907 lines
33 KiB
Rust
907 lines
33 KiB
Rust
// Copyright 2012 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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* Handles translation of callees as well as other call-related
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* things. Callees are a superset of normal rust values and sometimes
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* have different representations. In particular, top-level fn items
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* and methods are represented as just a fn ptr and not a full
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* closure.
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*/
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use std::vec;
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use back::abi;
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use driver::session;
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use lib::llvm::{ValueRef, NoAliasAttribute, StructRetAttribute};
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use lib::llvm::llvm;
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use metadata::csearch;
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use middle::trans::base;
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use middle::trans::base::*;
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use middle::trans::build::*;
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use middle::trans::callee;
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use middle::trans::cleanup;
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use middle::trans::cleanup::CleanupMethods;
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use middle::trans::common;
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use middle::trans::common::*;
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use middle::trans::datum::*;
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use middle::trans::datum::Datum;
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use middle::trans::expr;
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use middle::trans::glue;
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use middle::trans::inline;
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use middle::trans::meth;
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use middle::trans::monomorphize;
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use middle::trans::type_of;
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use middle::trans::foreign;
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use middle::ty;
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use middle::subst::Subst;
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use middle::typeck;
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use middle::typeck::coherence::make_substs_for_receiver_types;
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use middle::typeck::MethodCall;
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use util::ppaux::Repr;
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use middle::trans::type_::Type;
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use std::vec_ng::Vec;
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use std::vec_ng;
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use syntax::ast;
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use syntax::abi::AbiSet;
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use syntax::ast_map;
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pub struct MethodData {
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llfn: ValueRef,
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llself: ValueRef,
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}
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pub enum CalleeData {
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Closure(Datum<Lvalue>),
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// Represents a (possibly monomorphized) top-level fn item or method
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// item. Note that this is just the fn-ptr and is not a Rust closure
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// value (which is a pair).
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Fn(/* llfn */ ValueRef),
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TraitMethod(MethodData)
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}
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pub struct Callee<'a> {
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bcx: &'a Block<'a>,
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data: CalleeData
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}
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fn trans<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> Callee<'a> {
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let _icx = push_ctxt("trans_callee");
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debug!("callee::trans(expr={})", expr.repr(bcx.tcx()));
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// pick out special kinds of expressions that can be called:
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match expr.node {
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ast::ExprPath(_) => {
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return trans_def(bcx, bcx.def(expr.id), expr);
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}
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_ => {}
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}
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// any other expressions are closures:
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return datum_callee(bcx, expr);
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fn datum_callee<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> Callee<'a> {
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let DatumBlock {bcx: mut bcx, datum} = expr::trans(bcx, expr);
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match ty::get(datum.ty).sty {
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ty::ty_bare_fn(..) => {
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let llval = datum.to_llscalarish(bcx);
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return Callee {bcx: bcx, data: Fn(llval)};
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}
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ty::ty_closure(..) => {
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let datum = unpack_datum!(
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bcx, datum.to_lvalue_datum(bcx, "callee", expr.id));
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return Callee {bcx: bcx, data: Closure(datum)};
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}
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_ => {
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bcx.tcx().sess.span_bug(
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expr.span,
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format!("type of callee is neither bare-fn nor closure: {}",
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bcx.ty_to_str(datum.ty)));
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}
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}
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}
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fn fn_callee<'a>(bcx: &'a Block<'a>, llfn: ValueRef) -> Callee<'a> {
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return Callee {bcx: bcx, data: Fn(llfn)};
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}
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fn trans_def<'a>(bcx: &'a Block<'a>, def: ast::Def, ref_expr: &ast::Expr)
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-> Callee<'a> {
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match def {
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ast::DefFn(did, _) |
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ast::DefStaticMethod(did, ast::FromImpl(_), _) => {
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fn_callee(bcx, trans_fn_ref(bcx, did, ExprId(ref_expr.id)))
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}
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ast::DefStaticMethod(impl_did,
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ast::FromTrait(trait_did),
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_) => {
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fn_callee(bcx, meth::trans_static_method_callee(bcx, impl_did,
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trait_did,
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ref_expr.id))
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}
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ast::DefVariant(tid, vid, _) => {
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// nullary variants are not callable
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assert!(ty::enum_variant_with_id(bcx.tcx(),
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tid,
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vid).args.len() > 0u);
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fn_callee(bcx, trans_fn_ref(bcx, vid, ExprId(ref_expr.id)))
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}
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ast::DefStruct(def_id) => {
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fn_callee(bcx, trans_fn_ref(bcx, def_id, ExprId(ref_expr.id)))
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}
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ast::DefStatic(..) |
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ast::DefArg(..) |
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ast::DefLocal(..) |
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ast::DefBinding(..) |
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ast::DefUpvar(..) => {
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datum_callee(bcx, ref_expr)
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}
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ast::DefMod(..) | ast::DefForeignMod(..) | ast::DefTrait(..) |
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ast::DefTy(..) | ast::DefPrimTy(..) |
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ast::DefUse(..) | ast::DefTyParamBinder(..) |
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ast::DefRegion(..) | ast::DefLabel(..) | ast::DefTyParam(..) |
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ast::DefSelfTy(..) | ast::DefMethod(..) => {
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bcx.tcx().sess.span_bug(
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ref_expr.span,
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format!("cannot translate def {:?} \
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to a callable thing!", def));
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}
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}
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}
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}
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pub fn trans_fn_ref(bcx: &Block, def_id: ast::DefId, node: ExprOrMethodCall) -> ValueRef {
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/*!
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*
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* Translates a reference (with id `ref_id`) to the fn/method
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* with id `def_id` into a function pointer. This may require
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* monomorphization or inlining. */
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let _icx = push_ctxt("trans_fn_ref");
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let type_params = node_id_type_params(bcx, node);
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let vtables = match node {
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ExprId(id) => node_vtables(bcx, id),
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MethodCall(method_call) if method_call.autoderef == 0 => {
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node_vtables(bcx, method_call.expr_id)
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}
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_ => None
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};
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debug!("trans_fn_ref(def_id={}, node={:?}, type_params={}, vtables={})",
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def_id.repr(bcx.tcx()), node, type_params.repr(bcx.tcx()),
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vtables.repr(bcx.tcx()));
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trans_fn_ref_with_vtables(bcx, def_id, node,
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type_params.as_slice(),
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vtables)
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}
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fn trans_fn_ref_with_vtables_to_callee<'a>(bcx: &'a Block<'a>,
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def_id: ast::DefId,
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ref_id: ast::NodeId,
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type_params: &[ty::t],
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vtables: Option<typeck::vtable_res>)
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-> Callee<'a> {
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Callee {bcx: bcx,
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data: Fn(trans_fn_ref_with_vtables(bcx, def_id, ExprId(ref_id),
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type_params, vtables))}
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}
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fn resolve_default_method_vtables(bcx: &Block,
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impl_id: ast::DefId,
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method: &ty::Method,
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substs: &ty::substs,
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impl_vtables: Option<typeck::vtable_res>)
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-> (typeck::vtable_res, typeck::vtable_param_res) {
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// Get the vtables that the impl implements the trait at
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let impl_res = ty::lookup_impl_vtables(bcx.tcx(), impl_id);
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// Build up a param_substs that we are going to resolve the
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// trait_vtables under.
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let param_substs = Some(@param_substs {
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tys: substs.tps.clone(),
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self_ty: substs.self_ty,
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vtables: impl_vtables,
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self_vtables: None
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});
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let trait_vtables_fixed = resolve_vtables_under_param_substs(
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bcx.tcx(), param_substs, impl_res.trait_vtables);
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// Now we pull any vtables for parameters on the actual method.
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let num_method_vtables = method.generics.type_param_defs().len();
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let method_vtables = match impl_vtables {
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Some(vtables) => {
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let num_impl_type_parameters =
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vtables.len() - num_method_vtables;
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vtables.tailn(num_impl_type_parameters).to_owned()
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},
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None => vec::from_elem(num_method_vtables, @Vec::new())
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};
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let param_vtables = @(vec_ng::append((*trait_vtables_fixed).clone(),
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method_vtables));
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let self_vtables = resolve_param_vtables_under_param_substs(
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bcx.tcx(), param_substs, impl_res.self_vtables);
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(param_vtables, self_vtables)
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}
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pub fn trans_fn_ref_with_vtables(
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bcx: &Block, //
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def_id: ast::DefId, // def id of fn
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node: ExprOrMethodCall, // node id of use of fn; may be zero if N/A
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type_params: &[ty::t], // values for fn's ty params
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vtables: Option<typeck::vtable_res>) // vtables for the call
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-> ValueRef {
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/*!
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* Translates a reference to a fn/method item, monomorphizing and
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* inlining as it goes.
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*
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* # Parameters
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*
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* - `bcx`: the current block where the reference to the fn occurs
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* - `def_id`: def id of the fn or method item being referenced
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* - `node`: node id of the reference to the fn/method, if applicable.
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* This parameter may be zero; but, if so, the resulting value may not
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* have the right type, so it must be cast before being used.
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* - `type_params`: values for each of the fn/method's type parameters
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* - `vtables`: values for each bound on each of the type parameters
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*/
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let _icx = push_ctxt("trans_fn_ref_with_vtables");
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let ccx = bcx.ccx();
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let tcx = ccx.tcx;
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debug!("trans_fn_ref_with_vtables(bcx={}, def_id={}, node={:?}, \
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type_params={}, vtables={})",
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bcx.to_str(),
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def_id.repr(bcx.tcx()),
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node,
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type_params.repr(bcx.tcx()),
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vtables.repr(bcx.tcx()));
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assert!(type_params.iter().all(|t| !ty::type_needs_infer(*t)));
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// Polytype of the function item (may have type params)
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let fn_tpt = ty::lookup_item_type(tcx, def_id);
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let substs = ty::substs { regions: ty::ErasedRegions,
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self_ty: None,
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tps: /*bad*/ Vec::from_slice(type_params) };
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// Load the info for the appropriate trait if necessary.
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match ty::trait_of_method(tcx, def_id) {
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None => {}
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Some(trait_id) => {
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ty::populate_implementations_for_trait_if_necessary(tcx, trait_id)
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}
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}
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// We need to do a bunch of special handling for default methods.
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// We need to modify the def_id and our substs in order to monomorphize
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// the function.
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let (is_default, def_id, substs, self_vtables, vtables) =
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match ty::provided_source(tcx, def_id) {
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None => (false, def_id, substs, None, vtables),
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Some(source_id) => {
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// There are two relevant substitutions when compiling
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// default methods. First, there is the substitution for
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// the type parameters of the impl we are using and the
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// method we are calling. This substitution is the substs
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// argument we already have.
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// In order to compile a default method, though, we need
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// to consider another substitution: the substitution for
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// the type parameters on trait; the impl we are using
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// implements the trait at some particular type
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// parameters, and we need to substitute for those first.
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// So, what we need to do is find this substitution and
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// compose it with the one we already have.
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let impl_id = ty::method(tcx, def_id).container_id();
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let method = ty::method(tcx, source_id);
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let trait_ref = ty::impl_trait_ref(tcx, impl_id)
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.expect("could not find trait_ref for impl with \
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default methods");
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// Compute the first substitution
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let first_subst = make_substs_for_receiver_types(
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tcx, impl_id, trait_ref, method);
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// And compose them
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let new_substs = first_subst.subst(tcx, &substs);
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let (param_vtables, self_vtables) =
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resolve_default_method_vtables(bcx, impl_id,
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method, &substs, vtables);
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debug!("trans_fn_with_vtables - default method: \
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substs = {}, trait_subst = {}, \
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first_subst = {}, new_subst = {}, \
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vtables = {}, \
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self_vtable = {}, param_vtables = {}",
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substs.repr(tcx), trait_ref.substs.repr(tcx),
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first_subst.repr(tcx), new_substs.repr(tcx),
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vtables.repr(tcx),
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self_vtables.repr(tcx), param_vtables.repr(tcx));
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(true, source_id,
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new_substs, Some(self_vtables), Some(param_vtables))
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}
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};
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// Check whether this fn has an inlined copy and, if so, redirect
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// def_id to the local id of the inlined copy.
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let def_id = {
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if def_id.krate != ast::LOCAL_CRATE {
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inline::maybe_instantiate_inline(ccx, def_id)
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} else {
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def_id
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}
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};
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// We must monomorphise if the fn has type parameters, is a rust
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// intrinsic, or is a default method. In particular, if we see an
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// intrinsic that is inlined from a different crate, we want to reemit the
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// intrinsic instead of trying to call it in the other crate.
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let must_monomorphise = if type_params.len() > 0 || is_default {
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true
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} else if def_id.krate == ast::LOCAL_CRATE {
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let map_node = session::expect(
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ccx.sess,
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ccx.tcx.map.find(def_id.node),
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|| format!("local item should be in ast map"));
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match map_node {
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ast_map::NodeForeignItem(_) => {
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ccx.tcx.map.get_foreign_abis(def_id.node).is_intrinsic()
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}
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_ => false
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}
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} else {
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false
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};
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// Create a monomorphic verison of generic functions
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if must_monomorphise {
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// Should be either intra-crate or inlined.
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assert_eq!(def_id.krate, ast::LOCAL_CRATE);
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let ref_id = match node {
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ExprId(id) if id != 0 => Some(id),
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_ => None
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};
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let (val, must_cast) =
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monomorphize::monomorphic_fn(ccx, def_id, &substs,
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vtables, self_vtables,
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ref_id);
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let mut val = val;
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if must_cast && node != ExprId(0) {
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// Monotype of the REFERENCE to the function (type params
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// are subst'd)
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let ref_ty = match node {
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ExprId(id) => node_id_type(bcx, id),
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MethodCall(method_call) => {
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let t = bcx.ccx().maps.method_map.borrow().get().get(&method_call).ty;
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monomorphize_type(bcx, t)
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}
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};
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val = PointerCast(
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bcx, val, type_of::type_of_fn_from_ty(ccx, ref_ty).ptr_to());
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}
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return val;
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}
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// Find the actual function pointer.
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let mut val = {
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if def_id.krate == ast::LOCAL_CRATE {
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// Internal reference.
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get_item_val(ccx, def_id.node)
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} else {
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// External reference.
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trans_external_path(ccx, def_id, fn_tpt.ty)
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}
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};
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// This is subtle and surprising, but sometimes we have to bitcast
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// the resulting fn pointer. The reason has to do with external
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// functions. If you have two crates that both bind the same C
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// library, they may not use precisely the same types: for
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// example, they will probably each declare their own structs,
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// which are distinct types from LLVM's point of view (nominal
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// types).
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//
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// Now, if those two crates are linked into an application, and
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// they contain inlined code, you can wind up with a situation
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// where both of those functions wind up being loaded into this
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// application simultaneously. In that case, the same function
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// (from LLVM's point of view) requires two types. But of course
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// LLVM won't allow one function to have two types.
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//
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// What we currently do, therefore, is declare the function with
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// one of the two types (whichever happens to come first) and then
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// bitcast as needed when the function is referenced to make sure
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// it has the type we expect.
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//
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// This can occur on either a crate-local or crate-external
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// reference. It also occurs when testing libcore and in some
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// other weird situations. Annoying.
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let llty = type_of::type_of_fn_from_ty(ccx, fn_tpt.ty);
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let llptrty = llty.ptr_to();
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if val_ty(val) != llptrty {
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val = BitCast(bcx, val, llptrty);
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}
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val
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}
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// ______________________________________________________________________
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// Translating calls
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|
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pub fn trans_call<'a>(
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in_cx: &'a Block<'a>,
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call_ex: &ast::Expr,
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f: &ast::Expr,
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args: CallArgs,
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dest: expr::Dest)
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-> &'a Block<'a> {
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let _icx = push_ctxt("trans_call");
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trans_call_inner(in_cx,
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Some(common::expr_info(call_ex)),
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expr_ty(in_cx, f),
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|cx, _| trans(cx, f),
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args,
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Some(dest)).bcx
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}
|
|
|
|
pub fn trans_method_call<'a>(
|
|
bcx: &'a Block<'a>,
|
|
call_ex: &ast::Expr,
|
|
rcvr: &ast::Expr,
|
|
args: CallArgs,
|
|
dest: expr::Dest)
|
|
-> &'a Block<'a> {
|
|
let _icx = push_ctxt("trans_method_call");
|
|
debug!("trans_method_call(call_ex={})", call_ex.repr(bcx.tcx()));
|
|
let method_call = MethodCall::expr(call_ex.id);
|
|
let method_ty = bcx.ccx().maps.method_map.borrow().get().get(&method_call).ty;
|
|
trans_call_inner(
|
|
bcx,
|
|
Some(common::expr_info(call_ex)),
|
|
monomorphize_type(bcx, method_ty),
|
|
|cx, arg_cleanup_scope| {
|
|
meth::trans_method_callee(cx, method_call, Some(rcvr), arg_cleanup_scope)
|
|
},
|
|
args,
|
|
Some(dest)).bcx
|
|
}
|
|
|
|
pub fn trans_lang_call<'a>(
|
|
bcx: &'a Block<'a>,
|
|
did: ast::DefId,
|
|
args: &[ValueRef],
|
|
dest: Option<expr::Dest>)
|
|
-> Result<'a> {
|
|
let fty = if did.krate == ast::LOCAL_CRATE {
|
|
ty::node_id_to_type(bcx.ccx().tcx, did.node)
|
|
} else {
|
|
csearch::get_type(bcx.ccx().tcx, did).ty
|
|
};
|
|
callee::trans_call_inner(bcx,
|
|
None,
|
|
fty,
|
|
|bcx, _| {
|
|
trans_fn_ref_with_vtables_to_callee(bcx,
|
|
did,
|
|
0,
|
|
[],
|
|
None)
|
|
},
|
|
ArgVals(args),
|
|
dest)
|
|
}
|
|
|
|
pub fn trans_lang_call_with_type_params<'a>(
|
|
bcx: &'a Block<'a>,
|
|
did: ast::DefId,
|
|
args: &[ValueRef],
|
|
type_params: &[ty::t],
|
|
dest: expr::Dest)
|
|
-> &'a Block<'a> {
|
|
let fty;
|
|
if did.krate == ast::LOCAL_CRATE {
|
|
fty = ty::node_id_to_type(bcx.tcx(), did.node);
|
|
} else {
|
|
fty = csearch::get_type(bcx.tcx(), did).ty;
|
|
}
|
|
|
|
return callee::trans_call_inner(
|
|
bcx,
|
|
None,
|
|
fty,
|
|
|bcx, _| {
|
|
let callee =
|
|
trans_fn_ref_with_vtables_to_callee(bcx, did, 0,
|
|
type_params,
|
|
None);
|
|
|
|
let new_llval;
|
|
match callee.data {
|
|
Fn(llfn) => {
|
|
let substituted = ty::subst_tps(callee.bcx.tcx(),
|
|
type_params,
|
|
None,
|
|
fty);
|
|
let llfnty = type_of::type_of(callee.bcx.ccx(),
|
|
substituted);
|
|
new_llval = PointerCast(callee.bcx, llfn, llfnty);
|
|
}
|
|
_ => fail!()
|
|
}
|
|
Callee { bcx: callee.bcx, data: Fn(new_llval) }
|
|
},
|
|
ArgVals(args), Some(dest)).bcx;
|
|
}
|
|
|
|
pub fn trans_call_inner<'a>(
|
|
bcx: &'a Block<'a>,
|
|
call_info: Option<NodeInfo>,
|
|
callee_ty: ty::t,
|
|
get_callee: |bcx: &'a Block<'a>,
|
|
arg_cleanup_scope: cleanup::ScopeId|
|
|
-> Callee<'a>,
|
|
args: CallArgs,
|
|
dest: Option<expr::Dest>)
|
|
-> Result<'a> {
|
|
/*!
|
|
* This behemoth of a function translates function calls.
|
|
* Unfortunately, in order to generate more efficient LLVM
|
|
* output at -O0, it has quite a complex signature (refactoring
|
|
* this into two functions seems like a good idea).
|
|
*
|
|
* In particular, for lang items, it is invoked with a dest of
|
|
* None, and in that case the return value contains the result of
|
|
* the fn. The lang item must not return a structural type or else
|
|
* all heck breaks loose.
|
|
*
|
|
* For non-lang items, `dest` is always Some, and hence the result
|
|
* is written into memory somewhere. Nonetheless we return the
|
|
* actual return value of the function.
|
|
*/
|
|
|
|
// Introduce a temporary cleanup scope that will contain cleanups
|
|
// for the arguments while they are being evaluated. The purpose
|
|
// this cleanup is to ensure that, should a failure occur while
|
|
// evaluating argument N, the values for arguments 0...N-1 are all
|
|
// cleaned up. If no failure occurs, the values are handed off to
|
|
// the callee, and hence none of the cleanups in this temporary
|
|
// scope will ever execute.
|
|
let fcx = bcx.fcx;
|
|
let ccx = fcx.ccx;
|
|
let arg_cleanup_scope = fcx.push_custom_cleanup_scope();
|
|
|
|
let callee = get_callee(bcx, cleanup::CustomScope(arg_cleanup_scope));
|
|
let mut bcx = callee.bcx;
|
|
|
|
let (llfn, llenv, llself) = match callee.data {
|
|
Fn(llfn) => {
|
|
(llfn, None, None)
|
|
}
|
|
TraitMethod(d) => {
|
|
(d.llfn, None, Some(d.llself))
|
|
}
|
|
Closure(d) => {
|
|
// Closures are represented as (llfn, llclosure) pair:
|
|
// load the requisite values out.
|
|
let pair = d.to_llref();
|
|
let llfn = GEPi(bcx, pair, [0u, abi::fn_field_code]);
|
|
let llfn = Load(bcx, llfn);
|
|
let llenv = GEPi(bcx, pair, [0u, abi::fn_field_box]);
|
|
let llenv = Load(bcx, llenv);
|
|
(llfn, Some(llenv), None)
|
|
}
|
|
};
|
|
|
|
let (abi, ret_ty) = match ty::get(callee_ty).sty {
|
|
ty::ty_bare_fn(ref f) => (f.abis, f.sig.output),
|
|
ty::ty_closure(ref f) => (AbiSet::Rust(), f.sig.output),
|
|
_ => fail!("expected bare rust fn or closure in trans_call_inner")
|
|
};
|
|
let is_rust_fn =
|
|
abi.is_rust() ||
|
|
abi.is_intrinsic();
|
|
|
|
// Generate a location to store the result. If the user does
|
|
// not care about the result, just make a stack slot.
|
|
let opt_llretslot = match dest {
|
|
None => {
|
|
assert!(!type_of::return_uses_outptr(ccx, ret_ty));
|
|
None
|
|
}
|
|
Some(expr::SaveIn(dst)) => Some(dst),
|
|
Some(expr::Ignore) => {
|
|
if !type_is_zero_size(ccx, ret_ty) {
|
|
Some(alloc_ty(bcx, ret_ty, "__llret"))
|
|
} else {
|
|
let llty = type_of::type_of(ccx, ret_ty);
|
|
Some(C_undef(llty.ptr_to()))
|
|
}
|
|
}
|
|
};
|
|
|
|
let mut llresult = unsafe {
|
|
llvm::LLVMGetUndef(Type::nil().ptr_to().to_ref())
|
|
};
|
|
|
|
// The code below invokes the function, using either the Rust
|
|
// conventions (if it is a rust fn) or the native conventions
|
|
// (otherwise). The important part is that, when all is sad
|
|
// and done, either the return value of the function will have been
|
|
// written in opt_llretslot (if it is Some) or `llresult` will be
|
|
// set appropriately (otherwise).
|
|
if is_rust_fn {
|
|
let mut llargs = Vec::new();
|
|
|
|
// Push the out-pointer if we use an out-pointer for this
|
|
// return type, otherwise push "undef".
|
|
if type_of::return_uses_outptr(ccx, ret_ty) {
|
|
llargs.push(opt_llretslot.unwrap());
|
|
}
|
|
|
|
// Push the environment (or a trait object's self).
|
|
match (llenv, llself) {
|
|
(Some(llenv), None) => llargs.push(llenv),
|
|
(None, Some(llself)) => llargs.push(llself),
|
|
_ => {}
|
|
}
|
|
|
|
// Push the arguments.
|
|
bcx = trans_args(bcx, args, callee_ty, &mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope),
|
|
llself.is_some());
|
|
|
|
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
|
|
|
|
// A function pointer is called without the declaration
|
|
// available, so we have to apply any attributes with ABI
|
|
// implications directly to the call instruction. Right now,
|
|
// the only attribute we need to worry about is `sret`.
|
|
let mut attrs = Vec::new();
|
|
if type_of::return_uses_outptr(ccx, ret_ty) {
|
|
attrs.push((1, StructRetAttribute));
|
|
}
|
|
|
|
// The `noalias` attribute on the return value is useful to a
|
|
// function ptr caller.
|
|
match ty::get(ret_ty).sty {
|
|
// `~` pointer return values never alias because ownership
|
|
// is transferred
|
|
ty::ty_uniq(..) | ty::ty_vec(_, ty::vstore_uniq) => {
|
|
attrs.push((0, NoAliasAttribute));
|
|
}
|
|
_ => {}
|
|
}
|
|
|
|
// Invoke the actual rust fn and update bcx/llresult.
|
|
let (llret, b) = base::invoke(bcx,
|
|
llfn,
|
|
llargs,
|
|
attrs.as_slice(),
|
|
call_info);
|
|
bcx = b;
|
|
llresult = llret;
|
|
|
|
// If the Rust convention for this type is return via
|
|
// the return value, copy it into llretslot.
|
|
match opt_llretslot {
|
|
Some(llretslot) => {
|
|
if !type_of::return_uses_outptr(bcx.ccx(), ret_ty) &&
|
|
!type_is_zero_size(bcx.ccx(), ret_ty)
|
|
{
|
|
Store(bcx, llret, llretslot);
|
|
}
|
|
}
|
|
None => {}
|
|
}
|
|
} else {
|
|
// Lang items are the only case where dest is None, and
|
|
// they are always Rust fns.
|
|
assert!(dest.is_some());
|
|
|
|
let mut llargs = Vec::new();
|
|
let arg_tys = match args {
|
|
ArgExprs(a) => a.iter().map(|x| expr_ty(bcx, *x)).collect(),
|
|
_ => fail!("expected arg exprs.")
|
|
};
|
|
bcx = trans_args(bcx, args, callee_ty, &mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope), false);
|
|
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
|
|
bcx = foreign::trans_native_call(bcx, callee_ty,
|
|
llfn, opt_llretslot.unwrap(),
|
|
llargs.as_slice(), arg_tys);
|
|
}
|
|
|
|
// If the caller doesn't care about the result of this fn call,
|
|
// drop the temporary slot we made.
|
|
match dest {
|
|
None => {
|
|
assert!(!type_of::return_uses_outptr(bcx.ccx(), ret_ty));
|
|
}
|
|
Some(expr::Ignore) => {
|
|
// drop the value if it is not being saved.
|
|
bcx = glue::drop_ty(bcx, opt_llretslot.unwrap(), ret_ty);
|
|
}
|
|
Some(expr::SaveIn(_)) => { }
|
|
}
|
|
|
|
if ty::type_is_bot(ret_ty) {
|
|
Unreachable(bcx);
|
|
}
|
|
|
|
rslt(bcx, llresult)
|
|
}
|
|
|
|
pub enum CallArgs<'a> {
|
|
ArgExprs(&'a [@ast::Expr]),
|
|
ArgOverloadedOp(Datum<Expr>, Option<(Datum<Expr>, ast::NodeId)>),
|
|
ArgVals(&'a [ValueRef])
|
|
}
|
|
|
|
fn trans_args<'a>(cx: &'a Block<'a>,
|
|
args: CallArgs,
|
|
fn_ty: ty::t,
|
|
llargs: &mut Vec<ValueRef> ,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
ignore_self: bool)
|
|
-> &'a Block<'a> {
|
|
let _icx = push_ctxt("trans_args");
|
|
let arg_tys = ty::ty_fn_args(fn_ty);
|
|
let variadic = ty::fn_is_variadic(fn_ty);
|
|
|
|
let mut bcx = cx;
|
|
|
|
// First we figure out the caller's view of the types of the arguments.
|
|
// This will be needed if this is a generic call, because the callee has
|
|
// to cast her view of the arguments to the caller's view.
|
|
match args {
|
|
ArgExprs(arg_exprs) => {
|
|
let num_formal_args = arg_tys.len();
|
|
for (i, &arg_expr) in arg_exprs.iter().enumerate() {
|
|
if i == 0 && ignore_self {
|
|
continue;
|
|
}
|
|
let arg_ty = if i >= num_formal_args {
|
|
assert!(variadic);
|
|
expr_ty_adjusted(cx, arg_expr)
|
|
} else {
|
|
*arg_tys.get(i)
|
|
};
|
|
|
|
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, arg_expr));
|
|
llargs.push(unpack_result!(bcx, {
|
|
trans_arg_datum(bcx, arg_ty, arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg)
|
|
}));
|
|
}
|
|
}
|
|
ArgOverloadedOp(lhs, rhs) => {
|
|
assert!(!variadic);
|
|
|
|
llargs.push(unpack_result!(bcx, {
|
|
trans_arg_datum(bcx, *arg_tys.get(0), lhs,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg)
|
|
}));
|
|
|
|
match rhs {
|
|
Some((rhs, rhs_id)) => {
|
|
assert_eq!(arg_tys.len(), 2);
|
|
|
|
llargs.push(unpack_result!(bcx, {
|
|
trans_arg_datum(bcx, *arg_tys.get(1), rhs,
|
|
arg_cleanup_scope,
|
|
DoAutorefArg(rhs_id))
|
|
}));
|
|
}
|
|
None => assert_eq!(arg_tys.len(), 1)
|
|
}
|
|
}
|
|
ArgVals(vs) => {
|
|
llargs.push_all(vs);
|
|
}
|
|
}
|
|
|
|
bcx
|
|
}
|
|
|
|
pub enum AutorefArg {
|
|
DontAutorefArg,
|
|
DoAutorefArg(ast::NodeId)
|
|
}
|
|
|
|
pub fn trans_arg_datum<'a>(
|
|
bcx: &'a Block<'a>,
|
|
formal_arg_ty: ty::t,
|
|
arg_datum: Datum<Expr>,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
autoref_arg: AutorefArg)
|
|
-> Result<'a> {
|
|
let _icx = push_ctxt("trans_arg_datum");
|
|
let mut bcx = bcx;
|
|
let ccx = bcx.ccx();
|
|
|
|
debug!("trans_arg_datum({})",
|
|
formal_arg_ty.repr(bcx.tcx()));
|
|
|
|
let arg_datum_ty = arg_datum.ty;
|
|
|
|
debug!(" arg datum: {}", arg_datum.to_str(bcx.ccx()));
|
|
|
|
let mut val;
|
|
if ty::type_is_bot(arg_datum_ty) {
|
|
// For values of type _|_, we generate an
|
|
// "undef" value, as such a value should never
|
|
// be inspected. It's important for the value
|
|
// to have type lldestty (the callee's expected type).
|
|
let llformal_arg_ty = type_of::type_of(ccx, formal_arg_ty);
|
|
unsafe {
|
|
val = llvm::LLVMGetUndef(llformal_arg_ty.to_ref());
|
|
}
|
|
} else {
|
|
// FIXME(#3548) use the adjustments table
|
|
match autoref_arg {
|
|
DoAutorefArg(arg_id) => {
|
|
// We will pass argument by reference
|
|
// We want an lvalue, so that we can pass by reference and
|
|
let arg_datum = unpack_datum!(
|
|
bcx, arg_datum.to_lvalue_datum(bcx, "arg", arg_id));
|
|
val = arg_datum.val;
|
|
}
|
|
DontAutorefArg => {
|
|
// Make this an rvalue, since we are going to be
|
|
// passing ownership.
|
|
let arg_datum = unpack_datum!(
|
|
bcx, arg_datum.to_rvalue_datum(bcx, "arg"));
|
|
|
|
// Now that arg_datum is owned, get it into the appropriate
|
|
// mode (ref vs value).
|
|
let arg_datum = unpack_datum!(
|
|
bcx, arg_datum.to_appropriate_datum(bcx));
|
|
|
|
// Technically, ownership of val passes to the callee.
|
|
// However, we must cleanup should we fail before the
|
|
// callee is actually invoked.
|
|
val = arg_datum.add_clean(bcx.fcx, arg_cleanup_scope);
|
|
}
|
|
}
|
|
|
|
if formal_arg_ty != arg_datum_ty {
|
|
// this could happen due to e.g. subtyping
|
|
let llformal_arg_ty = type_of::type_of_explicit_arg(ccx, formal_arg_ty);
|
|
debug!("casting actual type ({}) to match formal ({})",
|
|
bcx.val_to_str(val), bcx.llty_str(llformal_arg_ty));
|
|
val = PointerCast(bcx, val, llformal_arg_ty);
|
|
}
|
|
}
|
|
|
|
debug!("--- trans_arg_datum passing {}", bcx.val_to_str(val));
|
|
rslt(bcx, val)
|
|
}
|