auto merge of #10696 : fhahn/rust/issue9543-remove-extern-mod-foo, r=pcwalton

This patch for  #9543 throws an `obsolete syntax` error for `extern mod foo (name="bar")` . 
I was wondering if [this](https://github.com/fhahn/rust/compare/mozilla:master...fhahn:issue9543-remove-extern-mod-foo?expand=1#diff-da9d34ca1d0f6beee2838cf02e07345cR4444) is the correct place to do this?

I think the wording of the error message could probably be improved as well.

If this approach is OK, I'm going to run the whole test suite tomorrow and update the old syntax to the new one.

18 files changed, 62 insertions, 37 deletions

diff --git a/src/librustc/front/std_inject.rs b/src/librustc/front/std_inject.rs
index 97ffc1490f5..cebf42eff11 100644
--- a/src/librustc/front/std_inject.rs
+++ b/src/librustc/front/std_inject.rs
@@ -21,7 +21,7 @@ use syntax::fold;
 use syntax::opt_vec;
 use syntax::util::small_vector::SmallVector;
 
-static STD_VERSION: &'static str = "0.9-pre";
+pub static VERSION: &'static str = "0.9-pre";
 
 pub fn maybe_inject_libstd_ref(sess: Session, crate: ast::Crate)
                                -> ast::Crate {
@@ -57,12 +57,10 @@ struct StandardLibraryInjector {
 
 impl fold::ast_fold for StandardLibraryInjector {
     fn fold_crate(&mut self, crate: ast::Crate) -> ast::Crate {
-        let version = STD_VERSION.to_managed();
-        let vers_item = attr::mk_name_value_item_str(@"vers", version);
         let mut vis = ~[ast::view_item {
             node: ast::view_item_extern_mod(self.sess.ident_of("std"),
-                                            None,
-                                            ~[vers_item.clone()],
+                                            Some((format!("std\\#{}", VERSION).to_managed(),
+                                                  ast::CookedStr)),
                                             ast::DUMMY_NODE_ID),
             attrs: ~[],
             vis: ast::private,
@@ -72,8 +70,8 @@ impl fold::ast_fold for StandardLibraryInjector {
         if use_uv(&crate) && !self.sess.building_library.get() {
             vis.push(ast::view_item {
                 node: ast::view_item_extern_mod(self.sess.ident_of("green"),
-                                                None,
-                                                ~[vers_item],
+                                                Some((format!("green\\#{}", VERSION).to_managed(),
+                                                      ast::CookedStr)),
                                                 ast::DUMMY_NODE_ID),
                 attrs: ~[],
                 vis: ast::private,
@@ -81,8 +79,8 @@ impl fold::ast_fold for StandardLibraryInjector {
             });
             vis.push(ast::view_item {
                 node: ast::view_item_extern_mod(self.sess.ident_of("rustuv"),
-                                                None,
-                                                ~[vers_item],
+                                                Some((format!("rustuv\\#{}", VERSION).to_managed(),
+                                                      ast::CookedStr)),
                                                 ast::DUMMY_NODE_ID),
                 attrs: ~[],
                 vis: ast::private,
diff --git a/src/librustc/front/test.rs b/src/librustc/front/test.rs
index 2b104cde95a..6acd3060e9f 100644
--- a/src/librustc/front/test.rs
+++ b/src/librustc/front/test.rs
@@ -13,6 +13,7 @@
 
 use driver::session;
 use front::config;
+use front::std_inject::VERSION;
 
 use std::cell::RefCell;
 use std::vec;
@@ -291,8 +292,10 @@ fn mk_std(cx: &TestCtxt) -> ast::view_item {
                                             path_node(~[id_extra]),
                                             ast::DUMMY_NODE_ID))])
     } else {
-        let mi = attr::mk_name_value_item_str(@"vers", @"0.9-pre");
-        ast::view_item_extern_mod(id_extra, None, ~[mi], ast::DUMMY_NODE_ID)
+        ast::view_item_extern_mod(id_extra,
+                                  Some((format!("extra\\#{}", VERSION).to_managed(),
+                                        ast::CookedStr)),
+                                  ast::DUMMY_NODE_ID)
     };
     ast::view_item {
         node: vi,
diff --git a/src/librustc/metadata/creader.rs b/src/librustc/metadata/creader.rs
index 33e407dec1a..f14c9780bc4 100644
--- a/src/librustc/metadata/creader.rs
+++ b/src/librustc/metadata/creader.rs
@@ -132,7 +132,7 @@ fn visit_crate(e: &Env, c: &ast::Crate) {
 
 fn visit_view_item(e: &mut Env, i: &ast::view_item) {
     match i.node {
-      ast::view_item_extern_mod(ident, path_opt, _, id) => {
+      ast::view_item_extern_mod(ident, path_opt, id) => {
           let ident = token::ident_to_str(&ident);
           debug!("resolving extern mod stmt. ident: {:?} path_opt: {:?}",
                  ident, path_opt);
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index 5de4de89b8e..905213fe95b 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -1507,7 +1507,7 @@ impl Resolver {
                 }
             }
 
-            view_item_extern_mod(name, _, _, node_id) => {
+            view_item_extern_mod(name, _, node_id) => {
                 // n.b. we don't need to look at the path option here, because cstore already did
                 match self.session.cstore.find_extern_mod_stmt_cnum(node_id) {
                     Some(crate_id) => {
diff --git a/src/librustdoc/clean.rs b/src/librustdoc/clean.rs
index ab36079585f..4bcf1985ef2 100644
--- a/src/librustdoc/clean.rs
+++ b/src/librustdoc/clean.rs
@@ -994,15 +994,15 @@ impl Clean<Item> for ast::view_item {
 
 #[deriving(Clone, Encodable, Decodable)]
 pub enum ViewItemInner {
-    ExternMod(~str, Option<~str>, ~[Attribute], ast::NodeId),
+    ExternMod(~str, Option<~str>, ast::NodeId),
     Import(~[ViewPath])
 }
 
 impl Clean<ViewItemInner> for ast::view_item_ {
     fn clean(&self) -> ViewItemInner {
         match self {
-            &ast::view_item_extern_mod(ref i, ref p, ref mi, ref id) =>
-                ExternMod(i.clean(), p.map(|(ref x, _)| x.to_owned()),  mi.clean(), *id),
+            &ast::view_item_extern_mod(ref i, ref p, ref id) =>
+                ExternMod(i.clean(), p.map(|(ref x, _)| x.to_owned()), *id),
             &ast::view_item_use(ref vp) => Import(vp.clean())
         }
     }
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 8a14e37c816..7c3d3b4b44f 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -995,7 +995,7 @@ fn item_module(w: &mut Writer, cx: &Context,
 
             clean::ViewItemItem(ref item) => {
                 match item.inner {
-                    clean::ExternMod(ref name, ref src, _, _) => {
+                    clean::ExternMod(ref name, ref src, _) => {
                         write!(w, "<tr><td><code>extern mod {}",
                                name.as_slice());
                         match *src {
diff --git a/src/librustpkg/path_util.rs b/src/librustpkg/path_util.rs
index 1b8a988ab2c..aaaf56af436 100644
--- a/src/librustpkg/path_util.rs
+++ b/src/librustpkg/path_util.rs
@@ -14,7 +14,8 @@
 
 pub use crate_id::CrateId;
 pub use target::{OutputType, Main, Lib, Test, Bench, Target, Build, Install};
-pub use version::{Version, NoVersion, split_version_general, try_parsing_version};
+pub use version::{Version, ExactRevision, NoVersion, split_version, split_version_general,
+    try_parsing_version};
 pub use rustc::metadata::filesearch::rust_path;
 use rustc::metadata::filesearch::libdir;
 use rustc::driver::driver::host_triple;
@@ -213,8 +214,9 @@ pub fn library_in_workspace(path: &Path, short_name: &str, where: Target,
 }
 
 // rustc doesn't use target-specific subdirectories
-pub fn system_library(sysroot: &Path, lib_name: &str) -> Option<Path> {
-    library_in(lib_name, &NoVersion, &sysroot.join(libdir()))
+pub fn system_library(sysroot: &Path, crate_id: &str) -> Option<Path> {
+    let (lib_name, version) = split_crate_id(crate_id);
+    library_in(lib_name, &version, &sysroot.join(libdir()))
 }
 
 fn library_in(short_name: &str, version: &Version, dir_to_search: &Path) -> Option<Path> {
@@ -268,6 +270,7 @@ fn library_in(short_name: &str, version: &Version, dir_to_search: &Path) -> Opti
                                }
                                None => break
                            }
+
                        }
                        _ => { f_name = f_name.slice(0, i); }
                  }
@@ -293,6 +296,22 @@ fn library_in(short_name: &str, version: &Version, dir_to_search: &Path) -> Opti
     abs_path
 }
 
+fn split_crate_id<'a>(crate_id: &'a str) -> (&'a str, Version) {
+    match split_version(crate_id) {
+        Some((name, vers)) =>
+            match vers {
+                ExactRevision(ref v) => match v.find('-') {
+                    Some(pos) => (name, ExactRevision(v.slice(0, pos).to_owned())),
+                    None => (name, ExactRevision(v.to_owned()))
+                },
+                _ => (name, vers)
+            },
+        None => (crate_id, NoVersion)
+    }
+}
+
+
+
 /// Returns the executable that would be installed for <crateid>
 /// in <workspace>
 /// As a side effect, creates the bin-dir if it doesn't exist
diff --git a/src/librustpkg/util.rs b/src/librustpkg/util.rs
index a081c2a31af..c5648d811ed 100644
--- a/src/librustpkg/util.rs
+++ b/src/librustpkg/util.rs
@@ -461,7 +461,7 @@ impl<'a> Visitor<()> for ViewItemVisitor<'a> {
 
         match vi.node {
             // ignore metadata, I guess
-            ast::view_item_extern_mod(lib_ident, path_opt, _, _) => {
+            ast::view_item_extern_mod(lib_ident, path_opt, _) => {
                 let lib_name = match path_opt {
                     Some((p, _)) => p,
                     None => self.sess.str_of(lib_ident)
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 8e6e0625138..51aa7cd4377 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1057,7 +1057,7 @@ pub enum view_item_ {
     // optional @str: if present, this is a location (containing
     // arbitrary characters) from which to fetch the crate sources
     // For example, extern mod whatever = "github.com/mozilla/rust"
-    view_item_extern_mod(Ident, Option<(@str, StrStyle)>, ~[@MetaItem], NodeId),
+    view_item_extern_mod(Ident, Option<(@str, StrStyle)>, NodeId),
     view_item_use(~[@view_path]),
 }
 
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 87448278687..f93eb6754ad 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -419,7 +419,7 @@ impl<'a, O: IdVisitingOperation> Visitor<()> for IdVisitor<'a, O> {
 
     fn visit_view_item(&mut self, view_item: &view_item, env: ()) {
         match view_item.node {
-            view_item_extern_mod(_, _, _, node_id) => {
+            view_item_extern_mod(_, _, node_id) => {
                 self.operation.visit_id(node_id)
             }
             view_item_use(ref view_paths) => {
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 9edde7c9c87..4a2adc04fbd 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -66,11 +66,9 @@ pub trait ast_fold {
         let inner_view_item = match vi.node {
             view_item_extern_mod(ref ident,
                                  string,
-                                 ref meta_items,
                                  node_id) => {
                 view_item_extern_mod(ident.clone(),
                                      string,
-                                     self.fold_meta_items(*meta_items),
                                      self.new_id(node_id))
             }
             view_item_use(ref view_paths) => {
diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index d739fca99da..df6fbe98aed 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -45,6 +45,7 @@ pub enum ObsoleteSyntax {
     ObsoleteBoxedClosure,
     ObsoleteClosureType,
     ObsoleteMultipleImport,
+    ObsoleteExternModAttributesInParens
 }
 
 impl to_bytes::IterBytes for ObsoleteSyntax {
@@ -145,6 +146,11 @@ impl ParserObsoleteMethods for Parser {
                 "multiple imports",
                 "only one import is allowed per `use` statement"
             ),
+            ObsoleteExternModAttributesInParens => (
+                "`extern mod` with linkage attribute list",
+                "use `extern mod foo = \"bar\";` instead of \
+                `extern mod foo (name = \"bar\")`"
+            )
         };
 
         self.report(sp, kind, kind_str, desc);
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 729d0320435..5e2b022d175 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4446,11 +4446,18 @@ impl Parser {
             self.span_err(*self.span, "an ABI may not be specified here");
         }
 
+
+        if *self.token == token::LPAREN {
+            // `extern mod foo (name = "bar"[,vers = "version"]) is obsolete,
+            // `extern mod foo = "bar#[version]";` should be used.
+            // Parse obsolete options to avoid wired parser errors
+            self.parse_optional_meta();
+            self.obsolete(*self.span, ObsoleteExternModAttributesInParens);
+        }
         // extern mod foo;
-        let metadata = self.parse_optional_meta();
         self.expect(&token::SEMI);
         iovi_view_item(ast::view_item {
-            node: view_item_extern_mod(ident, maybe_path, metadata, ast::DUMMY_NODE_ID),
+            node: view_item_extern_mod(ident, maybe_path, ast::DUMMY_NODE_ID),
             attrs: attrs,
             vis: visibility,
             span: mk_sp(lo, self.last_span.hi)
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 960e28ca84f..79ef9c2cbbe 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1952,7 +1952,7 @@ pub fn print_view_item(s: @ps, item: &ast::view_item) {
     print_outer_attributes(s, item.attrs);
     print_visibility(s, item.vis);
     match item.node {
-        ast::view_item_extern_mod(id, ref optional_path, ref mta, _) => {
+        ast::view_item_extern_mod(id, ref optional_path, _) => {
             head(s, "extern mod");
             print_ident(s, id);
             for &(ref p, style) in optional_path.iter() {
@@ -1961,11 +1961,6 @@ pub fn print_view_item(s: @ps, item: &ast::view_item) {
                 space(s.s);
                 print_string(s, *p, style);
             }
-            if !mta.is_empty() {
-                popen(s);
-                commasep(s, consistent, *mta, |p, &i| print_meta_item(p, i));
-                pclose(s);
-            }
         }
 
         ast::view_item_use(ref vps) => {
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 8cc6fc4990f..2e83a038c58 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -139,7 +139,7 @@ pub fn walk_mod<E:Clone, V:Visitor<E>>(visitor: &mut V, module: &_mod, env: E) {
 
 pub fn walk_view_item<E:Clone, V:Visitor<E>>(visitor: &mut V, vi: &view_item, env: E) {
     match vi.node {
-        view_item_extern_mod(name, _, _, _) => {
+        view_item_extern_mod(name, _, _) => {
             visitor.visit_ident(vi.span, name, env)
         }
         view_item_use(ref paths) => {
diff --git a/src/test/run-pass/crateresolve8.rs b/src/test/run-pass/crateresolve8.rs
index 1dd1b9c098b..d329b8546b6 100644
--- a/src/test/run-pass/crateresolve8.rs
+++ b/src/test/run-pass/crateresolve8.rs
@@ -13,7 +13,7 @@
 
 #[crate_id="crateresolve8#0.1"];
 
-extern mod crateresolve8(vers = "0.1", package_id="crateresolve8#0.1");
+extern mod crateresolve8 = "crateresolve8#0.1";
 //extern mod crateresolve8(vers = "0.1");
 
 pub fn main() {
diff --git a/src/test/run-pass/extern-crosscrate.rs b/src/test/run-pass/extern-crosscrate.rs
index f1255c7e8f1..2b27a56dc79 100644
--- a/src/test/run-pass/extern-crosscrate.rs
+++ b/src/test/run-pass/extern-crosscrate.rs
@@ -11,7 +11,7 @@
 // xfail-fast
 //aux-build:extern-crosscrate-source.rs
 
-extern mod externcallback(vers = "0.1");
+extern mod externcallback = "externcallback#0.1";
 
 fn fact(n: uint) -> uint {
     unsafe {
diff --git a/src/test/run-pass/issue-6919.rs b/src/test/run-pass/issue-6919.rs
index 8482af9e7c4..1af4d892a1a 100644
--- a/src/test/run-pass/issue-6919.rs
+++ b/src/test/run-pass/issue-6919.rs
@@ -12,7 +12,6 @@
 // xfail-fast
 
 #[crate_id="issue-6919"];
-
 extern mod issue6919_3;
 
 pub fn main() {