1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10 //! Translate the completed AST to the LLVM IR.
12 //! Some functions here, such as trans_block and trans_expr, return a value --
13 //! the result of the translation to LLVM -- while others, such as trans_fn,
14 //! trans_impl, and trans_item, are called only for the side effect of adding a
15 //! particular definition to the LLVM IR output we're producing.
17 //! Hopefully useful general knowledge about trans:
19 //! * There's no way to find out the Ty type of a ValueRef. Doing so
20 //! would be "trying to get the eggs out of an omelette" (credit:
21 //! pcwalton). You can, instead, find out its TypeRef by calling val_ty,
22 //! but one TypeRef corresponds to many `Ty`s; for instance, tup(int, int,
23 //! int) and rec(x=int, y=int, z=int) will have the same TypeRef.
25 #![allow(non_camel_case_types)]
27 pub use self::ValueOrigin
::*;
29 use super::CrateTranslation
;
30 use super::ModuleTranslation
;
32 use back
::link
::mangle_exported_name
;
33 use back
::{link, abi}
;
35 use llvm
::{BasicBlockRef, Linkage, ValueRef, Vector, get_param}
;
38 use middle
::cstore
::CrateStore
;
39 use middle
::def_id
::DefId
;
41 use middle
::lang_items
::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem}
;
42 use middle
::weak_lang_items
;
43 use middle
::pat_util
::simple_name
;
44 use middle
::subst
::{self, Substs}
;
46 use middle
::ty
::{self, Ty, TypeFoldable}
;
47 use middle
::ty
::adjustment
::CustomCoerceUnsized
;
48 use rustc
::dep_graph
::DepNode
;
49 use rustc
::front
::map
as hir_map
;
50 use rustc
::util
::common
::time
;
51 use rustc
::mir
::mir_map
::MirMap
;
52 use session
::config
::{self, NoDebugInfo, FullDebugInfo}
;
56 use trans
::assert_dep_graph
;
57 use trans
::attributes
;
59 use trans
::builder
::{Builder, noname}
;
61 use trans
::cleanup
::{self, CleanupMethods, DropHint}
;
63 use trans
::common
::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_uint, C_integral}
;
64 use trans
::collector
::{self, TransItem, TransItemState, TransItemCollectionMode}
;
65 use trans
::common
::{C_null, C_struct_in_context, C_u64, C_u8, C_undef}
;
66 use trans
::common
::{CrateContext, DropFlagHintsMap, Field, FunctionContext}
;
67 use trans
::common
::{Result, NodeIdAndSpan, VariantInfo}
;
68 use trans
::common
::{node_id_type, return_type_is_void, fulfill_obligation}
;
69 use trans
::common
::{type_is_immediate, type_is_zero_size, val_ty}
;
72 use trans
::context
::SharedCrateContext
;
73 use trans
::controlflow
;
75 use trans
::debuginfo
::{self, DebugLoc, ToDebugLoc}
;
82 use trans
::machine
::{llsize_of, llsize_of_real}
;
85 use trans
::monomorphize
;
87 use trans
::type_
::Type
;
89 use trans
::type_of
::*;
90 use trans
::value
::Value
;
92 use util
::common
::indenter
;
93 use util
::sha2
::Sha256
;
94 use util
::nodemap
::{NodeMap, NodeSet}
;
96 use arena
::TypedArena
;
98 use std
::ffi
::{CStr, CString}
;
99 use std
::cell
::{Cell, RefCell}
;
100 use std
::collections
::{HashMap, HashSet}
;
102 use std
::{i8, i16, i32, i64}
;
103 use syntax
::abi
::Abi
;
104 use syntax
::codemap
::{Span, DUMMY_SP}
;
105 use syntax
::parse
::token
::InternedString
;
106 use syntax
::attr
::AttrMetaMethods
;
109 use rustc_front
::intravisit
::{self, Visitor}
;
110 use rustc_front
::hir
;
114 static TASK_LOCAL_INSN_KEY
: RefCell
<Option
<Vec
<&'
static str>>> = {
119 pub fn with_insn_ctxt
<F
>(blk
: F
)
120 where F
: FnOnce(&[&'
static str])
122 TASK_LOCAL_INSN_KEY
.with(move |slot
| {
123 slot
.borrow().as_ref().map(move |s
| blk(s
));
127 pub fn init_insn_ctxt() {
128 TASK_LOCAL_INSN_KEY
.with(|slot
| {
129 *slot
.borrow_mut() = Some(Vec
::new());
133 pub struct _InsnCtxt
{
134 _cannot_construct_outside_of_this_module
: (),
137 impl Drop
for _InsnCtxt
{
139 TASK_LOCAL_INSN_KEY
.with(|slot
| {
140 match slot
.borrow_mut().as_mut() {
150 pub fn push_ctxt(s
: &'
static str) -> _InsnCtxt
{
151 debug
!("new InsnCtxt: {}", s
);
152 TASK_LOCAL_INSN_KEY
.with(|slot
| {
153 if let Some(ctx
) = slot
.borrow_mut().as_mut() {
158 _cannot_construct_outside_of_this_module
: (),
162 pub struct StatRecorder
<'a
, 'tcx
: 'a
> {
163 ccx
: &'a CrateContext
<'a
, 'tcx
>,
164 name
: Option
<String
>,
168 impl<'a
, 'tcx
> StatRecorder
<'a
, 'tcx
> {
169 pub fn new(ccx
: &'a CrateContext
<'a
, 'tcx
>, name
: String
) -> StatRecorder
<'a
, 'tcx
> {
170 let istart
= ccx
.stats().n_llvm_insns
.get();
179 impl<'a
, 'tcx
> Drop
for StatRecorder
<'a
, 'tcx
> {
181 if self.ccx
.sess().trans_stats() {
182 let iend
= self.ccx
.stats().n_llvm_insns
.get();
187 .push((self.name
.take().unwrap(), iend
- self.istart
));
188 self.ccx
.stats().n_fns
.set(self.ccx
.stats().n_fns
.get() + 1);
189 // Reset LLVM insn count to avoid compound costs.
190 self.ccx
.stats().n_llvm_insns
.set(self.istart
);
195 fn get_extern_rust_fn
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
200 if let Some(n
) = ccx
.externs().borrow().get(name
) {
204 let f
= declare
::declare_rust_fn(ccx
, name
, fn_ty
);
206 let attrs
= ccx
.sess().cstore
.item_attrs(did
);
207 attributes
::from_fn_attrs(ccx
, &attrs
[..], f
);
209 ccx
.externs().borrow_mut().insert(name
.to_string(), f
);
213 pub fn self_type_for_closure
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
217 let closure_kind
= ccx
.tcx().closure_kind(closure_id
);
219 ty
::FnClosureKind
=> {
220 ccx
.tcx().mk_imm_ref(ccx
.tcx().mk_region(ty
::ReStatic
), fn_ty
)
222 ty
::FnMutClosureKind
=> {
223 ccx
.tcx().mk_mut_ref(ccx
.tcx().mk_region(ty
::ReStatic
), fn_ty
)
225 ty
::FnOnceClosureKind
=> fn_ty
,
229 pub fn kind_for_closure(ccx
: &CrateContext
, closure_id
: DefId
) -> ty
::ClosureKind
{
230 *ccx
.tcx().tables
.borrow().closure_kinds
.get(&closure_id
).unwrap()
233 pub fn get_extern_const
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
237 let name
= ccx
.sess().cstore
.item_symbol(did
);
238 let ty
= type_of(ccx
, t
);
239 if let Some(n
) = ccx
.externs().borrow_mut().get(&name
) {
242 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
243 // FIXME(nagisa): investigate whether it can be changed into define_global
244 let c
= declare
::declare_global(ccx
, &name
[..], ty
);
245 // Thread-local statics in some other crate need to *always* be linked
246 // against in a thread-local fashion, so we need to be sure to apply the
247 // thread-local attribute locally if it was present remotely. If we
248 // don't do this then linker errors can be generated where the linker
249 // complains that one object files has a thread local version of the
250 // symbol and another one doesn't.
251 for attr
in ccx
.tcx().get_attrs(did
).iter() {
252 if attr
.check_name("thread_local") {
253 llvm
::set_thread_local(c
, true);
256 if ccx
.use_dll_storage_attrs() {
257 llvm
::SetDLLStorageClass(c
, llvm
::DLLImportStorageClass
);
259 ccx
.externs().borrow_mut().insert(name
.to_string(), c
);
263 fn require_alloc_fn
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>, info_ty
: Ty
<'tcx
>, it
: LangItem
) -> DefId
{
264 match bcx
.tcx().lang_items
.require(it
) {
267 bcx
.sess().fatal(&format
!("allocation of `{}` {}", info_ty
, s
));
272 // The following malloc_raw_dyn* functions allocate a box to contain
273 // a given type, but with a potentially dynamic size.
275 pub fn malloc_raw_dyn
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
281 -> Result
<'blk
, 'tcx
> {
282 let _icx
= push_ctxt("malloc_raw_exchange");
285 let r
= callee
::trans_lang_call(bcx
,
286 require_alloc_fn(bcx
, info_ty
, ExchangeMallocFnLangItem
),
291 Result
::new(r
.bcx
, PointerCast(r
.bcx
, r
.val
, llty_ptr
))
295 pub fn bin_op_to_icmp_predicate(ccx
: &CrateContext
,
298 -> llvm
::IntPredicate
{
300 hir
::BiEq
=> llvm
::IntEQ
,
301 hir
::BiNe
=> llvm
::IntNE
,
302 hir
::BiLt
=> if signed { llvm::IntSLT }
else { llvm::IntULT }
,
303 hir
::BiLe
=> if signed { llvm::IntSLE }
else { llvm::IntULE }
,
304 hir
::BiGt
=> if signed { llvm::IntSGT }
else { llvm::IntUGT }
,
305 hir
::BiGe
=> if signed { llvm::IntSGE }
else { llvm::IntUGE }
,
308 .bug(&format
!("comparison_op_to_icmp_predicate: expected comparison operator, \
315 pub fn bin_op_to_fcmp_predicate(ccx
: &CrateContext
, op
: hir
::BinOp_
) -> llvm
::RealPredicate
{
317 hir
::BiEq
=> llvm
::RealOEQ
,
318 hir
::BiNe
=> llvm
::RealUNE
,
319 hir
::BiLt
=> llvm
::RealOLT
,
320 hir
::BiLe
=> llvm
::RealOLE
,
321 hir
::BiGt
=> llvm
::RealOGT
,
322 hir
::BiGe
=> llvm
::RealOGE
,
325 .bug(&format
!("comparison_op_to_fcmp_predicate: expected comparison operator, \
332 pub fn compare_fat_ptrs
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
343 let addr_eq
= ICmp(bcx
, llvm
::IntEQ
, lhs_addr
, rhs_addr
, debug_loc
);
344 let extra_eq
= ICmp(bcx
, llvm
::IntEQ
, lhs_extra
, rhs_extra
, debug_loc
);
345 And(bcx
, addr_eq
, extra_eq
, debug_loc
)
348 let addr_eq
= ICmp(bcx
, llvm
::IntNE
, lhs_addr
, rhs_addr
, debug_loc
);
349 let extra_eq
= ICmp(bcx
, llvm
::IntNE
, lhs_extra
, rhs_extra
, debug_loc
);
350 Or(bcx
, addr_eq
, extra_eq
, debug_loc
)
352 hir
::BiLe
| hir
::BiLt
| hir
::BiGe
| hir
::BiGt
=> {
353 // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
354 let (op
, strict_op
) = match op
{
355 hir
::BiLt
=> (llvm
::IntULT
, llvm
::IntULT
),
356 hir
::BiLe
=> (llvm
::IntULE
, llvm
::IntULT
),
357 hir
::BiGt
=> (llvm
::IntUGT
, llvm
::IntUGT
),
358 hir
::BiGe
=> (llvm
::IntUGE
, llvm
::IntUGT
),
362 let addr_eq
= ICmp(bcx
, llvm
::IntEQ
, lhs_addr
, rhs_addr
, debug_loc
);
363 let extra_op
= ICmp(bcx
, op
, lhs_extra
, rhs_extra
, debug_loc
);
364 let addr_eq_extra_op
= And(bcx
, addr_eq
, extra_op
, debug_loc
);
366 let addr_strict
= ICmp(bcx
, strict_op
, lhs_addr
, rhs_addr
, debug_loc
);
367 Or(bcx
, addr_strict
, addr_eq_extra_op
, debug_loc
)
370 bcx
.tcx().sess
.bug("unexpected fat ptr binop");
375 pub fn compare_scalar_types
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
383 ty
::TyTuple(ref tys
) if tys
.is_empty() => {
384 // We don't need to do actual comparisons for nil.
385 // () == () holds but () < () does not.
387 hir
::BiEq
| hir
::BiLe
| hir
::BiGe
=> return C_bool(bcx
.ccx(), true),
388 hir
::BiNe
| hir
::BiLt
| hir
::BiGt
=> return C_bool(bcx
.ccx(), false),
389 // refinements would be nice
390 _
=> bcx
.sess().bug("compare_scalar_types: must be a comparison operator"),
393 ty
::TyBareFn(..) | ty
::TyBool
| ty
::TyUint(_
) | ty
::TyChar
=> {
395 bin_op_to_icmp_predicate(bcx
.ccx(), op
, false),
400 ty
::TyRawPtr(mt
) if common
::type_is_sized(bcx
.tcx(), mt
.ty
) => {
402 bin_op_to_icmp_predicate(bcx
.ccx(), op
, false),
408 let lhs_addr
= Load(bcx
, GEPi(bcx
, lhs
, &[0, abi
::FAT_PTR_ADDR
]));
409 let lhs_extra
= Load(bcx
, GEPi(bcx
, lhs
, &[0, abi
::FAT_PTR_EXTRA
]));
411 let rhs_addr
= Load(bcx
, GEPi(bcx
, rhs
, &[0, abi
::FAT_PTR_ADDR
]));
412 let rhs_extra
= Load(bcx
, GEPi(bcx
, rhs
, &[0, abi
::FAT_PTR_EXTRA
]));
413 compare_fat_ptrs(bcx
,
424 bin_op_to_icmp_predicate(bcx
.ccx(), op
, true),
431 bin_op_to_fcmp_predicate(bcx
.ccx(), op
),
436 // Should never get here, because t is scalar.
437 _
=> bcx
.sess().bug("non-scalar type passed to compare_scalar_types"),
441 pub fn compare_simd_types
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
449 let signed
= match t
.sty
{
451 let cmp
= bin_op_to_fcmp_predicate(bcx
.ccx(), op
);
452 return SExt(bcx
, FCmp(bcx
, cmp
, lhs
, rhs
, debug_loc
), ret_ty
);
454 ty
::TyUint(_
) => false,
455 ty
::TyInt(_
) => true,
456 _
=> bcx
.sess().bug("compare_simd_types: invalid SIMD type"),
459 let cmp
= bin_op_to_icmp_predicate(bcx
.ccx(), op
, signed
);
460 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
461 // to get the correctly sized type. This will compile to a single instruction
462 // once the IR is converted to assembly if the SIMD instruction is supported
463 // by the target architecture.
464 SExt(bcx
, ICmp(bcx
, cmp
, lhs
, rhs
, debug_loc
), ret_ty
)
467 // Iterates through the elements of a structural type.
468 pub fn iter_structural_ty
<'blk
, 'tcx
, F
>(cx
: Block
<'blk
, 'tcx
>,
473 where F
: FnMut(Block
<'blk
, 'tcx
>, ValueRef
, Ty
<'tcx
>) -> Block
<'blk
, 'tcx
>
475 let _icx
= push_ctxt("iter_structural_ty");
477 fn iter_variant
<'blk
, 'tcx
, F
>(cx
: Block
<'blk
, 'tcx
>,
478 repr
: &adt
::Repr
<'tcx
>,
479 av
: adt
::MaybeSizedValue
,
480 variant
: ty
::VariantDef
<'tcx
>,
481 substs
: &Substs
<'tcx
>,
484 where F
: FnMut(Block
<'blk
, 'tcx
>, ValueRef
, Ty
<'tcx
>) -> Block
<'blk
, 'tcx
>
486 let _icx
= push_ctxt("iter_variant");
490 for (i
, field
) in variant
.fields
.iter().enumerate() {
491 let arg
= monomorphize
::field_ty(tcx
, substs
, field
);
493 adt
::trans_field_ptr(cx
, repr
, av
, Disr
::from(variant
.disr_val
), i
),
499 let value
= if common
::type_is_sized(cx
.tcx(), t
) {
500 adt
::MaybeSizedValue
::sized(av
)
502 let data
= Load(cx
, expr
::get_dataptr(cx
, av
));
503 let info
= Load(cx
, expr
::get_meta(cx
, av
));
504 adt
::MaybeSizedValue
::unsized_(data
, info
)
509 ty
::TyStruct(..) => {
510 let repr
= adt
::represent_type(cx
.ccx(), t
);
511 let VariantInfo { fields, discr }
= VariantInfo
::from_ty(cx
.tcx(), t
, None
);
512 for (i
, &Field(_
, field_ty
)) in fields
.iter().enumerate() {
513 let llfld_a
= adt
::trans_field_ptr(cx
, &repr
, value
, Disr
::from(discr
), i
);
515 let val
= if common
::type_is_sized(cx
.tcx(), field_ty
) {
518 let scratch
= datum
::rvalue_scratch_datum(cx
, field_ty
, "__fat_ptr_iter");
519 Store(cx
, llfld_a
, expr
::get_dataptr(cx
, scratch
.val
));
520 Store(cx
, value
.meta
, expr
::get_meta(cx
, scratch
.val
));
523 cx
= f(cx
, val
, field_ty
);
526 ty
::TyClosure(_
, ref substs
) => {
527 let repr
= adt
::represent_type(cx
.ccx(), t
);
528 for (i
, upvar_ty
) in substs
.upvar_tys
.iter().enumerate() {
529 let llupvar
= adt
::trans_field_ptr(cx
, &repr
, value
, Disr(0), i
);
530 cx
= f(cx
, llupvar
, upvar_ty
);
533 ty
::TyArray(_
, n
) => {
534 let (base
, len
) = tvec
::get_fixed_base_and_len(cx
, value
.value
, n
);
535 let unit_ty
= t
.sequence_element_type(cx
.tcx());
536 cx
= tvec
::iter_vec_raw(cx
, base
, unit_ty
, len
, f
);
538 ty
::TySlice(_
) | ty
::TyStr
=> {
539 let unit_ty
= t
.sequence_element_type(cx
.tcx());
540 cx
= tvec
::iter_vec_raw(cx
, value
.value
, unit_ty
, value
.meta
, f
);
542 ty
::TyTuple(ref args
) => {
543 let repr
= adt
::represent_type(cx
.ccx(), t
);
544 for (i
, arg
) in args
.iter().enumerate() {
545 let llfld_a
= adt
::trans_field_ptr(cx
, &repr
, value
, Disr(0), i
);
546 cx
= f(cx
, llfld_a
, *arg
);
549 ty
::TyEnum(en
, substs
) => {
553 let repr
= adt
::represent_type(ccx
, t
);
554 let n_variants
= en
.variants
.len();
556 // NB: we must hit the discriminant first so that structural
557 // comparison know not to proceed when the discriminants differ.
559 match adt
::trans_switch(cx
, &repr
, av
, false) {
560 (_match
::Single
, None
) => {
562 assert
!(n_variants
== 1);
563 cx
= iter_variant(cx
, &repr
, adt
::MaybeSizedValue
::sized(av
),
564 &en
.variants
[0], substs
, &mut f
);
567 (_match
::Switch
, Some(lldiscrim_a
)) => {
568 cx
= f(cx
, lldiscrim_a
, cx
.tcx().types
.isize);
570 // Create a fall-through basic block for the "else" case of
571 // the switch instruction we're about to generate. Note that
572 // we do **not** use an Unreachable instruction here, even
573 // though most of the time this basic block will never be hit.
575 // When an enum is dropped it's contents are currently
576 // overwritten to DTOR_DONE, which means the discriminant
577 // could have changed value to something not within the actual
578 // range of the discriminant. Currently this function is only
579 // used for drop glue so in this case we just return quickly
580 // from the outer function, and any other use case will only
581 // call this for an already-valid enum in which case the `ret
582 // void` will never be hit.
583 let ret_void_cx
= fcx
.new_temp_block("enum-iter-ret-void");
584 RetVoid(ret_void_cx
, DebugLoc
::None
);
585 let llswitch
= Switch(cx
, lldiscrim_a
, ret_void_cx
.llbb
, n_variants
);
586 let next_cx
= fcx
.new_temp_block("enum-iter-next");
588 for variant
in &en
.variants
{
589 let variant_cx
= fcx
.new_temp_block(&format
!("enum-iter-variant-{}",
592 let case_val
= adt
::trans_case(cx
, &repr
, Disr
::from(variant
.disr_val
));
593 AddCase(llswitch
, case_val
, variant_cx
.llbb
);
594 let variant_cx
= iter_variant(variant_cx
,
600 Br(variant_cx
, next_cx
.llbb
, DebugLoc
::None
);
604 _
=> ccx
.sess().unimpl("value from adt::trans_switch in iter_structural_ty"),
608 cx
.sess().unimpl(&format
!("type in iter_structural_ty: {}", t
))
615 /// Retrieve the information we are losing (making dynamic) in an unsizing
618 /// The `old_info` argument is a bit funny. It is intended for use
619 /// in an upcast, where the new vtable for an object will be drived
620 /// from the old one.
621 pub fn unsized_info
<'ccx
, 'tcx
>(ccx
: &CrateContext
<'ccx
, 'tcx
>,
624 old_info
: Option
<ValueRef
>,
625 param_substs
: &'tcx Substs
<'tcx
>)
627 let (source
, target
) = ccx
.tcx().struct_lockstep_tails(source
, target
);
628 match (&source
.sty
, &target
.sty
) {
629 (&ty
::TyArray(_
, len
), &ty
::TySlice(_
)) => C_uint(ccx
, len
),
630 (&ty
::TyTrait(_
), &ty
::TyTrait(_
)) => {
631 // For now, upcasts are limited to changes in marker
632 // traits, and hence never actually require an actual
633 // change to the vtable.
634 old_info
.expect("unsized_info: missing old info for trait upcast")
636 (_
, &ty
::TyTrait(box ty
::TraitTy { ref principal, .. }
)) => {
637 // Note that we preserve binding levels here:
638 let substs
= principal
.0.substs
.with_self_ty(source
).erase_regions();
639 let substs
= ccx
.tcx().mk_substs(substs
);
640 let trait_ref
= ty
::Binder(ty
::TraitRef
{
641 def_id
: principal
.def_id(),
644 consts
::ptrcast(meth
::get_vtable(ccx
, trait_ref
, param_substs
),
645 Type
::vtable_ptr(ccx
))
647 _
=> ccx
.sess().bug(&format
!("unsized_info: invalid unsizing {:?} -> {:?}",
653 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
654 pub fn unsize_thin_ptr
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
658 -> (ValueRef
, ValueRef
) {
659 debug
!("unsize_thin_ptr: {:?} => {:?}", src_ty
, dst_ty
);
660 match (&src_ty
.sty
, &dst_ty
.sty
) {
661 (&ty
::TyBox(a
), &ty
::TyBox(b
)) |
662 (&ty
::TyRef(_
, ty
::TypeAndMut { ty: a, .. }
),
663 &ty
::TyRef(_
, ty
::TypeAndMut { ty: b, .. }
)) |
664 (&ty
::TyRef(_
, ty
::TypeAndMut { ty: a, .. }
),
665 &ty
::TyRawPtr(ty
::TypeAndMut { ty: b, .. }
)) |
666 (&ty
::TyRawPtr(ty
::TypeAndMut { ty: a, .. }
),
667 &ty
::TyRawPtr(ty
::TypeAndMut { ty: b, .. }
)) => {
668 assert
!(common
::type_is_sized(bcx
.tcx(), a
));
669 let ptr_ty
= type_of
::in_memory_type_of(bcx
.ccx(), b
).ptr_to();
670 (PointerCast(bcx
, src
, ptr_ty
),
671 unsized_info(bcx
.ccx(), a
, b
, None
, bcx
.fcx
.param_substs
))
673 _
=> bcx
.sess().bug("unsize_thin_ptr: called on bad types"),
677 /// Coerce `src`, which is a reference to a value of type `src_ty`,
678 /// to a value of type `dst_ty` and store the result in `dst`
679 pub fn coerce_unsized_into
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
684 match (&src_ty
.sty
, &dst_ty
.sty
) {
685 (&ty
::TyBox(..), &ty
::TyBox(..)) |
686 (&ty
::TyRef(..), &ty
::TyRef(..)) |
687 (&ty
::TyRef(..), &ty
::TyRawPtr(..)) |
688 (&ty
::TyRawPtr(..), &ty
::TyRawPtr(..)) => {
689 let (base
, info
) = if common
::type_is_fat_ptr(bcx
.tcx(), src_ty
) {
690 // fat-ptr to fat-ptr unsize preserves the vtable
691 load_fat_ptr(bcx
, src
, src_ty
)
693 let base
= load_ty(bcx
, src
, src_ty
);
694 unsize_thin_ptr(bcx
, base
, src_ty
, dst_ty
)
696 store_fat_ptr(bcx
, base
, info
, dst
, dst_ty
);
699 // This can be extended to enums and tuples in the future.
700 // (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) |
701 (&ty
::TyStruct(def_a
, _
), &ty
::TyStruct(def_b
, _
)) => {
702 assert_eq
!(def_a
, def_b
);
704 let src_repr
= adt
::represent_type(bcx
.ccx(), src_ty
);
705 let src_fields
= match &*src_repr
{
706 &adt
::Repr
::Univariant(ref s
, _
) => &s
.fields
,
707 _
=> bcx
.sess().bug("struct has non-univariant repr"),
709 let dst_repr
= adt
::represent_type(bcx
.ccx(), dst_ty
);
710 let dst_fields
= match &*dst_repr
{
711 &adt
::Repr
::Univariant(ref s
, _
) => &s
.fields
,
712 _
=> bcx
.sess().bug("struct has non-univariant repr"),
715 let src
= adt
::MaybeSizedValue
::sized(src
);
716 let dst
= adt
::MaybeSizedValue
::sized(dst
);
718 let iter
= src_fields
.iter().zip(dst_fields
).enumerate();
719 for (i
, (src_fty
, dst_fty
)) in iter
{
720 if type_is_zero_size(bcx
.ccx(), dst_fty
) {
724 let src_f
= adt
::trans_field_ptr(bcx
, &src_repr
, src
, Disr(0), i
);
725 let dst_f
= adt
::trans_field_ptr(bcx
, &dst_repr
, dst
, Disr(0), i
);
726 if src_fty
== dst_fty
{
727 memcpy_ty(bcx
, dst_f
, src_f
, src_fty
);
729 coerce_unsized_into(bcx
, src_f
, src_fty
, dst_f
, dst_fty
);
733 _
=> bcx
.sess().bug(&format
!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
739 pub fn custom_coerce_unsize_info
<'ccx
, 'tcx
>(ccx
: &CrateContext
<'ccx
, 'tcx
>,
742 -> CustomCoerceUnsized
{
743 let trait_substs
= Substs
::erased(subst
::VecPerParamSpace
::new(vec
![target_ty
],
746 let trait_ref
= ty
::Binder(ty
::TraitRef
{
747 def_id
: ccx
.tcx().lang_items
.coerce_unsized_trait().unwrap(),
748 substs
: ccx
.tcx().mk_substs(trait_substs
)
751 match fulfill_obligation(ccx
, DUMMY_SP
, trait_ref
) {
752 traits
::VtableImpl(traits
::VtableImplData { impl_def_id, .. }
) => {
753 ccx
.tcx().custom_coerce_unsized_kind(impl_def_id
)
756 ccx
.sess().bug(&format
!("invalid CoerceUnsized vtable: {:?}",
762 pub fn cast_shift_expr_rhs(cx
: Block
, op
: hir
::BinOp_
, lhs
: ValueRef
, rhs
: ValueRef
) -> ValueRef
{
763 cast_shift_rhs(op
, lhs
, rhs
, |a
, b
| Trunc(cx
, a
, b
), |a
, b
| ZExt(cx
, a
, b
))
766 pub fn cast_shift_const_rhs(op
: hir
::BinOp_
, lhs
: ValueRef
, rhs
: ValueRef
) -> ValueRef
{
770 |a
, b
| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) }
,
771 |a
, b
| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) }
)
774 fn cast_shift_rhs
<F
, G
>(op
: hir
::BinOp_
,
780 where F
: FnOnce(ValueRef
, Type
) -> ValueRef
,
781 G
: FnOnce(ValueRef
, Type
) -> ValueRef
783 // Shifts may have any size int on the rhs
784 if rustc_front
::util
::is_shift_binop(op
) {
785 let mut rhs_llty
= val_ty(rhs
);
786 let mut lhs_llty
= val_ty(lhs
);
787 if rhs_llty
.kind() == Vector
{
788 rhs_llty
= rhs_llty
.element_type()
790 if lhs_llty
.kind() == Vector
{
791 lhs_llty
= lhs_llty
.element_type()
793 let rhs_sz
= rhs_llty
.int_width();
794 let lhs_sz
= lhs_llty
.int_width();
797 } else if lhs_sz
> rhs_sz
{
798 // FIXME (#1877: If shifting by negative
799 // values becomes not undefined then this is wrong.
809 pub fn llty_and_min_for_signed_ty
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>,
814 let llty
= Type
::int_from_ty(cx
.ccx(), t
);
816 ast
::IntTy
::Is
if llty
== Type
::i32(cx
.ccx()) => i32::MIN
as u64,
817 ast
::IntTy
::Is
=> i64::MIN
as u64,
818 ast
::IntTy
::I8
=> i8::MIN
as u64,
819 ast
::IntTy
::I16
=> i16::MIN
as u64,
820 ast
::IntTy
::I32
=> i32::MIN
as u64,
821 ast
::IntTy
::I64
=> i64::MIN
as u64,
829 pub fn fail_if_zero_or_overflows
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>,
830 call_info
: NodeIdAndSpan
,
835 -> Block
<'blk
, 'tcx
> {
836 let (zero_text
, overflow_text
) = if divrem
.node
== hir
::BiDiv
{
837 ("attempted to divide by zero",
838 "attempted to divide with overflow")
840 ("attempted remainder with a divisor of zero",
841 "attempted remainder with overflow")
843 let debug_loc
= call_info
.debug_loc();
845 let (is_zero
, is_signed
) = match rhs_t
.sty
{
847 let zero
= C_integral(Type
::int_from_ty(cx
.ccx(), t
), 0, false);
848 (ICmp(cx
, llvm
::IntEQ
, rhs
, zero
, debug_loc
), true)
851 let zero
= C_integral(Type
::uint_from_ty(cx
.ccx(), t
), 0, false);
852 (ICmp(cx
, llvm
::IntEQ
, rhs
, zero
, debug_loc
), false)
854 ty
::TyStruct(def
, _
) if def
.is_simd() => {
855 let mut res
= C_bool(cx
.ccx(), false);
856 for i
in 0..rhs_t
.simd_size(cx
.tcx()) {
859 IsNull(cx
, ExtractElement(cx
, rhs
, C_int(cx
.ccx(), i
as i64))),
865 cx
.sess().bug(&format
!("fail-if-zero on unexpected type: {}", rhs_t
));
868 let bcx
= with_cond(cx
, is_zero
, |bcx
| {
869 controlflow
::trans_fail(bcx
, call_info
, InternedString
::new(zero_text
))
872 // To quote LLVM's documentation for the sdiv instruction:
874 // Division by zero leads to undefined behavior. Overflow also leads
875 // to undefined behavior; this is a rare case, but can occur, for
876 // example, by doing a 32-bit division of -2147483648 by -1.
878 // In order to avoid undefined behavior, we perform runtime checks for
879 // signed division/remainder which would trigger overflow. For unsigned
880 // integers, no action beyond checking for zero need be taken.
882 let (llty
, min
) = llty_and_min_for_signed_ty(cx
, rhs_t
);
883 let minus_one
= ICmp(bcx
,
886 C_integral(llty
, !0, false),
888 with_cond(bcx
, minus_one
, |bcx
| {
889 let is_min
= ICmp(bcx
,
892 C_integral(llty
, min
, true),
894 with_cond(bcx
, is_min
, |bcx
| {
895 controlflow
::trans_fail(bcx
, call_info
, InternedString
::new(overflow_text
))
903 pub fn trans_external_path
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
907 let name
= ccx
.sess().cstore
.item_symbol(did
);
909 ty
::TyBareFn(_
, ref fn_ty
) => {
910 match ccx
.sess().target
.target
.adjust_abi(fn_ty
.abi
) {
911 Abi
::Rust
| Abi
::RustCall
=> {
912 get_extern_rust_fn(ccx
, t
, &name
[..], did
)
914 Abi
::RustIntrinsic
| Abi
::PlatformIntrinsic
=> {
915 ccx
.sess().bug("unexpected intrinsic in trans_external_path")
918 let attrs
= ccx
.sess().cstore
.item_attrs(did
);
919 foreign
::register_foreign_item_fn(ccx
, fn_ty
.abi
, t
, &name
, &attrs
)
924 get_extern_const(ccx
, did
, t
)
929 pub fn invoke
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
934 -> (ValueRef
, Block
<'blk
, 'tcx
>) {
935 let _icx
= push_ctxt("invoke_");
936 if bcx
.unreachable
.get() {
937 return (C_null(Type
::i8(bcx
.ccx())), bcx
);
940 let attributes
= attributes
::from_fn_type(bcx
.ccx(), fn_ty
);
942 match bcx
.opt_node_id
{
944 debug
!("invoke at ???");
947 debug
!("invoke at {}", bcx
.tcx().map
.node_to_string(id
));
951 if need_invoke(bcx
) {
952 debug
!("invoking {} at {:?}", bcx
.val_to_string(llfn
), bcx
.llbb
);
953 for &llarg
in llargs
{
954 debug
!("arg: {}", bcx
.val_to_string(llarg
));
956 let normal_bcx
= bcx
.fcx
.new_temp_block("normal-return");
957 let landing_pad
= bcx
.fcx
.get_landing_pad();
959 let llresult
= Invoke(bcx
,
966 return (llresult
, normal_bcx
);
968 debug
!("calling {} at {:?}", bcx
.val_to_string(llfn
), bcx
.llbb
);
969 for &llarg
in llargs
{
970 debug
!("arg: {}", bcx
.val_to_string(llarg
));
973 let llresult
= Call(bcx
, llfn
, &llargs
[..], Some(attributes
), debug_loc
);
974 return (llresult
, bcx
);
978 /// Returns whether this session's target will use SEH-based unwinding.
980 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
981 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
982 /// 64-bit MinGW) instead of "full SEH".
983 pub fn wants_msvc_seh(sess
: &Session
) -> bool
{
984 sess
.target
.target
.options
.is_like_msvc
987 pub fn avoid_invoke(bcx
: Block
) -> bool
{
988 bcx
.sess().no_landing_pads() || bcx
.lpad().is_some()
991 pub fn need_invoke(bcx
: Block
) -> bool
{
992 if avoid_invoke(bcx
) {
995 bcx
.fcx
.needs_invoke()
999 pub fn load_if_immediate
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, v
: ValueRef
, t
: Ty
<'tcx
>) -> ValueRef
{
1000 let _icx
= push_ctxt("load_if_immediate");
1001 if type_is_immediate(cx
.ccx(), t
) {
1002 return load_ty(cx
, v
, t
);
1007 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1008 /// differs from the type used for SSA values. Also handles various special cases where the type
1009 /// gives us better information about what we are loading.
1010 pub fn load_ty
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, ptr
: ValueRef
, t
: Ty
<'tcx
>) -> ValueRef
{
1011 if cx
.unreachable
.get() || type_is_zero_size(cx
.ccx(), t
) {
1012 return C_undef(type_of
::type_of(cx
.ccx(), t
));
1015 let ptr
= to_arg_ty_ptr(cx
, ptr
, t
);
1016 let align
= type_of
::align_of(cx
.ccx(), t
);
1018 if type_is_immediate(cx
.ccx(), t
) && type_of
::type_of(cx
.ccx(), t
).is_aggregate() {
1019 let load
= Load(cx
, ptr
);
1021 llvm
::LLVMSetAlignment(load
, align
);
1027 let global
= llvm
::LLVMIsAGlobalVariable(ptr
);
1028 if !global
.is_null() && llvm
::LLVMIsGlobalConstant(global
) == llvm
::True
{
1029 let val
= llvm
::LLVMGetInitializer(global
);
1031 return to_arg_ty(cx
, val
, t
);
1036 let val
= if t
.is_bool() {
1037 LoadRangeAssert(cx
, ptr
, 0, 2, llvm
::False
)
1038 } else if t
.is_char() {
1039 // a char is a Unicode codepoint, and so takes values from 0
1040 // to 0x10FFFF inclusive only.
1041 LoadRangeAssert(cx
, ptr
, 0, 0x10FFFF + 1, llvm
::False
)
1042 } else if (t
.is_region_ptr() || t
.is_unique()) && !common
::type_is_fat_ptr(cx
.tcx(), t
) {
1043 LoadNonNull(cx
, ptr
)
1049 llvm
::LLVMSetAlignment(val
, align
);
1052 to_arg_ty(cx
, val
, t
)
1055 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1056 /// differs from the type used for SSA values.
1057 pub fn store_ty
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, v
: ValueRef
, dst
: ValueRef
, t
: Ty
<'tcx
>) {
1058 if cx
.unreachable
.get() {
1062 debug
!("store_ty: {} : {:?} <- {}",
1063 cx
.val_to_string(dst
),
1065 cx
.val_to_string(v
));
1067 if common
::type_is_fat_ptr(cx
.tcx(), t
) {
1069 ExtractValue(cx
, v
, abi
::FAT_PTR_ADDR
),
1070 expr
::get_dataptr(cx
, dst
));
1072 ExtractValue(cx
, v
, abi
::FAT_PTR_EXTRA
),
1073 expr
::get_meta(cx
, dst
));
1075 let store
= Store(cx
, from_arg_ty(cx
, v
, t
), to_arg_ty_ptr(cx
, dst
, t
));
1077 llvm
::LLVMSetAlignment(store
, type_of
::align_of(cx
.ccx(), t
));
1082 pub fn store_fat_ptr
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>,
1087 // FIXME: emit metadata
1088 Store(cx
, data
, expr
::get_dataptr(cx
, dst
));
1089 Store(cx
, extra
, expr
::get_meta(cx
, dst
));
1092 pub fn load_fat_ptr
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>,
1095 -> (ValueRef
, ValueRef
) {
1096 // FIXME: emit metadata
1097 (Load(cx
, expr
::get_dataptr(cx
, src
)),
1098 Load(cx
, expr
::get_meta(cx
, src
)))
1101 pub fn from_arg_ty(bcx
: Block
, val
: ValueRef
, ty
: Ty
) -> ValueRef
{
1103 ZExt(bcx
, val
, Type
::i8(bcx
.ccx()))
1109 pub fn to_arg_ty(bcx
: Block
, val
: ValueRef
, ty
: Ty
) -> ValueRef
{
1111 Trunc(bcx
, val
, Type
::i1(bcx
.ccx()))
1117 pub fn to_arg_ty_ptr
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>, ptr
: ValueRef
, ty
: Ty
<'tcx
>) -> ValueRef
{
1118 if type_is_immediate(bcx
.ccx(), ty
) && type_of
::type_of(bcx
.ccx(), ty
).is_aggregate() {
1119 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1120 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1121 // and we have to convert it
1122 BitCast(bcx
, ptr
, type_of
::arg_type_of(bcx
.ccx(), ty
).ptr_to())
1128 pub fn init_local
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>, local
: &hir
::Local
) -> Block
<'blk
, 'tcx
> {
1129 debug
!("init_local(bcx={}, local.id={})", bcx
.to_str(), local
.id
);
1130 let _indenter
= indenter();
1131 let _icx
= push_ctxt("init_local");
1132 _match
::store_local(bcx
, local
)
1135 pub fn raw_block
<'blk
, 'tcx
>(fcx
: &'blk FunctionContext
<'blk
, 'tcx
>,
1136 llbb
: BasicBlockRef
)
1137 -> Block
<'blk
, 'tcx
> {
1138 common
::BlockS
::new(llbb
, None
, fcx
)
1141 pub fn with_cond
<'blk
, 'tcx
, F
>(bcx
: Block
<'blk
, 'tcx
>, val
: ValueRef
, f
: F
) -> Block
<'blk
, 'tcx
>
1142 where F
: FnOnce(Block
<'blk
, 'tcx
>) -> Block
<'blk
, 'tcx
>
1144 let _icx
= push_ctxt("with_cond");
1146 if bcx
.unreachable
.get() || common
::const_to_opt_uint(val
) == Some(0) {
1151 let next_cx
= fcx
.new_temp_block("next");
1152 let cond_cx
= fcx
.new_temp_block("cond");
1153 CondBr(bcx
, val
, cond_cx
.llbb
, next_cx
.llbb
, DebugLoc
::None
);
1154 let after_cx
= f(cond_cx
);
1155 if !after_cx
.terminated
.get() {
1156 Br(after_cx
, next_cx
.llbb
, DebugLoc
::None
);
1161 enum Lifetime { Start, End }
1163 // If LLVM lifetime intrinsic support is enabled (i.e. optimizations
1164 // on), and `ptr` is nonzero-sized, then extracts the size of `ptr`
1165 // and the intrinsic for `lt` and passes them to `emit`, which is in
1166 // charge of generating code to call the passed intrinsic on whatever
1167 // block of generated code is targetted for the intrinsic.
1169 // If LLVM lifetime intrinsic support is disabled (i.e. optimizations
1170 // off) or `ptr` is zero-sized, then no-op (does not call `emit`).
1171 fn core_lifetime_emit
<'blk
, 'tcx
, F
>(ccx
: &'blk CrateContext
<'blk
, 'tcx
>,
1175 where F
: FnOnce(&'blk CrateContext
<'blk
, 'tcx
>, machine
::llsize
, ValueRef
)
1177 if ccx
.sess().opts
.optimize
== config
::OptLevel
::No
{
1181 let _icx
= push_ctxt(match lt
{
1182 Lifetime
::Start
=> "lifetime_start",
1183 Lifetime
::End
=> "lifetime_end"
1186 let size
= machine
::llsize_of_alloc(ccx
, val_ty(ptr
).element_type());
1191 let lifetime_intrinsic
= ccx
.get_intrinsic(match lt
{
1192 Lifetime
::Start
=> "llvm.lifetime.start",
1193 Lifetime
::End
=> "llvm.lifetime.end"
1195 emit(ccx
, size
, lifetime_intrinsic
)
1198 pub fn call_lifetime_start(cx
: Block
, ptr
: ValueRef
) {
1199 core_lifetime_emit(cx
.ccx(), ptr
, Lifetime
::Start
, |ccx
, size
, lifetime_start
| {
1200 let ptr
= PointerCast(cx
, ptr
, Type
::i8p(ccx
));
1203 &[C_u64(ccx
, size
), ptr
],
1209 pub fn call_lifetime_end(cx
: Block
, ptr
: ValueRef
) {
1210 core_lifetime_emit(cx
.ccx(), ptr
, Lifetime
::End
, |ccx
, size
, lifetime_end
| {
1211 let ptr
= PointerCast(cx
, ptr
, Type
::i8p(ccx
));
1214 &[C_u64(ccx
, size
), ptr
],
1220 // Generates code for resumption of unwind at the end of a landing pad.
1221 pub fn trans_unwind_resume(bcx
: Block
, lpval
: ValueRef
) {
1222 if !bcx
.sess().target
.target
.options
.custom_unwind_resume
{
1225 let exc_ptr
= ExtractValue(bcx
, lpval
, 0);
1226 let llunwresume
= bcx
.fcx
.eh_unwind_resume();
1227 Call(bcx
, llunwresume
, &[exc_ptr
], None
, DebugLoc
::None
);
1233 pub fn call_memcpy(cx
: Block
, dst
: ValueRef
, src
: ValueRef
, n_bytes
: ValueRef
, align
: u32) {
1234 let _icx
= push_ctxt("call_memcpy");
1236 let ptr_width
= &ccx
.sess().target
.target
.target_pointer_width
[..];
1237 let key
= format
!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width
);
1238 let memcpy
= ccx
.get_intrinsic(&key
);
1239 let src_ptr
= PointerCast(cx
, src
, Type
::i8p(ccx
));
1240 let dst_ptr
= PointerCast(cx
, dst
, Type
::i8p(ccx
));
1241 let size
= IntCast(cx
, n_bytes
, ccx
.int_type());
1242 let align
= C_i32(ccx
, align
as i32);
1243 let volatile
= C_bool(ccx
, false);
1246 &[dst_ptr
, src_ptr
, size
, align
, volatile
],
1251 pub fn memcpy_ty
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>, dst
: ValueRef
, src
: ValueRef
, t
: Ty
<'tcx
>) {
1252 let _icx
= push_ctxt("memcpy_ty");
1253 let ccx
= bcx
.ccx();
1255 if type_is_zero_size(ccx
, t
) {
1259 if t
.is_structural() {
1260 let llty
= type_of
::type_of(ccx
, t
);
1261 let llsz
= llsize_of(ccx
, llty
);
1262 let llalign
= type_of
::align_of(ccx
, t
);
1263 call_memcpy(bcx
, dst
, src
, llsz
, llalign
as u32);
1264 } else if common
::type_is_fat_ptr(bcx
.tcx(), t
) {
1265 let (data
, extra
) = load_fat_ptr(bcx
, src
, t
);
1266 store_fat_ptr(bcx
, data
, extra
, dst
, t
);
1268 store_ty(bcx
, load_ty(bcx
, src
, t
), dst
, t
);
1272 pub fn drop_done_fill_mem
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, llptr
: ValueRef
, t
: Ty
<'tcx
>) {
1273 if cx
.unreachable
.get() {
1276 let _icx
= push_ctxt("drop_done_fill_mem");
1278 memfill(&B(bcx
), llptr
, t
, adt
::DTOR_DONE
);
1281 pub fn init_zero_mem
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, llptr
: ValueRef
, t
: Ty
<'tcx
>) {
1282 if cx
.unreachable
.get() {
1285 let _icx
= push_ctxt("init_zero_mem");
1287 memfill(&B(bcx
), llptr
, t
, 0);
1290 // Always use this function instead of storing a constant byte to the memory
1291 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
1292 // allocation for large data structures, and the generated code will be
1293 // awful. (A telltale sign of this is large quantities of
1294 // `mov [byte ptr foo],0` in the generated code.)
1295 fn memfill
<'a
, 'tcx
>(b
: &Builder
<'a
, 'tcx
>, llptr
: ValueRef
, ty
: Ty
<'tcx
>, byte
: u8) {
1296 let _icx
= push_ctxt("memfill");
1299 let llty
= type_of
::type_of(ccx
, ty
);
1300 let ptr_width
= &ccx
.sess().target
.target
.target_pointer_width
[..];
1301 let intrinsic_key
= format
!("llvm.memset.p0i8.i{}", ptr_width
);
1303 let llintrinsicfn
= ccx
.get_intrinsic(&intrinsic_key
);
1304 let llptr
= b
.pointercast(llptr
, Type
::i8(ccx
).ptr_to());
1305 let llzeroval
= C_u8(ccx
, byte
);
1306 let size
= machine
::llsize_of(ccx
, llty
);
1307 let align
= C_i32(ccx
, type_of
::align_of(ccx
, ty
) as i32);
1308 let volatile
= C_bool(ccx
, false);
1309 b
.call(llintrinsicfn
,
1310 &[llptr
, llzeroval
, size
, align
, volatile
],
1314 /// In general, when we create an scratch value in an alloca, the
1315 /// creator may not know if the block (that initializes the scratch
1316 /// with the desired value) actually dominates the cleanup associated
1317 /// with the scratch value.
1319 /// To deal with this, when we do an alloca (at the *start* of whole
1320 /// function body), we optionally can also set the associated
1321 /// dropped-flag state of the alloca to "dropped."
1322 #[derive(Copy, Clone, Debug)]
1323 pub enum InitAlloca
{
1324 /// Indicates that the state should have its associated drop flag
1325 /// set to "dropped" at the point of allocation.
1327 /// Indicates the value of the associated drop flag is irrelevant.
1328 /// The embedded string literal is a programmer provided argument
1329 /// for why. This is a safeguard forcing compiler devs to
1330 /// document; it might be a good idea to also emit this as a
1331 /// comment with the alloca itself when emitting LLVM output.ll.
1332 Uninit(&'
static str),
1336 pub fn alloc_ty
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
1338 name
: &str) -> ValueRef
{
1339 // pnkfelix: I do not know why alloc_ty meets the assumptions for
1340 // passing Uninit, but it was never needed (even back when we had
1341 // the original boolean `zero` flag on `lvalue_scratch_datum`).
1342 alloc_ty_init(bcx
, t
, InitAlloca
::Uninit("all alloc_ty are uninit"), name
)
1345 /// This variant of `fn alloc_ty` does not necessarily assume that the
1346 /// alloca should be created with no initial value. Instead the caller
1347 /// controls that assumption via the `init` flag.
1349 /// Note that if the alloca *is* initialized via `init`, then we will
1350 /// also inject an `llvm.lifetime.start` before that initialization
1351 /// occurs, and thus callers should not call_lifetime_start
1352 /// themselves. But if `init` says "uninitialized", then callers are
1353 /// in charge of choosing where to call_lifetime_start and
1354 /// subsequently populate the alloca.
1356 /// (See related discussion on PR #30823.)
1357 pub fn alloc_ty_init
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
1360 name
: &str) -> ValueRef
{
1361 let _icx
= push_ctxt("alloc_ty");
1362 let ccx
= bcx
.ccx();
1363 let ty
= type_of
::type_of(ccx
, t
);
1364 assert
!(!t
.has_param_types());
1366 InitAlloca
::Dropped
=> alloca_dropped(bcx
, t
, name
),
1367 InitAlloca
::Uninit(_
) => alloca(bcx
, ty
, name
),
1371 pub fn alloca_dropped
<'blk
, 'tcx
>(cx
: Block
<'blk
, 'tcx
>, ty
: Ty
<'tcx
>, name
: &str) -> ValueRef
{
1372 let _icx
= push_ctxt("alloca_dropped");
1373 let llty
= type_of
::type_of(cx
.ccx(), ty
);
1374 if cx
.unreachable
.get() {
1375 unsafe { return llvm::LLVMGetUndef(llty.ptr_to().to_ref()); }
1377 let p
= alloca(cx
, llty
, name
);
1378 let b
= cx
.fcx
.ccx
.builder();
1379 b
.position_before(cx
.fcx
.alloca_insert_pt
.get().unwrap());
1381 // This is just like `call_lifetime_start` (but latter expects a
1382 // Block, which we do not have for `alloca_insert_pt`).
1383 core_lifetime_emit(cx
.ccx(), p
, Lifetime
::Start
, |ccx
, size
, lifetime_start
| {
1384 let ptr
= b
.pointercast(p
, Type
::i8p(ccx
));
1385 b
.call(lifetime_start
, &[C_u64(ccx
, size
), ptr
], None
, None
);
1387 memfill(&b
, p
, ty
, adt
::DTOR_DONE
);
1391 pub fn alloca(cx
: Block
, ty
: Type
, name
: &str) -> ValueRef
{
1392 let _icx
= push_ctxt("alloca");
1393 if cx
.unreachable
.get() {
1395 return llvm
::LLVMGetUndef(ty
.ptr_to().to_ref());
1398 debuginfo
::clear_source_location(cx
.fcx
);
1399 Alloca(cx
, ty
, name
)
1402 pub fn set_value_name(val
: ValueRef
, name
: &str) {
1404 let name
= CString
::new(name
).unwrap();
1405 llvm
::LLVMSetValueName(val
, name
.as_ptr());
1409 // Creates the alloca slot which holds the pointer to the slot for the final return value
1410 pub fn make_return_slot_pointer
<'a
, 'tcx
>(fcx
: &FunctionContext
<'a
, 'tcx
>,
1411 output_type
: Ty
<'tcx
>)
1413 let lloutputtype
= type_of
::type_of(fcx
.ccx
, output_type
);
1415 // We create an alloca to hold a pointer of type `output_type`
1416 // which will hold the pointer to the right alloca which has the
1418 if fcx
.needs_ret_allocas
{
1419 // Let's create the stack slot
1420 let slot
= AllocaFcx(fcx
, lloutputtype
.ptr_to(), "llretslotptr");
1422 // and if we're using an out pointer, then store that in our newly made slot
1423 if type_of
::return_uses_outptr(fcx
.ccx
, output_type
) {
1424 let outptr
= get_param(fcx
.llfn
, 0);
1426 let b
= fcx
.ccx
.builder();
1427 b
.position_before(fcx
.alloca_insert_pt
.get().unwrap());
1428 b
.store(outptr
, slot
);
1433 // But if there are no nested returns, we skip the indirection and have a single
1436 if type_of
::return_uses_outptr(fcx
.ccx
, output_type
) {
1437 get_param(fcx
.llfn
, 0)
1439 AllocaFcx(fcx
, lloutputtype
, "sret_slot")
1444 struct FindNestedReturn
{
1448 impl FindNestedReturn
{
1449 fn new() -> FindNestedReturn
{
1456 impl<'v
> Visitor
<'v
> for FindNestedReturn
{
1457 fn visit_expr(&mut self, e
: &hir
::Expr
) {
1459 hir
::ExprRet(..) => {
1462 _
=> intravisit
::walk_expr(self, e
),
1467 fn build_cfg(tcx
: &ty
::ctxt
, id
: ast
::NodeId
) -> (ast
::NodeId
, Option
<cfg
::CFG
>) {
1468 let blk
= match tcx
.map
.find(id
) {
1469 Some(hir_map
::NodeItem(i
)) => {
1471 hir
::ItemFn(_
, _
, _
, _
, _
, ref blk
) => {
1474 _
=> tcx
.sess
.bug("unexpected item variant in has_nested_returns"),
1477 Some(hir_map
::NodeTraitItem(trait_item
)) => {
1478 match trait_item
.node
{
1479 hir
::MethodTraitItem(_
, Some(ref body
)) => body
,
1481 tcx
.sess
.bug("unexpected variant: trait item other than a provided method in \
1482 has_nested_returns")
1486 Some(hir_map
::NodeImplItem(impl_item
)) => {
1487 match impl_item
.node
{
1488 hir
::ImplItemKind
::Method(_
, ref body
) => body
,
1490 tcx
.sess
.bug("unexpected variant: non-method impl item in has_nested_returns")
1494 Some(hir_map
::NodeExpr(e
)) => {
1496 hir
::ExprClosure(_
, _
, ref blk
) => blk
,
1497 _
=> tcx
.sess
.bug("unexpected expr variant in has_nested_returns"),
1500 Some(hir_map
::NodeVariant(..)) |
1501 Some(hir_map
::NodeStructCtor(..)) => return (ast
::DUMMY_NODE_ID
, None
),
1504 None
if id
== ast
::DUMMY_NODE_ID
=> return (ast
::DUMMY_NODE_ID
, None
),
1506 _
=> tcx
.sess
.bug(&format
!("unexpected variant in has_nested_returns: {}",
1507 tcx
.map
.path_to_string(id
))),
1510 (blk
.id
, Some(cfg
::CFG
::new(tcx
, blk
)))
1513 // Checks for the presence of "nested returns" in a function.
1514 // Nested returns are when the inner expression of a return expression
1515 // (the 'expr' in 'return expr') contains a return expression. Only cases
1516 // where the outer return is actually reachable are considered. Implicit
1517 // returns from the end of blocks are considered as well.
1519 // This check is needed to handle the case where the inner expression is
1520 // part of a larger expression that may have already partially-filled the
1521 // return slot alloca. This can cause errors related to clean-up due to
1522 // the clobbering of the existing value in the return slot.
1523 fn has_nested_returns(tcx
: &ty
::ctxt
, cfg
: &cfg
::CFG
, blk_id
: ast
::NodeId
) -> bool
{
1524 for index
in cfg
.graph
.depth_traverse(cfg
.entry
) {
1525 let n
= cfg
.graph
.node_data(index
);
1526 match tcx
.map
.find(n
.id()) {
1527 Some(hir_map
::NodeExpr(ex
)) => {
1528 if let hir
::ExprRet(Some(ref ret_expr
)) = ex
.node
{
1529 let mut visitor
= FindNestedReturn
::new();
1530 intravisit
::walk_expr(&mut visitor
, &ret_expr
);
1536 Some(hir_map
::NodeBlock(blk
)) if blk
.id
== blk_id
=> {
1537 let mut visitor
= FindNestedReturn
::new();
1538 walk_list
!(&mut visitor
, visit_expr
, &blk
.expr
);
1550 // NB: must keep 4 fns in sync:
1553 // - create_datums_for_fn_args.
1557 // Be warned! You must call `init_function` before doing anything with the
1558 // returned function context.
1559 pub fn new_fn_ctxt
<'a
, 'tcx
>(ccx
: &'a CrateContext
<'a
, 'tcx
>,
1563 output_type
: ty
::FnOutput
<'tcx
>,
1564 param_substs
: &'tcx Substs
<'tcx
>,
1566 block_arena
: &'a TypedArena
<common
::BlockS
<'a
, 'tcx
>>)
1567 -> FunctionContext
<'a
, 'tcx
> {
1568 common
::validate_substs(param_substs
);
1570 debug
!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1574 ccx
.tcx().map
.path_to_string(id
).to_string()
1579 let uses_outptr
= match output_type
{
1580 ty
::FnConverging(output_type
) => {
1581 let substd_output_type
= monomorphize
::apply_param_substs(ccx
.tcx(),
1584 type_of
::return_uses_outptr(ccx
, substd_output_type
)
1586 ty
::FnDiverging
=> false,
1588 let debug_context
= debuginfo
::create_function_debug_context(ccx
, id
, param_substs
, llfndecl
);
1589 let (blk_id
, cfg
) = build_cfg(ccx
.tcx(), id
);
1590 let nested_returns
= if let Some(ref cfg
) = cfg
{
1591 has_nested_returns(ccx
.tcx(), cfg
, blk_id
)
1596 let mir
= ccx
.mir_map().map
.get(&id
);
1598 let mut fcx
= FunctionContext
{
1602 llretslotptr
: Cell
::new(None
),
1603 param_env
: ccx
.tcx().empty_parameter_environment(),
1604 alloca_insert_pt
: Cell
::new(None
),
1605 llreturn
: Cell
::new(None
),
1606 needs_ret_allocas
: nested_returns
,
1607 landingpad_alloca
: Cell
::new(None
),
1608 caller_expects_out_pointer
: uses_outptr
,
1609 lllocals
: RefCell
::new(NodeMap()),
1610 llupvars
: RefCell
::new(NodeMap()),
1611 lldropflag_hints
: RefCell
::new(DropFlagHintsMap
::new()),
1613 param_substs
: param_substs
,
1615 block_arena
: block_arena
,
1616 lpad_arena
: TypedArena
::new(),
1618 debug_context
: debug_context
,
1619 scopes
: RefCell
::new(Vec
::new()),
1624 fcx
.llenv
= Some(get_param(fcx
.llfn
, fcx
.env_arg_pos() as c_uint
))
1630 /// Performs setup on a newly created function, creating the entry scope block
1631 /// and allocating space for the return pointer.
1632 pub fn init_function
<'a
, 'tcx
>(fcx
: &'a FunctionContext
<'a
, 'tcx
>,
1634 output
: ty
::FnOutput
<'tcx
>)
1635 -> Block
<'a
, 'tcx
> {
1636 let entry_bcx
= fcx
.new_temp_block("entry-block");
1638 // Use a dummy instruction as the insertion point for all allocas.
1639 // This is later removed in FunctionContext::cleanup.
1640 fcx
.alloca_insert_pt
.set(Some(unsafe {
1641 Load(entry_bcx
, C_null(Type
::i8p(fcx
.ccx
)));
1642 llvm
::LLVMGetFirstInstruction(entry_bcx
.llbb
)
1645 if let ty
::FnConverging(output_type
) = output
{
1646 // This shouldn't need to recompute the return type,
1647 // as new_fn_ctxt did it already.
1648 let substd_output_type
= fcx
.monomorphize(&output_type
);
1649 if !return_type_is_void(fcx
.ccx
, substd_output_type
) {
1650 // If the function returns nil/bot, there is no real return
1651 // value, so do not set `llretslotptr`.
1652 if !skip_retptr
|| fcx
.caller_expects_out_pointer
{
1653 // Otherwise, we normally allocate the llretslotptr, unless we
1654 // have been instructed to skip it for immediate return
1656 fcx
.llretslotptr
.set(Some(make_return_slot_pointer(fcx
, substd_output_type
)));
1661 // Create the drop-flag hints for every unfragmented path in the function.
1662 let tcx
= fcx
.ccx
.tcx();
1663 let fn_did
= tcx
.map
.local_def_id(fcx
.id
);
1664 let tables
= tcx
.tables
.borrow();
1665 let mut hints
= fcx
.lldropflag_hints
.borrow_mut();
1666 let fragment_infos
= tcx
.fragment_infos
.borrow();
1668 // Intern table for drop-flag hint datums.
1669 let mut seen
= HashMap
::new();
1671 if let Some(fragment_infos
) = fragment_infos
.get(&fn_did
) {
1672 for &info
in fragment_infos
{
1674 let make_datum
= |id
| {
1675 let init_val
= C_u8(fcx
.ccx
, adt
::DTOR_NEEDED_HINT
);
1676 let llname
= &format
!("dropflag_hint_{}", id
);
1677 debug
!("adding hint {}", llname
);
1678 let ty
= tcx
.types
.u8;
1679 let ptr
= alloc_ty(entry_bcx
, ty
, llname
);
1680 Store(entry_bcx
, init_val
, ptr
);
1681 let flag
= datum
::Lvalue
::new_dropflag_hint("base::init_function");
1682 datum
::Datum
::new(ptr
, ty
, flag
)
1685 let (var
, datum
) = match info
{
1686 ty
::FragmentInfo
::Moved { var, .. }
|
1687 ty
::FragmentInfo
::Assigned { var, .. }
=> {
1688 let opt_datum
= seen
.get(&var
).cloned().unwrap_or_else(|| {
1689 let ty
= tables
.node_types
[&var
];
1690 if fcx
.type_needs_drop(ty
) {
1691 let datum
= make_datum(var
);
1692 seen
.insert(var
, Some(datum
.clone()));
1695 // No drop call needed, so we don't need a dropflag hint
1699 if let Some(datum
) = opt_datum
{
1707 ty
::FragmentInfo
::Moved { move_expr: expr_id, .. }
=> {
1708 debug
!("FragmentInfo::Moved insert drop hint for {}", expr_id
);
1709 hints
.insert(expr_id
, DropHint
::new(var
, datum
));
1711 ty
::FragmentInfo
::Assigned { assignee_id: expr_id, .. }
=> {
1712 debug
!("FragmentInfo::Assigned insert drop hint for {}", expr_id
);
1713 hints
.insert(expr_id
, DropHint
::new(var
, datum
));
1722 // NB: must keep 4 fns in sync:
1725 // - create_datums_for_fn_args.
1729 pub fn arg_kind
<'a
, 'tcx
>(cx
: &FunctionContext
<'a
, 'tcx
>, t
: Ty
<'tcx
>) -> datum
::Rvalue
{
1730 use trans
::datum
::{ByRef, ByValue}
;
1733 mode
: if arg_is_indirect(cx
.ccx
, t
) { ByRef }
else { ByValue }
1737 // create_datums_for_fn_args: creates lvalue datums for each of the
1738 // incoming function arguments.
1739 pub fn create_datums_for_fn_args
<'a
, 'tcx
>(mut bcx
: Block
<'a
, 'tcx
>,
1741 arg_tys
: &[Ty
<'tcx
>],
1742 has_tupled_arg
: bool
,
1743 arg_scope
: cleanup
::CustomScopeIndex
)
1744 -> Block
<'a
, 'tcx
> {
1745 let _icx
= push_ctxt("create_datums_for_fn_args");
1747 let arg_scope_id
= cleanup
::CustomScope(arg_scope
);
1749 debug
!("create_datums_for_fn_args");
1751 // Return an array wrapping the ValueRefs that we get from `get_param` for
1752 // each argument into datums.
1754 // For certain mode/type combinations, the raw llarg values are passed
1755 // by value. However, within the fn body itself, we want to always
1756 // have all locals and arguments be by-ref so that we can cancel the
1757 // cleanup and for better interaction with LLVM's debug info. So, if
1758 // the argument would be passed by value, we store it into an alloca.
1759 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1760 // the event it's not truly needed.
1761 let mut idx
= fcx
.arg_offset() as c_uint
;
1762 let uninit_reason
= InitAlloca
::Uninit("fn_arg populate dominates dtor");
1763 for (i
, &arg_ty
) in arg_tys
.iter().enumerate() {
1764 let arg_datum
= if !has_tupled_arg
|| i
< arg_tys
.len() - 1 {
1765 if type_of
::arg_is_indirect(bcx
.ccx(), arg_ty
) &&
1766 bcx
.sess().opts
.debuginfo
!= FullDebugInfo
{
1767 // Don't copy an indirect argument to an alloca, the caller
1768 // already put it in a temporary alloca and gave it up, unless
1769 // we emit extra-debug-info, which requires local allocas :(.
1770 let llarg
= get_param(fcx
.llfn
, idx
);
1772 bcx
.fcx
.schedule_lifetime_end(arg_scope_id
, llarg
);
1773 bcx
.fcx
.schedule_drop_mem(arg_scope_id
, llarg
, arg_ty
, None
);
1775 datum
::Datum
::new(llarg
,
1777 datum
::Lvalue
::new("create_datum_for_fn_args"))
1778 } else if common
::type_is_fat_ptr(bcx
.tcx(), arg_ty
) {
1779 let data
= get_param(fcx
.llfn
, idx
);
1780 let extra
= get_param(fcx
.llfn
, idx
+ 1);
1782 unpack_datum
!(bcx
, datum
::lvalue_scratch_datum(bcx
, arg_ty
, "", uninit_reason
,
1783 arg_scope_id
, (data
, extra
),
1784 |(data
, extra
), bcx
, dst
| {
1785 debug
!("populate call for create_datum_for_fn_args \
1786 early fat arg, on arg[{}] ty={:?}", i
, arg_ty
);
1788 Store(bcx
, data
, expr
::get_dataptr(bcx
, dst
));
1789 Store(bcx
, extra
, expr
::get_meta(bcx
, dst
));
1793 let llarg
= get_param(fcx
.llfn
, idx
);
1795 let tmp
= datum
::Datum
::new(llarg
, arg_ty
, arg_kind(fcx
, arg_ty
));
1797 datum
::lvalue_scratch_datum(bcx
,
1805 debug
!("populate call for create_datum_for_fn_args \
1806 early thin arg, on arg[{}] ty={:?}", i
, arg_ty
);
1808 tmp
.store_to(bcx
, dst
)
1812 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1814 ty
::TyTuple(ref tupled_arg_tys
) => {
1816 datum
::lvalue_scratch_datum(bcx
,
1825 debug
!("populate call for create_datum_for_fn_args \
1826 tupled_args, on arg[{}] ty={:?}", i
, arg_ty
);
1827 for (j
, &tupled_arg_ty
) in
1828 tupled_arg_tys
.iter().enumerate() {
1829 let lldest
= StructGEP(bcx
, llval
, j
);
1830 if common
::type_is_fat_ptr(bcx
.tcx(), tupled_arg_ty
) {
1831 let data
= get_param(bcx
.fcx
.llfn
, idx
);
1832 let extra
= get_param(bcx
.fcx
.llfn
, idx
+ 1);
1833 Store(bcx
, data
, expr
::get_dataptr(bcx
, lldest
));
1834 Store(bcx
, extra
, expr
::get_meta(bcx
, lldest
));
1837 let datum
= datum
::Datum
::new(
1838 get_param(bcx
.fcx
.llfn
, idx
),
1840 arg_kind(bcx
.fcx
, tupled_arg_ty
));
1842 bcx
= datum
.store_to(bcx
, lldest
);
1851 .bug("last argument of a function with `rust-call` ABI isn't a tuple?!")
1856 let pat
= &*args
[i
].pat
;
1857 bcx
= if let Some(name
) = simple_name(pat
) {
1858 // Generate nicer LLVM for the common case of fn a pattern
1860 set_value_name(arg_datum
.val
, &bcx
.name(name
));
1861 bcx
.fcx
.lllocals
.borrow_mut().insert(pat
.id
, arg_datum
);
1864 // General path. Copy out the values that are used in the
1866 _match
::bind_irrefutable_pat(bcx
, pat
, arg_datum
.match_input(), arg_scope_id
)
1868 debuginfo
::create_argument_metadata(bcx
, &args
[i
]);
1874 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1875 // and builds the return block.
1876 pub fn finish_fn
<'blk
, 'tcx
>(fcx
: &'blk FunctionContext
<'blk
, 'tcx
>,
1877 last_bcx
: Block
<'blk
, 'tcx
>,
1878 retty
: ty
::FnOutput
<'tcx
>,
1879 ret_debug_loc
: DebugLoc
) {
1880 let _icx
= push_ctxt("finish_fn");
1882 let ret_cx
= match fcx
.llreturn
.get() {
1884 if !last_bcx
.terminated
.get() {
1885 Br(last_bcx
, llreturn
, DebugLoc
::None
);
1887 raw_block(fcx
, llreturn
)
1892 // This shouldn't need to recompute the return type,
1893 // as new_fn_ctxt did it already.
1894 let substd_retty
= fcx
.monomorphize(&retty
);
1895 build_return_block(fcx
, ret_cx
, substd_retty
, ret_debug_loc
);
1897 debuginfo
::clear_source_location(fcx
);
1901 // Builds the return block for a function.
1902 pub fn build_return_block
<'blk
, 'tcx
>(fcx
: &FunctionContext
<'blk
, 'tcx
>,
1903 ret_cx
: Block
<'blk
, 'tcx
>,
1904 retty
: ty
::FnOutput
<'tcx
>,
1905 ret_debug_location
: DebugLoc
) {
1906 if fcx
.llretslotptr
.get().is_none() ||
1907 (!fcx
.needs_ret_allocas
&& fcx
.caller_expects_out_pointer
) {
1908 return RetVoid(ret_cx
, ret_debug_location
);
1911 let retslot
= if fcx
.needs_ret_allocas
{
1912 Load(ret_cx
, fcx
.llretslotptr
.get().unwrap())
1914 fcx
.llretslotptr
.get().unwrap()
1916 let retptr
= Value(retslot
);
1917 match retptr
.get_dominating_store(ret_cx
) {
1918 // If there's only a single store to the ret slot, we can directly return
1919 // the value that was stored and omit the store and the alloca
1921 let retval
= s
.get_operand(0).unwrap().get();
1922 s
.erase_from_parent();
1924 if retptr
.has_no_uses() {
1925 retptr
.erase_from_parent();
1928 let retval
= if retty
== ty
::FnConverging(fcx
.ccx
.tcx().types
.bool
) {
1929 Trunc(ret_cx
, retval
, Type
::i1(fcx
.ccx
))
1934 if fcx
.caller_expects_out_pointer
{
1935 if let ty
::FnConverging(retty
) = retty
{
1936 store_ty(ret_cx
, retval
, get_param(fcx
.llfn
, 0), retty
);
1938 RetVoid(ret_cx
, ret_debug_location
)
1940 Ret(ret_cx
, retval
, ret_debug_location
)
1943 // Otherwise, copy the return value to the ret slot
1944 None
=> match retty
{
1945 ty
::FnConverging(retty
) => {
1946 if fcx
.caller_expects_out_pointer
{
1947 memcpy_ty(ret_cx
, get_param(fcx
.llfn
, 0), retslot
, retty
);
1948 RetVoid(ret_cx
, ret_debug_location
)
1950 Ret(ret_cx
, load_ty(ret_cx
, retslot
, retty
), ret_debug_location
)
1953 ty
::FnDiverging
=> {
1954 if fcx
.caller_expects_out_pointer
{
1955 RetVoid(ret_cx
, ret_debug_location
)
1957 Ret(ret_cx
, C_undef(Type
::nil(fcx
.ccx
)), ret_debug_location
)
1964 /// Builds an LLVM function out of a source function.
1966 /// If the function closes over its environment a closure will be returned.
1967 pub fn trans_closure
<'a
, 'b
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
1971 param_substs
: &'tcx Substs
<'tcx
>,
1972 fn_ast_id
: ast
::NodeId
,
1973 attributes
: &[ast
::Attribute
],
1974 output_type
: ty
::FnOutput
<'tcx
>,
1976 closure_env
: closure
::ClosureEnv
<'b
>) {
1977 ccx
.stats().n_closures
.set(ccx
.stats().n_closures
.get() + 1);
1979 record_translation_item_as_generated(ccx
, fn_ast_id
, param_substs
);
1981 let _icx
= push_ctxt("trans_closure");
1982 attributes
::emit_uwtable(llfndecl
, true);
1984 debug
!("trans_closure(..., param_substs={:?})", param_substs
);
1986 let has_env
= match closure_env
{
1987 closure
::ClosureEnv
::Closure(..) => true,
1988 closure
::ClosureEnv
::NotClosure
=> false,
1991 let (arena
, fcx
): (TypedArena
<_
>, FunctionContext
);
1992 arena
= TypedArena
::new();
1993 fcx
= new_fn_ctxt(ccx
,
2001 let mut bcx
= init_function(&fcx
, false, output_type
);
2003 if attributes
.iter().any(|item
| item
.check_name("rustc_mir")) {
2004 mir
::trans_mir(bcx
.build());
2009 // cleanup scope for the incoming arguments
2010 let fn_cleanup_debug_loc
= debuginfo
::get_cleanup_debug_loc_for_ast_node(ccx
,
2014 let arg_scope
= fcx
.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc
);
2016 let block_ty
= node_id_type(bcx
, body
.id
);
2018 // Set up arguments to the function.
2019 let monomorphized_arg_types
= decl
.inputs
2021 .map(|arg
| node_id_type(bcx
, arg
.id
))
2022 .collect
::<Vec
<_
>>();
2023 for monomorphized_arg_type
in &monomorphized_arg_types
{
2024 debug
!("trans_closure: monomorphized_arg_type: {:?}",
2025 monomorphized_arg_type
);
2027 debug
!("trans_closure: function lltype: {}",
2028 bcx
.fcx
.ccx
.tn().val_to_string(bcx
.fcx
.llfn
));
2030 let has_tupled_arg
= match closure_env
{
2031 closure
::ClosureEnv
::NotClosure
=> abi
== Abi
::RustCall
,
2035 bcx
= create_datums_for_fn_args(bcx
,
2037 &monomorphized_arg_types
,
2041 bcx
= closure_env
.load(bcx
, cleanup
::CustomScope(arg_scope
));
2043 // Up until here, IR instructions for this function have explicitly not been annotated with
2044 // source code location, so we don't step into call setup code. From here on, source location
2045 // emitting should be enabled.
2046 debuginfo
::start_emitting_source_locations(&fcx
);
2048 let dest
= match fcx
.llretslotptr
.get() {
2049 Some(_
) => expr
::SaveIn(fcx
.get_ret_slot(bcx
, ty
::FnConverging(block_ty
), "iret_slot")),
2051 assert
!(type_is_zero_size(bcx
.ccx(), block_ty
));
2056 // This call to trans_block is the place where we bridge between
2057 // translation calls that don't have a return value (trans_crate,
2058 // trans_mod, trans_item, et cetera) and those that do
2059 // (trans_block, trans_expr, et cetera).
2060 bcx
= controlflow
::trans_block(bcx
, body
, dest
);
2063 expr
::SaveIn(slot
) if fcx
.needs_ret_allocas
=> {
2064 Store(bcx
, slot
, fcx
.llretslotptr
.get().unwrap());
2069 match fcx
.llreturn
.get() {
2071 Br(bcx
, fcx
.return_exit_block(), DebugLoc
::None
);
2072 fcx
.pop_custom_cleanup_scope(arg_scope
);
2075 // Microoptimization writ large: avoid creating a separate
2076 // llreturn basic block
2077 bcx
= fcx
.pop_and_trans_custom_cleanup_scope(bcx
, arg_scope
);
2081 // Put return block after all other blocks.
2082 // This somewhat improves single-stepping experience in debugger.
2084 let llreturn
= fcx
.llreturn
.get();
2085 if let Some(llreturn
) = llreturn
{
2086 llvm
::LLVMMoveBasicBlockAfter(llreturn
, bcx
.llbb
);
2090 let ret_debug_loc
= DebugLoc
::At(fn_cleanup_debug_loc
.id
, fn_cleanup_debug_loc
.span
);
2092 // Insert the mandatory first few basic blocks before lltop.
2093 finish_fn(&fcx
, bcx
, output_type
, ret_debug_loc
);
2095 fn record_translation_item_as_generated
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2096 node_id
: ast
::NodeId
,
2097 param_substs
: &'tcx Substs
<'tcx
>) {
2098 if !collector
::collecting_debug_information(ccx
) {
2102 let def_id
= match ccx
.tcx().node_id_to_type(node_id
).sty
{
2103 ty
::TyClosure(def_id
, _
) => def_id
,
2104 _
=> ccx
.external_srcs()
2108 .unwrap_or_else(|| ccx
.tcx().map
.local_def_id(node_id
)),
2111 ccx
.record_translation_item_as_generated(TransItem
::Fn
{
2113 substs
: ccx
.tcx().mk_substs(ccx
.tcx().erase_regions(param_substs
)),
2118 /// Creates an LLVM function corresponding to a source language function.
2119 pub fn trans_fn
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2123 param_substs
: &'tcx Substs
<'tcx
>,
2125 attrs
: &[ast
::Attribute
]) {
2126 let _s
= StatRecorder
::new(ccx
, ccx
.tcx().map
.path_to_string(id
).to_string());
2127 debug
!("trans_fn(param_substs={:?})", param_substs
);
2128 let _icx
= push_ctxt("trans_fn");
2129 let fn_ty
= ccx
.tcx().node_id_to_type(id
);
2130 let fn_ty
= monomorphize
::apply_param_substs(ccx
.tcx(), param_substs
, &fn_ty
);
2131 let sig
= fn_ty
.fn_sig();
2132 let sig
= ccx
.tcx().erase_late_bound_regions(&sig
);
2133 let sig
= infer
::normalize_associated_type(ccx
.tcx(), &sig
);
2134 let output_type
= sig
.output
;
2135 let abi
= fn_ty
.fn_abi();
2145 closure
::ClosureEnv
::NotClosure
);
2148 pub fn trans_enum_variant
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2149 ctor_id
: ast
::NodeId
,
2151 param_substs
: &'tcx Substs
<'tcx
>,
2152 llfndecl
: ValueRef
) {
2153 let _icx
= push_ctxt("trans_enum_variant");
2155 trans_enum_variant_or_tuple_like_struct(ccx
, ctor_id
, disr
, param_substs
, llfndecl
);
2158 pub fn trans_named_tuple_constructor
<'blk
, 'tcx
>(mut bcx
: Block
<'blk
, 'tcx
>,
2161 args
: callee
::CallArgs
,
2163 debug_loc
: DebugLoc
)
2164 -> Result
<'blk
, 'tcx
> {
2166 let ccx
= bcx
.fcx
.ccx
;
2168 let sig
= ccx
.tcx().erase_late_bound_regions(&ctor_ty
.fn_sig());
2169 let sig
= infer
::normalize_associated_type(ccx
.tcx(), &sig
);
2170 let result_ty
= sig
.output
.unwrap();
2172 // Get location to store the result. If the user does not care about
2173 // the result, just make a stack slot
2174 let llresult
= match dest
{
2175 expr
::SaveIn(d
) => d
,
2177 if !type_is_zero_size(ccx
, result_ty
) {
2178 let llresult
= alloc_ty(bcx
, result_ty
, "constructor_result");
2179 call_lifetime_start(bcx
, llresult
);
2182 C_undef(type_of
::type_of(ccx
, result_ty
).ptr_to())
2187 if !type_is_zero_size(ccx
, result_ty
) {
2189 callee
::ArgExprs(exprs
) => {
2190 let fields
= exprs
.iter().map(|x
| &**x
).enumerate().collect
::<Vec
<_
>>();
2191 bcx
= expr
::trans_adt(bcx
,
2196 expr
::SaveIn(llresult
),
2199 _
=> ccx
.sess().bug("expected expr as arguments for variant/struct tuple constructor"),
2202 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
2203 // contents, there could be side-effects we need from them.
2205 callee
::ArgExprs(exprs
) => {
2207 bcx
= expr
::trans_into(bcx
, expr
, expr
::Ignore
);
2214 // If the caller doesn't care about the result
2215 // drop the temporary we made
2216 let bcx
= match dest
{
2217 expr
::SaveIn(_
) => bcx
,
2219 let bcx
= glue
::drop_ty(bcx
, llresult
, result_ty
, debug_loc
);
2220 if !type_is_zero_size(ccx
, result_ty
) {
2221 call_lifetime_end(bcx
, llresult
);
2227 Result
::new(bcx
, llresult
)
2230 pub fn trans_tuple_struct
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2231 ctor_id
: ast
::NodeId
,
2232 param_substs
: &'tcx Substs
<'tcx
>,
2233 llfndecl
: ValueRef
) {
2234 let _icx
= push_ctxt("trans_tuple_struct");
2236 trans_enum_variant_or_tuple_like_struct(ccx
, ctor_id
, Disr(0), param_substs
, llfndecl
);
2239 fn trans_enum_variant_or_tuple_like_struct
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2240 ctor_id
: ast
::NodeId
,
2242 param_substs
: &'tcx Substs
<'tcx
>,
2243 llfndecl
: ValueRef
) {
2244 let ctor_ty
= ccx
.tcx().node_id_to_type(ctor_id
);
2245 let ctor_ty
= monomorphize
::apply_param_substs(ccx
.tcx(), param_substs
, &ctor_ty
);
2247 let sig
= ccx
.tcx().erase_late_bound_regions(&ctor_ty
.fn_sig());
2248 let sig
= infer
::normalize_associated_type(ccx
.tcx(), &sig
);
2249 let arg_tys
= sig
.inputs
;
2250 let result_ty
= sig
.output
;
2252 let (arena
, fcx
): (TypedArena
<_
>, FunctionContext
);
2253 arena
= TypedArena
::new();
2254 fcx
= new_fn_ctxt(ccx
,
2262 let bcx
= init_function(&fcx
, false, result_ty
);
2264 assert
!(!fcx
.needs_ret_allocas
);
2266 if !type_is_zero_size(fcx
.ccx
, result_ty
.unwrap()) {
2267 let dest
= fcx
.get_ret_slot(bcx
, result_ty
, "eret_slot");
2268 let dest_val
= adt
::MaybeSizedValue
::sized(dest
); // Can return unsized value
2269 let repr
= adt
::represent_type(ccx
, result_ty
.unwrap());
2270 let mut llarg_idx
= fcx
.arg_offset() as c_uint
;
2271 for (i
, arg_ty
) in arg_tys
.into_iter().enumerate() {
2272 let lldestptr
= adt
::trans_field_ptr(bcx
, &repr
, dest_val
, Disr
::from(disr
), i
);
2273 if common
::type_is_fat_ptr(bcx
.tcx(), arg_ty
) {
2275 get_param(fcx
.llfn
, llarg_idx
),
2276 expr
::get_dataptr(bcx
, lldestptr
));
2278 get_param(fcx
.llfn
, llarg_idx
+ 1),
2279 expr
::get_meta(bcx
, lldestptr
));
2282 let arg
= get_param(fcx
.llfn
, llarg_idx
);
2285 if arg_is_indirect(ccx
, arg_ty
) {
2286 memcpy_ty(bcx
, lldestptr
, arg
, arg_ty
);
2288 store_ty(bcx
, arg
, lldestptr
, arg_ty
);
2292 adt
::trans_set_discr(bcx
, &repr
, dest
, disr
);
2295 finish_fn(&fcx
, bcx
, result_ty
, DebugLoc
::None
);
2298 fn enum_variant_size_lint(ccx
: &CrateContext
, enum_def
: &hir
::EnumDef
, sp
: Span
, id
: ast
::NodeId
) {
2299 let mut sizes
= Vec
::new(); // does no allocation if no pushes, thankfully
2301 let print_info
= ccx
.sess().print_enum_sizes();
2303 let levels
= ccx
.tcx().node_lint_levels
.borrow();
2304 let lint_id
= lint
::LintId
::of(lint
::builtin
::VARIANT_SIZE_DIFFERENCES
);
2305 let lvlsrc
= levels
.get(&(id
, lint_id
));
2306 let is_allow
= lvlsrc
.map_or(true, |&(lvl
, _
)| lvl
== lint
::Allow
);
2308 if is_allow
&& !print_info
{
2309 // we're not interested in anything here
2313 let ty
= ccx
.tcx().node_id_to_type(id
);
2314 let avar
= adt
::represent_type(ccx
, ty
);
2316 adt
::General(_
, ref variants
, _
) => {
2317 for var
in variants
{
2319 for field
in var
.fields
.iter().skip(1) {
2320 // skip the discriminant
2321 size
+= llsize_of_real(ccx
, sizing_type_of(ccx
, *field
));
2326 _
=> { /* its size is either constant or unimportant */ }
2329 let (largest
, slargest
, largest_index
) = sizes
.iter().enumerate().fold((0, 0, 0),
2330 |(l
, s
, li
), (idx
, &size
)|
2333 } else if size
> s
{
2340 // FIXME(#30505) Should use logging for this.
2342 let llty
= type_of
::sizing_type_of(ccx
, ty
);
2344 let sess
= &ccx
.tcx().sess
;
2345 sess
.span_note_without_error(sp
,
2346 &format
!("total size: {} bytes", llsize_of_real(ccx
, llty
)));
2348 adt
::General(..) => {
2349 for (i
, var
) in enum_def
.variants
.iter().enumerate() {
2352 .span_note_without_error(var
.span
,
2353 &format
!("variant data: {} bytes", sizes
[i
]));
2360 // we only warn if the largest variant is at least thrice as large as
2361 // the second-largest.
2362 if !is_allow
&& largest
> slargest
* 3 && slargest
> 0 {
2363 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2364 // pass for the latter already ran.
2365 lint
::raw_struct_lint(&ccx
.tcx().sess
,
2366 &ccx
.tcx().sess
.lint_store
.borrow(),
2367 lint
::builtin
::VARIANT_SIZE_DIFFERENCES
,
2370 &format
!("enum variant is more than three times larger ({} bytes) \
2371 than the next largest (ignoring padding)",
2373 .span_note(enum_def
.variants
[largest_index
].span
,
2374 "this variant is the largest")
2379 pub fn llvm_linkage_by_name(name
: &str) -> Option
<Linkage
> {
2380 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2381 // applicable to variable declarations and may not really make sense for
2382 // Rust code in the first place but whitelist them anyway and trust that
2383 // the user knows what s/he's doing. Who knows, unanticipated use cases
2384 // may pop up in the future.
2386 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2387 // and don't have to be, LLVM treats them as no-ops.
2389 "appending" => Some(llvm
::AppendingLinkage
),
2390 "available_externally" => Some(llvm
::AvailableExternallyLinkage
),
2391 "common" => Some(llvm
::CommonLinkage
),
2392 "extern_weak" => Some(llvm
::ExternalWeakLinkage
),
2393 "external" => Some(llvm
::ExternalLinkage
),
2394 "internal" => Some(llvm
::InternalLinkage
),
2395 "linkonce" => Some(llvm
::LinkOnceAnyLinkage
),
2396 "linkonce_odr" => Some(llvm
::LinkOnceODRLinkage
),
2397 "private" => Some(llvm
::PrivateLinkage
),
2398 "weak" => Some(llvm
::WeakAnyLinkage
),
2399 "weak_odr" => Some(llvm
::WeakODRLinkage
),
2405 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2406 #[derive(Copy, Clone)]
2407 pub enum ValueOrigin
{
2408 /// The LLVM `Value` is in this context because the corresponding item was
2409 /// assigned to the current compilation unit.
2410 OriginalTranslation
,
2411 /// The `Value`'s corresponding item was assigned to some other compilation
2412 /// unit, but the `Value` was translated in this context anyway because the
2413 /// item is marked `#[inline]`.
2417 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2418 /// If the `llval` is the direct translation of a specific Rust item, `id`
2419 /// should be set to the `NodeId` of that item. (This mapping should be
2420 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2421 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2422 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2423 /// assigned to a different compilation unit.
2424 pub fn update_linkage(ccx
: &CrateContext
,
2426 id
: Option
<ast
::NodeId
>,
2427 llval_origin
: ValueOrigin
) {
2428 match llval_origin
{
2430 // `llval` is a translation of an item defined in a separate
2431 // compilation unit. This only makes sense if there are at least
2432 // two compilation units.
2433 assert
!(ccx
.sess().opts
.cg
.codegen_units
> 1);
2434 // `llval` is a copy of something defined elsewhere, so use
2435 // `AvailableExternallyLinkage` to avoid duplicating code in the
2437 llvm
::SetLinkage(llval
, llvm
::AvailableExternallyLinkage
);
2440 OriginalTranslation
=> {}
,
2443 if let Some(id
) = id
{
2444 let item
= ccx
.tcx().map
.get(id
);
2445 if let hir_map
::NodeItem(i
) = item
{
2446 if let Some(name
) = attr
::first_attr_value_str_by_name(&i
.attrs
, "linkage") {
2447 if let Some(linkage
) = llvm_linkage_by_name(&name
) {
2448 llvm
::SetLinkage(llval
, linkage
);
2450 ccx
.sess().span_fatal(i
.span
, "invalid linkage specified");
2458 Some(id
) if ccx
.reachable().contains(&id
) => {
2459 llvm
::SetLinkage(llval
, llvm
::ExternalLinkage
);
2462 // `id` does not refer to an item in `ccx.reachable`.
2463 if ccx
.sess().opts
.cg
.codegen_units
> 1 {
2464 llvm
::SetLinkage(llval
, llvm
::ExternalLinkage
);
2466 llvm
::SetLinkage(llval
, llvm
::InternalLinkage
);
2472 fn set_global_section(ccx
: &CrateContext
, llval
: ValueRef
, i
: &hir
::Item
) {
2473 match attr
::first_attr_value_str_by_name(&i
.attrs
, "link_section") {
2475 if contains_null(§
) {
2476 ccx
.sess().fatal(&format
!("Illegal null byte in link_section value: `{}`", §
));
2479 let buf
= CString
::new(sect
.as_bytes()).unwrap();
2480 llvm
::LLVMSetSection(llval
, buf
.as_ptr());
2487 pub fn trans_item(ccx
: &CrateContext
, item
: &hir
::Item
) {
2488 let _icx
= push_ctxt("trans_item");
2490 let from_external
= ccx
.external_srcs().borrow().contains_key(&item
.id
);
2493 hir
::ItemFn(ref decl
, _
, _
, abi
, ref generics
, ref body
) => {
2494 if !generics
.is_type_parameterized() {
2495 let trans_everywhere
= attr
::requests_inline(&item
.attrs
);
2496 // Ignore `trans_everywhere` for cross-crate inlined items
2497 // (`from_external`). `trans_item` will be called once for each
2498 // compilation unit that references the item, so it will still get
2499 // translated everywhere it's needed.
2500 for (ref ccx
, is_origin
) in ccx
.maybe_iter(!from_external
&& trans_everywhere
) {
2501 let llfn
= get_item_val(ccx
, item
.id
);
2502 let empty_substs
= ccx
.tcx().mk_substs(Substs
::trans_empty());
2503 if abi
!= Abi
::Rust
{
2504 foreign
::trans_rust_fn_with_foreign_abi(ccx
,
2521 set_global_section(ccx
, llfn
, item
);
2531 if is_entry_fn(ccx
.sess(), item
.id
) {
2532 create_entry_wrapper(ccx
, item
.span
, llfn
);
2533 // check for the #[rustc_error] annotation, which forces an
2534 // error in trans. This is used to write compile-fail tests
2535 // that actually test that compilation succeeds without
2536 // reporting an error.
2537 let item_def_id
= ccx
.tcx().map
.local_def_id(item
.id
);
2538 if ccx
.tcx().has_attr(item_def_id
, "rustc_error") {
2539 ccx
.tcx().sess
.span_fatal(item
.span
, "compilation successful");
2545 hir
::ItemImpl(_
, _
, ref generics
, _
, _
, ref impl_items
) => {
2546 meth
::trans_impl(ccx
, item
.name
, impl_items
, generics
, item
.id
);
2548 hir
::ItemMod(_
) => {
2549 // modules have no equivalent at runtime, they just affect
2550 // the mangled names of things contained within
2552 hir
::ItemEnum(ref enum_definition
, ref gens
) => {
2553 if gens
.ty_params
.is_empty() {
2554 // sizes only make sense for non-generic types
2556 enum_variant_size_lint(ccx
, enum_definition
, item
.span
, item
.id
);
2559 hir
::ItemConst(..) => {}
2560 hir
::ItemStatic(_
, m
, ref expr
) => {
2561 let g
= match consts
::trans_static(ccx
, m
, expr
, item
.id
, &item
.attrs
) {
2563 Err(err
) => ccx
.tcx().sess
.span_fatal(expr
.span
, &err
.description()),
2565 set_global_section(ccx
, g
, item
);
2566 update_linkage(ccx
, g
, Some(item
.id
), OriginalTranslation
);
2568 hir
::ItemForeignMod(ref foreign_mod
) => {
2569 foreign
::trans_foreign_mod(ccx
, foreign_mod
);
2571 hir
::ItemTrait(..) => {}
2578 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2579 pub fn register_fn_llvmty(ccx
: &CrateContext
,
2582 node_id
: ast
::NodeId
,
2586 debug
!("register_fn_llvmty id={} sym={}", node_id
, sym
);
2588 let llfn
= declare
::define_fn(ccx
, &sym
[..], cc
, llfty
,
2589 ty
::FnConverging(ccx
.tcx().mk_nil())).unwrap_or_else(||{
2590 ccx
.sess().span_fatal(sp
, &format
!("symbol `{}` is already defined", sym
));
2592 finish_register_fn(ccx
, sym
, node_id
);
2596 fn finish_register_fn(ccx
: &CrateContext
, sym
: String
, node_id
: ast
::NodeId
) {
2597 ccx
.item_symbols().borrow_mut().insert(node_id
, sym
);
2600 fn register_fn
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2603 node_id
: ast
::NodeId
,
2604 node_type
: Ty
<'tcx
>)
2606 if let ty
::TyBareFn(_
, ref f
) = node_type
.sty
{
2607 if f
.abi
!= Abi
::Rust
&& f
.abi
!= Abi
::RustCall
{
2608 ccx
.sess().span_bug(sp
,
2609 &format
!("only the `{}` or `{}` calling conventions are valid \
2610 for this function; `{}` was specified",
2612 Abi
::RustCall
.name(),
2616 ccx
.sess().span_bug(sp
, "expected bare rust function")
2619 let llfn
= declare
::define_rust_fn(ccx
, &sym
[..], node_type
).unwrap_or_else(|| {
2620 ccx
.sess().span_fatal(sp
, &format
!("symbol `{}` is already defined", sym
));
2622 finish_register_fn(ccx
, sym
, node_id
);
2626 pub fn is_entry_fn(sess
: &Session
, node_id
: ast
::NodeId
) -> bool
{
2627 match *sess
.entry_fn
.borrow() {
2628 Some((entry_id
, _
)) => node_id
== entry_id
,
2633 /// Create the `main` function which will initialise the rust runtime and call users’ main
2635 pub fn create_entry_wrapper(ccx
: &CrateContext
, sp
: Span
, main_llfn
: ValueRef
) {
2636 let et
= ccx
.sess().entry_type
.get().unwrap();
2638 config
::EntryMain
=> {
2639 create_entry_fn(ccx
, sp
, main_llfn
, true);
2641 config
::EntryStart
=> create_entry_fn(ccx
, sp
, main_llfn
, false),
2642 config
::EntryNone
=> {}
// Do nothing.
2645 fn create_entry_fn(ccx
: &CrateContext
,
2647 rust_main
: ValueRef
,
2648 use_start_lang_item
: bool
) {
2649 let llfty
= Type
::func(&[ccx
.int_type(), Type
::i8p(ccx
).ptr_to()], &ccx
.int_type());
2651 let llfn
= declare
::define_cfn(ccx
, "main", llfty
, ccx
.tcx().mk_nil()).unwrap_or_else(|| {
2652 // FIXME: We should be smart and show a better diagnostic here.
2653 ccx
.sess().struct_span_err(sp
, "entry symbol `main` defined multiple times")
2654 .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
2656 ccx
.sess().abort_if_errors();
2661 llvm
::LLVMAppendBasicBlockInContext(ccx
.llcx(), llfn
, "top\0".as_ptr() as *const _
)
2663 let bld
= ccx
.raw_builder();
2665 llvm
::LLVMPositionBuilderAtEnd(bld
, llbb
);
2667 debuginfo
::gdb
::insert_reference_to_gdb_debug_scripts_section_global(ccx
);
2669 let (start_fn
, args
) = if use_start_lang_item
{
2670 let start_def_id
= match ccx
.tcx().lang_items
.require(StartFnLangItem
) {
2673 ccx
.sess().fatal(&s
[..]);
2676 let start_fn
= if let Some(start_node_id
) = ccx
.tcx()
2678 .as_local_node_id(start_def_id
) {
2679 get_item_val(ccx
, start_node_id
)
2681 let start_fn_type
= ccx
.tcx().lookup_item_type(start_def_id
).ty
;
2682 trans_external_path(ccx
, start_def_id
, start_fn_type
)
2685 let opaque_rust_main
=
2686 llvm
::LLVMBuildPointerCast(bld
,
2688 Type
::i8p(ccx
).to_ref(),
2689 "rust_main\0".as_ptr() as *const _
);
2691 vec
![opaque_rust_main
, get_param(llfn
, 0), get_param(llfn
, 1)]
2695 debug
!("using user-defined start fn");
2696 let args
= vec
![get_param(llfn
, 0 as c_uint
), get_param(llfn
, 1 as c_uint
)];
2701 let result
= llvm
::LLVMRustBuildCall(bld
,
2704 args
.len() as c_uint
,
2708 llvm
::LLVMBuildRet(bld
, result
);
2713 fn exported_name
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>,
2716 attrs
: &[ast
::Attribute
])
2718 match ccx
.external_srcs().borrow().get(&id
) {
2720 let sym
= ccx
.sess().cstore
.item_symbol(did
);
2721 debug
!("found item {} in other crate...", sym
);
2727 match attr
::find_export_name_attr(ccx
.sess().diagnostic(), attrs
) {
2728 // Use provided name
2729 Some(name
) => name
.to_string(),
2731 let path
= ccx
.tcx().map
.def_path_from_id(id
);
2732 if attr
::contains_name(attrs
, "no_mangle") {
2734 path
.last().unwrap().data
.to_string()
2736 match weak_lang_items
::link_name(attrs
) {
2737 Some(name
) => name
.to_string(),
2739 // Usual name mangling
2740 mangle_exported_name(ccx
, path
, ty
, id
)
2748 fn contains_null(s
: &str) -> bool
{
2749 s
.bytes().any(|b
| b
== 0)
2752 pub fn get_item_val(ccx
: &CrateContext
, id
: ast
::NodeId
) -> ValueRef
{
2753 debug
!("get_item_val(id=`{}`)", id
);
2755 if let Some(v
) = ccx
.item_vals().borrow().get(&id
).cloned() {
2759 let item
= ccx
.tcx().map
.get(id
);
2760 debug
!("get_item_val: id={} item={:?}", id
, item
);
2761 let val
= match item
{
2762 hir_map
::NodeItem(i
) => {
2763 let ty
= ccx
.tcx().node_id_to_type(i
.id
);
2764 let sym
= || exported_name(ccx
, id
, ty
, &i
.attrs
);
2766 let v
= match i
.node
{
2767 hir
::ItemStatic(..) => {
2768 // If this static came from an external crate, then
2769 // we need to get the symbol from metadata instead of
2770 // using the current crate's name/version
2771 // information in the hash of the symbol
2773 debug
!("making {}", sym
);
2775 // Create the global before evaluating the initializer;
2776 // this is necessary to allow recursive statics.
2777 let llty
= type_of(ccx
, ty
);
2778 let g
= declare
::define_global(ccx
, &sym
[..], llty
).unwrap_or_else(|| {
2780 .span_fatal(i
.span
, &format
!("symbol `{}` is already defined", sym
))
2783 ccx
.item_symbols().borrow_mut().insert(i
.id
, sym
);
2787 hir
::ItemFn(_
, _
, _
, abi
, _
, _
) => {
2789 let llfn
= if abi
== Abi
::Rust
{
2790 register_fn(ccx
, i
.span
, sym
, i
.id
, ty
)
2792 foreign
::register_rust_fn_with_foreign_abi(ccx
, i
.span
, sym
, i
.id
)
2794 attributes
::from_fn_attrs(ccx
, &i
.attrs
, llfn
);
2798 _
=> ccx
.sess().bug("get_item_val: weird result in table"),
2804 hir_map
::NodeTraitItem(trait_item
) => {
2805 debug
!("get_item_val(): processing a NodeTraitItem");
2806 match trait_item
.node
{
2807 hir
::MethodTraitItem(_
, Some(_
)) => {
2808 register_method(ccx
, id
, &trait_item
.attrs
, trait_item
.span
)
2811 ccx
.sess().span_bug(trait_item
.span
,
2812 "unexpected variant: trait item other than a provided \
2813 method in get_item_val()");
2818 hir_map
::NodeImplItem(impl_item
) => {
2819 match impl_item
.node
{
2820 hir
::ImplItemKind
::Method(..) => {
2821 register_method(ccx
, id
, &impl_item
.attrs
, impl_item
.span
)
2824 ccx
.sess().span_bug(impl_item
.span
,
2825 "unexpected variant: non-method impl item in \
2831 hir_map
::NodeForeignItem(ni
) => {
2833 hir
::ForeignItemFn(..) => {
2834 let abi
= ccx
.tcx().map
.get_foreign_abi(id
);
2835 let ty
= ccx
.tcx().node_id_to_type(ni
.id
);
2836 let name
= foreign
::link_name(&ni
);
2837 foreign
::register_foreign_item_fn(ccx
, abi
, ty
, &name
, &ni
.attrs
)
2839 hir
::ForeignItemStatic(..) => {
2840 foreign
::register_static(ccx
, &ni
)
2845 hir_map
::NodeVariant(ref v
) => {
2847 let fields
= if v
.node
.data
.is_struct() {
2848 ccx
.sess().bug("struct variant kind unexpected in get_item_val")
2850 v
.node
.data
.fields()
2852 assert
!(!fields
.is_empty());
2853 let ty
= ccx
.tcx().node_id_to_type(id
);
2854 let parent
= ccx
.tcx().map
.get_parent(id
);
2855 let enm
= ccx
.tcx().map
.expect_item(parent
);
2856 let sym
= exported_name(ccx
, id
, ty
, &enm
.attrs
);
2858 llfn
= match enm
.node
{
2859 hir
::ItemEnum(_
, _
) => {
2860 register_fn(ccx
, (*v
).span
, sym
, id
, ty
)
2862 _
=> ccx
.sess().bug("NodeVariant, shouldn't happen"),
2864 attributes
::inline(llfn
, attributes
::InlineAttr
::Hint
);
2868 hir_map
::NodeStructCtor(struct_def
) => {
2869 // Only register the constructor if this is a tuple-like struct.
2870 let ctor_id
= if struct_def
.is_struct() {
2871 ccx
.sess().bug("attempt to register a constructor of a non-tuple-like struct")
2875 let parent
= ccx
.tcx().map
.get_parent(id
);
2876 let struct_item
= ccx
.tcx().map
.expect_item(parent
);
2877 let ty
= ccx
.tcx().node_id_to_type(ctor_id
);
2878 let sym
= exported_name(ccx
, id
, ty
, &struct_item
.attrs
);
2879 let llfn
= register_fn(ccx
, struct_item
.span
, sym
, ctor_id
, ty
);
2880 attributes
::inline(llfn
, attributes
::InlineAttr
::Hint
);
2885 ccx
.sess().bug(&format
!("get_item_val(): unexpected variant: {:?}", variant
))
2889 // All LLVM globals and functions are initially created as external-linkage
2890 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2891 // into a definition, it adjusts the linkage then (using `update_linkage`).
2893 // The exception is foreign items, which have their linkage set inside the
2894 // call to `foreign::register_*` above. We don't touch the linkage after
2895 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2896 // other item translation functions do).
2898 ccx
.item_vals().borrow_mut().insert(id
, val
);
2902 fn register_method(ccx
: &CrateContext
,
2904 attrs
: &[ast
::Attribute
],
2907 let mty
= ccx
.tcx().node_id_to_type(id
);
2909 let sym
= exported_name(ccx
, id
, mty
, &attrs
);
2911 if let ty
::TyBareFn(_
, ref f
) = mty
.sty
{
2912 let llfn
= if f
.abi
== Abi
::Rust
|| f
.abi
== Abi
::RustCall
{
2913 register_fn(ccx
, span
, sym
, id
, mty
)
2915 foreign
::register_rust_fn_with_foreign_abi(ccx
, span
, sym
, id
)
2917 attributes
::from_fn_attrs(ccx
, &attrs
, llfn
);
2920 ccx
.sess().span_bug(span
, "expected bare rust function");
2924 pub fn write_metadata
<'a
, 'tcx
>(cx
: &SharedCrateContext
<'a
, 'tcx
>,
2926 reachable
: &NodeSet
,
2927 mir_map
: &MirMap
<'tcx
>)
2931 let any_library
= cx
.sess()
2935 .any(|ty
| *ty
!= config
::CrateTypeExecutable
);
2940 let cstore
= &cx
.tcx().sess
.cstore
;
2941 let metadata
= cstore
.encode_metadata(cx
.tcx(),
2948 let mut compressed
= cstore
.metadata_encoding_version().to_vec();
2949 compressed
.extend_from_slice(&flate
::deflate_bytes(&metadata
));
2951 let llmeta
= C_bytes_in_context(cx
.metadata_llcx(), &compressed
[..]);
2952 let llconst
= C_struct_in_context(cx
.metadata_llcx(), &[llmeta
], false);
2953 let name
= format
!("rust_metadata_{}_{}",
2954 cx
.link_meta().crate_name
,
2955 cx
.link_meta().crate_hash
);
2956 let buf
= CString
::new(name
).unwrap();
2957 let llglobal
= unsafe {
2958 llvm
::LLVMAddGlobal(cx
.metadata_llmod(), val_ty(llconst
).to_ref(), buf
.as_ptr())
2961 llvm
::LLVMSetInitializer(llglobal
, llconst
);
2963 cx
.tcx().sess
.cstore
.metadata_section_name(&cx
.sess().target
.target
);
2964 let name
= CString
::new(name
).unwrap();
2965 llvm
::LLVMSetSection(llglobal
, name
.as_ptr())
2970 /// Find any symbols that are defined in one compilation unit, but not declared
2971 /// in any other compilation unit. Give these symbols internal linkage.
2972 fn internalize_symbols(cx
: &SharedCrateContext
, reachable
: &HashSet
<&str>) {
2974 let mut declared
= HashSet
::new();
2976 // Collect all external declarations in all compilation units.
2977 for ccx
in cx
.iter() {
2978 for val
in iter_globals(ccx
.llmod()).chain(iter_functions(ccx
.llmod())) {
2979 let linkage
= llvm
::LLVMGetLinkage(val
);
2980 // We only care about external declarations (not definitions)
2981 // and available_externally definitions.
2982 if !(linkage
== llvm
::ExternalLinkage
as c_uint
&&
2983 llvm
::LLVMIsDeclaration(val
) != 0) &&
2984 !(linkage
== llvm
::AvailableExternallyLinkage
as c_uint
) {
2988 let name
= CStr
::from_ptr(llvm
::LLVMGetValueName(val
))
2991 declared
.insert(name
);
2995 // Examine each external definition. If the definition is not used in
2996 // any other compilation unit, and is not reachable from other crates,
2997 // then give it internal linkage.
2998 for ccx
in cx
.iter() {
2999 for val
in iter_globals(ccx
.llmod()).chain(iter_functions(ccx
.llmod())) {
3000 // We only care about external definitions.
3001 if !(llvm
::LLVMGetLinkage(val
) == llvm
::ExternalLinkage
as c_uint
&&
3002 llvm
::LLVMIsDeclaration(val
) == 0) {
3006 let name
= CStr
::from_ptr(llvm
::LLVMGetValueName(val
))
3009 if !declared
.contains(&name
) &&
3010 !reachable
.contains(str::from_utf8(&name
).unwrap()) {
3011 llvm
::SetLinkage(val
, llvm
::InternalLinkage
);
3012 llvm
::SetDLLStorageClass(val
, llvm
::DefaultStorageClass
);
3019 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
3020 // This is required to satisfy `dllimport` references to static data in .rlibs
3021 // when using MSVC linker. We do this only for data, as linker can fix up
3022 // code references on its own.
3023 // See #26591, #27438
3024 fn create_imps(cx
: &SharedCrateContext
) {
3025 // The x86 ABI seems to require that leading underscores are added to symbol
3026 // names, so we need an extra underscore on 32-bit. There's also a leading
3027 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
3028 // underscores added in front).
3029 let prefix
= if cx
.sess().target
.target
.target_pointer_width
== "32" {
3035 for ccx
in cx
.iter() {
3036 let exported
: Vec
<_
> = iter_globals(ccx
.llmod())
3038 llvm
::LLVMGetLinkage(val
) ==
3039 llvm
::ExternalLinkage
as c_uint
&&
3040 llvm
::LLVMIsDeclaration(val
) == 0
3044 let i8p_ty
= Type
::i8p(&ccx
);
3045 for val
in exported
{
3046 let name
= CStr
::from_ptr(llvm
::LLVMGetValueName(val
));
3047 let mut imp_name
= prefix
.as_bytes().to_vec();
3048 imp_name
.extend(name
.to_bytes());
3049 let imp_name
= CString
::new(imp_name
).unwrap();
3050 let imp
= llvm
::LLVMAddGlobal(ccx
.llmod(),
3052 imp_name
.as_ptr() as *const _
);
3053 let init
= llvm
::LLVMConstBitCast(val
, i8p_ty
.to_ref());
3054 llvm
::LLVMSetInitializer(imp
, init
);
3055 llvm
::SetLinkage(imp
, llvm
::ExternalLinkage
);
3063 step
: unsafe extern "C" fn(ValueRef
) -> ValueRef
,
3066 impl Iterator
for ValueIter
{
3067 type Item
= ValueRef
;
3069 fn next(&mut self) -> Option
<ValueRef
> {
3072 self.cur
= unsafe { (self.step)(old) }
;
3080 fn iter_globals(llmod
: llvm
::ModuleRef
) -> ValueIter
{
3083 cur
: llvm
::LLVMGetFirstGlobal(llmod
),
3084 step
: llvm
::LLVMGetNextGlobal
,
3089 fn iter_functions(llmod
: llvm
::ModuleRef
) -> ValueIter
{
3092 cur
: llvm
::LLVMGetFirstFunction(llmod
),
3093 step
: llvm
::LLVMGetNextFunction
,
3098 /// The context provided lists a set of reachable ids as calculated by
3099 /// middle::reachable, but this contains far more ids and symbols than we're
3100 /// actually exposing from the object file. This function will filter the set in
3101 /// the context to the set of ids which correspond to symbols that are exposed
3102 /// from the object file being generated.
3104 /// This list is later used by linkers to determine the set of symbols needed to
3105 /// be exposed from a dynamic library and it's also encoded into the metadata.
3106 pub fn filter_reachable_ids(ccx
: &SharedCrateContext
) -> NodeSet
{
3107 ccx
.reachable().iter().map(|x
| *x
).filter(|id
| {
3108 // First, only worry about nodes which have a symbol name
3109 ccx
.item_symbols().borrow().contains_key(id
)
3111 // Next, we want to ignore some FFI functions that are not exposed from
3112 // this crate. Reachable FFI functions can be lumped into two
3115 // 1. Those that are included statically via a static library
3116 // 2. Those included otherwise (e.g. dynamically or via a framework)
3118 // Although our LLVM module is not literally emitting code for the
3119 // statically included symbols, it's an export of our library which
3120 // needs to be passed on to the linker and encoded in the metadata.
3122 // As a result, if this id is an FFI item (foreign item) then we only
3123 // let it through if it's included statically.
3124 match ccx
.tcx().map
.get(id
) {
3125 hir_map
::NodeForeignItem(..) => {
3126 ccx
.sess().cstore
.is_statically_included_foreign_item(id
)
3133 pub fn trans_crate
<'tcx
>(tcx
: &ty
::ctxt
<'tcx
>,
3134 mir_map
: &MirMap
<'tcx
>,
3135 analysis
: ty
::CrateAnalysis
)
3136 -> CrateTranslation
{
3137 let _task
= tcx
.dep_graph
.in_task(DepNode
::TransCrate
);
3139 // Be careful with this krate: obviously it gives access to the
3140 // entire contents of the krate. So if you push any subtasks of
3141 // `TransCrate`, you need to be careful to register "reads" of the
3142 // particular items that will be processed.
3143 let krate
= tcx
.map
.krate();
3145 let ty
::CrateAnalysis { export_map, reachable, name, .. }
= analysis
;
3147 let check_overflow
= if let Some(v
) = tcx
.sess
.opts
.debugging_opts
.force_overflow_checks
{
3150 tcx
.sess
.opts
.debug_assertions
3153 let check_dropflag
= if let Some(v
) = tcx
.sess
.opts
.debugging_opts
.force_dropflag_checks
{
3156 tcx
.sess
.opts
.debug_assertions
3159 // Before we touch LLVM, make sure that multithreading is enabled.
3161 use std
::sync
::Once
;
3162 static INIT
: Once
= Once
::new();
3163 static mut POISONED
: bool
= false;
3165 if llvm
::LLVMStartMultithreaded() != 1 {
3166 // use an extra bool to make sure that all future usage of LLVM
3167 // cannot proceed despite the Once not running more than once.
3171 ::back
::write
::configure_llvm(&tcx
.sess
);
3175 tcx
.sess
.bug("couldn't enable multi-threaded LLVM");
3179 let link_meta
= link
::build_link_meta(&tcx
.sess
, krate
, name
);
3181 let codegen_units
= tcx
.sess
.opts
.cg
.codegen_units
;
3182 let shared_ccx
= SharedCrateContext
::new(&link_meta
.crate_name
,
3194 let ccx
= shared_ccx
.get_ccx(0);
3196 // First, verify intrinsics.
3197 intrinsic
::check_intrinsics(&ccx
);
3199 collect_translation_items(&ccx
);
3201 // Next, translate all items. See `TransModVisitor` for
3202 // details on why we walk in this particular way.
3204 let _icx
= push_ctxt("text");
3205 intravisit
::walk_mod(&mut TransItemsWithinModVisitor { ccx: &ccx }
, &krate
.module
);
3206 krate
.visit_all_items(&mut TransModVisitor { ccx: &ccx }
);
3209 collector
::print_collection_results(&ccx
);
3212 for ccx
in shared_ccx
.iter() {
3213 if ccx
.sess().opts
.debuginfo
!= NoDebugInfo
{
3214 debuginfo
::finalize(&ccx
);
3216 for &(old_g
, new_g
) in ccx
.statics_to_rauw().borrow().iter() {
3218 let bitcast
= llvm
::LLVMConstPointerCast(new_g
, llvm
::LLVMTypeOf(old_g
));
3219 llvm
::LLVMReplaceAllUsesWith(old_g
, bitcast
);
3220 llvm
::LLVMDeleteGlobal(old_g
);
3225 let reachable_symbol_ids
= filter_reachable_ids(&shared_ccx
);
3227 // Translate the metadata.
3228 let metadata
= time(tcx
.sess
.time_passes(), "write metadata", || {
3229 write_metadata(&shared_ccx
, krate
, &reachable_symbol_ids
, mir_map
)
3232 if shared_ccx
.sess().trans_stats() {
3233 let stats
= shared_ccx
.stats();
3234 println
!("--- trans stats ---");
3235 println
!("n_glues_created: {}", stats
.n_glues_created
.get());
3236 println
!("n_null_glues: {}", stats
.n_null_glues
.get());
3237 println
!("n_real_glues: {}", stats
.n_real_glues
.get());
3239 println
!("n_fns: {}", stats
.n_fns
.get());
3240 println
!("n_monos: {}", stats
.n_monos
.get());
3241 println
!("n_inlines: {}", stats
.n_inlines
.get());
3242 println
!("n_closures: {}", stats
.n_closures
.get());
3243 println
!("fn stats:");
3244 stats
.fn_stats
.borrow_mut().sort_by(|&(_
, insns_a
), &(_
, insns_b
)| {
3245 insns_b
.cmp(&insns_a
)
3247 for tuple
in stats
.fn_stats
.borrow().iter() {
3249 (ref name
, insns
) => {
3250 println
!("{} insns, {}", insns
, *name
);
3255 if shared_ccx
.sess().count_llvm_insns() {
3256 for (k
, v
) in shared_ccx
.stats().llvm_insns
.borrow().iter() {
3257 println
!("{:7} {}", *v
, *k
);
3261 let modules
= shared_ccx
.iter()
3262 .map(|ccx
| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() }
)
3265 let sess
= shared_ccx
.sess();
3266 let mut reachable_symbols
= reachable_symbol_ids
.iter().map(|id
| {
3267 shared_ccx
.item_symbols().borrow()[id
].to_string()
3268 }).collect
::<Vec
<_
>>();
3269 if sess
.entry_fn
.borrow().is_some() {
3270 reachable_symbols
.push("main".to_string());
3273 // For the purposes of LTO, we add to the reachable set all of the upstream
3274 // reachable extern fns. These functions are all part of the public ABI of
3275 // the final product, so LTO needs to preserve them.
3277 for cnum
in sess
.cstore
.crates() {
3278 let syms
= sess
.cstore
.reachable_ids(cnum
);
3279 reachable_symbols
.extend(syms
.into_iter().filter(|did
| {
3280 sess
.cstore
.is_extern_item(shared_ccx
.tcx(), *did
)
3282 sess
.cstore
.item_symbol(did
)
3287 if codegen_units
> 1 {
3288 internalize_symbols(&shared_ccx
,
3289 &reachable_symbols
.iter().map(|x
| &x
[..]).collect());
3292 if sess
.target
.target
.options
.is_like_msvc
&&
3293 sess
.crate_types
.borrow().iter().any(|ct
| *ct
== config
::CrateTypeRlib
) {
3294 create_imps(&shared_ccx
);
3297 let metadata_module
= ModuleTranslation
{
3298 llcx
: shared_ccx
.metadata_llcx(),
3299 llmod
: shared_ccx
.metadata_llmod(),
3301 let no_builtins
= attr
::contains_name(&krate
.attrs
, "no_builtins");
3303 assert_dep_graph
::assert_dep_graph(tcx
);
3307 metadata_module
: metadata_module
,
3310 reachable
: reachable_symbols
,
3311 no_builtins
: no_builtins
,
3315 /// We visit all the items in the krate and translate them. We do
3316 /// this in two walks. The first walk just finds module items. It then
3317 /// walks the full contents of those module items and translates all
3318 /// the items within. Note that this entire process is O(n). The
3319 /// reason for this two phased walk is that each module is
3320 /// (potentially) placed into a distinct codegen-unit. This walk also
3321 /// ensures that the immediate contents of each module is processed
3322 /// entirely before we proceed to find more modules, helping to ensure
3323 /// an equitable distribution amongst codegen-units.
3324 pub struct TransModVisitor
<'a
, 'tcx
: 'a
> {
3325 pub ccx
: &'a CrateContext
<'a
, 'tcx
>,
3328 impl<'a
, 'tcx
, 'v
> Visitor
<'v
> for TransModVisitor
<'a
, 'tcx
> {
3329 fn visit_item(&mut self, i
: &hir
::Item
) {
3331 hir
::ItemMod(_
) => {
3332 let item_ccx
= self.ccx
.rotate();
3333 intravisit
::walk_item(&mut TransItemsWithinModVisitor { ccx: &item_ccx }
, i
);
3340 /// Translates all the items within a given module. Expects owner to
3341 /// invoke `walk_item` on a module item. Ignores nested modules.
3342 pub struct TransItemsWithinModVisitor
<'a
, 'tcx
: 'a
> {
3343 pub ccx
: &'a CrateContext
<'a
, 'tcx
>,
3346 impl<'a
, 'tcx
, 'v
> Visitor
<'v
> for TransItemsWithinModVisitor
<'a
, 'tcx
> {
3347 fn visit_nested_item(&mut self, item_id
: hir
::ItemId
) {
3348 self.visit_item(self.ccx
.tcx().map
.expect_item(item_id
.id
));
3351 fn visit_item(&mut self, i
: &hir
::Item
) {
3353 hir
::ItemMod(..) => {
3354 // skip modules, they will be uncovered by the TransModVisitor
3357 let def_id
= self.ccx
.tcx().map
.local_def_id(i
.id
);
3358 let tcx
= self.ccx
.tcx();
3360 // Create a subtask for trans'ing a particular item. We are
3361 // giving `trans_item` access to this item, so also record a read.
3362 tcx
.dep_graph
.with_task(DepNode
::TransCrateItem(def_id
), || {
3363 tcx
.dep_graph
.read(DepNode
::Hir(def_id
));
3365 // We are going to be accessing various tables
3366 // generated by TypeckItemBody; we also assume
3367 // that the body passes type check. These tables
3368 // are not individually tracked, so just register
3370 tcx
.dep_graph
.read(DepNode
::TypeckItemBody(def_id
));
3372 trans_item(self.ccx
, i
);
3375 intravisit
::walk_item(self, i
);
3381 fn collect_translation_items
<'a
, 'tcx
>(ccx
: &CrateContext
<'a
, 'tcx
>) {
3382 let time_passes
= ccx
.sess().time_passes();
3384 let collection_mode
= match ccx
.sess().opts
.debugging_opts
.print_trans_items
{
3386 let mode_string
= s
.to_lowercase();
3387 let mode_string
= mode_string
.trim();
3388 if mode_string
== "eager" {
3389 TransItemCollectionMode
::Eager
3391 if mode_string
!= "lazy" {
3392 let message
= format
!("Unknown codegen-item collection mode '{}'. \
3393 Falling back to 'lazy' mode.",
3395 ccx
.sess().warn(&message
);
3398 TransItemCollectionMode
::Lazy
3401 None
=> TransItemCollectionMode
::Lazy
3404 let items
= time(time_passes
, "translation item collection", || {
3405 collector
::collect_crate_translation_items(&ccx
, collection_mode
)
3408 if ccx
.sess().opts
.debugging_opts
.print_trans_items
.is_some() {
3409 let mut item_keys
: Vec
<_
> = items
.iter()
3410 .map(|i
| i
.to_string(ccx
))
3414 for item
in item_keys
{
3415 println
!("TRANS_ITEM {}", item
);
3418 let mut ccx_map
= ccx
.translation_items().borrow_mut();
3421 ccx_map
.insert(cgi
, TransItemState
::PredictedButNotGenerated
);