One of the pending issues with Rust's build system integration is
the bloated executables caused by the use of staticlibs.
For an example of what this means, see the following test:
hello.c:
extern void hello(void);
int main(void)
{
hello();
}
hello.rs:
#![no_main]
#[no_mangle]
extern "C" fn hello() {
println!("hello world");
}
staticlib + gcc:
$ rustc -Copt-level=2 --crate-type=staticlib hello.rs --emit link=libhello.a
$ gcc hello.c -lhello -O2
$ size ./a.out
text data bss dec hex filename
917435 39593 352 957380 e9bc4 ./a.out
rustc + static libstd:
$ gcc -c -o hello.o hello.c -O2
$ rustc hello.rs -Clink-arg=hello.o
$ size ./hello
text data bss dec hex filename
322684 14464 590 337738 5274a ./hello
rustc + dynamic libstd:
$ gcc -c -o hello.o hello.c -O2
$ rustc hello.rs -Clink-arg=-Wl,-R$(rustc --print target-libdir)
-Clink-arg=hello.o -Cprefer-dynamic
$ size ./hello
text data bss dec hex filename
1809 600 993 3402 d4a ./hello
The second and third methods will be supported by Meson 1.9.0
(https://mesonbuild.com/Release-notes-for-1-9-0.html). Modify the final
link pass to use a Rust source file directly, instead of going through
a staticlib, when the target includes Rust crates; Meson will then do
the right thing automatically.
Paolo
Paolo Bonzini (2):
rust: do not link C libraries into Rust rlibs
meson: let Meson handle mixed-language linking of Rust and C objects
meson.build | 19 ++++++++-----------
rust/hw/char/pl011/meson.build | 2 +-
rust/hw/timer/hpet/meson.build | 2 +-
rust/meson.build | 2 --
rust/qemu-api/meson.build | 15 +++++++++------
scripts/rust/rust_root_crate.sh | 1 +
6 files changed, 20 insertions(+), 21 deletions(-)
--
2.50.1
