extendr_ffi/
backports.rs

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1//! Backport functions
2//!
3//! R's C API is changing and is stabilizing. As such some functions
4//! that were available in previous versions of R are not available
5//! in later versions of R, or they cause a warning in `R CMD check`.
6//!
7//! Use the functions in this module to ensure backwards compatibility.
8
9// R 4.5 backports notes saved in wayback machine here:
10// https://web.archive.org/web/20250325171443/https://rstudio.github.io/r-manuals/r-exts/The-R-API.html#moving-into-c-api-compliance
11
12use crate::SEXP;
13// In your extern "C" block:
14extern "C" {
15    #[cfg(not(r_4_5))]
16    fn ENCLOS(x: SEXP) -> SEXP;
17
18    #[cfg(r_4_5)]
19    fn R_ParentEnv(x: SEXP) -> SEXP;
20
21    #[cfg(not(r_4_5))]
22    fn Rf_findVar(arg1: SEXP, arg2: SEXP) -> SEXP;
23
24    #[cfg(r_4_5)]
25    fn R_getVar(arg1: SEXP, arg2: SEXP) -> SEXP;
26
27    #[cfg(not(r_4_5))]
28    fn Rf_findVarInFrame(arg1: SEXP, arg2: SEXP) -> SEXP;
29
30    #[cfg(r_4_5)]
31    fn R_getVarEx(arg1: SEXP, arg2: SEXP) -> SEXP;
32
33    #[cfg(not(r_4_5))]
34    fn CLOENV(x: SEXP) -> SEXP;
35
36    #[cfg(r_4_5)]
37    fn R_ClosureEnv(x: SEXP) -> SEXP;
38
39    #[cfg(not(r_4_5))]
40    fn BODY(x: SEXP) -> SEXP;
41
42    #[cfg(r_4_5)]
43    fn R_ClosureBody(x: SEXP) -> SEXP;
44
45    #[cfg(not(r_4_5))]
46    fn FORMALS(x: SEXP) -> SEXP;
47
48    #[cfg(r_4_5)]
49    fn R_ClosureFormals(x: SEXP) -> SEXP;
50
51    #[cfg(not(r_4_5))]
52    fn DATAPTR(x: SEXP) -> *mut ::std::os::raw::c_void;
53
54    #[cfg(r_4_5)]
55    fn DATAPTR_RO(x: SEXP) -> *const ::std::os::raw::c_void;
56}
57
58/// Returns the enclosing environment of env, which will usually be of type ENVSXP, except for the special environment R_EmptyEnv, which terminates the environment chain; its enclosing environment is R_NilValue.
59#[inline]
60pub unsafe fn get_parent_env(x: SEXP) -> SEXP {
61    #[cfg(not(r_4_5))]
62    {
63        ENCLOS(x)
64    }
65    #[cfg(r_4_5)]
66    {
67        R_ParentEnv(x)
68    }
69}
70
71/// Returns a variable from an environment
72#[inline]
73pub unsafe fn get_var(symbol: SEXP, env: SEXP) -> SEXP {
74    #[cfg(not(r_4_5))]
75    {
76        Rf_findVar(symbol, env)
77    }
78    #[cfg(r_4_5)]
79    {
80        R_getVar(symbol, env)
81    }
82}
83
84/// Returns the value of the requested variable in an environment
85#[inline]
86pub unsafe fn get_var_in_frame(symbol: SEXP, env: SEXP) -> SEXP {
87    #[cfg(not(r_4_5))]
88    {
89        Rf_findVarInFrame(symbol, env)
90    }
91    #[cfg(r_4_5)]
92    {
93        R_getVarEx(env, symbol)
94    }
95}
96
97/// Return the environment of a closure
98#[inline]
99pub unsafe fn get_closure_env(x: SEXP) -> SEXP {
100    #[cfg(not(r_4_5))]
101    {
102        CLOENV(x)
103    }
104    #[cfg(r_4_5)]
105    {
106        R_ClosureEnv(x)
107    }
108}
109
110/// Return the body of a closure
111#[inline]
112pub unsafe fn get_closure_body(x: SEXP) -> SEXP {
113    #[cfg(not(r_4_5))]
114    {
115        BODY(x)
116    }
117    #[cfg(r_4_5)]
118    {
119        R_ClosureBody(x)
120    }
121}
122
123/// Access a closure's arguments
124#[inline]
125pub unsafe fn get_closure_formals(x: SEXP) -> SEXP {
126    #[cfg(not(r_4_5))]
127    {
128        FORMALS(x)
129    }
130    #[cfg(r_4_5)]
131    {
132        R_ClosureFormals(x)
133    }
134}
135
136/// Access a DATAPTR
137#[inline]
138pub unsafe fn dataptr(x: SEXP) -> *const ::std::os::raw::c_void {
139    #[cfg(not(r_4_5))]
140    {
141        DATAPTR(x) as *const _
142    }
143    #[cfg(r_4_5)]
144    {
145        DATAPTR_RO(x)
146    }
147}
extendr_ffi/backports.rs

extendr_ffi/
backports.rs
