Auto merge of #7626 - ehuss:remove-dep-targets, r=alexcrichton

Remove dep_targets.

This is just some code cleanup.  The `dep_targets` method has been replaced by `unit_deps`, which doesn't force the creation of a new Vec.

src/cargo/core/compiler/build_plan.rs

@@ -113,9 +113,9 @@ impl BuildPlan {
         let id = self.plan.invocations.len();
         self.invocation_map.insert(unit.buildkey(), id);
         let deps = cx
-            .dep_targets(unit)
+            .unit_deps(unit)
             .iter()
-            .map(|dep| self.invocation_map[&dep.buildkey()])
+            .map(|dep| self.invocation_map[&dep.unit.buildkey()])
             .collect();
         let invocation = Invocation::new(unit, deps);
         self.plan.invocations.push(invocation);

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

@@ -458,8 +458,8 @@ fn metadata_of<'a, 'cfg>(
     if !metas.contains_key(unit) {
         let meta = compute_metadata(unit, cx, metas);
         metas.insert(*unit, meta);
-        for unit in cx.dep_targets(unit) {
-            metadata_of(&unit, cx, metas);
+        for dep in cx.unit_deps(unit) {
+            metadata_of(&dep.unit, cx, metas);
         }
     }
     metas[unit].clone()
@@ -532,15 +532,13 @@ fn compute_metadata<'a, 'cfg>(
     unit.features.hash(&mut hasher);
 
     // Mix in the target-metadata of all the dependencies of this target.
-    {
-        let mut deps_metadata = cx
-            .dep_targets(unit)
-            .iter()
-            .map(|dep| metadata_of(dep, cx, metas))
-            .collect::<Vec<_>>();
-        deps_metadata.sort();
-        deps_metadata.hash(&mut hasher);
-    }
+    let mut deps_metadata = cx
+        .unit_deps(unit)
+        .iter()
+        .map(|dep| metadata_of(&dep.unit, cx, metas))
+        .collect::<Vec<_>>();
+    deps_metadata.sort();
+    deps_metadata.hash(&mut hasher);
 
     // Throw in the profile we're compiling with. This helps caching
     // `panic=abort` and `panic=unwind` artifacts, additionally with various

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

@@ -187,18 +187,20 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
 
             // If the unit has a build script, add `OUT_DIR` to the
             // environment variables.
-            for dep in self.dep_targets(unit).iter() {
-                if !unit.target.is_lib() {
-                    continue;
-                }
-
-                if dep.mode.is_run_custom_build() {
-                    let out_dir = self.files().build_script_out_dir(dep).display().to_string();
-                    self.compilation
-                        .extra_env
-                        .entry(dep.pkg.package_id())
-                        .or_insert_with(Vec::new)
-                        .push(("OUT_DIR".to_string(), out_dir));
+            if unit.target.is_lib() {
+                for dep in &self.unit_dependencies[unit] {
+                    if dep.unit.mode.is_run_custom_build() {
+                        let out_dir = self
+                            .files()
+                            .build_script_out_dir(&dep.unit)
+                            .display()
+                            .to_string();
+                        self.compilation
+                            .extra_env
+                            .entry(dep.unit.pkg.package_id())
+                            .or_insert_with(Vec::new)
+                            .push(("OUT_DIR".to_string(), out_dir));
+                    }
                 }
             }
 
@@ -361,18 +363,6 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
         self.files.as_ref().unwrap().outputs(unit, self.bcx)
     }
 
-    /// For a package, return all targets which are registered as dependencies
-    /// for that package.
-    /// NOTE: This is deprecated, use `unit_deps` instead.
-    //
-    // TODO: this ideally should be `-> &[Unit<'a>]`.
-    pub fn dep_targets(&self, unit: &Unit<'a>) -> Vec<Unit<'a>> {
-        self.unit_dependencies[unit]
-            .iter()
-            .map(|dep| dep.unit)
-            .collect()
-    }
-
     /// Direct dependencies for the given unit.
     pub fn unit_deps(&self, unit: &Unit<'a>) -> &[UnitDep<'a>] {
         &self.unit_dependencies[unit]

src/cargo/core/compiler/custom_build.rs

@@ -133,10 +133,11 @@ fn emit_build_output(
 fn build_work<'a, 'cfg>(cx: &mut Context<'a, 'cfg>, unit: &Unit<'a>) -> CargoResult<Job> {
     assert!(unit.mode.is_run_custom_build());
     let bcx = &cx.bcx;
-    let dependencies = cx.dep_targets(unit);
+    let dependencies = cx.unit_deps(unit);
     let build_script_unit = dependencies
         .iter()
-        .find(|d| !d.mode.is_run_custom_build() && d.target.is_custom_build())
+        .find(|d| !d.unit.mode.is_run_custom_build() && d.unit.target.is_custom_build())
+        .map(|d| &d.unit)
         .expect("running a script not depending on an actual script");
     let script_dir = cx.files().build_script_dir(build_script_unit);
     let script_out_dir = cx.files().build_script_out_dir(unit);
@@ -225,21 +226,19 @@ fn build_work<'a, 'cfg>(cx: &mut Context<'a, 'cfg>, unit: &Unit<'a>) -> CargoRes
     //
     // This information will be used at build-time later on to figure out which
     // sorts of variables need to be discovered at that time.
-    let lib_deps = {
-        dependencies
-            .iter()
-            .filter_map(|unit| {
-                if unit.mode.is_run_custom_build() {
-                    Some((
-                        unit.pkg.manifest().links().unwrap().to_string(),
-                        unit.pkg.package_id(),
-                    ))
-                } else {
-                    None
-                }
-            })
-            .collect::<Vec<_>>()
-    };
+    let lib_deps = dependencies
+        .iter()
+        .filter_map(|dep| {
+            if dep.unit.mode.is_run_custom_build() {
+                Some((
+                    dep.unit.pkg.manifest().links().unwrap().to_string(),
+                    dep.unit.pkg.package_id(),
+                ))
+            } else {
+                None
+            }
+        })
+        .collect::<Vec<_>>();
     let pkg_name = unit.pkg.to_string();
     let build_script_outputs = Arc::clone(&cx.build_script_outputs);
     let id = unit.pkg.package_id();
@@ -563,15 +562,15 @@ fn prepare_metabuild<'a, 'cfg>(
     deps: &[String],
 ) -> CargoResult<()> {
     let mut output = Vec::new();
-    let available_deps = cx.dep_targets(unit);
+    let available_deps = cx.unit_deps(unit);
     // Filter out optional dependencies, and look up the actual lib name.
     let meta_deps: Vec<_> = deps
         .iter()
         .filter_map(|name| {
             available_deps
                 .iter()
-                .find(|u| u.pkg.name().as_str() == name.as_str())
-                .map(|dep| dep.target.crate_name())
+                .find(|d| d.unit.pkg.name().as_str() == name.as_str())
+                .map(|d| d.unit.target.crate_name())
         })
         .collect();
     for dep in &meta_deps {
@@ -669,7 +668,7 @@ pub fn build_map<'b, 'cfg>(cx: &mut Context<'b, 'cfg>, units: &[Unit<'b>]) -> Ca
         // to rustc invocation caching schemes, so be sure to generate the same
         // set of build script dependency orderings via sorting the targets that
         // come out of the `Context`.
-        let mut dependencies = cx.dep_targets(unit);
+        let mut dependencies: Vec<Unit<'_>> = cx.unit_deps(unit).iter().map(|d| d.unit).collect();
         dependencies.sort_by_key(|u| u.pkg.package_id());
 
         for dep_unit in dependencies.iter() {

src/cargo/core/compiler/job_queue.rs

@@ -159,26 +159,25 @@ impl<'a, 'cfg> JobQueue<'a, 'cfg> {
         unit: &Unit<'a>,
         job: Job,
     ) -> CargoResult<()> {
-        let dependencies = cx.dep_targets(unit);
+        let dependencies = cx.unit_deps(unit);
         let mut queue_deps = dependencies
             .iter()
-            .cloned()
-            .filter(|unit| {
+            .filter(|dep| {
                 // Binaries aren't actually needed to *compile* tests, just to run
                 // them, so we don't include this dependency edge in the job graph.
-                !unit.target.is_test() && !unit.target.is_bin()
+                !dep.unit.target.is_test() && !dep.unit.target.is_bin()
             })
             .map(|dep| {
                 // Handle the case here where our `unit -> dep` dependency may
                 // only require the metadata, not the full compilation to
                 // finish. Use the tables in `cx` to figure out what kind
                 // of artifact is associated with this dependency.
-                let artifact = if cx.only_requires_rmeta(unit, &dep) {
+                let artifact = if cx.only_requires_rmeta(unit, &dep.unit) {
                     Artifact::Metadata
                 } else {
                     Artifact::All
                 };
-                (dep, artifact)
+                (dep.unit, artifact)
             })
             .collect::<HashMap<_, _>>();
 
@@ -205,17 +204,17 @@ impl<'a, 'cfg> JobQueue<'a, 'cfg> {
         // transitively contains the `Metadata` edge.
         if unit.requires_upstream_objects() {
             for dep in dependencies {
-                depend_on_deps_of_deps(cx, &mut queue_deps, dep);
+                depend_on_deps_of_deps(cx, &mut queue_deps, dep.unit);
             }
 
             fn depend_on_deps_of_deps<'a>(
                 cx: &Context<'a, '_>,
                 deps: &mut HashMap<Unit<'a>, Artifact>,
                 unit: Unit<'a>,
             ) {
-                for dep in cx.dep_targets(&unit) {
-                    if deps.insert(dep, Artifact::All).is_none() {
-                        depend_on_deps_of_deps(cx, deps, dep);
+                for dep in cx.unit_deps(&unit) {
+                    if deps.insert(dep.unit, Artifact::All).is_none() {
+                        depend_on_deps_of_deps(cx, deps, dep.unit);
                     }
                 }
             }

src/cargo/core/compiler/mod.rs

@@ -157,8 +157,9 @@ fn compile<'a, 'cfg: 'a>(
     drop(p);
 
     // Be sure to compile all dependencies of this target as well.
-    for unit in cx.dep_targets(unit).iter() {
-        compile(cx, jobs, plan, unit, exec, false)?;
+    let deps = Vec::from(cx.unit_deps(unit)); // Create vec due to mutable borrow.
+    for dep in deps {
+        compile(cx, jobs, plan, &dep.unit, exec, false)?;
     }
     if build_plan {
         plan.add(cx, unit)?;

src/cargo/core/compiler/output_depinfo.rs

@@ -90,10 +90,11 @@ fn add_deps_for_unit<'a, 'b>(
     }
 
     // Recursively traverse all transitive dependencies
-    for dep_unit in context.dep_targets(unit).iter() {
-        let source_id = dep_unit.pkg.package_id().source_id();
+    let unit_deps = Vec::from(context.unit_deps(unit)); // Create vec due to mutable borrow.
+    for dep in unit_deps {
+        let source_id = dep.unit.pkg.package_id().source_id();
         if source_id.is_path() {
-            add_deps_for_unit(deps, context, dep_unit, visited)?;
+            add_deps_for_unit(deps, context, &dep.unit, visited)?;
         }
     }
     Ok(())