Auto merge of #112025 - matthiaskrgr:rollup-j693v67, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #108630 (Fix docs for `alloc::realloc`)
 - #109084 (rustc driver: Remove argument 0 before at-expansion to prevent ICE)
 - #111181 (fix(parse): return unpected when current token is EOF)
 - #111656 (Use an unbounded lifetime in `String::leak`.)
 - #111946 (rustdoc: Add `ItemTemplate` trait and related functions to avoid repetitively wrapping existing functions)
 - #112018 (Clean up usage of `cx.tcx` when `tcx` is already set into a variable)

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

compiler/rustc_driver_impl/src/args.rs

@@ -18,6 +18,9 @@ fn arg_expand(arg: String) -> Result<Vec<String>, Error> {
     }
 }
 
+/// **Note:** This function doesn't interpret argument 0 in any special way.
+/// If this function is intended to be used with command line arguments,
+/// `argv[0]` must be removed prior to calling it manually.
 pub fn arg_expand_all(at_args: &[String]) -> Vec<String> {
     let mut args = Vec::new();
     for arg in at_args {

compiler/rustc_driver_impl/src/lib.rs

@@ -250,6 +250,16 @@ fn run_compiler(
         Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
     >,
 ) -> interface::Result<()> {
+    // Throw away the first argument, the name of the binary.
+    // In case of at_args being empty, as might be the case by
+    // passing empty argument array to execve under some platforms,
+    // just use an empty slice.
+    //
+    // This situation was possible before due to arg_expand_all being
+    // called before removing the argument, enabling a crash by calling
+    // the compiler with @empty_file as argv[0] and no more arguments.
+    let at_args = at_args.get(1..).unwrap_or_default();
+
     let args = args::arg_expand_all(at_args);
 
     let Some(matches) = handle_options(&args) else { return Ok(()) };
@@ -1074,9 +1084,6 @@ fn print_flag_list<T>(
 /// So with all that in mind, the comments below have some more detail about the
 /// contortions done here to get things to work out correctly.
 pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
-    // Throw away the first argument, the name of the binary
-    let args = &args[1..];
-
     if args.is_empty() {
         // user did not write `-v` nor `-Z unstable-options`, so do not
         // include that extra information.

compiler/rustc_parse/src/parser/mod.rs

@@ -536,7 +536,9 @@ impl<'a> Parser<'a> {
         } else if inedible.contains(&self.token.kind) {
             // leave it in the input
             Ok(false)
-        } else if self.last_unexpected_token_span == Some(self.token.span) {
+        } else if self.token.kind != token::Eof
+            && self.last_unexpected_token_span == Some(self.token.span)
+        {
             FatalError.raise();
         } else {
             self.expected_one_of_not_found(edible, inedible)

library/alloc/src/string.rs

@@ -1851,7 +1851,7 @@ impl String {
     }
 
     /// Consumes and leaks the `String`, returning a mutable reference to the contents,
-    /// `&'static mut str`.
+    /// `&'a mut str`.
     ///
     /// This is mainly useful for data that lives for the remainder of
     /// the program's life. Dropping the returned reference will cause a memory
@@ -1874,7 +1874,7 @@ impl String {
     /// ```
     #[unstable(feature = "string_leak", issue = "102929")]
     #[inline]
-    pub fn leak(self) -> &'static mut str {
+    pub fn leak<'a>(self) -> &'a mut str {
         let slice = self.vec.leak();
         unsafe { from_utf8_unchecked_mut(slice) }
     }

library/core/src/alloc/global.rs

@@ -235,7 +235,8 @@ pub unsafe trait GlobalAlloc {
     /// * `new_size` must be greater than zero.
     ///
     /// * `new_size`, when rounded up to the nearest multiple of `layout.align()`,
-    ///   must not overflow (i.e., the rounded value must be less than `usize::MAX`).
+    ///   must not overflow isize (i.e., the rounded value must be less than or
+    ///   equal to `isize::MAX`).
     ///
     /// (Extension subtraits might provide more specific bounds on
     /// behavior, e.g., guarantee a sentinel address or a null pointer

src/librustdoc/clean/inline.rs

@@ -355,9 +355,9 @@ pub(crate) fn build_impl(
         return;
     }
 
-    let _prof_timer = cx.tcx.sess.prof.generic_activity("build_impl");
-
     let tcx = cx.tcx;
+    let _prof_timer = tcx.sess.prof.generic_activity("build_impl");
+
     let associated_trait = tcx.impl_trait_ref(did).map(ty::EarlyBinder::skip_binder);
 
     // Only inline impl if the implemented trait is

src/librustdoc/clean/utils.rs

@@ -193,7 +193,7 @@ pub(crate) fn build_deref_target_impls(
         };
 
         if let Some(prim) = target.primitive_type() {
-            let _prof_timer = cx.tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
+            let _prof_timer = tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
             for did in prim.impls(tcx).filter(|did| !did.is_local()) {
                 inline::build_impl(cx, did, None, ret);
             }

src/librustdoc/config.rs

@@ -314,7 +314,6 @@ impl Options {
         matches: &getopts::Matches,
         args: Vec<String>,
     ) -> Result<(Options, RenderOptions), i32> {
-        let args = &args[1..];
         // Check for unstable options.
         nightly_options::check_nightly_options(matches, &opts());
 

src/librustdoc/formats/cache.rs

@@ -147,7 +147,7 @@ impl Cache {
 
         // Cache where all our extern crates are located
         // FIXME: this part is specific to HTML so it'd be nice to remove it from the common code
-        for &crate_num in cx.tcx.crates(()) {
+        for &crate_num in tcx.crates(()) {
             let e = ExternalCrate { crate_num };
 
             let name = e.name(tcx);

src/librustdoc/html/render/print_item.rs

@@ -9,6 +9,8 @@ use rustc_middle::middle::stability;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Symbol};
+use std::borrow::Borrow;
+use std::cell::{RefCell, RefMut};
 use std::cmp::Ordering;
 use std::fmt;
 use std::rc::Rc;
@@ -216,6 +218,53 @@ fn toggle_close(mut w: impl fmt::Write) {
     w.write_str("</details>").unwrap();
 }
 
+trait ItemTemplate<'a, 'cx: 'a>: askama::Template + fmt::Display {
+    fn item_and_mut_cx(&self) -> (&'a clean::Item, RefMut<'_, &'a mut Context<'cx>>);
+}
+
+fn item_template_document<'a: 'b, 'b, 'cx: 'a>(
+    templ: &'b impl ItemTemplate<'a, 'cx>,
+) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+    display_fn(move |f| {
+        let (item, mut cx) = templ.item_and_mut_cx();
+        let v = document(*cx, item, None, HeadingOffset::H2);
+        write!(f, "{v}")
+    })
+}
+
+fn item_template_document_type_layout<'a: 'b, 'b, 'cx: 'a>(
+    templ: &'b impl ItemTemplate<'a, 'cx>,
+) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+    display_fn(move |f| {
+        let (item, cx) = templ.item_and_mut_cx();
+        let def_id = item.item_id.expect_def_id();
+        let v = document_type_layout(*cx, def_id);
+        write!(f, "{v}")
+    })
+}
+
+fn item_template_render_attributes_in_pre<'a: 'b, 'b, 'cx: 'a>(
+    templ: &'b impl ItemTemplate<'a, 'cx>,
+) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+    display_fn(move |f| {
+        let (item, cx) = templ.item_and_mut_cx();
+        let tcx = cx.tcx();
+        let v = render_attributes_in_pre(item, "", tcx);
+        write!(f, "{v}")
+    })
+}
+
+fn item_template_render_assoc_items<'a: 'b, 'b, 'cx: 'a>(
+    templ: &'b impl ItemTemplate<'a, 'cx>,
+) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
+    display_fn(move |f| {
+        let (item, mut cx) = templ.item_and_mut_cx();
+        let def_id = item.item_id.expect_def_id();
+        let v = render_assoc_items(*cx, item, def_id, AssocItemRender::All);
+        write!(f, "{v}")
+    })
+}
+
 fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items: &[clean::Item]) {
     write!(w, "{}", document(cx, item, None, HeadingOffset::H2));
 
@@ -356,18 +405,18 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
 
             clean::ImportItem(ref import) => {
                 let stab_tags = if let Some(import_def_id) = import.source.did {
-                    let ast_attrs = cx.tcx().get_attrs_unchecked(import_def_id);
+                    let ast_attrs = tcx.get_attrs_unchecked(import_def_id);
                     let import_attrs = Box::new(clean::Attributes::from_ast(ast_attrs));
 
                     // Just need an item with the correct def_id and attrs
                     let import_item = clean::Item {
                         item_id: import_def_id.into(),
                         attrs: import_attrs,
-                        cfg: ast_attrs.cfg(cx.tcx(), &cx.cache().hidden_cfg),
+                        cfg: ast_attrs.cfg(tcx, &cx.cache().hidden_cfg),
                         ..myitem.clone()
                     };
 
-                    let stab_tags = Some(extra_info_tags(&import_item, item, cx.tcx()).to_string());
+                    let stab_tags = Some(extra_info_tags(&import_item, item, tcx).to_string());
                     stab_tags
                 } else {
                     None
@@ -405,8 +454,7 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
 
                 let unsafety_flag = match *myitem.kind {
                     clean::FunctionItem(_) | clean::ForeignFunctionItem(_)
-                        if myitem.fn_header(cx.tcx()).unwrap().unsafety
-                            == hir::Unsafety::Unsafe =>
+                        if myitem.fn_header(tcx).unwrap().unsafety == hir::Unsafety::Unsafe =>
                     {
                         "<sup title=\"unsafe function\">⚠</sup>"
                     }
@@ -439,7 +487,7 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
                      {docs_before}{docs}{docs_after}",
                     name = myitem.name.unwrap(),
                     visibility_emoji = visibility_emoji,
-                    stab_tags = extra_info_tags(myitem, item, cx.tcx()),
+                    stab_tags = extra_info_tags(myitem, item, tcx),
                     class = myitem.type_(),
                     unsafety_flag = unsafety_flag,
                     href = item_path(myitem.type_(), myitem.name.unwrap().as_str()),
@@ -886,7 +934,7 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
             write_small_section_header(w, "foreign-impls", "Implementations on Foreign Types", "");
 
             for implementor in foreign {
-                let provided_methods = implementor.inner_impl().provided_trait_methods(cx.tcx());
+                let provided_methods = implementor.inner_impl().provided_trait_methods(tcx);
                 let assoc_link =
                     AssocItemLink::GotoSource(implementor.impl_item.item_id, &provided_methods);
                 render_impl(
@@ -919,7 +967,7 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
         }
         w.write_str("</div>");
 
-        if t.is_auto(cx.tcx()) {
+        if t.is_auto(tcx) {
             write_small_section_header(
                 w,
                 "synthetic-implementors",
@@ -948,7 +996,7 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
             "<div id=\"implementors-list\"></div>",
         );
 
-        if t.is_auto(cx.tcx()) {
+        if t.is_auto(tcx) {
             write_small_section_header(
                 w,
                 "synthetic-implementors",
@@ -1131,55 +1179,25 @@ fn item_union(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean:
     #[derive(Template)]
     #[template(path = "item_union.html")]
     struct ItemUnion<'a, 'cx> {
-        cx: std::cell::RefCell<&'a mut Context<'cx>>,
+        cx: RefCell<&'a mut Context<'cx>>,
         it: &'a clean::Item,
         s: &'a clean::Union,
     }
 
-    impl<'a, 'cx: 'a> ItemUnion<'a, 'cx> {
-        fn render_assoc_items<'b>(
-            &'b self,
-        ) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-            display_fn(move |f| {
-                let def_id = self.it.item_id.expect_def_id();
-                let mut cx = self.cx.borrow_mut();
-                let v = render_assoc_items(*cx, self.it, def_id, AssocItemRender::All);
-                write!(f, "{v}")
-            })
-        }
-        fn document_type_layout<'b>(
-            &'b self,
-        ) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-            display_fn(move |f| {
-                let def_id = self.it.item_id.expect_def_id();
-                let cx = self.cx.borrow_mut();
-                let v = document_type_layout(*cx, def_id);
-                write!(f, "{v}")
-            })
+    impl<'a, 'cx: 'a> ItemTemplate<'a, 'cx> for ItemUnion<'a, 'cx> {
+        fn item_and_mut_cx(&self) -> (&'a clean::Item, RefMut<'_, &'a mut Context<'cx>>) {
+            (self.it, self.cx.borrow_mut())
         }
+    }
+
+    impl<'a, 'cx: 'a> ItemUnion<'a, 'cx> {
         fn render_union<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
             display_fn(move |f| {
                 let cx = self.cx.borrow_mut();
                 let v = render_union(self.it, Some(&self.s.generics), &self.s.fields, *cx);
                 write!(f, "{v}")
             })
         }
-        fn render_attributes_in_pre<'b>(
-            &'b self,
-        ) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-            display_fn(move |f| {
-                let tcx = self.cx.borrow().tcx();
-                let v = render_attributes_in_pre(self.it, "", tcx);
-                write!(f, "{v}")
-            })
-        }
-        fn document<'b>(&'b self) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
-            display_fn(move |f| {
-                let mut cx = self.cx.borrow_mut();
-                let v = document(*cx, self.it, None, HeadingOffset::H2);
-                write!(f, "{v}")
-            })
-        }
         fn document_field<'b>(
             &'b self,
             field: &'a clean::Item,
@@ -1219,7 +1237,7 @@ fn item_union(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean:
         }
     }
 
-    ItemUnion { cx: std::cell::RefCell::new(cx), it, s }.render_into(w).unwrap();
+    ItemUnion { cx: RefCell::new(cx), it, s }.render_into(w).unwrap();
 }
 
 fn print_tuple_struct_fields<'a, 'cx: 'a>(

src/librustdoc/html/render/type_layout.rs

@@ -54,13 +54,13 @@ pub(crate) fn document_type_layout<'a, 'cx: 'a>(
                     } else if let Primitive::Int(i, _) = tag.primitive() {
                         i.size().bytes()
                     } else {
-                        span_bug!(cx.tcx().def_span(ty_def_id), "tag is neither niche nor int")
+                        span_bug!(tcx.def_span(ty_def_id), "tag is neither niche nor int")
                     };
                 variants
                     .iter_enumerated()
                     .map(|(variant_idx, variant_layout)| {
                         let Adt(adt, _) = type_layout.ty.kind() else {
-                            span_bug!(cx.tcx().def_span(ty_def_id), "not an adt")
+                            span_bug!(tcx.def_span(ty_def_id), "not an adt")
                         };
                         let name = adt.variant(variant_idx).name;
                         let is_unsized = variant_layout.abi.is_unsized();

src/librustdoc/html/templates/item_union.html

@@ -1,8 +1,8 @@
 <pre class="rust item-decl"><code>
-    {{ self.render_attributes_in_pre() | safe }}
+    {{ self::item_template_render_attributes_in_pre(self.borrow()) | safe }}
     {{ self.render_union() | safe }}
 </code></pre>
-{{ self.document() | safe }}
+{{ self::item_template_document(self.borrow()) | safe }}
 {% if self.fields_iter().peek().is_some() %}
     <h2 id="fields" class="fields small-section-header">
         Fields<a href="#fields" class="anchor">§</a>
@@ -19,5 +19,5 @@ <h2 id="fields" class="fields small-section-header">
         {{ self.document_field(field) | safe }}
     {% endfor %}
 {% endif %}
-{{ self.render_assoc_items() | safe }}
-{{ self.document_type_layout() | safe }}
+{{ self::item_template_render_assoc_items(self.borrow()) | safe }}
+{{ self::item_template_document_type_layout(self.borrow()) | safe }}

src/librustdoc/lib.rs

@@ -712,13 +712,23 @@ fn run_renderer<'tcx, T: formats::FormatRenderer<'tcx>>(
 }
 
 fn main_args(at_args: &[String]) -> MainResult {
+    // Throw away the first argument, the name of the binary.
+    // In case of at_args being empty, as might be the case by
+    // passing empty argument array to execve under some platforms,
+    // just use an empty slice.
+    //
+    // This situation was possible before due to arg_expand_all being
+    // called before removing the argument, enabling a crash by calling
+    // the compiler with @empty_file as argv[0] and no more arguments.
+    let at_args = at_args.get(1..).unwrap_or_default();
+
     let args = rustc_driver::args::arg_expand_all(at_args);
 
     let mut options = getopts::Options::new();
     for option in opts() {
         (option.apply)(&mut options);
     }
-    let matches = match options.parse(&args[1..]) {
+    let matches = match options.parse(&args) {
         Ok(m) => m,
         Err(err) => {
             early_error(ErrorOutputType::default(), err.to_string());

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -723,7 +723,7 @@ fn resolve_associated_trait_item<'a>(
         .iter()
         .flat_map(|&(impl_, trait_)| {
             filter_assoc_items_by_name_and_namespace(
-                cx.tcx,
+                tcx,
                 trait_,
                 Ident::with_dummy_span(item_name),
                 ns,
@@ -1743,7 +1743,7 @@ fn resolution_failure(
                             if let Ok(v_res) = collector.resolve(start, ns, item_id, module_id) {
                                 debug!("found partial_res={:?}", v_res);
                                 if !v_res.is_empty() {
-                                    *partial_res = Some(full_res(collector.cx.tcx, v_res[0]));
+                                    *partial_res = Some(full_res(tcx, v_res[0]));
                                     *unresolved = end.into();
                                     break 'outer;
                                 }