953 lines
36 KiB
Rust
953 lines
36 KiB
Rust
//! Codegen the completed AST to the LLVM IR.
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//!
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//! Some functions here, such as `codegen_block` and `codegen_expr`, return a value --
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//! the result of the codegen to LLVM -- while others, such as `codegen_fn`
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//! and `mono_item`, are called only for the side effect of adding a
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//! particular definition to the LLVM IR output we're producing.
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//!
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//! Hopefully useful general knowledge about codegen:
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//!
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//! * There's no way to find out the `Ty` type of a `Value`. Doing so
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//! would be "trying to get the eggs out of an omelette" (credit:
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//! pcwalton). You can, instead, find out its `llvm::Type` by calling `val_ty`,
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//! but one `llvm::Type` corresponds to many `Ty`s; for instance, `tup(int, int,
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//! int)` and `rec(x=int, y=int, z=int)` will have the same `llvm::Type`.
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use crate::back::write::{
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start_async_codegen, submit_codegened_module_to_llvm, submit_post_lto_module_to_llvm,
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submit_pre_lto_module_to_llvm, OngoingCodegen,
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};
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use crate::common::{IntPredicate, RealPredicate, TypeKind};
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use crate::meth;
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use crate::mir;
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use crate::mir::operand::OperandValue;
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use crate::mir::place::PlaceRef;
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use crate::traits::*;
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use crate::{CachedModuleCodegen, CrateInfo, MemFlags, ModuleCodegen, ModuleKind};
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use rustc_attr as attr;
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use rustc_data_structures::fx::FxHashMap;
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use rustc_data_structures::profiling::print_time_passes_entry;
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use rustc_data_structures::sync::{par_iter, Lock, ParallelIterator};
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use rustc_hir as hir;
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use rustc_hir::def_id::{DefId, LOCAL_CRATE};
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use rustc_hir::lang_items::StartFnLangItem;
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use rustc_index::vec::Idx;
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use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
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use rustc_middle::middle::cstore::EncodedMetadata;
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use rustc_middle::middle::cstore::{self, LinkagePreference};
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use rustc_middle::middle::lang_items;
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use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
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use rustc_middle::ty::layout::{self, HasTyCtxt, TyAndLayout};
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use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
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use rustc_middle::ty::query::Providers;
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use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
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use rustc_session::cgu_reuse_tracker::CguReuse;
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use rustc_session::config::{self, EntryFnType, Lto};
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use rustc_session::Session;
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use rustc_span::Span;
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use rustc_symbol_mangling::test as symbol_names_test;
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use rustc_target::abi::{Abi, Align, LayoutOf, Scalar, VariantIdx};
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use std::cmp;
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use std::ops::{Deref, DerefMut};
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use std::time::{Duration, Instant};
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pub fn bin_op_to_icmp_predicate(op: hir::BinOpKind, signed: bool) -> IntPredicate {
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match op {
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hir::BinOpKind::Eq => IntPredicate::IntEQ,
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hir::BinOpKind::Ne => IntPredicate::IntNE,
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hir::BinOpKind::Lt => {
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if signed {
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IntPredicate::IntSLT
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} else {
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IntPredicate::IntULT
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}
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}
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hir::BinOpKind::Le => {
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if signed {
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IntPredicate::IntSLE
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} else {
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IntPredicate::IntULE
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}
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}
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hir::BinOpKind::Gt => {
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if signed {
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IntPredicate::IntSGT
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} else {
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IntPredicate::IntUGT
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}
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}
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hir::BinOpKind::Ge => {
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if signed {
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IntPredicate::IntSGE
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} else {
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IntPredicate::IntUGE
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}
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}
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op => bug!(
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"comparison_op_to_icmp_predicate: expected comparison operator, \
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found {:?}",
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op
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),
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}
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}
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pub fn bin_op_to_fcmp_predicate(op: hir::BinOpKind) -> RealPredicate {
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match op {
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hir::BinOpKind::Eq => RealPredicate::RealOEQ,
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hir::BinOpKind::Ne => RealPredicate::RealUNE,
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hir::BinOpKind::Lt => RealPredicate::RealOLT,
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hir::BinOpKind::Le => RealPredicate::RealOLE,
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hir::BinOpKind::Gt => RealPredicate::RealOGT,
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hir::BinOpKind::Ge => RealPredicate::RealOGE,
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op => {
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bug!(
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"comparison_op_to_fcmp_predicate: expected comparison operator, \
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found {:?}",
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op
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);
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}
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}
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}
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pub fn compare_simd_types<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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lhs: Bx::Value,
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rhs: Bx::Value,
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t: Ty<'tcx>,
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ret_ty: Bx::Type,
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op: hir::BinOpKind,
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) -> Bx::Value {
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let signed = match t.kind {
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ty::Float(_) => {
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let cmp = bin_op_to_fcmp_predicate(op);
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let cmp = bx.fcmp(cmp, lhs, rhs);
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return bx.sext(cmp, ret_ty);
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}
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ty::Uint(_) => false,
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ty::Int(_) => true,
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_ => bug!("compare_simd_types: invalid SIMD type"),
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};
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let cmp = bin_op_to_icmp_predicate(op, signed);
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let cmp = bx.icmp(cmp, lhs, rhs);
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// LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
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// to get the correctly sized type. This will compile to a single instruction
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// once the IR is converted to assembly if the SIMD instruction is supported
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// by the target architecture.
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bx.sext(cmp, ret_ty)
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}
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/// Retrieves the information we are losing (making dynamic) in an unsizing
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/// adjustment.
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///
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/// The `old_info` argument is a bit odd. It is intended for use in an upcast,
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/// where the new vtable for an object will be derived from the old one.
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pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
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cx: &Cx,
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source: Ty<'tcx>,
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target: Ty<'tcx>,
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old_info: Option<Cx::Value>,
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) -> Cx::Value {
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let (source, target) =
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cx.tcx().struct_lockstep_tails_erasing_lifetimes(source, target, cx.param_env());
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match (&source.kind, &target.kind) {
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(&ty::Array(_, len), &ty::Slice(_)) => {
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cx.const_usize(len.eval_usize(cx.tcx(), ty::ParamEnv::reveal_all()))
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}
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(&ty::Dynamic(..), &ty::Dynamic(..)) => {
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// For now, upcasts are limited to changes in marker
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// traits, and hence never actually require an actual
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// change to the vtable.
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old_info.expect("unsized_info: missing old info for trait upcast")
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}
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(_, &ty::Dynamic(ref data, ..)) => {
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let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target)).field(cx, FAT_PTR_EXTRA);
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cx.const_ptrcast(
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meth::get_vtable(cx, source, data.principal()),
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cx.backend_type(vtable_ptr),
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)
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}
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_ => bug!("unsized_info: invalid unsizing {:?} -> {:?}", source, target),
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}
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}
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/// Coerces `src` to `dst_ty`. `src_ty` must be a thin pointer.
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pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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src: Bx::Value,
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src_ty: Ty<'tcx>,
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dst_ty: Ty<'tcx>,
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) -> (Bx::Value, Bx::Value) {
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debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
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match (&src_ty.kind, &dst_ty.kind) {
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(&ty::Ref(_, a, _), &ty::Ref(_, b, _))
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| (&ty::Ref(_, a, _), &ty::RawPtr(ty::TypeAndMut { ty: b, .. }))
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| (&ty::RawPtr(ty::TypeAndMut { ty: a, .. }), &ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
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assert!(bx.cx().type_is_sized(a));
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let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
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(bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
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}
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(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
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assert_eq!(def_a, def_b);
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let src_layout = bx.cx().layout_of(src_ty);
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let dst_layout = bx.cx().layout_of(dst_ty);
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let mut result = None;
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for i in 0..src_layout.fields.count() {
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let src_f = src_layout.field(bx.cx(), i);
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assert_eq!(src_layout.fields.offset(i).bytes(), 0);
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assert_eq!(dst_layout.fields.offset(i).bytes(), 0);
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if src_f.is_zst() {
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continue;
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}
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assert_eq!(src_layout.size, src_f.size);
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let dst_f = dst_layout.field(bx.cx(), i);
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assert_ne!(src_f.ty, dst_f.ty);
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assert_eq!(result, None);
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result = Some(unsize_thin_ptr(bx, src, src_f.ty, dst_f.ty));
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}
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let (lldata, llextra) = result.unwrap();
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// HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
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// FIXME(eddyb) move these out of this `match` arm, so they're always
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// applied, uniformly, no matter the source/destination types.
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(
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bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
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bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)),
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)
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}
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_ => bug!("unsize_thin_ptr: called on bad types"),
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}
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}
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/// Coerces `src`, which is a reference to a value of type `src_ty`,
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/// to a value of type `dst_ty`, and stores the result in `dst`.
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pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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src: PlaceRef<'tcx, Bx::Value>,
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dst: PlaceRef<'tcx, Bx::Value>,
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) {
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let src_ty = src.layout.ty;
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let dst_ty = dst.layout.ty;
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match (&src_ty.kind, &dst_ty.kind) {
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(&ty::Ref(..), &ty::Ref(..))
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| (&ty::Ref(..), &ty::RawPtr(..))
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| (&ty::RawPtr(..), &ty::RawPtr(..)) => {
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let (base, info) = match bx.load_operand(src).val {
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OperandValue::Pair(base, info) => {
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// fat-ptr to fat-ptr unsize preserves the vtable
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// i.e., &'a fmt::Debug+Send => &'a fmt::Debug
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// So we need to pointercast the base to ensure
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// the types match up.
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// FIXME(eddyb) use `scalar_pair_element_backend_type` here,
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// like `unsize_thin_ptr` does.
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let thin_ptr = dst.layout.field(bx.cx(), FAT_PTR_ADDR);
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(bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
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}
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OperandValue::Immediate(base) => unsize_thin_ptr(bx, base, src_ty, dst_ty),
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OperandValue::Ref(..) => bug!(),
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};
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OperandValue::Pair(base, info).store(bx, dst);
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}
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(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
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assert_eq!(def_a, def_b);
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for i in 0..def_a.variants[VariantIdx::new(0)].fields.len() {
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let src_f = src.project_field(bx, i);
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let dst_f = dst.project_field(bx, i);
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if dst_f.layout.is_zst() {
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continue;
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}
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if src_f.layout.ty == dst_f.layout.ty {
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memcpy_ty(
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bx,
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dst_f.llval,
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dst_f.align,
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src_f.llval,
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src_f.align,
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src_f.layout,
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MemFlags::empty(),
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);
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} else {
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coerce_unsized_into(bx, src_f, dst_f);
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}
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}
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}
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_ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}", src_ty, dst_ty,),
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}
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}
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pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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op: hir::BinOpKind,
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lhs: Bx::Value,
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rhs: Bx::Value,
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) -> Bx::Value {
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cast_shift_rhs(bx, op, lhs, rhs)
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}
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fn cast_shift_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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op: hir::BinOpKind,
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lhs: Bx::Value,
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rhs: Bx::Value,
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) -> Bx::Value {
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// Shifts may have any size int on the rhs
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if op.is_shift() {
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let mut rhs_llty = bx.cx().val_ty(rhs);
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let mut lhs_llty = bx.cx().val_ty(lhs);
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if bx.cx().type_kind(rhs_llty) == TypeKind::Vector {
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rhs_llty = bx.cx().element_type(rhs_llty)
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}
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if bx.cx().type_kind(lhs_llty) == TypeKind::Vector {
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lhs_llty = bx.cx().element_type(lhs_llty)
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}
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let rhs_sz = bx.cx().int_width(rhs_llty);
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let lhs_sz = bx.cx().int_width(lhs_llty);
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if lhs_sz < rhs_sz {
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bx.trunc(rhs, lhs_llty)
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} else if lhs_sz > rhs_sz {
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// FIXME (#1877: If in the future shifting by negative
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// values is no longer undefined then this is wrong.
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bx.zext(rhs, lhs_llty)
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} else {
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rhs
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}
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} else {
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rhs
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}
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}
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/// Returns `true` if this session's target will use SEH-based unwinding.
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///
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/// This is only true for MSVC targets, and even then the 64-bit MSVC target
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/// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
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/// 64-bit MinGW) instead of "full SEH".
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pub fn wants_msvc_seh(sess: &Session) -> bool {
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sess.target.target.options.is_like_msvc
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}
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pub fn from_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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val: Bx::Value,
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) -> Bx::Value {
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if bx.cx().val_ty(val) == bx.cx().type_i1() { bx.zext(val, bx.cx().type_i8()) } else { val }
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}
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pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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val: Bx::Value,
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layout: layout::TyAndLayout<'_>,
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) -> Bx::Value {
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if let Abi::Scalar(ref scalar) = layout.abi {
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return to_immediate_scalar(bx, val, scalar);
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}
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val
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}
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pub fn to_immediate_scalar<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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val: Bx::Value,
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scalar: &Scalar,
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) -> Bx::Value {
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if scalar.is_bool() {
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return bx.trunc(val, bx.cx().type_i1());
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}
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val
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}
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pub fn memcpy_ty<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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dst: Bx::Value,
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dst_align: Align,
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src: Bx::Value,
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src_align: Align,
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layout: TyAndLayout<'tcx>,
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flags: MemFlags,
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) {
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let size = layout.size.bytes();
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if size == 0 {
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return;
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}
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bx.memcpy(dst, dst_align, src, src_align, bx.cx().const_usize(size), flags);
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}
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pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
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cx: &'a Bx::CodegenCx,
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instance: Instance<'tcx>,
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) {
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// this is an info! to allow collecting monomorphization statistics
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// and to allow finding the last function before LLVM aborts from
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// release builds.
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info!("codegen_instance({})", instance);
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mir::codegen_mir::<Bx>(cx, instance);
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}
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/// Creates the `main` function which will initialize the rust runtime and call
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/// users main function.
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pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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cx: &'a Bx::CodegenCx,
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) -> Option<Bx::Function> {
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let (main_def_id, span) = match cx.tcx().entry_fn(LOCAL_CRATE) {
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Some((def_id, _)) => (def_id, cx.tcx().def_span(def_id)),
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None => return None,
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};
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let instance = Instance::mono(cx.tcx(), main_def_id);
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if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
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// We want to create the wrapper in the same codegen unit as Rust's main
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// function.
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return None;
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}
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let main_llfn = cx.get_fn_addr(instance);
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return cx.tcx().entry_fn(LOCAL_CRATE).map(|(_, et)| {
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let use_start_lang_item = EntryFnType::Start != et;
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create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, use_start_lang_item)
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});
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fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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cx: &'a Bx::CodegenCx,
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sp: Span,
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rust_main: Bx::Value,
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rust_main_def_id: DefId,
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use_start_lang_item: bool,
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) -> Bx::Function {
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// The entry function is either `int main(void)` or `int main(int argc, char **argv)`,
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// depending on whether the target needs `argc` and `argv` to be passed in.
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let llfty = if cx.sess().target.target.options.main_needs_argc_argv {
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cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], cx.type_int())
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} else {
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cx.type_func(&[], cx.type_int())
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};
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|
||
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());
|
||
|
||
if cx.get_declared_value("main").is_some() {
|
||
// FIXME: We should be smart and show a better diagnostic here.
|
||
cx.sess()
|
||
.struct_span_err(sp, "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!();
|
||
}
|
||
let llfn = cx.declare_cfn("main", llfty);
|
||
|
||
// `main` should respect same config for frame pointer elimination as rest of code
|
||
cx.set_frame_pointer_elimination(llfn);
|
||
cx.apply_target_cpu_attr(llfn);
|
||
|
||
let mut bx = Bx::new_block(&cx, llfn, "top");
|
||
|
||
bx.insert_reference_to_gdb_debug_scripts_section_global();
|
||
|
||
let (arg_argc, arg_argv) = get_argc_argv(cx, &mut bx);
|
||
|
||
let (start_fn, args) = if use_start_lang_item {
|
||
let start_def_id = cx.tcx().require_lang_item(StartFnLangItem, 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(),
|
||
);
|
||
(
|
||
start_fn,
|
||
vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())), arg_argc, arg_argv],
|
||
)
|
||
} else {
|
||
debug!("using user-defined start fn");
|
||
(rust_main, vec![arg_argc, arg_argv])
|
||
};
|
||
|
||
let result = bx.call(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.target.options.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 const CODEGEN_WORKER_ID: usize = usize::MAX;
|
||
|
||
pub fn codegen_crate<B: ExtraBackendMethods>(
|
||
backend: B,
|
||
tcx: TyCtxt<'tcx>,
|
||
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, metadata, 1);
|
||
|
||
ongoing_codegen.codegen_finished(tcx);
|
||
|
||
finalize_tcx(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(LOCAL_CRATE).1;
|
||
let codegen_units = (*codegen_units).clone();
|
||
|
||
// 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.codegen_unit(cgu.name());
|
||
}
|
||
}
|
||
|
||
let ongoing_codegen = start_async_codegen(backend.clone(), tcx, 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(LOCAL_CRATE).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));
|
||
|
||
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);
|
||
}
|
||
|
||
// We sort the codegen units by size. This way we can schedule work for LLVM
|
||
// a bit more efficiently.
|
||
let codegen_units = {
|
||
let mut codegen_units = codegen_units;
|
||
codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
|
||
codegen_units
|
||
};
|
||
|
||
let total_codegen_time = Lock::new(Duration::new(0, 0));
|
||
|
||
// 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.
|
||
par_iter(cgus)
|
||
.map(|(i, _)| {
|
||
let start_time = Instant::now();
|
||
let module = backend.compile_codegen_unit(tcx, codegen_units[i].name());
|
||
let mut time = total_codegen_time.lock();
|
||
*time += start_time.elapsed();
|
||
(i, module)
|
||
})
|
||
.collect()
|
||
})
|
||
} else {
|
||
FxHashMap::default()
|
||
}
|
||
};
|
||
|
||
let mut cgu_reuse = Vec::new();
|
||
let mut pre_compiled_cgus: Option<FxHashMap<usize, _>> = None;
|
||
|
||
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
|
||
pre_compiled_cgus = Some(pre_compile_cgus(&cgu_reuse));
|
||
}
|
||
|
||
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());
|
||
let mut time = total_codegen_time.lock();
|
||
*time += start_time.elapsed();
|
||
module
|
||
};
|
||
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.
|
||
print_time_passes_entry(
|
||
tcx.sess.time_passes(),
|
||
"codegen_to_LLVM_IR",
|
||
total_codegen_time.into_inner(),
|
||
);
|
||
|
||
::rustc_incremental::assert_module_sources::assert_module_sources(tcx);
|
||
|
||
symbol_names_test::report_symbol_names(tcx);
|
||
|
||
ongoing_codegen.check_for_errors(tcx.sess);
|
||
|
||
finalize_tcx(tcx);
|
||
|
||
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();
|
||
}
|
||
}
|
||
}
|
||
|
||
fn finalize_tcx(tcx: TyCtxt<'_>) {
|
||
tcx.sess.time("assert_dep_graph", || ::rustc_incremental::assert_dep_graph(tcx));
|
||
tcx.sess.time("serialize_dep_graph", || ::rustc_incremental::save_dep_graph(tcx));
|
||
|
||
// We assume that no queries are run past here. If there are new queries
|
||
// after this point, they'll show up as "<unknown>" in self-profiling data.
|
||
{
|
||
let _prof_timer = tcx.prof.generic_activity("self_profile_alloc_query_strings");
|
||
tcx.alloc_self_profile_query_strings();
|
||
}
|
||
}
|
||
|
||
impl CrateInfo {
|
||
pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
|
||
let mut info = CrateInfo {
|
||
panic_runtime: None,
|
||
compiler_builtins: None,
|
||
profiler_runtime: None,
|
||
is_no_builtins: Default::default(),
|
||
native_libraries: Default::default(),
|
||
used_libraries: tcx.native_libraries(LOCAL_CRATE),
|
||
link_args: tcx.link_args(LOCAL_CRATE),
|
||
crate_name: Default::default(),
|
||
used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
|
||
used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
|
||
used_crate_source: Default::default(),
|
||
lang_item_to_crate: Default::default(),
|
||
missing_lang_items: Default::default(),
|
||
dependency_formats: tcx.dependency_formats(LOCAL_CRATE),
|
||
};
|
||
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));
|
||
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_panic_runtime(cnum) {
|
||
info.panic_runtime = Some(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 are whitelisted and don't
|
||
// actually need to exist.
|
||
let missing =
|
||
missing.iter().cloned().filter(|&l| !lang_items::whitelisted(tcx, l)).collect();
|
||
info.missing_lang_items.insert(cnum, missing);
|
||
}
|
||
|
||
info
|
||
}
|
||
}
|
||
|
||
pub fn provide_both(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
|
||
};
|
||
|
||
providers.dllimport_foreign_items = |tcx, krate| {
|
||
let module_map = tcx.foreign_modules(krate);
|
||
let module_map =
|
||
module_map.iter().map(|lib| (lib.def_id, lib)).collect::<FxHashMap<_, _>>();
|
||
|
||
let dllimports = tcx
|
||
.native_libraries(krate)
|
||
.iter()
|
||
.filter(|lib| {
|
||
if lib.kind != cstore::NativeLibraryKind::NativeUnknown {
|
||
return false;
|
||
}
|
||
let cfg = match lib.cfg {
|
||
Some(ref cfg) => cfg,
|
||
None => return true,
|
||
};
|
||
attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
|
||
})
|
||
.filter_map(|lib| lib.foreign_module)
|
||
.map(|id| &module_map[&id])
|
||
.flat_map(|module| module.foreign_items.iter().cloned())
|
||
.collect();
|
||
tcx.arena.alloc(dllimports)
|
||
};
|
||
|
||
providers.is_dllimport_foreign_item =
|
||
|tcx, def_id| tcx.dllimport_foreign_items(def_id.krate).contains(&def_id);
|
||
}
|
||
|
||
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.dep_graph.try_mark_green(tcx, &dep_node).is_some() {
|
||
// We can re-use either the pre- or the post-thinlto state
|
||
if tcx.sess.lto() != Lto::No { CguReuse::PreLto } else { CguReuse::PostLto }
|
||
} else {
|
||
CguReuse::No
|
||
}
|
||
}
|