rollup merge of #18318 : arielb1/transmute-cleanup

4 files changed, 23 insertions, 29 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index a2c859cf9fd..1edcb35289a 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -119,7 +119,7 @@ impl Name {
     pub fn as_str<'a>(&'a self) -> &'a str {
         unsafe {
             // FIXME #12938: can't use copy_lifetime since &str isn't a &T
-            ::std::mem::transmute(token::get_name(*self).get())
+            ::std::mem::transmute::<&str,&str>(token::get_name(*self).get())
         }
     }
 
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 8b0e1f32fd4..863f53be798 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -21,7 +21,6 @@ use ptr::P;
 use visit::Visitor;
 use visit;
 
-use std::cell::Cell;
 use std::cmp;
 use std::u32;
 
@@ -333,20 +332,20 @@ impl IdRange {
 }
 
 pub trait IdVisitingOperation {
-    fn visit_id(&self, node_id: NodeId);
+    fn visit_id(&mut self, node_id: NodeId);
 }
 
 /// A visitor that applies its operation to all of the node IDs
 /// in a visitable thing.
 
 pub struct IdVisitor<'a, O:'a> {
-    pub operation: &'a O,
+    pub operation: &'a mut O,
     pub pass_through_items: bool,
     pub visited_outermost: bool,
 }
 
 impl<'a, O: IdVisitingOperation> IdVisitor<'a, O> {
-    fn visit_generics_helper(&self, generics: &Generics) {
+    fn visit_generics_helper(&mut self, generics: &Generics) {
         for type_parameter in generics.ty_params.iter() {
             self.operation.visit_id(type_parameter.id)
         }
@@ -540,7 +539,7 @@ impl<'a, 'v, O: IdVisitingOperation> Visitor<'v> for IdVisitor<'a, O> {
 }
 
 pub fn visit_ids_for_inlined_item<O: IdVisitingOperation>(item: &InlinedItem,
-                                                          operation: &O) {
+                                                          operation: &mut O) {
     let mut id_visitor = IdVisitor {
         operation: operation,
         pass_through_items: true,
@@ -551,23 +550,21 @@ pub fn visit_ids_for_inlined_item<O: IdVisitingOperation>(item: &InlinedItem,
 }
 
 struct IdRangeComputingVisitor {
-    result: Cell<IdRange>,
+    result: IdRange,
 }
 
 impl IdVisitingOperation for IdRangeComputingVisitor {
-    fn visit_id(&self, id: NodeId) {
-        let mut id_range = self.result.get();
-        id_range.add(id);
-        self.result.set(id_range)
+    fn visit_id(&mut self, id: NodeId) {
+        self.result.add(id);
     }
 }
 
 pub fn compute_id_range_for_inlined_item(item: &InlinedItem) -> IdRange {
-    let visitor = IdRangeComputingVisitor {
-        result: Cell::new(IdRange::max())
+    let mut visitor = IdRangeComputingVisitor {
+        result: IdRange::max()
     };
-    visit_ids_for_inlined_item(item, &visitor);
-    visitor.result.get()
+    visit_ids_for_inlined_item(item, &mut visitor);
+    visitor.result
 }
 
 pub fn compute_id_range_for_fn_body(fk: visit::FnKind,
@@ -582,16 +579,16 @@ pub fn compute_id_range_for_fn_body(fk: visit::FnKind,
      * ignoring nested items.
      */
 
-    let visitor = IdRangeComputingVisitor {
-        result: Cell::new(IdRange::max())
+    let mut visitor = IdRangeComputingVisitor {
+        result: IdRange::max()
     };
     let mut id_visitor = IdVisitor {
-        operation: &visitor,
+        operation: &mut visitor,
         pass_through_items: false,
         visited_outermost: false,
     };
     id_visitor.visit_fn(fk, decl, body, sp, id);
-    visitor.result.get()
+    id_visitor.operation.result
 }
 
 pub fn walk_pat(pat: &Pat, it: |&Pat| -> bool) -> bool {
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index d56aa8da72a..615cd34ca14 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -668,12 +668,12 @@ impl InternedString {
 
 impl BytesContainer for InternedString {
     fn container_as_bytes<'a>(&'a self) -> &'a [u8] {
-        // FIXME(pcwalton): This is a workaround for the incorrect signature
+        // FIXME #12938: This is a workaround for the incorrect signature
         // of `BytesContainer`, which is itself a workaround for the lack of
         // DST.
         unsafe {
             let this = self.get();
-            mem::transmute(this.container_as_bytes())
+            mem::transmute::<&[u8],&[u8]>(this.container_as_bytes())
         }
     }
 }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 386fd8ae5a6..4cfc95d4c3f 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -169,17 +169,14 @@ pub fn to_string(f: |&mut State| -> IoResult<()>) -> String {
     let mut s = rust_printer(box MemWriter::new());
     f(&mut s).unwrap();
     eof(&mut s.s).unwrap();
-    unsafe {
+    let wr = unsafe {
         // FIXME(pcwalton): A nasty function to extract the string from an `io::Writer`
         // that we "know" to be a `MemWriter` that works around the lack of checked
         // downcasts.
-        let obj: TraitObject = mem::transmute_copy(&s.s.out);
-        let wr: Box<MemWriter> = mem::transmute(obj.data);
-        let result =
-            String::from_utf8(wr.get_ref().as_slice().to_vec()).unwrap();
-        mem::forget(wr);
-        result.to_string()
-    }
+        let obj: &TraitObject = mem::transmute(&s.s.out);
+        mem::transmute::<*mut (), &MemWriter>(obj.data)
+    };
+    String::from_utf8(wr.get_ref().to_vec()).unwrap()
 }
 
 pub fn binop_to_string(op: BinOpToken) -> &'static str {