Function lower_closure_to_oomir

src/lib.rs:62–133

Helper function to lower a closure definition to OOMIR This function is called when we encounter a closure call and need to ensure the closure's implementation is available in the OOMIR module.

(
    tcx: TyCtxt<'tcx>,
    closure_def_id: rustc_hir::def_id::DefId,
    oomir_module: &mut oomir::Module,
)

use oomir::Type;
use rustc_codegen_ssa::back::archive::{ArArchiveBuilder, ArchiveBuilder, ArchiveBuilderBuilder};
use rustc_codegen_ssa::{
    CompiledModule, CompiledModules, CrateInfo, ModuleKind, traits::CodegenBackend,
};
use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
use rustc_hir::def::DefKind;
use std::collections::VecDeque;

use rustc_data_structures::unord::UnordMap;
use rustc_metadata::EncodedMetadata;
use rustc_middle::{
    dep_graph::{WorkProduct, WorkProductId},
    mono::MonoItem,
    ty::{
        EarlyBinder, GenericArgs, Instance, InstanceKind, ShimKind, TyCtxt, TyKind,
        TypeVisitableExt, TypingEnv, Unnormalized, VtblEntry,
    },
};
use rustc_session::{
    IncrCompSession, Session,
    config::OutputFilenames,
};
use rustc_span::def_id::{DefId, LOCAL_CRATE};
use rustc_structures::CrateType;
use std::{
    any::Any,
    io::{BufReader, BufWriter, Read, Write},
    path::{Path, PathBuf},
    sync::{Arc, Mutex, mpsc},
};

mod instrumentation;
mod lower1;
mod lower2;
mod oomir;
mod optimise1;
mod stable_hash;

/// An instance of our Java bytecode codegen backend.
struct MyBackend;

/// Rustc's codegen-unit partitioning is tuned for native backends which lower
/// functions into independently owned LLVM modules. Keep each OOMIR shard
/// bounded as a second line of defence for unusually large codegen units.
const MAX_MONO_ITEMS_PER_OOMIR_SHARD: usize = 256;
// Four lower2 workers usefully saturate large crates without retaining an
// unbounded number of prepared OOMIR modules on many-core hosts.
const MAX_CODEGEN_WORKERS: usize = 4;
const OOMIR_SHARD_QUEUE_DEPTH: usize = 1;
const CLASS_BUNDLE_MAGIC: &[u8; 8] = b"RCJVMB1\0";

fn combine_class_bundles(path: &Path, bundles: &[(String, PathBuf)]) -> std::io::Result<()> {
    let mut output = BufWriter::new(std::fs::File::create(path)?);
    output.write_all(CLASS_BUNDLE_MAGIC)?;
    for (_, bundle_path) in bundles {
        let mut bundle = BufReader::new(std::fs::File::open(bundle_path)?);
        let mut magic = [0u8; CLASS_BUNDLE_MAGIC.len()];
        bundle.read_exact(&mut magic)?;
        if &magic != CLASS_BUNDLE_MAGIC {