bjoernager/rust
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Avoid unnecessary MetaItem/Attribute conversions.

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`check_builtin_attribute` calls `parse_meta` to convert an `Attribute`
to a `MetaItem`, which it then checks. However, many callers of
`check_builtin_attribute` start with a `MetaItem`, and then convert it
to an `Attribute` by calling `cx.attribute(meta_item)`. This `MetaItem`
to `Attribute` to `MetaItem` conversion is silly.

This commit adds a new function `check_builtin_meta_item`, which can be
called instead from these call sites. `check_builtin_attribute` also now
calls it. The commit also renames `check_meta` as `check_attr` to better
match its arguments.
This commit is contained in:
Nicholas Nethercote 2022-11-24 16:00:57 +11:00
parent 2585bcea0b
commit c9ae38c71e
6 changed files with 44 additions and 29 deletions
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43
compiler/rustc_parse/src/validate_attr.rs
View file

@ -10,9 +10,9 @@ use rustc_errors::{Applicability, FatalError, PResult};
use rustc_feature::{AttributeTemplate, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
use rustc_session::lint::builtin::ILL_FORMED_ATTRIBUTE_INPUT;
use rustc_session::parse::ParseSess;
use rustc_span::{sym, Symbol};
use rustc_span::{sym, Span, Symbol};
pub fn check_meta(sess: &ParseSess, attr: &Attribute) {
pub fn check_attr(sess: &ParseSess, attr: &Attribute) {
if attr.is_doc_comment() {
return;
}
@ -115,25 +115,34 @@ pub fn check_builtin_attribute(
name: Symbol,
template: AttributeTemplate,
) {
// Some special attributes like `cfg` must be checked
// before the generic check, so we skip them here.
let should_skip = |name| name == sym::cfg;
match parse_meta(sess, attr) {
Ok(meta) => {
if !should_skip(name) && !is_attr_template_compatible(&template, &meta.kind) {
emit_malformed_attribute(sess, attr, name, template);
}
}
Ok(meta) => check_builtin_meta_item(sess, &meta, attr.style, name, template),
Err(mut err) => {
err.emit();
}
}
}
pub fn check_builtin_meta_item(
sess: &ParseSess,
meta: &MetaItem,
style: ast::AttrStyle,
name: Symbol,
template: AttributeTemplate,
) {
// Some special attributes like `cfg` must be checked
// before the generic check, so we skip them here.
let should_skip = |name| name == sym::cfg;
if !should_skip(name) && !is_attr_template_compatible(&template, &meta.kind) {
emit_malformed_attribute(sess, style, meta.span, name, template);
}
}
fn emit_malformed_attribute(
sess: &ParseSess,
attr: &Attribute,
style: ast::AttrStyle,
span: Span,
name: Symbol,
template: AttributeTemplate,
) {
@ -147,7 +156,7 @@ fn emit_malformed_attribute(
let mut msg = "attribute must be of the form ".to_owned();
let mut suggestions = vec![];
let mut first = true;
let inner = if attr.style == ast::AttrStyle::Inner { "!" } else { "" };
let inner = if style == ast::AttrStyle::Inner { "!" } else { "" };
if template.word {
first = false;
let code = format!("#{}[{}]", inner, name);
@ -172,12 +181,12 @@ fn emit_malformed_attribute(
suggestions.push(code);
}
if should_warn(name) {
sess.buffer_lint(&ILL_FORMED_ATTRIBUTE_INPUT, attr.span, ast::CRATE_NODE_ID, &msg);
sess.buffer_lint(&ILL_FORMED_ATTRIBUTE_INPUT, span, ast::CRATE_NODE_ID, &msg);
} else {
sess.span_diagnostic
.struct_span_err(attr.span, &error_msg)
.struct_span_err(span, &error_msg)
.span_suggestions(
attr.span,
span,
if suggestions.len() == 1 {
"must be of the form"
} else {
@ -196,7 +205,7 @@ pub fn emit_fatal_malformed_builtin_attribute(
name: Symbol,
) -> ! {
let template = BUILTIN_ATTRIBUTE_MAP.get(&name).expect("builtin attr defined").template;
emit_malformed_attribute(sess, attr, name, template);
emit_malformed_attribute(sess, attr.style, attr.span, name, template);
// This is fatal, otherwise it will likely cause a cascade of other errors
// (and an error here is expected to be very rare).
FatalError.raise()