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-rw-r--r--third_party/rust/cargo-platform/src/lib.rs146
1 files changed, 146 insertions, 0 deletions
diff --git a/third_party/rust/cargo-platform/src/lib.rs b/third_party/rust/cargo-platform/src/lib.rs
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+//! Platform definition used by Cargo.
+//!
+//! This defines a [`Platform`] type which is used in Cargo to specify a target platform.
+//! There are two kinds, a named target like `x86_64-apple-darwin`, and a "cfg expression"
+//! like `cfg(any(target_os = "macos", target_os = "ios"))`.
+//!
+//! See `examples/matches.rs` for an example of how to match against a `Platform`.
+//!
+//! [`Platform`]: enum.Platform.html
+
+use std::fmt;
+use std::str::FromStr;
+
+mod cfg;
+mod error;
+
+pub use cfg::{Cfg, CfgExpr};
+pub use error::{ParseError, ParseErrorKind};
+
+/// Platform definition.
+#[derive(Eq, PartialEq, Hash, Ord, PartialOrd, Clone, Debug)]
+pub enum Platform {
+ /// A named platform, like `x86_64-apple-darwin`.
+ Name(String),
+ /// A cfg expression, like `cfg(windows)`.
+ Cfg(CfgExpr),
+}
+
+impl Platform {
+ /// Returns whether the Platform matches the given target and cfg.
+ ///
+ /// The named target and cfg values should be obtained from `rustc`.
+ pub fn matches(&self, name: &str, cfg: &[Cfg]) -> bool {
+ match *self {
+ Platform::Name(ref p) => p == name,
+ Platform::Cfg(ref p) => p.matches(cfg),
+ }
+ }
+
+ fn validate_named_platform(name: &str) -> Result<(), ParseError> {
+ if let Some(ch) = name
+ .chars()
+ .find(|&c| !(c.is_alphanumeric() || c == '_' || c == '-' || c == '.'))
+ {
+ if name.chars().any(|c| c == '(') {
+ return Err(ParseError::new(
+ name,
+ ParseErrorKind::InvalidTarget(
+ "unexpected `(` character, cfg expressions must start with `cfg(`"
+ .to_string(),
+ ),
+ ));
+ }
+ return Err(ParseError::new(
+ name,
+ ParseErrorKind::InvalidTarget(format!(
+ "unexpected character {} in target name",
+ ch
+ )),
+ ));
+ }
+ Ok(())
+ }
+
+ pub fn check_cfg_attributes(&self, warnings: &mut Vec<String>) {
+ fn check_cfg_expr(expr: &CfgExpr, warnings: &mut Vec<String>) {
+ match *expr {
+ CfgExpr::Not(ref e) => check_cfg_expr(e, warnings),
+ CfgExpr::All(ref e) | CfgExpr::Any(ref e) => {
+ for e in e {
+ check_cfg_expr(e, warnings);
+ }
+ }
+ CfgExpr::Value(ref e) => match e {
+ Cfg::Name(name) => match name.as_str() {
+ "test" | "debug_assertions" | "proc_macro" =>
+ warnings.push(format!(
+ "Found `{}` in `target.'cfg(...)'.dependencies`. \
+ This value is not supported for selecting dependencies \
+ and will not work as expected. \
+ To learn more visit \
+ https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#platform-specific-dependencies",
+ name
+ )),
+ _ => (),
+ },
+ Cfg::KeyPair(name, _) => if name.as_str() == "feature" {
+ warnings.push(String::from(
+ "Found `feature = ...` in `target.'cfg(...)'.dependencies`. \
+ This key is not supported for selecting dependencies \
+ and will not work as expected. \
+ Use the [features] section instead: \
+ https://doc.rust-lang.org/cargo/reference/features.html"
+ ))
+ },
+ }
+ }
+ }
+
+ if let Platform::Cfg(cfg) = self {
+ check_cfg_expr(cfg, warnings);
+ }
+ }
+}
+
+impl serde::Serialize for Platform {
+ fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
+ where
+ S: serde::Serializer,
+ {
+ self.to_string().serialize(s)
+ }
+}
+
+impl<'de> serde::Deserialize<'de> for Platform {
+ fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ let s = String::deserialize(deserializer)?;
+ FromStr::from_str(&s).map_err(serde::de::Error::custom)
+ }
+}
+
+impl FromStr for Platform {
+ type Err = ParseError;
+
+ fn from_str(s: &str) -> Result<Platform, ParseError> {
+ if s.starts_with("cfg(") && s.ends_with(')') {
+ let s = &s[4..s.len() - 1];
+ s.parse().map(Platform::Cfg)
+ } else {
+ Platform::validate_named_platform(s)?;
+ Ok(Platform::Name(s.to_string()))
+ }
+ }
+}
+
+impl fmt::Display for Platform {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match *self {
+ Platform::Name(ref n) => n.fmt(f),
+ Platform::Cfg(ref e) => write!(f, "cfg({})", e),
+ }
+ }
+}