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) where
114 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() {
135 Some(ctx) => { ctx.pop(); }
142 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
143 debug!("new InsnCtxt: {}", s);
144 TASK_LOCAL_INSN_KEY.with(|slot| {
145 match slot.borrow_mut().as_mut() {
146 Some(ctx) => ctx.push(s),
150 _InsnCtxt { _cannot_construct_outside_of_this_module: () }
153 pub struct StatRecorder<'a, 'tcx: 'a> {
154 ccx: &'a CrateContext<'a, 'tcx>,
155 name: Option<String>,
159 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
160 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
161 -> StatRecorder<'a, 'tcx> {
162 let istart = ccx.stats().n_llvm_insns.get();
171 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
173 if self.ccx.sess().trans_stats() {
174 let iend = self.ccx.stats().n_llvm_insns.get();
175 self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
176 iend - self.istart));
177 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
178 // Reset LLVM insn count to avoid compound costs.
179 self.ccx.stats().n_llvm_insns.set(self.istart);
184 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>,
185 name: &str, did: DefId) -> ValueRef {
186 match ccx.externs().borrow().get(name) {
187 Some(n) => return *n,
191 let f = declare::declare_rust_fn(ccx, name, fn_ty);
193 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
194 attributes::from_fn_attrs(ccx, &attrs[..], f);
196 ccx.externs().borrow_mut().insert(name.to_string(), f);
200 pub fn self_type_for_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
205 let closure_kind = ccx.tcx().closure_kind(closure_id);
207 ty::FnClosureKind => {
208 ccx.tcx().mk_imm_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
210 ty::FnMutClosureKind => {
211 ccx.tcx().mk_mut_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
213 ty::FnOnceClosureKind => fn_ty
217 pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
218 *ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
221 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: DefId,
222 t: Ty<'tcx>) -> ValueRef {
223 let name = csearch::get_symbol(&ccx.sess().cstore, did);
224 let ty = type_of(ccx, t);
225 match ccx.externs().borrow_mut().get(&name) {
226 Some(n) => return *n,
229 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
230 // FIXME(nagisa): investigate whether it can be changed into define_global
231 let c = declare::declare_global(ccx, &name[..], ty);
232 // Thread-local statics in some other crate need to *always* be linked
233 // against in a thread-local fashion, so we need to be sure to apply the
234 // thread-local attribute locally if it was present remotely. If we
235 // don't do this then linker errors can be generated where the linker
236 // complains that one object files has a thread local version of the
237 // symbol and another one doesn't.
238 for attr in ccx.tcx().get_attrs(did).iter() {
239 if attr.check_name("thread_local") {
240 llvm::set_thread_local(c, true);
243 if ccx.use_dll_storage_attrs() {
244 llvm::SetDLLStorageClass(c, llvm::DLLImportStorageClass);
246 ccx.externs().borrow_mut().insert(name.to_string(), c);
250 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
251 info_ty: Ty<'tcx>, it: LangItem) -> DefId {
252 match bcx.tcx().lang_items.require(it) {
255 bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
260 // The following malloc_raw_dyn* functions allocate a box to contain
261 // a given type, but with a potentially dynamic size.
263 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
269 -> Result<'blk, 'tcx> {
270 let _icx = push_ctxt("malloc_raw_exchange");
273 let r = callee::trans_lang_call(bcx,
274 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
279 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
283 pub fn bin_op_to_icmp_predicate(ccx: &CrateContext, op: hir::BinOp_, signed: bool)
284 -> llvm::IntPredicate {
286 hir::BiEq => llvm::IntEQ,
287 hir::BiNe => llvm::IntNE,
288 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
289 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
290 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
291 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
293 ccx.sess().bug(&format!("comparison_op_to_icmp_predicate: expected \
294 comparison operator, found {:?}", op));
299 pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: hir::BinOp_)
300 -> llvm::RealPredicate {
302 hir::BiEq => llvm::RealOEQ,
303 hir::BiNe => llvm::RealUNE,
304 hir::BiLt => llvm::RealOLT,
305 hir::BiLe => llvm::RealOLE,
306 hir::BiGt => llvm::RealOGT,
307 hir::BiGe => llvm::RealOGE,
309 ccx.sess().bug(&format!("comparison_op_to_fcmp_predicate: expected \
310 comparison operator, found {:?}", op));
315 pub fn compare_fat_ptrs<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
326 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
327 let extra_eq = ICmp(bcx, llvm::IntEQ, lhs_extra, rhs_extra, debug_loc);
328 And(bcx, addr_eq, extra_eq, debug_loc)
331 let addr_eq = ICmp(bcx, llvm::IntNE, lhs_addr, rhs_addr, debug_loc);
332 let extra_eq = ICmp(bcx, llvm::IntNE, lhs_extra, rhs_extra, debug_loc);
333 Or(bcx, addr_eq, extra_eq, debug_loc)
335 hir::BiLe | hir::BiLt | hir::BiGe | hir::BiGt => {
336 // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
337 let (op, strict_op) = match op {
338 hir::BiLt => (llvm::IntULT, llvm::IntULT),
339 hir::BiLe => (llvm::IntULE, llvm::IntULT),
340 hir::BiGt => (llvm::IntUGT, llvm::IntUGT),
341 hir::BiGe => (llvm::IntUGE, llvm::IntUGT),
345 let addr_eq = ICmp(bcx, llvm::IntEQ, lhs_addr, rhs_addr, debug_loc);
346 let extra_op = ICmp(bcx, op, lhs_extra, rhs_extra, debug_loc);
347 let addr_eq_extra_op = And(bcx, addr_eq, extra_op, debug_loc);
349 let addr_strict = ICmp(bcx, strict_op, lhs_addr, rhs_addr, debug_loc);
350 Or(bcx, addr_strict, addr_eq_extra_op, debug_loc)
353 bcx.tcx().sess.bug("unexpected fat ptr binop");
358 pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
366 ty::TyTuple(ref tys) if tys.is_empty() => {
367 // We don't need to do actual comparisons for nil.
368 // () == () holds but () < () does not.
370 hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
371 hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
372 // refinements would be nice
373 _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator")
376 ty::TyBareFn(..) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
377 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
379 ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
380 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
383 let lhs_addr = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_ADDR]));
384 let lhs_extra = Load(bcx, GEPi(bcx, lhs, &[0, abi::FAT_PTR_EXTRA]));
386 let rhs_addr = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_ADDR]));
387 let rhs_extra = Load(bcx, GEPi(bcx, rhs, &[0, abi::FAT_PTR_EXTRA]));
388 compare_fat_ptrs(bcx,
394 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, true), lhs, rhs, debug_loc)
397 FCmp(bcx, bin_op_to_fcmp_predicate(bcx.ccx(), op), lhs, rhs, debug_loc)
399 // Should never get here, because t is scalar.
400 _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types")
404 pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
412 let signed = match t.sty {
414 let cmp = bin_op_to_fcmp_predicate(bcx.ccx(), op);
415 return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
417 ty::TyUint(_) => false,
418 ty::TyInt(_) => true,
419 _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
422 let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
423 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
424 // to get the correctly sized type. This will compile to a single instruction
425 // once the IR is converted to assembly if the SIMD instruction is supported
426 // by the target architecture.
427 SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
430 // Iterates through the elements of a structural type.
431 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
435 -> Block<'blk, 'tcx> where
436 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
438 let _icx = push_ctxt("iter_structural_ty");
440 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
441 repr: &adt::Repr<'tcx>,
443 variant: ty::VariantDef<'tcx>,
444 substs: &Substs<'tcx>,
446 -> Block<'blk, 'tcx> where
447 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
449 let _icx = push_ctxt("iter_variant");
453 for (i, field) in variant.fields.iter().enumerate() {
454 let arg = monomorphize::field_ty(tcx, substs, field);
455 cx = f(cx, adt::trans_field_ptr(cx, repr, av, variant.disr_val, i), arg);
460 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
463 let data = expr::get_dataptr(cx, av);
464 let info = expr::get_meta(cx, av);
465 (Load(cx, data), Some(Load(cx, info)))
470 ty::TyStruct(..) => {
471 let repr = adt::represent_type(cx.ccx(), t);
472 let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
473 for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
474 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
476 let val = if common::type_is_sized(cx.tcx(), field_ty) {
479 let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
480 Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
481 Store(cx, info.unwrap(), expr::get_meta(cx, scratch.val));
484 cx = f(cx, val, field_ty);
487 ty::TyClosure(_, ref substs) => {
488 let repr = adt::represent_type(cx.ccx(), t);
489 for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
490 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
491 cx = f(cx, llupvar, upvar_ty);
494 ty::TyArray(_, n) => {
495 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
496 let unit_ty = t.sequence_element_type(cx.tcx());
497 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
499 ty::TySlice(_) | ty::TyStr => {
500 let unit_ty = t.sequence_element_type(cx.tcx());
501 cx = tvec::iter_vec_raw(cx, data_ptr, unit_ty, info.unwrap(), f);
503 ty::TyTuple(ref args) => {
504 let repr = adt::represent_type(cx.ccx(), t);
505 for (i, arg) in args.iter().enumerate() {
506 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
507 cx = f(cx, llfld_a, *arg);
510 ty::TyEnum(en, substs) => {
514 let repr = adt::represent_type(ccx, t);
515 let n_variants = en.variants.len();
517 // NB: we must hit the discriminant first so that structural
518 // comparison know not to proceed when the discriminants differ.
520 match adt::trans_switch(cx, &*repr, av) {
521 (_match::Single, None) => {
523 assert!(n_variants == 1);
524 cx = iter_variant(cx, &*repr, av, &en.variants[0],
528 (_match::Switch, Some(lldiscrim_a)) => {
529 cx = f(cx, lldiscrim_a, cx.tcx().types.isize);
531 // Create a fall-through basic block for the "else" case of
532 // the switch instruction we're about to generate. Note that
533 // we do **not** use an Unreachable instruction here, even
534 // though most of the time this basic block will never be hit.
536 // When an enum is dropped it's contents are currently
537 // overwritten to DTOR_DONE, which means the discriminant
538 // could have changed value to something not within the actual
539 // range of the discriminant. Currently this function is only
540 // used for drop glue so in this case we just return quickly
541 // from the outer function, and any other use case will only
542 // call this for an already-valid enum in which case the `ret
543 // void` will never be hit.
544 let ret_void_cx = fcx.new_temp_block("enum-iter-ret-void");
545 RetVoid(ret_void_cx, DebugLoc::None);
546 let llswitch = Switch(cx, lldiscrim_a, ret_void_cx.llbb,
548 let next_cx = fcx.new_temp_block("enum-iter-next");
550 for variant in &en.variants {
553 &format!("enum-iter-variant-{}",
554 &variant.disr_val.to_string())
556 let case_val = adt::trans_case(cx, &*repr, variant.disr_val);
557 AddCase(llswitch, case_val, variant_cx.llbb);
559 iter_variant(variant_cx,
565 Br(variant_cx, next_cx.llbb, DebugLoc::None);
569 _ => ccx.sess().unimpl("value from adt::trans_switch \
570 in iter_structural_ty")
574 cx.sess().unimpl(&format!("type in iter_structural_ty: {}", t))
581 /// Retrieve the information we are losing (making dynamic) in an unsizing
584 /// The `old_info` argument is a bit funny. It is intended for use
585 /// in an upcast, where the new vtable for an object will be drived
586 /// from the old one.
587 pub fn unsized_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
590 old_info: Option<ValueRef>,
591 param_substs: &'tcx Substs<'tcx>)
593 let (source, target) = ccx.tcx().struct_lockstep_tails(source, target);
594 match (&source.sty, &target.sty) {
595 (&ty::TyArray(_, len), &ty::TySlice(_)) => C_uint(ccx, len),
596 (&ty::TyTrait(_), &ty::TyTrait(_)) => {
597 // For now, upcasts are limited to changes in marker
598 // traits, and hence never actually require an actual
599 // change to the vtable.
600 old_info.expect("unsized_info: missing old info for trait upcast")
602 (_, &ty::TyTrait(box ty::TraitTy { ref principal, .. })) => {
603 // Note that we preserve binding levels here:
604 let substs = principal.0.substs.with_self_ty(source).erase_regions();
605 let substs = ccx.tcx().mk_substs(substs);
606 let trait_ref = ty::Binder(ty::TraitRef { def_id: principal.def_id(),
608 consts::ptrcast(meth::get_vtable(ccx, trait_ref, param_substs),
609 Type::vtable_ptr(ccx))
611 _ => ccx.sess().bug(&format!("unsized_info: invalid unsizing {:?} -> {:?}",
617 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
618 pub fn unsize_thin_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
622 -> (ValueRef, ValueRef) {
623 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
624 match (&src_ty.sty, &dst_ty.sty) {
625 (&ty::TyBox(a), &ty::TyBox(b)) |
626 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
627 &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) |
628 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
629 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) |
630 (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }),
631 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => {
632 assert!(common::type_is_sized(bcx.tcx(), a));
633 let ptr_ty = type_of::in_memory_type_of(bcx.ccx(), b).ptr_to();
634 (PointerCast(bcx, src, ptr_ty),
635 unsized_info(bcx.ccx(), a, b, None, bcx.fcx.param_substs))
638 &format!("unsize_thin_ptr: called on bad types"))
642 /// Coerce `src`, which is a reference to a value of type `src_ty`,
643 /// to a value of type `dst_ty` and store the result in `dst`
644 pub fn coerce_unsized_into<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
649 match (&src_ty.sty, &dst_ty.sty) {
650 (&ty::TyBox(..), &ty::TyBox(..)) |
651 (&ty::TyRef(..), &ty::TyRef(..)) |
652 (&ty::TyRef(..), &ty::TyRawPtr(..)) |
653 (&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => {
654 let (base, info) = if common::type_is_fat_ptr(bcx.tcx(), src_ty) {
655 // fat-ptr to fat-ptr unsize preserves the vtable
656 load_fat_ptr(bcx, src, src_ty)
658 let base = load_ty(bcx, src, src_ty);
659 unsize_thin_ptr(bcx, base, src_ty, dst_ty)
661 store_fat_ptr(bcx, base, info, dst, dst_ty);
664 // This can be extended to enums and tuples in the future.
665 // (&ty::TyEnum(def_id_a, _), &ty::TyEnum(def_id_b, _)) |
666 (&ty::TyStruct(def_a, _), &ty::TyStruct(def_b, _)) => {
667 assert_eq!(def_a, def_b);
669 let src_repr = adt::represent_type(bcx.ccx(), src_ty);
670 let src_fields = match &*src_repr {
671 &adt::Repr::Univariant(ref s, _) => &s.fields,
672 _ => bcx.sess().bug("struct has non-univariant repr")
674 let dst_repr = adt::represent_type(bcx.ccx(), dst_ty);
675 let dst_fields = match &*dst_repr {
676 &adt::Repr::Univariant(ref s, _) => &s.fields,
677 _ => bcx.sess().bug("struct has non-univariant repr")
680 let iter = src_fields.iter().zip(dst_fields).enumerate();
681 for (i, (src_fty, dst_fty)) in iter {
682 if type_is_zero_size(bcx.ccx(), dst_fty) { continue; }
684 let src_f = adt::trans_field_ptr(bcx, &src_repr, src, 0, i);
685 let dst_f = adt::trans_field_ptr(bcx, &dst_repr, dst, 0, i);
686 if src_fty == dst_fty {
687 memcpy_ty(bcx, dst_f, src_f, src_fty);
697 _ => bcx.sess().bug(&format!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
703 pub fn cast_shift_expr_rhs(cx: Block,
708 cast_shift_rhs(op, lhs, rhs,
709 |a,b| Trunc(cx, a, b),
710 |a,b| ZExt(cx, a, b))
713 pub fn cast_shift_const_rhs(op: hir::BinOp_,
714 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
715 cast_shift_rhs(op, lhs, rhs,
716 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
717 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
720 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
726 F: FnOnce(ValueRef, Type) -> ValueRef,
727 G: FnOnce(ValueRef, Type) -> ValueRef,
729 // Shifts may have any size int on the rhs
730 if rustc_front::util::is_shift_binop(op) {
731 let mut rhs_llty = val_ty(rhs);
732 let mut lhs_llty = val_ty(lhs);
733 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
734 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
735 let rhs_sz = rhs_llty.int_width();
736 let lhs_sz = lhs_llty.int_width();
739 } else if lhs_sz > rhs_sz {
740 // FIXME (#1877: If shifting by negative
741 // values becomes not undefined then this is wrong.
751 pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
752 val_t: Ty<'tcx>) -> (Type, u64) {
755 let llty = Type::int_from_ty(cx.ccx(), t);
757 ast::TyIs if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
758 ast::TyIs => i64::MIN as u64,
759 ast::TyI8 => i8::MIN as u64,
760 ast::TyI16 => i16::MIN as u64,
761 ast::TyI32 => i32::MIN as u64,
762 ast::TyI64 => i64::MIN as u64,
770 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
771 cx: Block<'blk, 'tcx>,
772 call_info: NodeIdAndSpan,
777 -> Block<'blk, 'tcx> {
778 let (zero_text, overflow_text) = if divrem.node == hir::BiDiv {
779 ("attempted to divide by zero",
780 "attempted to divide with overflow")
782 ("attempted remainder with a divisor of zero",
783 "attempted remainder with overflow")
785 let debug_loc = call_info.debug_loc();
787 let (is_zero, is_signed) = match rhs_t.sty {
789 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
790 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
793 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
794 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
796 ty::TyStruct(def, _) if def.is_simd() => {
797 let mut res = C_bool(cx.ccx(), false);
798 for i in 0 .. rhs_t.simd_size(cx.tcx()) {
801 ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))), debug_loc);
806 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}", rhs_t));
809 let bcx = with_cond(cx, is_zero, |bcx| {
810 controlflow::trans_fail(bcx, call_info, InternedString::new(zero_text))
813 // To quote LLVM's documentation for the sdiv instruction:
815 // Division by zero leads to undefined behavior. Overflow also leads
816 // to undefined behavior; this is a rare case, but can occur, for
817 // example, by doing a 32-bit division of -2147483648 by -1.
819 // In order to avoid undefined behavior, we perform runtime checks for
820 // signed division/remainder which would trigger overflow. For unsigned
821 // integers, no action beyond checking for zero need be taken.
823 let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
824 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
825 C_integral(llty, !0, false), debug_loc);
826 with_cond(bcx, minus_one, |bcx| {
827 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
828 C_integral(llty, min, true), debug_loc);
829 with_cond(bcx, is_min, |bcx| {
830 controlflow::trans_fail(bcx,
832 InternedString::new(overflow_text))
840 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
841 did: DefId, t: Ty<'tcx>) -> ValueRef {
842 let name = csearch::get_symbol(&ccx.sess().cstore, did);
844 ty::TyBareFn(_, ref fn_ty) => {
845 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
847 get_extern_rust_fn(ccx, t, &name[..], did)
849 RustIntrinsic | PlatformIntrinsic => {
850 ccx.sess().bug("unexpected intrinsic in trans_external_path")
853 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
854 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t, &name, &attrs)
859 get_extern_const(ccx, did, t)
864 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
869 -> (ValueRef, Block<'blk, 'tcx>) {
870 let _icx = push_ctxt("invoke_");
871 if bcx.unreachable.get() {
872 return (C_null(Type::i8(bcx.ccx())), bcx);
875 let attributes = attributes::from_fn_type(bcx.ccx(), fn_ty);
877 match bcx.opt_node_id {
879 debug!("invoke at ???");
882 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
886 if need_invoke(bcx) {
887 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
888 for &llarg in llargs {
889 debug!("arg: {}", bcx.val_to_string(llarg));
891 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
892 let landing_pad = bcx.fcx.get_landing_pad();
894 let llresult = Invoke(bcx,
901 return (llresult, normal_bcx);
903 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
904 for &llarg in llargs {
905 debug!("arg: {}", bcx.val_to_string(llarg));
908 let llresult = Call(bcx,
913 return (llresult, bcx);
917 /// Returns whether this session's target will use SEH-based unwinding.
919 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
920 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
921 /// 64-bit MinGW) instead of "full SEH".
922 pub fn wants_msvc_seh(sess: &Session) -> bool {
923 sess.target.target.options.is_like_msvc && sess.target.target.arch == "x86"
926 pub fn need_invoke(bcx: Block) -> bool {
927 // FIXME(#25869) currently SEH-based unwinding is pretty buggy in LLVM and
928 // is being overhauled as this is being written. Until that
929 // time such that upstream LLVM's implementation is more solid
930 // and we start binding it we need to skip invokes for any
931 // target which wants SEH-based unwinding.
932 if bcx.sess().no_landing_pads() || wants_msvc_seh(bcx.sess()) {
936 // Avoid using invoke if we are already inside a landing pad.
941 bcx.fcx.needs_invoke()
944 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
945 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
946 let _icx = push_ctxt("load_if_immediate");
947 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
951 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
952 /// differs from the type used for SSA values. Also handles various special cases where the type
953 /// gives us better information about what we are loading.
954 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
955 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
956 if cx.unreachable.get() || type_is_zero_size(cx.ccx(), t) {
957 return C_undef(type_of::type_of(cx.ccx(), t));
960 let ptr = to_arg_ty_ptr(cx, ptr, t);
961 let align = type_of::align_of(cx.ccx(), t);
963 if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
964 let load = Load(cx, ptr);
966 llvm::LLVMSetAlignment(load, align);
972 let global = llvm::LLVMIsAGlobalVariable(ptr);
973 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
974 let val = llvm::LLVMGetInitializer(global);
976 return to_arg_ty(cx, val, t);
981 let val = if t.is_bool() {
982 LoadRangeAssert(cx, ptr, 0, 2, llvm::False)
983 } else if t.is_char() {
984 // a char is a Unicode codepoint, and so takes values from 0
985 // to 0x10FFFF inclusive only.
986 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
987 } else if (t.is_region_ptr() || t.is_unique())
988 && !common::type_is_fat_ptr(cx.tcx(), t) {
995 llvm::LLVMSetAlignment(val, align);
998 to_arg_ty(cx, val, t)
1001 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1002 /// differs from the type used for SSA values.
1003 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1004 if cx.unreachable.get() {
1008 debug!("store_ty: {} : {:?} <- {}",
1009 cx.val_to_string(dst), t,
1010 cx.val_to_string(v));
1012 if common::type_is_fat_ptr(cx.tcx(), t) {
1013 Store(cx, ExtractValue(cx, v, abi::FAT_PTR_ADDR), expr::get_dataptr(cx, dst));
1014 Store(cx, ExtractValue(cx, v, abi::FAT_PTR_EXTRA), expr::get_meta(cx, dst));
1016 let store = Store(cx, from_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
1018 llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
1023 pub fn store_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1028 // FIXME: emit metadata
1029 Store(cx, data, expr::get_dataptr(cx, dst));
1030 Store(cx, extra, expr::get_meta(cx, dst));
1033 pub fn load_fat_ptr<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1035 _ty: Ty<'tcx>) -> (ValueRef, ValueRef)
1037 // FIXME: emit metadata
1038 (Load(cx, expr::get_dataptr(cx, src)),
1039 Load(cx, expr::get_meta(cx, src)))
1042 pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1044 ZExt(bcx, val, Type::i8(bcx.ccx()))
1050 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
1052 Trunc(bcx, val, Type::i1(bcx.ccx()))
1058 pub fn to_arg_ty_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef, ty: Ty<'tcx>) -> ValueRef {
1059 if type_is_immediate(bcx.ccx(), ty) && type_of::type_of(bcx.ccx(), ty).is_aggregate() {
1060 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1061 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1062 // and we have to convert it
1063 BitCast(bcx, ptr, type_of::arg_type_of(bcx.ccx(), ty).ptr_to())
1069 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local)
1070 -> Block<'blk, 'tcx> {
1071 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1072 let _indenter = indenter();
1073 let _icx = push_ctxt("init_local");
1074 _match::store_local(bcx, local)
1077 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1079 llbb: BasicBlockRef)
1080 -> Block<'blk, 'tcx> {
1081 common::BlockS::new(llbb, is_lpad, None, fcx)
1084 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
1087 -> Block<'blk, 'tcx> where
1088 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
1090 let _icx = push_ctxt("with_cond");
1092 if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
1097 let next_cx = fcx.new_temp_block("next");
1098 let cond_cx = fcx.new_temp_block("cond");
1099 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
1100 let after_cx = f(cond_cx);
1101 if !after_cx.terminated.get() {
1102 Br(after_cx, next_cx.llbb, DebugLoc::None);
1107 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1108 if cx.sess().opts.optimize == config::No {
1112 let _icx = push_ctxt("lifetime_start");
1115 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1120 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1121 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1122 Call(cx, lifetime_start, &[C_u64(ccx, size), ptr], None, DebugLoc::None);
1125 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1126 if cx.sess().opts.optimize == config::No {
1130 let _icx = push_ctxt("lifetime_end");
1133 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
1138 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1139 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1140 Call(cx, lifetime_end, &[C_u64(ccx, size), ptr], None, DebugLoc::None);
1143 // Generates code for resumption of unwind at the end of a landing pad.
1144 pub fn trans_unwind_resume(bcx: Block, lpval: ValueRef) {
1145 if !bcx.sess().target.target.options.custom_unwind_resume {
1148 let exc_ptr = ExtractValue(bcx, lpval, 0);
1149 let llunwresume = bcx.fcx.eh_unwind_resume();
1150 Call(bcx, llunwresume, &[exc_ptr], None, DebugLoc::None);
1156 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1157 let _icx = push_ctxt("call_memcpy");
1159 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1160 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
1161 let memcpy = ccx.get_intrinsic(&key);
1162 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1163 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1164 let size = IntCast(cx, n_bytes, ccx.int_type());
1165 let align = C_i32(ccx, align as i32);
1166 let volatile = C_bool(ccx, false);
1167 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None, DebugLoc::None);
1170 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1171 dst: ValueRef, src: ValueRef,
1173 let _icx = push_ctxt("memcpy_ty");
1174 let ccx = bcx.ccx();
1176 if type_is_zero_size(ccx, t) {
1180 if t.is_structural() {
1181 let llty = type_of::type_of(ccx, t);
1182 let llsz = llsize_of(ccx, llty);
1183 let llalign = type_of::align_of(ccx, t);
1184 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1186 store_ty(bcx, load_ty(bcx, src, t), dst, t);
1190 pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1191 if cx.unreachable.get() { return; }
1192 let _icx = push_ctxt("drop_done_fill_mem");
1194 memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
1197 pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1198 if cx.unreachable.get() { return; }
1199 let _icx = push_ctxt("init_zero_mem");
1201 memfill(&B(bcx), llptr, t, 0);
1204 // Always use this function instead of storing a constant byte to the memory
1205 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
1206 // allocation for large data structures, and the generated code will be
1207 // awful. (A telltale sign of this is large quantities of
1208 // `mov [byte ptr foo],0` in the generated code.)
1209 fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
1210 let _icx = push_ctxt("memfill");
1213 let llty = type_of::type_of(ccx, ty);
1214 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1215 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
1217 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1218 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1219 let llzeroval = C_u8(ccx, byte);
1220 let size = machine::llsize_of(ccx, llty);
1221 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1222 let volatile = C_bool(ccx, false);
1223 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1226 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1227 let _icx = push_ctxt("alloc_ty");
1228 let ccx = bcx.ccx();
1229 let ty = type_of::type_of(ccx, t);
1230 assert!(!t.has_param_types());
1231 alloca(bcx, ty, name)
1234 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1235 let _icx = push_ctxt("alloca");
1236 if cx.unreachable.get() {
1238 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1241 debuginfo::clear_source_location(cx.fcx);
1242 Alloca(cx, ty, name)
1245 pub fn set_value_name(val: ValueRef, name: &str) {
1247 let name = CString::new(name).unwrap();
1248 llvm::LLVMSetValueName(val, name.as_ptr());
1252 // Creates the alloca slot which holds the pointer to the slot for the final return value
1253 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1254 output_type: Ty<'tcx>) -> ValueRef {
1255 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1257 // We create an alloca to hold a pointer of type `output_type`
1258 // which will hold the pointer to the right alloca which has the
1260 if fcx.needs_ret_allocas {
1261 // Let's create the stack slot
1262 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1264 // and if we're using an out pointer, then store that in our newly made slot
1265 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1266 let outptr = get_param(fcx.llfn, 0);
1268 let b = fcx.ccx.builder();
1269 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1270 b.store(outptr, slot);
1275 // But if there are no nested returns, we skip the indirection and have a single
1278 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1279 get_param(fcx.llfn, 0)
1281 AllocaFcx(fcx, lloutputtype, "sret_slot")
1286 struct FindNestedReturn {
1290 impl FindNestedReturn {
1291 fn new() -> FindNestedReturn {
1292 FindNestedReturn { found: false }
1296 impl<'v> Visitor<'v> for FindNestedReturn {
1297 fn visit_expr(&mut self, e: &hir::Expr) {
1299 hir::ExprRet(..) => {
1302 _ => intravisit::walk_expr(self, e)
1307 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1308 let blk = match tcx.map.find(id) {
1309 Some(hir_map::NodeItem(i)) => {
1311 hir::ItemFn(_, _, _, _, _, ref blk) => {
1314 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1317 Some(hir_map::NodeTraitItem(trait_item)) => {
1318 match trait_item.node {
1319 hir::MethodTraitItem(_, Some(ref body)) => body,
1321 tcx.sess.bug("unexpected variant: trait item other than a \
1322 provided method in has_nested_returns")
1326 Some(hir_map::NodeImplItem(impl_item)) => {
1327 match impl_item.node {
1328 hir::ImplItemKind::Method(_, ref body) => body,
1330 tcx.sess.bug("unexpected variant: non-method impl item in \
1331 has_nested_returns")
1335 Some(hir_map::NodeExpr(e)) => {
1337 hir::ExprClosure(_, _, ref blk) => blk,
1338 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1341 Some(hir_map::NodeVariant(..)) |
1342 Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1345 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1347 _ => tcx.sess.bug(&format!("unexpected variant in has_nested_returns: {}",
1348 tcx.map.path_to_string(id)))
1351 (blk.id, Some(cfg::CFG::new(tcx, blk)))
1354 // Checks for the presence of "nested returns" in a function.
1355 // Nested returns are when the inner expression of a return expression
1356 // (the 'expr' in 'return expr') contains a return expression. Only cases
1357 // where the outer return is actually reachable are considered. Implicit
1358 // returns from the end of blocks are considered as well.
1360 // This check is needed to handle the case where the inner expression is
1361 // part of a larger expression that may have already partially-filled the
1362 // return slot alloca. This can cause errors related to clean-up due to
1363 // the clobbering of the existing value in the return slot.
1364 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1365 for index in cfg.graph.depth_traverse(cfg.entry) {
1366 let n = cfg.graph.node_data(index);
1367 match tcx.map.find(n.id()) {
1368 Some(hir_map::NodeExpr(ex)) => {
1369 if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
1370 let mut visitor = FindNestedReturn::new();
1371 intravisit::walk_expr(&mut visitor, &**ret_expr);
1377 Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
1378 let mut visitor = FindNestedReturn::new();
1379 walk_list!(&mut visitor, visit_expr, &blk.expr);
1391 // NB: must keep 4 fns in sync:
1394 // - create_datums_for_fn_args.
1398 // Be warned! You must call `init_function` before doing anything with the
1399 // returned function context.
1400 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1404 output_type: ty::FnOutput<'tcx>,
1405 param_substs: &'tcx Substs<'tcx>,
1407 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1408 -> FunctionContext<'a, 'tcx> {
1409 common::validate_substs(param_substs);
1411 debug!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1415 ccx.tcx().map.path_to_string(id).to_string()
1419 let uses_outptr = match output_type {
1420 ty::FnConverging(output_type) => {
1421 let substd_output_type =
1422 monomorphize::apply_param_substs(ccx.tcx(), param_substs, &output_type);
1423 type_of::return_uses_outptr(ccx, substd_output_type)
1425 ty::FnDiverging => false
1427 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1428 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1429 let nested_returns = if let Some(ref cfg) = cfg {
1430 has_nested_returns(ccx.tcx(), cfg, blk_id)
1435 let mir = ccx.mir_map().get(&id);
1437 let mut fcx = FunctionContext {
1441 llretslotptr: Cell::new(None),
1442 param_env: ccx.tcx().empty_parameter_environment(),
1443 alloca_insert_pt: Cell::new(None),
1444 llreturn: Cell::new(None),
1445 needs_ret_allocas: nested_returns,
1446 personality: Cell::new(None),
1447 caller_expects_out_pointer: uses_outptr,
1448 lllocals: RefCell::new(NodeMap()),
1449 llupvars: RefCell::new(NodeMap()),
1450 lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
1452 param_substs: param_substs,
1454 block_arena: block_arena,
1456 debug_context: debug_context,
1457 scopes: RefCell::new(Vec::new()),
1462 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1468 /// Performs setup on a newly created function, creating the entry scope block
1469 /// and allocating space for the return pointer.
1470 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1472 output: ty::FnOutput<'tcx>)
1473 -> Block<'a, 'tcx> {
1474 let entry_bcx = fcx.new_temp_block("entry-block");
1476 // Use a dummy instruction as the insertion point for all allocas.
1477 // This is later removed in FunctionContext::cleanup.
1478 fcx.alloca_insert_pt.set(Some(unsafe {
1479 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1480 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1483 if let ty::FnConverging(output_type) = output {
1484 // This shouldn't need to recompute the return type,
1485 // as new_fn_ctxt did it already.
1486 let substd_output_type = fcx.monomorphize(&output_type);
1487 if !return_type_is_void(fcx.ccx, substd_output_type) {
1488 // If the function returns nil/bot, there is no real return
1489 // value, so do not set `llretslotptr`.
1490 if !skip_retptr || fcx.caller_expects_out_pointer {
1491 // Otherwise, we normally allocate the llretslotptr, unless we
1492 // have been instructed to skip it for immediate return
1494 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1499 // Create the drop-flag hints for every unfragmented path in the function.
1500 let tcx = fcx.ccx.tcx();
1501 let fn_did = tcx.map.local_def_id(fcx.id);
1502 let mut hints = fcx.lldropflag_hints.borrow_mut();
1503 let fragment_infos = tcx.fragment_infos.borrow();
1505 // Intern table for drop-flag hint datums.
1506 let mut seen = HashMap::new();
1508 if let Some(fragment_infos) = fragment_infos.get(&fn_did) {
1509 for &info in fragment_infos {
1511 let make_datum = |id| {
1512 let init_val = C_u8(fcx.ccx, adt::DTOR_NEEDED_HINT);
1513 let llname = &format!("dropflag_hint_{}", id);
1514 debug!("adding hint {}", llname);
1515 let ty = tcx.types.u8;
1516 let ptr = alloc_ty(entry_bcx, ty, llname);
1517 Store(entry_bcx, init_val, ptr);
1518 let flag = datum::Lvalue::new_dropflag_hint("base::init_function");
1519 datum::Datum::new(ptr, ty, flag)
1522 let (var, datum) = match info {
1523 ty::FragmentInfo::Moved { var, .. } |
1524 ty::FragmentInfo::Assigned { var, .. } => {
1525 let datum = seen.get(&var).cloned().unwrap_or_else(|| {
1526 let datum = make_datum(var);
1527 seen.insert(var, datum.clone());
1534 ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
1535 debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
1536 hints.insert(expr_id, DropHint::new(var, datum));
1538 ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
1539 debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
1540 hints.insert(expr_id, DropHint::new(var, datum));
1549 // NB: must keep 4 fns in sync:
1552 // - create_datums_for_fn_args.
1556 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1558 use trans::datum::{ByRef, ByValue};
1561 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1565 // create_datums_for_fn_args: creates lvalue datums for each of the
1566 // incoming function arguments.
1567 pub fn create_datums_for_fn_args<'a, 'tcx>(mut bcx: Block<'a, 'tcx>,
1569 arg_tys: &[Ty<'tcx>],
1570 has_tupled_arg: bool,
1571 arg_scope: cleanup::CustomScopeIndex)
1572 -> Block<'a, 'tcx> {
1573 let _icx = push_ctxt("create_datums_for_fn_args");
1575 let arg_scope_id = cleanup::CustomScope(arg_scope);
1577 // Return an array wrapping the ValueRefs that we get from `get_param` for
1578 // each argument into datums.
1580 // For certain mode/type combinations, the raw llarg values are passed
1581 // by value. However, within the fn body itself, we want to always
1582 // have all locals and arguments be by-ref so that we can cancel the
1583 // cleanup and for better interaction with LLVM's debug info. So, if
1584 // the argument would be passed by value, we store it into an alloca.
1585 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1586 // the event it's not truly needed.
1587 let mut idx = fcx.arg_offset() as c_uint;
1588 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1589 let arg_datum = if !has_tupled_arg || i < arg_tys.len() - 1 {
1590 if type_of::arg_is_indirect(bcx.ccx(), arg_ty)
1591 && bcx.sess().opts.debuginfo != FullDebugInfo {
1592 // Don't copy an indirect argument to an alloca, the caller
1593 // already put it in a temporary alloca and gave it up, unless
1594 // we emit extra-debug-info, which requires local allocas :(.
1595 let llarg = get_param(fcx.llfn, idx);
1597 bcx.fcx.schedule_lifetime_end(arg_scope_id, llarg);
1598 bcx.fcx.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
1600 datum::Datum::new(llarg, arg_ty, datum::Lvalue::new("create_datum_for_fn_args"))
1601 } else if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1602 let data = get_param(fcx.llfn, idx);
1603 let extra = get_param(fcx.llfn, idx + 1);
1605 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1606 arg_scope_id, (data, extra),
1607 |(data, extra), bcx, dst| {
1608 Store(bcx, data, expr::get_dataptr(bcx, dst));
1609 Store(bcx, extra, expr::get_meta(bcx, dst));
1613 let llarg = get_param(fcx.llfn, idx);
1615 let tmp = datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty));
1616 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1618 |tmp, bcx, dst| tmp.store_to(bcx, dst)))
1621 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1623 ty::TyTuple(ref tupled_arg_tys) => {
1625 datum::lvalue_scratch_datum(bcx,
1633 for (j, &tupled_arg_ty) in
1634 tupled_arg_tys.iter().enumerate() {
1635 let lldest = StructGEP(bcx, llval, j);
1636 if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
1637 let data = get_param(bcx.fcx.llfn, idx);
1638 let extra = get_param(bcx.fcx.llfn, idx + 1);
1639 Store(bcx, data, expr::get_dataptr(bcx, lldest));
1640 Store(bcx, extra, expr::get_meta(bcx, lldest));
1643 let datum = datum::Datum::new(
1644 get_param(bcx.fcx.llfn, idx),
1646 arg_kind(bcx.fcx, tupled_arg_ty));
1648 bcx = datum.store_to(bcx, lldest);
1655 bcx.tcx().sess.bug("last argument of a function with \
1656 `rust-call` ABI isn't a tuple?!")
1661 let pat = &*args[i].pat;
1662 bcx = if let Some(name) = simple_name(pat) {
1663 // Generate nicer LLVM for the common case of fn a pattern
1665 set_value_name(arg_datum.val, &bcx.name(name));
1666 bcx.fcx.lllocals.borrow_mut().insert(pat.id, arg_datum);
1669 // General path. Copy out the values that are used in the
1671 _match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
1673 debuginfo::create_argument_metadata(bcx, &args[i]);
1679 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1680 // and builds the return block.
1681 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1682 last_bcx: Block<'blk, 'tcx>,
1683 retty: ty::FnOutput<'tcx>,
1684 ret_debug_loc: DebugLoc) {
1685 let _icx = push_ctxt("finish_fn");
1687 let ret_cx = match fcx.llreturn.get() {
1689 if !last_bcx.terminated.get() {
1690 Br(last_bcx, llreturn, DebugLoc::None);
1692 raw_block(fcx, false, llreturn)
1697 // This shouldn't need to recompute the return type,
1698 // as new_fn_ctxt did it already.
1699 let substd_retty = fcx.monomorphize(&retty);
1700 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1702 debuginfo::clear_source_location(fcx);
1706 // Builds the return block for a function.
1707 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1708 ret_cx: Block<'blk, 'tcx>,
1709 retty: ty::FnOutput<'tcx>,
1710 ret_debug_location: DebugLoc) {
1711 if fcx.llretslotptr.get().is_none() ||
1712 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1713 return RetVoid(ret_cx, ret_debug_location);
1716 let retslot = if fcx.needs_ret_allocas {
1717 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1719 fcx.llretslotptr.get().unwrap()
1721 let retptr = Value(retslot);
1722 match retptr.get_dominating_store(ret_cx) {
1723 // If there's only a single store to the ret slot, we can directly return
1724 // the value that was stored and omit the store and the alloca
1726 let retval = s.get_operand(0).unwrap().get();
1727 s.erase_from_parent();
1729 if retptr.has_no_uses() {
1730 retptr.erase_from_parent();
1733 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1734 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1739 if fcx.caller_expects_out_pointer {
1740 if let ty::FnConverging(retty) = retty {
1741 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1743 RetVoid(ret_cx, ret_debug_location)
1745 Ret(ret_cx, retval, ret_debug_location)
1748 // Otherwise, copy the return value to the ret slot
1749 None => match retty {
1750 ty::FnConverging(retty) => {
1751 if fcx.caller_expects_out_pointer {
1752 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1753 RetVoid(ret_cx, ret_debug_location)
1755 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1758 ty::FnDiverging => {
1759 if fcx.caller_expects_out_pointer {
1760 RetVoid(ret_cx, ret_debug_location)
1762 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1769 /// Builds an LLVM function out of a source function.
1771 /// If the function closes over its environment a closure will be returned.
1772 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1776 param_substs: &'tcx Substs<'tcx>,
1777 fn_ast_id: ast::NodeId,
1778 attributes: &[ast::Attribute],
1779 output_type: ty::FnOutput<'tcx>,
1781 closure_env: closure::ClosureEnv<'b>) {
1782 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1784 let _icx = push_ctxt("trans_closure");
1785 attributes::emit_uwtable(llfndecl, true);
1787 debug!("trans_closure(..., param_substs={:?})",
1790 let has_env = match closure_env {
1791 closure::ClosureEnv::Closure(..) => true,
1792 closure::ClosureEnv::NotClosure => false,
1795 let (arena, fcx): (TypedArena<_>, FunctionContext);
1796 arena = TypedArena::new();
1797 fcx = new_fn_ctxt(ccx,
1805 let mut bcx = init_function(&fcx, false, output_type);
1807 if attributes.iter().any(|item| item.check_name("rustc_mir")) {
1808 mir::trans_mir(bcx);
1813 // cleanup scope for the incoming arguments
1814 let fn_cleanup_debug_loc =
1815 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1816 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1818 let block_ty = node_id_type(bcx, body.id);
1820 // Set up arguments to the function.
1821 let monomorphized_arg_types =
1823 .map(|arg| node_id_type(bcx, arg.id))
1824 .collect::<Vec<_>>();
1825 for monomorphized_arg_type in &monomorphized_arg_types {
1826 debug!("trans_closure: monomorphized_arg_type: {:?}",
1827 monomorphized_arg_type);
1829 debug!("trans_closure: function lltype: {}",
1830 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1832 let has_tupled_arg = match closure_env {
1833 closure::ClosureEnv::NotClosure => abi == RustCall,
1837 bcx = create_datums_for_fn_args(bcx, &decl.inputs, &monomorphized_arg_types,
1838 has_tupled_arg, arg_scope);
1840 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1842 // Up until here, IR instructions for this function have explicitly not been annotated with
1843 // source code location, so we don't step into call setup code. From here on, source location
1844 // emitting should be enabled.
1845 debuginfo::start_emitting_source_locations(&fcx);
1847 let dest = match fcx.llretslotptr.get() {
1848 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1850 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1855 // This call to trans_block is the place where we bridge between
1856 // translation calls that don't have a return value (trans_crate,
1857 // trans_mod, trans_item, et cetera) and those that do
1858 // (trans_block, trans_expr, et cetera).
1859 bcx = controlflow::trans_block(bcx, body, dest);
1862 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1863 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1868 match fcx.llreturn.get() {
1870 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
1871 fcx.pop_custom_cleanup_scope(arg_scope);
1874 // Microoptimization writ large: avoid creating a separate
1875 // llreturn basic block
1876 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1880 // Put return block after all other blocks.
1881 // This somewhat improves single-stepping experience in debugger.
1883 let llreturn = fcx.llreturn.get();
1884 if let Some(llreturn) = llreturn {
1885 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1889 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id,
1890 fn_cleanup_debug_loc.span);
1892 // Insert the mandatory first few basic blocks before lltop.
1893 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
1896 /// Creates an LLVM function corresponding to a source language function.
1897 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1901 param_substs: &'tcx Substs<'tcx>,
1903 attrs: &[ast::Attribute]) {
1904 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1905 debug!("trans_fn(param_substs={:?})", param_substs);
1906 let _icx = push_ctxt("trans_fn");
1907 let fn_ty = ccx.tcx().node_id_to_type(id);
1908 let fn_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &fn_ty);
1909 let sig = fn_ty.fn_sig();
1910 let sig = ccx.tcx().erase_late_bound_regions(&sig);
1911 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
1912 let output_type = sig.output;
1913 let abi = fn_ty.fn_abi();
1914 trans_closure(ccx, decl, body, llfndecl, param_substs, id, attrs, output_type, abi,
1915 closure::ClosureEnv::NotClosure);
1918 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1919 ctor_id: ast::NodeId,
1921 param_substs: &'tcx Substs<'tcx>,
1922 llfndecl: ValueRef) {
1923 let _icx = push_ctxt("trans_enum_variant");
1925 trans_enum_variant_or_tuple_like_struct(
1933 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1936 args: callee::CallArgs,
1938 debug_loc: DebugLoc)
1939 -> Result<'blk, 'tcx> {
1941 let ccx = bcx.fcx.ccx;
1943 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
1944 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
1945 let result_ty = sig.output.unwrap();
1947 // Get location to store the result. If the user does not care about
1948 // the result, just make a stack slot
1949 let llresult = match dest {
1950 expr::SaveIn(d) => d,
1952 if !type_is_zero_size(ccx, result_ty) {
1953 let llresult = alloc_ty(bcx, result_ty, "constructor_result");
1954 call_lifetime_start(bcx, llresult);
1957 C_undef(type_of::type_of(ccx, result_ty).ptr_to())
1962 if !type_is_zero_size(ccx, result_ty) {
1964 callee::ArgExprs(exprs) => {
1965 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
1966 bcx = expr::trans_adt(bcx,
1971 expr::SaveIn(llresult),
1974 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
1977 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
1978 // contents, there could be side-effects we need from them.
1980 callee::ArgExprs(exprs) => {
1982 bcx = expr::trans_into(bcx, expr, expr::Ignore);
1989 // If the caller doesn't care about the result
1990 // drop the temporary we made
1991 let bcx = match dest {
1992 expr::SaveIn(_) => bcx,
1994 let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
1995 if !type_is_zero_size(ccx, result_ty) {
1996 call_lifetime_end(bcx, llresult);
2002 Result::new(bcx, llresult)
2005 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2006 ctor_id: ast::NodeId,
2007 param_substs: &'tcx Substs<'tcx>,
2008 llfndecl: ValueRef) {
2009 let _icx = push_ctxt("trans_tuple_struct");
2011 trans_enum_variant_or_tuple_like_struct(
2019 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2020 ctor_id: ast::NodeId,
2022 param_substs: &'tcx Substs<'tcx>,
2023 llfndecl: ValueRef) {
2024 let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
2025 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2027 let sig = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_sig());
2028 let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
2029 let arg_tys = sig.inputs;
2030 let result_ty = sig.output;
2032 let (arena, fcx): (TypedArena<_>, FunctionContext);
2033 arena = TypedArena::new();
2034 fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
2035 param_substs, None, &arena);
2036 let bcx = init_function(&fcx, false, result_ty);
2038 assert!(!fcx.needs_ret_allocas);
2040 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2041 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2042 let repr = adt::represent_type(ccx, result_ty.unwrap());
2043 let mut llarg_idx = fcx.arg_offset() as c_uint;
2044 for (i, arg_ty) in arg_tys.into_iter().enumerate() {
2045 let lldestptr = adt::trans_field_ptr(bcx,
2050 if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
2051 Store(bcx, get_param(fcx.llfn, llarg_idx), expr::get_dataptr(bcx, lldestptr));
2052 Store(bcx, get_param(fcx.llfn, llarg_idx + 1), expr::get_meta(bcx, lldestptr));
2055 let arg = get_param(fcx.llfn, llarg_idx);
2058 if arg_is_indirect(ccx, arg_ty) {
2059 memcpy_ty(bcx, lldestptr, arg, arg_ty);
2061 store_ty(bcx, arg, lldestptr, arg_ty);
2065 adt::trans_set_discr(bcx, &*repr, dest, disr);
2068 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
2071 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &hir::EnumDef, sp: Span, id: ast::NodeId) {
2072 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2074 let print_info = ccx.sess().print_enum_sizes();
2076 let levels = ccx.tcx().node_lint_levels.borrow();
2077 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2078 let lvlsrc = levels.get(&(id, lint_id));
2079 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2081 if is_allow && !print_info {
2082 // we're not interested in anything here
2086 let ty = ccx.tcx().node_id_to_type(id);
2087 let avar = adt::represent_type(ccx, ty);
2089 adt::General(_, ref variants, _) => {
2090 for var in variants {
2092 for field in var.fields.iter().skip(1) {
2093 // skip the discriminant
2094 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2099 _ => { /* its size is either constant or unimportant */ }
2102 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2103 |(l, s, li), (idx, &size)|
2106 } else if size > s {
2114 let llty = type_of::sizing_type_of(ccx, ty);
2116 let sess = &ccx.tcx().sess;
2117 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2119 adt::General(..) => {
2120 for (i, var) in enum_def.variants.iter().enumerate() {
2121 ccx.tcx().sess.span_note(var.span,
2122 &*format!("variant data: {} bytes", sizes[i]));
2129 // we only warn if the largest variant is at least thrice as large as
2130 // the second-largest.
2131 if !is_allow && largest > slargest * 3 && slargest > 0 {
2132 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2133 // pass for the latter already ran.
2134 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
2135 *lvlsrc.unwrap(), Some(sp),
2136 &format!("enum variant is more than three times larger \
2137 ({} bytes) than the next largest (ignoring padding)",
2140 ccx.sess().span_note(enum_def.variants[largest_index].span,
2141 "this variant is the largest");
2145 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2146 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2147 // applicable to variable declarations and may not really make sense for
2148 // Rust code in the first place but whitelist them anyway and trust that
2149 // the user knows what s/he's doing. Who knows, unanticipated use cases
2150 // may pop up in the future.
2152 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2153 // and don't have to be, LLVM treats them as no-ops.
2155 "appending" => Some(llvm::AppendingLinkage),
2156 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2157 "common" => Some(llvm::CommonLinkage),
2158 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2159 "external" => Some(llvm::ExternalLinkage),
2160 "internal" => Some(llvm::InternalLinkage),
2161 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2162 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2163 "private" => Some(llvm::PrivateLinkage),
2164 "weak" => Some(llvm::WeakAnyLinkage),
2165 "weak_odr" => Some(llvm::WeakODRLinkage),
2171 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2172 #[derive(Copy, Clone)]
2173 pub enum ValueOrigin {
2174 /// The LLVM `Value` is in this context because the corresponding item was
2175 /// assigned to the current compilation unit.
2176 OriginalTranslation,
2177 /// The `Value`'s corresponding item was assigned to some other compilation
2178 /// unit, but the `Value` was translated in this context anyway because the
2179 /// item is marked `#[inline]`.
2183 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2184 /// If the `llval` is the direct translation of a specific Rust item, `id`
2185 /// should be set to the `NodeId` of that item. (This mapping should be
2186 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2187 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2188 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2189 /// assigned to a different compilation unit.
2190 pub fn update_linkage(ccx: &CrateContext,
2192 id: Option<ast::NodeId>,
2193 llval_origin: ValueOrigin) {
2194 match llval_origin {
2196 // `llval` is a translation of an item defined in a separate
2197 // compilation unit. This only makes sense if there are at least
2198 // two compilation units.
2199 assert!(ccx.sess().opts.cg.codegen_units > 1);
2200 // `llval` is a copy of something defined elsewhere, so use
2201 // `AvailableExternallyLinkage` to avoid duplicating code in the
2203 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2206 OriginalTranslation => {},
2209 if let Some(id) = id {
2210 let item = ccx.tcx().map.get(id);
2211 if let hir_map::NodeItem(i) = item {
2212 if let Some(name) = attr::first_attr_value_str_by_name(&i.attrs, "linkage") {
2213 if let Some(linkage) = llvm_linkage_by_name(&name) {
2214 llvm::SetLinkage(llval, linkage);
2216 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2224 Some(id) if ccx.reachable().contains(&id) => {
2225 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2228 // `id` does not refer to an item in `ccx.reachable`.
2229 if ccx.sess().opts.cg.codegen_units > 1 {
2230 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2232 llvm::SetLinkage(llval, llvm::InternalLinkage);
2238 fn set_global_section(ccx: &CrateContext, llval: ValueRef, i: &hir::Item) {
2239 match attr::first_attr_value_str_by_name(&i.attrs,
2242 if contains_null(§) {
2243 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`",
2247 let buf = CString::new(sect.as_bytes()).unwrap();
2248 llvm::LLVMSetSection(llval, buf.as_ptr());
2255 pub fn trans_item(ccx: &CrateContext, item: &hir::Item) {
2256 let _icx = push_ctxt("trans_item");
2258 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2261 hir::ItemFn(ref decl, _, _, abi, ref generics, ref body) => {
2262 if !generics.is_type_parameterized() {
2263 let trans_everywhere = attr::requests_inline(&item.attrs);
2264 // Ignore `trans_everywhere` for cross-crate inlined items
2265 // (`from_external`). `trans_item` will be called once for each
2266 // compilation unit that references the item, so it will still get
2267 // translated everywhere it's needed.
2268 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2269 let llfn = get_item_val(ccx, item.id);
2270 let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
2272 foreign::trans_rust_fn_with_foreign_abi(ccx, &**decl, &**body, &item.attrs,
2273 llfn, empty_substs, item.id, None);
2275 trans_fn(ccx, &**decl, &**body, llfn, empty_substs, item.id, &item.attrs);
2277 set_global_section(ccx, llfn, item);
2278 update_linkage(ccx, llfn, Some(item.id),
2279 if is_origin { OriginalTranslation } else { InlinedCopy });
2281 if is_entry_fn(ccx.sess(), item.id) {
2282 create_entry_wrapper(ccx, item.span, llfn);
2283 // check for the #[rustc_error] annotation, which forces an
2284 // error in trans. This is used to write compile-fail tests
2285 // that actually test that compilation succeeds without
2286 // reporting an error.
2287 let item_def_id = ccx.tcx().map.local_def_id(item.id);
2288 if ccx.tcx().has_attr(item_def_id, "rustc_error") {
2289 ccx.tcx().sess.span_fatal(item.span, "compilation successful");
2295 hir::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2296 meth::trans_impl(ccx,
2302 hir::ItemMod(_) => {
2303 // modules have no equivalent at runtime, they just affect
2304 // the mangled names of things contained within
2306 hir::ItemEnum(ref enum_definition, ref gens) => {
2307 if gens.ty_params.is_empty() {
2308 // sizes only make sense for non-generic types
2310 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2313 hir::ItemConst(..) => {
2315 hir::ItemStatic(_, m, ref expr) => {
2316 let g = match consts::trans_static(ccx, m, expr, item.id, &item.attrs) {
2318 Err(err) => ccx.tcx().sess.span_fatal(expr.span, &err.description()),
2320 set_global_section(ccx, g, item);
2321 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2323 hir::ItemForeignMod(ref foreign_mod) => {
2324 foreign::trans_foreign_mod(ccx, foreign_mod);
2326 hir::ItemTrait(..) => {
2328 _ => {/* fall through */ }
2332 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2333 pub fn register_fn_llvmty(ccx: &CrateContext,
2336 node_id: ast::NodeId,
2338 llfty: Type) -> ValueRef {
2339 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2341 let llfn = declare::define_fn(ccx, &sym[..], cc, llfty,
2342 ty::FnConverging(ccx.tcx().mk_nil())).unwrap_or_else(||{
2343 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2345 finish_register_fn(ccx, sym, node_id);
2349 fn finish_register_fn(ccx: &CrateContext, sym: String, node_id: ast::NodeId) {
2350 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2353 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2356 node_id: ast::NodeId,
2357 node_type: Ty<'tcx>)
2359 if let ty::TyBareFn(_, ref f) = node_type.sty {
2360 if f.abi != Rust && f.abi != RustCall {
2361 ccx.sess().span_bug(sp, &format!("only the `{}` or `{}` calling conventions are valid \
2362 for this function; `{}` was specified",
2363 Rust.name(), RustCall.name(), f.abi.name()));
2366 ccx.sess().span_bug(sp, "expected bare rust function")
2369 let llfn = declare::define_rust_fn(ccx, &sym[..], node_type).unwrap_or_else(||{
2370 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2372 finish_register_fn(ccx, sym, node_id);
2376 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2377 match *sess.entry_fn.borrow() {
2378 Some((entry_id, _)) => node_id == entry_id,
2383 /// Create the `main` function which will initialise the rust runtime and call users’ main
2385 pub fn create_entry_wrapper(ccx: &CrateContext,
2387 main_llfn: ValueRef) {
2388 let et = ccx.sess().entry_type.get().unwrap();
2390 config::EntryMain => {
2391 create_entry_fn(ccx, sp, main_llfn, true);
2393 config::EntryStart => create_entry_fn(ccx, sp, main_llfn, false),
2394 config::EntryNone => {} // Do nothing.
2397 fn create_entry_fn(ccx: &CrateContext,
2399 rust_main: ValueRef,
2400 use_start_lang_item: bool) {
2401 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2404 let llfn = declare::define_cfn(ccx, "main", llfty,
2405 ccx.tcx().mk_nil()).unwrap_or_else(||{
2406 ccx.sess().span_err(sp, "entry symbol `main` defined multiple times");
2407 // FIXME: We should be smart and show a better diagnostic here.
2408 ccx.sess().help("did you use #[no_mangle] on `fn main`? Use #[start] instead");
2409 ccx.sess().abort_if_errors();
2414 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn,
2415 "top\0".as_ptr() as *const _)
2417 let bld = ccx.raw_builder();
2419 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2421 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2423 let (start_fn, args) = if use_start_lang_item {
2424 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2426 Err(s) => { ccx.sess().fatal(&s[..]); }
2429 if let Some(start_node_id) = ccx.tcx().map.as_local_node_id(start_def_id) {
2430 get_item_val(ccx, start_node_id)
2432 let start_fn_type = csearch::get_type(ccx.tcx(),
2434 trans_external_path(ccx, start_def_id, start_fn_type)
2438 let opaque_rust_main = llvm::LLVMBuildPointerCast(bld,
2439 rust_main, Type::i8p(ccx).to_ref(),
2440 "rust_main\0".as_ptr() as *const _);
2450 debug!("using user-defined start fn");
2452 get_param(llfn, 0 as c_uint),
2453 get_param(llfn, 1 as c_uint)
2459 let result = llvm::LLVMBuildCall(bld,
2462 args.len() as c_uint,
2465 llvm::LLVMBuildRet(bld, result);
2470 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, id: ast::NodeId,
2471 ty: Ty<'tcx>, attrs: &[ast::Attribute]) -> String {
2472 match ccx.external_srcs().borrow().get(&id) {
2474 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2475 debug!("found item {} in other crate...", sym);
2481 match attr::find_export_name_attr(ccx.sess().diagnostic(), attrs) {
2482 // Use provided name
2483 Some(name) => name.to_string(),
2485 let path = ccx.tcx().map.def_path_from_id(id);
2486 if attr::contains_name(attrs, "no_mangle") {
2488 path.last().unwrap().data.to_string()
2490 match weak_lang_items::link_name(attrs) {
2491 Some(name) => name.to_string(),
2493 // Usual name mangling
2494 mangle_exported_name(ccx, path, ty, id)
2502 fn contains_null(s: &str) -> bool {
2503 s.bytes().any(|b| b == 0)
2506 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2507 debug!("get_item_val(id=`{}`)", id);
2509 match ccx.item_vals().borrow().get(&id).cloned() {
2510 Some(v) => return v,
2514 let item = ccx.tcx().map.get(id);
2515 debug!("get_item_val: id={} item={:?}", id, item);
2516 let val = match item {
2517 hir_map::NodeItem(i) => {
2518 let ty = ccx.tcx().node_id_to_type(i.id);
2519 let sym = || exported_name(ccx, id, ty, &i.attrs);
2521 let v = match i.node {
2522 hir::ItemStatic(..) => {
2523 // If this static came from an external crate, then
2524 // we need to get the symbol from csearch instead of
2525 // using the current crate's name/version
2526 // information in the hash of the symbol
2528 debug!("making {}", sym);
2530 // Create the global before evaluating the initializer;
2531 // this is necessary to allow recursive statics.
2532 let llty = type_of(ccx, ty);
2533 let g = declare::define_global(ccx, &sym[..],
2534 llty).unwrap_or_else(|| {
2535 ccx.sess().span_fatal(i.span, &format!("symbol `{}` is already defined",
2539 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2543 hir::ItemFn(_, _, _, abi, _, _) => {
2545 let llfn = if abi == Rust {
2546 register_fn(ccx, i.span, sym, i.id, ty)
2548 foreign::register_rust_fn_with_foreign_abi(ccx, i.span, sym, i.id)
2550 attributes::from_fn_attrs(ccx, &i.attrs, llfn);
2554 _ => ccx.sess().bug("get_item_val: weird result in table")
2560 hir_map::NodeTraitItem(trait_item) => {
2561 debug!("get_item_val(): processing a NodeTraitItem");
2562 match trait_item.node {
2563 hir::MethodTraitItem(_, Some(_)) => {
2564 register_method(ccx, id, &trait_item.attrs, trait_item.span)
2567 ccx.sess().span_bug(trait_item.span,
2568 "unexpected variant: trait item other than a provided \
2569 method in get_item_val()");
2574 hir_map::NodeImplItem(impl_item) => {
2575 match impl_item.node {
2576 hir::ImplItemKind::Method(..) => {
2577 register_method(ccx, id, &impl_item.attrs, impl_item.span)
2580 ccx.sess().span_bug(impl_item.span,
2581 "unexpected variant: non-method impl item in \
2587 hir_map::NodeForeignItem(ni) => {
2589 hir::ForeignItemFn(..) => {
2590 let abi = ccx.tcx().map.get_foreign_abi(id);
2591 let ty = ccx.tcx().node_id_to_type(ni.id);
2592 let name = foreign::link_name(&*ni);
2593 foreign::register_foreign_item_fn(ccx, abi, ty, &name, &ni.attrs)
2595 hir::ForeignItemStatic(..) => {
2596 foreign::register_static(ccx, &*ni)
2601 hir_map::NodeVariant(ref v) => {
2603 let fields = if v.node.data.is_struct() {
2604 ccx.sess().bug("struct variant kind unexpected in get_item_val")
2606 v.node.data.fields()
2608 assert!(!fields.is_empty());
2609 let ty = ccx.tcx().node_id_to_type(id);
2610 let parent = ccx.tcx().map.get_parent(id);
2611 let enm = ccx.tcx().map.expect_item(parent);
2612 let sym = exported_name(ccx,
2617 llfn = match enm.node {
2618 hir::ItemEnum(_, _) => {
2619 register_fn(ccx, (*v).span, sym, id, ty)
2621 _ => ccx.sess().bug("NodeVariant, shouldn't happen")
2623 attributes::inline(llfn, attributes::InlineAttr::Hint);
2627 hir_map::NodeStructCtor(struct_def) => {
2628 // Only register the constructor if this is a tuple-like struct.
2629 let ctor_id = if struct_def.is_struct() {
2630 ccx.sess().bug("attempt to register a constructor of \
2631 a non-tuple-like struct")
2635 let parent = ccx.tcx().map.get_parent(id);
2636 let struct_item = ccx.tcx().map.expect_item(parent);
2637 let ty = ccx.tcx().node_id_to_type(ctor_id);
2638 let sym = exported_name(ccx,
2641 &struct_item.attrs);
2642 let llfn = register_fn(ccx, struct_item.span,
2644 attributes::inline(llfn, attributes::InlineAttr::Hint);
2649 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}",
2654 // All LLVM globals and functions are initially created as external-linkage
2655 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2656 // into a definition, it adjusts the linkage then (using `update_linkage`).
2658 // The exception is foreign items, which have their linkage set inside the
2659 // call to `foreign::register_*` above. We don't touch the linkage after
2660 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2661 // other item translation functions do).
2663 ccx.item_vals().borrow_mut().insert(id, val);
2667 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2668 attrs: &[ast::Attribute], span: Span) -> ValueRef {
2669 let mty = ccx.tcx().node_id_to_type(id);
2671 let sym = exported_name(ccx, id, mty, &attrs);
2673 if let ty::TyBareFn(_, ref f) = mty.sty {
2674 let llfn = if f.abi == Rust || f.abi == RustCall {
2675 register_fn(ccx, span, sym, id, mty)
2677 foreign::register_rust_fn_with_foreign_abi(ccx, span, sym, id)
2679 attributes::from_fn_attrs(ccx, &attrs, llfn);
2682 ccx.sess().span_bug(span, "expected bare rust function");
2686 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'a, 'tcx>,
2687 ie: encoder::EncodeInlinedItem<'a>,
2688 reachable: &'a NodeSet)
2689 -> encoder::EncodeParams<'a, 'tcx> {
2690 encoder::EncodeParams {
2691 diag: cx.sess().diagnostic(),
2693 reexports: cx.export_map(),
2694 item_symbols: cx.item_symbols(),
2695 link_meta: cx.link_meta(),
2696 cstore: &cx.sess().cstore,
2697 encode_inlined_item: ie,
2698 reachable: reachable,
2702 pub fn write_metadata(cx: &SharedCrateContext, krate: &hir::Crate,
2703 reachable: &NodeSet) -> Vec<u8> {
2706 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2707 *ty != config::CrateTypeExecutable
2713 let encode_inlined_item: encoder::EncodeInlinedItem =
2714 Box::new(|ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii));
2716 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item,
2718 let metadata = encoder::encode_metadata(encode_parms, krate);
2719 let mut compressed = encoder::metadata_encoding_version.to_vec();
2720 compressed.push_all(&flate::deflate_bytes(&metadata));
2721 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
2722 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2723 let name = format!("rust_metadata_{}_{}",
2724 cx.link_meta().crate_name,
2725 cx.link_meta().crate_hash);
2726 let buf = CString::new(name).unwrap();
2727 let llglobal = unsafe {
2728 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(),
2732 llvm::LLVMSetInitializer(llglobal, llconst);
2733 let name = loader::meta_section_name(&cx.sess().target.target);
2734 let name = CString::new(name).unwrap();
2735 llvm::LLVMSetSection(llglobal, name.as_ptr())
2740 /// Find any symbols that are defined in one compilation unit, but not declared
2741 /// in any other compilation unit. Give these symbols internal linkage.
2742 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<&str>) {
2744 let mut declared = HashSet::new();
2746 // Collect all external declarations in all compilation units.
2747 for ccx in cx.iter() {
2748 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2749 let linkage = llvm::LLVMGetLinkage(val);
2750 // We only care about external declarations (not definitions)
2751 // and available_externally definitions.
2752 if !(linkage == llvm::ExternalLinkage as c_uint &&
2753 llvm::LLVMIsDeclaration(val) != 0) &&
2754 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
2758 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2759 .to_bytes().to_vec();
2760 declared.insert(name);
2764 // Examine each external definition. If the definition is not used in
2765 // any other compilation unit, and is not reachable from other crates,
2766 // then give it internal linkage.
2767 for ccx in cx.iter() {
2768 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2769 // We only care about external definitions.
2770 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2771 llvm::LLVMIsDeclaration(val) == 0) {
2775 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2776 .to_bytes().to_vec();
2777 if !declared.contains(&name) &&
2778 !reachable.contains(str::from_utf8(&name).unwrap()) {
2779 llvm::SetLinkage(val, llvm::InternalLinkage);
2780 llvm::SetDLLStorageClass(val, llvm::DefaultStorageClass);
2787 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
2788 // This is required to satisfy `dllimport` references to static data in .rlibs
2789 // when using MSVC linker. We do this only for data, as linker can fix up
2790 // code references on its own.
2791 // See #26591, #27438
2792 fn create_imps(cx: &SharedCrateContext) {
2793 // The x86 ABI seems to require that leading underscores are added to symbol
2794 // names, so we need an extra underscore on 32-bit. There's also a leading
2795 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
2796 // underscores added in front).
2797 let prefix = if cx.sess().target.target.target_pointer_width == "32" {
2803 for ccx in cx.iter() {
2804 let exported: Vec<_> = iter_globals(ccx.llmod())
2805 .filter(|&val| llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2806 llvm::LLVMIsDeclaration(val) == 0)
2809 let i8p_ty = Type::i8p(&ccx);
2810 for val in exported {
2811 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
2812 let mut imp_name = prefix.as_bytes().to_vec();
2813 imp_name.extend(name.to_bytes());
2814 let imp_name = CString::new(imp_name).unwrap();
2815 let imp = llvm::LLVMAddGlobal(ccx.llmod(), i8p_ty.to_ref(),
2816 imp_name.as_ptr() as *const _);
2817 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
2818 llvm::LLVMSetInitializer(imp, init);
2819 llvm::SetLinkage(imp, llvm::ExternalLinkage);
2827 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
2830 impl Iterator for ValueIter {
2831 type Item = ValueRef;
2833 fn next(&mut self) -> Option<ValueRef> {
2836 self.cur = unsafe { (self.step)(old) };
2844 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
2847 cur: llvm::LLVMGetFirstGlobal(llmod),
2848 step: llvm::LLVMGetNextGlobal,
2853 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
2856 cur: llvm::LLVMGetFirstFunction(llmod),
2857 step: llvm::LLVMGetNextFunction,
2862 /// The context provided lists a set of reachable ids as calculated by
2863 /// middle::reachable, but this contains far more ids and symbols than we're
2864 /// actually exposing from the object file. This function will filter the set in
2865 /// the context to the set of ids which correspond to symbols that are exposed
2866 /// from the object file being generated.
2868 /// This list is later used by linkers to determine the set of symbols needed to
2869 /// be exposed from a dynamic library and it's also encoded into the metadata.
2870 pub fn filter_reachable_ids(ccx: &SharedCrateContext) -> NodeSet {
2871 ccx.reachable().iter().map(|x| *x).filter(|id| {
2872 // First, only worry about nodes which have a symbol name
2873 ccx.item_symbols().borrow().contains_key(id)
2875 // Next, we want to ignore some FFI functions that are not exposed from
2876 // this crate. Reachable FFI functions can be lumped into two
2879 // 1. Those that are included statically via a static library
2880 // 2. Those included otherwise (e.g. dynamically or via a framework)
2882 // Although our LLVM module is not literally emitting code for the
2883 // statically included symbols, it's an export of our library which
2884 // needs to be passed on to the linker and encoded in the metadata.
2886 // As a result, if this id is an FFI item (foreign item) then we only
2887 // let it through if it's included statically.
2888 match ccx.tcx().map.get(id) {
2889 hir_map::NodeForeignItem(..) => {
2890 ccx.sess().cstore.is_statically_included_foreign_item(id)
2897 pub fn trans_crate<'tcx>(tcx: &ty::ctxt<'tcx>,
2898 mir_map: &MirMap<'tcx>,
2899 analysis: ty::CrateAnalysis)
2900 -> CrateTranslation {
2901 let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
2902 let krate = tcx.map.krate();
2904 let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
2907 tcx.sess.opts.debug_assertions
2910 let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
2913 tcx.sess.opts.debug_assertions
2916 // Before we touch LLVM, make sure that multithreading is enabled.
2918 use std::sync::Once;
2919 static INIT: Once = Once::new();
2920 static mut POISONED: bool = false;
2922 if llvm::LLVMStartMultithreaded() != 1 {
2923 // use an extra bool to make sure that all future usage of LLVM
2924 // cannot proceed despite the Once not running more than once.
2928 ::back::write::configure_llvm(&tcx.sess);
2932 tcx.sess.bug("couldn't enable multi-threaded LLVM");
2936 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
2938 let codegen_units = tcx.sess.opts.cg.codegen_units;
2939 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name,
2951 let ccx = shared_ccx.get_ccx(0);
2953 // First, verify intrinsics.
2954 intrinsic::check_intrinsics(&ccx);
2956 // Next, translate all items. See `TransModVisitor` for
2957 // details on why we walk in this particular way.
2959 let _icx = push_ctxt("text");
2960 intravisit::walk_mod(&mut TransItemsWithinModVisitor { ccx: &ccx }, &krate.module);
2961 krate.visit_all_items(&mut TransModVisitor { ccx: &ccx });
2965 for ccx in shared_ccx.iter() {
2966 if ccx.sess().opts.debuginfo != NoDebugInfo {
2967 debuginfo::finalize(&ccx);
2969 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
2971 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
2972 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
2973 llvm::LLVMDeleteGlobal(old_g);
2978 let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
2980 // Translate the metadata.
2981 let metadata = write_metadata(&shared_ccx, krate, &reachable_symbol_ids);
2983 if shared_ccx.sess().trans_stats() {
2984 let stats = shared_ccx.stats();
2985 println!("--- trans stats ---");
2986 println!("n_glues_created: {}", stats.n_glues_created.get());
2987 println!("n_null_glues: {}", stats.n_null_glues.get());
2988 println!("n_real_glues: {}", stats.n_real_glues.get());
2990 println!("n_fns: {}", stats.n_fns.get());
2991 println!("n_monos: {}", stats.n_monos.get());
2992 println!("n_inlines: {}", stats.n_inlines.get());
2993 println!("n_closures: {}", stats.n_closures.get());
2994 println!("fn stats:");
2995 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
2996 insns_b.cmp(&insns_a)
2998 for tuple in stats.fn_stats.borrow().iter() {
3000 (ref name, insns) => {
3001 println!("{} insns, {}", insns, *name);
3006 if shared_ccx.sess().count_llvm_insns() {
3007 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3008 println!("{:7} {}", *v, *k);
3012 let modules = shared_ccx.iter()
3013 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3016 let sess = shared_ccx.sess();
3017 let mut reachable_symbols = reachable_symbol_ids.iter().map(|id| {
3018 shared_ccx.item_symbols().borrow()[id].to_string()
3019 }).collect::<Vec<_>>();
3020 if sess.entry_fn.borrow().is_some() {
3021 reachable_symbols.push("main".to_string());
3024 // For the purposes of LTO, we add to the reachable set all of the upstream
3025 // reachable extern fns. These functions are all part of the public ABI of
3026 // the final product, so LTO needs to preserve them.
3028 sess.cstore.iter_crate_data(|cnum, _| {
3029 let syms = csearch::get_reachable_ids(&sess.cstore, cnum);
3030 reachable_symbols.extend(syms.into_iter().filter(|did| {
3031 csearch::is_extern_fn(&sess.cstore, *did, shared_ccx.tcx()) ||
3032 csearch::is_static(&sess.cstore, *did)
3034 csearch::get_symbol(&sess.cstore, did)
3039 if codegen_units > 1 {
3040 internalize_symbols(&shared_ccx,
3041 &reachable_symbols.iter().map(|x| &x[..]).collect());
3044 if sess.target.target.options.is_like_msvc &&
3045 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
3046 create_imps(&shared_ccx);
3049 let metadata_module = ModuleTranslation {
3050 llcx: shared_ccx.metadata_llcx(),
3051 llmod: shared_ccx.metadata_llmod(),
3053 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
3057 metadata_module: metadata_module,
3060 reachable: reachable_symbols,
3061 no_builtins: no_builtins,
3065 /// We visit all the items in the krate and translate them. We do
3066 /// this in two walks. The first walk just finds module items. It then
3067 /// walks the full contents of those module items and translates all
3068 /// the items within. Note that this entire process is O(n). The
3069 /// reason for this two phased walk is that each module is
3070 /// (potentially) placed into a distinct codegen-unit. This walk also
3071 /// ensures that the immediate contents of each module is processed
3072 /// entirely before we proceed to find more modules, helping to ensure
3073 /// an equitable distribution amongst codegen-units.
3074 pub struct TransModVisitor<'a, 'tcx: 'a> {
3075 pub ccx: &'a CrateContext<'a, 'tcx>,
3078 impl<'a, 'tcx, 'v> Visitor<'v> for TransModVisitor<'a, 'tcx> {
3079 fn visit_item(&mut self, i: &hir::Item) {
3081 hir::ItemMod(_) => {
3082 let item_ccx = self.ccx.rotate();
3083 intravisit::walk_item(&mut TransItemsWithinModVisitor { ccx: &item_ccx }, i);
3090 /// Translates all the items within a given module. Expects owner to
3091 /// invoke `walk_item` on a module item. Ignores nested modules.
3092 pub struct TransItemsWithinModVisitor<'a, 'tcx: 'a> {
3093 pub ccx: &'a CrateContext<'a, 'tcx>,
3096 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemsWithinModVisitor<'a, 'tcx> {
3097 fn visit_nested_item(&mut self, item_id: hir::ItemId) {
3098 self.visit_item(self.ccx.tcx().map.expect_item(item_id.id));
3101 fn visit_item(&mut self, i: &hir::Item) {
3103 hir::ItemMod(..) => {
3104 // skip modules, they will be uncovered by the TransModVisitor
3107 trans_item(self.ccx, i);
3108 intravisit::walk_item(self, i);