rustc: Repurpose the --crate-name CLI flag

In a cargo-driven world the primary location for the name of a crate will be in
its manifest, not in the source file itself. The purpose of this flag is to
reduce required duplication for new cargo projects.

This is a breaking change because the existing --crate-name flag actually
printed the crate name. This flag was renamed to --print-crate-name, and to
maintain consistence, the --crate-file-name flag was renamed to
--print-file-name.

To maintain backwards compatibility, the --crate-file-name flag is still
recognized, but it is deprecated.

[breaking-change]

1 files changed, 10 insertions, 0 deletions

diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
index 497fcab44e1..c306a184ca1 100644
--- a/src/librustc/back/link.rs
+++ b/src/librustc/back/link.rs
@@ -556,6 +556,16 @@ pub fn find_crate_name(sess: Option<&Session>,
         s
     };
 
+    match sess {
+        Some(sess) => {
+            match sess.opts.crate_name {
+                Some(ref s) => return validate(s.clone(), None),
+                None => {}
+            }
+        }
+        None => {}
+    }
+
     let crate_name = attrs.iter().find(|at| at.check_name("crate_name"))
                           .and_then(|at| at.value_str().map(|s| (at, s)));
     match crate_name {