1 /*
2  * RRoutines.hpp
3  *
4  * Copyright (C) 2021 by RStudio, PBC
5  *
6  * Unless you have received this program directly from RStudio pursuant
7  * to the terms of a commercial license agreement with RStudio, then
8  * this program is licensed to you under the terms of version 3 of the
9  * GNU Affero General Public License. This program is distributed WITHOUT
10  * ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
11  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
12  * AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
13  *
14  */
15 
16 #ifndef R_ROUTINES_HPP
17 #define R_ROUTINES_HPP
18 
19 #include <vector>
20 
21 #include <r/RSexp.hpp>
22 
23 #include <R_ext/Rdynload.h>
24 
25 #include <core/type_traits/TypeTraits.hpp>
26 
27 namespace rstudio {
28 namespace r {
29 namespace routines {
30 
31 namespace internal {
32 
33 template <typename ReturnType, typename... ArgumentTypes>
n_arguments(ReturnType (ArgumentTypes...))34 int n_arguments(ReturnType(ArgumentTypes...)) {
35     return sizeof...(ArgumentTypes);
36 }
37 
38 template <typename... ArgumentTypes>
39 struct validate_args
40 {
41    typedef std::true_type type;
42 };
43 
44 template <typename T, typename... ArgumentTypes>
45 struct validate_args<T, ArgumentTypes...>
46 {
47    static_assert(
48          std::is_same<T, SEXP>::value,
49          "Registered .Call methods should only accept SEXP parameters");
50 
51    typedef typename validate_args<ArgumentTypes...>::type type;
52 };
53 
54 template <typename ReturnType, typename... ArgumentTypes>
validate(ReturnType (ArgumentTypes...))55 void validate(ReturnType(ArgumentTypes...))
56 {
57    static_assert(
58             std::is_same<ReturnType, SEXP>::value,
59             "Registered .Call methods should have SEXP return type");
60 
61    (void) typename validate_args<ArgumentTypes...>::type{};
62 }
63 
64 } // end namespace internal
65 
66 void addCallMethod(const R_CallMethodDef method);
67 void registerCallMethod(const char* name, DL_FUNC fun, int numArgs);
68 void registerAll();
69 
70 // NOTE: This macro accepts multiple arguments but only uses the first one.
71 // This is just for backwards compatibility, so that existing calls that
72 // attempt to declare the number of arguments can continue to do so, while new
73 // usages can omit it and still do the right thing. (This is done primarily to
74 // avoid noisy diffs across the codebase where this macro is used)
75 #define RS_REGISTER_CALL_METHOD(__NAME__, ...)                         \
76    do                                                                  \
77    {                                                                   \
78       using namespace core::type_traits;                               \
79       ::rstudio::r::routines::internal::validate(__NAME__);            \
80       int n = ::rstudio::r::routines::internal::n_arguments(__NAME__); \
81       R_CallMethodDef callMethodDef;                                   \
82       callMethodDef.name = #__NAME__;                                  \
83       callMethodDef.fun = reinterpret_cast<DL_FUNC>(__NAME__);         \
84       callMethodDef.numArgs = n;                                       \
85       ::rstudio::r::routines::addCallMethod(callMethodDef);            \
86    }                                                                   \
87    while (false)
88 
89 } // namespace routines
90 } // namespace r
91 } // namespace rstudio
92 
93 
94 #endif // R_ROUTINES_HPP
95 
96