// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! Translate the completed AST to the LLVM IR. //! //! Some functions here, such as trans_block and trans_expr, return a value -- //! the result of the translation to LLVM -- while others, such as trans_fn //! and trans_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 trans: //! //! * There's no way to find out the Ty type of a ValueRef. Doing so //! would be "trying to get the eggs out of an omelette" (credit: //! pcwalton). You can, instead, find out its TypeRef by calling val_ty, //! but one TypeRef corresponds to many `Ty`s; for instance, tup(int, int, //! int) and rec(x=int, y=int, z=int) will have the same TypeRef. use super::ModuleLlvm; use super::ModuleSource; use super::ModuleTranslation; use super::ModuleKind; use abi; use back::link; use back::write::{self, OngoingCrateTranslation, create_target_machine}; use llvm::{ContextRef, ModuleRef, ValueRef, Vector, get_param}; use llvm; use metadata; use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE}; use rustc::middle::lang_items::StartFnLangItem; use rustc::mir::mono::{Linkage, Visibility, Stats}; use rustc::middle::cstore::{EncodedMetadata}; use rustc::ty::{self, Ty, TyCtxt}; use rustc::ty::layout::{self, Align, TyLayout, LayoutOf}; use rustc::ty::maps::Providers; use rustc::dep_graph::{DepNode, DepConstructor}; use rustc::ty::subst::Kind; use rustc::middle::cstore::{self, LinkMeta, LinkagePreference}; use rustc::middle::exported_symbols; use rustc::util::common::{time, print_time_passes_entry}; use rustc::session::config::{self, NoDebugInfo}; use rustc::session::Session; use rustc_incremental; use allocator; use mir::place::PlaceRef; use attributes; use builder::Builder; use callee; use common::{C_bool, C_bytes_in_context, C_i32, C_usize}; use rustc_mir::monomorphize::collector::{self, MonoItemCollectionMode}; use common::{self, C_struct_in_context, C_array, val_ty}; use consts; use context::{self, CodegenCx}; use debuginfo; use declare; use meth; use mir; use monomorphize::Instance; use monomorphize::partitioning::{self, PartitioningStrategy, CodegenUnit, CodegenUnitExt}; use rustc_trans_utils::symbol_names_test; use time_graph; use trans_item::{MonoItem, BaseMonoItemExt, MonoItemExt, DefPathBasedNames}; use type_::Type; use type_of::LayoutLlvmExt; use rustc::util::nodemap::{FxHashMap, FxHashSet, DefIdSet}; use CrateInfo; use std::any::Any; use std::ffi::CString; use std::str; use std::sync::Arc; use std::time::{Instant, Duration}; use std::{i32, usize}; use std::iter; use std::sync::mpsc; use syntax_pos::Span; use syntax_pos::symbol::InternedString; use syntax::attr; use rustc::hir; use syntax::ast; use mir::operand::OperandValue; pub use rustc_trans_utils::check_for_rustc_errors_attr; pub struct StatRecorder<'a, 'tcx: 'a> { cx: &'a CodegenCx<'a, 'tcx>, name: Option, istart: usize, } impl<'a, 'tcx> StatRecorder<'a, 'tcx> { pub fn new(cx: &'a CodegenCx<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> { let istart = cx.stats.borrow().n_llvm_insns; StatRecorder { cx, name: Some(name), istart, } } } impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> { fn drop(&mut self) { if self.cx.sess().trans_stats() { let mut stats = self.cx.stats.borrow_mut(); let iend = stats.n_llvm_insns; stats.fn_stats.push((self.name.take().unwrap(), iend - self.istart)); stats.n_fns += 1; // Reset LLVM insn count to avoid compound costs. stats.n_llvm_insns = self.istart; } } } pub fn bin_op_to_icmp_predicate(op: hir::BinOp_, signed: bool) -> llvm::IntPredicate { match op { hir::BiEq => llvm::IntEQ, hir::BiNe => llvm::IntNE, hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT }, hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE }, hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT }, hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE }, op => { bug!("comparison_op_to_icmp_predicate: expected comparison operator, \ found {:?}", op) } } } pub fn bin_op_to_fcmp_predicate(op: hir::BinOp_) -> llvm::RealPredicate { match op { hir::BiEq => llvm::RealOEQ, hir::BiNe => llvm::RealUNE, hir::BiLt => llvm::RealOLT, hir::BiLe => llvm::RealOLE, hir::BiGt => llvm::RealOGT, hir::BiGe => llvm::RealOGE, op => { bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \ found {:?}", op); } } } pub fn compare_simd_types<'a, 'tcx>( bx: &Builder<'a, 'tcx>, lhs: ValueRef, rhs: ValueRef, t: Ty<'tcx>, ret_ty: Type, op: hir::BinOp_ ) -> ValueRef { let signed = match t.sty { ty::TyFloat(_) => { let cmp = bin_op_to_fcmp_predicate(op); return bx.sext(bx.fcmp(cmp, lhs, rhs), ret_ty); }, ty::TyUint(_) => false, ty::TyInt(_) => true, _ => bug!("compare_simd_types: invalid SIMD type"), }; let cmp = bin_op_to_icmp_predicate(op, signed); // 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(bx.icmp(cmp, lhs, rhs), ret_ty) } /// Retrieve 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<'cx, 'tcx>(cx: &CodegenCx<'cx, 'tcx>, source: Ty<'tcx>, target: Ty<'tcx>, old_info: Option) -> ValueRef { let (source, target) = cx.tcx.struct_lockstep_tails(source, target); match (&source.sty, &target.sty) { (&ty::TyArray(_, len), &ty::TySlice(_)) => { C_usize(cx, len.val.unwrap_u64()) } (&ty::TyDynamic(..), &ty::TyDynamic(..)) => { // 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::TyDynamic(ref data, ..)) => { let vtable_ptr = cx.layout_of(cx.tcx.mk_mut_ptr(target)) .field(cx, abi::FAT_PTR_EXTRA); consts::ptrcast(meth::get_vtable(cx, source, data.principal()), vtable_ptr.llvm_type(cx)) } _ => 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: &Builder<'a, 'tcx>, src: ValueRef, src_ty: Ty<'tcx>, dst_ty: Ty<'tcx> ) -> (ValueRef, ValueRef) { debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty); match (&src_ty.sty, &dst_ty.sty) { (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) | (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) | (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }), &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => { assert!(bx.cx.type_is_sized(a)); let ptr_ty = bx.cx.layout_of(b).llvm_type(bx.cx).ptr_to(); (bx.pointercast(src, ptr_ty), unsized_info(bx.cx, a, b, None)) } (&ty::TyAdt(def_a, _), &ty::TyAdt(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.layout_of(b).llvm_type(bx.cx).ptr_to(); (bx.pointercast(src, ptr_ty), unsized_info(bx.cx, a, b, None)) } (&ty::TyAdt(def_a, _), &ty::TyAdt(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, dst_layout.scalar_pair_element_llvm_type(bx.cx, 0)), bx.bitcast(llextra, dst_layout.scalar_pair_element_llvm_type(bx.cx, 1))) } _ => 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: &Builder<'a, 'tcx>, src: PlaceRef<'tcx>, dst: PlaceRef<'tcx>) { let src_ty = src.layout.ty; let dst_ty = dst.layout.ty; let coerce_ptr = || { let (base, info) = match src.load(bx).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, abi::FAT_PTR_ADDR); (bx.pointercast(base, thin_ptr.llvm_type(bx.cx)), 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::TyRef(..), &ty::TyRef(..)) | (&ty::TyRef(..), &ty::TyRawPtr(..)) | (&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => { coerce_ptr() } (&ty::TyAdt(def_a, _), &ty::TyAdt(def_b, _)) if def_a.is_box() && def_b.is_box() => { coerce_ptr() } (&ty::TyAdt(def_a, _), &ty::TyAdt(def_b, _)) => { assert_eq!(def_a, def_b); for i in 0..def_a.variants[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, src_f.llval, src_f.layout, src_f.align.min(dst_f.align)); } 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( cx: &Builder, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef ) -> ValueRef { cast_shift_rhs(op, lhs, rhs, |a, b| cx.trunc(a, b), |a, b| cx.zext(a, b)) } fn cast_shift_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef, trunc: F, zext: G) -> ValueRef where F: FnOnce(ValueRef, Type) -> ValueRef, G: FnOnce(ValueRef, Type) -> ValueRef { // Shifts may have any size int on the rhs if op.is_shift() { let mut rhs_llty = val_ty(rhs); let mut lhs_llty = val_ty(lhs); if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() } if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() } let rhs_sz = rhs_llty.int_width(); let lhs_sz = lhs_llty.int_width(); if lhs_sz < rhs_sz { trunc(rhs, lhs_llty) } else if lhs_sz > rhs_sz { // FIXME (#1877: If shifting by negative // values becomes not undefined then this is wrong. zext(rhs, lhs_llty) } else { rhs } } else { rhs } } /// Returns whether 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 call_assume<'a, 'tcx>(bx: &Builder<'a, 'tcx>, val: ValueRef) { let assume_intrinsic = bx.cx.get_intrinsic("llvm.assume"); bx.call(assume_intrinsic, &[val], None); } pub fn from_immediate(bx: &Builder, val: ValueRef) -> ValueRef { if val_ty(val) == Type::i1(bx.cx) { bx.zext(val, Type::i8(bx.cx)) } else { val } } pub fn to_immediate(bx: &Builder, val: ValueRef, layout: layout::TyLayout) -> ValueRef { if let layout::Abi::Scalar(ref scalar) = layout.abi { if scalar.is_bool() { return bx.trunc(val, Type::i1(bx.cx)); } } val } pub fn call_memcpy(bx: &Builder, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: Align) { let cx = bx.cx; let ptr_width = &cx.sess().target.target.target_pointer_width; let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width); let memcpy = cx.get_intrinsic(&key); let src_ptr = bx.pointercast(src, Type::i8p(cx)); let dst_ptr = bx.pointercast(dst, Type::i8p(cx)); let size = bx.intcast(n_bytes, cx.isize_ty, false); let align = C_i32(cx, align.abi() as i32); let volatile = C_bool(cx, false); bx.call(memcpy, &[dst_ptr, src_ptr, size, align, volatile], None); } pub fn memcpy_ty<'a, 'tcx>( bx: &Builder<'a, 'tcx>, dst: ValueRef, src: ValueRef, layout: TyLayout<'tcx>, align: Align, ) { let size = layout.size.bytes(); if size == 0 { return; } call_memcpy(bx, dst, src, C_usize(bx.cx, size), align); } pub fn call_memset<'a, 'tcx>(bx: &Builder<'a, 'tcx>, ptr: ValueRef, fill_byte: ValueRef, size: ValueRef, align: ValueRef, volatile: bool) -> ValueRef { let ptr_width = &bx.cx.sess().target.target.target_pointer_width; let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width); let llintrinsicfn = bx.cx.get_intrinsic(&intrinsic_key); let volatile = C_bool(bx.cx, volatile); bx.call(llintrinsicfn, &[ptr, fill_byte, size, align, volatile], None) } pub fn trans_instance<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, instance: Instance<'tcx>) { let _s = if cx.sess().trans_stats() { let mut instance_name = String::new(); DefPathBasedNames::new(cx.tcx, true, true) .push_def_path(instance.def_id(), &mut instance_name); Some(StatRecorder::new(cx, instance_name)) } else { None }; // this is an info! to allow collecting monomorphization statistics // and to allow finding the last function before LLVM aborts from // release builds. info!("trans_instance({})", instance); let fn_ty = instance.ty(cx.tcx); let sig = common::ty_fn_sig(cx, fn_ty); let sig = cx.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig); let lldecl = match cx.instances.borrow().get(&instance) { Some(&val) => val, None => bug!("Instance `{:?}` not already declared", instance) }; cx.stats.borrow_mut().n_closures += 1; // The `uwtable` attribute according to LLVM is: // // This attribute indicates that the ABI being targeted requires that an // unwind table entry be produced for this function even if we can show // that no exceptions passes by it. This is normally the case for the // ELF x86-64 abi, but it can be disabled for some compilation units. // // Typically when we're compiling with `-C panic=abort` (which implies this // `no_landing_pads` check) we don't need `uwtable` because we can't // generate any exceptions! On Windows, however, exceptions include other // events such as illegal instructions, segfaults, etc. This means that on // Windows we end up still needing the `uwtable` attribute even if the `-C // panic=abort` flag is passed. // // You can also find more info on why Windows is whitelisted here in: // https://bugzilla.mozilla.org/show_bug.cgi?id=1302078 if !cx.sess().no_landing_pads() || cx.sess().target.target.options.is_like_windows { attributes::emit_uwtable(lldecl, true); } let mir = cx.tcx.instance_mir(instance.def); mir::trans_mir(cx, lldecl, &mir, instance, sig); } pub fn set_link_section(cx: &CodegenCx, llval: ValueRef, attrs: &[ast::Attribute]) { if let Some(sect) = attr::first_attr_value_str_by_name(attrs, "link_section") { if contains_null(§.as_str()) { cx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", §)); } unsafe { let buf = CString::new(sect.as_str().as_bytes()).unwrap(); llvm::LLVMSetSection(llval, buf.as_ptr()); } } } /// Create the `main` function which will initialize the rust runtime and call /// users main function. fn maybe_create_entry_wrapper(cx: &CodegenCx) { let (main_def_id, span) = match *cx.sess().entry_fn.borrow() { Some((id, span)) => { (cx.tcx.hir.local_def_id(id), span) } 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 = callee::get_fn(cx, instance); let et = cx.sess().entry_type.get().unwrap(); match et { config::EntryMain => create_entry_fn(cx, span, main_llfn, main_def_id, true), config::EntryStart => create_entry_fn(cx, span, main_llfn, main_def_id, false), config::EntryNone => {} // Do nothing. } fn create_entry_fn<'cx>(cx: &'cx CodegenCx, sp: Span, rust_main: ValueRef, rust_main_def_id: DefId, use_start_lang_item: bool) { let llfty = Type::func(&[Type::c_int(cx), Type::i8p(cx).ptr_to()], &Type::c_int(cx)); 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 = main_ret_ty.no_late_bound_regions().unwrap(); if declare::get_defined_value(cx, "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 = declare::declare_cfn(cx, "main", llfty); // `main` should respect same config for frame pointer elimination as rest of code attributes::set_frame_pointer_elimination(cx, llfn); let bx = Builder::new_block(cx, llfn, "top"); debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(&bx); // Params from native main() used as args for rust start function let param_argc = get_param(llfn, 0); let param_argv = get_param(llfn, 1); let arg_argc = bx.intcast(param_argc, cx.isize_ty, 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.mk_substs( iter::once(Kind::from(main_ret_ty)))); (start_fn, vec![bx.pointercast(rust_main, Type::i8p(cx).ptr_to()), 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); bx.ret(bx.intcast(result, Type::c_int(cx), true)); } } fn contains_null(s: &str) -> bool { s.bytes().any(|b| b == 0) } fn write_metadata<'a, 'gcx>(tcx: TyCtxt<'a, 'gcx, 'gcx>, llmod_id: &str, link_meta: &LinkMeta) -> (ContextRef, ModuleRef, EncodedMetadata) { use std::io::Write; use flate2::Compression; use flate2::write::DeflateEncoder; let (metadata_llcx, metadata_llmod) = unsafe { context::create_context_and_module(tcx.sess, llmod_id) }; #[derive(PartialEq, Eq, PartialOrd, Ord)] enum MetadataKind { None, Uncompressed, Compressed } let kind = tcx.sess.crate_types.borrow().iter().map(|ty| { match *ty { config::CrateTypeExecutable | config::CrateTypeStaticlib | config::CrateTypeCdylib => MetadataKind::None, config::CrateTypeRlib => MetadataKind::Uncompressed, config::CrateTypeDylib | config::CrateTypeProcMacro => MetadataKind::Compressed, } }).max().unwrap(); if kind == MetadataKind::None { return (metadata_llcx, metadata_llmod, EncodedMetadata::new()); } let metadata = tcx.encode_metadata(link_meta); if kind == MetadataKind::Uncompressed { return (metadata_llcx, metadata_llmod, metadata); } assert!(kind == MetadataKind::Compressed); let mut compressed = tcx.metadata_encoding_version(); DeflateEncoder::new(&mut compressed, Compression::fast()) .write_all(&metadata.raw_data).unwrap(); let llmeta = C_bytes_in_context(metadata_llcx, &compressed); let llconst = C_struct_in_context(metadata_llcx, &[llmeta], false); let name = exported_symbols::metadata_symbol_name(tcx); let buf = CString::new(name).unwrap(); let llglobal = unsafe { llvm::LLVMAddGlobal(metadata_llmod, val_ty(llconst).to_ref(), buf.as_ptr()) }; unsafe { llvm::LLVMSetInitializer(llglobal, llconst); let section_name = metadata::metadata_section_name(&tcx.sess.target.target); let name = CString::new(section_name).unwrap(); llvm::LLVMSetSection(llglobal, name.as_ptr()); // Also generate a .section directive to force no // flags, at least for ELF outputs, so that the // metadata doesn't get loaded into memory. let directive = format!(".section {}", section_name); let directive = CString::new(directive).unwrap(); llvm::LLVMSetModuleInlineAsm(metadata_llmod, directive.as_ptr()) } return (metadata_llcx, metadata_llmod, metadata); } pub struct ValueIter { cur: ValueRef, step: unsafe extern "C" fn(ValueRef) -> ValueRef, } impl Iterator for ValueIter { type Item = ValueRef; fn next(&mut self) -> Option { let old = self.cur; if !old.is_null() { self.cur = unsafe { (self.step)(old) }; Some(old) } else { None } } } pub fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter { unsafe { ValueIter { cur: llvm::LLVMGetFirstGlobal(llmod), step: llvm::LLVMGetNextGlobal, } } } pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, rx: mpsc::Receiver>) -> OngoingCrateTranslation { check_for_rustc_errors_attr(tcx); if let Some(true) = tcx.sess.opts.debugging_opts.thinlto { if unsafe { !llvm::LLVMRustThinLTOAvailable() } { tcx.sess.fatal("this compiler's LLVM does not support ThinLTO"); } } let crate_hash = tcx.crate_hash(LOCAL_CRATE); let link_meta = link::build_link_meta(crate_hash); // Translate the metadata. let llmod_id = "metadata"; let (metadata_llcx, metadata_llmod, metadata) = time(tcx.sess, "write metadata", || { write_metadata(tcx, llmod_id, &link_meta) }); let metadata_module = ModuleTranslation { name: link::METADATA_MODULE_NAME.to_string(), llmod_id: llmod_id.to_string(), source: ModuleSource::Translated(ModuleLlvm { llcx: metadata_llcx, llmod: metadata_llmod, tm: create_target_machine(tcx.sess), }), kind: ModuleKind::Metadata, }; let time_graph = if tcx.sess.opts.debugging_opts.trans_time_graph { Some(time_graph::TimeGraph::new()) } else { None }; // Skip crate items and just output metadata in -Z no-trans mode. if tcx.sess.opts.debugging_opts.no_trans || !tcx.sess.opts.output_types.should_trans() { let ongoing_translation = write::start_async_translation( tcx, time_graph.clone(), link_meta, metadata, rx, 1); ongoing_translation.submit_pre_translated_module_to_llvm(tcx, metadata_module); ongoing_translation.translation_finished(tcx); assert_and_save_dep_graph(tcx); ongoing_translation.check_for_errors(tcx.sess); return ongoing_translation; } // Run the translation item collector and partition the collected items into // codegen units. let codegen_units = tcx.collect_and_partition_translation_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_translation = write::start_async_translation( tcx, time_graph.clone(), link_meta, metadata, rx, codegen_units.len()); // Translate an allocator shim, if any let allocator_module = if let Some(kind) = tcx.sess.allocator_kind.get() { unsafe { let llmod_id = "allocator"; let (llcx, llmod) = context::create_context_and_module(tcx.sess, llmod_id); let modules = ModuleLlvm { llmod, llcx, tm: create_target_machine(tcx.sess), }; time(tcx.sess, "write allocator module", || { allocator::trans(tcx, &modules, kind) }); Some(ModuleTranslation { name: link::ALLOCATOR_MODULE_NAME.to_string(), llmod_id: llmod_id.to_string(), source: ModuleSource::Translated(modules), kind: ModuleKind::Allocator, }) } } else { None }; if let Some(allocator_module) = allocator_module { ongoing_translation.submit_pre_translated_module_to_llvm(tcx, allocator_module); } ongoing_translation.submit_pre_translated_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_key(|cgu| usize::MAX - cgu.size_estimate()); codegen_units }; let mut total_trans_time = Duration::new(0, 0); let mut all_stats = Stats::default(); for cgu in codegen_units.into_iter() { ongoing_translation.wait_for_signal_to_translate_item(); ongoing_translation.check_for_errors(tcx.sess); // First, if incremental compilation is enabled, we try to re-use the // codegen unit from the cache. if tcx.dep_graph.is_fully_enabled() { let cgu_id = cgu.work_product_id(); // Check whether there is a previous work-product we can // re-use. Not only must the file exist, and the inputs not // be dirty, but the hash of the symbols we will generate must // be the same. if let Some(buf) = tcx.dep_graph.previous_work_product(&cgu_id) { let dep_node = &DepNode::new(tcx, DepConstructor::CompileCodegenUnit(cgu.name().clone())); // We try to mark the DepNode::CompileCodegenUnit green. If we // succeed it means that none of the dependencies has changed // and we can safely re-use. if let Some(dep_node_index) = tcx.dep_graph.try_mark_green(tcx, dep_node) { // Append ".rs" to LLVM module identifier. // // LLVM code generator emits a ".file filename" directive // for ELF backends. Value of the "filename" is set as the // LLVM module identifier. Due to a LLVM MC bug[1], LLVM // crashes if the module identifier is same as other symbols // such as a function name in the module. // 1. http://llvm.org/bugs/show_bug.cgi?id=11479 let llmod_id = format!("{}.rs", cgu.name()); let module = ModuleTranslation { name: cgu.name().to_string(), source: ModuleSource::Preexisting(buf), kind: ModuleKind::Regular, llmod_id, }; tcx.dep_graph.mark_loaded_from_cache(dep_node_index, true); write::submit_translated_module_to_llvm(tcx, module, 0); // Continue to next cgu, this one is done. continue } } else { // This can happen if files were deleted from the cache // directory for some reason. We just re-compile then. } } let _timing_guard = time_graph.as_ref().map(|time_graph| { time_graph.start(write::TRANS_WORKER_TIMELINE, write::TRANS_WORK_PACKAGE_KIND, &format!("codegen {}", cgu.name())) }); let start_time = Instant::now(); all_stats.extend(tcx.compile_codegen_unit(*cgu.name())); total_trans_time += start_time.elapsed(); ongoing_translation.check_for_errors(tcx.sess); } ongoing_translation.translation_finished(tcx); // Since the main thread is sometimes blocked during trans, we keep track // -Ztime-passes output manually. print_time_passes_entry(tcx.sess.time_passes(), "translate to LLVM IR", total_trans_time); if tcx.sess.opts.incremental.is_some() { ::rustc_incremental::assert_module_sources::assert_module_sources(tcx); } symbol_names_test::report_symbol_names(tcx); if tcx.sess.trans_stats() { println!("--- trans stats ---"); println!("n_glues_created: {}", all_stats.n_glues_created); println!("n_null_glues: {}", all_stats.n_null_glues); println!("n_real_glues: {}", all_stats.n_real_glues); println!("n_fns: {}", all_stats.n_fns); println!("n_inlines: {}", all_stats.n_inlines); println!("n_closures: {}", all_stats.n_closures); println!("fn stats:"); all_stats.fn_stats.sort_by_key(|&(_, insns)| insns); for &(ref name, insns) in all_stats.fn_stats.iter() { println!("{} insns, {}", insns, *name); } } if tcx.sess.count_llvm_insns() { for (k, v) in all_stats.llvm_insns.iter() { println!("{:7} {}", *v, *k); } } ongoing_translation.check_for_errors(tcx.sess); assert_and_save_dep_graph(tcx); ongoing_translation } fn assert_and_save_dep_graph<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { time(tcx.sess, "assert dep graph", || rustc_incremental::assert_dep_graph(tcx)); time(tcx.sess, "serialize dep graph", || rustc_incremental::save_dep_graph(tcx)); } fn collect_and_partition_translation_items<'a, 'tcx>( tcx: TyCtxt<'a, 'tcx, 'tcx>, cnum: CrateNum, ) -> (Arc, Arc>>>) { assert_eq!(cnum, LOCAL_CRATE); let collection_mode = match tcx.sess.opts.debugging_opts.print_trans_items { Some(ref s) => { let mode_string = s.to_lowercase(); let mode_string = mode_string.trim(); if mode_string == "eager" { MonoItemCollectionMode::Eager } else { if mode_string != "lazy" { let message = format!("Unknown codegen-item collection mode '{}'. \ Falling back to 'lazy' mode.", mode_string); tcx.sess.warn(&message); } MonoItemCollectionMode::Lazy } } None => { if tcx.sess.opts.cg.link_dead_code { MonoItemCollectionMode::Eager } else { MonoItemCollectionMode::Lazy } } }; let (items, inlining_map) = time(tcx.sess, "translation item collection", || { collector::collect_crate_mono_items(tcx, collection_mode) }); tcx.sess.abort_if_errors(); ::rustc_mir::monomorphize::assert_symbols_are_distinct(tcx, items.iter()); let strategy = if tcx.sess.opts.incremental.is_some() { PartitioningStrategy::PerModule } else { PartitioningStrategy::FixedUnitCount(tcx.sess.codegen_units()) }; let codegen_units = time(tcx.sess, "codegen unit partitioning", || { partitioning::partition(tcx, items.iter().cloned(), strategy, &inlining_map) .into_iter() .map(Arc::new) .collect::>() }); let translation_items: DefIdSet = items.iter().filter_map(|trans_item| { match *trans_item { MonoItem::Fn(ref instance) => Some(instance.def_id()), MonoItem::Static(def_id) => Some(def_id), _ => None, } }).collect(); if tcx.sess.opts.debugging_opts.print_trans_items.is_some() { let mut item_to_cgus = FxHashMap(); for cgu in &codegen_units { for (&trans_item, &linkage) in cgu.items() { item_to_cgus.entry(trans_item) .or_insert(Vec::new()) .push((cgu.name().clone(), linkage)); } } let mut item_keys: Vec<_> = items .iter() .map(|i| { let mut output = i.to_string(tcx); output.push_str(" @@"); let mut empty = Vec::new(); let cgus = item_to_cgus.get_mut(i).unwrap_or(&mut empty); cgus.as_mut_slice().sort_by_key(|&(ref name, _)| name.clone()); cgus.dedup(); for &(ref cgu_name, (linkage, _)) in cgus.iter() { output.push_str(" "); output.push_str(&cgu_name); let linkage_abbrev = match linkage { Linkage::External => "External", Linkage::AvailableExternally => "Available", Linkage::LinkOnceAny => "OnceAny", Linkage::LinkOnceODR => "OnceODR", Linkage::WeakAny => "WeakAny", Linkage::WeakODR => "WeakODR", Linkage::Appending => "Appending", Linkage::Internal => "Internal", Linkage::Private => "Private", Linkage::ExternalWeak => "ExternalWeak", Linkage::Common => "Common", }; output.push_str("["); output.push_str(linkage_abbrev); output.push_str("]"); } output }) .collect(); item_keys.sort(); for item in item_keys { println!("TRANS_ITEM {}", item); } } (Arc::new(translation_items), Arc::new(codegen_units)) } 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: FxHashSet(), native_libraries: FxHashMap(), used_libraries: tcx.native_libraries(LOCAL_CRATE), link_args: tcx.link_args(LOCAL_CRATE), crate_name: FxHashMap(), used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic), used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic), used_crate_source: FxHashMap(), }; for &cnum in tcx.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); } } return info } } fn is_translated_item(tcx: TyCtxt, id: DefId) -> bool { let (all_trans_items, _) = tcx.collect_and_partition_translation_items(LOCAL_CRATE); all_trans_items.contains(&id) } fn compile_codegen_unit<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, cgu: InternedString) -> Stats { let cgu = tcx.codegen_unit(cgu); let start_time = Instant::now(); let (stats, module) = module_translation(tcx, cgu); let time_to_translate = start_time.elapsed(); // We assume that the cost to run LLVM on a CGU is proportional to // the time we needed for translating it. let cost = time_to_translate.as_secs() * 1_000_000_000 + time_to_translate.subsec_nanos() as u64; write::submit_translated_module_to_llvm(tcx, module, cost); return stats; fn module_translation<'a, 'tcx>( tcx: TyCtxt<'a, 'tcx, 'tcx>, cgu: Arc>) -> (Stats, ModuleTranslation) { let cgu_name = cgu.name().to_string(); // Append ".rs" to LLVM module identifier. // // LLVM code generator emits a ".file filename" directive // for ELF backends. Value of the "filename" is set as the // LLVM module identifier. Due to a LLVM MC bug[1], LLVM // crashes if the module identifier is same as other symbols // such as a function name in the module. // 1. http://llvm.org/bugs/show_bug.cgi?id=11479 let llmod_id = format!("{}-{}.rs", cgu.name(), tcx.crate_disambiguator(LOCAL_CRATE) .to_fingerprint().to_hex()); // Instantiate translation items without filling out definitions yet... let cx = CodegenCx::new(tcx, cgu, &llmod_id); let module = { let trans_items = cx.codegen_unit .items_in_deterministic_order(cx.tcx); for &(trans_item, (linkage, visibility)) in &trans_items { trans_item.predefine(&cx, linkage, visibility); } // ... and now that we have everything pre-defined, fill out those definitions. for &(trans_item, _) in &trans_items { trans_item.define(&cx); } // If this codegen unit contains the main function, also create the // wrapper here maybe_create_entry_wrapper(&cx); // Run replace-all-uses-with for statics that need it for &(old_g, new_g) in cx.statics_to_rauw.borrow().iter() { unsafe { let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g)); llvm::LLVMReplaceAllUsesWith(old_g, bitcast); llvm::LLVMDeleteGlobal(old_g); } } // Create the llvm.used variable // This variable has type [N x i8*] and is stored in the llvm.metadata section if !cx.used_statics.borrow().is_empty() { let name = CString::new("llvm.used").unwrap(); let section = CString::new("llvm.metadata").unwrap(); let array = C_array(Type::i8(&cx).ptr_to(), &*cx.used_statics.borrow()); unsafe { let g = llvm::LLVMAddGlobal(cx.llmod, val_ty(array).to_ref(), name.as_ptr()); llvm::LLVMSetInitializer(g, array); llvm::LLVMRustSetLinkage(g, llvm::Linkage::AppendingLinkage); llvm::LLVMSetSection(g, section.as_ptr()); } } // Finalize debuginfo if cx.sess().opts.debuginfo != NoDebugInfo { debuginfo::finalize(&cx); } let llvm_module = ModuleLlvm { llcx: cx.llcx, llmod: cx.llmod, tm: create_target_machine(cx.sess()), }; ModuleTranslation { name: cgu_name, source: ModuleSource::Translated(llvm_module), kind: ModuleKind::Regular, llmod_id, } }; (cx.into_stats(), module) } } pub fn provide(providers: &mut Providers) { providers.collect_and_partition_translation_items = collect_and_partition_translation_items; providers.is_translated_item = is_translated_item; providers.codegen_unit = |tcx, name| { let (_, all) = tcx.collect_and_partition_translation_items(LOCAL_CRATE); all.iter() .find(|cgu| *cgu.name() == name) .cloned() .expect(&format!("failed to find cgu with name {:?}", name)) }; providers.compile_codegen_unit = compile_codegen_unit; } pub fn linkage_to_llvm(linkage: Linkage) -> llvm::Linkage { match linkage { Linkage::External => llvm::Linkage::ExternalLinkage, Linkage::AvailableExternally => llvm::Linkage::AvailableExternallyLinkage, Linkage::LinkOnceAny => llvm::Linkage::LinkOnceAnyLinkage, Linkage::LinkOnceODR => llvm::Linkage::LinkOnceODRLinkage, Linkage::WeakAny => llvm::Linkage::WeakAnyLinkage, Linkage::WeakODR => llvm::Linkage::WeakODRLinkage, Linkage::Appending => llvm::Linkage::AppendingLinkage, Linkage::Internal => llvm::Linkage::InternalLinkage, Linkage::Private => llvm::Linkage::PrivateLinkage, Linkage::ExternalWeak => llvm::Linkage::ExternalWeakLinkage, Linkage::Common => llvm::Linkage::CommonLinkage, } } pub fn visibility_to_llvm(linkage: Visibility) -> llvm::Visibility { match linkage { Visibility::Default => llvm::Visibility::Default, Visibility::Hidden => llvm::Visibility::Hidden, Visibility::Protected => llvm::Visibility::Protected, } } // FIXME(mw): Anything that is produced via DepGraph::with_task() must implement // the HashStable trait. Normally DepGraph::with_task() calls are // hidden behind queries, but CGU creation is a special case in two // ways: (1) it's not a query and (2) CGU are output nodes, so their // Fingerprints are not actually needed. It remains to be clarified // how exactly this case will be handled in the red/green system but // for now we content ourselves with providing a no-op HashStable // implementation for CGUs. mod temp_stable_hash_impls { use rustc_data_structures::stable_hasher::{StableHasherResult, StableHasher, HashStable}; use ModuleTranslation; impl HashStable for ModuleTranslation { fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) { // do nothing } } }