b9343e5 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/atan_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cos_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cos_valarray.pass.cpp
index 182b8bc3a9f..bc58e4af23c 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cos_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cos_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cosh_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cosh_valarray.pass.cpp
index fb0965bb3b2..b453edd08c8 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cosh_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/cosh_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/exp_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/exp_valarray.pass.cpp
index 3c19e3edfa1..8e95f870410 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/exp_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/exp_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log10_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log10_valarray.pass.cpp
index 70ba211a82a..39514ed6833 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log10_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log10_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log_valarray.pass.cpp
index 3e616a062bb..050d58fa599 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/log_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_valarray.pass.cpp
index 096cd5d322e..93b8a14cbe6 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -50,4 +50,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_value.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_value.pass.cpp
index 902c9f3216f..62c140c04da 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_value.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_valarray_value.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_value_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_value_valarray.pass.cpp
index 39449782330..0c8a76b6dac 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_value_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/pow_value_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sin_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sin_valarray.pass.cpp
index 2cf38b88bda..92d6f4492a5 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sin_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sin_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sinh_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sinh_valarray.pass.cpp
index fa591d0c6e3..190c212ac8b 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sinh_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sinh_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sqrt_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sqrt_valarray.pass.cpp
index eb40e61b314..805bde633e3 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sqrt_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/sqrt_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tan_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tan_valarray.pass.cpp
index 6395ee55079..4f5b69d0884 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tan_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tan_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }
diff --git a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tanh_valarray.pass.cpp b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tanh_valarray.pass.cpp
index 10e0a22be2c..c63696a8380 100644
--- a/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tanh_valarray.pass.cpp
+++ b/libcxx/test/std/numerics/numarray/valarray.nonmembers/valarray.transcend/tanh_valarray.pass.cpp
@@ -31,7 +31,7 @@ bool is_about(double x, double y, int p)
     return a == o.str();
 }
 
-int main()
+int main(int, char**)
 {
     {
         typedef double T;
@@ -48,4 +48,6 @@ int main()
         for (std::size_t i = 0; i < v3.size(); ++i)
             assert(is_about(v3[i], a3[i], 10));
     }
+
+  return 0;
 }