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use super::{Config, ConfigKey, ConfigRelativePath, OptValue, PathAndArgs, StringList, CV};
use crate::core::compiler::BuildOutput;
use crate::util::CargoResult;
use serde::Deserialize;
use std::collections::{BTreeMap, HashMap};
use std::path::PathBuf;
/// Config definition of a [target.'cfg(…)'] table.
///
/// This is a subset of `TargetConfig`.
#[derive(Debug, Deserialize)]
pub struct TargetCfgConfig {
pub runner: OptValue<PathAndArgs>,
pub rustflags: OptValue<StringList>,
// This is here just to ignore fields from normal `TargetConfig` because
// all `[target]` tables are getting deserialized, whether they start with
// `cfg(` or not.
#[serde(flatten)]
pub other: BTreeMap<String, toml::Value>,
}
/// Config definition of a [target] table.
#[derive(Debug)]
pub struct TargetConfig {
/// Process to run as a wrapper for `cargo run`, `test`, and `bench` commands.
pub runner: OptValue<PathAndArgs>,
/// Additional rustc flags to pass.
pub rustflags: OptValue<StringList>,
/// The path of the linker for this target.
pub linker: OptValue<ConfigRelativePath>,
/// Build script override for the given library name.
///
/// Any package with a `links` value for the given library name will skip
/// running its build script and instead use the given output from the
/// config file.
pub links_overrides: BTreeMap<String, BuildOutput>,
}
/// Loads all of the `target.'cfg()'` tables.
pub(super) fn load_target_cfgs(config: &Config) -> CargoResult<Vec<(String, TargetCfgConfig)>> {
// Load all [target] tables, filter out the cfg() entries.
let mut result = Vec::new();
// Use a BTreeMap so the keys are sorted. This is important for
// deterministic ordering of rustflags, which affects fingerprinting and
// rebuilds. We may perhaps one day wish to ensure a deterministic
// ordering via the order keys were defined in files perhaps.
let target: BTreeMap<String, TargetCfgConfig> = config.get("target")?;
log::debug!("Got all targets {:#?}", target);
for (key, cfg) in target {
if key.starts_with("cfg(") {
// Unfortunately this is not able to display the location of the
// unused key. Using config::Value<toml::Value> doesn't work. One
// solution might be to create a special "Any" type, but I think
// that will be quite difficult with the current design.
for other_key in cfg.other.keys() {
config.shell().warn(format!(
"unused key `{}` in [target] config table `{}`",
other_key, key
))?;
}
result.push((key, cfg));
}
}
Ok(result)
}
/// Loads a single `[target]` table for the given triple.
pub(super) fn load_target_triple(config: &Config, triple: &str) -> CargoResult<TargetConfig> {
// This needs to get each field individually because it cannot fetch the
// struct all at once due to `links_overrides`. Can't use `serde(flatten)`
// because it causes serde to use `deserialize_map` which means the config
// deserializer does not know which keys to deserialize, which means
// environment variables would not work.
let runner: OptValue<PathAndArgs> = config.get(&format!("target.{}.runner", triple))?;
let rustflags: OptValue<StringList> = config.get(&format!("target.{}.rustflags", triple))?;
let linker: OptValue<ConfigRelativePath> = config.get(&format!("target.{}.linker", triple))?;
// Links do not support environment variables.
let target_key = ConfigKey::from_str(&format!("target.{}", triple));
let links_overrides = match config.get_table(&target_key)? {
Some(links) => parse_links_overrides(&target_key, links.val)?,
None => BTreeMap::new(),
};
Ok(TargetConfig {
runner,
rustflags,
linker,
links_overrides,
})
}
fn parse_links_overrides(
target_key: &ConfigKey,
links: HashMap<String, CV>,
) -> CargoResult<BTreeMap<String, BuildOutput>> {
let mut links_overrides = BTreeMap::new();
for (lib_name, value) in links {
// Skip these keys, it shares the namespace with `TargetConfig`.
match lib_name.as_str() {
// `ar` is a historical thing.
"ar" | "linker" | "runner" | "rustflags" => continue,
_ => {}
}
let mut output = BuildOutput::default();
let table = value.table(&format!("{}.{}", target_key, lib_name))?.0;
// We require deterministic order of evaluation, so we must sort the pairs by key first.
let mut pairs = Vec::new();
for (k, value) in table {
pairs.push((k, value));
}
pairs.sort_by_key(|p| p.0);
for (key, value) in pairs {
match key.as_str() {
"rustc-flags" => {
let flags = value.string(key)?;
let whence = format!("target config `{}.{}` (in {})", target_key, key, flags.1);
let (paths, links) = BuildOutput::parse_rustc_flags(flags.0, &whence)?;
output.library_paths.extend(paths);
output.library_links.extend(links);
}
"rustc-link-lib" => {
let list = value.list(key)?;
output
.library_links
.extend(list.iter().map(|v| v.0.clone()));
}
"rustc-link-search" => {
let list = value.list(key)?;
output
.library_paths
.extend(list.iter().map(|v| PathBuf::from(&v.0)));
}
"rustc-cdylib-link-arg" => {
let args = value.list(key)?;
output.linker_args.extend(args.iter().map(|v| v.0.clone()));
}
"rustc-cfg" => {
let list = value.list(key)?;
output.cfgs.extend(list.iter().map(|v| v.0.clone()));
}
"rustc-env" => {
for (name, val) in value.table(key)?.0 {
let val = val.string(name)?.0;
output.env.push((name.clone(), val.to_string()));
}
}
"warning" | "rerun-if-changed" | "rerun-if-env-changed" => {
anyhow::bail!("`{}` is not supported in build script overrides", key);
}
_ => {
let val = value.string(key)?.0;
output.metadata.push((key.clone(), val.to_string()));
}
}
}
links_overrides.insert(lib_name, output);
}
Ok(links_overrides)
}