Use cfg_attr as a name more.

In various functions where the attribute being processed is known to be a `#[cfg_attr(...)]` attribute. I find this a helpful reminder.

compiler/rustc_expand/src/config.rs

@@ -253,9 +253,9 @@ impl<'a> StripUnconfigured<'a> {
  /// Gives a compiler warning when the `cfg_attr` contains no attributes and
  /// is in the original source file. Gives a compiler error if the syntax of
  /// the attribute is incorrect.
- pub(crate) fn expand_cfg_attr(&self, attr: &Attribute, recursive: bool) -> Vec<Attribute> {
+ pub(crate) fn expand_cfg_attr(&self, cfg_attr: &Attribute, recursive: bool) -> Vec<Attribute> {
  let Some((cfg_predicate, expanded_attrs)) =
- rustc_parse::parse_cfg_attr(attr, &self.sess.psess)
+ rustc_parse::parse_cfg_attr(cfg_attr, &self.sess.psess)
  else {
  return vec![];
  };
@@ -264,7 +264,7 @@ impl<'a> StripUnconfigured<'a> {
  if expanded_attrs.is_empty() {
  self.sess.psess.buffer_lint(
  rustc_lint_defs::builtin::UNUSED_ATTRIBUTES,
- attr.span,
+ cfg_attr.span,
  ast::CRATE_NODE_ID,
  BuiltinLintDiag::CfgAttrNoAttributes,
  );
@@ -280,16 +280,16 @@ impl<'a> StripUnconfigured<'a> {
  // `#[cfg_attr(false, cfg_attr(true, some_attr))]`.
  expanded_attrs
  .into_iter()
- .flat_map(|item| self.process_cfg_attr(&self.expand_cfg_attr_item(attr, item)))
+ .flat_map(|item| self.process_cfg_attr(&self.expand_cfg_attr_item(cfg_attr, item)))
  .collect()
  } else {
- expanded_attrs.into_iter().map(|item| self.expand_cfg_attr_item(attr, item)).collect()
+ expanded_attrs.into_iter().map(|item| self.expand_cfg_attr_item(cfg_attr, item)).collect()
  }
  }
 
  fn expand_cfg_attr_item(
  &self,
- attr: &Attribute,
+ cfg_attr: &Attribute,
  (item, item_span): (ast::AttrItem, Span),
  ) -> Attribute {
  // We are taking an attribute of the form `#[cfg_attr(pred, attr)]`
@@ -300,11 +300,11 @@ impl<'a> StripUnconfigured<'a> {
 
  // Use the `#` in `#[cfg_attr(pred, attr)]` as the `#` token
  // for `attr` when we expand it to `#[attr]`
- let mut orig_trees = attr.token_trees().into_iter();
+ let mut orig_trees = cfg_attr.token_trees().into_iter();
  let TokenTree::Token(pound_token @ Token { kind: TokenKind::Pound, .. }, _) =
  orig_trees.next().unwrap().clone()
  else {
- panic!("Bad tokens for attribute {attr:?}");
+ panic!("Bad tokens for attribute {cfg_attr:?}");
  };
 
  // We don't really have a good span to use for the synthesized `[]`
@@ -318,12 +318,12 @@ impl<'a> StripUnconfigured<'a> {
  .unwrap_or_else(|| panic!("Missing tokens for {item:?}"))
  .to_attr_token_stream(),
  );
- let trees = if attr.style == AttrStyle::Inner {
+ let trees = if cfg_attr.style == AttrStyle::Inner {
  // For inner attributes, we do the same thing for the `!` in `#![some_attr]`
  let TokenTree::Token(bang_token @ Token { kind: TokenKind::Not, .. }, _) =
  orig_trees.next().unwrap().clone()
  else {
- panic!("Bad tokens for attribute {attr:?}");
+ panic!("Bad tokens for attribute {cfg_attr:?}");
  };
  vec![
  AttrTokenTree::Token(pound_token, Spacing::Joint),
@@ -338,7 +338,7 @@ impl<'a> StripUnconfigured<'a> {
  &self.sess.psess.attr_id_generator,
  item,
  tokens,
- attr.style,
+ cfg_attr.style,
  item_span,
  );
  if attr.has_name(sym::crate_type) {

compiler/rustc_parse/src/lib.rs

@@ -157,14 +157,14 @@ pub fn fake_token_stream_for_crate(psess: &ParseSess, krate: &ast::Crate) -> Tok
 }
 
 pub fn parse_cfg_attr(
- attr: &Attribute,
+ cfg_attr: &Attribute,
  psess: &ParseSess,
 ) -> Option<(MetaItem, Vec<(AttrItem, Span)>)> {
  const CFG_ATTR_GRAMMAR_HELP: &str = "#[cfg_attr(condition, attribute, other_attribute, ...)]";
  const CFG_ATTR_NOTE_REF: &str = "for more information, visit \
  <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg_attr-attribute>";
 
- match attr.get_normal_item().args {
+ match cfg_attr.get_normal_item().args {
  ast::AttrArgs::Delimited(ast::DelimArgs { dspan, delim, ref tokens })
  if !tokens.is_empty() =>
  {
@@ -180,7 +180,7 @@ pub fn parse_cfg_attr(
  }
  _ => {
  psess.dcx().emit_err(errors::MalformedCfgAttr {
- span: attr.span,
+ span: cfg_attr.span,
  sugg: CFG_ATTR_GRAMMAR_HELP,
  });
  }