Auto merge of rust-lang#130100 - matthiaskrgr:rollup-nk36g91, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#129337 (rustdoc rfc#3662 changes under unstable flags)
 - rust-lang#129473 (use  `download-ci-llvm=true` in the default compiler config)
 - rust-lang#129529 (Add test to build crates used by r-a on stable)
 - rust-lang#130025 (Also emit `missing_docs` lint with `--test` to fulfil expectations)
 - rust-lang#130070 (Rename variant `AddrOfRegion` of `RegionVariableOrigin` to `BorrowRegion`)
 - rust-lang#130087 (remove 'const' from 'Option::iter')
 - rust-lang#130092 (Fixes typo in wasm32-wasip2 doc comment)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: compiler/rustc_hir_typeck/src/expr.rs

@@ -447,7 +447,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // this time with enough precision to check that the value
                 // whose address was taken can actually be made to live as long
                 // as it needs to live.
-                let region = self.next_region_var(infer::AddrOfRegion(expr.span));
+                let region = self.next_region_var(infer::BorrowRegion(expr.span));
                 Ty::new_ref(self.tcx, region, ty, mutbl)
             }
         }

Diff for: compiler/rustc_infer/src/infer/mod.rs

@@ -458,8 +458,8 @@ pub enum RegionVariableOrigin {
     PatternRegion(Span),
 
     /// Regions created by `&` operator.
-    ///
-    AddrOfRegion(Span),
+    BorrowRegion(Span),
+
     /// Regions created as part of an autoref of a method receiver.
     Autoref(Span),
 
@@ -1741,7 +1741,7 @@ impl RegionVariableOrigin {
         match *self {
             MiscVariable(a)
             | PatternRegion(a)
-            | AddrOfRegion(a)
+            | BorrowRegion(a)
             | Autoref(a)
             | Coercion(a)
             | RegionParameterDefinition(a, ..)

Diff for: compiler/rustc_lint/src/builtin.rs

@@ -426,12 +426,6 @@ impl MissingDoc {
         article: &'static str,
         desc: &'static str,
     ) {
-        // If we're building a test harness, then warning about
-        // documentation is probably not really relevant right now.
-        if cx.sess().opts.test {
-            return;
-        }
-
         // Only check publicly-visible items, using the result from the privacy pass.
         // It's an option so the crate root can also use this function (it doesn't
         // have a `NodeId`).
@@ -444,11 +438,10 @@ impl MissingDoc {
         let attrs = cx.tcx.hir().attrs(cx.tcx.local_def_id_to_hir_id(def_id));
         let has_doc = attrs.iter().any(has_doc);
         if !has_doc {
-            cx.emit_span_lint(
-                MISSING_DOCS,
-                cx.tcx.def_span(def_id),
-                BuiltinMissingDoc { article, desc },
-            );
+            let sp = cx.tcx.def_span(def_id);
+            if !sp.is_dummy() {
+                cx.emit_span_lint(MISSING_DOCS, sp, BuiltinMissingDoc { article, desc });
+            }
         }
     }
 }

Diff for: compiler/rustc_target/src/spec/targets/wasm32_wasip2.rs

@@ -1,6 +1,6 @@
 //! The `wasm32-wasip2` target is the next evolution of the
 //! wasm32-wasi target. While the wasi specification is still under
-//! active development, the {review 2 iteration is considered an "island
+//! active development, the preview 2 iteration is considered an "island
 //! of stability" that should allow users to rely on it indefinitely.
 //!
 //! The `wasi` target is a proposal to define a standardized set of WebAssembly

Diff for: compiler/rustc_trait_selection/src/error_reporting/infer/region.rs

@@ -1018,7 +1018,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         let var_description = match var_origin {
             infer::MiscVariable(_) => String::new(),
             infer::PatternRegion(_) => " for pattern".to_string(),
-            infer::AddrOfRegion(_) => " for borrow expression".to_string(),
+            infer::BorrowRegion(_) => " for borrow expression".to_string(),
             infer::Autoref(_) => " for autoref".to_string(),
             infer::Coercion(_) => " for automatic coercion".to_string(),
             infer::BoundRegion(_, br, infer::FnCall) => {

Diff for: compiler/rustc_type_ir/src/elaborate.rs

@@ -237,7 +237,7 @@ pub fn supertrait_def_ids<I: Interner>(
     cx: I,
     trait_def_id: I::DefId,
 ) -> impl Iterator<Item = I::DefId> {
-    let mut set: HashSet<I::DefId> = HashSet::default();
+    let mut set = HashSet::default();
     let mut stack = vec![trait_def_id];
 
     set.insert(trait_def_id);

Diff for: config.example.toml

@@ -42,6 +42,9 @@
 # Unless you're developing for a target where Rust CI doesn't build a compiler
 # toolchain or changing LLVM locally, you probably want to leave this enabled.
 #
+# Set this to `true` to download if CI llvm available otherwise it builds
+# from `src/llvm-project`.
+#
 # Set this to `"if-unchanged"` to download only if the llvm-project has not
 # been modified. You can also use this if you are unsure whether you're on a
 # tier 1 target. All tier 1 targets are currently supported.
@@ -236,7 +239,7 @@
 # Instead of downloading the src/stage0 version of cargo-clippy specified,
 # use this cargo-clippy binary instead as the stage0 snapshot cargo-clippy.
 #
-# Note that this option should be used with the same toolchain as the `rustc` option above. 
+# Note that this option should be used with the same toolchain as the `rustc` option above.
 # Otherwise, clippy is likely to fail due to a toolchain conflict.
 #cargo-clippy = "/path/to/cargo-clippy"
 

Diff for: library/alloc/src/slice.rs

@@ -96,6 +96,7 @@ pub(crate) mod hack {
     // We shouldn't add inline attribute to this since this is used in
     // `vec!` macro mostly and causes perf regression. See #71204 for
     // discussion and perf results.
+    #[allow(missing_docs)]
     pub fn into_vec<T, A: Allocator>(b: Box<[T], A>) -> Vec<T, A> {
         unsafe {
             let len = b.len();
@@ -105,6 +106,7 @@ pub(crate) mod hack {
     }
 
     #[cfg(not(no_global_oom_handling))]
+    #[allow(missing_docs)]
     #[inline]
     pub fn to_vec<T: ConvertVec, A: Allocator>(s: &[T], alloc: A) -> Vec<T, A> {
         T::to_vec(s, alloc)

Diff for: library/alloc/src/string.rs

@@ -508,6 +508,7 @@ impl String {
     // NB see the slice::hack module in slice.rs for more information
     #[inline]
     #[cfg(test)]
+    #[allow(missing_docs)]
     pub fn from_str(_: &str) -> String {
         panic!("not available with cfg(test)");
     }

Diff for: library/core/src/option.rs

@@ -1338,9 +1338,8 @@ impl<T> Option<T> {
     /// assert_eq!(x.iter().next(), None);
     /// ```
     #[inline]
-    #[rustc_const_unstable(feature = "const_option", issue = "67441")]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub const fn iter(&self) -> Iter<'_, T> {
+    pub fn iter(&self) -> Iter<'_, T> {
         Iter { inner: Item { opt: self.as_ref() } }
     }
 

Diff for: library/std/src/io/buffered/bufreader.rs

@@ -267,6 +267,7 @@ impl<R: ?Sized> BufReader<R> {
 // This is only used by a test which asserts that the initialization-tracking is correct.
 #[cfg(test)]
 impl<R: ?Sized> BufReader<R> {
+    #[allow(missing_docs)]
     pub fn initialized(&self) -> usize {
         self.buf.initialized()
     }

Diff for: src/bootstrap/defaults/config.compiler.toml

@@ -27,4 +27,5 @@ assertions = false
 # Enable warnings during the LLVM compilation (when LLVM is changed, causing a compilation)
 enable-warnings = true
 # Will download LLVM from CI if available on your platform.
-download-ci-llvm = "if-unchanged"
+# If you intend to modify `src/llvm-project`, use `"if-unchanged"` or `false` instead.
+download-ci-llvm = true

Diff for: src/bootstrap/src/core/config/config.rs

@@ -2781,7 +2781,8 @@ impl Config {
                     );
                 }
 
-                b
+                // If download-ci-llvm=true we also want to check that CI llvm is available
+                b && llvm::is_ci_llvm_available(self, asserts)
             }
             Some(StringOrBool::String(s)) if s == "if-unchanged" => if_unchanged(),
             Some(StringOrBool::String(other)) => {

Diff for: src/bootstrap/src/utils/change_tracker.rs

@@ -250,4 +250,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Info,
         summary: "New option `llvm.enzyme` to control whether the llvm based autodiff tool (Enzyme) is built.",
     },
+    ChangeInfo {
+        change_id: 129473,
+        severity: ChangeSeverity::Warning,
+        summary: "`download-ci-llvm = true` now checks if CI llvm is available and has become the default for the compiler profile",
+    },
 ];

Diff for: src/librustdoc/config.rs

@@ -53,12 +53,18 @@ impl TryFrom<&str> for OutputFormat {
     }
 }
 
+/// Either an input crate, markdown file, or nothing (--merge=finalize).
+pub(crate) enum InputMode {
+    /// The `--merge=finalize` step does not need an input crate to rustdoc.
+    NoInputMergeFinalize,
+    /// A crate or markdown file.
+    HasFile(Input),
+}
+
 /// Configuration options for rustdoc.
 #[derive(Clone)]
 pub(crate) struct Options {
     // Basic options / Options passed directly to rustc
-    /// The crate root or Markdown file to load.
-    pub(crate) input: Input,
     /// The name of the crate being documented.
     pub(crate) crate_name: Option<String>,
     /// Whether or not this is a bin crate
@@ -179,7 +185,6 @@ impl fmt::Debug for Options {
         }
 
         f.debug_struct("Options")
-            .field("input", &self.input.source_name())
             .field("crate_name", &self.crate_name)
             .field("bin_crate", &self.bin_crate)
             .field("proc_macro_crate", &self.proc_macro_crate)
@@ -289,6 +294,12 @@ pub(crate) struct RenderOptions {
     /// This field is only used for the JSON output. If it's set to true, no file will be created
     /// and content will be displayed in stdout directly.
     pub(crate) output_to_stdout: bool,
+    /// Whether we should read or write rendered cross-crate info in the doc root.
+    pub(crate) should_merge: ShouldMerge,
+    /// Path to crate-info for external crates.
+    pub(crate) include_parts_dir: Vec<PathToParts>,
+    /// Where to write crate-info
+    pub(crate) parts_out_dir: Option<PathToParts>,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
@@ -348,7 +359,7 @@ impl Options {
         early_dcx: &mut EarlyDiagCtxt,
         matches: &getopts::Matches,
         args: Vec<String>,
-    ) -> Option<(Options, RenderOptions)> {
+    ) -> Option<(InputMode, Options, RenderOptions)> {
         // Check for unstable options.
         nightly_options::check_nightly_options(early_dcx, matches, &opts());
 
@@ -478,22 +489,34 @@ impl Options {
         let (lint_opts, describe_lints, lint_cap) = get_cmd_lint_options(early_dcx, matches);
 
         let input = if describe_lints {
-            "" // dummy, this won't be used
+            InputMode::HasFile(make_input(early_dcx, ""))
         } else {
             match matches.free.as_slice() {
+                [] if matches.opt_str("merge").as_deref() == Some("finalize") => {
+                    InputMode::NoInputMergeFinalize
+                }
                 [] => dcx.fatal("missing file operand"),
-                [input] => input,
+                [input] => InputMode::HasFile(make_input(early_dcx, input)),
                 _ => dcx.fatal("too many file operands"),
             }
         };
-        let input = make_input(early_dcx, input);
 
         let externs = parse_externs(early_dcx, matches, &unstable_opts);
         let extern_html_root_urls = match parse_extern_html_roots(matches) {
             Ok(ex) => ex,
             Err(err) => dcx.fatal(err),
         };
 
+        let parts_out_dir =
+            match matches.opt_str("parts-out-dir").map(|p| PathToParts::from_flag(p)).transpose() {
+                Ok(parts_out_dir) => parts_out_dir,
+                Err(e) => dcx.fatal(e),
+            };
+        let include_parts_dir = match parse_include_parts_dir(matches) {
+            Ok(include_parts_dir) => include_parts_dir,
+            Err(e) => dcx.fatal(e),
+        };
+
         let default_settings: Vec<Vec<(String, String)>> = vec![
             matches
                 .opt_str("default-theme")
@@ -735,6 +758,10 @@ impl Options {
         let extern_html_root_takes_precedence =
             matches.opt_present("extern-html-root-takes-precedence");
         let html_no_source = matches.opt_present("html-no-source");
+        let should_merge = match parse_merge(matches) {
+            Ok(result) => result,
+            Err(e) => dcx.fatal(format!("--merge option error: {e}")),
+        };
 
         if generate_link_to_definition && (show_coverage || output_format != OutputFormat::Html) {
             dcx.struct_warn(
@@ -751,7 +778,6 @@ impl Options {
         let unstable_features =
             rustc_feature::UnstableFeatures::from_environment(crate_name.as_deref());
         let options = Options {
-            input,
             bin_crate,
             proc_macro_crate,
             error_format,
@@ -823,16 +849,17 @@ impl Options {
             no_emit_shared: false,
             html_no_source,
             output_to_stdout,
+            should_merge,
+            include_parts_dir,
+            parts_out_dir,
         };
-        Some((options, render_options))
+        Some((input, options, render_options))
     }
+}
 
-    /// Returns `true` if the file given as `self.input` is a Markdown file.
-    pub(crate) fn markdown_input(&self) -> Option<&Path> {
-        self.input
-            .opt_path()
-            .filter(|p| matches!(p.extension(), Some(e) if e == "md" || e == "markdown"))
-    }
+/// Returns `true` if the file given as `self.input` is a Markdown file.
+pub(crate) fn markdown_input(input: &Input) -> Option<&Path> {
+    input.opt_path().filter(|p| matches!(p.extension(), Some(e) if e == "md" || e == "markdown"))
 }
 
 fn parse_remap_path_prefix(
@@ -900,3 +927,71 @@ fn parse_extern_html_roots(
     }
     Ok(externs)
 }
+
+/// Path directly to crate-info file.
+///
+/// For example, `/home/user/project/target/doc.parts/<crate>/crate-info`.
+#[derive(Clone, Debug)]
+pub(crate) struct PathToParts(pub(crate) PathBuf);
+
+impl PathToParts {
+    fn from_flag(path: String) -> Result<PathToParts, String> {
+        let mut path = PathBuf::from(path);
+        // check here is for diagnostics
+        if path.exists() && !path.is_dir() {
+            Err(format!(
+                "--parts-out-dir and --include-parts-dir expect directories, found: {}",
+                path.display(),
+            ))
+        } else {
+            // if it doesn't exist, we'll create it. worry about that in write_shared
+            path.push("crate-info");
+            Ok(PathToParts(path))
+        }
+    }
+}
+
+/// Reports error if --include-parts-dir / crate-info is not a file
+fn parse_include_parts_dir(m: &getopts::Matches) -> Result<Vec<PathToParts>, String> {
+    let mut ret = Vec::new();
+    for p in m.opt_strs("include-parts-dir") {
+        let p = PathToParts::from_flag(p)?;
+        // this is just for diagnostic
+        if !p.0.is_file() {
+            return Err(format!("--include-parts-dir expected {} to be a file", p.0.display()));
+        }
+        ret.push(p);
+    }
+    Ok(ret)
+}
+
+/// Controls merging of cross-crate information
+#[derive(Debug, Clone)]
+pub(crate) struct ShouldMerge {
+    /// Should we append to existing cci in the doc root
+    pub(crate) read_rendered_cci: bool,
+    /// Should we write cci to the doc root
+    pub(crate) write_rendered_cci: bool,
+}
+
+/// Extracts read_rendered_cci and write_rendered_cci from command line arguments, or
+/// reports an error if an invalid option was provided
+fn parse_merge(m: &getopts::Matches) -> Result<ShouldMerge, &'static str> {
+    match m.opt_str("merge").as_deref() {
+        // default = read-write
+        None => Ok(ShouldMerge { read_rendered_cci: true, write_rendered_cci: true }),
+        Some("none") if m.opt_present("include-parts-dir") => {
+            Err("--include-parts-dir not allowed if --merge=none")
+        }
+        Some("none") => Ok(ShouldMerge { read_rendered_cci: false, write_rendered_cci: false }),
+        Some("shared") if m.opt_present("parts-out-dir") || m.opt_present("include-parts-dir") => {
+            Err("--parts-out-dir and --include-parts-dir not allowed if --merge=shared")
+        }
+        Some("shared") => Ok(ShouldMerge { read_rendered_cci: true, write_rendered_cci: true }),
+        Some("finalize") if m.opt_present("parts-out-dir") => {
+            Err("--parts-out-dir not allowed if --merge=finalize")
+        }
+        Some("finalize") => Ok(ShouldMerge { read_rendered_cci: false, write_rendered_cci: true }),
+        Some(_) => Err("argument to --merge must be `none`, `shared`, or `finalize`"),
+    }
+}

Diff for: src/librustdoc/core.rs

@@ -20,7 +20,7 @@ use rustc_interface::interface;
 use rustc_lint::{late_lint_mod, MissingDoc};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
-use rustc_session::config::{self, CrateType, ErrorOutputType, ResolveDocLinks};
+use rustc_session::config::{self, CrateType, ErrorOutputType, Input, ResolveDocLinks};
 pub(crate) use rustc_session::config::{Options, UnstableOptions};
 use rustc_session::{lint, Session};
 use rustc_span::symbol::sym;
@@ -177,8 +177,8 @@ pub(crate) fn new_dcx(
 
 /// Parse, resolve, and typecheck the given crate.
 pub(crate) fn create_config(
+    input: Input,
     RustdocOptions {
-        input,
         crate_name,
         proc_macro_crate,
         error_format,