Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Includes/cpython/pycapsule.pxd

Index: third_party/cython/src/Cython/Includes/cpython/pycapsule.pxd
diff --git a/third_party/cython/src/Cython/Includes/cpython/pycapsule.pxd b/third_party/cython/src/Cython/Includes/cpython/pycapsule.pxd
new file mode 100644
index 0000000000000000000000000000000000000000..f0b326bc2cba32402c63a17f5a926a3de70f893d
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+++ b/third_party/cython/src/Cython/Includes/cpython/pycapsule.pxd
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+from cpython.ref cimport PyObject
+
+# available since Python 3.1!
+
+# note all char* in the below functions are actually const char*
+
+cdef extern from "Python.h":
+
+    ctypedef struct PyCapsule_Type
+    # This subtype of PyObject represents an opaque value, useful for
+    # C extension modules who need to pass an opaque value (as a void*
+    # pointer) through Python code to other C code. It is often used
+    # to make a C function pointer defined in one module available to
+    # other modules, so the regular import mechanism can be used to
+    # access C APIs defined in dynamically loaded modules.
+
+
+    ctypedef void (*PyCapsule_Destructor)(object o)
+    # The type of a destructor callback for a capsule.
+    #
+    # See PyCapsule_New() for the semantics of PyCapsule_Destructor
+    # callbacks.
+
+
+    bint PyCapsule_CheckExact(object o)
+    # Return true if its argument is a PyCapsule.
+
+
+    object PyCapsule_New(void *pointer, char *name,
+                         PyCapsule_Destructor destructor)
+    # Return value: New reference.
+    #
+    # Create a PyCapsule encapsulating the pointer. The pointer
+    # argument may not be NULL.
+    #
+    # On failure, set an exception and return NULL.
+    #
+    # The name string may either be NULL or a pointer to a valid C
+    # string. If non-NULL, this string must outlive the
+    # capsule. (Though it is permitted to free it inside the
+    # destructor.)
+    #
+    # If the destructor argument is not NULL, it will be called with
+    # the capsule as its argument when it is destroyed.
+    #
+    # If this capsule will be stored as an attribute of a module, the
+    # name should be specified as modulename.attributename. This will
+    # enable other modules to import the capsule using
+    # PyCapsule_Import().
+
+
+    void* PyCapsule_GetPointer(object capsule, char *name) except? NULL
+    # Retrieve the pointer stored in the capsule. On failure, set an
+    # exception and return NULL.
+    #
+    # The name parameter must compare exactly to the name stored in
+    # the capsule. If the name stored in the capsule is NULL, the name
+    # passed in must also be NULL. Python uses the C function strcmp()
+    # to compare capsule names.
+
+
+    PyCapsule_Destructor PyCapsule_GetDestructor(object capsule) except? NULL
+    # Return the current destructor stored in the capsule. On failure,
+    # set an exception and return NULL.
+    #
+    # It is legal for a capsule to have a NULL destructor. This makes
+    # a NULL return code somewhat ambiguous; use PyCapsule_IsValid()
+    # or PyErr_Occurred() to disambiguate.
+
+
+    char* PyCapsule_GetName(object capsule) except? NULL
+    # Return the current name stored in the capsule. On failure, set
+    # an exception and return NULL.
+    #
+    # It is legal for a capsule to have a NULL name. This makes a NULL
+    # return code somewhat ambiguous; use PyCapsule_IsValid() or
+    # PyErr_Occurred() to disambiguate.
+
+
+    void* PyCapsule_GetContext(object capsule) except? NULL
+    # Return the current context stored in the capsule. On failure,
+    # set an exception and return NULL.
+    #
+    # It is legal for a capsule to have a NULL context. This makes a
+    # NULL return code somewhat ambiguous; use PyCapsule_IsValid() or
+    # PyErr_Occurred() to disambiguate.
+
+
+    bint PyCapsule_IsValid(object capsule, char *name)
+    # Determines whether or not capsule is a valid capsule. A valid
+    # capsule is non-NULL, passes PyCapsule_CheckExact(), has a
+    # non-NULL pointer stored in it, and its internal name matches the
+    # name parameter. (See PyCapsule_GetPointer() for information on
+    # how capsule names are compared.)
+    #
+    # In other words, if PyCapsule_IsValid() returns a true value,
+    # calls to any of the accessors (any function starting with
+    # PyCapsule_Get()) are guaranteed to succeed.
+    #
+    # Return a nonzero value if the object is valid and matches the
+    # name passed in. Return 0 otherwise. This function will not fail.
+
+
+    int PyCapsule_SetPointer(object capsule, void *pointer) except -1
+    # Set the void pointer inside capsule to pointer. The pointer may
+    # not be NULL.
+    #
+    # Return 0 on success. Return nonzero and set an exception on
+    # failure.
+
+
+    int PyCapsule_SetDestructor(object capsule, PyCapsule_Destructor destructor) except -1
+    # Set the destructor inside capsule to destructor.
+    #
+    # Return 0 on success. Return nonzero and set an exception on
+    # failure.
+
+
+    int PyCapsule_SetName(object capsule, char *name) except -1
+    # Set the name inside capsule to name. If non-NULL, the name must
+    # outlive the capsule. If the previous name stored in the capsule
+    # was not NULL, no attempt is made to free it.
+    #
+    # Return 0 on success. Return nonzero and set an exception on
+    # failure.
+
+
+    int PyCapsule_SetContext(object capsule, void *context) except -1
+    # Set the context pointer inside capsule to context.  Return 0 on
+    # success. Return nonzero and set an exception on failure.
+
+
+    void* PyCapsule_Import(char *name, int no_block) except? NULL
+    # Import a pointer to a C object from a capsule attribute in a
+    # module. The name parameter should specify the full name to the
+    # attribute, as in module.attribute. The name stored in the
+    # capsule must match this string exactly. If no_block is true,
+    # import the module without blocking (using
+    # PyImport_ImportModuleNoBlock()). If no_block is false, import
+    # the module conventionally (using PyImport_ImportModule()).
+    #
+    # Return the capsule’s internal pointer on success. On failure,
+    # set an exception and return NULL. However, if PyCapsule_Import()
+    # failed to import the module, and no_block was true, no exception
+    # is set.
+