allow rustc to use artifact dep environment variables, but…

…it needs some adjustments to actually setup the unit dependency graph
with artifacts as well.
Right now it will only setup dependencies for artifacts that are libs,
but not the artifacts themselves, completely ignoring them when they
are not libs.

src/cargo/core/compiler/mod.rs

@@ -620,7 +620,7 @@ fn prepare_rustc(
         base.inherit_jobserver(&cx.jobserver);
     }
     build_base_args(cx, &mut base, unit, crate_types)?;
-    build_deps_args(&mut base, cx, unit)?;
+    build_deps_args(&mut base, cx, unit, ProcessKind::Rustc)?;
     Ok(base)
 }
 
@@ -698,7 +698,7 @@ fn rustdoc(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Work> {
         }
     }
 
-    build_deps_args(&mut rustdoc, cx, unit)?;
+    build_deps_args(&mut rustdoc, cx, unit, ProcessKind::Rustdoc)?;
     rustdoc::add_root_urls(cx, unit, &mut rustdoc)?;
 
     rustdoc.args(bcx.rustdocflags_args(unit));
@@ -1087,6 +1087,7 @@ fn build_deps_args(
     cmd: &mut ProcessBuilder,
     cx: &mut Context<'_, '_>,
     unit: &Unit,
+    kind: ProcessKind,
 ) -> CargoResult<()> {
     let bcx = cx.bcx;
     cmd.arg("-L").arg(&{
@@ -1107,6 +1108,10 @@ fn build_deps_args(
 
     let deps = cx.unit_deps(unit);
 
+    if let ProcessKind::Rustc = kind {
+        artifact::set_env(cx, deps, cmd)?;
+    }
+
     // If there is not one linkable target but should, rustc fails later
     // on if there is an `extern crate` for it. This may turn into a hard
     // error in the future (see PR #4797).
@@ -1551,3 +1556,8 @@ fn replay_output_cache(
         Ok(())
     })
 }
+
+enum ProcessKind {
+    Rustc,
+    Rustdoc,
+}

src/cargo/core/compiler/unit_dependencies.rs

@@ -503,7 +503,7 @@ fn match_artifacts_kind_with_targets<'a>(
     targets: &'a [Target],
 ) -> CargoResult<HashSet<&'a Target>> {
     let mut out = HashSet::new();
-    let artifact_requirements = artifact_dep.artifact().expect("artifact preset");
+    let artifact_requirements = artifact_dep.artifact().expect("artifact present");
     for artifact_kind in artifact_requirements.kinds() {
         let start = out.len();
         match artifact_kind {

tests/testsuite/artifact_dep.rs

@@ -457,6 +457,7 @@ fn build_script_with_selected_dashed_bin_artifact_and_lib_true() {
 
 // TODO(ST): impl this, and add static and cdylib artifacts, too.
 #[cargo_test]
+#[ignore]
 fn lib_with_selected_dashed_bin_artifact_and_lib_true() {
     let p = project()
         .file(
@@ -554,6 +555,11 @@ fn allow_artifact_and_no_artifact_dep_to_same_package_within_different_dep_categ
 #[ignore]
 fn disallow_using_example_binaries_as_artifacts() {}
 
+// I think compiles it, so 'env!()' must work and be set, along with built artifacts.
+#[cargo_test]
+#[ignore]
+fn rustdoc_works_on_libs_with_artifacts() {}
+
 #[cargo_test]
 #[ignore]
 fn disallow_dep_renames_with_multiple_versions() {