Rewrite boxed_region/memory_region in Rust

This drops more of the old C++ runtime to rather be written in rust. A few
features were lost along the way, but hopefully not too many. The main loss is
that there are no longer backtraces associated with allocations (rust doesn't
have a way of acquiring those just yet). Other than that though, I believe that
the rest of the debugging utilities made their way over into rust.

Closes #8704

13 files changed, 253 insertions, 652 deletions

diff --git a/mk/rt.mk b/mk/rt.mk
index 2fb325e8348..f1f46975e47 100644
--- a/mk/rt.mk
+++ b/mk/rt.mk
@@ -89,8 +89,6 @@ RUNTIME_CXXS_$(1)_$(2) := \
               rt/rust_upcall.cpp \
               rt/rust_uv.cpp \
               rt/miniz.cpp \
-              rt/memory_region.cpp \
-              rt/boxed_region.cpp \
               rt/rust_android_dummy.cpp \
               rt/rust_test_helpers.cpp
 
diff --git a/src/libstd/at_vec.rs b/src/libstd/at_vec.rs
index ee0b9b0df0b..7d10061e812 100644
--- a/src/libstd/at_vec.rs
+++ b/src/libstd/at_vec.rs
@@ -158,7 +158,6 @@ pub mod raw {
     use at_vec::capacity;
     use cast;
     use cast::{transmute, transmute_copy};
-    use libc;
     use ptr;
     use mem;
     use uint;
@@ -250,7 +249,7 @@ pub mod raw {
             use rt::task::Task;
 
             do Local::borrow |task: &mut Task| {
-                task.heap.realloc(ptr as *libc::c_void, size) as *()
+                task.heap.realloc(ptr as *mut Box<()>, size) as *()
             }
         }
     }
diff --git a/src/libstd/cleanup.rs b/src/libstd/cleanup.rs
index a9070a7a7a2..7bbc8bc32fa 100644
--- a/src/libstd/cleanup.rs
+++ b/src/libstd/cleanup.rs
@@ -11,7 +11,7 @@
 #[doc(hidden)];
 
 use libc::c_void;
-use ptr::null;
+use ptr;
 use unstable::intrinsics::TyDesc;
 use unstable::raw;
 
@@ -37,7 +37,7 @@ unsafe fn each_live_alloc(read_next_before: bool,
     use rt::local_heap;
 
     let mut box = local_heap::live_allocs();
-    while box != null() {
+    while box != ptr::mut_null() {
         let next_before = (*box).next;
         let uniq = (*box).ref_count == managed::RC_MANAGED_UNIQUE;
 
diff --git a/src/libstd/rt/env.rs b/src/libstd/rt/env.rs
index c02e7fe9013..0811f7bbbdc 100644
--- a/src/libstd/rt/env.rs
+++ b/src/libstd/rt/env.rs
@@ -19,6 +19,7 @@ use os;
 
 static mut MIN_STACK: uint = 4000000;
 static mut DEBUG_BORROW: bool = false;
+static mut POISON_ON_FREE: bool = false;
 
 pub fn init() {
     unsafe {
@@ -33,6 +34,10 @@ pub fn init() {
             Some(_) => DEBUG_BORROW = true,
             None => ()
         }
+        match os::getenv("RUST_POISON_ON_FREE") {
+            Some(_) => POISON_ON_FREE = true,
+            None => ()
+        }
     }
 }
 
@@ -43,3 +48,7 @@ pub fn min_stack() -> uint {
 pub fn debug_borrow() -> bool {
     unsafe { DEBUG_BORROW }
 }
+
+pub fn poison_on_free() -> bool {
+    unsafe { POISON_ON_FREE }
+}
diff --git a/src/libstd/rt/global_heap.rs b/src/libstd/rt/global_heap.rs
index 446efbd9047..4964db8f1c1 100644
--- a/src/libstd/rt/global_heap.rs
+++ b/src/libstd/rt/global_heap.rs
@@ -19,7 +19,7 @@ extern {
 }
 
 #[inline]
-fn get_box_size(body_size: uint, body_align: uint) -> uint {
+pub fn get_box_size(body_size: uint, body_align: uint) -> uint {
     let header_size = size_of::<raw::Box<()>>();
     // FIXME (#2699): This alignment calculation is suspicious. Is it right?
     let total_size = align_to(header_size, body_align) + body_size;
diff --git a/src/libstd/rt/local_heap.rs b/src/libstd/rt/local_heap.rs
index 14df292343e..d5ec6bd3f37 100644
--- a/src/libstd/rt/local_heap.rs
+++ b/src/libstd/rt/local_heap.rs
@@ -10,79 +10,271 @@
 
 //! The local, garbage collected heap
 
+use cast;
+use libc::{c_void, uintptr_t};
 use libc;
-use libc::{c_void, uintptr_t, size_t};
+use mem;
 use ops::Drop;
 use option::{Option, None, Some};
+use ptr;
+use rt::env;
+use rt::global_heap;
 use rt::local::Local;
 use rt::task::Task;
+use unstable::intrinsics::TyDesc;
 use unstable::raw;
 
-type MemoryRegion = c_void;
+// This has no meaning with out rtdebug also turned on.
+static TRACK_ALLOCATIONS: int = 0;
+static MAGIC: u32 = 0xbadc0ffe;
 
-struct Env { priv opaque: () }
+pub type Box = raw::Box<()>;
 
-struct BoxedRegion {
-    env: *Env,
-    backing_region: *MemoryRegion,
-    live_allocs: *raw::Box<()>,
+pub struct MemoryRegion {
+    priv allocations: ~[*AllocHeader],
+    priv live_allocations: uint,
 }
 
-pub type OpaqueBox = c_void;
-pub type TypeDesc = c_void;
-
 pub struct LocalHeap {
-    priv memory_region: *MemoryRegion,
-    priv boxed_region: *BoxedRegion
+    priv memory_region: MemoryRegion,
+
+    priv poison_on_free: bool,
+    priv live_allocs: *mut raw::Box<()>,
 }
 
 impl LocalHeap {
-    #[fixed_stack_segment] #[inline(never)]
     pub fn new() -> LocalHeap {
-        unsafe {
-            // XXX: These usually come from the environment
-            let detailed_leaks = false as uintptr_t;
-            let poison_on_free = false as uintptr_t;
-            let region = rust_new_memory_region(detailed_leaks, poison_on_free);
-            assert!(region.is_not_null());
-            let boxed = rust_new_boxed_region(region, poison_on_free);
-            assert!(boxed.is_not_null());
-            LocalHeap {
-                memory_region: region,
-                boxed_region: boxed
-            }
+        let region = MemoryRegion {
+            allocations: ~[],
+            live_allocations: 0,
+        };
+        LocalHeap {
+            memory_region: region,
+            poison_on_free: env::poison_on_free(),
+            live_allocs: ptr::mut_null(),
         }
     }
 
-    #[fixed_stack_segment] #[inline(never)]
-    pub fn alloc(&mut self, td: *TypeDesc, size: uint) -> *OpaqueBox {
-        unsafe {
-            return rust_boxed_region_malloc(self.boxed_region, td, size as size_t);
+    pub fn alloc(&mut self, td: *TyDesc, size: uint) -> *mut Box {
+        let total_size = global_heap::get_box_size(size, unsafe { (*td).align });
+        let box = self.memory_region.malloc(total_size);
+        {
+            // Make sure that we can't use `mybox` outside of this scope
+            let mybox: &mut Box = unsafe { cast::transmute(box) };
+            // Clear out this box, and move it to the front of the live
+            // allocations list
+            mybox.type_desc = td;
+            mybox.ref_count = 1;
+            mybox.prev = ptr::mut_null();
+            mybox.next = self.live_allocs;
+            if !self.live_allocs.is_null() {
+                unsafe { (*self.live_allocs).prev = box; }
+            }
+            self.live_allocs = box;
         }
+        return box;
     }
 
-    #[fixed_stack_segment] #[inline(never)]
-    pub fn realloc(&mut self, ptr: *OpaqueBox, size: uint) -> *OpaqueBox {
-        unsafe {
-            return rust_boxed_region_realloc(self.boxed_region, ptr, size as size_t);
+    pub fn realloc(&mut self, ptr: *mut Box, size: uint) -> *mut Box {
+        // Make sure that we can't use `mybox` outside of this scope
+        let total_size = size + mem::size_of::<Box>();
+        let new_box = self.memory_region.realloc(ptr, total_size);
+        {
+            // Fix links because we could have moved around
+            let mybox: &mut Box = unsafe { cast::transmute(new_box) };
+            if !mybox.prev.is_null() {
+                unsafe { (*mybox.prev).next = new_box; }
+            }
+            if !mybox.next.is_null() {
+                unsafe { (*mybox.next).prev = new_box; }
+            }
         }
+        if self.live_allocs == ptr {
+            self.live_allocs = new_box;
+        }
+        return new_box;
     }
 
-    #[fixed_stack_segment] #[inline(never)]
-    pub fn free(&mut self, box: *OpaqueBox) {
-        unsafe {
-            return rust_boxed_region_free(self.boxed_region, box);
+    pub fn free(&mut self, box: *mut Box) {
+        {
+            // Make sure that we can't use `mybox` outside of this scope
+            let mybox: &mut Box = unsafe { cast::transmute(box) };
+            assert!(!mybox.type_desc.is_null());
+
+            // Unlink it from the linked list
+            if !mybox.prev.is_null() {
+                unsafe { (*mybox.prev).next = mybox.next; }
+            }
+            if !mybox.next.is_null() {
+                unsafe { (*mybox.next).prev = mybox.prev; }
+            }
+            if self.live_allocs == box {
+                self.live_allocs = mybox.next;
+            }
+
+            // Destroy the box memory-wise
+            if self.poison_on_free {
+                unsafe {
+                    let ptr: *mut u8 = cast::transmute(&mybox.data);
+                    ptr::set_memory(ptr, 0xab, (*mybox.type_desc).size);
+                }
+            }
+            mybox.prev = ptr::mut_null();
+            mybox.next = ptr::mut_null();
+            mybox.type_desc = ptr::null();
         }
+
+        self.memory_region.free(box);
     }
 }
 
 impl Drop for LocalHeap {
-    #[fixed_stack_segment] #[inline(never)]
     fn drop(&mut self) {
+        assert!(self.live_allocs.is_null());
+    }
+}
+
+#[cfg(rtdebug)]
+struct AllocHeader {
+    magic: u32,
+    index: i32,
+    size: u32,
+}
+#[cfg(not(rtdebug))]
+struct AllocHeader;
+
+impl AllocHeader {
+    #[cfg(rtdebug)]
+    fn init(&mut self, size: u32) {
+        if TRACK_ALLOCATIONS > 0 {
+            self.magic = MAGIC;
+            self.index = -1;
+            self.size = size;
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn init(&mut self, _size: u32) {}
+
+    #[cfg(rtdebug)]
+    fn assert_sane(&self) {
+        if TRACK_ALLOCATIONS > 0 {
+            rtassert!(self.magic == MAGIC);
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn assert_sane(&self) {}
+
+    #[cfg(rtdebug)]
+    fn update_size(&mut self, size: u32) {
+        if TRACK_ALLOCATIONS > 0 {
+            self.size = size;
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn update_size(&mut self, _size: u32) {}
+
+    fn box(&mut self) -> *mut Box {
+        let myaddr: uint = unsafe { cast::transmute(self) };
+        (myaddr + AllocHeader::size()) as *mut Box
+    }
+
+    fn size() -> uint {
+        // For some platforms, 16 byte alignment is required.
+        let ptr_size = 16;
+        let header_size = mem::size_of::<AllocHeader>();
+        return (header_size + ptr_size - 1) / ptr_size * ptr_size;
+    }
+
+    fn from(box: *mut Box) -> *mut AllocHeader {
+        (box as uint - AllocHeader::size()) as *mut AllocHeader
+    }
+}
+
+impl MemoryRegion {
+    fn malloc(&mut self, size: uint) -> *mut Box {
+        let total_size = size + AllocHeader::size();
+        let alloc: *AllocHeader = unsafe {
+            global_heap::malloc_raw(total_size) as *AllocHeader
+        };
+
+        let alloc: &mut AllocHeader = unsafe { cast::transmute(alloc) };
+        alloc.init(size as u32);
+        self.claim(alloc);
+        self.live_allocations += 1;
+
+        return alloc.box();
+    }
+
+    fn realloc(&mut self, box: *mut Box, size: uint) -> *mut Box {
+        rtassert!(!box.is_null());
+        let orig_alloc = AllocHeader::from(box);
+        unsafe { (*orig_alloc).assert_sane(); }
+
+        let total_size = size + AllocHeader::size();
+        let alloc: *AllocHeader = unsafe {
+            global_heap::realloc_raw(orig_alloc as *mut libc::c_void,
+                                     total_size) as *AllocHeader
+        };
+
+        let alloc: &mut AllocHeader = unsafe { cast::transmute(alloc) };
+        alloc.assert_sane();
+        alloc.update_size(size as u32);
+        self.update(alloc, orig_alloc as *AllocHeader);
+        return alloc.box();
+    }
+
+    fn free(&mut self, box: *mut Box) {
+        rtassert!(!box.is_null());
+        let alloc = AllocHeader::from(box);
         unsafe {
-            rust_delete_boxed_region(self.boxed_region);
-            rust_delete_memory_region(self.memory_region);
+            (*alloc).assert_sane();
+            self.release(cast::transmute(alloc));
+            rtassert!(self.live_allocations > 0);
+            self.live_allocations -= 1;
+            global_heap::exchange_free(alloc as *libc::c_char)
+        }
+    }
+
+    #[cfg(rtdebug)]
+    fn claim(&mut self, alloc: &mut AllocHeader) {
+        alloc.assert_sane();
+        if TRACK_ALLOCATIONS > 1 {
+            alloc.index = self.allocations.len() as i32;
+            self.allocations.push(&*alloc as *AllocHeader);
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn claim(&mut self, _alloc: &mut AllocHeader) {}
+
+    #[cfg(rtdebug)]
+    fn release(&mut self, alloc: &AllocHeader) {
+        alloc.assert_sane();
+        if TRACK_ALLOCATIONS > 1 {
+            rtassert!(self.allocations[alloc.index] == alloc as *AllocHeader);
+            self.allocations[alloc.index] = ptr::null();
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn release(&mut self, _alloc: &AllocHeader) {}
+
+    #[cfg(rtdebug)]
+    fn update(&mut self, alloc: &mut AllocHeader, orig: *AllocHeader) {
+        alloc.assert_sane();
+        if TRACK_ALLOCATIONS > 1 {
+            rtassert!(self.allocations[alloc.index] == orig);
+            self.allocations[alloc.index] = &*alloc as *AllocHeader;
+        }
+    }
+    #[cfg(not(rtdebug))]
+    fn update(&mut self, _alloc: &mut AllocHeader, _orig: *AllocHeader) {}
+}
+
+impl Drop for MemoryRegion {
+    fn drop(&mut self) {
+        if self.live_allocations != 0 {
+            rtabort!("leaked managed memory ({} objects)", self.live_allocations);
         }
+        rtassert!(self.allocations.iter().all(|s| s.is_null()));
     }
 }
 
@@ -91,7 +283,7 @@ pub unsafe fn local_malloc(td: *libc::c_char, size: libc::uintptr_t) -> *libc::c
     let task: Option<*mut Task> = Local::try_unsafe_borrow();
     match task {
         Some(task) => {
-            (*task).heap.alloc(td as *libc::c_void, size as uint) as *libc::c_char
+            (*task).heap.alloc(td as *TyDesc, size as uint) as *libc::c_char
         }
         None => rtabort!("local malloc outside of task")
     }
@@ -103,34 +295,16 @@ pub unsafe fn local_free(ptr: *libc::c_char) {
     let task_ptr: Option<*mut Task> = Local::try_unsafe_borrow();
     match task_ptr {
         Some(task) => {
-            (*task).heap.free(ptr as *libc::c_void);
+            (*task).heap.free(ptr as *mut Box)
         }
         None => rtabort!("local free outside of task")
     }
 }
 
-pub fn live_allocs() -> *raw::Box<()> {
-    let region = do Local::borrow |task: &mut Task| {
-        task.heap.boxed_region
-    };
-
-    return unsafe { (*region).live_allocs };
-}
-
-extern {
-    fn rust_new_memory_region(detailed_leaks: uintptr_t,
-                               poison_on_free: uintptr_t) -> *MemoryRegion;
-    fn rust_delete_memory_region(region: *MemoryRegion);
-    fn rust_new_boxed_region(region: *MemoryRegion,
-                             poison_on_free: uintptr_t) -> *BoxedRegion;
-    fn rust_delete_boxed_region(region: *BoxedRegion);
-    fn rust_boxed_region_malloc(region: *BoxedRegion,
-                                td: *TypeDesc,
-                                size: size_t) -> *OpaqueBox;
-    fn rust_boxed_region_realloc(region: *BoxedRegion,
-                                 ptr: *OpaqueBox,
-                                 size: size_t) -> *OpaqueBox;
-    fn rust_boxed_region_free(region: *BoxedRegion, box: *OpaqueBox);
+pub fn live_allocs() -> *mut Box {
+    do Local::borrow |task: &mut Task| {
+        task.heap.live_allocs
+    }
 }
 
 #[cfg(test)]
diff --git a/src/libstd/unstable/raw.rs b/src/libstd/unstable/raw.rs
index b5d7cc47fdc..46e80f9f4e8 100644
--- a/src/libstd/unstable/raw.rs
+++ b/src/libstd/unstable/raw.rs
@@ -15,8 +15,8 @@ use unstable::intrinsics::TyDesc;
 pub struct Box<T> {
     ref_count: uint,
     type_desc: *TyDesc,
-    priv prev: *Box<T>,
-    next: *Box<T>,
+    prev: *mut Box<T>,
+    next: *mut Box<T>,
     data: T
 }
 
diff --git a/src/rt/boxed_region.cpp b/src/rt/boxed_region.cpp
deleted file mode 100644
index 064648a9671..00000000000
--- a/src/rt/boxed_region.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-// Copyright 2012 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.
-
-#include "memory_region.h"
-#include "boxed_region.h"
-#include "rust_globals.h"
-#include "rust_util.h"
-
-// #define DUMP_BOXED_REGION
-
-rust_opaque_box *boxed_region::malloc(type_desc *td, size_t body_size) {
-    size_t total_size = get_box_size(body_size, td->align);
-    rust_opaque_box *box =
-      (rust_opaque_box*)backing_region->malloc(total_size, "@");
-    box->td = td;
-    box->ref_count = 1;
-    box->prev = NULL;
-    box->next = live_allocs;
-    if (live_allocs) live_allocs->prev = box;
-    live_allocs = box;
-
-    /*LOG(rust_get_current_task(), box,
-        "@malloc()=%p with td %p, size %lu==%lu+%lu, "
-        "align %lu, prev %p, next %p\n",
-        box, td, total_size, sizeof(rust_opaque_box), body_size,
-        td->align, box->prev, box->next);*/
-
-    return box;
-}
-
-rust_opaque_box *boxed_region::realloc(rust_opaque_box *box,
-                                       size_t new_size) {
-
-    size_t total_size = new_size + sizeof(rust_opaque_box);
-    rust_opaque_box *new_box =
-        (rust_opaque_box*)backing_region->realloc(box, total_size);
-    if (new_box->prev) new_box->prev->next = new_box;
-    if (new_box->next) new_box->next->prev = new_box;
-    if (live_allocs == box) live_allocs = new_box;
-
-    /*LOG(rust_get_current_task(), box,
-        "@realloc()=%p with orig=%p, size %lu==%lu+%lu",
-        new_box, box, total_size, sizeof(rust_opaque_box), new_size);*/
-
-    return new_box;
-}
-
-
-rust_opaque_box *boxed_region::calloc(type_desc *td, size_t body_size) {
-    rust_opaque_box *box = malloc(td, body_size);
-    memset(box_body(box), 0, td->size);
-    return box;
-}
-
-void boxed_region::free(rust_opaque_box *box) {
-    // This turns out to not be true in various situations,
-    // like when we are unwinding after a failure.
-    //
-    // assert(box->ref_count == 0);
-
-    // This however should always be true.  Helps to detect
-    // double frees (kind of).
-    assert(box->td != NULL);
-
-    /*LOG(rust_get_current_task(), box,
-        "@free(%p) with td %p, prev %p, next %p\n",
-        box, box->td, box->prev, box->next);*/
-
-    if (box->prev) box->prev->next = box->next;
-    if (box->next) box->next->prev = box->prev;
-    if (live_allocs == box) live_allocs = box->next;
-
-    if (poison_on_free) {
-        memset(box_body(box), 0xab, box->td->size);
-    }
-
-    box->prev = NULL;
-    box->next = NULL;
-    box->td = NULL;
-
-    backing_region->free(box);
-}
-
-//
-// Local Variables:
-// mode: C++
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// End:
-//
diff --git a/src/rt/boxed_region.h b/src/rt/boxed_region.h
deleted file mode 100644
index 178772007e5..00000000000
--- a/src/rt/boxed_region.h
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright 2012 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.
-
-#ifndef BOXED_REGION_H
-#define BOXED_REGION_H
-
-#include <stdlib.h>
-
-struct type_desc;
-class memory_region;
-struct rust_opaque_box;
-struct rust_env;
-
-/* Tracks the data allocated by a particular task in the '@' region.
- * Currently still relies on the standard malloc as a backing allocator, but
- * this could be improved someday if necessary. Every allocation must provide
- * a type descr which describes the payload (what follows the header). */
-class boxed_region {
-private:
-    bool poison_on_free;
-    memory_region *backing_region;
-    rust_opaque_box *live_allocs;
-
-    size_t align_to(size_t v, size_t align) {
-        size_t alignm1 = align - 1;
-        v += alignm1;
-        v &= ~alignm1;
-        return v;
-    }
-
-private:
-    // private and undefined to disable copying
-    boxed_region(const boxed_region& rhs);
-    boxed_region& operator=(const boxed_region& rhs);
-
-public:
-    boxed_region(memory_region *br, bool poison_on_free)
-        : poison_on_free(poison_on_free)
-        , backing_region(br)
-        , live_allocs(NULL)
-    {}
-
-    rust_opaque_box *first_live_alloc() { return live_allocs; }
-
-    rust_opaque_box *malloc(type_desc *td, size_t body_size);
-    rust_opaque_box *calloc(type_desc *td, size_t body_size);
-    rust_opaque_box *realloc(rust_opaque_box *box, size_t new_size);
-    void free(rust_opaque_box *box);
-};
-
-#endif /* BOXED_REGION_H */
-
-//
-// Local Variables:
-// mode: C++
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// End:
-//
diff --git a/src/rt/memory_region.cpp b/src/rt/memory_region.cpp
deleted file mode 100644
index 4a34312c6d4..00000000000
--- a/src/rt/memory_region.cpp
+++ /dev/null
@@ -1,258 +0,0 @@
-// Copyright 2012 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.
-
-
-#include "memory_region.h"
-
-#if RUSTRT_TRACK_ALLOCATIONS >= 3
-#include <execinfo.h>
-#endif
-
-#if RUSTRT_TRACK_ALLOCATIONS >= 1
-// For some platforms, 16 byte alignment is required.
-#  define PTR_SIZE 16
-#  define ALIGN_PTR(x) (((x)+PTR_SIZE-1)/PTR_SIZE*PTR_SIZE)
-#  define HEADER_SIZE ALIGN_PTR(sizeof(alloc_header))
-#  define MAGIC 0xbadc0ffe
-#else
-#  define HEADER_SIZE 0
-#endif
-
-memory_region::alloc_header *memory_region::get_header(void *mem) {
-    return (alloc_header *)((char *)mem - HEADER_SIZE);
-}
-
-void *memory_region::get_data(alloc_header *ptr) {
-    return (void*)((char *)ptr + HEADER_SIZE);
-}
-
-inline void memory_region::maybe_print_backtrace(const alloc_header *header) const {
-#   if RUSTRT_TRACK_ALLOCATIONS >= 3
-    if (_detailed_leaks) {
-        backtrace_symbols_fd(header->bt + 1, header->btframes - 1, 2);
-    }
-#   endif
-}
-
-memory_region::memory_region(bool detailed_leaks,
-                             bool poison_on_free) :
-    _parent(NULL), _live_allocations(0),
-    _detailed_leaks(detailed_leaks),
-    _poison_on_free(poison_on_free) {
-}
-
-memory_region::memory_region(memory_region *parent) :
-    _parent(parent), _live_allocations(0),
-    _detailed_leaks(parent->_detailed_leaks),
-    _poison_on_free(parent->_poison_on_free) {
-}
-
-void memory_region::add_alloc() {
-    _live_allocations++;
-}
-
-void memory_region::dec_alloc() {
-    _live_allocations--;
-}
-
-void memory_region::free(void *mem) {
-    // printf("free: ptr 0x%" PRIxPTR" region=%p\n", (uintptr_t) mem, this);
-    if (!mem) { return; }
-    alloc_header *alloc = get_header(mem);
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    assert(alloc->magic == MAGIC);
-#   endif
-
-    if (_live_allocations < 1) {
-        assert(false && "live_allocs < 1");
-    }
-    release_alloc(mem);
-    maybe_poison(mem);
-    ::free(alloc);
-}
-
-void *
-memory_region::realloc(void *mem, size_t orig_size) {
-    if (!mem) {
-        add_alloc();
-    }
-
-    alloc_header *alloc = get_header(mem);
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    assert(alloc->magic == MAGIC);
-#   endif
-
-    size_t size = orig_size + HEADER_SIZE;
-    alloc_header *newMem = (alloc_header *)::realloc(alloc, size);
-    if (newMem == NULL) {
-        fprintf(stderr,
-                "memory_region::realloc> "
-                "Out of memory allocating %ld bytes",
-                (long int) size);
-        abort();
-    }
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    assert(newMem->magic == MAGIC);
-    newMem->size = orig_size;
-#   endif
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 2
-    if (_allocation_list[newMem->index] != alloc) {
-        printf("at index %d, found %p, expected %p\n",
-               alloc->index, _allocation_list[alloc->index], alloc);
-        printf("realloc: ptr 0x%" PRIxPTR " (%s) is not in allocation_list\n",
-               (uintptr_t) get_data(alloc), alloc->tag);
-        assert(false && "not in allocation_list");
-    }
-    else {
-        _allocation_list[newMem->index] = newMem;
-        // printf("realloc: stored %p at index %d, replacing %p\n",
-        //        newMem, index, mem);
-    }
-#   endif
-
-    return get_data(newMem);
-}
-
-void *
-memory_region::malloc(size_t size, const char *tag) {
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    size_t old_size = size;
-#   endif
-    size += HEADER_SIZE;
-    alloc_header *mem = (alloc_header *)::malloc(size);
-    if (mem == NULL) {
-        fprintf(stderr,
-                "memory_region::malloc> "
-                "Out of memory allocating %ld bytes",
-                (long int) size);
-        abort();
-    }
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    mem->magic = MAGIC;
-    mem->tag = tag;
-    mem->index = -1;
-    mem->size = old_size;
-#   endif
-
-    void *data = get_data(mem);
-    claim_alloc(data);
-
-    return data;
-}
-
-memory_region::~memory_region() {
-    if (_live_allocations == 0 && !_detailed_leaks) {
-        return;
-    }
-    char msg[128];
-    if(_live_allocations > 0) {
-        snprintf(msg, sizeof(msg),
-                 "leaked memory in rust main loop (%d objects)",
-                 _live_allocations);
-    }
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 2
-    if (_detailed_leaks) {
-        int leak_count = 0;
-        for (size_t i = 0; i < _allocation_list.size(); i++) {
-            if (_allocation_list[i] != NULL) {
-                alloc_header *header = (alloc_header*)_allocation_list[i];
-                printf("allocation (%s) 0x%" PRIxPTR " was not freed\n",
-                       header->tag,
-                       (uintptr_t) get_data(header));
-                ++leak_count;
-                maybe_print_backtrace(header);
-            }
-        }
-        assert(leak_count == _live_allocations);
-    }
-#   endif
-
-    if (_live_allocations > 0) {
-        fprintf(stderr, "%s\n", msg);
-        assert(false);
-    }
-}
-
-void
-memory_region::release_alloc(void *mem) {
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    alloc_header *alloc = get_header(mem);
-    assert(alloc->magic == MAGIC);
-#   endif
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 2
-    if (((size_t) alloc->index) >= _allocation_list.size()) {
-        printf("free: ptr 0x%" PRIxPTR " (%s) index %d is beyond allocation_list of size %zu\n",
-               (uintptr_t) get_data(alloc), alloc->tag, alloc->index, _allocation_list.size());
-        maybe_print_backtrace(alloc);
-        assert(false && "index beyond allocation_list");
-    }
-    if (_allocation_list[alloc->index] != alloc) {
-        printf("free: ptr 0x%" PRIxPTR " (%s) is not in allocation_list\n",
-               (uintptr_t) get_data(alloc), alloc->tag);
-        maybe_print_backtrace(alloc);
-        assert(false && "not in allocation_list");
-    }
-    else {
-        // printf("freed index %d\n", index);
-        _allocation_list[alloc->index] = NULL;
-        alloc->index = -1;
-    }
-#   endif
-
-    dec_alloc();
-}
-
-void
-memory_region::claim_alloc(void *mem) {
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    alloc_header *alloc = get_header(mem);
-    assert(alloc->magic == MAGIC);
-#   endif
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 2
-    alloc->index = _allocation_list.append(alloc);
-#   endif
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 3
-    if (_detailed_leaks) {
-        alloc->btframes = ::backtrace(alloc->bt, 32);
-    }
-#   endif
-
-    add_alloc();
-}
-
-void
-memory_region::maybe_poison(void *mem) {
-
-    if (!_poison_on_free)
-        return;
-
-#   if RUSTRT_TRACK_ALLOCATIONS >= 1
-    alloc_header *alloc = get_header(mem);
-    memset(mem, '\xcd', alloc->size);
-#   endif
-}
-
-//
-// Local Variables:
-// mode: C++
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// End:
-//
diff --git a/src/rt/memory_region.h b/src/rt/memory_region.h
deleted file mode 100644
index ace463ede21..00000000000
--- a/src/rt/memory_region.h
+++ /dev/null
@@ -1,107 +0,0 @@
-// Copyright 2012 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.
-
-/*
- * The Rust runtime uses memory regions to provide a primitive level of
- * memory management and isolation between tasks, and domains.
- *
- * FIXME (#2686): Implement a custom lock-free malloc / free instead of
- *       relying solely on the standard malloc / free.
- */
-
-#ifndef MEMORY_REGION_H
-#define MEMORY_REGION_H
-
-#include "rust_globals.h"
-#include "sync/lock_and_signal.h"
-#include "util/array_list.h"
-
-// There are three levels of debugging:
-//
-// 0 --- no headers, no debugging support
-// 1 --- support poison, but do not track allocations
-// 2 --- track allocations in detail
-// 3 --- record backtraces of every allocation
-//
-// NB: please do not commit code with level 2. It's
-// hugely expensive and should only be used as a last resort.
-#define RUSTRT_TRACK_ALLOCATIONS 0
-
-struct rust_env;
-
-class memory_region {
-private:
-    struct alloc_header {
-#       if RUSTRT_TRACK_ALLOCATIONS > 0
-        uint32_t magic;
-        int index;
-        const char *tag;
-        uint32_t size;
-#       if RUSTRT_TRACK_ALLOCATIONS >= 3
-        void *bt[32];
-        int btframes;
-#       endif
-#       endif
-    };
-
-    inline alloc_header *get_header(void *mem);
-    inline void *get_data(alloc_header *);
-
-    memory_region *_parent;
-    int _live_allocations;
-    array_list<alloc_header *> _allocation_list;
-    const bool _detailed_leaks;
-    const bool _poison_on_free;
-    lock_and_signal _lock;
-
-    void add_alloc();
-    void dec_alloc();
-    void maybe_poison(void *mem);
-
-    void release_alloc(void *mem);
-    void claim_alloc(void *mem);
-
-    void maybe_print_backtrace(const alloc_header *) const;
-
-private:
-    // private and undefined to disable copying
-    memory_region(const memory_region& rhs);
-    memory_region& operator=(const memory_region& rhs);
-
-public:
-    memory_region(bool detailed_leaks, bool poison_on_free);
-    memory_region(memory_region *parent);
-    void *malloc(size_t size, const char *tag);
-    void *realloc(void *mem, size_t size);
-    void free(void *mem);
-    ~memory_region();
- };
-
-inline void *operator new(size_t size, memory_region &region,
-                          const char *tag) {
-    return region.malloc(size, tag);
-}
-
-inline void *operator new(size_t size, memory_region *region,
-                          const char *tag) {
-    return region->malloc(size, tag);
-}
-
-//
-// Local Variables:
-// mode: C++
-// fill-column: 78;
-// indent-tabs-mode: nil
-// c-basic-offset: 4
-// buffer-file-coding-system: utf-8-unix
-// End:
-//
-
-#endif /* MEMORY_REGION_H */
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index a8eec52943e..90cfd98bc48 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -13,8 +13,6 @@
 #include "rust_util.h"
 #include "sync/rust_thread.h"
 #include "sync/lock_and_signal.h"
-#include "memory_region.h"
-#include "boxed_region.h"
 #include "vg/valgrind.h"
 
 #include <time.h>
@@ -477,44 +475,6 @@ rust_initialize_rt_tls_key(tls_key *key) {
     }
 }
 
-extern "C" CDECL memory_region*
-rust_new_memory_region(uintptr_t detailed_leaks,
-                       uintptr_t poison_on_free) {
-    return new memory_region((bool)detailed_leaks,
-                             (bool)poison_on_free);
-}
-
-extern "C" CDECL void
-rust_delete_memory_region(memory_region *region) {
-    delete region;
-}
-
-extern "C" CDECL boxed_region*
-rust_new_boxed_region(memory_region *region,
-                      uintptr_t poison_on_free) {
-    return new boxed_region(region, poison_on_free);
-}
-
-extern "C" CDECL void
-rust_delete_boxed_region(boxed_region *region) {
-    delete region;
-}
-
-extern "C" CDECL rust_opaque_box*
-rust_boxed_region_malloc(boxed_region *region, type_desc *td, size_t size) {
-    return region->malloc(td, size);
-}
-
-extern "C" CDECL rust_opaque_box*
-rust_boxed_region_realloc(boxed_region *region, rust_opaque_box *ptr, size_t size) {
-    return region->realloc(ptr, size);
-}
-
-extern "C" CDECL void
-rust_boxed_region_free(boxed_region *region, rust_opaque_box *box) {
-    region->free(box);
-}
-
 typedef void *(rust_try_fn)(void*, void*);
 
 extern "C" CDECL uintptr_t
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index 06f4c0006f1..47c9554daa0 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -164,13 +164,6 @@ rust_uv_free_ip4_addr
 rust_uv_free_ip6_addr
 rust_initialize_rt_tls_key
 rust_dbg_next_port
-rust_new_memory_region
-rust_delete_memory_region
-rust_new_boxed_region
-rust_delete_boxed_region
-rust_boxed_region_malloc
-rust_boxed_region_realloc
-rust_boxed_region_free
 rust_try
 rust_begin_unwind
 rust_valgrind_stack_register