How Small a GLIC Rust static Link binary can be?

rust-static-link-gnu-analysis.md

Analyzing Rust GNU static link

• Creating the rust project:

cargo init gnustatic && cd gnustatic

• Creating .cargo configuration directory

mkdir -p .cargo

It creates a hello world by default in src/main.rs:

fn main() {
    println!("Hello, world!");
}

• Adding GNU static linking rules:

[target.x86_64-unknown-linux-gnu]  # Adjust this to your target triple
rustflags = [
  "-C", "target-feature=+crt-static"
]

So:

echo "[target.x86_64-unknown-linux-gnu]  # Adjust this to your target triple
rustflags = [
  \"-C\", \"target-feature=+crt-static\"
]" >> .cargo/config.toml

• Adding size optimization options for the binary:

The optimizations:

[profile.release]
panic = "abort"
strip = true
opt-level = "z"
lto = true
codegen-units = 1

Adding:

echo "

[profile.release]
panic = \"abort\"
strip = true
opt-level = \"z\"
lto = true
codegen-units = 1
" >> Cargo.toml
"

• Compile the Hello World binary:

cargo build --target x86_64-unknown-linux-gnu --release

• Check if it is static linked:

file target/x86_64-unknown-linux-gnu/release/gnustatic

ldd target/x86_64-unknown-linux-gnu/release/gnustatic

• Check the size:

$ du -sh target/x86_64-unknown-linux-gnu/release/gnustatic
1.2M	target/x86_64-unknown-linux-gnu/release/gnustatic

Reducing with UPX compression

upx --best --lzma target/x86_64-unknown-linux-gnu/release/gnustatic

• check the size:

$ du -sh target/x86_64-unknown-linux-gnu/release/gnustatic           
416K	target/x86_64-unknown-linux-gnu/release/gnustatic

• Check if it is static linked:

$ ldd target/x86_64-unknown-linux-gnu/release/gnustatic   
	not a dynamic executable

$ file target/x86_64-unknown-linux-gnu/release/gnustatic 
target/x86_64-unknown-linux-gnu/release/gnustatic: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), statically linked, no section header

Could you extend by adding binary compression with upx?

@farshidtz sure, done!