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