auto merge of #11723 : eddyb/rust/more-trans-cleanup, r=pcwalton

8 files changed, 62 insertions, 146 deletions

diff --git a/src/librustc/back/abi.rs b/src/librustc/back/abi.rs
index 8f639a5e499..83a17bd3231 100644
--- a/src/librustc/back/abi.rs
+++ b/src/librustc/back/abi.rs
@@ -42,11 +42,10 @@ pub static general_code_alignment: uint = 16u;
 
 pub static tydesc_field_size: uint = 0u;
 pub static tydesc_field_align: uint = 1u;
-pub static tydesc_field_take_glue: uint = 2u;
-pub static tydesc_field_drop_glue: uint = 3u;
-pub static tydesc_field_visit_glue: uint = 4u;
-pub static tydesc_field_name_offset: uint = 5u;
-pub static n_tydesc_fields: uint = 6u;
+pub static tydesc_field_drop_glue: uint = 2u;
+pub static tydesc_field_visit_glue: uint = 3u;
+pub static tydesc_field_name_offset: uint = 4u;
+pub static n_tydesc_fields: uint = 5u;
 
 // The two halves of a closure: code and environment.
 pub static fn_field_code: uint = 0u;
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index c71469f0c3d..1dea31939f5 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -777,9 +777,6 @@ pub fn iter_structural_ty<'r,
                       let variant_cx =
                           fcx.new_temp_block(~"enum-iter-variant-" +
                                              variant.disr_val.to_str());
-                      let variant_cx =
-                          iter_variant(variant_cx, repr, av, *variant,
-                                       substs.tps, |x,y,z| f(x,y,z));
                       match adt::trans_case(cx, repr, variant.disr_val) {
                           _match::single_result(r) => {
                               AddCase(llswitch, r.val, variant_cx.llbb)
@@ -787,6 +784,9 @@ pub fn iter_structural_ty<'r,
                           _ => ccx.sess.unimpl("value from adt::trans_case \
                                                 in iter_structural_ty")
                       }
+                      let variant_cx =
+                          iter_variant(variant_cx, repr, av, *variant,
+                                       substs.tps, |x,y,z| f(x,y,z));
                       Br(variant_cx, next_cx.llbb);
                   }
                   cx = next_cx;
@@ -1458,16 +1458,16 @@ pub fn build_return_block(fcx: &FunctionContext, ret_cx: &Block) {
 // trans_closure: Builds an LLVM function out of a source function.
 // If the function closes over its environment a closure will be
 // returned.
-pub fn trans_closure(ccx: @CrateContext,
-                     path: ast_map::Path,
-                     decl: &ast::FnDecl,
-                     body: &ast::Block,
-                     llfndecl: ValueRef,
-                     param_substs: Option<@param_substs>,
-                     id: ast::NodeId,
-                     _attributes: &[ast::Attribute],
-                     output_type: ty::t,
-                     maybe_load_env: |&FunctionContext|) {
+pub fn trans_closure<'a>(ccx: @CrateContext,
+                         path: ast_map::Path,
+                         decl: &ast::FnDecl,
+                         body: &ast::Block,
+                         llfndecl: ValueRef,
+                         param_substs: Option<@param_substs>,
+                         id: ast::NodeId,
+                         _attributes: &[ast::Attribute],
+                         output_type: ty::t,
+                         maybe_load_env: |&'a Block<'a>| -> &'a Block<'a>) {
     ccx.stats.n_closures.set(ccx.stats.n_closures.get() + 1);
 
     let _icx = push_ctxt("trans_closure");
@@ -1500,7 +1500,7 @@ pub fn trans_closure(ccx: @CrateContext,
 
     bcx = copy_args_to_allocas(&fcx, arg_scope, bcx, decl.inputs, arg_datums);
 
-    maybe_load_env(&fcx);
+    bcx = maybe_load_env(bcx);
 
     // Up until here, IR instructions for this function have explicitly not been annotated with
     // source code location, so we don't step into call setup code. From here on, source location
@@ -1558,16 +1558,8 @@ pub fn trans_fn(ccx: @CrateContext,
     debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx));
     let _icx = push_ctxt("trans_fn");
     let output_type = ty::ty_fn_ret(ty::node_id_to_type(ccx.tcx, id));
-    trans_closure(ccx,
-                  path.clone(),
-                  decl,
-                  body,
-                  llfndecl,
-                  param_substs,
-                  id,
-                  attrs,
-                  output_type,
-                  |_fcx| { });
+    trans_closure(ccx, path.clone(), decl, body, llfndecl,
+                  param_substs, id, attrs, output_type, |bcx| bcx);
 }
 
 pub fn trans_enum_variant(ccx: @CrateContext,
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index 4d171bc86b1..5a8039f9c4d 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/src/librustc/middle/trans/closure.rs
@@ -282,23 +282,22 @@ fn build_closure<'a>(bcx0: &'a Block<'a>,
 // Given an enclosing block context, a new function context, a closure type,
 // and a list of upvars, generate code to load and populate the environment
 // with the upvars and type descriptors.
-fn load_environment(fcx: &FunctionContext, cdata_ty: ty::t,
-                    cap_vars: &[moves::CaptureVar], sigil: ast::Sigil) {
+fn load_environment<'a>(bcx: &'a Block<'a>, cdata_ty: ty::t,
+                        cap_vars: &[moves::CaptureVar],
+                        sigil: ast::Sigil) -> &'a Block<'a> {
     let _icx = push_ctxt("closure::load_environment");
 
     // Don't bother to create the block if there's nothing to load
     if cap_vars.len() == 0 {
-        return;
+        return bcx;
     }
 
-    let bcx = fcx.entry_bcx.get().unwrap();
-
     // Load a pointer to the closure data, skipping over the box header:
-    let llcdata = at_box_body(bcx, cdata_ty, fcx.llenv.unwrap());
+    let llcdata = at_box_body(bcx, cdata_ty, bcx.fcx.llenv.unwrap());
 
     // Store the pointer to closure data in an alloca for debug info because that's what the
     // llvm.dbg.declare intrinsic expects
-    let env_pointer_alloca = if fcx.ccx.sess.opts.extra_debuginfo {
+    let env_pointer_alloca = if bcx.ccx().sess.opts.extra_debuginfo {
         let alloc = alloc_ty(bcx, ty::mk_mut_ptr(bcx.tcx(), cdata_ty), "__debuginfo_env_ptr");
         Store(bcx, llcdata, alloc);
         Some(alloc)
@@ -317,7 +316,7 @@ fn load_environment(fcx: &FunctionContext, cdata_ty: ty::t,
         let def_id = ast_util::def_id_of_def(cap_var.def);
 
         {
-            let mut llupvars = fcx.llupvars.borrow_mut();
+            let mut llupvars = bcx.fcx.llupvars.borrow_mut();
             llupvars.get().insert(def_id.node, upvarptr);
         }
 
@@ -334,6 +333,8 @@ fn load_environment(fcx: &FunctionContext, cdata_ty: ty::t,
 
         i += 1u;
     }
+
+    bcx
 }
 
 fn fill_fn_pair(bcx: &Block, pair: ValueRef, llfn: ValueRef, llenvptr: ValueRef) {
@@ -405,7 +406,7 @@ pub fn trans_expr_fn<'a>(
     trans_closure(ccx, sub_path, decl, body, llfn,
                     bcx.fcx.param_substs, user_id,
                     [], ty::ty_fn_ret(fty),
-                    |fcx| load_environment(fcx, cdata_ty, cap_vars, sigil));
+                    |bcx| load_environment(bcx, cdata_ty, cap_vars, sigil));
     fill_fn_pair(bcx, dest_addr, llfn, llbox);
 
     bcx
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 45f5d84eb8a..38badc20c19 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -114,7 +114,6 @@ pub struct tydesc_info {
     size: ValueRef,
     align: ValueRef,
     name: ValueRef,
-    take_glue: Cell<Option<ValueRef>>,
     drop_glue: Cell<Option<ValueRef>>,
     visit_glue: Cell<Option<ValueRef>>,
 }
diff --git a/src/librustc/middle/trans/datum.rs b/src/librustc/middle/trans/datum.rs
index 467501449b8..4888c2ce4d5 100644
--- a/src/librustc/middle/trans/datum.rs
+++ b/src/librustc/middle/trans/datum.rs
@@ -491,7 +491,7 @@ impl Datum<Expr> {
                     }
                     ByValue => {
                         let v = load(bcx, l.val, l.ty);
-                        l.kind.post_store(bcx, l.val, l.ty);
+                        bcx = l.kind.post_store(bcx, l.val, l.ty);
                         DatumBlock(bcx, Datum(v, l.ty, Rvalue(ByValue)))
                     }
                 }
diff --git a/src/librustc/middle/trans/glue.rs b/src/librustc/middle/trans/glue.rs
index 5004bcca91e..ea5e6e8d386 100644
--- a/src/librustc/middle/trans/glue.rs
+++ b/src/librustc/middle/trans/glue.rs
@@ -58,14 +58,24 @@ pub fn trans_exchange_free<'a>(cx: &'a Block<'a>, v: ValueRef)
         Some(expr::Ignore)).bcx
 }
 
-pub fn take_ty<'a>(cx: &'a Block<'a>, v: ValueRef, t: ty::t)
+pub fn take_ty<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t)
                -> &'a Block<'a> {
     // NB: v is an *alias* of type t here, not a direct value.
     let _icx = push_ctxt("take_ty");
-    if ty::type_needs_drop(cx.tcx(), t) {
-        return call_tydesc_glue(cx, v, t, abi::tydesc_field_take_glue);
+    match ty::get(t).sty {
+        ty::ty_box(_) |
+        ty::ty_vec(_, ty::vstore_box) | ty::ty_str(ty::vstore_box) => {
+            incr_refcnt_of_boxed(bcx, v)
+        }
+        ty::ty_trait(_, _, ty::BoxTraitStore, _, _) => {
+            incr_refcnt_of_boxed(bcx, GEPi(bcx, v, [0u, abi::trt_field_box]))
+        }
+        _ if ty::type_is_structural(t)
+          && ty::type_needs_drop(bcx.tcx(), t) => {
+            iter_structural_ty(bcx, v, t, take_ty)
+        }
+        _ => bcx
     }
-    return cx;
 }
 
 pub fn drop_ty<'a>(cx: &'a Block<'a>, v: ValueRef, t: ty::t)
@@ -88,30 +98,15 @@ pub fn drop_ty_immediate<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t)
 
 pub fn lazily_emit_all_tydesc_glue(ccx: @CrateContext,
                                    static_ti: @tydesc_info) {
-    lazily_emit_tydesc_glue(ccx, abi::tydesc_field_take_glue, static_ti);
     lazily_emit_tydesc_glue(ccx, abi::tydesc_field_drop_glue, static_ti);
     lazily_emit_tydesc_glue(ccx, abi::tydesc_field_visit_glue, static_ti);
 }
 
 fn simplified_glue_type(tcx: ty::ctxt, field: uint, t: ty::t) -> ty::t {
-    if (field == abi::tydesc_field_take_glue || field == abi::tydesc_field_drop_glue)
-        && !ty::type_needs_drop(tcx, t) {
-        return ty::mk_nil();
-    }
-
-    if field == abi::tydesc_field_take_glue {
-        match ty::get(t).sty {
-            ty::ty_str(ty::vstore_uniq) |  ty::ty_vec(_, ty::vstore_uniq) |
-            ty::ty_unboxed_vec(..) | ty::ty_uniq(..) => return ty::mk_nil(),
-            _ => {}
-        }
-    }
-
-    if field == abi::tydesc_field_take_glue && ty::type_is_boxed(t) {
-        return ty::mk_box(tcx, ty::mk_nil());
-    }
-
     if field == abi::tydesc_field_drop_glue {
+        if !ty::type_needs_drop(tcx, t) {
+            return ty::mk_nil();
+        }
         match ty::get(t).sty {
             ty::ty_box(typ)
                 if !ty::type_needs_drop(tcx, typ) =>
@@ -145,9 +140,7 @@ fn lazily_emit_tydesc_glue(ccx: @CrateContext, field: uint, ti: @tydesc_info) {
         let simpl_ti = get_tydesc(ccx, simpl);
         lazily_emit_tydesc_glue(ccx, field, simpl_ti);
 
-        if field == abi::tydesc_field_take_glue {
-            ti.take_glue.set(simpl_ti.take_glue.get());
-        } else if field == abi::tydesc_field_drop_glue {
+        if field == abi::tydesc_field_drop_glue {
             ti.drop_glue.set(simpl_ti.drop_glue.get());
         } else if field == abi::tydesc_field_visit_glue {
             ti.visit_glue.set(simpl_ti.visit_glue.get());
@@ -158,20 +151,7 @@ fn lazily_emit_tydesc_glue(ccx: @CrateContext, field: uint, ti: @tydesc_info) {
 
     let llfnty = Type::glue_fn(type_of(ccx, ti.ty).ptr_to());
 
-    if field == abi::tydesc_field_take_glue {
-        match ti.take_glue.get() {
-          Some(_) => (),
-          None => {
-            debug!("+++ lazily_emit_tydesc_glue TAKE {}",
-                   ppaux::ty_to_str(ccx.tcx, ti.ty));
-            let glue_fn = declare_generic_glue(ccx, ti.ty, llfnty, "take");
-            ti.take_glue.set(Some(glue_fn));
-            make_generic_glue(ccx, ti.ty, glue_fn, make_take_glue, "take");
-            debug!("--- lazily_emit_tydesc_glue TAKE {}",
-                   ppaux::ty_to_str(ccx.tcx, ti.ty));
-          }
-        }
-    } else if field == abi::tydesc_field_drop_glue {
+    if field == abi::tydesc_field_drop_glue {
         match ti.drop_glue.get() {
           Some(_) => (),
           None => {
@@ -213,9 +193,7 @@ pub fn call_tydesc_glue_full(bcx: &Block, v: ValueRef, tydesc: ValueRef,
         None => None,
         Some(sti) => {
             lazily_emit_tydesc_glue(ccx, field, sti);
-            if field == abi::tydesc_field_take_glue {
-                sti.take_glue.get()
-            } else if field == abi::tydesc_field_drop_glue {
+            if field == abi::tydesc_field_drop_glue {
                 sti.drop_glue.get()
             } else if field == abi::tydesc_field_visit_glue {
                 sti.visit_glue.get()
@@ -472,53 +450,16 @@ fn decr_refcnt_maybe_free<'a>(bcx: &'a Block<'a>, box_ptr_ptr: ValueRef,
     next_bcx
 }
 
-fn make_take_glue<'a>(bcx: &'a Block<'a>, v: ValueRef, t: ty::t) -> &'a Block<'a> {
-    let _icx = push_ctxt("make_take_glue");
-    // NB: v is a *pointer* to type t here, not a direct value.
-    match ty::get(t).sty {
-        ty::ty_box(_) |
-        ty::ty_vec(_, ty::vstore_box) | ty::ty_str(ty::vstore_box) => {
-            incr_refcnt_of_boxed(bcx, Load(bcx, v)); bcx
-        }
-        ty::ty_vec(_, ty::vstore_slice(_))
-        | ty::ty_str(ty::vstore_slice(_)) => {
-            bcx
-        }
-        ty::ty_closure(_) => bcx,
-        ty::ty_trait(_, _, ty::BoxTraitStore, _, _) => {
-            let llbox = Load(bcx, GEPi(bcx, v, [0u, abi::trt_field_box]));
-            incr_refcnt_of_boxed(bcx, llbox);
-            bcx
-        }
-        ty::ty_trait(_, _, ty::UniqTraitStore, _, _) => {
-            let lluniquevalue = GEPi(bcx, v, [0, abi::trt_field_box]);
-            let llvtable = Load(bcx, GEPi(bcx, v, [0, abi::trt_field_vtable]));
-
-            // Cast the vtable to a pointer to a pointer to a tydesc.
-            let llvtable = PointerCast(bcx, llvtable,
-                                       bcx.ccx().tydesc_type.ptr_to().ptr_to());
-            let lltydesc = Load(bcx, llvtable);
-            call_tydesc_glue_full(bcx,
-                                  lluniquevalue,
-                                  lltydesc,
-                                  abi::tydesc_field_take_glue,
-                                  None);
-            bcx
-        }
-        _ if ty::type_is_structural(t) => {
-            iter_structural_ty(bcx, v, t, take_ty)
-        }
-        _ => bcx
-    }
-}
-
-fn incr_refcnt_of_boxed(cx: &Block, box_ptr: ValueRef) {
+fn incr_refcnt_of_boxed<'a>(bcx: &'a Block<'a>,
+                            box_ptr_ptr: ValueRef) -> &'a Block<'a> {
     let _icx = push_ctxt("incr_refcnt_of_boxed");
-    let ccx = cx.ccx();
-    let rc_ptr = GEPi(cx, box_ptr, [0u, abi::box_field_refcnt]);
-    let rc = Load(cx, rc_ptr);
-    let rc = Add(cx, rc, C_int(ccx, 1));
-    Store(cx, rc, rc_ptr);
+    let ccx = bcx.ccx();
+    let box_ptr = Load(bcx, box_ptr_ptr);
+    let rc_ptr = GEPi(bcx, box_ptr, [0u, abi::box_field_refcnt]);
+    let rc = Load(bcx, rc_ptr);
+    let rc = Add(bcx, rc, C_int(ccx, 1));
+    Store(bcx, rc, rc_ptr);
+    bcx
 }
 
 
@@ -554,7 +495,6 @@ pub fn declare_tydesc(ccx: &CrateContext, t: ty::t) -> @tydesc_info {
         size: llsize,
         align: llalign,
         name: ty_name,
-        take_glue: Cell::new(None),
         drop_glue: Cell::new(None),
         visit_glue: Cell::new(None),
     };
@@ -616,21 +556,6 @@ pub fn emit_tydescs(ccx: &CrateContext) {
         // before being put into the tydesc because we only have a singleton
         // tydesc type. Then we'll recast each function to its real type when
         // calling it.
-        let take_glue =
-            match ti.take_glue.get() {
-              None => {
-                  ccx.stats.n_null_glues.set(ccx.stats.n_null_glues.get() +
-                                             1);
-                  C_null(glue_fn_ty)
-              }
-              Some(v) => {
-                unsafe {
-                    ccx.stats.n_real_glues.set(ccx.stats.n_real_glues.get() +
-                                               1);
-                    llvm::LLVMConstPointerCast(v, glue_fn_ty.to_ref())
-                }
-              }
-            };
         let drop_glue =
             match ti.drop_glue.get() {
               None => {
@@ -665,7 +590,6 @@ pub fn emit_tydescs(ccx: &CrateContext) {
         let tydesc = C_named_struct(ccx.tydesc_type,
                                     [ti.size, // size
                                      ti.align, // align
-                                     take_glue, // take_glue
                                      drop_glue, // drop_glue
                                      visit_glue, // visit_glue
                                      ti.name]); // name
diff --git a/src/librustc/middle/trans/type_.rs b/src/librustc/middle/trans/type_.rs
index bbaf94afabe..e685849cbd8 100644
--- a/src/librustc/middle/trans/type_.rs
+++ b/src/librustc/middle/trans/type_.rs
@@ -211,7 +211,6 @@ impl Type {
 
         let elems = [int_ty,     // size
                      int_ty,     // align
-                     glue_fn_ty, // take
                      glue_fn_ty, // drop
                      glue_fn_ty, // visit
                      Type::struct_([Type::i8p(), Type::int(arch)], false)]; // name
diff --git a/src/libstd/unstable/intrinsics.rs b/src/libstd/unstable/intrinsics.rs
index 1988993707f..067826f04dc 100644
--- a/src/libstd/unstable/intrinsics.rs
+++ b/src/libstd/unstable/intrinsics.rs
@@ -57,6 +57,8 @@ pub struct TyDesc {
     align: uint,
 
     // Called on a copy of a value of type `T` *after* memcpy
+    // NOTE remove after next snapshot
+    #[cfg(stage0)]
     take_glue: GlueFn,
 
     // Called when a value of type `T` is no longer needed