New namespaced features implementation.

Author: ehuss

crates/cargo-test-support/src/lib.rs

@@ -1218,7 +1218,7 @@ enum MatchKind {
 
 /// Compares a line with an expected pattern.
 /// - Use `[..]` as a wildcard to match 0 or more characters on the same line
-///   (similar to `.*` in a regex).
+///   (similar to `.*` in a regex). It is non-greedy.
 /// - Use `[EXE]` to optionally add `.exe` on Windows (empty string on other
 ///   platforms).
 /// - There is a wide range of macros (such as `[COMPILING]` or `[WARNING]`)

crates/resolver-tests/src/lib.rs

@@ -170,14 +170,7 @@ pub fn resolve_with_config_raw(
         list: registry,
         used: HashSet::new(),
     };
-    let summary = Summary::new(
-        pkg_id("root"),
-        deps,
-        &BTreeMap::<String, Vec<String>>::new(),
-        None::<&String>,
-        false,
-    )
-    .unwrap();
+    let summary = Summary::new(pkg_id("root"), deps, &BTreeMap::new(), None::<&String>).unwrap();
     let opts = ResolveOpts::everything();
     let start = Instant::now();
     let resolve = resolver::resolve(
@@ -571,14 +564,7 @@ pub fn pkg_dep<T: ToPkgId>(name: T, dep: Vec<Dependency>) -> Summary {
     } else {
         None
     };
-    Summary::new(
-        name.to_pkgid(),
-        dep,
-        &BTreeMap::<String, Vec<String>>::new(),
-        link,
-        false,
-    )
-    .unwrap()
+    Summary::new(name.to_pkgid(), dep, &BTreeMap::new(), link).unwrap()
 }
 
 pub fn pkg_id(name: &str) -> PackageId {
@@ -599,14 +585,7 @@ pub fn pkg_loc(name: &str, loc: &str) -> Summary {
     } else {
         None
     };
-    Summary::new(
-        pkg_id_loc(name, loc),
-        Vec::new(),
-        &BTreeMap::<String, Vec<String>>::new(),
-        link,
-        false,
-    )
-    .unwrap()
+    Summary::new(pkg_id_loc(name, loc), Vec::new(), &BTreeMap::new(), link).unwrap()
 }
 
 pub fn remove_dep(sum: &Summary, ind: usize) -> Summary {
@@ -616,9 +595,8 @@ pub fn remove_dep(sum: &Summary, ind: usize) -> Summary {
     Summary::new(
         sum.package_id(),
         deps,
-        &BTreeMap::<String, Vec<String>>::new(),
+        &BTreeMap::new(),
         sum.links().map(|a| a.as_str()),
-        sum.namespaced_features(),
     )
     .unwrap()
 }

crates/resolver-tests/tests/resolve.rs

@@ -228,6 +228,7 @@ proptest! {
 }
 
 #[test]
+#[should_panic(expected = "pub dep")] // The error handling is not yet implemented.
 fn pub_fail() {
     let input = vec![
         pkg!(("a", "0.0.4")),

src/bin/cargo/cli.rs

@@ -35,13 +35,14 @@ pub fn main(config: &mut Config) -> CliResult {
             "
 Available unstable (nightly-only) flags:
 
-    -Z avoid-dev-deps   -- Avoid installing dev-dependencies if possible
-    -Z minimal-versions -- Install minimal dependency versions instead of maximum
-    -Z no-index-update  -- Do not update the registry, avoids a network request for benchmarking
-    -Z unstable-options -- Allow the usage of unstable options
-    -Z timings          -- Display concurrency information
-    -Z doctest-xcompile -- Compile and run doctests for non-host target using runner config
-    -Z terminal-width   -- Provide a terminal width to rustc for error truncation
+    -Z avoid-dev-deps      -- Avoid installing dev-dependencies if possible
+    -Z minimal-versions    -- Install minimal dependency versions instead of maximum
+    -Z no-index-update     -- Do not update the registry, avoids a network request for benchmarking
+    -Z unstable-options    -- Allow the usage of unstable options
+    -Z timings             -- Display concurrency information
+    -Z doctest-xcompile    -- Compile and run doctests for non-host target using runner config
+    -Z terminal-width      -- Provide a terminal width to rustc for error truncation
+    -Z namespaced-features -- Allow features with `crate:` prefix
 
 Run with 'cargo -Z [FLAG] [SUBCOMMAND]'"
         );

src/cargo/core/compiler/unit_dependencies.rs

@@ -713,6 +713,16 @@ impl<'a, 'cfg> State<'a, 'cfg> {
         features.activated_features(pkg_id, features_for)
     }
 
+    fn is_dep_activated(
+        &self,
+        pkg_id: PackageId,
+        features_for: FeaturesFor,
+        dep_name: InternedString,
+    ) -> bool {
+        self.features()
+            .is_dep_activated(pkg_id, features_for, dep_name)
+    }
+
     fn get(&self, id: PackageId) -> &'a Package {
         self.package_set
             .get_one(id)
@@ -738,9 +748,7 @@ impl<'a, 'cfg> State<'a, 'cfg> {
                     // did not enable it, don't include it.
                     if dep.is_optional() {
                         let features_for = unit_for.map_to_features_for();
-
-                        let feats = self.activated_features(pkg_id, features_for);
-                        if !feats.contains(&dep.name_in_toml()) {
+                        if !self.is_dep_activated(pkg_id, features_for, dep.name_in_toml()) {
                             return false;
                         }
                     }

src/cargo/core/features.rs

@@ -197,9 +197,6 @@ features! {
         // Overriding profiles for dependencies.
         [stable] profile_overrides: bool,
 
-        // Separating the namespaces for features and dependencies
-        [unstable] namespaced_features: bool,
-
         // "default-run" manifest option,
         [stable] default_run: bool,
 
@@ -360,6 +357,7 @@ pub struct CliUnstable {
     pub multitarget: bool,
     pub rustdoc_map: bool,
     pub terminal_width: Option<Option<usize>>,
+    pub namespaced_features: bool,
 }
 
 fn deserialize_build_std<'de, D>(deserializer: D) -> Result<Option<Vec<String>>, D::Error>
@@ -465,6 +463,7 @@ impl CliUnstable {
             "multitarget" => self.multitarget = parse_empty(k, v)?,
             "rustdoc-map" => self.rustdoc_map = parse_empty(k, v)?,
             "terminal-width" => self.terminal_width = Some(parse_usize_opt(v)?),
+            "namespaced-features" => self.namespaced_features = parse_empty(k, v)?,
             _ => bail!("unknown `-Z` flag specified: {}", k),
         }
 

src/cargo/core/package.rs

@@ -1,6 +1,6 @@
 use std::cell::{Cell, Ref, RefCell, RefMut};
 use std::cmp::Ordering;
-use std::collections::{BTreeSet, HashMap, HashSet};
+use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::fmt;
 use std::hash;
 use std::mem;
@@ -23,7 +23,7 @@ use crate::core::dependency::DepKind;
 use crate::core::resolver::{HasDevUnits, Resolve};
 use crate::core::source::MaybePackage;
 use crate::core::{Dependency, Manifest, PackageId, SourceId, Target};
-use crate::core::{FeatureMap, SourceMap, Summary, Workspace};
+use crate::core::{SourceMap, Summary, Workspace};
 use crate::ops;
 use crate::util::config::PackageCacheLock;
 use crate::util::errors::{CargoResult, CargoResultExt, HttpNot200};
@@ -87,7 +87,7 @@ struct SerializedPackage<'a> {
     source: SourceId,
     dependencies: &'a [Dependency],
     targets: Vec<&'a Target>,
-    features: &'a FeatureMap,
+    features: &'a BTreeMap<InternedString, Vec<InternedString>>,
     manifest_path: &'a Path,
     metadata: Option<&'a toml::Value>,
     publish: Option<&'a Vec<String>>,
@@ -131,6 +131,12 @@ impl ser::Serialize for Package {
             .iter()
             .filter(|t| t.src_path().is_path())
             .collect();
+        let empty_feats = BTreeMap::new();
+        let features = self
+            .manifest()
+            .original()
+            .features()
+            .unwrap_or(&empty_feats);
 
         SerializedPackage {
             name: &*package_id.name(),
@@ -142,7 +148,7 @@ impl ser::Serialize for Package {
             source: summary.source_id(),
             dependencies: summary.dependencies(),
             targets,
-            features: summary.features(),
+            features,
             manifest_path: self.manifest_path(),
             metadata: self.manifest().custom_metadata(),
             authors,