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 // If find_features is true this won't access `sess.crate_types` by assuming
115 // that `is_pie_binary` is false. When we discover LLVM target features
116 // `sess.crate_types` is uninitialized so we cannot access it.
117 pub fn target_machine_factory(
119 optlvl: config::OptLevel,
121 ) -> Arc<dyn Fn() -> Result<&'static mut llvm::TargetMachine, String> + Send + Sync> {
122 let reloc_model = get_reloc_model(sess);
124 let (opt_level, _) = to_llvm_opt_settings(optlvl);
125 let use_softfp = sess.opts.cg.soft_float;
127 let ffunction_sections = sess.target.target.options.function_sections;
128 let fdata_sections = ffunction_sections;
131 sess.opts.cg.code_model.as_ref().or(sess.target.target.options.code_model.as_ref());
133 let code_model = match code_model_arg {
134 Some(s) => match CODE_GEN_MODEL_ARGS.iter().find(|arg| arg.0 == s) {
137 sess.err(&format!("{:?} is not a valid code model", code_model_arg));
138 sess.abort_if_errors();
142 None => llvm::CodeModel::None,
145 let features = attributes::llvm_target_features(sess).collect::<Vec<_>>();
146 let mut singlethread = sess.target.target.options.singlethread;
148 // On the wasm target once the `atomics` feature is enabled that means that
149 // we're no longer single-threaded, or otherwise we don't want LLVM to
150 // lower atomic operations to single-threaded operations.
152 && sess.target.target.llvm_target.contains("wasm32")
153 && features.iter().any(|s| *s == "+atomics")
155 singlethread = false;
158 let triple = SmallCStr::new(&sess.target.target.llvm_target);
159 let cpu = SmallCStr::new(llvm_util::target_cpu(sess));
160 let features = features.join(",");
161 let features = CString::new(features).unwrap();
162 let abi = SmallCStr::new(&sess.target.target.options.llvm_abiname);
163 let is_pie_binary = !find_features && is_pie_binary(sess);
164 let trap_unreachable = sess.target.target.options.trap_unreachable;
165 let emit_stack_size_section = sess.opts.debugging_opts.emit_stack_sizes;
167 let asm_comments = sess.asm_comments();
168 let relax_elf_relocations = sess.target.target.options.relax_elf_relocations;
171 llvm::LLVMRustCreateTargetMachine(
186 emit_stack_size_section,
187 relax_elf_relocations,
192 format!("Could not create LLVM TargetMachine for triple: {}", triple.to_str().unwrap())
197 pub(crate) fn save_temp_bitcode(
198 cgcx: &CodegenContext<LlvmCodegenBackend>,
199 module: &ModuleCodegen<ModuleLlvm>,
202 if !cgcx.save_temps {
206 let ext = format!("{}.bc", name);
207 let cgu = Some(&module.name[..]);
208 let path = cgcx.output_filenames.temp_path_ext(&ext, cgu);
209 let cstr = path_to_c_string(&path);
210 let llmod = module.module_llvm.llmod();
211 llvm::LLVMWriteBitcodeToFile(llmod, cstr.as_ptr());
215 pub struct DiagnosticHandlers<'a> {
216 data: *mut (&'a CodegenContext<LlvmCodegenBackend>, &'a Handler),
217 llcx: &'a llvm::Context,
220 impl<'a> DiagnosticHandlers<'a> {
222 cgcx: &'a CodegenContext<LlvmCodegenBackend>,
223 handler: &'a Handler,
224 llcx: &'a llvm::Context,
226 let data = Box::into_raw(Box::new((cgcx, handler)));
228 llvm::LLVMRustSetInlineAsmDiagnosticHandler(llcx, inline_asm_handler, data.cast());
229 llvm::LLVMContextSetDiagnosticHandler(llcx, diagnostic_handler, data.cast());
231 DiagnosticHandlers { data, llcx }
235 impl<'a> Drop for DiagnosticHandlers<'a> {
237 use std::ptr::null_mut;
239 llvm::LLVMRustSetInlineAsmDiagnosticHandler(self.llcx, inline_asm_handler, null_mut());
240 llvm::LLVMContextSetDiagnosticHandler(self.llcx, diagnostic_handler, null_mut());
241 drop(Box::from_raw(self.data));
246 unsafe extern "C" fn report_inline_asm(
247 cgcx: &CodegenContext<LlvmCodegenBackend>,
251 cgcx.diag_emitter.inline_asm_error(cookie as u32, msg.to_owned());
254 unsafe extern "C" fn inline_asm_handler(diag: &SMDiagnostic, user: *const c_void, cookie: c_uint) {
258 let (cgcx, _) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
260 let msg = llvm::build_string(|s| llvm::LLVMRustWriteSMDiagnosticToString(diag, s))
261 .expect("non-UTF8 SMDiagnostic");
263 report_inline_asm(cgcx, &msg, cookie);
266 unsafe extern "C" fn diagnostic_handler(info: &DiagnosticInfo, user: *mut c_void) {
270 let (cgcx, diag_handler) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
272 match llvm::diagnostic::Diagnostic::unpack(info) {
273 llvm::diagnostic::InlineAsm(inline) => {
274 report_inline_asm(cgcx, &llvm::twine_to_string(inline.message), inline.cookie);
277 llvm::diagnostic::Optimization(opt) => {
278 let enabled = match cgcx.remark {
280 Passes::Some(ref v) => v.iter().any(|s| *s == opt.pass_name),
284 diag_handler.note_without_error(&format!(
285 "optimization {} for {} at {}:{}:{}: {}",
295 llvm::diagnostic::PGO(diagnostic_ref) | llvm::diagnostic::Linker(diagnostic_ref) => {
296 let msg = llvm::build_string(|s| {
297 llvm::LLVMRustWriteDiagnosticInfoToString(diagnostic_ref, s)
299 .expect("non-UTF8 diagnostic");
300 diag_handler.warn(&msg);
302 llvm::diagnostic::UnknownDiagnostic(..) => {}
306 // Unsafe due to LLVM calls.
307 pub(crate) unsafe fn optimize(
308 cgcx: &CodegenContext<LlvmCodegenBackend>,
309 diag_handler: &Handler,
310 module: &ModuleCodegen<ModuleLlvm>,
311 config: &ModuleConfig,
312 ) -> Result<(), FatalError> {
313 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_optimize", &module.name[..]);
315 let llmod = module.module_llvm.llmod();
316 let llcx = &*module.module_llvm.llcx;
317 let tm = &*module.module_llvm.tm;
318 let _handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
320 let module_name = module.name.clone();
321 let module_name = Some(&module_name[..]);
323 if config.emit_no_opt_bc {
324 let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
325 let out = path_to_c_string(&out);
326 llvm::LLVMWriteBitcodeToFile(llmod, out.as_ptr());
329 if let Some(opt_level) = config.opt_level {
330 // Create the two optimizing pass managers. These mirror what clang
331 // does, and are by populated by LLVM's default PassManagerBuilder.
332 // Each manager has a different set of passes, but they also share
333 // some common passes.
334 let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
335 let mpm = llvm::LLVMCreatePassManager();
338 let find_pass = |pass_name: &str| {
339 let pass_name = SmallCStr::new(pass_name);
340 llvm::LLVMRustFindAndCreatePass(pass_name.as_ptr())
343 if config.verify_llvm_ir {
344 // Verification should run as the very first pass.
345 llvm::LLVMRustAddPass(fpm, find_pass("verify").unwrap());
348 let mut extra_passes = Vec::new();
349 let mut have_name_anon_globals_pass = false;
351 for pass_name in &config.passes {
352 if pass_name == "lint" {
353 // Linting should also be performed early, directly on the generated IR.
354 llvm::LLVMRustAddPass(fpm, find_pass("lint").unwrap());
358 if let Some(pass) = find_pass(pass_name) {
359 extra_passes.push(pass);
361 diag_handler.warn(&format!("unknown pass `{}`, ignoring", pass_name));
364 if pass_name == "name-anon-globals" {
365 have_name_anon_globals_pass = true;
369 add_sanitizer_passes(config, &mut extra_passes);
371 // Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
372 // to make sure we run LLVM's NameAnonGlobals pass when emitting bitcode; otherwise
373 // we'll get errors in LLVM.
374 let using_thin_buffers = config.bitcode_needed();
375 if !config.no_prepopulate_passes {
376 llvm::LLVMAddAnalysisPasses(tm, fpm);
377 llvm::LLVMAddAnalysisPasses(tm, mpm);
378 let opt_level = to_llvm_opt_settings(opt_level).0;
379 let prepare_for_thin_lto = cgcx.lto == Lto::Thin
380 || cgcx.lto == Lto::ThinLocal
381 || (cgcx.lto != Lto::Fat && cgcx.opts.cg.linker_plugin_lto.enabled());
382 with_llvm_pmb(llmod, &config, opt_level, prepare_for_thin_lto, &mut |b| {
383 llvm::LLVMRustAddLastExtensionPasses(
385 extra_passes.as_ptr(),
386 extra_passes.len() as size_t,
388 llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
389 llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
392 have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
393 if using_thin_buffers && !prepare_for_thin_lto {
394 llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
395 have_name_anon_globals_pass = true;
398 // If we don't use the standard pipeline, directly populate the MPM
399 // with the extra passes.
400 for pass in extra_passes {
401 llvm::LLVMRustAddPass(mpm, pass);
405 if using_thin_buffers && !have_name_anon_globals_pass {
406 // As described above, this will probably cause an error in LLVM
407 if config.no_prepopulate_passes {
409 "The current compilation is going to use thin LTO buffers \
410 without running LLVM's NameAnonGlobals pass. \
411 This will likely cause errors in LLVM. Consider adding \
412 -C passes=name-anon-globals to the compiler command line.",
416 "We are using thin LTO buffers without running the NameAnonGlobals pass. \
417 This will likely cause errors in LLVM and should never happen."
423 diag_handler.abort_if_errors();
425 // Finally, run the actual optimization passes
427 let _timer = cgcx.prof.extra_verbose_generic_activity(
428 "LLVM_module_optimize_function_passes",
431 llvm::LLVMRustRunFunctionPassManager(fpm, llmod);
434 let _timer = cgcx.prof.extra_verbose_generic_activity(
435 "LLVM_module_optimize_module_passes",
438 llvm::LLVMRunPassManager(mpm, llmod);
441 // Deallocate managers that we're now done with
442 llvm::LLVMDisposePassManager(fpm);
443 llvm::LLVMDisposePassManager(mpm);
448 unsafe fn add_sanitizer_passes(config: &ModuleConfig, passes: &mut Vec<&'static mut llvm::Pass>) {
449 let sanitizer = match &config.sanitizer {
454 let recover = config.sanitizer_recover.contains(sanitizer);
456 Sanitizer::Address => {
457 passes.push(llvm::LLVMRustCreateAddressSanitizerFunctionPass(recover));
458 passes.push(llvm::LLVMRustCreateModuleAddressSanitizerPass(recover));
460 Sanitizer::Memory => {
461 let track_origins = config.sanitizer_memory_track_origins as c_int;
462 passes.push(llvm::LLVMRustCreateMemorySanitizerPass(track_origins, recover));
464 Sanitizer::Thread => {
465 passes.push(llvm::LLVMRustCreateThreadSanitizerPass());
467 Sanitizer::Leak => {}
471 pub(crate) unsafe fn codegen(
472 cgcx: &CodegenContext<LlvmCodegenBackend>,
473 diag_handler: &Handler,
474 module: ModuleCodegen<ModuleLlvm>,
475 config: &ModuleConfig,
476 ) -> Result<CompiledModule, FatalError> {
477 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_codegen", &module.name[..]);
479 let llmod = module.module_llvm.llmod();
480 let llcx = &*module.module_llvm.llcx;
481 let tm = &*module.module_llvm.tm;
482 let module_name = module.name.clone();
483 let module_name = Some(&module_name[..]);
484 let handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
486 if cgcx.msvc_imps_needed {
487 create_msvc_imps(cgcx, llcx, llmod);
490 // A codegen-specific pass manager is used to generate object
491 // files for an LLVM module.
493 // Apparently each of these pass managers is a one-shot kind of
494 // thing, so we create a new one for each type of output. The
495 // pass manager passed to the closure should be ensured to not
496 // escape the closure itself, and the manager should only be
498 unsafe fn with_codegen<'ll, F, R>(
499 tm: &'ll llvm::TargetMachine,
500 llmod: &'ll llvm::Module,
505 F: FnOnce(&'ll mut PassManager<'ll>) -> R,
507 let cpm = llvm::LLVMCreatePassManager();
508 llvm::LLVMAddAnalysisPasses(tm, cpm);
509 llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
513 // If we don't have the integrated assembler, then we need to emit asm
514 // from LLVM and use `gcc` to create the object file.
515 let asm_to_obj = config.emit_obj && config.no_integrated_as;
517 // Change what we write and cleanup based on whether obj files are
518 // just llvm bitcode. In that case write bitcode, and possibly
519 // delete the bitcode if it wasn't requested. Don't generate the
520 // machine code, instead copy the .o file from the .bc
521 let write_bc = config.emit_bc || config.obj_is_bitcode;
522 let rm_bc = !config.emit_bc && config.obj_is_bitcode;
523 let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm_to_obj;
524 let copy_bc_to_obj = config.emit_obj && config.obj_is_bitcode;
526 let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
527 let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
529 if write_bc || config.emit_bc_compressed || config.embed_bitcode {
532 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &module.name[..]);
533 let thin = ThinBuffer::new(llmod);
534 let data = thin.data();
537 let _timer = cgcx.prof.generic_activity_with_arg(
538 "LLVM_module_codegen_emit_bitcode",
541 if let Err(e) = fs::write(&bc_out, data) {
542 let msg = format!("failed to write bytecode to {}: {}", bc_out.display(), e);
543 diag_handler.err(&msg);
547 if config.embed_bitcode {
548 let _timer = cgcx.prof.generic_activity_with_arg(
549 "LLVM_module_codegen_embed_bitcode",
552 embed_bitcode(cgcx, llcx, llmod, Some(data));
555 if config.emit_bc_compressed {
556 let _timer = cgcx.prof.generic_activity_with_arg(
557 "LLVM_module_codegen_emit_compressed_bitcode",
560 let dst = bc_out.with_extension(RLIB_BYTECODE_EXTENSION);
561 let data = bytecode::encode(&module.name, data);
562 if let Err(e) = fs::write(&dst, data) {
563 let msg = format!("failed to write bytecode to {}: {}", dst.display(), e);
564 diag_handler.err(&msg);
567 } else if config.embed_bitcode_marker {
568 embed_bitcode(cgcx, llcx, llmod, None);
575 .generic_activity_with_arg("LLVM_module_codegen_emit_ir", &module.name[..]);
576 let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
577 let out_c = path_to_c_string(&out);
579 extern "C" fn demangle_callback(
580 input_ptr: *const c_char,
582 output_ptr: *mut c_char,
586 slice::from_raw_parts(input_ptr as *const u8, input_len as usize)
589 let input = match str::from_utf8(input) {
594 let output = unsafe {
595 slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
597 let mut cursor = io::Cursor::new(output);
599 let demangled = match rustc_demangle::try_demangle(input) {
604 if let Err(_) = write!(cursor, "{:#}", demangled) {
605 // Possible only if provided buffer is not big enough
609 cursor.position() as size_t
612 let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
613 result.into_result().map_err(|()| {
614 let msg = format!("failed to write LLVM IR to {}", out.display());
615 llvm_err(diag_handler, &msg)
619 if config.emit_asm || asm_to_obj {
622 .generic_activity_with_arg("LLVM_module_codegen_emit_asm", &module.name[..]);
623 let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
625 // We can't use the same module for asm and binary output, because that triggers
626 // various errors like invalid IR or broken binaries, so we might have to clone the
627 // module to produce the asm output
628 let llmod = if config.emit_obj { llvm::LLVMCloneModule(llmod) } else { llmod };
629 with_codegen(tm, llmod, config.no_builtins, |cpm| {
636 llvm::FileType::AssemblyFile,
644 .generic_activity_with_arg("LLVM_module_codegen_emit_obj", &module.name[..]);
645 with_codegen(tm, llmod, config.no_builtins, |cpm| {
652 llvm::FileType::ObjectFile,
655 } else if asm_to_obj {
658 .generic_activity_with_arg("LLVM_module_codegen_asm_to_obj", &module.name[..]);
659 let assembly = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
660 run_assembler(cgcx, diag_handler, &assembly, &obj_out);
662 if !config.emit_asm && !cgcx.save_temps {
663 drop(fs::remove_file(&assembly));
669 debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
670 if let Err(e) = link_or_copy(&bc_out, &obj_out) {
671 diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
676 debug!("removing_bitcode {:?}", bc_out);
677 if let Err(e) = fs::remove_file(&bc_out) {
678 diag_handler.err(&format!("failed to remove bitcode: {}", e));
684 Ok(module.into_compiled_module(
687 config.emit_bc_compressed,
688 &cgcx.output_filenames,
692 /// Embed the bitcode of an LLVM module in the LLVM module itself.
694 /// This is done primarily for iOS where it appears to be standard to compile C
695 /// code at least with `-fembed-bitcode` which creates two sections in the
698 /// * __LLVM,__bitcode
699 /// * __LLVM,__cmdline
701 /// It appears *both* of these sections are necessary to get the linker to
702 /// recognize what's going on. For us though we just always throw in an empty
705 /// Furthermore debug/O1 builds don't actually embed bitcode but rather just
706 /// embed an empty section.
708 /// Basically all of this is us attempting to follow in the footsteps of clang
709 /// on iOS. See #35968 for lots more info.
710 unsafe fn embed_bitcode(
711 cgcx: &CodegenContext<LlvmCodegenBackend>,
712 llcx: &llvm::Context,
713 llmod: &llvm::Module,
714 bitcode: Option<&[u8]>,
716 let llconst = common::bytes_in_context(llcx, bitcode.unwrap_or(&[]));
717 let llglobal = llvm::LLVMAddGlobal(
719 common::val_ty(llconst),
720 "rustc.embedded.module\0".as_ptr().cast(),
722 llvm::LLVMSetInitializer(llglobal, llconst);
724 let is_apple = cgcx.opts.target_triple.triple().contains("-ios")
725 || cgcx.opts.target_triple.triple().contains("-darwin");
727 let section = if is_apple { "__LLVM,__bitcode\0" } else { ".llvmbc\0" };
728 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
729 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
730 llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
732 let llconst = common::bytes_in_context(llcx, &[]);
733 let llglobal = llvm::LLVMAddGlobal(
735 common::val_ty(llconst),
736 "rustc.embedded.cmdline\0".as_ptr().cast(),
738 llvm::LLVMSetInitializer(llglobal, llconst);
739 let section = if is_apple { "__LLVM,__cmdline\0" } else { ".llvmcmd\0" };
740 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
741 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
744 pub unsafe fn with_llvm_pmb(
745 llmod: &llvm::Module,
746 config: &ModuleConfig,
747 opt_level: llvm::CodeGenOptLevel,
748 prepare_for_thin_lto: bool,
749 f: &mut dyn FnMut(&llvm::PassManagerBuilder),
753 // Create the PassManagerBuilder for LLVM. We configure it with
754 // reasonable defaults and prepare it to actually populate the pass
756 let builder = llvm::LLVMPassManagerBuilderCreate();
758 config.opt_size.map(|x| to_llvm_opt_settings(x).1).unwrap_or(llvm::CodeGenOptSizeNone);
759 let inline_threshold = config.inline_threshold;
761 let pgo_gen_path = match config.pgo_gen {
762 SwitchWithOptPath::Enabled(ref opt_dir_path) => {
763 let path = if let Some(dir_path) = opt_dir_path {
764 dir_path.join("default_%m.profraw")
766 PathBuf::from("default_%m.profraw")
769 Some(CString::new(format!("{}", path.display())).unwrap())
771 SwitchWithOptPath::Disabled => None,
774 let pgo_use_path = config
777 .map(|path_buf| CString::new(path_buf.to_string_lossy().as_bytes()).unwrap());
779 llvm::LLVMRustConfigurePassManagerBuilder(
782 config.merge_functions,
783 config.vectorize_slp,
784 config.vectorize_loop,
785 prepare_for_thin_lto,
786 pgo_gen_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
787 pgo_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
790 llvm::LLVMPassManagerBuilderSetSizeLevel(builder, opt_size as u32);
792 if opt_size != llvm::CodeGenOptSizeNone {
793 llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
796 llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
798 // Here we match what clang does (kinda). For O0 we only inline
799 // always-inline functions (but don't add lifetime intrinsics), at O1 we
800 // inline with lifetime intrinsics, and O2+ we add an inliner with a
801 // thresholds copied from clang.
802 match (opt_level, opt_size, inline_threshold) {
804 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, t as u32);
806 (llvm::CodeGenOptLevel::Aggressive, ..) => {
807 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275);
809 (_, llvm::CodeGenOptSizeDefault, _) => {
810 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 75);
812 (_, llvm::CodeGenOptSizeAggressive, _) => {
813 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 25);
815 (llvm::CodeGenOptLevel::None, ..) => {
816 llvm::LLVMRustAddAlwaysInlinePass(builder, false);
818 (llvm::CodeGenOptLevel::Less, ..) => {
819 llvm::LLVMRustAddAlwaysInlinePass(builder, true);
821 (llvm::CodeGenOptLevel::Default, ..) => {
822 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225);
824 (llvm::CodeGenOptLevel::Other, ..) => bug!("CodeGenOptLevel::Other selected"),
828 llvm::LLVMPassManagerBuilderDispose(builder);
831 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
832 // This is required to satisfy `dllimport` references to static data in .rlibs
833 // when using MSVC linker. We do this only for data, as linker can fix up
834 // code references on its own.
835 // See #26591, #27438
837 cgcx: &CodegenContext<LlvmCodegenBackend>,
838 llcx: &llvm::Context,
839 llmod: &llvm::Module,
841 if !cgcx.msvc_imps_needed {
844 // The x86 ABI seems to require that leading underscores are added to symbol
845 // names, so we need an extra underscore on x86. There's also a leading
846 // '\x01' here which disables LLVM's symbol mangling (e.g., no extra
847 // underscores added in front).
848 let prefix = if cgcx.target_arch == "x86" { "\x01__imp__" } else { "\x01__imp_" };
851 let i8p_ty = Type::i8p_llcx(llcx);
852 let globals = base::iter_globals(llmod)
854 llvm::LLVMRustGetLinkage(val) == llvm::Linkage::ExternalLinkage
855 && llvm::LLVMIsDeclaration(val) == 0
858 // Exclude some symbols that we know are not Rust symbols.
859 let name = llvm::get_value_name(val);
860 if ignored(name) { None } else { Some((val, name)) }
862 .map(move |(val, name)| {
863 let mut imp_name = prefix.as_bytes().to_vec();
864 imp_name.extend(name);
865 let imp_name = CString::new(imp_name).unwrap();
868 .collect::<Vec<_>>();
870 for (imp_name, val) in globals {
871 let imp = llvm::LLVMAddGlobal(llmod, i8p_ty, imp_name.as_ptr().cast());
872 llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty));
873 llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage);
877 // Use this function to exclude certain symbols from `__imp` generation.
878 fn ignored(symbol_name: &[u8]) -> bool {
879 // These are symbols generated by LLVM's profiling instrumentation
880 symbol_name.starts_with(b"__llvm_profile_")