/
callee.rs
1197 lines (1075 loc) · 44 KB
/
callee.rs
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// 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 arena::TypedArena;
use back::abi;
use back::link;
use driver::session;
use llvm::{ValueRef, get_param};
use llvm;
use metadata::csearch;
use middle::def;
use middle::subst;
use middle::subst::{Subst, VecPerParamSpace};
use middle::trans::adt;
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::closure;
use middle::trans::common;
use middle::trans::common::*;
use middle::trans::datum::*;
use middle::trans::datum::{Datum, KindOps};
use middle::trans::expr;
use middle::trans::glue;
use middle::trans::inline;
use middle::trans::foreign;
use middle::trans::intrinsic;
use middle::trans::meth;
use middle::trans::monomorphize;
use middle::trans::type_::Type;
use middle::trans::type_of;
use middle::ty;
use middle::typeck;
use middle::typeck::coherence::make_substs_for_receiver_types;
use middle::typeck::MethodCall;
use util::ppaux::Repr;
use std::gc::Gc;
use syntax::ast;
use syntax::ast_map;
use synabi = syntax::abi;
pub struct MethodData {
pub llfn: ValueRef,
pub llself: ValueRef,
}
pub enum CalleeData {
Closure(Datum<Lvalue>),
// Constructor for enum variant/tuple-like-struct
// i.e. Some, Ok
NamedTupleConstructor(subst::Substs, ty::Disr),
// 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).
Fn(/* llfn */ ValueRef),
Intrinsic(ast::NodeId, subst::Substs),
TraitMethod(MethodData)
}
pub struct Callee<'a> {
pub bcx: &'a Block<'a>,
pub 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(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_string(datum.ty)).as_slice());
}
}
}
fn fn_callee<'a>(bcx: &'a Block<'a>, llfn: ValueRef) -> Callee<'a> {
return Callee {
bcx: bcx,
data: Fn(llfn),
};
}
fn trans_def<'a>(bcx: &'a Block<'a>, def: def::Def, ref_expr: &ast::Expr)
-> Callee<'a> {
debug!("trans_def(def={}, ref_expr={})", def.repr(bcx.tcx()), ref_expr.repr(bcx.tcx()));
let expr_ty = node_id_type(bcx, ref_expr.id);
match def {
def::DefFn(did, _) if {
let def_id = if did.krate != ast::LOCAL_CRATE {
inline::maybe_instantiate_inline(bcx.ccx(), did)
} else {
did
};
match bcx.tcx().map.find(def_id.node) {
Some(ast_map::NodeStructCtor(_)) => true,
_ => false
}
} => {
let substs = node_id_substs(bcx, ExprId(ref_expr.id));
Callee {
bcx: bcx,
data: NamedTupleConstructor(substs, 0)
}
}
def::DefFn(did, _) if match ty::get(expr_ty).sty {
ty::ty_bare_fn(ref f) => f.abi == synabi::RustIntrinsic,
_ => false
} => {
let substs = node_id_substs(bcx, ExprId(ref_expr.id));
let def_id = if did.krate != ast::LOCAL_CRATE {
inline::maybe_instantiate_inline(bcx.ccx(), did)
} else {
did
};
Callee { bcx: bcx, data: Intrinsic(def_id.node, substs) }
}
def::DefFn(did, _) |
def::DefStaticMethod(did, def::FromImpl(_), _) => {
fn_callee(bcx, trans_fn_ref(bcx, did, ExprId(ref_expr.id)))
}
def::DefStaticMethod(impl_did,
def::FromTrait(trait_did),
_) => {
fn_callee(bcx, meth::trans_static_method_callee(bcx, impl_did,
trait_did,
ref_expr.id))
}
def::DefVariant(tid, vid, _) => {
let vinfo = ty::enum_variant_with_id(bcx.tcx(), tid, vid);
let substs = node_id_substs(bcx, ExprId(ref_expr.id));
// Nullary variants are not callable
assert!(vinfo.args.len() > 0u);
Callee {
bcx: bcx,
data: NamedTupleConstructor(substs, vinfo.disr_val)
}
}
def::DefStruct(_) => {
let substs = node_id_substs(bcx, ExprId(ref_expr.id));
Callee {
bcx: bcx,
data: NamedTupleConstructor(substs, 0)
}
}
def::DefStatic(..) |
def::DefArg(..) |
def::DefLocal(..) |
def::DefBinding(..) |
def::DefUpvar(..) => {
datum_callee(bcx, ref_expr)
}
def::DefMod(..) | def::DefForeignMod(..) | def::DefTrait(..) |
def::DefTy(..) | def::DefPrimTy(..) |
def::DefUse(..) | def::DefTyParamBinder(..) |
def::DefRegion(..) | def::DefLabel(..) | def::DefTyParam(..) |
def::DefSelfTy(..) | def::DefMethod(..) => {
bcx.tcx().sess.span_bug(
ref_expr.span,
format!("cannot translate def {:?} \
to a callable thing!", def).as_slice());
}
}
}
}
pub fn trans_fn_ref(bcx: &Block, def_id: ast::DefId, node: ExprOrMethodCall) -> ValueRef {
/*!
* 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 substs = node_id_substs(bcx, node);
let vtable_key = match node {
ExprId(id) => MethodCall::expr(id),
MethodCall(method_call) => method_call
};
let vtables = node_vtables(bcx, vtable_key);
debug!("trans_fn_ref(def_id={}, node={:?}, substs={}, vtables={})",
def_id.repr(bcx.tcx()),
node,
substs.repr(bcx.tcx()),
vtables.repr(bcx.tcx()));
trans_fn_ref_with_vtables(bcx, def_id, node, substs, vtables)
}
fn trans_fn_ref_with_vtables_to_callee<'a>(bcx: &'a Block<'a>,
def_id: ast::DefId,
ref_id: ast::NodeId,
substs: subst::Substs,
vtables: typeck::vtable_res)
-> Callee<'a> {
Callee {
bcx: bcx,
data: Fn(trans_fn_ref_with_vtables(bcx,
def_id,
ExprId(ref_id),
substs,
vtables)),
}
}
fn resolve_default_method_vtables(bcx: &Block,
impl_id: ast::DefId,
substs: &subst::Substs,
impl_vtables: typeck::vtable_res)
-> typeck::vtable_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 = param_substs {
substs: (*substs).clone(),
vtables: impl_vtables.clone()
};
let mut param_vtables = resolve_vtables_under_param_substs(
bcx.tcx(), ¶m_substs, &impl_res);
// Now we pull any vtables for parameters on the actual method.
param_vtables.push_all(subst::FnSpace,
impl_vtables.get_slice(subst::FnSpace));
param_vtables
}
/// Translates the adapter that deconstructs a `Box<Trait>` object into
/// `Trait` so that a by-value self method can be called.
pub fn trans_unboxing_shim(bcx: &Block,
llshimmedfn: ValueRef,
method: &ty::Method,
method_id: ast::DefId,
substs: subst::Substs)
-> ValueRef {
let _icx = push_ctxt("trans_unboxing_shim");
let ccx = bcx.ccx();
let tcx = bcx.tcx();
// Transform the self type to `Box<self_type>`.
let self_type = *method.fty.sig.inputs.get(0);
let boxed_self_type = ty::mk_uniq(tcx, self_type);
let boxed_function_type = ty::FnSig {
binder_id: method.fty.sig.binder_id,
inputs: method.fty.sig.inputs.iter().enumerate().map(|(i, typ)| {
if i == 0 {
boxed_self_type
} else {
*typ
}
}).collect(),
output: method.fty.sig.output,
variadic: false,
};
let boxed_function_type = ty::BareFnTy {
fn_style: method.fty.fn_style,
abi: method.fty.abi,
sig: boxed_function_type,
};
let boxed_function_type =
ty::mk_bare_fn(tcx, boxed_function_type).subst(tcx, &substs);
let function_type =
ty::mk_bare_fn(tcx, method.fty.clone()).subst(tcx, &substs);
let function_name = ty::with_path(tcx, method_id, |path| {
link::mangle_internal_name_by_path_and_seq(path, "unboxing_shim")
});
let llfn = decl_internal_rust_fn(ccx,
boxed_function_type,
function_name.as_slice());
let block_arena = TypedArena::new();
let empty_param_substs = param_substs::empty();
let return_type = ty::ty_fn_ret(boxed_function_type);
let fcx = new_fn_ctxt(ccx,
llfn,
ast::DUMMY_NODE_ID,
false,
return_type,
&empty_param_substs,
None,
&block_arena,
TranslateItems);
let mut bcx = init_function(&fcx, false, return_type);
// Create the substituted versions of the self type.
let arg_scope = fcx.push_custom_cleanup_scope();
let arg_scope_id = cleanup::CustomScope(arg_scope);
let boxed_arg_types = ty::ty_fn_args(boxed_function_type);
let boxed_self_type = *boxed_arg_types.get(0);
let arg_types = ty::ty_fn_args(function_type);
let self_type = *arg_types.get(0);
let boxed_self_kind = arg_kind(&fcx, boxed_self_type);
// Create a datum for self.
let llboxedself = get_param(fcx.llfn, fcx.arg_pos(0) as u32);
let llboxedself = Datum::new(llboxedself,
boxed_self_type,
boxed_self_kind);
let boxed_self =
unpack_datum!(bcx,
llboxedself.to_lvalue_datum_in_scope(bcx,
"boxedself",
arg_scope_id));
// This `Load` is needed because lvalue data are always by-ref.
let llboxedself = Load(bcx, boxed_self.val);
let llself = if type_is_immediate(ccx, self_type) {
let llboxedself = Load(bcx, llboxedself);
immediate_rvalue(llboxedself, self_type)
} else {
let llself = rvalue_scratch_datum(bcx, self_type, "self");
memcpy_ty(bcx, llself.val, llboxedself, self_type);
llself
};
// Make sure we don't free the box twice!
boxed_self.kind.post_store(bcx, boxed_self.val, boxed_self_type);
// Schedule a cleanup to free the box.
fcx.schedule_free_value(arg_scope_id,
llboxedself,
cleanup::HeapExchange,
self_type);
// Now call the function.
let mut llshimmedargs = vec!(llself.val);
for i in range(1, arg_types.len()) {
llshimmedargs.push(get_param(fcx.llfn, fcx.arg_pos(i) as u32));
}
assert!(!fcx.needs_ret_allocas);
let dest = match fcx.llretslotptr.get() {
Some(_) => Some(expr::SaveIn(fcx.get_ret_slot(bcx, return_type, "ret_slot"))),
None => None
};
bcx = trans_call_inner(bcx,
None,
function_type,
|bcx, _| {
Callee {
bcx: bcx,
data: Fn(llshimmedfn),
}
},
ArgVals(llshimmedargs.as_slice()),
dest).bcx;
bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
finish_fn(&fcx, bcx, return_type);
llfn
}
pub fn trans_fn_ref_with_vtables(
bcx: &Block, //
def_id: ast::DefId, // def id of fn
node: ExprOrMethodCall, // node id of use of fn; may be zero if N/A
substs: subst::Substs, // values for fn's ty params
vtables: typeck::vtable_res) // vtables for the call
-> ValueRef
{
/*!
* 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
* - `node`: 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.
* - `substs`: values for each of the fn/method's 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 = bcx.tcx();
debug!("trans_fn_ref_with_vtables(bcx={}, def_id={}, node={:?}, \
substs={}, vtables={})",
bcx.to_str(),
def_id.repr(tcx),
node,
substs.repr(tcx),
vtables.repr(tcx));
assert!(substs.types.all(|t| !ty::type_needs_infer(*t)));
// 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, vtables) =
match ty::provided_source(tcx, def_id) {
None => (false, def_id, substs, 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, &*trait_ref, &*method);
// And compose them
let new_substs = first_subst.subst(tcx, &substs);
debug!("trans_fn_with_vtables - default method: \
substs = {}, trait_subst = {}, \
first_subst = {}, new_subst = {}, \
vtables = {}",
substs.repr(tcx), trait_ref.substs.repr(tcx),
first_subst.repr(tcx), new_substs.repr(tcx),
vtables.repr(tcx));
let param_vtables =
resolve_default_method_vtables(bcx, impl_id, &substs, vtables);
debug!("trans_fn_with_vtables - default method: \
param_vtables = {}",
param_vtables.repr(tcx));
(true, source_id, new_substs, param_vtables)
}
};
// If this is an unboxed closure, redirect to it.
match closure::get_or_create_declaration_if_unboxed_closure(ccx, def_id) {
None => {}
Some(llfn) => return llfn,
}
// 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.krate != ast::LOCAL_CRATE {
inline::maybe_instantiate_inline(ccx, def_id)
} else {
def_id
}
};
// We must monomorphise if the fn has type parameters, is a default method,
// or is a named tuple constructor.
let must_monomorphise = if !substs.types.is_empty() || is_default {
true
} else if def_id.krate == ast::LOCAL_CRATE {
let map_node = session::expect(
ccx.sess(),
tcx.map.find(def_id.node),
|| "local item should be in ast map".to_string());
match map_node {
ast_map::NodeVariant(v) => match v.node.kind {
ast::TupleVariantKind(ref args) => args.len() > 0,
_ => false
},
ast_map::NodeStructCtor(_) => true,
_ => false
}
} else {
false
};
// Create a monomorphic version of generic functions
if must_monomorphise {
// Should be either intra-crate or inlined.
assert_eq!(def_id.krate, ast::LOCAL_CRATE);
let opt_ref_id = match node {
ExprId(id) => if id != 0 { Some(id) } else { None },
MethodCall(_) => None,
};
let (val, must_cast) =
monomorphize::monomorphic_fn(ccx, def_id, &substs,
vtables, opt_ref_id);
let mut val = val;
if must_cast && node != ExprId(0) {
// Monotype of the REFERENCE to the function (type params
// are subst'd)
let ref_ty = match node {
ExprId(id) => node_id_type(bcx, id),
MethodCall(method_call) => {
let t = bcx.tcx().method_map.borrow().get(&method_call).ty;
monomorphize_type(bcx, t)
}
};
val = PointerCast(
bcx, val, type_of::type_of_fn_from_ty(ccx, ref_ty).ptr_to());
}
return val;
}
// Polytype of the function item (may have type params)
let fn_tpt = ty::lookup_item_type(tcx, def_id);
// Find the actual function pointer.
let mut val = {
if def_id.krate == 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, fn_tpt.ty);
let llptrty = llty.ptr_to();
if val_ty(val) != llptrty {
debug!("trans_fn_ref_with_vtables(): casting pointer!");
val = BitCast(bcx, val, llptrty);
} else {
debug!("trans_fn_ref_with_vtables(): not casting pointer!");
}
val
}
// ______________________________________________________________________
// Translating calls
pub fn trans_call<'a>(
in_cx: &'a Block<'a>,
call_ex: &ast::Expr,
f: &ast::Expr,
args: CallArgs,
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),
|cx, _| trans(cx, f),
args,
Some(dest)).bcx
}
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.tcx().method_map.borrow().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.tcx(), did.node)
} else {
csearch::get_type(bcx.tcx(), did).ty
};
callee::trans_call_inner(bcx,
None,
fty,
|bcx, _| {
trans_fn_ref_with_vtables_to_callee(bcx,
did,
0,
subst::Substs::empty(),
VecPerParamSpace::empty())
},
ArgVals(args),
dest)
}
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 (abi, ret_ty) = match ty::get(callee_ty).sty {
ty::ty_bare_fn(ref f) => (f.abi, f.sig.output),
ty::ty_closure(ref f) => (f.abi, f.sig.output),
_ => fail!("expected bare rust fn or closure in trans_call_inner")
};
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)
}
Intrinsic(node, substs) => {
assert!(abi == synabi::RustIntrinsic);
assert!(dest.is_some());
let call_info = call_info.expect("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(substs, disr) => {
assert!(dest.is_some());
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
let ctor_ty = callee_ty.subst(bcx.tcx(), &substs);
return base::trans_named_tuple_constructor(bcx, ctor_ty, disr,
args, dest.unwrap());
}
};
// Intrinsics should not become actual functions.
// We trans them in place in `trans_intrinsic_call`
assert!(abi != synabi::RustIntrinsic);
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 = match dest {
None => {
assert!(!type_of::return_uses_outptr(ccx, ret_ty));
None
}
Some(expr::SaveIn(dst)) => Some(dst),
Some(expr::Ignore) if !is_rust_fn ||
type_of::return_uses_outptr(ccx, ret_ty) ||
ty::type_needs_drop(bcx.tcx(), ret_ty) => {
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()))
}
}
Some(expr::Ignore) => 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 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(),
abi);
fcx.pop_custom_cleanup_scope(arg_cleanup_scope);
// Invoke the actual rust fn and update bcx/llresult.
let (llret, b) = base::invoke(bcx,
llfn,
llargs,
callee_ty,
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_ty(bcx, llret, llretslot, ret_ty)
}
}
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,
abi);
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, opt_llretslot) {
(Some(expr::Ignore), Some(llretslot)) => {
// drop the value if it is not being saved.
bcx = glue::drop_ty(bcx, llretslot, ret_ty);
call_lifetime_end(bcx, llretslot);
}
_ => {}
}
if ty::type_is_bot(ret_ty) {
Unreachable(bcx);
}
Result::new(bcx, llresult)
}
pub enum CallArgs<'a> {
// 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 [Gc<ast::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))`. `lhs`
// is the left-hand-side and `rhs/rhs_id` is the datum/expr-id of
// the right-hand-side (if any).
ArgOverloadedOp(Datum<Expr>, Option<(Datum<Expr>, ast::NodeId)>),
// Supply value of arguments as a list of expressions that must be
// translated, for overloaded call operators.
ArgOverloadedCall(&'a [Gc<ast::Expr>]),
}
fn trans_args_under_call_abi<'a>(
mut bcx: &'a Block<'a>,
arg_exprs: &[Gc<ast::Expr>],
fn_ty: ty::t,
llargs: &mut Vec<ValueRef>,
arg_cleanup_scope: cleanup::ScopeId,
ignore_self: bool)
-> &'a Block<'a> {
// Translate the `self` argument first.
let arg_tys = ty::ty_fn_args(fn_ty);
if !ignore_self {
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &*arg_exprs[0]));
llargs.push(unpack_result!(bcx, {
trans_arg_datum(bcx,
*arg_tys.get(0),
arg_datum,
arg_cleanup_scope,
DontAutorefArg)
}))
}
// Now untuple the rest of the arguments.
let tuple_expr = arg_exprs[1];
let tuple_type = node_id_type(bcx, tuple_expr.id);
match ty::get(tuple_type).sty {
ty::ty_tup(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 in range(0, field_types.len()) {
let arg_datum = tuple_lvalue_datum.get_element(
*field_types.get(i),
|srcval| {
adt::trans_field_ptr(bcx, repr_ptr, srcval, 0, i)
});
let arg_datum = arg_datum.to_expr_datum();
let arg_datum =
unpack_datum!(bcx, arg_datum.to_rvalue_datum(bcx, "arg"));
let arg_datum =
unpack_datum!(bcx, arg_datum.to_appropriate_datum(bcx));
llargs.push(arg_datum.add_clean(bcx.fcx, arg_cleanup_scope));
}
}
ty::ty_nil => {}
_ => {
bcx.sess().span_bug(tuple_expr.span,
"argument to `.call()` wasn't a tuple?!")
}
};
bcx
}
fn trans_overloaded_call_args<'a>(
mut bcx: &'a Block<'a>,
arg_exprs: &[Gc<ast::Expr>],
fn_ty: ty::t,
llargs: &mut Vec<ValueRef>,
arg_cleanup_scope: cleanup::ScopeId,
ignore_self: bool)
-> &'a Block<'a> {
// Translate the `self` argument first.
let arg_tys = ty::ty_fn_args(fn_ty);
if !ignore_self {
let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &*arg_exprs[0]));
llargs.push(unpack_result!(bcx, {
trans_arg_datum(bcx,