Move get_landing_pad onto DropVal.

Author: Mark-Simulacrum

src/librustc_trans/cleanup.rs

@@ -46,6 +46,74 @@ impl<'tcx> DropValue<'tcx> {
     fn trans<'a>(&self, funclet: Option<&'a Funclet>, bcx: &BlockAndBuilder<'a, 'tcx>) {
         glue::call_drop_glue(bcx, self.val, self.ty, self.skip_dtor, funclet)
     }
+
+    /// Creates a landing pad for the top scope. The landing pad will perform all cleanups necessary
+    /// for an unwind and then `resume` to continue error propagation:
+    ///
+    ///     landing_pad -> ... cleanups ... -> [resume]
+    ///
+    /// This should only be called once per function, as it creates an alloca for the landingpad.
+    fn get_landing_pad<'a>(&self, fcx: &FunctionContext<'a, 'tcx>) -> BasicBlockRef {
+        debug!("get_landing_pad");
+
+        let mut pad_bcx = fcx.build_new_block("unwind_custom_");
+
+        let llpersonality = pad_bcx.fcx().eh_personality();
+
+        let resume_bcx = fcx.build_new_block("resume");
+        let val = if base::wants_msvc_seh(fcx.ccx.sess()) {
+            // A cleanup pad requires a personality function to be specified, so
+            // we do that here explicitly (happens implicitly below through
+            // creation of the landingpad instruction). We then create a
+            // cleanuppad instruction which has no filters to run cleanup on all
+            // exceptions.
+            pad_bcx.set_personality_fn(llpersonality);
+            let llretval = pad_bcx.cleanup_pad(None, &[]);
+            resume_bcx.cleanup_ret(resume_bcx.cleanup_pad(None, &[]), None);
+            UnwindKind::CleanupPad(llretval)
+        } else {
+            // The landing pad return type (the type being propagated). Not sure
+            // what this represents but it's determined by the personality
+            // function and this is what the EH proposal example uses.
+            let llretty = Type::struct_(fcx.ccx, &[Type::i8p(fcx.ccx), Type::i32(fcx.ccx)], false);
+
+            // The only landing pad clause will be 'cleanup'
+            let llretval = pad_bcx.landing_pad(llretty, llpersonality, 1, pad_bcx.fcx().llfn);
+
+            // The landing pad block is a cleanup
+            pad_bcx.set_cleanup(llretval);
+
+            let addr = pad_bcx.fcx().alloca(common::val_ty(llretval), "");
+            Lifetime::Start.call(&pad_bcx, addr);
+            pad_bcx.store(llretval, addr);
+            let lp = resume_bcx.load(addr);
+            Lifetime::End.call(&resume_bcx, addr);
+            if !resume_bcx.sess().target.target.options.custom_unwind_resume {
+                resume_bcx.resume(lp);
+            } else {
+                let exc_ptr = resume_bcx.extract_value(lp, 0);
+                resume_bcx.call(fcx.eh_unwind_resume().reify(fcx.ccx), &[exc_ptr], None);
+            }
+            UnwindKind::LandingPad
+        };
+
+        let mut cleanup = fcx.build_new_block("clean_custom_");
+
+        // Insert cleanup instructions into the cleanup block
+        let funclet = match val {
+            UnwindKind::CleanupPad(_) => Some(Funclet::new(cleanup.cleanup_pad(None, &[]))),
+            UnwindKind::LandingPad => None,
+        };
+        self.trans(funclet.as_ref(), &cleanup);
+
+        // Insert instruction into cleanup block to branch to the exit
+        val.branch(&mut cleanup, resume_bcx.llbb());
+
+        // Branch into the cleanup block
+        val.branch(&mut pad_bcx, cleanup.llbb());
+
+        pad_bcx.llbb()
+    }
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -73,16 +141,6 @@ impl UnwindKind {
     }
 }
 
-impl PartialEq for UnwindKind {
-    fn eq(&self, label: &UnwindKind) -> bool {
-        match (*self, *label) {
-            (UnwindKind::LandingPad, UnwindKind::LandingPad) |
-            (UnwindKind::CleanupPad(..), UnwindKind::CleanupPad(..)) => true,
-            _ => false,
-        }
-    }
-}
-
 impl<'a, 'tcx> FunctionContext<'a, 'tcx> {
     /// Schedules a (deep) drop of `val`, which is a pointer to an instance of `ty`
     pub fn schedule_drop_mem(&self, val: ValueRef, ty: Ty<'tcx>) -> CleanupScope<'tcx> {
@@ -126,7 +184,7 @@ impl<'tcx> CleanupScope<'tcx> {
         CleanupScope {
             cleanup: Some(drop_val),
             landing_pad: if !fcx.ccx.sess().no_landing_pads() {
-                Some(CleanupScope::get_landing_pad(fcx, &drop_val))
+                Some(drop_val.get_landing_pad(fcx))
             } else {
                 None
             },
@@ -145,73 +203,4 @@ impl<'tcx> CleanupScope<'tcx> {
             cleanup.trans(None, &bcx);
         }
     }
-
-    /// Creates a landing pad for the top scope. The landing pad will perform all cleanups necessary
-    /// for an unwind and then `resume` to continue error propagation:
-    ///
-    ///     landing_pad -> ... cleanups ... -> [resume]
-    ///
-    /// This should only be called once per function, as it creates an alloca for the landingpad.
-    fn get_landing_pad<'a>(fcx: &FunctionContext<'a, 'tcx>, drop_val: &DropValue<'tcx>)
-        -> BasicBlockRef {
-        debug!("get_landing_pad");
-
-        let mut pad_bcx = fcx.build_new_block("unwind_custom_");
-
-        let llpersonality = pad_bcx.fcx().eh_personality();
-
-        let resume_bcx = fcx.build_new_block("resume");
-        let val = if base::wants_msvc_seh(fcx.ccx.sess()) {
-            // A cleanup pad requires a personality function to be specified, so
-            // we do that here explicitly (happens implicitly below through
-            // creation of the landingpad instruction). We then create a
-            // cleanuppad instruction which has no filters to run cleanup on all
-            // exceptions.
-            pad_bcx.set_personality_fn(llpersonality);
-            let llretval = pad_bcx.cleanup_pad(None, &[]);
-            resume_bcx.cleanup_ret(resume_bcx.cleanup_pad(None, &[]), None);
-            UnwindKind::CleanupPad(llretval)
-        } else {
-            // The landing pad return type (the type being propagated). Not sure
-            // what this represents but it's determined by the personality
-            // function and this is what the EH proposal example uses.
-            let llretty = Type::struct_(fcx.ccx, &[Type::i8p(fcx.ccx), Type::i32(fcx.ccx)], false);
-
-            // The only landing pad clause will be 'cleanup'
-            let llretval = pad_bcx.landing_pad(llretty, llpersonality, 1, pad_bcx.fcx().llfn);
-
-            // The landing pad block is a cleanup
-            pad_bcx.set_cleanup(llretval);
-
-            let addr = pad_bcx.fcx().alloca(common::val_ty(llretval), "");
-            Lifetime::Start.call(&pad_bcx, addr);
-            pad_bcx.store(llretval, addr);
-            let lp = resume_bcx.load(addr);
-            Lifetime::End.call(&resume_bcx, addr);
-            if !resume_bcx.sess().target.target.options.custom_unwind_resume {
-                resume_bcx.resume(lp);
-            } else {
-                let exc_ptr = resume_bcx.extract_value(lp, 0);
-                resume_bcx.call(fcx.eh_unwind_resume().reify(fcx.ccx), &[exc_ptr], None);
-            }
-            UnwindKind::LandingPad
-        };
-
-        let mut cleanup = fcx.build_new_block("clean_custom_");
-
-        // Insert cleanup instructions into the cleanup block
-        let funclet = match val {
-            UnwindKind::CleanupPad(_) => Some(Funclet::new(cleanup.cleanup_pad(None, &[]))),
-            UnwindKind::LandingPad => None,
-        };
-        drop_val.trans(funclet.as_ref(), &cleanup);
-
-        // Insert instruction into cleanup block to branch to the exit
-        val.branch(&mut cleanup, resume_bcx.llbb());
-
-        // Branch into the cleanup block
-        val.branch(&mut pad_bcx, cleanup.llbb());
-
-        return pad_bcx.llbb();
-    }
 }