auto merge of #9244 : thestinger/rust/drop, r=catamorphism

This doesn't close any bugs as the goal is to convert the parameter to by-value, but this is a step towards being able to make guarantees about `&T` pointers (where T is Freeze) to LLVM.

Author: bors

doc/tutorial-ffi.md

@@ -321,7 +321,7 @@ impl<T: Send> Unique<T> {
 
 #[unsafe_destructor]
 impl<T: Send> Drop for Unique<T> {
-    fn drop(&self) {
+    fn drop(&mut self) {
         #[fixed_stack_segment];
         #[inline(never)];
         

doc/tutorial.md

@@ -1898,7 +1898,7 @@ struct TimeBomb {
 }
 
 impl Drop for TimeBomb {
-    fn drop(&self) {
+    fn drop(&mut self) {
         for _ in range(0, self.explosivity) {
             println("blam!");
         }

src/libextra/arc.rs

@@ -313,7 +313,7 @@ struct PoisonOnFail {
 }
 
 impl Drop for PoisonOnFail {
-    fn drop(&self) {
+    fn drop(&mut self) {
         unsafe {
             /* assert!(!*self.failed);
                -- might be false in case of cond.wait() */

src/libextra/arena.rs

@@ -93,7 +93,7 @@ fn chunk(size: uint, is_pod: bool) -> Chunk {
 
 #[unsafe_destructor]
 impl Drop for Arena {
-    fn drop(&self) {
+    fn drop(&mut self) {
         unsafe {
             destroy_chunk(&self.head);
             do self.chunks.each |chunk| {

src/libextra/c_vec.rs

@@ -56,7 +56,7 @@ struct DtorRes {
 
 #[unsafe_destructor]
 impl Drop for DtorRes {
-    fn drop(&self) {
+    fn drop(&mut self) {
         match self.dtor {
             option::None => (),
             option::Some(f) => f()

src/libextra/dlist.rs

@@ -415,14 +415,11 @@ impl<T: Ord> DList<T> {
 
 #[unsafe_destructor]
 impl<T> Drop for DList<T> {
-    fn drop(&self) {
-        let mut_self = unsafe {
-            cast::transmute_mut(self)
-        };
+    fn drop(&mut self) {
         // Dissolve the dlist in backwards direction
         // Just dropping the list_head can lead to stack exhaustion
         // when length is >> 1_000_000
-        let mut tail = mut_self.list_tail;
+        let mut tail = self.list_tail;
         loop {
             match tail.resolve() {
                 None => break,
@@ -432,9 +429,9 @@ impl<T> Drop for DList<T> {
                 }
             }
         }
-        mut_self.length = 0;
-        mut_self.list_head = None;
-        mut_self.list_tail = Rawlink::none();
+        self.length = 0;
+        self.list_head = None;
+        self.list_tail = Rawlink::none();
     }
 }
 

src/libextra/future.rs

@@ -43,7 +43,7 @@ pub struct Future<A> {
 // over ~fn's that have pipes and so forth within!
 #[unsafe_destructor]
 impl<A> Drop for Future<A> {
-    fn drop(&self) {}
+    fn drop(&mut self) {}
 }
 
 enum FutureState<A> {

src/libextra/rc.rs

@@ -73,7 +73,7 @@ impl<T> Rc<T> {
 
 #[unsafe_destructor]
 impl<T> Drop for Rc<T> {
-    fn drop(&self) {
+    fn drop(&mut self) {
         unsafe {
             if self.ptr.is_not_null() {
                 (*self.ptr).count -= 1;
@@ -218,7 +218,7 @@ impl<T> RcMut<T> {
 
 #[unsafe_destructor]
 impl<T> Drop for RcMut<T> {
-    fn drop(&self) {
+    fn drop(&mut self) {
         unsafe {
             if self.ptr.is_not_null() {
                 (*self.ptr).count -= 1;

src/libextra/task_pool.rs

@@ -34,7 +34,7 @@ pub struct TaskPool<T> {
 
 #[unsafe_destructor]
 impl<T> Drop for TaskPool<T> {
-    fn drop(&self) {
+    fn drop(&mut self) {
         for channel in self.channels.iter() {
             channel.send(Quit);
         }

src/libextra/workcache.rs

@@ -201,7 +201,7 @@ impl Database {
 // FIXME #4330: use &mut self here
 #[unsafe_destructor]
 impl Drop for Database {
-    fn drop(&self) {
+    fn drop(&mut self) {
         if self.db_dirty {
             self.save();
         }