Add api_test extension for test C API, initially add PySet_Size test.

I think we need a place to test new added C API. And Pyston missed
PySet_Size implementation(already declared it). Add and test it.

Makefile

@@ -969,7 +969,7 @@ bench_exceptions:
 	zsh -c 'ulimit -m $(MAX_MEM_KB); time ./bench_exceptions'
 	rm bench_exceptions
 
-TEST_EXT_MODULE_NAMES := basic_test descr_test slots_test
+TEST_EXT_MODULE_NAMES := basic_test descr_test slots_test type_test api_test
 TEST_EXT_MODULE_SRCS := $(TEST_EXT_MODULE_NAMES:%=test/test_extension/%.c)
 TEST_EXT_MODULE_OBJS := $(TEST_EXT_MODULE_NAMES:%=test/test_extension/%.pyston.so)
 

src/runtime/set.cpp

@@ -457,6 +457,14 @@ extern "C" int PySet_Add(PyObject* set, PyObject* key) noexcept {
     }
 }
 
+extern "C" Py_ssize_t PySet_Size(PyObject* anyset) noexcept {
+    if (!PyAnySet_Check(anyset)) {
+        PyErr_BadInternalCall();
+        return -1;
+    }
+    BoxedSet* self = (BoxedSet*)anyset;
+    return self->s.size();
+}
 
 Box* setClear(BoxedSet* self) {
     RELEASE_ASSERT(isSubclass(self->cls, set_cls), "");

test/test_extension/CMakeLists.txt

 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/build/lib.linux-x86_64-2.7/basic_test.so
                    COMMAND python setup.py build --build-lib ${CMAKE_CURRENT_BINARY_DIR}/build/lib.linux-x86_64-2.7
-                   DEPENDS basic_test.c descr_test.c slots_test.c type_test.c
+                   DEPENDS basic_test.c descr_test.c slots_test.c type_test.c api_test.c
                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 
 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/basic_test.pyston.so
                    COMMAND ${CMAKE_BINARY_DIR}/pyston setup.py build --build-lib ${CMAKE_CURRENT_BINARY_DIR}
-                   DEPENDS pyston copy_stdlib copy_libpyston basic_test.c descr_test.c slots_test.c type_test.c
+                   DEPENDS pyston copy_stdlib copy_libpyston basic_test.c descr_test.c slots_test.c type_test.c api_test.c
                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 
 add_custom_target(ext_cpython DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/build/lib.linux-x86_64-2.7/basic_test.so)

test/test_extension/api_test.c

+#include <Python.h>
+
+static PyObject *
+set_size(PyObject *self, PyObject *so)
+{
+    return Py_BuildValue("i", PySet_Size(so));
+}
+
+static PyMethodDef TestMethods[] = {
+    {"set_size",  set_size, METH_O, "Get set size by PySet_Size." },
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+PyMODINIT_FUNC
+initapi_test(void)
+{
+    PyObject *m;
+
+    m = Py_InitModule("api_test", TestMethods);
+    if (m == NULL)
+        return;
+}

test/test_extension/setup.py

@@ -7,6 +7,7 @@ extensions = [
     Extension("descr_test", sources = ["descr_test.c"]),
     Extension("slots_test", sources = ["slots_test.c"]),
     Extension("type_test", sources = ["type_test.c"]),
+    Extension("api_test", sources = ["api_test.c"]),
 ]
 
 def relpath(fn):

test/tests/set.expected

@@ -539,3 +539,4 @@ calling __hash__
 False
 set([1L]) set([1]) set([1]) set([1L])
 set([1])
+4

test/tests/set.py

@@ -269,3 +269,8 @@ print {1, 1L}, {1L, 1}, set([1, 1L]), set([1L, 1])
 s = {1}
 s.add(1L)
 print s
+
+from api_test import set_size
+
+s = set([1, 2, 3, 4])
+print(set_size(s))