utils.rs

use crate::config::dep_tracking::DepTrackingHash;
use crate::config::ErrorOutputType;
use crate::session::Session;
use rustc_data_structures::profiling::VerboseTimingGuard;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use std::collections::hash_map::DefaultHasher;
use std::fs::File;
use std::io::Read;
use std::path::{Path, PathBuf};

impl Session {
    pub fn timer<'a>(&'a self, what: &'static str) -> VerboseTimingGuard<'a> {
        self.prof.verbose_generic_activity(what)
    }
    pub fn time<R>(&self, what: &'static str, f: impl FnOnce() -> R) -> R {
        self.prof.verbose_generic_activity(what).run(f)
    }
}

#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
#[derive(HashStable_Generic)]
pub enum NativeLibKind {
    /// Static library (e.g. `libfoo.a` on Linux or `foo.lib` on Windows/MSVC)
    Static {
        /// Whether to bundle objects from static library into produced rlib
        bundle: Option<bool>,
        /// Whether to link static library without throwing any object files away
        whole_archive: Option<bool>,
    },
    /// Dynamic library (e.g. `libfoo.so` on Linux)
    /// or an import library corresponding to a dynamic library (e.g. `foo.lib` on Windows/MSVC).
    Dylib {
        /// Whether the dynamic library will be linked only if it satisfies some undefined symbols
        as_needed: Option<bool>,
    },
    /// Dynamic library (e.g. `foo.dll` on Windows) without a corresponding import library.
    RawDylib,
    /// A macOS-specific kind of dynamic libraries.
    Framework {
        /// Whether the framework will be linked only if it satisfies some undefined symbols
        as_needed: Option<bool>,
    },
    /// Argument which is passed to linker, relative order with libraries and other arguments
    /// is preserved
    LinkArg,
    /// The library kind wasn't specified, `Dylib` is currently used as a default.
    Unspecified,
}

impl NativeLibKind {
    pub fn has_modifiers(&self) -> bool {
        match self {
            NativeLibKind::Static { bundle, whole_archive } => {
                bundle.is_some() || whole_archive.is_some()
            }
            NativeLibKind::Dylib { as_needed } | NativeLibKind::Framework { as_needed } => {
                as_needed.is_some()
            }
            NativeLibKind::RawDylib | NativeLibKind::Unspecified | NativeLibKind::LinkArg => false,
        }
    }
}

#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
#[derive(HashStable_Generic)]
pub struct NativeLib {
    pub name: String,
    pub new_name: Option<String>,
    pub kind: NativeLibKind,
    pub verbatim: Option<bool>,
}

impl NativeLib {
    pub fn has_modifiers(&self) -> bool {
        self.verbatim.is_some() || self.kind.has_modifiers()
    }
}

/// A path that has been canonicalized along with its original, non-canonicalized form
#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
pub struct CanonicalizedPath {
    // Optional since canonicalization can sometimes fail
    canonicalized: Option<PathBuf>,
    original: PathBuf,
}

impl CanonicalizedPath {
    pub fn new(path: &Path) -> Self {
        Self { original: path.to_owned(), canonicalized: std::fs::canonicalize(path).ok() }
    }

    pub fn canonicalized(&self) -> &PathBuf {
        self.canonicalized.as_ref().unwrap_or(self.original())
    }

    pub fn original(&self) -> &PathBuf {
        &self.original
    }
}

/// A path that should be invalidated when the file that it points to has changed.
/// `ContentHashedFilePath` is identified by its contents only, so even if the filepath itself
/// changes, but the contents stay the same, it will contain the same hash.
#[derive(Clone, Debug)]
pub struct ContentHashedFilePath {
    path: PathBuf,
    hash: (u64, u64),
}

impl ContentHashedFilePath {
    pub fn new(path: PathBuf) -> Self {
        // If the file does not exist or couldn't be hashed, just use a placeholder hash
        let hash = hash_file(&path).unwrap_or((0, 0));
        Self { path, hash }
    }

    pub fn as_path(&self) -> &Path {
        self.path.as_path()
    }
}

impl From<ContentHashedFilePath> for PathBuf {
    fn from(path: ContentHashedFilePath) -> Self {
        path.path
    }
}

impl DepTrackingHash for ContentHashedFilePath {
    fn hash(
        &self,
        hasher: &mut DefaultHasher,
        _error_format: ErrorOutputType,
        _for_crate_hash: bool,
    ) {
        std::hash::Hash::hash(&self.hash, hasher);
    }
}

fn hash_file(path: &Path) -> std::io::Result<(u64, u64)> {
    let mut hasher = StableHasher::new();

    let mut file = File::open(path)?;
    let mut buffer = [0; 128 * 1024];

    loop {
        let count = file.read(&mut buffer)?;
        if count == 0 {
            break;
        }

        buffer[..count].hash_stable(&mut (), &mut hasher);
    }

    Ok(hasher.finalize())
}