[WIP] mtime+content tracking

Cargo.toml

@@ -45,6 +45,7 @@ lazycell = "1.2.0"
 libc = "0.2"
 log = "0.4.6"
 libgit2-sys = "0.12.14"
+md-5 = "0.8"
 memchr = "2.1.3"
 num_cpus = "1.0"
 opener = "0.4"
@@ -55,6 +56,7 @@ semver = { version = "0.10", features = ["serde"] }
 serde = { version = "1.0.82", features = ["derive"] }
 serde_ignored = "0.1.0"
 serde_json = { version = "1.0.30", features = ["raw_value"] }
+sha-1 = "0.8"
 shell-escape = "0.1.4"
 strip-ansi-escapes = "0.1.0"
 tar = { version = "0.4.26", default-features = false }
@@ -68,12 +70,18 @@ clap = "2.31.2"
 unicode-width = "0.1.5"
 openssl = { version = '0.10.11', optional = true }
 im-rc = "15.0.0"
+ar="0.8"
 
 # A noop dependency that changes in the Rust repository, it's a bit of a hack.
 # See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`
 # for more information.
 rustc-workspace-hack = "1.0.0"
 
+[dependencies.object]
+version = "0.20.0"
+default-features = false
+features = ['read_core', 'elf', 'macho', 'pe', 'unaligned']
+
 [target.'cfg(target_os = "macos")'.dependencies]
 core-foundation = { version = "0.9.0", features = ["mac_os_10_7_support"] }
 

src/cargo/core/compiler/context/mod.rs

@@ -2,9 +2,9 @@ use std::collections::{BTreeSet, HashMap, HashSet};
 use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 
-use filetime::FileTime;
 use jobserver::Client;
 
+use crate::core::compiler::fingerprint::{CurrentFileprint, RustcDepInfo};
 use crate::core::compiler::{self, compilation, Unit};
 use crate::core::PackageId;
 use crate::util::errors::{CargoResult, CargoResultExt};
@@ -38,7 +38,9 @@ pub struct Context<'a, 'cfg> {
     /// Fingerprints used to detect if a unit is out-of-date.
     pub fingerprints: HashMap<Unit, Arc<Fingerprint>>,
     /// Cache of file mtimes to reduce filesystem hits.
-    pub mtime_cache: HashMap<PathBuf, FileTime>,
+    pub mtime_cache: HashMap<PathBuf, CurrentFileprint>,
+    /// Cache of dep_info to reduce filesystem hits.
+    pub dep_info_cache: HashMap<PathBuf, RustcDepInfo>,
     /// A set used to track which units have been compiled.
     /// A unit may appear in the job graph multiple times as a dependency of
     /// multiple packages, but it only needs to run once.
@@ -107,6 +109,7 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
             build_script_outputs: Arc::new(Mutex::new(BuildScriptOutputs::default())),
             fingerprints: HashMap::new(),
             mtime_cache: HashMap::new(),
+            dep_info_cache: HashMap::new(),
             compiled: HashSet::new(),
             build_scripts: HashMap::new(),
             build_explicit_deps: HashMap::new(),