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]

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 {

src/librustc/driver/config.rs

@@ -11,7 +11,7 @@
 //! Contains infrastructure for configuring the compiler, including parsing
 //! command line options.
 
-use driver::early_error;
+use driver::{early_error, early_warn};
 use driver::driver;
 use driver::session::Session;
 
@@ -96,6 +96,7 @@ pub struct Options {
     pub cg: CodegenOptions,
     pub color: ColorConfig,
     pub externs: HashMap<String, Vec<String>>,
+    pub crate_name: Option<String>,
 }
 
 /// Some reasonable defaults
@@ -122,6 +123,7 @@ pub fn basic_options() -> Options {
         cg: basic_codegen_options(),
         color: Auto,
         externs: HashMap::new(),
+        crate_name: None,
     }
 }
 
@@ -511,9 +513,12 @@ pub fn optgroups() -> Vec<getopts::OptGroup> {
                  "[bin|lib|rlib|dylib|staticlib]"),
         optmulti("", "emit", "Comma separated list of types of output for the compiler to emit",
                  "[asm|bc|ir|obj|link]"),
-        optflag("", "crate-name", "Output the crate name and exit"),
-        optflag("", "crate-file-name", "Output the file(s) that would be written if compilation \
+        optopt("", "crate-name", "Specify the name of the crate being built",
+               "NAME"),
+        optflag("", "print-crate-name", "Output the crate name and exit"),
+        optflag("", "print-file-name", "Output the file(s) that would be written if compilation \
               continued and exit"),
+        optflag("", "crate-file-name", "deprecated in favor of --print-file-name"),
         optflag("g",  "",  "Equivalent to --debuginfo=2"),
         optopt("",  "debuginfo",  "Emit DWARF debug info to the objects created:
              0 = no debug info,
@@ -716,8 +721,13 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
                                  matches.opt_str("dep-info")
                                         .map(|p| Path::new(p)));
 
-    let print_metas = (matches.opt_present("crate-name"),
+    let print_metas = (matches.opt_present("print-crate-name"),
+                       matches.opt_present("print-file-name") ||
                        matches.opt_present("crate-file-name"));
+    if matches.opt_present("crate-file-name") {
+        early_warn("the --crate-file-name argument has been renamed to \
+                    --print-file-name");
+    }
     let cg = build_codegen_options(matches);
 
     let color = match matches.opt_str("color").as_ref().map(|s| s.as_slice()) {
@@ -749,6 +759,8 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         locs.push(location.to_string());
     }
 
+    let crate_name = matches.opt_str("crate-name");
+
     Options {
         crate_types: crate_types,
         gc: gc,
@@ -771,6 +783,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         cg: cg,
         color: color,
         externs: externs,
+        crate_name: crate_name,
     }
 }
 

src/librustc/driver/mod.rs

@@ -389,6 +389,11 @@ pub fn early_error(msg: &str) -> ! {
     fail!(diagnostic::FatalError);
 }
 
+pub fn early_warn(msg: &str) {
+    let mut emitter = diagnostic::EmitterWriter::stderr(diagnostic::Auto);
+    emitter.emit(None, msg, diagnostic::Warning);
+}
+
 pub fn list_metadata(sess: &Session, path: &Path,
                      out: &mut io::Writer) -> io::IoResult<()> {
     metadata::loader::list_file_metadata(sess.targ_cfg.os, path, out)

src/test/run-make/crate-data-smoke/Makefile

@@ -1,9 +1,9 @@
 -include ../tools.mk
 
 all:
-	[ `$(RUSTC) --crate-name crate.rs` = "foo" ]
-	[ `$(RUSTC) --crate-file-name crate.rs` = "foo" ]
-	[ `$(RUSTC) --crate-file-name --crate-type=lib --test crate.rs` = "foo" ]
-	[ `$(RUSTC) --crate-file-name --test lib.rs` = "mylib" ]
-	$(RUSTC) --crate-file-name lib.rs
-	$(RUSTC) --crate-file-name rlib.rs
+	[ `$(RUSTC) --print-crate-name crate.rs` = "foo" ]
+	[ `$(RUSTC) --print-file-name crate.rs` = "foo" ]
+	[ `$(RUSTC) --print-file-name --crate-type=lib --test crate.rs` = "foo" ]
+	[ `$(RUSTC) --print-file-name --test lib.rs` = "mylib" ]
+	$(RUSTC) --print-file-name lib.rs
+	$(RUSTC) --print-file-name rlib.rs

src/test/run-make/manual-crate-name/Makefile

@@ -0,0 +1,5 @@
+-include ../tools.mk
+
+all:
+	$(RUSTC) --crate-name foo bar.rs
+	rm $(TMPDIR)/libfoo.rlib

src/test/run-make/manual-crate-name/bar.rs

@@ -0,0 +1,11 @@
+// Copyright 2014 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.
+
+#![crate_type = "rlib"]