Rollup of 10 pull requests

compiler/rustc_attr_parsing/src/attributes/stability.rs

@@ -54,6 +54,7 @@ const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
     Allow(Target::Static),
     Allow(Target::ForeignFn),
     Allow(Target::ForeignStatic),
+    Allow(Target::ExternCrate),
 ]);
 
 #[derive(Default)]

compiler/rustc_builtin_macros/src/deriving/from.rs

@@ -27,21 +27,39 @@ pub(crate) fn expand_deriving_from(
         cx.dcx().bug("derive(From) used on something else than an item");
     };
 
-    // #[derive(From)] is currently usable only on structs with exactly one field.
-    let field = if let ItemKind::Struct(_, _, data) = &item.kind
-        && let [field] = data.fields()
-    {
-        Some(field.clone())
-    } else {
-        None
+    let err_span = || {
+        let item_span = item.kind.ident().map(|ident| ident.span).unwrap_or(item.span);
+        MultiSpan::from_spans(vec![span, item_span])
     };
 
-    let from_type = match &field {
-        Some(field) => Ty::AstTy(field.ty.clone()),
-        // We don't have a type to put into From<...> if we don't have a single field, so just put
-        // unit there.
-        None => Ty::Unit,
+    // `#[derive(From)]` is currently usable only on structs with exactly one field.
+    let field = match &item.kind {
+        ItemKind::Struct(_, _, data) => {
+            if let [field] = data.fields() {
+                Ok(field.clone())
+            } else {
+                let guar = cx.dcx().emit_err(errors::DeriveFromWrongFieldCount {
+                    span: err_span(),
+                    multiple_fields: data.fields().len() > 1,
+                });
+                Err(guar)
+            }
+        }
+        ItemKind::Enum(_, _, _) | ItemKind::Union(_, _, _) => {
+            let guar = cx.dcx().emit_err(errors::DeriveFromWrongTarget {
+                span: err_span(),
+                kind: &format!("{} {}", item.kind.article(), item.kind.descr()),
+            });
+            Err(guar)
+        }
+        _ => cx.dcx().bug("Invalid derive(From) ADT input"),
     };
+
+    let from_type = Ty::AstTy(match field {
+        Ok(ref field) => field.ty.clone(),
+        Err(guar) => cx.ty(span, ast::TyKind::Err(guar)),
+    });
+
     let path =
         Path::new_(pathvec_std!(convert::From), vec![Box::new(from_type.clone())], PathKind::Std);
 
@@ -71,34 +89,17 @@ pub(crate) fn expand_deriving_from(
             attributes: thin_vec![cx.attr_word(sym::inline, span)],
             fieldless_variants_strategy: FieldlessVariantsStrategy::Default,
             combine_substructure: combine_substructure(Box::new(|cx, span, substructure| {
-                let Some(field) = &field else {
-                    let item_span = item.kind.ident().map(|ident| ident.span).unwrap_or(item.span);
-                    let err_span = MultiSpan::from_spans(vec![span, item_span]);
-                    let error = match &item.kind {
-                        ItemKind::Struct(_, _, data) => {
-                            cx.dcx().emit_err(errors::DeriveFromWrongFieldCount {
-                                span: err_span,
-                                multiple_fields: data.fields().len() > 1,
-                            })
-                        }
-                        ItemKind::Enum(_, _, _) | ItemKind::Union(_, _, _) => {
-                            cx.dcx().emit_err(errors::DeriveFromWrongTarget {
-                                span: err_span,
-                                kind: &format!("{} {}", item.kind.article(), item.kind.descr()),
-                            })
-                        }
-                        _ => cx.dcx().bug("Invalid derive(From) ADT input"),
-                    };
-
-                    return BlockOrExpr::new_expr(DummyResult::raw_expr(span, Some(error)));
+                let field = match field {
+                    Ok(ref field) => field,
+                    Err(guar) => {
+                        return BlockOrExpr::new_expr(DummyResult::raw_expr(span, Some(guar)));
+                    }
                 };
 
                 let self_kw = Ident::new(kw::SelfUpper, span);
                 let expr: Box<ast::Expr> = match substructure.fields {
                     SubstructureFields::StaticStruct(variant, _) => match variant {
-                        // Self {
-                        //     field: value
-                        // }
+                        // Self { field: value }
                         VariantData::Struct { .. } => cx.expr_struct_ident(
                             span,
                             self_kw,

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -2435,6 +2435,13 @@ fn linker_with_args(
     // Passed after compiler-generated options to support manual overriding when necessary.
     add_user_defined_link_args(cmd, sess);
 
+    // ------------ Builtin configurable linker scripts ------------
+    // The user's link args should be able to overwrite symbols in the compiler's
+    // linker script that were weakly defined (i.e. defined with `PROVIDE()`). For this
+    // to work correctly, the user needs to be able to specify linker arguments like
+    // `--defsym` and `--script` *before* any builtin linker scripts are evaluated.
+    add_link_script(cmd, sess, tmpdir, crate_type);
+
     // ------------ Object code and libraries, order-dependent ------------
 
     // Post-link CRT objects.
@@ -2469,8 +2476,6 @@ fn add_order_independent_options(
 
     let apple_sdk_root = add_apple_sdk(cmd, sess, flavor);
 
-    add_link_script(cmd, sess, tmpdir, crate_type);
-
     if sess.target.os == "fuchsia"
         && crate_type == CrateType::Executable
         && !matches!(flavor, LinkerFlavor::Gnu(Cc::Yes, _))

compiler/rustc_parse/src/lexer/mod.rs

@@ -49,14 +49,15 @@ pub(crate) fn lex_token_trees<'psess, 'src>(
     mut src: &'src str,
     mut start_pos: BytePos,
     override_span: Option<Span>,
+    frontmatter_allowed: FrontmatterAllowed,
 ) -> Result<TokenStream, Vec<Diag<'psess>>> {
     // Skip `#!`, if present.
     if let Some(shebang_len) = rustc_lexer::strip_shebang(src) {
         src = &src[shebang_len..];
         start_pos = start_pos + BytePos::from_usize(shebang_len);
     }
 
-    let cursor = Cursor::new(src, FrontmatterAllowed::Yes);
+    let cursor = Cursor::new(src, frontmatter_allowed);
     let mut lexer = Lexer {
         psess,
         start_pos,

compiler/rustc_parse/src/lib.rs

@@ -20,6 +20,7 @@ use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::{AttrItem, Attribute, MetaItemInner, token};
 use rustc_ast_pretty::pprust;
 use rustc_errors::{Diag, EmissionGuarantee, FatalError, PResult, pluralize};
+use rustc_lexer::FrontmatterAllowed;
 use rustc_session::parse::ParseSess;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{FileName, SourceFile, Span};
@@ -146,7 +147,7 @@ fn new_parser_from_source_file(
     source_file: Arc<SourceFile>,
 ) -> Result<Parser<'_>, Vec<Diag<'_>>> {
     let end_pos = source_file.end_position();
-    let stream = source_file_to_stream(psess, source_file, None)?;
+    let stream = source_file_to_stream(psess, source_file, None, FrontmatterAllowed::Yes)?;
     let mut parser = Parser::new(psess, stream, None);
     if parser.token == token::Eof {
         parser.token.span = Span::new(end_pos, end_pos, parser.token.span.ctxt(), None);
@@ -161,7 +162,9 @@ pub fn source_str_to_stream(
     override_span: Option<Span>,
 ) -> Result<TokenStream, Vec<Diag<'_>>> {
     let source_file = psess.source_map().new_source_file(name, source);
-    source_file_to_stream(psess, source_file, override_span)
+    // used mainly for `proc_macro` and the likes, not for our parsing purposes, so don't parse
+    // frontmatters as frontmatters.
+    source_file_to_stream(psess, source_file, override_span, FrontmatterAllowed::No)
 }
 
 /// Given a source file, produces a sequence of token trees. Returns any buffered errors from
@@ -170,6 +173,7 @@ fn source_file_to_stream<'psess>(
     psess: &'psess ParseSess,
     source_file: Arc<SourceFile>,
     override_span: Option<Span>,
+    frontmatter_allowed: FrontmatterAllowed,
 ) -> Result<TokenStream, Vec<Diag<'psess>>> {
     let src = source_file.src.as_ref().unwrap_or_else(|| {
         psess.dcx().bug(format!(
@@ -178,7 +182,13 @@ fn source_file_to_stream<'psess>(
         ));
     });
 
-    lexer::lex_token_trees(psess, src.as_str(), source_file.start_pos, override_span)
+    lexer::lex_token_trees(
+        psess,
+        src.as_str(),
+        source_file.start_pos,
+        override_span,
+        frontmatter_allowed,
+    )
 }
 
 /// Runs the given subparser `f` on the tokens of the given `attr`'s item.

compiler/rustc_target/src/spec/targets/armv7a_vex_v5_linker_script.ld

@@ -17,15 +17,25 @@ PROVIDE(__vcodesig_type = 0);               /* V5_SIG_TYPE_USER     */
 PROVIDE(__vcodesig_owner = 2);              /* V5_SIG_OWNER_PARTNER */
 PROVIDE(__vcodesig_options = 0);            /* none (0)             */
 
-PROVIDE(__user_ram_start = 0x03800000);
-PROVIDE(__user_ram_length = 48M);
-PROVIDE(__user_ram_end = __user_ram_start + __user_ram_length); /* 0x8000000 */
+__user_ram_start = 0x03800000;
+__user_ram_end   = 0x08000000;
+/* (0x48 =) 72 MiB length */
+__user_ram_length = __user_ram_start - __user_ram_end;
 
-PROVIDE(__code_signature_length = 0x20);
+/*
+ * VEXos provides a method for pre-loading a "linked file" at a specified
+ * address in User RAM, conventionally near the end, after the primary
+ * program binary. We need to be sure not to place any data in that location,
+ * so we allow the user of this linker script to inform the start address of
+ * this blob.
+ */
+PROVIDE(__linked_file_length = 0);
+PROVIDE(__linked_file_end = __user_ram_end);
+PROVIDE(__linked_file_start = __linked_file_end - __linked_file_length);
 
 PROVIDE(__stack_length = 4M);
-PROVIDE(__heap_end = __user_ram_end - __stack_length);
-PROVIDE(__user_length = __heap_start - __user_ram_start);
+PROVIDE(__stack_top = __linked_file_start);
+PROVIDE(__stack_bottom = __linked_file_start - __stack_length);
 
 MEMORY {
     USER_RAM (RWX) : ORIGIN = __user_ram_start, LENGTH = __user_ram_length
@@ -44,7 +54,7 @@ SECTIONS {
         LONG(__vcodesig_options)
 
         FILL(0)
-        . = __user_ram_start + __code_signature_length;
+        . = __user_ram_start + 0x20;
     } > USER_RAM
 
     /*
@@ -125,7 +135,8 @@ SECTIONS {
      */
     .heap (NOLOAD) : {
         __heap_start = .;
-        . = __heap_end;
+        . = __stack_bottom;
+        __heap_end = .;
     } > USER_RAM
 
     .stack (NOLOAD) : ALIGN(8) {

library/std/src/io/buffered/bufreader/buffer.rs

@@ -122,7 +122,7 @@ impl Buffer {
 
     /// Remove bytes that have already been read from the buffer.
     pub fn backshift(&mut self) {
-        self.buf.copy_within(self.pos.., 0);
+        self.buf.copy_within(self.pos..self.filled, 0);
         self.filled -= self.pos;
         self.pos = 0;
     }

src/bootstrap/src/core/build_steps/compile.rs

@@ -38,7 +38,7 @@ use crate::{
 };
 
 /// Build a standard library for the given `target` using the given `build_compiler`.
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Std {
     pub target: TargetSelection,
     /// Compiler that builds the standard library.
@@ -948,7 +948,7 @@ pub struct BuiltRustc {
 ///   so that it can compile build scripts and proc macros when building this `rustc`.
 /// - Makes sure that `build_compiler` has a standard library prepared for `target`,
 ///   so that the built `rustc` can *link to it* and use it at runtime.
-#[derive(Debug, PartialOrd, Ord, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Rustc {
     /// The target on which rustc will run (its host).
     pub target: TargetSelection,
@@ -1959,7 +1959,7 @@ impl Step for Sysroot {
 /// linker wrappers (LLD, LLVM bitcode linker, etc.).
 ///
 /// This will assemble a compiler in `build/$target/stage$stage`.
-#[derive(Debug, PartialOrd, Ord, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Assemble {
     /// The compiler which we will produce in this step. Assemble itself will
     /// take care of ensuring that the necessary prerequisites to do so exist,

src/bootstrap/src/core/build_steps/dist.rs

@@ -54,7 +54,7 @@ fn should_build_extended_tool(builder: &Builder<'_>, tool: &str) -> bool {
     builder.config.tools.as_ref().is_none_or(|tools| tools.contains(tool))
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Docs {
     pub host: TargetSelection,
 }
@@ -91,7 +91,7 @@ impl Step for Docs {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct JsonDocs {
     build_compiler: Compiler,
     target: TargetSelection,
@@ -354,7 +354,7 @@ fn get_cc_search_dirs(
     (bin_path, lib_path)
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Mingw {
     pub host: TargetSelection,
 }
@@ -394,7 +394,7 @@ impl Step for Mingw {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Rustc {
     pub compiler: Compiler,
 }
@@ -730,7 +730,7 @@ fn copy_target_libs(
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Std {
     pub compiler: Compiler,
     pub target: TargetSelection,
@@ -785,7 +785,7 @@ impl Step for Std {
 /// `rust.download-rustc`.
 ///
 /// (Don't confuse this with [`RustDev`], without the `c`!)
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct RustcDev {
     pub compiler: Compiler,
     pub target: TargetSelection,
@@ -1026,7 +1026,7 @@ fn copy_src_dirs(
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Src;
 
 impl Step for Src {
@@ -1087,7 +1087,7 @@ impl Step for Src {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct PlainSourceTarball;
 
 impl Step for PlainSourceTarball {
@@ -1233,7 +1233,7 @@ impl Step for PlainSourceTarball {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Cargo {
     pub build_compiler: Compiler,
     pub target: TargetSelection,
@@ -1287,7 +1287,7 @@ impl Step for Cargo {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct RustAnalyzer {
     pub build_compiler: Compiler,
     pub target: TargetSelection,
@@ -1563,7 +1563,7 @@ impl Step for Rustfmt {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Extended {
     stage: u32,
     host: TargetSelection,
@@ -2404,7 +2404,7 @@ impl Step for LlvmTools {
 
 /// Distributes the `llvm-bitcode-linker` tool so that it can be used by a compiler whose host
 /// is `target`.
-#[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct LlvmBitcodeLinker {
     /// The linker will be compiled by this compiler.
     pub build_compiler: Compiler,