1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 // Code relating to taking, dropping, etc as well as type descriptors.
18 use llvm::{ValueRef, True, get_param};
20 use middle::lang_items::ExchangeFreeFnLangItem;
22 use middle::subst::Subst;
23 use middle::trans::adt;
24 use middle::trans::base::*;
25 use middle::trans::build::*;
26 use middle::trans::callee;
27 use middle::trans::cleanup;
28 use middle::trans::cleanup::CleanupMethods;
29 use middle::trans::common::*;
30 use middle::trans::datum;
31 use middle::trans::debuginfo;
32 use middle::trans::expr;
33 use middle::trans::machine::*;
34 use middle::trans::reflect;
35 use middle::trans::tvec;
36 use middle::trans::type_::Type;
37 use middle::trans::type_of::{type_of, sizing_type_of, align_of};
39 use util::ppaux::{ty_to_short_str, Repr};
42 use arena::TypedArena;
43 use std::c_str::ToCStr;
47 use syntax::parse::token;
49 pub fn trans_exchange_free_dyn<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef,
50 size: ValueRef, align: ValueRef)
51 -> Block<'blk, 'tcx> {
52 let _icx = push_ctxt("trans_exchange_free");
54 callee::trans_lang_call(cx,
55 langcall(cx, None, "", ExchangeFreeFnLangItem),
56 [PointerCast(cx, v, Type::i8p(ccx)), size, align],
57 Some(expr::Ignore)).bcx
60 pub fn trans_exchange_free<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef,
61 size: u64, align: u64) -> Block<'blk, 'tcx> {
62 trans_exchange_free_dyn(cx, v, C_uint(cx.ccx(), size as uint),
63 C_uint(cx.ccx(), align as uint))
66 pub fn trans_exchange_free_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef,
67 content_ty: ty::t) -> Block<'blk, 'tcx> {
68 assert!(ty::type_is_sized(bcx.ccx().tcx(), content_ty));
69 let sizing_type = sizing_type_of(bcx.ccx(), content_ty);
70 let content_size = llsize_of_alloc(bcx.ccx(), sizing_type);
72 // `Box<ZeroSizeType>` does not allocate.
73 if content_size != 0 {
74 let content_align = align_of(bcx.ccx(), content_ty);
75 trans_exchange_free(bcx, ptr, content_size, content_align)
81 pub fn get_drop_glue_type(ccx: &CrateContext, t: ty::t) -> ty::t {
83 // Even if there is no dtor for t, there might be one deeper down and we
84 // might need to pass in the vtable ptr.
85 if !ty::type_is_sized(tcx, t) {
88 if !ty::type_needs_drop(tcx, t) {
91 match ty::get(t).sty {
92 ty::ty_uniq(typ) if !ty::type_needs_drop(tcx, typ)
93 && ty::type_is_sized(tcx, typ) => {
94 let llty = sizing_type_of(ccx, typ);
95 // `Box<ZeroSizeType>` does not allocate.
96 if llsize_of_alloc(ccx, llty) == 0 {
106 pub fn drop_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
109 source_location: Option<NodeInfo>)
110 -> Block<'blk, 'tcx> {
111 // NB: v is an *alias* of type t here, not a direct value.
112 debug!("drop_ty(t={})", t.repr(bcx.tcx()));
113 let _icx = push_ctxt("drop_ty");
114 if ty::type_needs_drop(bcx.tcx(), t) {
116 let glue = get_drop_glue(ccx, t);
117 let glue_type = get_drop_glue_type(ccx, t);
118 let ptr = if glue_type != t {
119 PointerCast(bcx, v, type_of(ccx, glue_type).ptr_to())
124 match source_location {
125 Some(sl) => debuginfo::set_source_location(bcx.fcx, sl.id, sl.span),
126 None => debuginfo::clear_source_location(bcx.fcx)
129 Call(bcx, glue, [ptr], None);
134 pub fn drop_ty_immediate<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
137 source_location: Option<NodeInfo>)
138 -> Block<'blk, 'tcx> {
139 let _icx = push_ctxt("drop_ty_immediate");
140 let vp = alloca(bcx, type_of(bcx.ccx(), t), "");
142 drop_ty(bcx, vp, t, source_location)
145 pub fn get_drop_glue(ccx: &CrateContext, t: ty::t) -> ValueRef {
146 debug!("make drop glue for {}", ppaux::ty_to_string(ccx.tcx(), t));
147 let t = get_drop_glue_type(ccx, t);
148 debug!("drop glue type {}", ppaux::ty_to_string(ccx.tcx(), t));
149 match ccx.drop_glues().borrow().find(&t) {
150 Some(&glue) => return glue,
154 let llty = if ty::type_is_sized(ccx.tcx(), t) {
155 type_of(ccx, t).ptr_to()
157 type_of(ccx, ty::mk_uniq(ccx.tcx(), t)).ptr_to()
160 let llfnty = Type::glue_fn(ccx, llty);
162 let (glue, new_sym) = match ccx.available_drop_glues().borrow().find(&t) {
164 let glue = decl_cdecl_fn(ccx, old_sym.as_slice(), llfnty, ty::mk_nil());
168 let (sym, glue) = declare_generic_glue(ccx, t, llfnty, "drop");
173 ccx.drop_glues().borrow_mut().insert(t, glue);
175 // To avoid infinite recursion, don't `make_drop_glue` until after we've
176 // added the entry to the `drop_glues` cache.
179 ccx.available_drop_glues().borrow_mut().insert(t, sym);
180 // We're creating a new drop glue, so also generate a body.
181 make_generic_glue(ccx, t, glue, make_drop_glue, "drop");
189 pub fn lazily_emit_visit_glue(ccx: &CrateContext, ti: &tydesc_info) -> ValueRef {
190 let _icx = push_ctxt("lazily_emit_visit_glue");
192 let llfnty = Type::glue_fn(ccx, type_of(ccx, ti.ty).ptr_to());
194 match ti.visit_glue.get() {
195 Some(visit_glue) => visit_glue,
197 debug!("+++ lazily_emit_tydesc_glue VISIT {}", ppaux::ty_to_string(ccx.tcx(), ti.ty));
199 let (glue_fn, new_sym) = match ccx.available_visit_glues().borrow().find(&ti.ty) {
201 let glue_fn = decl_cdecl_fn(ccx, old_sym.as_slice(), llfnty, ty::mk_nil());
205 let (sym, glue_fn) = declare_generic_glue(ccx, ti.ty, llfnty, "visit");
210 ti.visit_glue.set(Some(glue_fn));
214 ccx.available_visit_glues().borrow_mut().insert(ti.ty, sym);
215 make_generic_glue(ccx, ti.ty, glue_fn, make_visit_glue, "visit");
220 debug!("--- lazily_emit_tydesc_glue VISIT {}", ppaux::ty_to_string(ccx.tcx(), ti.ty));
226 // See [Note-arg-mode]
227 pub fn call_visit_glue(bcx: Block, v: ValueRef, tydesc: ValueRef) {
228 let _icx = push_ctxt("call_visit_glue");
230 // Select the glue function to call from the tydesc
231 let llfn = Load(bcx, GEPi(bcx, tydesc, [0u, abi::tydesc_field_visit_glue]));
232 let llrawptr = PointerCast(bcx, v, Type::i8p(bcx.ccx()));
234 Call(bcx, llfn, [llrawptr], None);
237 fn make_visit_glue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, v: ValueRef, t: ty::t)
238 -> Block<'blk, 'tcx> {
239 let _icx = push_ctxt("make_visit_glue");
241 let (visitor_trait, object_ty) = match ty::visitor_object_ty(bcx.tcx(),
246 bcx.tcx().sess.fatal(s.as_slice());
249 let v = PointerCast(bcx, v, type_of(bcx.ccx(), object_ty).ptr_to());
250 bcx = reflect::emit_calls_to_trait_visit_ty(bcx, t, v, visitor_trait.def_id);
254 fn trans_struct_drop_flag<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
257 dtor_did: ast::DefId,
258 class_did: ast::DefId,
259 substs: &subst::Substs)
260 -> Block<'blk, 'tcx> {
261 let repr = adt::represent_type(bcx.ccx(), t);
262 let struct_data = if ty::type_is_sized(bcx.tcx(), t) {
265 let llval = GEPi(bcx, v0, [0, abi::slice_elt_base]);
268 let drop_flag = unpack_datum!(bcx, adt::trans_drop_flag_ptr(bcx, &*repr, struct_data));
269 with_cond(bcx, load_ty(bcx, drop_flag.val, ty::mk_bool()), |cx| {
270 trans_struct_drop(cx, t, v0, dtor_did, class_did, substs)
274 fn trans_struct_drop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
277 dtor_did: ast::DefId,
278 class_did: ast::DefId,
279 substs: &subst::Substs)
280 -> Block<'blk, 'tcx> {
281 let repr = adt::represent_type(bcx.ccx(), t);
283 // Find and call the actual destructor
284 let dtor_addr = get_res_dtor(bcx.ccx(), dtor_did, t,
287 // The first argument is the "self" argument for drop
288 let params = unsafe {
289 let ty = Type::from_ref(llvm::LLVMTypeOf(dtor_addr));
290 ty.element_type().func_params()
293 let fty = ty::lookup_item_type(bcx.tcx(), dtor_did).ty.subst(bcx.tcx(), substs);
294 let self_ty = match ty::get(fty).sty {
295 ty::ty_bare_fn(ref f) => {
296 assert!(f.sig.inputs.len() == 1);
299 _ => bcx.sess().bug(format!("Expected function type, found {}",
300 bcx.ty_to_string(fty)).as_slice())
303 let (struct_data, info) = if ty::type_is_sized(bcx.tcx(), t) {
306 let data = GEPi(bcx, v0, [0, abi::slice_elt_base]);
307 let info = GEPi(bcx, v0, [0, abi::slice_elt_len]);
308 (Load(bcx, data), Some(Load(bcx, info)))
311 adt::fold_variants(bcx, &*repr, struct_data, |variant_cx, st, value| {
312 // Be sure to put all of the fields into a scope so we can use an invoke
313 // instruction to call the user destructor but still call the field
314 // destructors if the user destructor fails.
315 let field_scope = variant_cx.fcx.push_custom_cleanup_scope();
317 // Class dtors have no explicit args, so the params should
318 // just consist of the environment (self).
319 assert_eq!(params.len(), 1);
320 let self_arg = if ty::type_is_fat_ptr(bcx.tcx(), self_ty) {
321 // The dtor expects a fat pointer, so make one, even if we have to fake it.
322 let boxed_ty = ty::mk_open(bcx.tcx(), t);
323 let scratch = datum::rvalue_scratch_datum(bcx, boxed_ty, "__fat_ptr_drop_self");
324 Store(bcx, value, GEPi(bcx, scratch.val, [0, abi::slice_elt_base]));
326 // If we just had a thin pointer, make a fat pointer by sticking
327 // null where we put the unsizing info. This works because t
328 // is a sized type, so we will only unpack the fat pointer, never
329 // use the fake info.
330 info.unwrap_or(C_null(Type::i8p(bcx.ccx()))),
331 GEPi(bcx, scratch.val, [0, abi::slice_elt_len]));
332 PointerCast(variant_cx, scratch.val, *params.get(0))
334 PointerCast(variant_cx, value, *params.get(0))
336 let args = vec!(self_arg);
338 // Add all the fields as a value which needs to be cleaned at the end of
339 // this scope. Iterate in reverse order so a Drop impl doesn't reverse
340 // the order in which fields get dropped.
341 for (i, ty) in st.fields.iter().enumerate().rev() {
342 let llfld_a = adt::struct_field_ptr(variant_cx, &*st, value, i, false);
344 let val = if ty::type_is_sized(bcx.tcx(), *ty) {
347 let boxed_ty = ty::mk_open(bcx.tcx(), *ty);
348 let scratch = datum::rvalue_scratch_datum(bcx, boxed_ty, "__fat_ptr_drop_field");
349 Store(bcx, llfld_a, GEPi(bcx, scratch.val, [0, abi::slice_elt_base]));
350 Store(bcx, info.unwrap(), GEPi(bcx, scratch.val, [0, abi::slice_elt_len]));
353 variant_cx.fcx.schedule_drop_mem(cleanup::CustomScope(field_scope),
357 let dtor_ty = ty::mk_ctor_fn(variant_cx.tcx(), ast::DUMMY_NODE_ID,
358 [get_drop_glue_type(bcx.ccx(), t)], ty::mk_nil());
359 let (_, variant_cx) = invoke(variant_cx, dtor_addr, args, dtor_ty, None, false);
361 variant_cx.fcx.pop_and_trans_custom_cleanup_scope(variant_cx, field_scope);
366 fn size_and_align_of_dst(bcx: Block, t :ty::t, info: ValueRef) -> (ValueRef, ValueRef) {
367 debug!("calculate size of DST: {}; with lost info: {}",
368 bcx.ty_to_string(t), bcx.val_to_string(info));
369 if ty::type_is_sized(bcx.tcx(), t) {
370 let sizing_type = sizing_type_of(bcx.ccx(), t);
371 let size = C_uint(bcx.ccx(), llsize_of_alloc(bcx.ccx(), sizing_type) as uint);
372 let align = C_uint(bcx.ccx(), align_of(bcx.ccx(), t) as uint);
373 return (size, align);
375 match ty::get(t).sty {
376 ty::ty_struct(id, ref substs) => {
378 // First get the size of all statically known fields.
379 // Don't use type_of::sizing_type_of because that expects t to be sized.
380 assert!(!ty::type_is_simd(bcx.tcx(), t));
381 let repr = adt::represent_type(ccx, t);
382 let sizing_type = adt::sizing_type_of(ccx, &*repr, true);
383 let sized_size = C_uint(ccx, llsize_of_alloc(ccx, sizing_type) as uint);
384 let sized_align = C_uint(ccx, llalign_of_min(ccx, sizing_type) as uint);
386 // Recurse to get the size of the dynamically sized field (must be
388 let fields = ty::struct_fields(bcx.tcx(), id, substs);
389 let last_field = fields[fields.len()-1];
390 let field_ty = last_field.mt.ty;
391 let (unsized_size, unsized_align) = size_and_align_of_dst(bcx, field_ty, info);
393 // Return the sum of sizes and max of aligns.
394 let size = Add(bcx, sized_size, unsized_size);
395 let align = Select(bcx,
396 ICmp(bcx, llvm::IntULT, sized_align, unsized_align),
401 ty::ty_trait(..) => {
402 // info points to the vtable and the second entry in the vtable is the
403 // dynamic size of the object.
404 let info = PointerCast(bcx, info, Type::int(bcx.ccx()).ptr_to());
405 let size_ptr = GEPi(bcx, info, [1u]);
406 let align_ptr = GEPi(bcx, info, [2u]);
407 (Load(bcx, size_ptr), Load(bcx, align_ptr))
409 ty::ty_vec(unit_ty, None) => {
410 // The info in this case is the length of the vec, so the size is that
411 // times the unit size.
412 let llunit_ty = sizing_type_of(bcx.ccx(), unit_ty);
413 let unit_size = llsize_of_alloc(bcx.ccx(), llunit_ty);
414 (Mul(bcx, info, C_uint(bcx.ccx(), unit_size as uint)), C_uint(bcx.ccx(), 8))
416 _ => bcx.sess().bug(format!("Unexpected unsized type, found {}",
417 bcx.ty_to_string(t)).as_slice())
421 fn make_drop_glue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, v0: ValueRef, t: ty::t)
422 -> Block<'blk, 'tcx> {
423 // NB: v0 is an *alias* of type t here, not a direct value.
424 let _icx = push_ctxt("make_drop_glue");
425 match ty::get(t).sty {
426 ty::ty_uniq(content_ty) => {
427 match ty::get(content_ty).sty {
428 ty::ty_vec(ty, None) => {
429 tvec::make_drop_glue_unboxed(bcx, v0, ty, true)
432 let unit_ty = ty::sequence_element_type(bcx.tcx(), content_ty);
433 tvec::make_drop_glue_unboxed(bcx, v0, unit_ty, true)
435 ty::ty_trait(..) => {
436 let lluniquevalue = GEPi(bcx, v0, [0, abi::trt_field_box]);
437 // Only drop the value when it is non-null
438 let concrete_ptr = Load(bcx, lluniquevalue);
439 with_cond(bcx, IsNotNull(bcx, concrete_ptr), |bcx| {
440 let dtor_ptr = Load(bcx, GEPi(bcx, v0, [0, abi::trt_field_vtable]));
441 let dtor = Load(bcx, dtor_ptr);
444 [PointerCast(bcx, lluniquevalue, Type::i8p(bcx.ccx()))],
449 ty::ty_struct(..) if !ty::type_is_sized(bcx.tcx(), content_ty) => {
450 let llval = GEPi(bcx, v0, [0, abi::slice_elt_base]);
451 let llbox = Load(bcx, llval);
452 let not_null = IsNotNull(bcx, llbox);
453 with_cond(bcx, not_null, |bcx| {
454 let bcx = drop_ty(bcx, v0, content_ty, None);
455 let info = GEPi(bcx, v0, [0, abi::slice_elt_len]);
456 let info = Load(bcx, info);
457 let (llsize, llalign) = size_and_align_of_dst(bcx, content_ty, info);
458 trans_exchange_free_dyn(bcx, llbox, llsize, llalign)
462 assert!(ty::type_is_sized(bcx.tcx(), content_ty));
464 let llbox = Load(bcx, llval);
465 let not_null = IsNotNull(bcx, llbox);
466 with_cond(bcx, not_null, |bcx| {
467 let bcx = drop_ty(bcx, llbox, content_ty, None);
468 trans_exchange_free_ty(bcx, llbox, content_ty)
473 ty::ty_struct(did, ref substs) | ty::ty_enum(did, ref substs) => {
475 match ty::ty_dtor(tcx, did) {
476 ty::TraitDtor(dtor, true) => {
477 // FIXME(16758) Since the struct is unsized, it is hard to
478 // find the drop flag (which is at the end of the struct).
479 // Lets just ignore the flag and pretend everything will be
481 if ty::type_is_sized(bcx.tcx(), t) {
482 trans_struct_drop_flag(bcx, t, v0, dtor, did, substs)
484 // Give the user a heads up that we are doing something
485 // stupid and dangerous.
486 bcx.sess().warn(format!("Ignoring drop flag in destructor for {}\
487 because the struct is unsized. See issue\
489 bcx.ty_to_string(t)).as_slice());
490 trans_struct_drop(bcx, t, v0, dtor, did, substs)
493 ty::TraitDtor(dtor, false) => {
494 trans_struct_drop(bcx, t, v0, dtor, did, substs)
497 // No dtor? Just the default case
498 iter_structural_ty(bcx, v0, t, |bb, vv, tt| drop_ty(bb, vv, tt, None))
502 ty::ty_unboxed_closure(..) => iter_structural_ty(bcx,
505 |bb, vv, tt| drop_ty(bb, vv, tt, None)),
506 ty::ty_closure(ref f) if f.store == ty::UniqTraitStore => {
507 let box_cell_v = GEPi(bcx, v0, [0u, abi::fn_field_box]);
508 let env = Load(bcx, box_cell_v);
509 let env_ptr_ty = Type::at_box(bcx.ccx(), Type::i8(bcx.ccx())).ptr_to();
510 let env = PointerCast(bcx, env, env_ptr_ty);
511 with_cond(bcx, IsNotNull(bcx, env), |bcx| {
512 let dtor_ptr = GEPi(bcx, env, [0u, abi::box_field_drop_glue]);
513 let dtor = Load(bcx, dtor_ptr);
514 Call(bcx, dtor, [PointerCast(bcx, box_cell_v, Type::i8p(bcx.ccx()))], None);
518 ty::ty_trait(..) => {
519 // No need to do a null check here (as opposed to the Box<trait case
520 // above), because this happens for a trait field in an unsized
521 // struct. If anything is null, it is the whole struct and we won't
523 let lluniquevalue = GEPi(bcx, v0, [0, abi::trt_field_box]);
524 let dtor_ptr = Load(bcx, GEPi(bcx, v0, [0, abi::trt_field_vtable]));
525 let dtor = Load(bcx, dtor_ptr);
528 [PointerCast(bcx, Load(bcx, lluniquevalue), Type::i8p(bcx.ccx()))],
532 ty::ty_vec(ty, None) => tvec::make_drop_glue_unboxed(bcx, v0, ty, false),
534 assert!(ty::type_is_sized(bcx.tcx(), t));
535 if ty::type_needs_drop(bcx.tcx(), t) &&
536 ty::type_is_structural(t) {
537 iter_structural_ty(bcx, v0, t, |bb, vv, tt| drop_ty(bb, vv, tt, None))
545 // Generates the declaration for (but doesn't emit) a type descriptor.
546 pub fn declare_tydesc(ccx: &CrateContext, t: ty::t) -> tydesc_info {
547 // If emit_tydescs already ran, then we shouldn't be creating any new
549 assert!(!ccx.finished_tydescs().get());
551 let llty = type_of(ccx, t);
553 if ccx.sess().count_type_sizes() {
554 println!("{}\t{}", llsize_of_real(ccx, llty),
555 ppaux::ty_to_string(ccx.tcx(), t));
558 let llsize = llsize_of(ccx, llty);
559 let llalign = llalign_of(ccx, llty);
560 let name = mangle_internal_name_by_type_and_seq(ccx, t, "tydesc");
561 debug!("+++ declare_tydesc {} {}", ppaux::ty_to_string(ccx.tcx(), t), name);
562 let gvar = name.as_slice().with_c_str(|buf| {
564 llvm::LLVMAddGlobal(ccx.llmod(), ccx.tydesc_type().to_ref(), buf)
567 note_unique_llvm_symbol(ccx, name);
569 let ty_name = token::intern_and_get_ident(
570 ppaux::ty_to_string(ccx.tcx(), t).as_slice());
571 let ty_name = C_str_slice(ccx, ty_name);
573 debug!("--- declare_tydesc {}", ppaux::ty_to_string(ccx.tcx(), t));
580 visit_glue: Cell::new(None),
584 fn declare_generic_glue(ccx: &CrateContext, t: ty::t, llfnty: Type,
585 name: &str) -> (String, ValueRef) {
586 let _icx = push_ctxt("declare_generic_glue");
587 let fn_nm = mangle_internal_name_by_type_and_seq(
590 format!("glue_{}", name).as_slice());
591 let llfn = decl_cdecl_fn(ccx, fn_nm.as_slice(), llfnty, ty::mk_nil());
592 note_unique_llvm_symbol(ccx, fn_nm.clone());
593 return (fn_nm, llfn);
596 fn make_generic_glue(ccx: &CrateContext,
599 helper: <'blk, 'tcx> |Block<'blk, 'tcx>, ValueRef, ty::t|
600 -> Block<'blk, 'tcx>,
603 let _icx = push_ctxt("make_generic_glue");
604 let glue_name = format!("glue {} {}", name, ty_to_short_str(ccx.tcx(), t));
605 let _s = StatRecorder::new(ccx, glue_name);
607 let arena = TypedArena::new();
608 let empty_param_substs = param_substs::empty();
609 let fcx = new_fn_ctxt(ccx, llfn, ast::DUMMY_NODE_ID, false, ty::mk_nil(),
610 &empty_param_substs, None, &arena);
612 let bcx = init_function(&fcx, false, ty::mk_nil());
614 update_linkage(ccx, llfn, None, OriginalTranslation);
616 ccx.stats().n_glues_created.set(ccx.stats().n_glues_created.get() + 1u);
617 // All glue functions take values passed *by alias*; this is a
618 // requirement since in many contexts glue is invoked indirectly and
619 // the caller has no idea if it's dealing with something that can be
622 // llfn is expected be declared to take a parameter of the appropriate
623 // type, so we don't need to explicitly cast the function parameter.
625 let llrawptr0 = get_param(llfn, fcx.arg_pos(0) as c_uint);
626 let bcx = helper(bcx, llrawptr0, t);
627 finish_fn(&fcx, bcx, ty::mk_nil());
632 pub fn emit_tydescs(ccx: &CrateContext) {
633 let _icx = push_ctxt("emit_tydescs");
634 // As of this point, allow no more tydescs to be created.
635 ccx.finished_tydescs().set(true);
636 let glue_fn_ty = Type::generic_glue_fn(ccx).ptr_to();
637 for (_, ti) in ccx.tydescs().borrow().iter() {
638 // Each of the glue functions needs to be cast to a generic type
639 // before being put into the tydesc because we only have a singleton
640 // tydesc type. Then we'll recast each function to its real type when
642 let drop_glue = unsafe {
643 llvm::LLVMConstPointerCast(get_drop_glue(ccx, ti.ty), glue_fn_ty.to_ref())
645 ccx.stats().n_real_glues.set(ccx.stats().n_real_glues.get() + 1);
647 match ti.visit_glue.get() {
649 ccx.stats().n_null_glues.set(ccx.stats().n_null_glues.get() +
655 ccx.stats().n_real_glues.set(ccx.stats().n_real_glues.get() +
657 llvm::LLVMConstPointerCast(v, glue_fn_ty.to_ref())
662 let tydesc = C_named_struct(ccx.tydesc_type(),
665 drop_glue, // drop_glue
666 visit_glue, // visit_glue
670 let gvar = ti.tydesc;
671 llvm::LLVMSetInitializer(gvar, tydesc);
672 llvm::LLVMSetGlobalConstant(gvar, True);
673 llvm::SetLinkage(gvar, llvm::InternalLinkage);