Stop relying on linking details of std’s default allocator

We’ve been bitten before by symbol names changing:
https://github.com/servo/heapsize/pull/46
and upstream is planning to stop using jemalloc by default:
https://github.com/rust-lang/rust/issues/33082#issuecomment-309781465

So use the (relatively) new `#[global_allocator]` attribute
to explicitly select the system allocator on Windows
and jemalloc (now in an external crate) on other platforms.
This choice matches current defaults.

Cargo.lock

@@ -347,6 +347,11 @@ dependencies = [
  "unicode-normalization 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "cexpr"
 version = "0.2.0"
@@ -1110,6 +1115,7 @@ dependencies = [
  "range 0.0.1",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo-fontconfig 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo_allocator 0.0.1",
  "servo_arc 0.0.1",
  "servo_atoms 0.0.1",
  "servo_geometry 0.0.1",
@@ -1439,6 +1445,24 @@ name = "itoa"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "jemalloc-sys"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cc 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "jemallocator"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "jemalloc-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "jpeg-decoder"
 version = "0.1.13"
@@ -1571,6 +1595,7 @@ dependencies = [
  "script_traits 0.0.1",
  "selectors 0.19.0",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo_allocator 0.0.1",
  "servo_arc 0.0.1",
  "servo_atoms 0.0.1",
  "servo_config 0.0.1",
@@ -1733,7 +1758,6 @@ dependencies = [
  "euclid 0.15.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "hashglobe 0.1.0",
  "js 0.1.6 (git+https://github.com/servo/rust-mozjs)",
- "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_arc 0.0.1",
  "smallbitvec 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2363,6 +2387,7 @@ dependencies = [
  "heartbeats-simple 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "influent 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jemalloc-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile_traits 0.0.1",
@@ -2381,6 +2406,7 @@ dependencies = [
  "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "profile 0.0.1",
  "profile_traits 0.0.1",
+ "servo_allocator 0.0.1",
 ]
 
 [[package]]
@@ -2630,6 +2656,7 @@ dependencies = [
  "selectors 0.19.0",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo_allocator 0.0.1",
  "servo_arc 0.0.1",
  "servo_atoms 0.0.1",
  "servo_config 0.0.1",
@@ -2921,6 +2948,14 @@ dependencies = [
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "servo_allocator"
+version = "0.0.1"
+dependencies = [
+ "jemallocator 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "servo_arc"
 version = "0.0.1"
@@ -3782,6 +3817,7 @@ dependencies = [
 "checksum byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c40977b0ee6b9885c9013cd41d9feffdd22deb3bb4dc3a71d901cc7a77de18c8"
 "checksum bytes 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c129aff112dcc562970abb69e2508b40850dd24c274761bb50fb8a0067ba6c27"
 "checksum caseless 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8950b075cff75cdabadee97148a8b5816c7cf62e5948a6005b5255d564b42fe7"
+"checksum cc 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2c674f0870e3dbd4105184ea035acb1c32c8ae69939c9e228d2b11bbfe29efad"
 "checksum cexpr 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "393a5f0088efbe41f9d1fcd062f24e83c278608420e62109feb2c8abee07de7d"
 "checksum cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c819a1287eb618df47cc647173c5c4c66ba19d888a6e50d605672aed3140de"
 "checksum cgl 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "86765cb42c2a2c497e142af72517c1b4d7ae5bb2f25dfa77a5c69642f2342d89"
@@ -3873,6 +3909,8 @@ dependencies = [
 "checksum ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c10ed089b1921b01ef342c736a37ee0788eeb9a5f373bb2df1ba88d01125064f"
 "checksum itertools 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4833d6978da405305126af4ac88569b5d71ff758581ce5a987dbfa3755f694fc"
 "checksum itoa 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "eb2f404fbc66fd9aac13e998248505e7ecb2ad8e44ab6388684c5fb11c6c251c"
+"checksum jemalloc-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94fb624d7e8345e5c42caab8d1db6ec925fdadff3fd0cb7dd781b41be8442828"
+"checksum jemallocator 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1850725977c344d63af66e8fd00857646e3ec936c490cd63667860b7b03ab5c1"
 "checksum jpeg-decoder 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2805ccb10ffe4d10e06ef68a158ff94c255211ecbae848fbde2146b098f93ce7"
 "checksum js 0.1.6 (git+https://github.com/servo/rust-mozjs)" = "<none>"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"

components/allocator/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "servo_allocator"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+license = "MPL-2.0"
+publish = false
+
+[lib]
+path = "lib.rs"
+
+[features]
+unstable = ["kernel32-sys", "jemallocator"]
+
+[target.'cfg(not(windows))'.dependencies]
+jemallocator = { version = "0.1.3", optional = true }
+
+[target.'cfg(windows)'.dependencies]
+kernel32-sys = { version = "0.2.1", optional = true }

components/allocator/lib.rs

@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Selecting the default global allocator for Servo
+
+#![cfg_attr(all(feature = "unstable", windows), feature(alloc_system, allocator_api))]
+#![cfg_attr(feature = "unstable", feature(global_allocator))]
+
+#[cfg(feature = "unstable")]
+#[global_allocator]
+static ALLOC: platform::Allocator = platform::Allocator;
+
+pub use platform::usable_size;
+
+
+#[cfg(all(feature = "unstable", not(windows)))]
+mod platform {
+    extern crate jemallocator;
+
+    pub use self::jemallocator::Jemalloc as Allocator;
+    use std::os::raw::c_void;
+
+    /// Get the size of a heap block.
+    pub unsafe extern "C" fn usable_size(ptr: *const c_void) -> usize {
+        jemallocator::usable_size(ptr)
+    }
+}
+
+#[cfg(all(feature = "unstable", windows))]
+mod platform {
+    extern crate alloc_system;
+    extern crate kernel32;
+
+    pub use self::alloc_system::System as Allocator;
+    use self::kernel32::{GetProcessHeap, HeapSize, HeapValidate};
+    use std::os::raw::c_void;
+
+    /// Get the size of a heap block.
+    pub unsafe extern "C" fn usable_size(mut ptr: *const c_void) -> usize {
+        let heap = GetProcessHeap();
+
+        if HeapValidate(heap, 0, ptr) == 0 {
+            ptr = *(ptr as *const *const c_void).offset(-1);
+        }
+
+        HeapSize(heap, 0, ptr) as usize
+    }
+}
+
+#[cfg(not(feature = "unstable"))]
+mod platform {
+    use std::os::raw::c_void;
+
+    /// Without `#[global_allocator]` we cannot be certain of what allocator is used
+    /// or how it is linked. We therefore disable memory reporting. (Return zero.)
+    pub unsafe extern "C" fn usable_size(_ptr: *const c_void) -> usize {
+        0
+    }
+}
+
+

components/gfx/Cargo.toml

@@ -53,6 +53,7 @@ core-text = "7.0"
 
 [target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
 freetype = "0.3"
+servo_allocator = {path = "../allocator"}
 
 [target.'cfg(target_os = "linux")'.dependencies]
 servo-fontconfig = "0.2.1"

components/gfx/lib.rs

@@ -27,8 +27,8 @@ extern crate fnv;
 #[cfg(target_os = "linux")]
 extern crate fontconfig;
 extern crate fontsan;
-#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg(any(target_os = "linux", target_os = "android"))] extern crate freetype;
-extern crate freetype;
+#[cfg(any(target_os = "linux", target_os = "android"))] extern crate servo_allocator;
 extern crate gfx_traits;
 
 // Eventually we would like the shaper to be pluggable, as many operating systems have their own

components/gfx/platform/freetype/font_context.rs

@@ -8,7 +8,8 @@ use freetype::freetype::FT_Library;
 use freetype::freetype::FT_Memory;
 use freetype::freetype::FT_MemoryRec_;
 use freetype::freetype::FT_New_Library;
-use malloc_size_of::{malloc_size_of, MallocSizeOf, MallocSizeOfOps};
+use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
+use servo_allocator::usable_size;
 use std::mem;
 use std::os::raw::{c_long, c_void};
 use std::ptr;
@@ -31,7 +32,7 @@ extern fn ft_alloc(mem: FT_Memory, req_size: c_long) -> *mut c_void {
     mem::forget(vec);
 
     unsafe {
-        let actual_size = malloc_size_of(ptr as *const _);
+        let actual_size = usable_size(ptr as *const _);
         let user = (*mem).user as *mut User;
         (*user).size += actual_size;
     }
@@ -41,7 +42,7 @@ extern fn ft_alloc(mem: FT_Memory, req_size: c_long) -> *mut c_void {
 
 extern fn ft_free(mem: FT_Memory, ptr: *mut c_void) {
     unsafe {
-        let actual_size = malloc_size_of(ptr as *const _);
+        let actual_size = usable_size(ptr as *const _);
         let user = (*mem).user as *mut User;
         (*user).size -= actual_size;
 
@@ -50,13 +51,14 @@ extern fn ft_free(mem: FT_Memory, ptr: *mut c_void) {
     }
 }
 
-extern fn ft_realloc(mem: FT_Memory, _cur_size: c_long, new_req_size: c_long,
+extern fn ft_realloc(mem: FT_Memory, old_size: c_long, new_req_size: c_long,
                      old_ptr: *mut c_void) -> *mut c_void {
     let old_actual_size;
     let mut vec;
     unsafe {
-        old_actual_size = malloc_size_of(old_ptr as *const _);
+        old_actual_size = usable_size(old_ptr as *const _);
-        vec = Vec::<u8>::from_raw_parts(old_ptr as *mut u8, old_actual_size, old_actual_size);
+        let old_size = old_size as usize;
+        vec = Vec::<u8>::from_raw_parts(old_ptr as *mut u8, old_size, old_size);
     };
 
     let new_req_size = new_req_size as usize;
@@ -71,7 +73,7 @@ extern fn ft_realloc(mem: FT_Memory, _cur_size: c_long, new_req_size: c_long,
     mem::forget(vec);
 
     unsafe {
-        let new_actual_size = malloc_size_of(new_ptr as *const _);
+        let new_actual_size = usable_size(new_ptr as *const _);
         let user = (*mem).user as *mut User;
         (*user).size += new_actual_size;
         (*user).size -= old_actual_size;

components/layout_thread/Cargo.toml

@@ -40,6 +40,7 @@ script_layout_interface = {path = "../script_layout_interface"}
 script_traits = {path = "../script_traits"}
 selectors = { path = "../selectors" }
 serde_json = "1.0"
+servo_allocator = {path = "../allocator"}
 servo_arc = {path = "../servo_arc"}
 servo_atoms = {path = "../atoms"}
 servo_config = {path = "../config"}

components/layout_thread/lib.rs

@@ -39,6 +39,7 @@ extern crate script_layout_interface;
 extern crate script_traits;
 extern crate selectors;
 extern crate serde_json;
+extern crate servo_allocator;
 extern crate servo_arc;
 extern crate servo_atoms;
 extern crate servo_config;
@@ -84,7 +85,7 @@ use layout::webrender_helpers::WebRenderDisplayListConverter;
 use layout::wrapper::LayoutNodeLayoutData;
 use layout_traits::LayoutThreadFactory;
 use libc::c_void;
-use malloc_size_of::{malloc_size_of, MallocSizeOf, MallocSizeOfOps};
+use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use metrics::{PaintTimeMetrics, ProfilerMetadataFactory};
 use msg::constellation_msg::PipelineId;
 use msg::constellation_msg::TopLevelBrowsingContextId;
@@ -775,7 +776,7 @@ impl LayoutThread {
         let mut reports = vec![];
         // Servo uses vanilla jemalloc, which doesn't have a
         // malloc_enclosing_size_of function.
-        let mut ops = MallocSizeOfOps::new(malloc_size_of, None, None);
+        let mut ops = MallocSizeOfOps::new(::servo_allocator::usable_size, None, None);
 
         // FIXME(njn): Just measuring the display tree for now.
         let rw_data = possibly_locked_rw_data.lock();

components/malloc_size_of/Cargo.toml

@@ -8,9 +8,6 @@ publish = false
 [lib]
 path = "lib.rs"
 
-[target.'cfg(windows)'.dependencies]
-kernel32-sys = "0.2.1"
-
 [features]
 servo = ["js", "string_cache", "url", "webrender_api", "xml5ever"]
 

components/malloc_size_of/lib.rs

@@ -49,8 +49,6 @@ extern crate euclid;
 extern crate hashglobe;
 #[cfg(feature = "servo")]
 extern crate js;
-#[cfg(target_os = "windows")]
-extern crate kernel32;
 extern crate servo_arc;
 extern crate smallbitvec;
 extern crate smallvec;
@@ -63,8 +61,6 @@ extern crate webrender_api;
 #[cfg(feature = "servo")]
 extern crate xml5ever;
 
-#[cfg(target_os = "windows")]
-use kernel32::{GetProcessHeap, HeapSize, HeapValidate};
 use std::hash::{BuildHasher, Hash};
 use std::mem::size_of;
 use std::ops::Range;
@@ -146,33 +142,6 @@ impl MallocSizeOfOps {
     }
 }
 
-/// Get the size of a heap block.
-#[cfg(not(target_os = "windows"))]
-pub unsafe extern "C" fn malloc_size_of(ptr: *const c_void) -> usize {
-    // The C prototype is `je_malloc_usable_size(JEMALLOC_USABLE_SIZE_CONST void *ptr)`. On some
-    // platforms `JEMALLOC_USABLE_SIZE_CONST` is `const` and on some it is empty. But in practice
-    // this function doesn't modify the contents of the block that `ptr` points to, so we use
-    // `*const c_void` here.
-    extern "C" {
-        #[cfg_attr(any(prefixed_jemalloc, target_os = "macos", target_os = "ios", target_os = "android"),
-                   link_name = "je_malloc_usable_size")]
-        fn malloc_usable_size(ptr: *const c_void) -> usize;
-    }
-    malloc_usable_size(ptr)
-}
-
-/// Get the size of a heap block.
-#[cfg(target_os = "windows")]
-pub unsafe extern "C" fn malloc_size_of(mut ptr: *const c_void) -> usize {
-    let heap = GetProcessHeap();
-
-    if HeapValidate(heap, 0, ptr) == 0 {
-        ptr = *(ptr as *const *const c_void).offset(-1);
-    }
-
-    HeapSize(heap, 0, ptr) as usize
-}
-
 /// Trait for measuring the "deep" heap usage of a data structure. This is the
 /// most commonly-used of the traits.
 pub trait MallocSizeOf {

components/profile/Cargo.toml

@@ -10,7 +10,7 @@ name = "profile"
 path = "lib.rs"
 
 [features]
-unstable = []
+unstable = ["jemalloc-sys"]
 
 [dependencies]
 profile_traits = {path = "../profile_traits"}
@@ -31,3 +31,4 @@ regex = "0.2"
 
 [target.'cfg(not(target_os = "windows"))'.dependencies]
 libc = "0.2"
+jemalloc-sys = {version = "0.1.3", optional = true}

components/profile/lib.rs

@@ -2,17 +2,14 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#![cfg_attr(all(feature = "unstable", not(target_os = "windows")), feature(alloc_jemalloc))]
-
 #![deny(unsafe_code)]
 
 #[allow(unused_extern_crates)]
-#[cfg(all(feature = "unstable", not(target_os = "windows")))]
-extern crate alloc_jemalloc;
 extern crate heartbeats_simple;
 extern crate influent;
 extern crate ipc_channel;
-#[allow(unused_extern_crates)]
+#[cfg(all(feature = "unstable", not(target_os = "windows")))]
+extern crate jemalloc_sys;
 #[cfg(not(target_os = "windows"))]
 extern crate libc;
 #[macro_use]

components/profile/mem.rs

@@ -354,7 +354,7 @@ impl ReportsForest {
 
 mod system_reporter {
     #[cfg(all(feature = "unstable", not(target_os = "windows")))]
-    use libc::{c_char, c_void, size_t};
+    use libc::{c_void, size_t};
     #[cfg(target_os = "linux")]
     use libc::c_int;
     use profile_traits::mem::{Report, ReportKind, ReporterRequest};
@@ -460,11 +460,7 @@ mod system_reporter {
     }
 
     #[cfg(all(feature = "unstable", not(target_os = "windows")))]
-    extern {
+    use jemalloc_sys::mallctl;
-        #[cfg_attr(any(target_os = "macos", target_os = "android"), link_name = "je_mallctl")]
-        fn mallctl(name: *const c_char, oldp: *mut c_void, oldlenp: *mut size_t,
-                   newp: *mut c_void, newlen: size_t) -> ::libc::c_int;
-    }
 
     #[cfg(all(feature = "unstable", not(target_os = "windows")))]
     fn jemalloc_stat(value_name: &str) -> Option<usize> {

components/script/Cargo.toml

@@ -13,7 +13,7 @@ path = "lib.rs"
 
 [features]
 debugmozjs = ['js/debugmozjs']
-unstable = []
+unstable = ["servo_allocator/unstable"]
 
 [build-dependencies]
 cmake = "0.1"
@@ -77,6 +77,7 @@ script_plugins = {path = "../script_plugins"}
 script_traits = {path = "../script_traits"}
 selectors = { path = "../selectors" }
 serde = "1.0"
+servo_allocator = {path = "../allocator"}
 servo_arc = {path = "../servo_arc"}
 servo_atoms = {path = "../atoms"}
 servo_config = {path = "../config"}

components/script/lib.rs

@@ -78,6 +78,7 @@ extern crate script_layout_interface;
 extern crate script_traits;
 extern crate selectors;
 extern crate serde;
+extern crate servo_allocator;
 extern crate servo_arc;
 #[macro_use] extern crate servo_atoms;
 extern crate servo_config;

components/script/script_thread.rs

@@ -73,7 +73,7 @@ use js::jsapi::{JSAutoCompartment, JSContext, JS_SetWrapObjectCallbacks};
 use js::jsapi::{JSTracer, SetWindowProxyClass};
 use js::jsval::UndefinedValue;
 use js::rust::Runtime;
-use malloc_size_of::{malloc_size_of, MallocSizeOfOps};
+use malloc_size_of::MallocSizeOfOps;
 use mem::malloc_size_of_including_self;
 use metrics::PaintTimeMetrics;
 use microtask::{MicrotaskQueue, Microtask};
@@ -1506,7 +1506,7 @@ impl ScriptThread {
         let mut reports = vec![];
         // Servo uses vanilla jemalloc, which doesn't have a
         // malloc_enclosing_size_of function.
-        let mut ops = MallocSizeOfOps::new(malloc_size_of, None, None);
+        let mut ops = MallocSizeOfOps::new(::servo_allocator::usable_size, None, None);
 
         for (_, document) in self.documents.borrow().iter() {
             let current_url = document.url();

ports/servo/Cargo.toml

@@ -37,7 +37,7 @@ energy-profiling = ["libservo/energy-profiling"]
 debugmozjs = ["libservo/debugmozjs"]
 googlevr = ["libservo/googlevr"]
 oculusvr = ["libservo/oculusvr"]
-unstable = ["libservo/unstable"]
+unstable = ["libservo/unstable", "profile_tests/unstable"]
 
 [dependencies]
 backtrace = "0.3"

python/tidy/servo_tidy/tidy.py

@@ -626,6 +626,10 @@ def check_rust(file_name, lines):
                       + decl_found.format(crate_name))
             prev_crate[indent] = crate_name
 
+        if line == "}":
+            for i in [i for i in prev_crate.keys() if i > indent]:
+                del prev_crate[i]
+
         # check alphabetical order of feature attributes in lib.rs files
         if is_lib_rs_file:
             match = re.search(r"#!\[feature\((.*)\)\]", line)

tests/unit/profile/Cargo.toml

@@ -9,7 +9,13 @@ name = "profile_tests"
 path = "lib.rs"
 doctest = false
 
+[features]
+unstable = ["servo_allocator/unstable"]
+
 [dependencies]
 ipc-channel = "0.9"
 profile = {path = "../../../components/profile"}
 profile_traits = {path = "../../../components/profile_traits"}
+
+# Work around https://github.com/alexcrichton/jemallocator/issues/19
+servo_allocator = {path = "../../../components/allocator"}

tests/unit/profile/lib.rs

@@ -5,6 +5,7 @@
 extern crate ipc_channel;
 extern crate profile;
 extern crate profile_traits;
+extern crate servo_allocator;
 
 #[cfg(test)]
 mod time;