auto merge of #9135 : jbclements/rust/let-var-hygiene, r=erickt

Fixes issue #9110, changes field_ty element to Name, adds test case, improves fail error message

Author: bors

Diff for: src/librustc/metadata/decoder.rs

@@ -1202,10 +1202,11 @@ pub fn get_struct_fields(intr: @ident_interner, cdata: Cmd, id: ast::NodeId)
     do reader::tagged_docs(item, tag_item_field) |an_item| {
         let f = item_family(an_item);
         if f == PublicField || f == PrivateField || f == InheritedField {
+            // FIXME #6993: name should be of type Name, not Ident
             let name = item_name(intr, an_item);
             let did = item_def_id(an_item, cdata);
             result.push(ty::field_ty {
-                ident: name,
+                name: name.name,
                 id: did, vis:
                 struct_field_family_to_visibility(f),
             });
@@ -1215,7 +1216,7 @@ pub fn get_struct_fields(intr: @ident_interner, cdata: Cmd, id: ast::NodeId)
     do reader::tagged_docs(item, tag_item_unnamed_field) |an_item| {
         let did = item_def_id(an_item, cdata);
         result.push(ty::field_ty {
-            ident: special_idents::unnamed_field,
+            name: special_idents::unnamed_field.name,
             id: did,
             vis: ast::inherited,
         });

Diff for: src/librustc/middle/check_match.rs

@@ -700,7 +700,7 @@ pub fn specialize(cx: &MatchCheckCtxt,
                         }
                         let args = class_fields.iter().map(|class_field| {
                             match flds.iter().find(|f|
-                                            f.ident == class_field.ident) {
+                                            f.ident.name == class_field.name) {
                                 Some(f) => f.pat,
                                 _ => wild()
                             }

Diff for: src/librustc/middle/mem_categorization.rs

@@ -1059,6 +1059,7 @@ impl mem_categorization_ctxt {
 /// an enum to determine which variant is in use.
 pub fn field_mutbl(tcx: ty::ctxt,
                    base_ty: ty::t,
+                   // FIXME #6993: change type to Name
                    f_name: ast::Ident,
                    node_id: ast::NodeId)
                 -> Option<ast::Mutability> {
@@ -1067,7 +1068,7 @@ pub fn field_mutbl(tcx: ty::ctxt,
       ty::ty_struct(did, _) => {
         let r = ty::lookup_struct_fields(tcx, did);
         for fld in r.iter() {
-            if fld.ident == f_name {
+            if fld.name == f_name.name {
                 return Some(ast::MutImmutable);
             }
         }
@@ -1077,7 +1078,7 @@ pub fn field_mutbl(tcx: ty::ctxt,
           ast::DefVariant(_, variant_id, _) => {
             let r = ty::lookup_struct_fields(tcx, variant_id);
             for fld in r.iter() {
-                if fld.ident == f_name {
+                if fld.name == f_name.name {
                     return Some(ast::MutImmutable);
                 }
             }

Diff for: src/librustc/middle/privacy.rs

@@ -203,10 +203,11 @@ impl PrivacyVisitor {
     }
 
     // Checks that a private field is in scope.
+    // FIXME #6993: change type (and name) from Ident to Name
     fn check_field(&mut self, span: Span, id: ast::DefId, ident: ast::Ident) {
         let fields = ty::lookup_struct_fields(self.tcx, id);
         for field in fields.iter() {
-            if field.ident.name != ident.name { loop; }
+            if field.name != ident.name { loop; }
             if field.vis == private {
                 self.tcx.sess.span_err(span, fmt!("field `%s` is private",
                                              token::ident_to_str(&ident)));

Diff for: src/librustc/middle/trans/_match.rs

@@ -672,7 +672,7 @@ fn enter_opt<'r>(bcx: @mut Block,
                     let r = ty::lookup_struct_fields(tcx, struct_id);
                     for field in r.iter() {
                             match field_pats.iter().find(|p| p.ident.name
-                                                         == field.ident.name) {
+                                                         == field.name) {
                                 None => reordered_patterns.push(dummy),
                                 Some(fp) => reordered_patterns.push(fp.pat)
                             }

Diff for: src/librustc/middle/ty.rs

@@ -156,7 +156,7 @@ pub enum SelfMode {
 }
 
 pub struct field_ty {
-    ident: Ident,
+    name: Name,
     id: DefId,
     vis: ast::visibility,
 }
@@ -1757,7 +1757,7 @@ fn type_is_newtype_immediate(cx: ctxt, ty: t) -> bool {
         ty_struct(def_id, ref substs) => {
             let fields = struct_fields(cx, def_id, substs);
             fields.len() == 1 &&
-                fields[0].ident == token::special_idents::unnamed_field &&
+                fields[0].ident.name == token::special_idents::unnamed_field.name &&
                 type_is_immediate(cx, fields[0].mt.ty)
         }
         _ => false
@@ -4227,15 +4227,15 @@ fn struct_field_tys(fields: &[@struct_field]) -> ~[field_ty] {
         match field.node.kind {
             named_field(ident, visibility) => {
                 field_ty {
-                    ident: ident,
+                    name: ident.name,
                     id: ast_util::local_def(field.node.id),
                     vis: visibility,
                 }
             }
             unnamed_field => {
                 field_ty {
-                    ident:
-                        syntax::parse::token::special_idents::unnamed_field,
+                    name:
+                        syntax::parse::token::special_idents::unnamed_field.name,
                     id: ast_util::local_def(field.node.id),
                     vis: ast::public,
                 }
@@ -4250,7 +4250,8 @@ pub fn struct_fields(cx: ctxt, did: ast::DefId, substs: &substs)
                      -> ~[field] {
     do lookup_struct_fields(cx, did).map |f| {
        field {
-            ident: f.ident,
+            // FIXME #6993: change type of field to Name and get rid of new()
+            ident: ast::Ident::new(f.name),
             mt: mt {
                 ty: lookup_field_type(cx, did, f.id, substs),
                 mutbl: MutImmutable

Diff for: src/librustc/middle/typeck/check/_match.rs

@@ -21,6 +21,7 @@ use middle::typeck::require_same_types;
 use std::hashmap::{HashMap, HashSet};
 use syntax::ast;
 use syntax::ast_util;
+use syntax::parse::token;
 use syntax::codemap::Span;
 use syntax::print::pprust;
 
@@ -296,7 +297,7 @@ pub fn check_struct_pat_fields(pcx: &pat_ctxt,
     // Index the class fields.
     let mut field_map = HashMap::new();
     for (i, class_field) in class_fields.iter().enumerate() {
-        field_map.insert(class_field.ident.name, i);
+        field_map.insert(class_field.name, i);
     }
 
     // Typecheck each field.
@@ -333,7 +334,7 @@ pub fn check_struct_pat_fields(pcx: &pat_ctxt,
             }
             tcx.sess.span_err(span,
                               fmt!("pattern does not mention field `%s`",
-                                   tcx.sess.str_of(field.ident)));
+                                   token::interner_get(field.name)));
         }
     }
 }

Diff for: src/librustc/middle/typeck/check/mod.rs

@@ -1120,7 +1120,7 @@ pub fn lookup_field_ty(tcx: ty::ctxt,
                        fieldname: ast::Name,
                        substs: &ty::substs) -> Option<ty::t> {
 
-    let o_field = items.iter().find(|f| f.ident.name == fieldname);
+    let o_field = items.iter().find(|f| f.name == fieldname);
     do o_field.map() |f| {
         ty::lookup_field_type(tcx, class_id, f.id, substs)
     }
@@ -2018,7 +2018,7 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
         let mut class_field_map = HashMap::new();
         let mut fields_found = 0;
         for field in field_types.iter() {
-            class_field_map.insert(field.ident.name, (field.id, false));
+            class_field_map.insert(field.name, (field.id, false));
         }
 
         let mut error_happened = false;
@@ -2070,7 +2070,7 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
             if fields_found < field_types.len() {
                 let mut missing_fields = ~[];
                 for class_field in field_types.iter() {
-                    let name = class_field.ident.name;
+                    let name = class_field.name;
                     let (_, seen) = *class_field_map.get(&name);
                     if !seen {
                         missing_fields.push(

Diff for: src/libsyntax/ast.rs

@@ -47,7 +47,8 @@ impl Eq for Ident {
             // if it should be non-hygienic (most things are), just compare the
             // 'name' fields of the idents. Or, even better, replace the idents
             // with Name's.
-            fail!(fmt!("not allowed to compare these idents: %?, %?", self, other));
+            fail!(fmt!("not allowed to compare these idents: %?, %?. Probably \
+                       related to issue #6993", self, other));
         }
     }
     fn ne(&self, other: &Ident) -> bool {

Diff for: src/test/run-pass/issue-9110.rs

@@ -0,0 +1,22 @@
+// Copyright 2013 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.
+
+macro_rules! silly_macro(
+    () => (
+        pub mod Qux {
+            pub struct Foo { x : u8 }
+            pub fn bar(_foo : Foo) {}
+        }
+    );
+)
+
+silly_macro!()
+
+fn main() {}