embassy/embassy-usb/build.rs

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2.8 KiB
Rust
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use std::collections::HashMap;
use std::fmt::Write;
use std::path::PathBuf;
use std::{env, fs};
static CONFIGS: &[(&str, usize)] = &[
// BEGIN AUTOGENERATED CONFIG FEATURES
// Generated by gen_config.py. DO NOT EDIT.
("MAX_INTERFACE_COUNT", 4),
("MAX_HANDLER_COUNT", 4),
// END AUTOGENERATED CONFIG FEATURES
];
struct ConfigState {
value: usize,
seen_feature: bool,
seen_env: bool,
}
fn main() {
let crate_name = env::var("CARGO_PKG_NAME")
.unwrap()
.to_ascii_uppercase()
.replace('-', "_");
// only rebuild if build.rs changed. Otherwise Cargo will rebuild if any
// other file changed.
println!("cargo:rerun-if-changed=build.rs");
// Rebuild if config envvar changed.
for (name, _) in CONFIGS {
println!("cargo:rerun-if-env-changed={crate_name}_{name}");
}
let mut configs = HashMap::new();
for (name, default) in CONFIGS {
configs.insert(
*name,
ConfigState {
value: *default,
seen_env: false,
seen_feature: false,
},
);
}
let prefix = format!("{crate_name}_");
for (var, value) in env::vars() {
if let Some(name) = var.strip_prefix(&prefix) {
let Some(cfg) = configs.get_mut(name) else {
panic!("Unknown env var {name}")
};
let Ok(value) = value.parse::<usize>() else {
panic!("Invalid value for env var {name}: {value}")
};
cfg.value = value;
cfg.seen_env = true;
}
if let Some(feature) = var.strip_prefix("CARGO_FEATURE_") {
if let Some(i) = feature.rfind('_') {
let name = &feature[..i];
let value = &feature[i + 1..];
if let Some(cfg) = configs.get_mut(name) {
let Ok(value) = value.parse::<usize>() else {
panic!("Invalid value for feature {name}: {value}")
};
// envvars take priority.
if !cfg.seen_env {
2023-10-15 23:45:44 +02:00
assert!(
!cfg.seen_feature,
"multiple values set for feature {}: {} and {}",
name, cfg.value, value
);
cfg.value = value;
cfg.seen_feature = true;
}
}
}
}
}
let mut data = String::new();
for (name, cfg) in &configs {
writeln!(&mut data, "pub const {}: usize = {};", name, cfg.value).unwrap();
}
let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
let out_file = out_dir.join("config.rs").to_string_lossy().to_string();
fs::write(out_file, data).unwrap();
}