Rollup of 7 pull requests

INSTALL.md

@@ -96,7 +96,7 @@ See [the rustc-dev-guide for more info][sysllvm].
       --set llvm.libzstd=true \
       --set llvm.ninja=false \
       --set rust.debug-assertions=false \
-      --set rust.jemalloc \
+      --set rust.override-allocator=jemalloc \
       --set rust.bootstrap-override-lld=true \
       --set rust.lto=thin \
       --set rust.codegen-units=1

bootstrap.example.toml

@@ -853,9 +853,15 @@
 # Useful for reproducible builds. Generally only set for releases
 #rust.remap-debuginfo = false
 
-# Link the compiler and LLVM against `jemalloc` instead of the default libc allocator.
+# Link the compiler and LLVM against the specified allocator instead of the default libc allocator.
 # This option is only tested on Linux and OSX. It can also be configured per-target in the
 # [target.<tuple>] section.
+# Possible options: "jemalloc"
+#rust.override-allocator = "jemalloc"
+
+# Deprecated alias for `rust.override-allocator`. Setting this to `true` is
+# equivalent to `rust.override-allocator = "jemalloc"`. If both are set, they
+# must agree.
 #rust.jemalloc = false
 
 # Run tests in various test suites with the "nll compare mode" in addition to
@@ -1164,8 +1170,11 @@
 # order to run `x check`.
 #optimized-compiler-builtins = build.optimized-compiler-builtins (bool or path)
 
-# Link the compiler and LLVM against `jemalloc` instead of the default libc allocator.
-# This overrides the global `rust.jemalloc` option. See that option for more info.
+# Link the compiler and LLVM against the specified allocator instead of the default libc allocator.
+# This overrides the global `rust.override-allocator` option. See that option for more info.
+#override-allocator = rust.override-allocator (string)
+
+# Deprecated alias for `override-allocator`. See `rust.jemalloc` for more info.
 #jemalloc = rust.jemalloc (bool)
 
 # The linker configuration that will *override* the default linker used for Linux

compiler/rustc_ast/src/ast.rs

@@ -3413,6 +3413,29 @@ pub struct Attribute {
     /// Denotes if the attribute decorates the following construct (outer)
     /// or the construct this attribute is contained within (inner).
     pub style: AttrStyle,
+
+    /// The carets in the examples below show the spans for various cases.
+    /// ```text
+    /// #[foo]                  - A vanilla parsed attribute.
+    /// ^^^^^^                  - Its span covers it all.
+    ///
+    /// /** abc */  /// xyz     - A parsed doc comment.
+    /// ^^^^^^^^^^  ^^^^^^^     - Its span covers the text and comment marker(s).
+    ///                         - The same span is also used if the doc comment is desugared (into
+    ///                           a new normal `#[doc = r"..."]` attribute) by
+    ///                           `desugar_doc_comments` before being passed to a macro (which
+    ///                           is done so that `#[$m:meta]` will match).
+    ///
+    /// #[cfg_attr(pred, foo)]  - A parsed `cfg_attr` attribute.
+    /// ^^^^^^^^^^^^^^^^^^^^^^  - Its span covers it all.
+    ///                  ^^^    - Span of the new replacement attribute (equivalent to `#[foo]`)
+    ///                           created by `cfg_attr` expansion (if `pred` is true).
+    /// ^^^^^^^^^^^^^^^^^^^^^^  - Span of the synthetic `CfgAttrTrace` attribute created by
+    ///                           `cfg_attr` expansion. (`CfgTrace` is derived from `#[cfg(..)]` and
+    ///                           handled similarly.)
+    /// ```
+    /// Finally, for compiler-generated attributes the span is whatever the construction site
+    /// chooses. Usually `DUMMY_SP` or some relevant span from the source code.
     pub span: Span,
 }
 

compiler/rustc_ast/src/attr/mod.rs

@@ -7,7 +7,7 @@ use std::fmt::Debug;
 use std::sync::atomic::{AtomicU32, Ordering};
 
 use rustc_index::bit_set::GrowableBitSet;
-use rustc_span::{Ident, Span, Symbol, kw, sym};
+use rustc_span::{Ident, Span, Symbol, sym};
 use smallvec::{SmallVec, smallvec};
 use thin_vec::{ThinVec, thin_vec};
 
@@ -748,29 +748,9 @@ pub fn mk_attr_from_item(
 
 fn mk_attr_tokens(
     style: AttrStyle,
-    unsafety: Safety,
     item_tokens: AttrTokenStream,
     span: Span,
 ) -> LazyAttrTokenStream {
-    let safety_kw = match unsafety {
-        Safety::Default => None,
-        Safety::Unsafe(span) => Some((kw::Unsafe, span)),
-        Safety::Safe(span) => Some((kw::Safe, span)),
-    };
-    let item_tokens = if let Some((kw, kw_span)) = safety_kw {
-        AttrTokenStream::new(vec![
-            AttrTokenTree::Token(Token::from_ast_ident(Ident::new(kw, kw_span)), Spacing::Alone),
-            AttrTokenTree::Delimited(
-                DelimSpan::from_single(span),
-                DelimSpacing::new(Spacing::JointHidden, Spacing::Alone),
-                Delimiter::Parenthesis,
-                item_tokens,
-            ),
-        ])
-    } else {
-        item_tokens
-    };
-
     let mut tokens = match style {
         AttrStyle::Outer => {
             vec![AttrTokenTree::Token(Token::new(token::Pound, span), Spacing::JointHidden)]
@@ -792,35 +772,33 @@ fn mk_attr_tokens(
 
 // `span` is used for the `Attribute` and everything within it (except for any span within
 // `unsafety`).
-pub fn mk_attr_word(
-    g: &AttrIdGenerator,
-    style: AttrStyle,
-    unsafety: Safety,
-    name: Symbol,
-    span: Span,
-) -> Attribute {
+pub fn mk_attr_word(g: &AttrIdGenerator, style: AttrStyle, name: Symbol, span: Span) -> Attribute {
     let path = Path::from_ident(Ident::new(name, span));
     let args = AttrArgs::Empty;
 
     let tokens = Some(mk_attr_tokens(
         style,
-        unsafety,
         AttrTokenStream::new(vec![AttrTokenTree::Token(
             Token::from_ast_ident(Ident::new(name, span)),
             Spacing::Alone,
         )]),
         span,
     ));
 
-    mk_attr_from_item(g, AttrItem { unsafety, path, args, span }, tokens, style, span)
+    mk_attr_from_item(
+        g,
+        AttrItem { unsafety: Safety::Default, path, args, span },
+        tokens,
+        style,
+        span,
+    )
 }
 
 // `span` is used for the `Attribute` and everything within it (except for any span within
 // `unsafety`).
 pub fn mk_attr_nested_word(
     g: &AttrIdGenerator,
     style: AttrStyle,
-    unsafety: Safety,
     outer: Symbol,
     inner: Symbol,
     span: Span,
@@ -839,7 +817,6 @@ pub fn mk_attr_nested_word(
 
     let tokens = Some(mk_attr_tokens(
         style,
-        unsafety,
         AttrTokenStream::new(vec![
             AttrTokenTree::Token(Token::from_ast_ident(Ident::new(outer, span)), Spacing::Alone),
             AttrTokenTree::Delimited(
@@ -855,15 +832,20 @@ pub fn mk_attr_nested_word(
         span,
     ));
 
-    mk_attr_from_item(g, AttrItem { unsafety, path, args: attr_args, span }, tokens, style, span)
+    mk_attr_from_item(
+        g,
+        AttrItem { unsafety: Safety::Default, path, args: attr_args, span },
+        tokens,
+        style,
+        span,
+    )
 }
 
 // `span` is used for the `Attribute` and everything within it (except for any span within
 // `unsafety`).
 pub fn mk_attr_name_value_str(
     g: &AttrIdGenerator,
     style: AttrStyle,
-    unsafety: Safety,
     name: Symbol,
     val: Symbol,
     span: Span,
@@ -881,7 +863,6 @@ pub fn mk_attr_name_value_str(
 
     let tokens = Some(mk_attr_tokens(
         style,
-        unsafety,
         AttrTokenStream::new(vec![
             AttrTokenTree::Token(Token::from_ast_ident(Ident::new(name, span)), Spacing::Alone),
             AttrTokenTree::Token(Token::new(token::Eq, span), Spacing::Alone),
@@ -893,7 +874,13 @@ pub fn mk_attr_name_value_str(
         span,
     ));
 
-    mk_attr_from_item(g, AttrItem { unsafety, path, args, span }, tokens, style, span)
+    mk_attr_from_item(
+        g,
+        AttrItem { unsafety: Safety::Default, path, args, span },
+        tokens,
+        style,
+        span,
+    )
 }
 
 pub fn filter_by_name(attrs: &[Attribute], name: Symbol) -> impl Iterator<Item = &Attribute> {

compiler/rustc_ast_lowering/src/expr.rs

@@ -2323,7 +2323,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let attr = attr::mk_attr_nested_word(
             &self.tcx.sess.psess.attr_id_generator,
             AttrStyle::Outer,
-            Safety::Default,
             sym::allow,
             sym::unreachable_code,
             span,