rustpkg: Handle requested versions in extern mod directives properly

Closes rust-lang#8711

Author: catamorphism

src/librustc/metadata/creader.rs

@@ -13,12 +13,11 @@
 
 use metadata::cstore;
 use metadata::decoder;
-use metadata::filesearch::FileSearch;
+use metadata::filesearch::{FileSearch, split_version};
 use metadata::loader;
 
 use std::hashmap::HashMap;
 use syntax::ast;
-use std::vec;
 use syntax::attr;
 use syntax::attr::AttrMetaMethods;
 use syntax::codemap::{Span, dummy_sp};
@@ -143,15 +142,30 @@ fn visit_view_item(e: @mut Env, i: &ast::view_item) {
           let meta_items = match path_opt {
               None => meta_items.clone(),
               Some((p, _path_str_style)) => {
-                  let p_path = Path::new(p);
-                  match p_path.filestem_str() {
-                      None|Some("") =>
-                          e.diag.span_bug(i.span, "Bad package path in `extern mod` item"),
-                      Some(s) =>
-                          vec::append(
-                              ~[attr::mk_name_value_item_str(@"package_id", p),
-                               attr::mk_name_value_item_str(@"name", s.to_managed())],
-                              *meta_items)
+                  match split_version(p) {
+                      None => {
+                          let p_path = Path::new(p);
+                          let s = match p_path.filestem_str() {
+                                None|Some("") =>
+                                    e.diag.span_bug(i.span,
+                                                    "Bad package path in `extern mod` item"),
+                                Some(s) => s,
+                          };
+                            ~[attr::mk_name_value_item_str(@"package_id", p),
+                              attr::mk_name_value_item_str(@"name", s.to_managed())]
+                      }
+                      Some((name, version)) => {
+                          let p_path = Path::new(name);
+                          let s = match p_path.filestem_str() {
+                                None|Some("") =>
+                                    e.diag.span_bug(i.span,
+                                                    "Bad package path in `extern mod` item"),
+                                Some(s) => s,
+                          };
+                          ~[attr::mk_name_value_item_str(@"package_id", name.to_managed()),
+                            attr::mk_name_value_item_str(@"name", s.to_managed()),
+                            attr::mk_name_value_item_str(@"vers", version.to_managed())]
+                      }
                   }
             }
           };

src/librustc/metadata/filesearch.rs

@@ -236,3 +236,27 @@ pub fn rust_path() -> ~[Path] {
 pub fn libdir() -> ~str {
     (env!("CFG_LIBDIR")).to_owned()
 }
+
+
+/// If s is of the form foo#bar, where bar is a valid version
+/// number, return the prefix before the # and the version.
+/// Otherwise, return None.
+pub fn split_version<'a>(s: &'a str) -> Option<(&'a str, &'a str)> {
+    // Check for extra '#' characters separately
+    if s.split_iter('#').len() > 2 {
+        return None;
+    }
+    split_version_general(s, '#')
+}
+
+pub fn split_version_general<'a>(s: &'a str, sep: char) -> Option<(&'a str, &'a str)> {
+    match s.rfind(sep) {
+        Some(i) => {
+            let path = s.slice(0, i);
+            Some((path, s.slice(i + 1, s.len())))
+        }
+        None => {
+            None
+        }
+    }
+}

src/librustpkg/lib.rs

@@ -433,17 +433,19 @@ impl CtxMethods for BuildContext {
         let pkgid = pkg_src.id.clone();
 
         debug!("build: workspace = {} (in Rust path? {:?} is git dir? {:?} \
-                pkgid = {} pkgsrc start_dir = {}", workspace.display(),
+               pkgid = {} pkgsrc start_dir = {}", workspace.display(),
                in_rust_path(&workspace), is_git_dir(&workspace.join(&pkgid.path)),
-               pkgid.to_str(), pkg_src.start_dir.display());
+               pkgid.to_str(),
+               pkg_src.start_dir.display());
+        let pkg_dir = workspace.join(&pkgid.path);
         debug!("build: what to build = {:?}", what_to_build);
 
         // If workspace isn't in the RUST_PATH, and it's a git repo,
         // then clone it into the first entry in RUST_PATH, and repeat
-        if !in_rust_path(&workspace) && is_git_dir(&workspace.join(&pkgid.path)) {
+        if !in_rust_path(&workspace) && is_git_dir(&pkg_dir) {
             let mut out_dir = default_workspace().join("src");
             out_dir.push(&pkgid.path);
-            let git_result = source_control::safe_git_clone(&workspace.join(&pkgid.path),
+            let git_result = source_control::safe_git_clone(&pkg_dir,
                                                             &pkgid.version,
                                                             &out_dir);
             match git_result {
@@ -516,7 +518,7 @@ impl CtxMethods for BuildContext {
                 JustOne(ref p) => {
                     // We expect that p is relative to the package source's start directory,
                     // so check that assumption
-                    debug!("JustOne: p = {}", p.display());
+                    debug!("JustOne: p = {} and {}", p.display(), pkg_src.start_dir.display());
                     assert!(pkg_src.start_dir.join(p).exists());
                     if is_lib(p) {
                         PkgSrc::push_crate(&mut pkg_src.libs, 0, p);