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::{Rust, RustCall, RustIntrinsic, PlatformIntrinsic, 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 match slot.borrow_mut().as_mut() {
154 Some(ctx) => ctx.push(s),
159 _cannot_construct_outside_of_this_module: (),
163 pub struct StatRecorder<'a, 'tcx: 'a> {
164 ccx: &'a CrateContext<'a, 'tcx>,
165 name: Option<String>,
169 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
170 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> {
171 let istart = ccx.stats().n_llvm_insns.get();
180 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
182 if self.ccx.sess().trans_stats() {
183 let iend = self.ccx.stats().n_llvm_insns.get();
188 .push((self.name.take().unwrap(), iend - self.istart));
189 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
190 // Reset LLVM insn count to avoid compound costs.
191 self.ccx.stats().n_llvm_insns.set(self.istart);
196 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
201 match ccx.externs().borrow().get(name) {
202 Some(n) => return *n,
206 let f = declare::declare_rust_fn(ccx, name, fn_ty);
208 let attrs = ccx.sess().cstore.item_attrs(did);
209 attributes::from_fn_attrs(ccx, &attrs[..], f);
211 ccx.externs().borrow_mut().insert(name.to_string(), f);
215 pub fn self_type_for_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
219 let closure_kind = ccx.tcx().closure_kind(closure_id);
221 ty::FnClosureKind => {
222 ccx.tcx().mk_imm_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
224 ty::FnMutClosureKind => {
225 ccx.tcx().mk_mut_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
227 ty::FnOnceClosureKind => fn_ty,
231 pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
232 *ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
235 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
239 let name = ccx.sess().cstore.item_symbol(did);
240 let ty = type_of(ccx, t);
241 match ccx.externs().borrow_mut().get(&name) {
242 Some(n) => return *n,
245 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
246 // FIXME(nagisa): investigate whether it can be changed into define_global
247 let c = declare::declare_global(ccx, &name[..], ty);
248 // Thread-local statics in some other crate need to *always* be linked
249 // against in a thread-local fashion, so we need to be sure to apply the
250 // thread-local attribute locally if it was present remotely. If we
251 // don't do this then linker errors can be generated where the linker
252 // complains that one object files has a thread local version of the
253 // symbol and another one doesn't.
254 for attr in ccx.tcx().get_attrs(did).iter() {
255 if attr.check_name("thread_local") {
256 llvm::set_thread_local(c, true);
259 if ccx.use_dll_storage_attrs() {
260 llvm::SetDLLStorageClass(c, llvm::DLLImportStorageClass);
262 ccx.externs().borrow_mut().insert(name.to_string(), c);
266 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, info_ty: Ty<'tcx>, it: LangItem) -> DefId {
267 match bcx.tcx().lang_items.require(it) {
270 bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
275 // The following malloc_raw_dyn* functions allocate a box to contain
276 // a given type, but with a potentially dynamic size.
278 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
284 -> Result<'blk, 'tcx> {
285 let _icx = push_ctxt("malloc_raw_exchange");
288 let r = callee::trans_lang_call(bcx,
289 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
294 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
298 pub fn bin_op_to_icmp_predicate(ccx: &CrateContext,
301 -> llvm::IntPredicate {
303 hir::BiEq => llvm::IntEQ,
304 hir::BiNe => llvm::IntNE,
305 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
306 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
307 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
308 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
311 .bug(&format!("comparison_op_to_icmp_predicate: expected comparison operator, \
318 pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: hir::BinOp_) -> llvm::RealPredicate {
320 hir::BiEq => llvm::RealOEQ,
321 hir::BiNe => llvm::RealUNE,
322 hir::BiLt => llvm::RealOLT,
323 hir::BiLe => llvm::RealOLE,
324 hir::BiGt => llvm::RealOGT,
325 hir::BiGe => llvm::RealOGE,
328 .bug(&format!("comparison_op_to_fcmp_predicate: expected comparison operator, \
335 pub fn compare_fat_ptrs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
346 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
347 let extra_eq = ICmp(bcx, llvm::IntEQ, lhs_extra, rhs_extra, debug_loc);
348 And(bcx, addr_eq, extra_eq, debug_loc)
351 let addr_eq = ICmp(bcx, llvm::IntNE, lhs_addr, rhs_addr, debug_loc);
352 let extra_eq = ICmp(bcx, llvm::IntNE, lhs_extra, rhs_extra, debug_loc);
353 Or(bcx, addr_eq, extra_eq, debug_loc)
355 hir::BiLe | hir::BiLt | hir::BiGe | hir::BiGt => {
356 // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
357 let (op, strict_op) = match op {
358 hir::BiLt => (llvm::IntULT, llvm::IntULT),
359 hir::BiLe => (llvm::IntULE, llvm::IntULT),
360 hir::BiGt => (llvm::IntUGT, llvm::IntUGT),
361 hir::BiGe => (llvm::IntUGE, llvm::IntUGT),
365 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
366 let extra_op = ICmp(bcx, op, lhs_extra, rhs_extra, debug_loc);
367 let addr_eq_extra_op = And(bcx, addr_eq, extra_op, debug_loc);
369 let addr_strict = ICmp(bcx, strict_op, lhs_addr, rhs_addr, debug_loc);
370 Or(bcx, addr_strict, addr_eq_extra_op, debug_loc)
373 bcx.tcx().sess.bug("unexpected fat ptr binop");
378 pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
386 ty::TyTuple(ref tys) if tys.is_empty() => {
387 // We don't need to do actual comparisons for nil.
388 // () == () holds but () < () does not.
390 hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
391 hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
392 // refinements would be nice
393 _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator"),
396 ty::TyBareFn(..) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
398 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
403 ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
405 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
411 let lhs_addr = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_ADDR]));
412 let lhs_extra = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_EXTRA]));
414 let rhs_addr = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_ADDR]));
415 let rhs_extra = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_EXTRA]));
416 compare_fat_ptrs(bcx,
427 bin_op_to_icmp_predicate(bcx.ccx(), op, true),
434 bin_op_to_fcmp_predicate(bcx.ccx(), op),
439 // Should never get here, because t is scalar.
440 _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types"),
444 pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
452 let signed = match t.sty {
454 let cmp = bin_op_to_fcmp_predicate(bcx.ccx(), op);
455 return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
457 ty::TyUint(_) => false,
458 ty::TyInt(_) => true,
459 _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
462 let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
463 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
464 // to get the correctly sized type. This will compile to a single instruction
465 // once the IR is converted to assembly if the SIMD instruction is supported
466 // by the target architecture.
467 SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
470 // Iterates through the elements of a structural type.
471 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
476 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
478 let _icx = push_ctxt("iter_structural_ty");
480 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
481 repr: &adt::Repr<'tcx>,
482 av: adt::MaybeSizedValue,
483 variant: ty::VariantDef<'tcx>,
484 substs: &Substs<'tcx>,
487 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
489 let _icx = push_ctxt("iter_variant");
493 for (i, field) in variant.fields.iter().enumerate() {
494 let arg = monomorphize::field_ty(tcx, substs, field);
496 adt::trans_field_ptr(cx, repr, av, Disr::from(variant.disr_val), i),
502 let value = if common::type_is_sized(cx.tcx(), t) {
503 adt::MaybeSizedValue::sized(av)
505 let data = Load(cx, expr::get_dataptr(cx, av));
506 let info = Load(cx, expr::get_meta(cx, av));
507 adt::MaybeSizedValue::unsized_(data, info)
512 ty::TyStruct(..) => {
513 let repr = adt::represent_type(cx.ccx(), t);
514 let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
515 for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
516 let llfld_a = adt::trans_field_ptr(cx, &*repr, value, Disr::from(discr), i);
518 let val = if common::type_is_sized(cx.tcx(), field_ty) {
521 let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
522 Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
523 Store(cx, value.meta, expr::get_meta(cx, scratch.val));
526 cx = f(cx, val, field_ty);
529 ty::TyClosure(_, ref substs) => {
530 let repr = adt::represent_type(cx.ccx(), t);
531 for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
532 let llupvar = adt::trans_field_ptr(cx, &*repr, value, Disr(0), i);
533 cx = f(cx, llupvar, upvar_ty);
536 ty::TyArray(_, n) => {
537 let (base, len) = tvec::get_fixed_base_and_len(cx, value.value, n);
538 let unit_ty = t.sequence_element_type(cx.tcx());
539 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
541 ty::TySlice(_) | ty::TyStr => {
542 let unit_ty = t.sequence_element_type(cx.tcx());
543 cx = tvec::iter_vec_raw(cx, value.value, unit_ty, value.meta, f);
545 ty::TyTuple(ref args) => {
546 let repr = adt::represent_type(cx.ccx(), t);
547 for (i, arg) in args.iter().enumerate() {
548 let llfld_a = adt::trans_field_ptr(cx, &*repr, value, Disr(0), i);
549 cx = f(cx, llfld_a, *arg);
552 ty::TyEnum(en, substs) => {
556 let repr = adt::represent_type(ccx, t);
557 let n_variants = en.variants.len();
559 // NB: we must hit the discriminant first so that structural
560 // comparison know not to proceed when the discriminants differ.
562 match adt::trans_switch(cx, &*repr, av, false) {
563 (_match::Single, None) => {
565 assert!(n_variants == 1);
566 cx = iter_variant(cx, &*repr, adt::MaybeSizedValue::sized(av),
567 &en.variants[0], substs, &mut f);
570 (_match::Switch, Some(lldiscrim_a)) => {
571 cx = f(cx, lldiscrim_a, cx.tcx().types.isize);
573 // Create a fall-through basic block for the "else" case of
574 // the switch instruction we're about to generate. Note that
575 // we do **not** use an Unreachable instruction here, even
576 // though most of the time this basic block will never be hit.
578 // When an enum is dropped it's contents are currently
579 // overwritten to DTOR_DONE, which means the discriminant
580 // could have changed value to something not within the actual
581 // range of the discriminant. Currently this function is only
582 // used for drop glue so in this case we just return quickly
583 // from the outer function, and any other use case will only
584 // call this for an already-valid enum in which case the `ret
585 // void` will never be hit.
586 let ret_void_cx = fcx.new_temp_block("enum-iter-ret-void");
587 RetVoid(ret_void_cx, DebugLoc::None);
588 let llswitch = Switch(cx, lldiscrim_a, ret_void_cx.llbb, n_variants);
589 let next_cx = fcx.new_temp_block("enum-iter-next");
591 for variant in &en.variants {
592 let variant_cx = fcx.new_temp_block(&format!("enum-iter-variant-{}",
595 let case_val = adt::trans_case(cx, &*repr, Disr::from(variant.disr_val));
596 AddCase(llswitch, case_val, variant_cx.llbb);
597 let variant_cx = iter_variant(variant_cx,
603 Br(variant_cx, next_cx.llbb, DebugLoc::None);
607 _ => ccx.sess().unimpl("value from adt::trans_switch in iter_structural_ty"),
611 cx.sess().unimpl(&format!("type in iter_structural_ty: {}", t))
618 /// Retrieve the information we are losing (making dynamic) in an unsizing
621 /// The `old_info` argument is a bit funny. It is intended for use
622 /// in an upcast, where the new vtable for an object will be drived
623 /// from the old one.
624 pub fn unsized_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
627 old_info: Option<ValueRef>,
628 param_substs: &'tcx Substs<'tcx>)
630 let (source, target) = ccx.tcx().struct_lockstep_tails(source, target);
631 match (&source.sty, &target.sty) {
632 (&ty::TyArray(_, len), &ty::TySlice(_)) => C_uint(ccx, len),
633 (&ty::TyTrait(_), &ty::TyTrait(_)) => {
634 // For now, upcasts are limited to changes in marker
635 // traits, and hence never actually require an actual
636 // change to the vtable.
637 old_info.expect("unsized_info: missing old info for trait upcast")
639 (_, &ty::TyTrait(box ty::TraitTy { ref principal, .. })) => {
640 // Note that we preserve binding levels here:
641 let substs = principal.0.substs.with_self_ty(source).erase_regions();
642 let substs = ccx.tcx().mk_substs(substs);
643 let trait_ref = ty::Binder(ty::TraitRef {
644 def_id: principal.def_id(),
647 consts::ptrcast(meth::get_vtable(ccx, trait_ref, param_substs),
648 Type::vtable_ptr(ccx))
650 _ => ccx.sess().bug(&format!("unsized_info: invalid unsizing {:?} -> {:?}",
656 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
657 pub fn unsize_thin_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
661 -> (ValueRef, ValueRef) {
662 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
663 match (&src_ty.sty, &dst_ty.sty) {
664 (&ty::TyBox(a), &ty::TyBox(b)) |
665 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
666 &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) |
667 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
668 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) |
669 (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }),
670 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => {
671 assert!(common::type_is_sized(bcx.tcx(), a));
672 let ptr_ty = type_of::in_memory_type_of(bcx.ccx(), b).ptr_to();
673 (PointerCast(bcx, src, ptr_ty),
674 unsized_info(bcx.ccx(), a, b, None, bcx.fcx.param_substs))
676 _ => bcx.sess().bug("unsize_thin_ptr: called on bad types"),
680 /// Coerce `src`, which is a reference to a value of type `src_ty`,
681 /// to a value of type `dst_ty` and store the result in `dst`
682 pub fn coerce_unsized_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
687 match (&src_ty.sty, &dst_ty.sty) {
688 (&ty::TyBox(..), &ty::TyBox(..)) |
689 (&ty::TyRef(..), &ty::TyRef(..)) |
690 (&ty::TyRef(..), &ty::TyRawPtr(..)) |
691 (&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => {
692 let (base, info) = if common::type_is_fat_ptr(bcx.tcx(), src_ty) {
693 // fat-ptr to fat-ptr unsize preserves the vtable
694 load_fat_ptr(bcx, src, src_ty)
696 let base = load_ty(bcx, src, src_ty);
697 unsize_thin_ptr(bcx, base, src_ty, dst_ty)
699 store_fat_ptr(bcx, base, info, dst, dst_ty);
702 // This can be extended to enums and tuples in the future.
703 // (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) |
704 (&ty::TyStruct(def_a, _), &ty::TyStruct(def_b, _)) => {
705 assert_eq!(def_a, def_b);
707 let src_repr = adt::represent_type(bcx.ccx(), src_ty);
708 let src_fields = match &*src_repr {
709 &adt::Repr::Univariant(ref s, _) => &s.fields,
710 _ => bcx.sess().bug("struct has non-univariant repr"),
712 let dst_repr = adt::represent_type(bcx.ccx(), dst_ty);
713 let dst_fields = match &*dst_repr {
714 &adt::Repr::Univariant(ref s, _) => &s.fields,
715 _ => bcx.sess().bug("struct has non-univariant repr"),
718 let src = adt::MaybeSizedValue::sized(src);
719 let dst = adt::MaybeSizedValue::sized(dst);
721 let iter = src_fields.iter().zip(dst_fields).enumerate();
722 for (i, (src_fty, dst_fty)) in iter {
723 if type_is_zero_size(bcx.ccx(), dst_fty) {
727 let src_f = adt::trans_field_ptr(bcx, &src_repr, src, Disr(0), i);
728 let dst_f = adt::trans_field_ptr(bcx, &dst_repr, dst, Disr(0), i);
729 if src_fty == dst_fty {
730 memcpy_ty(bcx, dst_f, src_f, src_fty);
732 coerce_unsized_into(bcx, src_f, src_fty, dst_f, dst_fty);
736 _ => bcx.sess().bug(&format!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
742 pub fn custom_coerce_unsize_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
745 -> CustomCoerceUnsized {
746 let trait_substs = Substs::erased(subst::VecPerParamSpace::new(vec![target_ty],
749 let trait_ref = ty::Binder(ty::TraitRef {
750 def_id: ccx.tcx().lang_items.coerce_unsized_trait().unwrap(),
751 substs: ccx.tcx().mk_substs(trait_substs)
754 match fulfill_obligation(ccx, DUMMY_SP, trait_ref) {
755 traits::VtableImpl(traits::VtableImplData { impl_def_id, .. }) => {
756 ccx.tcx().custom_coerce_unsized_kind(impl_def_id)
759 ccx.sess().bug(&format!("invalid CoerceUnsized vtable: {:?}",
765 pub fn cast_shift_expr_rhs(cx: Block, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
766 cast_shift_rhs(op, lhs, rhs, |a, b| Trunc(cx, a, b), |a, b| ZExt(cx, a, b))
769 pub fn cast_shift_const_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
773 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
774 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
777 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
783 where F: FnOnce(ValueRef, Type) -> ValueRef,
784 G: FnOnce(ValueRef, Type) -> ValueRef
786 // Shifts may have any size int on the rhs
787 if rustc_front::util::is_shift_binop(op) {
788 let mut rhs_llty = val_ty(rhs);
789 let mut lhs_llty = val_ty(lhs);
790 if rhs_llty.kind() == Vector {
791 rhs_llty = rhs_llty.element_type()
793 if lhs_llty.kind() == Vector {
794 lhs_llty = lhs_llty.element_type()
796 let rhs_sz = rhs_llty.int_width();
797 let lhs_sz = lhs_llty.int_width();
800 } else if lhs_sz > rhs_sz {
801 // FIXME (#1877: If shifting by negative
802 // values becomes not undefined then this is wrong.
812 pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
817 let llty = Type::int_from_ty(cx.ccx(), t);
819 ast::TyIs if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
820 ast::TyIs => i64::MIN as u64,
821 ast::TyI8 => i8::MIN as u64,
822 ast::TyI16 => i16::MIN as u64,
823 ast::TyI32 => i32::MIN as u64,
824 ast::TyI64 => i64::MIN as u64,
832 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
833 call_info: NodeIdAndSpan,
838 -> Block<'blk, 'tcx> {
839 let (zero_text, overflow_text) = if divrem.node == hir::BiDiv {
840 ("attempted to divide by zero",
841 "attempted to divide with overflow")
843 ("attempted remainder with a divisor of zero",
844 "attempted remainder with overflow")
846 let debug_loc = call_info.debug_loc();
848 let (is_zero, is_signed) = match rhs_t.sty {
850 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
851 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
854 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
855 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
857 ty::TyStruct(def, _) if def.is_simd() => {
858 let mut res = C_bool(cx.ccx(), false);
859 for i in 0..rhs_t.simd_size(cx.tcx()) {
862 IsNull(cx, ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))),
868 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}", rhs_t));
871 let bcx = with_cond(cx, is_zero, |bcx| {
872 controlflow::trans_fail(bcx, call_info, InternedString::new(zero_text))
875 // To quote LLVM's documentation for the sdiv instruction:
877 // Division by zero leads to undefined behavior. Overflow also leads
878 // to undefined behavior; this is a rare case, but can occur, for
879 // example, by doing a 32-bit division of -2147483648 by -1.
881 // In order to avoid undefined behavior, we perform runtime checks for
882 // signed division/remainder which would trigger overflow. For unsigned
883 // integers, no action beyond checking for zero need be taken.
885 let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
886 let minus_one = ICmp(bcx,
889 C_integral(llty, !0, false),
891 with_cond(bcx, minus_one, |bcx| {
892 let is_min = ICmp(bcx,
895 C_integral(llty, min, true),
897 with_cond(bcx, is_min, |bcx| {
898 controlflow::trans_fail(bcx, call_info, InternedString::new(overflow_text))
906 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
910 let name = ccx.sess().cstore.item_symbol(did);
912 ty::TyBareFn(_, ref fn_ty) => {
913 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
915 get_extern_rust_fn(ccx, t, &name[..], did)
917 RustIntrinsic | PlatformIntrinsic => {
918 ccx.sess().bug("unexpected intrinsic in trans_external_path")
921 let attrs = ccx.sess().cstore.item_attrs(did);
922 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t, &name, &attrs)
927 get_extern_const(ccx, did, t)
932 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
937 -> (ValueRef, Block<'blk, 'tcx>) {
938 let _icx = push_ctxt("invoke_");
939 if bcx.unreachable.get() {
940 return (C_null(Type::i8(bcx.ccx())), bcx);
943 let attributes = attributes::from_fn_type(bcx.ccx(), fn_ty);
945 match bcx.opt_node_id {
947 debug!("invoke at ???");
950 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
954 if need_invoke(bcx) {
955 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
956 for &llarg in llargs {
957 debug!("arg: {}", bcx.val_to_string(llarg));
959 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
960 let landing_pad = bcx.fcx.get_landing_pad();
962 let llresult = Invoke(bcx,
969 return (llresult, normal_bcx);
971 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
972 for &llarg in llargs {
973 debug!("arg: {}", bcx.val_to_string(llarg));
976 let llresult = Call(bcx, llfn, &llargs[..], Some(attributes), debug_loc);
977 return (llresult, bcx);
981 /// Returns whether this session's target will use SEH-based unwinding.
983 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
984 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
985 /// 64-bit MinGW) instead of "full SEH".
986 pub fn wants_msvc_seh(sess: &Session) -> bool {
987 sess.target.target.options.is_like_msvc
990 pub fn avoid_invoke(bcx: Block) -> bool {
991 bcx.sess().no_landing_pads() || bcx.lpad().is_some()
994 pub fn need_invoke(bcx: Block) -> bool {
995 if avoid_invoke(bcx) {
998 bcx.fcx.needs_invoke()
1002 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, t: Ty<'tcx>) -> ValueRef {
1003 let _icx = push_ctxt("load_if_immediate");
1004 if type_is_immediate(cx.ccx(), t) {
1005 return load_ty(cx, v, t);
1010 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1011 /// differs from the type used for SSA values. Also handles various special cases where the type
1012 /// gives us better information about what we are loading.
1013 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
1014 if cx.unreachable.get() || type_is_zero_size(cx.ccx(), t) {
1015 return C_undef(type_of::type_of(cx.ccx(), t));
1018 let ptr = to_arg_ty_ptr(cx, ptr, t);
1019 let align = type_of::align_of(cx.ccx(), t);
1021 if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
1022 let load = Load(cx, ptr);
1024 llvm::LLVMSetAlignment(load, align);
1030 let global = llvm::LLVMIsAGlobalVariable(ptr);
1031 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
1032 let val = llvm::LLVMGetInitializer(global);
1034 return to_arg_ty(cx, val, t);
1039 let val = if t.is_bool() {
1040 LoadRangeAssert(cx, ptr, 0, 2, llvm::False)
1041 } else if t.is_char() {
1042 // a char is a Unicode codepoint, and so takes values from 0
1043 // to 0x10FFFF inclusive only.
1044 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1045 } else if (t.is_region_ptr() || t.is_unique()) && !common::type_is_fat_ptr(cx.tcx(), t) {
1046 LoadNonNull(cx, ptr)
1052 llvm::LLVMSetAlignment(val, align);
1055 to_arg_ty(cx, val, t)
1058 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1059 /// differs from the type used for SSA values.
1060 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1061 if cx.unreachable.get() {
1065 debug!("store_ty: {} : {:?} <- {}",
1066 cx.val_to_string(dst),
1068 cx.val_to_string(v));
1070 if common::type_is_fat_ptr(cx.tcx(), t) {
1072 ExtractValue(cx, v, abi::FAT_PTR_ADDR),
1073 expr::get_dataptr(cx, dst));
1075 ExtractValue(cx, v, abi::FAT_PTR_EXTRA),
1076 expr::get_meta(cx, dst));
1078 let store = Store(cx, from_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
1080 llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
1085 pub fn store_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1090 // FIXME: emit metadata
1091 Store(cx, data, expr::get_dataptr(cx, dst));
1092 Store(cx, extra, expr::get_meta(cx, dst));
1095 pub fn load_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1098 -> (ValueRef, ValueRef) {
1099 // FIXME: emit metadata
1100 (Load(cx, expr::get_dataptr(cx, src)),
1101 Load(cx, expr::get_meta(cx, src)))
1104 pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1106 ZExt(bcx, val, Type::i8(bcx.ccx()))
1112 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1114 Trunc(bcx, val, Type::i1(bcx.ccx()))
1120 pub fn to_arg_ty_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef, ty: Ty<'tcx>) -> ValueRef {
1121 if type_is_immediate(bcx.ccx(), ty) && type_of::type_of(bcx.ccx(), ty).is_aggregate() {
1122 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1123 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1124 // and we have to convert it
1125 BitCast(bcx, ptr, type_of::arg_type_of(bcx.ccx(), ty).ptr_to())
1131 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local) -> Block<'blk, 'tcx> {
1132 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1133 let _indenter = indenter();
1134 let _icx = push_ctxt("init_local");
1135 _match::store_local(bcx, local)
1138 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1139 llbb: BasicBlockRef)
1140 -> Block<'blk, 'tcx> {
1141 common::BlockS::new(llbb, None, fcx)
1144 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>, val: ValueRef, f: F) -> Block<'blk, 'tcx>
1145 where F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>
1147 let _icx = push_ctxt("with_cond");
1149 if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
1154 let next_cx = fcx.new_temp_block("next");
1155 let cond_cx = fcx.new_temp_block("cond");
1156 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
1157 let after_cx = f(cond_cx);
1158 if !after_cx.terminated.get() {
1159 Br(after_cx, next_cx.llbb, DebugLoc::None);
1164 enum Lifetime { Start, End }
1166 // If LLVM lifetime intrinsic support is enabled (i.e. optimizations
1167 // on), and `ptr` is nonzero-sized, then extracts the size of `ptr`
1168 // and the intrinsic for `lt` and passes them to `emit`, which is in
1169 // charge of generating code to call the passed intrinsic on whatever
1170 // block of generated code is targetted for the intrinsic.
1172 // If LLVM lifetime intrinsic support is disabled (i.e. optimizations
1173 // off) or `ptr` is zero-sized, then no-op (does not call `emit`).
1174 fn core_lifetime_emit<'blk, 'tcx, F>(ccx: &'blk CrateContext<'blk, 'tcx>,
1178 where F: FnOnce(&'blk CrateContext<'blk, 'tcx>, machine::llsize, ValueRef)
1180 if ccx.sess().opts.optimize == config::OptLevel::No {
1184 let _icx = push_ctxt(match lt {
1185 Lifetime::Start => "lifetime_start",
1186 Lifetime::End => "lifetime_end"
1189 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1194 let lifetime_intrinsic = ccx.get_intrinsic(match lt {
1195 Lifetime::Start => "llvm.lifetime.start",
1196 Lifetime::End => "llvm.lifetime.end"
1198 emit(ccx, size, lifetime_intrinsic)
1201 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1202 core_lifetime_emit(cx.ccx(), ptr, Lifetime::Start, |ccx, size, lifetime_start| {
1203 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1206 &[C_u64(ccx, size), ptr],
1212 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1213 core_lifetime_emit(cx.ccx(), ptr, Lifetime::End, |ccx, size, lifetime_end| {
1214 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1217 &[C_u64(ccx, size), ptr],
1223 // Generates code for resumption of unwind at the end of a landing pad.
1224 pub fn trans_unwind_resume(bcx: Block, lpval: ValueRef) {
1225 if !bcx.sess().target.target.options.custom_unwind_resume {
1228 let exc_ptr = ExtractValue(bcx, lpval, 0);
1229 let llunwresume = bcx.fcx.eh_unwind_resume();
1230 Call(bcx, llunwresume, &[exc_ptr], None, DebugLoc::None);
1236 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1237 let _icx = push_ctxt("call_memcpy");
1239 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1240 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
1241 let memcpy = ccx.get_intrinsic(&key);
1242 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1243 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1244 let size = IntCast(cx, n_bytes, ccx.int_type());
1245 let align = C_i32(ccx, align as i32);
1246 let volatile = C_bool(ccx, false);
1249 &[dst_ptr, src_ptr, size, align, volatile],
1254 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, dst: ValueRef, src: ValueRef, t: Ty<'tcx>) {
1255 let _icx = push_ctxt("memcpy_ty");
1256 let ccx = bcx.ccx();
1258 if type_is_zero_size(ccx, t) {
1262 if t.is_structural() {
1263 let llty = type_of::type_of(ccx, t);
1264 let llsz = llsize_of(ccx, llty);
1265 let llalign = type_of::align_of(ccx, t);
1266 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1267 } else if common::type_is_fat_ptr(bcx.tcx(), t) {
1268 let (data, extra) = load_fat_ptr(bcx, src, t);
1269 store_fat_ptr(bcx, data, extra, dst, t);
1271 store_ty(bcx, load_ty(bcx, src, t), dst, t);
1275 pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1276 if cx.unreachable.get() {
1279 let _icx = push_ctxt("drop_done_fill_mem");
1281 memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
1284 pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1285 if cx.unreachable.get() {
1288 let _icx = push_ctxt("init_zero_mem");
1290 memfill(&B(bcx), llptr, t, 0);
1293 // Always use this function instead of storing a constant byte to the memory
1294 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
1295 // allocation for large data structures, and the generated code will be
1296 // awful. (A telltale sign of this is large quantities of
1297 // `mov [byte ptr foo],0` in the generated code.)
1298 fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
1299 let _icx = push_ctxt("memfill");
1302 let llty = type_of::type_of(ccx, ty);
1303 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1304 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
1306 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1307 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1308 let llzeroval = C_u8(ccx, byte);
1309 let size = machine::llsize_of(ccx, llty);
1310 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1311 let volatile = C_bool(ccx, false);
1312 b.call(llintrinsicfn,
1313 &[llptr, llzeroval, size, align, volatile],
1317 /// In general, when we create an scratch value in an alloca, the
1318 /// creator may not know if the block (that initializes the scratch
1319 /// with the desired value) actually dominates the cleanup associated
1320 /// with the scratch value.
1322 /// To deal with this, when we do an alloca (at the *start* of whole
1323 /// function body), we optionally can also set the associated
1324 /// dropped-flag state of the alloca to "dropped."
1325 #[derive(Copy, Clone, Debug)]
1326 pub enum InitAlloca {
1327 /// Indicates that the state should have its associated drop flag
1328 /// set to "dropped" at the point of allocation.
1330 /// Indicates the value of the associated drop flag is irrelevant.
1331 /// The embedded string literal is a programmer provided argument
1332 /// for why. This is a safeguard forcing compiler devs to
1333 /// document; it might be a good idea to also emit this as a
1334 /// comment with the alloca itself when emitting LLVM output.ll.
1335 Uninit(&'static str),
1339 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1341 name: &str) -> ValueRef {
1342 // pnkfelix: I do not know why alloc_ty meets the assumptions for
1343 // passing Uninit, but it was never needed (even back when we had
1344 // the original boolean `zero` flag on `lvalue_scratch_datum`).
1345 alloc_ty_init(bcx, t, InitAlloca::Uninit("all alloc_ty are uninit"), name)
1348 /// This variant of `fn alloc_ty` does not necessarily assume that the
1349 /// alloca should be created with no initial value. Instead the caller
1350 /// controls that assumption via the `init` flag.
1352 /// Note that if the alloca *is* initialized via `init`, then we will
1353 /// also inject an `llvm.lifetime.start` before that initialization
1354 /// occurs, and thus callers should not call_lifetime_start
1355 /// themselves. But if `init` says "uninitialized", then callers are
1356 /// in charge of choosing where to call_lifetime_start and
1357 /// subsequently populate the alloca.
1359 /// (See related discussion on PR #30823.)
1360 pub fn alloc_ty_init<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1363 name: &str) -> ValueRef {
1364 let _icx = push_ctxt("alloc_ty");
1365 let ccx = bcx.ccx();
1366 let ty = type_of::type_of(ccx, t);
1367 assert!(!t.has_param_types());
1369 InitAlloca::Dropped => alloca_dropped(bcx, t, name),
1370 InitAlloca::Uninit(_) => alloca(bcx, ty, name),
1374 pub fn alloca_dropped<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>, name: &str) -> ValueRef {
1375 let _icx = push_ctxt("alloca_dropped");
1376 let llty = type_of::type_of(cx.ccx(), ty);
1377 if cx.unreachable.get() {
1378 unsafe { return llvm::LLVMGetUndef(llty.ptr_to().to_ref()); }
1380 let p = alloca(cx, llty, name);
1381 let b = cx.fcx.ccx.builder();
1382 b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
1384 // This is just like `call_lifetime_start` (but latter expects a
1385 // Block, which we do not have for `alloca_insert_pt`).
1386 core_lifetime_emit(cx.ccx(), p, Lifetime::Start, |ccx, size, lifetime_start| {
1387 let ptr = b.pointercast(p, Type::i8p(ccx));
1388 b.call(lifetime_start, &[C_u64(ccx, size), ptr], None, None);
1390 memfill(&b, p, ty, adt::DTOR_DONE);
1394 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1395 let _icx = push_ctxt("alloca");
1396 if cx.unreachable.get() {
1398 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1401 debuginfo::clear_source_location(cx.fcx);
1402 Alloca(cx, ty, name)
1405 pub fn set_value_name(val: ValueRef, name: &str) {
1407 let name = CString::new(name).unwrap();
1408 llvm::LLVMSetValueName(val, name.as_ptr());
1412 // Creates the alloca slot which holds the pointer to the slot for the final return value
1413 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1414 output_type: Ty<'tcx>)
1416 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1418 // We create an alloca to hold a pointer of type `output_type`
1419 // which will hold the pointer to the right alloca which has the
1421 if fcx.needs_ret_allocas {
1422 // Let's create the stack slot
1423 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1425 // and if we're using an out pointer, then store that in our newly made slot
1426 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1427 let outptr = get_param(fcx.llfn, 0);
1429 let b = fcx.ccx.builder();
1430 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1431 b.store(outptr, slot);
1436 // But if there are no nested returns, we skip the indirection and have a single
1439 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1440 get_param(fcx.llfn, 0)
1442 AllocaFcx(fcx, lloutputtype, "sret_slot")
1447 struct FindNestedReturn {
1451 impl FindNestedReturn {
1452 fn new() -> FindNestedReturn {
1459 impl<'v> Visitor<'v> for FindNestedReturn {
1460 fn visit_expr(&mut self, e: &hir::Expr) {
1462 hir::ExprRet(..) => {
1465 _ => intravisit::walk_expr(self, e),
1470 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1471 let blk = match tcx.map.find(id) {
1472 Some(hir_map::NodeItem(i)) => {
1474 hir::ItemFn(_, _, _, _, _, ref blk) => {
1477 _ => tcx.sess.bug("unexpected item variant in has_nested_returns"),
1480 Some(hir_map::NodeTraitItem(trait_item)) => {
1481 match trait_item.node {
1482 hir::MethodTraitItem(_, Some(ref body)) => body,
1484 tcx.sess.bug("unexpected variant: trait item other than a provided method in \
1485 has_nested_returns")
1489 Some(hir_map::NodeImplItem(impl_item)) => {
1490 match impl_item.node {
1491 hir::ImplItemKind::Method(_, ref body) => body,
1493 tcx.sess.bug("unexpected variant: non-method impl item in has_nested_returns")
1497 Some(hir_map::NodeExpr(e)) => {
1499 hir::ExprClosure(_, _, ref blk) => blk,
1500 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns"),
1503 Some(hir_map::NodeVariant(..)) |
1504 Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1507 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1509 _ => tcx.sess.bug(&format!("unexpected variant in has_nested_returns: {}",
1510 tcx.map.path_to_string(id))),
1513 (blk.id, Some(cfg::CFG::new(tcx, blk)))
1516 // Checks for the presence of "nested returns" in a function.
1517 // Nested returns are when the inner expression of a return expression
1518 // (the 'expr' in 'return expr') contains a return expression. Only cases
1519 // where the outer return is actually reachable are considered. Implicit
1520 // returns from the end of blocks are considered as well.
1522 // This check is needed to handle the case where the inner expression is
1523 // part of a larger expression that may have already partially-filled the
1524 // return slot alloca. This can cause errors related to clean-up due to
1525 // the clobbering of the existing value in the return slot.
1526 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1527 for index in cfg.graph.depth_traverse(cfg.entry) {
1528 let n = cfg.graph.node_data(index);
1529 match tcx.map.find(n.id()) {
1530 Some(hir_map::NodeExpr(ex)) => {
1531 if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
1532 let mut visitor = FindNestedReturn::new();
1533 intravisit::walk_expr(&mut visitor, &**ret_expr);
1539 Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
1540 let mut visitor = FindNestedReturn::new();
1541 walk_list!(&mut visitor, visit_expr, &blk.expr);
1553 // NB: must keep 4 fns in sync:
1556 // - create_datums_for_fn_args.
1560 // Be warned! You must call `init_function` before doing anything with the
1561 // returned function context.
1562 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1566 output_type: ty::FnOutput<'tcx>,
1567 param_substs: &'tcx Substs<'tcx>,
1569 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1570 -> FunctionContext<'a, 'tcx> {
1571 common::validate_substs(param_substs);
1573 debug!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1577 ccx.tcx().map.path_to_string(id).to_string()
1582 let uses_outptr = match output_type {
1583 ty::FnConverging(output_type) => {
1584 let substd_output_type = monomorphize::apply_param_substs(ccx.tcx(),
1587 type_of::return_uses_outptr(ccx, substd_output_type)
1589 ty::FnDiverging => false,
1591 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1592 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1593 let nested_returns = if let Some(ref cfg) = cfg {
1594 has_nested_returns(ccx.tcx(), cfg, blk_id)
1599 let mir = ccx.mir_map().map.get(&id);
1601 let mut fcx = FunctionContext {
1605 llretslotptr: Cell::new(None),
1606 param_env: ccx.tcx().empty_parameter_environment(),
1607 alloca_insert_pt: Cell::new(None),
1608 llreturn: Cell::new(None),
1609 needs_ret_allocas: nested_returns,
1610 landingpad_alloca: Cell::new(None),
1611 caller_expects_out_pointer: uses_outptr,
1612 lllocals: RefCell::new(NodeMap()),
1613 llupvars: RefCell::new(NodeMap()),
1614 lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
1616 param_substs: param_substs,
1618 block_arena: block_arena,
1619 lpad_arena: TypedArena::new(),
1621 debug_context: debug_context,
1622 scopes: RefCell::new(Vec::new()),
1627 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1633 /// Performs setup on a newly created function, creating the entry scope block
1634 /// and allocating space for the return pointer.
1635 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1637 output: ty::FnOutput<'tcx>)
1638 -> Block<'a, 'tcx> {
1639 let entry_bcx = fcx.new_temp_block("entry-block");
1641 // Use a dummy instruction as the insertion point for all allocas.
1642 // This is later removed in FunctionContext::cleanup.
1643 fcx.alloca_insert_pt.set(Some(unsafe {
1644 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1645 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1648 if let ty::FnConverging(output_type) = output {
1649 // This shouldn't need to recompute the return type,
1650 // as new_fn_ctxt did it already.
1651 let substd_output_type = fcx.monomorphize(&output_type);
1652 if !return_type_is_void(fcx.ccx, substd_output_type) {
1653 // If the function returns nil/bot, there is no real return
1654 // value, so do not set `llretslotptr`.
1655 if !skip_retptr || fcx.caller_expects_out_pointer {
1656 // Otherwise, we normally allocate the llretslotptr, unless we
1657 // have been instructed to skip it for immediate return
1659 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1664 // Create the drop-flag hints for every unfragmented path in the function.
1665 let tcx = fcx.ccx.tcx();
1666 let fn_did = tcx.map.local_def_id(fcx.id);
1667 let tables = tcx.tables.borrow();
1668 let mut hints = fcx.lldropflag_hints.borrow_mut();
1669 let fragment_infos = tcx.fragment_infos.borrow();
1671 // Intern table for drop-flag hint datums.
1672 let mut seen = HashMap::new();
1674 if let Some(fragment_infos) = fragment_infos.get(&fn_did) {
1675 for &info in fragment_infos {
1677 let make_datum = |id| {
1678 let init_val = C_u8(fcx.ccx, adt::DTOR_NEEDED_HINT);
1679 let llname = &format!("dropflag_hint_{}", id);
1680 debug!("adding hint {}", llname);
1681 let ty = tcx.types.u8;
1682 let ptr = alloc_ty(entry_bcx, ty, llname);
1683 Store(entry_bcx, init_val, ptr);
1684 let flag = datum::Lvalue::new_dropflag_hint("base::init_function");
1685 datum::Datum::new(ptr, ty, flag)
1688 let (var, datum) = match info {
1689 ty::FragmentInfo::Moved { var, .. } |
1690 ty::FragmentInfo::Assigned { var, .. } => {
1691 let opt_datum = seen.get(&var).cloned().unwrap_or_else(|| {
1692 let ty = tables.node_types[&var];
1693 if fcx.type_needs_drop(ty) {
1694 let datum = make_datum(var);
1695 seen.insert(var, Some(datum.clone()));
1698 // No drop call needed, so we don't need a dropflag hint
1702 if let Some(datum) = opt_datum {
1710 ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
1711 debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
1712 hints.insert(expr_id, DropHint::new(var, datum));
1714 ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
1715 debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
1716 hints.insert(expr_id, DropHint::new(var, datum));
1725 // NB: must keep 4 fns in sync:
1728 // - create_datums_for_fn_args.
1732 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>) -> datum::Rvalue {
1733 use trans::datum::{ByRef, ByValue};
1736 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1740 // create_datums_for_fn_args: creates lvalue datums for each of the
1741 // incoming function arguments.
1742 pub fn create_datums_for_fn_args<'a, 'tcx>(mut bcx: Block<'a, 'tcx>,
1744 arg_tys: &[Ty<'tcx>],
1745 has_tupled_arg: bool,
1746 arg_scope: cleanup::CustomScopeIndex)
1747 -> Block<'a, 'tcx> {
1748 let _icx = push_ctxt("create_datums_for_fn_args");
1750 let arg_scope_id = cleanup::CustomScope(arg_scope);
1752 debug!("create_datums_for_fn_args");
1754 // Return an array wrapping the ValueRefs that we get from `get_param` for
1755 // each argument into datums.
1757 // For certain mode/type combinations, the raw llarg values are passed
1758 // by value. However, within the fn body itself, we want to always
1759 // have all locals and arguments be by-ref so that we can cancel the
1760 // cleanup and for better interaction with LLVM's debug info. So, if
1761 // the argument would be passed by value, we store it into an alloca.
1762 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1763 // the event it's not truly needed.
1764 let mut idx = fcx.arg_offset() as c_uint;
1765 let uninit_reason = InitAlloca::Uninit("fn_arg populate dominates dtor");
1766 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1767 let arg_datum = if !has_tupled_arg || i < arg_tys.len() - 1 {
1768 if type_of::arg_is_indirect(bcx.ccx(), arg_ty) &&
1769 bcx.sess().opts.debuginfo != FullDebugInfo {
1770 // Don't copy an indirect argument to an alloca, the caller
1771 // already put it in a temporary alloca and gave it up, unless
1772 // we emit extra-debug-info, which requires local allocas :(.
1773 let llarg = get_param(fcx.llfn, idx);
1775 bcx.fcx.schedule_lifetime_end(arg_scope_id, llarg);
1776 bcx.fcx.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
1778 datum::Datum::new(llarg,
1780 datum::Lvalue::new("create_datum_for_fn_args"))
1781 } else if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1782 let data = get_param(fcx.llfn, idx);
1783 let extra = get_param(fcx.llfn, idx + 1);
1785 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "", uninit_reason,
1786 arg_scope_id, (data, extra),
1787 |(data, extra), bcx, dst| {
1788 debug!("populate call for create_datum_for_fn_args \
1789 early fat arg, on arg[{}] ty={:?}", i, arg_ty);
1791 Store(bcx, data, expr::get_dataptr(bcx, dst));
1792 Store(bcx, extra, expr::get_meta(bcx, dst));
1796 let llarg = get_param(fcx.llfn, idx);
1798 let tmp = datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty));
1800 datum::lvalue_scratch_datum(bcx,
1808 debug!("populate call for create_datum_for_fn_args \
1809 early thin arg, on arg[{}] ty={:?}", i, arg_ty);
1811 tmp.store_to(bcx, dst)
1815 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1817 ty::TyTuple(ref tupled_arg_tys) => {
1819 datum::lvalue_scratch_datum(bcx,
1828 debug!("populate call for create_datum_for_fn_args \
1829 tupled_args, on arg[{}] ty={:?}", i, arg_ty);
1830 for (j, &tupled_arg_ty) in
1831 tupled_arg_tys.iter().enumerate() {
1832 let lldest = StructGEP(bcx, llval, j);
1833 if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
1834 let data = get_param(bcx.fcx.llfn, idx);
1835 let extra = get_param(bcx.fcx.llfn, idx + 1);
1836 Store(bcx, data, expr::get_dataptr(bcx, lldest));
1837 Store(bcx, extra, expr::get_meta(bcx, lldest));
1840 let datum = datum::Datum::new(
1841 get_param(bcx.fcx.llfn, idx),
1843 arg_kind(bcx.fcx, tupled_arg_ty));
1845 bcx = datum.store_to(bcx, lldest);
1854 .bug("last argument of a function with `rust-call` ABI isn't a tuple?!")
1859 let pat = &*args[i].pat;
1860 bcx = if let Some(name) = simple_name(pat) {
1861 // Generate nicer LLVM for the common case of fn a pattern
1863 set_value_name(arg_datum.val, &bcx.name(name));
1864 bcx.fcx.lllocals.borrow_mut().insert(pat.id, arg_datum);
1867 // General path. Copy out the values that are used in the
1869 _match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
1871 debuginfo::create_argument_metadata(bcx, &args[i]);
1877 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1878 // and builds the return block.
1879 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1880 last_bcx: Block<'blk, 'tcx>,
1881 retty: ty::FnOutput<'tcx>,
1882 ret_debug_loc: DebugLoc) {
1883 let _icx = push_ctxt("finish_fn");
1885 let ret_cx = match fcx.llreturn.get() {
1887 if !last_bcx.terminated.get() {
1888 Br(last_bcx, llreturn, DebugLoc::None);
1890 raw_block(fcx, llreturn)
1895 // This shouldn't need to recompute the return type,
1896 // as new_fn_ctxt did it already.
1897 let substd_retty = fcx.monomorphize(&retty);
1898 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1900 debuginfo::clear_source_location(fcx);
1904 // Builds the return block for a function.
1905 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1906 ret_cx: Block<'blk, 'tcx>,
1907 retty: ty::FnOutput<'tcx>,
1908 ret_debug_location: DebugLoc) {
1909 if fcx.llretslotptr.get().is_none() ||
1910 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1911 return RetVoid(ret_cx, ret_debug_location);
1914 let retslot = if fcx.needs_ret_allocas {
1915 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1917 fcx.llretslotptr.get().unwrap()
1919 let retptr = Value(retslot);
1920 match retptr.get_dominating_store(ret_cx) {
1921 // If there's only a single store to the ret slot, we can directly return
1922 // the value that was stored and omit the store and the alloca
1924 let retval = s.get_operand(0).unwrap().get();
1925 s.erase_from_parent();
1927 if retptr.has_no_uses() {
1928 retptr.erase_from_parent();
1931 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1932 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1937 if fcx.caller_expects_out_pointer {
1938 if let ty::FnConverging(retty) = retty {
1939 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1941 RetVoid(ret_cx, ret_debug_location)
1943 Ret(ret_cx, retval, ret_debug_location)
1946 // Otherwise, copy the return value to the ret slot
1947 None => match retty {
1948 ty::FnConverging(retty) => {
1949 if fcx.caller_expects_out_pointer {
1950 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1951 RetVoid(ret_cx, ret_debug_location)
1953 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1956 ty::FnDiverging => {
1957 if fcx.caller_expects_out_pointer {
1958 RetVoid(ret_cx, ret_debug_location)
1960 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1967 /// Builds an LLVM function out of a source function.
1969 /// If the function closes over its environment a closure will be returned.
1970 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1974 param_substs: &'tcx Substs<'tcx>,
1975 fn_ast_id: ast::NodeId,
1976 attributes: &[ast::Attribute],
1977 output_type: ty::FnOutput<'tcx>,
1979 closure_env: closure::ClosureEnv<'b>) {
1980 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1982 record_translation_item_as_generated(ccx, fn_ast_id, param_substs);
1984 let _icx = push_ctxt("trans_closure");
1985 attributes::emit_uwtable(llfndecl, true);
1987 debug!("trans_closure(..., param_substs={:?})", param_substs);
1989 let has_env = match closure_env {
1990 closure::ClosureEnv::Closure(..) => true,
1991 closure::ClosureEnv::NotClosure => false,
1994 let (arena, fcx): (TypedArena<_>, FunctionContext);
1995 arena = TypedArena::new();
1996 fcx = new_fn_ctxt(ccx,
2004 let mut bcx = init_function(&fcx, false, output_type);
2006 if attributes.iter().any(|item| item.check_name("rustc_mir")) {
2007 mir::trans_mir(bcx.build());
2012 // cleanup scope for the incoming arguments
2013 let fn_cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(ccx,
2017 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
2019 let block_ty = node_id_type(bcx, body.id);
2021 // Set up arguments to the function.
2022 let monomorphized_arg_types = decl.inputs
2024 .map(|arg| node_id_type(bcx, arg.id))
2025 .collect::<Vec<_>>();
2026 for monomorphized_arg_type in &monomorphized_arg_types {
2027 debug!("trans_closure: monomorphized_arg_type: {:?}",
2028 monomorphized_arg_type);
2030 debug!("trans_closure: function lltype: {}",
2031 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
2033 let has_tupled_arg = match closure_env {
2034 closure::ClosureEnv::NotClosure => abi == RustCall,
2038 bcx = create_datums_for_fn_args(bcx,
2040 &monomorphized_arg_types,
2044 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
2046 // Up until here, IR instructions for this function have explicitly not been annotated with
2047 // source code location, so we don't step into call setup code. From here on, source location
2048 // emitting should be enabled.
2049 debuginfo::start_emitting_source_locations(&fcx);
2051 let dest = match fcx.llretslotptr.get() {
2052 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
2054 assert!(type_is_zero_size(bcx.ccx(), block_ty));
2059 // This call to trans_block is the place where we bridge between
2060 // translation calls that don't have a return value (trans_crate,
2061 // trans_mod, trans_item, et cetera) and those that do
2062 // (trans_block, trans_expr, et cetera).
2063 bcx = controlflow::trans_block(bcx, body, dest);
2066 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
2067 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
2072 match fcx.llreturn.get() {
2074 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
2075 fcx.pop_custom_cleanup_scope(arg_scope);
2078 // Microoptimization writ large: avoid creating a separate
2079 // llreturn basic block
2080 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
2084 // Put return block after all other blocks.
2085 // This somewhat improves single-stepping experience in debugger.
2087 let llreturn = fcx.llreturn.get();
2088 if let Some(llreturn) = llreturn {
2089 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
2093 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id, fn_cleanup_debug_loc.span);
2095 // Insert the mandatory first few basic blocks before lltop.
2096 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
2098 fn record_translation_item_as_generated<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2099 node_id: ast::NodeId,
2100 param_substs: &'tcx Substs<'tcx>) {
2101 if !collector::collecting_debug_information(ccx) {
2105 let def_id = match ccx.tcx().node_id_to_type(node_id).sty {
2106 ty::TyClosure(def_id, _) => def_id,
2107 _ => ccx.external_srcs()
2111 .unwrap_or_else(|| ccx.tcx().map.local_def_id(node_id)),
2114 ccx.record_translation_item_as_generated(TransItem::Fn{
2116 substs: ccx.tcx().mk_substs(ccx.tcx().erase_regions(param_substs)),
2121 /// Creates an LLVM function corresponding to a source language function.
2122 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2126 param_substs: &'tcx Substs<'tcx>,
2128 attrs: &[ast::Attribute]) {
2129 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
2130 debug!("trans_fn(param_substs={:?})", param_substs);
2131 let _icx = push_ctxt("trans_fn");
2132 let fn_ty = ccx.tcx().node_id_to_type(id);
2133 let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &fn_ty);
2134 let sig = fn_ty.fn_sig();
2135 let sig = ccx.tcx().erase_late_bound_regions(&sig);
2136 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2137 let output_type = sig.output;
2138 let abi = fn_ty.fn_abi();
2148 closure::ClosureEnv::NotClosure);
2151 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2152 ctor_id: ast::NodeId,
2154 param_substs: &'tcx Substs<'tcx>,
2155 llfndecl: ValueRef) {
2156 let _icx = push_ctxt("trans_enum_variant");
2158 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, disr, param_substs, llfndecl);
2161 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
2164 args: callee::CallArgs,
2166 debug_loc: DebugLoc)
2167 -> Result<'blk, 'tcx> {
2169 let ccx = bcx.fcx.ccx;
2171 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2172 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2173 let result_ty = sig.output.unwrap();
2175 // Get location to store the result. If the user does not care about
2176 // the result, just make a stack slot
2177 let llresult = match dest {
2178 expr::SaveIn(d) => d,
2180 if !type_is_zero_size(ccx, result_ty) {
2181 let llresult = alloc_ty(bcx, result_ty, "constructor_result");
2182 call_lifetime_start(bcx, llresult);
2185 C_undef(type_of::type_of(ccx, result_ty).ptr_to())
2190 if !type_is_zero_size(ccx, result_ty) {
2192 callee::ArgExprs(exprs) => {
2193 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2194 bcx = expr::trans_adt(bcx,
2199 expr::SaveIn(llresult),
2202 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor"),
2205 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
2206 // contents, there could be side-effects we need from them.
2208 callee::ArgExprs(exprs) => {
2210 bcx = expr::trans_into(bcx, expr, expr::Ignore);
2217 // If the caller doesn't care about the result
2218 // drop the temporary we made
2219 let bcx = match dest {
2220 expr::SaveIn(_) => bcx,
2222 let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
2223 if !type_is_zero_size(ccx, result_ty) {
2224 call_lifetime_end(bcx, llresult);
2230 Result::new(bcx, llresult)
2233 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2234 ctor_id: ast::NodeId,
2235 param_substs: &'tcx Substs<'tcx>,
2236 llfndecl: ValueRef) {
2237 let _icx = push_ctxt("trans_tuple_struct");
2239 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, Disr(0), param_substs, llfndecl);
2242 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2243 ctor_id: ast::NodeId,
2245 param_substs: &'tcx Substs<'tcx>,
2246 llfndecl: ValueRef) {
2247 let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
2248 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2250 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2251 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2252 let arg_tys = sig.inputs;
2253 let result_ty = sig.output;
2255 let (arena, fcx): (TypedArena<_>, FunctionContext);
2256 arena = TypedArena::new();
2257 fcx = new_fn_ctxt(ccx,
2265 let bcx = init_function(&fcx, false, result_ty);
2267 assert!(!fcx.needs_ret_allocas);
2269 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2270 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2271 let dest_val = adt::MaybeSizedValue::sized(dest); // Can return unsized value
2272 let repr = adt::represent_type(ccx, result_ty.unwrap());
2273 let mut llarg_idx = fcx.arg_offset() as c_uint;
2274 for (i, arg_ty) in arg_tys.into_iter().enumerate() {
2275 let lldestptr = adt::trans_field_ptr(bcx, &*repr, dest_val, Disr::from(disr), i);
2276 if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
2278 get_param(fcx.llfn, llarg_idx),
2279 expr::get_dataptr(bcx, lldestptr));
2281 get_param(fcx.llfn, llarg_idx + 1),
2282 expr::get_meta(bcx, lldestptr));
2285 let arg = get_param(fcx.llfn, llarg_idx);
2288 if arg_is_indirect(ccx, arg_ty) {
2289 memcpy_ty(bcx, lldestptr, arg, arg_ty);
2291 store_ty(bcx, arg, lldestptr, arg_ty);
2295 adt::trans_set_discr(bcx, &*repr, dest, disr);
2298 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
2301 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &hir::EnumDef, sp: Span, id: ast::NodeId) {
2302 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2304 let print_info = ccx.sess().print_enum_sizes();
2306 let levels = ccx.tcx().node_lint_levels.borrow();
2307 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2308 let lvlsrc = levels.get(&(id, lint_id));
2309 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2311 if is_allow && !print_info {
2312 // we're not interested in anything here
2316 let ty = ccx.tcx().node_id_to_type(id);
2317 let avar = adt::represent_type(ccx, ty);
2319 adt::General(_, ref variants, _) => {
2320 for var in variants {
2322 for field in var.fields.iter().skip(1) {
2323 // skip the discriminant
2324 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2329 _ => { /* its size is either constant or unimportant */ }
2332 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2333 |(l, s, li), (idx, &size)|
2336 } else if size > s {
2343 // FIXME(#30505) Should use logging for this.
2345 let llty = type_of::sizing_type_of(ccx, ty);
2347 let sess = &ccx.tcx().sess;
2348 sess.span_note_without_error(sp,
2349 &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2351 adt::General(..) => {
2352 for (i, var) in enum_def.variants.iter().enumerate() {
2355 .span_note_without_error(var.span,
2356 &*format!("variant data: {} bytes", sizes[i]));
2363 // we only warn if the largest variant is at least thrice as large as
2364 // the second-largest.
2365 if !is_allow && largest > slargest * 3 && slargest > 0 {
2366 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2367 // pass for the latter already ran.
2368 lint::raw_struct_lint(&ccx.tcx().sess,
2369 &ccx.tcx().sess.lint_store.borrow(),
2370 lint::builtin::VARIANT_SIZE_DIFFERENCES,
2373 &format!("enum variant is more than three times larger ({} bytes) \
2374 than the next largest (ignoring padding)",
2376 .span_note(enum_def.variants[largest_index].span,
2377 "this variant is the largest")
2382 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2383 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2384 // applicable to variable declarations and may not really make sense for
2385 // Rust code in the first place but whitelist them anyway and trust that
2386 // the user knows what s/he's doing. Who knows, unanticipated use cases
2387 // may pop up in the future.
2389 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2390 // and don't have to be, LLVM treats them as no-ops.
2392 "appending" => Some(llvm::AppendingLinkage),
2393 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2394 "common" => Some(llvm::CommonLinkage),
2395 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2396 "external" => Some(llvm::ExternalLinkage),
2397 "internal" => Some(llvm::InternalLinkage),
2398 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2399 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2400 "private" => Some(llvm::PrivateLinkage),
2401 "weak" => Some(llvm::WeakAnyLinkage),
2402 "weak_odr" => Some(llvm::WeakODRLinkage),
2408 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2409 #[derive(Copy, Clone)]
2410 pub enum ValueOrigin {
2411 /// The LLVM `Value` is in this context because the corresponding item was
2412 /// assigned to the current compilation unit.
2413 OriginalTranslation,
2414 /// The `Value`'s corresponding item was assigned to some other compilation
2415 /// unit, but the `Value` was translated in this context anyway because the
2416 /// item is marked `#[inline]`.
2420 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2421 /// If the `llval` is the direct translation of a specific Rust item, `id`
2422 /// should be set to the `NodeId` of that item. (This mapping should be
2423 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2424 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2425 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2426 /// assigned to a different compilation unit.
2427 pub fn update_linkage(ccx: &CrateContext,
2429 id: Option<ast::NodeId>,
2430 llval_origin: ValueOrigin) {
2431 match llval_origin {
2433 // `llval` is a translation of an item defined in a separate
2434 // compilation unit. This only makes sense if there are at least
2435 // two compilation units.
2436 assert!(ccx.sess().opts.cg.codegen_units > 1);
2437 // `llval` is a copy of something defined elsewhere, so use
2438 // `AvailableExternallyLinkage` to avoid duplicating code in the
2440 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2443 OriginalTranslation => {},
2446 if let Some(id) = id {
2447 let item = ccx.tcx().map.get(id);
2448 if let hir_map::NodeItem(i) = item {
2449 if let Some(name) = attr::first_attr_value_str_by_name(&i.attrs, "linkage") {
2450 if let Some(linkage) = llvm_linkage_by_name(&name) {
2451 llvm::SetLinkage(llval, linkage);
2453 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2461 Some(id) if ccx.reachable().contains(&id) => {
2462 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2465 // `id` does not refer to an item in `ccx.reachable`.
2466 if ccx.sess().opts.cg.codegen_units > 1 {
2467 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2469 llvm::SetLinkage(llval, llvm::InternalLinkage);
2475 fn set_global_section(ccx: &CrateContext, llval: ValueRef, i: &hir::Item) {
2476 match attr::first_attr_value_str_by_name(&i.attrs, "link_section") {
2478 if contains_null(§) {
2479 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", §));
2482 let buf = CString::new(sect.as_bytes()).unwrap();
2483 llvm::LLVMSetSection(llval, buf.as_ptr());
2490 pub fn trans_item(ccx: &CrateContext, item: &hir::Item) {
2491 let _icx = push_ctxt("trans_item");
2493 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2496 hir::ItemFn(ref decl, _, _, abi, ref generics, ref body) => {
2497 if !generics.is_type_parameterized() {
2498 let trans_everywhere = attr::requests_inline(&item.attrs);
2499 // Ignore `trans_everywhere` for cross-crate inlined items
2500 // (`from_external`). `trans_item` will be called once for each
2501 // compilation unit that references the item, so it will still get
2502 // translated everywhere it's needed.
2503 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2504 let llfn = get_item_val(ccx, item.id);
2505 let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
2507 foreign::trans_rust_fn_with_foreign_abi(ccx,
2524 set_global_section(ccx, llfn, item);
2534 if is_entry_fn(ccx.sess(), item.id) {
2535 create_entry_wrapper(ccx, item.span, llfn);
2536 // check for the #[rustc_error] annotation, which forces an
2537 // error in trans. This is used to write compile-fail tests
2538 // that actually test that compilation succeeds without
2539 // reporting an error.
2540 let item_def_id = ccx.tcx().map.local_def_id(item.id);
2541 if ccx.tcx().has_attr(item_def_id, "rustc_error") {
2542 ccx.tcx().sess.span_fatal(item.span, "compilation successful");
2548 hir::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2549 meth::trans_impl(ccx, item.name, impl_items, generics, item.id);
2551 hir::ItemMod(_) => {
2552 // modules have no equivalent at runtime, they just affect
2553 // the mangled names of things contained within
2555 hir::ItemEnum(ref enum_definition, ref gens) => {
2556 if gens.ty_params.is_empty() {
2557 // sizes only make sense for non-generic types
2559 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2562 hir::ItemConst(..) => {}
2563 hir::ItemStatic(_, m, ref expr) => {
2564 let g = match consts::trans_static(ccx, m, expr, item.id, &item.attrs) {
2566 Err(err) => ccx.tcx().sess.span_fatal(expr.span, &err.description()),
2568 set_global_section(ccx, g, item);
2569 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2571 hir::ItemForeignMod(ref foreign_mod) => {
2572 foreign::trans_foreign_mod(ccx, foreign_mod);
2574 hir::ItemTrait(..) => {}
2581 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2582 pub fn register_fn_llvmty(ccx: &CrateContext,
2585 node_id: ast::NodeId,
2589 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2591 let llfn = declare::define_fn(ccx, &sym[..], cc, llfty,
2592 ty::FnConverging(ccx.tcx().mk_nil())).unwrap_or_else(||{
2593 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2595 finish_register_fn(ccx, sym, node_id);
2599 fn finish_register_fn(ccx: &CrateContext, sym: String, node_id: ast::NodeId) {
2600 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2603 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2606 node_id: ast::NodeId,
2607 node_type: Ty<'tcx>)
2609 if let ty::TyBareFn(_, ref f) = node_type.sty {
2610 if f.abi != Rust && f.abi != RustCall {
2611 ccx.sess().span_bug(sp,
2612 &format!("only the `{}` or `{}` calling conventions are valid \
2613 for this function; `{}` was specified",
2619 ccx.sess().span_bug(sp, "expected bare rust function")
2622 let llfn = declare::define_rust_fn(ccx, &sym[..], node_type).unwrap_or_else(|| {
2623 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2625 finish_register_fn(ccx, sym, node_id);
2629 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2630 match *sess.entry_fn.borrow() {
2631 Some((entry_id, _)) => node_id == entry_id,
2636 /// Create the `main` function which will initialise the rust runtime and call users’ main
2638 pub fn create_entry_wrapper(ccx: &CrateContext, sp: Span, main_llfn: ValueRef) {
2639 let et = ccx.sess().entry_type.get().unwrap();
2641 config::EntryMain => {
2642 create_entry_fn(ccx, sp, main_llfn, true);
2644 config::EntryStart => create_entry_fn(ccx, sp, main_llfn, false),
2645 config::EntryNone => {} // Do nothing.
2648 fn create_entry_fn(ccx: &CrateContext,
2650 rust_main: ValueRef,
2651 use_start_lang_item: bool) {
2652 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()], &ccx.int_type());
2654 let llfn = declare::define_cfn(ccx, "main", llfty, ccx.tcx().mk_nil()).unwrap_or_else(|| {
2655 // FIXME: We should be smart and show a better diagnostic here.
2656 ccx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
2657 .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
2659 ccx.sess().abort_if_errors();
2664 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, "top\0".as_ptr() as *const _)
2666 let bld = ccx.raw_builder();
2668 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2670 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2672 let (start_fn, args) = if use_start_lang_item {
2673 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2676 ccx.sess().fatal(&s[..]);
2679 let start_fn = if let Some(start_node_id) = ccx.tcx()
2681 .as_local_node_id(start_def_id) {
2682 get_item_val(ccx, start_node_id)
2684 let start_fn_type = ccx.tcx().lookup_item_type(start_def_id).ty;
2685 trans_external_path(ccx, start_def_id, start_fn_type)
2688 let opaque_rust_main =
2689 llvm::LLVMBuildPointerCast(bld,
2691 Type::i8p(ccx).to_ref(),
2692 "rust_main\0".as_ptr() as *const _);
2694 vec![opaque_rust_main, get_param(llfn, 0), get_param(llfn, 1)]
2698 debug!("using user-defined start fn");
2699 let args = vec![get_param(llfn, 0 as c_uint), get_param(llfn, 1 as c_uint)];
2704 let result = llvm::LLVMRustBuildCall(bld,
2707 args.len() as c_uint,
2711 llvm::LLVMBuildRet(bld, result);
2716 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2719 attrs: &[ast::Attribute])
2721 match ccx.external_srcs().borrow().get(&id) {
2723 let sym = ccx.sess().cstore.item_symbol(did);
2724 debug!("found item {} in other crate...", sym);
2730 match attr::find_export_name_attr(ccx.sess().diagnostic(), attrs) {
2731 // Use provided name
2732 Some(name) => name.to_string(),
2734 let path = ccx.tcx().map.def_path_from_id(id);
2735 if attr::contains_name(attrs, "no_mangle") {
2737 path.last().unwrap().data.to_string()
2739 match weak_lang_items::link_name(attrs) {
2740 Some(name) => name.to_string(),
2742 // Usual name mangling
2743 mangle_exported_name(ccx, path, ty, id)
2751 fn contains_null(s: &str) -> bool {
2752 s.bytes().any(|b| b == 0)
2755 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2756 debug!("get_item_val(id=`{}`)", id);
2758 match ccx.item_vals().borrow().get(&id).cloned() {
2759 Some(v) => return v,
2763 let item = ccx.tcx().map.get(id);
2764 debug!("get_item_val: id={} item={:?}", id, item);
2765 let val = match item {
2766 hir_map::NodeItem(i) => {
2767 let ty = ccx.tcx().node_id_to_type(i.id);
2768 let sym = || exported_name(ccx, id, ty, &i.attrs);
2770 let v = match i.node {
2771 hir::ItemStatic(..) => {
2772 // If this static came from an external crate, then
2773 // we need to get the symbol from metadata instead of
2774 // using the current crate's name/version
2775 // information in the hash of the symbol
2777 debug!("making {}", sym);
2779 // Create the global before evaluating the initializer;
2780 // this is necessary to allow recursive statics.
2781 let llty = type_of(ccx, ty);
2782 let g = declare::define_global(ccx, &sym[..], llty).unwrap_or_else(|| {
2784 .span_fatal(i.span, &format!("symbol `{}` is already defined", sym))
2787 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2791 hir::ItemFn(_, _, _, abi, _, _) => {
2793 let llfn = if abi == Rust {
2794 register_fn(ccx, i.span, sym, i.id, ty)
2796 foreign::register_rust_fn_with_foreign_abi(ccx, i.span, sym, i.id)
2798 attributes::from_fn_attrs(ccx, &i.attrs, llfn);
2802 _ => ccx.sess().bug("get_item_val: weird result in table"),
2808 hir_map::NodeTraitItem(trait_item) => {
2809 debug!("get_item_val(): processing a NodeTraitItem");
2810 match trait_item.node {
2811 hir::MethodTraitItem(_, Some(_)) => {
2812 register_method(ccx, id, &trait_item.attrs, trait_item.span)
2815 ccx.sess().span_bug(trait_item.span,
2816 "unexpected variant: trait item other than a provided \
2817 method in get_item_val()");
2822 hir_map::NodeImplItem(impl_item) => {
2823 match impl_item.node {
2824 hir::ImplItemKind::Method(..) => {
2825 register_method(ccx, id, &impl_item.attrs, impl_item.span)
2828 ccx.sess().span_bug(impl_item.span,
2829 "unexpected variant: non-method impl item in \
2835 hir_map::NodeForeignItem(ni) => {
2837 hir::ForeignItemFn(..) => {
2838 let abi = ccx.tcx().map.get_foreign_abi(id);
2839 let ty = ccx.tcx().node_id_to_type(ni.id);
2840 let name = foreign::link_name(&*ni);
2841 foreign::register_foreign_item_fn(ccx, abi, ty, &name, &ni.attrs)
2843 hir::ForeignItemStatic(..) => {
2844 foreign::register_static(ccx, &*ni)
2849 hir_map::NodeVariant(ref v) => {
2851 let fields = if v.node.data.is_struct() {
2852 ccx.sess().bug("struct variant kind unexpected in get_item_val")
2854 v.node.data.fields()
2856 assert!(!fields.is_empty());
2857 let ty = ccx.tcx().node_id_to_type(id);
2858 let parent = ccx.tcx().map.get_parent(id);
2859 let enm = ccx.tcx().map.expect_item(parent);
2860 let sym = exported_name(ccx, id, ty, &enm.attrs);
2862 llfn = match enm.node {
2863 hir::ItemEnum(_, _) => {
2864 register_fn(ccx, (*v).span, sym, id, ty)
2866 _ => ccx.sess().bug("NodeVariant, shouldn't happen"),
2868 attributes::inline(llfn, attributes::InlineAttr::Hint);
2872 hir_map::NodeStructCtor(struct_def) => {
2873 // Only register the constructor if this is a tuple-like struct.
2874 let ctor_id = if struct_def.is_struct() {
2875 ccx.sess().bug("attempt to register a constructor of a non-tuple-like struct")
2879 let parent = ccx.tcx().map.get_parent(id);
2880 let struct_item = ccx.tcx().map.expect_item(parent);
2881 let ty = ccx.tcx().node_id_to_type(ctor_id);
2882 let sym = exported_name(ccx, id, ty, &struct_item.attrs);
2883 let llfn = register_fn(ccx, struct_item.span, sym, ctor_id, ty);
2884 attributes::inline(llfn, attributes::InlineAttr::Hint);
2889 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}", variant))
2893 // All LLVM globals and functions are initially created as external-linkage
2894 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2895 // into a definition, it adjusts the linkage then (using `update_linkage`).
2897 // The exception is foreign items, which have their linkage set inside the
2898 // call to `foreign::register_*` above. We don't touch the linkage after
2899 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2900 // other item translation functions do).
2902 ccx.item_vals().borrow_mut().insert(id, val);
2906 fn register_method(ccx: &CrateContext,
2908 attrs: &[ast::Attribute],
2911 let mty = ccx.tcx().node_id_to_type(id);
2913 let sym = exported_name(ccx, id, mty, &attrs);
2915 if let ty::TyBareFn(_, ref f) = mty.sty {
2916 let llfn = if f.abi == Rust || f.abi == RustCall {
2917 register_fn(ccx, span, sym, id, mty)
2919 foreign::register_rust_fn_with_foreign_abi(ccx, span, sym, id)
2921 attributes::from_fn_attrs(ccx, &attrs, llfn);
2924 ccx.sess().span_bug(span, "expected bare rust function");
2928 pub fn write_metadata<'a, 'tcx>(cx: &SharedCrateContext<'a, 'tcx>,
2930 reachable: &NodeSet,
2931 mir_map: &MirMap<'tcx>)
2935 let any_library = cx.sess()
2939 .any(|ty| *ty != config::CrateTypeExecutable);
2944 let cstore = &cx.tcx().sess.cstore;
2945 let metadata = cstore.encode_metadata(cx.tcx(),
2952 let mut compressed = cstore.metadata_encoding_version().to_vec();
2953 compressed.extend_from_slice(&flate::deflate_bytes(&metadata));
2955 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
2956 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2957 let name = format!("rust_metadata_{}_{}",
2958 cx.link_meta().crate_name,
2959 cx.link_meta().crate_hash);
2960 let buf = CString::new(name).unwrap();
2961 let llglobal = unsafe {
2962 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf.as_ptr())
2965 llvm::LLVMSetInitializer(llglobal, llconst);
2967 cx.tcx().sess.cstore.metadata_section_name(&cx.sess().target.target);
2968 let name = CString::new(name).unwrap();
2969 llvm::LLVMSetSection(llglobal, name.as_ptr())
2974 /// Find any symbols that are defined in one compilation unit, but not declared
2975 /// in any other compilation unit. Give these symbols internal linkage.
2976 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<&str>) {
2978 let mut declared = HashSet::new();
2980 // Collect all external declarations in all compilation units.
2981 for ccx in cx.iter() {
2982 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2983 let linkage = llvm::LLVMGetLinkage(val);
2984 // We only care about external declarations (not definitions)
2985 // and available_externally definitions.
2986 if !(linkage == llvm::ExternalLinkage as c_uint &&
2987 llvm::LLVMIsDeclaration(val) != 0) &&
2988 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
2992 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2995 declared.insert(name);
2999 // Examine each external definition. If the definition is not used in
3000 // any other compilation unit, and is not reachable from other crates,
3001 // then give it internal linkage.
3002 for ccx in cx.iter() {
3003 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3004 // We only care about external definitions.
3005 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
3006 llvm::LLVMIsDeclaration(val) == 0) {
3010 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
3013 if !declared.contains(&name) &&
3014 !reachable.contains(str::from_utf8(&name).unwrap()) {
3015 llvm::SetLinkage(val, llvm::InternalLinkage);
3016 llvm::SetDLLStorageClass(val, llvm::DefaultStorageClass);
3023 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
3024 // This is required to satisfy `dllimport` references to static data in .rlibs
3025 // when using MSVC linker. We do this only for data, as linker can fix up
3026 // code references on its own.
3027 // See #26591, #27438
3028 fn create_imps(cx: &SharedCrateContext) {
3029 // The x86 ABI seems to require that leading underscores are added to symbol
3030 // names, so we need an extra underscore on 32-bit. There's also a leading
3031 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
3032 // underscores added in front).
3033 let prefix = if cx.sess().target.target.target_pointer_width == "32" {
3039 for ccx in cx.iter() {
3040 let exported: Vec<_> = iter_globals(ccx.llmod())
3042 llvm::LLVMGetLinkage(val) ==
3043 llvm::ExternalLinkage as c_uint &&
3044 llvm::LLVMIsDeclaration(val) == 0
3048 let i8p_ty = Type::i8p(&ccx);
3049 for val in exported {
3050 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
3051 let mut imp_name = prefix.as_bytes().to_vec();
3052 imp_name.extend(name.to_bytes());
3053 let imp_name = CString::new(imp_name).unwrap();
3054 let imp = llvm::LLVMAddGlobal(ccx.llmod(),
3056 imp_name.as_ptr() as *const _);
3057 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
3058 llvm::LLVMSetInitializer(imp, init);
3059 llvm::SetLinkage(imp, llvm::ExternalLinkage);
3067 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
3070 impl Iterator for ValueIter {
3071 type Item = ValueRef;
3073 fn next(&mut self) -> Option<ValueRef> {
3076 self.cur = unsafe { (self.step)(old) };
3084 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
3087 cur: llvm::LLVMGetFirstGlobal(llmod),
3088 step: llvm::LLVMGetNextGlobal,
3093 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
3096 cur: llvm::LLVMGetFirstFunction(llmod),
3097 step: llvm::LLVMGetNextFunction,
3102 /// The context provided lists a set of reachable ids as calculated by
3103 /// middle::reachable, but this contains far more ids and symbols than we're
3104 /// actually exposing from the object file. This function will filter the set in
3105 /// the context to the set of ids which correspond to symbols that are exposed
3106 /// from the object file being generated.
3108 /// This list is later used by linkers to determine the set of symbols needed to
3109 /// be exposed from a dynamic library and it's also encoded into the metadata.
3110 pub fn filter_reachable_ids(ccx: &SharedCrateContext) -> NodeSet {
3111 ccx.reachable().iter().map(|x| *x).filter(|id| {
3112 // First, only worry about nodes which have a symbol name
3113 ccx.item_symbols().borrow().contains_key(id)
3115 // Next, we want to ignore some FFI functions that are not exposed from
3116 // this crate. Reachable FFI functions can be lumped into two
3119 // 1. Those that are included statically via a static library
3120 // 2. Those included otherwise (e.g. dynamically or via a framework)
3122 // Although our LLVM module is not literally emitting code for the
3123 // statically included symbols, it's an export of our library which
3124 // needs to be passed on to the linker and encoded in the metadata.
3126 // As a result, if this id is an FFI item (foreign item) then we only
3127 // let it through if it's included statically.
3128 match ccx.tcx().map.get(id) {
3129 hir_map::NodeForeignItem(..) => {
3130 ccx.sess().cstore.is_statically_included_foreign_item(id)
3137 pub fn trans_crate<'tcx>(tcx: &ty::ctxt<'tcx>,
3138 mir_map: &MirMap<'tcx>,
3139 analysis: ty::CrateAnalysis)
3140 -> CrateTranslation {
3141 let _task = tcx.dep_graph.in_task(DepNode::TransCrate);
3143 // Be careful with this krate: obviously it gives access to the
3144 // entire contents of the krate. So if you push any subtasks of
3145 // `TransCrate`, you need to be careful to register "reads" of the
3146 // particular items that will be processed.
3147 let krate = tcx.map.krate();
3149 let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
3151 let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
3154 tcx.sess.opts.debug_assertions
3157 let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
3160 tcx.sess.opts.debug_assertions
3163 // Before we touch LLVM, make sure that multithreading is enabled.
3165 use std::sync::Once;
3166 static INIT: Once = Once::new();
3167 static mut POISONED: bool = false;
3169 if llvm::LLVMStartMultithreaded() != 1 {
3170 // use an extra bool to make sure that all future usage of LLVM
3171 // cannot proceed despite the Once not running more than once.
3175 ::back::write::configure_llvm(&tcx.sess);
3179 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3183 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3185 let codegen_units = tcx.sess.opts.cg.codegen_units;
3186 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name,
3198 let ccx = shared_ccx.get_ccx(0);
3200 // First, verify intrinsics.
3201 intrinsic::check_intrinsics(&ccx);
3203 collect_translation_items(&ccx);
3205 // Next, translate all items. See `TransModVisitor` for
3206 // details on why we walk in this particular way.
3208 let _icx = push_ctxt("text");
3209 intravisit::walk_mod(&mut TransItemsWithinModVisitor { ccx: &ccx }, &krate.module);
3210 krate.visit_all_items(&mut TransModVisitor { ccx: &ccx });
3213 collector::print_collection_results(&ccx);
3216 for ccx in shared_ccx.iter() {
3217 if ccx.sess().opts.debuginfo != NoDebugInfo {
3218 debuginfo::finalize(&ccx);
3220 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
3222 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
3223 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
3224 llvm::LLVMDeleteGlobal(old_g);
3229 let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
3231 // Translate the metadata.
3232 let metadata = time(tcx.sess.time_passes(), "write metadata", || {
3233 write_metadata(&shared_ccx, krate, &reachable_symbol_ids, mir_map)
3236 if shared_ccx.sess().trans_stats() {
3237 let stats = shared_ccx.stats();
3238 println!("--- trans stats ---");
3239 println!("n_glues_created: {}", stats.n_glues_created.get());
3240 println!("n_null_glues: {}", stats.n_null_glues.get());
3241 println!("n_real_glues: {}", stats.n_real_glues.get());
3243 println!("n_fns: {}", stats.n_fns.get());
3244 println!("n_monos: {}", stats.n_monos.get());
3245 println!("n_inlines: {}", stats.n_inlines.get());
3246 println!("n_closures: {}", stats.n_closures.get());
3247 println!("fn stats:");
3248 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3249 insns_b.cmp(&insns_a)
3251 for tuple in stats.fn_stats.borrow().iter() {
3253 (ref name, insns) => {
3254 println!("{} insns, {}", insns, *name);
3259 if shared_ccx.sess().count_llvm_insns() {
3260 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3261 println!("{:7} {}", *v, *k);
3265 let modules = shared_ccx.iter()
3266 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3269 let sess = shared_ccx.sess();
3270 let mut reachable_symbols = reachable_symbol_ids.iter().map(|id| {
3271 shared_ccx.item_symbols().borrow()[id].to_string()
3272 }).collect::<Vec<_>>();
3273 if sess.entry_fn.borrow().is_some() {
3274 reachable_symbols.push("main".to_string());
3277 // For the purposes of LTO, we add to the reachable set all of the upstream
3278 // reachable extern fns. These functions are all part of the public ABI of
3279 // the final product, so LTO needs to preserve them.
3281 for cnum in sess.cstore.crates() {
3282 let syms = sess.cstore.reachable_ids(cnum);
3283 reachable_symbols.extend(syms.into_iter().filter(|did| {
3284 sess.cstore.is_extern_fn(shared_ccx.tcx(), *did) ||
3285 sess.cstore.is_static(*did)
3287 sess.cstore.item_symbol(did)
3292 if codegen_units > 1 {
3293 internalize_symbols(&shared_ccx,
3294 &reachable_symbols.iter().map(|x| &x[..]).collect());
3297 if sess.target.target.options.is_like_msvc &&
3298 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
3299 create_imps(&shared_ccx);
3302 let metadata_module = ModuleTranslation {
3303 llcx: shared_ccx.metadata_llcx(),
3304 llmod: shared_ccx.metadata_llmod(),
3306 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
3308 assert_dep_graph::assert_dep_graph(tcx);
3312 metadata_module: metadata_module,
3315 reachable: reachable_symbols,
3316 no_builtins: no_builtins,
3320 /// We visit all the items in the krate and translate them. We do
3321 /// this in two walks. The first walk just finds module items. It then
3322 /// walks the full contents of those module items and translates all
3323 /// the items within. Note that this entire process is O(n). The
3324 /// reason for this two phased walk is that each module is
3325 /// (potentially) placed into a distinct codegen-unit. This walk also
3326 /// ensures that the immediate contents of each module is processed
3327 /// entirely before we proceed to find more modules, helping to ensure
3328 /// an equitable distribution amongst codegen-units.
3329 pub struct TransModVisitor<'a, 'tcx: 'a> {
3330 pub ccx: &'a CrateContext<'a, 'tcx>,
3333 impl<'a, 'tcx, 'v> Visitor<'v> for TransModVisitor<'a, 'tcx> {
3334 fn visit_item(&mut self, i: &hir::Item) {
3336 hir::ItemMod(_) => {
3337 let item_ccx = self.ccx.rotate();
3338 intravisit::walk_item(&mut TransItemsWithinModVisitor { ccx: &item_ccx }, i);
3345 /// Translates all the items within a given module. Expects owner to
3346 /// invoke `walk_item` on a module item. Ignores nested modules.
3347 pub struct TransItemsWithinModVisitor<'a, 'tcx: 'a> {
3348 pub ccx: &'a CrateContext<'a, 'tcx>,
3351 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemsWithinModVisitor<'a, 'tcx> {
3352 fn visit_nested_item(&mut self, item_id: hir::ItemId) {
3353 self.visit_item(self.ccx.tcx().map.expect_item(item_id.id));
3356 fn visit_item(&mut self, i: &hir::Item) {
3358 hir::ItemMod(..) => {
3359 // skip modules, they will be uncovered by the TransModVisitor
3362 let def_id = self.ccx.tcx().map.local_def_id(i.id);
3363 let tcx = self.ccx.tcx();
3365 // Create a subtask for trans'ing a particular item. We are
3366 // giving `trans_item` access to this item, so also record a read.
3367 tcx.dep_graph.with_task(DepNode::TransCrateItem(def_id), || {
3368 tcx.dep_graph.read(DepNode::Hir(def_id));
3370 // We are going to be accessing various tables
3371 // generated by TypeckItemBody; we also assume
3372 // that the body passes type check. These tables
3373 // are not individually tracked, so just register
3375 tcx.dep_graph.read(DepNode::TypeckItemBody(def_id));
3377 trans_item(self.ccx, i);
3380 intravisit::walk_item(self, i);
3386 fn collect_translation_items<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>) {
3387 let time_passes = ccx.sess().time_passes();
3389 let collection_mode = match ccx.sess().opts.debugging_opts.print_trans_items {
3391 let mode_string = s.to_lowercase();
3392 let mode_string = mode_string.trim();
3393 if mode_string == "eager" {
3394 TransItemCollectionMode::Eager
3396 if mode_string != "lazy" {
3397 let message = format!("Unknown codegen-item collection mode '{}'. \
3398 Falling back to 'lazy' mode.",
3400 ccx.sess().warn(&message);
3403 TransItemCollectionMode::Lazy
3406 None => TransItemCollectionMode::Lazy
3409 let items = time(time_passes, "translation item collection", || {
3410 collector::collect_crate_translation_items(&ccx, collection_mode)
3413 if ccx.sess().opts.debugging_opts.print_trans_items.is_some() {
3414 let mut item_keys: Vec<_> = items.iter()
3415 .map(|i| i.to_string(ccx))
3419 for item in item_keys {
3420 println!("TRANS_ITEM {}", item);
3423 let mut ccx_map = ccx.translation_items().borrow_mut();
3426 ccx_map.insert(cgi, TransItemState::PredictedButNotGenerated);