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;
41 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
42 use middle::weak_lang_items;
43 use middle::pat_util::simple_name;
44 use middle::subst::Substs;
45 use middle::ty::{self, Ty, HasTypeFlags};
46 use rustc::front::map as hir_map;
47 use session::config::{self, NoDebugInfo, FullDebugInfo};
51 use trans::attributes;
53 use trans::builder::{Builder, noname};
55 use trans::cleanup::{self, CleanupMethods, DropHint};
57 use trans::common::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_integral};
58 use trans::common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
59 use trans::common::{CrateContext, DropFlagHintsMap, Field, FunctionContext};
60 use trans::common::{Result, NodeIdAndSpan, VariantInfo};
61 use trans::common::{node_id_type, return_type_is_void};
62 use trans::common::{type_is_immediate, type_is_zero_size, val_ty};
65 use trans::context::SharedCrateContext;
66 use trans::controlflow;
68 use trans::debuginfo::{self, DebugLoc, ToDebugLoc};
75 use trans::machine::{llsize_of, llsize_of_real};
77 use trans::monomorphize;
79 use trans::type_::Type;
81 use trans::type_of::*;
82 use trans::value::Value;
83 use util::common::indenter;
84 use util::sha2::Sha256;
85 use util::nodemap::{NodeMap, NodeSet};
87 use arena::TypedArena;
89 use std::ffi::{CStr, CString};
90 use std::cell::{Cell, RefCell};
91 use std::collections::{HashMap, HashSet};
94 use std::{i8, i16, i32, i64};
95 use syntax::abi::{Rust, RustCall, RustIntrinsic, PlatformIntrinsic, Abi};
96 use syntax::codemap::Span;
97 use syntax::parse::token::InternedString;
98 use syntax::attr::AttrMetaMethods;
101 use rustc_front::visit::Visitor;
102 use rustc_front::visit;
103 use rustc_front::hir;
107 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
112 pub fn with_insn_ctxt<F>(blk: F) where
113 F: FnOnce(&[&'static str]),
115 TASK_LOCAL_INSN_KEY.with(move |slot| {
116 slot.borrow().as_ref().map(move |s| blk(s));
120 pub fn init_insn_ctxt() {
121 TASK_LOCAL_INSN_KEY.with(|slot| {
122 *slot.borrow_mut() = Some(Vec::new());
126 pub struct _InsnCtxt {
127 _cannot_construct_outside_of_this_module: ()
130 impl Drop for _InsnCtxt {
132 TASK_LOCAL_INSN_KEY.with(|slot| {
133 match slot.borrow_mut().as_mut() {
134 Some(ctx) => { ctx.pop(); }
141 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
142 debug!("new InsnCtxt: {}", s);
143 TASK_LOCAL_INSN_KEY.with(|slot| {
144 match slot.borrow_mut().as_mut() {
145 Some(ctx) => ctx.push(s),
149 _InsnCtxt { _cannot_construct_outside_of_this_module: () }
152 pub struct StatRecorder<'a, 'tcx: 'a> {
153 ccx: &'a CrateContext<'a, 'tcx>,
154 name: Option<String>,
158 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
159 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
160 -> StatRecorder<'a, 'tcx> {
161 let istart = ccx.stats().n_llvm_insns.get();
170 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
172 if self.ccx.sess().trans_stats() {
173 let iend = self.ccx.stats().n_llvm_insns.get();
174 self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
175 iend - self.istart));
176 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
177 // Reset LLVM insn count to avoid compound costs.
178 self.ccx.stats().n_llvm_insns.set(self.istart);
183 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>,
184 name: &str, did: DefId) -> ValueRef {
185 match ccx.externs().borrow().get(name) {
186 Some(n) => return *n,
190 let f = declare::declare_rust_fn(ccx, name, fn_ty);
192 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
193 attributes::from_fn_attrs(ccx, &attrs[..], f);
195 ccx.externs().borrow_mut().insert(name.to_string(), f);
199 pub fn self_type_for_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
204 let closure_kind = ccx.tcx().closure_kind(closure_id);
206 ty::FnClosureKind => {
207 ccx.tcx().mk_imm_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
209 ty::FnMutClosureKind => {
210 ccx.tcx().mk_mut_ref(ccx.tcx().mk_region(ty::ReStatic), fn_ty)
212 ty::FnOnceClosureKind => fn_ty
216 pub fn kind_for_closure(ccx: &CrateContext, closure_id: DefId) -> ty::ClosureKind {
217 *ccx.tcx().tables.borrow().closure_kinds.get(&closure_id).unwrap()
220 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: DefId,
221 t: Ty<'tcx>) -> ValueRef {
222 let name = csearch::get_symbol(&ccx.sess().cstore, did);
223 let ty = type_of(ccx, t);
224 match ccx.externs().borrow_mut().get(&name) {
225 Some(n) => return *n,
228 // FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
229 // FIXME(nagisa): investigate whether it can be changed into define_global
230 let c = declare::declare_global(ccx, &name[..], ty);
231 // Thread-local statics in some other crate need to *always* be linked
232 // against in a thread-local fashion, so we need to be sure to apply the
233 // thread-local attribute locally if it was present remotely. If we
234 // don't do this then linker errors can be generated where the linker
235 // complains that one object files has a thread local version of the
236 // symbol and another one doesn't.
237 for attr in ccx.tcx().get_attrs(did).iter() {
238 if attr.check_name("thread_local") {
239 llvm::set_thread_local(c, true);
242 if ccx.use_dll_storage_attrs() {
243 llvm::SetDLLStorageClass(c, llvm::DLLImportStorageClass);
245 ccx.externs().borrow_mut().insert(name.to_string(), c);
249 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
250 info_ty: Ty<'tcx>, it: LangItem) -> DefId {
251 match bcx.tcx().lang_items.require(it) {
254 bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
259 // The following malloc_raw_dyn* functions allocate a box to contain
260 // a given type, but with a potentially dynamic size.
262 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
268 -> Result<'blk, 'tcx> {
269 let _icx = push_ctxt("malloc_raw_exchange");
272 let r = callee::trans_lang_call(bcx,
273 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
278 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
282 pub fn bin_op_to_icmp_predicate(ccx: &CrateContext, op: hir::BinOp_, signed: bool)
283 -> llvm::IntPredicate {
285 hir::BiEq => llvm::IntEQ,
286 hir::BiNe => llvm::IntNE,
287 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
288 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
289 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
290 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
292 ccx.sess().bug(&format!("comparison_op_to_icmp_predicate: expected \
293 comparison operator, found {:?}", op));
298 pub fn bin_op_to_fcmp_predicate(ccx: &CrateContext, op: hir::BinOp_)
299 -> llvm::RealPredicate {
301 hir::BiEq => llvm::RealOEQ,
302 hir::BiNe => llvm::RealUNE,
303 hir::BiLt => llvm::RealOLT,
304 hir::BiLe => llvm::RealOLE,
305 hir::BiGt => llvm::RealOGT,
306 hir::BiGe => llvm::RealOGE,
308 ccx.sess().bug(&format!("comparison_op_to_fcmp_predicate: expected \
309 comparison operator, found {:?}", op));
314 pub fn compare_scalar_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
322 ty::TyTuple(ref tys) if tys.is_empty() => {
323 // We don't need to do actual comparisons for nil.
324 // () == () holds but () < () does not.
326 hir::BiEq | hir::BiLe | hir::BiGe => return C_bool(bcx.ccx(), true),
327 hir::BiNe | hir::BiLt | hir::BiGt => return C_bool(bcx.ccx(), false),
328 // refinements would be nice
329 _ => bcx.sess().bug("compare_scalar_types: must be a comparison operator")
332 ty::TyBareFn(..) | ty::TyBool | ty::TyUint(_) | ty::TyChar => {
333 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
335 ty::TyRawPtr(mt) if common::type_is_sized(bcx.tcx(), mt.ty) => {
336 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, false), lhs, rhs, debug_loc)
339 ICmp(bcx, bin_op_to_icmp_predicate(bcx.ccx(), op, true), lhs, rhs, debug_loc)
342 FCmp(bcx, bin_op_to_fcmp_predicate(bcx.ccx(), op), lhs, rhs, debug_loc)
344 // Should never get here, because t is scalar.
345 _ => bcx.sess().bug("non-scalar type passed to compare_scalar_types")
349 pub fn compare_simd_types<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
357 let signed = match t.sty {
359 let cmp = bin_op_to_fcmp_predicate(bcx.ccx(), op);
360 return SExt(bcx, FCmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty);
362 ty::TyUint(_) => false,
363 ty::TyInt(_) => true,
364 _ => bcx.sess().bug("compare_simd_types: invalid SIMD type"),
367 let cmp = bin_op_to_icmp_predicate(bcx.ccx(), op, signed);
368 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
369 // to get the correctly sized type. This will compile to a single instruction
370 // once the IR is converted to assembly if the SIMD instruction is supported
371 // by the target architecture.
372 SExt(bcx, ICmp(bcx, cmp, lhs, rhs, debug_loc), ret_ty)
375 // Iterates through the elements of a structural type.
376 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
380 -> Block<'blk, 'tcx> where
381 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
383 let _icx = push_ctxt("iter_structural_ty");
385 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
386 repr: &adt::Repr<'tcx>,
388 variant: ty::VariantDef<'tcx>,
389 substs: &Substs<'tcx>,
391 -> Block<'blk, 'tcx> where
392 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
394 let _icx = push_ctxt("iter_variant");
398 for (i, field) in variant.fields.iter().enumerate() {
399 let arg = monomorphize::field_ty(tcx, substs, field);
400 cx = f(cx, adt::trans_field_ptr(cx, repr, av, variant.disr_val, i), arg);
405 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
408 let data = expr::get_dataptr(cx, av);
409 let info = expr::get_meta(cx, av);
410 (Load(cx, data), Some(Load(cx, info)))
415 ty::TyStruct(..) => {
416 let repr = adt::represent_type(cx.ccx(), t);
417 let VariantInfo { fields, discr } = VariantInfo::from_ty(cx.tcx(), t, None);
418 for (i, &Field(_, field_ty)) in fields.iter().enumerate() {
419 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
421 let val = if common::type_is_sized(cx.tcx(), field_ty) {
424 let scratch = datum::rvalue_scratch_datum(cx, field_ty, "__fat_ptr_iter");
425 Store(cx, llfld_a, expr::get_dataptr(cx, scratch.val));
426 Store(cx, info.unwrap(), expr::get_meta(cx, scratch.val));
429 cx = f(cx, val, field_ty);
432 ty::TyClosure(_, ref substs) => {
433 let repr = adt::represent_type(cx.ccx(), t);
434 for (i, upvar_ty) in substs.upvar_tys.iter().enumerate() {
435 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
436 cx = f(cx, llupvar, upvar_ty);
439 ty::TyArray(_, n) => {
440 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
441 let unit_ty = t.sequence_element_type(cx.tcx());
442 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
444 ty::TySlice(_) | ty::TyStr => {
445 let unit_ty = t.sequence_element_type(cx.tcx());
446 cx = tvec::iter_vec_raw(cx, data_ptr, unit_ty, info.unwrap(), f);
448 ty::TyTuple(ref args) => {
449 let repr = adt::represent_type(cx.ccx(), t);
450 for (i, arg) in args.iter().enumerate() {
451 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
452 cx = f(cx, llfld_a, *arg);
455 ty::TyEnum(en, substs) => {
459 let repr = adt::represent_type(ccx, t);
460 let n_variants = en.variants.len();
462 // NB: we must hit the discriminant first so that structural
463 // comparison know not to proceed when the discriminants differ.
465 match adt::trans_switch(cx, &*repr, av) {
466 (_match::Single, None) => {
468 assert!(n_variants == 1);
469 cx = iter_variant(cx, &*repr, av, &en.variants[0],
473 (_match::Switch, Some(lldiscrim_a)) => {
474 cx = f(cx, lldiscrim_a, cx.tcx().types.isize);
476 // Create a fall-through basic block for the "else" case of
477 // the switch instruction we're about to generate. Note that
478 // we do **not** use an Unreachable instruction here, even
479 // though most of the time this basic block will never be hit.
481 // When an enum is dropped it's contents are currently
482 // overwritten to DTOR_DONE, which means the discriminant
483 // could have changed value to something not within the actual
484 // range of the discriminant. Currently this function is only
485 // used for drop glue so in this case we just return quickly
486 // from the outer function, and any other use case will only
487 // call this for an already-valid enum in which case the `ret
488 // void` will never be hit.
489 let ret_void_cx = fcx.new_temp_block("enum-iter-ret-void");
490 RetVoid(ret_void_cx, DebugLoc::None);
491 let llswitch = Switch(cx, lldiscrim_a, ret_void_cx.llbb,
493 let next_cx = fcx.new_temp_block("enum-iter-next");
495 for variant in &en.variants {
498 &format!("enum-iter-variant-{}",
499 &variant.disr_val.to_string())
501 match adt::trans_case(cx, &*repr, variant.disr_val) {
502 _match::SingleResult(r) => {
503 AddCase(llswitch, r.val, variant_cx.llbb)
505 _ => ccx.sess().unimpl("value from adt::trans_case \
506 in iter_structural_ty")
509 iter_variant(variant_cx,
515 Br(variant_cx, next_cx.llbb, DebugLoc::None);
519 _ => ccx.sess().unimpl("value from adt::trans_switch \
520 in iter_structural_ty")
524 cx.sess().unimpl(&format!("type in iter_structural_ty: {}", t))
530 pub fn cast_shift_expr_rhs(cx: Block,
535 cast_shift_rhs(op, lhs, rhs,
536 |a,b| Trunc(cx, a, b),
537 |a,b| ZExt(cx, a, b))
540 pub fn cast_shift_const_rhs(op: hir::BinOp_,
541 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
542 cast_shift_rhs(op, lhs, rhs,
543 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
544 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
547 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
553 F: FnOnce(ValueRef, Type) -> ValueRef,
554 G: FnOnce(ValueRef, Type) -> ValueRef,
556 // Shifts may have any size int on the rhs
557 if rustc_front::util::is_shift_binop(op) {
558 let mut rhs_llty = val_ty(rhs);
559 let mut lhs_llty = val_ty(lhs);
560 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
561 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
562 let rhs_sz = rhs_llty.int_width();
563 let lhs_sz = lhs_llty.int_width();
566 } else if lhs_sz > rhs_sz {
567 // FIXME (#1877: If shifting by negative
568 // values becomes not undefined then this is wrong.
578 pub fn llty_and_min_for_signed_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
579 val_t: Ty<'tcx>) -> (Type, u64) {
582 let llty = Type::int_from_ty(cx.ccx(), t);
584 ast::TyIs if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
585 ast::TyIs => i64::MIN as u64,
586 ast::TyI8 => i8::MIN as u64,
587 ast::TyI16 => i16::MIN as u64,
588 ast::TyI32 => i32::MIN as u64,
589 ast::TyI64 => i64::MIN as u64,
597 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
598 cx: Block<'blk, 'tcx>,
599 call_info: NodeIdAndSpan,
604 -> Block<'blk, 'tcx> {
605 let (zero_text, overflow_text) = if divrem.node == hir::BiDiv {
606 ("attempted to divide by zero",
607 "attempted to divide with overflow")
609 ("attempted remainder with a divisor of zero",
610 "attempted remainder with overflow")
612 let debug_loc = call_info.debug_loc();
614 let (is_zero, is_signed) = match rhs_t.sty {
616 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0, false);
617 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), true)
620 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0, false);
621 (ICmp(cx, llvm::IntEQ, rhs, zero, debug_loc), false)
623 ty::TyStruct(def, _) if def.is_simd() => {
624 let mut res = C_bool(cx.ccx(), false);
625 for i in 0 .. rhs_t.simd_size(cx.tcx()) {
628 ExtractElement(cx, rhs, C_int(cx.ccx(), i as i64))), debug_loc);
633 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}", rhs_t));
636 let bcx = with_cond(cx, is_zero, |bcx| {
637 controlflow::trans_fail(bcx, call_info, InternedString::new(zero_text))
640 // To quote LLVM's documentation for the sdiv instruction:
642 // Division by zero leads to undefined behavior. Overflow also leads
643 // to undefined behavior; this is a rare case, but can occur, for
644 // example, by doing a 32-bit division of -2147483648 by -1.
646 // In order to avoid undefined behavior, we perform runtime checks for
647 // signed division/remainder which would trigger overflow. For unsigned
648 // integers, no action beyond checking for zero need be taken.
650 let (llty, min) = llty_and_min_for_signed_ty(cx, rhs_t);
651 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
652 C_integral(llty, !0, false), debug_loc);
653 with_cond(bcx, minus_one, |bcx| {
654 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
655 C_integral(llty, min, true), debug_loc);
656 with_cond(bcx, is_min, |bcx| {
657 controlflow::trans_fail(bcx,
659 InternedString::new(overflow_text))
667 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
668 did: DefId, t: Ty<'tcx>) -> ValueRef {
669 let name = csearch::get_symbol(&ccx.sess().cstore, did);
671 ty::TyBareFn(_, ref fn_ty) => {
672 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
674 get_extern_rust_fn(ccx, t, &name[..], did)
676 RustIntrinsic | PlatformIntrinsic => {
677 ccx.sess().bug("unexpected intrinsic in trans_external_path")
680 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
681 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t, &name, &attrs)
686 get_extern_const(ccx, did, t)
691 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
696 -> (ValueRef, Block<'blk, 'tcx>) {
697 let _icx = push_ctxt("invoke_");
698 if bcx.unreachable.get() {
699 return (C_null(Type::i8(bcx.ccx())), bcx);
702 let attributes = attributes::from_fn_type(bcx.ccx(), fn_ty);
704 match bcx.opt_node_id {
706 debug!("invoke at ???");
709 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
713 if need_invoke(bcx) {
714 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
715 for &llarg in llargs {
716 debug!("arg: {}", bcx.val_to_string(llarg));
718 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
719 let landing_pad = bcx.fcx.get_landing_pad();
721 let llresult = Invoke(bcx,
728 return (llresult, normal_bcx);
730 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
731 for &llarg in llargs {
732 debug!("arg: {}", bcx.val_to_string(llarg));
735 let llresult = Call(bcx,
740 return (llresult, bcx);
744 /// Returns whether this session's target will use SEH-based unwinding.
746 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
747 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
748 /// 64-bit MinGW) instead of "full SEH".
749 pub fn wants_msvc_seh(sess: &Session) -> bool {
750 sess.target.target.options.is_like_msvc && sess.target.target.arch == "x86"
753 pub fn need_invoke(bcx: Block) -> bool {
754 // FIXME(#25869) currently SEH-based unwinding is pretty buggy in LLVM and
755 // is being overhauled as this is being written. Until that
756 // time such that upstream LLVM's implementation is more solid
757 // and we start binding it we need to skip invokes for any
758 // target which wants SEH-based unwinding.
759 if bcx.sess().no_landing_pads() || wants_msvc_seh(bcx.sess()) {
763 // Avoid using invoke if we are already inside a landing pad.
768 bcx.fcx.needs_invoke()
771 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
772 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
773 let _icx = push_ctxt("load_if_immediate");
774 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
778 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
779 /// differs from the type used for SSA values. Also handles various special cases where the type
780 /// gives us better information about what we are loading.
781 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
782 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
783 if cx.unreachable.get() || type_is_zero_size(cx.ccx(), t) {
784 return C_undef(type_of::type_of(cx.ccx(), t));
787 let ptr = to_arg_ty_ptr(cx, ptr, t);
788 let align = type_of::align_of(cx.ccx(), t);
790 if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
791 let load = Load(cx, ptr);
793 llvm::LLVMSetAlignment(load, align);
799 let global = llvm::LLVMIsAGlobalVariable(ptr);
800 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
801 let val = llvm::LLVMGetInitializer(global);
803 return to_arg_ty(cx, val, t);
808 let val = if t.is_bool() {
809 LoadRangeAssert(cx, ptr, 0, 2, llvm::False)
810 } else if t.is_char() {
811 // a char is a Unicode codepoint, and so takes values from 0
812 // to 0x10FFFF inclusive only.
813 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
814 } else if (t.is_region_ptr() || t.is_unique())
815 && !common::type_is_fat_ptr(cx.tcx(), t) {
822 llvm::LLVMSetAlignment(val, align);
825 to_arg_ty(cx, val, t)
828 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
829 /// differs from the type used for SSA values.
830 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
831 if cx.unreachable.get() {
835 if common::type_is_fat_ptr(cx.tcx(), t) {
836 Store(cx, ExtractValue(cx, v, abi::FAT_PTR_ADDR), expr::get_dataptr(cx, dst));
837 Store(cx, ExtractValue(cx, v, abi::FAT_PTR_EXTRA), expr::get_meta(cx, dst));
839 let store = Store(cx, from_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
841 llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
846 pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
848 ZExt(bcx, val, Type::i8(bcx.ccx()))
854 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
856 Trunc(bcx, val, Type::i1(bcx.ccx()))
862 pub fn to_arg_ty_ptr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ptr: ValueRef, ty: Ty<'tcx>) -> ValueRef {
863 if type_is_immediate(bcx.ccx(), ty) && type_of::type_of(bcx.ccx(), ty).is_aggregate() {
864 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
865 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
866 // and we have to convert it
867 BitCast(bcx, ptr, type_of::arg_type_of(bcx.ccx(), ty).ptr_to())
873 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &hir::Local)
874 -> Block<'blk, 'tcx> {
875 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
876 let _indenter = indenter();
877 let _icx = push_ctxt("init_local");
878 _match::store_local(bcx, local)
881 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
884 -> Block<'blk, 'tcx> {
885 common::BlockS::new(llbb, is_lpad, None, fcx)
888 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
891 -> Block<'blk, 'tcx> where
892 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
894 let _icx = push_ctxt("with_cond");
896 if bcx.unreachable.get() || common::const_to_opt_uint(val) == Some(0) {
901 let next_cx = fcx.new_temp_block("next");
902 let cond_cx = fcx.new_temp_block("cond");
903 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
904 let after_cx = f(cond_cx);
905 if !after_cx.terminated.get() {
906 Br(after_cx, next_cx.llbb, DebugLoc::None);
911 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
912 if cx.sess().opts.optimize == config::No {
916 let _icx = push_ctxt("lifetime_start");
919 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
924 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
925 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
926 Call(cx, lifetime_start, &[C_u64(ccx, size), ptr], None, DebugLoc::None);
929 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
930 if cx.sess().opts.optimize == config::No {
934 let _icx = push_ctxt("lifetime_end");
937 let size = machine::llsize_of_alloc(ccx, val_ty(ptr).element_type());
942 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
943 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
944 Call(cx, lifetime_end, &[C_u64(ccx, size), ptr], None, DebugLoc::None);
947 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
948 let _icx = push_ctxt("call_memcpy");
950 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
951 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
952 let memcpy = ccx.get_intrinsic(&key);
953 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
954 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
955 let size = IntCast(cx, n_bytes, ccx.int_type());
956 let align = C_i32(ccx, align as i32);
957 let volatile = C_bool(ccx, false);
958 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None, DebugLoc::None);
961 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
962 dst: ValueRef, src: ValueRef,
964 let _icx = push_ctxt("memcpy_ty");
967 if type_is_zero_size(ccx, t) {
971 if t.is_structural() {
972 let llty = type_of::type_of(ccx, t);
973 let llsz = llsize_of(ccx, llty);
974 let llalign = type_of::align_of(ccx, t);
975 call_memcpy(bcx, dst, src, llsz, llalign as u32);
977 store_ty(bcx, load_ty(bcx, src, t), dst, t);
981 pub fn drop_done_fill_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
982 if cx.unreachable.get() { return; }
983 let _icx = push_ctxt("drop_done_fill_mem");
985 memfill(&B(bcx), llptr, t, adt::DTOR_DONE);
988 pub fn init_zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
989 if cx.unreachable.get() { return; }
990 let _icx = push_ctxt("init_zero_mem");
992 memfill(&B(bcx), llptr, t, 0);
995 // Always use this function instead of storing a constant byte to the memory
996 // in question. e.g. if you store a zero constant, LLVM will drown in vreg
997 // allocation for large data structures, and the generated code will be
998 // awful. (A telltale sign of this is large quantities of
999 // `mov [byte ptr foo],0` in the generated code.)
1000 fn memfill<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>, byte: u8) {
1001 let _icx = push_ctxt("memfill");
1004 let llty = type_of::type_of(ccx, ty);
1005 let ptr_width = &ccx.sess().target.target.target_pointer_width[..];
1006 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
1008 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1009 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1010 let llzeroval = C_u8(ccx, byte);
1011 let size = machine::llsize_of(ccx, llty);
1012 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1013 let volatile = C_bool(ccx, false);
1014 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1017 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1018 let _icx = push_ctxt("alloc_ty");
1019 let ccx = bcx.ccx();
1020 let ty = type_of::type_of(ccx, t);
1021 assert!(!t.has_param_types());
1022 alloca(bcx, ty, name)
1025 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1026 let _icx = push_ctxt("alloca");
1027 if cx.unreachable.get() {
1029 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1032 debuginfo::clear_source_location(cx.fcx);
1033 Alloca(cx, ty, name)
1036 pub fn set_value_name(val: ValueRef, name: &str) {
1038 let name = CString::new(name).unwrap();
1039 llvm::LLVMSetValueName(val, name.as_ptr());
1043 // Creates the alloca slot which holds the pointer to the slot for the final return value
1044 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1045 output_type: Ty<'tcx>) -> ValueRef {
1046 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1048 // We create an alloca to hold a pointer of type `output_type`
1049 // which will hold the pointer to the right alloca which has the
1051 if fcx.needs_ret_allocas {
1052 // Let's create the stack slot
1053 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1055 // and if we're using an out pointer, then store that in our newly made slot
1056 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1057 let outptr = get_param(fcx.llfn, 0);
1059 let b = fcx.ccx.builder();
1060 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1061 b.store(outptr, slot);
1066 // But if there are no nested returns, we skip the indirection and have a single
1069 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1070 get_param(fcx.llfn, 0)
1072 AllocaFcx(fcx, lloutputtype, "sret_slot")
1077 struct FindNestedReturn {
1081 impl FindNestedReturn {
1082 fn new() -> FindNestedReturn {
1083 FindNestedReturn { found: false }
1087 impl<'v> Visitor<'v> for FindNestedReturn {
1088 fn visit_expr(&mut self, e: &hir::Expr) {
1090 hir::ExprRet(..) => {
1093 _ => visit::walk_expr(self, e)
1098 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1099 let blk = match tcx.map.find(id) {
1100 Some(hir_map::NodeItem(i)) => {
1102 hir::ItemFn(_, _, _, _, _, ref blk) => {
1105 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1108 Some(hir_map::NodeTraitItem(trait_item)) => {
1109 match trait_item.node {
1110 hir::MethodTraitItem(_, Some(ref body)) => body,
1112 tcx.sess.bug("unexpected variant: trait item other than a \
1113 provided method in has_nested_returns")
1117 Some(hir_map::NodeImplItem(impl_item)) => {
1118 match impl_item.node {
1119 hir::MethodImplItem(_, ref body) => body,
1121 tcx.sess.bug("unexpected variant: non-method impl item in \
1122 has_nested_returns")
1126 Some(hir_map::NodeExpr(e)) => {
1128 hir::ExprClosure(_, _, ref blk) => blk,
1129 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1132 Some(hir_map::NodeVariant(..)) |
1133 Some(hir_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1136 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1138 _ => tcx.sess.bug(&format!("unexpected variant in has_nested_returns: {}",
1139 tcx.map.path_to_string(id)))
1142 (blk.id, Some(cfg::CFG::new(tcx, blk)))
1145 // Checks for the presence of "nested returns" in a function.
1146 // Nested returns are when the inner expression of a return expression
1147 // (the 'expr' in 'return expr') contains a return expression. Only cases
1148 // where the outer return is actually reachable are considered. Implicit
1149 // returns from the end of blocks are considered as well.
1151 // This check is needed to handle the case where the inner expression is
1152 // part of a larger expression that may have already partially-filled the
1153 // return slot alloca. This can cause errors related to clean-up due to
1154 // the clobbering of the existing value in the return slot.
1155 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1156 for index in cfg.graph.depth_traverse(cfg.entry) {
1157 let n = cfg.graph.node_data(index);
1158 match tcx.map.find(n.id()) {
1159 Some(hir_map::NodeExpr(ex)) => {
1160 if let hir::ExprRet(Some(ref ret_expr)) = ex.node {
1161 let mut visitor = FindNestedReturn::new();
1162 visit::walk_expr(&mut visitor, &**ret_expr);
1168 Some(hir_map::NodeBlock(blk)) if blk.id == blk_id => {
1169 let mut visitor = FindNestedReturn::new();
1170 walk_list!(&mut visitor, visit_expr, &blk.expr);
1182 // NB: must keep 4 fns in sync:
1185 // - create_datums_for_fn_args.
1189 // Be warned! You must call `init_function` before doing anything with the
1190 // returned function context.
1191 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1195 output_type: ty::FnOutput<'tcx>,
1196 param_substs: &'tcx Substs<'tcx>,
1198 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1199 -> FunctionContext<'a, 'tcx> {
1200 common::validate_substs(param_substs);
1202 debug!("new_fn_ctxt(path={}, id={}, param_substs={:?})",
1206 ccx.tcx().map.path_to_string(id).to_string()
1210 let uses_outptr = match output_type {
1211 ty::FnConverging(output_type) => {
1212 let substd_output_type =
1213 monomorphize::apply_param_substs(ccx.tcx(), param_substs, &output_type);
1214 type_of::return_uses_outptr(ccx, substd_output_type)
1216 ty::FnDiverging => false
1218 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1219 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1220 let nested_returns = if let Some(ref cfg) = cfg {
1221 has_nested_returns(ccx.tcx(), cfg, blk_id)
1226 let mut fcx = FunctionContext {
1229 llretslotptr: Cell::new(None),
1230 param_env: ccx.tcx().empty_parameter_environment(),
1231 alloca_insert_pt: Cell::new(None),
1232 llreturn: Cell::new(None),
1233 needs_ret_allocas: nested_returns,
1234 personality: Cell::new(None),
1235 caller_expects_out_pointer: uses_outptr,
1236 lllocals: RefCell::new(NodeMap()),
1237 llupvars: RefCell::new(NodeMap()),
1238 lldropflag_hints: RefCell::new(DropFlagHintsMap::new()),
1240 param_substs: param_substs,
1242 block_arena: block_arena,
1244 debug_context: debug_context,
1245 scopes: RefCell::new(Vec::new()),
1250 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1256 /// Performs setup on a newly created function, creating the entry scope block
1257 /// and allocating space for the return pointer.
1258 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1260 output: ty::FnOutput<'tcx>)
1261 -> Block<'a, 'tcx> {
1262 let entry_bcx = fcx.new_temp_block("entry-block");
1264 // Use a dummy instruction as the insertion point for all allocas.
1265 // This is later removed in FunctionContext::cleanup.
1266 fcx.alloca_insert_pt.set(Some(unsafe {
1267 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1268 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1271 if let ty::FnConverging(output_type) = output {
1272 // This shouldn't need to recompute the return type,
1273 // as new_fn_ctxt did it already.
1274 let substd_output_type = fcx.monomorphize(&output_type);
1275 if !return_type_is_void(fcx.ccx, substd_output_type) {
1276 // If the function returns nil/bot, there is no real return
1277 // value, so do not set `llretslotptr`.
1278 if !skip_retptr || fcx.caller_expects_out_pointer {
1279 // Otherwise, we normally allocate the llretslotptr, unless we
1280 // have been instructed to skip it for immediate return
1282 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1287 // Create the drop-flag hints for every unfragmented path in the function.
1288 let tcx = fcx.ccx.tcx();
1289 let fn_did = tcx.map.local_def_id(fcx.id);
1290 let mut hints = fcx.lldropflag_hints.borrow_mut();
1291 let fragment_infos = tcx.fragment_infos.borrow();
1293 // Intern table for drop-flag hint datums.
1294 let mut seen = HashMap::new();
1296 if let Some(fragment_infos) = fragment_infos.get(&fn_did) {
1297 for &info in fragment_infos {
1299 let make_datum = |id| {
1300 let init_val = C_u8(fcx.ccx, adt::DTOR_NEEDED_HINT);
1301 let llname = &format!("dropflag_hint_{}", id);
1302 debug!("adding hint {}", llname);
1303 let ty = tcx.types.u8;
1304 let ptr = alloc_ty(entry_bcx, ty, llname);
1305 Store(entry_bcx, init_val, ptr);
1306 let flag = datum::Lvalue::new_dropflag_hint("base::init_function");
1307 datum::Datum::new(ptr, ty, flag)
1310 let (var, datum) = match info {
1311 ty::FragmentInfo::Moved { var, .. } |
1312 ty::FragmentInfo::Assigned { var, .. } => {
1313 let datum = seen.get(&var).cloned().unwrap_or_else(|| {
1314 let datum = make_datum(var);
1315 seen.insert(var, datum.clone());
1322 ty::FragmentInfo::Moved { move_expr: expr_id, .. } => {
1323 debug!("FragmentInfo::Moved insert drop hint for {}", expr_id);
1324 hints.insert(expr_id, DropHint::new(var, datum));
1326 ty::FragmentInfo::Assigned { assignee_id: expr_id, .. } => {
1327 debug!("FragmentInfo::Assigned insert drop hint for {}", expr_id);
1328 hints.insert(expr_id, DropHint::new(var, datum));
1337 // NB: must keep 4 fns in sync:
1340 // - create_datums_for_fn_args.
1344 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1346 use trans::datum::{ByRef, ByValue};
1349 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1353 // create_datums_for_fn_args: creates lvalue datums for each of the
1354 // incoming function arguments.
1355 pub fn create_datums_for_fn_args<'a, 'tcx>(mut bcx: Block<'a, 'tcx>,
1357 arg_tys: &[Ty<'tcx>],
1358 has_tupled_arg: bool,
1359 arg_scope: cleanup::CustomScopeIndex)
1360 -> Block<'a, 'tcx> {
1361 let _icx = push_ctxt("create_datums_for_fn_args");
1363 let arg_scope_id = cleanup::CustomScope(arg_scope);
1365 // Return an array wrapping the ValueRefs that we get from `get_param` for
1366 // each argument into datums.
1368 // For certain mode/type combinations, the raw llarg values are passed
1369 // by value. However, within the fn body itself, we want to always
1370 // have all locals and arguments be by-ref so that we can cancel the
1371 // cleanup and for better interaction with LLVM's debug info. So, if
1372 // the argument would be passed by value, we store it into an alloca.
1373 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1374 // the event it's not truly needed.
1375 let mut idx = fcx.arg_offset() as c_uint;
1376 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1377 let arg_datum = if !has_tupled_arg || i < arg_tys.len() - 1 {
1378 if type_of::arg_is_indirect(bcx.ccx(), arg_ty)
1379 && bcx.sess().opts.debuginfo != FullDebugInfo {
1380 // Don't copy an indirect argument to an alloca, the caller
1381 // already put it in a temporary alloca and gave it up, unless
1382 // we emit extra-debug-info, which requires local allocas :(.
1383 let llarg = get_param(fcx.llfn, idx);
1385 bcx.fcx.schedule_lifetime_end(arg_scope_id, llarg);
1386 bcx.fcx.schedule_drop_mem(arg_scope_id, llarg, arg_ty, None);
1388 datum::Datum::new(llarg, arg_ty, datum::Lvalue::new("create_datum_for_fn_args"))
1389 } else if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1390 let data = get_param(fcx.llfn, idx);
1391 let extra = get_param(fcx.llfn, idx + 1);
1393 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1394 arg_scope_id, (data, extra),
1395 |(data, extra), bcx, dst| {
1396 Store(bcx, data, expr::get_dataptr(bcx, dst));
1397 Store(bcx, extra, expr::get_meta(bcx, dst));
1401 let llarg = get_param(fcx.llfn, idx);
1403 let tmp = datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty));
1404 unpack_datum!(bcx, datum::lvalue_scratch_datum(bcx, arg_ty, "",
1406 |tmp, bcx, dst| tmp.store_to(bcx, dst)))
1409 // FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1411 ty::TyTuple(ref tupled_arg_tys) => {
1413 datum::lvalue_scratch_datum(bcx,
1421 for (j, &tupled_arg_ty) in
1422 tupled_arg_tys.iter().enumerate() {
1423 let lldest = StructGEP(bcx, llval, j);
1424 if common::type_is_fat_ptr(bcx.tcx(), tupled_arg_ty) {
1425 let data = get_param(bcx.fcx.llfn, idx);
1426 let extra = get_param(bcx.fcx.llfn, idx + 1);
1427 Store(bcx, data, expr::get_dataptr(bcx, lldest));
1428 Store(bcx, extra, expr::get_meta(bcx, lldest));
1431 let datum = datum::Datum::new(
1432 get_param(bcx.fcx.llfn, idx),
1434 arg_kind(bcx.fcx, tupled_arg_ty));
1436 bcx = datum.store_to(bcx, lldest);
1443 bcx.tcx().sess.bug("last argument of a function with \
1444 `rust-call` ABI isn't a tuple?!")
1449 let pat = &*args[i].pat;
1450 bcx = if let Some(name) = simple_name(pat) {
1451 // Generate nicer LLVM for the common case of fn a pattern
1453 set_value_name(arg_datum.val, &bcx.name(name));
1454 bcx.fcx.lllocals.borrow_mut().insert(pat.id, arg_datum);
1457 // General path. Copy out the values that are used in the
1459 _match::bind_irrefutable_pat(bcx, pat, arg_datum.match_input(), arg_scope_id)
1461 debuginfo::create_argument_metadata(bcx, &args[i]);
1467 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1468 // and builds the return block.
1469 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1470 last_bcx: Block<'blk, 'tcx>,
1471 retty: ty::FnOutput<'tcx>,
1472 ret_debug_loc: DebugLoc) {
1473 let _icx = push_ctxt("finish_fn");
1475 let ret_cx = match fcx.llreturn.get() {
1477 if !last_bcx.terminated.get() {
1478 Br(last_bcx, llreturn, DebugLoc::None);
1480 raw_block(fcx, false, llreturn)
1485 // This shouldn't need to recompute the return type,
1486 // as new_fn_ctxt did it already.
1487 let substd_retty = fcx.monomorphize(&retty);
1488 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1490 debuginfo::clear_source_location(fcx);
1494 // Builds the return block for a function.
1495 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1496 ret_cx: Block<'blk, 'tcx>,
1497 retty: ty::FnOutput<'tcx>,
1498 ret_debug_location: DebugLoc) {
1499 if fcx.llretslotptr.get().is_none() ||
1500 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1501 return RetVoid(ret_cx, ret_debug_location);
1504 let retslot = if fcx.needs_ret_allocas {
1505 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1507 fcx.llretslotptr.get().unwrap()
1509 let retptr = Value(retslot);
1510 match retptr.get_dominating_store(ret_cx) {
1511 // If there's only a single store to the ret slot, we can directly return
1512 // the value that was stored and omit the store and the alloca
1514 let retval = s.get_operand(0).unwrap().get();
1515 s.erase_from_parent();
1517 if retptr.has_no_uses() {
1518 retptr.erase_from_parent();
1521 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1522 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1527 if fcx.caller_expects_out_pointer {
1528 if let ty::FnConverging(retty) = retty {
1529 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1531 RetVoid(ret_cx, ret_debug_location)
1533 Ret(ret_cx, retval, ret_debug_location)
1536 // Otherwise, copy the return value to the ret slot
1537 None => match retty {
1538 ty::FnConverging(retty) => {
1539 if fcx.caller_expects_out_pointer {
1540 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1541 RetVoid(ret_cx, ret_debug_location)
1543 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1546 ty::FnDiverging => {
1547 if fcx.caller_expects_out_pointer {
1548 RetVoid(ret_cx, ret_debug_location)
1550 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1557 /// Builds an LLVM function out of a source function.
1559 /// If the function closes over its environment a closure will be returned.
1560 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1564 param_substs: &'tcx Substs<'tcx>,
1565 fn_ast_id: ast::NodeId,
1566 _attributes: &[ast::Attribute],
1567 output_type: ty::FnOutput<'tcx>,
1569 closure_env: closure::ClosureEnv<'b>) {
1570 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1572 let _icx = push_ctxt("trans_closure");
1573 attributes::emit_uwtable(llfndecl, true);
1575 debug!("trans_closure(..., param_substs={:?})",
1578 let has_env = match closure_env {
1579 closure::ClosureEnv::Closure(..) => true,
1580 closure::ClosureEnv::NotClosure => false,
1583 let (arena, fcx): (TypedArena<_>, FunctionContext);
1584 arena = TypedArena::new();
1585 fcx = new_fn_ctxt(ccx,
1593 let mut bcx = init_function(&fcx, false, output_type);
1595 // cleanup scope for the incoming arguments
1596 let fn_cleanup_debug_loc =
1597 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1598 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1600 let block_ty = node_id_type(bcx, body.id);
1602 // Set up arguments to the function.
1603 let monomorphized_arg_types =
1605 .map(|arg| node_id_type(bcx, arg.id))
1606 .collect::<Vec<_>>();
1607 for monomorphized_arg_type in &monomorphized_arg_types {
1608 debug!("trans_closure: monomorphized_arg_type: {:?}",
1609 monomorphized_arg_type);
1611 debug!("trans_closure: function lltype: {}",
1612 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1614 let has_tupled_arg = match closure_env {
1615 closure::ClosureEnv::NotClosure => abi == RustCall,
1619 bcx = create_datums_for_fn_args(bcx, &decl.inputs, &monomorphized_arg_types,
1620 has_tupled_arg, arg_scope);
1622 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1624 // Up until here, IR instructions for this function have explicitly not been annotated with
1625 // source code location, so we don't step into call setup code. From here on, source location
1626 // emitting should be enabled.
1627 debuginfo::start_emitting_source_locations(&fcx);
1629 let dest = match fcx.llretslotptr.get() {
1630 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1632 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1637 // This call to trans_block is the place where we bridge between
1638 // translation calls that don't have a return value (trans_crate,
1639 // trans_mod, trans_item, et cetera) and those that do
1640 // (trans_block, trans_expr, et cetera).
1641 bcx = controlflow::trans_block(bcx, body, dest);
1644 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1645 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1650 match fcx.llreturn.get() {
1652 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
1653 fcx.pop_custom_cleanup_scope(arg_scope);
1656 // Microoptimization writ large: avoid creating a separate
1657 // llreturn basic block
1658 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1662 // Put return block after all other blocks.
1663 // This somewhat improves single-stepping experience in debugger.
1665 let llreturn = fcx.llreturn.get();
1666 if let Some(llreturn) = llreturn {
1667 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1671 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id,
1672 fn_cleanup_debug_loc.span);
1674 // Insert the mandatory first few basic blocks before lltop.
1675 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
1678 /// Creates an LLVM function corresponding to a source language function.
1679 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1683 param_substs: &'tcx Substs<'tcx>,
1685 attrs: &[ast::Attribute]) {
1686 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1687 debug!("trans_fn(param_substs={:?})", param_substs);
1688 let _icx = push_ctxt("trans_fn");
1689 let fn_ty = ccx.tcx().node_id_to_type(id);
1690 let output_type = ccx.tcx().erase_late_bound_regions(&fn_ty.fn_ret());
1691 let abi = fn_ty.fn_abi();
1692 trans_closure(ccx, decl, body, llfndecl, param_substs, id, attrs, output_type, abi,
1693 closure::ClosureEnv::NotClosure);
1696 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1697 ctor_id: ast::NodeId,
1699 param_substs: &'tcx Substs<'tcx>,
1700 llfndecl: ValueRef) {
1701 let _icx = push_ctxt("trans_enum_variant");
1703 trans_enum_variant_or_tuple_like_struct(
1711 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1714 args: callee::CallArgs,
1716 debug_loc: DebugLoc)
1717 -> Result<'blk, 'tcx> {
1719 let ccx = bcx.fcx.ccx;
1721 let result_ty = match ctor_ty.sty {
1722 ty::TyBareFn(_, ref bft) => {
1723 bcx.tcx().erase_late_bound_regions(&bft.sig.output()).unwrap()
1725 _ => ccx.sess().bug(
1726 &format!("trans_enum_variant_constructor: \
1727 unexpected ctor return type {}",
1731 // Get location to store the result. If the user does not care about
1732 // the result, just make a stack slot
1733 let llresult = match dest {
1734 expr::SaveIn(d) => d,
1736 if !type_is_zero_size(ccx, result_ty) {
1737 let llresult = alloc_ty(bcx, result_ty, "constructor_result");
1738 call_lifetime_start(bcx, llresult);
1741 C_undef(type_of::type_of(ccx, result_ty).ptr_to())
1746 if !type_is_zero_size(ccx, result_ty) {
1748 callee::ArgExprs(exprs) => {
1749 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
1750 bcx = expr::trans_adt(bcx,
1755 expr::SaveIn(llresult),
1758 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
1761 // Just eval all the expressions (if any). Since expressions in Rust can have arbitrary
1762 // contents, there could be side-effects we need from them.
1764 callee::ArgExprs(exprs) => {
1766 bcx = expr::trans_into(bcx, expr, expr::Ignore);
1773 // If the caller doesn't care about the result
1774 // drop the temporary we made
1775 let bcx = match dest {
1776 expr::SaveIn(_) => bcx,
1778 let bcx = glue::drop_ty(bcx, llresult, result_ty, debug_loc);
1779 if !type_is_zero_size(ccx, result_ty) {
1780 call_lifetime_end(bcx, llresult);
1786 Result::new(bcx, llresult)
1789 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1790 ctor_id: ast::NodeId,
1791 param_substs: &'tcx Substs<'tcx>,
1792 llfndecl: ValueRef) {
1793 let _icx = push_ctxt("trans_tuple_struct");
1795 trans_enum_variant_or_tuple_like_struct(
1803 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1804 ctor_id: ast::NodeId,
1806 param_substs: &'tcx Substs<'tcx>,
1807 llfndecl: ValueRef) {
1808 let ctor_ty = ccx.tcx().node_id_to_type(ctor_id);
1809 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
1811 let result_ty = match ctor_ty.sty {
1812 ty::TyBareFn(_, ref bft) => {
1813 ccx.tcx().erase_late_bound_regions(&bft.sig.output())
1815 _ => ccx.sess().bug(
1816 &format!("trans_enum_variant_or_tuple_like_struct: \
1817 unexpected ctor return type {}",
1821 let (arena, fcx): (TypedArena<_>, FunctionContext);
1822 arena = TypedArena::new();
1823 fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
1824 param_substs, None, &arena);
1825 let bcx = init_function(&fcx, false, result_ty);
1827 assert!(!fcx.needs_ret_allocas);
1829 let arg_tys = ccx.tcx().erase_late_bound_regions(&ctor_ty.fn_args());
1831 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
1832 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
1833 let repr = adt::represent_type(ccx, result_ty.unwrap());
1834 let mut llarg_idx = fcx.arg_offset() as c_uint;
1835 for (i, arg_ty) in arg_tys.into_iter().enumerate() {
1836 let lldestptr = adt::trans_field_ptr(bcx,
1841 if common::type_is_fat_ptr(bcx.tcx(), arg_ty) {
1842 Store(bcx, get_param(fcx.llfn, llarg_idx), expr::get_dataptr(bcx, lldestptr));
1843 Store(bcx, get_param(fcx.llfn, llarg_idx + 1), expr::get_meta(bcx, lldestptr));
1846 let arg = get_param(fcx.llfn, llarg_idx);
1849 if arg_is_indirect(ccx, arg_ty) {
1850 memcpy_ty(bcx, lldestptr, arg, arg_ty);
1852 store_ty(bcx, arg, lldestptr, arg_ty);
1856 adt::trans_set_discr(bcx, &*repr, dest, disr);
1859 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
1862 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &hir::EnumDef, sp: Span, id: ast::NodeId) {
1863 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
1865 let print_info = ccx.sess().print_enum_sizes();
1867 let levels = ccx.tcx().node_lint_levels.borrow();
1868 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
1869 let lvlsrc = levels.get(&(id, lint_id));
1870 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
1872 if is_allow && !print_info {
1873 // we're not interested in anything here
1877 let ty = ccx.tcx().node_id_to_type(id);
1878 let avar = adt::represent_type(ccx, ty);
1880 adt::General(_, ref variants, _) => {
1881 for var in variants {
1883 for field in var.fields.iter().skip(1) {
1884 // skip the discriminant
1885 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
1890 _ => { /* its size is either constant or unimportant */ }
1893 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
1894 |(l, s, li), (idx, &size)|
1897 } else if size > s {
1905 let llty = type_of::sizing_type_of(ccx, ty);
1907 let sess = &ccx.tcx().sess;
1908 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
1910 adt::General(..) => {
1911 for (i, var) in enum_def.variants.iter().enumerate() {
1912 ccx.tcx().sess.span_note(var.span,
1913 &*format!("variant data: {} bytes", sizes[i]));
1920 // we only warn if the largest variant is at least thrice as large as
1921 // the second-largest.
1922 if !is_allow && largest > slargest * 3 && slargest > 0 {
1923 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
1924 // pass for the latter already ran.
1925 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
1926 *lvlsrc.unwrap(), Some(sp),
1927 &format!("enum variant is more than three times larger \
1928 ({} bytes) than the next largest (ignoring padding)",
1931 ccx.sess().span_note(enum_def.variants[largest_index].span,
1932 "this variant is the largest");
1936 pub struct TransItemVisitor<'a, 'tcx: 'a> {
1937 pub ccx: &'a CrateContext<'a, 'tcx>,
1940 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemVisitor<'a, 'tcx> {
1941 fn visit_item(&mut self, i: &hir::Item) {
1942 trans_item(self.ccx, i);
1946 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
1947 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
1948 // applicable to variable declarations and may not really make sense for
1949 // Rust code in the first place but whitelist them anyway and trust that
1950 // the user knows what s/he's doing. Who knows, unanticipated use cases
1951 // may pop up in the future.
1953 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
1954 // and don't have to be, LLVM treats them as no-ops.
1956 "appending" => Some(llvm::AppendingLinkage),
1957 "available_externally" => Some(llvm::AvailableExternallyLinkage),
1958 "common" => Some(llvm::CommonLinkage),
1959 "extern_weak" => Some(llvm::ExternalWeakLinkage),
1960 "external" => Some(llvm::ExternalLinkage),
1961 "internal" => Some(llvm::InternalLinkage),
1962 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
1963 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
1964 "private" => Some(llvm::PrivateLinkage),
1965 "weak" => Some(llvm::WeakAnyLinkage),
1966 "weak_odr" => Some(llvm::WeakODRLinkage),
1972 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
1973 #[derive(Copy, Clone)]
1974 pub enum ValueOrigin {
1975 /// The LLVM `Value` is in this context because the corresponding item was
1976 /// assigned to the current compilation unit.
1977 OriginalTranslation,
1978 /// The `Value`'s corresponding item was assigned to some other compilation
1979 /// unit, but the `Value` was translated in this context anyway because the
1980 /// item is marked `#[inline]`.
1984 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
1985 /// If the `llval` is the direct translation of a specific Rust item, `id`
1986 /// should be set to the `NodeId` of that item. (This mapping should be
1987 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
1988 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
1989 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
1990 /// assigned to a different compilation unit.
1991 pub fn update_linkage(ccx: &CrateContext,
1993 id: Option<ast::NodeId>,
1994 llval_origin: ValueOrigin) {
1995 match llval_origin {
1997 // `llval` is a translation of an item defined in a separate
1998 // compilation unit. This only makes sense if there are at least
1999 // two compilation units.
2000 assert!(ccx.sess().opts.cg.codegen_units > 1);
2001 // `llval` is a copy of something defined elsewhere, so use
2002 // `AvailableExternallyLinkage` to avoid duplicating code in the
2004 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2007 OriginalTranslation => {},
2010 if let Some(id) = id {
2011 let item = ccx.tcx().map.get(id);
2012 if let hir_map::NodeItem(i) = item {
2013 if let Some(name) = attr::first_attr_value_str_by_name(&i.attrs, "linkage") {
2014 if let Some(linkage) = llvm_linkage_by_name(&name) {
2015 llvm::SetLinkage(llval, linkage);
2017 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2025 Some(id) if ccx.reachable().contains(&id) => {
2026 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2029 // `id` does not refer to an item in `ccx.reachable`.
2030 if ccx.sess().opts.cg.codegen_units > 1 {
2031 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2033 llvm::SetLinkage(llval, llvm::InternalLinkage);
2039 fn set_global_section(ccx: &CrateContext, llval: ValueRef, i: &hir::Item) {
2040 match attr::first_attr_value_str_by_name(&i.attrs,
2043 if contains_null(§) {
2044 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`",
2048 let buf = CString::new(sect.as_bytes()).unwrap();
2049 llvm::LLVMSetSection(llval, buf.as_ptr());
2056 pub fn trans_item(ccx: &CrateContext, item: &hir::Item) {
2057 let _icx = push_ctxt("trans_item");
2059 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2062 hir::ItemFn(ref decl, _, _, abi, ref generics, ref body) => {
2063 if !generics.is_type_parameterized() {
2064 let trans_everywhere = attr::requests_inline(&item.attrs);
2065 // Ignore `trans_everywhere` for cross-crate inlined items
2066 // (`from_external`). `trans_item` will be called once for each
2067 // compilation unit that references the item, so it will still get
2068 // translated everywhere it's needed.
2069 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2070 let llfn = get_item_val(ccx, item.id);
2071 let empty_substs = ccx.tcx().mk_substs(Substs::trans_empty());
2073 foreign::trans_rust_fn_with_foreign_abi(ccx, &**decl, &**body, &item.attrs,
2074 llfn, empty_substs, item.id, None);
2076 trans_fn(ccx, &**decl, &**body, llfn, empty_substs, item.id, &item.attrs);
2078 set_global_section(ccx, llfn, item);
2079 update_linkage(ccx, llfn, Some(item.id),
2080 if is_origin { OriginalTranslation } else { InlinedCopy });
2082 if is_entry_fn(ccx.sess(), item.id) {
2083 create_entry_wrapper(ccx, item.span, llfn);
2084 // check for the #[rustc_error] annotation, which forces an
2085 // error in trans. This is used to write compile-fail tests
2086 // that actually test that compilation succeeds without
2087 // reporting an error.
2088 let item_def_id = ccx.tcx().map.local_def_id(item.id);
2089 if ccx.tcx().has_attr(item_def_id, "rustc_error") {
2090 ccx.tcx().sess.span_fatal(item.span, "compilation successful");
2096 // Be sure to travel more than just one layer deep to catch nested
2097 // items in blocks and such.
2098 let mut v = TransItemVisitor{ ccx: ccx };
2099 v.visit_block(&**body);
2101 hir::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2102 meth::trans_impl(ccx,
2108 hir::ItemMod(ref m) => {
2109 trans_mod(&ccx.rotate(), m);
2111 hir::ItemEnum(ref enum_definition, ref gens) => {
2112 if gens.ty_params.is_empty() {
2113 // sizes only make sense for non-generic types
2115 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2118 hir::ItemConst(_, ref expr) => {
2119 // Recurse on the expression to catch items in blocks
2120 let mut v = TransItemVisitor{ ccx: ccx };
2121 v.visit_expr(&**expr);
2123 hir::ItemStatic(_, m, ref expr) => {
2124 // Recurse on the expression to catch items in blocks
2125 let mut v = TransItemVisitor{ ccx: ccx };
2126 v.visit_expr(&**expr);
2128 let g = consts::trans_static(ccx, m, expr, item.id, &item.attrs);
2129 set_global_section(ccx, g, item);
2130 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2132 hir::ItemForeignMod(ref foreign_mod) => {
2133 foreign::trans_foreign_mod(ccx, foreign_mod);
2135 hir::ItemTrait(..) => {
2136 // Inside of this trait definition, we won't be actually translating any
2137 // functions, but the trait still needs to be walked. Otherwise default
2138 // methods with items will not get translated and will cause ICE's when
2139 // metadata time comes around.
2140 let mut v = TransItemVisitor{ ccx: ccx };
2141 visit::walk_item(&mut v, item);
2143 _ => {/* fall through */ }
2147 // Translate a module. Doing this amounts to translating the items in the
2148 // module; there ends up being no artifact (aside from linkage names) of
2149 // separate modules in the compiled program. That's because modules exist
2150 // only as a convenience for humans working with the code, to organize names
2151 // and control visibility.
2152 pub fn trans_mod(ccx: &CrateContext, m: &hir::Mod) {
2153 let _icx = push_ctxt("trans_mod");
2154 for item in &m.items {
2155 trans_item(ccx, &**item);
2160 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2161 pub fn register_fn_llvmty(ccx: &CrateContext,
2164 node_id: ast::NodeId,
2166 llfty: Type) -> ValueRef {
2167 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2169 let llfn = declare::define_fn(ccx, &sym[..], cc, llfty,
2170 ty::FnConverging(ccx.tcx().mk_nil())).unwrap_or_else(||{
2171 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2173 finish_register_fn(ccx, sym, node_id);
2177 fn finish_register_fn(ccx: &CrateContext, sym: String, node_id: ast::NodeId) {
2178 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2181 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2184 node_id: ast::NodeId,
2185 node_type: Ty<'tcx>)
2187 if let ty::TyBareFn(_, ref f) = node_type.sty {
2188 if f.abi != Rust && f.abi != RustCall {
2189 ccx.sess().span_bug(sp, &format!("only the `{}` or `{}` calling conventions are valid \
2190 for this function; `{}` was specified",
2191 Rust.name(), RustCall.name(), f.abi.name()));
2194 ccx.sess().span_bug(sp, "expected bare rust function")
2197 let llfn = declare::define_rust_fn(ccx, &sym[..], node_type).unwrap_or_else(||{
2198 ccx.sess().span_fatal(sp, &format!("symbol `{}` is already defined", sym));
2200 finish_register_fn(ccx, sym, node_id);
2204 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2205 match *sess.entry_fn.borrow() {
2206 Some((entry_id, _)) => node_id == entry_id,
2211 /// Create the `main` function which will initialise the rust runtime and call users’ main
2213 pub fn create_entry_wrapper(ccx: &CrateContext,
2215 main_llfn: ValueRef) {
2216 let et = ccx.sess().entry_type.get().unwrap();
2218 config::EntryMain => {
2219 create_entry_fn(ccx, sp, main_llfn, true);
2221 config::EntryStart => create_entry_fn(ccx, sp, main_llfn, false),
2222 config::EntryNone => {} // Do nothing.
2225 fn create_entry_fn(ccx: &CrateContext,
2227 rust_main: ValueRef,
2228 use_start_lang_item: bool) {
2229 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2232 let llfn = declare::define_cfn(ccx, "main", llfty,
2233 ccx.tcx().mk_nil()).unwrap_or_else(||{
2234 ccx.sess().span_err(sp, "entry symbol `main` defined multiple times");
2235 // FIXME: We should be smart and show a better diagnostic here.
2236 ccx.sess().help("did you use #[no_mangle] on `fn main`? Use #[start] instead");
2237 ccx.sess().abort_if_errors();
2242 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn,
2243 "top\0".as_ptr() as *const _)
2245 let bld = ccx.raw_builder();
2247 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2249 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2251 let (start_fn, args) = if use_start_lang_item {
2252 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2254 Err(s) => { ccx.sess().fatal(&s[..]); }
2257 if let Some(start_node_id) = ccx.tcx().map.as_local_node_id(start_def_id) {
2258 get_item_val(ccx, start_node_id)
2260 let start_fn_type = csearch::get_type(ccx.tcx(),
2262 trans_external_path(ccx, start_def_id, start_fn_type)
2266 let opaque_rust_main = llvm::LLVMBuildPointerCast(bld,
2267 rust_main, Type::i8p(ccx).to_ref(),
2268 "rust_main\0".as_ptr() as *const _);
2278 debug!("using user-defined start fn");
2280 get_param(llfn, 0 as c_uint),
2281 get_param(llfn, 1 as c_uint)
2287 let result = llvm::LLVMBuildCall(bld,
2290 args.len() as c_uint,
2293 llvm::LLVMBuildRet(bld, result);
2298 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, id: ast::NodeId,
2299 ty: Ty<'tcx>, attrs: &[ast::Attribute]) -> String {
2300 match ccx.external_srcs().borrow().get(&id) {
2302 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2303 debug!("found item {} in other crate...", sym);
2309 match attr::find_export_name_attr(ccx.sess().diagnostic(), attrs) {
2310 // Use provided name
2311 Some(name) => name.to_string(),
2313 let path = ccx.tcx().map.def_path_from_id(id);
2314 if attr::contains_name(attrs, "no_mangle") {
2316 path.last().unwrap().data.to_string()
2318 match weak_lang_items::link_name(attrs) {
2319 Some(name) => name.to_string(),
2321 // Usual name mangling
2322 mangle_exported_name(ccx, path, ty, id)
2330 fn contains_null(s: &str) -> bool {
2331 s.bytes().any(|b| b == 0)
2334 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2335 debug!("get_item_val(id=`{}`)", id);
2337 match ccx.item_vals().borrow().get(&id).cloned() {
2338 Some(v) => return v,
2342 let item = ccx.tcx().map.get(id);
2343 debug!("get_item_val: id={} item={:?}", id, item);
2344 let val = match item {
2345 hir_map::NodeItem(i) => {
2346 let ty = ccx.tcx().node_id_to_type(i.id);
2347 let sym = || exported_name(ccx, id, ty, &i.attrs);
2349 let v = match i.node {
2350 hir::ItemStatic(..) => {
2351 // If this static came from an external crate, then
2352 // we need to get the symbol from csearch instead of
2353 // using the current crate's name/version
2354 // information in the hash of the symbol
2356 debug!("making {}", sym);
2358 // Create the global before evaluating the initializer;
2359 // this is necessary to allow recursive statics.
2360 let llty = type_of(ccx, ty);
2361 let g = declare::define_global(ccx, &sym[..],
2362 llty).unwrap_or_else(|| {
2363 ccx.sess().span_fatal(i.span, &format!("symbol `{}` is already defined",
2367 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2371 hir::ItemFn(_, _, _, abi, _, _) => {
2373 let llfn = if abi == Rust {
2374 register_fn(ccx, i.span, sym, i.id, ty)
2376 foreign::register_rust_fn_with_foreign_abi(ccx, i.span, sym, i.id)
2378 attributes::from_fn_attrs(ccx, &i.attrs, llfn);
2382 _ => ccx.sess().bug("get_item_val: weird result in table")
2388 hir_map::NodeTraitItem(trait_item) => {
2389 debug!("get_item_val(): processing a NodeTraitItem");
2390 match trait_item.node {
2391 hir::MethodTraitItem(_, Some(_)) => {
2392 register_method(ccx, id, &trait_item.attrs, trait_item.span)
2395 ccx.sess().span_bug(trait_item.span,
2396 "unexpected variant: trait item other than a provided \
2397 method in get_item_val()");
2402 hir_map::NodeImplItem(impl_item) => {
2403 match impl_item.node {
2404 hir::MethodImplItem(..) => {
2405 register_method(ccx, id, &impl_item.attrs, impl_item.span)
2408 ccx.sess().span_bug(impl_item.span,
2409 "unexpected variant: non-method impl item in \
2415 hir_map::NodeForeignItem(ni) => {
2417 hir::ForeignItemFn(..) => {
2418 let abi = ccx.tcx().map.get_foreign_abi(id);
2419 let ty = ccx.tcx().node_id_to_type(ni.id);
2420 let name = foreign::link_name(&*ni);
2421 foreign::register_foreign_item_fn(ccx, abi, ty, &name, &ni.attrs)
2423 hir::ForeignItemStatic(..) => {
2424 foreign::register_static(ccx, &*ni)
2429 hir_map::NodeVariant(ref v) => {
2431 let fields = if v.node.data.is_struct() {
2432 ccx.sess().bug("struct variant kind unexpected in get_item_val")
2434 v.node.data.fields()
2436 assert!(fields.count() != 0);
2437 let ty = ccx.tcx().node_id_to_type(id);
2438 let parent = ccx.tcx().map.get_parent(id);
2439 let enm = ccx.tcx().map.expect_item(parent);
2440 let sym = exported_name(ccx,
2445 llfn = match enm.node {
2446 hir::ItemEnum(_, _) => {
2447 register_fn(ccx, (*v).span, sym, id, ty)
2449 _ => ccx.sess().bug("NodeVariant, shouldn't happen")
2451 attributes::inline(llfn, attributes::InlineAttr::Hint);
2455 hir_map::NodeStructCtor(struct_def) => {
2456 // Only register the constructor if this is a tuple-like struct.
2457 let ctor_id = if struct_def.is_struct() {
2458 ccx.sess().bug("attempt to register a constructor of \
2459 a non-tuple-like struct")
2463 let parent = ccx.tcx().map.get_parent(id);
2464 let struct_item = ccx.tcx().map.expect_item(parent);
2465 let ty = ccx.tcx().node_id_to_type(ctor_id);
2466 let sym = exported_name(ccx,
2469 &struct_item.attrs);
2470 let llfn = register_fn(ccx, struct_item.span,
2472 attributes::inline(llfn, attributes::InlineAttr::Hint);
2477 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}",
2482 // All LLVM globals and functions are initially created as external-linkage
2483 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2484 // into a definition, it adjusts the linkage then (using `update_linkage`).
2486 // The exception is foreign items, which have their linkage set inside the
2487 // call to `foreign::register_*` above. We don't touch the linkage after
2488 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2489 // other item translation functions do).
2491 ccx.item_vals().borrow_mut().insert(id, val);
2495 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2496 attrs: &[ast::Attribute], span: Span) -> ValueRef {
2497 let mty = ccx.tcx().node_id_to_type(id);
2499 let sym = exported_name(ccx, id, mty, &attrs);
2501 if let ty::TyBareFn(_, ref f) = mty.sty {
2502 let llfn = if f.abi == Rust || f.abi == RustCall {
2503 register_fn(ccx, span, sym, id, mty)
2505 foreign::register_rust_fn_with_foreign_abi(ccx, span, sym, id)
2507 attributes::from_fn_attrs(ccx, &attrs, llfn);
2510 ccx.sess().span_bug(span, "expected bare rust function");
2514 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'a, 'tcx>,
2515 ie: encoder::EncodeInlinedItem<'a>,
2516 reachable: &'a NodeSet)
2517 -> encoder::EncodeParams<'a, 'tcx> {
2518 encoder::EncodeParams {
2519 diag: cx.sess().diagnostic(),
2521 reexports: cx.export_map(),
2522 item_symbols: cx.item_symbols(),
2523 link_meta: cx.link_meta(),
2524 cstore: &cx.sess().cstore,
2525 encode_inlined_item: ie,
2526 reachable: reachable,
2530 pub fn write_metadata(cx: &SharedCrateContext, krate: &hir::Crate,
2531 reachable: &NodeSet) -> Vec<u8> {
2534 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2535 *ty != config::CrateTypeExecutable
2541 let encode_inlined_item: encoder::EncodeInlinedItem =
2542 Box::new(|ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii));
2544 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item,
2546 let metadata = encoder::encode_metadata(encode_parms, krate);
2547 let mut compressed = encoder::metadata_encoding_version.to_vec();
2548 compressed.push_all(&flate::deflate_bytes(&metadata));
2549 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[..]);
2550 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2551 let name = format!("rust_metadata_{}_{}",
2552 cx.link_meta().crate_name,
2553 cx.link_meta().crate_hash);
2554 let buf = CString::new(name).unwrap();
2555 let llglobal = unsafe {
2556 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(),
2560 llvm::LLVMSetInitializer(llglobal, llconst);
2561 let name = loader::meta_section_name(&cx.sess().target.target);
2562 let name = CString::new(name).unwrap();
2563 llvm::LLVMSetSection(llglobal, name.as_ptr())
2568 /// Find any symbols that are defined in one compilation unit, but not declared
2569 /// in any other compilation unit. Give these symbols internal linkage.
2570 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<&str>) {
2572 let mut declared = HashSet::new();
2574 // Collect all external declarations in all compilation units.
2575 for ccx in cx.iter() {
2576 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2577 let linkage = llvm::LLVMGetLinkage(val);
2578 // We only care about external declarations (not definitions)
2579 // and available_externally definitions.
2580 if !(linkage == llvm::ExternalLinkage as c_uint &&
2581 llvm::LLVMIsDeclaration(val) != 0) &&
2582 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
2586 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2587 .to_bytes().to_vec();
2588 declared.insert(name);
2592 // Examine each external definition. If the definition is not used in
2593 // any other compilation unit, and is not reachable from other crates,
2594 // then give it internal linkage.
2595 for ccx in cx.iter() {
2596 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
2597 // We only care about external definitions.
2598 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2599 llvm::LLVMIsDeclaration(val) == 0) {
2603 let name = CStr::from_ptr(llvm::LLVMGetValueName(val))
2604 .to_bytes().to_vec();
2605 if !declared.contains(&name) &&
2606 !reachable.contains(str::from_utf8(&name).unwrap()) {
2607 llvm::SetLinkage(val, llvm::InternalLinkage);
2608 llvm::SetDLLStorageClass(val, llvm::DefaultStorageClass);
2615 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
2616 // This is required to satisfy `dllimport` references to static data in .rlibs
2617 // when using MSVC linker. We do this only for data, as linker can fix up
2618 // code references on its own.
2619 // See #26591, #27438
2620 fn create_imps(cx: &SharedCrateContext) {
2621 // The x86 ABI seems to require that leading underscores are added to symbol
2622 // names, so we need an extra underscore on 32-bit. There's also a leading
2623 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
2624 // underscores added in front).
2625 let prefix = if cx.sess().target.target.target_pointer_width == "32" {
2631 for ccx in cx.iter() {
2632 let exported: Vec<_> = iter_globals(ccx.llmod())
2633 .filter(|&val| llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
2634 llvm::LLVMIsDeclaration(val) == 0)
2637 let i8p_ty = Type::i8p(&ccx);
2638 for val in exported {
2639 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
2640 let mut imp_name = prefix.as_bytes().to_vec();
2641 imp_name.extend(name.to_bytes());
2642 let imp_name = CString::new(imp_name).unwrap();
2643 let imp = llvm::LLVMAddGlobal(ccx.llmod(), i8p_ty.to_ref(),
2644 imp_name.as_ptr() as *const _);
2645 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
2646 llvm::LLVMSetInitializer(imp, init);
2647 llvm::SetLinkage(imp, llvm::ExternalLinkage);
2655 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
2658 impl Iterator for ValueIter {
2659 type Item = ValueRef;
2661 fn next(&mut self) -> Option<ValueRef> {
2665 let step: unsafe extern "C" fn(ValueRef) -> ValueRef =
2666 mem::transmute_copy(&self.step);
2676 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
2679 cur: llvm::LLVMGetFirstGlobal(llmod),
2680 step: llvm::LLVMGetNextGlobal,
2685 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
2688 cur: llvm::LLVMGetFirstFunction(llmod),
2689 step: llvm::LLVMGetNextFunction,
2694 /// The context provided lists a set of reachable ids as calculated by
2695 /// middle::reachable, but this contains far more ids and symbols than we're
2696 /// actually exposing from the object file. This function will filter the set in
2697 /// the context to the set of ids which correspond to symbols that are exposed
2698 /// from the object file being generated.
2700 /// This list is later used by linkers to determine the set of symbols needed to
2701 /// be exposed from a dynamic library and it's also encoded into the metadata.
2702 pub fn filter_reachable_ids(ccx: &SharedCrateContext) -> NodeSet {
2703 ccx.reachable().iter().map(|x| *x).filter(|id| {
2704 // First, only worry about nodes which have a symbol name
2705 ccx.item_symbols().borrow().contains_key(id)
2707 // Next, we want to ignore some FFI functions that are not exposed from
2708 // this crate. Reachable FFI functions can be lumped into two
2711 // 1. Those that are included statically via a static library
2712 // 2. Those included otherwise (e.g. dynamically or via a framework)
2714 // Although our LLVM module is not literally emitting code for the
2715 // statically included symbols, it's an export of our library which
2716 // needs to be passed on to the linker and encoded in the metadata.
2718 // As a result, if this id is an FFI item (foreign item) then we only
2719 // let it through if it's included statically.
2720 match ccx.tcx().map.get(id) {
2721 hir_map::NodeForeignItem(..) => {
2722 ccx.sess().cstore.is_statically_included_foreign_item(id)
2729 pub fn trans_crate(tcx: &ty::ctxt, analysis: ty::CrateAnalysis) -> CrateTranslation {
2730 let ty::CrateAnalysis { export_map, reachable, name, .. } = analysis;
2731 let krate = tcx.map.krate();
2733 let check_overflow = if let Some(v) = tcx.sess.opts.debugging_opts.force_overflow_checks {
2736 tcx.sess.opts.debug_assertions
2739 let check_dropflag = if let Some(v) = tcx.sess.opts.debugging_opts.force_dropflag_checks {
2742 tcx.sess.opts.debug_assertions
2745 // Before we touch LLVM, make sure that multithreading is enabled.
2747 use std::sync::Once;
2748 static INIT: Once = Once::new();
2749 static mut POISONED: bool = false;
2751 if llvm::LLVMStartMultithreaded() != 1 {
2752 // use an extra bool to make sure that all future usage of LLVM
2753 // cannot proceed despite the Once not running more than once.
2757 ::back::write::configure_llvm(&tcx.sess);
2761 tcx.sess.bug("couldn't enable multi-threaded LLVM");
2765 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
2767 let codegen_units = tcx.sess.opts.cg.codegen_units;
2768 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name,
2779 let ccx = shared_ccx.get_ccx(0);
2781 // First, verify intrinsics.
2782 intrinsic::check_intrinsics(&ccx);
2784 // Next, translate the module.
2786 let _icx = push_ctxt("text");
2787 trans_mod(&ccx, &krate.module);
2791 for ccx in shared_ccx.iter() {
2792 if ccx.sess().opts.debuginfo != NoDebugInfo {
2793 debuginfo::finalize(&ccx);
2795 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
2797 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
2798 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
2799 llvm::LLVMDeleteGlobal(old_g);
2804 let reachable_symbol_ids = filter_reachable_ids(&shared_ccx);
2806 // Translate the metadata.
2807 let metadata = write_metadata(&shared_ccx, krate, &reachable_symbol_ids);
2809 if shared_ccx.sess().trans_stats() {
2810 let stats = shared_ccx.stats();
2811 println!("--- trans stats ---");
2812 println!("n_glues_created: {}", stats.n_glues_created.get());
2813 println!("n_null_glues: {}", stats.n_null_glues.get());
2814 println!("n_real_glues: {}", stats.n_real_glues.get());
2816 println!("n_fns: {}", stats.n_fns.get());
2817 println!("n_monos: {}", stats.n_monos.get());
2818 println!("n_inlines: {}", stats.n_inlines.get());
2819 println!("n_closures: {}", stats.n_closures.get());
2820 println!("fn stats:");
2821 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
2822 insns_b.cmp(&insns_a)
2824 for tuple in stats.fn_stats.borrow().iter() {
2826 (ref name, insns) => {
2827 println!("{} insns, {}", insns, *name);
2832 if shared_ccx.sess().count_llvm_insns() {
2833 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
2834 println!("{:7} {}", *v, *k);
2838 let modules = shared_ccx.iter()
2839 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
2842 let sess = shared_ccx.sess();
2843 let mut reachable_symbols = reachable_symbol_ids.iter().map(|id| {
2844 shared_ccx.item_symbols().borrow()[id].to_string()
2845 }).collect::<Vec<_>>();
2846 if sess.entry_fn.borrow().is_some() {
2847 reachable_symbols.push("main".to_string());
2850 // For the purposes of LTO, we add to the reachable set all of the upstream
2851 // reachable extern fns. These functions are all part of the public ABI of
2852 // the final product, so LTO needs to preserve them.
2854 sess.cstore.iter_crate_data(|cnum, _| {
2855 let syms = csearch::get_reachable_ids(&sess.cstore, cnum);
2856 reachable_symbols.extend(syms.into_iter().filter(|did| {
2857 csearch::is_extern_fn(&sess.cstore, *did, shared_ccx.tcx())
2859 csearch::get_symbol(&sess.cstore, did)
2864 if codegen_units > 1 {
2865 internalize_symbols(&shared_ccx,
2866 &reachable_symbols.iter().map(|x| &x[..]).collect());
2869 if sess.target.target.options.is_like_msvc &&
2870 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
2871 create_imps(&shared_ccx);
2874 let metadata_module = ModuleTranslation {
2875 llcx: shared_ccx.metadata_llcx(),
2876 llmod: shared_ccx.metadata_llmod(),
2878 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
2882 metadata_module: metadata_module,
2885 reachable: reachable_symbols,
2886 no_builtins: no_builtins,