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| author | Vadim Petrochenkov <vadim.petrochenkov@gmail.com> | 2019-01-12 19:00:42 +0300 |
|---|---|---|
| committer | Vadim Petrochenkov <vadim.petrochenkov@gmail.com> | 2019-01-13 15:02:18 +0300 |
| commit | d3411d3ee8a350e2b8ec202a4a493e69c827245c (patch) | |
| tree | a9f78e1c94cf19c582d02a2dd8983f37d9d01925 /src/libsyntax | |
| parent | 41c65992c52113699451a6236148d408894f89ef (diff) | |
| download | rust-d3411d3ee8a350e2b8ec202a4a493e69c827245c.tar.gz rust-d3411d3ee8a350e2b8ec202a4a493e69c827245c.zip | |
Address review comments
Diffstat (limited to 'src/libsyntax')
| -rw-r--r-- | src/libsyntax/feature_gate.rs | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index a483e35a5b5..09fdf2d6618 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -717,6 +717,8 @@ pub enum AttributeGate { Ungated, } +/// A template that the attribute input must match. +/// Only top-level shape (`#[attr]` vs `#[attr(...)]` vs `#[attr = ...]`) is considered now. #[derive(Clone, Copy)] pub struct AttributeTemplate { word: bool, @@ -725,6 +727,7 @@ pub struct AttributeTemplate { } impl AttributeTemplate { + /// Check that the given meta-item is compatible with this template. fn compatible(&self, meta_item_kind: &ast::MetaItemKind) -> bool { match meta_item_kind { ast::MetaItemKind::Word => self.word, @@ -735,10 +738,10 @@ impl AttributeTemplate { } } +/// A convenience macro for constructing attribute templates. +/// E.g. `template!(Word, List: "description")` means that the attribute +/// supports forms `#[attr]` and `#[attr(description)]`. macro_rules! template { - (@ $word: expr, $list: expr, $name_value_str: expr) => { AttributeTemplate { - word: $word, list: $list, name_value_str: $name_value_str - } }; (Word) => { template!(@ true, None, None) }; (List: $descr: expr) => { template!(@ false, Some($descr), None) }; (NameValueStr: $descr: expr) => { template!(@ false, None, Some($descr)) }; @@ -750,6 +753,9 @@ macro_rules! template { (Word, List: $descr1: expr, NameValueStr: $descr2: expr) => { template!(@ true, Some($descr1), Some($descr2)) }; + (@ $word: expr, $list: expr, $name_value_str: expr) => { AttributeTemplate { + word: $word, list: $list, name_value_str: $name_value_str + } }; } impl AttributeGate { @@ -1084,7 +1090,8 @@ pub const BUILTIN_ATTRIBUTES: &[(&str, AttributeType, AttributeTemplate, Attribu is an experimental feature", cfg_fn!(fundamental))), - ("proc_macro_derive", Normal, template!(List: "TraitName, attributes(name1, name2, ...)"), + ("proc_macro_derive", Normal, template!(List: "TraitName, \ + /*opt*/ attributes(name1, name2, ...)"), Ungated), ("rustc_copy_clone_marker", Whitelisted, template!(Word), Gated(Stability::Unstable, |