compiler/rustc_codegen_llvm/src/lib.rs

   1 //! The Rust compiler.
   2 //!
   3 //! # Note
   4 //!
   5 //! This API is completely unstable and subject to change.
   6
   7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
   8 #![feature(bool_to_option)]
   9 #![feature(const_cstr_unchecked)]
  10 #![feature(crate_visibility_modifier)]
  11 #![feature(extern_types)]
  12 #![feature(in_band_lifetimes)]
  13 #![feature(iter_zip)]
  14 #![feature(nll)]
  15 #![recursion_limit = "256"]
  16
  17 use back::write::{create_informational_target_machine, create_target_machine};
  18
  19 pub use llvm_util::target_features;
  20 use rustc_ast::expand::allocator::AllocatorKind;
  21 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
  22 use rustc_codegen_ssa::back::write::{
  23     CodegenContext, FatLTOInput, ModuleConfig, TargetMachineFactoryConfig, TargetMachineFactoryFn,
  24 };
  25 use rustc_codegen_ssa::traits::*;
  26 use rustc_codegen_ssa::ModuleCodegen;
  27 use rustc_codegen_ssa::{CodegenResults, CompiledModule};
  28 use rustc_data_structures::fx::FxHashMap;
  29 use rustc_errors::{ErrorReported, FatalError, Handler};
  30 use rustc_metadata::EncodedMetadata;
  31 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
  32 use rustc_middle::ty::TyCtxt;
  33 use rustc_session::config::{OptLevel, OutputFilenames, PrintRequest};
  34 use rustc_session::Session;
  35 use rustc_span::symbol::Symbol;
  36
  37 use std::any::Any;
  38 use std::ffi::CStr;
  39
  40 mod back {
  41     pub mod archive;
  42     pub mod lto;
  43     mod profiling;
  44     pub mod write;
  45 }
  46
  47 mod abi;
  48 mod allocator;
  49 mod asm;
  50 mod attributes;
  51 mod base;
  52 mod builder;
  53 mod callee;
  54 mod common;
  55 mod consts;
  56 mod context;
  57 mod coverageinfo;
  58 mod debuginfo;
  59 mod declare;
  60 mod intrinsic;
  61
  62 // The following is a work around that replaces `pub mod llvm;` and that fixes issue 53912.
  63 #[path = "llvm/mod.rs"]
  64 mod llvm_;
  65 pub mod llvm {
  66     pub use super::llvm_::*;
  67 }
  68
  69 mod llvm_util;
  70 mod mono_item;
  71 mod type_;
  72 mod type_of;
  73 mod va_arg;
  74 mod value;
  75
  76 #[derive(Clone)]
  77 pub struct LlvmCodegenBackend(());
  78
  79 struct TimeTraceProfiler {
  80     enabled: bool,
  81 }
  82
  83 impl TimeTraceProfiler {
  84     fn new(enabled: bool) -> Self {
  85         if enabled {
  86             unsafe { llvm::LLVMTimeTraceProfilerInitialize() }
  87         }
  88         TimeTraceProfiler { enabled }
  89     }
  90 }
  91
  92 impl Drop for TimeTraceProfiler {
  93     fn drop(&mut self) {
  94         if self.enabled {
  95             unsafe { llvm::LLVMTimeTraceProfilerFinishThread() }
  96         }
  97     }
  98 }
  99
 100 impl ExtraBackendMethods for LlvmCodegenBackend {
 101     fn new_metadata(&self, tcx: TyCtxt<'_>, mod_name: &str) -> ModuleLlvm {
 102         ModuleLlvm::new_metadata(tcx, mod_name)
 103     }
 104
 105     fn write_compressed_metadata<'tcx>(
 106         &self,
 107         tcx: TyCtxt<'tcx>,
 108         metadata: &EncodedMetadata,
 109         llvm_module: &mut ModuleLlvm,
 110     ) {
 111         base::write_compressed_metadata(tcx, metadata, llvm_module)
 112     }
 113     fn codegen_allocator<'tcx>(
 114         &self,
 115         tcx: TyCtxt<'tcx>,
 116         module_llvm: &mut ModuleLlvm,
 117         module_name: &str,
 118         kind: AllocatorKind,
 119         has_alloc_error_handler: bool,
 120     ) {
 121         unsafe { allocator::codegen(tcx, module_llvm, module_name, kind, has_alloc_error_handler) }
 122     }
 123     fn compile_codegen_unit(
 124         &self,
 125         tcx: TyCtxt<'_>,
 126         cgu_name: Symbol,
 127     ) -> (ModuleCodegen<ModuleLlvm>, u64) {
 128         base::compile_codegen_unit(tcx, cgu_name)
 129     }
 130     fn target_machine_factory(
 131         &self,
 132         sess: &Session,
 133         optlvl: OptLevel,
 134     ) -> TargetMachineFactoryFn<Self> {
 135         back::write::target_machine_factory(sess, optlvl)
 136     }
 137     fn target_cpu<'b>(&self, sess: &'b Session) -> &'b str {
 138         llvm_util::target_cpu(sess)
 139     }
 140     fn tune_cpu<'b>(&self, sess: &'b Session) -> Option<&'b str> {
 141         llvm_util::tune_cpu(sess)
 142     }
 143
 144     fn spawn_thread<F, T>(time_trace: bool, f: F) -> std::thread::JoinHandle<T>
 145     where
 146         F: FnOnce() -> T,
 147         F: Send + 'static,
 148         T: Send + 'static,
 149     {
 150         std::thread::spawn(move || {
 151             let _profiler = TimeTraceProfiler::new(time_trace);
 152             f()
 153         })
 154     }
 155
 156     fn spawn_named_thread<F, T>(
 157         time_trace: bool,
 158         name: String,
 159         f: F,
 160     ) -> std::io::Result<std::thread::JoinHandle<T>>
 161     where
 162         F: FnOnce() -> T,
 163         F: Send + 'static,
 164         T: Send + 'static,
 165     {
 166         std::thread::Builder::new().name(name).spawn(move || {
 167             let _profiler = TimeTraceProfiler::new(time_trace);
 168             f()
 169         })
 170     }
 171 }
 172
 173 impl WriteBackendMethods for LlvmCodegenBackend {
 174     type Module = ModuleLlvm;
 175     type ModuleBuffer = back::lto::ModuleBuffer;
 176     type Context = llvm::Context;
 177     type TargetMachine = &'static mut llvm::TargetMachine;
 178     type ThinData = back::lto::ThinData;
 179     type ThinBuffer = back::lto::ThinBuffer;
 180     fn print_pass_timings(&self) {
 181         unsafe {
 182             llvm::LLVMRustPrintPassTimings();
 183         }
 184     }
 185     fn run_link(
 186         cgcx: &CodegenContext<Self>,
 187         diag_handler: &Handler,
 188         modules: Vec<ModuleCodegen<Self::Module>>,
 189     ) -> Result<ModuleCodegen<Self::Module>, FatalError> {
 190         back::write::link(cgcx, diag_handler, modules)
 191     }
 192     fn run_fat_lto(
 193         cgcx: &CodegenContext<Self>,
 194         modules: Vec<FatLTOInput<Self>>,
 195         cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
 196     ) -> Result<LtoModuleCodegen<Self>, FatalError> {
 197         back::lto::run_fat(cgcx, modules, cached_modules)
 198     }
 199     fn run_thin_lto(
 200         cgcx: &CodegenContext<Self>,
 201         modules: Vec<(String, Self::ThinBuffer)>,
 202         cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
 203     ) -> Result<(Vec<LtoModuleCodegen<Self>>, Vec<WorkProduct>), FatalError> {
 204         back::lto::run_thin(cgcx, modules, cached_modules)
 205     }
 206     unsafe fn optimize(
 207         cgcx: &CodegenContext<Self>,
 208         diag_handler: &Handler,
 209         module: &ModuleCodegen<Self::Module>,
 210         config: &ModuleConfig,
 211     ) -> Result<(), FatalError> {
 212         back::write::optimize(cgcx, diag_handler, module, config)
 213     }
 214     unsafe fn optimize_thin(
 215         cgcx: &CodegenContext<Self>,
 216         thin: &mut ThinModule<Self>,
 217     ) -> Result<ModuleCodegen<Self::Module>, FatalError> {
 218         back::lto::optimize_thin_module(thin, cgcx)
 219     }
 220     unsafe fn codegen(
 221         cgcx: &CodegenContext<Self>,
 222         diag_handler: &Handler,
 223         module: ModuleCodegen<Self::Module>,
 224         config: &ModuleConfig,
 225     ) -> Result<CompiledModule, FatalError> {
 226         back::write::codegen(cgcx, diag_handler, module, config)
 227     }
 228     fn prepare_thin(module: ModuleCodegen<Self::Module>) -> (String, Self::ThinBuffer) {
 229         back::lto::prepare_thin(module)
 230     }
 231     fn serialize_module(module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer) {
 232         (module.name, back::lto::ModuleBuffer::new(module.module_llvm.llmod()))
 233     }
 234     fn run_lto_pass_manager(
 235         cgcx: &CodegenContext<Self>,
 236         module: &ModuleCodegen<Self::Module>,
 237         config: &ModuleConfig,
 238         thin: bool,
 239     ) -> Result<(), FatalError> {
 240         let diag_handler = cgcx.create_diag_handler();
 241         back::lto::run_pass_manager(cgcx, &diag_handler, module, config, thin)
 242     }
 243 }
 244
 245 unsafe impl Send for LlvmCodegenBackend {} // Llvm is on a per-thread basis
 246 unsafe impl Sync for LlvmCodegenBackend {}
 247
 248 impl LlvmCodegenBackend {
 249     pub fn new() -> Box<dyn CodegenBackend> {
 250         Box::new(LlvmCodegenBackend(()))
 251     }
 252 }
 253
 254 impl CodegenBackend for LlvmCodegenBackend {
 255     fn init(&self, sess: &Session) {
 256         llvm_util::init(sess); // Make sure llvm is inited
 257     }
 258
 259     fn print(&self, req: PrintRequest, sess: &Session) {
 260         match req {
 261             PrintRequest::RelocationModels => {
 262                 println!("Available relocation models:");
 263                 for name in &[
 264                     "static",
 265                     "pic",
 266                     "pie",
 267                     "dynamic-no-pic",
 268                     "ropi",
 269                     "rwpi",
 270                     "ropi-rwpi",
 271                     "default",
 272                 ] {
 273                     println!("    {}", name);
 274                 }
 275                 println!();
 276             }
 277             PrintRequest::CodeModels => {
 278                 println!("Available code models:");
 279                 for name in &["tiny", "small", "kernel", "medium", "large"] {
 280                     println!("    {}", name);
 281                 }
 282                 println!();
 283             }
 284             PrintRequest::TlsModels => {
 285                 println!("Available TLS models:");
 286                 for name in &["global-dynamic", "local-dynamic", "initial-exec", "local-exec"] {
 287                     println!("    {}", name);
 288                 }
 289                 println!();
 290             }
 291             PrintRequest::StackProtectorStrategies => {
 292                 println!(
 293                     r#"Available stack protector strategies:
 294     all
 295         Generate stack canaries in all functions.
 296
 297     strong
 298         Generate stack canaries in a function if it either:
 299         - has a local variable of `[T; N]` type, regardless of `T` and `N`
 300         - takes the address of a local variable.
 301
 302           (Note that a local variable being borrowed is not equivalent to its
 303           address being taken: e.g. some borrows may be removed by optimization,
 304           while by-value argument passing may be implemented with reference to a
 305           local stack variable in the ABI.)
 306
 307     basic
 308         Generate stack canaries in functions with:
 309         - local variables of `[T; N]` type, where `T` is byte-sized and `N` > 8.
 310
 311     none
 312         Do not generate stack canaries.
 313 "#
 314                 );
 315             }
 316             req => llvm_util::print(req, sess),
 317         }
 318     }
 319
 320     fn print_passes(&self) {
 321         llvm_util::print_passes();
 322     }
 323
 324     fn print_version(&self) {
 325         llvm_util::print_version();
 326     }
 327
 328     fn target_features(&self, sess: &Session) -> Vec<Symbol> {
 329         target_features(sess)
 330     }
 331
 332     fn codegen_crate<'tcx>(
 333         &self,
 334         tcx: TyCtxt<'tcx>,
 335         metadata: EncodedMetadata,
 336         need_metadata_module: bool,
 337     ) -> Box<dyn Any> {
 338         Box::new(rustc_codegen_ssa::base::codegen_crate(
 339             LlvmCodegenBackend(()),
 340             tcx,
 341             crate::llvm_util::target_cpu(tcx.sess).to_string(),
 342             metadata,
 343             need_metadata_module,
 344         ))
 345     }
 346
 347     fn join_codegen(
 348         &self,
 349         ongoing_codegen: Box<dyn Any>,
 350         sess: &Session,
 351     ) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorReported> {
 352         let (codegen_results, work_products) = ongoing_codegen
 353             .downcast::<rustc_codegen_ssa::back::write::OngoingCodegen<LlvmCodegenBackend>>()
 354             .expect("Expected LlvmCodegenBackend's OngoingCodegen, found Box<Any>")
 355             .join(sess);
 356
 357         sess.time("llvm_dump_timing_file", || {
 358             if sess.opts.debugging_opts.llvm_time_trace {
 359                 llvm_util::time_trace_profiler_finish("llvm_timings.json");
 360             }
 361         });
 362
 363         Ok((codegen_results, work_products))
 364     }
 365
 366     fn link(
 367         &self,
 368         sess: &Session,
 369         codegen_results: CodegenResults,
 370         outputs: &OutputFilenames,
 371     ) -> Result<(), ErrorReported> {
 372         use crate::back::archive::LlvmArchiveBuilder;
 373         use rustc_codegen_ssa::back::link::link_binary;
 374
 375         // Run the linker on any artifacts that resulted from the LLVM run.
 376         // This should produce either a finished executable or library.
 377         link_binary::<LlvmArchiveBuilder<'_>>(sess, &codegen_results, outputs)
 378     }
 379 }
 380
 381 pub struct ModuleLlvm {
 382     llcx: &'static mut llvm::Context,
 383     llmod_raw: *const llvm::Module,
 384     tm: &'static mut llvm::TargetMachine,
 385 }
 386
 387 unsafe impl Send for ModuleLlvm {}
 388 unsafe impl Sync for ModuleLlvm {}
 389
 390 impl ModuleLlvm {
 391     fn new(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
 392         unsafe {
 393             let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
 394             let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
 395             ModuleLlvm { llmod_raw, llcx, tm: create_target_machine(tcx, mod_name) }
 396         }
 397     }
 398
 399     fn new_metadata(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
 400         unsafe {
 401             let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
 402             let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
 403             ModuleLlvm { llmod_raw, llcx, tm: create_informational_target_machine(tcx.sess) }
 404         }
 405     }
 406
 407     fn parse(
 408         cgcx: &CodegenContext<LlvmCodegenBackend>,
 409         name: &CStr,
 410         buffer: &[u8],
 411         handler: &Handler,
 412     ) -> Result<Self, FatalError> {
 413         unsafe {
 414             let llcx = llvm::LLVMRustContextCreate(cgcx.fewer_names);
 415             let llmod_raw = back::lto::parse_module(llcx, name, buffer, handler)?;
 416             let tm_factory_config = TargetMachineFactoryConfig::new(cgcx, name.to_str().unwrap());
 417             let tm = match (cgcx.tm_factory)(tm_factory_config) {
 418                 Ok(m) => m,
 419                 Err(e) => {
 420                     handler.struct_err(&e).emit();
 421                     return Err(FatalError);
 422                 }
 423             };
 424
 425             Ok(ModuleLlvm { llmod_raw, llcx, tm })
 426         }
 427     }
 428
 429     fn llmod(&self) -> &llvm::Module {
 430         unsafe { &*self.llmod_raw }
 431     }
 432 }
 433
 434 impl Drop for ModuleLlvm {
 435     fn drop(&mut self) {
 436         unsafe {
 437             llvm::LLVMRustDisposeTargetMachine(&mut *(self.tm as *mut _));
 438             llvm::LLVMContextDispose(&mut *(self.llcx as *mut _));
 439         }
 440     }
 441 }