Testing a small http-client on Linux using no_std & embedded reqwless.
Add nightly immediate-abort size build command
+90
+19
README.md
+19
README.md
···
75
75
- HTTPS profile (`--no-default-features --features backend-posix-libc,dns-getaddrinfo,https`)
76
76
- Before: `631408` bytes
77
77
- After: `296824` bytes
78
+
79
+
## Nightly aggressive size build
80
+
81
+
For nightly-only size optimizations, including location/detail stripping, debug-fmt stripping,
82
+
and `panic=immediate-abort`, use:
83
+
84
+
```bash
85
+
cargo run -p xtask -- nightly-size -- --no-default-features --features backend-posix-libc,dns-getaddrinfo
86
+
```
87
+
88
+
This command applies:
89
+
90
+
- `RUSTFLAGS="-Zlocation-detail=none -Zfmt-debug=none -Zunstable-options -Cpanic=immediate-abort"`
91
+
- `-Z build-std=std,panic_abort`
92
+
- `-Z build-std-features=`
93
+
94
+
Measured with the HTTP profile above on this repository:
95
+
96
+
- Nightly aggressive output size: `41288` bytes
+8
xtask/src/main.rs
+8
xtask/src/main.rs
···
1
1
// pattern: Imperative Shell
2
2
3
+
mod nightly_size;
3
4
mod validate;
4
5
5
6
use clap::{Parser, Subcommand};
7
+
use nightly_size::run_nightly_size_build;
6
8
use validate::{run_validate_tasks, ValidateTask};
7
9
8
10
#[derive(Parser)]
···
19
21
#[arg(value_enum)]
20
22
tasks: Vec<ValidateTask>,
21
23
},
24
+
/// Build with nightly-only size flags and panic=immediate-abort.
25
+
NightlySize {
26
+
#[arg(trailing_var_arg = true, allow_hyphen_values = true)]
27
+
args: Vec<String>,
28
+
},
22
29
}
23
30
24
31
fn main() {
···
32
39
let cli = Cli::parse();
33
40
match cli.command {
34
41
Task::Validate { tasks } => run_validate_tasks(&tasks),
42
+
Task::NightlySize { args } => run_nightly_size_build(&args),
35
43
}
36
44
}
+63
xtask/src/nightly_size.rs
+63
xtask/src/nightly_size.rs
···
1
+
use std::env;
2
+
use std::process::Command;
3
+
4
+
const NIGHTLY_SIZE_RUSTFLAGS: &str =
5
+
"-Zlocation-detail=none -Zfmt-debug=none -Zunstable-options -Cpanic=immediate-abort";
6
+
7
+
pub fn run_nightly_size_build(extra_args: &[String]) -> Result<(), String> {
8
+
let host_target = detect_host_target()?;
9
+
let rustflags = compose_rustflags();
10
+
11
+
let mut command = Command::new("cargo");
12
+
command
13
+
.arg("+nightly")
14
+
.arg("build")
15
+
.arg("--release")
16
+
.arg("-Z")
17
+
.arg("build-std=std,panic_abort")
18
+
.arg("-Z")
19
+
.arg("build-std-features=")
20
+
.arg("--target")
21
+
.arg(&host_target)
22
+
.args(extra_args)
23
+
.env("RUSTFLAGS", rustflags);
24
+
25
+
let status = command
26
+
.status()
27
+
.map_err(|error| format!("failed to run cargo +nightly build: {error}"))?;
28
+
if status.success() {
29
+
Ok(())
30
+
} else {
31
+
Err(format!("nightly size build failed with status {status}"))
32
+
}
33
+
}
34
+
35
+
fn compose_rustflags() -> String {
36
+
match env::var("RUSTFLAGS") {
37
+
Ok(existing_flags) if !existing_flags.trim().is_empty() => {
38
+
format!("{existing_flags} {NIGHTLY_SIZE_RUSTFLAGS}")
39
+
}
40
+
_ => NIGHTLY_SIZE_RUSTFLAGS.to_owned(),
41
+
}
42
+
}
43
+
44
+
fn detect_host_target() -> Result<String, String> {
45
+
let output = Command::new("rustc")
46
+
.arg("-vV")
47
+
.output()
48
+
.map_err(|error| format!("failed to run rustc -vV: {error}"))?;
49
+
if !output.status.success() {
50
+
return Err(format!("rustc -vV failed with status {}", output.status));
51
+
}
52
+
53
+
let stdout = String::from_utf8(output.stdout)
54
+
.map_err(|error| format!("rustc -vV output is not valid UTF-8: {error}"))?;
55
+
56
+
for line in stdout.lines() {
57
+
if let Some(host_target) = line.strip_prefix("host: ") {
58
+
return Ok(host_target.to_owned());
59
+
}
60
+
}
61
+
62
+
Err("failed to detect host target triple from rustc -vV".to_owned())
63
+
}