68517a2cca
NodeIds are sequential integers starting at zero, so we can achieve some memory savings by just storing the items all in a line in a vector. The occupancy for typical crates seems to be 75-80%, so we're already more efficient than a HashMap (maximum occupancy 75%), not even counting the extra book-keeping that HashMap does.
910 lines
33 KiB
Rust
910 lines
33 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
/*!
|
|
* Handles translation of callees as well as other call-related
|
|
* things. Callees are a superset of normal rust values and sometimes
|
|
* have different representations. In particular, top-level fn items
|
|
* and methods are represented as just a fn ptr and not a full
|
|
* closure.
|
|
*/
|
|
|
|
use std::vec;
|
|
|
|
use back::abi;
|
|
use driver::session;
|
|
use lib::llvm::{ValueRef, NoAliasAttribute, StructRetAttribute};
|
|
use lib::llvm::llvm;
|
|
use metadata::csearch;
|
|
use middle::trans::base;
|
|
use middle::trans::base::*;
|
|
use middle::trans::build::*;
|
|
use middle::trans::callee;
|
|
use middle::trans::cleanup;
|
|
use middle::trans::cleanup::CleanupMethods;
|
|
use middle::trans::common;
|
|
use middle::trans::common::*;
|
|
use middle::trans::datum::*;
|
|
use middle::trans::datum::Datum;
|
|
use middle::trans::expr;
|
|
use middle::trans::glue;
|
|
use middle::trans::inline;
|
|
use middle::trans::meth;
|
|
use middle::trans::monomorphize;
|
|
use middle::trans::type_of;
|
|
use middle::trans::foreign;
|
|
use middle::ty;
|
|
use middle::subst::Subst;
|
|
use middle::typeck;
|
|
use middle::typeck::coherence::make_substs_for_receiver_types;
|
|
use util::ppaux::Repr;
|
|
|
|
use middle::trans::type_::Type;
|
|
|
|
use syntax::ast;
|
|
use syntax::abi::AbiSet;
|
|
use syntax::ast_map;
|
|
|
|
// Represents a (possibly monomorphized) top-level fn item or method
|
|
// item. Note that this is just the fn-ptr and is not a Rust closure
|
|
// value (which is a pair).
|
|
pub struct FnData {
|
|
llfn: ValueRef,
|
|
}
|
|
|
|
pub struct MethodData {
|
|
llfn: ValueRef,
|
|
llself: ValueRef,
|
|
}
|
|
|
|
pub enum CalleeData {
|
|
Closure(Datum<Lvalue>),
|
|
Fn(FnData),
|
|
Method(MethodData)
|
|
}
|
|
|
|
pub struct Callee<'a> {
|
|
bcx: &'a Block<'a>,
|
|
data: CalleeData
|
|
}
|
|
|
|
fn trans<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> Callee<'a> {
|
|
let _icx = push_ctxt("trans_callee");
|
|
debug!("callee::trans(expr={})", expr.repr(bcx.tcx()));
|
|
|
|
// pick out special kinds of expressions that can be called:
|
|
match expr.node {
|
|
ast::ExprPath(_) => {
|
|
return trans_def(bcx, bcx.def(expr.id), expr);
|
|
}
|
|
_ => {}
|
|
}
|
|
|
|
// any other expressions are closures:
|
|
return datum_callee(bcx, expr);
|
|
|
|
fn datum_callee<'a>(bcx: &'a Block<'a>, expr: &ast::Expr) -> Callee<'a> {
|
|
let DatumBlock {bcx: mut bcx, datum} = expr::trans(bcx, expr);
|
|
match ty::get(datum.ty).sty {
|
|
ty::ty_bare_fn(..) => {
|
|
let llval = datum.to_llscalarish(bcx);
|
|
return Callee {bcx: bcx, data: Fn(FnData {llfn: llval})};
|
|
}
|
|
ty::ty_closure(..) => {
|
|
let datum = unpack_datum!(
|
|
bcx, datum.to_lvalue_datum(bcx, "callee", expr.id));
|
|
return Callee {bcx: bcx, data: Closure(datum)};
|
|
}
|
|
_ => {
|
|
bcx.tcx().sess.span_bug(
|
|
expr.span,
|
|
format!("Type of callee is neither bare-fn nor closure: {}",
|
|
bcx.ty_to_str(datum.ty)));
|
|
}
|
|
}
|
|
}
|
|
|
|
fn fn_callee<'a>(bcx: &'a Block<'a>, fd: FnData) -> Callee<'a> {
|
|
return Callee {bcx: bcx, data: Fn(fd)};
|
|
}
|
|
|
|
fn trans_def<'a>(bcx: &'a Block<'a>, def: ast::Def, ref_expr: &ast::Expr)
|
|
-> Callee<'a> {
|
|
match def {
|
|
ast::DefFn(did, _) |
|
|
ast::DefStaticMethod(did, ast::FromImpl(_), _) => {
|
|
fn_callee(bcx, trans_fn_ref(bcx, did, ref_expr.id))
|
|
}
|
|
ast::DefStaticMethod(impl_did,
|
|
ast::FromTrait(trait_did),
|
|
_) => {
|
|
fn_callee(bcx, meth::trans_static_method_callee(bcx, impl_did,
|
|
trait_did,
|
|
ref_expr.id))
|
|
}
|
|
ast::DefVariant(tid, vid, _) => {
|
|
// nullary variants are not callable
|
|
assert!(ty::enum_variant_with_id(bcx.tcx(),
|
|
tid,
|
|
vid).args.len() > 0u);
|
|
fn_callee(bcx, trans_fn_ref(bcx, vid, ref_expr.id))
|
|
}
|
|
ast::DefStruct(def_id) => {
|
|
fn_callee(bcx, trans_fn_ref(bcx, def_id, ref_expr.id))
|
|
}
|
|
ast::DefStatic(..) |
|
|
ast::DefArg(..) |
|
|
ast::DefLocal(..) |
|
|
ast::DefBinding(..) |
|
|
ast::DefUpvar(..) |
|
|
ast::DefSelf(..) => {
|
|
datum_callee(bcx, ref_expr)
|
|
}
|
|
ast::DefMod(..) | ast::DefForeignMod(..) | ast::DefTrait(..) |
|
|
ast::DefTy(..) | ast::DefPrimTy(..) |
|
|
ast::DefUse(..) | ast::DefTyParamBinder(..) |
|
|
ast::DefRegion(..) | ast::DefLabel(..) | ast::DefTyParam(..) |
|
|
ast::DefSelfTy(..) | ast::DefMethod(..) => {
|
|
bcx.tcx().sess.span_bug(
|
|
ref_expr.span,
|
|
format!("Cannot translate def {:?} \
|
|
to a callable thing!", def));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn trans_fn_ref_to_callee<'a>(
|
|
bcx: &'a Block<'a>,
|
|
def_id: ast::DefId,
|
|
ref_id: ast::NodeId)
|
|
-> Callee<'a> {
|
|
Callee {bcx: bcx,
|
|
data: Fn(trans_fn_ref(bcx, def_id, ref_id))}
|
|
}
|
|
|
|
pub fn trans_fn_ref(bcx: &Block, def_id: ast::DefId, ref_id: ast::NodeId)
|
|
-> FnData {
|
|
/*!
|
|
*
|
|
* Translates a reference (with id `ref_id`) to the fn/method
|
|
* with id `def_id` into a function pointer. This may require
|
|
* monomorphization or inlining. */
|
|
|
|
let _icx = push_ctxt("trans_fn_ref");
|
|
|
|
let type_params = node_id_type_params(bcx, ref_id);
|
|
let vtables = node_vtables(bcx, ref_id);
|
|
debug!("trans_fn_ref(def_id={}, ref_id={:?}, type_params={}, vtables={})",
|
|
def_id.repr(bcx.tcx()), ref_id, type_params.repr(bcx.tcx()),
|
|
vtables.repr(bcx.tcx()));
|
|
trans_fn_ref_with_vtables(bcx, def_id, ref_id, type_params, vtables)
|
|
}
|
|
|
|
pub fn trans_fn_ref_with_vtables_to_callee<'a>(
|
|
bcx: &'a Block<'a>,
|
|
def_id: ast::DefId,
|
|
ref_id: ast::NodeId,
|
|
type_params: &[ty::t],
|
|
vtables: Option<typeck::vtable_res>)
|
|
-> Callee<'a> {
|
|
Callee {bcx: bcx,
|
|
data: Fn(trans_fn_ref_with_vtables(bcx, def_id, ref_id,
|
|
type_params, vtables))}
|
|
}
|
|
|
|
fn resolve_default_method_vtables(bcx: &Block,
|
|
impl_id: ast::DefId,
|
|
method: &ty::Method,
|
|
substs: &ty::substs,
|
|
impl_vtables: Option<typeck::vtable_res>)
|
|
-> (typeck::vtable_res, typeck::vtable_param_res) {
|
|
|
|
// Get the vtables that the impl implements the trait at
|
|
let impl_res = ty::lookup_impl_vtables(bcx.tcx(), impl_id);
|
|
|
|
// Build up a param_substs that we are going to resolve the
|
|
// trait_vtables under.
|
|
let param_substs = Some(@param_substs {
|
|
tys: substs.tps.clone(),
|
|
self_ty: substs.self_ty,
|
|
vtables: impl_vtables,
|
|
self_vtables: None
|
|
});
|
|
|
|
let trait_vtables_fixed = resolve_vtables_under_param_substs(
|
|
bcx.tcx(), param_substs, impl_res.trait_vtables);
|
|
|
|
// Now we pull any vtables for parameters on the actual method.
|
|
let num_method_vtables = method.generics.type_param_defs.len();
|
|
let method_vtables = match impl_vtables {
|
|
Some(vtables) => {
|
|
let num_impl_type_parameters =
|
|
vtables.len() - num_method_vtables;
|
|
vtables.tailn(num_impl_type_parameters).to_owned()
|
|
},
|
|
None => vec::from_elem(num_method_vtables, @~[])
|
|
};
|
|
|
|
let param_vtables = @(*trait_vtables_fixed + method_vtables);
|
|
|
|
let self_vtables = resolve_param_vtables_under_param_substs(
|
|
bcx.tcx(), param_substs, impl_res.self_vtables);
|
|
|
|
(param_vtables, self_vtables)
|
|
}
|
|
|
|
|
|
pub fn trans_fn_ref_with_vtables(
|
|
bcx: &Block, //
|
|
def_id: ast::DefId, // def id of fn
|
|
ref_id: ast::NodeId, // node id of use of fn; may be zero if N/A
|
|
type_params: &[ty::t], // values for fn's ty params
|
|
vtables: Option<typeck::vtable_res>) // vtables for the call
|
|
-> FnData {
|
|
/*!
|
|
* Translates a reference to a fn/method item, monomorphizing and
|
|
* inlining as it goes.
|
|
*
|
|
* # Parameters
|
|
*
|
|
* - `bcx`: the current block where the reference to the fn occurs
|
|
* - `def_id`: def id of the fn or method item being referenced
|
|
* - `ref_id`: node id of the reference to the fn/method, if applicable.
|
|
* This parameter may be zero; but, if so, the resulting value may not
|
|
* have the right type, so it must be cast before being used.
|
|
* - `type_params`: values for each of the fn/method's type parameters
|
|
* - `vtables`: values for each bound on each of the type parameters
|
|
*/
|
|
|
|
let _icx = push_ctxt("trans_fn_ref_with_vtables");
|
|
let ccx = bcx.ccx();
|
|
let tcx = ccx.tcx;
|
|
|
|
debug!("trans_fn_ref_with_vtables(bcx={}, def_id={}, ref_id={:?}, \
|
|
type_params={}, vtables={})",
|
|
bcx.to_str(),
|
|
def_id.repr(bcx.tcx()),
|
|
ref_id,
|
|
type_params.repr(bcx.tcx()),
|
|
vtables.repr(bcx.tcx()));
|
|
|
|
assert!(type_params.iter().all(|t| !ty::type_needs_infer(*t)));
|
|
|
|
// Polytype of the function item (may have type params)
|
|
let fn_tpt = ty::lookup_item_type(tcx, def_id);
|
|
|
|
let substs = ty::substs { regions: ty::ErasedRegions,
|
|
self_ty: None,
|
|
tps: /*bad*/ type_params.to_owned() };
|
|
|
|
// Load the info for the appropriate trait if necessary.
|
|
match ty::trait_of_method(tcx, def_id) {
|
|
None => {}
|
|
Some(trait_id) => {
|
|
ty::populate_implementations_for_trait_if_necessary(tcx, trait_id)
|
|
}
|
|
}
|
|
|
|
// We need to do a bunch of special handling for default methods.
|
|
// We need to modify the def_id and our substs in order to monomorphize
|
|
// the function.
|
|
let (is_default, def_id, substs, self_vtables, vtables) =
|
|
match ty::provided_source(tcx, def_id) {
|
|
None => (false, def_id, substs, None, vtables),
|
|
Some(source_id) => {
|
|
// There are two relevant substitutions when compiling
|
|
// default methods. First, there is the substitution for
|
|
// the type parameters of the impl we are using and the
|
|
// method we are calling. This substitution is the substs
|
|
// argument we already have.
|
|
// In order to compile a default method, though, we need
|
|
// to consider another substitution: the substitution for
|
|
// the type parameters on trait; the impl we are using
|
|
// implements the trait at some particular type
|
|
// parameters, and we need to substitute for those first.
|
|
// So, what we need to do is find this substitution and
|
|
// compose it with the one we already have.
|
|
|
|
let impl_id = ty::method(tcx, def_id).container_id();
|
|
let method = ty::method(tcx, source_id);
|
|
let trait_ref = ty::impl_trait_ref(tcx, impl_id)
|
|
.expect("could not find trait_ref for impl with \
|
|
default methods");
|
|
|
|
// Compute the first substitution
|
|
let first_subst = make_substs_for_receiver_types(
|
|
tcx, impl_id, trait_ref, method);
|
|
|
|
// And compose them
|
|
let new_substs = first_subst.subst(tcx, &substs);
|
|
|
|
|
|
let (param_vtables, self_vtables) =
|
|
resolve_default_method_vtables(bcx, impl_id,
|
|
method, &substs, vtables);
|
|
|
|
debug!("trans_fn_with_vtables - default method: \
|
|
substs = {}, trait_subst = {}, \
|
|
first_subst = {}, new_subst = {}, \
|
|
vtables = {}, \
|
|
self_vtable = {}, param_vtables = {}",
|
|
substs.repr(tcx), trait_ref.substs.repr(tcx),
|
|
first_subst.repr(tcx), new_substs.repr(tcx),
|
|
vtables.repr(tcx),
|
|
self_vtables.repr(tcx), param_vtables.repr(tcx));
|
|
|
|
(true, source_id,
|
|
new_substs, Some(self_vtables), Some(param_vtables))
|
|
}
|
|
};
|
|
|
|
// Check whether this fn has an inlined copy and, if so, redirect
|
|
// def_id to the local id of the inlined copy.
|
|
let def_id = {
|
|
if def_id.crate != ast::LOCAL_CRATE {
|
|
inline::maybe_instantiate_inline(ccx, def_id)
|
|
} else {
|
|
def_id
|
|
}
|
|
};
|
|
|
|
// We must monomorphise if the fn has type parameters, is a rust
|
|
// intrinsic, or is a default method. In particular, if we see an
|
|
// intrinsic that is inlined from a different crate, we want to reemit the
|
|
// intrinsic instead of trying to call it in the other crate.
|
|
let must_monomorphise;
|
|
if type_params.len() > 0 || is_default {
|
|
must_monomorphise = true;
|
|
} else if def_id.crate == ast::LOCAL_CRATE {
|
|
{
|
|
let map_node = session::expect(
|
|
ccx.sess,
|
|
ccx.tcx.items.find(def_id.node),
|
|
|| format!("local item should be in ast map"));
|
|
|
|
match map_node {
|
|
ast_map::NodeForeignItem(_, abis, _, _) => {
|
|
must_monomorphise = abis.is_intrinsic()
|
|
}
|
|
_ => {
|
|
must_monomorphise = false;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
must_monomorphise = false;
|
|
}
|
|
|
|
// Create a monomorphic verison of generic functions
|
|
if must_monomorphise {
|
|
// Should be either intra-crate or inlined.
|
|
assert_eq!(def_id.crate, ast::LOCAL_CRATE);
|
|
|
|
let (val, must_cast) =
|
|
monomorphize::monomorphic_fn(ccx, def_id, &substs,
|
|
vtables, self_vtables,
|
|
Some(ref_id));
|
|
let mut val = val;
|
|
if must_cast && ref_id != 0 {
|
|
// Monotype of the REFERENCE to the function (type params
|
|
// are subst'd)
|
|
let ref_ty = common::node_id_type(bcx, ref_id);
|
|
|
|
val = PointerCast(
|
|
bcx, val, type_of::type_of_fn_from_ty(ccx, None, ref_ty).ptr_to());
|
|
}
|
|
return FnData {llfn: val};
|
|
}
|
|
|
|
// Find the actual function pointer.
|
|
let mut val = {
|
|
if def_id.crate == ast::LOCAL_CRATE {
|
|
// Internal reference.
|
|
get_item_val(ccx, def_id.node)
|
|
} else {
|
|
// External reference.
|
|
trans_external_path(ccx, def_id, fn_tpt.ty)
|
|
}
|
|
};
|
|
|
|
// 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, None, fn_tpt.ty);
|
|
let llptrty = llty.ptr_to();
|
|
if val_ty(val) != llptrty {
|
|
val = BitCast(bcx, val, llptrty);
|
|
}
|
|
|
|
return FnData {llfn: val};
|
|
}
|
|
|
|
// ______________________________________________________________________
|
|
// Translating calls
|
|
|
|
pub fn trans_call<'a>(
|
|
in_cx: &'a Block<'a>,
|
|
call_ex: &ast::Expr,
|
|
f: &ast::Expr,
|
|
args: CallArgs,
|
|
id: ast::NodeId,
|
|
dest: expr::Dest)
|
|
-> &'a Block<'a> {
|
|
let _icx = push_ctxt("trans_call");
|
|
trans_call_inner(in_cx,
|
|
Some(common::expr_info(call_ex)),
|
|
expr_ty(in_cx, f),
|
|
node_id_type(in_cx, id),
|
|
|cx, _| trans(cx, f),
|
|
args,
|
|
Some(dest),
|
|
DontAutorefArg).bcx
|
|
}
|
|
|
|
pub fn trans_method_call<'a>(
|
|
in_cx: &'a Block<'a>,
|
|
call_ex: &ast::Expr,
|
|
callee_id: ast::NodeId,
|
|
rcvr: &ast::Expr,
|
|
args: CallArgs,
|
|
dest: expr::Dest)
|
|
-> &'a Block<'a> {
|
|
let _icx = push_ctxt("trans_method_call");
|
|
debug!("trans_method_call(call_ex={}, rcvr={})",
|
|
call_ex.repr(in_cx.tcx()),
|
|
rcvr.repr(in_cx.tcx()));
|
|
trans_call_inner(
|
|
in_cx,
|
|
Some(common::expr_info(call_ex)),
|
|
node_id_type(in_cx, callee_id),
|
|
expr_ty(in_cx, call_ex),
|
|
|cx, arg_cleanup_scope| {
|
|
let origin_opt = {
|
|
let mut method_map = cx.ccx().maps.method_map.borrow_mut();
|
|
method_map.get().find_copy(&call_ex.id)
|
|
};
|
|
match origin_opt {
|
|
Some(origin) => {
|
|
debug!("origin for {}: {}",
|
|
call_ex.repr(in_cx.tcx()),
|
|
origin.repr(in_cx.tcx()));
|
|
|
|
meth::trans_method_callee(cx,
|
|
callee_id,
|
|
rcvr,
|
|
origin,
|
|
arg_cleanup_scope)
|
|
}
|
|
None => {
|
|
cx.tcx().sess.span_bug(call_ex.span, "method call expr wasn't in method map")
|
|
}
|
|
}
|
|
},
|
|
args,
|
|
Some(dest),
|
|
DontAutorefArg).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.crate == ast::LOCAL_CRATE {
|
|
ty::node_id_to_type(bcx.ccx().tcx, did.node)
|
|
} else {
|
|
csearch::get_type(bcx.ccx().tcx, did).ty
|
|
};
|
|
let rty = ty::ty_fn_ret(fty);
|
|
callee::trans_call_inner(bcx,
|
|
None,
|
|
fty,
|
|
rty,
|
|
|bcx, _| {
|
|
trans_fn_ref_with_vtables_to_callee(bcx,
|
|
did,
|
|
0,
|
|
[],
|
|
None)
|
|
},
|
|
ArgVals(args),
|
|
dest,
|
|
DontAutorefArg)
|
|
}
|
|
|
|
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.crate == ast::LOCAL_CRATE {
|
|
fty = ty::node_id_to_type(bcx.tcx(), did.node);
|
|
} else {
|
|
fty = csearch::get_type(bcx.tcx(), did).ty;
|
|
}
|
|
|
|
let rty = ty::ty_fn_ret(fty);
|
|
return callee::trans_call_inner(
|
|
bcx,
|
|
None,
|
|
fty,
|
|
rty,
|
|
|bcx, _| {
|
|
let callee =
|
|
trans_fn_ref_with_vtables_to_callee(bcx, did, 0,
|
|
type_params,
|
|
None);
|
|
|
|
let new_llval;
|
|
match callee.data {
|
|
Fn(fn_data) => {
|
|
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, fn_data.llfn, llfnty);
|
|
}
|
|
_ => fail!()
|
|
}
|
|
Callee { bcx: callee.bcx, data: Fn(FnData { llfn: new_llval }) }
|
|
},
|
|
ArgVals(args), Some(dest), DontAutorefArg).bcx;
|
|
}
|
|
|
|
pub fn trans_call_inner<'a>(
|
|
bcx: &'a Block<'a>,
|
|
call_info: Option<NodeInfo>,
|
|
callee_ty: ty::t,
|
|
ret_ty: ty::t,
|
|
get_callee: |bcx: &'a Block<'a>,
|
|
arg_cleanup_scope: cleanup::ScopeId|
|
|
-> Callee<'a>,
|
|
args: CallArgs,
|
|
dest: Option<expr::Dest>,
|
|
autoref_arg: AutorefArg)
|
|
-> 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) = unsafe {
|
|
match callee.data {
|
|
Fn(d) => {
|
|
(d.llfn, llvm::LLVMGetUndef(Type::opaque_box(ccx).ptr_to().to_ref()))
|
|
}
|
|
Method(d) => {
|
|
// Weird but true: we pass self in the *environment* slot!
|
|
(d.llfn, 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, llenv)
|
|
}
|
|
}
|
|
};
|
|
|
|
let abi = match ty::get(callee_ty).sty {
|
|
ty::ty_bare_fn(ref f) => f.abis,
|
|
_ => AbiSet::Rust()
|
|
};
|
|
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 = ~[];
|
|
|
|
// 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.
|
|
llargs.push(llenv);
|
|
|
|
// Push the arguments.
|
|
bcx = trans_args(bcx, args, callee_ty,
|
|
autoref_arg, &mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope));
|
|
|
|
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 = ~[];
|
|
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, 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 = ~[];
|
|
bcx = trans_args(bcx, args, callee_ty,
|
|
autoref_arg, &mut llargs,
|
|
cleanup::CustomScope(arg_cleanup_scope));
|
|
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
|
|
let arg_tys = match args {
|
|
ArgExprs(a) => a.iter().map(|x| expr_ty(bcx, *x)).collect(),
|
|
ArgVals(_) => fail!("expected arg exprs.")
|
|
};
|
|
bcx = foreign::trans_native_call(bcx, callee_ty,
|
|
llfn, opt_llretslot.unwrap(), llargs, 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]),
|
|
ArgVals(&'a [ValueRef])
|
|
}
|
|
|
|
pub fn trans_args<'a>(
|
|
cx: &'a Block<'a>,
|
|
args: CallArgs,
|
|
fn_ty: ty::t,
|
|
autoref_arg: AutorefArg,
|
|
llargs: &mut ~[ValueRef],
|
|
arg_cleanup_scope: cleanup::ScopeId)
|
|
-> &'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() {
|
|
let arg_ty = if i >= num_formal_args {
|
|
assert!(variadic);
|
|
expr_ty_adjusted(cx, *arg_expr)
|
|
} else {
|
|
arg_tys[i]
|
|
};
|
|
let arg_val = unpack_result!(bcx, {
|
|
trans_arg_expr(bcx,
|
|
arg_ty,
|
|
*arg_expr,
|
|
arg_cleanup_scope,
|
|
autoref_arg)
|
|
});
|
|
llargs.push(arg_val);
|
|
}
|
|
}
|
|
ArgVals(vs) => {
|
|
llargs.push_all(vs);
|
|
}
|
|
}
|
|
|
|
bcx
|
|
}
|
|
|
|
pub enum AutorefArg {
|
|
DontAutorefArg,
|
|
DoAutorefArg
|
|
}
|
|
|
|
pub fn trans_arg_expr<'a>(
|
|
bcx: &'a Block<'a>,
|
|
formal_arg_ty: ty::t,
|
|
arg_expr: &ast::Expr,
|
|
arg_cleanup_scope: cleanup::ScopeId,
|
|
autoref_arg: AutorefArg)
|
|
-> Result<'a> {
|
|
let _icx = push_ctxt("trans_arg_expr");
|
|
let mut bcx = bcx;
|
|
let ccx = bcx.ccx();
|
|
|
|
debug!("trans_arg_expr(formal_arg_ty=({}), arg_expr={})",
|
|
formal_arg_ty.repr(bcx.tcx()),
|
|
arg_expr.repr(bcx.tcx()));
|
|
|
|
// translate the arg expr to a datum
|
|
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, arg_expr));
|
|
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 => {
|
|
// 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_expr.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_expr passing {}", bcx.val_to_str(val));
|
|
return rslt(bcx, val);
|
|
}
|