bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Auto merge of #97903 - est31:unused_macro_rules_compile_error, r=petrochenkov

Browse source 
Never regard macro rules with compile_error! invocations as unused

The very point of compile_error! is to never be reached, and one of
the use cases of the macro, currently also listed as examples in the
documentation of compile_error, is to create nicer errors for wrong
macro invocations. Thus, we should never warn about unused macro arms
that contain invocations of compile_error.

See also https://github.com/rust-lang/rust/pull/96150#issuecomment-1126599107 and the discussion after that.

Furthermore, the PR also contains two commits to silence `unused_macro_rules` when a macro has an invalid rule, and to add a test that `unused_macros` does not behave badly in the same situation.

r? `@petrochenkov` as I've talked to them about this
This commit is contained in:
bors 2022-06-11 08:46:21 +00:00
commit fa68e73e99
10 changed files with 158 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_resolve/src/build_reduced_graph.rs
View file

@ -1220,12 +1220,12 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
ident: Ident,
def_id: LocalDefId,
node_id: NodeId,
rule_spans: &[Span],
rule_spans: &[(usize, Span)],
) {
if !ident.as_str().starts_with('_') {
self.r.unused_macros.insert(def_id, (node_id, ident));
for (rule_i, rule_span) in rule_spans.iter().enumerate() {
self.r.unused_macro_rules.insert((def_id, rule_i), (ident, *rule_span));
for (rule_i, rule_span) in rule_spans.iter() {
self.r.unused_macro_rules.insert((def_id, *rule_i), (ident, *rule_span));
}
}
}

2
compiler/rustc_resolve/src/macros.rs
View file

@ -870,7 +870,7 @@ impl<'a> Resolver<'a> {
&mut self,
item: &ast::Item,
edition: Edition,
) -> (SyntaxExtension, Vec<Span>) {
) -> (SyntaxExtension, Vec<(usize, Span)>) {
let (mut result, mut rule_spans) = compile_declarative_macro(
&self.session,
self.session.features_untracked(),