From f2a06f760bee698d3c9e1fe4cad33bf1558e3c78 Mon Sep 17 00:00:00 2001
From: Seo Sanghyeon <sanxiyn@gmail.com>
Date: Fri, 2 Jan 2015 20:55:31 +0900
Subject: [PATCH 1/2] Make type in ast::Local optional
---
src/librustc/middle/region.rs | 5 ++++-
src/librustc_resolve/lib.rs | 4 +++-
src/librustc_trans/save/mod.rs | 2 +-
src/librustc_typeck/check/mod.rs | 6 +++---
src/libsyntax/ast.rs | 2 +-
src/libsyntax/ext/build.rs | 4 ++--
src/libsyntax/ext/expand.rs | 2 +-
src/libsyntax/fold.rs | 2 +-
src/libsyntax/parse/parser.rs | 8 ++------
src/libsyntax/print/pprust.rs | 10 ++++------
src/libsyntax/visit.rs | 14 +++++++++-----
11 files changed, 31 insertions(+), 28 deletions(-)
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index be89b32cdaa..0e47f338bb9 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -649,7 +649,10 @@ fn resolve_local(visitor: &mut RegionResolutionVisitor, local: &ast::Local) {
Some(ref expr) => {
record_rvalue_scope_if_borrow_expr(visitor, &**expr, blk_scope);
- if is_binding_pat(&*local.pat) || is_borrowed_ty(&*local.ty) {
+ let is_borrow =
+ if let Some(ref ty) = local.ty { is_borrowed_ty(&**ty) } else { false };
+
+ if is_binding_pat(&*local.pat) || is_borrow {
record_rvalue_scope(visitor, &**expr, blk_scope);
}
}
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 10756f21551..b22b4bdc211 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -3401,7 +3401,9 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
fn resolve_local(&mut self, local: &Local) {
// Resolve the type.
- self.resolve_type(&*local.ty);
+ if let Some(ref ty) = local.ty {
+ self.resolve_type(&**ty);
+ }
// Resolve the initializer, if necessary.
match local.init {
diff --git a/src/librustc_trans/save/mod.rs b/src/librustc_trans/save/mod.rs
index 51ea0af8e10..4396740de4e 100644
--- a/src/librustc_trans/save/mod.rs
+++ b/src/librustc_trans/save/mod.rs
@@ -1496,7 +1496,7 @@ impl<'l, 'tcx, 'v> Visitor<'v> for DxrVisitor<'l, 'tcx> {
self.collected_paths.clear();
// Just walk the initialiser and type (don't want to walk the pattern again).
- self.visit_ty(&*l.ty);
+ visit::walk_ty_opt(self, &l.ty);
visit::walk_expr_opt(self, &l.init);
}
}
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 60bb96a2b84..c0ca540841f 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -485,9 +485,9 @@ impl<'a, 'tcx> GatherLocalsVisitor<'a, 'tcx> {
impl<'a, 'tcx, 'v> Visitor<'v> for GatherLocalsVisitor<'a, 'tcx> {
// Add explicitly-declared locals.
fn visit_local(&mut self, local: &ast::Local) {
- let o_ty = match local.ty.node {
- ast::TyInfer => None,
- _ => Some(self.fcx.to_ty(&*local.ty))
+ let o_ty = match local.ty {
+ Some(ref ty) => Some(self.fcx.to_ty(&**ty)),
+ None => None
};
self.assign(local.span, local.id, o_ty);
debug!("Local variable {} is assigned type {}",
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 12432c8c78f..93750867750 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -643,8 +643,8 @@ pub enum LocalSource {
/// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`
#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
pub struct Local {
- pub ty: P<Ty>,
pub pat: P<Pat>,
+ pub ty: Option<P<Ty>>,
pub init: Option<P<Expr>>,
pub id: NodeId,
pub span: Span,
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 239af188909..ea345f3a458 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -482,8 +482,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
self.pat_ident(sp, ident)
};
let local = P(ast::Local {
- ty: self.ty_infer(sp),
pat: pat,
+ ty: None,
init: Some(ex),
id: ast::DUMMY_NODE_ID,
span: sp,
@@ -506,8 +506,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
self.pat_ident(sp, ident)
};
let local = P(ast::Local {
- ty: typ,
pat: pat,
+ ty: Some(typ),
init: Some(ex),
id: ast::DUMMY_NODE_ID,
span: sp,
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 5de7068563d..dcf25a26e2c 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -712,7 +712,7 @@ fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroE
let rewritten_local = local.map(|Local {id, pat, ty, init, source, span}| {
// expand the ty since TyFixedLengthVec contains an Expr
// and thus may have a macro use
- let expanded_ty = fld.fold_ty(ty);
+ let expanded_ty = ty.map(|t| fld.fold_ty(t));
// expand the pat (it might contain macro uses):
let expanded_pat = fld.fold_pat(pat);
// find the PatIdents in the pattern:
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 4f0169e31f2..c134b11a0eb 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -553,7 +553,7 @@ pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesizedPara
pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
l.map(|Local {id, pat, ty, init, source, span}| Local {
id: fld.new_id(id),
- ty: fld.fold_ty(ty),
+ ty: ty.map(|t| fld.fold_ty(t)),
pat: fld.fold_pat(pat),
init: init.map(|e| fld.fold_expr(e)),
source: source,
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 457085f5cc8..c7327a24bb6 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3627,13 +3627,9 @@ impl<'a> Parser<'a> {
let lo = self.span.lo;
let pat = self.parse_pat();
- let mut ty = P(Ty {
- id: ast::DUMMY_NODE_ID,
- node: TyInfer,
- span: mk_sp(lo, lo),
- });
+ let mut ty = None;
if self.eat(&token::Colon) {
- ty = self.parse_ty_sum();
+ ty = Some(self.parse_ty_sum());
}
let init = self.parse_initializer();
P(ast::Local {
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 02a03285d3b..3f3af4ed709 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1858,13 +1858,11 @@ impl<'a> State<'a> {
pub fn print_local_decl(&mut self, loc: &ast::Local) -> IoResult<()> {
try!(self.print_pat(&*loc.pat));
- match loc.ty.node {
- ast::TyInfer => Ok(()),
- _ => {
- try!(self.word_space(":"));
- self.print_type(&*loc.ty)
- }
+ if let Some(ref ty) = loc.ty {
+ try!(self.word_space(":"));
+ try!(self.print_type(&**ty));
}
+ Ok(())
}
pub fn print_decl(&mut self, decl: &ast::Decl) -> IoResult<()> {
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 40ca6354ca6..e532c76347f 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -211,7 +211,7 @@ pub fn walk_view_item<'v, V: Visitor<'v>>(visitor: &mut V, vi: &'v ViewItem) {
pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
visitor.visit_pat(&*local.pat);
- visitor.visit_ty(&*local.ty);
+ walk_ty_opt(visitor, &local.ty);
walk_expr_opt(visitor, &local.init);
}
@@ -381,6 +381,13 @@ pub fn skip_ty<'v, V: Visitor<'v>>(_: &mut V, _: &'v Ty) {
// Empty!
}
+pub fn walk_ty_opt<'v, V: Visitor<'v>>(visitor: &mut V, optional_type: &'v Option<P<Ty>>) {
+ match *optional_type {
+ Some(ref ty) => visitor.visit_ty(&**ty),
+ None => ()
+ }
+}
+
pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
match typ.node {
TyVec(ref ty) | TyParen(ref ty) => {
@@ -583,10 +590,7 @@ pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
pub fn walk_ty_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v TyParam) {
visitor.visit_ident(param.span, param.ident);
walk_ty_param_bounds_helper(visitor, ¶m.bounds);
- match param.default {
- Some(ref ty) => visitor.visit_ty(&**ty),
- None => {}
- }
+ walk_ty_opt(visitor, ¶m.default);
}
pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
From 4ae7c38e7b3edce3343dee520fe588130f140dc8 Mon Sep 17 00:00:00 2001
From: Seo Sanghyeon <sanxiyn@gmail.com>
Date: Fri, 2 Jan 2015 22:28:53 +0900
Subject: [PATCH 2/2] Add a pretty-print test
---
src/test/pretty/let.rs | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
create mode 100644 src/test/pretty/let.rs
diff --git a/src/test/pretty/let.rs b/src/test/pretty/let.rs
new file mode 100644
index 00000000000..736ea3a0d10
--- /dev/null
+++ b/src/test/pretty/let.rs
@@ -0,0 +1,19 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// pp-exact
+
+// Check that `let x: _ = 0;` does not print as `let x = 0;`.
+
+fn main() {
+ let x: _ = 0;
+
+ let _ = x;
+}