auto merge of #15319 : alexcrichton/rust/no-crate-id, r=brson

This is an implementation of [RFC 35](https://github.com/rust-lang/rfcs/blob/master/active/0035-remove-crate-id.md).

The summary for this PR is the same as that of the RFC, with one addendum:


* Removes the `#[crate_id]` attribute and knowledge of versions from rustc.
* Added a `#[crate_name]` attribute similar to the old `#[crate_id]` attribute
* Output filenames no longer have versions or hashes
* Symbols no longer have versions (they still have hashes)
* A new flag, `--extern`, is used to override searching for external crates
* A new flag, `-C metadata=foo`, used when hashing symbols
* [added] An old flag, `--crate-name`, was re purposed to specify the crate name from the command line.

I tried to maintain backwards compatibility wherever possible (with warnings being printed). If I missed anywhere, however, please let me know!

[breaking-change]

Closes #14468
Closes #14469
Closes #14470
Closes #14471

Author: bors

mk/main.mk

@@ -16,6 +16,8 @@
 CFG_RELEASE_NUM=0.11.0
 CFG_RELEASE_LABEL=
 
+CFG_FILENAME_EXTRA=4e7c5e5c
+
 ifndef CFG_ENABLE_NIGHTLY
 # This is the normal version string
 CFG_RELEASE=$(CFG_RELEASE_NUM)$(CFG_RELEASE_LABEL)

mk/target.mk

@@ -44,6 +44,13 @@ $(foreach host,$(CFG_HOST),						    \
    $(foreach crate,$(CRATES),						    \
     $(eval $(call RUST_CRATE_FULLDEPS,$(stage),$(target),$(host),$(crate)))))))
 
+# NOTE: after a stage0 snap this should be just EXTRA_FILENAME, not with a stage
+# bound
+EXTRA_FILENAME_0 =
+EXTRA_FILENAME_1 = -C extra-filename=-$(CFG_FILENAME_EXTRA)
+EXTRA_FILENAME_2 = -C extra-filename=-$(CFG_FILENAME_EXTRA)
+EXTRA_FILENAME_3 = -C extra-filename=-$(CFG_FILENAME_EXTRA)
+
 # RUST_TARGET_STAGE_N template: This defines how target artifacts are built
 # for all stage/target architecture combinations. This is one giant rule which
 # works as follows:
@@ -85,7 +92,9 @@ $$(TLIB$(1)_T_$(2)_H_$(3))/stamp.$(4):				    \
 		-L "$$(LLVM_LIBDIR_$(2))" \
 		-L "$$(dir $$(LLVM_STDCPP_LOCATION_$(2)))" \
 		$$(RUSTFLAGS_$(4)) \
-		--out-dir $$(@D) $$<
+		--out-dir $$(@D) \
+		$$(EXTRA_FILENAME_$(1)) \
+		$$<
 	@touch $$@
 	$$(call LIST_ALL_OLD_GLOB_MATCHES,\
 	    $$(dir $$@)$$(call CFG_LIB_GLOB_$(2),$(4)))

src/liballoc/lib.rs

@@ -60,7 +60,8 @@
 //! by libc malloc/free.  The `libc_heap` module is defined to be wired up to
 //! the system malloc/free.
 
-#![crate_id = "alloc#0.11.0"]
+#![crate_id = "alloc#0.11.0"] // NOTE: remove after a stage0 snap
+#![crate_name = "alloc"]
 #![experimental]
 #![license = "MIT/ASL2"]
 #![crate_type = "rlib"]
@@ -70,6 +71,7 @@
 
 #![no_std]
 #![feature(lang_items, phase, unsafe_destructor)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 #[phase(plugin, link)]
 extern crate core;

src/libarena/lib.rs

@@ -20,6 +20,7 @@
 //! more complex, slower Arena which can hold objects of any type.
 
 #![crate_id = "arena#0.11.0"]
+#![crate_name = "arena"]
 #![experimental]
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
@@ -30,6 +31,7 @@
 
 #![feature(unsafe_destructor)]
 #![allow(missing_doc)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 use std::cell::{Cell, RefCell};
 use std::cmp;

src/libcollections/lib.rs

@@ -12,7 +12,8 @@
  * Collection types.
  */
 
-#![crate_id = "collections#0.11.0"]
+#![crate_id = "collections#0.11.0"] // NOTE: remove after stage0
+#![crate_name = "collections"]
 #![experimental]
 #![crate_type = "rlib"]
 #![license = "MIT/ASL2"]
@@ -24,6 +25,7 @@
 #![feature(macro_rules, managed_boxes, default_type_params, phase, globs)]
 #![feature(unsafe_destructor)]
 #![no_std]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 #[phase(plugin, link)] extern crate core;
 extern crate alloc;

src/libcore/lib.rs

@@ -48,6 +48,7 @@
 // separate crate, libcoretest, to avoid bizarre issues.
 
 #![crate_id = "core#0.11.0"]
+#![crate_name = "core"]
 #![experimental]
 #![license = "MIT/ASL2"]
 #![crate_type = "rlib"]
@@ -60,6 +61,7 @@
 #![feature(globs, intrinsics, lang_items, macro_rules, managed_boxes, phase)]
 #![feature(simd, unsafe_destructor)]
 #![deny(missing_doc)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 mod macros;
 

src/libdebug/lib.rs

@@ -16,7 +16,8 @@
 //! Additionally, it is not guaranteed that functionality such as reflection
 //! will persist into the future.
 
-#![crate_id = "debug#0.11.0"]
+#![crate_id = "debug#0.11.0"] // NOTE: remove after stage0
+#![crate_name = "debug"]
 #![experimental]
 #![license = "MIT/ASL2"]
 #![crate_type = "rlib"]
@@ -27,6 +28,7 @@
 #![experimental]
 #![feature(managed_boxes, macro_rules)]
 #![allow(experimental)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 pub mod fmt;
 pub mod reflect;

src/libflate/lib.rs

@@ -18,7 +18,8 @@ Simple [DEFLATE][def]-based compression. This is a wrapper around the
 
 */
 
-#![crate_id = "flate#0.11.0"]
+#![crate_id = "flate#0.11.0"] // NOTE: remove after stage0
+#![crate_name = "flate"]
 #![experimental]
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
@@ -27,6 +28,7 @@ Simple [DEFLATE][def]-based compression. This is a wrapper around the
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/0.11.0/")]
 #![feature(phase)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 #[cfg(test)] #[phase(plugin, link)] extern crate log;
 

src/libfmt_macros/lib.rs

@@ -14,12 +14,14 @@
 //! Parsing does not happen at runtime: structures of `std::fmt::rt` are
 //! generated instead.
 
-#![crate_id = "fmt_macros#0.11.0"]
+#![crate_id = "fmt_macros#0.11.0"] // NOTE: remove after stage0c
+#![crate_name = "fmt_macros"]
 #![experimental]
 #![license = "MIT/ASL2"]
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
 #![feature(macro_rules, globs)]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 use std::char;
 use std::str;

src/libfourcc/lib.rs

@@ -39,14 +39,16 @@ fn main() {
 
 */
 
-#![crate_id = "fourcc#0.11.0"]
+#![crate_id = "fourcc#0.11.0"] // NOTE: remove after stage0
+#![crate_name = "fourcc"]
 #![experimental]
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
 #![license = "MIT/ASL2"]
 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/0.11.0/")]
+#![allow(unused_attribute)] // NOTE: remove after stage0
 
 #![feature(plugin_registrar, managed_boxes)]