add parsing for well known trait Sized

Author: yaahc

chalk-integration/src/lowering.rs

@@ -1241,7 +1241,7 @@ impl LowerTrait for TraitDefn {
             binders: binders,
             flags: self.flags.lower(),
             associated_ty_ids,
-            well_known: None,
+            well_known: self.well_known.as_ref().map(|t| t.lower()),
         })
     }
 }
@@ -1343,6 +1343,18 @@ impl LowerQuantifiedGoal for Goal {
     }
 }
 
+trait LowerWellKnownTrait {
+    fn lower(&self) -> rust_ir::WellKnownTrait;
+}
+
+impl LowerWellKnownTrait for WellKnownTrait {
+    fn lower(&self) -> rust_ir::WellKnownTrait {
+        match self {
+            Self::SizedTrait => rust_ir::WellKnownTrait::SizedTrait,
+        }
+    }
+}
+
 /// Lowers LowerResult<Vec<T>> -> Vec<LowerResult<T>>.
 trait ApplyResult {
     type Output;

chalk-parse/src/ast.rs

@@ -48,6 +48,12 @@ pub struct TraitDefn {
     pub where_clauses: Vec<QuantifiedWhereClause>,
     pub assoc_ty_defns: Vec<AssocTyDefn>,
     pub flags: TraitFlags,
+    pub well_known: Option<WellKnownTrait>,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum WellKnownTrait {
+    SizedTrait,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]

chalk-parse/src/lib.rs

@@ -1,4 +1,5 @@
 #![recursion_limit = "1024"]
+#![allow(unused_parens)]
 
 #[macro_use]
 extern crate lalrpop_util;

chalk-parse/src/parser.lalrpop

@@ -43,6 +43,10 @@ FundamentalKeyword: () = "#" "[" "fundamental" "]";
 NonEnumerableKeyword: () = "#" "[" "non_enumerable" "]";
 CoinductiveKeyword: () = "#" "[" "coinductive" "]";
 
+WellKnownTrait: WellKnownTrait = {
+     "#" "[" "lang" "(" "sized" ")" "]" => WellKnownTrait::SizedTrait,
+};
+
 StructDefn: StructDefn = {
     <upstream:UpstreamKeyword?> <fundamental:FundamentalKeyword?> "struct" <n:Id><p:Angle<ParameterKind>>
         <w:QuantifiedWhereClauses> "{" <f:Fields> "}" => StructDefn
@@ -59,13 +63,14 @@ StructDefn: StructDefn = {
 };
 
 TraitDefn: TraitDefn = {
-    <auto:AutoKeyword?> <marker:MarkerKeyword?> <upstream:UpstreamKeyword?> <fundamental:FundamentalKeyword?> <non_enumerable:NonEnumerableKeyword?> <coinductive:CoinductiveKeyword?> "trait" <n:Id><p:Angle<ParameterKind>>
+    <auto:AutoKeyword?> <marker:MarkerKeyword?> <upstream:UpstreamKeyword?> <fundamental:FundamentalKeyword?> <non_enumerable:NonEnumerableKeyword?> <coinductive:CoinductiveKeyword?> <well_known:WellKnownTrait?> "trait" <n:Id><p:Angle<ParameterKind>>
         <w:QuantifiedWhereClauses> "{" <a:AssocTyDefn*> "}" => TraitDefn
     {
         name: n,
         parameter_kinds: p,
         where_clauses: w,
         assoc_ty_defns: a,
+        well_known,
         flags: TraitFlags {
             auto: auto.is_some(),
             marker: marker.is_some(),

chalk-solve/src/clauses.rs

@@ -10,9 +10,9 @@ use chalk_ir::*;
 use rustc_hash::FxHashSet;
 
 pub mod builder;
+mod builtin_traits;
 mod env_elaborator;
 pub mod program_clauses;
-mod builtin_traits;
 
 /// For auto-traits, we generate a default rule for every struct,
 /// unless there is a manual impl for that struct given explicitly.

chalk-solve/src/clauses/builtin_traits.rs

@@ -0,0 +1 @@
+