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};
37 use metadata::{csearch, encoder, loader};
38 use middle::astencode;
40 use middle::def_id::DefId;
42 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
43 use middle::weak_lang_items;
44 use middle::pat_util::simple_name;
45 use middle::subst::Substs;
46 use middle::ty::{self, Ty, HasTypeFlags};
47 use rustc::front::map as hir_map;
48 use rustc_mir::mir_map::MirMap;
49 use session::config::{self, NoDebugInfo, FullDebugInfo};
53 use trans::attributes;
55 use trans::builder::{Builder, noname};
57 use trans::cleanup::{self, CleanupMethods, DropHint};
59 use trans::common::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_uint, C_integral};
60 use trans::common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
61 use trans::common::{CrateContext, DropFlagHintsMap, Field, FunctionContext};
62 use trans::common::{Result, NodeIdAndSpan, VariantInfo};
63 use trans::common::{node_id_type, return_type_is_void};
64 use trans::common::{type_is_immediate, type_is_zero_size, val_ty};
67 use trans::context::SharedCrateContext;
68 use trans::controlflow;
70 use trans::debuginfo::{self, DebugLoc, ToDebugLoc};
77 use trans::machine::{llsize_of, llsize_of_real};
80 use trans::monomorphize;
82 use trans::type_::Type;
84 use trans::type_of::*;
85 use trans::value::Value;
86 use util::common::indenter;
87 use util::sha2::Sha256;
88 use util::nodemap::{NodeMap, NodeSet};
90 use arena::TypedArena;
92 use std::ffi::{CStr, CString};
93 use std::cell::{Cell, RefCell};
94 use std::collections::{HashMap, HashSet};
96 use std::{i8, i16, i32, i64};
97 use syntax::abi::{Rust, RustCall, RustIntrinsic, PlatformIntrinsic, Abi};
98 use syntax::codemap::Span;
99 use syntax::parse::token::InternedString;
100 use syntax::attr::AttrMetaMethods;
103 use rustc_front::intravisit::{self, Visitor};
104 use rustc_front::hir;
108 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
113 pub fn with_insn_ctxt<F>(blk: F)
114 where F: FnOnce(&[&'static str])
116 TASK_LOCAL_INSN_KEY.with(move |slot| {
117 slot.borrow().as_ref().map(move |s| blk(s));
121 pub fn init_insn_ctxt() {
122 TASK_LOCAL_INSN_KEY.with(|slot| {
123 *slot.borrow_mut() = Some(Vec::new());
127 pub struct _InsnCtxt {
128 _cannot_construct_outside_of_this_module: (),
131 impl Drop for _InsnCtxt {
133 TASK_LOCAL_INSN_KEY.with(|slot| {
134 match slot.borrow_mut().as_mut() {
144 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
145 debug!("new InsnCtxt: {}", s);
146 TASK_LOCAL_INSN_KEY.with(|slot| {
147 match slot.borrow_mut().as_mut() {
148 Some(ctx) => ctx.push(s),
153 _cannot_construct_outside_of_this_module: (),
157 pub struct StatRecorder<'a, 'tcx: 'a> {
158 ccx: &'a CrateContext<'a, 'tcx>,
159 name: Option<String>,
163 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
164 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> {
165 let istart = ccx.stats().n_llvm_insns.get();
174 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
176 if self.ccx.sess().trans_stats() {
177 let iend = self.ccx.stats().n_llvm_insns.get();
182 .push((self.name.take().unwrap(), iend - self.istart));
183 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
184 // Reset LLVM insn count to avoid compound costs.
185 self.ccx.stats().n_llvm_insns.set(self.istart);
190 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
195 match ccx.externs().borrow().get(name) {
196 Some(n) => return *n,
200 let f = declare::declare_rust_fn(ccx, name, fn_ty);
202 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
203 attributes::from_fn_attrs(ccx, &attrs[..], f);
205 ccx.externs().borrow_mut().insert(name.to_string(), f);
209 pub fn self_type_for_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
213 let closure_kind = ccx.tcx().closure_kind(closure_id);
215 ty::FnClosureKind => {
216 ccx.tcx().mk_imm_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
218 ty::FnMutClosureKind => {
219 ccx.tcx().mk_mut_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
221 ty::FnOnceClosureKind => fn_ty,
225 pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
226 *ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
229 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
233 let name = csearch::get_symbol(&ccx.sess().cstore, did);
234 let ty = type_of(ccx, t);
235 match ccx.externs().borrow_mut().get(&name) {
236 Some(n) => return *n,
239 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
240 // FIXME(nagisa): investigate whether it can be changed into define_global
241 let c = declare::declare_global(ccx, &name[..], ty);
242 // Thread-local statics in some other crate need to *always* be linked
243 // against in a thread-local fashion, so we need to be sure to apply the
244 // thread-local attribute locally if it was present remotely. If we
245 // don't do this then linker errors can be generated where the linker
246 // complains that one object files has a thread local version of the
247 // symbol and another one doesn't.
248 for attr in ccx.tcx().get_attrs(did).iter() {
249 if attr.check_name("thread_local") {
250 llvm::set_thread_local(c, true);
253 if ccx.use_dll_storage_attrs() {
254 llvm::SetDLLStorageClass(c, llvm::DLLImportStorageClass);
256 ccx.externs().borrow_mut().insert(name.to_string(), c);
260 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, info_ty: Ty<'tcx>, it: LangItem) -> DefId {
261 match bcx.tcx().lang_items.require(it) {
264 bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
269 // The following malloc_raw_dyn* functions allocate a box to contain
270 // a given type, but with a potentially dynamic size.
272 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
278 -> Result<'blk, 'tcx> {
279 let _icx = push_ctxt("malloc_raw_exchange");
282 let r = callee::trans_lang_call(bcx,
283 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
288 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
292 pub fn bin_op_to_icmp_predicate(ccx: &CrateContext,
295 -> llvm::IntPredicate {
297 hir::BiEq => llvm::IntEQ,
298 hir::BiNe => llvm::IntNE,
299 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
300 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
301 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
302 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
305 .bug(&format!("comparison_op_to_icmp_predicate: expected comparison operator, \
312 pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: hir::BinOp_) -> llvm::RealPredicate {
314 hir::BiEq => llvm::RealOEQ,
315 hir::BiNe => llvm::RealUNE,
316 hir::BiLt => llvm::RealOLT,
317 hir::BiLe => llvm::RealOLE,
318 hir::BiGt => llvm::RealOGT,
319 hir::BiGe => llvm::RealOGE,
322 .bug(&format!("comparison_op_to_fcmp_predicate: expected comparison operator, \
329 pub fn compare_fat_ptrs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
340 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
341 let extra_eq = ICmp(bcx, llvm::IntEQ, lhs_extra, rhs_extra, debug_loc);
342 And(bcx, addr_eq, extra_eq, debug_loc)
345 let addr_eq = ICmp(bcx, llvm::IntNE, lhs_addr, rhs_addr, debug_loc);
346 let extra_eq = ICmp(bcx, llvm::IntNE, lhs_extra, rhs_extra, debug_loc);
347 Or(bcx, addr_eq, extra_eq, debug_loc)
349 hir::BiLe | hir::BiLt | hir::BiGe | hir::BiGt => {
350 // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
351 let (op, strict_op) = match op {
352 hir::BiLt => (llvm::IntULT, llvm::IntULT),
353 hir::BiLe => (llvm::IntULE, llvm::IntULT),
354 hir::BiGt => (llvm::IntUGT, llvm::IntUGT),
355 hir::BiGe => (llvm::IntUGE, llvm::IntUGT),
359 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
360 let extra_op = ICmp(bcx, op, lhs_extra, rhs_extra, debug_loc);
361 let addr_eq_extra_op = And(bcx, addr_eq, extra_op, debug_loc);
363 let addr_strict = ICmp(bcx, strict_op, lhs_addr, rhs_addr, debug_loc);
364 Or(bcx, addr_strict, addr_eq_extra_op, debug_loc)
367 bcx.tcx().sess.bug("unexpected fat ptr binop");
372 pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
380 ty::TyTuple(ref tys) if tys.is_empty() => {
381 // We don't need to do actual comparisons for nil.
382 // () == () holds but () < () does not.
384 hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
385 hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
386 // refinements would be nice
387 _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator"),
390 ty::TyBareFn(..) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
392 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
397 ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
399 bin_op_to_icmp_predicate(bcx.ccx(), op, false),
405 let lhs_addr = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_ADDR]));
406 let lhs_extra = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_EXTRA]));
408 let rhs_addr = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_ADDR]));
409 let rhs_extra = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_EXTRA]));
410 compare_fat_ptrs(bcx,
421 bin_op_to_icmp_predicate(bcx.ccx(), op, true),
428 bin_op_to_fcmp_predicate(bcx.ccx(), op),
433 // Should never get here, because t is scalar.
434 _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types"),
438 pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
446 let signed = match t.sty {
448 let cmp = bin_op_to_fcmp_predicate(bcx.ccx(), op);
449 return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
451 ty::TyUint(_) => false,
452 ty::TyInt(_) => true,
453 _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
456 let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
457 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
458 // to get the correctly sized type. This will compile to a single instruction
459 // once the IR is converted to assembly if the SIMD instruction is supported
460 // by the target architecture.
461 SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
464 // Iterates through the elements of a structural type.
465 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
470 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
472 let _icx = push_ctxt("iter_structural_ty");
474 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
475 repr: &adt::Repr<'tcx>,
477 variant: ty::VariantDef<'tcx>,
478 substs: &Substs<'tcx>,
481 where F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>
483 let _icx = push_ctxt("iter_variant");
487 for (i, field) in variant.fields.iter().enumerate() {
488 let arg = monomorphize::field_ty(tcx, substs, field);
490 adt::trans_field_ptr(cx, repr, av, variant.disr_val, i),
496 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
499 let data = expr::get_dataptr(cx, av);
500 let info = expr::get_meta(cx, av);
501 (Load(cx, data), Some(Load(cx, info)))
506 ty::TyStruct(..) => {
507 let repr = adt::represent_type(cx.ccx(), t);
508 let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
509 for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
510 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
512 let val = if common::type_is_sized(cx.tcx(), field_ty) {
515 let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
516 Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
517 Store(cx, info.unwrap(), expr::get_meta(cx, scratch.val));
520 cx = f(cx, val, field_ty);
523 ty::TyClosure(_, ref substs) => {
524 let repr = adt::represent_type(cx.ccx(), t);
525 for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
526 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
527 cx = f(cx, llupvar, upvar_ty);
530 ty::TyArray(_, n) => {
531 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
532 let unit_ty = t.sequence_element_type(cx.tcx());
533 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
535 ty::TySlice(_) | ty::TyStr => {
536 let unit_ty = t.sequence_element_type(cx.tcx());
537 cx = tvec::iter_vec_raw(cx, data_ptr, unit_ty, info.unwrap(), f);
539 ty::TyTuple(ref args) => {
540 let repr = adt::represent_type(cx.ccx(), t);
541 for (i, arg) in args.iter().enumerate() {
542 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
543 cx = f(cx, llfld_a, *arg);
546 ty::TyEnum(en, substs) => {
550 let repr = adt::represent_type(ccx, t);
551 let n_variants = en.variants.len();
553 // NB: we must hit the discriminant first so that structural
554 // comparison know not to proceed when the discriminants differ.
556 match adt::trans_switch(cx, &*repr, av) {
557 (_match::Single, None) => {
559 assert!(n_variants == 1);
560 cx = iter_variant(cx, &*repr, av, &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 iter = src_fields.iter().zip(dst_fields).enumerate();
712 for (i, (src_fty, dst_fty)) in iter {
713 if type_is_zero_size(bcx.ccx(), dst_fty) {
717 let src_f = adt::trans_field_ptr(bcx, &src_repr, src, 0, i);
718 let dst_f = adt::trans_field_ptr(bcx, &dst_repr, dst, 0, i);
719 if src_fty == dst_fty {
720 memcpy_ty(bcx, dst_f, src_f, src_fty);
722 coerce_unsized_into(bcx, src_f, src_fty, dst_f, dst_fty);
726 _ => bcx.sess().bug(&format!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
732 pub fn cast_shift_expr_rhs(cx: Block, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
733 cast_shift_rhs(op, lhs, rhs, |a, b| Trunc(cx, a, b), |a, b| ZExt(cx, a, b))
736 pub fn cast_shift_const_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
740 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
741 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
744 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
750 where F: FnOnce(ValueRef, Type) -> ValueRef,
751 G: FnOnce(ValueRef, Type) -> ValueRef
753 // Shifts may have any size int on the rhs
754 if rustc_front::util::is_shift_binop(op) {
755 let mut rhs_llty = val_ty(rhs);
756 let mut lhs_llty = val_ty(lhs);
757 if rhs_llty.kind() == Vector {
758 rhs_llty = rhs_llty.element_type()
760 if lhs_llty.kind() == Vector {
761 lhs_llty = lhs_llty.element_type()
763 let rhs_sz = rhs_llty.int_width();
764 let lhs_sz = lhs_llty.int_width();
767 } else if lhs_sz > rhs_sz {
768 // FIXME (#1877: If shifting by negative
769 // values becomes not undefined then this is wrong.
779 pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
784 let llty = Type::int_from_ty(cx.ccx(), t);
786 ast::TyIs if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
787 ast::TyIs => i64::MIN as u64,
788 ast::TyI8 => i8::MIN as u64,
789 ast::TyI16 => i16::MIN as u64,
790 ast::TyI32 => i32::MIN as u64,
791 ast::TyI64 => i64::MIN as u64,
799 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
800 call_info: NodeIdAndSpan,
805 -> Block<'blk, 'tcx> {
806 let (zero_text, overflow_text) = if divrem.node == hir::BiDiv {
807 ("attempted to divide by zero",
808 "attempted to divide with overflow")
810 ("attempted remainder with a divisor of zero",
811 "attempted remainder with overflow")
813 let debug_loc = call_info.debug_loc();
815 let (is_zero, is_signed) = match rhs_t.sty {
817 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
818 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
821 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
822 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
824 ty::TyStruct(def, _) if def.is_simd() => {
825 let mut res = C_bool(cx.ccx(), false);
826 for i in 0..rhs_t.simd_size(cx.tcx()) {
829 IsNull(cx, ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))),
835 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}", rhs_t));
838 let bcx = with_cond(cx, is_zero, |bcx| {
839 controlflow::trans_fail(bcx, call_info, InternedString::new(zero_text))
842 // To quote LLVM's documentation for the sdiv instruction:
844 // Division by zero leads to undefined behavior. Overflow also leads
845 // to undefined behavior; this is a rare case, but can occur, for
846 // example, by doing a 32-bit division of -2147483648 by -1.
848 // In order to avoid undefined behavior, we perform runtime checks for
849 // signed division/remainder which would trigger overflow. For unsigned
850 // integers, no action beyond checking for zero need be taken.
852 let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
853 let minus_one = ICmp(bcx,
856 C_integral(llty, !0, false),
858 with_cond(bcx, minus_one, |bcx| {
859 let is_min = ICmp(bcx,
862 C_integral(llty, min, true),
864 with_cond(bcx, is_min, |bcx| {
865 controlflow::trans_fail(bcx, call_info, InternedString::new(overflow_text))
873 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
877 let name = csearch::get_symbol(&ccx.sess().cstore, did);
879 ty::TyBareFn(_, ref fn_ty) => {
880 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
882 get_extern_rust_fn(ccx, t, &name[..], did)
884 RustIntrinsic | PlatformIntrinsic => {
885 ccx.sess().bug("unexpected intrinsic in trans_external_path")
888 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
889 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t, &name, &attrs)
894 get_extern_const(ccx, did, t)
899 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
904 -> (ValueRef, Block<'blk, 'tcx>) {
905 let _icx = push_ctxt("invoke_");
906 if bcx.unreachable.get() {
907 return (C_null(Type::i8(bcx.ccx())), bcx);
910 let attributes = attributes::from_fn_type(bcx.ccx(), fn_ty);
912 match bcx.opt_node_id {
914 debug!("invoke at ???");
917 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
921 if need_invoke(bcx) {
922 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
923 for &llarg in llargs {
924 debug!("arg: {}", bcx.val_to_string(llarg));
926 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
927 let landing_pad = bcx.fcx.get_landing_pad();
929 let llresult = Invoke(bcx,
936 return (llresult, normal_bcx);
938 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
939 for &llarg in llargs {
940 debug!("arg: {}", bcx.val_to_string(llarg));
943 let llresult = Call(bcx, llfn, &llargs[..], Some(attributes), debug_loc);
944 return (llresult, bcx);
948 /// Returns whether this session's target will use SEH-based unwinding.
950 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
951 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
952 /// 64-bit MinGW) instead of "full SEH".
953 pub fn wants_msvc_seh(sess: &Session) -> bool {
954 sess.target.target.options.is_like_msvc && sess.target.target.arch == "x86"
957 pub fn need_invoke(bcx: Block) -> bool {
958 // FIXME(#25869) currently SEH-based unwinding is pretty buggy in LLVM and
959 // is being overhauled as this is being written. Until that
960 // time such that upstream LLVM's implementation is more solid
961 // and we start binding it we need to skip invokes for any
962 // target which wants SEH-based unwinding.
963 if bcx.sess().no_landing_pads() || wants_msvc_seh(bcx.sess()) {
967 // Avoid using invoke if we are already inside a landing pad.
972 bcx.fcx.needs_invoke()
975 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, t: Ty<'tcx>) -> ValueRef {
976 let _icx = push_ctxt("load_if_immediate");
977 if type_is_immediate(cx.ccx(), t) {
978 return load_ty(cx, v, t);
983 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
984 /// differs from the type used for SSA values. Also handles various special cases where the type
985 /// gives us better information about what we are loading.
986 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
987 if cx.unreachable.get() || type_is_zero_size(cx.ccx(), t) {
988 return C_undef(type_of::type_of(cx.ccx(), t));
991 let ptr = to_arg_ty_ptr(cx, ptr, t);
992 let align = type_of::align_of(cx.ccx(), t);
994 if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
995 let load = Load(cx, ptr);
997 llvm::LLVMSetAlignment(load, align);
1003 let global = llvm::LLVMIsAGlobalVariable(ptr);
1004 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
1005 let val = llvm::LLVMGetInitializer(global);
1007 return to_arg_ty(cx, val, t);
1012 let val = if t.is_bool() {
1013 LoadRangeAssert(cx, ptr, 0, 2, llvm::False)
1014 } else if t.is_char() {
1015 // a char is a Unicode codepoint, and so takes values from 0
1016 // to 0x10FFFF inclusive only.
1017 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1018 } else if (t.is_region_ptr() || t.is_unique()) && !common::type_is_fat_ptr(cx.tcx(), t) {
1019 LoadNonNull(cx, ptr)
1025 llvm::LLVMSetAlignment(val, align);
1028 to_arg_ty(cx, val, t)
1031 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1032 /// differs from the type used for SSA values.
1033 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1034 if cx.unreachable.get() {
1038 debug!("store_ty: {} : {:?} <- {}",
1039 cx.val_to_string(dst),
1041 cx.val_to_string(v));
1043 if common::type_is_fat_ptr(cx.tcx(), t) {
1045 ExtractValue(cx, v, abi::FAT_PTR_ADDR),
1046 expr::get_dataptr(cx, dst));
1048 ExtractValue(cx, v, abi::FAT_PTR_EXTRA),
1049 expr::get_meta(cx, dst));
1051 let store = Store(cx, from_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
1053 llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
1058 pub fn store_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1063 // FIXME: emit metadata
1064 Store(cx, data, expr::get_dataptr(cx, dst));
1065 Store(cx, extra, expr::get_meta(cx, dst));
1068 pub fn load_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1071 -> (ValueRef, ValueRef) {
1072 // FIXME: emit metadata
1073 (Load(cx, expr::get_dataptr(cx, src)),
1074 Load(cx, expr::get_meta(cx, src)))
1077 pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1079 ZExt(bcx, val, Type::i8(bcx.ccx()))
1085 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1087 Trunc(bcx, val, Type::i1(bcx.ccx()))
1093 pub fn to_arg_ty_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef, ty: Ty<'tcx>) -> ValueRef {
1094 if type_is_immediate(bcx.ccx(), ty) && type_of::type_of(bcx.ccx(), ty).is_aggregate() {
1095 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1096 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1097 // and we have to convert it
1098 BitCast(bcx, ptr, type_of::arg_type_of(bcx.ccx(), ty).ptr_to())
1104 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local) -> Block<'blk, 'tcx> {
1105 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1106 let _indenter = indenter();
1107 let _icx = push_ctxt("init_local");
1108 _match::store_local(bcx, local)
1111 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1113 llbb: BasicBlockRef)
1114 -> Block<'blk, 'tcx> {
1115 common::BlockS::new(llbb, is_lpad, None, fcx)
1118 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>, val: ValueRef, f: F) -> Block<'blk, 'tcx>
1119 where F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>
1121 let _icx = push_ctxt("with_cond");
1123 if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
1128 let next_cx = fcx.new_temp_block("next");
1129 let cond_cx = fcx.new_temp_block("cond");
1130 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
1131 let after_cx = f(cond_cx);
1132 if !after_cx.terminated.get() {
1133 Br(after_cx, next_cx.llbb, DebugLoc::None);
1138 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1139 if cx.sess().opts.optimize == config::No {
1143 let _icx = push_ctxt("lifetime_start");
1146 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1151 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1152 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1155 &[C_u64(ccx, size), ptr],
1160 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1161 if cx.sess().opts.optimize == config::No {
1165 let _icx = push_ctxt("lifetime_end");
1168 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1173 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1174 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1177 &[C_u64(ccx, size), ptr],
1182 // Generates code for resumption of unwind at the end of a landing pad.
1183 pub fn trans_unwind_resume(bcx: Block, lpval: ValueRef) {
1184 if !bcx.sess().target.target.options.custom_unwind_resume {
1187 let exc_ptr = ExtractValue(bcx, lpval, 0);
1188 let llunwresume = bcx.fcx.eh_unwind_resume();
1189 Call(bcx, llunwresume, &[exc_ptr], None, DebugLoc::None);
1195 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1196 let _icx = push_ctxt("call_memcpy");
1198 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1199 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
1200 let memcpy = ccx.get_intrinsic(&key);
1201 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1202 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1203 let size = IntCast(cx, n_bytes, ccx.int_type());
1204 let align = C_i32(ccx, align as i32);
1205 let volatile = C_bool(ccx, false);
1208 &[dst_ptr, src_ptr, size, align, volatile],
1213 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, dst: ValueRef, src: ValueRef, t: Ty<'tcx>) {
1214 let _icx = push_ctxt("memcpy_ty");
1215 let ccx = bcx.ccx();
1217 if type_is_zero_size(ccx, t) {
1221 if t.is_structural() {
1222 let llty = type_of::type_of(ccx, t);
1223 let llsz = llsize_of(ccx, llty);
1224 let llalign = type_of::align_of(ccx, t);
1225 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1227 store_ty(bcx, load_ty(bcx, src, t), dst, t);
1231 pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1232 if cx.unreachable.get() {
1235 let _icx = push_ctxt("drop_done_fill_mem");
1237 memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
1240 pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1241 if cx.unreachable.get() {
1244 let _icx = push_ctxt("init_zero_mem");
1246 memfill(&B(bcx), llptr, t, 0);
1249 // Always use this function instead of storing a constant byte to the memory
1250 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
1251 // allocation for large data structures, and the generated code will be
1252 // awful. (A telltale sign of this is large quantities of
1253 // `mov [byte ptr foo],0` in the generated code.)
1254 fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
1255 let _icx = push_ctxt("memfill");
1258 let llty = type_of::type_of(ccx, ty);
1259 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1260 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
1262 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1263 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1264 let llzeroval = C_u8(ccx, byte);
1265 let size = machine::llsize_of(ccx, llty);
1266 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1267 let volatile = C_bool(ccx, false);
1268 b.call(llintrinsicfn,
1269 &[llptr, llzeroval, size, align, volatile],
1273 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1274 let _icx = push_ctxt("alloc_ty");
1275 let ccx = bcx.ccx();
1276 let ty = type_of::type_of(ccx, t);
1277 assert!(!t.has_param_types());
1278 alloca(bcx, ty, name)
1281 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1282 let _icx = push_ctxt("alloca");
1283 if cx.unreachable.get() {
1285 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1288 debuginfo::clear_source_location(cx.fcx);
1289 Alloca(cx, ty, name)
1292 pub fn set_value_name(val: ValueRef, name: &str) {
1294 let name = CString::new(name).unwrap();
1295 llvm::LLVMSetValueName(val, name.as_ptr());
1299 // Creates the alloca slot which holds the pointer to the slot for the final return value
1300 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1301 output_type: Ty<'tcx>)
1303 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1305 // We create an alloca to hold a pointer of type `output_type`
1306 // which will hold the pointer to the right alloca which has the
1308 if fcx.needs_ret_allocas {
1309 // Let's create the stack slot
1310 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1312 // and if we're using an out pointer, then store that in our newly made slot
1313 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1314 let outptr = get_param(fcx.llfn, 0);
1316 let b = fcx.ccx.builder();
1317 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1318 b.store(outptr, slot);
1323 // But if there are no nested returns, we skip the indirection and have a single
1326 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1327 get_param(fcx.llfn, 0)
1329 AllocaFcx(fcx, lloutputtype, "sret_slot")
1334 struct FindNestedReturn {
1338 impl FindNestedReturn {
1339 fn new() -> FindNestedReturn {
1346 impl<'v> Visitor<'v> for FindNestedReturn {
1347 fn visit_expr(&mut self, e: &hir::Expr) {
1349 hir::ExprRet(..) => {
1352 _ => intravisit::walk_expr(self, e),
1357 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1358 let blk = match tcx.map.find(id) {
1359 Some(hir_map::NodeItem(i)) => {
1361 hir::ItemFn(_, _, _, _, _, ref blk) => {
1364 _ => tcx.sess.bug("unexpected item variant in has_nested_returns"),
1367 Some(hir_map::NodeTraitItem(trait_item)) => {
1368 match trait_item.node {
1369 hir::MethodTraitItem(_, Some(ref body)) => body,
1371 tcx.sess.bug("unexpected variant: trait item other than a provided method in \
1372 has_nested_returns")
1376 Some(hir_map::NodeImplItem(impl_item)) => {
1377 match impl_item.node {
1378 hir::ImplItemKind::Method(_, ref body) => body,
1380 tcx.sess.bug("unexpected variant: non-method impl item in has_nested_returns")
1384 Some(hir_map::NodeExpr(e)) => {
1386 hir::ExprClosure(_, _, ref blk) => blk,
1387 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns"),
1390 Some(hir_map::NodeVariant(..)) |
1391 Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1394 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1396 _ => tcx.sess.bug(&format!("unexpected variant in has_nested_returns: {}",
1397 tcx.map.path_to_string(id))),
1400 (blk.id, Some(cfg::CFG::new(tcx, blk)))
1403 // Checks for the presence of "nested returns" in a function.
1404 // Nested returns are when the inner expression of a return expression
1405 // (the 'expr' in 'return expr') contains a return expression. Only cases
1406 // where the outer return is actually reachable are considered. Implicit
1407 // returns from the end of blocks are considered as well.
1409 // This check is needed to handle the case where the inner expression is
1410 // part of a larger expression that may have already partially-filled the
1411 // return slot alloca. This can cause errors related to clean-up due to
1412 // the clobbering of the existing value in the return slot.
1413 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1414 for index in cfg.graph.depth_traverse(cfg.entry) {
1415 let n = cfg.graph.node_data(index);
1416 match tcx.map.find(n.id()) {
1417 Some(hir_map::NodeExpr(ex)) => {
1418 if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
1419 let mut visitor = FindNestedReturn::new();
1420 intravisit::walk_expr(&mut visitor, &**ret_expr);
1426 Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
1427 let mut visitor = FindNestedReturn::new();
1428 walk_list!(&mut visitor, visit_expr, &blk.expr);
1440 // NB: must keep 4 fns in sync:
1443 // - create_datums_for_fn_args.
1447 // Be warned! You must call `init_function` before doing anything with the
1448 // returned function context.
1449 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1453 output_type: ty::FnOutput<'tcx>,
1454 param_substs: &'tcx Substs<'tcx>,
1456 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1457 -> FunctionContext<'a, 'tcx> {
1458 common::validate_substs(param_substs);
1460 debug!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1464 ccx.tcx().map.path_to_string(id).to_string()
1469 let uses_outptr = match output_type {
1470 ty::FnConverging(output_type) => {
1471 let substd_output_type = monomorphize::apply_param_substs(ccx.tcx(),
1474 type_of::return_uses_outptr(ccx, substd_output_type)
1476 ty::FnDiverging => false,
1478 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1479 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1480 let nested_returns = if let Some(ref cfg) = cfg {
1481 has_nested_returns(ccx.tcx(), cfg, blk_id)
1486 let mir = ccx.mir_map().get(&id);
1488 let mut fcx = FunctionContext {
1492 llretslotptr: Cell::new(None),
1493 param_env: ccx.tcx().empty_parameter_environment(),
1494 alloca_insert_pt: Cell::new(None),
1495 llreturn: Cell::new(None),
1496 needs_ret_allocas: nested_returns,
1497 personality: Cell::new(None),
1498 caller_expects_out_pointer: uses_outptr,
1499 lllocals: RefCell::new(NodeMap()),
1500 llupvars: RefCell::new(NodeMap()),
1501 lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
1503 param_substs: param_substs,
1505 block_arena: block_arena,
1507 debug_context: debug_context,
1508 scopes: RefCell::new(Vec::new()),
1513 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1519 /// Performs setup on a newly created function, creating the entry scope block
1520 /// and allocating space for the return pointer.
1521 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1523 output: ty::FnOutput<'tcx>)
1524 -> Block<'a, 'tcx> {
1525 let entry_bcx = fcx.new_temp_block("entry-block");
1527 // Use a dummy instruction as the insertion point for all allocas.
1528 // This is later removed in FunctionContext::cleanup.
1529 fcx.alloca_insert_pt.set(Some(unsafe {
1530 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1531 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1534 if let ty::FnConverging(output_type) = output {
1535 // This shouldn't need to recompute the return type,
1536 // as new_fn_ctxt did it already.
1537 let substd_output_type = fcx.monomorphize(&output_type);
1538 if !return_type_is_void(fcx.ccx, substd_output_type) {
1539 // If the function returns nil/bot, there is no real return
1540 // value, so do not set `llretslotptr`.
1541 if !skip_retptr || fcx.caller_expects_out_pointer {
1542 // Otherwise, we normally allocate the llretslotptr, unless we
1543 // have been instructed to skip it for immediate return
1545 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1550 // Create the drop-flag hints for every unfragmented path in the function.
1551 let tcx = fcx.ccx.tcx();
1552 let fn_did = tcx.map.local_def_id(fcx.id);
1553 let mut hints = fcx.lldropflag_hints.borrow_mut();
1554 let fragment_infos = tcx.fragment_infos.borrow();
1556 // Intern table for drop-flag hint datums.
1557 let mut seen = HashMap::new();
1559 if let Some(fragment_infos) = fragment_infos.get(&fn_did) {
1560 for &info in fragment_infos {
1562 let make_datum = |id| {
1563 let init_val = C_u8(fcx.ccx, adt::DTOR_NEEDED_HINT);
1564 let llname = &format!("dropflag_hint_{}", id);
1565 debug!("adding hint {}", llname);
1566 let ty = tcx.types.u8;
1567 let ptr = alloc_ty(entry_bcx, ty, llname);
1568 Store(entry_bcx, init_val, ptr);
1569 let flag = datum::Lvalue::new_dropflag_hint("base::init_function");
1570 datum::Datum::new(ptr, ty, flag)
1573 let (var, datum) = match info {
1574 ty::FragmentInfo::Moved { var, .. } |
1575 ty::FragmentInfo::Assigned { var, .. } => {
1576 let datum = seen.get(&var).cloned().unwrap_or_else(|| {
1577 let datum = make_datum(var);
1578 seen.insert(var, datum.clone());
1585 ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
1586 debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
1587 hints.insert(expr_id, DropHint::new(var, datum));
1589 ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
1590 debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
1591 hints.insert(expr_id, DropHint::new(var, datum));
1600 // NB: must keep 4 fns in sync:
1603 // - create_datums_for_fn_args.
1607 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>) -> datum::Rvalue {
1608 use trans::datum::{ByRef, ByValue};
1611 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1615 // create_datums_for_fn_args: creates lvalue datums for each of the
1616 // incoming function arguments.
1617 pub fn create_datums_for_fn_args<'a, 'tcx>(mut bcx: Block<'a, 'tcx>,
1619 arg_tys: &[Ty<'tcx>],
1620 has_tupled_arg: bool,
1621 arg_scope: cleanup::CustomScopeIndex)
1622 -> Block<'a, 'tcx> {
1623 let _icx = push_ctxt("create_datums_for_fn_args");
1625 let arg_scope_id = cleanup::CustomScope(arg_scope);
1627 // Return an array wrapping the ValueRefs that we get from `get_param` for
1628 // each argument into datums.
1630 // For certain mode/type combinations, the raw llarg values are passed
1631 // by value. However, within the fn body itself, we want to always
1632 // have all locals and arguments be by-ref so that we can cancel the
1633 // cleanup and for better interaction with LLVM's debug info. So, if
1634 // the argument would be passed by value, we store it into an alloca.
1635 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1636 // the event it's not truly needed.
1637 let mut idx = fcx.arg_offset() as c_uint;
1638 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1639 let arg_datum = if !has_tupled_arg || i < arg_tys.len() - 1 {
1640 if type_of::arg_is_indirect(bcx.ccx(), arg_ty) &&
1641 bcx.sess().opts.debuginfo != FullDebugInfo {
1642 // Don't copy an indirect argument to an alloca, the caller
1643 // already put it in a temporary alloca and gave it up, unless
1644 // we emit extra-debug-info, which requires local allocas :(.
1645 let llarg = get_param(fcx.llfn, idx);
1647 bcx.fcx.schedule_lifetime_end(arg_scope_id, llarg);
1648 bcx.fcx.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
1650 datum::Datum::new(llarg,
1652 datum::Lvalue::new("create_datum_for_fn_args"))
1653 } else if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1654 let data = get_param(fcx.llfn, idx);
1655 let extra = get_param(fcx.llfn, idx + 1);
1657 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1658 arg_scope_id, (data, extra),
1659 |(data, extra), bcx, dst| {
1660 Store(bcx, data, expr::get_dataptr(bcx, dst));
1661 Store(bcx, extra, expr::get_meta(bcx, dst));
1665 let llarg = get_param(fcx.llfn, idx);
1667 let tmp = datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty));
1669 datum::lvalue_scratch_datum(bcx,
1674 |tmp, bcx, dst| tmp.store_to(bcx, dst)))
1677 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1679 ty::TyTuple(ref tupled_arg_tys) => {
1681 datum::lvalue_scratch_datum(bcx,
1689 for (j, &tupled_arg_ty) in
1690 tupled_arg_tys.iter().enumerate() {
1691 let lldest = StructGEP(bcx, llval, j);
1692 if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
1693 let data = get_param(bcx.fcx.llfn, idx);
1694 let extra = get_param(bcx.fcx.llfn, idx + 1);
1695 Store(bcx, data, expr::get_dataptr(bcx, lldest));
1696 Store(bcx, extra, expr::get_meta(bcx, lldest));
1699 let datum = datum::Datum::new(
1700 get_param(bcx.fcx.llfn, idx),
1702 arg_kind(bcx.fcx, tupled_arg_ty));
1704 bcx = datum.store_to(bcx, lldest);
1713 .bug("last argument of a function with `rust-call` ABI isn't a tuple?!")
1718 let pat = &*args[i].pat;
1719 bcx = if let Some(name) = simple_name(pat) {
1720 // Generate nicer LLVM for the common case of fn a pattern
1722 set_value_name(arg_datum.val, &bcx.name(name));
1723 bcx.fcx.lllocals.borrow_mut().insert(pat.id, arg_datum);
1726 // General path. Copy out the values that are used in the
1728 _match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
1730 debuginfo::create_argument_metadata(bcx, &args[i]);
1736 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1737 // and builds the return block.
1738 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1739 last_bcx: Block<'blk, 'tcx>,
1740 retty: ty::FnOutput<'tcx>,
1741 ret_debug_loc: DebugLoc) {
1742 let _icx = push_ctxt("finish_fn");
1744 let ret_cx = match fcx.llreturn.get() {
1746 if !last_bcx.terminated.get() {
1747 Br(last_bcx, llreturn, DebugLoc::None);
1749 raw_block(fcx, false, llreturn)
1754 // This shouldn't need to recompute the return type,
1755 // as new_fn_ctxt did it already.
1756 let substd_retty = fcx.monomorphize(&retty);
1757 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1759 debuginfo::clear_source_location(fcx);
1763 // Builds the return block for a function.
1764 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1765 ret_cx: Block<'blk, 'tcx>,
1766 retty: ty::FnOutput<'tcx>,
1767 ret_debug_location: DebugLoc) {
1768 if fcx.llretslotptr.get().is_none() ||
1769 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1770 return RetVoid(ret_cx, ret_debug_location);
1773 let retslot = if fcx.needs_ret_allocas {
1774 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1776 fcx.llretslotptr.get().unwrap()
1778 let retptr = Value(retslot);
1779 match retptr.get_dominating_store(ret_cx) {
1780 // If there's only a single store to the ret slot, we can directly return
1781 // the value that was stored and omit the store and the alloca
1783 let retval = s.get_operand(0).unwrap().get();
1784 s.erase_from_parent();
1786 if retptr.has_no_uses() {
1787 retptr.erase_from_parent();
1790 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1791 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1796 if fcx.caller_expects_out_pointer {
1797 if let ty::FnConverging(retty) = retty {
1798 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1800 RetVoid(ret_cx, ret_debug_location)
1802 Ret(ret_cx, retval, ret_debug_location)
1805 // Otherwise, copy the return value to the ret slot
1806 None => match retty {
1807 ty::FnConverging(retty) => {
1808 if fcx.caller_expects_out_pointer {
1809 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1810 RetVoid(ret_cx, ret_debug_location)
1812 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1815 ty::FnDiverging => {
1816 if fcx.caller_expects_out_pointer {
1817 RetVoid(ret_cx, ret_debug_location)
1819 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1826 /// Builds an LLVM function out of a source function.
1828 /// If the function closes over its environment a closure will be returned.
1829 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1833 param_substs: &'tcx Substs<'tcx>,
1834 fn_ast_id: ast::NodeId,
1835 attributes: &[ast::Attribute],
1836 output_type: ty::FnOutput<'tcx>,
1838 closure_env: closure::ClosureEnv<'b>) {
1839 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1841 let _icx = push_ctxt("trans_closure");
1842 attributes::emit_uwtable(llfndecl, true);
1844 debug!("trans_closure(..., param_substs={:?})", param_substs);
1846 let has_env = match closure_env {
1847 closure::ClosureEnv::Closure(..) => true,
1848 closure::ClosureEnv::NotClosure => false,
1851 let (arena, fcx): (TypedArena<_>, FunctionContext);
1852 arena = TypedArena::new();
1853 fcx = new_fn_ctxt(ccx,
1861 let mut bcx = init_function(&fcx, false, output_type);
1863 if attributes.iter().any(|item| item.check_name("rustc_mir")) {
1864 mir::trans_mir(bcx);
1869 // cleanup scope for the incoming arguments
1870 let fn_cleanup_debug_loc = debuginfo::get_cleanup_debug_loc_for_ast_node(ccx,
1874 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1876 let block_ty = node_id_type(bcx, body.id);
1878 // Set up arguments to the function.
1879 let monomorphized_arg_types = decl.inputs
1881 .map(|arg| node_id_type(bcx, arg.id))
1882 .collect::<Vec<_>>();
1883 for monomorphized_arg_type in &monomorphized_arg_types {
1884 debug!("trans_closure: monomorphized_arg_type: {:?}",
1885 monomorphized_arg_type);
1887 debug!("trans_closure: function lltype: {}",
1888 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1890 let has_tupled_arg = match closure_env {
1891 closure::ClosureEnv::NotClosure => abi == RustCall,
1895 bcx = create_datums_for_fn_args(bcx,
1897 &monomorphized_arg_types,
1901 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1903 // Up until here, IR instructions for this function have explicitly not been annotated with
1904 // source code location, so we don't step into call setup code. From here on, source location
1905 // emitting should be enabled.
1906 debuginfo::start_emitting_source_locations(&fcx);
1908 let dest = match fcx.llretslotptr.get() {
1909 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1911 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1916 // This call to trans_block is the place where we bridge between
1917 // translation calls that don't have a return value (trans_crate,
1918 // trans_mod, trans_item, et cetera) and those that do
1919 // (trans_block, trans_expr, et cetera).
1920 bcx = controlflow::trans_block(bcx, body, dest);
1923 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1924 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1929 match fcx.llreturn.get() {
1931 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
1932 fcx.pop_custom_cleanup_scope(arg_scope);
1935 // Microoptimization writ large: avoid creating a separate
1936 // llreturn basic block
1937 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1941 // Put return block after all other blocks.
1942 // This somewhat improves single-stepping experience in debugger.
1944 let llreturn = fcx.llreturn.get();
1945 if let Some(llreturn) = llreturn {
1946 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1950 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id, fn_cleanup_debug_loc.span);
1952 // Insert the mandatory first few basic blocks before lltop.
1953 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
1956 /// Creates an LLVM function corresponding to a source language function.
1957 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1961 param_substs: &'tcx Substs<'tcx>,
1963 attrs: &[ast::Attribute]) {
1964 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1965 debug!("trans_fn(param_substs={:?})", param_substs);
1966 let _icx = push_ctxt("trans_fn");
1967 let fn_ty = ccx.tcx().node_id_to_type(id);
1968 let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &fn_ty);
1969 let sig = fn_ty.fn_sig();
1970 let sig = ccx.tcx().erase_late_bound_regions(&sig);
1971 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
1972 let output_type = sig.output;
1973 let abi = fn_ty.fn_abi();
1983 closure::ClosureEnv::NotClosure);
1986 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1987 ctor_id: ast::NodeId,
1989 param_substs: &'tcx Substs<'tcx>,
1990 llfndecl: ValueRef) {
1991 let _icx = push_ctxt("trans_enum_variant");
1993 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, disr, param_substs, llfndecl);
1996 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1999 args: callee::CallArgs,
2001 debug_loc: DebugLoc)
2002 -> Result<'blk, 'tcx> {
2004 let ccx = bcx.fcx.ccx;
2006 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2007 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2008 let result_ty = sig.output.unwrap();
2010 // Get location to store the result. If the user does not care about
2011 // the result, just make a stack slot
2012 let llresult = match dest {
2013 expr::SaveIn(d) => d,
2015 if !type_is_zero_size(ccx, result_ty) {
2016 let llresult = alloc_ty(bcx, result_ty, "constructor_result");
2017 call_lifetime_start(bcx, llresult);
2020 C_undef(type_of::type_of(ccx, result_ty).ptr_to())
2025 if !type_is_zero_size(ccx, result_ty) {
2027 callee::ArgExprs(exprs) => {
2028 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2029 bcx = expr::trans_adt(bcx,
2034 expr::SaveIn(llresult),
2037 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor"),
2040 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
2041 // contents, there could be side-effects we need from them.
2043 callee::ArgExprs(exprs) => {
2045 bcx = expr::trans_into(bcx, expr, expr::Ignore);
2052 // If the caller doesn't care about the result
2053 // drop the temporary we made
2054 let bcx = match dest {
2055 expr::SaveIn(_) => bcx,
2057 let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
2058 if !type_is_zero_size(ccx, result_ty) {
2059 call_lifetime_end(bcx, llresult);
2065 Result::new(bcx, llresult)
2068 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2069 ctor_id: ast::NodeId,
2070 param_substs: &'tcx Substs<'tcx>,
2071 llfndecl: ValueRef) {
2072 let _icx = push_ctxt("trans_tuple_struct");
2074 trans_enum_variant_or_tuple_like_struct(ccx, ctor_id, 0, param_substs, llfndecl);
2077 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2078 ctor_id: ast::NodeId,
2080 param_substs: &'tcx Substs<'tcx>,
2081 llfndecl: ValueRef) {
2082 let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
2083 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2085 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2086 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2087 let arg_tys = sig.inputs;
2088 let result_ty = sig.output;
2090 let (arena, fcx): (TypedArena<_>, FunctionContext);
2091 arena = TypedArena::new();
2092 fcx = new_fn_ctxt(ccx,
2100 let bcx = init_function(&fcx, false, result_ty);
2102 assert!(!fcx.needs_ret_allocas);
2104 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2105 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2106 let repr = adt::represent_type(ccx, result_ty.unwrap());
2107 let mut llarg_idx = fcx.arg_offset() as c_uint;
2108 for (i, arg_ty) in arg_tys.into_iter().enumerate() {
2109 let lldestptr = adt::trans_field_ptr(bcx, &*repr, dest, disr, i);
2110 if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
2112 get_param(fcx.llfn, llarg_idx),
2113 expr::get_dataptr(bcx, lldestptr));
2115 get_param(fcx.llfn, llarg_idx + 1),
2116 expr::get_meta(bcx, lldestptr));
2119 let arg = get_param(fcx.llfn, llarg_idx);
2122 if arg_is_indirect(ccx, arg_ty) {
2123 memcpy_ty(bcx, lldestptr, arg, arg_ty);
2125 store_ty(bcx, arg, lldestptr, arg_ty);
2129 adt::trans_set_discr(bcx, &*repr, dest, disr);
2132 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
2135 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &hir::EnumDef, sp: Span, id: ast::NodeId) {
2136 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2138 let print_info = ccx.sess().print_enum_sizes();
2140 let levels = ccx.tcx().node_lint_levels.borrow();
2141 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2142 let lvlsrc = levels.get(&(id, lint_id));
2143 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2145 if is_allow && !print_info {
2146 // we're not interested in anything here
2150 let ty = ccx.tcx().node_id_to_type(id);
2151 let avar = adt::represent_type(ccx, ty);
2153 adt::General(_, ref variants, _) => {
2154 for var in variants {
2156 for field in var.fields.iter().skip(1) {
2157 // skip the discriminant
2158 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2163 _ => { /* its size is either constant or unimportant */ }
2166 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2167 |(l, s, li), (idx, &size)|
2170 } else if size > s {
2178 let llty = type_of::sizing_type_of(ccx, ty);
2180 let sess = &ccx.tcx().sess;
2181 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2183 adt::General(..) => {
2184 for (i, var) in enum_def.variants.iter().enumerate() {
2187 .span_note(var.span, &*format!("variant data: {} bytes", sizes[i]));
2194 // we only warn if the largest variant is at least thrice as large as
2195 // the second-largest.
2196 if !is_allow && largest > slargest * 3 && slargest > 0 {
2197 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2198 // pass for the latter already ran.
2199 lint::raw_emit_lint(&ccx.tcx().sess,
2200 lint::builtin::VARIANT_SIZE_DIFFERENCES,
2203 &format!("enum variant is more than three times larger ({} bytes) \
2204 than the next largest (ignoring padding)",
2207 ccx.sess().span_note(enum_def.variants[largest_index].span,
2208 "this variant is the largest");
2212 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2213 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2214 // applicable to variable declarations and may not really make sense for
2215 // Rust code in the first place but whitelist them anyway and trust that
2216 // the user knows what s/he's doing. Who knows, unanticipated use cases
2217 // may pop up in the future.
2219 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2220 // and don't have to be, LLVM treats them as no-ops.
2222 "appending" => Some(llvm::AppendingLinkage),
2223 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2224 "common" => Some(llvm::CommonLinkage),
2225 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2226 "external" => Some(llvm::ExternalLinkage),
2227 "internal" => Some(llvm::InternalLinkage),
2228 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2229 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2230 "private" => Some(llvm::PrivateLinkage),
2231 "weak" => Some(llvm::WeakAnyLinkage),
2232 "weak_odr" => Some(llvm::WeakODRLinkage),
2238 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2239 #[derive(Copy, Clone)]
2240 pub enum ValueOrigin {
2241 /// The LLVM `Value` is in this context because the corresponding item was
2242 /// assigned to the current compilation unit.
2243 OriginalTranslation,
2244 /// The `Value`'s corresponding item was assigned to some other compilation
2245 /// unit, but the `Value` was translated in this context anyway because the
2246 /// item is marked `#[inline]`.
2250 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2251 /// If the `llval` is the direct translation of a specific Rust item, `id`
2252 /// should be set to the `NodeId` of that item. (This mapping should be
2253 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2254 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2255 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2256 /// assigned to a different compilation unit.
2257 pub fn update_linkage(ccx: &CrateContext,
2259 id: Option<ast::NodeId>,
2260 llval_origin: ValueOrigin) {
2261 match llval_origin {
2263 // `llval` is a translation of an item defined in a separate
2264 // compilation unit. This only makes sense if there are at least
2265 // two compilation units.
2266 assert!(ccx.sess().opts.cg.codegen_units > 1);
2267 // `llval` is a copy of something defined elsewhere, so use
2268 // `AvailableExternallyLinkage` to avoid duplicating code in the
2270 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2273 OriginalTranslation => {},
2276 if let Some(id) = id {
2277 let item = ccx.tcx().map.get(id);
2278 if let hir_map::NodeItem(i) = item {
2279 if let Some(name) = attr::first_attr_value_str_by_name(&i.attrs, "linkage") {
2280 if let Some(linkage) = llvm_linkage_by_name(&name) {
2281 llvm::SetLinkage(llval, linkage);
2283 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2291 Some(id) if ccx.reachable().contains(&id) => {
2292 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2295 // `id` does not refer to an item in `ccx.reachable`.
2296 if ccx.sess().opts.cg.codegen_units > 1 {
2297 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2299 llvm::SetLinkage(llval, llvm::InternalLinkage);
2305 fn set_global_section(ccx: &CrateContext, llval: ValueRef, i: &hir::Item) {
2306 match attr::first_attr_value_str_by_name(&i.attrs, "link_section") {
2308 if contains_null(§) {
2309 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", §));
2312 let buf = CString::new(sect.as_bytes()).unwrap();
2313 llvm::LLVMSetSection(llval, buf.as_ptr());
2320 pub fn trans_item(ccx: &CrateContext, item: &hir::Item) {
2321 let _icx = push_ctxt("trans_item");
2323 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2326 hir::ItemFn(ref decl, _, _, abi, ref generics, ref body) => {
2327 if !generics.is_type_parameterized() {
2328 let trans_everywhere = attr::requests_inline(&item.attrs);
2329 // Ignore `trans_everywhere` for cross-crate inlined items
2330 // (`from_external`). `trans_item` will be called once for each
2331 // compilation unit that references the item, so it will still get
2332 // translated everywhere it's needed.
2333 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2334 let llfn = get_item_val(ccx, item.id);
2335 let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
2337 foreign::trans_rust_fn_with_foreign_abi(ccx,
2354 set_global_section(ccx, llfn, item);
2364 if is_entry_fn(ccx.sess(), item.id) {
2365 create_entry_wrapper(ccx, item.span, llfn);
2366 // check for the #[rustc_error] annotation, which forces an
2367 // error in trans. This is used to write compile-fail tests
2368 // that actually test that compilation succeeds without
2369 // reporting an error.
2370 let item_def_id = ccx.tcx().map.local_def_id(item.id);
2371 if ccx.tcx().has_attr(item_def_id, "rustc_error") {
2372 ccx.tcx().sess.span_fatal(item.span, "compilation successful");
2378 hir::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2379 meth::trans_impl(ccx, item.name, &impl_items[..], generics, item.id);
2381 hir::ItemMod(_) => {
2382 // modules have no equivalent at runtime, they just affect
2383 // the mangled names of things contained within
2385 hir::ItemEnum(ref enum_definition, ref gens) => {
2386 if gens.ty_params.is_empty() {
2387 // sizes only make sense for non-generic types
2389 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2392 hir::ItemConst(..) => {}
2393 hir::ItemStatic(_, m, ref expr) => {
2394 let g = match consts::trans_static(ccx, m, expr, item.id, &item.attrs) {
2396 Err(err) => ccx.tcx().sess.span_fatal(expr.span, &err.description()),
2398 set_global_section(ccx, g, item);
2399 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2401 hir::ItemForeignMod(ref foreign_mod) => {
2402 foreign::trans_foreign_mod(ccx, foreign_mod);
2404 hir::ItemTrait(..) => {}
2411 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2412 pub fn register_fn_llvmty(ccx: &CrateContext,
2415 node_id: ast::NodeId,
2419 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2421 let llfn = declare::define_fn(ccx, &sym[..], cc, llfty,
2422 ty::FnConverging(ccx.tcx().mk_nil())).unwrap_or_else(||{
2423 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2425 finish_register_fn(ccx, sym, node_id);
2429 fn finish_register_fn(ccx: &CrateContext, sym: String, node_id: ast::NodeId) {
2430 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2433 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2436 node_id: ast::NodeId,
2437 node_type: Ty<'tcx>)
2439 if let ty::TyBareFn(_, ref f) = node_type.sty {
2440 if f.abi != Rust && f.abi != RustCall {
2441 ccx.sess().span_bug(sp,
2442 &format!("only the `{}` or `{}` calling conventions are valid \
2443 for this function; `{}` was specified",
2449 ccx.sess().span_bug(sp, "expected bare rust function")
2452 let llfn = declare::define_rust_fn(ccx, &sym[..], node_type).unwrap_or_else(|| {
2453 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2455 finish_register_fn(ccx, sym, node_id);
2459 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2460 match *sess.entry_fn.borrow() {
2461 Some((entry_id, _)) => node_id == entry_id,
2466 /// Create the `main` function which will initialise the rust runtime and call users’ main
2468 pub fn create_entry_wrapper(ccx: &CrateContext, sp: Span, main_llfn: ValueRef) {
2469 let et = ccx.sess().entry_type.get().unwrap();
2471 config::EntryMain => {
2472 create_entry_fn(ccx, sp, main_llfn, true);
2474 config::EntryStart => create_entry_fn(ccx, sp, main_llfn, false),
2475 config::EntryNone => {} // Do nothing.
2478 fn create_entry_fn(ccx: &CrateContext,
2480 rust_main: ValueRef,
2481 use_start_lang_item: bool) {
2482 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()], &ccx.int_type());
2484 let llfn = declare::define_cfn(ccx, "main", llfty, ccx.tcx().mk_nil()).unwrap_or_else(|| {
2485 ccx.sess().span_err(sp, "entry symbol `main` defined multiple times");
2486 // FIXME: We should be smart and show a better diagnostic here.
2487 ccx.sess().help("did you use #[no_mangle] on `fn main`? Use #[start] instead");
2488 ccx.sess().abort_if_errors();
2493 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, "top\0".as_ptr() as *const _)
2495 let bld = ccx.raw_builder();
2497 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2499 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2501 let (start_fn, args) = if use_start_lang_item {
2502 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2505 ccx.sess().fatal(&s[..]);
2508 let start_fn = if let Some(start_node_id) = ccx.tcx()
2510 .as_local_node_id(start_def_id) {
2511 get_item_val(ccx, start_node_id)
2513 let start_fn_type = csearch::get_type(ccx.tcx(), start_def_id).ty;
2514 trans_external_path(ccx, start_def_id, start_fn_type)
2518 let opaque_rust_main =
2519 llvm::LLVMBuildPointerCast(bld,
2521 Type::i8p(ccx).to_ref(),
2522 "rust_main\0".as_ptr() as *const _);
2524 vec![opaque_rust_main, get_param(llfn, 0), get_param(llfn, 1)]
2528 debug!("using user-defined start fn");
2529 let args = vec![get_param(llfn, 0 as c_uint), get_param(llfn, 1 as c_uint)];
2534 let result = llvm::LLVMBuildCall(bld,
2537 args.len() as c_uint,
2540 llvm::LLVMBuildRet(bld, result);
2545 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2548 attrs: &[ast::Attribute])
2550 match ccx.external_srcs().borrow().get(&id) {
2552 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2553 debug!("found item {} in other crate...", sym);
2559 match attr::find_export_name_attr(ccx.sess().diagnostic(), attrs) {
2560 // Use provided name
2561 Some(name) => name.to_string(),
2563 let path = ccx.tcx().map.def_path_from_id(id);
2564 if attr::contains_name(attrs, "no_mangle") {
2566 path.last().unwrap().data.to_string()
2568 match weak_lang_items::link_name(attrs) {
2569 Some(name) => name.to_string(),
2571 // Usual name mangling
2572 mangle_exported_name(ccx, path, ty, id)
2580 fn contains_null(s: &str) -> bool {
2581 s.bytes().any(|b| b == 0)
2584 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2585 debug!("get_item_val(id=`{}`)", id);
2587 match ccx.item_vals().borrow().get(&id).cloned() {
2588 Some(v) => return v,
2592 let item = ccx.tcx().map.get(id);
2593 debug!("get_item_val: id={} item={:?}", id, item);
2594 let val = match item {
2595 hir_map::NodeItem(i) => {
2596 let ty = ccx.tcx().node_id_to_type(i.id);
2597 let sym = || exported_name(ccx, id, ty, &i.attrs);
2599 let v = match i.node {
2600 hir::ItemStatic(..) => {
2601 // If this static came from an external crate, then
2602 // we need to get the symbol from csearch instead of
2603 // using the current crate's name/version
2604 // information in the hash of the symbol
2606 debug!("making {}", sym);
2608 // Create the global before evaluating the initializer;
2609 // this is necessary to allow recursive statics.
2610 let llty = type_of(ccx, ty);
2611 let g = declare::define_global(ccx, &sym[..], llty).unwrap_or_else(|| {
2613 .span_fatal(i.span, &format!("symbol `{}` is already defined", sym))
2616 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2620 hir::ItemFn(_, _, _, abi, _, _) => {
2622 let llfn = if abi == Rust {
2623 register_fn(ccx, i.span, sym, i.id, ty)
2625 foreign::register_rust_fn_with_foreign_abi(ccx, i.span, sym, i.id)
2627 attributes::from_fn_attrs(ccx, &i.attrs, llfn);
2631 _ => ccx.sess().bug("get_item_val: weird result in table"),
2637 hir_map::NodeTraitItem(trait_item) => {
2638 debug!("get_item_val(): processing a NodeTraitItem");
2639 match trait_item.node {
2640 hir::MethodTraitItem(_, Some(_)) => {
2641 register_method(ccx, id, &trait_item.attrs, trait_item.span)
2644 ccx.sess().span_bug(trait_item.span,
2645 "unexpected variant: trait item other than a provided \
2646 method in get_item_val()");
2651 hir_map::NodeImplItem(impl_item) => {
2652 match impl_item.node {
2653 hir::ImplItemKind::Method(..) => {
2654 register_method(ccx, id, &impl_item.attrs, impl_item.span)
2657 ccx.sess().span_bug(impl_item.span,
2658 "unexpected variant: non-method impl item in \
2664 hir_map::NodeForeignItem(ni) => {
2666 hir::ForeignItemFn(..) => {
2667 let abi = ccx.tcx().map.get_foreign_abi(id);
2668 let ty = ccx.tcx().node_id_to_type(ni.id);
2669 let name = foreign::link_name(&*ni);
2670 foreign::register_foreign_item_fn(ccx, abi, ty, &name, &ni.attrs)
2672 hir::ForeignItemStatic(..) => {
2673 foreign::register_static(ccx, &*ni)
2678 hir_map::NodeVariant(ref v) => {
2680 let fields = if v.node.data.is_struct() {
2681 ccx.sess().bug("struct variant kind unexpected in get_item_val")
2683 v.node.data.fields()
2685 assert!(!fields.is_empty());
2686 let ty = ccx.tcx().node_id_to_type(id);
2687 let parent = ccx.tcx().map.get_parent(id);
2688 let enm = ccx.tcx().map.expect_item(parent);
2689 let sym = exported_name(ccx, id, ty, &enm.attrs);
2691 llfn = match enm.node {
2692 hir::ItemEnum(_, _) => {
2693 register_fn(ccx, (*v).span, sym, id, ty)
2695 _ => ccx.sess().bug("NodeVariant, shouldn't happen"),
2697 attributes::inline(llfn, attributes::InlineAttr::Hint);
2701 hir_map::NodeStructCtor(struct_def) => {
2702 // Only register the constructor if this is a tuple-like struct.
2703 let ctor_id = if struct_def.is_struct() {
2704 ccx.sess().bug("attempt to register a constructor of a non-tuple-like struct")
2708 let parent = ccx.tcx().map.get_parent(id);
2709 let struct_item = ccx.tcx().map.expect_item(parent);
2710 let ty = ccx.tcx().node_id_to_type(ctor_id);
2711 let sym = exported_name(ccx, id, ty, &struct_item.attrs);
2712 let llfn = register_fn(ccx, struct_item.span, sym, ctor_id, ty);
2713 attributes::inline(llfn, attributes::InlineAttr::Hint);
2718 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}", variant))
2722 // All LLVM globals and functions are initially created as external-linkage
2723 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2724 // into a definition, it adjusts the linkage then (using `update_linkage`).
2726 // The exception is foreign items, which have their linkage set inside the
2727 // call to `foreign::register_*` above. We don't touch the linkage after
2728 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2729 // other item translation functions do).
2731 ccx.item_vals().borrow_mut().insert(id, val);
2735 fn register_method(ccx: &CrateContext,
2737 attrs: &[ast::Attribute],
2740 let mty = ccx.tcx().node_id_to_type(id);
2742 let sym = exported_name(ccx, id, mty, &attrs);
2744 if let ty::TyBareFn(_, ref f) = mty.sty {
2745 let llfn = if f.abi == Rust || f.abi == RustCall {
2746 register_fn(ccx, span, sym, id, mty)
2748 foreign::register_rust_fn_with_foreign_abi(ccx, span, sym, id)
2750 attributes::from_fn_attrs(ccx, &attrs, llfn);
2753 ccx.sess().span_bug(span, "expected bare rust function");
2757 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'a, 'tcx>,
2758 ie: encoder::EncodeInlinedItem<'a>,
2759 reachable: &'a NodeSet)
2760 -> encoder::EncodeParams<'a, 'tcx> {
2761 encoder::EncodeParams {
2762 diag: cx.sess().diagnostic(),
2764 reexports: cx.export_map(),
2765 item_symbols: cx.item_symbols(),
2766 link_meta: cx.link_meta(),
2767 cstore: &cx.sess().cstore,
2768 encode_inlined_item: ie,
2769 reachable: reachable,
2773 pub fn write_metadata(cx: &SharedCrateContext, krate: &hir::Crate, reachable: &NodeSet) -> Vec<u8> {
2776 let any_library = cx.sess()
2780 .any(|ty| *ty != config::CrateTypeExecutable);
2785 let encode_inlined_item: encoder::EncodeInlinedItem = Box::new(|ecx, rbml_w, ii| {
2786 astencode::encode_inlined_item(ecx, rbml_w, ii)
2789 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item, reachable);
2790 let metadata = encoder::encode_metadata(encode_parms, krate);
2791 let mut compressed = encoder::metadata_encoding_version.to_vec();
2792 compressed.push_all(&flate::deflate_bytes(&metadata));
2793 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
2794 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2795 let name = format!("rust_metadata_{}_{}",
2796 cx.link_meta().crate_name,
2797 cx.link_meta().crate_hash);
2798 let buf = CString::new(name).unwrap();
2799 let llglobal = unsafe {
2800 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf.as_ptr())
2803 llvm::LLVMSetInitializer(llglobal, llconst);
2804 let name = loader::meta_section_name(&cx.sess().target.target);
2805 let name = CString::new(name).unwrap();
2806 llvm::LLVMSetSection(llglobal, name.as_ptr())
2811 /// Find any symbols that are defined in one compilation unit, but not declared
2812 /// in any other compilation unit. Give these symbols internal linkage.
2813 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<&str>) {
2815 let mut declared = HashSet::new();
2817 // Collect all external declarations in all compilation units.
2818 for ccx in cx.iter() {
2819 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2820 let linkage = llvm::LLVMGetLinkage(val);
2821 // We only care about external declarations (not definitions)
2822 // and available_externally definitions.
2823 if !(linkage == llvm::ExternalLinkage as c_uint &&
2824 llvm::LLVMIsDeclaration(val) != 0) &&
2825 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
2829 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2832 declared.insert(name);
2836 // Examine each external definition. If the definition is not used in
2837 // any other compilation unit, and is not reachable from other crates,
2838 // then give it internal linkage.
2839 for ccx in cx.iter() {
2840 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2841 // We only care about external definitions.
2842 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2843 llvm::LLVMIsDeclaration(val) == 0) {
2847 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2850 if !declared.contains(&name) &&
2851 !reachable.contains(str::from_utf8(&name).unwrap()) {
2852 llvm::SetLinkage(val, llvm::InternalLinkage);
2853 llvm::SetDLLStorageClass(val, llvm::DefaultStorageClass);
2860 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
2861 // This is required to satisfy `dllimport` references to static data in .rlibs
2862 // when using MSVC linker. We do this only for data, as linker can fix up
2863 // code references on its own.
2864 // See #26591, #27438
2865 fn create_imps(cx: &SharedCrateContext) {
2866 // The x86 ABI seems to require that leading underscores are added to symbol
2867 // names, so we need an extra underscore on 32-bit. There's also a leading
2868 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
2869 // underscores added in front).
2870 let prefix = if cx.sess().target.target.target_pointer_width == "32" {
2876 for ccx in cx.iter() {
2877 let exported: Vec<_> = iter_globals(ccx.llmod())
2879 llvm::LLVMGetLinkage(val) ==
2880 llvm::ExternalLinkage as c_uint &&
2881 llvm::LLVMIsDeclaration(val) == 0
2885 let i8p_ty = Type::i8p(&ccx);
2886 for val in exported {
2887 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
2888 let mut imp_name = prefix.as_bytes().to_vec();
2889 imp_name.extend(name.to_bytes());
2890 let imp_name = CString::new(imp_name).unwrap();
2891 let imp = llvm::LLVMAddGlobal(ccx.llmod(),
2893 imp_name.as_ptr() as *const _);
2894 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
2895 llvm::LLVMSetInitializer(imp, init);
2896 llvm::SetLinkage(imp, llvm::ExternalLinkage);
2904 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
2907 impl Iterator for ValueIter {
2908 type Item = ValueRef;
2910 fn next(&mut self) -> Option<ValueRef> {
2913 self.cur = unsafe { (self.step)(old) };
2921 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
2924 cur: llvm::LLVMGetFirstGlobal(llmod),
2925 step: llvm::LLVMGetNextGlobal,
2930 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
2933 cur: llvm::LLVMGetFirstFunction(llmod),
2934 step: llvm::LLVMGetNextFunction,
2939 /// The context provided lists a set of reachable ids as calculated by
2940 /// middle::reachable, but this contains far more ids and symbols than we're
2941 /// actually exposing from the object file. This function will filter the set in
2942 /// the context to the set of ids which correspond to symbols that are exposed
2943 /// from the object file being generated.
2945 /// This list is later used by linkers to determine the set of symbols needed to
2946 /// be exposed from a dynamic library and it's also encoded into the metadata.
2947 pub fn filter_reachable_ids(ccx: &SharedCrateContext) -> NodeSet {
2948 ccx.reachable().iter().map(|x| *x).filter(|id| {
2949 // First, only worry about nodes which have a symbol name
2950 ccx.item_symbols().borrow().contains_key(id)
2952 // Next, we want to ignore some FFI functions that are not exposed from
2953 // this crate. Reachable FFI functions can be lumped into two
2956 // 1. Those that are included statically via a static library
2957 // 2. Those included otherwise (e.g. dynamically or via a framework)
2959 // Although our LLVM module is not literally emitting code for the
2960 // statically included symbols, it's an export of our library which
2961 // needs to be passed on to the linker and encoded in the metadata.
2963 // As a result, if this id is an FFI item (foreign item) then we only
2964 // let it through if it's included statically.
2965 match ccx.tcx().map.get(id) {
2966 hir_map::NodeForeignItem(..) => {
2967 ccx.sess().cstore.is_statically_included_foreign_item(id)
2974 pub fn trans_crate<'tcx>(tcx: &ty::ctxt<'tcx>,
2975 mir_map: &MirMap<'tcx>,
2976 analysis: ty::CrateAnalysis)
2977 -> CrateTranslation {
2978 let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
2979 let krate = tcx.map.krate();
2981 let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
2984 tcx.sess.opts.debug_assertions
2987 let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
2990 tcx.sess.opts.debug_assertions
2993 // Before we touch LLVM, make sure that multithreading is enabled.
2995 use std::sync::Once;
2996 static INIT: Once = Once::new();
2997 static mut POISONED: bool = false;
2999 if llvm::LLVMStartMultithreaded() != 1 {
3000 // use an extra bool to make sure that all future usage of LLVM
3001 // cannot proceed despite the Once not running more than once.
3005 ::back::write::configure_llvm(&tcx.sess);
3009 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3013 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3015 let codegen_units = tcx.sess.opts.cg.codegen_units;
3016 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name,
3028 let ccx = shared_ccx.get_ccx(0);
3030 // First, verify intrinsics.
3031 intrinsic::check_intrinsics(&ccx);
3033 // Next, translate all items. See `TransModVisitor` for
3034 // details on why we walk in this particular way.
3036 let _icx = push_ctxt("text");
3037 intravisit::walk_mod(&mut TransItemsWithinModVisitor { ccx: &ccx }, &krate.module);
3038 krate.visit_all_items(&mut TransModVisitor { ccx: &ccx });
3042 for ccx in shared_ccx.iter() {
3043 if ccx.sess().opts.debuginfo != NoDebugInfo {
3044 debuginfo::finalize(&ccx);
3046 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
3048 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
3049 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
3050 llvm::LLVMDeleteGlobal(old_g);
3055 let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
3057 // Translate the metadata.
3058 let metadata = write_metadata(&shared_ccx, krate, &reachable_symbol_ids);
3060 if shared_ccx.sess().trans_stats() {
3061 let stats = shared_ccx.stats();
3062 println!("--- trans stats ---");
3063 println!("n_glues_created: {}", stats.n_glues_created.get());
3064 println!("n_null_glues: {}", stats.n_null_glues.get());
3065 println!("n_real_glues: {}", stats.n_real_glues.get());
3067 println!("n_fns: {}", stats.n_fns.get());
3068 println!("n_monos: {}", stats.n_monos.get());
3069 println!("n_inlines: {}", stats.n_inlines.get());
3070 println!("n_closures: {}", stats.n_closures.get());
3071 println!("fn stats:");
3072 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3073 insns_b.cmp(&insns_a)
3075 for tuple in stats.fn_stats.borrow().iter() {
3077 (ref name, insns) => {
3078 println!("{} insns, {}", insns, *name);
3083 if shared_ccx.sess().count_llvm_insns() {
3084 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3085 println!("{:7} {}", *v, *k);
3089 let modules = shared_ccx.iter()
3090 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3093 let sess = shared_ccx.sess();
3094 let mut reachable_symbols = reachable_symbol_ids.iter().map(|id| {
3095 shared_ccx.item_symbols().borrow()[id].to_string()
3096 }).collect::<Vec<_>>();
3097 if sess.entry_fn.borrow().is_some() {
3098 reachable_symbols.push("main".to_string());
3101 // For the purposes of LTO, we add to the reachable set all of the upstream
3102 // reachable extern fns. These functions are all part of the public ABI of
3103 // the final product, so LTO needs to preserve them.
3105 sess.cstore.iter_crate_data(|cnum, _| {
3106 let syms = csearch::get_reachable_ids(&sess.cstore, cnum);
3107 reachable_symbols.extend(syms.into_iter().filter(|did| {
3108 csearch::is_extern_fn(&sess.cstore, *did, shared_ccx.tcx()) ||
3109 csearch::is_static(&sess.cstore, *did)
3111 csearch::get_symbol(&sess.cstore, did)
3116 if codegen_units > 1 {
3117 internalize_symbols(&shared_ccx,
3118 &reachable_symbols.iter().map(|x| &x[..]).collect());
3121 if sess.target.target.options.is_like_msvc &&
3122 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
3123 create_imps(&shared_ccx);
3126 let metadata_module = ModuleTranslation {
3127 llcx: shared_ccx.metadata_llcx(),
3128 llmod: shared_ccx.metadata_llmod(),
3130 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
3134 metadata_module: metadata_module,
3137 reachable: reachable_symbols,
3138 no_builtins: no_builtins,
3142 /// We visit all the items in the krate and translate them. We do
3143 /// this in two walks. The first walk just finds module items. It then
3144 /// walks the full contents of those module items and translates all
3145 /// the items within. Note that this entire process is O(n). The
3146 /// reason for this two phased walk is that each module is
3147 /// (potentially) placed into a distinct codegen-unit. This walk also
3148 /// ensures that the immediate contents of each module is processed
3149 /// entirely before we proceed to find more modules, helping to ensure
3150 /// an equitable distribution amongst codegen-units.
3151 pub struct TransModVisitor<'a, 'tcx: 'a> {
3152 pub ccx: &'a CrateContext<'a, 'tcx>,
3155 impl<'a, 'tcx, 'v> Visitor<'v> for TransModVisitor<'a, 'tcx> {
3156 fn visit_item(&mut self, i: &hir::Item) {
3158 hir::ItemMod(_) => {
3159 let item_ccx = self.ccx.rotate();
3160 intravisit::walk_item(&mut TransItemsWithinModVisitor { ccx: &item_ccx }, i);
3167 /// Translates all the items within a given module. Expects owner to
3168 /// invoke `walk_item` on a module item. Ignores nested modules.
3169 pub struct TransItemsWithinModVisitor<'a, 'tcx: 'a> {
3170 pub ccx: &'a CrateContext<'a, 'tcx>,
3173 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemsWithinModVisitor<'a, 'tcx> {
3174 fn visit_nested_item(&mut self, item_id: hir::ItemId) {
3175 self.visit_item(self.ccx.tcx().map.expect_item(item_id.id));
3178 fn visit_item(&mut self, i: &hir::Item) {
3180 hir::ItemMod(..) => {
3181 // skip modules, they will be uncovered by the TransModVisitor
3184 trans_item(self.ccx, i);
3185 intravisit::walk_item(self, i);