Refactor get_landing_pad to take a CleanupScope

It unwrapped the Option anyway, so this more closely resembles the
reality of what's happening.

src/librustc_trans/callee.rs

@@ -743,7 +743,7 @@ fn trans_call_fn_once_adapter_shim<'a, 'blk, 'tcx>(
     let _icx = push_ctxt("invoke_");
     let (llret, bcx) = if cleanup_scope.is_some() && !bcx.sess().no_landing_pads() {
         let normal_bcx = bcx.fcx().build_new_block("normal-return");
-        let landing_pad = bcx.fcx().get_landing_pad(cleanup_scope);
+        let landing_pad = bcx.fcx().get_landing_pad(cleanup_scope.as_mut().unwrap());
 
         let llresult = bcx.invoke(llfn, &llargs[..], normal_bcx.llbb(), landing_pad, None);
         (llresult, normal_bcx)

src/librustc_trans/cleanup.rs

@@ -207,14 +207,10 @@ impl<'blk, 'tcx> FunctionContext<'blk, 'tcx> {
     ///
     /// (The cleanups and resume instruction are created by
     /// `trans_cleanups_to_exit_scope()`, not in this function itself.)
-    pub fn get_landing_pad(&'blk self, scope: &mut Option<CleanupScope<'tcx>>) -> BasicBlockRef {
-        // TODO: Factor out and take a CleanupScope.
-        assert!(scope.is_some());
-
+    pub fn get_landing_pad(&'blk self, scope: &mut CleanupScope<'tcx>) -> BasicBlockRef {
         debug!("get_landing_pad");
 
         // Check if a landing pad block exists; if not, create one.
-        let mut scope = scope.as_mut().unwrap();
         let mut pad_bcx = match scope.cached_landing_pad {
             Some(llbb) => return llbb,
             None => {
@@ -270,7 +266,21 @@ impl<'blk, 'tcx> FunctionContext<'blk, 'tcx> {
         return pad_bcx.llbb();
     }
 
-    fn generate_resume_block(&self, label: UnwindKind) -> BasicBlockRef {
+    /// Used when the caller wishes to jump to an early exit, such as a return,
+    /// break, continue, or unwind. This function will generate all cleanups
+    /// between the top of the stack and the exit `label` and return a basic
+    /// block that the caller can branch to.
+    fn trans_cleanups_to_exit_scope(
+        &'blk self,
+        label: UnwindKind,
+        scope: &mut CleanupScope<'tcx>
+    ) -> BasicBlockRef {
+        debug!("trans_cleanups_to_exit_scope label={:?}`", label);
+        let cached_exit = scope.cached_early_exit(label);
+
+        // Check if we have already cached the unwinding of this
+        // scope for this label. If so, we can just branch to the cached block.
+        let exit_llbb = cached_exit.unwrap_or_else(|| {
             // Generate a block that will resume unwinding to the calling function
             let bcx = self.build_new_block("resume");
             match label {
@@ -290,23 +300,7 @@ impl<'blk, 'tcx> FunctionContext<'blk, 'tcx> {
                 }
             }
             bcx.llbb()
-    }
-
-    /// Used when the caller wishes to jump to an early exit, such as a return,
-    /// break, continue, or unwind. This function will generate all cleanups
-    /// between the top of the stack and the exit `label` and return a basic
-    /// block that the caller can branch to.
-    fn trans_cleanups_to_exit_scope(
-        &'blk self,
-        label: UnwindKind,
-        scope: &mut CleanupScope<'tcx>
-    ) -> BasicBlockRef {
-        debug!("trans_cleanups_to_exit_scope label={:?}`", label);
-        let cached_exit = scope.cached_early_exit(label);
-
-        // Check if we have already cached the unwinding of this
-        // scope for this label. If so, we can just branch to the cached block.
-        let exit_llbb = cached_exit.unwrap_or_else(|| self.generate_resume_block(label));
+        });
 
         let name = scope.block_name("clean");
         debug!("generating cleanup for {}", name);

src/librustc_trans/glue.rs

@@ -312,7 +312,7 @@ fn trans_call_custom_dtor<'a, 'blk, 'tcx>(
     let _icx = push_ctxt("invoke_");
     let (llret, bcx) = if cleanup_scope.is_some() && !bcx.sess().no_landing_pads() {
         let normal_bcx = bcx.fcx().build_new_block("normal-return");
-        let landing_pad = bcx.fcx().get_landing_pad(cleanup_scope);
+        let landing_pad = bcx.fcx().get_landing_pad(cleanup_scope.as_mut().unwrap());
 
         let llresult = bcx.invoke(llfn, &llargs[..], normal_bcx.llbb(), landing_pad, None);
         (llresult, normal_bcx)