Tighten up error checking of library renames.

src/librustc_metadata/creader.rs

@@ -946,19 +946,51 @@ impl<'a> middle::cstore::CrateLoader for CrateLoader<'a> {
         }
 
         // Process libs passed on the command line
+        // First, check for errors
+        let mut renames = FxHashSet();
+        for &(ref name, ref new_name, _) in &self.sess.opts.libs {
+            if let &Some(ref new_name) = new_name {
+                if new_name.is_empty() {
+                    self.sess.err(
+                        &format!("an empty renaming target was specified for library `{}`",name));
+                } else if !self.cstore.get_used_libraries().borrow().iter()
+                                                           .any(|lib| lib.name == name as &str) {
+                    self.sess.err(&format!("renaming of the library `{}` was specified, \
+                                            however this crate contains no #[link(...)] \
+                                            attributes referencing this library.", name));
+                } else if renames.contains(name) {
+                    self.sess.err(&format!("multiple renamings were specified for library `{}` .",
+                                            name));
+                } else {
+                    renames.insert(name);
+                }
+            }
+        }
+        // Update kind and, optionally, the name of all native libaries
+        // (there may be more than one) with the specified name.
         for &(ref name, ref new_name, kind) in &self.sess.opts.libs {
-            // First, try to update existing lib(s) added via #[link(...)]
-            let new_name = new_name.as_ref().map(|s| &**s); // &Option<String> -> Option<&str>
-            if !self.cstore.update_used_library(name, new_name, kind) {
+            let mut found = false;
+            for lib in self.cstore.get_used_libraries().borrow_mut().iter_mut() {
+                if lib.name == name as &str {
+                    lib.kind = kind;
+                    if let &Some(ref new_name) = new_name {
+                        lib.name = Symbol::intern(new_name);
+                    }
+                    found = true;
+                    break;
+                }
+            }
+            if !found {
                 // Add if not found
+                let new_name = new_name.as_ref().map(|s| &**s); // &Option<String> -> Option<&str>
                 let lib = NativeLibrary {
-                    name: Symbol::intern(name),
+                    name: Symbol::intern(new_name.unwrap_or(name)),
                     kind: kind,
                     cfg: None,
                     foreign_items: Vec::new(),
                 };
                 register_native_lib(self.sess, self.cstore, None, lib);
-             }
+            }
         }
         self.register_statically_included_foreign_items();
         self.register_dllimport_foreign_items();

src/librustc_metadata/cstore.rs

@@ -232,23 +232,6 @@ impl CStore {
         self.used_libraries.borrow_mut().push(lib);
     }
 
-    // Update kind and, optionally, the name of all native libaries (there may be more than one)
-    // with the specified name.
-    pub fn update_used_library(&self, name: &str, new_name: Option<&str>,
-                               new_kind: NativeLibraryKind) -> bool {
-        let mut found = false;
-        for item in self.used_libraries.borrow_mut().iter_mut() {
-            if item.name == name {
-                item.kind = new_kind;
-                if let Some(new_name) = new_name {
-                    item.name = Symbol::intern(new_name);
-                }
-                found = true;
-            }
-        }
-        found
-    }
-
     pub fn get_used_libraries(&self) -> &RefCell<Vec<NativeLibrary>> {
         &self.used_libraries
     }

src/test/compile-fail/rfc1717/missing-link-attr.rs

@@ -0,0 +1,14 @@
+// Copyright 2016 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.
+
+// compile-flags: -l foo:bar
+// error-pattern: renaming of the library `foo` was specified
+
+#![crate_type = "lib"]

src/test/compile-fail/rfc1717/multiple-renames.rs

@@ -0,0 +1,17 @@
+// Copyright 2016 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.
+
+// compile-flags: -l foo:bar -l foo:baz
+// error-pattern: multiple renamings were specified for library
+
+#![crate_type = "lib"]
+
+#[link(name = "foo")]
+extern "C" {}

src/test/compile-fail/rfc1717/rename-to-empty.rs

@@ -0,0 +1,17 @@
+// Copyright 2016 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.
+
+// compile-flags: -l foo:
+// error-pattern: an empty renaming target was specified for library
+
+#![crate_type = "lib"]
+
+#[link(name = "foo")]
+extern "C" {}