auto merge of #17012 : thestinger/rust/sized, r=nikomatsakis

8 files changed, 186 insertions, 87 deletions

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index 38216fa5b59..c72a77702af 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -14,7 +14,7 @@
 
 use core::ptr::RawPtr;
 #[cfg(not(test))] use core::raw;
-#[cfg(not(test))] use util;
+#[cfg(stage0, not(test))] use util;
 
 /// Returns a pointer to `size` bytes of memory.
 ///
@@ -119,7 +119,7 @@ unsafe fn exchange_free(ptr: *mut u8, size: uint, align: uint) {
 }
 
 // FIXME: #7496
-#[cfg(not(test))]
+#[cfg(stage0, not(test))]
 #[lang="closure_exchange_malloc"]
 #[inline]
 #[allow(deprecated)]
@@ -134,6 +134,21 @@ unsafe fn closure_exchange_malloc(drop_glue: fn(*mut u8), size: uint,
     alloc as *mut u8
 }
 
+// FIXME: #7496
+#[cfg(not(stage0), not(test))]
+#[lang="closure_exchange_malloc"]
+#[inline]
+#[allow(deprecated)]
+unsafe fn closure_exchange_malloc(drop_glue: fn(*mut u8), size: uint,
+                                  align: uint) -> *mut u8 {
+    let p = allocate(size, align);
+
+    let alloc = p as *mut raw::Box<()>;
+    (*alloc).drop_glue = drop_glue;
+
+    alloc as *mut u8
+}
+
 #[cfg(jemalloc)]
 mod imp {
     use core::option::{None, Option};
diff --git a/src/libarena/lib.rs b/src/libarena/lib.rs
index 73464047319..e9189854853 100644
--- a/src/libarena/lib.rs
+++ b/src/libarena/lib.rs
@@ -39,17 +39,18 @@ use std::mem;
 use std::num;
 use std::ptr;
 use std::rc::Rc;
-use std::rt::heap::allocate;
+use std::rt::heap::{allocate, deallocate};
 
 // The way arena uses arrays is really deeply awful. The arrays are
 // allocated, and have capacities reserved, but the fill for the array
 // will always stay at 0.
 #[deriving(Clone, PartialEq)]
 struct Chunk {
-    data: Rc<RefCell<Vec<u8> >>,
+    data: Rc<RefCell<Vec<u8>>>,
     fill: Cell<uint>,
     is_copy: Cell<bool>,
 }
+
 impl Chunk {
     fn capacity(&self) -> uint {
         self.data.borrow().capacity()
@@ -357,13 +358,12 @@ pub struct TypedArena<T> {
     end: Cell<*const T>,
 
     /// A pointer to the first arena segment.
-    first: RefCell<TypedArenaChunkRef<T>>,
+    first: RefCell<*mut TypedArenaChunk<T>>,
 }
-type TypedArenaChunkRef<T> = Option<Box<TypedArenaChunk<T>>>;
 
 struct TypedArenaChunk<T> {
     /// Pointer to the next arena segment.
-    next: TypedArenaChunkRef<T>,
+    next: *mut TypedArenaChunk<T>,
 
     /// The number of elements that this chunk can hold.
     capacity: uint,
@@ -371,24 +371,24 @@ struct TypedArenaChunk<T> {
     // Objects follow here, suitably aligned.
 }
 
+fn calculate_size<T>(capacity: uint) -> uint {
+    let mut size = mem::size_of::<TypedArenaChunk<T>>();
+    size = round_up(size, mem::min_align_of::<T>());
+    let elem_size = mem::size_of::<T>();
+    let elems_size = elem_size.checked_mul(&capacity).unwrap();
+    size = size.checked_add(&elems_size).unwrap();
+    size
+}
+
 impl<T> TypedArenaChunk<T> {
     #[inline]
-    fn new(next: Option<Box<TypedArenaChunk<T>>>, capacity: uint)
-           -> Box<TypedArenaChunk<T>> {
-        let mut size = mem::size_of::<TypedArenaChunk<T>>();
-        size = round_up(size, mem::min_align_of::<T>());
-        let elem_size = mem::size_of::<T>();
-        let elems_size = elem_size.checked_mul(&capacity).unwrap();
-        size = size.checked_add(&elems_size).unwrap();
-
-        let mut chunk = unsafe {
-            let chunk = allocate(size, mem::min_align_of::<TypedArenaChunk<T>>());
-            let mut chunk: Box<TypedArenaChunk<T>> = mem::transmute(chunk);
-            ptr::write(&mut chunk.next, next);
-            chunk
-        };
-
-        chunk.capacity = capacity;
+    unsafe fn new(next: *mut TypedArenaChunk<T>, capacity: uint)
+           -> *mut TypedArenaChunk<T> {
+        let size = calculate_size::<T>(capacity);
+        let chunk = allocate(size, mem::min_align_of::<TypedArenaChunk<T>>())
+                    as *mut TypedArenaChunk<T>;
+        (*chunk).next = next;
+        (*chunk).capacity = capacity;
         chunk
     }
 
@@ -406,14 +406,13 @@ impl<T> TypedArenaChunk<T> {
         }
 
         // Destroy the next chunk.
-        let next_opt = mem::replace(&mut self.next, None);
-        match next_opt {
-            None => {}
-            Some(mut next) => {
-                // We assume that the next chunk is completely filled.
-                let capacity = next.capacity;
-                next.destroy(capacity)
-            }
+        let next = self.next;
+        let size = calculate_size::<T>(self.capacity);
+        deallocate(self as *mut TypedArenaChunk<T> as *mut u8, size,
+                   mem::min_align_of::<TypedArenaChunk<T>>());
+        if next.is_not_null() {
+            let capacity = (*next).capacity;
+            (*next).destroy(capacity);
         }
     }
 
@@ -448,11 +447,13 @@ impl<T> TypedArena<T> {
     /// objects.
     #[inline]
     pub fn with_capacity(capacity: uint) -> TypedArena<T> {
-        let chunk = TypedArenaChunk::<T>::new(None, capacity);
-        TypedArena {
-            ptr: Cell::new(chunk.start() as *const T),
-            end: Cell::new(chunk.end() as *const T),
-            first: RefCell::new(Some(chunk)),
+        unsafe {
+            let chunk = TypedArenaChunk::<T>::new(ptr::mut_null(), capacity);
+            TypedArena {
+                ptr: Cell::new((*chunk).start() as *const T),
+                end: Cell::new((*chunk).end() as *const T),
+                first: RefCell::new(chunk),
+            }
         }
     }
 
@@ -476,26 +477,28 @@ impl<T> TypedArena<T> {
     /// Grows the arena.
     #[inline(never)]
     fn grow(&self) {
-        let chunk = self.first.borrow_mut().take().unwrap();
-        let new_capacity = chunk.capacity.checked_mul(&2).unwrap();
-        let chunk = TypedArenaChunk::<T>::new(Some(chunk), new_capacity);
-        self.ptr.set(chunk.start() as *const T);
-        self.end.set(chunk.end() as *const T);
-        *self.first.borrow_mut() = Some(chunk)
+        unsafe {
+            let chunk = *self.first.borrow_mut();
+            let new_capacity = (*chunk).capacity.checked_mul(&2).unwrap();
+            let chunk = TypedArenaChunk::<T>::new(chunk, new_capacity);
+            self.ptr.set((*chunk).start() as *const T);
+            self.end.set((*chunk).end() as *const T);
+            *self.first.borrow_mut() = chunk
+        }
     }
 }
 
 #[unsafe_destructor]
 impl<T> Drop for TypedArena<T> {
     fn drop(&mut self) {
-        // Determine how much was filled.
-        let start = self.first.borrow().as_ref().unwrap().start() as uint;
-        let end = self.ptr.get() as uint;
-        let diff = (end - start) / mem::size_of::<T>();
-
-        // Pass that to the `destroy` method.
         unsafe {
-            self.first.borrow_mut().as_mut().unwrap().destroy(diff)
+            // Determine how much was filled.
+            let start = self.first.borrow().as_ref().unwrap().start() as uint;
+            let end = self.ptr.get() as uint;
+            let diff = (end - start) / mem::size_of::<T>();
+
+            // Pass that to the `destroy` method.
+            (**self.first.borrow_mut()).destroy(diff)
         }
     }
 }
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 49e058333e5..04700f74943 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -66,7 +66,7 @@ use middle::trans::glue;
 use middle::trans::inline;
 use middle::trans::intrinsic;
 use middle::trans::machine;
-use middle::trans::machine::{llsize_of, llsize_of_real};
+use middle::trans::machine::{llsize_of, llsize_of_real, llalign_of_min};
 use middle::trans::meth;
 use middle::trans::monomorphize;
 use middle::trans::tvec;
@@ -382,13 +382,44 @@ pub fn malloc_raw_dyn<'a>(bcx: &'a Block<'a>,
     Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
 }
 
+pub fn malloc_raw_dyn_proc<'a>(
+                      bcx: &'a Block<'a>,
+                      t: ty::t, alloc_fn: LangItem) -> Result<'a> {
+    let _icx = push_ctxt("malloc_raw_dyn_proc");
+    let ccx = bcx.ccx();
+
+    let langcall = require_alloc_fn(bcx, t, alloc_fn);
+
+    // Grab the TypeRef type of ptr_ty.
+    let ptr_ty = ty::mk_uniq(bcx.tcx(), t);
+    let ptr_llty = type_of(ccx, ptr_ty);
+
+    let llty = type_of(bcx.ccx(), t);
+    let size = llsize_of(bcx.ccx(), llty);
+    let llalign = C_uint(ccx, llalign_of_min(bcx.ccx(), llty) as uint);
+
+    // Allocate space:
+    let drop_glue = glue::get_drop_glue(ccx, ty::mk_uniq(bcx.tcx(), t));
+    let r = callee::trans_lang_call(
+        bcx,
+        langcall,
+        [
+            PointerCast(bcx, drop_glue, Type::glue_fn(ccx, Type::i8p(ccx)).ptr_to()),
+            size,
+            llalign
+        ],
+        None);
+    Result::new(r.bcx, PointerCast(r.bcx, r.val, ptr_llty))
+}
+
+
 pub fn malloc_raw_dyn_managed<'a>(
                       bcx: &'a Block<'a>,
                       t: ty::t,
                       alloc_fn: LangItem,
                       size: ValueRef)
                       -> Result<'a> {
-    let _icx = push_ctxt("malloc_raw_managed");
+    let _icx = push_ctxt("malloc_raw_dyn_managed");
     let ccx = bcx.ccx();
 
     let langcall = require_alloc_fn(bcx, t, alloc_fn);
diff --git a/src/librustc/middle/trans/cleanup.rs b/src/librustc/middle/trans/cleanup.rs
index 15d296ac723..cdfb8e48a46 100644
--- a/src/librustc/middle/trans/cleanup.rs
+++ b/src/librustc/middle/trans/cleanup.rs
@@ -340,6 +340,27 @@ impl<'a> CleanupMethods<'a> for FunctionContext<'a> {
         self.schedule_clean(cleanup_scope, drop as CleanupObj);
     }
 
+    fn schedule_free_slice(&self,
+                           cleanup_scope: ScopeId,
+                           val: ValueRef,
+                           size: ValueRef,
+                           align: ValueRef,
+                           heap: Heap) {
+        /*!
+         * Schedules a call to `free(val)`. Note that this is a shallow
+         * operation.
+         */
+
+        let drop = box FreeSlice { ptr: val, size: size, align: align, heap: heap };
+
+        debug!("schedule_free_slice({:?}, val={}, heap={:?})",
+               cleanup_scope,
+               self.ccx.tn().val_to_string(val),
+               heap);
+
+        self.schedule_clean(cleanup_scope, drop as CleanupObj);
+    }
+
     fn schedule_clean(&self,
                       cleanup_scope: ScopeId,
                       cleanup: CleanupObj) {
@@ -926,6 +947,34 @@ impl Cleanup for FreeValue {
     }
 }
 
+pub struct FreeSlice {
+    ptr: ValueRef,
+    size: ValueRef,
+    align: ValueRef,
+    heap: Heap,
+}
+
+impl Cleanup for FreeSlice {
+    fn must_unwind(&self) -> bool {
+        true
+    }
+
+    fn clean_on_unwind(&self) -> bool {
+        true
+    }
+
+    fn trans<'a>(&self, bcx: &'a Block<'a>) -> &'a Block<'a> {
+        match self.heap {
+            HeapManaged => {
+                glue::trans_free(bcx, self.ptr)
+            }
+            HeapExchange => {
+                glue::trans_exchange_free_dyn(bcx, self.ptr, self.size, self.align)
+            }
+        }
+    }
+}
+
 pub struct LifetimeEnd {
     ptr: ValueRef,
 }
@@ -1020,6 +1069,12 @@ pub trait CleanupMethods<'a> {
                            val: ValueRef,
                            heap: Heap,
                            content_ty: ty::t);
+    fn schedule_free_slice(&self,
+                           cleanup_scope: ScopeId,
+                           val: ValueRef,
+                           size: ValueRef,
+                           align: ValueRef,
+                           heap: Heap);
     fn schedule_clean(&self,
                       cleanup_scope: ScopeId,
                       cleanup: CleanupObj);
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index 4e9431f2629..b90ac39cf1d 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/src/librustc/middle/trans/closure.rs
@@ -24,7 +24,6 @@ use middle::trans::common::*;
 use middle::trans::datum::{Datum, DatumBlock, Expr, Lvalue, rvalue_scratch_datum};
 use middle::trans::debuginfo;
 use middle::trans::expr;
-use middle::trans::machine::llsize_of;
 use middle::trans::type_of::*;
 use middle::trans::type_::Type;
 use middle::ty;
@@ -144,15 +143,12 @@ fn allocate_cbox<'a>(bcx: &'a Block<'a>,
     let tcx = bcx.tcx();
 
     // Allocate and initialize the box:
+    let cbox_ty = tuplify_box_ty(tcx, cdata_ty);
     match store {
         ty::UniqTraitStore => {
-            let ty = type_of(bcx.ccx(), cdata_ty);
-            let size = llsize_of(bcx.ccx(), ty);
-            // we treat proc as @ here, which isn't ideal
-            malloc_raw_dyn_managed(bcx, cdata_ty, ClosureExchangeMallocFnLangItem, size)
+            malloc_raw_dyn_proc(bcx, cbox_ty, ClosureExchangeMallocFnLangItem)
         }
         ty::RegionTraitStore(..) => {
-            let cbox_ty = tuplify_box_ty(tcx, cdata_ty);
             let llbox = alloc_ty(bcx, cbox_ty, "__closure");
             Result::new(bcx, llbox)
         }
diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index c8a47532a92..09d28f03392 100644
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -53,7 +53,7 @@ pub fn trans_free<'a>(cx: &'a Block<'a>, v: ValueRef) -> &'a Block<'a> {
         Some(expr::Ignore)).bcx
 }
 
-fn trans_exchange_free_internal<'a>(cx: &'a Block<'a>, v: ValueRef, size: ValueRef,
+pub fn trans_exchange_free_dyn<'a>(cx: &'a Block<'a>, v: ValueRef, size: ValueRef,
                                align: ValueRef) -> &'a Block<'a> {
     let _icx = push_ctxt("trans_exchange_free");
     let ccx = cx.ccx();
@@ -65,10 +65,8 @@ fn trans_exchange_free_internal<'a>(cx: &'a Block<'a>, v: ValueRef, size: ValueR
 
 pub fn trans_exchange_free<'a>(cx: &'a Block<'a>, v: ValueRef, size: u64,
                                align: u64) -> &'a Block<'a> {
-    trans_exchange_free_internal(cx,
-                                 v,
-                                 C_uint(cx.ccx(), size as uint),
-                                 C_uint(cx.ccx(), align as uint))
+    trans_exchange_free_dyn(cx, v, C_uint(cx.ccx(), size as uint),
+                            C_uint(cx.ccx(), align as uint))
 }
 
 pub fn trans_exchange_free_ty<'a>(bcx: &'a Block<'a>, ptr: ValueRef,
@@ -111,9 +109,6 @@ pub fn get_drop_glue_type(ccx: &CrateContext, t: ty::t) -> ty::t {
         return ty::mk_i8();
     }
     match ty::get(t).sty {
-        ty::ty_box(typ) if !ty::type_needs_drop(tcx, typ) =>
-            ty::mk_box(tcx, ty::mk_i8()),
-
         ty::ty_uniq(typ) if !ty::type_needs_drop(tcx, typ)
                          && ty::type_is_sized(tcx, typ) => {
             let llty = sizing_type_of(ccx, typ);
@@ -121,7 +116,7 @@ pub fn get_drop_glue_type(ccx: &CrateContext, t: ty::t) -> ty::t {
             if llsize_of_alloc(ccx, llty) == 0 {
                 ty::mk_i8()
             } else {
-                ty::mk_uniq(tcx, ty::mk_i8())
+                t
             }
         }
         _ => t
@@ -470,7 +465,7 @@ fn make_drop_glue<'a>(bcx: &'a Block<'a>, v0: ValueRef, t: ty::t) -> &'a Block<'
                         let info = GEPi(bcx, v0, [0, abi::slice_elt_len]);
                         let info = Load(bcx, info);
                         let (llsize, llalign) = size_and_align_of_dst(bcx, content_ty, info);
-                        trans_exchange_free_internal(bcx, llbox, llsize, llalign)
+                        trans_exchange_free_dyn(bcx, llbox, llsize, llalign)
                     })
                 }
                 _ => {
@@ -523,12 +518,8 @@ fn make_drop_glue<'a>(bcx: &'a Block<'a>, v0: ValueRef, t: ty::t) -> &'a Block<'
             with_cond(bcx, IsNotNull(bcx, env), |bcx| {
                 let dtor_ptr = GEPi(bcx, env, [0u, abi::box_field_tydesc]);
                 let dtor = Load(bcx, dtor_ptr);
-                let cdata = GEPi(bcx, env, [0u, abi::box_field_body]);
-                Call(bcx, dtor, [PointerCast(bcx, cdata, Type::i8p(bcx.ccx()))], None);
-
-                // Free the environment itself
-                // FIXME: #13994: pass align and size here
-                trans_exchange_free(bcx, env, 0, 8)
+                Call(bcx, dtor, [PointerCast(bcx, box_cell_v, Type::i8p(bcx.ccx()))], None);
+                bcx
             })
         }
         ty::ty_trait(..) => {
diff --git a/src/librustc/middle/trans/tvec.rs b/src/librustc/middle/trans/tvec.rs
index 3701d83d6a1..285105d22f6 100644
--- a/src/librustc/middle/trans/tvec.rs
+++ b/src/librustc/middle/trans/tvec.rs
@@ -25,6 +25,7 @@ use middle::trans::datum::*;
 use middle::trans::expr::{Dest, Ignore, SaveIn};
 use middle::trans::expr;
 use middle::trans::glue;
+use middle::trans::machine;
 use middle::trans::machine::{nonzero_llsize_of, llsize_of_alloc};
 use middle::trans::type_::Type;
 use middle::trans::type_of;
@@ -59,6 +60,7 @@ pub fn make_drop_glue_unboxed<'a>(
                               -> &'a Block<'a> {
     let not_null = IsNotNull(bcx, vptr);
     with_cond(bcx, not_null, |bcx| {
+        let ccx = bcx.ccx();
         let tcx = bcx.tcx();
         let _icx = push_ctxt("tvec::make_drop_glue_unboxed");
 
@@ -73,8 +75,11 @@ pub fn make_drop_glue_unboxed<'a>(
         if should_deallocate {
             let not_null = IsNotNull(bcx, dataptr);
             with_cond(bcx, not_null, |bcx| {
-                // FIXME: #13994: the old `Box<[T]>` will not support sized deallocation
-                glue::trans_exchange_free(bcx, dataptr, 0, 8)
+                let llty = type_of::type_of(ccx, unit_ty);
+                let llsize = machine::llsize_of(ccx, llty);
+                let llalign = C_uint(ccx, machine::llalign_of_min(ccx, llty) as uint);
+                let size = Mul(bcx, llsize, get_len(bcx, vptr));
+                glue::trans_exchange_free_dyn(bcx, dataptr, size, llalign)
             })
         } else {
             bcx
@@ -281,15 +286,16 @@ pub fn trans_uniq_vec<'a>(bcx: &'a Block<'a>,
     debug!("    vt={}, count={:?}", vt.to_string(ccx), count);
     let vec_ty = node_id_type(bcx, uniq_expr.id);
 
-    let unit_sz = nonzero_llsize_of(ccx, type_of::type_of(ccx, vt.unit_ty));
+    let llty = type_of::type_of(ccx, vt.unit_ty);
+    let unit_sz = nonzero_llsize_of(ccx, llty);
     let llcount = if count < 4u {
         C_int(ccx, 4)
     } else {
         C_uint(ccx, count)
     };
     let alloc = Mul(bcx, llcount, unit_sz);
-    let llty_ptr = type_of::type_of(ccx, vt.unit_ty).ptr_to();
-    let align = C_uint(ccx, 8);
+    let llty_ptr = llty.ptr_to();
+    let align = C_uint(ccx, machine::llalign_of_min(ccx, llty) as uint);
     let Result { bcx: bcx, val: dataptr } = malloc_raw_dyn(bcx,
                                                            llty_ptr,
                                                            vec_ty,
@@ -299,16 +305,15 @@ pub fn trans_uniq_vec<'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
-    fcx.schedule_free_value(cleanup::CustomScope(temp_scope),
-                            dataptr, cleanup::HeapExchange, vt.unit_ty);
 
-        debug!("    alloc_uniq_vec() returned dataptr={}, len={}",
-               bcx.val_to_string(dataptr), count);
+    fcx.schedule_free_slice(cleanup::CustomScope(temp_scope),
+                            dataptr, alloc, align, cleanup::HeapExchange);
 
-        let bcx = write_content(bcx, &vt, uniq_expr,
-                                content_expr, SaveIn(dataptr));
+    debug!("    alloc_uniq_vec() returned dataptr={}, len={}",
+           bcx.val_to_string(dataptr), count);
+
+    let bcx = write_content(bcx, &vt, uniq_expr,
+                            content_expr, SaveIn(dataptr));
 
     fcx.pop_custom_cleanup_scope(temp_scope);
 
diff --git a/src/libsyntax/owned_slice.rs b/src/libsyntax/owned_slice.rs
index 7eb6709919a..d368477cd33 100644
--- a/src/libsyntax/owned_slice.rs
+++ b/src/libsyntax/owned_slice.rs
@@ -58,9 +58,12 @@ impl<T> OwnedSlice<T> {
         if len == 0 {
             OwnedSlice::empty()
         } else {
+            // drop excess capacity to avoid breaking sized deallocation
+            v.shrink_to_fit();
+
             let p = v.as_mut_ptr();
             // we own the allocation now
-            unsafe {mem::forget(v)}
+            unsafe { mem::forget(v) }
 
             OwnedSlice { data: p, len: len }
         }