Open
Description
Similarly to #47384, statics in a static library that are marked as used are not included in the resulting binary if a non-inlined function is used in the same module.
Example
This code can be found at mkroening/rust-issue-99721.
staticlib.rs:
mod note {
#[used]
#[link_section = ".note.my-note"]
static MY_NOTE: u8 = 0;
#[inline(always)]
pub fn dummy() {}
}
#[no_mangle]
pub extern "C" fn staticlib() {
note::dummy();
}bin.rs:
fn main() {
extern "C" {
fn staticlib();
}
unsafe {
staticlib();
}
}Build using:
rustc --crate-type staticlib staticlib.rs
rustc -L native=. -l static=staticlib bin.rs
Display static library notes:
$ readelf -Wn libstaticlib.a
[...]
File: libstaticlib.a(staticlib.staticlib.68b5aa53-cgu.0.rcgu.o)
Displaying notes found in: .note.my-note
Owner Data size Description
readelf: Warning: Corrupt note: only 1 byte remains, not enough for a full note
[...]
Display binary notes:
$ readelf -Wn bin
Displaying notes found in: .note.gnu.property
Owner Data size Description
GNU 0x00000010 NT_GNU_PROPERTY_TYPE_0 Properties: x86 ISA needed: x86-64-baseline
Displaying notes found in: .note.gnu.build-id
Owner Data size Description
GNU 0x00000014 NT_GNU_BUILD_ID (unique build ID bitstring) Build ID: 258d83311faf1a32cb84dd090ccc57abdbb1cb38
Displaying notes found in: .note.ABI-tag
Owner Data size Description
GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag) OS: Linux, ABI: 4.4.0
If note::dummy is made inline(never), the symbol is included in the resulting binary:
$ readelf -Wn bin
Displaying notes found in: .note.gnu.property
Owner Data size Description
GNU 0x00000010 NT_GNU_PROPERTY_TYPE_0 Properties: x86 ISA needed: x86-64-baseline
Displaying notes found in: .note.gnu.build-id
Owner Data size Description
GNU 0x00000014 NT_GNU_BUILD_ID (unique build ID bitstring) Build ID: 72d6efcf61e2b33563094c3f179ebcc511db7485
Displaying notes found in: .note.ABI-tag
Owner Data size Description
GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag) OS: Linux, ABI: 4.4.0
Displaying notes found in: .note.my-note
Owner Data size Description
readelf: Warning: Corrupt note: only 1 byte remains, not enough for a full note