Auto merge of #38511 - Mark-Simulacrum:drop-glue, r=eddyb

Make drop glue for unsized value pass two arguments instead of *(data, meta)

Fixes #36457

r? @eddyb

Author: bors

src/librustc_llvm/lib.rs

@@ -270,7 +270,8 @@ pub fn mk_section_iter(llof: ObjectFileRef) -> SectionIter {
 /// Safe wrapper around `LLVMGetParam`, because segfaults are no fun.
 pub fn get_param(llfn: ValueRef, index: c_uint) -> ValueRef {
     unsafe {
-        assert!(index < LLVMCountParams(llfn));
+        assert!(index < LLVMCountParams(llfn),
+            "out of bounds argument access: {} out of {} arguments", index, LLVMCountParams(llfn));
         LLVMGetParam(llfn, index)
     }
 }

src/librustc_trans/callee.rs

@@ -27,6 +27,7 @@ use base::*;
 use common::{
     self, CrateContext, FunctionContext, SharedCrateContext
 };
+use adt::MaybeSizedValue;
 use consts;
 use declare;
 use value::Value;
@@ -364,7 +365,7 @@ fn trans_fn_once_adapter_shim<'a, 'tcx>(
 
     // Call the by-ref closure body with `self` in a cleanup scope,
     // to drop `self` when the body returns, or in case it unwinds.
-    let self_scope = fcx.schedule_drop_mem(llenv, closure_ty);
+    let self_scope = fcx.schedule_drop_mem(MaybeSizedValue::sized(llenv), closure_ty);
 
     let llfn = callee.reify(bcx.ccx);
     let llret;

src/librustc_trans/cleanup.rs

@@ -18,12 +18,12 @@
 //! corresponds to a normal exit from a block (for example, an expression
 //! completing evaluation successfully without panic).
 
-use llvm::{BasicBlockRef, ValueRef};
+use llvm::BasicBlockRef;
 use base;
+use adt::MaybeSizedValue;
 use common::{BlockAndBuilder, FunctionContext, Funclet};
 use glue;
 use type_::Type;
-use value::Value;
 use rustc::ty::Ty;
 
 pub struct CleanupScope<'tcx> {
@@ -36,7 +36,7 @@ pub struct CleanupScope<'tcx> {
 
 #[derive(Copy, Clone)]
 pub struct DropValue<'tcx> {
-    val: ValueRef,
+    val: MaybeSizedValue,
     ty: Ty<'tcx>,
     skip_dtor: bool,
 }
@@ -94,16 +94,14 @@ impl<'tcx> DropValue<'tcx> {
 
 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> {
+    pub fn schedule_drop_mem(&self, val: MaybeSizedValue, ty: Ty<'tcx>) -> CleanupScope<'tcx> {
         if !self.ccx.shared().type_needs_drop(ty) { return CleanupScope::noop(); }
         let drop = DropValue {
             val: val,
             ty: ty,
             skip_dtor: false,
         };
 
-        debug!("schedule_drop_mem(val={:?}, ty={:?}) skip_dtor={}", Value(val), ty, drop.skip_dtor);
-
         CleanupScope::new(self, drop)
     }
 
@@ -112,7 +110,8 @@ impl<'a, 'tcx> FunctionContext<'a, 'tcx> {
     /// `ty`. The scheduled code handles extracting the discriminant
     /// and dropping the contents associated with that variant
     /// *without* executing any associated drop implementation.
-    pub fn schedule_drop_adt_contents(&self, val: ValueRef, ty: Ty<'tcx>) -> CleanupScope<'tcx> {
+    pub fn schedule_drop_adt_contents(&self, val: MaybeSizedValue, ty: Ty<'tcx>)
+        -> CleanupScope<'tcx> {
         // `if` below could be "!contents_needs_drop"; skipping drop
         // is just an optimization, so sound to be conservative.
         if !self.ccx.shared().type_needs_drop(ty) { return CleanupScope::noop(); }
@@ -123,9 +122,6 @@ impl<'a, 'tcx> FunctionContext<'a, 'tcx> {
             skip_dtor: true,
         };
 
-        debug!("schedule_drop_adt_contents(val={:?}, ty={:?}) skip_dtor={}",
-               Value(val), ty, drop.skip_dtor);
-
         CleanupScope::new(self, drop)
     }
 }