Replace SEXPREC with something truly opaque

MAINTAINERS_GUIDE.md

@@ -2,6 +2,20 @@
 
 ## Commit newly generated bindings
 
+You last commit must contain `[generate bindings]`. You can make an empty
+commit with this message:
+
+```sh
+git commit -m "[generate bindings]" --allow-empty
+```
+
+Then after successfully running workflows, GitHub Actions will push a commit
+with the updated bindings onto your PR branch.
+
+# GUIDE
+
+## Commit newly generated bindings
+
 Your last commit must contain `[generate bindings]`. You can make an empty
 commit with this message:
 

bindings/bindings-linux-aarch64-R4.2.rs

@@ -334,11 +334,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-linux-aarch64-R4.3.rs

@@ -340,11 +340,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-linux-aarch64-R4.4-devel.rs

@@ -341,11 +341,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-linux-x86_64-R4.2.rs

@@ -334,11 +334,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-linux-x86_64-R4.3.rs

@@ -340,11 +340,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-linux-x86_64-R4.4-devel.rs

@@ -341,11 +341,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-macos-aarch64-R4.3.rs

@@ -350,11 +350,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-macos-x86_64-R4.2.rs

@@ -344,11 +344,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-macos-x86_64-R4.3.rs

@@ -350,11 +350,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-macos-x86_64-R4.4-devel.rs

@@ -1,8 +1,8 @@
 /* automatically generated by rust-bindgen 0.69.1 */
 
 /* libR-sys version: 0.6.0 */
-/* bindgen clang version: Homebrew clang version 17.0.2 */
-/* clang-rs version: Homebrew clang version 17.0.2 */
+/* bindgen clang version: Homebrew clang version 17.0.3 */
+/* clang-rs version: Homebrew clang version 17.0.3 */
 /* r version: 4.4.0-devel */
 
 #[repr(C)]
@@ -351,11 +351,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-windows-x86_64-R4.2.rs

@@ -208,11 +208,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-windows-x86_64-R4.3.rs

@@ -214,11 +214,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

bindings/bindings-windows-x86_64-R4.4-devel.rs

@@ -215,11 +215,6 @@ pub type Rbyte = ::std::os::raw::c_uchar;
 pub type R_len_t = ::std::os::raw::c_int;
 #[doc = "NOT YET using enum:\n  1)\tThe internal SEXPREC struct has 'SEXPTYPE type : 5'\n\t(making FUNSXP and CLOSXP equivalent in there),\n\tgiving (-Wall only ?) warnings all over the place\n 2)\tMany switch(type) { case ... } statements need a final `default:'\n\tadded in order to avoid warnings like \\[e.g. l.170 of ../main/util.c\\]\n\t  \"enumeration value `FUNSXP' not handled in switch\""]
 pub type SEXPTYPE = ::std::os::raw::c_uint;
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct SEXPREC {
-    _unused: [u8; 0],
-}
 pub type SEXP = *mut SEXPREC;
 #[doc = "We sometimes need to coerce a protected value and place the new\ncoerced value under protection.  For these cases PROTECT_WITH_INDEX\nsaves an index of the protection location that can be used to\nreplace the protected value using REPROTECT."]
 pub type PROTECT_INDEX = ::std::os::raw::c_int;

build.rs

@@ -529,6 +529,9 @@ fn generate_bindings(r_paths: &InstallationPaths, version_info: &RVersionInfo) {
     // Remove all Fortran items, these are items with underscore _ postfix
     let bindgen_builder = bindgen_builder.blocklist_item("[A-Za-z_][A-Za-z0-9_]*[^_]_$");
 
+    // Ensure that `SEXPREC` is opaque to Rust
+    let bindgen_builder = bindgen_builder.blocklist_item("SEXPREC");
+
     // Finish the builder and generate the bindings.
     let bindings = bindgen_builder
         .raw_line(format!(

src/lib.rs

@@ -66,6 +66,11 @@
 
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 
+#[non_exhaustive]
+#[repr(transparent)]
+#[derive(Debug)]
+pub struct SEXPREC(std::ffi::c_void);
+
 #[cfg(test)]
 mod tests {
     use super::*;