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::back::write::{
17 start_async_codegen, submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm,
20 use crate::common::{IntPredicate, RealPredicate, TypeKind};
23 use crate::mir::operand::OperandValue;
24 use crate::mir::place::PlaceRef;
26 use crate::{CachedModuleCodegen, CrateInfo, MemFlags, ModuleCodegen, ModuleKind};
29 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
30 use rustc::middle::cstore::EncodedMetadata;
31 use rustc::middle::cstore::{self, LinkagePreference};
32 use rustc::middle::lang_items::StartFnLangItem;
33 use rustc::middle::weak_lang_items;
34 use rustc::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
35 use rustc::session::config::{self, EntryFnType, Lto};
36 use rustc::session::Session;
37 use rustc::ty::layout::{self, Align, HasTyCtxt, LayoutOf, TyLayout, VariantIdx};
38 use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
39 use rustc::ty::query::Providers;
40 use rustc::ty::{self, Instance, Ty, TyCtxt};
41 use rustc::util::common::{print_time_passes_entry, set_time_depth, time, time_depth};
42 use rustc::util::nodemap::FxHashMap;
43 use rustc_codegen_utils::{check_for_rustc_errors_attr, symbol_names_test};
44 use rustc_index::vec::Idx;
45 use rustc_session::cgu_reuse_tracker::CguReuse;
50 use std::ops::{Deref, DerefMut};
51 use std::time::{Duration, Instant};
53 pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind, signed: bool) -> IntPredicate {
55 hir::BinOpKind::Eq => IntPredicate::IntEQ,
56 hir::BinOpKind::Ne => IntPredicate::IntNE,
57 hir::BinOpKind::Lt => {
64 hir::BinOpKind::Le => {
71 hir::BinOpKind::Gt => {
78 hir::BinOpKind::Ge => {
86 "comparison_op_to_icmp_predicate: expected comparison operator, \
93 pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate {
95 hir::BinOpKind::Eq => RealPredicate::RealOEQ,
96 hir::BinOpKind::Ne => RealPredicate::RealUNE,
97 hir::BinOpKind::Lt => RealPredicate::RealOLT,
98 hir::BinOpKind::Le => RealPredicate::RealOLE,
99 hir::BinOpKind::Gt => RealPredicate::RealOGT,
100 hir::BinOpKind::Ge => RealPredicate::RealOGE,
103 "comparison_op_to_fcmp_predicate: expected comparison operator, \
111 pub fn compare_simd_types<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
119 let signed = match t.kind {
121 let cmp = bin_op_to_fcmp_predicate(op);
122 let cmp = bx.fcmp(cmp, lhs, rhs);
123 return bx.sext(cmp, ret_ty);
125 ty::Uint(_) => false,
127 _ => bug!("compare_simd_types: invalid SIMD type"),
130 let cmp = bin_op_to_icmp_predicate(op, signed);
131 let cmp = bx.icmp(cmp, lhs, rhs);
132 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
133 // to get the correctly sized type. This will compile to a single instruction
134 // once the IR is converted to assembly if the SIMD instruction is supported
135 // by the target architecture.
139 /// Retrieves the information we are losing (making dynamic) in an unsizing
142 /// The `old_info` argument is a bit odd. It is intended for use in an upcast,
143 /// where the new vtable for an object will be derived from the old one.
144 pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
148 old_info: Option<Cx::Value>,
150 let (source, target) =
151 cx.tcx().struct_lockstep_tails_erasing_lifetimes(source, target, cx.param_env());
152 match (&source.kind, &target.kind) {
153 (&ty::Array(_, len), &ty::Slice(_)) => {
154 cx.const_usize(len.eval_usize(cx.tcx(), ty::ParamEnv::reveal_all()))
156 (&ty::Dynamic(..), &ty::Dynamic(..)) => {
157 // For now, upcasts are limited to changes in marker
158 // traits, and hence never actually require an actual
159 // change to the vtable.
160 old_info.expect("unsized_info: missing old info for trait upcast")
162 (_, &ty::Dynamic(ref data, ..)) => {
163 let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target)).field(cx, FAT_PTR_EXTRA);
165 meth::get_vtable(cx, source, data.principal()),
166 cx.backend_type(vtable_ptr),
169 _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}", source, target),
173 /// Coerces `src` to `dst_ty`. `src_ty` must be a thin pointer.
174 pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
179 ) -> (Bx::Value, Bx::Value) {
180 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
181 match (&src_ty.kind, &dst_ty.kind) {
182 (&ty::Ref(_, a, _), &ty::Ref(_, b, _))
183 | (&ty::Ref(_, a, _), &ty::RawPtr(ty::TypeAndMut { ty: b, .. }))
184 | (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }), &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
185 assert!(bx.cx().type_is_sized(a));
186 let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
187 (bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
189 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
190 assert_eq!(def_a, def_b);
192 let src_layout = bx.cx().layout_of(src_ty);
193 let dst_layout = bx.cx().layout_of(dst_ty);
194 let mut result = None;
195 for i in 0..src_layout.fields.count() {
196 let src_f = src_layout.field(bx.cx(), i);
197 assert_eq!(src_layout.fields.offset(i).bytes(), 0);
198 assert_eq!(dst_layout.fields.offset(i).bytes(), 0);
202 assert_eq!(src_layout.size, src_f.size);
204 let dst_f = dst_layout.field(bx.cx(), i);
205 assert_ne!(src_f.ty, dst_f.ty);
206 assert_eq!(result, None);
207 result = Some(unsize_thin_ptr(bx, src, src_f.ty, dst_f.ty));
209 let (lldata, llextra) = result.unwrap();
210 // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
211 // FIXME(eddyb) move these out of this `match` arm, so they're always
212 // applied, uniformly, no matter the source/destination types.
214 bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
215 bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)),
218 _ => bug!("unsize_thin_ptr: called on bad types"),
222 /// Coerces `src`, which is a reference to a value of type `src_ty`,
223 /// to a value of type `dst_ty`, and stores the result in `dst`.
224 pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
226 src: PlaceRef<'tcx, Bx::Value>,
227 dst: PlaceRef<'tcx, Bx::Value>,
229 let src_ty = src.layout.ty;
230 let dst_ty = dst.layout.ty;
231 match (&src_ty.kind, &dst_ty.kind) {
232 (&ty::Ref(..), &ty::Ref(..))
233 | (&ty::Ref(..), &ty::RawPtr(..))
234 | (&ty::RawPtr(..), &ty::RawPtr(..)) => {
235 let (base, info) = match bx.load_operand(src).val {
236 OperandValue::Pair(base, info) => {
237 // fat-ptr to fat-ptr unsize preserves the vtable
238 // i.e., &'a fmt::Debug+Send => &'a fmt::Debug
239 // So we need to pointercast the base to ensure
240 // the types match up.
241 // FIXME(eddyb) use `scalar_pair_element_backend_type` here,
242 // like `unsize_thin_ptr` does.
243 let thin_ptr = dst.layout.field(bx.cx(), FAT_PTR_ADDR);
244 (bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
246 OperandValue::Immediate(base) => unsize_thin_ptr(bx, base, src_ty, dst_ty),
247 OperandValue::Ref(..) => bug!(),
249 OperandValue::Pair(base, info).store(bx, dst);
252 (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
253 assert_eq!(def_a, def_b);
255 for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() {
256 let src_f = src.project_field(bx, i);
257 let dst_f = dst.project_field(bx, i);
259 if dst_f.layout.is_zst() {
263 if src_f.layout.ty == dst_f.layout.ty {
274 coerce_unsized_into(bx, src_f, dst_f);
278 _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}", src_ty, dst_ty,),
282 pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
288 cast_shift_rhs(bx, op, lhs, rhs)
291 fn cast_shift_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
297 // Shifts may have any size int on the rhs
299 let mut rhs_llty = bx.cx().val_ty(rhs);
300 let mut lhs_llty = bx.cx().val_ty(lhs);
301 if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
302 rhs_llty = bx.cx().element_type(rhs_llty)
304 if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
305 lhs_llty = bx.cx().element_type(lhs_llty)
307 let rhs_sz = bx.cx().int_width(rhs_llty);
308 let lhs_sz = bx.cx().int_width(lhs_llty);
310 bx.trunc(rhs, lhs_llty)
311 } else if lhs_sz > rhs_sz {
312 // FIXME (#1877: If in the future shifting by negative
313 // values is no longer undefined then this is wrong.
314 bx.zext(rhs, lhs_llty)
323 /// Returns `true` if this session's target will use SEH-based unwinding.
325 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
326 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
327 /// 64-bit MinGW) instead of "full SEH".
328 pub fn wants_msvc_seh(sess: &Session) -> bool {
329 sess.target.target.options.is_like_msvc
332 pub fn from_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
336 if bx.cx().val_ty(val) == bx.cx().type_i1() { bx.zext(val, bx.cx().type_i8()) } else { val }
339 pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
342 layout: layout::TyLayout<'_>,
344 if let layout::Abi::Scalar(ref scalar) = layout.abi {
345 return to_immediate_scalar(bx, val, scalar);
350 pub fn to_immediate_scalar<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
353 scalar: &layout::Scalar,
355 if scalar.is_bool() {
356 return bx.trunc(val, bx.cx().type_i1());
361 pub fn memcpy_ty<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
367 layout: TyLayout<'tcx>,
370 let size = layout.size.bytes();
375 bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags);
378 pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
379 cx: &'a Bx::CodegenCx,
380 instance: Instance<'tcx>,
382 // this is an info! to allow collecting monomorphization statistics
383 // and to allow finding the last function before LLVM aborts from
385 info!("codegen_instance({})", instance);
387 mir::codegen_mir::<Bx>(cx, instance);
390 /// Creates the `main` function which will initialize the rust runtime and call
391 /// users main function.
392 pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'a Bx::CodegenCx) {
393 let (main_def_id, span) = match cx.tcx().entry_fn(LOCAL_CRATE) {
394 Some((def_id, _)) => (def_id, cx.tcx().def_span(def_id)),
398 let instance = Instance::mono(cx.tcx(), main_def_id);
400 if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
401 // We want to create the wrapper in the same codegen unit as Rust's main
406 let main_llfn = cx.get_fn_addr(instance);
408 let et = cx.tcx().entry_fn(LOCAL_CRATE).map(|e| e.1);
410 Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
411 Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
412 None => {} // Do nothing.
415 fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
416 cx: &'a Bx::CodegenCx,
418 rust_main: Bx::Value,
419 rust_main_def_id: DefId,
420 use_start_lang_item: bool,
422 // The entry function is either `int main(void)` or `int main(int argc, char **argv)`,
423 // depending on whether the target needs `argc` and `argv` to be passed in.
424 let llfty = if cx.sess().target.target.options.main_needs_argc_argv {
425 cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int())
427 cx.type_func(&[], cx.type_int())
430 let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
431 // Given that `main()` has no arguments,
432 // then its return type cannot have
433 // late-bound regions, since late-bound
434 // regions must appear in the argument
436 let main_ret_ty = cx.tcx().erase_regions(&main_ret_ty.no_bound_vars().unwrap());
438 if cx.get_defined_value("main").is_some() {
439 // FIXME: We should be smart and show a better diagnostic here.
441 .struct_span_err(sp, "entry symbol `main` defined multiple times")
442 .help("did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead")
444 cx.sess().abort_if_errors();
447 let llfn = cx.declare_cfn("main", llfty);
449 // `main` should respect same config for frame pointer elimination as rest of code
450 cx.set_frame_pointer_elimination(llfn);
451 cx.apply_target_cpu_attr(llfn);
453 let mut bx = Bx::new_block(&cx, llfn, "top");
455 bx.insert_reference_to_gdb_debug_scripts_section_global();
457 let (arg_argc, arg_argv) = get_argc_argv(cx, &mut bx);
459 let (start_fn, args) = if use_start_lang_item {
460 let start_def_id = cx.tcx().require_lang_item(StartFnLangItem, None);
461 let start_fn = cx.get_fn_addr(
462 ty::Instance::resolve(
464 ty::ParamEnv::reveal_all(),
466 cx.tcx().intern_substs(&[main_ret_ty.into()]),
472 vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())), arg_argc, arg_argv],
475 debug!("using user-defined start fn");
476 (rust_main, vec![arg_argc, arg_argv])
479 let result = bx.call(start_fn, &args, None);
480 let cast = bx.intcast(result, cx.type_int(), true);
485 /// Obtain the `argc` and `argv` values to pass to the rust start function.
486 fn get_argc_argv<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
487 cx: &'a Bx::CodegenCx,
489 ) -> (Bx::Value, Bx::Value) {
490 if cx.sess().target.target.options.main_needs_argc_argv {
491 // Params from native `main()` used as args for rust start function
492 let param_argc = bx.get_param(0);
493 let param_argv = bx.get_param(1);
494 let arg_argc = bx.intcast(param_argc, cx.type_isize(), true);
495 let arg_argv = param_argv;
498 // The Rust start function doesn't need `argc` and `argv`, so just pass zeros.
499 let arg_argc = bx.const_int(cx.type_int(), 0);
500 let arg_argv = bx.const_null(cx.type_ptr_to(cx.type_i8p()));
505 pub const CODEGEN_WORKER_ID: usize = ::std::usize::MAX;
507 pub fn codegen_crate<B: ExtraBackendMethods>(
510 metadata: EncodedMetadata,
511 need_metadata_module: bool,
512 ) -> OngoingCodegen<B> {
513 check_for_rustc_errors_attr(tcx);
515 // Skip crate items and just output metadata in -Z no-codegen mode.
516 if tcx.sess.opts.debugging_opts.no_codegen || !tcx.sess.opts.output_types.should_codegen() {
517 let ongoing_codegen = start_async_codegen(backend, tcx, metadata, 1);
519 ongoing_codegen.codegen_finished(tcx);
521 assert_and_save_dep_graph(tcx);
523 ongoing_codegen.check_for_errors(tcx.sess);
525 return ongoing_codegen;
528 let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
530 // Run the monomorphization collector and partition the collected items into
532 let codegen_units = tcx.collect_and_partition_mono_items(LOCAL_CRATE).1;
533 let codegen_units = (*codegen_units).clone();
535 // Force all codegen_unit queries so they are already either red or green
536 // when compile_codegen_unit accesses them. We are not able to re-execute
537 // the codegen_unit query from just the DepNode, so an unknown color would
538 // lead to having to re-execute compile_codegen_unit, possibly
540 if tcx.dep_graph.is_fully_enabled() {
541 for cgu in &codegen_units {
542 tcx.codegen_unit(cgu.name());
546 let ongoing_codegen = start_async_codegen(backend.clone(), tcx, metadata, codegen_units.len());
547 let ongoing_codegen = AbortCodegenOnDrop::<B>(Some(ongoing_codegen));
549 // Codegen an allocator shim, if necessary.
551 // If the crate doesn't have an `allocator_kind` set then there's definitely
552 // no shim to generate. Otherwise we also check our dependency graph for all
553 // our output crate types. If anything there looks like its a `Dynamic`
554 // linkage, then it's already got an allocator shim and we'll be using that
555 // one instead. If nothing exists then it's our job to generate the
557 let any_dynamic_crate = tcx.dependency_formats(LOCAL_CRATE).iter().any(|(_, list)| {
558 use rustc::middle::dependency_format::Linkage;
559 list.iter().any(|&linkage| linkage == Linkage::Dynamic)
561 let allocator_module = if any_dynamic_crate {
563 } else if let Some(kind) = tcx.allocator_kind() {
565 cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("allocator")).to_string();
566 let mut modules = backend.new_metadata(tcx, &llmod_id);
567 time(tcx.sess, "write allocator module", || {
568 backend.codegen_allocator(tcx, &mut modules, kind)
571 Some(ModuleCodegen { name: llmod_id, module_llvm: modules, kind: ModuleKind::Allocator })
576 if let Some(allocator_module) = allocator_module {
577 ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, allocator_module);
580 if need_metadata_module {
581 // Codegen the encoded metadata.
582 let metadata_cgu_name =
583 cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata")).to_string();
584 let mut metadata_llvm_module = backend.new_metadata(tcx, &metadata_cgu_name);
585 time(tcx.sess, "write compressed metadata", || {
586 backend.write_compressed_metadata(
588 &ongoing_codegen.metadata,
589 &mut metadata_llvm_module,
593 let metadata_module = ModuleCodegen {
594 name: metadata_cgu_name,
595 module_llvm: metadata_llvm_module,
596 kind: ModuleKind::Metadata,
598 ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, metadata_module);
601 // We sort the codegen units by size. This way we can schedule work for LLVM
602 // a bit more efficiently.
603 let codegen_units = {
604 let mut codegen_units = codegen_units;
605 codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
609 let mut total_codegen_time = Duration::new(0, 0);
611 for cgu in codegen_units.into_iter() {
612 ongoing_codegen.wait_for_signal_to_codegen_item();
613 ongoing_codegen.check_for_errors(tcx.sess);
615 let cgu_reuse = determine_cgu_reuse(tcx, &cgu);
616 tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
620 let start_time = Instant::now();
621 backend.compile_codegen_unit(tcx, cgu.name(), &ongoing_codegen.coordinator_send);
622 total_codegen_time += start_time.elapsed();
625 CguReuse::PreLto => {
626 submit_pre_lto_module_to_llvm(
629 &ongoing_codegen.coordinator_send,
630 CachedModuleCodegen {
631 name: cgu.name().to_string(),
632 source: cgu.work_product(tcx),
637 CguReuse::PostLto => {
638 submit_post_lto_module_to_llvm(
640 &ongoing_codegen.coordinator_send,
641 CachedModuleCodegen {
642 name: cgu.name().to_string(),
643 source: cgu.work_product(tcx),
651 ongoing_codegen.codegen_finished(tcx);
653 // Since the main thread is sometimes blocked during codegen, we keep track
654 // -Ztime-passes output manually.
655 let time_depth = time_depth();
656 set_time_depth(time_depth + 1);
657 print_time_passes_entry(tcx.sess.time_passes(), "codegen to LLVM IR", total_codegen_time);
658 set_time_depth(time_depth);
660 ::rustc_incremental::assert_module_sources::assert_module_sources(tcx);
662 symbol_names_test::report_symbol_names(tcx);
664 ongoing_codegen.check_for_errors(tcx.sess);
666 assert_and_save_dep_graph(tcx);
667 ongoing_codegen.into_inner()
670 /// A curious wrapper structure whose only purpose is to call `codegen_aborted`
671 /// when it's dropped abnormally.
673 /// In the process of working on rust-lang/rust#55238 a mysterious segfault was
674 /// stumbled upon. The segfault was never reproduced locally, but it was
675 /// suspected to be related to the fact that codegen worker threads were
676 /// sticking around by the time the main thread was exiting, causing issues.
678 /// This structure is an attempt to fix that issue where the `codegen_aborted`
679 /// message will block until all workers have finished. This should ensure that
680 /// even if the main codegen thread panics we'll wait for pending work to
681 /// complete before returning from the main thread, hopefully avoiding
684 /// If you see this comment in the code, then it means that this workaround
685 /// worked! We may yet one day track down the mysterious cause of that
687 struct AbortCodegenOnDrop<B: ExtraBackendMethods>(Option<OngoingCodegen<B>>);
689 impl<B: ExtraBackendMethods> AbortCodegenOnDrop<B> {
690 fn into_inner(mut self) -> OngoingCodegen<B> {
691 self.0.take().unwrap()
695 impl<B: ExtraBackendMethods> Deref for AbortCodegenOnDrop<B> {
696 type Target = OngoingCodegen<B>;
698 fn deref(&self) -> &OngoingCodegen<B> {
699 self.0.as_ref().unwrap()
703 impl<B: ExtraBackendMethods> DerefMut for AbortCodegenOnDrop<B> {
704 fn deref_mut(&mut self) -> &mut OngoingCodegen<B> {
705 self.0.as_mut().unwrap()
709 impl<B: ExtraBackendMethods> Drop for AbortCodegenOnDrop<B> {
711 if let Some(codegen) = self.0.take() {
712 codegen.codegen_aborted();
717 fn assert_and_save_dep_graph(tcx: TyCtxt<'_>) {
718 time(tcx.sess, "assert dep graph", || ::rustc_incremental::assert_dep_graph(tcx));
720 time(tcx.sess, "serialize dep graph", || ::rustc_incremental::save_dep_graph(tcx));
724 pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
725 let mut info = CrateInfo {
727 compiler_builtins: None,
728 profiler_runtime: None,
729 sanitizer_runtime: None,
730 is_no_builtins: Default::default(),
731 native_libraries: Default::default(),
732 used_libraries: tcx.native_libraries(LOCAL_CRATE),
733 link_args: tcx.link_args(LOCAL_CRATE),
734 crate_name: Default::default(),
735 used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
736 used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
737 used_crate_source: Default::default(),
738 lang_item_to_crate: Default::default(),
739 missing_lang_items: Default::default(),
740 dependency_formats: tcx.dependency_formats(LOCAL_CRATE),
742 let lang_items = tcx.lang_items();
744 let crates = tcx.crates();
746 let n_crates = crates.len();
747 info.native_libraries.reserve(n_crates);
748 info.crate_name.reserve(n_crates);
749 info.used_crate_source.reserve(n_crates);
750 info.missing_lang_items.reserve(n_crates);
752 for &cnum in crates.iter() {
753 info.native_libraries.insert(cnum, tcx.native_libraries(cnum));
754 info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string());
755 info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum));
756 if tcx.is_panic_runtime(cnum) {
757 info.panic_runtime = Some(cnum);
759 if tcx.is_compiler_builtins(cnum) {
760 info.compiler_builtins = Some(cnum);
762 if tcx.is_profiler_runtime(cnum) {
763 info.profiler_runtime = Some(cnum);
765 if tcx.is_sanitizer_runtime(cnum) {
766 info.sanitizer_runtime = Some(cnum);
768 if tcx.is_no_builtins(cnum) {
769 info.is_no_builtins.insert(cnum);
771 let missing = tcx.missing_lang_items(cnum);
772 for &item in missing.iter() {
773 if let Ok(id) = lang_items.require(item) {
774 info.lang_item_to_crate.insert(item, id.krate);
778 // No need to look for lang items that are whitelisted and don't
779 // actually need to exist.
780 let missing = missing
783 .filter(|&l| !weak_lang_items::whitelisted(tcx, l))
785 info.missing_lang_items.insert(cnum, missing);
792 pub fn provide_both(providers: &mut Providers<'_>) {
793 providers.backend_optimization_level = |tcx, cratenum| {
794 let for_speed = match tcx.sess.opts.optimize {
795 // If globally no optimisation is done, #[optimize] has no effect.
797 // This is done because if we ended up "upgrading" to `-O2` here, we’d populate the
798 // pass manager and it is likely that some module-wide passes (such as inliner or
799 // cross-function constant propagation) would ignore the `optnone` annotation we put
800 // on the functions, thus necessarily involving these functions into optimisations.
801 config::OptLevel::No => return config::OptLevel::No,
802 // If globally optimise-speed is already specified, just use that level.
803 config::OptLevel::Less => return config::OptLevel::Less,
804 config::OptLevel::Default => return config::OptLevel::Default,
805 config::OptLevel::Aggressive => return config::OptLevel::Aggressive,
806 // If globally optimize-for-size has been requested, use -O2 instead (if optimize(size)
808 config::OptLevel::Size => config::OptLevel::Default,
809 config::OptLevel::SizeMin => config::OptLevel::Default,
812 let (defids, _) = tcx.collect_and_partition_mono_items(cratenum);
814 let hir::CodegenFnAttrs { optimize, .. } = tcx.codegen_fn_attrs(*id);
816 attr::OptimizeAttr::None => continue,
817 attr::OptimizeAttr::Size => continue,
818 attr::OptimizeAttr::Speed => {
823 return tcx.sess.opts.optimize;
826 providers.dllimport_foreign_items = |tcx, krate| {
827 let module_map = tcx.foreign_modules(krate);
829 module_map.iter().map(|lib| (lib.def_id, lib)).collect::<FxHashMap<_, _>>();
832 .native_libraries(krate)
835 if lib.kind != cstore::NativeLibraryKind::NativeUnknown {
838 let cfg = match lib.cfg {
839 Some(ref cfg) => cfg,
842 attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
844 .filter_map(|lib| lib.foreign_module)
845 .map(|id| &module_map[&id])
846 .flat_map(|module| module.foreign_items.iter().cloned())
848 tcx.arena.alloc(dllimports)
851 providers.is_dllimport_foreign_item =
852 |tcx, def_id| tcx.dllimport_foreign_items(def_id.krate).contains(&def_id);
855 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {
856 if !tcx.dep_graph.is_fully_enabled() {
860 let work_product_id = &cgu.work_product_id();
861 if tcx.dep_graph.previous_work_product(work_product_id).is_none() {
862 // We don't have anything cached for this CGU. This can happen
863 // if the CGU did not exist in the previous session.
867 // Try to mark the CGU as green. If it we can do so, it means that nothing
868 // affecting the LLVM module has changed and we can re-use a cached version.
869 // If we compile with any kind of LTO, this means we can re-use the bitcode
870 // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only
871 // know that later). If we are not doing LTO, there is only one optimized
872 // version of each module, so we re-use that.
873 let dep_node = cgu.codegen_dep_node(tcx);
875 !tcx.dep_graph.dep_node_exists(&dep_node),
876 "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.",
880 if tcx.dep_graph.try_mark_green(tcx, &dep_node).is_some() {
881 // We can re-use either the pre- or the post-thinlto state
882 if tcx.sess.lto() != Lto::No { CguReuse::PreLto } else { CguReuse::PostLto }