add option to include private items in library docs

Author: pietroalbini

config.toml.example

@@ -233,6 +233,9 @@ changelog-seen = 2
 # and generated in already-minified form from the beginning.
 #docs-minification = true
 
+# Flag to specify whether private items should be included in the library docs.
+#library-docs-private-items = false
+
 # Indicate whether the compiler should be documented in addition to the standard
 # library and facade crates.
 #compiler-docs = false

src/bootstrap/config.rs

@@ -65,6 +65,7 @@ pub struct Config {
     pub verbose: usize,
     pub submodules: Option<bool>,
     pub compiler_docs: bool,
+    pub library_docs_private_items: bool,
     pub docs_minification: bool,
     pub docs: bool,
     pub locked_deps: bool,
@@ -606,6 +607,7 @@ define_config! {
         rustfmt: Option<PathBuf> = "rustfmt",
         docs: Option<bool> = "docs",
         compiler_docs: Option<bool> = "compiler-docs",
+        library_docs_private_items: Option<bool> = "library-docs-private-items",
         docs_minification: Option<bool> = "docs-minification",
         submodules: Option<bool> = "submodules",
         gdb: Option<String> = "gdb",
@@ -1015,6 +1017,7 @@ impl Config {
         config.submodules = build.submodules;
         set(&mut config.low_priority, build.low_priority);
         set(&mut config.compiler_docs, build.compiler_docs);
+        set(&mut config.library_docs_private_items, build.library_docs_private_items);
         set(&mut config.docs_minification, build.docs_minification);
         set(&mut config.docs, build.docs);
         set(&mut config.locked_deps, build.locked_deps);

src/bootstrap/doc.rs

@@ -597,6 +597,9 @@ fn doc_std(
             .arg("--resource-suffix")
             .arg(&builder.version)
             .args(extra_args);
+        if builder.config.library_docs_private_items {
+            cargo.arg("--document-private-items");
+        }
         builder.run(&mut cargo.into());
     };