diff options
| -rw-r--r-- | src/librustc_arena/lib.rs | 39 | ||||
| -rw-r--r-- | src/librustc_middle/ty/list.rs | 17 |
2 files changed, 24 insertions, 32 deletions
diff --git a/src/librustc_arena/lib.rs b/src/librustc_arena/lib.rs index 66c31cbebcc..6cf2db3e2da 100644 --- a/src/librustc_arena/lib.rs +++ b/src/librustc_arena/lib.rs @@ -22,6 +22,7 @@ extern crate alloc; use rustc_data_structures::cold_path; use smallvec::SmallVec; +use std::alloc::Layout; use std::cell::{Cell, RefCell}; use std::cmp; use std::intrinsics; @@ -363,13 +364,15 @@ impl DroplessArena { } } - /// Allocates a byte slice with specified size and alignment from the - /// current memory chunk. Returns `None` if there is no free space left to - /// satisfy the request. + /// Allocates a byte slice with specified layout from the current memory + /// chunk. Returns `None` if there is no free space left to satisfy the + /// request. #[inline] - fn alloc_raw_without_grow(&self, bytes: usize, align: usize) -> Option<*mut u8> { + fn alloc_raw_without_grow(&self, layout: Layout) -> Option<*mut u8> { let ptr = self.ptr.get() as usize; let end = self.end.get() as usize; + let align = layout.align(); + let bytes = layout.size(); // The allocation request fits into the current chunk iff: // // let aligned = align_to(ptr, align); @@ -390,15 +393,15 @@ impl DroplessArena { } #[inline] - pub fn alloc_raw(&self, bytes: usize, align: usize) -> *mut u8 { - assert!(bytes != 0); + pub fn alloc_raw(&self, layout: Layout) -> *mut u8 { + assert!(layout.size() != 0); loop { - if let Some(a) = self.alloc_raw_without_grow(bytes, align) { + if let Some(a) = self.alloc_raw_without_grow(layout) { break a; } // No free space left. Allocate a new chunk to satisfy the request. // On failure the grow will panic or abort. - self.grow(bytes); + self.grow(layout.size()); } } @@ -406,7 +409,7 @@ impl DroplessArena { pub fn alloc<T>(&self, object: T) -> &mut T { assert!(!mem::needs_drop::<T>()); - let mem = self.alloc_raw(mem::size_of::<T>(), mem::align_of::<T>()) as *mut T; + let mem = self.alloc_raw(Layout::for_value::<T>(&object)) as *mut T; unsafe { // Write into uninitialized memory. @@ -431,7 +434,7 @@ impl DroplessArena { assert!(mem::size_of::<T>() != 0); assert!(!slice.is_empty()); - let mem = self.alloc_raw(slice.len() * mem::size_of::<T>(), mem::align_of::<T>()) as *mut T; + let mem = self.alloc_raw(Layout::for_value::<[T]>(slice)) as *mut T; unsafe { mem.copy_from_nonoverlapping(slice.as_ptr(), slice.len()); @@ -477,8 +480,8 @@ impl DroplessArena { if len == 0 { return &mut []; } - let size = len.checked_mul(mem::size_of::<T>()).unwrap(); - let mem = self.alloc_raw(size, mem::align_of::<T>()) as *mut T; + + let mem = self.alloc_raw(Layout::array::<T>(len).unwrap()) as *mut T; unsafe { self.write_from_iter(iter, len, mem) } } (_, _) => { @@ -491,9 +494,8 @@ impl DroplessArena { // the content of the SmallVec unsafe { let len = vec.len(); - let start_ptr = self - .alloc_raw(len * mem::size_of::<T>(), mem::align_of::<T>()) - as *mut T; + let start_ptr = + self.alloc_raw(Layout::for_value::<[T]>(vec.as_slice())) as *mut T; vec.as_ptr().copy_to_nonoverlapping(start_ptr, len); vec.set_len(0); slice::from_raw_parts_mut(start_ptr, len) @@ -537,7 +539,7 @@ pub struct DropArena { impl DropArena { #[inline] pub unsafe fn alloc<T>(&self, object: T) -> &mut T { - let mem = self.arena.alloc_raw(mem::size_of::<T>(), mem::align_of::<T>()) as *mut T; + let mem = self.arena.alloc_raw(Layout::new::<T>()) as *mut T; // Write into uninitialized memory. ptr::write(mem, object); let result = &mut *mem; @@ -557,10 +559,7 @@ impl DropArena { } let len = vec.len(); - let start_ptr = self - .arena - .alloc_raw(len.checked_mul(mem::size_of::<T>()).unwrap(), mem::align_of::<T>()) - as *mut T; + let start_ptr = self.arena.alloc_raw(Layout::array::<T>(len).unwrap()) as *mut T; let mut destructors = self.destructors.borrow_mut(); // Reserve space for the destructors so we can't panic while adding them diff --git a/src/librustc_middle/ty/list.rs b/src/librustc_middle/ty/list.rs index 76c72e4c260..92d6dbb5f90 100644 --- a/src/librustc_middle/ty/list.rs +++ b/src/librustc_middle/ty/list.rs @@ -2,7 +2,8 @@ use crate::arena::Arena; use rustc_serialize::{Encodable, Encoder}; -use std::cmp::{self, Ordering}; +use std::alloc::Layout; +use std::cmp::Ordering; use std::fmt; use std::hash::{Hash, Hasher}; use std::iter; @@ -43,17 +44,9 @@ impl<T: Copy> List<T> { assert!(mem::size_of::<T>() != 0); assert!(!slice.is_empty()); - // Align up the size of the len (usize) field - let align = mem::align_of::<T>(); - let align_mask = align - 1; - let offset = mem::size_of::<usize>(); - let offset = (offset + align_mask) & !align_mask; - - let size = offset + slice.len() * mem::size_of::<T>(); - - let mem = arena - .dropless - .alloc_raw(size, cmp::max(mem::align_of::<T>(), mem::align_of::<usize>())); + let (layout, _offset) = + Layout::new::<usize>().extend(Layout::for_value::<[T]>(slice)).unwrap(); + let mem = arena.dropless.alloc_raw(layout); unsafe { let result = &mut *(mem as *mut List<T>); // Write the length |