Auto merge of #129337 - EtomicBomb:rfc, r=notriddle

rustdoc rfc#3662 changes under unstable flags

* All new functionality is under unstable options
* Adds `--merge=shared|none|finalize` flags
* Adds `--parts-out-dir=<crate specific directory>` for `--merge=none`
to write cross-crate info file for a single crate
* Adds `--include-parts-dir=<previously specified directory>` for
`--merge=finalize` to write cross-crate info files
* `tests/rustdoc/` tests for the new flags

Author: bors

src/librustdoc/doctest.rs

@@ -19,7 +19,7 @@ use rustc_errors::{ColorConfig, DiagCtxtHandle, ErrorGuaranteed, FatalError};
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_hir::CRATE_HIR_ID;
 use rustc_interface::interface;
-use rustc_session::config::{self, CrateType, ErrorOutputType};
+use rustc_session::config::{self, CrateType, ErrorOutputType, Input};
 use rustc_session::lint;
 use rustc_span::edition::Edition;
 use rustc_span::symbol::sym;
@@ -88,7 +88,11 @@ fn get_doctest_dir() -> io::Result<TempDir> {
     TempFileBuilder::new().prefix("rustdoctest").tempdir()
 }
 
-pub(crate) fn run(dcx: DiagCtxtHandle<'_>, options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
+pub(crate) fn run(
+    dcx: DiagCtxtHandle<'_>,
+    input: Input,
+    options: RustdocOptions,
+) -> Result<(), ErrorGuaranteed> {
     let invalid_codeblock_attributes_name = crate::lint::INVALID_CODEBLOCK_ATTRIBUTES.name;
 
     // See core::create_config for what's going on here.
@@ -135,7 +139,7 @@ pub(crate) fn run(dcx: DiagCtxtHandle<'_>, options: RustdocOptions) -> Result<()
         opts: sessopts,
         crate_cfg: cfgs,
         crate_check_cfg: options.check_cfgs.clone(),
-        input: options.input.clone(),
+        input: input.clone(),
         output_file: None,
         output_dir: None,
         file_loader: None,

src/librustdoc/doctest/markdown.rs

@@ -3,6 +3,7 @@
 use std::fs::read_to_string;
 use std::sync::{Arc, Mutex};
 
+use rustc_session::config::Input;
 use rustc_span::FileName;
 use tempfile::tempdir;
 
@@ -69,17 +70,16 @@ impl DocTestVisitor for MdCollector {
 }
 
 /// Runs any tests/code examples in the markdown file `options.input`.
-pub(crate) fn test(options: Options) -> Result<(), String> {
-    use rustc_session::config::Input;
-    let input_str = match &options.input {
+pub(crate) fn test(input: &Input, options: Options) -> Result<(), String> {
+    let input_str = match input {
         Input::File(path) => {
             read_to_string(path).map_err(|err| format!("{}: {err}", path.display()))?
         }
         Input::Str { name: _, input } => input.clone(),
     };
 
     // Obviously not a real crate name, but close enough for purposes of doctests.
-    let crate_name = options.input.filestem().to_string();
+    let crate_name = input.filestem().to_string();
     let temp_dir =
         tempdir().map_err(|error| format!("failed to create temporary directory: {error:?}"))?;
     let args_file = temp_dir.path().join("rustdoc-cfgs");
@@ -96,8 +96,7 @@ pub(crate) fn test(options: Options) -> Result<(), String> {
     let mut md_collector = MdCollector {
         tests: vec![],
         cur_path: vec![],
-        filename: options
-            .input
+        filename: input
             .opt_path()
             .map(ToOwned::to_owned)
             .map(FileName::from)