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::Substs;
45 use middle::ty::{self, Ty, HasTypeFlags};
46 use rustc::front::map as hir_map;
47 use rustc_mir::mir_map::MirMap;
48 use session::config::{self, NoDebugInfo, FullDebugInfo};
52 use trans::attributes;
54 use trans::builder::{Builder, noname};
56 use trans::cleanup::{self, CleanupMethods, DropHint};
58 use trans::common::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_uint, C_integral};
59 use trans::common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
60 use trans::common::{CrateContext, DropFlagHintsMap, Field, FunctionContext};
61 use trans::common::{Result, NodeIdAndSpan, VariantInfo};
62 use trans::common::{node_id_type, return_type_is_void};
63 use trans::common::{type_is_immediate, type_is_zero_size, val_ty};
66 use trans::context::SharedCrateContext;
67 use trans::controlflow;
69 use trans::debuginfo::{self, DebugLoc, ToDebugLoc};
76 use trans::machine::{llsize_of, llsize_of_real};
79 use trans::monomorphize;
81 use trans::type_::Type;
83 use trans::type_of::*;
84 use trans::value::Value;
85 use util::common::indenter;
86 use util::sha2::Sha256;
87 use util::nodemap::{NodeMap, NodeSet};
89 use arena::TypedArena;
91 use std::ffi::{CStr, CString};
92 use std::cell::{Cell, RefCell};
93 use std::collections::{HashMap, HashSet};
95 use std::{i8, i16, i32, i64};
96 use syntax::abi::{Rust, RustCall, RustIntrinsic, PlatformIntrinsic, Abi};
97 use syntax::codemap::Span;
98 use syntax::parse::token::InternedString;
99 use syntax::attr::AttrMetaMethods;
102 use rustc_front::intravisit::{self, Visitor};
103 use rustc_front::hir;
107 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
112 pub fn with_insn_ctxt<F>(blk: F)
113 where F: FnOnce(&[&'static str])
115 TASK_LOCAL_INSN_KEY.with(move |slot| {
116 slot.borrow().as_ref().map(move |s| blk(s));
120 pub fn init_insn_ctxt() {
121 TASK_LOCAL_INSN_KEY.with(|slot| {
122 *slot.borrow_mut() = Some(Vec::new());
126 pub struct _InsnCtxt {
127 _cannot_construct_outside_of_this_module: (),
130 impl Drop for _InsnCtxt {
132 TASK_LOCAL_INSN_KEY.with(|slot| {
133 match slot.borrow_mut().as_mut() {
143 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
144 debug!("new InsnCtxt: {}", s);
145 TASK_LOCAL_INSN_KEY.with(|slot| {
146 match slot.borrow_mut().as_mut() {
147 Some(ctx) => ctx.push(s),
152 _cannot_construct_outside_of_this_module: (),
156 pub struct StatRecorder<'a, 'tcx: 'a> {
157 ccx: &'a CrateContext<'a, 'tcx>,
158 name: Option<String>,
162 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
163 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> {
164 let istart = ccx.stats().n_llvm_insns.get();
173 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
175 if self.ccx.sess().trans_stats() {
176 let iend = self.ccx.stats().n_llvm_insns.get();
181 .push((self.name.take().unwrap(), iend - self.istart));
182 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
183 // Reset LLVM insn count to avoid compound costs.
184 self.ccx.stats().n_llvm_insns.set(self.istart);
189 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
194 match ccx.externs().borrow().get(name) {
195 Some(n) => return *n,
199 let f = declare::declare_rust_fn(ccx, name, fn_ty);
201 let attrs = ccx.sess().cstore.item_attrs(did);
202 attributes::from_fn_attrs(ccx, &attrs[..], f);
204 ccx.externs().borrow_mut().insert(name.to_string(), f);
208 pub fn self_type_for_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
212 let closure_kind = ccx.tcx().closure_kind(closure_id);
214 ty::FnClosureKind => {
215 ccx.tcx().mk_imm_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
217 ty::FnMutClosureKind => {
218 ccx.tcx().mk_mut_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
220 ty::FnOnceClosureKind => fn_ty,
224 pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
225 *ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
228 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
232 let name = ccx.sess().cstore.item_symbol(did);
233 let ty = type_of(ccx, t);
234 match ccx.externs().borrow_mut().get(&name) {
235 Some(n) => return *n,
238 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
239 // FIXME(nagisa): investigate whether it can be changed into define_global
240 let c = declare::declare_global(ccx, &name[..], ty);
241 // Thread-local statics in some other crate need to *always* be linked
242 // against in a thread-local fashion, so we need to be sure to apply the
243 // thread-local attribute locally if it was present remotely. If we
244 // don't do this then linker errors can be generated where the linker
245 // complains that one object files has a thread local version of the
246 // symbol and another one doesn't.
247 for attr in ccx.tcx().get_attrs(did).iter() {
248 if attr.check_name("thread_local") {
249 llvm::set_thread_local(c, true);
252 if ccx.use_dll_storage_attrs() {
253 llvm::SetDLLStorageClass(c, llvm::DLLImportStorageClass);
255 ccx.externs().borrow_mut().insert(name.to_string(), c);
259 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, info_ty: Ty<'tcx>, it: LangItem) -> DefId {
260 match bcx.tcx().lang_items.require(it) {
263 bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
268 // The following malloc_raw_dyn* functions allocate a box to contain
269 // a given type, but with a potentially dynamic size.
271 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
277 -> Result<'blk, 'tcx> {
278 let _icx = push_ctxt("malloc_raw_exchange");
281 let r = callee::trans_lang_call(bcx,
282 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
287 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
291 pub fn bin_op_to_icmp_predicate(ccx: &CrateContext,
294 -> llvm::IntPredicate {
296 hir::BiEq => llvm::IntEQ,
297 hir::BiNe => llvm::IntNE,
298 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
299 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
300 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
301 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
304 .bug(&format!("comparison_op_to_icmp_predicate: expected comparison operator, \
311 pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: hir::BinOp_) -> llvm::RealPredicate {
313 hir::BiEq => llvm::RealOEQ,
314 hir::BiNe => llvm::RealUNE,
315 hir::BiLt => llvm::RealOLT,
316 hir::BiLe => llvm::RealOLE,
317 hir::BiGt => llvm::RealOGT,
318 hir::BiGe => llvm::RealOGE,
321 .bug(&format!("comparison_op_to_fcmp_predicate: expected comparison operator, \
328 pub fn compare_fat_ptrs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
339 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
340 let extra_eq = ICmp(bcx, llvm::IntEQ, lhs_extra, rhs_extra, debug_loc);
341 And(bcx, addr_eq, extra_eq, debug_loc)
344 let addr_eq = ICmp(bcx, llvm::IntNE, lhs_addr, rhs_addr, debug_loc);
345 let extra_eq = ICmp(bcx, llvm::IntNE, lhs_extra, rhs_extra, debug_loc);
346 Or(bcx, addr_eq, extra_eq, debug_loc)
348 hir::BiLe | hir::BiLt | hir::BiGe | hir::BiGt => {
349 // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
350 let (op, strict_op) = match op {
351 hir::BiLt => (llvm::IntULT, llvm::IntULT),
352 hir::BiLe => (llvm::IntULE, llvm::IntULT),
353 hir::BiGt => (llvm::IntUGT, llvm::IntUGT),
354 hir::BiGe => (llvm::IntUGE, llvm::IntUGT),
358 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
359 let extra_op = ICmp(bcx, op, lhs_extra, rhs_extra, debug_loc);
360 let addr_eq_extra_op = And(bcx, addr_eq, extra_op, debug_loc);
362 let addr_strict = ICmp(bcx, strict_op, lhs_addr, rhs_addr, debug_loc);
363 Or(bcx, addr_strict, addr_eq_extra_op, debug_loc)
366 bcx.tcx().sess.bug("unexpected fat ptr binop");
371 pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
379 ty::TyTuple(ref tys) if tys.is_empty() => {
380 // We don't need to do actual comparisons for nil.
381 // () == () holds but () < () does not.
383 hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
384 hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
385 // refinements would be nice
386 _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator"),
389 ty::TyBareFn(..) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
391 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
396 ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
398 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
404 let lhs_addr = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_ADDR]));
405 let lhs_extra = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_EXTRA]));
407 let rhs_addr = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_ADDR]));
408 let rhs_extra = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_EXTRA]));
409 compare_fat_ptrs(bcx,
420 bin_op_to_icmp_predicate(bcx.ccx(), op, true),
427 bin_op_to_fcmp_predicate(bcx.ccx(), op),
432 // Should never get here, because t is scalar.
433 _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types"),
437 pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
445 let signed = match t.sty {
447 let cmp = bin_op_to_fcmp_predicate(bcx.ccx(), op);
448 return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
450 ty::TyUint(_) => false,
451 ty::TyInt(_) => true,
452 _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
455 let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
456 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
457 // to get the correctly sized type. This will compile to a single instruction
458 // once the IR is converted to assembly if the SIMD instruction is supported
459 // by the target architecture.
460 SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
463 // Iterates through the elements of a structural type.
464 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
469 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
471 let _icx = push_ctxt("iter_structural_ty");
473 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
474 repr: &adt::Repr<'tcx>,
475 av: adt::MaybeSizedValue,
476 variant: ty::VariantDef<'tcx>,
477 substs: &Substs<'tcx>,
480 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
482 let _icx = push_ctxt("iter_variant");
486 for (i, field) in variant.fields.iter().enumerate() {
487 let arg = monomorphize::field_ty(tcx, substs, field);
489 adt::trans_field_ptr(cx, repr, av, variant.disr_val, i),
495 let value = if common::type_is_sized(cx.tcx(), t) {
496 adt::MaybeSizedValue::sized(av)
498 let data = Load(cx, expr::get_dataptr(cx, av));
499 let info = Load(cx, expr::get_meta(cx, av));
500 adt::MaybeSizedValue::unsized_(data, info)
505 ty::TyStruct(..) => {
506 let repr = adt::represent_type(cx.ccx(), t);
507 let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
508 for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
509 let llfld_a = adt::trans_field_ptr(cx, &*repr, value, discr, i);
511 let val = if common::type_is_sized(cx.tcx(), field_ty) {
514 let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
515 Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
516 Store(cx, value.meta, expr::get_meta(cx, scratch.val));
519 cx = f(cx, val, field_ty);
522 ty::TyClosure(_, ref substs) => {
523 let repr = adt::represent_type(cx.ccx(), t);
524 for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
525 let llupvar = adt::trans_field_ptr(cx, &*repr, value, 0, i);
526 cx = f(cx, llupvar, upvar_ty);
529 ty::TyArray(_, n) => {
530 let (base, len) = tvec::get_fixed_base_and_len(cx, value.value, n);
531 let unit_ty = t.sequence_element_type(cx.tcx());
532 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
534 ty::TySlice(_) | ty::TyStr => {
535 let unit_ty = t.sequence_element_type(cx.tcx());
536 cx = tvec::iter_vec_raw(cx, value.value, unit_ty, value.meta, f);
538 ty::TyTuple(ref args) => {
539 let repr = adt::represent_type(cx.ccx(), t);
540 for (i, arg) in args.iter().enumerate() {
541 let llfld_a = adt::trans_field_ptr(cx, &*repr, value, 0, i);
542 cx = f(cx, llfld_a, *arg);
545 ty::TyEnum(en, substs) => {
549 let repr = adt::represent_type(ccx, t);
550 let n_variants = en.variants.len();
552 // NB: we must hit the discriminant first so that structural
553 // comparison know not to proceed when the discriminants differ.
555 match adt::trans_switch(cx, &*repr, av) {
556 (_match::Single, None) => {
558 assert!(n_variants == 1);
559 cx = iter_variant(cx, &*repr, adt::MaybeSizedValue::sized(av),
560 &en.variants[0], substs, &mut f);
563 (_match::Switch, Some(lldiscrim_a)) => {
564 cx = f(cx, lldiscrim_a, cx.tcx().types.isize);
566 // Create a fall-through basic block for the "else" case of
567 // the switch instruction we're about to generate. Note that
568 // we do **not** use an Unreachable instruction here, even
569 // though most of the time this basic block will never be hit.
571 // When an enum is dropped it's contents are currently
572 // overwritten to DTOR_DONE, which means the discriminant
573 // could have changed value to something not within the actual
574 // range of the discriminant. Currently this function is only
575 // used for drop glue so in this case we just return quickly
576 // from the outer function, and any other use case will only
577 // call this for an already-valid enum in which case the `ret
578 // void` will never be hit.
579 let ret_void_cx = fcx.new_temp_block("enum-iter-ret-void");
580 RetVoid(ret_void_cx, DebugLoc::None);
581 let llswitch = Switch(cx, lldiscrim_a, ret_void_cx.llbb, n_variants);
582 let next_cx = fcx.new_temp_block("enum-iter-next");
584 for variant in &en.variants {
585 let variant_cx = fcx.new_temp_block(&format!("enum-iter-variant-{}",
588 let case_val = adt::trans_case(cx, &*repr, variant.disr_val);
589 AddCase(llswitch, case_val, variant_cx.llbb);
590 let variant_cx = iter_variant(variant_cx,
596 Br(variant_cx, next_cx.llbb, DebugLoc::None);
600 _ => ccx.sess().unimpl("value from adt::trans_switch in iter_structural_ty"),
604 cx.sess().unimpl(&format!("type in iter_structural_ty: {}", t))
611 /// Retrieve the information we are losing (making dynamic) in an unsizing
614 /// The `old_info` argument is a bit funny. It is intended for use
615 /// in an upcast, where the new vtable for an object will be drived
616 /// from the old one.
617 pub fn unsized_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
620 old_info: Option<ValueRef>,
621 param_substs: &'tcx Substs<'tcx>)
623 let (source, target) = ccx.tcx().struct_lockstep_tails(source, target);
624 match (&source.sty, &target.sty) {
625 (&ty::TyArray(_, len), &ty::TySlice(_)) => C_uint(ccx, len),
626 (&ty::TyTrait(_), &ty::TyTrait(_)) => {
627 // For now, upcasts are limited to changes in marker
628 // traits, and hence never actually require an actual
629 // change to the vtable.
630 old_info.expect("unsized_info: missing old info for trait upcast")
632 (_, &ty::TyTrait(box ty::TraitTy { ref principal, .. })) => {
633 // Note that we preserve binding levels here:
634 let substs = principal.0.substs.with_self_ty(source).erase_regions();
635 let substs = ccx.tcx().mk_substs(substs);
636 let trait_ref = ty::Binder(ty::TraitRef {
637 def_id: principal.def_id(),
640 consts::ptrcast(meth::get_vtable(ccx, trait_ref, param_substs),
641 Type::vtable_ptr(ccx))
643 _ => ccx.sess().bug(&format!("unsized_info: invalid unsizing {:?} -> {:?}",
649 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
650 pub fn unsize_thin_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
654 -> (ValueRef, ValueRef) {
655 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
656 match (&src_ty.sty, &dst_ty.sty) {
657 (&ty::TyBox(a), &ty::TyBox(b)) |
658 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
659 &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) |
660 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
661 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) |
662 (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }),
663 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => {
664 assert!(common::type_is_sized(bcx.tcx(), a));
665 let ptr_ty = type_of::in_memory_type_of(bcx.ccx(), b).ptr_to();
666 (PointerCast(bcx, src, ptr_ty),
667 unsized_info(bcx.ccx(), a, b, None, bcx.fcx.param_substs))
669 _ => bcx.sess().bug("unsize_thin_ptr: called on bad types"),
673 /// Coerce `src`, which is a reference to a value of type `src_ty`,
674 /// to a value of type `dst_ty` and store the result in `dst`
675 pub fn coerce_unsized_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
680 match (&src_ty.sty, &dst_ty.sty) {
681 (&ty::TyBox(..), &ty::TyBox(..)) |
682 (&ty::TyRef(..), &ty::TyRef(..)) |
683 (&ty::TyRef(..), &ty::TyRawPtr(..)) |
684 (&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => {
685 let (base, info) = if common::type_is_fat_ptr(bcx.tcx(), src_ty) {
686 // fat-ptr to fat-ptr unsize preserves the vtable
687 load_fat_ptr(bcx, src, src_ty)
689 let base = load_ty(bcx, src, src_ty);
690 unsize_thin_ptr(bcx, base, src_ty, dst_ty)
692 store_fat_ptr(bcx, base, info, dst, dst_ty);
695 // This can be extended to enums and tuples in the future.
696 // (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) |
697 (&ty::TyStruct(def_a, _), &ty::TyStruct(def_b, _)) => {
698 assert_eq!(def_a, def_b);
700 let src_repr = adt::represent_type(bcx.ccx(), src_ty);
701 let src_fields = match &*src_repr {
702 &adt::Repr::Univariant(ref s, _) => &s.fields,
703 _ => bcx.sess().bug("struct has non-univariant repr"),
705 let dst_repr = adt::represent_type(bcx.ccx(), dst_ty);
706 let dst_fields = match &*dst_repr {
707 &adt::Repr::Univariant(ref s, _) => &s.fields,
708 _ => bcx.sess().bug("struct has non-univariant repr"),
711 let src = adt::MaybeSizedValue::sized(src);
712 let dst = adt::MaybeSizedValue::sized(dst);
714 let iter = src_fields.iter().zip(dst_fields).enumerate();
715 for (i, (src_fty, dst_fty)) in iter {
716 if type_is_zero_size(bcx.ccx(), dst_fty) {
720 let src_f = adt::trans_field_ptr(bcx, &src_repr, src, 0, i);
721 let dst_f = adt::trans_field_ptr(bcx, &dst_repr, dst, 0, i);
722 if src_fty == dst_fty {
723 memcpy_ty(bcx, dst_f, src_f, src_fty);
725 coerce_unsized_into(bcx, src_f, src_fty, dst_f, dst_fty);
729 _ => bcx.sess().bug(&format!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
735 pub fn cast_shift_expr_rhs(cx: Block, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
736 cast_shift_rhs(op, lhs, rhs, |a, b| Trunc(cx, a, b), |a, b| ZExt(cx, a, b))
739 pub fn cast_shift_const_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
743 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
744 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
747 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
753 where F: FnOnce(ValueRef, Type) -> ValueRef,
754 G: FnOnce(ValueRef, Type) -> ValueRef
756 // Shifts may have any size int on the rhs
757 if rustc_front::util::is_shift_binop(op) {
758 let mut rhs_llty = val_ty(rhs);
759 let mut lhs_llty = val_ty(lhs);
760 if rhs_llty.kind() == Vector {
761 rhs_llty = rhs_llty.element_type()
763 if lhs_llty.kind() == Vector {
764 lhs_llty = lhs_llty.element_type()
766 let rhs_sz = rhs_llty.int_width();
767 let lhs_sz = lhs_llty.int_width();
770 } else if lhs_sz > rhs_sz {
771 // FIXME (#1877: If shifting by negative
772 // values becomes not undefined then this is wrong.
782 pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
787 let llty = Type::int_from_ty(cx.ccx(), t);
789 ast::TyIs if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
790 ast::TyIs => i64::MIN as u64,
791 ast::TyI8 => i8::MIN as u64,
792 ast::TyI16 => i16::MIN as u64,
793 ast::TyI32 => i32::MIN as u64,
794 ast::TyI64 => i64::MIN as u64,
802 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
803 call_info: NodeIdAndSpan,
808 -> Block<'blk, 'tcx> {
809 let (zero_text, overflow_text) = if divrem.node == hir::BiDiv {
810 ("attempted to divide by zero",
811 "attempted to divide with overflow")
813 ("attempted remainder with a divisor of zero",
814 "attempted remainder with overflow")
816 let debug_loc = call_info.debug_loc();
818 let (is_zero, is_signed) = match rhs_t.sty {
820 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
821 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
824 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
825 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
827 ty::TyStruct(def, _) if def.is_simd() => {
828 let mut res = C_bool(cx.ccx(), false);
829 for i in 0..rhs_t.simd_size(cx.tcx()) {
832 IsNull(cx, ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))),
838 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}", rhs_t));
841 let bcx = with_cond(cx, is_zero, |bcx| {
842 controlflow::trans_fail(bcx, call_info, InternedString::new(zero_text))
845 // To quote LLVM's documentation for the sdiv instruction:
847 // Division by zero leads to undefined behavior. Overflow also leads
848 // to undefined behavior; this is a rare case, but can occur, for
849 // example, by doing a 32-bit division of -2147483648 by -1.
851 // In order to avoid undefined behavior, we perform runtime checks for
852 // signed division/remainder which would trigger overflow. For unsigned
853 // integers, no action beyond checking for zero need be taken.
855 let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
856 let minus_one = ICmp(bcx,
859 C_integral(llty, !0, false),
861 with_cond(bcx, minus_one, |bcx| {
862 let is_min = ICmp(bcx,
865 C_integral(llty, min, true),
867 with_cond(bcx, is_min, |bcx| {
868 controlflow::trans_fail(bcx, call_info, InternedString::new(overflow_text))
876 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
880 let name = ccx.sess().cstore.item_symbol(did);
882 ty::TyBareFn(_, ref fn_ty) => {
883 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
885 get_extern_rust_fn(ccx, t, &name[..], did)
887 RustIntrinsic | PlatformIntrinsic => {
888 ccx.sess().bug("unexpected intrinsic in trans_external_path")
891 let attrs = ccx.sess().cstore.item_attrs(did);
892 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t, &name, &attrs)
897 get_extern_const(ccx, did, t)
902 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
907 -> (ValueRef, Block<'blk, 'tcx>) {
908 let _icx = push_ctxt("invoke_");
909 if bcx.unreachable.get() {
910 return (C_null(Type::i8(bcx.ccx())), bcx);
913 let attributes = attributes::from_fn_type(bcx.ccx(), fn_ty);
915 match bcx.opt_node_id {
917 debug!("invoke at ???");
920 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
924 if need_invoke(bcx) {
925 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
926 for &llarg in llargs {
927 debug!("arg: {}", bcx.val_to_string(llarg));
929 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
930 let landing_pad = bcx.fcx.get_landing_pad();
932 let llresult = Invoke(bcx,
939 return (llresult, normal_bcx);
941 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
942 for &llarg in llargs {
943 debug!("arg: {}", bcx.val_to_string(llarg));
946 let llresult = Call(bcx, llfn, &llargs[..], Some(attributes), debug_loc);
947 return (llresult, bcx);
951 /// Returns whether this session's target will use SEH-based unwinding.
953 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
954 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
955 /// 64-bit MinGW) instead of "full SEH".
956 pub fn wants_msvc_seh(sess: &Session) -> bool {
957 sess.target.target.options.is_like_msvc && sess.target.target.arch == "x86"
960 pub fn need_invoke(bcx: Block) -> bool {
961 // FIXME(#25869) currently SEH-based unwinding is pretty buggy in LLVM and
962 // is being overhauled as this is being written. Until that
963 // time such that upstream LLVM's implementation is more solid
964 // and we start binding it we need to skip invokes for any
965 // target which wants SEH-based unwinding.
966 if bcx.sess().no_landing_pads() || wants_msvc_seh(bcx.sess()) {
970 // Avoid using invoke if we are already inside a landing pad.
975 bcx.fcx.needs_invoke()
978 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, t: Ty<'tcx>) -> ValueRef {
979 let _icx = push_ctxt("load_if_immediate");
980 if type_is_immediate(cx.ccx(), t) {
981 return load_ty(cx, v, t);
986 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
987 /// differs from the type used for SSA values. Also handles various special cases where the type
988 /// gives us better information about what we are loading.
989 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
990 if cx.unreachable.get() || type_is_zero_size(cx.ccx(), t) {
991 return C_undef(type_of::type_of(cx.ccx(), t));
994 let ptr = to_arg_ty_ptr(cx, ptr, t);
995 let align = type_of::align_of(cx.ccx(), t);
997 if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
998 let load = Load(cx, ptr);
1000 llvm::LLVMSetAlignment(load, align);
1006 let global = llvm::LLVMIsAGlobalVariable(ptr);
1007 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
1008 let val = llvm::LLVMGetInitializer(global);
1010 return to_arg_ty(cx, val, t);
1015 let val = if t.is_bool() {
1016 LoadRangeAssert(cx, ptr, 0, 2, llvm::False)
1017 } else if t.is_char() {
1018 // a char is a Unicode codepoint, and so takes values from 0
1019 // to 0x10FFFF inclusive only.
1020 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1021 } else if (t.is_region_ptr() || t.is_unique()) && !common::type_is_fat_ptr(cx.tcx(), t) {
1022 LoadNonNull(cx, ptr)
1028 llvm::LLVMSetAlignment(val, align);
1031 to_arg_ty(cx, val, t)
1034 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1035 /// differs from the type used for SSA values.
1036 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1037 if cx.unreachable.get() {
1041 debug!("store_ty: {} : {:?} <- {}",
1042 cx.val_to_string(dst),
1044 cx.val_to_string(v));
1046 if common::type_is_fat_ptr(cx.tcx(), t) {
1048 ExtractValue(cx, v, abi::FAT_PTR_ADDR),
1049 expr::get_dataptr(cx, dst));
1051 ExtractValue(cx, v, abi::FAT_PTR_EXTRA),
1052 expr::get_meta(cx, dst));
1054 let store = Store(cx, from_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
1056 llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
1061 pub fn store_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1066 // FIXME: emit metadata
1067 Store(cx, data, expr::get_dataptr(cx, dst));
1068 Store(cx, extra, expr::get_meta(cx, dst));
1071 pub fn load_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1074 -> (ValueRef, ValueRef) {
1075 // FIXME: emit metadata
1076 (Load(cx, expr::get_dataptr(cx, src)),
1077 Load(cx, expr::get_meta(cx, src)))
1080 pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1082 ZExt(bcx, val, Type::i8(bcx.ccx()))
1088 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1090 Trunc(bcx, val, Type::i1(bcx.ccx()))
1096 pub fn to_arg_ty_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef, ty: Ty<'tcx>) -> ValueRef {
1097 if type_is_immediate(bcx.ccx(), ty) && type_of::type_of(bcx.ccx(), ty).is_aggregate() {
1098 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1099 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1100 // and we have to convert it
1101 BitCast(bcx, ptr, type_of::arg_type_of(bcx.ccx(), ty).ptr_to())
1107 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local) -> Block<'blk, 'tcx> {
1108 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1109 let _indenter = indenter();
1110 let _icx = push_ctxt("init_local");
1111 _match::store_local(bcx, local)
1114 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1116 llbb: BasicBlockRef)
1117 -> Block<'blk, 'tcx> {
1118 common::BlockS::new(llbb, is_lpad, None, fcx)
1121 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>, val: ValueRef, f: F) -> Block<'blk, 'tcx>
1122 where F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>
1124 let _icx = push_ctxt("with_cond");
1126 if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
1131 let next_cx = fcx.new_temp_block("next");
1132 let cond_cx = fcx.new_temp_block("cond");
1133 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
1134 let after_cx = f(cond_cx);
1135 if !after_cx.terminated.get() {
1136 Br(after_cx, next_cx.llbb, DebugLoc::None);
1141 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1142 if cx.sess().opts.optimize == config::No {
1146 let _icx = push_ctxt("lifetime_start");
1149 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1154 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1155 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1158 &[C_u64(ccx, size), ptr],
1163 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1164 if cx.sess().opts.optimize == config::No {
1168 let _icx = push_ctxt("lifetime_end");
1171 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1176 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1177 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1180 &[C_u64(ccx, size), ptr],
1185 // Generates code for resumption of unwind at the end of a landing pad.
1186 pub fn trans_unwind_resume(bcx: Block, lpval: ValueRef) {
1187 if !bcx.sess().target.target.options.custom_unwind_resume {
1190 let exc_ptr = ExtractValue(bcx, lpval, 0);
1191 let llunwresume = bcx.fcx.eh_unwind_resume();
1192 Call(bcx, llunwresume, &[exc_ptr], None, DebugLoc::None);
1198 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1199 let _icx = push_ctxt("call_memcpy");
1201 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1202 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
1203 let memcpy = ccx.get_intrinsic(&key);
1204 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1205 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1206 let size = IntCast(cx, n_bytes, ccx.int_type());
1207 let align = C_i32(ccx, align as i32);
1208 let volatile = C_bool(ccx, false);
1211 &[dst_ptr, src_ptr, size, align, volatile],
1216 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, dst: ValueRef, src: ValueRef, t: Ty<'tcx>) {
1217 let _icx = push_ctxt("memcpy_ty");
1218 let ccx = bcx.ccx();
1220 if type_is_zero_size(ccx, t) {
1224 if t.is_structural() {
1225 let llty = type_of::type_of(ccx, t);
1226 let llsz = llsize_of(ccx, llty);
1227 let llalign = type_of::align_of(ccx, t);
1228 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1229 } else if common::type_is_fat_ptr(bcx.tcx(), t) {
1230 let (data, extra) = load_fat_ptr(bcx, src, t);
1231 store_fat_ptr(bcx, data, extra, dst, t);
1233 store_ty(bcx, load_ty(bcx, src, t), dst, t);
1237 pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1238 if cx.unreachable.get() {
1241 let _icx = push_ctxt("drop_done_fill_mem");
1243 memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
1246 pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1247 if cx.unreachable.get() {
1250 let _icx = push_ctxt("init_zero_mem");
1252 memfill(&B(bcx), llptr, t, 0);
1255 // Always use this function instead of storing a constant byte to the memory
1256 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
1257 // allocation for large data structures, and the generated code will be
1258 // awful. (A telltale sign of this is large quantities of
1259 // `mov [byte ptr foo],0` in the generated code.)
1260 fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
1261 let _icx = push_ctxt("memfill");
1264 let llty = type_of::type_of(ccx, ty);
1265 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1266 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
1268 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1269 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1270 let llzeroval = C_u8(ccx, byte);
1271 let size = machine::llsize_of(ccx, llty);
1272 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1273 let volatile = C_bool(ccx, false);
1274 b.call(llintrinsicfn,
1275 &[llptr, llzeroval, size, align, volatile],
1279 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1280 let _icx = push_ctxt("alloc_ty");
1281 let ccx = bcx.ccx();
1282 let ty = type_of::type_of(ccx, t);
1283 assert!(!t.has_param_types());
1284 alloca(bcx, ty, name)
1287 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1288 let _icx = push_ctxt("alloca");
1289 if cx.unreachable.get() {
1291 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1294 debuginfo::clear_source_location(cx.fcx);
1295 Alloca(cx, ty, name)
1298 pub fn set_value_name(val: ValueRef, name: &str) {
1300 let name = CString::new(name).unwrap();
1301 llvm::LLVMSetValueName(val, name.as_ptr());
1305 // Creates the alloca slot which holds the pointer to the slot for the final return value
1306 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1307 output_type: Ty<'tcx>)
1309 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1311 // We create an alloca to hold a pointer of type `output_type`
1312 // which will hold the pointer to the right alloca which has the
1314 if fcx.needs_ret_allocas {
1315 // Let's create the stack slot
1316 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1318 // and if we're using an out pointer, then store that in our newly made slot
1319 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1320 let outptr = get_param(fcx.llfn, 0);
1322 let b = fcx.ccx.builder();
1323 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1324 b.store(outptr, slot);
1329 // But if there are no nested returns, we skip the indirection and have a single
1332 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1333 get_param(fcx.llfn, 0)
1335 AllocaFcx(fcx, lloutputtype, "sret_slot")
1340 struct FindNestedReturn {
1344 impl FindNestedReturn {
1345 fn new() -> FindNestedReturn {
1352 impl<'v> Visitor<'v> for FindNestedReturn {
1353 fn visit_expr(&mut self, e: &hir::Expr) {
1355 hir::ExprRet(..) => {
1358 _ => intravisit::walk_expr(self, e),
1363 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1364 let blk = match tcx.map.find(id) {
1365 Some(hir_map::NodeItem(i)) => {
1367 hir::ItemFn(_, _, _, _, _, ref blk) => {
1370 _ => tcx.sess.bug("unexpected item variant in has_nested_returns"),
1373 Some(hir_map::NodeTraitItem(trait_item)) => {
1374 match trait_item.node {
1375 hir::MethodTraitItem(_, Some(ref body)) => body,
1377 tcx.sess.bug("unexpected variant: trait item other than a provided method in \
1378 has_nested_returns")
1382 Some(hir_map::NodeImplItem(impl_item)) => {
1383 match impl_item.node {
1384 hir::ImplItemKind::Method(_, ref body) => body,
1386 tcx.sess.bug("unexpected variant: non-method impl item in has_nested_returns")
1390 Some(hir_map::NodeExpr(e)) => {
1392 hir::ExprClosure(_, _, ref blk) => blk,
1393 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns"),
1396 Some(hir_map::NodeVariant(..)) |
1397 Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1400 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1402 _ => tcx.sess.bug(&format!("unexpected variant in has_nested_returns: {}",
1403 tcx.map.path_to_string(id))),
1406 (blk.id, Some(cfg::CFG::new(tcx, blk)))
1409 // Checks for the presence of "nested returns" in a function.
1410 // Nested returns are when the inner expression of a return expression
1411 // (the 'expr' in 'return expr') contains a return expression. Only cases
1412 // where the outer return is actually reachable are considered. Implicit
1413 // returns from the end of blocks are considered as well.
1415 // This check is needed to handle the case where the inner expression is
1416 // part of a larger expression that may have already partially-filled the
1417 // return slot alloca. This can cause errors related to clean-up due to
1418 // the clobbering of the existing value in the return slot.
1419 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1420 for index in cfg.graph.depth_traverse(cfg.entry) {
1421 let n = cfg.graph.node_data(index);
1422 match tcx.map.find(n.id()) {
1423 Some(hir_map::NodeExpr(ex)) => {
1424 if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
1425 let mut visitor = FindNestedReturn::new();
1426 intravisit::walk_expr(&mut visitor, &**ret_expr);
1432 Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
1433 let mut visitor = FindNestedReturn::new();
1434 walk_list!(&mut visitor, visit_expr, &blk.expr);
1446 // NB: must keep 4 fns in sync:
1449 // - create_datums_for_fn_args.
1453 // Be warned! You must call `init_function` before doing anything with the
1454 // returned function context.
1455 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1459 output_type: ty::FnOutput<'tcx>,
1460 param_substs: &'tcx Substs<'tcx>,
1462 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1463 -> FunctionContext<'a, 'tcx> {
1464 common::validate_substs(param_substs);
1466 debug!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1470 ccx.tcx().map.path_to_string(id).to_string()
1475 let uses_outptr = match output_type {
1476 ty::FnConverging(output_type) => {
1477 let substd_output_type = monomorphize::apply_param_substs(ccx.tcx(),
1480 type_of::return_uses_outptr(ccx, substd_output_type)
1482 ty::FnDiverging => false,
1484 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1485 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1486 let nested_returns = if let Some(ref cfg) = cfg {
1487 has_nested_returns(ccx.tcx(), cfg, blk_id)
1492 let mir = ccx.mir_map().get(&id);
1494 let mut fcx = FunctionContext {
1498 llretslotptr: Cell::new(None),
1499 param_env: ccx.tcx().empty_parameter_environment(),
1500 alloca_insert_pt: Cell::new(None),
1501 llreturn: Cell::new(None),
1502 needs_ret_allocas: nested_returns,
1503 personality: Cell::new(None),
1504 caller_expects_out_pointer: uses_outptr,
1505 lllocals: RefCell::new(NodeMap()),
1506 llupvars: RefCell::new(NodeMap()),
1507 lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
1509 param_substs: param_substs,
1511 block_arena: block_arena,
1513 debug_context: debug_context,
1514 scopes: RefCell::new(Vec::new()),
1519 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1525 /// Performs setup on a newly created function, creating the entry scope block
1526 /// and allocating space for the return pointer.
1527 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1529 output: ty::FnOutput<'tcx>)
1530 -> Block<'a, 'tcx> {
1531 let entry_bcx = fcx.new_temp_block("entry-block");
1533 // Use a dummy instruction as the insertion point for all allocas.
1534 // This is later removed in FunctionContext::cleanup.
1535 fcx.alloca_insert_pt.set(Some(unsafe {
1536 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1537 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1540 if let ty::FnConverging(output_type) = output {
1541 // This shouldn't need to recompute the return type,
1542 // as new_fn_ctxt did it already.
1543 let substd_output_type = fcx.monomorphize(&output_type);
1544 if !return_type_is_void(fcx.ccx, substd_output_type) {
1545 // If the function returns nil/bot, there is no real return
1546 // value, so do not set `llretslotptr`.
1547 if !skip_retptr || fcx.caller_expects_out_pointer {
1548 // Otherwise, we normally allocate the llretslotptr, unless we
1549 // have been instructed to skip it for immediate return
1551 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1556 // Create the drop-flag hints for every unfragmented path in the function.
1557 let tcx = fcx.ccx.tcx();
1558 let fn_did = tcx.map.local_def_id(fcx.id);
1559 let mut hints = fcx.lldropflag_hints.borrow_mut();
1560 let fragment_infos = tcx.fragment_infos.borrow();
1562 // Intern table for drop-flag hint datums.
1563 let mut seen = HashMap::new();
1565 if let Some(fragment_infos) = fragment_infos.get(&fn_did) {
1566 for &info in fragment_infos {
1568 let make_datum = |id| {
1569 let init_val = C_u8(fcx.ccx, adt::DTOR_NEEDED_HINT);
1570 let llname = &format!("dropflag_hint_{}", id);
1571 debug!("adding hint {}", llname);
1572 let ty = tcx.types.u8;
1573 let ptr = alloc_ty(entry_bcx, ty, llname);
1574 Store(entry_bcx, init_val, ptr);
1575 let flag = datum::Lvalue::new_dropflag_hint("base::init_function");
1576 datum::Datum::new(ptr, ty, flag)
1579 let (var, datum) = match info {
1580 ty::FragmentInfo::Moved { var, .. } |
1581 ty::FragmentInfo::Assigned { var, .. } => {
1582 let datum = seen.get(&var).cloned().unwrap_or_else(|| {
1583 let datum = make_datum(var);
1584 seen.insert(var, datum.clone());
1591 ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
1592 debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
1593 hints.insert(expr_id, DropHint::new(var, datum));
1595 ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
1596 debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
1597 hints.insert(expr_id, DropHint::new(var, datum));
1606 // NB: must keep 4 fns in sync:
1609 // - create_datums_for_fn_args.
1613 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>) -> datum::Rvalue {
1614 use trans::datum::{ByRef, ByValue};
1617 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1621 // create_datums_for_fn_args: creates lvalue datums for each of the
1622 // incoming function arguments.
1623 pub fn create_datums_for_fn_args<'a, 'tcx>(mut bcx: Block<'a, 'tcx>,
1625 arg_tys: &[Ty<'tcx>],
1626 has_tupled_arg: bool,
1627 arg_scope: cleanup::CustomScopeIndex)
1628 -> Block<'a, 'tcx> {
1629 let _icx = push_ctxt("create_datums_for_fn_args");
1631 let arg_scope_id = cleanup::CustomScope(arg_scope);
1633 // Return an array wrapping the ValueRefs that we get from `get_param` for
1634 // each argument into datums.
1636 // For certain mode/type combinations, the raw llarg values are passed
1637 // by value. However, within the fn body itself, we want to always
1638 // have all locals and arguments be by-ref so that we can cancel the
1639 // cleanup and for better interaction with LLVM's debug info. So, if
1640 // the argument would be passed by value, we store it into an alloca.
1641 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1642 // the event it's not truly needed.
1643 let mut idx = fcx.arg_offset() as c_uint;
1644 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1645 let arg_datum = if !has_tupled_arg || i < arg_tys.len() - 1 {
1646 if type_of::arg_is_indirect(bcx.ccx(), arg_ty) &&
1647 bcx.sess().opts.debuginfo != FullDebugInfo {
1648 // Don't copy an indirect argument to an alloca, the caller
1649 // already put it in a temporary alloca and gave it up, unless
1650 // we emit extra-debug-info, which requires local allocas :(.
1651 let llarg = get_param(fcx.llfn, idx);
1653 bcx.fcx.schedule_lifetime_end(arg_scope_id, llarg);
1654 bcx.fcx.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
1656 datum::Datum::new(llarg,
1658 datum::Lvalue::new("create_datum_for_fn_args"))
1659 } else if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1660 let data = get_param(fcx.llfn, idx);
1661 let extra = get_param(fcx.llfn, idx + 1);
1663 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1664 arg_scope_id, (data, extra),
1665 |(data, extra), bcx, dst| {
1666 Store(bcx, data, expr::get_dataptr(bcx, dst));
1667 Store(bcx, extra, expr::get_meta(bcx, dst));
1671 let llarg = get_param(fcx.llfn, idx);
1673 let tmp = datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty));
1675 datum::lvalue_scratch_datum(bcx,
1680 |tmp, bcx, dst| tmp.store_to(bcx, dst)))
1683 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1685 ty::TyTuple(ref tupled_arg_tys) => {
1687 datum::lvalue_scratch_datum(bcx,
1695 for (j, &tupled_arg_ty) in
1696 tupled_arg_tys.iter().enumerate() {
1697 let lldest = StructGEP(bcx, llval, j);
1698 if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
1699 let data = get_param(bcx.fcx.llfn, idx);
1700 let extra = get_param(bcx.fcx.llfn, idx + 1);
1701 Store(bcx, data, expr::get_dataptr(bcx, lldest));
1702 Store(bcx, extra, expr::get_meta(bcx, lldest));
1705 let datum = datum::Datum::new(
1706 get_param(bcx.fcx.llfn, idx),
1708 arg_kind(bcx.fcx, tupled_arg_ty));
1710 bcx = datum.store_to(bcx, lldest);
1719 .bug("last argument of a function with `rust-call` ABI isn't a tuple?!")
1724 let pat = &*args[i].pat;
1725 bcx = if let Some(name) = simple_name(pat) {
1726 // Generate nicer LLVM for the common case of fn a pattern
1728 set_value_name(arg_datum.val, &bcx.name(name));
1729 bcx.fcx.lllocals.borrow_mut().insert(pat.id, arg_datum);
1732 // General path. Copy out the values that are used in the
1734 _match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
1736 debuginfo::create_argument_metadata(bcx, &args[i]);
1742 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1743 // and builds the return block.
1744 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1745 last_bcx: Block<'blk, 'tcx>,
1746 retty: ty::FnOutput<'tcx>,
1747 ret_debug_loc: DebugLoc) {
1748 let _icx = push_ctxt("finish_fn");
1750 let ret_cx = match fcx.llreturn.get() {
1752 if !last_bcx.terminated.get() {
1753 Br(last_bcx, llreturn, DebugLoc::None);
1755 raw_block(fcx, false, llreturn)
1760 // This shouldn't need to recompute the return type,
1761 // as new_fn_ctxt did it already.
1762 let substd_retty = fcx.monomorphize(&retty);
1763 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1765 debuginfo::clear_source_location(fcx);
1769 // Builds the return block for a function.
1770 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1771 ret_cx: Block<'blk, 'tcx>,
1772 retty: ty::FnOutput<'tcx>,
1773 ret_debug_location: DebugLoc) {
1774 if fcx.llretslotptr.get().is_none() ||
1775 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1776 return RetVoid(ret_cx, ret_debug_location);
1779 let retslot = if fcx.needs_ret_allocas {
1780 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1782 fcx.llretslotptr.get().unwrap()
1784 let retptr = Value(retslot);
1785 match retptr.get_dominating_store(ret_cx) {
1786 // If there's only a single store to the ret slot, we can directly return
1787 // the value that was stored and omit the store and the alloca
1789 let retval = s.get_operand(0).unwrap().get();
1790 s.erase_from_parent();
1792 if retptr.has_no_uses() {
1793 retptr.erase_from_parent();
1796 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1797 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1802 if fcx.caller_expects_out_pointer {
1803 if let ty::FnConverging(retty) = retty {
1804 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1806 RetVoid(ret_cx, ret_debug_location)
1808 Ret(ret_cx, retval, ret_debug_location)
1811 // Otherwise, copy the return value to the ret slot
1812 None => match retty {
1813 ty::FnConverging(retty) => {
1814 if fcx.caller_expects_out_pointer {
1815 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1816 RetVoid(ret_cx, ret_debug_location)
1818 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1821 ty::FnDiverging => {
1822 if fcx.caller_expects_out_pointer {
1823 RetVoid(ret_cx, ret_debug_location)
1825 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1832 /// Builds an LLVM function out of a source function.
1834 /// If the function closes over its environment a closure will be returned.
1835 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1839 param_substs: &'tcx Substs<'tcx>,
1840 fn_ast_id: ast::NodeId,
1841 attributes: &[ast::Attribute],
1842 output_type: ty::FnOutput<'tcx>,
1844 closure_env: closure::ClosureEnv<'b>) {
1845 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1847 let _icx = push_ctxt("trans_closure");
1848 attributes::emit_uwtable(llfndecl, true);
1850 debug!("trans_closure(..., param_substs={:?})", param_substs);
1852 let has_env = match closure_env {
1853 closure::ClosureEnv::Closure(..) => true,
1854 closure::ClosureEnv::NotClosure => false,
1857 let (arena, fcx): (TypedArena<_>, FunctionContext);
1858 arena = TypedArena::new();
1859 fcx = new_fn_ctxt(ccx,
1867 let mut bcx = init_function(&fcx, false, output_type);
1869 if attributes.iter().any(|item| item.check_name("rustc_mir")) {
1870 mir::trans_mir(bcx);
1875 // cleanup scope for the incoming arguments
1876 let fn_cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(ccx,
1880 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1882 let block_ty = node_id_type(bcx, body.id);
1884 // Set up arguments to the function.
1885 let monomorphized_arg_types = decl.inputs
1887 .map(|arg| node_id_type(bcx, arg.id))
1888 .collect::<Vec<_>>();
1889 for monomorphized_arg_type in &monomorphized_arg_types {
1890 debug!("trans_closure: monomorphized_arg_type: {:?}",
1891 monomorphized_arg_type);
1893 debug!("trans_closure: function lltype: {}",
1894 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1896 let has_tupled_arg = match closure_env {
1897 closure::ClosureEnv::NotClosure => abi == RustCall,
1901 bcx = create_datums_for_fn_args(bcx,
1903 &monomorphized_arg_types,
1907 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1909 // Up until here, IR instructions for this function have explicitly not been annotated with
1910 // source code location, so we don't step into call setup code. From here on, source location
1911 // emitting should be enabled.
1912 debuginfo::start_emitting_source_locations(&fcx);
1914 let dest = match fcx.llretslotptr.get() {
1915 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1917 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1922 // This call to trans_block is the place where we bridge between
1923 // translation calls that don't have a return value (trans_crate,
1924 // trans_mod, trans_item, et cetera) and those that do
1925 // (trans_block, trans_expr, et cetera).
1926 bcx = controlflow::trans_block(bcx, body, dest);
1929 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1930 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1935 match fcx.llreturn.get() {
1937 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
1938 fcx.pop_custom_cleanup_scope(arg_scope);
1941 // Microoptimization writ large: avoid creating a separate
1942 // llreturn basic block
1943 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1947 // Put return block after all other blocks.
1948 // This somewhat improves single-stepping experience in debugger.
1950 let llreturn = fcx.llreturn.get();
1951 if let Some(llreturn) = llreturn {
1952 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1956 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id, fn_cleanup_debug_loc.span);
1958 // Insert the mandatory first few basic blocks before lltop.
1959 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
1962 /// Creates an LLVM function corresponding to a source language function.
1963 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1967 param_substs: &'tcx Substs<'tcx>,
1969 attrs: &[ast::Attribute]) {
1970 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1971 debug!("trans_fn(param_substs={:?})", param_substs);
1972 let _icx = push_ctxt("trans_fn");
1973 let fn_ty = ccx.tcx().node_id_to_type(id);
1974 let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &fn_ty);
1975 let sig = fn_ty.fn_sig();
1976 let sig = ccx.tcx().erase_late_bound_regions(&sig);
1977 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
1978 let output_type = sig.output;
1979 let abi = fn_ty.fn_abi();
1989 closure::ClosureEnv::NotClosure);
1992 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1993 ctor_id: ast::NodeId,
1995 param_substs: &'tcx Substs<'tcx>,
1996 llfndecl: ValueRef) {
1997 let _icx = push_ctxt("trans_enum_variant");
1999 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, disr, param_substs, llfndecl);
2002 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
2005 args: callee::CallArgs,
2007 debug_loc: DebugLoc)
2008 -> Result<'blk, 'tcx> {
2010 let ccx = bcx.fcx.ccx;
2012 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2013 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2014 let result_ty = sig.output.unwrap();
2016 // Get location to store the result. If the user does not care about
2017 // the result, just make a stack slot
2018 let llresult = match dest {
2019 expr::SaveIn(d) => d,
2021 if !type_is_zero_size(ccx, result_ty) {
2022 let llresult = alloc_ty(bcx, result_ty, "constructor_result");
2023 call_lifetime_start(bcx, llresult);
2026 C_undef(type_of::type_of(ccx, result_ty).ptr_to())
2031 if !type_is_zero_size(ccx, result_ty) {
2033 callee::ArgExprs(exprs) => {
2034 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2035 bcx = expr::trans_adt(bcx,
2040 expr::SaveIn(llresult),
2043 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor"),
2046 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
2047 // contents, there could be side-effects we need from them.
2049 callee::ArgExprs(exprs) => {
2051 bcx = expr::trans_into(bcx, expr, expr::Ignore);
2058 // If the caller doesn't care about the result
2059 // drop the temporary we made
2060 let bcx = match dest {
2061 expr::SaveIn(_) => bcx,
2063 let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
2064 if !type_is_zero_size(ccx, result_ty) {
2065 call_lifetime_end(bcx, llresult);
2071 Result::new(bcx, llresult)
2074 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2075 ctor_id: ast::NodeId,
2076 param_substs: &'tcx Substs<'tcx>,
2077 llfndecl: ValueRef) {
2078 let _icx = push_ctxt("trans_tuple_struct");
2080 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, 0, param_substs, llfndecl);
2083 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2084 ctor_id: ast::NodeId,
2086 param_substs: &'tcx Substs<'tcx>,
2087 llfndecl: ValueRef) {
2088 let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
2089 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2091 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2092 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2093 let arg_tys = sig.inputs;
2094 let result_ty = sig.output;
2096 let (arena, fcx): (TypedArena<_>, FunctionContext);
2097 arena = TypedArena::new();
2098 fcx = new_fn_ctxt(ccx,
2106 let bcx = init_function(&fcx, false, result_ty);
2108 assert!(!fcx.needs_ret_allocas);
2110 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2111 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2112 let dest_val = adt::MaybeSizedValue::sized(dest); // Can return unsized value
2113 let repr = adt::represent_type(ccx, result_ty.unwrap());
2114 let mut llarg_idx = fcx.arg_offset() as c_uint;
2115 for (i, arg_ty) in arg_tys.into_iter().enumerate() {
2116 let lldestptr = adt::trans_field_ptr(bcx, &*repr, dest_val, disr, i);
2117 if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
2119 get_param(fcx.llfn, llarg_idx),
2120 expr::get_dataptr(bcx, lldestptr));
2122 get_param(fcx.llfn, llarg_idx + 1),
2123 expr::get_meta(bcx, lldestptr));
2126 let arg = get_param(fcx.llfn, llarg_idx);
2129 if arg_is_indirect(ccx, arg_ty) {
2130 memcpy_ty(bcx, lldestptr, arg, arg_ty);
2132 store_ty(bcx, arg, lldestptr, arg_ty);
2136 adt::trans_set_discr(bcx, &*repr, dest, disr);
2139 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
2142 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &hir::EnumDef, sp: Span, id: ast::NodeId) {
2143 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2145 let print_info = ccx.sess().print_enum_sizes();
2147 let levels = ccx.tcx().node_lint_levels.borrow();
2148 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2149 let lvlsrc = levels.get(&(id, lint_id));
2150 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2152 if is_allow && !print_info {
2153 // we're not interested in anything here
2157 let ty = ccx.tcx().node_id_to_type(id);
2158 let avar = adt::represent_type(ccx, ty);
2160 adt::General(_, ref variants, _) => {
2161 for var in variants {
2163 for field in var.fields.iter().skip(1) {
2164 // skip the discriminant
2165 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2170 _ => { /* its size is either constant or unimportant */ }
2173 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2174 |(l, s, li), (idx, &size)|
2177 } else if size > s {
2184 // FIXME(#30505) Should use logging for this.
2186 let llty = type_of::sizing_type_of(ccx, ty);
2188 let sess = &ccx.tcx().sess;
2189 sess.span_note_without_error(sp,
2190 &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2192 adt::General(..) => {
2193 for (i, var) in enum_def.variants.iter().enumerate() {
2196 .span_note_without_error(var.span,
2197 &*format!("variant data: {} bytes", sizes[i]));
2204 // we only warn if the largest variant is at least thrice as large as
2205 // the second-largest.
2206 if !is_allow && largest > slargest * 3 && slargest > 0 {
2207 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2208 // pass for the latter already ran.
2209 lint::raw_struct_lint(&ccx.tcx().sess,
2210 lint::builtin::VARIANT_SIZE_DIFFERENCES,
2213 &format!("enum variant is more than three times larger ({} bytes) \
2214 than the next largest (ignoring padding)",
2216 .span_note(enum_def.variants[largest_index].span,
2217 "this variant is the largest")
2222 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2223 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2224 // applicable to variable declarations and may not really make sense for
2225 // Rust code in the first place but whitelist them anyway and trust that
2226 // the user knows what s/he's doing. Who knows, unanticipated use cases
2227 // may pop up in the future.
2229 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2230 // and don't have to be, LLVM treats them as no-ops.
2232 "appending" => Some(llvm::AppendingLinkage),
2233 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2234 "common" => Some(llvm::CommonLinkage),
2235 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2236 "external" => Some(llvm::ExternalLinkage),
2237 "internal" => Some(llvm::InternalLinkage),
2238 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2239 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2240 "private" => Some(llvm::PrivateLinkage),
2241 "weak" => Some(llvm::WeakAnyLinkage),
2242 "weak_odr" => Some(llvm::WeakODRLinkage),
2248 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2249 #[derive(Copy, Clone)]
2250 pub enum ValueOrigin {
2251 /// The LLVM `Value` is in this context because the corresponding item was
2252 /// assigned to the current compilation unit.
2253 OriginalTranslation,
2254 /// The `Value`'s corresponding item was assigned to some other compilation
2255 /// unit, but the `Value` was translated in this context anyway because the
2256 /// item is marked `#[inline]`.
2260 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2261 /// If the `llval` is the direct translation of a specific Rust item, `id`
2262 /// should be set to the `NodeId` of that item. (This mapping should be
2263 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2264 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2265 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2266 /// assigned to a different compilation unit.
2267 pub fn update_linkage(ccx: &CrateContext,
2269 id: Option<ast::NodeId>,
2270 llval_origin: ValueOrigin) {
2271 match llval_origin {
2273 // `llval` is a translation of an item defined in a separate
2274 // compilation unit. This only makes sense if there are at least
2275 // two compilation units.
2276 assert!(ccx.sess().opts.cg.codegen_units > 1);
2277 // `llval` is a copy of something defined elsewhere, so use
2278 // `AvailableExternallyLinkage` to avoid duplicating code in the
2280 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2283 OriginalTranslation => {},
2286 if let Some(id) = id {
2287 let item = ccx.tcx().map.get(id);
2288 if let hir_map::NodeItem(i) = item {
2289 if let Some(name) = attr::first_attr_value_str_by_name(&i.attrs, "linkage") {
2290 if let Some(linkage) = llvm_linkage_by_name(&name) {
2291 llvm::SetLinkage(llval, linkage);
2293 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2301 Some(id) if ccx.reachable().contains(&id) => {
2302 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2305 // `id` does not refer to an item in `ccx.reachable`.
2306 if ccx.sess().opts.cg.codegen_units > 1 {
2307 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2309 llvm::SetLinkage(llval, llvm::InternalLinkage);
2315 fn set_global_section(ccx: &CrateContext, llval: ValueRef, i: &hir::Item) {
2316 match attr::first_attr_value_str_by_name(&i.attrs, "link_section") {
2318 if contains_null(§) {
2319 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", §));
2322 let buf = CString::new(sect.as_bytes()).unwrap();
2323 llvm::LLVMSetSection(llval, buf.as_ptr());
2330 pub fn trans_item(ccx: &CrateContext, item: &hir::Item) {
2331 let _icx = push_ctxt("trans_item");
2333 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2336 hir::ItemFn(ref decl, _, _, abi, ref generics, ref body) => {
2337 if !generics.is_type_parameterized() {
2338 let trans_everywhere = attr::requests_inline(&item.attrs);
2339 // Ignore `trans_everywhere` for cross-crate inlined items
2340 // (`from_external`). `trans_item` will be called once for each
2341 // compilation unit that references the item, so it will still get
2342 // translated everywhere it's needed.
2343 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2344 let llfn = get_item_val(ccx, item.id);
2345 let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
2347 foreign::trans_rust_fn_with_foreign_abi(ccx,
2364 set_global_section(ccx, llfn, item);
2374 if is_entry_fn(ccx.sess(), item.id) {
2375 create_entry_wrapper(ccx, item.span, llfn);
2376 // check for the #[rustc_error] annotation, which forces an
2377 // error in trans. This is used to write compile-fail tests
2378 // that actually test that compilation succeeds without
2379 // reporting an error.
2380 let item_def_id = ccx.tcx().map.local_def_id(item.id);
2381 if ccx.tcx().has_attr(item_def_id, "rustc_error") {
2382 ccx.tcx().sess.span_fatal(item.span, "compilation successful");
2388 hir::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2389 meth::trans_impl(ccx, item.name, impl_items, generics, item.id);
2391 hir::ItemMod(_) => {
2392 // modules have no equivalent at runtime, they just affect
2393 // the mangled names of things contained within
2395 hir::ItemEnum(ref enum_definition, ref gens) => {
2396 if gens.ty_params.is_empty() {
2397 // sizes only make sense for non-generic types
2399 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2402 hir::ItemConst(..) => {}
2403 hir::ItemStatic(_, m, ref expr) => {
2404 let g = match consts::trans_static(ccx, m, expr, item.id, &item.attrs) {
2406 Err(err) => ccx.tcx().sess.span_fatal(expr.span, &err.description()),
2408 set_global_section(ccx, g, item);
2409 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2411 hir::ItemForeignMod(ref foreign_mod) => {
2412 foreign::trans_foreign_mod(ccx, foreign_mod);
2414 hir::ItemTrait(..) => {}
2421 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2422 pub fn register_fn_llvmty(ccx: &CrateContext,
2425 node_id: ast::NodeId,
2429 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2431 let llfn = declare::define_fn(ccx, &sym[..], cc, llfty,
2432 ty::FnConverging(ccx.tcx().mk_nil())).unwrap_or_else(||{
2433 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2435 finish_register_fn(ccx, sym, node_id);
2439 fn finish_register_fn(ccx: &CrateContext, sym: String, node_id: ast::NodeId) {
2440 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2443 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2446 node_id: ast::NodeId,
2447 node_type: Ty<'tcx>)
2449 if let ty::TyBareFn(_, ref f) = node_type.sty {
2450 if f.abi != Rust && f.abi != RustCall {
2451 ccx.sess().span_bug(sp,
2452 &format!("only the `{}` or `{}` calling conventions are valid \
2453 for this function; `{}` was specified",
2459 ccx.sess().span_bug(sp, "expected bare rust function")
2462 let llfn = declare::define_rust_fn(ccx, &sym[..], node_type).unwrap_or_else(|| {
2463 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2465 finish_register_fn(ccx, sym, node_id);
2469 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2470 match *sess.entry_fn.borrow() {
2471 Some((entry_id, _)) => node_id == entry_id,
2476 /// Create the `main` function which will initialise the rust runtime and call users’ main
2478 pub fn create_entry_wrapper(ccx: &CrateContext, sp: Span, main_llfn: ValueRef) {
2479 let et = ccx.sess().entry_type.get().unwrap();
2481 config::EntryMain => {
2482 create_entry_fn(ccx, sp, main_llfn, true);
2484 config::EntryStart => create_entry_fn(ccx, sp, main_llfn, false),
2485 config::EntryNone => {} // Do nothing.
2488 fn create_entry_fn(ccx: &CrateContext,
2490 rust_main: ValueRef,
2491 use_start_lang_item: bool) {
2492 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()], &ccx.int_type());
2494 let llfn = declare::define_cfn(ccx, "main", llfty, ccx.tcx().mk_nil()).unwrap_or_else(|| {
2495 // FIXME: We should be smart and show a better diagnostic here.
2496 ccx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
2497 .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
2499 ccx.sess().abort_if_errors();
2504 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, "top\0".as_ptr() as *const _)
2506 let bld = ccx.raw_builder();
2508 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2510 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2512 let (start_fn, args) = if use_start_lang_item {
2513 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2516 ccx.sess().fatal(&s[..]);
2519 let start_fn = if let Some(start_node_id) = ccx.tcx()
2521 .as_local_node_id(start_def_id) {
2522 get_item_val(ccx, start_node_id)
2524 let start_fn_type = ccx.tcx().lookup_item_type(start_def_id).ty;
2525 trans_external_path(ccx, start_def_id, start_fn_type)
2528 let opaque_rust_main =
2529 llvm::LLVMBuildPointerCast(bld,
2531 Type::i8p(ccx).to_ref(),
2532 "rust_main\0".as_ptr() as *const _);
2534 vec![opaque_rust_main, get_param(llfn, 0), get_param(llfn, 1)]
2538 debug!("using user-defined start fn");
2539 let args = vec![get_param(llfn, 0 as c_uint), get_param(llfn, 1 as c_uint)];
2544 let result = llvm::LLVMBuildCall(bld,
2547 args.len() as c_uint,
2550 llvm::LLVMBuildRet(bld, result);
2555 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2558 attrs: &[ast::Attribute])
2560 match ccx.external_srcs().borrow().get(&id) {
2562 let sym = ccx.sess().cstore.item_symbol(did);
2563 debug!("found item {} in other crate...", sym);
2569 match attr::find_export_name_attr(ccx.sess().diagnostic(), attrs) {
2570 // Use provided name
2571 Some(name) => name.to_string(),
2573 let path = ccx.tcx().map.def_path_from_id(id);
2574 if attr::contains_name(attrs, "no_mangle") {
2576 path.last().unwrap().data.to_string()
2578 match weak_lang_items::link_name(attrs) {
2579 Some(name) => name.to_string(),
2581 // Usual name mangling
2582 mangle_exported_name(ccx, path, ty, id)
2590 fn contains_null(s: &str) -> bool {
2591 s.bytes().any(|b| b == 0)
2594 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2595 debug!("get_item_val(id=`{}`)", id);
2597 match ccx.item_vals().borrow().get(&id).cloned() {
2598 Some(v) => return v,
2602 let item = ccx.tcx().map.get(id);
2603 debug!("get_item_val: id={} item={:?}", id, item);
2604 let val = match item {
2605 hir_map::NodeItem(i) => {
2606 let ty = ccx.tcx().node_id_to_type(i.id);
2607 let sym = || exported_name(ccx, id, ty, &i.attrs);
2609 let v = match i.node {
2610 hir::ItemStatic(..) => {
2611 // If this static came from an external crate, then
2612 // we need to get the symbol from metadata instead of
2613 // using the current crate's name/version
2614 // information in the hash of the symbol
2616 debug!("making {}", sym);
2618 // Create the global before evaluating the initializer;
2619 // this is necessary to allow recursive statics.
2620 let llty = type_of(ccx, ty);
2621 let g = declare::define_global(ccx, &sym[..], llty).unwrap_or_else(|| {
2623 .span_fatal(i.span, &format!("symbol `{}` is already defined", sym))
2626 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2630 hir::ItemFn(_, _, _, abi, _, _) => {
2632 let llfn = if abi == Rust {
2633 register_fn(ccx, i.span, sym, i.id, ty)
2635 foreign::register_rust_fn_with_foreign_abi(ccx, i.span, sym, i.id)
2637 attributes::from_fn_attrs(ccx, &i.attrs, llfn);
2641 _ => ccx.sess().bug("get_item_val: weird result in table"),
2647 hir_map::NodeTraitItem(trait_item) => {
2648 debug!("get_item_val(): processing a NodeTraitItem");
2649 match trait_item.node {
2650 hir::MethodTraitItem(_, Some(_)) => {
2651 register_method(ccx, id, &trait_item.attrs, trait_item.span)
2654 ccx.sess().span_bug(trait_item.span,
2655 "unexpected variant: trait item other than a provided \
2656 method in get_item_val()");
2661 hir_map::NodeImplItem(impl_item) => {
2662 match impl_item.node {
2663 hir::ImplItemKind::Method(..) => {
2664 register_method(ccx, id, &impl_item.attrs, impl_item.span)
2667 ccx.sess().span_bug(impl_item.span,
2668 "unexpected variant: non-method impl item in \
2674 hir_map::NodeForeignItem(ni) => {
2676 hir::ForeignItemFn(..) => {
2677 let abi = ccx.tcx().map.get_foreign_abi(id);
2678 let ty = ccx.tcx().node_id_to_type(ni.id);
2679 let name = foreign::link_name(&*ni);
2680 foreign::register_foreign_item_fn(ccx, abi, ty, &name, &ni.attrs)
2682 hir::ForeignItemStatic(..) => {
2683 foreign::register_static(ccx, &*ni)
2688 hir_map::NodeVariant(ref v) => {
2690 let fields = if v.node.data.is_struct() {
2691 ccx.sess().bug("struct variant kind unexpected in get_item_val")
2693 v.node.data.fields()
2695 assert!(!fields.is_empty());
2696 let ty = ccx.tcx().node_id_to_type(id);
2697 let parent = ccx.tcx().map.get_parent(id);
2698 let enm = ccx.tcx().map.expect_item(parent);
2699 let sym = exported_name(ccx, id, ty, &enm.attrs);
2701 llfn = match enm.node {
2702 hir::ItemEnum(_, _) => {
2703 register_fn(ccx, (*v).span, sym, id, ty)
2705 _ => ccx.sess().bug("NodeVariant, shouldn't happen"),
2707 attributes::inline(llfn, attributes::InlineAttr::Hint);
2711 hir_map::NodeStructCtor(struct_def) => {
2712 // Only register the constructor if this is a tuple-like struct.
2713 let ctor_id = if struct_def.is_struct() {
2714 ccx.sess().bug("attempt to register a constructor of a non-tuple-like struct")
2718 let parent = ccx.tcx().map.get_parent(id);
2719 let struct_item = ccx.tcx().map.expect_item(parent);
2720 let ty = ccx.tcx().node_id_to_type(ctor_id);
2721 let sym = exported_name(ccx, id, ty, &struct_item.attrs);
2722 let llfn = register_fn(ccx, struct_item.span, sym, ctor_id, ty);
2723 attributes::inline(llfn, attributes::InlineAttr::Hint);
2728 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}", variant))
2732 // All LLVM globals and functions are initially created as external-linkage
2733 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2734 // into a definition, it adjusts the linkage then (using `update_linkage`).
2736 // The exception is foreign items, which have their linkage set inside the
2737 // call to `foreign::register_*` above. We don't touch the linkage after
2738 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2739 // other item translation functions do).
2741 ccx.item_vals().borrow_mut().insert(id, val);
2745 fn register_method(ccx: &CrateContext,
2747 attrs: &[ast::Attribute],
2750 let mty = ccx.tcx().node_id_to_type(id);
2752 let sym = exported_name(ccx, id, mty, &attrs);
2754 if let ty::TyBareFn(_, ref f) = mty.sty {
2755 let llfn = if f.abi == Rust || f.abi == RustCall {
2756 register_fn(ccx, span, sym, id, mty)
2758 foreign::register_rust_fn_with_foreign_abi(ccx, span, sym, id)
2760 attributes::from_fn_attrs(ccx, &attrs, llfn);
2763 ccx.sess().span_bug(span, "expected bare rust function");
2767 pub fn write_metadata<'a, 'tcx>(cx: &SharedCrateContext<'a, 'tcx>,
2769 reachable: &NodeSet,
2770 mir_map: &MirMap<'tcx>)
2774 let any_library = cx.sess()
2778 .any(|ty| *ty != config::CrateTypeExecutable);
2783 let cstore = &cx.tcx().sess.cstore;
2784 let metadata = cstore.encode_metadata(cx.tcx(),
2791 let mut compressed = cstore.metadata_encoding_version().to_vec();
2792 compressed.extend_from_slice(&flate::deflate_bytes(&metadata));
2794 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
2795 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2796 let name = format!("rust_metadata_{}_{}",
2797 cx.link_meta().crate_name,
2798 cx.link_meta().crate_hash);
2799 let buf = CString::new(name).unwrap();
2800 let llglobal = unsafe {
2801 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf.as_ptr())
2804 llvm::LLVMSetInitializer(llglobal, llconst);
2806 cx.tcx().sess.cstore.metadata_section_name(&cx.sess().target.target);
2807 let name = CString::new(name).unwrap();
2808 llvm::LLVMSetSection(llglobal, name.as_ptr())
2813 /// Find any symbols that are defined in one compilation unit, but not declared
2814 /// in any other compilation unit. Give these symbols internal linkage.
2815 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<&str>) {
2817 let mut declared = HashSet::new();
2819 // Collect all external declarations in all compilation units.
2820 for ccx in cx.iter() {
2821 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2822 let linkage = llvm::LLVMGetLinkage(val);
2823 // We only care about external declarations (not definitions)
2824 // and available_externally definitions.
2825 if !(linkage == llvm::ExternalLinkage as c_uint &&
2826 llvm::LLVMIsDeclaration(val) != 0) &&
2827 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
2831 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2834 declared.insert(name);
2838 // Examine each external definition. If the definition is not used in
2839 // any other compilation unit, and is not reachable from other crates,
2840 // then give it internal linkage.
2841 for ccx in cx.iter() {
2842 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2843 // We only care about external definitions.
2844 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2845 llvm::LLVMIsDeclaration(val) == 0) {
2849 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2852 if !declared.contains(&name) &&
2853 !reachable.contains(str::from_utf8(&name).unwrap()) {
2854 llvm::SetLinkage(val, llvm::InternalLinkage);
2855 llvm::SetDLLStorageClass(val, llvm::DefaultStorageClass);
2862 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
2863 // This is required to satisfy `dllimport` references to static data in .rlibs
2864 // when using MSVC linker. We do this only for data, as linker can fix up
2865 // code references on its own.
2866 // See #26591, #27438
2867 fn create_imps(cx: &SharedCrateContext) {
2868 // The x86 ABI seems to require that leading underscores are added to symbol
2869 // names, so we need an extra underscore on 32-bit. There's also a leading
2870 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
2871 // underscores added in front).
2872 let prefix = if cx.sess().target.target.target_pointer_width == "32" {
2878 for ccx in cx.iter() {
2879 let exported: Vec<_> = iter_globals(ccx.llmod())
2881 llvm::LLVMGetLinkage(val) ==
2882 llvm::ExternalLinkage as c_uint &&
2883 llvm::LLVMIsDeclaration(val) == 0
2887 let i8p_ty = Type::i8p(&ccx);
2888 for val in exported {
2889 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
2890 let mut imp_name = prefix.as_bytes().to_vec();
2891 imp_name.extend(name.to_bytes());
2892 let imp_name = CString::new(imp_name).unwrap();
2893 let imp = llvm::LLVMAddGlobal(ccx.llmod(),
2895 imp_name.as_ptr() as *const _);
2896 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
2897 llvm::LLVMSetInitializer(imp, init);
2898 llvm::SetLinkage(imp, llvm::ExternalLinkage);
2906 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
2909 impl Iterator for ValueIter {
2910 type Item = ValueRef;
2912 fn next(&mut self) -> Option<ValueRef> {
2915 self.cur = unsafe { (self.step)(old) };
2923 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
2926 cur: llvm::LLVMGetFirstGlobal(llmod),
2927 step: llvm::LLVMGetNextGlobal,
2932 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
2935 cur: llvm::LLVMGetFirstFunction(llmod),
2936 step: llvm::LLVMGetNextFunction,
2941 /// The context provided lists a set of reachable ids as calculated by
2942 /// middle::reachable, but this contains far more ids and symbols than we're
2943 /// actually exposing from the object file. This function will filter the set in
2944 /// the context to the set of ids which correspond to symbols that are exposed
2945 /// from the object file being generated.
2947 /// This list is later used by linkers to determine the set of symbols needed to
2948 /// be exposed from a dynamic library and it's also encoded into the metadata.
2949 pub fn filter_reachable_ids(ccx: &SharedCrateContext) -> NodeSet {
2950 ccx.reachable().iter().map(|x| *x).filter(|id| {
2951 // First, only worry about nodes which have a symbol name
2952 ccx.item_symbols().borrow().contains_key(id)
2954 // Next, we want to ignore some FFI functions that are not exposed from
2955 // this crate. Reachable FFI functions can be lumped into two
2958 // 1. Those that are included statically via a static library
2959 // 2. Those included otherwise (e.g. dynamically or via a framework)
2961 // Although our LLVM module is not literally emitting code for the
2962 // statically included symbols, it's an export of our library which
2963 // needs to be passed on to the linker and encoded in the metadata.
2965 // As a result, if this id is an FFI item (foreign item) then we only
2966 // let it through if it's included statically.
2967 match ccx.tcx().map.get(id) {
2968 hir_map::NodeForeignItem(..) => {
2969 ccx.sess().cstore.is_statically_included_foreign_item(id)
2976 pub fn trans_crate<'tcx>(tcx: &ty::ctxt<'tcx>,
2977 mir_map: &MirMap<'tcx>,
2978 analysis: ty::CrateAnalysis)
2979 -> CrateTranslation {
2980 let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
2981 let krate = tcx.map.krate();
2983 let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
2986 tcx.sess.opts.debug_assertions
2989 let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
2992 tcx.sess.opts.debug_assertions
2995 // Before we touch LLVM, make sure that multithreading is enabled.
2997 use std::sync::Once;
2998 static INIT: Once = Once::new();
2999 static mut POISONED: bool = false;
3001 if llvm::LLVMStartMultithreaded() != 1 {
3002 // use an extra bool to make sure that all future usage of LLVM
3003 // cannot proceed despite the Once not running more than once.
3007 ::back::write::configure_llvm(&tcx.sess);
3011 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3015 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3017 let codegen_units = tcx.sess.opts.cg.codegen_units;
3018 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name,
3030 let ccx = shared_ccx.get_ccx(0);
3032 // First, verify intrinsics.
3033 intrinsic::check_intrinsics(&ccx);
3035 // Next, translate all items. See `TransModVisitor` for
3036 // details on why we walk in this particular way.
3038 let _icx = push_ctxt("text");
3039 intravisit::walk_mod(&mut TransItemsWithinModVisitor { ccx: &ccx }, &krate.module);
3040 krate.visit_all_items(&mut TransModVisitor { ccx: &ccx });
3044 for ccx in shared_ccx.iter() {
3045 if ccx.sess().opts.debuginfo != NoDebugInfo {
3046 debuginfo::finalize(&ccx);
3048 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
3050 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
3051 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
3052 llvm::LLVMDeleteGlobal(old_g);
3057 let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
3059 // Translate the metadata.
3060 let metadata = write_metadata(&shared_ccx, krate, &reachable_symbol_ids, mir_map);
3062 if shared_ccx.sess().trans_stats() {
3063 let stats = shared_ccx.stats();
3064 println!("--- trans stats ---");
3065 println!("n_glues_created: {}", stats.n_glues_created.get());
3066 println!("n_null_glues: {}", stats.n_null_glues.get());
3067 println!("n_real_glues: {}", stats.n_real_glues.get());
3069 println!("n_fns: {}", stats.n_fns.get());
3070 println!("n_monos: {}", stats.n_monos.get());
3071 println!("n_inlines: {}", stats.n_inlines.get());
3072 println!("n_closures: {}", stats.n_closures.get());
3073 println!("fn stats:");
3074 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3075 insns_b.cmp(&insns_a)
3077 for tuple in stats.fn_stats.borrow().iter() {
3079 (ref name, insns) => {
3080 println!("{} insns, {}", insns, *name);
3085 if shared_ccx.sess().count_llvm_insns() {
3086 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3087 println!("{:7} {}", *v, *k);
3091 let modules = shared_ccx.iter()
3092 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3095 let sess = shared_ccx.sess();
3096 let mut reachable_symbols = reachable_symbol_ids.iter().map(|id| {
3097 shared_ccx.item_symbols().borrow()[id].to_string()
3098 }).collect::<Vec<_>>();
3099 if sess.entry_fn.borrow().is_some() {
3100 reachable_symbols.push("main".to_string());
3103 // For the purposes of LTO, we add to the reachable set all of the upstream
3104 // reachable extern fns. These functions are all part of the public ABI of
3105 // the final product, so LTO needs to preserve them.
3107 for cnum in sess.cstore.crates() {
3108 let syms = sess.cstore.reachable_ids(cnum);
3109 reachable_symbols.extend(syms.into_iter().filter(|did| {
3110 sess.cstore.is_extern_fn(shared_ccx.tcx(), *did) ||
3111 sess.cstore.is_static(*did)
3113 sess.cstore.item_symbol(did)
3118 if codegen_units > 1 {
3119 internalize_symbols(&shared_ccx,
3120 &reachable_symbols.iter().map(|x| &x[..]).collect());
3123 if sess.target.target.options.is_like_msvc &&
3124 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
3125 create_imps(&shared_ccx);
3128 let metadata_module = ModuleTranslation {
3129 llcx: shared_ccx.metadata_llcx(),
3130 llmod: shared_ccx.metadata_llmod(),
3132 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
3136 metadata_module: metadata_module,
3139 reachable: reachable_symbols,
3140 no_builtins: no_builtins,
3144 /// We visit all the items in the krate and translate them. We do
3145 /// this in two walks. The first walk just finds module items. It then
3146 /// walks the full contents of those module items and translates all
3147 /// the items within. Note that this entire process is O(n). The
3148 /// reason for this two phased walk is that each module is
3149 /// (potentially) placed into a distinct codegen-unit. This walk also
3150 /// ensures that the immediate contents of each module is processed
3151 /// entirely before we proceed to find more modules, helping to ensure
3152 /// an equitable distribution amongst codegen-units.
3153 pub struct TransModVisitor<'a, 'tcx: 'a> {
3154 pub ccx: &'a CrateContext<'a, 'tcx>,
3157 impl<'a, 'tcx, 'v> Visitor<'v> for TransModVisitor<'a, 'tcx> {
3158 fn visit_item(&mut self, i: &hir::Item) {
3160 hir::ItemMod(_) => {
3161 let item_ccx = self.ccx.rotate();
3162 intravisit::walk_item(&mut TransItemsWithinModVisitor { ccx: &item_ccx }, i);
3169 /// Translates all the items within a given module. Expects owner to
3170 /// invoke `walk_item` on a module item. Ignores nested modules.
3171 pub struct TransItemsWithinModVisitor<'a, 'tcx: 'a> {
3172 pub ccx: &'a CrateContext<'a, 'tcx>,
3175 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemsWithinModVisitor<'a, 'tcx> {
3176 fn visit_nested_item(&mut self, item_id: hir::ItemId) {
3177 self.visit_item(self.ccx.tcx().map.expect_item(item_id.id));
3180 fn visit_item(&mut self, i: &hir::Item) {
3182 hir::ItemMod(..) => {
3183 // skip modules, they will be uncovered by the TransModVisitor
3186 trans_item(self.ccx, i);
3187 intravisit::walk_item(self, i);