auto merge of #8831 : catamorphism/rust/extend_rust_path, r=catamorphism

r? @brson

@metajack requested the ability to violate the "only workspaces can be in the RUST_PATH" rule for the purpose of bootstrapping Servo without having to restructure all the directories. This patch gives rustpkg the ability to find sources if a directory in the RUST_PATH directly contains one of rustpkg's "special" files (lib.rs, main.rs, bench.rs, or test.rs), even if it's not a workspace. In this case, it puts the build artifacts in the first workspace in the RUST_PATH.

I'm not sure whether or not it's a good idea to keep this feature in rustpkg permanently. Thus, I added a flag, ```--use-rust-path-hack```, and only enabled it when the flag is set.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/libstd/os.rs b/src/libstd/os.rs
index 07e0b0857a1..91408162788 100644
--- a/src/libstd/os.rs
+++ b/src/libstd/os.rs
@@ -1002,6 +1002,18 @@ pub fn remove_file(p: &Path) -> bool {
     }
 }
 
+/// Renames an existing file or directory
+pub fn rename_file(old: &Path, new: &Path) -> bool {
+    #[fixed_stack_segment]; #[inline(never)];
+    unsafe {
+       do old.with_c_str |old_buf| {
+            do new.with_c_str |new_buf| {
+                libc::rename(old_buf, new_buf) == (0 as c_int)
+            }
+       }
+    }
+}
+
 #[cfg(unix)]
 /// Returns the platform-specific value of errno
 pub fn errno() -> int {