Simplify doc meta mode

src/doc/rustdoc/src/unstable-features.md

@@ -206,17 +206,15 @@ This is very easy to use in scripts that manually invoke rustdoc, but it's also
 performs O(crates) work on every crate, meaning it performs O(crates<sup>2</sup>) work. When
 `--write-doc-meta-dir` and/or `--read-doc-meta-dir` are supplied, this is turned off.
 
-When `--write-doc-meta-dir` is supplied, rustdoc will write the crate's metadata to that directory.
-If this parameter is supplied but `--read-doc-meta-dir` isn't, it runs in *intermediate mode*:
-some pages may be written to the output dir, but there is a lot of functionality that won't work
-until rustdoc is run in *finalize mode*.
+When `--write-doc-meta-dir` is supplied, rustdoc will write the crate's shared metadata to
+that directory. This is an *intermediate mode* where it may write some files to the doc output
+directory, but some features won't work until it is finalized.
 
-When `--read-doc-meta-dir` is supplied, rustdoc runs in *finalize mode*. It will read the data from
-the supplied directory, and will write it to the doc output directory in the form that the web
-frontend will use.
+When `--read-doc-meta-dir` is supplied, it runs it in *finalize mode*. No crate source code is
+passed to rustdoc when it runs in this mode. Multiple `--read-doc-meta-dir` can be passed to
+rustdoc, so your build system can split the state between multiple directories if that helps.
 
-If both `--write-doc-meta-dir` and `--read-doc-meta-dir` are specified, the crate metadata will be
-written to both the HTML `--out-dir` and to the supplied `--write-doc-meta-dir`.
+Both `--write-doc-meta-dir` and `--read-doc-meta-dir` can't be supplied at once.
 
 ```console
 $ rustdoc crate1.rs --out-dir=doc
@@ -231,10 +229,13 @@ To delay shared-data merging until the end of a build, so that you only have to
 work, use `--write-doc-meta-dir` on every crate, and the last will use `--read-doc-meta-dir`.
 
 ```console
-$ rustdoc +nightly crate1.rs --write-doc-meta=crate1.d -Zunstable-options
+$ rustdoc +nightly crate1.rs --write-doc-meta-dir=crate1.d -Zunstable-options
 $ cat doc/search.index/crateNames/*
 cat: 'doc/search.index/crateNames/*': No such file or directory
-$ rustdoc +nightly crate2.rs --read-doc-meta=crate1.d -Zunstable-options
+$ rustdoc +nightly crate2.rs --write-doc-meta-dir=crate2.d -Zunstable-options
+$ cat doc/search.index/crateNames/*
+cat: 'doc/search.index/crateNames/*': No such file or directory
+$ rustdoc +nightly --read-doc-meta-dir=crate1.d --read-doc-meta-dir=crate2.d -Zunstable-options
 $ cat doc/search.index/crateNames/*
 rd_("fcrate1fcrate2")
 ```

src/librustdoc/html/render/write_shared.rs

@@ -111,28 +111,9 @@ pub(crate) fn write_shared(
             cx.shared.layout.css_file_extension.as_deref(),
             &cx.shared.resource_suffix,
             cx.info.include_sources,
+            &cx.shared.layout,
+            cx.shared.tcx,
         )?;
-        match &opt.index_page {
-            Some(index_page) if opt.enable_index_page => {
-                let mut md_opts = opt.clone();
-                md_opts.output = cx.dst.clone();
-                md_opts.external_html = cx.shared.layout.external_html.clone();
-                let file = try_err!(cx.sess().source_map().load_file(&index_page), &index_page);
-                try_err!(
-                    crate::markdown::render_and_write(file, md_opts, cx.shared.edition()),
-                    &index_page
-                );
-            }
-            None if opt.enable_index_page => {
-                write_rendered_cci::<CratesIndexPart, _>(
-                    || CratesIndexPart::blank(cx),
-                    &cx.dst,
-                    &crates,
-                    &opt.should_merge,
-                )?;
-            }
-            _ => {} // they don't want an index page
-        }
     }
 
     cx.shared.fs.set_sync_only(false);
@@ -150,9 +131,32 @@ pub(crate) fn write_not_crate_specific(
     css_file_extension: Option<&Path>,
     resource_suffix: &str,
     include_sources: bool,
+    layout: &layout::Layout,
+    tcx: TyCtxt<'_>,
 ) -> Result<(), Error> {
     write_rendered_cross_crate_info(crates, dst, opt, include_sources, resource_suffix)?;
     write_resources(dst, opt, style_files, css_file_extension, resource_suffix)?;
+    match &opt.index_page {
+        Some(index_page) if opt.enable_index_page => {
+            let mut md_opts = opt.clone();
+            md_opts.output = dst.to_path_buf();
+            md_opts.external_html = layout.external_html.clone();
+            let file = try_err!(tcx.sess.source_map().load_file(&index_page), &index_page);
+            try_err!(
+                crate::markdown::render_and_write(file, md_opts, tcx.sess.edition()),
+                &index_page
+            );
+        }
+        None if opt.enable_index_page => {
+            write_rendered_cci::<CratesIndexPart, _>(
+                || CratesIndexPart::blank(layout, opt, style_files),
+                &dst,
+                &crates,
+                &opt.should_merge,
+            )?;
+        }
+        _ => {} // they don't want an index page
+    }
     Ok(())
 }
 
@@ -399,19 +403,21 @@ impl CciPart for CratesIndexPart {
 }
 
 impl CratesIndexPart {
-    fn blank(cx: &Context<'_>) -> SortedTemplate<<Self as CciPart>::FileFormat> {
+    fn blank(
+        layout: &layout::Layout,
+        opt: &RenderOptions,
+        style_files: &[StylePath],
+    ) -> SortedTemplate<<Self as CciPart>::FileFormat> {
         let page = layout::Page {
             title: "Index of crates",
             short_title: "Crates",
             css_class: "mod sys",
             root_path: "./",
-            static_root_path: cx.shared.static_root_path.as_deref(),
+            static_root_path: opt.static_root_path.as_deref(),
             description: "List of crates",
-            resource_suffix: &cx.shared.resource_suffix,
+            resource_suffix: &opt.resource_suffix,
             rust_logo: true,
         };
-        let layout = &cx.shared.layout;
-        let style_files = &cx.shared.style_files;
         const DELIMITER: &str = "\u{FFFC}"; // users are being naughty if they have this
         let content = format_args!(
             "<div class=\"main-heading\">\

src/librustdoc/lib.rs

@@ -77,7 +77,7 @@ use rustc_errors::DiagCtxtHandle;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_interface::interface;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::config::{ErrorOutputType, RustcOptGroup, make_crate_type_option};
+use rustc_session::config::{ErrorOutputType, Input, RustcOptGroup, make_crate_type_option};
 use rustc_session::{EarlyDiagCtxt, getopts};
 use rustc_span::{BytePos, Span, SyntaxContext};
 use tracing::info;
@@ -772,7 +772,10 @@ fn run_renderer<
 /// Renders and writes cross-crate info files, like the search index. This function exists so that
 /// we can run rustdoc without a crate root in the `--merge=finalize` mode. Cross-crate info files
 /// discovered via `--read-doc-meta-dir` are combined and written to the doc root.
-fn run_merge_finalize(opt: config::RenderOptions) -> Result<(), error::Error> {
+fn run_merge_finalize(
+    opt: config::RenderOptions,
+    compiler: &interface::Compiler,
+) -> Result<(), error::Error> {
     assert!(
         opt.should_merge.write_rendered_cci,
         "config.rs only allows us to return InputMode::NoInputMergeFinalize if --merge=finalize"
@@ -783,16 +786,37 @@ fn run_merge_finalize(opt: config::RenderOptions) -> Result<(), error::Error> {
     );
     let crates = html::render::CrateInfo::read_many(&opt.include_parts_dir)?;
     let include_sources = !opt.html_no_source;
-    html::render::write_not_crate_specific(
-        &crates,
-        &opt.output,
-        &opt,
-        &opt.themes,
-        opt.extension_css.as_deref(),
-        &opt.resource_suffix,
-        include_sources,
-    )?;
-    Ok(())
+
+    let krate = ast::Crate {
+        attrs: Default::default(),
+        items: Default::default(),
+        spans: Default::default(),
+        id: ast::DUMMY_NODE_ID,
+        is_placeholder: false,
+    };
+    rustc_interface::create_and_enter_global_ctxt(compiler, krate, |tcx| {
+        html::render::write_not_crate_specific(
+            &crates,
+            &opt.output,
+            &opt,
+            &opt.themes,
+            opt.extension_css.as_deref(),
+            &opt.resource_suffix,
+            include_sources,
+            &crate::html::layout::Layout {
+                logo: String::new(),
+                favicon: String::new(),
+                external_html: opt.external_html.clone(),
+                default_settings: opt.default_settings.clone(),
+                krate: String::new(),
+                krate_version: String::new(),
+                css_file_extension: opt.extension_css.clone(),
+                scrape_examples_extension: false,
+            },
+            tcx,
+        )?;
+        Ok(())
+    })
 }
 
 fn main_args(early_dcx: &mut EarlyDiagCtxt, at_args: &[String]) {
@@ -834,10 +858,18 @@ fn main_args(early_dcx: &mut EarlyDiagCtxt, at_args: &[String]) {
     let input = match input {
         config::InputMode::HasFile(input) => input,
         config::InputMode::NoInputMergeFinalize => {
+            let config = core::create_config(
+                Input::Str {
+                    name: rustc_span::FileName::Custom(String::new()),
+                    input: String::new(),
+                },
+                options,
+                &render_options,
+            );
             return wrap_return(
                 dcx,
-                rustc_span::create_session_globals_then(options.edition, &[], None, || {
-                    run_merge_finalize(render_options)
+                interface::run_compiler(config, |compiler| {
+                    run_merge_finalize(render_options, compiler)
                         .map_err(|e| format!("could not write merged cross-crate info: {e}"))
                 }),
             );

tests/run-make/rustdoc-merge-cross-crate-info-cargo-transitive-read-write/rmake.rs

@@ -0,0 +1,59 @@
+//@ needs-target-std
+
+use run_make_support::{cwd, htmldocck, path, rust_lib_name, rustc, rustdoc};
+
+fn main() {
+    let merged_dir = path("merged");
+    let parts_out_dir = path("parts");
+    let lib_dir = path("lib");
+    let out_dir = path("out");
+
+    rustc().input("quebec.rs").crate_name("quebec").crate_type("rlib").run();
+    rustdoc()
+        .input("quebec.rs")
+        .crate_name("quebec")
+        .out_dir(&out_dir)
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir={}", parts_out_dir.display()))
+        .run();
+    assert!(parts_out_dir.join("quebec.json").exists());
+
+    rustc()
+        .input("tango.rs")
+        .crate_name("tango")
+        .crate_type("rlib")
+        .extern_("quebec", rust_lib_name("quebec"))
+        .run();
+    rustdoc()
+        .input("tango.rs")
+        .crate_name("tango")
+        .extern_("quebec", rust_lib_name("quebec"))
+        .out_dir(&out_dir)
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir={}", parts_out_dir.display()))
+        .run();
+    assert!(parts_out_dir.join("tango.json").exists());
+
+    rustdoc()
+        .input("sierra.rs")
+        .crate_name("sierra")
+        .extern_("tango", rust_lib_name("tango"))
+        .library_search_path(cwd())
+        .out_dir(&out_dir)
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir={}", parts_out_dir.display()))
+        .run();
+    assert!(parts_out_dir.join("sierra.json").exists());
+
+    let output = rustdoc()
+        .arg("-Zunstable-options")
+        .out_dir(&out_dir)
+        .arg(format!("--read-doc-meta-dir={}", parts_out_dir.display()))
+        .arg("--enable-index-page")
+        .run();
+    output.assert_stderr_not_contains("error: the compiler unexpectedly panicked. this is a bug.");
+
+    htmldocck().arg(&out_dir).arg("tango.rs").run();
+    htmldocck().arg(&out_dir).arg("quebec.rs").run();
+    htmldocck().arg(&out_dir).arg("sierra.rs").run();
+}

tests/run-make/rustdoc-merge-cross-crate-info-kitchen-sink-separate-dirs/rmake.rs

@@ -0,0 +1,99 @@
+//@ needs-target-std
+
+use run_make_support::{cwd, htmldocck, path, rust_lib_name, rustc, rustdoc};
+
+fn main() {
+    let merged_dir = path("merged");
+    let parts_out_dir = path("parts");
+    let lib_dir = path("lib");
+    let out_dir = path("out");
+
+    rustc().input("quebec.rs").crate_name("quebec").crate_type("rlib").run();
+    rustdoc()
+        .input("quebec.rs")
+        .crate_name("quebec")
+        .out_dir("quebec-out")
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir=info/doc.parts/quebec"))
+        .arg("--enable-index-page")
+        .run();
+
+    rustc()
+        .input("tango.rs")
+        .crate_name("tango")
+        .crate_type("rlib")
+        .extern_("quebec", rust_lib_name("quebec"))
+        .run();
+    rustdoc()
+        .input("tango.rs")
+        .crate_name("tango")
+        .extern_("quebec", rust_lib_name("quebec"))
+        .out_dir("tango-out")
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir=info/doc.parts/tango"))
+        .arg("--enable-index-page")
+        .run();
+
+    rustc()
+        .input("sierra.rs")
+        .crate_name("sierra")
+        .crate_type("rlib")
+        .extern_("tango", rust_lib_name("tango"))
+        .library_search_path(cwd())
+        .run();
+    rustdoc()
+        .input("sierra.rs")
+        .crate_name("sierra")
+        .extern_("tango", rust_lib_name("tango"))
+        .library_search_path(cwd())
+        .out_dir("sierra-out")
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir=info/doc.parts/sierra"))
+        .arg("--enable-index-page")
+        .run();
+
+    rustc()
+        .input("romeo.rs")
+        .crate_name("romeo")
+        .crate_type("rlib")
+        .extern_("sierra", rust_lib_name("sierra"))
+        .library_search_path(cwd())
+        .run();
+    rustdoc()
+        .input("romeo.rs")
+        .crate_name("romeo")
+        .extern_("sierra", rust_lib_name("sierra"))
+        .library_search_path(cwd())
+        .out_dir("romeo-out")
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir=info/doc.parts/romeo"))
+        .arg("--enable-index-page")
+        .run();
+
+    rustdoc()
+        .input("indigo.rs")
+        .crate_name("indigo")
+        .out_dir(&out_dir)
+        .arg("-Zunstable-options")
+        .arg(format!("--write-doc-meta-dir=info/doc.parts/indigo"))
+        .arg("--enable-index-page")
+        .run();
+
+    let output = rustdoc()
+        .arg("-Zunstable-options")
+        .out_dir(&out_dir)
+        .arg("--read-doc-meta-dir=info/doc.parts/tango")
+        .arg("--read-doc-meta-dir=info/doc.parts/romeo")
+        .arg("--read-doc-meta-dir=info/doc.parts/quebec")
+        .arg("--read-doc-meta-dir=info/doc.parts/sierra")
+        .arg("--read-doc-meta-dir=info/doc.parts/indigo")
+        .arg("--enable-index-page")
+        .run();
+    output.assert_stderr_not_contains("error: the compiler unexpectedly panicked. this is a bug.");
+
+    htmldocck().arg(&out_dir).arg("tango.rs").run();
+    htmldocck().arg(&out_dir).arg("quebec.rs").run();
+    htmldocck().arg(&out_dir).arg("sierra.rs").run();
+    htmldocck().arg(&out_dir).arg("indigo.rs").run();
+    htmldocck().arg(&out_dir).arg("romeo.rs").run();
+}