Exported cxxbuild symbols in cdylib

[waldemarKunkel]

I've build a cdylib with cargo with the following cxx bridge:

#[cxx::bridge]
mod ffi {
    unsafe extern "C++" {
        include!("helper.h");
        fn SendKey(key: c_char) -> u32;
    }
}

Now if I check the exported symbols with

nm -gD --defined-only libmylib.so

the output is:

0012abb5 T cxxbridge1$exception
0012aeed T cxxbridge1$rust_vec$bool$capacity
0012aef1 T cxxbridge1$rust_vec$bool$data
0012aed9 T cxxbridge1$rust_vec$bool$drop
0012aee9 T cxxbridge1$rust_vec$bool$len
0012aecd T cxxbridge1$rust_vec$bool$new
0012aef5 T cxxbridge1$rust_vec$bool$reserve_total
0012af1d T cxxbridge1$rust_vec$bool$set_len
0012af21 T cxxbridge1$rust_vec$bool$truncate
0012aeed T cxxbridge1$rust_vec$char$capacity
0012aef1 T cxxbridge1$rust_vec$char$data
0012aed9 T cxxbridge1$rust_vec$char$drop
0012aee9 T cxxbridge1$rust_vec$char$len
0012aecd T cxxbridge1$rust_vec$char$new
0012aef5 T cxxbridge1$rust_vec$char$reserve_total
0012af1d T cxxbridge1$rust_vec$char$set_len
0012af21 T cxxbridge1$rust_vec$char$truncate
0012aeed T cxxbridge1$rust_vec$f32$capacity
0012aef1 T cxxbridge1$rust_vec$f32$data
0012af81 T cxxbridge1$rust_vec$f32$drop
0012af93 T cxxbridge1$rust_vec$f32$len
0012af75 T cxxbridge1$rust_vec$f32$new
0012af97 T cxxbridge1$rust_vec$f32$reserve_total
0012af1d T cxxbridge1$rust_vec$f32$set_len
0012af21 T cxxbridge1$rust_vec$f32$truncate
0012aeed T cxxbridge1$rust_vec$f64$capacity
0012aef1 T cxxbridge1$rust_vec$f64$data
0012afcb T cxxbridge1$rust_vec$f64$drop
0012afdd T cxxbridge1$rust_vec$f64$len
0012afbf T cxxbridge1$rust_vec$f64$new
0012afe1 T cxxbridge1$rust_vec$f64$reserve_total
0012af1d T cxxbridge1$rust_vec$f64$set_len
0012af21 T cxxbridge1$rust_vec$f64$truncate
0012aeed T cxxbridge1$rust_vec$i16$capacity
0012aef1 T cxxbridge1$rust_vec$i16$data
0012af37 T cxxbridge1$rust_vec$i16$drop
0012af49 T cxxbridge1$rust_vec$i16$len
0012af2b T cxxbridge1$rust_vec$i16$new
0012af4d T cxxbridge1$rust_vec$i16$reserve_total
0012af1d T cxxbridge1$rust_vec$i16$set_len
0012af21 T cxxbridge1$rust_vec$i16$truncate
0012aeed T cxxbridge1$rust_vec$i32$capacity
0012aef1 T cxxbridge1$rust_vec$i32$data
0012af81 T cxxbridge1$rust_vec$i32$drop
0012af93 T cxxbridge1$rust_vec$i32$len
0012af75 T cxxbridge1$rust_vec$i32$new
0012af97 T cxxbridge1$rust_vec$i32$reserve_total
0012af1d T cxxbridge1$rust_vec$i32$set_len
0012af21 T cxxbridge1$rust_vec$i32$truncate
0012aeed T cxxbridge1$rust_vec$i64$capacity
0012aef1 T cxxbridge1$rust_vec$i64$data
0012afcb T cxxbridge1$rust_vec$i64$drop
0012afdd T cxxbridge1$rust_vec$i64$len
0012afbf T cxxbridge1$rust_vec$i64$new
0012afe1 T cxxbridge1$rust_vec$i64$reserve_total
0012af1d T cxxbridge1$rust_vec$i64$set_len
0012af21 T cxxbridge1$rust_vec$i64$truncate
0012aeed T cxxbridge1$rust_vec$i8$capacity
0012aef1 T cxxbridge1$rust_vec$i8$data
0012aed9 T cxxbridge1$rust_vec$i8$drop
0012aee9 T cxxbridge1$rust_vec$i8$len
0012aecd T cxxbridge1$rust_vec$i8$new
0012aef5 T cxxbridge1$rust_vec$i8$reserve_total
0012af1d T cxxbridge1$rust_vec$i8$set_len
0012af21 T cxxbridge1$rust_vec$i8$truncate
0012aeed T cxxbridge1$rust_vec$isize$capacity
0012aef1 T cxxbridge1$rust_vec$isize$data
0012af81 T cxxbridge1$rust_vec$isize$drop
0012af93 T cxxbridge1$rust_vec$isize$len
0012af75 T cxxbridge1$rust_vec$isize$new
0012af97 T cxxbridge1$rust_vec$isize$reserve_total
0012af1d T cxxbridge1$rust_vec$isize$set_len
0012af21 T cxxbridge1$rust_vec$isize$truncate
0012aeed T cxxbridge1$rust_vec$str$capacity
0012aef1 T cxxbridge1$rust_vec$str$data
0012b0a9 T cxxbridge1$rust_vec$str$drop
0012afdd T cxxbridge1$rust_vec$str$len
0012af75 T cxxbridge1$rust_vec$str$new
0012b0bb T cxxbridge1$rust_vec$str$reserve_total
0012af1d T cxxbridge1$rust_vec$str$set_len
0012af21 T cxxbridge1$rust_vec$str$truncate
0012aeed T cxxbridge1$rust_vec$string$capacity
0012aef1 T cxxbridge1$rust_vec$string$data
0012b009 T cxxbridge1$rust_vec$string$drop
0012b043 T cxxbridge1$rust_vec$string$len
0012af75 T cxxbridge1$rust_vec$string$new
0012b047 T cxxbridge1$rust_vec$string$reserve_total
0012af1d T cxxbridge1$rust_vec$string$set_len
0012b071 T cxxbridge1$rust_vec$string$truncate
0012aeed T cxxbridge1$rust_vec$u16$capacity
0012aef1 T cxxbridge1$rust_vec$u16$data
0012af37 T cxxbridge1$rust_vec$u16$drop
0012af49 T cxxbridge1$rust_vec$u16$len
0012af2b T cxxbridge1$rust_vec$u16$new
0012af4d T cxxbridge1$rust_vec$u16$reserve_total
0012af1d T cxxbridge1$rust_vec$u16$set_len
0012af21 T cxxbridge1$rust_vec$u16$truncate
0012aeed T cxxbridge1$rust_vec$u32$capacity
0012aef1 T cxxbridge1$rust_vec$u32$data
0012af81 T cxxbridge1$rust_vec$u32$drop
0012af93 T cxxbridge1$rust_vec$u32$len
0012af75 T cxxbridge1$rust_vec$u32$new
0012af97 T cxxbridge1$rust_vec$u32$reserve_total
0012af1d T cxxbridge1$rust_vec$u32$set_len
0012af21 T cxxbridge1$rust_vec$u32$truncate
0012aeed T cxxbridge1$rust_vec$u64$capacity
0012aef1 T cxxbridge1$rust_vec$u64$data
0012afcb T cxxbridge1$rust_vec$u64$drop
0012afdd T cxxbridge1$rust_vec$u64$len
0012afbf T cxxbridge1$rust_vec$u64$new
0012afe1 T cxxbridge1$rust_vec$u64$reserve_total
0012af1d T cxxbridge1$rust_vec$u64$set_len
0012af21 T cxxbridge1$rust_vec$u64$truncate
0012aeed T cxxbridge1$rust_vec$u8$capacity
0012aef1 T cxxbridge1$rust_vec$u8$data
0012aed9 T cxxbridge1$rust_vec$u8$drop
0012aee9 T cxxbridge1$rust_vec$u8$len
0012aecd T cxxbridge1$rust_vec$u8$new
0012aef5 T cxxbridge1$rust_vec$u8$reserve_total
0012af1d T cxxbridge1$rust_vec$u8$set_len
0012af21 T cxxbridge1$rust_vec$u8$truncate
0012aeed T cxxbridge1$rust_vec$usize$capacity
0012aef1 T cxxbridge1$rust_vec$usize$data
0012af81 T cxxbridge1$rust_vec$usize$drop
0012af93 T cxxbridge1$rust_vec$usize$len
0012af75 T cxxbridge1$rust_vec$usize$new
0012af97 T cxxbridge1$rust_vec$usize$reserve_total
0012af1d T cxxbridge1$rust_vec$usize$set_len
0012af21 T cxxbridge1$rust_vec$usize$truncate
0012ac8f T cxxbridge1$slice$len
0012ac85 T cxxbridge1$slice$new
0012ac8b T cxxbridge1$slice$ptr
0012aca7 T cxxbridge1$str$from
0012acd1 T cxxbridge1$str$len
0012ac93 T cxxbridge1$str$new
0012accd T cxxbridge1$str$ptr
0012ac9d T cxxbridge1$str$ref
0012ae7f T cxxbridge1$string$capacity
0012ace1 T cxxbridge1$string$clone
0012aba3 T cxxbridge1$string$drop
0012adf5 T cxxbridge1$string$from_utf16
0012ae1f T cxxbridge1$string$from_utf16_lossy
0012acfd T cxxbridge1$string$from_utf8
0012ad71 T cxxbridge1$string$from_utf8_lossy
0012ae7b T cxxbridge1$string$len
0012acd5 T cxxbridge1$string$new
0012ae77 T cxxbridge1$string$ptr
0012ae83 T cxxbridge1$string$reserve_additional
0012aea5 T cxxbridge1$string$reserve_total
000961a9 T explicit_init
0008059d T function1
00095ea9 T function2

How could I achieve that the cxxbridge symbols are not exported but only these three at the bottom:

000961a9 T explicit_init
0008059d T function1
00095ea9 T function2

[dtolnay]

Rustc always treats all #[no_mangle] symbols as exported. See rust-lang/rust#73958.

You can intercept rustc's linker invocation and replace it with your own version script by following the approach in #1520.