From b2d28096927839548f4a556aba644530f4549f06 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Sun, 18 Aug 2013 22:12:22 -0700
Subject: [PATCH] Prepare bootstrapping priv-by-default struct fields

---
 src/librustc/middle/privacy.rs  | 23 +++++--------------
 src/libsyntax/parse/obsolete.rs |  5 +++++
 src/libsyntax/parse/parser.rs   | 39 +++++++++++++++++----------------
 3 files changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs
index 54e7c79e97cc2..09ff02011c72a 100644
--- a/src/librustc/middle/privacy.rs
+++ b/src/librustc/middle/privacy.rs
@@ -208,7 +208,11 @@ pub fn check_crate<'mm>(tcx: ty::ctxt,
         let fields = ty::lookup_struct_fields(tcx, id);
         for field in fields.iter() {
             if field.ident != ident { loop; }
-            if field.vis == private {
+            // NOTE: this means that the next snapshot will totally not respect
+            //       visibility of struct fields at all. The plan is to move
+            //       from public-by-default to private-by-default, and this is
+            //       necessary for bootstrapping.
+            if !cfg!(stage3) && field.vis == private {
                 tcx.sess.span_err(span, fmt!("field `%s` is private",
                                              token::ident_to_str(&ident)));
             }
@@ -581,21 +585,6 @@ fn check_sane_privacy(tcx: ty::ctxt, item: @ast::item) {
             }
         }
 
-        ast::item_struct(ref def, _) => {
-            for f in def.fields.iter() {
-                match f.node.kind {
-                    ast::named_field(_, ast::public) => {
-                        tcx.sess.span_err(f.span, "unnecessary `pub` \
-                                                   visibility");
-                    }
-                    ast::named_field(_, ast::private) => {
-                        // Fields should really be private by default...
-                    }
-                    ast::named_field(*) | ast::unnamed_field => {}
-                }
-            }
-        }
-
         ast::item_trait(_, _, ref methods) => {
             for m in methods.iter() {
                 match *m {
@@ -616,6 +605,6 @@ fn check_sane_privacy(tcx: ty::ctxt, item: @ast::item) {
 
         ast::item_impl(*) | ast::item_static(*) | ast::item_foreign_mod(*) |
         ast::item_fn(*) | ast::item_mod(*) | ast::item_ty(*) |
-        ast::item_mac(*) => {}
+        ast::item_mac(*) | ast::item_struct(*) => {}
     }
 }
diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index 01c1af7464db6..e386916596802 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -65,6 +65,7 @@ pub enum ObsoleteSyntax {
     ObsoleteExternVisibility,
     ObsoleteUnsafeExternFn,
     ObsoletePrivVisibility,
+    ObsoletePrivStructFieldVisibility,
     ObsoleteTraitFuncVisibility,
 }
 
@@ -259,6 +260,10 @@ impl ParserObsoleteMethods for Parser {
                 "`priv` not necessary",
                 "an item without a visibility qualifier is private by default"
             ),
+            ObsoletePrivStructFieldVisibility=> (
+                "`priv` not necessary",
+                "struct fields are private by default",
+            ),
             ObsoleteTraitFuncVisibility => (
                 "visibility not necessary",
                 "trait functions inherit the visibility of the trait itself"
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index de7abb8d1f46d..689fcf529b3c2 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3824,9 +3824,9 @@ impl Parser {
             is_tuple_like = false;
             fields = ~[];
             while *self.token != token::RBRACE {
-                let r = self.parse_struct_decl_field();
-                for struct_field in r.iter() {
-                    fields.push(*struct_field)
+                match self.parse_struct_decl_field() {
+                    Some(f) => fields.push(f),
+                    None => {}
                 }
             }
             if fields.len() == 0 {
@@ -3913,27 +3913,28 @@ impl Parser {
     }
 
     // parse an element of a struct definition
-    fn parse_struct_decl_field(&self) -> ~[@struct_field] {
-
+    fn parse_struct_decl_field(&self) -> Option<@struct_field> {
         let attrs = self.parse_outer_attributes();
 
         if self.try_parse_obsolete_priv_section(attrs) {
-            return ~[];
-        }
-
-        if self.eat_keyword(keywords::Priv) {
-            return ~[self.parse_single_struct_field(private, attrs)]
-        }
-
-        if self.eat_keyword(keywords::Pub) {
-           return ~[self.parse_single_struct_field(public, attrs)];
+            return None;
         }
+        let vis = if self.eat_keyword(keywords::Priv) {
+            // NOTE: after a snapshot, acrichto needs to make a pull request to
+            //       finish this work.
+            // self.obsolete(*self.last_span, ObsoletePrivStructFieldVisibility);
+            private
+        } else if self.eat_keyword(keywords::Pub) {
+            public
+        } else {
+            inherited
+        };
 
         if self.try_parse_obsolete_struct_ctor() {
-            return ~[];
+            return None;
         }
 
-        return ~[self.parse_single_struct_field(inherited, attrs)];
+        return Some(self.parse_single_struct_field(vis, attrs));
     }
 
     // parse visiility: PUB, PRIV, or nothing
@@ -4341,9 +4342,9 @@ impl Parser {
     fn parse_struct_def(&self) -> @struct_def {
         let mut fields: ~[@struct_field] = ~[];
         while *self.token != token::RBRACE {
-            let r = self.parse_struct_decl_field();
-            for struct_field in r.iter() {
-                fields.push(*struct_field);
+            match self.parse_struct_decl_field() {
+                Some(f) => fields.push(f),
+                None => {}
             }
         }
         self.bump();