auto merge of #9664 : alexcrichton/rust/logging, r=huonw

This makes some headway on #3309, see commits for details.

src/test/auxiliary/logging_right_crate.rs

@@ -0,0 +1,14 @@
+// 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.
+
+pub fn foo<T>() {
+    fn death() -> int { fail2!() }
+    debug2!("{:?}", (||{ death() })());
+}

src/test/run-pass/logging-right-crate.rs

@@ -0,0 +1,30 @@
+// 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.
+
+// aux-build:logging_right_crate.rs
+// xfail-fast
+// exec-env:RUST_LOG=logging-right-crate=debug
+
+// This is a test for issue #3046 to make sure that when we monomorphize a
+// function from one crate to another the right top-level logging name is
+// preserved.
+//
+// It used to be the case that if logging were turned on for this crate, all
+// monomorphized functions from other crates had logging turned on (their
+// logging module names were all incorrect). This test ensures that this no
+// longer happens by enabling logging for *this* crate and then invoking a
+// function in an external crate which will fail when logging is enabled.
+
+extern mod logging_right_crate;
+
+fn main() {
+    // this function fails if logging is turned on
+    logging_right_crate::foo::<int>();
+}