Bump allocator

alloc/bump_allocator/Cargo.toml

@@ -0,0 +1,3 @@
+[package]
+name = "bump_allocator"
+version = "0.1.0"

alloc/bump_allocator/src/lib.rs

@@ -0,0 +1,47 @@
+//! A simple allocator that never frees, for testing
+
+#![feature(allocator)]
+#![allocator]
+#![no_std]
+
+pub static mut HEAP: usize = 10*1024*1024;
+
+#[no_mangle]
+pub extern fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
+    unsafe {
+        let mut ret = HEAP;
+        if align.is_power_of_two() {
+            ret += (align - 1);
+            ret &= !(align - 1);
+        } else {
+            assert_eq!(align, 0);
+        }
+        HEAP = ret + size;
+        ret as *mut u8
+    }
+}
+
+#[no_mangle]
+pub extern fn __rust_usable_size(size: usize, align: usize) -> usize {
+    size
+}
+
+#[no_mangle]
+pub extern fn __rust_deallocate(ptr: *mut u8, size: usize, align: usize) {
+
+}
+
+#[no_mangle]
+pub extern fn __rust_reallocate(ptr: *mut u8, size: usize, new_size: usize, align: usize) -> *mut u8 {
+    use core::{ptr, cmp};
+
+    let new_ptr = __rust_allocate(new_size, align);
+    unsafe { ptr::copy(ptr, new_ptr, cmp::min(size, new_size)) };
+    __rust_deallocate(ptr, size, align);
+    new_ptr
+}
+
+#[no_mangle]
+pub extern fn __rust_reallocate_inplace(ptr: *mut u8, size: usize, new_size: usize, align: usize) -> usize {
+    size
+}