1 //! Codegen the completed AST to the LLVM IR.
3 //! Some functions here, such as codegen_block and codegen_expr, return a value --
4 //! the result of the codegen to LLVM -- while others, such as codegen_fn
5 //! and mono_item, are called only for the side effect of adding a
6 //! particular definition to the LLVM IR output we're producing.
8 //! Hopefully useful general knowledge about codegen:
10 //! * There's no way to find out the `Ty` type of a Value. Doing so
11 //! would be "trying to get the eggs out of an omelette" (credit:
12 //! pcwalton). You can, instead, find out its `llvm::Type` by calling `val_ty`,
13 //! but one `llvm::Type` corresponds to many `Ty`s; for instance, `tup(int, int,
14 //! int)` and `rec(x=int, y=int, z=int)` will have the same `llvm::Type`.
16 use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen};
18 use rustc::dep_graph::cgu_reuse_tracker::CguReuse;
19 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
20 use rustc::middle::cstore::EncodedMetadata;
21 use rustc::middle::lang_items::StartFnLangItem;
22 use rustc::middle::weak_lang_items;
23 use rustc::mir::mono::{CodegenUnitNameBuilder, CodegenUnit, MonoItem};
24 use rustc::ty::{self, Ty, TyCtxt, Instance};
25 use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
26 use rustc::ty::query::Providers;
27 use rustc::middle::cstore::{self, LinkagePreference};
28 use rustc::util::common::{time, print_time_passes_entry};
29 use rustc::session::config::{self, EntryFnType, Lto};
30 use rustc::session::Session;
31 use rustc::util::nodemap::FxHashMap;
32 use rustc_data_structures::indexed_vec::Idx;
33 use rustc_codegen_utils::{symbol_names_test, check_for_rustc_errors_attr};
34 use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
35 use crate::mir::place::PlaceRef;
36 use crate::back::write::{OngoingCodegen, start_async_codegen, submit_pre_lto_module_to_llvm,
37 submit_post_lto_module_to_llvm};
38 use crate::{MemFlags, CrateInfo};
40 use crate::common::{RealPredicate, TypeKind, IntPredicate};
48 use std::ops::{Deref, DerefMut};
49 use std::time::{Instant, Duration};
55 use crate::mir::operand::OperandValue;
57 pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind,
61 hir::BinOpKind::Eq => IntPredicate::IntEQ,
62 hir::BinOpKind::Ne => IntPredicate::IntNE,
63 hir::BinOpKind::Lt => if signed { IntPredicate::IntSLT } else { IntPredicate::IntULT },
64 hir::BinOpKind::Le => if signed { IntPredicate::IntSLE } else { IntPredicate::IntULE },
65 hir::BinOpKind::Gt => if signed { IntPredicate::IntSGT } else { IntPredicate::IntUGT },
66 hir::BinOpKind::Ge => if signed { IntPredicate::IntSGE } else { IntPredicate::IntUGE },
68 bug!("comparison_op_to_icmp_predicate: expected comparison operator, \
75 pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate {
77 hir::BinOpKind::Eq => RealPredicate::RealOEQ,
78 hir::BinOpKind::Ne => RealPredicate::RealUNE,
79 hir::BinOpKind::Lt => RealPredicate::RealOLT,
80 hir::BinOpKind::Le => RealPredicate::RealOLE,
81 hir::BinOpKind::Gt => RealPredicate::RealOGT,
82 hir::BinOpKind::Ge => RealPredicate::RealOGE,
84 bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \
91 pub fn compare_simd_types<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
99 let signed = match t.sty {
101 let cmp = bin_op_to_fcmp_predicate(op);
102 let cmp = bx.fcmp(cmp, lhs, rhs);
103 return bx.sext(cmp, ret_ty);
105 ty::Uint(_) => false,
107 _ => bug!("compare_simd_types: invalid SIMD type"),
110 let cmp = bin_op_to_icmp_predicate(op, signed);
111 let cmp = bx.icmp(cmp, lhs, rhs);
112 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
113 // to get the correctly sized type. This will compile to a single instruction
114 // once the IR is converted to assembly if the SIMD instruction is supported
115 // by the target architecture.
119 /// Retrieves the information we are losing (making dynamic) in an unsizing
122 /// The `old_info` argument is a bit funny. It is intended for use
123 /// in an upcast, where the new vtable for an object will be derived
124 /// from the old one.
125 pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
129 old_info: Option<Cx::Value>,
131 let (source, target) = cx.tcx().struct_lockstep_tails(source, target);
132 match (&source.sty, &target.sty) {
133 (&ty::Array(_, len), &ty::Slice(_)) => {
134 cx.const_usize(len.unwrap_usize(cx.tcx()))
136 (&ty::Dynamic(..), &ty::Dynamic(..)) => {
137 // For now, upcasts are limited to changes in marker
138 // traits, and hence never actually require an actual
139 // change to the vtable.
140 old_info.expect("unsized_info: missing old info for trait upcast")
142 (_, &ty::Dynamic(ref data, ..)) => {
143 let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
144 .field(cx, FAT_PTR_EXTRA);
145 cx.const_ptrcast(meth::get_vtable(cx, source, data.principal()),
146 cx.backend_type(vtable_ptr))
148 _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
154 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
155 pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
160 ) -> (Bx::Value, Bx::Value) {
161 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
162 match (&src_ty.sty, &dst_ty.sty) {
166 &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) |
167 (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }),
168 &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
169 assert!(bx.cx().type_is_sized(a));
170 let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
171 (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
173 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
174 let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
175 assert!(bx.cx().type_is_sized(a));
176 let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
177 (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
179 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
180 assert_eq!(def_a, def_b);
182 let src_layout = bx.cx().layout_of(src_ty);
183 let dst_layout = bx.cx().layout_of(dst_ty);
184 let mut result = None;
185 for i in 0..src_layout.fields.count() {
186 let src_f = src_layout.field(bx.cx(), i);
187 assert_eq!(src_layout.fields.offset(i).bytes(), 0);
188 assert_eq!(dst_layout.fields.offset(i).bytes(), 0);
192 assert_eq!(src_layout.size, src_f.size);
194 let dst_f = dst_layout.field(bx.cx(), i);
195 assert_ne!(src_f.ty, dst_f.ty);
196 assert_eq!(result, None);
197 result = Some(unsize_thin_ptr(bx, src, src_f.ty, dst_f.ty));
199 let (lldata, llextra) = result.unwrap();
200 // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
201 (bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
202 bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)))
204 _ => bug!("unsize_thin_ptr: called on bad types"),
208 /// Coerce `src`, which is a reference to a value of type `src_ty`,
209 /// to a value of type `dst_ty` and store the result in `dst`
210 pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
212 src: PlaceRef<'tcx, Bx::Value>,
213 dst: PlaceRef<'tcx, Bx::Value>,
215 let src_ty = src.layout.ty;
216 let dst_ty = dst.layout.ty;
217 let mut coerce_ptr = || {
218 let (base, info) = match bx.load_operand(src).val {
219 OperandValue::Pair(base, info) => {
220 // fat-ptr to fat-ptr unsize preserves the vtable
221 // i.e., &'a fmt::Debug+Send => &'a fmt::Debug
222 // So we need to pointercast the base to ensure
223 // the types match up.
224 let thin_ptr = dst.layout.field(bx.cx(), FAT_PTR_ADDR);
225 (bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
227 OperandValue::Immediate(base) => {
228 unsize_thin_ptr(bx, base, src_ty, dst_ty)
230 OperandValue::Ref(..) => bug!()
232 OperandValue::Pair(base, info).store(bx, dst);
234 match (&src_ty.sty, &dst_ty.sty) {
235 (&ty::Ref(..), &ty::Ref(..)) |
236 (&ty::Ref(..), &ty::RawPtr(..)) |
237 (&ty::RawPtr(..), &ty::RawPtr(..)) => {
240 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
244 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
245 assert_eq!(def_a, def_b);
247 for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() {
248 let src_f = src.project_field(bx, i);
249 let dst_f = dst.project_field(bx, i);
251 if dst_f.layout.is_zst() {
255 if src_f.layout.ty == dst_f.layout.ty {
256 memcpy_ty(bx, dst_f.llval, dst_f.align, src_f.llval, src_f.align,
257 src_f.layout, MemFlags::empty());
259 coerce_unsized_into(bx, src_f, dst_f);
263 _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
269 pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
275 cast_shift_rhs(bx, op, lhs, rhs)
278 fn cast_shift_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
284 // Shifts may have any size int on the rhs
286 let mut rhs_llty = bx.cx().val_ty(rhs);
287 let mut lhs_llty = bx.cx().val_ty(lhs);
288 if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
289 rhs_llty = bx.cx().element_type(rhs_llty)
291 if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
292 lhs_llty = bx.cx().element_type(lhs_llty)
294 let rhs_sz = bx.cx().int_width(rhs_llty);
295 let lhs_sz = bx.cx().int_width(lhs_llty);
297 bx.trunc(rhs, lhs_llty)
298 } else if lhs_sz > rhs_sz {
299 // FIXME (#1877: If in the future shifting by negative
300 // values is no longer undefined then this is wrong.
301 bx.zext(rhs, lhs_llty)
310 /// Returns `true` if this session's target will use SEH-based unwinding.
312 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
313 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
314 /// 64-bit MinGW) instead of "full SEH".
315 pub fn wants_msvc_seh(sess: &Session) -> bool {
316 sess.target.target.options.is_like_msvc
319 pub fn from_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
323 if bx.cx().val_ty(val) == bx.cx().type_i1() {
324 bx.zext(val, bx.cx().type_i8())
330 pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
333 layout: layout::TyLayout<'_>,
335 if let layout::Abi::Scalar(ref scalar) = layout.abi {
336 return to_immediate_scalar(bx, val, scalar);
341 pub fn to_immediate_scalar<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
344 scalar: &layout::Scalar,
346 if scalar.is_bool() {
347 return bx.trunc(val, bx.cx().type_i1());
352 pub fn memcpy_ty<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
358 layout: TyLayout<'tcx>,
361 let size = layout.size.bytes();
366 bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags);
369 pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
370 cx: &'a Bx::CodegenCx,
371 instance: Instance<'tcx>,
373 // this is an info! to allow collecting monomorphization statistics
374 // and to allow finding the last function before LLVM aborts from
376 info!("codegen_instance({})", instance);
378 let sig = instance.fn_sig(cx.tcx());
379 let sig = cx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
381 let lldecl = cx.instances().borrow().get(&instance).cloned().unwrap_or_else(||
382 bug!("Instance `{:?}` not already declared", instance));
384 let mir = cx.tcx().instance_mir(instance.def);
385 mir::codegen_mir::<Bx>(cx, lldecl, &mir, instance, sig);
388 /// Creates the `main` function which will initialize the rust runtime and call
389 /// users main function.
390 pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'a Bx::CodegenCx) {
391 let (main_def_id, span) = match cx.tcx().entry_fn(LOCAL_CRATE) {
392 Some((def_id, _)) => { (def_id, cx.tcx().def_span(def_id)) },
396 let instance = Instance::mono(cx.tcx(), main_def_id);
398 if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
399 // We want to create the wrapper in the same codegen unit as Rust's main
404 let main_llfn = cx.get_fn(instance);
406 let et = cx.tcx().entry_fn(LOCAL_CRATE).map(|e| e.1);
408 Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
409 Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
410 None => {} // Do nothing.
413 fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
414 cx: &'a Bx::CodegenCx,
416 rust_main: Bx::Value,
417 rust_main_def_id: DefId,
418 use_start_lang_item: bool,
421 cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int());
423 let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
424 // Given that `main()` has no arguments,
425 // then its return type cannot have
426 // late-bound regions, since late-bound
427 // regions must appear in the argument
429 let main_ret_ty = cx.tcx().erase_regions(
430 &main_ret_ty.no_bound_vars().unwrap(),
433 if cx.get_defined_value("main").is_some() {
434 // FIXME: We should be smart and show a better diagnostic here.
435 cx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
436 .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
438 cx.sess().abort_if_errors();
441 let llfn = cx.declare_cfn("main", llfty);
443 // `main` should respect same config for frame pointer elimination as rest of code
444 cx.set_frame_pointer_elimination(llfn);
445 cx.apply_target_cpu_attr(llfn);
447 let mut bx = Bx::new_block(&cx, llfn, "top");
449 bx.insert_reference_to_gdb_debug_scripts_section_global();
451 // Params from native main() used as args for rust start function
452 let param_argc = bx.get_param(0);
453 let param_argv = bx.get_param(1);
454 let arg_argc = bx.intcast(param_argc, cx.type_isize(), true);
455 let arg_argv = param_argv;
457 let (start_fn, args) = if use_start_lang_item {
458 let start_def_id = cx.tcx().require_lang_item(StartFnLangItem);
459 let start_fn = callee::resolve_and_get_fn(
462 cx.tcx().intern_substs(&[main_ret_ty.into()]),
464 (start_fn, vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())),
467 debug!("using user-defined start fn");
468 (rust_main, vec![arg_argc, arg_argv])
471 let result = bx.call(start_fn, &args, None);
472 let cast = bx.intcast(result, cx.type_int(), true);
477 pub const CODEGEN_WORKER_ID: usize = ::std::usize::MAX;
479 pub fn codegen_crate<B: ExtraBackendMethods>(
482 metadata: EncodedMetadata,
483 need_metadata_module: bool,
484 rx: mpsc::Receiver<Box<dyn Any + Send>>,
485 ) -> OngoingCodegen<B> {
486 check_for_rustc_errors_attr(tcx);
488 // Skip crate items and just output metadata in -Z no-codegen mode.
489 if tcx.sess.opts.debugging_opts.no_codegen ||
490 !tcx.sess.opts.output_types.should_codegen() {
491 let ongoing_codegen = start_async_codegen(
498 ongoing_codegen.codegen_finished(tcx);
500 assert_and_save_dep_graph(tcx);
502 ongoing_codegen.check_for_errors(tcx.sess);
504 return ongoing_codegen;
507 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
509 // Run the monomorphization collector and partition the collected items into
511 let codegen_units = tcx.collect_and_partition_mono_items(LOCAL_CRATE).1;
512 let codegen_units = (*codegen_units).clone();
514 // Force all codegen_unit queries so they are already either red or green
515 // when compile_codegen_unit accesses them. We are not able to re-execute
516 // the codegen_unit query from just the DepNode, so an unknown color would
517 // lead to having to re-execute compile_codegen_unit, possibly
519 if tcx.dep_graph.is_fully_enabled() {
520 for cgu in &codegen_units {
521 tcx.codegen_unit(cgu.name().clone());
525 let ongoing_codegen = start_async_codegen(
530 codegen_units.len());
531 let ongoing_codegen = AbortCodegenOnDrop::<B>(Some(ongoing_codegen));
533 // Codegen an allocator shim, if necessary.
535 // If the crate doesn't have an `allocator_kind` set then there's definitely
536 // no shim to generate. Otherwise we also check our dependency graph for all
537 // our output crate types. If anything there looks like its a `Dynamic`
538 // linkage, then it's already got an allocator shim and we'll be using that
539 // one instead. If nothing exists then it's our job to generate the
541 let any_dynamic_crate = tcx.sess.dependency_formats.borrow()
544 use rustc::middle::dependency_format::Linkage;
545 list.iter().any(|&linkage| linkage == Linkage::Dynamic)
547 let allocator_module = if any_dynamic_crate {
549 } else if let Some(kind) = *tcx.sess.allocator_kind.get() {
550 let llmod_id = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
552 Some("allocator")).as_str()
554 let mut modules = backend.new_metadata(tcx, &llmod_id);
555 time(tcx.sess, "write allocator module", || {
556 backend.codegen_allocator(tcx, &mut modules, kind)
561 module_llvm: modules,
562 kind: ModuleKind::Allocator,
568 if let Some(allocator_module) = allocator_module {
569 ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, allocator_module);
572 if need_metadata_module {
573 // Codegen the encoded metadata.
574 tcx.sess.profiler(|p| p.start_activity("codegen crate metadata"));
576 let metadata_cgu_name = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
578 Some("metadata")).as_str()
580 let mut metadata_llvm_module = backend.new_metadata(tcx, &metadata_cgu_name);
581 time(tcx.sess, "write compressed metadata", || {
582 backend.write_compressed_metadata(tcx, &ongoing_codegen.metadata,
583 &mut metadata_llvm_module);
585 tcx.sess.profiler(|p| p.end_activity("codegen crate metadata"));
587 let metadata_module = ModuleCodegen {
588 name: metadata_cgu_name,
589 module_llvm: metadata_llvm_module,
590 kind: ModuleKind::Metadata,
592 ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, metadata_module);
595 // We sort the codegen units by size. This way we can schedule work for LLVM
596 // a bit more efficiently.
597 let codegen_units = {
598 let mut codegen_units = codegen_units;
599 codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
603 let mut total_codegen_time = Duration::new(0, 0);
605 for cgu in codegen_units.into_iter() {
606 ongoing_codegen.wait_for_signal_to_codegen_item();
607 ongoing_codegen.check_for_errors(tcx.sess);
609 let cgu_reuse = determine_cgu_reuse(tcx, &cgu);
610 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
614 tcx.sess.profiler(|p| p.start_activity(format!("codegen {}", cgu.name())));
615 let start_time = Instant::now();
616 backend.compile_codegen_unit(tcx, *cgu.name());
617 total_codegen_time += start_time.elapsed();
618 tcx.sess.profiler(|p| p.end_activity(format!("codegen {}", cgu.name())));
621 CguReuse::PreLto => {
622 submit_pre_lto_module_to_llvm(&backend, tcx, CachedModuleCodegen {
623 name: cgu.name().to_string(),
624 source: cgu.work_product(tcx),
628 CguReuse::PostLto => {
629 submit_post_lto_module_to_llvm(&backend, tcx, CachedModuleCodegen {
630 name: cgu.name().to_string(),
631 source: cgu.work_product(tcx),
638 ongoing_codegen.codegen_finished(tcx);
640 // Since the main thread is sometimes blocked during codegen, we keep track
641 // -Ztime-passes output manually.
642 print_time_passes_entry(tcx.sess.time_passes(),
643 "codegen to LLVM IR",
646 ::rustc_incremental::assert_module_sources::assert_module_sources(tcx);
648 symbol_names_test::report_symbol_names(tcx);
650 ongoing_codegen.check_for_errors(tcx.sess);
652 assert_and_save_dep_graph(tcx);
653 ongoing_codegen.into_inner()
656 /// A curious wrapper structure whose only purpose is to call `codegen_aborted`
657 /// when it's dropped abnormally.
659 /// In the process of working on rust-lang/rust#55238 a mysterious segfault was
660 /// stumbled upon. The segfault was never reproduced locally, but it was
661 /// suspected to be related to the fact that codegen worker threads were
662 /// sticking around by the time the main thread was exiting, causing issues.
664 /// This structure is an attempt to fix that issue where the `codegen_aborted`
665 /// message will block until all workers have finished. This should ensure that
666 /// even if the main codegen thread panics we'll wait for pending work to
667 /// complete before returning from the main thread, hopefully avoiding
670 /// If you see this comment in the code, then it means that this workaround
671 /// worked! We may yet one day track down the mysterious cause of that
673 struct AbortCodegenOnDrop<B: ExtraBackendMethods>(Option<OngoingCodegen<B>>);
675 impl<B: ExtraBackendMethods> AbortCodegenOnDrop<B> {
676 fn into_inner(mut self) -> OngoingCodegen<B> {
677 self.0.take().unwrap()
681 impl<B: ExtraBackendMethods> Deref for AbortCodegenOnDrop<B> {
682 type Target = OngoingCodegen<B>;
684 fn deref(&self) -> &OngoingCodegen<B> {
685 self.0.as_ref().unwrap()
689 impl<B: ExtraBackendMethods> DerefMut for AbortCodegenOnDrop<B> {
690 fn deref_mut(&mut self) -> &mut OngoingCodegen<B> {
691 self.0.as_mut().unwrap()
695 impl<B: ExtraBackendMethods> Drop for AbortCodegenOnDrop<B> {
697 if let Some(codegen) = self.0.take() {
698 codegen.codegen_aborted();
703 fn assert_and_save_dep_graph<'tcx>(tcx: TyCtxt<'tcx>) {
706 || ::rustc_incremental::assert_dep_graph(tcx));
709 "serialize dep graph",
710 || ::rustc_incremental::save_dep_graph(tcx));
714 pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
715 let mut info = CrateInfo {
717 compiler_builtins: None,
718 profiler_runtime: None,
719 sanitizer_runtime: None,
720 is_no_builtins: Default::default(),
721 native_libraries: Default::default(),
722 used_libraries: tcx.native_libraries(LOCAL_CRATE),
723 link_args: tcx.link_args(LOCAL_CRATE),
724 crate_name: Default::default(),
725 used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
726 used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
727 used_crate_source: Default::default(),
728 lang_item_to_crate: Default::default(),
729 missing_lang_items: Default::default(),
731 let lang_items = tcx.lang_items();
733 let crates = tcx.crates();
735 let n_crates = crates.len();
736 info.native_libraries.reserve(n_crates);
737 info.crate_name.reserve(n_crates);
738 info.used_crate_source.reserve(n_crates);
739 info.missing_lang_items.reserve(n_crates);
741 for &cnum in crates.iter() {
742 info.native_libraries.insert(cnum, tcx.native_libraries(cnum));
743 info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string());
744 info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum));
745 if tcx.is_panic_runtime(cnum) {
746 info.panic_runtime = Some(cnum);
748 if tcx.is_compiler_builtins(cnum) {
749 info.compiler_builtins = Some(cnum);
751 if tcx.is_profiler_runtime(cnum) {
752 info.profiler_runtime = Some(cnum);
754 if tcx.is_sanitizer_runtime(cnum) {
755 info.sanitizer_runtime = Some(cnum);
757 if tcx.is_no_builtins(cnum) {
758 info.is_no_builtins.insert(cnum);
760 let missing = tcx.missing_lang_items(cnum);
761 for &item in missing.iter() {
762 if let Ok(id) = lang_items.require(item) {
763 info.lang_item_to_crate.insert(item, id.krate);
767 // No need to look for lang items that are whitelisted and don't
768 // actually need to exist.
769 let missing = missing.iter()
771 .filter(|&l| !weak_lang_items::whitelisted(tcx, l))
773 info.missing_lang_items.insert(cnum, missing);
780 fn is_codegened_item(tcx: TyCtxt<'_>, id: DefId) -> bool {
781 let (all_mono_items, _) =
782 tcx.collect_and_partition_mono_items(LOCAL_CRATE);
783 all_mono_items.contains(&id)
786 pub fn provide_both(providers: &mut Providers<'_>) {
787 providers.backend_optimization_level = |tcx, cratenum| {
788 let for_speed = match tcx.sess.opts.optimize {
789 // If globally no optimisation is done, #[optimize] has no effect.
791 // This is done because if we ended up "upgrading" to `-O2` here, we’d populate the
792 // pass manager and it is likely that some module-wide passes (such as inliner or
793 // cross-function constant propagation) would ignore the `optnone` annotation we put
794 // on the functions, thus necessarily involving these functions into optimisations.
795 config::OptLevel::No => return config::OptLevel::No,
796 // If globally optimise-speed is already specified, just use that level.
797 config::OptLevel::Less => return config::OptLevel::Less,
798 config::OptLevel::Default => return config::OptLevel::Default,
799 config::OptLevel::Aggressive => return config::OptLevel::Aggressive,
800 // If globally optimize-for-size has been requested, use -O2 instead (if optimize(size)
802 config::OptLevel::Size => config::OptLevel::Default,
803 config::OptLevel::SizeMin => config::OptLevel::Default,
806 let (defids, _) = tcx.collect_and_partition_mono_items(cratenum);
808 let hir::CodegenFnAttrs { optimize, .. } = tcx.codegen_fn_attrs(*id);
810 attr::OptimizeAttr::None => continue,
811 attr::OptimizeAttr::Size => continue,
812 attr::OptimizeAttr::Speed => {
817 return tcx.sess.opts.optimize;
820 providers.dllimport_foreign_items = |tcx, krate| {
821 let module_map = tcx.foreign_modules(krate);
822 let module_map = module_map.iter()
823 .map(|lib| (lib.def_id, lib))
824 .collect::<FxHashMap<_, _>>();
826 let dllimports = tcx.native_libraries(krate)
829 if lib.kind != cstore::NativeLibraryKind::NativeUnknown {
832 let cfg = match lib.cfg {
833 Some(ref cfg) => cfg,
836 attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
838 .filter_map(|lib| lib.foreign_module)
839 .map(|id| &module_map[&id])
840 .flat_map(|module| module.foreign_items.iter().cloned())
842 tcx.arena.alloc(dllimports)
845 providers.is_dllimport_foreign_item = |tcx, def_id| {
846 tcx.dllimport_foreign_items(def_id.krate).contains(&def_id)
850 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
851 if !tcx.dep_graph.is_fully_enabled() {
855 let work_product_id = &cgu.work_product_id();
856 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
857 // We don't have anything cached for this CGU. This can happen
858 // if the CGU did not exist in the previous session.
862 // Try to mark the CGU as green. If it we can do so, it means that nothing
863 // affecting the LLVM module has changed and we can re-use a cached version.
864 // If we compile with any kind of LTO, this means we can re-use the bitcode
865 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
866 // know that later). If we are not doing LTO, there is only one optimized
867 // version of each module, so we re-use that.
868 let dep_node = cgu.codegen_dep_node(tcx);
869 assert!(!tcx.dep_graph.dep_node_exists(&dep_node),
870 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
873 if tcx.dep_graph.try_mark_green(tcx, &dep_node).is_some() {
874 // We can re-use either the pre- or the post-thinlto state
875 if tcx.sess.lto() != Lto::No {