rust/src/rustc/middle/trans/impl.rs

303 lines
11 KiB
Rust

import libc::c_uint;
import base::*;
import common::*;
import type_of::*;
import build::*;
import driver::session::session;
import syntax::{ast, ast_map};
import ast_map::{path, path_mod, path_name, node_id_to_str};
import driver::session::expect;
import syntax::ast_util::{local_def, split_class_items};
import metadata::csearch;
import back::{link, abi};
import lib::llvm::llvm;
import lib::llvm::{ValueRef, TypeRef};
import lib::llvm::llvm::LLVMGetParam;
import std::map::hashmap;
fn trans_impl(ccx: @crate_ctxt, path: path, name: ast::ident,
methods: ~[@ast::method], tps: ~[ast::ty_param]) {
let _icx = ccx.insn_ctxt(~"impl::trans_impl");
if tps.len() > 0u { ret; }
let sub_path = vec::append_one(path, path_name(name));
for vec::each(methods) |m| {
if m.tps.len() == 0u {
let llfn = get_item_val(ccx, m.id);
trans_fn(ccx,
vec::append_one(sub_path, path_name(m.ident)),
m.decl, m.body,
llfn, impl_self(ty::node_id_to_type(ccx.tcx, m.self_id)),
none, m.id);
}
}
}
fn trans_self_arg(bcx: block, base: @ast::expr, derefs: uint) -> result {
let _icx = bcx.insn_ctxt(~"impl::trans_self_arg");
let basety = expr_ty(bcx, base);
let m_by_ref = ast::expl(ast::by_ref);
let mut temp_cleanups = ~[];
let result = trans_arg_expr(bcx, {mode: m_by_ref, ty: basety},
T_ptr(type_of::type_of(bcx.ccx(), basety)),
base, temp_cleanups, none, derefs);
// by-ref self argument should not require cleanup in the case of
// other arguments failing:
assert temp_cleanups == ~[];
ret result;
}
fn trans_method_callee(bcx: block, callee_id: ast::node_id,
self: @ast::expr, mentry: typeck::method_map_entry)
-> lval_maybe_callee {
let _icx = bcx.insn_ctxt(~"impl::trans_method_callee");
alt mentry.origin {
typeck::method_static(did) {
let {bcx, val} = trans_self_arg(bcx, self, mentry.derefs);
{env: self_env(val, node_id_type(bcx, self.id), none)
with lval_static_fn(bcx, did, callee_id)}
}
typeck::method_param({trait_id:iid, method_num:off,
param_num:p, bound_num:b}) {
alt check bcx.fcx.param_substs {
some(substs) {
trans_monomorphized_callee(bcx, callee_id, self, mentry.derefs,
iid, off, p, b, substs)
}
}
}
typeck::method_trait(_, off) {
let {bcx, val} = trans_temp_expr(bcx, self);
let fty = node_id_type(bcx, callee_id);
trans_trait_callee(bcx, val, fty, off)
}
}
}
fn method_from_methods(ms: ~[@ast::method], name: ast::ident)
-> ast::def_id {
local_def(option::get(vec::find(ms, |m| m.ident == name)).id)
}
fn method_with_name(ccx: @crate_ctxt, impl_id: ast::def_id,
name: ast::ident) -> ast::def_id {
if impl_id.crate == ast::local_crate {
alt check ccx.tcx.items.get(impl_id.node) {
ast_map::node_item(@{node: ast::item_impl(_, _, _, ms), _}, _) {
method_from_methods(ms, name)
}
ast_map::node_item(@{node:
ast::item_class(_, _, items, _, _), _}, _) {
let (_,ms) = split_class_items(items);
method_from_methods(ms, name)
}
}
} else {
csearch::get_impl_method(ccx.sess.cstore, impl_id, name)
}
}
fn method_ty_param_count(ccx: @crate_ctxt, m_id: ast::def_id,
i_id: ast::def_id) -> uint {
if m_id.crate == ast::local_crate {
alt check ccx.tcx.items.get(m_id.node) {
ast_map::node_method(m, _, _) { vec::len(m.tps) }
}
} else {
csearch::get_type_param_count(ccx.sess.cstore, m_id) -
csearch::get_type_param_count(ccx.sess.cstore, i_id)
}
}
fn trans_monomorphized_callee(bcx: block, callee_id: ast::node_id,
base: @ast::expr, derefs: uint,
trait_id: ast::def_id, n_method: uint,
n_param: uint, n_bound: uint,
substs: param_substs) -> lval_maybe_callee {
let _icx = bcx.insn_ctxt(~"impl::trans_monomorphized_callee");
alt find_vtable_in_fn_ctxt(substs, n_param, n_bound) {
typeck::vtable_static(impl_did, impl_substs, sub_origins) {
let ccx = bcx.ccx();
let mname = ty::trait_methods(ccx.tcx, trait_id)[n_method].ident;
let mth_id = method_with_name(bcx.ccx(), impl_did, mname);
let n_m_tps = method_ty_param_count(ccx, mth_id, impl_did);
let node_substs = node_id_type_params(bcx, callee_id);
let ty_substs
= vec::append(impl_substs,
vec::tailn(node_substs,
node_substs.len() - n_m_tps));
let {bcx, val} = trans_self_arg(bcx, base, derefs);
let lval = lval_static_fn_inner(bcx, mth_id, callee_id, ty_substs,
some(sub_origins));
{env: self_env(val, node_id_type(bcx, base.id), none),
val: PointerCast(bcx, lval.val, T_ptr(type_of_fn_from_ty(
ccx, node_id_type(bcx, callee_id))))
with lval}
}
typeck::vtable_trait(iid, tps) {
let {bcx, val} = trans_temp_expr(bcx, base);
let fty = node_id_type(bcx, callee_id);
trans_trait_callee(bcx, val, fty, n_method)
}
typeck::vtable_param(n_param, n_bound) {
fail ~"vtable_param left in monomorphized function's vtable substs";
}
}
}
// Method callee where the vtable comes from a boxed trait
fn trans_trait_callee(bcx: block, val: ValueRef,
callee_ty: ty::t, n_method: uint)
-> lval_maybe_callee {
let _icx = bcx.insn_ctxt(~"impl::trans_trait_callee");
let ccx = bcx.ccx();
let vtable = Load(bcx, PointerCast(bcx, GEPi(bcx, val, ~[0u, 0u]),
T_ptr(T_ptr(T_vtable()))));
let llbox = Load(bcx, GEPi(bcx, val, ~[0u, 1u]));
// FIXME[impl] I doubt this is alignment-safe (#2534)
let self = GEPi(bcx, llbox, ~[0u, abi::box_field_body]);
let env = self_env(self, ty::mk_opaque_box(bcx.tcx()), some(llbox));
let llfty = type_of::type_of_fn_from_ty(ccx, callee_ty);
let vtable = PointerCast(bcx, vtable,
T_ptr(T_array(T_ptr(llfty), n_method + 1u)));
let mptr = Load(bcx, GEPi(bcx, vtable, ~[0u, n_method]));
{bcx: bcx, val: mptr, kind: owned, env: env}
}
fn find_vtable_in_fn_ctxt(ps: param_substs, n_param: uint, n_bound: uint)
-> typeck::vtable_origin {
let mut vtable_off = n_bound, i = 0u;
// Vtables are stored in a flat array, finding the right one is
// somewhat awkward
for vec::each(*ps.bounds) |bounds| {
if i >= n_param { break; }
for vec::each(*bounds) |bound| {
alt bound { ty::bound_trait(_) { vtable_off += 1u; } _ {} }
}
i += 1u;
}
option::get(ps.vtables)[vtable_off]
}
fn resolve_vtables_in_fn_ctxt(fcx: fn_ctxt, vts: typeck::vtable_res)
-> typeck::vtable_res {
@vec::map(*vts, |d| resolve_vtable_in_fn_ctxt(fcx, d))
}
fn resolve_vtable_in_fn_ctxt(fcx: fn_ctxt, vt: typeck::vtable_origin)
-> typeck::vtable_origin {
alt vt {
typeck::vtable_static(iid, tys, sub) {
let tys = alt fcx.param_substs {
some(substs) {
vec::map(tys, |t| ty::subst_tps(fcx.ccx.tcx, substs.tys, t))
}
_ { tys }
};
typeck::vtable_static(iid, tys, resolve_vtables_in_fn_ctxt(fcx, sub))
}
typeck::vtable_param(n_param, n_bound) {
alt check fcx.param_substs {
some(substs) {
find_vtable_in_fn_ctxt(substs, n_param, n_bound)
}
}
}
_ { vt }
}
}
fn vtable_id(ccx: @crate_ctxt, origin: typeck::vtable_origin) -> mono_id {
alt check origin {
typeck::vtable_static(impl_id, substs, sub_vtables) {
make_mono_id(ccx, impl_id, substs,
if (*sub_vtables).len() == 0u { none }
else { some(sub_vtables) }, none)
}
typeck::vtable_trait(trait_id, substs) {
@{def: trait_id,
params: vec::map(substs, |t| mono_precise(t, none))}
}
}
}
fn get_vtable(ccx: @crate_ctxt, origin: typeck::vtable_origin)
-> ValueRef {
let hash_id = vtable_id(ccx, origin);
alt ccx.vtables.find(hash_id) {
some(val) { val }
none {
alt check origin {
typeck::vtable_static(id, substs, sub_vtables) {
make_impl_vtable(ccx, id, substs, sub_vtables)
}
}
}
}
}
fn make_vtable(ccx: @crate_ctxt, ptrs: ~[ValueRef]) -> ValueRef {
let _icx = ccx.insn_ctxt(~"impl::make_vtable");
let tbl = C_struct(ptrs);
let vt_gvar = str::as_c_str(ccx.names(~"vtable"), |buf| {
llvm::LLVMAddGlobal(ccx.llmod, val_ty(tbl), buf)
});
llvm::LLVMSetInitializer(vt_gvar, tbl);
llvm::LLVMSetGlobalConstant(vt_gvar, lib::llvm::True);
lib::llvm::SetLinkage(vt_gvar, lib::llvm::InternalLinkage);
vt_gvar
}
fn make_impl_vtable(ccx: @crate_ctxt, impl_id: ast::def_id, substs: ~[ty::t],
vtables: typeck::vtable_res) -> ValueRef {
let _icx = ccx.insn_ctxt(~"impl::make_impl_vtable");
let tcx = ccx.tcx;
let ifce_id = expect(ccx.sess,
ty::ty_to_def_id(option::get(ty::impl_trait(tcx,
impl_id))),
|| ~"make_impl_vtable: non-trait-type implemented");
let has_tps = (*ty::lookup_item_type(ccx.tcx, impl_id).bounds).len() > 0u;
make_vtable(ccx, vec::map(*ty::trait_methods(tcx, ifce_id), |im| {
let fty = ty::subst_tps(tcx, substs, ty::mk_fn(tcx, im.fty));
if (*im.tps).len() > 0u || ty::type_has_self(fty) {
C_null(T_ptr(T_nil()))
} else {
let mut m_id = method_with_name(ccx, impl_id, im.ident);
if has_tps {
// If the method is in another crate, need to make an inlined
// copy first
if m_id.crate != ast::local_crate {
m_id = maybe_instantiate_inline(ccx, m_id);
}
monomorphic_fn(ccx, m_id, substs, some(vtables), none).val
} else if m_id.crate == ast::local_crate {
get_item_val(ccx, m_id.node)
} else {
trans_external_path(ccx, m_id, fty)
}
}
}))
}
fn trans_cast(bcx: block, val: @ast::expr, id: ast::node_id, dest: dest)
-> block {
let _icx = bcx.insn_ctxt(~"impl::trans_cast");
if dest == ignore { ret trans_expr(bcx, val, ignore); }
let ccx = bcx.ccx();
let v_ty = expr_ty(bcx, val);
let {box: llbox, body: body} = malloc_boxed(bcx, v_ty);
add_clean_free(bcx, llbox, heap_shared);
let bcx = trans_expr_save_in(bcx, val, body);
revoke_clean(bcx, llbox);
let result = get_dest_addr(dest);
Store(bcx, llbox, PointerCast(bcx, GEPi(bcx, result, ~[0u, 1u]),
T_ptr(val_ty(llbox))));
let orig = ccx.maps.vtable_map.get(id)[0];
let orig = resolve_vtable_in_fn_ctxt(bcx.fcx, orig);
let vtable = get_vtable(bcx.ccx(), orig);
Store(bcx, vtable, PointerCast(bcx, GEPi(bcx, result, ~[0u, 0u]),
T_ptr(val_ty(vtable))));
bcx
}