auto merge of #14322 : thestinger/rust/secret_santa_heap, r=alexcrichton

Author: bors

src/liballoc/heap.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // FIXME: #13994: port to the sized deallocation API when available
-// FIXME: #13996: need a way to mark the `allocate` and `reallocate` return values as `noalias`
+// FIXME: #13996: mark the `allocate` and `reallocate` return value as `noalias` and `nonnull`
 
 use core::intrinsics::{abort, cttz32};
 use core::option::{None, Option};
@@ -119,14 +119,8 @@ pub fn stats_print() {
 /// The allocator for unique pointers.
 #[cfg(not(test))]
 #[lang="exchange_malloc"]
-#[inline(always)]
-pub unsafe fn exchange_malloc_(size: uint, align: uint) -> *mut u8 {
-    exchange_malloc(size, align)
-}
-
-/// The allocator for unique pointers.
 #[inline]
-pub unsafe fn exchange_malloc(size: uint, align: uint) -> *mut u8 {
+unsafe fn exchange_malloc(size: uint, align: uint) -> *mut u8 {
     // The compiler never calls `exchange_free` on ~ZeroSizeType, so zero-size
     // allocations can point to this `static`. It would be incorrect to use a null
     // pointer, due to enums assuming types like unique pointers are never null.
@@ -139,14 +133,20 @@ pub unsafe fn exchange_malloc(size: uint, align: uint) -> *mut u8 {
     }
 }
 
-#[cfg(not(test))]
+#[cfg(not(test), stage0)]
 #[lang="exchange_free"]
 #[inline]
-// FIXME: #13994 (rustc should pass align and size here)
 unsafe fn exchange_free(ptr: *mut u8) {
     deallocate(ptr, 0, 8);
 }
 
+#[cfg(not(test), not(stage0))]
+#[lang="exchange_free"]
+#[inline]
+unsafe fn exchange_free(ptr: *mut u8, size: uint, align: uint) {
+    deallocate(ptr, size, align);
+}
+
 // FIXME: #7496
 #[cfg(not(test))]
 #[lang="closure_exchange_malloc"]
@@ -167,16 +167,16 @@ unsafe fn closure_exchange_malloc(drop_glue: fn(*mut u8), size: uint, align: uin
 #[doc(hidden)]
 #[deprecated]
 #[cfg(not(test))]
-pub unsafe extern "C" fn rust_malloc(size: uint, align: uint) -> *mut u8 {
-    exchange_malloc(size, align)
+pub unsafe extern "C" fn rust_allocate(size: uint, align: uint) -> *mut u8 {
+    allocate(size, align)
 }
 
 // hack for libcore
 #[no_mangle]
 #[doc(hidden)]
 #[deprecated]
 #[cfg(not(test))]
-pub unsafe extern "C" fn rust_free(ptr: *mut u8, size: uint, align: uint) {
+pub unsafe extern "C" fn rust_deallocate(ptr: *mut u8, size: uint, align: uint) {
     deallocate(ptr, size, align)
 }
 

src/libarena/lib.rs

@@ -38,7 +38,7 @@ use std::mem;
 use std::num;
 use std::ptr::read;
 use std::rc::Rc;
-use std::rt::heap::exchange_malloc;
+use std::rt::heap::allocate;
 
 // The way arena uses arrays is really deeply awful. The arrays are
 // allocated, and have capacities reserved, but the fill for the array
@@ -358,8 +358,7 @@ impl<T> TypedArenaChunk<T> {
         size = size.checked_add(&elems_size).unwrap();
 
         let mut chunk = unsafe {
-            let chunk = exchange_malloc(size,
-                                        mem::min_align_of::<TypedArenaChunk<T>>());
+            let chunk = allocate(size, mem::min_align_of::<TypedArenaChunk<T>>());
             let mut chunk: Box<TypedArenaChunk<T>> = mem::transmute(chunk);
             mem::overwrite(&mut chunk.next, next);
             chunk

src/libcore/should_not_exist.rs

@@ -44,14 +44,14 @@ use str::StrSlice;
 
 #[allow(ctypes)]
 extern {
-    fn rust_malloc(size: uint, align: uint) -> *u8;
-    fn rust_free(ptr: *u8, size: uint, align: uint);
+    fn rust_allocate(size: uint, align: uint) -> *u8;
+    fn rust_deallocate(ptr: *u8, size: uint, align: uint);
 }
 
 unsafe fn alloc(cap: uint) -> *mut Vec<()> {
     let cap = cap.checked_add(&mem::size_of::<Vec<()>>()).unwrap();
     // this should use the real alignment, but the new representation will take care of that
-    let ret = rust_malloc(cap, 8) as *mut Vec<()>;
+    let ret = rust_allocate(cap, 8) as *mut Vec<()>;
     if ret.is_null() {
         intrinsics::abort();
     }
@@ -119,7 +119,7 @@ impl FromIterator<char> for ~str {
                                                     &(*ptr).data,
                                                     len);
                     // FIXME: #13994: port to the sized deallocation API when available
-                    rust_free(ptr as *u8, 0, 8);
+                    rust_deallocate(ptr as *u8, 0, 8);
                     mem::forget(ret);
                     ret = mem::transmute(ptr2);
                     ptr = ptr2;
@@ -191,7 +191,7 @@ impl<A: Clone> Clone for ~[A] {
                     for j in range(0, *i as int) {
                         ptr::read(&*p.offset(j));
                     }
-                    rust_free(ret as *u8, 0, 8);
+                    rust_deallocate(ret as *u8, 0, 8);
                 });
             mem::transmute(ret)
         }

src/librustc/middle/trans/cleanup.rs

@@ -278,13 +278,14 @@ impl<'a> CleanupMethods<'a> for FunctionContext<'a> {
     fn schedule_free_value(&self,
                            cleanup_scope: ScopeId,
                            val: ValueRef,
-                           heap: Heap) {
+                           heap: Heap,
+                           content_ty: ty::t) {
         /*!
          * Schedules a call to `free(val)`. Note that this is a shallow
          * operation.
          */
 
-        let drop = box FreeValue { ptr: val, heap: heap };
+        let drop = box FreeValue { ptr: val, heap: heap, content_ty: content_ty };
 
         debug!("schedule_free_value({:?}, val={}, heap={:?})",
                cleanup_scope,
@@ -847,6 +848,7 @@ pub enum Heap {
 pub struct FreeValue {
     ptr: ValueRef,
     heap: Heap,
+    content_ty: ty::t
 }
 
 impl Cleanup for FreeValue {
@@ -860,7 +862,7 @@ impl Cleanup for FreeValue {
                 glue::trans_free(bcx, self.ptr)
             }
             HeapExchange => {
-                glue::trans_exchange_free(bcx, self.ptr)
+                glue::trans_exchange_free_ty(bcx, self.ptr, self.content_ty)
             }
         }
     }
@@ -931,7 +933,8 @@ pub trait CleanupMethods<'a> {
     fn schedule_free_value(&self,
                            cleanup_scope: ScopeId,
                            val: ValueRef,
-                           heap: Heap);
+                           heap: Heap,
+                           content_ty: ty::t);
     fn schedule_clean(&self,
                       cleanup_scope: ScopeId,
                       cleanup: Box<Cleanup>);

src/librustc/middle/trans/expr.rs

@@ -1183,7 +1183,7 @@ fn trans_uniq_expr<'a>(bcx: &'a Block<'a>,
     } else {
         let custom_cleanup_scope = fcx.push_custom_cleanup_scope();
         fcx.schedule_free_value(cleanup::CustomScope(custom_cleanup_scope),
-                                val, cleanup::HeapExchange);
+                                val, cleanup::HeapExchange, contents_ty);
         let bcx = trans_into(bcx, contents, SaveIn(val));
         fcx.pop_custom_cleanup_scope(custom_cleanup_scope);
         bcx
@@ -1205,7 +1205,7 @@ fn trans_managed_expr<'a>(bcx: &'a Block<'a>,
 
     let custom_cleanup_scope = fcx.push_custom_cleanup_scope();
     fcx.schedule_free_value(cleanup::CustomScope(custom_cleanup_scope),
-                            bx, cleanup::HeapManaged);
+                            bx, cleanup::HeapManaged, contents_ty);
     let bcx = trans_into(bcx, contents, SaveIn(body));
     fcx.pop_custom_cleanup_scope(custom_cleanup_scope);
     immediate_rvalue_bcx(bcx, bx, box_ty).to_expr_datumblock()
@@ -1789,13 +1789,14 @@ fn deref_once<'a>(bcx: &'a Block<'a>,
                 let scope = cleanup::temporary_scope(bcx.tcx(), expr.id);
                 let ptr = Load(bcx, datum.val);
                 if !type_is_zero_size(bcx.ccx(), content_ty) {
-                    bcx.fcx.schedule_free_value(scope, ptr, cleanup::HeapExchange);
+                    bcx.fcx.schedule_free_value(scope, ptr, cleanup::HeapExchange, content_ty);
                 }
             }
             RvalueExpr(Rvalue { mode: ByValue }) => {
                 let scope = cleanup::temporary_scope(bcx.tcx(), expr.id);
                 if !type_is_zero_size(bcx.ccx(), content_ty) {
-                    bcx.fcx.schedule_free_value(scope, datum.val, cleanup::HeapExchange);
+                    bcx.fcx.schedule_free_value(scope, datum.val, cleanup::HeapExchange,
+                                                content_ty);
                 }
             }
             LvalueExpr => { }

src/librustc/middle/trans/glue.rs

@@ -50,15 +50,30 @@ pub fn trans_free<'a>(cx: &'a Block<'a>, v: ValueRef) -> &'a Block<'a> {
         Some(expr::Ignore)).bcx
 }
 
-pub fn trans_exchange_free<'a>(cx: &'a Block<'a>, v: ValueRef)
-                           -> &'a Block<'a> {
+fn trans_exchange_free<'a>(cx: &'a Block<'a>, v: ValueRef, size: u64,
+                               align: u64) -> &'a Block<'a> {
     let _icx = push_ctxt("trans_exchange_free");
+    let ccx = cx.ccx();
     callee::trans_lang_call(cx,
         langcall(cx, None, "", ExchangeFreeFnLangItem),
-        [PointerCast(cx, v, Type::i8p(cx.ccx()))],
+        [PointerCast(cx, v, Type::i8p(ccx)), C_uint(ccx, size as uint), C_uint(ccx, align as uint)],
         Some(expr::Ignore)).bcx
 }
 
+pub fn trans_exchange_free_ty<'a>(bcx: &'a Block<'a>, ptr: ValueRef,
+                                  content_ty: ty::t) -> &'a Block<'a> {
+    let sizing_type = sizing_type_of(bcx.ccx(), content_ty);
+    let content_size = llsize_of_alloc(bcx.ccx(), sizing_type);
+
+    // `Box<ZeroSizeType>` does not allocate.
+    if content_size != 0 {
+        let content_align = llalign_of_min(bcx.ccx(), sizing_type);
+        trans_exchange_free(bcx, ptr, content_size, content_align)
+    } else {
+        bcx
+    }
+}
+
 pub fn take_ty<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t)
                -> &'a Block<'a> {
     // NB: v is an *alias* of type t here, not a direct value.
@@ -87,17 +102,15 @@ fn get_drop_glue_type(ccx: &CrateContext, t: ty::t) -> ty::t {
                 ty::ty_vec(_, None) | ty::ty_str => t,
                 _ => {
                     let llty = sizing_type_of(ccx, typ);
-                    // Unique boxes do not allocate for zero-size types. The standard
-                    // library may assume that `free` is never called on the pointer
-                    // returned for `Box<ZeroSizeType>`.
+                    // `Box<ZeroSizeType>` does not allocate.
                     if llsize_of_alloc(ccx, llty) == 0 {
                         ty::mk_i8()
                     } else {
                         ty::mk_uniq(tcx, ty::mk_i8())
                     }
-                        }
-                    }
                 }
+            }
+        }
         _ => t
     }
 }
@@ -285,20 +298,22 @@ fn make_drop_glue<'a>(bcx: &'a Block<'a>, v0: ValueRef, t: ty::t) -> &'a Block<'
                 ty::ty_vec(mt, None) => {
                     with_cond(bcx, not_null, |bcx| {
                         let bcx = tvec::make_drop_glue_unboxed(bcx, llbox, mt.ty);
-                        trans_exchange_free(bcx, llbox)
+                        // FIXME: #13994: the old `Box<[T]>` will not support sized deallocation
+                        trans_exchange_free(bcx, llbox, 0, 8)
                     })
                 }
                 ty::ty_str => {
                     with_cond(bcx, not_null, |bcx| {
                         let unit_ty = ty::sequence_element_type(bcx.tcx(), t);
                         let bcx = tvec::make_drop_glue_unboxed(bcx, llbox, unit_ty);
-                        trans_exchange_free(bcx, llbox)
+                        // FIXME: #13994: the old `Box<str>` will not support sized deallocation
+                        trans_exchange_free(bcx, llbox, 0, 8)
                     })
                 }
                 _ => {
                     with_cond(bcx, not_null, |bcx| {
                         let bcx = drop_ty(bcx, llbox, content_ty);
-                        trans_exchange_free(bcx, llbox)
+                        trans_exchange_free_ty(bcx, llbox, content_ty)
                     })
                 }
             }
@@ -340,7 +355,8 @@ fn make_drop_glue<'a>(bcx: &'a Block<'a>, v0: ValueRef, t: ty::t) -> &'a Block<'
                 Call(bcx, dtor, [PointerCast(bcx, cdata, Type::i8p(bcx.ccx()))], []);
 
                 // Free the environment itself
-                trans_exchange_free(bcx, env)
+                // FIXME: #13994: pass align and size here
+                trans_exchange_free(bcx, env, 0, 8)
             })
         }
         _ => {

src/librustc/middle/trans/tvec.rs

@@ -287,8 +287,11 @@ pub fn trans_uniq_vstore<'a>(bcx: &'a Block<'a>,
     // Create a temporary scope lest execution should fail while
     // constructing the vector.
     let temp_scope = fcx.push_custom_cleanup_scope();
+
+    // FIXME: #13994: the old `Box<[T]> will not support sized deallocation, this is a placeholder
+    let content_ty = vt.unit_ty;
     fcx.schedule_free_value(cleanup::CustomScope(temp_scope),
-                            val, cleanup::HeapExchange);
+                            val, cleanup::HeapExchange, content_ty);
 
     let dataptr = get_dataptr(bcx, val);
 

src/libstd/slice.rs

@@ -109,7 +109,7 @@ use ops::Drop;
 use option::{None, Option, Some};
 use ptr::RawPtr;
 use ptr;
-use rt::heap::{exchange_malloc, deallocate};
+use rt::heap::{allocate, deallocate};
 use unstable::finally::try_finally;
 use vec::Vec;
 
@@ -304,7 +304,7 @@ impl<'a, T: Clone> CloneableVector<T> for &'a [T] {
 
         unsafe {
             // this should pass the real required alignment
-            let ret = exchange_malloc(size, 8) as *mut RawVec<()>;
+            let ret = allocate(size, 8) as *mut RawVec<()>;
 
             let a_size = mem::size_of::<T>();
             let a_size = if a_size == 0 {1} else {a_size};
@@ -968,7 +968,7 @@ mod tests {
         assert_eq!(v_b[0], 2);
         assert_eq!(v_b[1], 3);
 
-        // Test on exchange heap.
+        // Test `Box<[T]>`
         let vec_unique = box [1, 2, 3, 4, 5, 6];
         let v_d = vec_unique.slice(1u, 6u).to_owned();
         assert_eq!(v_d.len(), 5u);