1096 lines
41 KiB
Rust
1096 lines
41 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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//! 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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pub use self::AutorefArg::*;
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pub use self::CalleeData::*;
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pub use self::CallArgs::*;
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use arena::TypedArena;
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use back::link;
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use session;
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use llvm::{self, ValueRef, get_params};
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use middle::cstore::LOCAL_CRATE;
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use middle::def;
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use middle::def_id::DefId;
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use middle::infer;
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use middle::subst;
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use middle::subst::{Substs};
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use rustc::front::map as hir_map;
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use trans::adt;
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use trans::base;
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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::common::{self, Block, Result, NodeIdAndSpan, ExprId, CrateContext,
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ExprOrMethodCall, FunctionContext, MethodCallKey};
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use trans::consts;
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use trans::datum::*;
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use trans::debuginfo::{DebugLoc, ToDebugLoc};
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use trans::declare;
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use trans::expr;
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use trans::glue;
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use trans::inline;
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use trans::foreign;
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use trans::intrinsic;
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use trans::meth;
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use trans::monomorphize;
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use trans::type_::Type;
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use trans::type_of;
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use middle::ty::{self, Ty, HasTypeFlags, RegionEscape};
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use middle::ty::MethodCall;
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use rustc_front::hir;
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use syntax::abi as synabi;
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use syntax::ast;
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use syntax::ptr::P;
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#[derive(Copy, Clone)]
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pub struct MethodData {
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pub llfn: ValueRef,
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pub llself: ValueRef,
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}
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pub enum CalleeData<'tcx> {
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// Constructor for enum variant/tuple-like-struct
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// i.e. Some, Ok
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NamedTupleConstructor(ty::Disr),
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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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Intrinsic(ast::NodeId, subst::Substs<'tcx>),
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TraitItem(MethodData)
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}
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pub struct Callee<'blk, 'tcx: 'blk> {
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pub bcx: Block<'blk, 'tcx>,
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pub data: CalleeData<'tcx>,
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pub ty: Ty<'tcx>
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}
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fn trans<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, expr: &hir::Expr)
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-> Callee<'blk, 'tcx> {
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let _icx = push_ctxt("trans_callee");
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debug!("callee::trans(expr={:?})", expr);
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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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hir::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<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, expr: &hir::Expr)
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-> Callee<'blk, 'tcx> {
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let DatumBlock { bcx, datum, .. } = expr::trans(bcx, expr);
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match datum.ty.sty {
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ty::TyBareFn(..) => {
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Callee {
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bcx: bcx,
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ty: datum.ty,
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data: Fn(datum.to_llscalarish(bcx))
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}
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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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datum.ty));
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}
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}
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}
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fn fn_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, datum: Datum<'tcx, Rvalue>)
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-> Callee<'blk, 'tcx> {
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Callee {
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bcx: bcx,
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data: Fn(datum.val),
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ty: datum.ty
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}
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}
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fn trans_def<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
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def: def::Def,
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ref_expr: &hir::Expr)
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-> Callee<'blk, 'tcx> {
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debug!("trans_def(def={:?}, ref_expr={:?})", def, ref_expr);
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let expr_ty = common::node_id_type(bcx, ref_expr.id);
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match def {
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def::DefFn(did, _) if {
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let maybe_def_id = inline::get_local_instance(bcx.ccx(), did);
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let maybe_ast_node = maybe_def_id.and_then(|def_id| {
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let node_id = bcx.tcx().map.as_local_node_id(def_id).unwrap();
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bcx.tcx().map.find(node_id)
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});
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match maybe_ast_node {
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Some(hir_map::NodeStructCtor(_)) => true,
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_ => false
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}
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} => {
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Callee {
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bcx: bcx,
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data: NamedTupleConstructor(0),
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ty: expr_ty
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}
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}
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def::DefFn(did, _) if match expr_ty.sty {
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ty::TyBareFn(_, ref f) => f.abi == synabi::RustIntrinsic ||
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f.abi == synabi::PlatformIntrinsic,
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_ => false
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} => {
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let substs = common::node_id_substs(bcx.ccx(),
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ExprId(ref_expr.id),
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bcx.fcx.param_substs);
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let def_id = inline::maybe_instantiate_inline(bcx.ccx(), did);
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let node_id = bcx.tcx().map.as_local_node_id(def_id).unwrap();
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Callee { bcx: bcx, data: Intrinsic(node_id, substs), ty: expr_ty }
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}
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def::DefFn(did, _) => {
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fn_callee(bcx, trans_fn_ref(bcx.ccx(), did, ExprId(ref_expr.id),
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bcx.fcx.param_substs))
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}
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def::DefMethod(meth_did) => {
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let method_item = bcx.tcx().impl_or_trait_item(meth_did);
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let fn_datum = match method_item.container() {
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ty::ImplContainer(_) => {
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trans_fn_ref(bcx.ccx(), meth_did,
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ExprId(ref_expr.id),
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bcx.fcx.param_substs)
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}
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ty::TraitContainer(trait_did) => {
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meth::trans_static_method_callee(bcx.ccx(),
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meth_did,
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trait_did,
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ref_expr.id,
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bcx.fcx.param_substs)
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}
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};
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fn_callee(bcx, fn_datum)
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}
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def::DefVariant(tid, vid, _) => {
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let vinfo = bcx.tcx().lookup_adt_def(tid).variant_with_id(vid);
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assert_eq!(vinfo.kind(), ty::VariantKind::Tuple);
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Callee {
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bcx: bcx,
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data: NamedTupleConstructor(vinfo.disr_val),
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ty: expr_ty
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}
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}
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def::DefStruct(_) => {
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Callee {
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bcx: bcx,
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data: NamedTupleConstructor(0),
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ty: expr_ty
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}
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}
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def::DefStatic(..) |
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def::DefConst(..) |
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def::DefAssociatedConst(..) |
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def::DefLocal(..) |
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def::DefUpvar(..) => {
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datum_callee(bcx, ref_expr)
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}
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def::DefMod(..) | def::DefForeignMod(..) | def::DefTrait(..) |
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def::DefTy(..) | def::DefPrimTy(..) | def::DefAssociatedTy(..) |
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def::DefLabel(..) | def::DefTyParam(..) |
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def::DefSelfTy(..) | def::DefErr => {
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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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/// Translates a reference (with id `ref_id`) to the fn/method with id `def_id` into a function
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/// pointer. This may require monomorphization or inlining.
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pub fn trans_fn_ref<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
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def_id: DefId,
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node: ExprOrMethodCall,
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param_substs: &'tcx subst::Substs<'tcx>)
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-> Datum<'tcx, Rvalue> {
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let _icx = push_ctxt("trans_fn_ref");
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let substs = common::node_id_substs(ccx, node, param_substs);
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debug!("trans_fn_ref(def_id={:?}, node={:?}, substs={:?})",
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def_id,
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node,
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substs);
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trans_fn_ref_with_substs(ccx, def_id, node, param_substs, substs)
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}
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/// Translates an adapter that implements the `Fn` trait for a fn
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/// pointer. This is basically the equivalent of something like:
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///
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/// ```
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/// impl<'a> Fn(&'a int) -> &'a int for fn(&int) -> &int {
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/// extern "rust-abi" fn call(&self, args: (&'a int,)) -> &'a int {
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/// (*self)(args.0)
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/// }
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/// }
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/// ```
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///
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/// but for the bare function type given.
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pub fn trans_fn_pointer_shim<'a, 'tcx>(
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ccx: &'a CrateContext<'a, 'tcx>,
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closure_kind: ty::ClosureKind,
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bare_fn_ty: Ty<'tcx>)
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-> ValueRef
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{
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let _icx = push_ctxt("trans_fn_pointer_shim");
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let tcx = ccx.tcx();
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// Normalize the type for better caching.
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let bare_fn_ty = tcx.erase_regions(&bare_fn_ty);
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// If this is an impl of `Fn` or `FnMut` trait, the receiver is `&self`.
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let is_by_ref = match closure_kind {
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ty::FnClosureKind | ty::FnMutClosureKind => true,
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ty::FnOnceClosureKind => false,
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};
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let bare_fn_ty_maybe_ref = if is_by_ref {
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tcx.mk_imm_ref(tcx.mk_region(ty::ReStatic), bare_fn_ty)
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} else {
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bare_fn_ty
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};
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// Check if we already trans'd this shim.
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match ccx.fn_pointer_shims().borrow().get(&bare_fn_ty_maybe_ref) {
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Some(&llval) => { return llval; }
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None => { }
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}
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debug!("trans_fn_pointer_shim(bare_fn_ty={:?})",
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bare_fn_ty);
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// Construct the "tuply" version of `bare_fn_ty`. It takes two arguments: `self`,
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// which is the fn pointer, and `args`, which is the arguments tuple.
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let (opt_def_id, sig) =
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match bare_fn_ty.sty {
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ty::TyBareFn(opt_def_id,
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&ty::BareFnTy { unsafety: hir::Unsafety::Normal,
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abi: synabi::Rust,
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ref sig }) => {
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(opt_def_id, sig)
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}
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_ => {
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tcx.sess.bug(&format!("trans_fn_pointer_shim invoked on invalid type: {}",
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bare_fn_ty));
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}
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};
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let sig = tcx.erase_late_bound_regions(sig);
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let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
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let tuple_input_ty = tcx.mk_tup(sig.inputs.to_vec());
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let tuple_fn_ty = tcx.mk_fn(opt_def_id,
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tcx.mk_bare_fn(ty::BareFnTy {
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unsafety: hir::Unsafety::Normal,
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abi: synabi::RustCall,
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sig: ty::Binder(ty::FnSig {
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inputs: vec![bare_fn_ty_maybe_ref,
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tuple_input_ty],
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output: sig.output,
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variadic: false
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})}));
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debug!("tuple_fn_ty: {:?}", tuple_fn_ty);
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//
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let function_name = link::mangle_internal_name_by_type_and_seq(ccx, bare_fn_ty,
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"fn_pointer_shim");
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let llfn = declare::declare_internal_rust_fn(ccx, &function_name[..], tuple_fn_ty);
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//
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let empty_substs = tcx.mk_substs(Substs::trans_empty());
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let (block_arena, fcx): (TypedArena<_>, FunctionContext);
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block_arena = TypedArena::new();
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fcx = new_fn_ctxt(ccx,
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llfn,
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ast::DUMMY_NODE_ID,
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false,
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sig.output,
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empty_substs,
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None,
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&block_arena);
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let mut bcx = init_function(&fcx, false, sig.output);
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let llargs = get_params(fcx.llfn);
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let self_idx = fcx.arg_offset();
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// the first argument (`self`) will be ptr to the fn pointer
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let llfnpointer = if is_by_ref {
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Load(bcx, llargs[self_idx])
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} else {
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llargs[self_idx]
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};
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assert!(!fcx.needs_ret_allocas);
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let dest = fcx.llretslotptr.get().map(|_|
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expr::SaveIn(fcx.get_ret_slot(bcx, sig.output, "ret_slot"))
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);
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bcx = trans_call_inner(bcx, DebugLoc::None, |bcx, _| {
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Callee {
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bcx: bcx,
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data: Fn(llfnpointer),
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ty: bare_fn_ty
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}
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}, ArgVals(&llargs[(self_idx + 1)..]), dest).bcx;
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finish_fn(&fcx, bcx, sig.output, DebugLoc::None);
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ccx.fn_pointer_shims().borrow_mut().insert(bare_fn_ty_maybe_ref, llfn);
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llfn
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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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/// - `ccx`: the crate context
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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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/// - `param_substs`: if the `node` is in a polymorphic function, these
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/// are the substitutions required to monomorphize its type
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/// - `substs`: values for each of the fn/method's parameters
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pub fn trans_fn_ref_with_substs<'a, 'tcx>(
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ccx: &CrateContext<'a, 'tcx>,
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def_id: DefId,
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node: ExprOrMethodCall,
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param_substs: &'tcx subst::Substs<'tcx>,
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substs: subst::Substs<'tcx>)
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-> Datum<'tcx, Rvalue>
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{
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let _icx = push_ctxt("trans_fn_ref_with_substs");
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let tcx = ccx.tcx();
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debug!("trans_fn_ref_with_substs(def_id={:?}, node={:?}, \
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param_substs={:?}, substs={:?})",
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def_id,
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node,
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param_substs,
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substs);
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assert!(!substs.types.needs_infer());
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assert!(!substs.types.has_escaping_regions());
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let substs = substs.erase_regions();
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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 = inline::maybe_instantiate_inline(ccx, def_id);
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fn is_named_tuple_constructor(tcx: &ty::ctxt, def_id: DefId) -> bool {
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let node_id = match tcx.map.as_local_node_id(def_id) {
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Some(n) => n,
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None => { return false; }
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};
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let map_node = session::expect(
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&tcx.sess,
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tcx.map.find(node_id),
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|| "local item should be in ast map".to_string());
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match map_node {
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hir_map::NodeVariant(v) => {
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v.node.data.is_tuple()
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}
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hir_map::NodeStructCtor(_) => true,
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_ => false
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}
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}
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let must_monomorphise =
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!substs.types.is_empty() || is_named_tuple_constructor(tcx, def_id);
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debug!("trans_fn_ref_with_substs({:?}) must_monomorphise: {}",
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def_id, must_monomorphise);
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// Create a monomorphic version 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, LOCAL_CRATE);
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let opt_ref_id = match node {
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ExprId(id) => if id != 0 { Some(id) } else { None },
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MethodCallKey(_) => None,
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};
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let substs = tcx.mk_substs(substs);
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let (val, fn_ty, must_cast) =
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monomorphize::monomorphic_fn(ccx, def_id, substs, opt_ref_id);
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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) => tcx.node_id_to_type(id),
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MethodCallKey(method_call) => {
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tcx.tables.borrow().method_map[&method_call].ty
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}
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};
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let ref_ty = monomorphize::apply_param_substs(tcx,
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param_substs,
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&ref_ty);
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let llptrty = type_of::type_of_fn_from_ty(ccx, ref_ty).ptr_to();
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if llptrty != common::val_ty(val) {
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let val = consts::ptrcast(val, llptrty);
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return Datum::new(val, ref_ty, Rvalue::new(ByValue));
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}
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}
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return Datum::new(val, fn_ty, Rvalue::new(ByValue));
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}
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// Type scheme of the function item (may have type params)
|
|
let fn_type_scheme = tcx.lookup_item_type(def_id);
|
|
let fn_type = infer::normalize_associated_type(tcx, &fn_type_scheme.ty);
|
|
|
|
// Find the actual function pointer.
|
|
let mut val = {
|
|
if let Some(node_id) = ccx.tcx().map.as_local_node_id(def_id) {
|
|
// Internal reference.
|
|
get_item_val(ccx, node_id)
|
|
} else {
|
|
// External reference.
|
|
trans_external_path(ccx, def_id, fn_type)
|
|
}
|
|
};
|
|
|
|
// This is subtle and surprising, but sometimes we have to bitcast
|
|
// the resulting fn pointer. The reason has to do with external
|
|
// functions. If you have two crates that both bind the same C
|
|
// library, they may not use precisely the same types: for
|
|
// example, they will probably each declare their own structs,
|
|
// which are distinct types from LLVM's point of view (nominal
|
|
// types).
|
|
//
|
|
// Now, if those two crates are linked into an application, and
|
|
// they contain inlined code, you can wind up with a situation
|
|
// where both of those functions wind up being loaded into this
|
|
// application simultaneously. In that case, the same function
|
|
// (from LLVM's point of view) requires two types. But of course
|
|
// LLVM won't allow one function to have two types.
|
|
//
|
|
// What we currently do, therefore, is declare the function with
|
|
// one of the two types (whichever happens to come first) and then
|
|
// bitcast as needed when the function is referenced to make sure
|
|
// it has the type we expect.
|
|
//
|
|
// This can occur on either a crate-local or crate-external
|
|
// reference. It also occurs when testing libcore and in some
|
|
// other weird situations. Annoying.
|
|
let llty = type_of::type_of_fn_from_ty(ccx, fn_type);
|
|
let llptrty = llty.ptr_to();
|
|
if common::val_ty(val) != llptrty {
|
|
debug!("trans_fn_ref_with_substs(): casting pointer!");
|
|
val = consts::ptrcast(val, llptrty);
|
|
} else {
|
|
debug!("trans_fn_ref_with_substs(): not casting pointer!");
|
|
}
|
|
|
|
Datum::new(val, fn_type, Rvalue::new(ByValue))
|
|
}
|
|
|
|
// ______________________________________________________________________
|
|
// Translating calls
|
|
|
|
pub fn trans_call<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
|
|
call_expr: &hir::Expr,
|
|
f: &hir::Expr,
|
|
args: CallArgs<'a, 'tcx>,
|
|
dest: expr::Dest)
|
|
-> Block<'blk, 'tcx> {
|
|
let _icx = push_ctxt("trans_call");
|
|
trans_call_inner(bcx,
|
|
call_expr.debug_loc(),
|
|
|bcx, _| trans(bcx, f),
|
|
args,
|
|
Some(dest)).bcx
|
|
}
|
|
|
|
pub fn trans_method_call<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
|
|
call_expr: &hir::Expr,
|
|
rcvr: &hir::Expr,
|
|
args: CallArgs<'a, 'tcx>,
|
|
dest: expr::Dest)
|
|
-> Block<'blk, 'tcx> {
|
|
let _icx = push_ctxt("trans_method_call");
|
|
debug!("trans_method_call(call_expr={:?})", call_expr);
|
|
let method_call = MethodCall::expr(call_expr.id);
|
|
trans_call_inner(
|
|
bcx,
|
|
call_expr.debug_loc(),
|
|
|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<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
|
|
did: DefId,
|
|
args: &[ValueRef],
|
|
dest: Option<expr::Dest>,
|
|
debug_loc: DebugLoc)
|
|
-> Result<'blk, 'tcx> {
|
|
callee::trans_call_inner(bcx, debug_loc, |bcx, _| {
|
|
let datum = trans_fn_ref_with_substs(bcx.ccx(),
|
|
did,
|
|
ExprId(0),
|
|
bcx.fcx.param_substs,
|
|
subst::Substs::trans_empty());
|
|
Callee {
|
|
bcx: bcx,
|
|
data: Fn(datum.val),
|
|
ty: datum.ty
|
|
}
|
|
}, ArgVals(args), dest)
|
|
}
|
|
|
|
/// 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.
|
|
pub fn trans_call_inner<'a, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
|
|
debug_loc: DebugLoc,
|
|
get_callee: F,
|
|
args: CallArgs<'a, 'tcx>,
|
|
dest: Option<expr::Dest>)
|
|
-> Result<'blk, 'tcx> where
|
|
F: FnOnce(Block<'blk, 'tcx>, cleanup::ScopeId) -> Callee<'blk, 'tcx>,
|
|
{
|
|
// 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 panic occur while
|
|
// evaluating argument N, the values for arguments 0...N-1 are all
|
|
// cleaned up. If no panic 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 (abi, ret_ty) = match callee.ty.sty {
|
|
ty::TyBareFn(_, ref f) => {
|
|
let sig = bcx.tcx().erase_late_bound_regions(&f.sig);
|
|
let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
|
|
(f.abi, sig.output)
|
|
}
|
|
_ => panic!("expected bare rust fn or closure in trans_call_inner")
|
|
};
|
|
|
|
let (llfn, llself) = match callee.data {
|
|
Fn(llfn) => {
|
|
(llfn, None)
|
|
}
|
|
TraitItem(d) => {
|
|
(d.llfn, Some(d.llself))
|
|
}
|
|
Intrinsic(node, substs) => {
|
|
assert!(abi == synabi::RustIntrinsic || abi == synabi::PlatformIntrinsic);
|
|
assert!(dest.is_some());
|
|
|
|
let call_info = match debug_loc {
|
|
DebugLoc::At(id, span) => NodeIdAndSpan { id: id, span: span },
|
|
DebugLoc::None => {
|
|
bcx.sess().bug("No call info for intrinsic call?")
|
|
}
|
|
};
|
|
|
|
return intrinsic::trans_intrinsic_call(bcx, node, callee.ty,
|
|
arg_cleanup_scope, args,
|
|
dest.unwrap(), substs,
|
|
call_info);
|
|
}
|
|
NamedTupleConstructor(disr) => {
|
|
assert!(dest.is_some());
|
|
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
|
|
|
|
return base::trans_named_tuple_constructor(bcx,
|
|
callee.ty,
|
|
disr,
|
|
args,
|
|
dest.unwrap(),
|
|
debug_loc);
|
|
}
|
|
};
|
|
|
|
// Intrinsics should not become actual functions.
|
|
// We trans them in place in `trans_intrinsic_call`
|
|
assert!(abi != synabi::RustIntrinsic && abi != synabi::PlatformIntrinsic);
|
|
|
|
let is_rust_fn = abi == synabi::Rust || abi == synabi::RustCall;
|
|
|
|
// Generate a location to store the result. If the user does
|
|
// not care about the result, just make a stack slot.
|
|
let opt_llretslot = dest.and_then(|dest| match dest {
|
|
expr::SaveIn(dst) => Some(dst),
|
|
expr::Ignore => {
|
|
let ret_ty = match ret_ty {
|
|
ty::FnConverging(ret_ty) => ret_ty,
|
|
ty::FnDiverging => ccx.tcx().mk_nil()
|
|
};
|
|
if !is_rust_fn ||
|
|
type_of::return_uses_outptr(ccx, ret_ty) ||
|
|
bcx.fcx.type_needs_drop(ret_ty) {
|
|
// Push the out-pointer if we use an out-pointer for this
|
|
// return type, otherwise push "undef".
|
|
if common::type_is_zero_size(ccx, ret_ty) {
|
|
let llty = type_of::type_of(ccx, ret_ty);
|
|
Some(common::C_undef(llty.ptr_to()))
|
|
} else {
|
|
let llresult = alloc_ty(bcx, ret_ty, "__llret");
|
|
call_lifetime_start(bcx, llresult);
|
|
Some(llresult)
|
|
}
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
});
|
|
|
|
let mut llresult = unsafe {
|
|
llvm::LLVMGetUndef(Type::nil(ccx).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 said
|
|
// 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();
|
|
|
|
if let (ty::FnConverging(ret_ty), Some(mut llretslot)) = (ret_ty, opt_llretslot) {
|
|
if type_of::return_uses_outptr(ccx, ret_ty) {
|
|
let llformal_ret_ty = type_of::type_of(ccx, ret_ty).ptr_to();
|
|
let llret_ty = common::val_ty(llretslot);
|
|
if llformal_ret_ty != llret_ty {
|
|
// this could happen due to e.g. subtyping
|
|
debug!("casting actual return type ({}) to match formal ({})",
|
|
bcx.llty_str(llret_ty), bcx.llty_str(llformal_ret_ty));
|
|
llretslot = PointerCast(bcx, llretslot, llformal_ret_ty);
|
|
}
|
|
llargs.push(llretslot);
|
|
}
|
|
}
|
|
|
|
// Push a trait object's self.
|
|
if let Some(llself) = llself {
|
|
llargs.push(llself);
|
|
}
|
|
|
|
// Push the arguments.
|
|
bcx = trans_args(bcx,
|
|
args,
|
|
callee.ty,
|
|
&mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope),
|
|
llself.is_some(),
|
|
abi);
|
|
|
|
fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
|
|
|
|
// Invoke the actual rust fn and update bcx/llresult.
|
|
let (llret, b) = base::invoke(bcx,
|
|
llfn,
|
|
&llargs[..],
|
|
callee.ty,
|
|
debug_loc);
|
|
bcx = b;
|
|
llresult = llret;
|
|
|
|
// If the Rust convention for this type is return via
|
|
// the return value, copy it into llretslot.
|
|
match (opt_llretslot, ret_ty) {
|
|
(Some(llretslot), ty::FnConverging(ret_ty)) => {
|
|
if !type_of::return_uses_outptr(bcx.ccx(), ret_ty) &&
|
|
!common::type_is_zero_size(bcx.ccx(), ret_ty)
|
|
{
|
|
store_ty(bcx, llret, llretslot, ret_ty)
|
|
}
|
|
}
|
|
(_, _) => {}
|
|
}
|
|
} 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| common::expr_ty_adjusted(bcx, &**x)).collect(),
|
|
_ => panic!("expected arg exprs.")
|
|
};
|
|
bcx = trans_args(bcx,
|
|
args,
|
|
callee.ty,
|
|
&mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope),
|
|
false,
|
|
abi);
|
|
fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
|
|
|
|
bcx = foreign::trans_native_call(bcx,
|
|
callee.ty,
|
|
llfn,
|
|
opt_llretslot.unwrap(),
|
|
&llargs[..],
|
|
arg_tys,
|
|
debug_loc);
|
|
}
|
|
|
|
fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_cleanup_scope);
|
|
|
|
// If the caller doesn't care about the result of this fn call,
|
|
// drop the temporary slot we made.
|
|
match (dest, opt_llretslot, ret_ty) {
|
|
(Some(expr::Ignore), Some(llretslot), ty::FnConverging(ret_ty)) => {
|
|
// drop the value if it is not being saved.
|
|
bcx = glue::drop_ty(bcx,
|
|
llretslot,
|
|
ret_ty,
|
|
debug_loc);
|
|
call_lifetime_end(bcx, llretslot);
|
|
}
|
|
_ => {}
|
|
}
|
|
|
|
if ret_ty == ty::FnDiverging {
|
|
Unreachable(bcx);
|
|
}
|
|
|
|
Result::new(bcx, llresult)
|
|
}
|
|
|
|
pub enum CallArgs<'a, 'tcx> {
|
|
// Supply value of arguments as a list of expressions that must be
|
|
// translated. This is used in the common case of `foo(bar, qux)`.
|
|
ArgExprs(&'a [P<hir::Expr>]),
|
|
|
|
// Supply value of arguments as a list of LLVM value refs; frequently
|
|
// used with lang items and so forth, when the argument is an internal
|
|
// value.
|
|
ArgVals(&'a [ValueRef]),
|
|
|
|
// For overloaded operators: `(lhs, Option(rhs, rhs_id), autoref)`. `lhs`
|
|
// is the left-hand-side and `rhs/rhs_id` is the datum/expr-id of
|
|
// the right-hand-side argument (if any). `autoref` indicates whether the `rhs`
|
|
// arguments should be auto-referenced
|
|
ArgOverloadedOp(Datum<'tcx, Expr>, Option<(Datum<'tcx, Expr>, ast::NodeId)>, bool),
|
|
|
|
// Supply value of arguments as a list of expressions that must be
|
|
// translated, for overloaded call operators.
|
|
ArgOverloadedCall(Vec<&'a hir::Expr>),
|
|
}
|
|
|
|
fn trans_args_under_call_abi<'blk, 'tcx>(
|
|
mut bcx: Block<'blk, 'tcx>,
|
|
arg_exprs: &[P<hir::Expr>],
|
|
fn_ty: Ty<'tcx>,
|
|
llargs: &mut Vec<ValueRef>,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
ignore_self: bool)
|
|
-> Block<'blk, 'tcx>
|
|
{
|
|
let sig = bcx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
|
|
let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
|
|
let args = sig.inputs;
|
|
|
|
// Translate the `self` argument first.
|
|
if !ignore_self {
|
|
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &*arg_exprs[0]));
|
|
bcx = trans_arg_datum(bcx,
|
|
args[0],
|
|
arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
}
|
|
|
|
// Now untuple the rest of the arguments.
|
|
let tuple_expr = &arg_exprs[1];
|
|
let tuple_type = common::node_id_type(bcx, tuple_expr.id);
|
|
|
|
match tuple_type.sty {
|
|
ty::TyTuple(ref field_types) => {
|
|
let tuple_datum = unpack_datum!(bcx,
|
|
expr::trans(bcx, &**tuple_expr));
|
|
let tuple_lvalue_datum =
|
|
unpack_datum!(bcx,
|
|
tuple_datum.to_lvalue_datum(bcx,
|
|
"args",
|
|
tuple_expr.id));
|
|
let repr = adt::represent_type(bcx.ccx(), tuple_type);
|
|
let repr_ptr = &*repr;
|
|
for (i, field_type) in field_types.iter().enumerate() {
|
|
let arg_datum = tuple_lvalue_datum.get_element(
|
|
bcx,
|
|
field_type,
|
|
|srcval| {
|
|
adt::trans_field_ptr(bcx, repr_ptr, srcval, 0, i)
|
|
}).to_expr_datum();
|
|
bcx = trans_arg_datum(bcx,
|
|
field_type,
|
|
arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
}
|
|
}
|
|
_ => {
|
|
bcx.sess().span_bug(tuple_expr.span,
|
|
"argument to `.call()` wasn't a tuple?!")
|
|
}
|
|
};
|
|
|
|
bcx
|
|
}
|
|
|
|
fn trans_overloaded_call_args<'blk, 'tcx>(
|
|
mut bcx: Block<'blk, 'tcx>,
|
|
arg_exprs: Vec<&hir::Expr>,
|
|
fn_ty: Ty<'tcx>,
|
|
llargs: &mut Vec<ValueRef>,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
ignore_self: bool)
|
|
-> Block<'blk, 'tcx> {
|
|
// Translate the `self` argument first.
|
|
let sig = bcx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
|
|
let sig = infer::normalize_associated_type(bcx.tcx(), &sig);
|
|
let arg_tys = sig.inputs;
|
|
|
|
if !ignore_self {
|
|
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, arg_exprs[0]));
|
|
bcx = trans_arg_datum(bcx,
|
|
arg_tys[0],
|
|
arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
}
|
|
|
|
// Now untuple the rest of the arguments.
|
|
let tuple_type = arg_tys[1];
|
|
match tuple_type.sty {
|
|
ty::TyTuple(ref field_types) => {
|
|
for (i, &field_type) in field_types.iter().enumerate() {
|
|
let arg_datum =
|
|
unpack_datum!(bcx, expr::trans(bcx, arg_exprs[i + 1]));
|
|
bcx = trans_arg_datum(bcx,
|
|
field_type,
|
|
arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
}
|
|
}
|
|
_ => {
|
|
bcx.sess().span_bug(arg_exprs[0].span,
|
|
"argument to `.call()` wasn't a tuple?!")
|
|
}
|
|
};
|
|
|
|
bcx
|
|
}
|
|
|
|
pub fn trans_args<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
|
|
args: CallArgs<'a, 'tcx>,
|
|
fn_ty: Ty<'tcx>,
|
|
llargs: &mut Vec<ValueRef>,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
ignore_self: bool,
|
|
abi: synabi::Abi)
|
|
-> Block<'blk, 'tcx> {
|
|
debug!("trans_args(abi={})", abi);
|
|
|
|
let _icx = push_ctxt("trans_args");
|
|
let sig = cx.tcx().erase_late_bound_regions(&fn_ty.fn_sig());
|
|
let sig = infer::normalize_associated_type(cx.tcx(), &sig);
|
|
let arg_tys = sig.inputs;
|
|
let variadic = sig.variadic;
|
|
|
|
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) => {
|
|
if abi == synabi::RustCall {
|
|
// This is only used for direct calls to the `call`,
|
|
// `call_mut` or `call_once` functions.
|
|
return trans_args_under_call_abi(cx,
|
|
arg_exprs,
|
|
fn_ty,
|
|
llargs,
|
|
arg_cleanup_scope,
|
|
ignore_self)
|
|
}
|
|
|
|
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);
|
|
common::expr_ty_adjusted(cx, &**arg_expr)
|
|
} else {
|
|
arg_tys[i]
|
|
};
|
|
|
|
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &**arg_expr));
|
|
bcx = trans_arg_datum(bcx, arg_ty, arg_datum,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
}
|
|
}
|
|
ArgOverloadedCall(arg_exprs) => {
|
|
return trans_overloaded_call_args(cx,
|
|
arg_exprs,
|
|
fn_ty,
|
|
llargs,
|
|
arg_cleanup_scope,
|
|
ignore_self)
|
|
}
|
|
ArgOverloadedOp(lhs, rhs, autoref) => {
|
|
assert!(!variadic);
|
|
|
|
bcx = trans_arg_datum(bcx, arg_tys[0], lhs,
|
|
arg_cleanup_scope,
|
|
DontAutorefArg,
|
|
llargs);
|
|
|
|
if let Some((rhs, rhs_id)) = rhs {
|
|
assert_eq!(arg_tys.len(), 2);
|
|
bcx = trans_arg_datum(bcx, arg_tys[1], rhs,
|
|
arg_cleanup_scope,
|
|
if autoref { DoAutorefArg(rhs_id) } else { DontAutorefArg },
|
|
llargs);
|
|
} else {
|
|
assert_eq!(arg_tys.len(), 1);
|
|
}
|
|
}
|
|
ArgVals(vs) => {
|
|
llargs.extend_from_slice(vs);
|
|
}
|
|
}
|
|
|
|
bcx
|
|
}
|
|
|
|
#[derive(Copy, Clone)]
|
|
pub enum AutorefArg {
|
|
DontAutorefArg,
|
|
DoAutorefArg(ast::NodeId)
|
|
}
|
|
|
|
pub fn trans_arg_datum<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
|
|
formal_arg_ty: Ty<'tcx>,
|
|
arg_datum: Datum<'tcx, Expr>,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
autoref_arg: AutorefArg,
|
|
llargs: &mut Vec<ValueRef>)
|
|
-> Block<'blk, 'tcx> {
|
|
let _icx = push_ctxt("trans_arg_datum");
|
|
let mut bcx = bcx;
|
|
let ccx = bcx.ccx();
|
|
|
|
debug!("trans_arg_datum({:?})",
|
|
formal_arg_ty);
|
|
|
|
let arg_datum_ty = arg_datum.ty;
|
|
|
|
debug!(" arg datum: {}", arg_datum.to_string(bcx.ccx()));
|
|
|
|
let mut val;
|
|
// 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 if common::type_is_fat_ptr(bcx.tcx(), arg_datum_ty) &&
|
|
!bcx.fcx.type_needs_drop(arg_datum_ty) => {
|
|
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 panic before the
|
|
// callee is actually invoked.
|
|
val = arg_datum.add_clean(bcx.fcx, arg_cleanup_scope);
|
|
}
|
|
}
|
|
|
|
if type_of::arg_is_indirect(ccx, formal_arg_ty) && 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_string(val), bcx.llty_str(llformal_arg_ty));
|
|
debug!("Rust types: {:?}; {:?}", arg_datum_ty,
|
|
formal_arg_ty);
|
|
val = PointerCast(bcx, val, llformal_arg_ty);
|
|
}
|
|
|
|
debug!("--- trans_arg_datum passing {}", bcx.val_to_string(val));
|
|
|
|
if common::type_is_fat_ptr(bcx.tcx(), formal_arg_ty) {
|
|
llargs.push(Load(bcx, expr::get_dataptr(bcx, val)));
|
|
llargs.push(Load(bcx, expr::get_meta(bcx, val)));
|
|
} else {
|
|
llargs.push(val);
|
|
}
|
|
|
|
bcx
|
|
}
|