From d31b9ebef5c39de3fff9da02eea880d1838a8a3b Mon Sep 17 00:00:00 2001
From: Eduard Burtescu <edy.burt@gmail.com>
Date: Tue, 17 Feb 2015 19:29:13 +0200
Subject: Implement `<T>::method` UFCS expression syntax.

---
 src/libsyntax/ext/build.rs         | 26 +++++++++++++-------------
 src/libsyntax/ext/concat_idents.rs |  2 +-
 src/libsyntax/ext/expand.rs        | 11 ++++-------
 3 files changed, 18 insertions(+), 21 deletions(-)

(limited to 'src/libsyntax/ext')

diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 90842bbab47..d916651b056 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -43,14 +43,14 @@ pub trait AstBuilder {
     fn qpath(&self, self_type: P<ast::Ty>,
              trait_path: ast::Path,
              ident: ast::Ident)
-             -> ast::QPath;
+             -> (ast::QSelf, ast::Path);
     fn qpath_all(&self, self_type: P<ast::Ty>,
                 trait_path: ast::Path,
                 ident: ast::Ident,
                 lifetimes: Vec<ast::Lifetime>,
                 types: Vec<P<ast::Ty>>,
                 bindings: Vec<P<ast::TypeBinding>>)
-                -> ast::QPath;
+                -> (ast::QSelf, ast::Path);
 
     // types
     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy;
@@ -114,7 +114,7 @@ pub trait AstBuilder {
     // expressions
     fn expr(&self, span: Span, node: ast::Expr_) -> P<ast::Expr>;
     fn expr_path(&self, path: ast::Path) -> P<ast::Expr>;
-    fn expr_qpath(&self, span: Span, qpath: ast::QPath) -> P<ast::Expr>;
+    fn expr_qpath(&self, span: Span, qself: ast::QSelf, path: ast::Path) -> P<ast::Expr>;
     fn expr_ident(&self, span: Span, id: ast::Ident) -> P<ast::Expr>;
 
     fn expr_self(&self, span: Span) -> P<ast::Expr>;
@@ -351,7 +351,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
              self_type: P<ast::Ty>,
              trait_path: ast::Path,
              ident: ast::Ident)
-             -> ast::QPath {
+             -> (ast::QSelf, ast::Path) {
         self.qpath_all(self_type, trait_path, ident, vec![], vec![], vec![])
     }
 
@@ -365,7 +365,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
                  lifetimes: Vec<ast::Lifetime>,
                  types: Vec<P<ast::Ty>>,
                  bindings: Vec<P<ast::TypeBinding>>)
-                 -> ast::QPath {
+                 -> (ast::QSelf, ast::Path) {
         let mut path = trait_path;
         path.segments.push(ast::PathSegment {
             identifier: ident,
@@ -376,10 +376,10 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             })
         });
 
-        ast::QPath {
-            self_type: self_type,
-            path: path
-        }
+        (ast::QSelf {
+            ty: self_type,
+            position: path.segments.len() - 1
+        }, path)
     }
 
     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy {
@@ -398,7 +398,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     }
 
     fn ty_path(&self, path: ast::Path) -> P<ast::Ty> {
-        self.ty(path.span, ast::TyPath(path))
+        self.ty(path.span, ast::TyPath(None, path))
     }
 
     fn ty_sum(&self, path: ast::Path, bounds: OwnedSlice<ast::TyParamBound>) -> P<ast::Ty> {
@@ -603,12 +603,12 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     }
 
     fn expr_path(&self, path: ast::Path) -> P<ast::Expr> {
-        self.expr(path.span, ast::ExprPath(path))
+        self.expr(path.span, ast::ExprPath(None, path))
     }
 
     /// Constructs a QPath expression.
-    fn expr_qpath(&self, span: Span, qpath: ast::QPath) -> P<ast::Expr> {
-        self.expr(span, ast::ExprQPath(qpath))
+    fn expr_qpath(&self, span: Span, qself: ast::QSelf, path: ast::Path) -> P<ast::Expr> {
+        self.expr(span, ast::ExprPath(Some(qself), path))
     }
 
     fn expr_ident(&self, span: Span, id: ast::Ident) -> P<ast::Expr> {
diff --git a/src/libsyntax/ext/concat_idents.rs b/src/libsyntax/ext/concat_idents.rs
index 9410a51e7a5..2303eb9645b 100644
--- a/src/libsyntax/ext/concat_idents.rs
+++ b/src/libsyntax/ext/concat_idents.rs
@@ -53,7 +53,7 @@ pub fn expand_syntax_ext<'cx>(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree]
 
     let e = P(ast::Expr {
         id: ast::DUMMY_NODE_ID,
-        node: ast::ExprPath(
+        node: ast::ExprPath(None,
             ast::Path {
                  span: sp,
                  global: false,
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index f7014d6cc3c..b6e7b309f35 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -41,7 +41,7 @@ pub fn expand_type(t: P<ast::Ty>,
     debug!("expanding type {:?} with impl_ty {:?}", t, impl_ty);
     let t = match (t.node.clone(), impl_ty) {
         // Expand uses of `Self` in impls to the concrete type.
-        (ast::Ty_::TyPath(ref path), Some(ref impl_ty)) => {
+        (ast::Ty_::TyPath(None, ref path), Some(ref impl_ty)) => {
             let path_as_ident = path_to_ident(path);
             // Note unhygenic comparison here. I think this is correct, since
             // even though `Self` is almost just a type parameter, the treatment
@@ -1594,13 +1594,10 @@ mod test {
 
     impl<'v> Visitor<'v> for PathExprFinderContext {
         fn visit_expr(&mut self, expr: &ast::Expr) {
-            match expr.node {
-                ast::ExprPath(ref p) => {
-                    self.path_accumulator.push(p.clone());
-                    // not calling visit_path, but it should be fine.
-                }
-                _ => visit::walk_expr(self, expr)
+            if let ast::ExprPath(None, ref p) = expr.node {
+                self.path_accumulator.push(p.clone());
             }
+            visit::walk_expr(self, expr);
         }
     }
 
-- 
cgit 1.4.1-3-g733a5