Don't document libs with doc=false

src/cargo/core/compiler/unit_dependencies.rs

@@ -326,7 +326,7 @@ fn compute_deps(
     if unit.target.is_lib() && unit.mode != CompileMode::Doctest {
         return Ok(ret);
     }
-    ret.extend(maybe_lib(unit, state, unit_for, None)?);
+    ret.extend(maybe_lib(unit, state, unit_for)?);
 
     // If any integration tests/benches are being run, make sure that
     // binaries are built as well.
@@ -431,7 +431,7 @@ fn compute_deps_doc(
     let mut ret = Vec::new();
     for (id, _deps) in deps {
         let dep = state.get(id);
-        let lib = match dep.targets().iter().find(|t| t.is_lib()) {
+        let lib = match dep.targets().iter().find(|t| t.is_lib() && t.documented()) {
             Some(lib) => lib,
             None => continue,
         };
@@ -470,9 +470,26 @@ fn compute_deps_doc(
     // If we document a binary/example, we need the library available.
     if unit.target.is_bin() || unit.target.is_example() {
         // build the lib
-        ret.extend(maybe_lib(unit, state, unit_for, None)?);
+        ret.extend(maybe_lib(unit, state, unit_for)?);
         // and also the lib docs for intra-doc links
-        ret.extend(maybe_lib(unit, state, unit_for, Some(unit.mode))?);
+        if let Some(lib) = unit
+            .pkg
+            .targets()
+            .iter()
+            .find(|t| t.is_linkable() && t.documented())
+        {
+            let dep_unit_for = unit_for.with_dependency(unit, lib);
+            let lib_doc_unit = new_unit_dep(
+                state,
+                unit,
+                &unit.pkg,
+                lib,
+                dep_unit_for,
+                unit.kind.for_target(lib),
+                unit.mode,
+            )?;
+            ret.push(lib_doc_unit);
+        }
     }
 
     // Add all units being scraped for examples as a dependency of Doc units.
@@ -500,14 +517,13 @@ fn maybe_lib(
     unit: &Unit,
     state: &mut State<'_, '_>,
     unit_for: UnitFor,
-    force_mode: Option<CompileMode>,
 ) -> CargoResult<Option<UnitDep>> {
     unit.pkg
         .targets()
         .iter()
         .find(|t| t.is_linkable())
         .map(|t| {
-            let mode = force_mode.unwrap_or_else(|| check_or_build_mode(unit.mode, t));
+            let mode = check_or_build_mode(unit.mode, t);
             let dep_unit_for = unit_for.with_dependency(unit, t);
             new_unit_dep(
                 state,

tests/testsuite/doc.rs

@@ -2513,3 +2513,53 @@ fn lib_before_bin() {
     let bin_html = p.read_file("target/doc/somebin/index.html");
     assert!(bin_html.contains("../foo/fn.abc.html"));
 }
+
+#[cargo_test]
+fn doc_lib_false() {
+    // doc = false for a library
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+
+                [lib]
+                doc = false
+
+                [dependencies]
+                bar = {path = "bar"}
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .file("src/bin/some-bin.rs", "fn main() {}")
+        .file(
+            "bar/Cargo.toml",
+            r#"
+                [package]
+                name = "bar"
+                version = "0.1.0"
+
+                [lib]
+                doc = false
+            "#,
+        )
+        .file("bar/src/lib.rs", "")
+        .build();
+
+    p.cargo("doc")
+        .with_stderr(
+            "\
+[CHECKING] bar v0.1.0 [..]
+[CHECKING] foo v0.1.0 [..]
+[DOCUMENTING] foo v0.1.0 [..]
+[FINISHED] [..]
+",
+        )
+        .run();
+
+    assert!(!p.build_dir().join("doc/foo").exists());
+    assert!(!p.build_dir().join("doc/bar").exists());
+    assert!(p.build_dir().join("doc/some_bin").exists());
+}