librustc: Disallow "unsafe" for external functions

7 files changed, 22 insertions, 10 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index d6bee4fe19f..11f2c7005bc 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1077,7 +1077,7 @@ pub struct foreign_item {
 
 #[deriving(Eq, Encodable, Decodable,IterBytes)]
 pub enum foreign_item_ {
-    foreign_item_fn(fn_decl, purity, Generics),
+    foreign_item_fn(fn_decl, Generics),
     foreign_item_static(Ty, /* is_mutbl */ bool),
 }
 
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index f0b00f5681c..9bda1189a8e 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -223,7 +223,7 @@ fn noop_fold_foreign_item(ni: @foreign_item, fld: @ast_fold)
         attrs: ni.attrs.map(|x| fold_attribute(*x)),
         node:
             match ni.node {
-                foreign_item_fn(ref fdec, purity, ref generics) => {
+                foreign_item_fn(ref fdec, ref generics) => {
                     foreign_item_fn(
                         ast::fn_decl {
                             inputs: fdec.inputs.map(|a|
@@ -231,7 +231,6 @@ fn noop_fold_foreign_item(ni: @foreign_item, fld: @ast_fold)
                             output: fld.fold_ty(&fdec.output),
                             cf: fdec.cf,
                         },
-                        purity,
                         fold_generics(generics, fld))
                 }
                 foreign_item_static(ref t, m) => {
diff --git a/src/libsyntax/oldvisit.rs b/src/libsyntax/oldvisit.rs
index c421ded6d75..a39dc38a856 100644
--- a/src/libsyntax/oldvisit.rs
+++ b/src/libsyntax/oldvisit.rs
@@ -339,7 +339,7 @@ pub fn visit_pat<E:Clone>(p: &pat, (e, v): (E, vt<E>)) {
 
 pub fn visit_foreign_item<E:Clone>(ni: &foreign_item, (e, v): (E, vt<E>)) {
     match ni.node {
-        foreign_item_fn(ref fd, _, ref generics) => {
+        foreign_item_fn(ref fd, ref generics) => {
             visit_fn_decl(fd, (e.clone(), v));
             (v.visit_generics)(generics, (e, v));
         }
diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index 3472b9f1d67..ec956f61863 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -63,6 +63,7 @@ pub enum ObsoleteSyntax {
     ObsoleteMultipleLocalDecl,
     ObsoleteMutWithMultipleBindings,
     ObsoleteExternVisibility,
+    ObsoleteUnsafeExternFn,
 }
 
 impl to_bytes::IterBytes for ObsoleteSyntax {
@@ -246,7 +247,12 @@ impl ParserObsoleteMethods for Parser {
                 "`pub extern` or `priv extern`",
                 "place the `pub` or `priv` on the individual external items \
                  instead"
-            )
+            ),
+            ObsoleteUnsafeExternFn => (
+                "unsafe external function",
+                "external functions are always unsafe; remove the `unsafe` \
+                 keyword"
+            ),
         };
 
         self.report(sp, kind, kind_str, desc);
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 1d61c5be83d..386f027d6e1 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -84,7 +84,8 @@ use parse::obsolete::{ObsoletePurity, ObsoleteStaticMethod};
 use parse::obsolete::{ObsoleteConstItem, ObsoleteFixedLengthVectorType};
 use parse::obsolete::{ObsoleteNamedExternModule, ObsoleteMultipleLocalDecl};
 use parse::obsolete::{ObsoleteMutWithMultipleBindings};
-use parse::obsolete::{ObsoleteExternVisibility, ParserObsoleteMethods};
+use parse::obsolete::{ObsoleteExternVisibility, ObsoleteUnsafeExternFn};
+use parse::obsolete::{ParserObsoleteMethods};
 use parse::token::{can_begin_expr, get_ident_interner, ident_to_str, is_ident};
 use parse::token::{is_ident_or_path};
 use parse::token::{is_plain_ident, INTERPOLATED, keywords, special_idents};
@@ -4066,14 +4067,20 @@ impl Parser {
     fn parse_item_foreign_fn(&self,  attrs: ~[Attribute]) -> @foreign_item {
         let lo = self.span.lo;
         let vis = self.parse_visibility();
+
+        // Parse obsolete purity.
         let purity = self.parse_fn_purity();
+        if purity != impure_fn {
+            self.obsolete(*self.last_span, ObsoleteUnsafeExternFn);
+        }
+
         let (ident, generics) = self.parse_fn_header();
         let decl = self.parse_fn_decl();
         let hi = self.span.hi;
         self.expect(&token::SEMI);
         @ast::foreign_item { ident: ident,
                              attrs: attrs,
-                             node: foreign_item_fn(decl, purity, generics),
+                             node: foreign_item_fn(decl, generics),
                              id: self.get_id(),
                              span: mk_sp(lo, hi),
                              vis: vis }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index d24dd86fda1..7d885837a60 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -454,8 +454,8 @@ pub fn print_foreign_item(s: @ps, item: &ast::foreign_item) {
     maybe_print_comment(s, item.span.lo);
     print_outer_attributes(s, item.attrs);
     match item.node {
-      ast::foreign_item_fn(ref decl, purity, ref generics) => {
-        print_fn(s, decl, Some(purity), AbiSet::Rust(), item.ident, generics, None,
+      ast::foreign_item_fn(ref decl, ref generics) => {
+        print_fn(s, decl, None, AbiSet::Rust(), item.ident, generics, None,
                  item.vis);
         end(s); // end head-ibox
         word(s.s, ";");
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 7278bdeb376..6f228a9a43b 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -317,7 +317,7 @@ pub fn visit_foreign_item<E:Clone>(visitor: @Visitor<E>,
                                    foreign_item: &foreign_item,
                                    env: E) {
     match foreign_item.node {
-        foreign_item_fn(ref function_declaration, _, ref generics) => {
+        foreign_item_fn(ref function_declaration, ref generics) => {
             visit_fn_decl(visitor, function_declaration, env.clone());
             visitor.visit_generics(generics, env)
         }