rust/src/driver/aot.rs

287 lines
9.2 KiB
Rust

use rustc::dep_graph::{WorkProduct, WorkProductFileKind, WorkProductId};
use rustc::middle::cstore::EncodedMetadata;
use rustc::mir::mono::CodegenUnit;
use rustc_session::config::{DebugInfo, OutputType};
use rustc_session::cgu_reuse_tracker::CguReuse;
use rustc_codegen_ssa::back::linker::LinkerInfo;
use rustc_codegen_ssa::CrateInfo;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use crate::prelude::*;
use crate::backend::{Emit, WriteDebugInfo};
fn new_module(tcx: TyCtxt<'_>, name: String) -> Module<crate::backend::Backend> {
let module = crate::backend::make_module(tcx.sess, name);
assert_eq!(pointer_ty(tcx), module.target_config().pointer_type());
module
}
struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>);
impl<HCX> HashStable<HCX> for ModuleCodegenResult {
fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) {
// do nothing
}
}
fn emit_module<B: Backend>(
tcx: TyCtxt<'_>,
name: String,
kind: ModuleKind,
mut module: Module<B>,
debug: Option<DebugContext>,
) -> ModuleCodegenResult
where B::Product: Emit + WriteDebugInfo,
{
module.finalize_definitions();
let mut product = module.finish();
if let Some(mut debug) = debug {
debug.emit(&mut product);
}
let tmp_file = tcx
.output_filenames(LOCAL_CRATE)
.temp_path(OutputType::Object, Some(&name));
let obj = product.emit();
std::fs::write(&tmp_file, obj).unwrap();
let work_product = if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() {
None
} else {
rustc_incremental::copy_cgu_workproducts_to_incr_comp_cache_dir(
tcx.sess,
&name,
&[(WorkProductFileKind::Object, tmp_file.clone())],
)
};
ModuleCodegenResult(
CompiledModule {
name,
kind,
object: Some(tmp_file),
bytecode: None,
bytecode_compressed: None,
},
work_product,
)
}
fn reuse_workproduct_for_cgu(
tcx: TyCtxt<'_>,
cgu: &CodegenUnit,
work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
) -> CompiledModule {
let incr_comp_session_dir = tcx.sess.incr_comp_session_dir();
let mut object = None;
let work_product = cgu.work_product(tcx);
for (kind, saved_file) in &work_product.saved_files {
let obj_out = match kind {
WorkProductFileKind::Object => {
let path = tcx.output_filenames(LOCAL_CRATE).temp_path(OutputType::Object, Some(&cgu.name().as_str()));
object = Some(path.clone());
path
}
WorkProductFileKind::Bytecode | WorkProductFileKind::BytecodeCompressed => {
panic!("cg_clif doesn't use bytecode");
}
};
let source_file = rustc_incremental::in_incr_comp_dir(&incr_comp_session_dir, &saved_file);
if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) {
tcx.sess.err(&format!(
"unable to copy {} to {}: {}",
source_file.display(),
obj_out.display(),
err
));
}
}
work_products.insert(cgu.work_product_id(), work_product);
CompiledModule {
name: cgu.name().to_string(),
kind: ModuleKind::Regular,
object,
bytecode: None,
bytecode_compressed: None,
}
}
fn module_codegen(tcx: TyCtxt<'_>, cgu_name: rustc_span::Symbol) -> ModuleCodegenResult {
let cgu = tcx.codegen_unit(cgu_name);
let mono_items = cgu.items_in_deterministic_order(tcx);
let mut module = new_module(tcx, cgu_name.as_str().to_string());
let mut debug = if tcx.sess.opts.debuginfo != DebugInfo::None {
let debug = DebugContext::new(
tcx,
module.target_config().pointer_type().bytes() as u8,
);
Some(debug)
} else {
None
};
super::codegen_mono_items(tcx, &mut module, debug.as_mut(), mono_items);
crate::main_shim::maybe_create_entry_wrapper(tcx, &mut module);
emit_module(
tcx,
cgu.name().as_str().to_string(),
ModuleKind::Regular,
module,
debug,
)
}
pub(super) fn run_aot(
tcx: TyCtxt<'_>,
metadata: EncodedMetadata,
need_metadata_module: bool,
) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> {
let mut work_products = FxHashMap::default();
let (_, cgus) = tcx.collect_and_partition_mono_items(LOCAL_CRATE);
if tcx.dep_graph.is_fully_enabled() {
for cgu in &*cgus {
tcx.codegen_unit(cgu.name());
}
}
let modules = super::time(tcx, "codegen mono items", || {
cgus.iter().map(|cgu| {
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 {
_ if std::env::var("CG_CLIF_INCR_CACHE_DISABLED").is_ok() => {}
CguReuse::No => {}
CguReuse::PreLto => {
return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products);
}
CguReuse::PostLto => unreachable!(),
}
let dep_node = cgu.codegen_dep_node(tcx);
let (ModuleCodegenResult(module, work_product), _) =
tcx.dep_graph.with_task(dep_node, tcx, cgu.name(), module_codegen, rustc::dep_graph::hash_result);
if let Some((id, product)) = work_product {
work_products.insert(id, product);
}
module
}).collect::<Vec<_>>()
});
tcx.sess.abort_if_errors();
let mut allocator_module = new_module(tcx, "allocator_shim".to_string());
let created_alloc_shim = crate::allocator::codegen(tcx, &mut allocator_module);
let allocator_module = if created_alloc_shim {
let ModuleCodegenResult(module, work_product) = emit_module(
tcx,
"allocator_shim".to_string(),
ModuleKind::Allocator,
allocator_module,
None,
);
if let Some((id, product)) = work_product {
work_products.insert(id, product);
}
Some(module)
} else {
None
};
rustc_incremental::assert_dep_graph(tcx);
rustc_incremental::save_dep_graph(tcx);
let metadata_module = if need_metadata_module {
let _timer = tcx.prof.generic_activity("codegen crate metadata");
let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || {
use rustc::mir::mono::CodegenUnitNameBuilder;
let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
let metadata_cgu_name = cgu_name_builder
.build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata"))
.as_str()
.to_string();
let tmp_file = tcx
.output_filenames(LOCAL_CRATE)
.temp_path(OutputType::Metadata, Some(&metadata_cgu_name));
let obj = crate::backend::with_object(tcx.sess, &metadata_cgu_name, |object| {
crate::metadata::write_metadata(tcx, object);
});
std::fs::write(&tmp_file, obj).unwrap();
(metadata_cgu_name, tmp_file)
});
Some(CompiledModule {
name: metadata_cgu_name,
kind: ModuleKind::Metadata,
object: Some(tmp_file),
bytecode: None,
bytecode_compressed: None,
})
} else {
None
};
Box::new((CodegenResults {
crate_name: tcx.crate_name(LOCAL_CRATE),
modules,
allocator_module,
metadata_module,
crate_hash: tcx.crate_hash(LOCAL_CRATE),
metadata,
windows_subsystem: None, // Windows is not yet supported
linker_info: LinkerInfo::new(tcx),
crate_info: CrateInfo::new(tcx),
}, work_products))
}
// Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953
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() {
CguReuse::PreLto
} else {
CguReuse::No
}
}