auto merge of #10528 : alexcrichton/rust/static-linking-v2, r=pcwalton

In this series of commits, I've implemented static linking for rust. The scheme I implemented was the same as my [mailing list post](https://mail.mozilla.org/pipermail/rust-dev/2013-November/006686.html).

The commits have more details to the nitty gritty of what went on. I've rebased this on top of my native mutex pull request (#10479), but I imagine that it will land before this lands, I just wanted to pre-emptively get all the rebase conflicts out of the way (becuase this is reorganizing building librustrt as well).

Some contentious points I want to make sure are all good:

* I've added more "compiler chooses a default" behavior than I would like, I want to make sure that this is all very clearly outlined in the code, and if not I would like to remove behavior or make it clearer.
* I want to make sure that the new "fancy suite" tests are ok (using make/python instead of another rust crate)

If we do indeed pursue this, I would be more than willing to write up a document describing how linking in rust works. I believe that this behavior should be very understandable, and the compiler should never hinder someone just because linking is a little fuzzy.

2 files changed, 59 insertions, 10 deletions

diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index a72bc6b8328..296091d26e6 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -51,7 +51,9 @@
 
 #[comment = "The Rust standard library"];
 #[license = "MIT/ASL2"];
-#[crate_type = "lib"];
+#[crate_type = "lib"]; // NOTE: remove after stage0 snapshot
+#[crate_type = "rlib"];
+#[crate_type = "dylib"];
 
 #[doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
@@ -64,6 +66,7 @@
 
 #[deny(non_camel_case_types)];
 #[deny(missing_doc)];
+#[allow(attribute_usage)]; // NOTE: remove after the next snapshot
 
 // When testing libstd, bring in libuv as the I/O backend so tests can print
 // things and all of the std::io tests have an I/O interface to run on top
@@ -79,15 +82,7 @@
 #[cfg(test)] pub use ops = realstd::ops;
 #[cfg(test)] pub use cmp = realstd::cmp;
 
-// On Linux, link to the runtime with -lrt.
-#[cfg(target_os = "linux")]
-#[doc(hidden)]
-pub mod linkhack {
-    #[link_args="-lrustrt -lrt"]
-    #[link_args = "-lpthread"]
-    extern {
-    }
-}
+mod rtdeps;
 
 /* The Prelude. */
 
diff --git a/src/libstd/rtdeps.rs b/src/libstd/rtdeps.rs
new file mode 100644
index 00000000000..ba4f120f626
--- /dev/null
+++ b/src/libstd/rtdeps.rs
@@ -0,0 +1,54 @@
+// Copyright 2013 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.
+
+//! This module contains the linkage attributes to all runtime dependencies of
+//! the stndard library This varies per-platform, but these libraries are
+//! necessary for running libstd.
+
+// All platforms need to link to rustrt
+#[link(name = "rustrt", kind = "static")]
+extern {}
+
+// LLVM implements the `frem` instruction as a call to `fmod`, which lives in
+// libm. Hence, we must explicitly link to it.
+//
+// On linux librt and libdl are indirect dependencies via rustrt,
+// and binutils 2.22+ won't add them automatically
+#[cfg(target_os = "linux")]
+#[link(name = "rt")]
+#[link(name = "dl")]
+#[link(name = "m")]
+#[link(name = "pthread")]
+#[link(name = "stdc++")]
+extern {}
+
+#[cfg(target_os = "android")]
+#[link(name = "dl")]
+#[link(name = "log")]
+#[link(name = "supc++")]
+#[link(name = "gnustl_shared")]
+#[link(name = "m")]
+extern {}
+
+#[cfg(target_os = "freebsd")]
+#[link(name = "execinfo")]
+#[link(name = "rt")]
+#[link(name = "stdc++")]
+#[link(name = "pthread")]
+extern {}
+
+#[cfg(target_os = "macos")]
+#[link(name = "pthread")]
+#[link(name = "stdc++")]
+extern {}
+
+#[cfg(stage0)]
+#[link_args = "-lstdc++"]
+extern {}