use #[feature(core_ffi_c)] when available

Author: pvdrz

src/codegen/helpers.rs

@@ -166,9 +166,19 @@ pub mod ast_ty {
                     #prefix::#ident
                 }
             }
-            None => quote! {
-                ::std::os::raw::#ident
-            },
+            None => {
+                if ctx.options().use_core &&
+                    ctx.options().rust_features().core_ffi_c
+                {
+                    quote! {
+                        ::core::ffi::#ident
+                    }
+                } else {
+                    quote! {
+                        ::std::os::raw::#ident
+                    }
+                }
+            }
         }
     }
 

src/features.rs

@@ -130,6 +130,7 @@ macro_rules! rust_target_base {
             /// Nightly rust
             ///  * `thiscall` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/42202))
             ///  * `vectorcall` calling convention (no tracking issue)
+            ///  * `core_ffi_c` ([Tracking issue](https://github.com/rust-lang/rust/issues/94501))
             => Nightly => nightly;
         );
     }
@@ -236,6 +237,7 @@ rust_feature_def!(
     Nightly {
         => thiscall_abi;
         => vectorcall_abi;
+        => core_ffi_c;
     }
 );
 

tests/expectations/tests/core_ffi_c.rs

@@ -0,0 +1,14 @@
+// bindgen-flags: --rust-target nightly --use-core --no-convert-floats
+typedef char c_char;
+typedef double c_double;
+typedef float c_float;
+typedef int c_int;
+typedef long c_long;
+typedef long long c_longlong;
+typedef signed char c_schar;
+typedef short c_short;
+typedef unsigned char c_uchar;
+typedef unsigned int c_uint;
+typedef unsigned long c_ulong;
+typedef unsigned long long c_ulonglong;
+typedef unsigned short c_ushort;