2 use crate::back::bytecode;
3 use crate::back::lto::ThinBuffer;
7 use crate::context::{get_reloc_model, is_pie_binary};
8 use crate::llvm::{self, DiagnosticInfo, PassManager, SMDiagnostic};
10 use crate::type_::Type;
11 use crate::LlvmCodegenBackend;
12 use crate::ModuleLlvm;
15 use rustc::session::config::{self, Lto, OutputType, Passes, Sanitizer, SwitchWithOptPath};
16 use rustc::session::Session;
17 use rustc::ty::TyCtxt;
18 use rustc_codegen_ssa::back::write::{run_assembler, CodegenContext, ModuleConfig};
19 use rustc_codegen_ssa::traits::*;
20 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, RLIB_BYTECODE_EXTENSION};
21 use rustc_data_structures::small_c_str::SmallCStr;
22 use rustc_errors::{FatalError, Handler};
23 use rustc_fs_util::{link_or_copy, path_to_c_string};
24 use rustc_hir::def_id::LOCAL_CRATE;
26 use libc::{c_char, c_int, c_uint, c_void, size_t};
27 use std::ffi::CString;
29 use std::io::{self, Write};
30 use std::path::{Path, PathBuf};
35 pub const RELOC_MODEL_ARGS: [(&str, llvm::RelocMode); 7] = [
36 ("pic", llvm::RelocMode::PIC),
37 ("static", llvm::RelocMode::Static),
38 ("default", llvm::RelocMode::Default),
39 ("dynamic-no-pic", llvm::RelocMode::DynamicNoPic),
40 ("ropi", llvm::RelocMode::ROPI),
41 ("rwpi", llvm::RelocMode::RWPI),
42 ("ropi-rwpi", llvm::RelocMode::ROPI_RWPI),
45 pub const CODE_GEN_MODEL_ARGS: &[(&str, llvm::CodeModel)] = &[
46 ("small", llvm::CodeModel::Small),
47 ("kernel", llvm::CodeModel::Kernel),
48 ("medium", llvm::CodeModel::Medium),
49 ("large", llvm::CodeModel::Large),
52 pub const TLS_MODEL_ARGS: [(&str, llvm::ThreadLocalMode); 4] = [
53 ("global-dynamic", llvm::ThreadLocalMode::GeneralDynamic),
54 ("local-dynamic", llvm::ThreadLocalMode::LocalDynamic),
55 ("initial-exec", llvm::ThreadLocalMode::InitialExec),
56 ("local-exec", llvm::ThreadLocalMode::LocalExec),
59 pub fn llvm_err(handler: &rustc_errors::Handler, msg: &str) -> FatalError {
60 match llvm::last_error() {
61 Some(err) => handler.fatal(&format!("{}: {}", msg, err)),
62 None => handler.fatal(&msg),
66 pub fn write_output_file(
67 handler: &rustc_errors::Handler,
68 target: &'ll llvm::TargetMachine,
69 pm: &llvm::PassManager<'ll>,
72 file_type: llvm::FileType,
73 ) -> Result<(), FatalError> {
75 let output_c = path_to_c_string(output);
76 let result = llvm::LLVMRustWriteOutputFile(target, pm, m, output_c.as_ptr(), file_type);
77 result.into_result().map_err(|()| {
78 let msg = format!("could not write output to {}", output.display());
79 llvm_err(handler, &msg)
84 pub fn create_informational_target_machine(
87 ) -> &'static mut llvm::TargetMachine {
88 target_machine_factory(sess, config::OptLevel::No, find_features)()
89 .unwrap_or_else(|err| llvm_err(sess.diagnostic(), &err).raise())
92 pub fn create_target_machine(
95 ) -> &'static mut llvm::TargetMachine {
96 target_machine_factory(&tcx.sess, tcx.backend_optimization_level(LOCAL_CRATE), find_features)()
97 .unwrap_or_else(|err| llvm_err(tcx.sess.diagnostic(), &err).raise())
100 pub fn to_llvm_opt_settings(
101 cfg: config::OptLevel,
102 ) -> (llvm::CodeGenOptLevel, llvm::CodeGenOptSize) {
103 use self::config::OptLevel::*;
105 No => (llvm::CodeGenOptLevel::None, llvm::CodeGenOptSizeNone),
106 Less => (llvm::CodeGenOptLevel::Less, llvm::CodeGenOptSizeNone),
107 Default => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeNone),
108 Aggressive => (llvm::CodeGenOptLevel::Aggressive, llvm::CodeGenOptSizeNone),
109 Size => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeDefault),
110 SizeMin => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeAggressive),
114 fn to_pass_builder_opt_level(cfg: config::OptLevel) -> llvm::PassBuilderOptLevel {
115 use config::OptLevel::*;
117 No => llvm::PassBuilderOptLevel::O0,
118 Less => llvm::PassBuilderOptLevel::O1,
119 Default => llvm::PassBuilderOptLevel::O2,
120 Aggressive => llvm::PassBuilderOptLevel::O3,
121 Size => llvm::PassBuilderOptLevel::Os,
122 SizeMin => llvm::PassBuilderOptLevel::Oz,
126 // If find_features is true this won't access `sess.crate_types` by assuming
127 // that `is_pie_binary` is false. When we discover LLVM target features
128 // `sess.crate_types` is uninitialized so we cannot access it.
129 pub fn target_machine_factory(
131 optlvl: config::OptLevel,
133 ) -> Arc<dyn Fn() -> Result<&'static mut llvm::TargetMachine, String> + Send + Sync> {
134 let reloc_model = get_reloc_model(sess);
136 let (opt_level, _) = to_llvm_opt_settings(optlvl);
137 let use_softfp = sess.opts.cg.soft_float;
139 let ffunction_sections = sess.target.target.options.function_sections;
140 let fdata_sections = ffunction_sections;
143 sess.opts.cg.code_model.as_ref().or(sess.target.target.options.code_model.as_ref());
145 let code_model = match code_model_arg {
146 Some(s) => match CODE_GEN_MODEL_ARGS.iter().find(|arg| arg.0 == s) {
149 sess.err(&format!("{:?} is not a valid code model", code_model_arg));
150 sess.abort_if_errors();
154 None => llvm::CodeModel::None,
157 let features = attributes::llvm_target_features(sess).collect::<Vec<_>>();
158 let mut singlethread = sess.target.target.options.singlethread;
160 // On the wasm target once the `atomics` feature is enabled that means that
161 // we're no longer single-threaded, or otherwise we don't want LLVM to
162 // lower atomic operations to single-threaded operations.
164 && sess.target.target.llvm_target.contains("wasm32")
165 && features.iter().any(|s| *s == "+atomics")
167 singlethread = false;
170 let triple = SmallCStr::new(&sess.target.target.llvm_target);
171 let cpu = SmallCStr::new(llvm_util::target_cpu(sess));
172 let features = features.join(",");
173 let features = CString::new(features).unwrap();
174 let abi = SmallCStr::new(&sess.target.target.options.llvm_abiname);
175 let is_pie_binary = !find_features && is_pie_binary(sess);
176 let trap_unreachable = sess.target.target.options.trap_unreachable;
177 let emit_stack_size_section = sess.opts.debugging_opts.emit_stack_sizes;
179 let asm_comments = sess.asm_comments();
180 let relax_elf_relocations = sess.target.target.options.relax_elf_relocations;
183 llvm::LLVMRustCreateTargetMachine(
198 emit_stack_size_section,
199 relax_elf_relocations,
204 format!("Could not create LLVM TargetMachine for triple: {}", triple.to_str().unwrap())
209 pub(crate) fn save_temp_bitcode(
210 cgcx: &CodegenContext<LlvmCodegenBackend>,
211 module: &ModuleCodegen<ModuleLlvm>,
214 if !cgcx.save_temps {
218 let ext = format!("{}.bc", name);
219 let cgu = Some(&module.name[..]);
220 let path = cgcx.output_filenames.temp_path_ext(&ext, cgu);
221 let cstr = path_to_c_string(&path);
222 let llmod = module.module_llvm.llmod();
223 llvm::LLVMWriteBitcodeToFile(llmod, cstr.as_ptr());
227 pub struct DiagnosticHandlers<'a> {
228 data: *mut (&'a CodegenContext<LlvmCodegenBackend>, &'a Handler),
229 llcx: &'a llvm::Context,
232 impl<'a> DiagnosticHandlers<'a> {
234 cgcx: &'a CodegenContext<LlvmCodegenBackend>,
235 handler: &'a Handler,
236 llcx: &'a llvm::Context,
238 let data = Box::into_raw(Box::new((cgcx, handler)));
240 llvm::LLVMRustSetInlineAsmDiagnosticHandler(llcx, inline_asm_handler, data.cast());
241 llvm::LLVMContextSetDiagnosticHandler(llcx, diagnostic_handler, data.cast());
243 DiagnosticHandlers { data, llcx }
247 impl<'a> Drop for DiagnosticHandlers<'a> {
249 use std::ptr::null_mut;
251 llvm::LLVMRustSetInlineAsmDiagnosticHandler(self.llcx, inline_asm_handler, null_mut());
252 llvm::LLVMContextSetDiagnosticHandler(self.llcx, diagnostic_handler, null_mut());
253 drop(Box::from_raw(self.data));
258 unsafe extern "C" fn report_inline_asm(
259 cgcx: &CodegenContext<LlvmCodegenBackend>,
263 cgcx.diag_emitter.inline_asm_error(cookie as u32, msg.to_owned());
266 unsafe extern "C" fn inline_asm_handler(diag: &SMDiagnostic, user: *const c_void, cookie: c_uint) {
270 let (cgcx, _) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
272 let msg = llvm::build_string(|s| llvm::LLVMRustWriteSMDiagnosticToString(diag, s))
273 .expect("non-UTF8 SMDiagnostic");
275 report_inline_asm(cgcx, &msg, cookie);
278 unsafe extern "C" fn diagnostic_handler(info: &DiagnosticInfo, user: *mut c_void) {
282 let (cgcx, diag_handler) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
284 match llvm::diagnostic::Diagnostic::unpack(info) {
285 llvm::diagnostic::InlineAsm(inline) => {
286 report_inline_asm(cgcx, &llvm::twine_to_string(inline.message), inline.cookie);
289 llvm::diagnostic::Optimization(opt) => {
290 let enabled = match cgcx.remark {
292 Passes::Some(ref v) => v.iter().any(|s| *s == opt.pass_name),
296 diag_handler.note_without_error(&format!(
297 "optimization {} for {} at {}:{}:{}: {}",
307 llvm::diagnostic::PGO(diagnostic_ref) | llvm::diagnostic::Linker(diagnostic_ref) => {
308 let msg = llvm::build_string(|s| {
309 llvm::LLVMRustWriteDiagnosticInfoToString(diagnostic_ref, s)
311 .expect("non-UTF8 diagnostic");
312 diag_handler.warn(&msg);
314 llvm::diagnostic::UnknownDiagnostic(..) => {}
318 fn get_pgo_gen_path(config: &ModuleConfig) -> Option<CString> {
319 match config.pgo_gen {
320 SwitchWithOptPath::Enabled(ref opt_dir_path) => {
321 let path = if let Some(dir_path) = opt_dir_path {
322 dir_path.join("default_%m.profraw")
324 PathBuf::from("default_%m.profraw")
327 Some(CString::new(format!("{}", path.display())).unwrap())
329 SwitchWithOptPath::Disabled => None,
333 fn get_pgo_use_path(config: &ModuleConfig) -> Option<CString> {
337 .map(|path_buf| CString::new(path_buf.to_string_lossy().as_bytes()).unwrap())
340 pub(crate) fn should_use_new_llvm_pass_manager(config: &ModuleConfig) -> bool {
341 // We only support the new pass manager starting with LLVM 9.
342 if llvm_util::get_major_version() < 9 {
346 // The new pass manager is disabled by default.
347 config.new_llvm_pass_manager.unwrap_or(false)
350 pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
351 module: &ModuleCodegen<ModuleLlvm>,
352 config: &ModuleConfig,
353 opt_level: config::OptLevel,
354 opt_stage: llvm::OptStage,
357 opt_level != config::OptLevel::Size && opt_level != config::OptLevel::SizeMin;
358 let using_thin_buffers = opt_stage == llvm::OptStage::PreLinkThinLTO || config.bitcode_needed();
359 let pgo_gen_path = get_pgo_gen_path(config);
360 let pgo_use_path = get_pgo_use_path(config);
361 let is_lto = opt_stage == llvm::OptStage::ThinLTO || opt_stage == llvm::OptStage::FatLTO;
362 // Sanitizer instrumentation is only inserted during the pre-link optimization stage.
363 let sanitizer_options = if !is_lto {
364 config.sanitizer.as_ref().map(|s| llvm::SanitizerOptions {
365 sanitize_memory: *s == Sanitizer::Memory,
366 sanitize_thread: *s == Sanitizer::Thread,
367 sanitize_address: *s == Sanitizer::Address,
368 sanitize_recover: config.sanitizer_recover.contains(s),
369 sanitize_memory_track_origins: config.sanitizer_memory_track_origins as c_int,
375 // FIXME: NewPM doesn't provide a facility to pass custom InlineParams.
376 // We would have to add upstream support for this first, before we can support
377 // config.inline_threshold and our more aggressive default thresholds.
378 // FIXME: NewPM uses an different and more explicit way to textually represent
379 // pass pipelines. It would probably make sense to expose this, but it would
380 // require a different format than the current -C passes.
381 llvm::LLVMRustOptimizeWithNewPassManager(
382 module.module_llvm.llmod(),
383 &*module.module_llvm.tm,
384 to_pass_builder_opt_level(opt_level),
386 config.no_prepopulate_passes,
387 config.verify_llvm_ir,
389 config.merge_functions,
391 config.vectorize_slp,
392 config.vectorize_loop,
394 sanitizer_options.as_ref(),
395 pgo_gen_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
396 pgo_use_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
400 // Unsafe due to LLVM calls.
401 pub(crate) unsafe fn optimize(
402 cgcx: &CodegenContext<LlvmCodegenBackend>,
403 diag_handler: &Handler,
404 module: &ModuleCodegen<ModuleLlvm>,
405 config: &ModuleConfig,
406 ) -> Result<(), FatalError> {
407 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_optimize", &module.name[..]);
409 let llmod = module.module_llvm.llmod();
410 let llcx = &*module.module_llvm.llcx;
411 let tm = &*module.module_llvm.tm;
412 let _handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
414 let module_name = module.name.clone();
415 let module_name = Some(&module_name[..]);
417 if config.emit_no_opt_bc {
418 let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
419 let out = path_to_c_string(&out);
420 llvm::LLVMWriteBitcodeToFile(llmod, out.as_ptr());
423 if let Some(opt_level) = config.opt_level {
424 if should_use_new_llvm_pass_manager(config) {
425 let opt_stage = match cgcx.lto {
426 Lto::Fat => llvm::OptStage::PreLinkFatLTO,
427 Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO,
428 _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO,
429 _ => llvm::OptStage::PreLinkNoLTO,
431 optimize_with_new_llvm_pass_manager(module, config, opt_level, opt_stage);
435 // Create the two optimizing pass managers. These mirror what clang
436 // does, and are by populated by LLVM's default PassManagerBuilder.
437 // Each manager has a different set of passes, but they also share
438 // some common passes.
439 let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
440 let mpm = llvm::LLVMCreatePassManager();
443 let find_pass = |pass_name: &str| {
444 let pass_name = SmallCStr::new(pass_name);
445 llvm::LLVMRustFindAndCreatePass(pass_name.as_ptr())
448 if config.verify_llvm_ir {
449 // Verification should run as the very first pass.
450 llvm::LLVMRustAddPass(fpm, find_pass("verify").unwrap());
453 let mut extra_passes = Vec::new();
454 let mut have_name_anon_globals_pass = false;
456 for pass_name in &config.passes {
457 if pass_name == "lint" {
458 // Linting should also be performed early, directly on the generated IR.
459 llvm::LLVMRustAddPass(fpm, find_pass("lint").unwrap());
463 if let Some(pass) = find_pass(pass_name) {
464 extra_passes.push(pass);
466 diag_handler.warn(&format!("unknown pass `{}`, ignoring", pass_name));
469 if pass_name == "name-anon-globals" {
470 have_name_anon_globals_pass = true;
474 add_sanitizer_passes(config, &mut extra_passes);
476 // Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
477 // to make sure we run LLVM's NameAnonGlobals pass when emitting bitcode; otherwise
478 // we'll get errors in LLVM.
479 let using_thin_buffers = config.bitcode_needed();
480 if !config.no_prepopulate_passes {
481 llvm::LLVMAddAnalysisPasses(tm, fpm);
482 llvm::LLVMAddAnalysisPasses(tm, mpm);
483 let opt_level = to_llvm_opt_settings(opt_level).0;
484 let prepare_for_thin_lto = cgcx.lto == Lto::Thin
485 || cgcx.lto == Lto::ThinLocal
486 || (cgcx.lto != Lto::Fat && cgcx.opts.cg.linker_plugin_lto.enabled());
487 with_llvm_pmb(llmod, &config, opt_level, prepare_for_thin_lto, &mut |b| {
488 llvm::LLVMRustAddLastExtensionPasses(
490 extra_passes.as_ptr(),
491 extra_passes.len() as size_t,
493 llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
494 llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
497 have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
498 if using_thin_buffers && !prepare_for_thin_lto {
499 llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
500 have_name_anon_globals_pass = true;
503 // If we don't use the standard pipeline, directly populate the MPM
504 // with the extra passes.
505 for pass in extra_passes {
506 llvm::LLVMRustAddPass(mpm, pass);
510 if using_thin_buffers && !have_name_anon_globals_pass {
511 // As described above, this will probably cause an error in LLVM
512 if config.no_prepopulate_passes {
514 "The current compilation is going to use thin LTO buffers \
515 without running LLVM's NameAnonGlobals pass. \
516 This will likely cause errors in LLVM. Consider adding \
517 -C passes=name-anon-globals to the compiler command line.",
521 "We are using thin LTO buffers without running the NameAnonGlobals pass. \
522 This will likely cause errors in LLVM and should never happen."
528 diag_handler.abort_if_errors();
530 // Finally, run the actual optimization passes
532 let _timer = cgcx.prof.extra_verbose_generic_activity(
533 "LLVM_module_optimize_function_passes",
536 llvm::LLVMRustRunFunctionPassManager(fpm, llmod);
539 let _timer = cgcx.prof.extra_verbose_generic_activity(
540 "LLVM_module_optimize_module_passes",
543 llvm::LLVMRunPassManager(mpm, llmod);
546 // Deallocate managers that we're now done with
547 llvm::LLVMDisposePassManager(fpm);
548 llvm::LLVMDisposePassManager(mpm);
553 unsafe fn add_sanitizer_passes(config: &ModuleConfig, passes: &mut Vec<&'static mut llvm::Pass>) {
554 let sanitizer = match &config.sanitizer {
559 let recover = config.sanitizer_recover.contains(sanitizer);
561 Sanitizer::Address => {
562 passes.push(llvm::LLVMRustCreateAddressSanitizerFunctionPass(recover));
563 passes.push(llvm::LLVMRustCreateModuleAddressSanitizerPass(recover));
565 Sanitizer::Memory => {
566 let track_origins = config.sanitizer_memory_track_origins as c_int;
567 passes.push(llvm::LLVMRustCreateMemorySanitizerPass(track_origins, recover));
569 Sanitizer::Thread => {
570 passes.push(llvm::LLVMRustCreateThreadSanitizerPass());
572 Sanitizer::Leak => {}
576 pub(crate) unsafe fn codegen(
577 cgcx: &CodegenContext<LlvmCodegenBackend>,
578 diag_handler: &Handler,
579 module: ModuleCodegen<ModuleLlvm>,
580 config: &ModuleConfig,
581 ) -> Result<CompiledModule, FatalError> {
582 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_codegen", &module.name[..]);
584 let llmod = module.module_llvm.llmod();
585 let llcx = &*module.module_llvm.llcx;
586 let tm = &*module.module_llvm.tm;
587 let module_name = module.name.clone();
588 let module_name = Some(&module_name[..]);
589 let handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
591 if cgcx.msvc_imps_needed {
592 create_msvc_imps(cgcx, llcx, llmod);
595 // A codegen-specific pass manager is used to generate object
596 // files for an LLVM module.
598 // Apparently each of these pass managers is a one-shot kind of
599 // thing, so we create a new one for each type of output. The
600 // pass manager passed to the closure should be ensured to not
601 // escape the closure itself, and the manager should only be
603 unsafe fn with_codegen<'ll, F, R>(
604 tm: &'ll llvm::TargetMachine,
605 llmod: &'ll llvm::Module,
610 F: FnOnce(&'ll mut PassManager<'ll>) -> R,
612 let cpm = llvm::LLVMCreatePassManager();
613 llvm::LLVMAddAnalysisPasses(tm, cpm);
614 llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
618 // If we don't have the integrated assembler, then we need to emit asm
619 // from LLVM and use `gcc` to create the object file.
620 let asm_to_obj = config.emit_obj && config.no_integrated_as;
622 // Change what we write and cleanup based on whether obj files are
623 // just llvm bitcode. In that case write bitcode, and possibly
624 // delete the bitcode if it wasn't requested. Don't generate the
625 // machine code, instead copy the .o file from the .bc
626 let write_bc = config.emit_bc || config.obj_is_bitcode;
627 let rm_bc = !config.emit_bc && config.obj_is_bitcode;
628 let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm_to_obj;
629 let copy_bc_to_obj = config.emit_obj && config.obj_is_bitcode;
631 let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
632 let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
634 if write_bc || config.emit_bc_compressed || config.embed_bitcode {
637 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &module.name[..]);
638 let thin = ThinBuffer::new(llmod);
639 let data = thin.data();
642 let _timer = cgcx.prof.generic_activity_with_arg(
643 "LLVM_module_codegen_emit_bitcode",
646 if let Err(e) = fs::write(&bc_out, data) {
647 let msg = format!("failed to write bytecode to {}: {}", bc_out.display(), e);
648 diag_handler.err(&msg);
652 if config.embed_bitcode {
653 let _timer = cgcx.prof.generic_activity_with_arg(
654 "LLVM_module_codegen_embed_bitcode",
657 embed_bitcode(cgcx, llcx, llmod, Some(data));
660 if config.emit_bc_compressed {
661 let _timer = cgcx.prof.generic_activity_with_arg(
662 "LLVM_module_codegen_emit_compressed_bitcode",
665 let dst = bc_out.with_extension(RLIB_BYTECODE_EXTENSION);
666 let data = bytecode::encode(&module.name, data);
667 if let Err(e) = fs::write(&dst, data) {
668 let msg = format!("failed to write bytecode to {}: {}", dst.display(), e);
669 diag_handler.err(&msg);
672 } else if config.embed_bitcode_marker {
673 embed_bitcode(cgcx, llcx, llmod, None);
680 .generic_activity_with_arg("LLVM_module_codegen_emit_ir", &module.name[..]);
681 let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
682 let out_c = path_to_c_string(&out);
684 extern "C" fn demangle_callback(
685 input_ptr: *const c_char,
687 output_ptr: *mut c_char,
691 slice::from_raw_parts(input_ptr as *const u8, input_len as usize)
694 let input = match str::from_utf8(input) {
699 let output = unsafe {
700 slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
702 let mut cursor = io::Cursor::new(output);
704 let demangled = match rustc_demangle::try_demangle(input) {
709 if let Err(_) = write!(cursor, "{:#}", demangled) {
710 // Possible only if provided buffer is not big enough
714 cursor.position() as size_t
717 let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
718 result.into_result().map_err(|()| {
719 let msg = format!("failed to write LLVM IR to {}", out.display());
720 llvm_err(diag_handler, &msg)
724 if config.emit_asm || asm_to_obj {
727 .generic_activity_with_arg("LLVM_module_codegen_emit_asm", &module.name[..]);
728 let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
730 // We can't use the same module for asm and binary output, because that triggers
731 // various errors like invalid IR or broken binaries, so we might have to clone the
732 // module to produce the asm output
733 let llmod = if config.emit_obj { llvm::LLVMCloneModule(llmod) } else { llmod };
734 with_codegen(tm, llmod, config.no_builtins, |cpm| {
741 llvm::FileType::AssemblyFile,
749 .generic_activity_with_arg("LLVM_module_codegen_emit_obj", &module.name[..]);
750 with_codegen(tm, llmod, config.no_builtins, |cpm| {
757 llvm::FileType::ObjectFile,
760 } else if asm_to_obj {
763 .generic_activity_with_arg("LLVM_module_codegen_asm_to_obj", &module.name[..]);
764 let assembly = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
765 run_assembler(cgcx, diag_handler, &assembly, &obj_out);
767 if !config.emit_asm && !cgcx.save_temps {
768 drop(fs::remove_file(&assembly));
774 debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
775 if let Err(e) = link_or_copy(&bc_out, &obj_out) {
776 diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
781 debug!("removing_bitcode {:?}", bc_out);
782 if let Err(e) = fs::remove_file(&bc_out) {
783 diag_handler.err(&format!("failed to remove bitcode: {}", e));
789 Ok(module.into_compiled_module(
792 config.emit_bc_compressed,
793 &cgcx.output_filenames,
797 /// Embed the bitcode of an LLVM module in the LLVM module itself.
799 /// This is done primarily for iOS where it appears to be standard to compile C
800 /// code at least with `-fembed-bitcode` which creates two sections in the
803 /// * __LLVM,__bitcode
804 /// * __LLVM,__cmdline
806 /// It appears *both* of these sections are necessary to get the linker to
807 /// recognize what's going on. For us though we just always throw in an empty
810 /// Furthermore debug/O1 builds don't actually embed bitcode but rather just
811 /// embed an empty section.
813 /// Basically all of this is us attempting to follow in the footsteps of clang
814 /// on iOS. See #35968 for lots more info.
815 unsafe fn embed_bitcode(
816 cgcx: &CodegenContext<LlvmCodegenBackend>,
817 llcx: &llvm::Context,
818 llmod: &llvm::Module,
819 bitcode: Option<&[u8]>,
821 let llconst = common::bytes_in_context(llcx, bitcode.unwrap_or(&[]));
822 let llglobal = llvm::LLVMAddGlobal(
824 common::val_ty(llconst),
825 "rustc.embedded.module\0".as_ptr().cast(),
827 llvm::LLVMSetInitializer(llglobal, llconst);
829 let is_apple = cgcx.opts.target_triple.triple().contains("-ios")
830 || cgcx.opts.target_triple.triple().contains("-darwin");
832 let section = if is_apple { "__LLVM,__bitcode\0" } else { ".llvmbc\0" };
833 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
834 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
835 llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
837 let llconst = common::bytes_in_context(llcx, &[]);
838 let llglobal = llvm::LLVMAddGlobal(
840 common::val_ty(llconst),
841 "rustc.embedded.cmdline\0".as_ptr().cast(),
843 llvm::LLVMSetInitializer(llglobal, llconst);
844 let section = if is_apple { "__LLVM,__cmdline\0" } else { ".llvmcmd\0" };
845 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
846 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
849 pub unsafe fn with_llvm_pmb(
850 llmod: &llvm::Module,
851 config: &ModuleConfig,
852 opt_level: llvm::CodeGenOptLevel,
853 prepare_for_thin_lto: bool,
854 f: &mut dyn FnMut(&llvm::PassManagerBuilder),
858 // Create the PassManagerBuilder for LLVM. We configure it with
859 // reasonable defaults and prepare it to actually populate the pass
861 let builder = llvm::LLVMPassManagerBuilderCreate();
863 config.opt_size.map(|x| to_llvm_opt_settings(x).1).unwrap_or(llvm::CodeGenOptSizeNone);
864 let inline_threshold = config.inline_threshold;
865 let pgo_gen_path = get_pgo_gen_path(config);
866 let pgo_use_path = get_pgo_use_path(config);
868 llvm::LLVMRustConfigurePassManagerBuilder(
871 config.merge_functions,
872 config.vectorize_slp,
873 config.vectorize_loop,
874 prepare_for_thin_lto,
875 pgo_gen_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
876 pgo_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
879 llvm::LLVMPassManagerBuilderSetSizeLevel(builder, opt_size as u32);
881 if opt_size != llvm::CodeGenOptSizeNone {
882 llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
885 llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
887 // Here we match what clang does (kinda). For O0 we only inline
888 // always-inline functions (but don't add lifetime intrinsics), at O1 we
889 // inline with lifetime intrinsics, and O2+ we add an inliner with a
890 // thresholds copied from clang.
891 match (opt_level, opt_size, inline_threshold) {
893 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, t as u32);
895 (llvm::CodeGenOptLevel::Aggressive, ..) => {
896 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275);
898 (_, llvm::CodeGenOptSizeDefault, _) => {
899 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 75);
901 (_, llvm::CodeGenOptSizeAggressive, _) => {
902 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 25);
904 (llvm::CodeGenOptLevel::None, ..) => {
905 llvm::LLVMRustAddAlwaysInlinePass(builder, false);
907 (llvm::CodeGenOptLevel::Less, ..) => {
908 llvm::LLVMRustAddAlwaysInlinePass(builder, true);
910 (llvm::CodeGenOptLevel::Default, ..) => {
911 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225);
913 (llvm::CodeGenOptLevel::Other, ..) => bug!("CodeGenOptLevel::Other selected"),
917 llvm::LLVMPassManagerBuilderDispose(builder);
920 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
921 // This is required to satisfy `dllimport` references to static data in .rlibs
922 // when using MSVC linker. We do this only for data, as linker can fix up
923 // code references on its own.
924 // See #26591, #27438
926 cgcx: &CodegenContext<LlvmCodegenBackend>,
927 llcx: &llvm::Context,
928 llmod: &llvm::Module,
930 if !cgcx.msvc_imps_needed {
933 // The x86 ABI seems to require that leading underscores are added to symbol
934 // names, so we need an extra underscore on x86. There's also a leading
935 // '\x01' here which disables LLVM's symbol mangling (e.g., no extra
936 // underscores added in front).
937 let prefix = if cgcx.target_arch == "x86" { "\x01__imp__" } else { "\x01__imp_" };
940 let i8p_ty = Type::i8p_llcx(llcx);
941 let globals = base::iter_globals(llmod)
943 llvm::LLVMRustGetLinkage(val) == llvm::Linkage::ExternalLinkage
944 && llvm::LLVMIsDeclaration(val) == 0
947 // Exclude some symbols that we know are not Rust symbols.
948 let name = llvm::get_value_name(val);
949 if ignored(name) { None } else { Some((val, name)) }
951 .map(move |(val, name)| {
952 let mut imp_name = prefix.as_bytes().to_vec();
953 imp_name.extend(name);
954 let imp_name = CString::new(imp_name).unwrap();
957 .collect::<Vec<_>>();
959 for (imp_name, val) in globals {
960 let imp = llvm::LLVMAddGlobal(llmod, i8p_ty, imp_name.as_ptr().cast());
961 llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty));
962 llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage);
966 // Use this function to exclude certain symbols from `__imp` generation.
967 fn ignored(symbol_name: &[u8]) -> bool {
968 // These are symbols generated by LLVM's profiling instrumentation
969 symbol_name.starts_with(b"__llvm_profile_")