| use crate::back::write::{ |
| compute_per_cgu_lto_type, start_async_codegen, submit_codegened_module_to_llvm, |
| submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm, ComputedLtoType, OngoingCodegen, |
| }; |
| use crate::common::{IntPredicate, RealPredicate, TypeKind}; |
| use crate::meth; |
| use crate::mir; |
| use crate::mir::operand::OperandValue; |
| use crate::mir::place::PlaceRef; |
| use crate::traits::*; |
| use crate::{CachedModuleCodegen, CrateInfo, MemFlags, ModuleCodegen, ModuleKind}; |
| |
| use rustc_attr as attr; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::profiling::{get_resident_set_size, print_time_passes_entry}; |
| use rustc_data_structures::sync::{par_iter, ParallelIterator}; |
| use rustc_hir as hir; |
| use rustc_hir::def_id::{DefId, LOCAL_CRATE}; |
| use rustc_hir::lang_items::LangItem; |
| use rustc_index::vec::Idx; |
| use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs; |
| use rustc_middle::middle::cstore::EncodedMetadata; |
| use rustc_middle::middle::lang_items; |
| use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem}; |
| use rustc_middle::ty::layout::{HasTyCtxt, TyAndLayout}; |
| use rustc_middle::ty::query::Providers; |
| use rustc_middle::ty::{self, Instance, Ty, TyCtxt}; |
| use rustc_session::cgu_reuse_tracker::CguReuse; |
| use rustc_session::config::{self, EntryFnType}; |
| use rustc_session::Session; |
| use rustc_span::symbol::sym; |
| use rustc_target::abi::{Align, LayoutOf, VariantIdx}; |
| |
| use std::convert::TryFrom; |
| use std::ops::{Deref, DerefMut}; |
| use std::time::{Duration, Instant}; |
| |
| use itertools::Itertools; |
| |
| pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind, signed: bool) -> IntPredicate { |
| match op { |
| hir::BinOpKind::Eq => IntPredicate::IntEQ, |
| hir::BinOpKind::Ne => IntPredicate::IntNE, |
| hir::BinOpKind::Lt => { |
| if signed { |
| IntPredicate::IntSLT |
| } else { |
| IntPredicate::IntULT |
| } |
| } |
| hir::BinOpKind::Le => { |
| if signed { |
| IntPredicate::IntSLE |
| } else { |
| IntPredicate::IntULE |
| } |
| } |
| hir::BinOpKind::Gt => { |
| if signed { |
| IntPredicate::IntSGT |
| } else { |
| IntPredicate::IntUGT |
| } |
| } |
| hir::BinOpKind::Ge => { |
| if signed { |
| IntPredicate::IntSGE |
| } else { |
| IntPredicate::IntUGE |
| } |
| } |
| op => bug!( |
| "comparison_op_to_icmp_predicate: expected comparison operator, \ |
| found {:?}", |
| op |
| ), |
| } |
| } |
| |
| pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate { |
| match op { |
| hir::BinOpKind::Eq => RealPredicate::RealOEQ, |
| hir::BinOpKind::Ne => RealPredicate::RealUNE, |
| hir::BinOpKind::Lt => RealPredicate::RealOLT, |
| hir::BinOpKind::Le => RealPredicate::RealOLE, |
| hir::BinOpKind::Gt => RealPredicate::RealOGT, |
| hir::BinOpKind::Ge => RealPredicate::RealOGE, |
| op => { |
| bug!( |
| "comparison_op_to_fcmp_predicate: expected comparison operator, \ |
| found {:?}", |
| op |
| ); |
| } |
| } |
| } |
| |
| pub fn compare_simd_types<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| lhs: Bx::Value, |
| rhs: Bx::Value, |
| t: Ty<'tcx>, |
| ret_ty: Bx::Type, |
| op: hir::BinOpKind, |
| ) -> Bx::Value { |
| let signed = match t.kind() { |
| ty::Float(_) => { |
| let cmp = bin_op_to_fcmp_predicate(op); |
| let cmp = bx.fcmp(cmp, lhs, rhs); |
| return bx.sext(cmp, ret_ty); |
| } |
| ty::Uint(_) => false, |
| ty::Int(_) => true, |
| _ => bug!("compare_simd_types: invalid SIMD type"), |
| }; |
| |
| let cmp = bin_op_to_icmp_predicate(op, signed); |
| let cmp = bx.icmp(cmp, lhs, rhs); |
| // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension |
| // to get the correctly sized type. This will compile to a single instruction |
| // once the IR is converted to assembly if the SIMD instruction is supported |
| // by the target architecture. |
| bx.sext(cmp, ret_ty) |
| } |
| |
| /// Retrieves the information we are losing (making dynamic) in an unsizing |
| /// adjustment. |
| /// |
| /// The `old_info` argument is a bit odd. It is intended for use in an upcast, |
| /// where the new vtable for an object will be derived from the old one. |
| pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| source: Ty<'tcx>, |
| target: Ty<'tcx>, |
| old_info: Option<Bx::Value>, |
| ) -> Bx::Value { |
| let cx = bx.cx(); |
| let (source, target) = |
| cx.tcx().struct_lockstep_tails_erasing_lifetimes(source, target, bx.param_env()); |
| match (source.kind(), target.kind()) { |
| (&ty::Array(_, len), &ty::Slice(_)) => { |
| cx.const_usize(len.eval_usize(cx.tcx(), ty::ParamEnv::reveal_all())) |
| } |
| (&ty::Dynamic(ref data_a, ..), &ty::Dynamic(ref data_b, ..)) => { |
| let old_info = |
| old_info.expect("unsized_info: missing old info for trait upcasting coercion"); |
| if data_a.principal_def_id() == data_b.principal_def_id() { |
| return old_info; |
| } |
| |
| // trait upcasting coercion |
| |
| let vptr_entry_idx = |
| cx.tcx().vtable_trait_upcasting_coercion_new_vptr_slot((source, target)); |
| |
| if let Some(entry_idx) = vptr_entry_idx { |
| let ptr_ty = cx.type_i8p(); |
| let ptr_align = cx.tcx().data_layout.pointer_align.abi; |
| let llvtable = bx.pointercast(old_info, bx.type_ptr_to(ptr_ty)); |
| let gep = bx.inbounds_gep( |
| ptr_ty, |
| llvtable, |
| &[bx.const_usize(u64::try_from(entry_idx).unwrap())], |
| ); |
| let new_vptr = bx.load(ptr_ty, gep, ptr_align); |
| bx.nonnull_metadata(new_vptr); |
| // Vtable loads are invariant. |
| bx.set_invariant_load(new_vptr); |
| new_vptr |
| } else { |
| old_info |
| } |
| } |
| (_, &ty::Dynamic(ref data, ..)) => { |
| let vtable_ptr_ty = cx.scalar_pair_element_backend_type( |
| cx.layout_of(cx.tcx().mk_mut_ptr(target)), |
| 1, |
| true, |
| ); |
| cx.const_ptrcast(meth::get_vtable(cx, source, data.principal()), vtable_ptr_ty) |
| } |
| _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}", source, target), |
| } |
| } |
| |
| /// Coerces `src` to `dst_ty`. `src_ty` must be a pointer. |
| pub fn unsize_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| src: Bx::Value, |
| src_ty: Ty<'tcx>, |
| dst_ty: Ty<'tcx>, |
| old_info: Option<Bx::Value>, |
| ) -> (Bx::Value, Bx::Value) { |
| debug!("unsize_ptr: {:?} => {:?}", src_ty, dst_ty); |
| match (src_ty.kind(), dst_ty.kind()) { |
| (&ty::Ref(_, a, _), &ty::Ref(_, b, _) | &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) |
| | (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }), &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => { |
| assert_eq!(bx.cx().type_is_sized(a), old_info.is_none()); |
| let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b))); |
| (bx.pointercast(src, ptr_ty), unsized_info(bx, a, b, old_info)) |
| } |
| (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => { |
| assert_eq!(def_a, def_b); |
| let src_layout = bx.cx().layout_of(src_ty); |
| let dst_layout = bx.cx().layout_of(dst_ty); |
| if src_ty == dst_ty { |
| return (src, old_info.unwrap()); |
| } |
| let mut result = None; |
| for i in 0..src_layout.fields.count() { |
| let src_f = src_layout.field(bx.cx(), i); |
| assert_eq!(src_layout.fields.offset(i).bytes(), 0); |
| assert_eq!(dst_layout.fields.offset(i).bytes(), 0); |
| if src_f.is_zst() { |
| continue; |
| } |
| assert_eq!(src_layout.size, src_f.size); |
| |
| let dst_f = dst_layout.field(bx.cx(), i); |
| assert_ne!(src_f.ty, dst_f.ty); |
| assert_eq!(result, None); |
| result = Some(unsize_ptr(bx, src, src_f.ty, dst_f.ty, old_info)); |
| } |
| let (lldata, llextra) = result.unwrap(); |
| let lldata_ty = bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true); |
| let llextra_ty = bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true); |
| // HACK(eddyb) have to bitcast pointers until LLVM removes pointee types. |
| (bx.bitcast(lldata, lldata_ty), bx.bitcast(llextra, llextra_ty)) |
| } |
| _ => bug!("unsize_ptr: called on bad types"), |
| } |
| } |
| |
| /// Coerces `src`, which is a reference to a value of type `src_ty`, |
| /// to a value of type `dst_ty`, and stores the result in `dst`. |
| pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| src: PlaceRef<'tcx, Bx::Value>, |
| dst: PlaceRef<'tcx, Bx::Value>, |
| ) { |
| let src_ty = src.layout.ty; |
| let dst_ty = dst.layout.ty; |
| match (src_ty.kind(), dst_ty.kind()) { |
| (&ty::Ref(..), &ty::Ref(..) | &ty::RawPtr(..)) | (&ty::RawPtr(..), &ty::RawPtr(..)) => { |
| let (base, info) = match bx.load_operand(src).val { |
| OperandValue::Pair(base, info) => unsize_ptr(bx, base, src_ty, dst_ty, Some(info)), |
| OperandValue::Immediate(base) => unsize_ptr(bx, base, src_ty, dst_ty, None), |
| OperandValue::Ref(..) => bug!(), |
| }; |
| OperandValue::Pair(base, info).store(bx, dst); |
| } |
| |
| (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => { |
| assert_eq!(def_a, def_b); |
| |
| for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() { |
| let src_f = src.project_field(bx, i); |
| let dst_f = dst.project_field(bx, i); |
| |
| if dst_f.layout.is_zst() { |
| continue; |
| } |
| |
| if src_f.layout.ty == dst_f.layout.ty { |
| memcpy_ty( |
| bx, |
| dst_f.llval, |
| dst_f.align, |
| src_f.llval, |
| src_f.align, |
| src_f.layout, |
| MemFlags::empty(), |
| ); |
| } else { |
| coerce_unsized_into(bx, src_f, dst_f); |
| } |
| } |
| } |
| _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}", src_ty, dst_ty,), |
| } |
| } |
| |
| pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| op: hir::BinOpKind, |
| lhs: Bx::Value, |
| rhs: Bx::Value, |
| ) -> Bx::Value { |
| cast_shift_rhs(bx, op, lhs, rhs) |
| } |
| |
| fn cast_shift_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| op: hir::BinOpKind, |
| lhs: Bx::Value, |
| rhs: Bx::Value, |
| ) -> Bx::Value { |
| // Shifts may have any size int on the rhs |
| if op.is_shift() { |
| let mut rhs_llty = bx.cx().val_ty(rhs); |
| let mut lhs_llty = bx.cx().val_ty(lhs); |
| if bx.cx().type_kind(rhs_llty) == TypeKind::Vector { |
| rhs_llty = bx.cx().element_type(rhs_llty) |
| } |
| if bx.cx().type_kind(lhs_llty) == TypeKind::Vector { |
| lhs_llty = bx.cx().element_type(lhs_llty) |
| } |
| let rhs_sz = bx.cx().int_width(rhs_llty); |
| let lhs_sz = bx.cx().int_width(lhs_llty); |
| if lhs_sz < rhs_sz { |
| bx.trunc(rhs, lhs_llty) |
| } else if lhs_sz > rhs_sz { |
| // FIXME (#1877: If in the future shifting by negative |
| // values is no longer undefined then this is wrong. |
| bx.zext(rhs, lhs_llty) |
| } else { |
| rhs |
| } |
| } else { |
| rhs |
| } |
| } |
| |
| /// Returns `true` if this session's target will use SEH-based unwinding. |
| /// |
| /// This is only true for MSVC targets, and even then the 64-bit MSVC target |
| /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as |
| /// 64-bit MinGW) instead of "full SEH". |
| pub fn wants_msvc_seh(sess: &Session) -> bool { |
| sess.target.is_like_msvc |
| } |
| |
| pub fn memcpy_ty<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| bx: &mut Bx, |
| dst: Bx::Value, |
| dst_align: Align, |
| src: Bx::Value, |
| src_align: Align, |
| layout: TyAndLayout<'tcx>, |
| flags: MemFlags, |
| ) { |
| let size = layout.size.bytes(); |
| if size == 0 { |
| return; |
| } |
| |
| bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags); |
| } |
| |
| pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>( |
| cx: &'a Bx::CodegenCx, |
| instance: Instance<'tcx>, |
| ) { |
| // this is an info! to allow collecting monomorphization statistics |
| // and to allow finding the last function before LLVM aborts from |
| // release builds. |
| info!("codegen_instance({})", instance); |
| |
| mir::codegen_mir::<Bx>(cx, instance); |
| } |
| |
| /// Creates the `main` function which will initialize the rust runtime and call |
| /// users main function. |
| pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| cx: &'a Bx::CodegenCx, |
| ) -> Option<Bx::Function> { |
| let (main_def_id, entry_type) = cx.tcx().entry_fn(())?; |
| let main_is_local = main_def_id.is_local(); |
| let instance = Instance::mono(cx.tcx(), main_def_id); |
| |
| if main_is_local { |
| // We want to create the wrapper in the same codegen unit as Rust's main |
| // function. |
| if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) { |
| return None; |
| } |
| } else if !cx.codegen_unit().is_primary() { |
| // We want to create the wrapper only when the codegen unit is the primary one |
| return None; |
| } |
| |
| let main_llfn = cx.get_fn_addr(instance); |
| |
| let use_start_lang_item = EntryFnType::Start != entry_type; |
| let entry_fn = create_entry_fn::<Bx>(cx, main_llfn, main_def_id, use_start_lang_item); |
| return Some(entry_fn); |
| |
| fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| cx: &'a Bx::CodegenCx, |
| rust_main: Bx::Value, |
| rust_main_def_id: DefId, |
| use_start_lang_item: bool, |
| ) -> Bx::Function { |
| // The entry function is either `int main(void)` or `int main(int argc, char **argv)`, |
| // depending on whether the target needs `argc` and `argv` to be passed in. |
| let llfty = if cx.sess().target.main_needs_argc_argv { |
| cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int()) |
| } else { |
| cx.type_func(&[], cx.type_int()) |
| }; |
| |
| let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output(); |
| // Given that `main()` has no arguments, |
| // then its return type cannot have |
| // late-bound regions, since late-bound |
| // regions must appear in the argument |
| // listing. |
| let main_ret_ty = cx.tcx().erase_regions(main_ret_ty.no_bound_vars().unwrap()); |
| |
| let llfn = match cx.declare_c_main(llfty) { |
| Some(llfn) => llfn, |
| None => { |
| // FIXME: We should be smart and show a better diagnostic here. |
| let span = cx.tcx().def_span(rust_main_def_id); |
| cx.sess() |
| .struct_span_err(span, "entry symbol `main` declared multiple times") |
| .help("did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead") |
| .emit(); |
| cx.sess().abort_if_errors(); |
| bug!(); |
| } |
| }; |
| |
| // `main` should respect same config for frame pointer elimination as rest of code |
| cx.set_frame_pointer_type(llfn); |
| cx.apply_target_cpu_attr(llfn); |
| |
| let llbb = Bx::append_block(&cx, llfn, "top"); |
| let mut bx = Bx::build(&cx, llbb); |
| |
| bx.insert_reference_to_gdb_debug_scripts_section_global(); |
| |
| let isize_ty = cx.type_isize(); |
| let i8pp_ty = cx.type_ptr_to(cx.type_i8p()); |
| let (arg_argc, arg_argv) = get_argc_argv(cx, &mut bx); |
| |
| let (start_fn, start_ty, args) = if use_start_lang_item { |
| let start_def_id = cx.tcx().require_lang_item(LangItem::Start, None); |
| let start_fn = cx.get_fn_addr( |
| ty::Instance::resolve( |
| cx.tcx(), |
| ty::ParamEnv::reveal_all(), |
| start_def_id, |
| cx.tcx().intern_substs(&[main_ret_ty.into()]), |
| ) |
| .unwrap() |
| .unwrap(), |
| ); |
| let start_ty = cx.type_func(&[cx.val_ty(rust_main), isize_ty, i8pp_ty], isize_ty); |
| (start_fn, start_ty, vec![rust_main, arg_argc, arg_argv]) |
| } else { |
| debug!("using user-defined start fn"); |
| let start_ty = cx.type_func(&[isize_ty, i8pp_ty], isize_ty); |
| (rust_main, start_ty, vec![arg_argc, arg_argv]) |
| }; |
| |
| let result = bx.call(start_ty, start_fn, &args, None); |
| let cast = bx.intcast(result, cx.type_int(), true); |
| bx.ret(cast); |
| |
| llfn |
| } |
| } |
| |
| /// Obtain the `argc` and `argv` values to pass to the rust start function. |
| fn get_argc_argv<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( |
| cx: &'a Bx::CodegenCx, |
| bx: &mut Bx, |
| ) -> (Bx::Value, Bx::Value) { |
| if cx.sess().target.main_needs_argc_argv { |
| // Params from native `main()` used as args for rust start function |
| let param_argc = bx.get_param(0); |
| let param_argv = bx.get_param(1); |
| let arg_argc = bx.intcast(param_argc, cx.type_isize(), true); |
| let arg_argv = param_argv; |
| (arg_argc, arg_argv) |
| } else { |
| // The Rust start function doesn't need `argc` and `argv`, so just pass zeros. |
| let arg_argc = bx.const_int(cx.type_int(), 0); |
| let arg_argv = bx.const_null(cx.type_ptr_to(cx.type_i8p())); |
| (arg_argc, arg_argv) |
| } |
| } |
| |
| pub fn codegen_crate<B: ExtraBackendMethods>( |
| backend: B, |
| tcx: TyCtxt<'tcx>, |
| target_cpu: String, |
| metadata: EncodedMetadata, |
| need_metadata_module: bool, |
| ) -> OngoingCodegen<B> { |
| // Skip crate items and just output metadata in -Z no-codegen mode. |
| if tcx.sess.opts.debugging_opts.no_codegen || !tcx.sess.opts.output_types.should_codegen() { |
| let ongoing_codegen = start_async_codegen(backend, tcx, target_cpu, metadata, 1); |
| |
| ongoing_codegen.codegen_finished(tcx); |
| |
| ongoing_codegen.check_for_errors(tcx.sess); |
| |
| return ongoing_codegen; |
| } |
| |
| let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx); |
| |
| // Run the monomorphization collector and partition the collected items into |
| // codegen units. |
| let codegen_units = tcx.collect_and_partition_mono_items(()).1; |
| |
| // Force all codegen_unit queries so they are already either red or green |
| // when compile_codegen_unit accesses them. We are not able to re-execute |
| // the codegen_unit query from just the DepNode, so an unknown color would |
| // lead to having to re-execute compile_codegen_unit, possibly |
| // unnecessarily. |
| if tcx.dep_graph.is_fully_enabled() { |
| for cgu in codegen_units { |
| tcx.ensure().codegen_unit(cgu.name()); |
| } |
| } |
| |
| let ongoing_codegen = |
| start_async_codegen(backend.clone(), tcx, target_cpu, metadata, codegen_units.len()); |
| let ongoing_codegen = AbortCodegenOnDrop::<B>(Some(ongoing_codegen)); |
| |
| // Codegen an allocator shim, if necessary. |
| // |
| // If the crate doesn't have an `allocator_kind` set then there's definitely |
| // no shim to generate. Otherwise we also check our dependency graph for all |
| // our output crate types. If anything there looks like its a `Dynamic` |
| // linkage, then it's already got an allocator shim and we'll be using that |
| // one instead. If nothing exists then it's our job to generate the |
| // allocator! |
| let any_dynamic_crate = tcx.dependency_formats(()).iter().any(|(_, list)| { |
| use rustc_middle::middle::dependency_format::Linkage; |
| list.iter().any(|&linkage| linkage == Linkage::Dynamic) |
| }); |
| let allocator_module = if any_dynamic_crate { |
| None |
| } else if let Some(kind) = tcx.allocator_kind(()) { |
| let llmod_id = |
| cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("allocator")).to_string(); |
| let mut modules = backend.new_metadata(tcx, &llmod_id); |
| tcx.sess.time("write_allocator_module", || { |
| backend.codegen_allocator(tcx, &mut modules, kind, tcx.lang_items().oom().is_some()) |
| }); |
| |
| Some(ModuleCodegen { name: llmod_id, module_llvm: modules, kind: ModuleKind::Allocator }) |
| } else { |
| None |
| }; |
| |
| if let Some(allocator_module) = allocator_module { |
| ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, allocator_module); |
| } |
| |
| if need_metadata_module { |
| // Codegen the encoded metadata. |
| let metadata_cgu_name = |
| cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata")).to_string(); |
| let mut metadata_llvm_module = backend.new_metadata(tcx, &metadata_cgu_name); |
| tcx.sess.time("write_compressed_metadata", || { |
| backend.write_compressed_metadata( |
| tcx, |
| &ongoing_codegen.metadata, |
| &mut metadata_llvm_module, |
| ); |
| }); |
| |
| let metadata_module = ModuleCodegen { |
| name: metadata_cgu_name, |
| module_llvm: metadata_llvm_module, |
| kind: ModuleKind::Metadata, |
| }; |
| ongoing_codegen.submit_pre_codegened_module_to_llvm(tcx, metadata_module); |
| } |
| |
| // For better throughput during parallel processing by LLVM, we used to sort |
| // CGUs largest to smallest. This would lead to better thread utilization |
| // by, for example, preventing a large CGU from being processed last and |
| // having only one LLVM thread working while the rest remained idle. |
| // |
| // However, this strategy would lead to high memory usage, as it meant the |
| // LLVM-IR for all of the largest CGUs would be resident in memory at once. |
| // |
| // Instead, we can compromise by ordering CGUs such that the largest and |
| // smallest are first, second largest and smallest are next, etc. If there |
| // are large size variations, this can reduce memory usage significantly. |
| let codegen_units: Vec<_> = { |
| let mut sorted_cgus = codegen_units.iter().collect::<Vec<_>>(); |
| sorted_cgus.sort_by_cached_key(|cgu| cgu.size_estimate()); |
| |
| let (first_half, second_half) = sorted_cgus.split_at(sorted_cgus.len() / 2); |
| second_half.iter().rev().interleave(first_half).copied().collect() |
| }; |
| |
| // The non-parallel compiler can only translate codegen units to LLVM IR |
| // on a single thread, leading to a staircase effect where the N LLVM |
| // threads have to wait on the single codegen threads to generate work |
| // for them. The parallel compiler does not have this restriction, so |
| // we can pre-load the LLVM queue in parallel before handing off |
| // coordination to the OnGoingCodegen scheduler. |
| // |
| // This likely is a temporary measure. Once we don't have to support the |
| // non-parallel compiler anymore, we can compile CGUs end-to-end in |
| // parallel and get rid of the complicated scheduling logic. |
| let pre_compile_cgus = |cgu_reuse: &[CguReuse]| { |
| if cfg!(parallel_compiler) { |
| tcx.sess.time("compile_first_CGU_batch", || { |
| // Try to find one CGU to compile per thread. |
| let cgus: Vec<_> = cgu_reuse |
| .iter() |
| .enumerate() |
| .filter(|&(_, reuse)| reuse == &CguReuse::No) |
| .take(tcx.sess.threads()) |
| .collect(); |
| |
| // Compile the found CGUs in parallel. |
| let start_time = Instant::now(); |
| |
| let pre_compiled_cgus = par_iter(cgus) |
| .map(|(i, _)| { |
| let module = backend.compile_codegen_unit(tcx, codegen_units[i].name()); |
| (i, module) |
| }) |
| .collect(); |
| |
| (pre_compiled_cgus, start_time.elapsed()) |
| }) |
| } else { |
| (FxHashMap::default(), Duration::new(0, 0)) |
| } |
| }; |
| |
| let mut cgu_reuse = Vec::new(); |
| let mut pre_compiled_cgus: Option<FxHashMap<usize, _>> = None; |
| let mut total_codegen_time = Duration::new(0, 0); |
| let start_rss = tcx.sess.time_passes().then(|| get_resident_set_size()); |
| |
| for (i, cgu) in codegen_units.iter().enumerate() { |
| ongoing_codegen.wait_for_signal_to_codegen_item(); |
| ongoing_codegen.check_for_errors(tcx.sess); |
| |
| // Do some setup work in the first iteration |
| if pre_compiled_cgus.is_none() { |
| // Calculate the CGU reuse |
| cgu_reuse = tcx.sess.time("find_cgu_reuse", || { |
| codegen_units.iter().map(|cgu| determine_cgu_reuse(tcx, &cgu)).collect() |
| }); |
| // Pre compile some CGUs |
| let (compiled_cgus, codegen_time) = pre_compile_cgus(&cgu_reuse); |
| pre_compiled_cgus = Some(compiled_cgus); |
| total_codegen_time += codegen_time; |
| } |
| |
| let cgu_reuse = cgu_reuse[i]; |
| tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse); |
| |
| match cgu_reuse { |
| CguReuse::No => { |
| let (module, cost) = |
| if let Some(cgu) = pre_compiled_cgus.as_mut().unwrap().remove(&i) { |
| cgu |
| } else { |
| let start_time = Instant::now(); |
| let module = backend.compile_codegen_unit(tcx, cgu.name()); |
| total_codegen_time += start_time.elapsed(); |
| module |
| }; |
| // This will unwind if there are errors, which triggers our `AbortCodegenOnDrop` |
| // guard. Unfortunately, just skipping the `submit_codegened_module_to_llvm` makes |
| // compilation hang on post-monomorphization errors. |
| tcx.sess.abort_if_errors(); |
| |
| submit_codegened_module_to_llvm( |
| &backend, |
| &ongoing_codegen.coordinator_send, |
| module, |
| cost, |
| ); |
| false |
| } |
| CguReuse::PreLto => { |
| submit_pre_lto_module_to_llvm( |
| &backend, |
| tcx, |
| &ongoing_codegen.coordinator_send, |
| CachedModuleCodegen { |
| name: cgu.name().to_string(), |
| source: cgu.work_product(tcx), |
| }, |
| ); |
| true |
| } |
| CguReuse::PostLto => { |
| submit_post_lto_module_to_llvm( |
| &backend, |
| &ongoing_codegen.coordinator_send, |
| CachedModuleCodegen { |
| name: cgu.name().to_string(), |
| source: cgu.work_product(tcx), |
| }, |
| ); |
| true |
| } |
| }; |
| } |
| |
| ongoing_codegen.codegen_finished(tcx); |
| |
| // Since the main thread is sometimes blocked during codegen, we keep track |
| // -Ztime-passes output manually. |
| if tcx.sess.time_passes() { |
| let end_rss = get_resident_set_size(); |
| |
| print_time_passes_entry( |
| "codegen_to_LLVM_IR", |
| total_codegen_time, |
| start_rss.unwrap(), |
| end_rss, |
| ); |
| } |
| |
| ongoing_codegen.check_for_errors(tcx.sess); |
| |
| ongoing_codegen.into_inner() |
| } |
| |
| /// A curious wrapper structure whose only purpose is to call `codegen_aborted` |
| /// when it's dropped abnormally. |
| /// |
| /// In the process of working on rust-lang/rust#55238 a mysterious segfault was |
| /// stumbled upon. The segfault was never reproduced locally, but it was |
| /// suspected to be related to the fact that codegen worker threads were |
| /// sticking around by the time the main thread was exiting, causing issues. |
| /// |
| /// This structure is an attempt to fix that issue where the `codegen_aborted` |
| /// message will block until all workers have finished. This should ensure that |
| /// even if the main codegen thread panics we'll wait for pending work to |
| /// complete before returning from the main thread, hopefully avoiding |
| /// segfaults. |
| /// |
| /// If you see this comment in the code, then it means that this workaround |
| /// worked! We may yet one day track down the mysterious cause of that |
| /// segfault... |
| struct AbortCodegenOnDrop<B: ExtraBackendMethods>(Option<OngoingCodegen<B>>); |
| |
| impl<B: ExtraBackendMethods> AbortCodegenOnDrop<B> { |
| fn into_inner(mut self) -> OngoingCodegen<B> { |
| self.0.take().unwrap() |
| } |
| } |
| |
| impl<B: ExtraBackendMethods> Deref for AbortCodegenOnDrop<B> { |
| type Target = OngoingCodegen<B>; |
| |
| fn deref(&self) -> &OngoingCodegen<B> { |
| self.0.as_ref().unwrap() |
| } |
| } |
| |
| impl<B: ExtraBackendMethods> DerefMut for AbortCodegenOnDrop<B> { |
| fn deref_mut(&mut self) -> &mut OngoingCodegen<B> { |
| self.0.as_mut().unwrap() |
| } |
| } |
| |
| impl<B: ExtraBackendMethods> Drop for AbortCodegenOnDrop<B> { |
| fn drop(&mut self) { |
| if let Some(codegen) = self.0.take() { |
| codegen.codegen_aborted(); |
| } |
| } |
| } |
| |
| impl CrateInfo { |
| pub fn new(tcx: TyCtxt<'_>, target_cpu: String) -> CrateInfo { |
| let exported_symbols = tcx |
| .sess |
| .crate_types() |
| .iter() |
| .map(|&c| (c, crate::back::linker::exported_symbols(tcx, c))) |
| .collect(); |
| let local_crate_name = tcx.crate_name(LOCAL_CRATE); |
| let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID); |
| let subsystem = tcx.sess.first_attr_value_str_by_name(crate_attrs, sym::windows_subsystem); |
| let windows_subsystem = subsystem.map(|subsystem| { |
| if subsystem != sym::windows && subsystem != sym::console { |
| tcx.sess.fatal(&format!( |
| "invalid windows subsystem `{}`, only \ |
| `windows` and `console` are allowed", |
| subsystem |
| )); |
| } |
| subsystem.to_string() |
| }); |
| |
| // This list is used when generating the command line to pass through to |
| // system linker. The linker expects undefined symbols on the left of the |
| // command line to be defined in libraries on the right, not the other way |
| // around. For more info, see some comments in the add_used_library function |
| // below. |
| // |
| // In order to get this left-to-right dependency ordering, we use the reverse |
| // postorder of all crates putting the leaves at the right-most positions. |
| let used_crates = tcx |
| .postorder_cnums(()) |
| .iter() |
| .rev() |
| .copied() |
| .filter(|&cnum| !tcx.dep_kind(cnum).macros_only()) |
| .collect(); |
| |
| let mut info = CrateInfo { |
| target_cpu, |
| exported_symbols, |
| local_crate_name, |
| compiler_builtins: None, |
| profiler_runtime: None, |
| is_no_builtins: Default::default(), |
| native_libraries: Default::default(), |
| used_libraries: tcx.native_libraries(LOCAL_CRATE).iter().map(Into::into).collect(), |
| crate_name: Default::default(), |
| used_crates, |
| used_crate_source: Default::default(), |
| lang_item_to_crate: Default::default(), |
| missing_lang_items: Default::default(), |
| dependency_formats: tcx.dependency_formats(()), |
| windows_subsystem, |
| }; |
| let lang_items = tcx.lang_items(); |
| |
| let crates = tcx.crates(()); |
| |
| let n_crates = crates.len(); |
| info.native_libraries.reserve(n_crates); |
| info.crate_name.reserve(n_crates); |
| info.used_crate_source.reserve(n_crates); |
| info.missing_lang_items.reserve(n_crates); |
| |
| for &cnum in crates.iter() { |
| info.native_libraries |
| .insert(cnum, tcx.native_libraries(cnum).iter().map(Into::into).collect()); |
| info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string()); |
| info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum)); |
| if tcx.is_compiler_builtins(cnum) { |
| info.compiler_builtins = Some(cnum); |
| } |
| if tcx.is_profiler_runtime(cnum) { |
| info.profiler_runtime = Some(cnum); |
| } |
| if tcx.is_no_builtins(cnum) { |
| info.is_no_builtins.insert(cnum); |
| } |
| let missing = tcx.missing_lang_items(cnum); |
| for &item in missing.iter() { |
| if let Ok(id) = lang_items.require(item) { |
| info.lang_item_to_crate.insert(item, id.krate); |
| } |
| } |
| |
| // No need to look for lang items that don't actually need to exist. |
| let missing = |
| missing.iter().cloned().filter(|&l| lang_items::required(tcx, l)).collect(); |
| info.missing_lang_items.insert(cnum, missing); |
| } |
| |
| info |
| } |
| } |
| |
| pub fn provide(providers: &mut Providers) { |
| providers.backend_optimization_level = |tcx, cratenum| { |
| let for_speed = match tcx.sess.opts.optimize { |
| // If globally no optimisation is done, #[optimize] has no effect. |
| // |
| // This is done because if we ended up "upgrading" to `-O2` here, we’d populate the |
| // pass manager and it is likely that some module-wide passes (such as inliner or |
| // cross-function constant propagation) would ignore the `optnone` annotation we put |
| // on the functions, thus necessarily involving these functions into optimisations. |
| config::OptLevel::No => return config::OptLevel::No, |
| // If globally optimise-speed is already specified, just use that level. |
| config::OptLevel::Less => return config::OptLevel::Less, |
| config::OptLevel::Default => return config::OptLevel::Default, |
| config::OptLevel::Aggressive => return config::OptLevel::Aggressive, |
| // If globally optimize-for-size has been requested, use -O2 instead (if optimize(size) |
| // are present). |
| config::OptLevel::Size => config::OptLevel::Default, |
| config::OptLevel::SizeMin => config::OptLevel::Default, |
| }; |
| |
| let (defids, _) = tcx.collect_and_partition_mono_items(cratenum); |
| for id in &*defids { |
| let CodegenFnAttrs { optimize, .. } = tcx.codegen_fn_attrs(*id); |
| match optimize { |
| attr::OptimizeAttr::None => continue, |
| attr::OptimizeAttr::Size => continue, |
| attr::OptimizeAttr::Speed => { |
| return for_speed; |
| } |
| } |
| } |
| tcx.sess.opts.optimize |
| }; |
| } |
| |
| fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse { |
| if !tcx.dep_graph.is_fully_enabled() { |
| return CguReuse::No; |
| } |
| |
| let work_product_id = &cgu.work_product_id(); |
| if tcx.dep_graph.previous_work_product(work_product_id).is_none() { |
| // We don't have anything cached for this CGU. This can happen |
| // if the CGU did not exist in the previous session. |
| return CguReuse::No; |
| } |
| |
| // Try to mark the CGU as green. If it we can do so, it means that nothing |
| // affecting the LLVM module has changed and we can re-use a cached version. |
| // If we compile with any kind of LTO, this means we can re-use the bitcode |
| // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only |
| // know that later). If we are not doing LTO, there is only one optimized |
| // version of each module, so we re-use that. |
| let dep_node = cgu.codegen_dep_node(tcx); |
| assert!( |
| !tcx.dep_graph.dep_node_exists(&dep_node), |
| "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.", |
| cgu.name() |
| ); |
| |
| if tcx.try_mark_green(&dep_node) { |
| // We can re-use either the pre- or the post-thinlto state. If no LTO is |
| // being performed then we can use post-LTO artifacts, otherwise we must |
| // reuse pre-LTO artifacts |
| match compute_per_cgu_lto_type( |
| &tcx.sess.lto(), |
| &tcx.sess.opts, |
| &tcx.sess.crate_types(), |
| ModuleKind::Regular, |
| ) { |
| ComputedLtoType::No => CguReuse::PostLto, |
| _ => CguReuse::PreLto, |
| } |
| } else { |
| CguReuse::No |
| } |
| } |
