Compute non custom build and non transitive deps for doc

Signed-off-by: hi-rustin <[email protected]>

Author: 0xPoe

src/cargo/core/compiler/unit_dependencies.rs

@@ -18,7 +18,6 @@
 use crate::core::compiler::unit_graph::{UnitDep, UnitGraph};
 use crate::core::compiler::UnitInterner;
 use crate::core::compiler::{CompileKind, CompileMode, RustcTargetData, Unit};
-use crate::core::dependency::DepKind;
 use crate::core::profiles::{Profile, Profiles, UnitFor};
 use crate::core::resolver::features::{FeaturesFor, ResolvedFeatures};
 use crate::core::resolver::Resolve;
@@ -243,29 +242,7 @@ fn compute_deps(
     }
 
     let id = unit.pkg.package_id();
-    let filtered_deps = state.deps(unit, unit_for, &|dep| {
-        // If this target is a build command, then we only want build
-        // dependencies, otherwise we want everything *other than* build
-        // dependencies.
-        if unit.target.is_custom_build() != dep.is_build() {
-            return false;
-        }
-
-        // If this dependency is **not** a transitive dependency, then it
-        // only applies to test/example targets.
-        if !dep.is_transitive()
-            && !unit.target.is_test()
-            && !unit.target.is_example()
-            && !unit.mode.is_doc_scrape()
-            && !unit.mode.is_any_test()
-        {
-            return false;
-        }
-
-        // If we've gotten past all that, then this dependency is
-        // actually used!
-        true
-    });
+    let filtered_deps = non_custom_build_and_non_transitive_deps(unit, state, unit_for);
 
     let mut ret = Vec::new();
     let mut dev_deps = Vec::new();
@@ -372,6 +349,37 @@ fn compute_deps(
     Ok(ret)
 }
 
+/// Returns non-custom and non-transitive dependencies.
+fn non_custom_build_and_non_transitive_deps<'a>(
+    unit: &Unit,
+    state: &'a State<'_, '_>,
+    unit_for: UnitFor,
+) -> Vec<(PackageId, &'a HashSet<Dependency>)> {
+    state.deps(unit, unit_for, &|dep| {
+        // If this target is a build command, then we only want build
+        // dependencies, otherwise we want everything *other than* build
+        // dependencies.
+        if unit.target.is_custom_build() != dep.is_build() {
+            return false;
+        }
+
+        // If this dependency is **not** a transitive dependency, then it
+        // only applies to test/example targets.
+        if !dep.is_transitive()
+            && !unit.target.is_test()
+            && !unit.target.is_example()
+            && !unit.mode.is_doc_scrape()
+            && !unit.mode.is_any_test()
+        {
+            return false;
+        }
+
+        // If we've gotten past all that, then this dependency is
+        // actually used!
+        true
+    })
+}
+
 /// Returns the dependencies needed to run a build script.
 ///
 /// The `unit` provided must represent an execution of a build script, and
@@ -423,7 +431,7 @@ fn compute_deps_doc(
     state: &mut State<'_, '_>,
     unit_for: UnitFor,
 ) -> CargoResult<Vec<UnitDep>> {
-    let deps = state.deps(unit, unit_for, &|dep| dep.kind() == DepKind::Normal);
+    let deps = non_custom_build_and_non_transitive_deps(unit, state, unit_for);
 
     // To document a library, we depend on dependencies actually being
     // built. If we're documenting *all* libraries, then we also depend on

tests/testsuite/doc.rs

@@ -1815,6 +1815,70 @@ fn doc_example() {
         .exists());
 }
 
+#[cargo_test]
+fn doc_example_with_deps() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+            [package]
+            name = "foo"
+            version = "0.1.0"
+            edition = "2018"
+
+            [[example]]
+            crate-type = ["lib"]
+            name = "ex"
+            doc = true
+
+            [dev-dependencies]
+            a = {path = "a"}
+            b = {path = "b"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file(
+            "examples/ex.rs",
+            r#"
+            use a::fun;
+
+            /// Example
+            pub fn x() { fun(); }
+            "#,
+        )
+        .file(
+            "a/Cargo.toml",
+            r#"
+            [package]
+            name = "a"
+            version = "0.0.1"
+
+            [dependencies]
+            b = {path = "../b"}
+            "#,
+        )
+        .file("a/src/fun.rs", "pub fn fun() {}")
+        .file("a/src/lib.rs", "pub mod fun;")
+        .file(
+            "b/Cargo.toml",
+            r#"
+            [package]
+            name = "b"
+            version = "0.0.1"
+            "#,
+        )
+        .file("b/src/lib.rs", "")
+        .build();
+
+    p.cargo("doc --examples").run();
+    assert!(p
+        .build_dir()
+        .join("doc")
+        .join("ex")
+        .join("fn.x.html")
+        .exists());
+}
+
 #[cargo_test]
 fn bin_private_items() {
     let p = project()