get rid of libc_heap::{malloc_raw, realloc_raw}

The C standard library functions should be used directly. The quirky
NULL / zero-size allocation workaround is no longer necessary and was
adding an extra branch to the allocator code path in a build without
jemalloc. This is a small step towards liballoc being compatible with
handling OOM errors instead of aborting (#18292).

[breaking-change]

src/liballoc/heap.rs

@@ -213,8 +213,8 @@ mod imp {
 mod imp {
     use core::cmp;
     use core::ptr;
+    use core::ptr::RawPtr;
     use libc;
-    use libc_heap;
     use super::MIN_ALIGN;
 
     extern {
@@ -226,7 +226,11 @@ mod imp {
     #[inline]
     pub unsafe fn allocate(size: uint, align: uint) -> *mut u8 {
         if align <= MIN_ALIGN {
-            libc_heap::malloc_raw(size)
+            let ptr = libc::malloc(size as libc::size_t);
+            if ptr.is_null() {
+                ::oom();
+            }
+            ptr as *mut u8
         } else {
             let mut out = 0 as *mut libc::c_void;
             let ret = posix_memalign(&mut out,
@@ -242,7 +246,11 @@ mod imp {
     #[inline]
     pub unsafe fn reallocate(ptr: *mut u8, old_size: uint, size: uint, align: uint) -> *mut u8 {
         if align <= MIN_ALIGN {
-            libc_heap::realloc_raw(ptr, size)
+            let ptr = libc::realloc(ptr as *mut libc::c_void, size as libc::size_t);
+            if ptr.is_null() {
+                ::oom();
+            }
+            ptr as *mut u8
         } else {
             let new_ptr = allocate(size, align);
             ptr::copy_memory(new_ptr, ptr as *const u8, cmp::min(size, old_size));
@@ -274,7 +282,6 @@ mod imp {
 mod imp {
     use libc::{c_void, size_t};
     use libc;
-    use libc_heap;
     use core::ptr::RawPtr;
     use super::MIN_ALIGN;
 
@@ -288,7 +295,11 @@ mod imp {
     #[inline]
     pub unsafe fn allocate(size: uint, align: uint) -> *mut u8 {
         if align <= MIN_ALIGN {
-            libc_heap::malloc_raw(size)
+            let ptr = libc::malloc(size as size_t);
+            if ptr.is_null() {
+                ::oom();
+            }
+            ptr as *mut u8
         } else {
             let ptr = _aligned_malloc(size as size_t, align as size_t);
             if ptr.is_null() {
@@ -301,7 +312,11 @@ mod imp {
     #[inline]
     pub unsafe fn reallocate(ptr: *mut u8, _old_size: uint, size: uint, align: uint) -> *mut u8 {
         if align <= MIN_ALIGN {
-            libc_heap::realloc_raw(ptr, size)
+            let ptr = libc::realloc(ptr as *mut c_void, size as size_t);
+            if ptr.is_null() {
+                ::oom();
+            }
+            ptr as *mut u8
         } else {
             let ptr = _aligned_realloc(ptr as *mut c_void, size as size_t,
                                        align as size_t);

src/liballoc/lib.rs

@@ -54,11 +54,8 @@
 //!
 //! ## Heap interfaces
 //!
-//! The [`heap`](heap/index.html) and [`libc_heap`](libc_heap/index.html)
-//! modules are the unsafe interfaces to the underlying allocation systems. The
-//! `heap` module is considered the default heap, and is not necessarily backed
-//! by libc malloc/free.  The `libc_heap` module is defined to be wired up to
-//! the system malloc/free.
+//! The [`heap`](heap/index.html) module defines the low-level interface to the
+//! default global allocator. It is not compatible with the libc allocator API.
 
 #![crate_name = "alloc"]
 #![experimental]
@@ -90,7 +87,6 @@ pub use boxed as owned;
 // Heaps provided for low-level allocation strategies
 
 pub mod heap;
-pub mod libc_heap;
 
 // Primitive types using the heaps above
 

src/liballoc/libc_heap.rs

@@ -1,48 +0,0 @@
-// Copyright 2012-2014 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 global (exchange) heap.
-
-use libc::{c_void, size_t, free, malloc, realloc};
-use core::ptr::{RawPtr, null_mut};
-
-/// A wrapper around libc::malloc, aborting on out-of-memory.
-#[inline]
-pub unsafe fn malloc_raw(size: uint) -> *mut u8 {
-    // `malloc(0)` may allocate, but it may also return a null pointer
-    // http://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html
-    if size == 0 {
-        null_mut()
-    } else {
-        let p = malloc(size as size_t);
-        if p.is_null() {
-            ::oom();
-        }
-        p as *mut u8
-    }
-}
-
-/// A wrapper around libc::realloc, aborting on out-of-memory.
-#[inline]
-pub unsafe fn realloc_raw(ptr: *mut u8, size: uint) -> *mut u8 {
-    // `realloc(ptr, 0)` may allocate, but it may also return a null pointer
-    // http://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html
-    if size == 0 {
-        free(ptr as *mut c_void);
-        null_mut()
-    } else {
-        let p = realloc(ptr as *mut c_void, size as size_t);
-        if p.is_null() {
-            ::oom();
-        }
-        p as *mut u8
-    }
-}