6ef08406dc
Currently, small aggregates are passed to functions as immediate values as is. This has two consequences. One is that aggregates are passed component-wise by LLVM, so e.g. a struct containing four u8 values (e.g. an RGBA struct) will be passed as four individual values. The other is that LLVM isn't very good at optimizing loads/stores of first class attributes. What clang does is converting the aggregate to an appropriately sized integer type (e.g. i32 for the four u8 values), and using that for the function argument. This allows LLVM to create code that is a lot better. Fixes #20450 #20149 #16506 #13927
589 lines
24 KiB
Rust
589 lines
24 KiB
Rust
// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//!
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//
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// Code relating to taking, dropping, etc as well as type descriptors.
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use back::abi;
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use back::link::*;
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use llvm::{ValueRef, True, get_param};
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use llvm;
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use middle::lang_items::ExchangeFreeFnLangItem;
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use middle::subst;
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use middle::subst::{Subst, Substs};
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use trans::adt;
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use trans::base::*;
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use trans::build::*;
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use trans::callee;
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use trans::cleanup;
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use trans::cleanup::CleanupMethods;
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use trans::consts;
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use trans::common::*;
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use trans::datum;
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use trans::debuginfo;
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use trans::expr;
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use trans::machine::*;
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use trans::tvec;
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use trans::type_::Type;
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use trans::type_of::{type_of, sizing_type_of, align_of};
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use middle::ty::{self, Ty};
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use util::ppaux::{ty_to_short_str, Repr};
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use util::ppaux;
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use arena::TypedArena;
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use libc::c_uint;
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use std::ffi::CString;
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use syntax::ast;
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use syntax::parse::token;
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pub fn trans_exchange_free_dyn<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef,
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size: ValueRef, align: ValueRef)
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-> Block<'blk, 'tcx> {
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let _icx = push_ctxt("trans_exchange_free");
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let ccx = cx.ccx();
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callee::trans_lang_call(cx,
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langcall(cx, None, "", ExchangeFreeFnLangItem),
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&[PointerCast(cx, v, Type::i8p(ccx)), size, align],
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Some(expr::Ignore)).bcx
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}
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pub fn trans_exchange_free<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef,
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size: u64, align: u32) -> Block<'blk, 'tcx> {
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trans_exchange_free_dyn(cx, v, C_uint(cx.ccx(), size),
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C_uint(cx.ccx(), align))
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}
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pub fn trans_exchange_free_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef,
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content_ty: Ty<'tcx>) -> Block<'blk, 'tcx> {
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assert!(type_is_sized(bcx.ccx().tcx(), content_ty));
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let sizing_type = sizing_type_of(bcx.ccx(), content_ty);
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let content_size = llsize_of_alloc(bcx.ccx(), sizing_type);
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// `Box<ZeroSizeType>` does not allocate.
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if content_size != 0 {
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let content_align = align_of(bcx.ccx(), content_ty);
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trans_exchange_free(bcx, ptr, content_size, content_align)
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} else {
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bcx
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}
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}
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pub fn get_drop_glue_type<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
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t: Ty<'tcx>) -> Ty<'tcx> {
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let tcx = ccx.tcx();
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// Even if there is no dtor for t, there might be one deeper down and we
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// might need to pass in the vtable ptr.
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if !type_is_sized(tcx, t) {
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return t
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}
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if !type_needs_drop(tcx, t) {
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return tcx.types.i8;
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}
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match t.sty {
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ty::ty_uniq(typ) if !type_needs_drop(tcx, typ)
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&& type_is_sized(tcx, typ) => {
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let llty = sizing_type_of(ccx, typ);
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// `Box<ZeroSizeType>` does not allocate.
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if llsize_of_alloc(ccx, llty) == 0 {
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tcx.types.i8
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} else {
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t
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}
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}
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_ => t
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}
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}
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pub fn drop_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
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v: ValueRef,
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t: Ty<'tcx>,
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source_location: Option<NodeInfo>)
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-> Block<'blk, 'tcx> {
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// NB: v is an *alias* of type t here, not a direct value.
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debug!("drop_ty(t={})", t.repr(bcx.tcx()));
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let _icx = push_ctxt("drop_ty");
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if type_needs_drop(bcx.tcx(), t) {
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let ccx = bcx.ccx();
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let glue = get_drop_glue(ccx, t);
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let glue_type = get_drop_glue_type(ccx, t);
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let ptr = if glue_type != t {
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PointerCast(bcx, v, type_of(ccx, glue_type).ptr_to())
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} else {
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v
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};
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match source_location {
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Some(sl) => debuginfo::set_source_location(bcx.fcx, sl.id, sl.span),
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None => debuginfo::clear_source_location(bcx.fcx)
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};
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Call(bcx, glue, &[ptr], None);
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}
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bcx
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}
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pub fn drop_ty_immediate<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
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v: ValueRef,
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t: Ty<'tcx>,
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source_location: Option<NodeInfo>)
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-> Block<'blk, 'tcx> {
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let _icx = push_ctxt("drop_ty_immediate");
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let vp = alloca(bcx, type_of(bcx.ccx(), t), "");
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store_ty(bcx, v, vp, t);
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drop_ty(bcx, vp, t, source_location)
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}
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pub fn get_drop_glue<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>) -> ValueRef {
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debug!("make drop glue for {}", ppaux::ty_to_string(ccx.tcx(), t));
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let t = get_drop_glue_type(ccx, t);
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debug!("drop glue type {}", ppaux::ty_to_string(ccx.tcx(), t));
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match ccx.drop_glues().borrow().get(&t) {
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Some(&glue) => return glue,
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_ => { }
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}
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let llty = if type_is_sized(ccx.tcx(), t) {
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type_of(ccx, t).ptr_to()
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} else {
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type_of(ccx, ty::mk_uniq(ccx.tcx(), t)).ptr_to()
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};
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let llfnty = Type::glue_fn(ccx, llty);
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let (glue, new_sym) = match ccx.available_drop_glues().borrow().get(&t) {
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Some(old_sym) => {
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let glue = decl_cdecl_fn(ccx, &old_sym[], llfnty, ty::mk_nil(ccx.tcx()));
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(glue, None)
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},
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None => {
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let (sym, glue) = declare_generic_glue(ccx, t, llfnty, "drop");
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(glue, Some(sym))
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},
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};
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ccx.drop_glues().borrow_mut().insert(t, glue);
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// To avoid infinite recursion, don't `make_drop_glue` until after we've
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// added the entry to the `drop_glues` cache.
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match new_sym {
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Some(sym) => {
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ccx.available_drop_glues().borrow_mut().insert(t, sym);
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// We're creating a new drop glue, so also generate a body.
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make_generic_glue(ccx, t, glue, make_drop_glue, "drop");
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},
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None => {},
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}
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glue
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}
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fn trans_struct_drop_flag<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
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t: Ty<'tcx>,
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v0: ValueRef,
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dtor_did: ast::DefId,
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class_did: ast::DefId,
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substs: &subst::Substs<'tcx>)
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-> Block<'blk, 'tcx> {
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let repr = adt::represent_type(bcx.ccx(), t);
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let struct_data = if type_is_sized(bcx.tcx(), t) {
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v0
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} else {
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let llval = GEPi(bcx, v0, &[0, abi::FAT_PTR_ADDR]);
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Load(bcx, llval)
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};
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let drop_flag = unpack_datum!(bcx, adt::trans_drop_flag_ptr(bcx, &*repr, struct_data));
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with_cond(bcx, load_ty(bcx, drop_flag.val, bcx.tcx().types.bool), |cx| {
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trans_struct_drop(cx, t, v0, dtor_did, class_did, substs)
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})
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}
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fn trans_struct_drop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
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t: Ty<'tcx>,
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v0: ValueRef,
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dtor_did: ast::DefId,
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class_did: ast::DefId,
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substs: &subst::Substs<'tcx>)
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-> Block<'blk, 'tcx>
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{
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let repr = adt::represent_type(bcx.ccx(), t);
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// Find and call the actual destructor
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let dtor_addr = get_res_dtor(bcx.ccx(), dtor_did, t,
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class_did, substs);
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// The first argument is the "self" argument for drop
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let params = unsafe {
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let ty = Type::from_ref(llvm::LLVMTypeOf(dtor_addr));
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ty.element_type().func_params()
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};
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let fty = ty::lookup_item_type(bcx.tcx(), dtor_did).ty.subst(bcx.tcx(), substs);
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let self_ty = match fty.sty {
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ty::ty_bare_fn(_, ref f) => {
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let sig = ty::erase_late_bound_regions(bcx.tcx(), &f.sig);
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assert!(sig.inputs.len() == 1);
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sig.inputs[0]
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}
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_ => bcx.sess().bug(&format!("Expected function type, found {}",
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bcx.ty_to_string(fty))[])
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};
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let (struct_data, info) = if type_is_sized(bcx.tcx(), t) {
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(v0, None)
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} else {
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let data = GEPi(bcx, v0, &[0, abi::FAT_PTR_ADDR]);
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let info = GEPi(bcx, v0, &[0, abi::FAT_PTR_EXTRA]);
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(Load(bcx, data), Some(Load(bcx, info)))
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};
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adt::fold_variants(bcx, &*repr, struct_data, |variant_cx, st, value| {
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// Be sure to put all of the fields into a scope so we can use an invoke
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// instruction to call the user destructor but still call the field
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// destructors if the user destructor panics.
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let field_scope = variant_cx.fcx.push_custom_cleanup_scope();
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// Class dtors have no explicit args, so the params should
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// just consist of the environment (self).
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assert_eq!(params.len(), 1);
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let self_arg = if type_is_fat_ptr(bcx.tcx(), self_ty) {
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// The dtor expects a fat pointer, so make one, even if we have to fake it.
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let boxed_ty = ty::mk_open(bcx.tcx(), t);
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let scratch = datum::rvalue_scratch_datum(bcx, boxed_ty, "__fat_ptr_drop_self");
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Store(bcx, value, GEPi(bcx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
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Store(bcx,
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// If we just had a thin pointer, make a fat pointer by sticking
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// null where we put the unsizing info. This works because t
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// is a sized type, so we will only unpack the fat pointer, never
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// use the fake info.
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info.unwrap_or(C_null(Type::i8p(bcx.ccx()))),
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GEPi(bcx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
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PointerCast(variant_cx, scratch.val, params[0])
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} else {
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PointerCast(variant_cx, value, params[0])
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};
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let args = vec!(self_arg);
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// Add all the fields as a value which needs to be cleaned at the end of
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// this scope. Iterate in reverse order so a Drop impl doesn't reverse
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// the order in which fields get dropped.
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for (i, ty) in st.fields.iter().enumerate().rev() {
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let llfld_a = adt::struct_field_ptr(variant_cx, &*st, value, i, false);
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let val = if type_is_sized(bcx.tcx(), *ty) {
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llfld_a
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} else {
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let boxed_ty = ty::mk_open(bcx.tcx(), *ty);
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let scratch = datum::rvalue_scratch_datum(bcx, boxed_ty, "__fat_ptr_drop_field");
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Store(bcx, llfld_a, GEPi(bcx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
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Store(bcx, info.unwrap(), GEPi(bcx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
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scratch.val
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};
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variant_cx.fcx.schedule_drop_mem(cleanup::CustomScope(field_scope),
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val, *ty);
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}
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let dtor_ty = ty::mk_ctor_fn(bcx.tcx(),
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class_did,
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&[get_drop_glue_type(bcx.ccx(), t)],
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ty::mk_nil(bcx.tcx()));
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let (_, variant_cx) = invoke(variant_cx, dtor_addr, &args[], dtor_ty, None);
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variant_cx.fcx.pop_and_trans_custom_cleanup_scope(variant_cx, field_scope);
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variant_cx
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})
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}
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fn size_and_align_of_dst<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, info: ValueRef)
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-> (ValueRef, ValueRef) {
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debug!("calculate size of DST: {}; with lost info: {}",
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bcx.ty_to_string(t), bcx.val_to_string(info));
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if type_is_sized(bcx.tcx(), t) {
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let sizing_type = sizing_type_of(bcx.ccx(), t);
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let size = C_uint(bcx.ccx(), llsize_of_alloc(bcx.ccx(), sizing_type));
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let align = C_uint(bcx.ccx(), align_of(bcx.ccx(), t));
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return (size, align);
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}
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match t.sty {
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ty::ty_struct(id, substs) => {
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let ccx = bcx.ccx();
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// First get the size of all statically known fields.
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// Don't use type_of::sizing_type_of because that expects t to be sized.
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assert!(!ty::type_is_simd(bcx.tcx(), t));
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let repr = adt::represent_type(ccx, t);
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let sizing_type = adt::sizing_type_of(ccx, &*repr, true);
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let sized_size = C_uint(ccx, llsize_of_alloc(ccx, sizing_type));
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let sized_align = C_uint(ccx, llalign_of_min(ccx, sizing_type));
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// Recurse to get the size of the dynamically sized field (must be
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// the last field).
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let fields = ty::struct_fields(bcx.tcx(), id, substs);
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let last_field = fields[fields.len()-1];
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let field_ty = last_field.mt.ty;
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let (unsized_size, unsized_align) = size_and_align_of_dst(bcx, field_ty, info);
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// Return the sum of sizes and max of aligns.
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let size = Add(bcx, sized_size, unsized_size);
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let align = Select(bcx,
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ICmp(bcx, llvm::IntULT, sized_align, unsized_align),
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sized_align,
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unsized_align);
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(size, align)
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}
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ty::ty_trait(..) => {
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// info points to the vtable and the second entry in the vtable is the
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// dynamic size of the object.
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let info = PointerCast(bcx, info, Type::int(bcx.ccx()).ptr_to());
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let size_ptr = GEPi(bcx, info, &[1u]);
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let align_ptr = GEPi(bcx, info, &[2u]);
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(Load(bcx, size_ptr), Load(bcx, align_ptr))
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}
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ty::ty_vec(unit_ty, None) => {
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// The info in this case is the length of the vec, so the size is that
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// times the unit size.
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let llunit_ty = sizing_type_of(bcx.ccx(), unit_ty);
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let unit_size = llsize_of_alloc(bcx.ccx(), llunit_ty);
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(Mul(bcx, info, C_uint(bcx.ccx(), unit_size)), C_uint(bcx.ccx(), 8u))
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}
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_ => bcx.sess().bug(&format!("Unexpected unsized type, found {}",
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bcx.ty_to_string(t))[])
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}
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}
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fn make_drop_glue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, v0: ValueRef, t: Ty<'tcx>)
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-> Block<'blk, 'tcx> {
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// NB: v0 is an *alias* of type t here, not a direct value.
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let _icx = push_ctxt("make_drop_glue");
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match t.sty {
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ty::ty_uniq(content_ty) => {
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match content_ty.sty {
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ty::ty_vec(ty, None) => {
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tvec::make_drop_glue_unboxed(bcx, v0, ty, true)
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}
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ty::ty_str => {
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let unit_ty = ty::sequence_element_type(bcx.tcx(), content_ty);
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tvec::make_drop_glue_unboxed(bcx, v0, unit_ty, true)
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}
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ty::ty_trait(..) => {
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let lluniquevalue = GEPi(bcx, v0, &[0, abi::FAT_PTR_ADDR]);
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// Only drop the value when it is non-null
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let concrete_ptr = Load(bcx, lluniquevalue);
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with_cond(bcx, IsNotNull(bcx, concrete_ptr), |bcx| {
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let dtor_ptr = Load(bcx, GEPi(bcx, v0, &[0, abi::FAT_PTR_EXTRA]));
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let dtor = Load(bcx, dtor_ptr);
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Call(bcx,
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dtor,
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&[PointerCast(bcx, lluniquevalue, Type::i8p(bcx.ccx()))],
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None);
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bcx
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})
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}
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ty::ty_struct(..) if !type_is_sized(bcx.tcx(), content_ty) => {
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let llval = GEPi(bcx, v0, &[0, abi::FAT_PTR_ADDR]);
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let llbox = Load(bcx, llval);
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let not_null = IsNotNull(bcx, llbox);
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with_cond(bcx, not_null, |bcx| {
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let bcx = drop_ty(bcx, v0, content_ty, None);
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let info = GEPi(bcx, v0, &[0, abi::FAT_PTR_EXTRA]);
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let info = Load(bcx, info);
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let (llsize, llalign) = size_and_align_of_dst(bcx, content_ty, info);
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trans_exchange_free_dyn(bcx, llbox, llsize, llalign)
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})
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}
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_ => {
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assert!(type_is_sized(bcx.tcx(), content_ty));
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let llval = v0;
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let llbox = Load(bcx, llval);
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let not_null = IsNotNull(bcx, llbox);
|
|
with_cond(bcx, not_null, |bcx| {
|
|
let bcx = drop_ty(bcx, llbox, content_ty, None);
|
|
trans_exchange_free_ty(bcx, llbox, content_ty)
|
|
})
|
|
}
|
|
}
|
|
}
|
|
ty::ty_struct(did, substs) | ty::ty_enum(did, substs) => {
|
|
let tcx = bcx.tcx();
|
|
match ty::ty_dtor(tcx, did) {
|
|
ty::TraitDtor(dtor, true) => {
|
|
// FIXME(16758) Since the struct is unsized, it is hard to
|
|
// find the drop flag (which is at the end of the struct).
|
|
// Lets just ignore the flag and pretend everything will be
|
|
// OK.
|
|
if type_is_sized(bcx.tcx(), t) {
|
|
trans_struct_drop_flag(bcx, t, v0, dtor, did, substs)
|
|
} else {
|
|
// Give the user a heads up that we are doing something
|
|
// stupid and dangerous.
|
|
bcx.sess().warn(&format!("Ignoring drop flag in destructor for {}\
|
|
because the struct is unsized. See issue\
|
|
#16758",
|
|
bcx.ty_to_string(t))[]);
|
|
trans_struct_drop(bcx, t, v0, dtor, did, substs)
|
|
}
|
|
}
|
|
ty::TraitDtor(dtor, false) => {
|
|
trans_struct_drop(bcx, t, v0, dtor, did, substs)
|
|
}
|
|
ty::NoDtor => {
|
|
// No dtor? Just the default case
|
|
iter_structural_ty(bcx, v0, t, |bb, vv, tt| drop_ty(bb, vv, tt, None))
|
|
}
|
|
}
|
|
}
|
|
ty::ty_unboxed_closure(..) => iter_structural_ty(bcx,
|
|
v0,
|
|
t,
|
|
|bb, vv, tt| drop_ty(bb, vv, tt, None)),
|
|
ty::ty_trait(..) => {
|
|
// No need to do a null check here (as opposed to the Box<trait case
|
|
// above), because this happens for a trait field in an unsized
|
|
// struct. If anything is null, it is the whole struct and we won't
|
|
// get here.
|
|
let lluniquevalue = GEPi(bcx, v0, &[0, abi::FAT_PTR_ADDR]);
|
|
let dtor_ptr = Load(bcx, GEPi(bcx, v0, &[0, abi::FAT_PTR_EXTRA]));
|
|
let dtor = Load(bcx, dtor_ptr);
|
|
Call(bcx,
|
|
dtor,
|
|
&[PointerCast(bcx, Load(bcx, lluniquevalue), Type::i8p(bcx.ccx()))],
|
|
None);
|
|
bcx
|
|
}
|
|
ty::ty_vec(ty, None) => tvec::make_drop_glue_unboxed(bcx, v0, ty, false),
|
|
_ => {
|
|
assert!(type_is_sized(bcx.tcx(), t));
|
|
if type_needs_drop(bcx.tcx(), t) &&
|
|
ty::type_is_structural(t) {
|
|
iter_structural_ty(bcx, v0, t, |bb, vv, tt| drop_ty(bb, vv, tt, None))
|
|
} else {
|
|
bcx
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Generates the declaration for (but doesn't emit) a type descriptor.
|
|
pub fn declare_tydesc<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>)
|
|
-> tydesc_info<'tcx> {
|
|
// If emit_tydescs already ran, then we shouldn't be creating any new
|
|
// tydescs.
|
|
assert!(!ccx.finished_tydescs().get());
|
|
|
|
let llty = type_of(ccx, t);
|
|
|
|
if ccx.sess().count_type_sizes() {
|
|
println!("{}\t{}", llsize_of_real(ccx, llty),
|
|
ppaux::ty_to_string(ccx.tcx(), t));
|
|
}
|
|
|
|
let llsize = llsize_of(ccx, llty);
|
|
let llalign = llalign_of(ccx, llty);
|
|
let name = mangle_internal_name_by_type_and_seq(ccx, t, "tydesc");
|
|
debug!("+++ declare_tydesc {} {}", ppaux::ty_to_string(ccx.tcx(), t), name);
|
|
let buf = CString::from_slice(name.as_bytes());
|
|
let gvar = unsafe {
|
|
llvm::LLVMAddGlobal(ccx.llmod(), ccx.tydesc_type().to_ref(),
|
|
buf.as_ptr())
|
|
};
|
|
note_unique_llvm_symbol(ccx, name);
|
|
|
|
let ty_name = token::intern_and_get_ident(
|
|
&ppaux::ty_to_string(ccx.tcx(), t)[]);
|
|
let ty_name = C_str_slice(ccx, ty_name);
|
|
|
|
debug!("--- declare_tydesc {}", ppaux::ty_to_string(ccx.tcx(), t));
|
|
tydesc_info {
|
|
ty: t,
|
|
tydesc: gvar,
|
|
size: llsize,
|
|
align: llalign,
|
|
name: ty_name,
|
|
}
|
|
}
|
|
|
|
fn declare_generic_glue<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>,
|
|
llfnty: Type, name: &str) -> (String, ValueRef) {
|
|
let _icx = push_ctxt("declare_generic_glue");
|
|
let fn_nm = mangle_internal_name_by_type_and_seq(
|
|
ccx,
|
|
t,
|
|
&format!("glue_{}", name)[]);
|
|
let llfn = decl_cdecl_fn(ccx, &fn_nm[], llfnty, ty::mk_nil(ccx.tcx()));
|
|
note_unique_llvm_symbol(ccx, fn_nm.clone());
|
|
return (fn_nm, llfn);
|
|
}
|
|
|
|
fn make_generic_glue<'a, 'tcx, F>(ccx: &CrateContext<'a, 'tcx>,
|
|
t: Ty<'tcx>,
|
|
llfn: ValueRef,
|
|
helper: F,
|
|
name: &str)
|
|
-> ValueRef where
|
|
F: for<'blk> FnOnce(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
|
|
{
|
|
let _icx = push_ctxt("make_generic_glue");
|
|
let glue_name = format!("glue {} {}", name, ty_to_short_str(ccx.tcx(), t));
|
|
let _s = StatRecorder::new(ccx, glue_name);
|
|
|
|
let arena = TypedArena::new();
|
|
let empty_param_substs = Substs::trans_empty();
|
|
let fcx = new_fn_ctxt(ccx, llfn, ast::DUMMY_NODE_ID, false,
|
|
ty::FnConverging(ty::mk_nil(ccx.tcx())),
|
|
&empty_param_substs, None, &arena);
|
|
|
|
let bcx = init_function(&fcx, false, ty::FnConverging(ty::mk_nil(ccx.tcx())));
|
|
|
|
update_linkage(ccx, llfn, None, OriginalTranslation);
|
|
|
|
ccx.stats().n_glues_created.set(ccx.stats().n_glues_created.get() + 1u);
|
|
// All glue functions take values passed *by alias*; this is a
|
|
// requirement since in many contexts glue is invoked indirectly and
|
|
// the caller has no idea if it's dealing with something that can be
|
|
// passed by value.
|
|
//
|
|
// llfn is expected be declared to take a parameter of the appropriate
|
|
// type, so we don't need to explicitly cast the function parameter.
|
|
|
|
let llrawptr0 = get_param(llfn, fcx.arg_pos(0) as c_uint);
|
|
let bcx = helper(bcx, llrawptr0, t);
|
|
finish_fn(&fcx, bcx, ty::FnConverging(ty::mk_nil(ccx.tcx())));
|
|
|
|
llfn
|
|
}
|
|
|
|
pub fn emit_tydescs(ccx: &CrateContext) {
|
|
let _icx = push_ctxt("emit_tydescs");
|
|
// As of this point, allow no more tydescs to be created.
|
|
ccx.finished_tydescs().set(true);
|
|
let glue_fn_ty = Type::generic_glue_fn(ccx).ptr_to();
|
|
for (_, ti) in ccx.tydescs().borrow().iter() {
|
|
// Each of the glue functions needs to be cast to a generic type
|
|
// 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 drop_glue = consts::ptrcast(get_drop_glue(ccx, ti.ty), glue_fn_ty);
|
|
ccx.stats().n_real_glues.set(ccx.stats().n_real_glues.get() + 1);
|
|
|
|
let tydesc = C_named_struct(ccx.tydesc_type(),
|
|
&[ti.size, // size
|
|
ti.align, // align
|
|
drop_glue, // drop_glue
|
|
ti.name]); // name
|
|
|
|
unsafe {
|
|
let gvar = ti.tydesc;
|
|
llvm::LLVMSetInitializer(gvar, tydesc);
|
|
llvm::LLVMSetGlobalConstant(gvar, True);
|
|
llvm::SetLinkage(gvar, llvm::InternalLinkage);
|
|
}
|
|
};
|
|
}
|