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//! Codegen the completed AST to the LLVM IR.
//!
//! Some functions here, such as codegen_block and codegen_expr, return a value --
//! the result of the codegen to LLVM -- while others, such as codegen_fn
//! and mono_item, are called only for the side effect of adding a
//! particular definition to the LLVM IR output we're producing.
//!
//! Hopefully useful general knowledge about codegen:
//!
//! * There's no way to find out the `Ty` type of a Value. Doing so
//! would be "trying to get the eggs out of an omelette" (credit:
//! pcwalton). You can, instead, find out its `llvm::Type` by calling `val_ty`,
//! but one `llvm::Type` corresponds to many `Ty`s; for instance, `tup(int, int,
//! int)` and `rec(x=int, y=int, z=int)` will have the same `llvm::Type`.
use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen};
use rustc::dep_graph::cgu_reuse_tracker::CguReuse;
use rustc::hir::def_id::{DefId, LOCAL_CRATE};
use rustc::middle::cstore::EncodedMetadata;
use rustc::middle::lang_items::StartFnLangItem;
use rustc::middle::weak_lang_items;
use rustc::mir::mono::{CodegenUnitNameBuilder, CodegenUnit, MonoItem};
use rustc::ty::{self, Ty, TyCtxt, Instance};
use rustc::ty::layout::{self, Align, TyLayout, LayoutOf, VariantIdx, HasTyCtxt};
use rustc::ty::query::Providers;
use rustc::middle::cstore::{self, LinkagePreference};
use rustc::util::common::{time, print_time_passes_entry, set_time_depth, time_depth};
use rustc::session::config::{self, EntryFnType, Lto};
use rustc::session::Session;
use rustc::util::nodemap::FxHashMap;
use rustc_data_structures::indexed_vec::Idx;
use rustc_codegen_utils::{symbol_names_test, check_for_rustc_errors_attr};
use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
use crate::mir::place::PlaceRef;
use crate::back::write::{OngoingCodegen, start_async_codegen, submit_pre_lto_module_to_llvm,
submit_post_lto_module_to_llvm};
use crate::{MemFlags, CrateInfo};
use crate::callee;
use crate::common::{RealPredicate, TypeKind, IntPredicate};
use crate::meth;
use crate::mir;
use crate::traits::*;
use std::any::Any;
use std::cmp;
use std::ops::{Deref, DerefMut};
use std::time::{Instant, Duration};
use std::sync::mpsc;
use syntax_pos::Span;
use syntax::attr;
use rustc::hir;
use crate::mir::operand::OperandValue;
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.sty {
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 funny. 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<'tcx, Cx: CodegenMethods<'tcx>>(
cx: &Cx,
source: Ty<'tcx>,
target: Ty<'tcx>,
old_info: Option<Cx::Value>,
) -> Cx::Value {
let (source, target) =
cx.tcx().struct_lockstep_tails_erasing_lifetimes(source, target, cx.param_env());
match (&source.sty, &target.sty) {
(&ty::Array(_, len), &ty::Slice(_)) => {
cx.const_usize(len.unwrap_usize(cx.tcx()))
}
(&ty::Dynamic(..), &ty::Dynamic(..)) => {
// For now, upcasts are limited to changes in marker
// traits, and hence never actually require an actual
// change to the vtable.
old_info.expect("unsized_info: missing old info for trait upcast")
}
(_, &ty::Dynamic(ref data, ..)) => {
let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
.field(cx, FAT_PTR_EXTRA);
cx.const_ptrcast(meth::get_vtable(cx, source, data.principal()),
cx.backend_type(vtable_ptr))
}
_ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
source,
target),
}
}
/// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
pub fn unsize_thin_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
src: Bx::Value,
src_ty: Ty<'tcx>,
dst_ty: Ty<'tcx>,
) -> (Bx::Value, Bx::Value) {
debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
match (&src_ty.sty, &dst_ty.sty) {
(&ty::Ref(_, a, _),
&ty::Ref(_, b, _)) |
(&ty::Ref(_, a, _),
&ty::RawPtr(ty::TypeAndMut { ty: b, .. })) |
(&ty::RawPtr(ty::TypeAndMut { ty: a, .. }),
&ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
assert!(bx.cx().type_is_sized(a));
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.cx(), a, b, None))
}
(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
assert!(bx.cx().type_is_sized(a));
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.cx(), a, b, None))
}
(&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);
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_thin_ptr(bx, src, src_f.ty, dst_f.ty));
}
let (lldata, llextra) = result.unwrap();
// HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
(bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)))
}
_ => bug!("unsize_thin_ptr: called on bad types"),
}
}
/// Coerce `src`, which is a reference to a value of type `src_ty`,
/// to a value of type `dst_ty` and store 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;
let mut coerce_ptr = || {
let (base, info) = match bx.load_operand(src).val {
OperandValue::Pair(base, info) => {
// fat-ptr to fat-ptr unsize preserves the vtable
// i.e., &'a fmt::Debug+Send => &'a fmt::Debug
// So we need to pointercast the base to ensure
// the types match up.
let thin_ptr = dst.layout.field(bx.cx(), FAT_PTR_ADDR);
(bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
}
OperandValue::Immediate(base) => {
unsize_thin_ptr(bx, base, src_ty, dst_ty)
}
OperandValue::Ref(..) => bug!()
};
OperandValue::Pair(base, info).store(bx, dst);
};
match (&src_ty.sty, &dst_ty.sty) {
(&ty::Ref(..), &ty::Ref(..)) |
(&ty::Ref(..), &ty::RawPtr(..)) |
(&ty::RawPtr(..), &ty::RawPtr(..)) => {
coerce_ptr()
}
(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
coerce_ptr()
}
(&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.target.options.is_like_msvc
}
pub fn from_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
val: Bx::Value,
) -> Bx::Value {
if bx.cx().val_ty(val) == bx.cx().type_i1() {
bx.zext(val, bx.cx().type_i8())
} else {
val
}
}
pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
val: Bx::Value,
layout: layout::TyLayout<'_>,
) -> Bx::Value {
if let layout::Abi::Scalar(ref scalar) = layout.abi {
return to_immediate_scalar(bx, val, scalar);
}
val
}
pub fn to_immediate_scalar<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
bx: &mut Bx,
val: Bx::Value,
scalar: &layout::Scalar,
) -> Bx::Value {
if scalar.is_bool() {
return bx.trunc(val, bx.cx().type_i1());
}
val
}
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: TyLayout<'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);
let sig = instance.fn_sig(cx.tcx());
let sig = cx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
let lldecl = cx.instances().borrow().get(&instance).cloned().unwrap_or_else(||
bug!("Instance `{:?}` not already declared", instance));
let mir = cx.tcx().instance_mir(instance.def);
mir::codegen_mir::<Bx>(cx, lldecl, &mir, instance, sig);
}
/// 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) {
let (main_def_id, span) = match cx.tcx().entry_fn(LOCAL_CRATE) {
Some((def_id, _)) => { (def_id, cx.tcx().def_span(def_id)) },
None => return,
};
let instance = Instance::mono(cx.tcx(), main_def_id);
if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
// We want to create the wrapper in the same codegen unit as Rust's main
// function.
return;
}
let main_llfn = cx.get_fn(instance);
let et = cx.tcx().entry_fn(LOCAL_CRATE).map(|e| e.1);
match et {
Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
None => {} // Do nothing.
}
fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
cx: &'a Bx::CodegenCx,
sp: Span,
rust_main: Bx::Value,
rust_main_def_id: DefId,
use_start_lang_item: bool,
) {
let llfty =
cx.type_func(&[cx.type_int(), cx.type_ptr_to(cx.type_i8p())], 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(),
);
if cx.get_defined_value("main").is_some() {
// FIXME: We should be smart and show a better diagnostic here.
cx.sess().struct_span_err(sp, "entry symbol `main` defined 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();
// 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;
let (start_fn, args) = if use_start_lang_item {
let start_def_id = cx.tcx().require_lang_item(StartFnLangItem);
let start_fn = callee::resolve_and_get_fn(
cx,
start_def_id,
cx.tcx().intern_substs(&[main_ret_ty.into()]),
);
(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);
}
}
pub const CODEGEN_WORKER_ID: usize = ::std::usize::MAX;
pub fn codegen_crate<B: ExtraBackendMethods>(
backend: B,
tcx: TyCtxt<'tcx>,
metadata: EncodedMetadata,
need_metadata_module: bool,
rx: mpsc::Receiver<Box<dyn Any + Send>>,
) -> OngoingCodegen<B> {
check_for_rustc_errors_attr(tcx);
// 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,
rx,
1);
ongoing_codegen.codegen_finished(tcx);
assert_and_save_dep_graph(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().clone());
}
}
let ongoing_codegen = start_async_codegen(
backend.clone(),
tcx,
metadata,
rx,
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.sess.dependency_formats.borrow()
.iter()
.any(|(_, list)| {
use rustc::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.sess.allocator_kind.get() {
let llmod_id = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
&["crate"],
Some("allocator")).as_str()
.to_string();
let mut modules = backend.new_metadata(tcx, &llmod_id);
time(tcx.sess, "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.
tcx.sess.profiler(|p| p.start_activity("codegen crate metadata"));
let metadata_cgu_name = cgu_name_builder.build_cgu_name(LOCAL_CRATE,
&["crate"],
Some("metadata")).as_str()
.to_string();
let mut metadata_llvm_module = backend.new_metadata(tcx, &metadata_cgu_name);
time(tcx.sess, "write compressed metadata", || {
backend.write_compressed_metadata(tcx, &ongoing_codegen.metadata,
&mut metadata_llvm_module);
});
tcx.sess.profiler(|p| p.end_activity("codegen crate metadata"));
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 mut total_codegen_time = Duration::new(0, 0);
for cgu in codegen_units.into_iter() {
ongoing_codegen.wait_for_signal_to_codegen_item();
ongoing_codegen.check_for_errors(tcx.sess);
let cgu_reuse = determine_cgu_reuse(tcx, &cgu);
tcx.sess.cgu_reuse_tracker.set_actual_reuse(&cgu.name().as_str(), cgu_reuse);
match cgu_reuse {
CguReuse::No => {
tcx.sess.profiler(|p| p.start_activity(format!("codegen {}", cgu.name())));
let start_time = Instant::now();
backend.compile_codegen_unit(tcx, *cgu.name());
total_codegen_time += start_time.elapsed();
tcx.sess.profiler(|p| p.end_activity(format!("codegen {}", cgu.name())));
false
}
CguReuse::PreLto => {
submit_pre_lto_module_to_llvm(&backend, tcx, CachedModuleCodegen {
name: cgu.name().to_string(),
source: cgu.work_product(tcx),
});
true
}
CguReuse::PostLto => {
submit_post_lto_module_to_llvm(&backend, tcx, 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.
let time_depth = time_depth();
set_time_depth(time_depth + 1);
print_time_passes_entry(tcx.sess.time_passes(),
"codegen to LLVM IR",
total_codegen_time);
set_time_depth(time_depth);
::rustc_incremental::assert_module_sources::assert_module_sources(tcx);
symbol_names_test::report_symbol_names(tcx);
ongoing_codegen.check_for_errors(tcx.sess);
assert_and_save_dep_graph(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 assert_and_save_dep_graph(tcx: TyCtxt<'_>) {
time(tcx.sess,
"assert dep graph",
|| ::rustc_incremental::assert_dep_graph(tcx));
time(tcx.sess,
"serialize dep graph",
|| ::rustc_incremental::save_dep_graph(tcx));
}
impl CrateInfo {
pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
let mut info = CrateInfo {
panic_runtime: None,
compiler_builtins: None,
profiler_runtime: None,
sanitizer_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(),
};
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_sanitizer_runtime(cnum) {
info.sanitizer_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| !weak_lang_items::whitelisted(tcx, l))
.collect();
info.missing_lang_items.insert(cnum, missing);
}
return info;
}
}
fn is_codegened_item(tcx: TyCtxt<'_>, id: DefId) -> bool {
let (all_mono_items, _) =
tcx.collect_and_partition_mono_items(LOCAL_CRATE);
all_mono_items.contains(&id)
}
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 hir::CodegenFnAttrs { optimize, .. } = tcx.codegen_fn_attrs(*id);
match optimize {
attr::OptimizeAttr::None => continue,
attr::OptimizeAttr::Size => continue,
attr::OptimizeAttr::Speed => {
return for_speed;
}
}
}
return 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
}
}
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