auto merge of #8296 : erickt/rust/remove-str-trailing-nulls, r=erickt

This PR fixes #7235 and #3371, which removes trailing nulls from `str` types. Instead, it replaces the creation of c strings with a new type, `std::c_str::CString`, which wraps a malloced byte array, and respects:

*  No interior nulls
* Ends with a trailing null

4 files changed, 25 insertions, 23 deletions

diff --git a/src/libstd/rt/borrowck.rs b/src/libstd/rt/borrowck.rs
index afbb0fcb567..f620a7347a4 100644
--- a/src/libstd/rt/borrowck.rs
+++ b/src/libstd/rt/borrowck.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use c_str::ToCStr;
 use cast::transmute;
 use libc::{c_char, size_t, STDERR_FILENO};
 use io;
@@ -51,8 +52,8 @@ unsafe fn fail_borrowed(box: *mut raw::Box<()>, file: *c_char, line: size_t) {
     match try_take_task_borrow_list() {
         None => { // not recording borrows
             let msg = "borrowed";
-            do msg.as_c_str |msg_p| {
-                sys::begin_unwind_(msg_p as *c_char, file, line);
+            do msg.to_c_str().with_ref |msg_p| {
+                sys::begin_unwind_(msg_p, file, line);
             }
         }
         Some(borrow_list) => { // recording borrows
@@ -67,8 +68,8 @@ unsafe fn fail_borrowed(box: *mut raw::Box<()>, file: *c_char, line: size_t) {
                     sep = " and at ";
                 }
             }
-            do msg.as_c_str |msg_p| {
-                sys::begin_unwind_(msg_p as *c_char, file, line)
+            do msg.to_c_str().with_ref |msg_p| {
+                sys::begin_unwind_(msg_p, file, line)
             }
         }
     }
@@ -207,8 +208,8 @@ pub unsafe fn unrecord_borrow(a: *u8, old_ref_count: uint,
             let br = borrow_list.pop();
             if br.box != a || br.file != file || br.line != line {
                 let err = fmt!("wrong borrow found, br=%?", br);
-                do err.as_c_str |msg_p| {
-                    sys::begin_unwind_(msg_p as *c_char, file, line)
+                do err.to_c_str().with_ref |msg_p| {
+                    sys::begin_unwind_(msg_p, file, line)
                 }
             }
             borrow_list
diff --git a/src/libstd/rt/logging.rs b/src/libstd/rt/logging.rs
index 9056f0d52e0..117795f6c90 100644
--- a/src/libstd/rt/logging.rs
+++ b/src/libstd/rt/logging.rs
@@ -58,15 +58,15 @@ impl Logger for StdErrLogger {
 /// Configure logging by traversing the crate map and setting the
 /// per-module global logging flags based on the logging spec
 pub fn init(crate_map: *u8) {
+    use c_str::ToCStr;
     use os;
-    use str::StrSlice;
     use ptr;
     use option::{Some, None};
 
     let log_spec = os::getenv("RUST_LOG");
     match log_spec {
         Some(spec) => {
-            do spec.as_c_str |buf| {
+            do spec.to_c_str().with_ref |buf| {
                 unsafe { rust_update_log_settings(crate_map, buf) }
             }
         }
diff --git a/src/libstd/rt/uv/uvio.rs b/src/libstd/rt/uv/uvio.rs
index 70a397199ab..038ebad3540 100644
--- a/src/libstd/rt/uv/uvio.rs
+++ b/src/libstd/rt/uv/uvio.rs
@@ -8,26 +8,26 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use option::*;
-use result::*;
-use ops::Drop;
-use cell::Cell;
-use cast;
+use c_str::ToCStr;
 use cast::transmute;
+use cast;
+use cell::Cell;
 use clone::Clone;
 use libc::{c_int, c_uint, c_void};
+use ops::Drop;
+use option::*;
 use ptr;
+use result::*;
 use rt::io::IoError;
 use rt::io::net::ip::{SocketAddr, IpAddr};
-use rt::uv::*;
-use rt::uv::idle::IdleWatcher;
-use rt::uv::net::{UvIpv4SocketAddr, UvIpv6SocketAddr};
+use rt::io::{standard_error, OtherIoError};
+use rt::local::Local;
 use rt::rtio::*;
 use rt::sched::Scheduler;
-use rt::io::{standard_error, OtherIoError};
 use rt::tube::Tube;
-use rt::local::Local;
-use str::StrSlice;
+use rt::uv::*;
+use rt::uv::idle::IdleWatcher;
+use rt::uv::net::{UvIpv4SocketAddr, UvIpv6SocketAddr};
 use unstable::sync::Exclusive;
 
 #[cfg(test)] use container::Container;
@@ -654,7 +654,7 @@ impl RtioUdpSocket for UvUdpSocket {
 
     fn join_multicast(&mut self, multi: IpAddr) -> Result<(), IoError> {
         let r = unsafe {
-            do multi.to_str().as_c_str |m_addr| {
+            do multi.to_str().to_c_str().with_ref |m_addr| {
                 uvll::udp_set_membership(self.native_handle(), m_addr,
                                          ptr::null(), uvll::UV_JOIN_GROUP)
             }
@@ -668,7 +668,7 @@ impl RtioUdpSocket for UvUdpSocket {
 
     fn leave_multicast(&mut self, multi: IpAddr) -> Result<(), IoError> {
         let r = unsafe {
-            do multi.to_str().as_c_str |m_addr| {
+            do multi.to_str().to_c_str().with_ref |m_addr| {
                 uvll::udp_set_membership(self.native_handle(), m_addr,
                                          ptr::null(), uvll::UV_LEAVE_GROUP)
             }
diff --git a/src/libstd/rt/uv/uvll.rs b/src/libstd/rt/uv/uvll.rs
index a06247a1036..e240395a495 100644
--- a/src/libstd/rt/uv/uvll.rs
+++ b/src/libstd/rt/uv/uvll.rs
@@ -29,6 +29,7 @@
 
 #[allow(non_camel_case_types)]; // C types
 
+use c_str::ToCStr;
 use libc::{size_t, c_int, c_uint, c_void, c_char, uintptr_t};
 use libc::{malloc, free};
 use libc;
@@ -372,12 +373,12 @@ pub unsafe fn is_ip6_addr(addr: *sockaddr) -> bool {
 }
 
 pub unsafe fn malloc_ip4_addr(ip: &str, port: int) -> *sockaddr_in {
-    do ip.as_c_str |ip_buf| {
+    do ip.to_c_str().with_ref |ip_buf| {
         rust_uv_ip4_addrp(ip_buf as *u8, port as libc::c_int)
     }
 }
 pub unsafe fn malloc_ip6_addr(ip: &str, port: int) -> *sockaddr_in6 {
-    do ip.as_c_str |ip_buf| {
+    do ip.to_c_str().with_ref |ip_buf| {
         rust_uv_ip6_addrp(ip_buf as *u8, port as libc::c_int)
     }
 }