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fuchsia / third_party / rust / 80ff0f74b0c4a8d384160af81a1b21f53622d8af / . / src / librustc_trans / back / write.rs
blob: da67940abcb776973862a2c1a71896be0c68b5cc [file] [log] [blame]
// Copyright 2013-2015 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use back::bytecode::{self, RLIB_BYTECODE_EXTENSION};
use back::lto::{self, ModuleBuffer, ThinBuffer};
use back::link::{self, get_linker, remove};
use back::linker::LinkerInfo;
use back::symbol_export::ExportedSymbols;
use base;
use consts;
use rustc_incremental::{save_trans_partition, in_incr_comp_dir};
use rustc::dep_graph::{DepGraph, WorkProductFileKind};
use rustc::middle::cstore::{LinkMeta, EncodedMetadata};
use rustc::session::config::{self, OutputFilenames, OutputType, OutputTypes, Passes, SomePasses,
AllPasses, Sanitizer};
use rustc::session::Session;
use rustc::util::nodemap::FxHashMap;
use rustc_back::LinkerFlavor;
use time_graph::{self, TimeGraph, Timeline};
use llvm;
use llvm::{ModuleRef, TargetMachineRef, PassManagerRef, DiagnosticInfoRef};
use llvm::{SMDiagnosticRef, ContextRef};
use {CrateTranslation, ModuleSource, ModuleTranslation, CompiledModule, ModuleKind};
use CrateInfo;
use rustc::hir::def_id::{CrateNum, LOCAL_CRATE};
use rustc::ty::TyCtxt;
use rustc::util::common::{time, time_depth, set_time_depth, path2cstr, print_time_passes_entry};
use rustc::util::fs::{link_or_copy, rename_or_copy_remove};
use errors::{self, Handler, Level, DiagnosticBuilder, FatalError, DiagnosticId};
use errors::emitter::{Emitter};
use syntax::attr;
use syntax::ext::hygiene::Mark;
use syntax_pos::MultiSpan;
use syntax_pos::symbol::Symbol;
use type_::Type;
use context::{is_pie_binary, get_reloc_model};
use jobserver::{Client, Acquired};
use rustc_demangle;
use std::any::Any;
use std::ffi::{CString, CStr};
use std::fs::{self, File};
use std::io;
use std::io::{Read, Write};
use std::mem;
use std::path::{Path, PathBuf};
use std::str;
use std::sync::Arc;
use std::sync::mpsc::{channel, Sender, Receiver};
use std::slice;
use std::time::Instant;
use std::thread;
use libc::{c_uint, c_void, c_char, size_t};
pub const RELOC_MODEL_ARGS : [(&'static str, llvm::RelocMode); 7] = [
("pic", llvm::RelocMode::PIC),
("static", llvm::RelocMode::Static),
("default", llvm::RelocMode::Default),
("dynamic-no-pic", llvm::RelocMode::DynamicNoPic),
("ropi", llvm::RelocMode::ROPI),
("rwpi", llvm::RelocMode::RWPI),
("ropi-rwpi", llvm::RelocMode::ROPI_RWPI),
];
pub const CODE_GEN_MODEL_ARGS : [(&'static str, llvm::CodeModel); 5] = [
("default", llvm::CodeModel::Default),
("small", llvm::CodeModel::Small),
("kernel", llvm::CodeModel::Kernel),
("medium", llvm::CodeModel::Medium),
("large", llvm::CodeModel::Large),
];
pub const TLS_MODEL_ARGS : [(&'static str, llvm::ThreadLocalMode); 4] = [
("global-dynamic", llvm::ThreadLocalMode::GeneralDynamic),
("local-dynamic", llvm::ThreadLocalMode::LocalDynamic),
("initial-exec", llvm::ThreadLocalMode::InitialExec),
("local-exec", llvm::ThreadLocalMode::LocalExec),
];
pub fn llvm_err(handler: &errors::Handler, msg: String) -> FatalError {
match llvm::last_error() {
Some(err) => handler.fatal(&format!("{}: {}", msg, err)),
None => handler.fatal(&msg),
}
}
pub fn write_output_file(
handler: &errors::Handler,
target: llvm::TargetMachineRef,
pm: llvm::PassManagerRef,
m: ModuleRef,
output: &Path,
file_type: llvm::FileType) -> Result<(), FatalError> {
unsafe {
let output_c = path2cstr(output);
let result = llvm::LLVMRustWriteOutputFile(
target, pm, m, output_c.as_ptr(), file_type);
if result.into_result().is_err() {
let msg = format!("could not write output to {}", output.display());
Err(llvm_err(handler, msg))
} else {
Ok(())
}
}
}
// On android, we by default compile for armv7 processors. This enables
// things like double word CAS instructions (rather than emulating them)
// which are *far* more efficient. This is obviously undesirable in some
// cases, so if any sort of target feature is specified we don't append v7
// to the feature list.
//
// On iOS only armv7 and newer are supported. So it is useful to
// get all hardware potential via VFP3 (hardware floating point)
// and NEON (SIMD) instructions supported by LLVM.
// Note that without those flags various linking errors might
// arise as some of intrinsics are converted into function calls
// and nobody provides implementations those functions
fn target_feature(sess: &Session) -> String {
let rustc_features = [
"crt-static",
];
let requested_features = sess.opts.cg.target_feature.split(',');
let llvm_features = requested_features.filter(|f| {
!rustc_features.iter().any(|s| f.contains(s))
});
format!("{},{}",
sess.target.target.options.features,
llvm_features.collect::<Vec<_>>().join(","))
}
fn get_llvm_opt_level(optimize: config::OptLevel) -> llvm::CodeGenOptLevel {
match optimize {
config::OptLevel::No => llvm::CodeGenOptLevel::None,
config::OptLevel::Less => llvm::CodeGenOptLevel::Less,
config::OptLevel::Default => llvm::CodeGenOptLevel::Default,
config::OptLevel::Aggressive => llvm::CodeGenOptLevel::Aggressive,
_ => llvm::CodeGenOptLevel::Default,
}
}
fn get_llvm_opt_size(optimize: config::OptLevel) -> llvm::CodeGenOptSize {
match optimize {
config::OptLevel::Size => llvm::CodeGenOptSizeDefault,
config::OptLevel::SizeMin => llvm::CodeGenOptSizeAggressive,
_ => llvm::CodeGenOptSizeNone,
}
}
pub fn create_target_machine(sess: &Session) -> TargetMachineRef {
target_machine_factory(sess)().unwrap_or_else(|err| {
panic!(llvm_err(sess.diagnostic(), err))
})
}
pub fn target_machine_factory(sess: &Session)
-> Arc<Fn() -> Result<TargetMachineRef, String> + Send + Sync>
{
let reloc_model = get_reloc_model(sess);
let opt_level = get_llvm_opt_level(sess.opts.optimize);
let use_softfp = sess.opts.cg.soft_float;
let ffunction_sections = sess.target.target.options.function_sections;
let fdata_sections = ffunction_sections;
let code_model_arg = match sess.opts.cg.code_model {
Some(ref s) => &s,
None => &sess.target.target.options.code_model,
};
let code_model = match CODE_GEN_MODEL_ARGS.iter().find(
|&&arg| arg.0 == code_model_arg) {
Some(x) => x.1,
_ => {
sess.err(&format!("{:?} is not a valid code model",
code_model_arg));
sess.abort_if_errors();
bug!();
}
};
let singlethread = sess.target.target.options.singlethread;
let triple = &sess.target.target.llvm_target;
let triple = CString::new(triple.as_bytes()).unwrap();
let cpu = match sess.opts.cg.target_cpu {
Some(ref s) => &**s,
None => &*sess.target.target.options.cpu
};
let cpu = CString::new(cpu.as_bytes()).unwrap();
let features = CString::new(target_feature(sess).as_bytes()).unwrap();
let is_pie_binary = is_pie_binary(sess);
let trap_unreachable = sess.target.target.options.trap_unreachable;
Arc::new(move || {
let tm = unsafe {
llvm::LLVMRustCreateTargetMachine(
triple.as_ptr(), cpu.as_ptr(), features.as_ptr(),
code_model,
reloc_model,
opt_level,
use_softfp,
is_pie_binary,
ffunction_sections,
fdata_sections,
trap_unreachable,
singlethread,
)
};
if tm.is_null() {
Err(format!("Could not create LLVM TargetMachine for triple: {}",
triple.to_str().unwrap()))
} else {
Ok(tm)
}
})
}
/// Module-specific configuration for `optimize_and_codegen`.
pub struct ModuleConfig {
/// Names of additional optimization passes to run.
passes: Vec<String>,
/// Some(level) to optimize at a certain level, or None to run
/// absolutely no optimizations (used for the metadata module).
pub opt_level: Option<llvm::CodeGenOptLevel>,
/// Some(level) to optimize binary size, or None to not affect program size.
opt_size: Option<llvm::CodeGenOptSize>,
// Flags indicating which outputs to produce.
emit_no_opt_bc: bool,
emit_bc: bool,
emit_bc_compressed: bool,
emit_lto_bc: bool,
emit_ir: bool,
emit_asm: bool,
emit_obj: bool,
// Miscellaneous flags. These are mostly copied from command-line
// options.
no_verify: bool,
no_prepopulate_passes: bool,
no_builtins: bool,
time_passes: bool,
vectorize_loop: bool,
vectorize_slp: bool,
merge_functions: bool,
inline_threshold: Option<usize>,
// Instead of creating an object file by doing LLVM codegen, just
// make the object file bitcode. Provides easy compatibility with
// emscripten's ecc compiler, when used as the linker.
obj_is_bitcode: bool,
}
impl ModuleConfig {
fn new(passes: Vec<String>) -> ModuleConfig {
ModuleConfig {
passes,
opt_level: None,
opt_size: None,
emit_no_opt_bc: false,
emit_bc: false,
emit_bc_compressed: false,
emit_lto_bc: false,
emit_ir: false,
emit_asm: false,
emit_obj: false,
obj_is_bitcode: false,
no_verify: false,
no_prepopulate_passes: false,
no_builtins: false,
time_passes: false,
vectorize_loop: false,
vectorize_slp: false,
merge_functions: false,
inline_threshold: None
}
}
fn set_flags(&mut self, sess: &Session, no_builtins: bool) {
self.no_verify = sess.no_verify();
self.no_prepopulate_passes = sess.opts.cg.no_prepopulate_passes;
self.no_builtins = no_builtins || sess.target.target.options.no_builtins;
self.time_passes = sess.time_passes();
self.inline_threshold = sess.opts.cg.inline_threshold;
self.obj_is_bitcode = sess.target.target.options.obj_is_bitcode;
// Copy what clang does by turning on loop vectorization at O2 and
// slp vectorization at O3. Otherwise configure other optimization aspects
// of this pass manager builder.
// Turn off vectorization for emscripten, as it's not very well supported.
self.vectorize_loop = !sess.opts.cg.no_vectorize_loops &&
(sess.opts.optimize == config::OptLevel::Default ||
sess.opts.optimize == config::OptLevel::Aggressive) &&
!sess.target.target.options.is_like_emscripten;
self.vectorize_slp = !sess.opts.cg.no_vectorize_slp &&
sess.opts.optimize == config::OptLevel::Aggressive &&
!sess.target.target.options.is_like_emscripten;
self.merge_functions = sess.opts.optimize == config::OptLevel::Default ||
sess.opts.optimize == config::OptLevel::Aggressive;
}
}
/// Additional resources used by optimize_and_codegen (not module specific)
#[derive(Clone)]
pub struct CodegenContext {
// Resouces needed when running LTO
pub time_passes: bool,
pub lto: bool,
pub thinlto: bool,
pub no_landing_pads: bool,
pub save_temps: bool,
pub exported_symbols: Arc<ExportedSymbols>,
pub opts: Arc<config::Options>,
pub crate_types: Vec<config::CrateType>,
pub each_linked_rlib_for_lto: Vec<(CrateNum, PathBuf)>,
output_filenames: Arc<OutputFilenames>,
regular_module_config: Arc<ModuleConfig>,
metadata_module_config: Arc<ModuleConfig>,
allocator_module_config: Arc<ModuleConfig>,
pub tm_factory: Arc<Fn() -> Result<TargetMachineRef, String> + Send + Sync>,
pub msvc_imps_needed: bool,
pub target_pointer_width: String,
binaryen_linker: bool,
debuginfo: config::DebugInfoLevel,
wasm_import_memory: bool,
// Number of cgus excluding the allocator/metadata modules
pub total_cgus: usize,
// Handler to use for diagnostics produced during codegen.
pub diag_emitter: SharedEmitter,
// LLVM passes added by plugins.
pub plugin_passes: Vec<String>,
// LLVM optimizations for which we want to print remarks.
pub remark: Passes,
// Worker thread number
pub worker: usize,
// The incremental compilation session directory, or None if we are not
// compiling incrementally
pub incr_comp_session_dir: Option<PathBuf>,
// Channel back to the main control thread to send messages to
coordinator_send: Sender<Box<Any + Send>>,
// A reference to the TimeGraph so we can register timings. None means that
// measuring is disabled.
time_graph: Option<TimeGraph>,
}
impl CodegenContext {
pub fn create_diag_handler(&self) -> Handler {
Handler::with_emitter(true, false, Box::new(self.diag_emitter.clone()))
}
pub fn config(&self, kind: ModuleKind) -> &ModuleConfig {
match kind {
ModuleKind::Regular => &self.regular_module_config,
ModuleKind::Metadata => &self.metadata_module_config,
ModuleKind::Allocator => &self.allocator_module_config,
}
}
pub fn save_temp_bitcode(&self, trans: &ModuleTranslation, name: &str) {
if !self.save_temps {
return
}
unsafe {
let ext = format!("{}.bc", name);
let cgu = Some(&trans.name[..]);
let path = self.output_filenames.temp_path_ext(&ext, cgu);
let cstr = path2cstr(&path);
let llmod = trans.llvm().unwrap().llmod;
llvm::LLVMWriteBitcodeToFile(llmod, cstr.as_ptr());
}
}
}
struct DiagnosticHandlers<'a> {
inner: Box<(&'a CodegenContext, &'a Handler)>,
llcx: ContextRef,
}
impl<'a> DiagnosticHandlers<'a> {
fn new(cgcx: &'a CodegenContext,
handler: &'a Handler,
llcx: ContextRef) -> DiagnosticHandlers<'a> {
let data = Box::new((cgcx, handler));
unsafe {
let arg = &*data as &(_, _) as *const _ as *mut _;
llvm::LLVMRustSetInlineAsmDiagnosticHandler(llcx, inline_asm_handler, arg);
llvm::LLVMContextSetDiagnosticHandler(llcx, diagnostic_handler, arg);
}
DiagnosticHandlers {
inner: data,
llcx: llcx,
}
}
}
impl<'a> Drop for DiagnosticHandlers<'a> {
fn drop(&mut self) {
unsafe {
llvm::LLVMRustSetInlineAsmDiagnosticHandler(self.llcx, inline_asm_handler, 0 as *mut _);
llvm::LLVMContextSetDiagnosticHandler(self.llcx, diagnostic_handler, 0 as *mut _);
}
}
}
unsafe extern "C" fn report_inline_asm<'a, 'b>(cgcx: &'a CodegenContext,
msg: &'b str,
cookie: c_uint) {
cgcx.diag_emitter.inline_asm_error(cookie as u32, msg.to_string());
}
unsafe extern "C" fn inline_asm_handler(diag: SMDiagnosticRef,
user: *const c_void,
cookie: c_uint) {
if user.is_null() {
return
}
let (cgcx, _) = *(user as *const (&CodegenContext, &Handler));
let msg = llvm::build_string(|s| llvm::LLVMRustWriteSMDiagnosticToString(diag, s))
.expect("non-UTF8 SMDiagnostic");
report_inline_asm(cgcx, &msg, cookie);
}
unsafe extern "C" fn diagnostic_handler(info: DiagnosticInfoRef, user: *mut c_void) {
if user.is_null() {
return
}
let (cgcx, diag_handler) = *(user as *const (&CodegenContext, &Handler));
match llvm::diagnostic::Diagnostic::unpack(info) {
llvm::diagnostic::InlineAsm(inline) => {
report_inline_asm(cgcx,
&llvm::twine_to_string(inline.message),
inline.cookie);
}
llvm::diagnostic::Optimization(opt) => {
let enabled = match cgcx.remark {
AllPasses => true,
SomePasses(ref v) => v.iter().any(|s| *s == opt.pass_name),
};
if enabled {
diag_handler.note_without_error(&format!("optimization {} for {} at {}:{}:{}: {}",
opt.kind.describe(),
opt.pass_name,
opt.filename,
opt.line,
opt.column,
opt.message));
}
}
_ => (),
}
}
// Unsafe due to LLVM calls.
unsafe fn optimize(cgcx: &CodegenContext,
diag_handler: &Handler,
mtrans: &ModuleTranslation,
config: &ModuleConfig,
timeline: &mut Timeline)
-> Result<(), FatalError>
{
let (llmod, llcx, tm) = match mtrans.source {
ModuleSource::Translated(ref llvm) => (llvm.llmod, llvm.llcx, llvm.tm),
ModuleSource::Preexisting(_) => {
bug!("optimize_and_codegen: called with ModuleSource::Preexisting")
}
};
let _handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
let module_name = mtrans.name.clone();
let module_name = Some(&module_name[..]);
if config.emit_no_opt_bc {
let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
let out = path2cstr(&out);
llvm::LLVMWriteBitcodeToFile(llmod, out.as_ptr());
}
if config.opt_level.is_some() {
// Create the two optimizing pass managers. These mirror what clang
// does, and are by populated by LLVM's default PassManagerBuilder.
// Each manager has a different set of passes, but they also share
// some common passes.
let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
let mpm = llvm::LLVMCreatePassManager();
// If we're verifying or linting, add them to the function pass
// manager.
let addpass = |pass_name: &str| {
let pass_name = CString::new(pass_name).unwrap();
let pass = llvm::LLVMRustFindAndCreatePass(pass_name.as_ptr());
if pass.is_null() {
return false;
}
let pass_manager = match llvm::LLVMRustPassKind(pass) {
llvm::PassKind::Function => fpm,
llvm::PassKind::Module => mpm,
llvm::PassKind::Other => {
diag_handler.err("Encountered LLVM pass kind we can't handle");
return true
},
};
llvm::LLVMRustAddPass(pass_manager, pass);
true
};
if !config.no_verify { assert!(addpass("verify")); }
if !config.no_prepopulate_passes {
llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod);
llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod);
let opt_level = config.opt_level.unwrap_or(llvm::CodeGenOptLevel::None);
with_llvm_pmb(llmod, &config, opt_level, &mut |b| {
llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
})
}
for pass in &config.passes {
if !addpass(pass) {
diag_handler.warn(&format!("unknown pass `{}`, ignoring",
pass));
}
}
for pass in &cgcx.plugin_passes {
if !addpass(pass) {
diag_handler.err(&format!("a plugin asked for LLVM pass \
`{}` but LLVM does not \
recognize it", pass));
}
}
diag_handler.abort_if_errors();
// Finally, run the actual optimization passes
time(config.time_passes, &format!("llvm function passes [{}]", module_name.unwrap()), ||
llvm::LLVMRustRunFunctionPassManager(fpm, llmod));
timeline.record("fpm");
time(config.time_passes, &format!("llvm module passes [{}]", module_name.unwrap()), ||
llvm::LLVMRunPassManager(mpm, llmod));
// Deallocate managers that we're now done with
llvm::LLVMDisposePassManager(fpm);
llvm::LLVMDisposePassManager(mpm);
}
Ok(())
}
fn generate_lto_work(cgcx: &CodegenContext,
modules: Vec<ModuleTranslation>)
-> Vec<(WorkItem, u64)>
{
let mut timeline = cgcx.time_graph.as_ref().map(|tg| {
tg.start(TRANS_WORKER_TIMELINE,
TRANS_WORK_PACKAGE_KIND,
"generate lto")
}).unwrap_or(Timeline::noop());
let mode = if cgcx.lto {
lto::LTOMode::WholeCrateGraph
} else {
lto::LTOMode::JustThisCrate
};
let lto_modules = lto::run(cgcx, modules, mode, &mut timeline)
.unwrap_or_else(|e| panic!(e));
lto_modules.into_iter().map(|module| {
let cost = module.cost();
(WorkItem::LTO(module), cost)
}).collect()
}
unsafe fn codegen(cgcx: &CodegenContext,
diag_handler: &Handler,
mtrans: ModuleTranslation,
config: &ModuleConfig,
timeline: &mut Timeline)
-> Result<CompiledModule, FatalError>
{
timeline.record("codegen");
let (llmod, llcx, tm) = match mtrans.source {
ModuleSource::Translated(ref llvm) => (llvm.llmod, llvm.llcx, llvm.tm),
ModuleSource::Preexisting(_) => {
bug!("codegen: called with ModuleSource::Preexisting")
}
};
let module_name = mtrans.name.clone();
let module_name = Some(&module_name[..]);
let handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
if cgcx.msvc_imps_needed {
create_msvc_imps(cgcx, llcx, llmod);
}
// A codegen-specific pass manager is used to generate object
// files for an LLVM module.
//
// Apparently each of these pass managers is a one-shot kind of
// thing, so we create a new one for each type of output. The
// pass manager passed to the closure should be ensured to not
// escape the closure itself, and the manager should only be
// used once.
unsafe fn with_codegen<F, R>(tm: TargetMachineRef,
llmod: ModuleRef,
no_builtins: bool,
f: F) -> R
where F: FnOnce(PassManagerRef) -> R,
{
let cpm = llvm::LLVMCreatePassManager();
llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod);
llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
f(cpm)
}
// If we're going to generate wasm code from the assembly that llvm
// generates then we'll be transitively affecting a ton of options below.
// This only happens on the wasm target now.
let asm2wasm = cgcx.binaryen_linker &&
!cgcx.crate_types.contains(&config::CrateTypeRlib) &&
mtrans.kind == ModuleKind::Regular;
// Change what we write and cleanup based on whether obj files are
// just llvm bitcode. In that case write bitcode, and possibly
// delete the bitcode if it wasn't requested. Don't generate the
// machine code, instead copy the .o file from the .bc
let write_bc = config.emit_bc || (config.obj_is_bitcode && !asm2wasm);
let rm_bc = !config.emit_bc && config.obj_is_bitcode && !asm2wasm;
let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm2wasm;
let copy_bc_to_obj = config.emit_obj && config.obj_is_bitcode && !asm2wasm;
let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
if write_bc || config.emit_bc_compressed {
let thin;
let old;
let data = if llvm::LLVMRustThinLTOAvailable() {
thin = ThinBuffer::new(llmod);
thin.data()
} else {
old = ModuleBuffer::new(llmod);
old.data()
};
timeline.record("make-bc");
if write_bc {
if let Err(e) = File::create(&bc_out).and_then(|mut f| f.write_all(data)) {
diag_handler.err(&format!("failed to write bytecode: {}", e));
}
timeline.record("write-bc");
}
if config.emit_bc_compressed {
let dst = bc_out.with_extension(RLIB_BYTECODE_EXTENSION);
let data = bytecode::encode(&mtrans.llmod_id, data);
if let Err(e) = File::create(&dst).and_then(|mut f| f.write_all(&data)) {
diag_handler.err(&format!("failed to write bytecode: {}", e));
}
timeline.record("compress-bc");
}
}
time(config.time_passes, &format!("codegen passes [{}]", module_name.unwrap()),
|| -> Result<(), FatalError> {
if config.emit_ir {
let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
let out = path2cstr(&out);
extern "C" fn demangle_callback(input_ptr: *const c_char,
input_len: size_t,
output_ptr: *mut c_char,
output_len: size_t) -> size_t {
let input = unsafe {
slice::from_raw_parts(input_ptr as *const u8, input_len as usize)
};
let input = match str::from_utf8(input) {
Ok(s) => s,
Err(_) => return 0,
};
let output = unsafe {
slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
};
let mut cursor = io::Cursor::new(output);
let demangled = match rustc_demangle::try_demangle(input) {
Ok(d) => d,
Err(_) => return 0,
};
if let Err(_) = write!(cursor, "{:#}", demangled) {
// Possible only if provided buffer is not big enough
return 0;
}
cursor.position() as size_t
}
with_codegen(tm, llmod, config.no_builtins, |cpm| {
llvm::LLVMRustPrintModule(cpm, llmod, out.as_ptr(), demangle_callback);
llvm::LLVMDisposePassManager(cpm);
});
timeline.record("ir");
}
if config.emit_asm || (asm2wasm && config.emit_obj) {
let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
// We can't use the same module for asm and binary output, because that triggers
// various errors like invalid IR or broken binaries, so we might have to clone the
// module to produce the asm output
let llmod = if config.emit_obj {
llvm::LLVMCloneModule(llmod)
} else {
llmod
};
with_codegen(tm, llmod, config.no_builtins, |cpm| {
write_output_file(diag_handler, tm, cpm, llmod, &path,
llvm::FileType::AssemblyFile)
})?;
if config.emit_obj {
llvm::LLVMDisposeModule(llmod);
}
timeline.record("asm");
}
if asm2wasm && config.emit_obj {
let assembly = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
binaryen_assemble(cgcx, diag_handler, &assembly, &obj_out);
timeline.record("binaryen");
if !config.emit_asm {
drop(fs::remove_file(&assembly));
}
} else if write_obj {
with_codegen(tm, llmod, config.no_builtins, |cpm| {
write_output_file(diag_handler, tm, cpm, llmod, &obj_out,
llvm::FileType::ObjectFile)
})?;
timeline.record("obj");
}
Ok(())
})?;
if copy_bc_to_obj {
debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
if let Err(e) = link_or_copy(&bc_out, &obj_out) {
diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
}
}
if rm_bc {
debug!("removing_bitcode {:?}", bc_out);
if let Err(e) = fs::remove_file(&bc_out) {
diag_handler.err(&format!("failed to remove bitcode: {}", e));
}
}
drop(handlers);
Ok(mtrans.into_compiled_module(config.emit_obj,
config.emit_bc,
config.emit_bc_compressed,
&cgcx.output_filenames))
}
/// Translates the LLVM-generated `assembly` on the filesystem into a wasm
/// module using binaryen, placing the output at `object`.
///
/// In this case the "object" is actually a full and complete wasm module. We
/// won't actually be doing anything else to the output for now. This is all
/// pretty janky and will get removed as soon as a linker for wasm exists.
fn binaryen_assemble(cgcx: &CodegenContext,
handler: &Handler,
assembly: &Path,
object: &Path) {
use rustc_binaryen::{Module, ModuleOptions};
let input = File::open(&assembly).and_then(|mut f| {
let mut contents = Vec::new();
f.read_to_end(&mut contents)?;
Ok(CString::new(contents)?)
});
let mut options = ModuleOptions::new();
if cgcx.debuginfo != config::NoDebugInfo {
options.debuginfo(true);
}
if cgcx.crate_types.contains(&config::CrateTypeExecutable) {
options.start("main");
}
options.stack(1024 * 1024);
options.import_memory(cgcx.wasm_import_memory);
let assembled = input.and_then(|input| {
Module::new(&input, &options)
.map_err(|e| io::Error::new(io::ErrorKind::Other, e))
});
let err = assembled.and_then(|binary| {
File::create(&object).and_then(|mut f| f.write_all(binary.data()))
});
if let Err(e) = err {
handler.err(&format!("failed to run binaryen assembler: {}", e));
}
}
pub struct CompiledModules {
pub modules: Vec<CompiledModule>,
pub metadata_module: CompiledModule,
pub allocator_module: Option<CompiledModule>,
}
fn need_crate_bitcode_for_rlib(sess: &Session) -> bool {
sess.crate_types.borrow().contains(&config::CrateTypeRlib) &&
sess.opts.output_types.contains_key(&OutputType::Exe)
}
pub fn start_async_translation(tcx: TyCtxt,
time_graph: Option<TimeGraph>,
link: LinkMeta,
metadata: EncodedMetadata,
coordinator_receive: Receiver<Box<Any + Send>>,
total_cgus: usize)
-> OngoingCrateTranslation {
let sess = tcx.sess;
let crate_output = tcx.output_filenames(LOCAL_CRATE);
let crate_name = tcx.crate_name(LOCAL_CRATE);
let no_builtins = attr::contains_name(&tcx.hir.krate().attrs, "no_builtins");
let subsystem = attr::first_attr_value_str_by_name(&tcx.hir.krate().attrs,
"windows_subsystem");
let windows_subsystem = subsystem.map(|subsystem| {
if subsystem != "windows" && subsystem != "console" {
tcx.sess.fatal(&format!("invalid windows subsystem `{}`, only \
`windows` and `console` are allowed",
subsystem));
}
subsystem.to_string()
});
let no_integrated_as = tcx.sess.opts.cg.no_integrated_as ||
(tcx.sess.target.target.options.no_integrated_as &&
(crate_output.outputs.contains_key(&OutputType::Object) ||
crate_output.outputs.contains_key(&OutputType::Exe)));
let linker_info = LinkerInfo::new(tcx);
let crate_info = CrateInfo::new(tcx);
let output_types_override = if no_integrated_as {
OutputTypes::new(&[(OutputType::Assembly, None)])
} else {
sess.opts.output_types.clone()
};
// Figure out what we actually need to build.
let mut modules_config = ModuleConfig::new(sess.opts.cg.passes.clone());
let mut metadata_config = ModuleConfig::new(vec![]);
let mut allocator_config = ModuleConfig::new(vec![]);
if let Some(ref sanitizer) = sess.opts.debugging_opts.sanitizer {
match *sanitizer {
Sanitizer::Address => {
modules_config.passes.push("asan".to_owned());
modules_config.passes.push("asan-module".to_owned());
}
Sanitizer::Memory => {
modules_config.passes.push("msan".to_owned())
}
Sanitizer::Thread => {
modules_config.passes.push("tsan".to_owned())
}
_ => {}
}
}
if sess.opts.debugging_opts.profile {
modules_config.passes.push("insert-gcov-profiling".to_owned())
}
modules_config.opt_level = Some(get_llvm_opt_level(sess.opts.optimize));
modules_config.opt_size = Some(get_llvm_opt_size(sess.opts.optimize));
// Save all versions of the bytecode if we're saving our temporaries.
if sess.opts.cg.save_temps {
modules_config.emit_no_opt_bc = true;
modules_config.emit_bc = true;
modules_config.emit_lto_bc = true;
metadata_config.emit_bc = true;
allocator_config.emit_bc = true;
}
// Emit compressed bitcode files for the crate if we're emitting an rlib.
// Whenever an rlib is created, the bitcode is inserted into the archive in
// order to allow LTO against it.
if need_crate_bitcode_for_rlib(sess) {
modules_config.emit_bc_compressed = true;
allocator_config.emit_bc_compressed = true;
}
for output_type in output_types_override.keys() {
match *output_type {
OutputType::Bitcode => { modules_config.emit_bc = true; }
OutputType::LlvmAssembly => { modules_config.emit_ir = true; }
OutputType::Assembly => {
modules_config.emit_asm = true;
// If we're not using the LLVM assembler, this function
// could be invoked specially with output_type_assembly, so
// in this case we still want the metadata object file.
if !sess.opts.output_types.contains_key(&OutputType::Assembly) {
metadata_config.emit_obj = true;
allocator_config.emit_obj = true;
}
}
OutputType::Object => { modules_config.emit_obj = true; }
OutputType::Metadata => { metadata_config.emit_obj = true; }
OutputType::Exe => {
modules_config.emit_obj = true;
metadata_config.emit_obj = true;
allocator_config.emit_obj = true;
},
OutputType::Mir => {}
OutputType::DepInfo => {}
}
}
modules_config.set_flags(sess, no_builtins);
metadata_config.set_flags(sess, no_builtins);
allocator_config.set_flags(sess, no_builtins);
// Exclude metadata and allocator modules from time_passes output, since
// they throw off the "LLVM passes" measurement.
metadata_config.time_passes = false;
allocator_config.time_passes = false;
let client = sess.jobserver_from_env.clone().unwrap_or_else(|| {
// Pick a "reasonable maximum" if we don't otherwise have a jobserver in
// our environment, capping out at 32 so we don't take everything down
// by hogging the process run queue.
Client::new(32).expect("failed to create jobserver")
});
let (shared_emitter, shared_emitter_main) = SharedEmitter::new();
let (trans_worker_send, trans_worker_receive) = channel();
let coordinator_thread = start_executing_work(tcx,
&crate_info,
shared_emitter,
trans_worker_send,
coordinator_receive,
total_cgus,
client,
time_graph.clone(),
Arc::new(modules_config),
Arc::new(metadata_config),
Arc::new(allocator_config));
OngoingCrateTranslation {
crate_name,
link,
metadata,
windows_subsystem,
linker_info,
no_integrated_as,
crate_info,
time_graph,
coordinator_send: tcx.tx_to_llvm_workers.clone(),
trans_worker_receive,
shared_emitter_main,
future: coordinator_thread,
output_filenames: tcx.output_filenames(LOCAL_CRATE),
}
}
fn copy_module_artifacts_into_incr_comp_cache(sess: &Session,
dep_graph: &DepGraph,
compiled_modules: &CompiledModules) {
if sess.opts.incremental.is_none() {
return;
}
for module in compiled_modules.modules.iter() {
let mut files = vec![];
if let Some(ref path) = module.object {
files.push((WorkProductFileKind::Object, path.clone()));
}
if let Some(ref path) = module.bytecode {
files.push((WorkProductFileKind::Bytecode, path.clone()));
}
if let Some(ref path) = module.bytecode_compressed {
files.push((WorkProductFileKind::BytecodeCompressed, path.clone()));
}
save_trans_partition(sess, dep_graph, &module.name, &files);
}
}
fn produce_final_output_artifacts(sess: &Session,
compiled_modules: &CompiledModules,
crate_output: &OutputFilenames) {
let mut user_wants_bitcode = false;
let mut user_wants_objects = false;
// Produce final compile outputs.
let copy_gracefully = |from: &Path, to: &Path| {
if let Err(e) = fs::copy(from, to) {
sess.err(&format!("could not copy {:?} to {:?}: {}", from, to, e));
}
};
let copy_if_one_unit = |output_type: OutputType,
keep_numbered: bool| {
if compiled_modules.modules.len() == 1 {
// 1) Only one codegen unit. In this case it's no difficulty
// to copy `foo.0.x` to `foo.x`.
let module_name = Some(&compiled_modules.modules[0].name[..]);
let path = crate_output.temp_path(output_type, module_name);
copy_gracefully(&path,
&crate_output.path(output_type));
if !sess.opts.cg.save_temps && !keep_numbered {
// The user just wants `foo.x`, not `foo.#module-name#.x`.
remove(sess, &path);
}
} else {
let ext = crate_output.temp_path(output_type, None)
.extension()
.unwrap()
.to_str()
.unwrap()
.to_owned();
if crate_output.outputs.contains_key(&output_type) {
// 2) Multiple codegen units, with `--emit foo=some_name`. We have
// no good solution for this case, so warn the user.
sess.warn(&format!("ignoring emit path because multiple .{} files \
were produced", ext));
} else if crate_output.single_output_file.is_some() {
// 3) Multiple codegen units, with `-o some_name`. We have
// no good solution for this case, so warn the user.
sess.warn(&format!("ignoring -o because multiple .{} files \
were produced", ext));
} else {
// 4) Multiple codegen units, but no explicit name. We
// just leave the `foo.0.x` files in place.
// (We don't have to do any work in this case.)
}
}
};
// Flag to indicate whether the user explicitly requested bitcode.
// Otherwise, we produced it only as a temporary output, and will need
// to get rid of it.
for output_type in crate_output.outputs.keys() {
match *output_type {
OutputType::Bitcode => {
user_wants_bitcode = true;
// Copy to .bc, but always keep the .0.bc. There is a later
// check to figure out if we should delete .0.bc files, or keep
// them for making an rlib.
copy_if_one_unit(OutputType::Bitcode, true);
}
OutputType::LlvmAssembly => {
copy_if_one_unit(OutputType::LlvmAssembly, false);
}
OutputType::Assembly => {
copy_if_one_unit(OutputType::Assembly, false);
}
OutputType::Object => {
user_wants_objects = true;
copy_if_one_unit(OutputType::Object, true);
}
OutputType::Mir |
OutputType::Metadata |
OutputType::Exe |
OutputType::DepInfo => {}
}
}
// Clean up unwanted temporary files.
// We create the following files by default:
// - #crate#.#module-name#.bc
// - #crate#.#module-name#.o
// - #crate#.crate.metadata.bc
// - #crate#.crate.metadata.o
// - #crate#.o (linked from crate.##.o)
// - #crate#.bc (copied from crate.##.bc)
// We may create additional files if requested by the user (through
// `-C save-temps` or `--emit=` flags).
if !sess.opts.cg.save_temps {
// Remove the temporary .#module-name#.o objects. If the user didn't
// explicitly request bitcode (with --emit=bc), and the bitcode is not
// needed for building an rlib, then we must remove .#module-name#.bc as
// well.
// Specific rules for keeping .#module-name#.bc:
// - If the user requested bitcode (`user_wants_bitcode`), and
// codegen_units > 1, then keep it.
// - If the user requested bitcode but codegen_units == 1, then we
// can toss .#module-name#.bc because we copied it to .bc earlier.
// - If we're not building an rlib and the user didn't request
// bitcode, then delete .#module-name#.bc.
// If you change how this works, also update back::link::link_rlib,
// where .#module-name#.bc files are (maybe) deleted after making an
// rlib.
let needs_crate_object = crate_output.outputs.contains_key(&OutputType::Exe);
let keep_numbered_bitcode = user_wants_bitcode && sess.codegen_units() > 1;
let keep_numbered_objects = needs_crate_object ||
(user_wants_objects && sess.codegen_units() > 1);
for module in compiled_modules.modules.iter() {
if let Some(ref path) = module.object {
if !keep_numbered_objects {
remove(sess, path);
}
}
if let Some(ref path) = module.bytecode {
if !keep_numbered_bitcode {
remove(sess, path);
}
}
}
if !user_wants_bitcode {
if let Some(ref path) = compiled_modules.metadata_module.bytecode {
remove(sess, &path);
}
if let Some(ref allocator_module) = compiled_modules.allocator_module {
if let Some(ref path) = allocator_module.bytecode {
remove(sess, path);
}
}
}
}
// We leave the following files around by default:
// - #crate#.o
// - #crate#.crate.metadata.o
// - #crate#.bc
// These are used in linking steps and will be cleaned up afterward.
}
pub fn dump_incremental_data(trans: &CrateTranslation) {
println!("[incremental] Re-using {} out of {} modules",
trans.modules.iter().filter(|m| m.pre_existing).count(),
trans.modules.len());
}
enum WorkItem {
Optimize(ModuleTranslation),
LTO(lto::LtoModuleTranslation),
}
impl WorkItem {
fn kind(&self) -> ModuleKind {
match *self {
WorkItem::Optimize(ref m) => m.kind,
WorkItem::LTO(_) => ModuleKind::Regular,
}
}
fn name(&self) -> String {
match *self {
WorkItem::Optimize(ref m) => format!("optimize: {}", m.name),
WorkItem::LTO(ref m) => format!("lto: {}", m.name()),
}
}
}
enum WorkItemResult {
Compiled(CompiledModule),
NeedsLTO(ModuleTranslation),
}
fn execute_work_item(cgcx: &CodegenContext,
work_item: WorkItem,
timeline: &mut Timeline)
-> Result<WorkItemResult, FatalError>
{
let diag_handler = cgcx.create_diag_handler();
let config = cgcx.config(work_item.kind());
let mtrans = match work_item {
WorkItem::Optimize(mtrans) => mtrans,
WorkItem::LTO(mut lto) => {
unsafe {
let module = lto.optimize(cgcx, timeline)?;
let module = codegen(cgcx, &diag_handler, module, config, timeline)?;
return Ok(WorkItemResult::Compiled(module))
}
}
};
let module_name = mtrans.name.clone();
let pre_existing = match mtrans.source {
ModuleSource::Translated(_) => None,
ModuleSource::Preexisting(ref wp) => Some(wp.clone()),
};
if let Some(wp) = pre_existing {
let incr_comp_session_dir = cgcx.incr_comp_session_dir
.as_ref()
.unwrap();
let name = &mtrans.name;
let mut object = None;
let mut bytecode = None;
let mut bytecode_compressed = None;
for (kind, saved_file) in wp.saved_files {
let obj_out = match kind {
WorkProductFileKind::Object => {
let path = cgcx.output_filenames.temp_path(OutputType::Object, Some(name));
object = Some(path.clone());
path
}
WorkProductFileKind::Bytecode => {
let path = cgcx.output_filenames.temp_path(OutputType::Bitcode, Some(name));
bytecode = Some(path.clone());
path
}
WorkProductFileKind::BytecodeCompressed => {
let path = cgcx.output_filenames.temp_path(OutputType::Bitcode, Some(name))
.with_extension(RLIB_BYTECODE_EXTENSION);
bytecode_compressed = Some(path.clone());
path
}
};
let source_file = in_incr_comp_dir(&incr_comp_session_dir,
&saved_file);
debug!("copying pre-existing module `{}` from {:?} to {}",
mtrans.name,
source_file,
obj_out.display());
match link_or_copy(&source_file, &obj_out) {
Ok(_) => { }
Err(err) => {
diag_handler.err(&format!("unable to copy {} to {}: {}",
source_file.display(),
obj_out.display(),
err));
}
}
}
assert_eq!(object.is_some(), config.emit_obj);
assert_eq!(bytecode.is_some(), config.emit_bc);
assert_eq!(bytecode_compressed.is_some(), config.emit_bc_compressed);
Ok(WorkItemResult::Compiled(CompiledModule {
llmod_id: mtrans.llmod_id.clone(),
name: module_name,
kind: ModuleKind::Regular,
pre_existing: true,
object,
bytecode,
bytecode_compressed,
}))
} else {
debug!("llvm-optimizing {:?}", module_name);
unsafe {
optimize(cgcx, &diag_handler, &mtrans, config, timeline)?;
let lto = cgcx.lto;
let auto_thin_lto =
cgcx.thinlto &&
cgcx.total_cgus > 1 &&
mtrans.kind != ModuleKind::Allocator;
// If we're a metadata module we never participate in LTO.
//
// If LTO was explicitly requested on the command line, we always
// LTO everything else.
//
// If LTO *wasn't* explicitly requested and we're not a metdata
// module, then we may automatically do ThinLTO if we've got
// multiple codegen units. Note, however, that the allocator module
// doesn't participate here automatically because of linker
// shenanigans later on.
if mtrans.kind == ModuleKind::Metadata || (!lto && !auto_thin_lto) {
let module = codegen(cgcx, &diag_handler, mtrans, config, timeline)?;
Ok(WorkItemResult::Compiled(module))
} else {
Ok(WorkItemResult::NeedsLTO(mtrans))
}
}
}
}
enum Message {
Token(io::Result<Acquired>),
NeedsLTO {
result: ModuleTranslation,
worker_id: usize,
},
Done {
result: Result<CompiledModule, ()>,
worker_id: usize,
},
TranslationDone {
llvm_work_item: WorkItem,
cost: u64,
},
TranslationComplete,
TranslateItem,
}
struct Diagnostic {
msg: String,
code: Option<DiagnosticId>,
lvl: Level,
}
#[derive(PartialEq, Clone, Copy, Debug)]
enum MainThreadWorkerState {
Idle,
Translating,
LLVMing,
}
fn start_executing_work(tcx: TyCtxt,
crate_info: &CrateInfo,
shared_emitter: SharedEmitter,
trans_worker_send: Sender<Message>,
coordinator_receive: Receiver<Box<Any + Send>>,
total_cgus: usize,
jobserver: Client,
time_graph: Option<TimeGraph>,
modules_config: Arc<ModuleConfig>,
metadata_config: Arc<ModuleConfig>,
allocator_config: Arc<ModuleConfig>)
-> thread::JoinHandle<Result<CompiledModules, ()>> {
let coordinator_send = tcx.tx_to_llvm_workers.clone();
let mut exported_symbols = FxHashMap();
exported_symbols.insert(LOCAL_CRATE, tcx.exported_symbols(LOCAL_CRATE));
for &cnum in tcx.crates().iter() {
exported_symbols.insert(cnum, tcx.exported_symbols(cnum));
}
let exported_symbols = Arc::new(exported_symbols);
let sess = tcx.sess;
// First up, convert our jobserver into a helper thread so we can use normal
// mpsc channels to manage our messages and such. Once we've got the helper
// thread then request `n-1` tokens because all of our work items are ready
// to go.
//
// Note that the `n-1` is here because we ourselves have a token (our
// process) and we'll use that token to execute at least one unit of work.
//
// After we've requested all these tokens then we'll, when we can, get
// tokens on `rx` above which will get managed in the main loop below.
let coordinator_send2 = coordinator_send.clone();
let helper = jobserver.into_helper_thread(move |token| {
drop(coordinator_send2.send(Box::new(Message::Token(token))));
}).expect("failed to spawn helper thread");
let mut each_linked_rlib_for_lto = Vec::new();
drop(link::each_linked_rlib(sess, crate_info, &mut |cnum, path| {
if link::ignored_for_lto(sess, crate_info, cnum) {
return
}
each_linked_rlib_for_lto.push((cnum, path.to_path_buf()));
}));
let crate_types = sess.crate_types.borrow();
let only_rlib = crate_types.len() == 1 &&
crate_types[0] == config::CrateTypeRlib;
let wasm_import_memory =
attr::contains_name(&tcx.hir.krate().attrs, "wasm_import_memory");
let cgcx = CodegenContext {
crate_types: sess.crate_types.borrow().clone(),
each_linked_rlib_for_lto,
// If we're only building an rlibc then allow the LTO flag to be passed
// but don't actually do anything, the full LTO will happen later
lto: sess.lto() && !only_rlib,
// Enable ThinLTO if requested, but only if the target we're compiling
// for doesn't require full LTO. Some targets require one LLVM module
// (they effectively don't have a linker) so it's up to us to use LTO to
// link everything together.
thinlto: sess.opts.debugging_opts.thinlto &&
!sess.target.target.options.requires_lto,
no_landing_pads: sess.no_landing_pads(),
save_temps: sess.opts.cg.save_temps,
opts: Arc::new(sess.opts.clone()),
time_passes: sess.time_passes(),
exported_symbols,
plugin_passes: sess.plugin_llvm_passes.borrow().clone(),
remark: sess.opts.cg.remark.clone(),
worker: 0,
incr_comp_session_dir: sess.incr_comp_session_dir_opt().map(|r| r.clone()),
coordinator_send,
diag_emitter: shared_emitter.clone(),
time_graph,
output_filenames: tcx.output_filenames(LOCAL_CRATE),
regular_module_config: modules_config,
metadata_module_config: metadata_config,
allocator_module_config: allocator_config,
tm_factory: target_machine_factory(tcx.sess),
total_cgus,
msvc_imps_needed: msvc_imps_needed(tcx),
target_pointer_width: tcx.sess.target.target.target_pointer_width.clone(),
binaryen_linker: tcx.sess.linker_flavor() == LinkerFlavor::Binaryen,
debuginfo: tcx.sess.opts.debuginfo,
wasm_import_memory: wasm_import_memory,
};
// This is the "main loop" of parallel work happening for parallel codegen.
// It's here that we manage parallelism, schedule work, and work with
// messages coming from clients.
//
// There are a few environmental pre-conditions that shape how the system
// is set up:
//
// - Error reporting only can happen on the main thread because that's the
// only place where we have access to the compiler `Session`.
// - LLVM work can be done on any thread.
// - Translation can only happen on the main thread.
// - Each thread doing substantial work most be in possession of a `Token`
// from the `Jobserver`.
// - The compiler process always holds one `Token`. Any additional `Tokens`
// have to be requested from the `Jobserver`.
//
// Error Reporting
// ===============
// The error reporting restriction is handled separately from the rest: We
// set up a `SharedEmitter` the holds an open channel to the main thread.
// When an error occurs on any thread, the shared emitter will send the
// error message to the receiver main thread (`SharedEmitterMain`). The
// main thread will periodically query this error message queue and emit
// any error messages it has received. It might even abort compilation if
// has received a fatal error. In this case we rely on all other threads
// being torn down automatically with the main thread.
// Since the main thread will often be busy doing translation work, error
// reporting will be somewhat delayed, since the message queue can only be
// checked in between to work packages.
//
// Work Processing Infrastructure
// ==============================
// The work processing infrastructure knows three major actors:
//
// - the coordinator thread,
// - the main thread, and
// - LLVM worker threads
//
// The coordinator thread is running a message loop. It instructs the main
// thread about what work to do when, and it will spawn off LLVM worker
// threads as open LLVM WorkItems become available.
//
// The job of the main thread is to translate CGUs into LLVM work package
// (since the main thread is the only thread that can do this). The main
// thread will block until it receives a message from the coordinator, upon
// which it will translate one CGU, send it to the coordinator and block
// again. This way the coordinator can control what the main thread is
// doing.
//
// The coordinator keeps a queue of LLVM WorkItems, and when a `Token` is
// available, it will spawn off a new LLVM worker thread and let it process
// that a WorkItem. When a LLVM worker thread is done with its WorkItem,
// it will just shut down, which also frees all resources associated with
// the given LLVM module, and sends a message to the coordinator that the
// has been completed.
//
// Work Scheduling
// ===============
// The scheduler's goal is to minimize the time it takes to complete all
// work there is, however, we also want to keep memory consumption low
// if possible. These two goals are at odds with each other: If memory
// consumption were not an issue, we could just let the main thread produce
// LLVM WorkItems at full speed, assuring maximal utilization of
// Tokens/LLVM worker threads. However, since translation usual is faster
// than LLVM processing, the queue of LLVM WorkItems would fill up and each
// WorkItem potentially holds on to a substantial amount of memory.
//
// So the actual goal is to always produce just enough LLVM WorkItems as
// not to starve our LLVM worker threads. That means, once we have enough
// WorkItems in our queue, we can block the main thread, so it does not
// produce more until we need them.
//
// Doing LLVM Work on the Main Thread
// ----------------------------------
// Since the main thread owns the compiler processes implicit `Token`, it is
// wasteful to keep it blocked without doing any work. Therefore, what we do
// in this case is: We spawn off an additional LLVM worker thread that helps
// reduce the queue. The work it is doing corresponds to the implicit
// `Token`. The coordinator will mark the main thread as being busy with
// LLVM work. (The actual work happens on another OS thread but we just care
// about `Tokens`, not actual threads).
//
// When any LLVM worker thread finishes while the main thread is marked as
// "busy with LLVM work", we can do a little switcheroo: We give the Token
// of the just finished thread to the LLVM worker thread that is working on
// behalf of the main thread's implicit Token, thus freeing up the main
// thread again. The coordinator can then again decide what the main thread
// should do. This allows the coordinator to make decisions at more points
// in time.
//
// Striking a Balance between Throughput and Memory Consumption
// ------------------------------------------------------------
// Since our two goals, (1) use as many Tokens as possible and (2) keep
// memory consumption as low as possible, are in conflict with each other,
// we have to find a trade off between them. Right now, the goal is to keep
// all workers busy, which means that no worker should find the queue empty
// when it is ready to start.
// How do we do achieve this? Good question :) We actually never know how
// many `Tokens` are potentially available so it's hard to say how much to
// fill up the queue before switching the main thread to LLVM work. Also we
// currently don't have a means to estimate how long a running LLVM worker
// will still be busy with it's current WorkItem. However, we know the
// maximal count of available Tokens that makes sense (=the number of CPU
// cores), so we can take a conservative guess. The heuristic we use here
// is implemented in the `queue_full_enough()` function.
//
// Some Background on Jobservers
// -----------------------------
// It's worth also touching on the management of parallelism here. We don't
// want to just spawn a thread per work item because while that's optimal
// parallelism it may overload a system with too many threads or violate our
// configuration for the maximum amount of cpu to use for this process. To
// manage this we use the `jobserver` crate.
//
// Job servers are an artifact of GNU make and are used to manage
// parallelism between processes. A jobserver is a glorified IPC semaphore
// basically. Whenever we want to run some work we acquire the semaphore,
// and whenever we're done with that work we release the semaphore. In this
// manner we can ensure that the maximum number of parallel workers is
// capped at any one point in time.
//
// LTO and the coordinator thread
// ------------------------------
//
// The final job the coordinator thread is responsible for is managing LTO
// and how that works. When LTO is requested what we'll to is collect all
// optimized LLVM modules into a local vector on the coordinator. Once all
// modules have been translated and optimized we hand this to the `lto`
// module for further optimization. The `lto` module will return back a list
// of more modules to work on, which the coordinator will continue to spawn
// work for.
//
// Each LLVM module is automatically sent back to the coordinator for LTO if
// necessary. There's already optimizations in place to avoid sending work
// back to the coordinator if LTO isn't requested.
return thread::spawn(move || {
// We pretend to be within the top-level LLVM time-passes task here:
set_time_depth(1);
let max_workers = ::num_cpus::get();
let mut worker_id_counter = 0;
let mut free_worker_ids = Vec::new();
let mut get_worker_id = |free_worker_ids: &mut Vec<usize>| {
if let Some(id) = free_worker_ids.pop() {
id
} else {
let id = worker_id_counter;
worker_id_counter += 1;
id
}
};
// This is where we collect codegen units that have gone all the way
// through translation and LLVM.
let mut compiled_modules = vec![];
let mut compiled_metadata_module = None;
let mut compiled_allocator_module = None;
let mut needs_lto = Vec::new();
let mut started_lto = false;
// This flag tracks whether all items have gone through translations
let mut translation_done = false;
// This is the queue of LLVM work items that still need processing.
let mut work_items = Vec::<(WorkItem, u64)>::new();
// This are the Jobserver Tokens we currently hold. Does not include
// the implicit Token the compiler process owns no matter what.
let mut tokens = Vec::new();
let mut main_thread_worker_state = MainThreadWorkerState::Idle;
let mut running = 0;
let mut llvm_start_time = None;
// Run the message loop while there's still anything that needs message
// processing:
while !translation_done ||
work_items.len() > 0 ||
running > 0 ||
needs_lto.len() > 0 ||
main_thread_worker_state != MainThreadWorkerState::Idle {
// While there are still CGUs to be translated, the coordinator has
// to decide how to utilize the compiler processes implicit Token:
// For translating more CGU or for running them through LLVM.
if !translation_done {
if main_thread_worker_state == MainThreadWorkerState::Idle {
if !queue_full_enough(work_items.len(), running, max_workers) {
// The queue is not full enough, translate more items:
if let Err(_) = trans_worker_send.send(Message::TranslateItem) {
panic!("Could not send Message::TranslateItem to main thread")
}
main_thread_worker_state = MainThreadWorkerState::Translating;
} else {
// The queue is full enough to not let the worker
// threads starve. Use the implicit Token to do some
// LLVM work too.
let (item, _) = work_items.pop()
.expect("queue empty - queue_full_enough() broken?");
let cgcx = CodegenContext {
worker: get_worker_id(&mut free_worker_ids),
.. cgcx.clone()
};
maybe_start_llvm_timer(cgcx.config(item.kind()),
&mut llvm_start_time);
main_thread_worker_state = MainThreadWorkerState::LLVMing;
spawn_work(cgcx, item);
}
}
} else {
// If we've finished everything related to normal translation
// then it must be the case that we've got some LTO work to do.
// Perform the serial work here of figuring out what we're
// going to LTO and then push a bunch of work items onto our
// queue to do LTO
if work_items.len() == 0 &&
running == 0 &&
main_thread_worker_state == MainThreadWorkerState::Idle {
assert!(!started_lto);
assert!(needs_lto.len() > 0);
started_lto = true;
let modules = mem::replace(&mut needs_lto, Vec::new());
for (work, cost) in generate_lto_work(&cgcx, modules) {
let insertion_index = work_items
.binary_search_by_key(&cost, |&(_, cost)| cost)
.unwrap_or_else(|e| e);
work_items.insert(insertion_index, (work, cost));
helper.request_token();
}
}
// In this branch, we know that everything has been translated,
// so it's just a matter of determining whether the implicit
// Token is free to use for LLVM work.
match main_thread_worker_state {
MainThreadWorkerState::Idle => {
if let Some((item, _)) = work_items.pop() {
let cgcx = CodegenContext {
worker: get_worker_id(&mut free_worker_ids),
.. cgcx.clone()
};
maybe_start_llvm_timer(cgcx.config(item.kind()),
&mut llvm_start_time);
main_thread_worker_state = MainThreadWorkerState::LLVMing;
spawn_work(cgcx, item);
} else {
// There is no unstarted work, so let the main thread
// take over for a running worker. Otherwise the
// implicit token would just go to waste.
// We reduce the `running` counter by one. The
// `tokens.truncate()` below will take care of
// giving the Token back.
debug_assert!(running > 0);
running -= 1;
main_thread_worker_state = MainThreadWorkerState::LLVMing;
}
}
MainThreadWorkerState::Translating => {
bug!("trans worker should not be translating after \
translation was already completed")
}
MainThreadWorkerState::LLVMing => {
// Already making good use of that token
}
}
}
// Spin up what work we can, only doing this while we've got available
// parallelism slots and work left to spawn.
while work_items.len() > 0 && running < tokens.len() {
let (item, _) = work_items.pop().unwrap();
maybe_start_llvm_timer(cgcx.config(item.kind()),
&mut llvm_start_time);
let cgcx = CodegenContext {
worker: get_worker_id(&mut free_worker_ids),
.. cgcx.clone()
};
spawn_work(cgcx, item);
running += 1;
}
// Relinquish accidentally acquired extra tokens
tokens.truncate(running);
let msg = coordinator_receive.recv().unwrap();
match *msg.downcast::<Message>().ok().unwrap() {
// Save the token locally and the next turn of the loop will use
// this to spawn a new unit of work, or it may get dropped
// immediately if we have no more work to spawn.
Message::Token(token) => {
match token {
Ok(token) => {
tokens.push(token);
if main_thread_worker_state == MainThreadWorkerState::LLVMing {
// If the main thread token is used for LLVM work
// at the moment, we turn that thread into a regular
// LLVM worker thread, so the main thread is free
// to react to translation demand.
main_thread_worker_state = MainThreadWorkerState::Idle;
running += 1;
}
}
Err(e) => {
let msg = &format!("failed to acquire jobserver token: {}", e);
shared_emitter.fatal(msg);
// Exit the coordinator thread
panic!("{}", msg)
}
}
}
Message::TranslationDone { llvm_work_item, cost } => {
// We keep the queue sorted by estimated processing cost,
// so that more expensive items are processed earlier. This
// is good for throughput as it gives the main thread more
// time to fill up the queue and it avoids scheduling
// expensive items to the end.
// Note, however, that this is not ideal for memory
// consumption, as LLVM module sizes are not evenly
// distributed.
let insertion_index =
work_items.binary_search_by_key(&cost, |&(_, cost)| cost);
let insertion_index = match insertion_index {
Ok(idx) | Err(idx) => idx
};
work_items.insert(insertion_index, (llvm_work_item, cost));
helper.request_token();
assert_eq!(main_thread_worker_state,
MainThreadWorkerState::Translating);
main_thread_worker_state = MainThreadWorkerState::Idle;
}
Message::TranslationComplete => {
translation_done = true;
assert_eq!(main_thread_worker_state,
MainThreadWorkerState::Translating);
main_thread_worker_state = MainThreadWorkerState::Idle;
}
// If a thread exits successfully then we drop a token associated
// with that worker and update our `running` count. We may later
// re-acquire a token to continue running more work. We may also not
// actually drop a token here if the worker was running with an
// "ephemeral token"
//
// Note that if the thread failed that means it panicked, so we
// abort immediately.
Message::Done { result: Ok(compiled_module), worker_id } => {
if main_thread_worker_state == MainThreadWorkerState::LLVMing {
main_thread_worker_state = MainThreadWorkerState::Idle;
} else {
running -= 1;
}
free_worker_ids.push(worker_id);
match compiled_module.kind {
ModuleKind::Regular => {
compiled_modules.push(compiled_module);
}
ModuleKind::Metadata => {
assert!(compiled_metadata_module.is_none());
compiled_metadata_module = Some(compiled_module);
}
ModuleKind::Allocator => {
assert!(compiled_allocator_module.is_none());
compiled_allocator_module = Some(compiled_module);
}
}
}
Message::NeedsLTO { result, worker_id } => {
assert!(!started_lto);
if main_thread_worker_state == MainThreadWorkerState::LLVMing {
main_thread_worker_state = MainThreadWorkerState::Idle;
} else {
running -= 1;
}
free_worker_ids.push(worker_id);
needs_lto.push(result);
}
Message::Done { result: Err(()), worker_id: _ } => {
shared_emitter.fatal("aborting due to worker thread failure");
// Exit the coordinator thread
return Err(())
}
Message::TranslateItem => {
bug!("the coordinator should not receive translation requests")
}
}
}
if let Some(llvm_start_time) = llvm_start_time {
let total_llvm_time = Instant::now().duration_since(llvm_start_time);
// This is the top-level timing for all of LLVM, set the time-depth
// to zero.
set_time_depth(0);
print_time_passes_entry(cgcx.time_passes,
"LLVM passes",
total_llvm_time);
}
// Regardless of what order these modules completed in, report them to
// the backend in the same order every time to ensure that we're handing
// out deterministic results.
compiled_modules.sort_by(|a, b| a.name.cmp(&b.name));
let compiled_metadata_module = compiled_metadata_module
.expect("Metadata module not compiled?");
Ok(CompiledModules {
modules: compiled_modules,
metadata_module: compiled_metadata_module,
allocator_module: compiled_allocator_module,
})
});
// A heuristic that determines if we have enough LLVM WorkItems in the
// queue so that the main thread can do LLVM work instead of translation
fn queue_full_enough(items_in_queue: usize,
workers_running: usize,
max_workers: usize) -> bool {
// Tune me, plz.
items_in_queue > 0 &&
items_in_queue >= max_workers.saturating_sub(workers_running / 2)
}
fn maybe_start_llvm_timer(config: &ModuleConfig,
llvm_start_time: &mut Option<Instant>) {
// We keep track of the -Ztime-passes output manually,
// since the closure-based interface does not fit well here.
if config.time_passes {
if llvm_start_time.is_none() {
*llvm_start_time = Some(Instant::now());
}
}
}
}
pub const TRANS_WORKER_ID: usize = ::std::usize::MAX;
pub const TRANS_WORKER_TIMELINE: time_graph::TimelineId =
time_graph::TimelineId(TRANS_WORKER_ID);
pub const TRANS_WORK_PACKAGE_KIND: time_graph::WorkPackageKind =
time_graph::WorkPackageKind(&["#DE9597", "#FED1D3", "#FDC5C7", "#B46668", "#88494B"]);
const LLVM_WORK_PACKAGE_KIND: time_graph::WorkPackageKind =
time_graph::WorkPackageKind(&["#7DB67A", "#C6EEC4", "#ACDAAA", "#579354", "#3E6F3C"]);
fn spawn_work(cgcx: CodegenContext, work: WorkItem) {
let depth = time_depth();
thread::spawn(move || {
set_time_depth(depth);
// Set up a destructor which will fire off a message that we're done as
// we exit.
struct Bomb {
coordinator_send: Sender<Box<Any + Send>>,
result: Option<WorkItemResult>,
worker_id: usize,
}
impl Drop for Bomb {
fn drop(&mut self) {
let worker_id = self.worker_id;
let msg = match self.result.take() {
Some(WorkItemResult::Compiled(m)) => {
Message::Done { result: Ok(m), worker_id }
}
Some(WorkItemResult::NeedsLTO(m)) => {
Message::NeedsLTO { result: m, worker_id }
}
None => Message::Done { result: Err(()), worker_id }
};
drop(self.coordinator_send.send(Box::new(msg)));
}
}
let mut bomb = Bomb {
coordinator_send: cgcx.coordinator_send.clone(),
result: None,
worker_id: cgcx.worker,
};
// Execute the work itself, and if it finishes successfully then flag
// ourselves as a success as well.
//
// Note that we ignore any `FatalError` coming out of `execute_work_item`,
// as a diagnostic was already sent off to the main thread - just
// surface that there was an error in this worker.
bomb.result = {
let timeline = cgcx.time_graph.as_ref().map(|tg| {
tg.start(time_graph::TimelineId(cgcx.worker),
LLVM_WORK_PACKAGE_KIND,
&work.name())
});
let mut timeline = timeline.unwrap_or(Timeline::noop());
execute_work_item(&cgcx, work, &mut timeline).ok()
};
});
}
pub fn run_assembler(sess: &Session, outputs: &OutputFilenames) {
let (pname, mut cmd, _) = get_linker(sess);
for arg in &sess.target.target.options.asm_args {
cmd.arg(arg);
}
cmd.arg("-c").arg("-o").arg(&outputs.path(OutputType::Object))
.arg(&outputs.temp_path(OutputType::Assembly, None));
debug!("{:?}", cmd);
match cmd.output() {
Ok(prog) => {
if !prog.status.success() {
let mut note = prog.stderr.clone();
note.extend_from_slice(&prog.stdout);
sess.struct_err(&format!("linking with `{}` failed: {}",
pname,
prog.status))
.note(&format!("{:?}", &cmd))
.note(str::from_utf8(&note[..]).unwrap())
.emit();
sess.abort_if_errors();
}
},
Err(e) => {
sess.err(&format!("could not exec the linker `{}`: {}", pname, e));
sess.abort_if_errors();
}
}
}
pub unsafe fn with_llvm_pmb(llmod: ModuleRef,
config: &ModuleConfig,
opt_level: llvm::CodeGenOptLevel,
f: &mut FnMut(llvm::PassManagerBuilderRef)) {
// Create the PassManagerBuilder for LLVM. We configure it with
// reasonable defaults and prepare it to actually populate the pass
// manager.
let builder = llvm::LLVMPassManagerBuilderCreate();
let opt_size = config.opt_size.unwrap_or(llvm::CodeGenOptSizeNone);
let inline_threshold = config.inline_threshold;
llvm::LLVMRustConfigurePassManagerBuilder(builder,
opt_level,
config.merge_functions,
config.vectorize_slp,
config.vectorize_loop);
llvm::LLVMPassManagerBuilderSetSizeLevel(builder, opt_size as u32);
if opt_size != llvm::CodeGenOptSizeNone {
llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
}
llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
// Here we match what clang does (kinda). For O0 we only inline
// always-inline functions (but don't add lifetime intrinsics), at O1 we
// inline with lifetime intrinsics, and O2+ we add an inliner with a
// thresholds copied from clang.
match (opt_level, opt_size, inline_threshold) {
(.., Some(t)) => {
llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, t as u32);
}
(llvm::CodeGenOptLevel::Aggressive, ..) => {
llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275);
}
(_, llvm::CodeGenOptSizeDefault, _) => {
llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 75);
}
(_, llvm::CodeGenOptSizeAggressive, _) => {
llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 25);
}
(llvm::CodeGenOptLevel::None, ..) => {
llvm::LLVMRustAddAlwaysInlinePass(builder, false);
}
(llvm::CodeGenOptLevel::Less, ..) => {
llvm::LLVMRustAddAlwaysInlinePass(builder, true);
}
(llvm::CodeGenOptLevel::Default, ..) => {
llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225);
}
(llvm::CodeGenOptLevel::Other, ..) => {
bug!("CodeGenOptLevel::Other selected")
}
}
f(builder);
llvm::LLVMPassManagerBuilderDispose(builder);
}
enum SharedEmitterMessage {
Diagnostic(Diagnostic),
InlineAsmError(u32, String),
AbortIfErrors,
Fatal(String),
}
#[derive(Clone)]
pub struct SharedEmitter {
sender: Sender<SharedEmitterMessage>,
}
pub struct SharedEmitterMain {
receiver: Receiver<SharedEmitterMessage>,
}
impl SharedEmitter {
pub fn new() -> (SharedEmitter, SharedEmitterMain) {
let (sender, receiver) = channel();
(SharedEmitter { sender }, SharedEmitterMain { receiver })
}
fn inline_asm_error(&self, cookie: u32, msg: String) {
drop(self.sender.send(SharedEmitterMessage::InlineAsmError(cookie, msg)));
}
fn fatal(&self, msg: &str) {
drop(self.sender.send(SharedEmitterMessage::Fatal(msg.to_string())));
}
}
impl Emitter for SharedEmitter {
fn emit(&mut self, db: &DiagnosticBuilder) {
drop(self.sender.send(SharedEmitterMessage::Diagnostic(Diagnostic {
msg: db.message(),
code: db.code.clone(),
lvl: db.level,
})));
for child in &db.children {
drop(self.sender.send(SharedEmitterMessage::Diagnostic(Diagnostic {
msg: child.message(),
code: None,
lvl: child.level,
})));
}
drop(self.sender.send(SharedEmitterMessage::AbortIfErrors));
}
}
impl SharedEmitterMain {
pub fn check(&self, sess: &Session, blocking: bool) {
loop {
let message = if blocking {
match self.receiver.recv() {
Ok(message) => Ok(message),
Err(_) => Err(()),
}
} else {
match self.receiver.try_recv() {
Ok(message) => Ok(message),
Err(_) => Err(()),
}
};
match message {
Ok(SharedEmitterMessage::Diagnostic(diag)) => {
let handler = sess.diagnostic();
match diag.code {
Some(ref code) => {
handler.emit_with_code(&MultiSpan::new(),
&diag.msg,
code.clone(),
diag.lvl);
}
None => {
handler.emit(&MultiSpan::new(),
&diag.msg,
diag.lvl);
}
}
}
Ok(SharedEmitterMessage::InlineAsmError(cookie, msg)) => {
match Mark::from_u32(cookie).expn_info() {
Some(ei) => sess.span_err(ei.call_site, &msg),
None => sess.err(&msg),
}
}
Ok(SharedEmitterMessage::AbortIfErrors) => {
sess.abort_if_errors();
}
Ok(SharedEmitterMessage::Fatal(msg)) => {
sess.fatal(&msg);
}
Err(_) => {
break;
}
}
}
}
}
pub struct OngoingCrateTranslation {
crate_name: Symbol,
link: LinkMeta,
metadata: EncodedMetadata,
windows_subsystem: Option<String>,
linker_info: LinkerInfo,
no_integrated_as: bool,
crate_info: CrateInfo,
time_graph: Option<TimeGraph>,
coordinator_send: Sender<Box<Any + Send>>,
trans_worker_receive: Receiver<Message>,
shared_emitter_main: SharedEmitterMain,
future: thread::JoinHandle<Result<CompiledModules, ()>>,
output_filenames: Arc<OutputFilenames>,
}
impl OngoingCrateTranslation {
pub fn join(self, sess: &Session, dep_graph: &DepGraph) -> CrateTranslation {
self.shared_emitter_main.check(sess, true);
let compiled_modules = match self.future.join() {
Ok(Ok(compiled_modules)) => compiled_modules,
Ok(Err(())) => {
sess.abort_if_errors();
panic!("expected abort due to worker thread errors")
},
Err(_) => {
sess.fatal("Error during translation/LLVM phase.");
}
};
sess.abort_if_errors();
if let Some(time_graph) = self.time_graph {
time_graph.dump(&format!("{}-timings", self.crate_name));
}
copy_module_artifacts_into_incr_comp_cache(sess,
dep_graph,
&compiled_modules);
produce_final_output_artifacts(sess,
&compiled_modules,
&self.output_filenames);
// FIXME: time_llvm_passes support - does this use a global context or
// something?
if sess.codegen_units() == 1 && sess.time_llvm_passes() {
unsafe { llvm::LLVMRustPrintPassTimings(); }
}
let trans = CrateTranslation {
crate_name: self.crate_name,
link: self.link,
metadata: self.metadata,
windows_subsystem: self.windows_subsystem,
linker_info: self.linker_info,
crate_info: self.crate_info,
modules: compiled_modules.modules,
allocator_module: compiled_modules.allocator_module,
metadata_module: compiled_modules.metadata_module,
};
if self.no_integrated_as {
run_assembler(sess, &self.output_filenames);
// HACK the linker expects the object file to be named foo.0.o but
// `run_assembler` produces an object named just foo.o. Rename it if we
// are going to build an executable
if sess.opts.output_types.contains_key(&OutputType::Exe) {
let f = self.output_filenames.path(OutputType::Object);
rename_or_copy_remove(&f,
f.with_file_name(format!("{}.0.o",
f.file_stem().unwrap().to_string_lossy()))).unwrap();
}
// Remove assembly source, unless --save-temps was specified
if !sess.opts.cg.save_temps {
fs::remove_file(&self.output_filenames
.temp_path(OutputType::Assembly, None)).unwrap();
}
}
trans
}
pub fn submit_pre_translated_module_to_llvm(&self,
tcx: TyCtxt,
mtrans: ModuleTranslation) {
self.wait_for_signal_to_translate_item();
self.check_for_errors(tcx.sess);
// These are generally cheap and won't through off scheduling.
let cost = 0;
submit_translated_module_to_llvm(tcx, mtrans, cost);
}
pub fn translation_finished(&self, tcx: TyCtxt) {
self.wait_for_signal_to_translate_item();
self.check_for_errors(tcx.sess);
drop(self.coordinator_send.send(Box::new(Message::TranslationComplete)));
}
pub fn check_for_errors(&self, sess: &Session) {
self.shared_emitter_main.check(sess, false);
}
pub fn wait_for_signal_to_translate_item(&self) {
match self.trans_worker_receive.recv() {
Ok(Message::TranslateItem) => {
// Nothing to do
}
Ok(_) => panic!("unexpected message"),
Err(_) => {
// One of the LLVM threads must have panicked, fall through so
// error handling can be reached.
}
}
}
}
pub fn submit_translated_module_to_llvm(tcx: TyCtxt,
mtrans: ModuleTranslation,
cost: u64) {
let llvm_work_item = WorkItem::Optimize(mtrans);
drop(tcx.tx_to_llvm_workers.send(Box::new(Message::TranslationDone {
llvm_work_item,
cost,
})));
}
fn msvc_imps_needed(tcx: TyCtxt) -> bool {
tcx.sess.target.target.options.is_like_msvc &&
tcx.sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib)
}
// Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
// This is required to satisfy `dllimport` references to static data in .rlibs
// when using MSVC linker. We do this only for data, as linker can fix up
// code references on its own.
// See #26591, #27438
fn create_msvc_imps(cgcx: &CodegenContext, llcx: ContextRef, llmod: ModuleRef) {
if !cgcx.msvc_imps_needed {
return
}
// The x86 ABI seems to require that leading underscores are added to symbol
// names, so we need an extra underscore on 32-bit. There's also a leading
// '\x01' here which disables LLVM's symbol mangling (e.g. no extra
// underscores added in front).
let prefix = if cgcx.target_pointer_width == "32" {
"\x01__imp__"
} else {
"\x01__imp_"
};
unsafe {
let i8p_ty = Type::i8p_llcx(llcx);
let globals = base::iter_globals(llmod)
.filter(|&val| {
llvm::LLVMRustGetLinkage(val) == llvm::Linkage::ExternalLinkage &&
llvm::LLVMIsDeclaration(val) == 0
})
.map(move |val| {
let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
let mut imp_name = prefix.as_bytes().to_vec();
imp_name.extend(name.to_bytes());
let imp_name = CString::new(imp_name).unwrap();
(imp_name, val)
})
.collect::<Vec<_>>();
for (imp_name, val) in globals {
let imp = llvm::LLVMAddGlobal(llmod,
i8p_ty.to_ref(),
imp_name.as_ptr() as *const _);
llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty));
llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage);
}
}
}