1 files changed, 125 insertions, 0 deletions
diff --git a/src/libstd/rt/args.rs b/src/libstd/rt/args.rs
new file mode 100644
index 00000000000..75ee4f381f6
--- /dev/null
+++ b/src/libstd/rt/args.rs
@@ -0,0 +1,125 @@
+// Copyright 2012-2013 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.
+
+//! Global storage for command line arguments
+//!
+//! The current incarnation of the Rust runtime expects for
+//! the processes `argc` and `argv` arguments to be stored
+//! in a globally-accessible location for use by the `os` module.
+//!
+//! XXX: Would be nice for this to not exist.
+//! XXX: This has a lot of C glue for lack of globals.
+
+use libc;
+use option::{Option, Some, None};
+use str;
+use uint;
+use unstable::finally::Finally;
+use util;
+
+/// One-time global initialization.
+pub unsafe fn init(argc: int, argv: **u8) {
+    let args = load_argc_and_argv(argc, argv);
+    put(args);
+}
+
+/// One-time global cleanup.
+pub fn cleanup() {
+    rtassert!(take().is_some());
+}
+
+/// Take the global arguments from global storage.
+pub fn take() -> Option<~[~str]> {
+    with_lock(|| unsafe {
+        let ptr = get_global_ptr();
+        let val = util::replace(&mut *ptr, None);
+        val.map(|s: &~~[~str]| (**s).clone())
+    })
+}
+
+/// Give the global arguments to global storage.
+///
+/// It is an error if the arguments already exist.
+pub fn put(args: ~[~str]) {
+    with_lock(|| unsafe {
+        let ptr = get_global_ptr();
+        rtassert!((*ptr).is_none());
+        (*ptr) = Some(~args.clone());
+    })
+}
+
+/// Make a clone of the global arguments.
+pub fn clone() -> Option<~[~str]> {
+    with_lock(|| unsafe {
+        let ptr = get_global_ptr();
+        (*ptr).map(|s: &~~[~str]| (**s).clone())
+    })
+}
+
+fn with_lock<T>(f: &fn() -> T) -> T {
+    do (|| {
+        unsafe {
+            rust_take_global_args_lock();
+            f()
+        }
+    }).finally {
+        unsafe {
+            rust_drop_global_args_lock();
+        }
+    }
+}
+
+fn get_global_ptr() -> *mut Option<~~[~str]> {
+    unsafe { rust_get_global_args_ptr() }
+}
+
+// Copied from `os`.
+unsafe fn load_argc_and_argv(argc: int, argv: **u8) -> ~[~str] {
+    let mut args = ~[];
+    for uint::range(0, argc as uint) |i| {
+        args.push(str::raw::from_c_str(*(argv as **libc::c_char).offset(i)));
+    }
+    return args;
+}
+
+extern {
+    fn rust_take_global_args_lock();
+    fn rust_drop_global_args_lock();
+    fn rust_get_global_args_ptr() -> *mut Option<~~[~str]>;
+}
+
+#[cfg(test)]
+mod tests {
+    use option::{Some, None};
+    use super::*;
+    use unstable::finally::Finally;
+
+    #[test]
+    fn smoke_test() {
+        // Preserve the actual global state.
+        let saved_value = take();
+
+        let expected = ~[~"happy", ~"today?"];
+
+        put(expected.clone());
+        assert!(clone() == Some(expected.clone()));
+        assert!(take() == Some(expected.clone()));
+        assert!(take() == None);
+
+        do (|| {
+        }).finally {
+            // Restore the actual global state.
+            match saved_value {
+                Some(ref args) => put(args.clone()),
+                None => ()
+            }
+        }
+    }
+}