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9fa01778 1use crate::attributes;
48663c56 2use crate::back::bytecode;
9fa01778 3use crate::back::lto::ThinBuffer;
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4use crate::back::profiling::{
5 selfprofile_after_pass_callback, selfprofile_before_pass_callback, LlvmSelfProfiler,
6};
9fa01778 7use crate::base;
dfeec247 8use crate::common;
9fa01778 9use crate::consts;
dfeec247 10use crate::context::{get_reloc_model, is_pie_binary};
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11use crate::llvm::{self, DiagnosticInfo, PassManager, SMDiagnostic};
12use crate::llvm_util;
9fa01778 13use crate::type_::Type;
9fa01778 14use crate::LlvmCodegenBackend;
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15use crate::ModuleLlvm;
16use log::debug;
ba9703b0 17use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig};
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18use rustc_codegen_ssa::traits::*;
19use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, RLIB_BYTECODE_EXTENSION};
b7449926 20use rustc_data_structures::small_c_str::SmallCStr;
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21use rustc_errors::{FatalError, Handler};
22use rustc_fs_util::{link_or_copy, path_to_c_string};
23use rustc_hir::def_id::LOCAL_CRATE;
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24use rustc_middle::bug;
25use rustc_middle::ty::TyCtxt;
26use rustc_session::config::{self, Lto, OutputType, Passes, Sanitizer, SwitchWithOptPath};
27use rustc_session::Session;
1a4d82fc 28
dfeec247 29use libc::{c_char, c_int, c_uint, c_void, size_t};
60c5eb7d 30use std::ffi::CString;
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31use std::fs;
32use std::io::{self, Write};
48663c56 33use std::path::{Path, PathBuf};
dfeec247 34use std::slice;
1a4d82fc 35use std::str;
3b2f2976 36use std::sync::Arc;
1a4d82fc 37
dfeec247 38pub const RELOC_MODEL_ARGS: [(&str, llvm::RelocMode); 7] = [
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39 ("pic", llvm::RelocMode::PIC),
40 ("static", llvm::RelocMode::Static),
41 ("default", llvm::RelocMode::Default),
42 ("dynamic-no-pic", llvm::RelocMode::DynamicNoPic),
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43 ("ropi", llvm::RelocMode::ROPI),
44 ("rwpi", llvm::RelocMode::RWPI),
45 ("ropi-rwpi", llvm::RelocMode::ROPI_RWPI),
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46];
47
2c00a5a8 48pub const CODE_GEN_MODEL_ARGS: &[(&str, llvm::CodeModel)] = &[
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49 ("small", llvm::CodeModel::Small),
50 ("kernel", llvm::CodeModel::Kernel),
51 ("medium", llvm::CodeModel::Medium),
52 ("large", llvm::CodeModel::Large),
53];
54
dfeec247 55pub const TLS_MODEL_ARGS: [(&str, llvm::ThreadLocalMode); 4] = [
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56 ("global-dynamic", llvm::ThreadLocalMode::GeneralDynamic),
57 ("local-dynamic", llvm::ThreadLocalMode::LocalDynamic),
58 ("initial-exec", llvm::ThreadLocalMode::InitialExec),
59 ("local-exec", llvm::ThreadLocalMode::LocalExec),
60];
61
60c5eb7d 62pub fn llvm_err(handler: &rustc_errors::Handler, msg: &str) -> FatalError {
7453a54e 63 match llvm::last_error() {
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64 Some(err) => handler.fatal(&format!("{}: {}", msg, err)),
65 None => handler.fatal(&msg),
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66 }
67}
68
69pub fn write_output_file(
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70 handler: &rustc_errors::Handler,
71 target: &'ll llvm::TargetMachine,
72 pm: &llvm::PassManager<'ll>,
73 m: &'ll llvm::Module,
74 output: &Path,
75 file_type: llvm::FileType,
76) -> Result<(), FatalError> {
1a4d82fc 77 unsafe {
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78 let output_c = path_to_c_string(output);
79 let result = llvm::LLVMRustWriteOutputFile(target, pm, m, output_c.as_ptr(), file_type);
532ac7d7 80 result.into_result().map_err(|()| {
041b39d2 81 let msg = format!("could not write output to {}", output.display());
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82 llvm_err(handler, &msg)
83 })
1a4d82fc 84 }
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85}
86
9fa01778 87pub fn create_informational_target_machine(
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88 sess: &Session,
89 find_features: bool,
90) -> &'static mut llvm::TargetMachine {
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91 target_machine_factory(sess, config::OptLevel::No, find_features)()
92 .unwrap_or_else(|err| llvm_err(sess.diagnostic(), &err).raise())
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93}
94
532ac7d7 95pub fn create_target_machine(
dc9dc135 96 tcx: TyCtxt<'_>,
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97 find_features: bool,
98) -> &'static mut llvm::TargetMachine {
99 target_machine_factory(&tcx.sess, tcx.backend_optimization_level(LOCAL_CRATE), find_features)()
dfeec247 100 .unwrap_or_else(|err| llvm_err(tcx.sess.diagnostic(), &err).raise())
532ac7d7 101}
9fa01778 102
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103pub fn to_llvm_opt_settings(
104 cfg: config::OptLevel,
105) -> (llvm::CodeGenOptLevel, llvm::CodeGenOptSize) {
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106 use self::config::OptLevel::*;
107 match cfg {
108 No => (llvm::CodeGenOptLevel::None, llvm::CodeGenOptSizeNone),
109 Less => (llvm::CodeGenOptLevel::Less, llvm::CodeGenOptSizeNone),
110 Default => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeNone),
111 Aggressive => (llvm::CodeGenOptLevel::Aggressive, llvm::CodeGenOptSizeNone),
112 Size => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeDefault),
113 SizeMin => (llvm::CodeGenOptLevel::Default, llvm::CodeGenOptSizeAggressive),
114 }
115}
116
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117fn to_pass_builder_opt_level(cfg: config::OptLevel) -> llvm::PassBuilderOptLevel {
118 use config::OptLevel::*;
119 match cfg {
120 No => llvm::PassBuilderOptLevel::O0,
121 Less => llvm::PassBuilderOptLevel::O1,
122 Default => llvm::PassBuilderOptLevel::O2,
123 Aggressive => llvm::PassBuilderOptLevel::O3,
124 Size => llvm::PassBuilderOptLevel::Os,
125 SizeMin => llvm::PassBuilderOptLevel::Oz,
126 }
127}
128
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129// If find_features is true this won't access `sess.crate_types` by assuming
130// that `is_pie_binary` is false. When we discover LLVM target features
131// `sess.crate_types` is uninitialized so we cannot access it.
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132pub fn target_machine_factory(
133 sess: &Session,
134 optlvl: config::OptLevel,
135 find_features: bool,
136) -> Arc<dyn Fn() -> Result<&'static mut llvm::TargetMachine, String> + Send + Sync> {
5bcae85e 137 let reloc_model = get_reloc_model(sess);
1a4d82fc 138
9fa01778 139 let (opt_level, _) = to_llvm_opt_settings(optlvl);
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140 let use_softfp = sess.opts.cg.soft_float;
141
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142 let ffunction_sections = sess.target.target.options.function_sections;
143 let fdata_sections = ffunction_sections;
144
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145 let code_model_arg =
146 sess.opts.cg.code_model.as_ref().or(sess.target.target.options.code_model.as_ref());
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147
148 let code_model = match code_model_arg {
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149 Some(s) => match CODE_GEN_MODEL_ARGS.iter().find(|arg| arg.0 == s) {
150 Some(x) => x.1,
151 _ => {
152 sess.err(&format!("{:?} is not a valid code model", code_model_arg));
153 sess.abort_if_errors();
154 bug!();
2c00a5a8 155 }
dfeec247 156 },
2c00a5a8 157 None => llvm::CodeModel::None,
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158 };
159
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160 let features = attributes::llvm_target_features(sess).collect::<Vec<_>>();
161 let mut singlethread = sess.target.target.options.singlethread;
abe05a73 162
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163 // On the wasm target once the `atomics` feature is enabled that means that
164 // we're no longer single-threaded, or otherwise we don't want LLVM to
165 // lower atomic operations to single-threaded operations.
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166 if singlethread
167 && sess.target.target.llvm_target.contains("wasm32")
168 && features.iter().any(|s| *s == "+atomics")
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169 {
170 singlethread = false;
171 }
1a4d82fc 172
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173 let triple = SmallCStr::new(&sess.target.target.llvm_target);
174 let cpu = SmallCStr::new(llvm_util::target_cpu(sess));
175 let features = features.join(",");
83c7162d 176 let features = CString::new(features).unwrap();
60c5eb7d 177 let abi = SmallCStr::new(&sess.target.target.options.llvm_abiname);
83c7162d 178 let is_pie_binary = !find_features && is_pie_binary(sess);
abe05a73 179 let trap_unreachable = sess.target.target.options.trap_unreachable;
0bf4aa26 180 let emit_stack_size_section = sess.opts.debugging_opts.emit_stack_sizes;
ea8adc8c 181
b7449926 182 let asm_comments = sess.asm_comments();
60c5eb7d 183 let relax_elf_relocations = sess.target.target.options.relax_elf_relocations;
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184 Arc::new(move || {
185 let tm = unsafe {
186 llvm::LLVMRustCreateTargetMachine(
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187 triple.as_ptr(),
188 cpu.as_ptr(),
189 features.as_ptr(),
190 abi.as_ptr(),
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191 code_model,
192 reloc_model,
193 opt_level,
194 use_softfp,
195 is_pie_binary,
196 ffunction_sections,
197 fdata_sections,
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198 trap_unreachable,
199 singlethread,
b7449926 200 asm_comments,
0bf4aa26 201 emit_stack_size_section,
60c5eb7d 202 relax_elf_relocations,
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203 )
204 };
1a4d82fc 205
b7449926 206 tm.ok_or_else(|| {
dfeec247 207 format!("Could not create LLVM TargetMachine for triple: {}", triple.to_str().unwrap())
b7449926 208 })
ea8adc8c 209 })
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210}
211
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212pub(crate) fn save_temp_bitcode(
213 cgcx: &CodegenContext<LlvmCodegenBackend>,
214 module: &ModuleCodegen<ModuleLlvm>,
dfeec247 215 name: &str,
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216) {
217 if !cgcx.save_temps {
dfeec247 218 return;
ea8adc8c 219 }
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220 unsafe {
221 let ext = format!("{}.bc", name);
222 let cgu = Some(&module.name[..]);
223 let path = cgcx.output_filenames.temp_path_ext(&ext, cgu);
224 let cstr = path_to_c_string(&path);
225 let llmod = module.module_llvm.llmod();
226 llvm::LLVMWriteBitcodeToFile(llmod, cstr.as_ptr());
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227 }
228}
229
b7449926 230pub struct DiagnosticHandlers<'a> {
a1dfa0c6 231 data: *mut (&'a CodegenContext<LlvmCodegenBackend>, &'a Handler),
b7449926 232 llcx: &'a llvm::Context,
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233}
234
235impl<'a> DiagnosticHandlers<'a> {
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236 pub fn new(
237 cgcx: &'a CodegenContext<LlvmCodegenBackend>,
238 handler: &'a Handler,
239 llcx: &'a llvm::Context,
240 ) -> Self {
8faf50e0 241 let data = Box::into_raw(Box::new((cgcx, handler)));
ea8adc8c 242 unsafe {
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243 llvm::LLVMRustSetInlineAsmDiagnosticHandler(llcx, inline_asm_handler, data.cast());
244 llvm::LLVMContextSetDiagnosticHandler(llcx, diagnostic_handler, data.cast());
ea8adc8c 245 }
8faf50e0 246 DiagnosticHandlers { data, llcx }
ea8adc8c 247 }
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248}
249
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250impl<'a> Drop for DiagnosticHandlers<'a> {
251 fn drop(&mut self) {
8faf50e0 252 use std::ptr::null_mut;
ea8adc8c 253 unsafe {
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254 llvm::LLVMRustSetInlineAsmDiagnosticHandler(self.llcx, inline_asm_handler, null_mut());
255 llvm::LLVMContextSetDiagnosticHandler(self.llcx, diagnostic_handler, null_mut());
256 drop(Box::from_raw(self.data));
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257 }
258 }
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259}
260
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261unsafe extern "C" fn report_inline_asm(
262 cgcx: &CodegenContext<LlvmCodegenBackend>,
263 msg: &str,
264 cookie: c_uint,
265) {
a1dfa0c6 266 cgcx.diag_emitter.inline_asm_error(cookie as u32, msg.to_owned());
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267}
268
dfeec247 269unsafe extern "C" fn inline_asm_handler(diag: &SMDiagnostic, user: *const c_void, cookie: c_uint) {
ea8adc8c 270 if user.is_null() {
dfeec247 271 return;
ea8adc8c 272 }
a1dfa0c6 273 let (cgcx, _) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
85aaf69f 274
5bcae85e 275 let msg = llvm::build_string(|s| llvm::LLVMRustWriteSMDiagnosticToString(diag, s))
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276 .expect("non-UTF8 SMDiagnostic");
277
cc61c64b 278 report_inline_asm(cgcx, &msg, cookie);
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279}
280
b7449926 281unsafe extern "C" fn diagnostic_handler(info: &DiagnosticInfo, user: *mut c_void) {
ea8adc8c 282 if user.is_null() {
dfeec247 283 return;
ea8adc8c 284 }
a1dfa0c6 285 let (cgcx, diag_handler) = *(user as *const (&CodegenContext<LlvmCodegenBackend>, &Handler));
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286
287 match llvm::diagnostic::Diagnostic::unpack(info) {
85aaf69f 288 llvm::diagnostic::InlineAsm(inline) => {
dfeec247 289 report_inline_asm(cgcx, &llvm::twine_to_string(inline.message), inline.cookie);
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290 }
291
1a4d82fc 292 llvm::diagnostic::Optimization(opt) => {
1a4d82fc 293 let enabled = match cgcx.remark {
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294 Passes::All => true,
295 Passes::Some(ref v) => v.iter().any(|s| *s == opt.pass_name),
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296 };
297
298 if enabled {
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299 diag_handler.note_without_error(&format!(
300 "optimization {} for {} at {}:{}:{}: {}",
301 opt.kind.describe(),
302 opt.pass_name,
303 opt.filename,
304 opt.line,
305 opt.column,
306 opt.message
307 ));
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308 }
309 }
dfeec247 310 llvm::diagnostic::PGO(diagnostic_ref) | llvm::diagnostic::Linker(diagnostic_ref) => {
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311 let msg = llvm::build_string(|s| {
312 llvm::LLVMRustWriteDiagnosticInfoToString(diagnostic_ref, s)
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313 })
314 .expect("non-UTF8 diagnostic");
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315 diag_handler.warn(&msg);
316 }
dfeec247 317 llvm::diagnostic::UnknownDiagnostic(..) => {}
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318 }
319}
320
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321fn get_pgo_gen_path(config: &ModuleConfig) -> Option<CString> {
322 match config.pgo_gen {
323 SwitchWithOptPath::Enabled(ref opt_dir_path) => {
324 let path = if let Some(dir_path) = opt_dir_path {
325 dir_path.join("default_%m.profraw")
326 } else {
327 PathBuf::from("default_%m.profraw")
328 };
329
330 Some(CString::new(format!("{}", path.display())).unwrap())
331 }
332 SwitchWithOptPath::Disabled => None,
333 }
334}
335
336fn get_pgo_use_path(config: &ModuleConfig) -> Option<CString> {
337 config
338 .pgo_use
339 .as_ref()
340 .map(|path_buf| CString::new(path_buf.to_string_lossy().as_bytes()).unwrap())
341}
342
343pub(crate) fn should_use_new_llvm_pass_manager(config: &ModuleConfig) -> bool {
344 // We only support the new pass manager starting with LLVM 9.
345 if llvm_util::get_major_version() < 9 {
346 return false;
347 }
348
349 // The new pass manager is disabled by default.
ba9703b0 350 config.new_llvm_pass_manager
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351}
352
353pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
354 cgcx: &CodegenContext<LlvmCodegenBackend>,
355 module: &ModuleCodegen<ModuleLlvm>,
356 config: &ModuleConfig,
357 opt_level: config::OptLevel,
358 opt_stage: llvm::OptStage,
359) {
360 let unroll_loops =
361 opt_level != config::OptLevel::Size && opt_level != config::OptLevel::SizeMin;
362 let using_thin_buffers = opt_stage == llvm::OptStage::PreLinkThinLTO || config.bitcode_needed();
363 let pgo_gen_path = get_pgo_gen_path(config);
364 let pgo_use_path = get_pgo_use_path(config);
365 let is_lto = opt_stage == llvm::OptStage::ThinLTO || opt_stage == llvm::OptStage::FatLTO;
366 // Sanitizer instrumentation is only inserted during the pre-link optimization stage.
367 let sanitizer_options = if !is_lto {
368 config.sanitizer.as_ref().map(|s| llvm::SanitizerOptions {
369 sanitize_memory: *s == Sanitizer::Memory,
370 sanitize_thread: *s == Sanitizer::Thread,
371 sanitize_address: *s == Sanitizer::Address,
372 sanitize_recover: config.sanitizer_recover.contains(s),
373 sanitize_memory_track_origins: config.sanitizer_memory_track_origins as c_int,
374 })
375 } else {
376 None
377 };
378
379 let llvm_selfprofiler = if cgcx.prof.llvm_recording_enabled() {
380 let mut llvm_profiler = LlvmSelfProfiler::new(cgcx.prof.get_self_profiler().unwrap());
381 &mut llvm_profiler as *mut _ as *mut c_void
382 } else {
383 std::ptr::null_mut()
384 };
385
386 // FIXME: NewPM doesn't provide a facility to pass custom InlineParams.
387 // We would have to add upstream support for this first, before we can support
388 // config.inline_threshold and our more aggressive default thresholds.
389 // FIXME: NewPM uses an different and more explicit way to textually represent
390 // pass pipelines. It would probably make sense to expose this, but it would
391 // require a different format than the current -C passes.
392 llvm::LLVMRustOptimizeWithNewPassManager(
393 module.module_llvm.llmod(),
394 &*module.module_llvm.tm,
395 to_pass_builder_opt_level(opt_level),
396 opt_stage,
397 config.no_prepopulate_passes,
398 config.verify_llvm_ir,
399 using_thin_buffers,
400 config.merge_functions,
401 unroll_loops,
402 config.vectorize_slp,
403 config.vectorize_loop,
404 config.no_builtins,
405 sanitizer_options.as_ref(),
406 pgo_gen_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
407 pgo_use_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
408 llvm_selfprofiler,
409 selfprofile_before_pass_callback,
410 selfprofile_after_pass_callback,
411 );
412}
413
1a4d82fc 414// Unsafe due to LLVM calls.
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415pub(crate) unsafe fn optimize(
416 cgcx: &CodegenContext<LlvmCodegenBackend>,
417 diag_handler: &Handler,
418 module: &ModuleCodegen<ModuleLlvm>,
419 config: &ModuleConfig,
420) -> Result<(), FatalError> {
74b04a01 421 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_optimize", &module.name[..]);
e74abb32 422
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423 let llmod = module.module_llvm.llmod();
424 let llcx = &*module.module_llvm.llcx;
425 let tm = &*module.module_llvm.tm;
ea8adc8c 426 let _handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
1a4d82fc 427
94b46f34 428 let module_name = module.name.clone();
3b2f2976 429 let module_name = Some(&module_name[..]);
5bcae85e 430
1a4d82fc 431 if config.emit_no_opt_bc {
ea8adc8c 432 let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
a1dfa0c6 433 let out = path_to_c_string(&out);
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434 llvm::LLVMWriteBitcodeToFile(llmod, out.as_ptr());
435 }
436
60c5eb7d 437 if let Some(opt_level) = config.opt_level {
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438 if should_use_new_llvm_pass_manager(config) {
439 let opt_stage = match cgcx.lto {
440 Lto::Fat => llvm::OptStage::PreLinkFatLTO,
441 Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO,
442 _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO,
443 _ => llvm::OptStage::PreLinkNoLTO,
444 };
445 optimize_with_new_llvm_pass_manager(cgcx, module, config, opt_level, opt_stage);
446 return Ok(());
447 }
448
449 if cgcx.prof.llvm_recording_enabled() {
450 diag_handler
451 .warn("`-Z self-profile-events = llvm` requires `-Z new-llvm-pass-manager`");
452 }
453
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454 // Create the two optimizing pass managers. These mirror what clang
455 // does, and are by populated by LLVM's default PassManagerBuilder.
456 // Each manager has a different set of passes, but they also share
457 // some common passes.
458 let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
459 let mpm = llvm::LLVMCreatePassManager();
460
b7449926 461 {
416331ca 462 let find_pass = |pass_name: &str| {
b7449926 463 let pass_name = SmallCStr::new(pass_name);
416331ca 464 llvm::LLVMRustFindAndCreatePass(pass_name.as_ptr())
7453a54e 465 };
1a4d82fc 466
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467 if config.verify_llvm_ir {
468 // Verification should run as the very first pass.
469 llvm::LLVMRustAddPass(fpm, find_pass("verify").unwrap());
470 }
471
472 let mut extra_passes = Vec::new();
473 let mut have_name_anon_globals_pass = false;
474
475 for pass_name in &config.passes {
476 if pass_name == "lint" {
477 // Linting should also be performed early, directly on the generated IR.
478 llvm::LLVMRustAddPass(fpm, find_pass("lint").unwrap());
479 continue;
480 }
481
482 if let Some(pass) = find_pass(pass_name) {
483 extra_passes.push(pass);
484 } else {
485 diag_handler.warn(&format!("unknown pass `{}`, ignoring", pass_name));
486 }
487
488 if pass_name == "name-anon-globals" {
489 have_name_anon_globals_pass = true;
490 }
491 }
492
60c5eb7d 493 add_sanitizer_passes(config, &mut extra_passes);
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494
495 // Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
496 // to make sure we run LLVM's NameAnonGlobals pass when emitting bitcode; otherwise
497 // we'll get errors in LLVM.
a1dfa0c6 498 let using_thin_buffers = config.bitcode_needed();
b7449926 499 if !config.no_prepopulate_passes {
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500 llvm::LLVMAddAnalysisPasses(tm, fpm);
501 llvm::LLVMAddAnalysisPasses(tm, mpm);
502 let opt_level = to_llvm_opt_settings(opt_level).0;
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503 let prepare_for_thin_lto = cgcx.lto == Lto::Thin
504 || cgcx.lto == Lto::ThinLocal
505 || (cgcx.lto != Lto::Fat && cgcx.opts.cg.linker_plugin_lto.enabled());
a1dfa0c6 506 with_llvm_pmb(llmod, &config, opt_level, prepare_for_thin_lto, &mut |b| {
416331ca 507 llvm::LLVMRustAddLastExtensionPasses(
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508 b,
509 extra_passes.as_ptr(),
510 extra_passes.len() as size_t,
511 );
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512 llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
513 llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
514 });
515
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516 have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
517 if using_thin_buffers && !prepare_for_thin_lto {
416331ca 518 llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
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519 have_name_anon_globals_pass = true;
520 }
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521 } else {
522 // If we don't use the standard pipeline, directly populate the MPM
523 // with the extra passes.
524 for pass in extra_passes {
525 llvm::LLVMRustAddPass(mpm, pass);
b7449926 526 }
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527 }
528
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529 if using_thin_buffers && !have_name_anon_globals_pass {
530 // As described above, this will probably cause an error in LLVM
531 if config.no_prepopulate_passes {
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532 diag_handler.err(
533 "The current compilation is going to use thin LTO buffers \
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534 without running LLVM's NameAnonGlobals pass. \
535 This will likely cause errors in LLVM. Consider adding \
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536 -C passes=name-anon-globals to the compiler command line.",
537 );
b7449926 538 } else {
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539 bug!(
540 "We are using thin LTO buffers without running the NameAnonGlobals pass. \
541 This will likely cause errors in LLVM and should never happen."
542 );
b7449926 543 }
9346a6ac 544 }
c1a9b12d 545 }
9346a6ac 546
3b2f2976 547 diag_handler.abort_if_errors();
9346a6ac 548
c1a9b12d 549 // Finally, run the actual optimization passes
532ac7d7 550 {
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551 let _timer = cgcx.prof.extra_verbose_generic_activity(
552 "LLVM_module_optimize_function_passes",
553 &module.name[..],
554 );
dfeec247 555 llvm::LLVMRustRunFunctionPassManager(fpm, llmod);
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556 }
557 {
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558 let _timer = cgcx.prof.extra_verbose_generic_activity(
559 "LLVM_module_optimize_module_passes",
560 &module.name[..],
561 );
dfeec247 562 llvm::LLVMRunPassManager(mpm, llmod);
532ac7d7 563 }
1a4d82fc 564
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565 // Deallocate managers that we're now done with
566 llvm::LLVMDisposePassManager(fpm);
567 llvm::LLVMDisposePassManager(mpm);
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568 }
569 Ok(())
570}
1a4d82fc 571
dfeec247 572unsafe fn add_sanitizer_passes(config: &ModuleConfig, passes: &mut Vec<&'static mut llvm::Pass>) {
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573 let sanitizer = match &config.sanitizer {
574 None => return,
575 Some(s) => s,
576 };
577
578 let recover = config.sanitizer_recover.contains(sanitizer);
579 match sanitizer {
580 Sanitizer::Address => {
581 passes.push(llvm::LLVMRustCreateAddressSanitizerFunctionPass(recover));
582 passes.push(llvm::LLVMRustCreateModuleAddressSanitizerPass(recover));
583 }
584 Sanitizer::Memory => {
585 let track_origins = config.sanitizer_memory_track_origins as c_int;
586 passes.push(llvm::LLVMRustCreateMemorySanitizerPass(track_origins, recover));
587 }
588 Sanitizer::Thread => {
589 passes.push(llvm::LLVMRustCreateThreadSanitizerPass());
590 }
591 Sanitizer::Leak => {}
592 }
593}
594
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595pub(crate) unsafe fn codegen(
596 cgcx: &CodegenContext<LlvmCodegenBackend>,
597 diag_handler: &Handler,
598 module: ModuleCodegen<ModuleLlvm>,
599 config: &ModuleConfig,
600) -> Result<CompiledModule, FatalError> {
74b04a01 601 let _timer = cgcx.prof.generic_activity_with_arg("LLVM_module_codegen", &module.name[..]);
1a4d82fc 602 {
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603 let llmod = module.module_llvm.llmod();
604 let llcx = &*module.module_llvm.llcx;
605 let tm = &*module.module_llvm.tm;
606 let module_name = module.name.clone();
607 let module_name = Some(&module_name[..]);
608 let handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
1a4d82fc 609
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610 if cgcx.msvc_imps_needed {
611 create_msvc_imps(cgcx, llcx, llmod);
612 }
613
614 // A codegen-specific pass manager is used to generate object
615 // files for an LLVM module.
616 //
617 // Apparently each of these pass managers is a one-shot kind of
618 // thing, so we create a new one for each type of output. The
619 // pass manager passed to the closure should be ensured to not
620 // escape the closure itself, and the manager should only be
621 // used once.
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622 unsafe fn with_codegen<'ll, F, R>(
623 tm: &'ll llvm::TargetMachine,
624 llmod: &'ll llvm::Module,
625 no_builtins: bool,
626 f: F,
627 ) -> R
628 where
629 F: FnOnce(&'ll mut PassManager<'ll>) -> R,
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630 {
631 let cpm = llvm::LLVMCreatePassManager();
60c5eb7d 632 llvm::LLVMAddAnalysisPasses(tm, cpm);
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633 llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins);
634 f(cpm)
635 }
636
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637 // Two things to note:
638 // - If object files are just LLVM bitcode we write bitcode, copy it to
639 // the .o file, and delete the bitcode if it wasn't otherwise
640 // requested.
641 // - If we don't have the integrated assembler then we need to emit
642 // asm from LLVM and use `gcc` to create the object file.
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643
644 let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
645 let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
646
ba9703b0 647 if config.bitcode_needed() {
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648 let _timer = cgcx
649 .prof
650 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &module.name[..]);
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651 let thin = ThinBuffer::new(llmod);
652 let data = thin.data();
abe05a73 653
ba9703b0 654 if config.emit_bc || config.emit_obj == EmitObj::Bitcode {
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655 let _timer = cgcx.prof.generic_activity_with_arg(
656 "LLVM_module_codegen_emit_bitcode",
657 &module.name[..],
658 );
b7449926 659 if let Err(e) = fs::write(&bc_out, data) {
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660 let msg = format!("failed to write bytecode to {}: {}", bc_out.display(), e);
661 diag_handler.err(&msg);
b7449926 662 }
abe05a73 663 }
abe05a73 664
ba9703b0 665 if config.emit_obj == EmitObj::ObjectCode(BitcodeSection::Full) {
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666 let _timer = cgcx.prof.generic_activity_with_arg(
667 "LLVM_module_codegen_embed_bitcode",
668 &module.name[..],
669 );
b7449926 670 embed_bitcode(cgcx, llcx, llmod, Some(data));
b7449926 671 }
0531ce1d 672
b7449926 673 if config.emit_bc_compressed {
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674 let _timer = cgcx.prof.generic_activity_with_arg(
675 "LLVM_module_codegen_emit_compressed_bitcode",
676 &module.name[..],
677 );
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678 let dst = bc_out.with_extension(RLIB_BYTECODE_EXTENSION);
679 let data = bytecode::encode(&module.name, data);
680 if let Err(e) = fs::write(&dst, data) {
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681 let msg = format!("failed to write bytecode to {}: {}", dst.display(), e);
682 diag_handler.err(&msg);
b7449926 683 }
abe05a73 684 }
ba9703b0 685 } else if config.emit_obj == EmitObj::ObjectCode(BitcodeSection::Marker) {
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686 embed_bitcode(cgcx, llcx, llmod, None);
687 }
688
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689 if config.emit_ir {
690 let _timer = cgcx
691 .prof
692 .generic_activity_with_arg("LLVM_module_codegen_emit_ir", &module.name[..]);
693 let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
694 let out_c = path_to_c_string(&out);
695
696 extern "C" fn demangle_callback(
697 input_ptr: *const c_char,
698 input_len: size_t,
699 output_ptr: *mut c_char,
700 output_len: size_t,
701 ) -> size_t {
702 let input =
703 unsafe { slice::from_raw_parts(input_ptr as *const u8, input_len as usize) };
704
705 let input = match str::from_utf8(input) {
706 Ok(s) => s,
707 Err(_) => return 0,
708 };
709
710 let output = unsafe {
711 slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
712 };
713 let mut cursor = io::Cursor::new(output);
714
715 let demangled = match rustc_demangle::try_demangle(input) {
716 Ok(d) => d,
717 Err(_) => return 0,
718 };
719
720 if write!(cursor, "{:#}", demangled).is_err() {
721 // Possible only if provided buffer is not big enough
722 return 0;
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723 }
724
ba9703b0 725 cursor.position() as size_t
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726 }
727
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728 let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
729 result.into_result().map_err(|()| {
730 let msg = format!("failed to write LLVM IR to {}", out.display());
731 llvm_err(diag_handler, &msg)
732 })?;
733 }
9cc50fc6 734
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735 if config.emit_asm {
736 let _timer = cgcx
737 .prof
738 .generic_activity_with_arg("LLVM_module_codegen_emit_asm", &module.name[..]);
739 let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
740
741 // We can't use the same module for asm and object code output,
742 // because that triggers various errors like invalid IR or broken
743 // binaries. So we must clone the module to produce the asm output
744 // if we are also producing object code.
745 let llmod = if let EmitObj::ObjectCode(_) = config.emit_obj {
746 llvm::LLVMCloneModule(llmod)
747 } else {
748 llmod
749 };
750 with_codegen(tm, llmod, config.no_builtins, |cpm| {
751 write_output_file(diag_handler, tm, cpm, llmod, &path, llvm::FileType::AssemblyFile)
752 })?;
753 }
1a4d82fc 754
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755 match config.emit_obj {
756 EmitObj::ObjectCode(_) => {
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757 let _timer = cgcx
758 .prof
759 .generic_activity_with_arg("LLVM_module_codegen_emit_obj", &module.name[..]);
b7449926 760 with_codegen(tm, llmod, config.no_builtins, |cpm| {
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761 write_output_file(
762 diag_handler,
763 tm,
764 cpm,
765 llmod,
766 &obj_out,
767 llvm::FileType::ObjectFile,
768 )
b7449926 769 })?;
ba9703b0 770 }
b7449926 771
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772 EmitObj::Bitcode => {
773 debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
774 if let Err(e) = link_or_copy(&bc_out, &obj_out) {
775 diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
b7449926 776 }
1a4d82fc 777
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778 if !config.emit_bc {
779 debug!("removing_bitcode {:?}", bc_out);
780 if let Err(e) = fs::remove_file(&bc_out) {
781 diag_handler.err(&format!("failed to remove bitcode: {}", e));
782 }
783 }
b7449926 784 }
7453a54e 785
ba9703b0 786 EmitObj::None => {}
7453a54e 787 }
7453a54e 788
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789 drop(handlers);
790 }
ba9703b0 791
dfeec247 792 Ok(module.into_compiled_module(
ba9703b0 793 config.emit_obj != EmitObj::None,
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794 config.emit_bc,
795 config.emit_bc_compressed,
796 &cgcx.output_filenames,
797 ))
1a4d82fc
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798}
799
0531ce1d 800/// Embed the bitcode of an LLVM module in the LLVM module itself.
abe05a73 801///
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802/// This is done primarily for iOS where it appears to be standard to compile C
803/// code at least with `-fembed-bitcode` which creates two sections in the
804/// executable:
805///
806/// * __LLVM,__bitcode
807/// * __LLVM,__cmdline
808///
809/// It appears *both* of these sections are necessary to get the linker to
810/// recognize what's going on. For us though we just always throw in an empty
811/// cmdline section.
812///
813/// Furthermore debug/O1 builds don't actually embed bitcode but rather just
814/// embed an empty section.
815///
816/// Basically all of this is us attempting to follow in the footsteps of clang
817/// on iOS. See #35968 for lots more info.
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818unsafe fn embed_bitcode(
819 cgcx: &CodegenContext<LlvmCodegenBackend>,
820 llcx: &llvm::Context,
821 llmod: &llvm::Module,
822 bitcode: Option<&[u8]>,
823) {
a1dfa0c6 824 let llconst = common::bytes_in_context(llcx, bitcode.unwrap_or(&[]));
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825 let llglobal = llvm::LLVMAddGlobal(
826 llmod,
a1dfa0c6 827 common::val_ty(llconst),
e74abb32 828 "rustc.embedded.module\0".as_ptr().cast(),
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829 );
830 llvm::LLVMSetInitializer(llglobal, llconst);
83c7162d 831
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832 let is_apple = cgcx.opts.target_triple.triple().contains("-ios")
833 || cgcx.opts.target_triple.triple().contains("-darwin");
83c7162d 834
dfeec247 835 let section = if is_apple { "__LLVM,__bitcode\0" } else { ".llvmbc\0" };
e74abb32 836 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
0531ce1d 837 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
83c7162d 838 llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
0531ce1d 839
a1dfa0c6 840 let llconst = common::bytes_in_context(llcx, &[]);
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841 let llglobal = llvm::LLVMAddGlobal(
842 llmod,
a1dfa0c6 843 common::val_ty(llconst),
e74abb32 844 "rustc.embedded.cmdline\0".as_ptr().cast(),
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845 );
846 llvm::LLVMSetInitializer(llglobal, llconst);
dfeec247 847 let section = if is_apple { "__LLVM,__cmdline\0" } else { ".llvmcmd\0" };
e74abb32 848 llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
0531ce1d 849 llvm::LLVMRustSetLinkage(llglobal, llvm::Linkage::PrivateLinkage);
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850}
851
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852pub unsafe fn with_llvm_pmb(
853 llmod: &llvm::Module,
854 config: &ModuleConfig,
855 opt_level: llvm::CodeGenOptLevel,
856 prepare_for_thin_lto: bool,
857 f: &mut dyn FnMut(&llvm::PassManagerBuilder),
858) {
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859 use std::ptr;
860
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861 // Create the PassManagerBuilder for LLVM. We configure it with
862 // reasonable defaults and prepare it to actually populate the pass
863 // manager.
864 let builder = llvm::LLVMPassManagerBuilderCreate();
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865 let opt_size =
866 config.opt_size.map(|x| to_llvm_opt_settings(x).1).unwrap_or(llvm::CodeGenOptSizeNone);
92a42be0 867 let inline_threshold = config.inline_threshold;
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868 let pgo_gen_path = get_pgo_gen_path(config);
869 let pgo_use_path = get_pgo_use_path(config);
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870
871 llvm::LLVMRustConfigurePassManagerBuilder(
872 builder,
873 opt_level,
874 config.merge_functions,
875 config.vectorize_slp,
876 config.vectorize_loop,
94b46f34 877 prepare_for_thin_lto,
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878 pgo_gen_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
879 pgo_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
880 );
881
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882 llvm::LLVMPassManagerBuilderSetSizeLevel(builder, opt_size as u32);
883
884 if opt_size != llvm::CodeGenOptSizeNone {
885 llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
886 }
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887
888 llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
889
890 // Here we match what clang does (kinda). For O0 we only inline
891 // always-inline functions (but don't add lifetime intrinsics), at O1 we
892 // inline with lifetime intrinsics, and O2+ we add an inliner with a
893 // thresholds copied from clang.
a7813a04 894 match (opt_level, opt_size, inline_threshold) {
9e0c209e 895 (.., Some(t)) => {
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896 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, t as u32);
897 }
9e0c209e 898 (llvm::CodeGenOptLevel::Aggressive, ..) => {
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899 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275);
900 }
901 (_, llvm::CodeGenOptSizeDefault, _) => {
902 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 75);
903 }
904 (_, llvm::CodeGenOptSizeAggressive, _) => {
905 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 25);
906 }
9e0c209e 907 (llvm::CodeGenOptLevel::None, ..) => {
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908 llvm::LLVMRustAddAlwaysInlinePass(builder, false);
909 }
9e0c209e 910 (llvm::CodeGenOptLevel::Less, ..) => {
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911 llvm::LLVMRustAddAlwaysInlinePass(builder, true);
912 }
9e0c209e 913 (llvm::CodeGenOptLevel::Default, ..) => {
62682a34 914 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225);
1a4d82fc 915 }
dfeec247 916 (llvm::CodeGenOptLevel::Other, ..) => bug!("CodeGenOptLevel::Other selected"),
1a4d82fc 917 }
1a4d82fc 918
c1a9b12d 919 f(builder);
1a4d82fc 920 llvm::LLVMPassManagerBuilderDispose(builder);
1a4d82fc 921}
3b2f2976 922
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923// Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
924// This is required to satisfy `dllimport` references to static data in .rlibs
925// when using MSVC linker. We do this only for data, as linker can fix up
926// code references on its own.
927// See #26591, #27438
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928fn create_msvc_imps(
929 cgcx: &CodegenContext<LlvmCodegenBackend>,
930 llcx: &llvm::Context,
dfeec247 931 llmod: &llvm::Module,
a1dfa0c6 932) {
abe05a73 933 if !cgcx.msvc_imps_needed {
dfeec247 934 return;
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935 }
936 // The x86 ABI seems to require that leading underscores are added to symbol
48663c56 937 // names, so we need an extra underscore on x86. There's also a leading
0731742a 938 // '\x01' here which disables LLVM's symbol mangling (e.g., no extra
abe05a73 939 // underscores added in front).
dfeec247 940 let prefix = if cgcx.target_arch == "x86" { "\x01__imp__" } else { "\x01__imp_" };
48663c56 941
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942 unsafe {
943 let i8p_ty = Type::i8p_llcx(llcx);
944 let globals = base::iter_globals(llmod)
945 .filter(|&val| {
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946 llvm::LLVMRustGetLinkage(val) == llvm::Linkage::ExternalLinkage
947 && llvm::LLVMIsDeclaration(val) == 0
abe05a73 948 })
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949 .filter_map(|val| {
950 // Exclude some symbols that we know are not Rust symbols.
60c5eb7d 951 let name = llvm::get_value_name(val);
dfeec247 952 if ignored(name) { None } else { Some((val, name)) }
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953 })
954 .map(move |(val, name)| {
abe05a73 955 let mut imp_name = prefix.as_bytes().to_vec();
60c5eb7d 956 imp_name.extend(name);
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957 let imp_name = CString::new(imp_name).unwrap();
958 (imp_name, val)
959 })
960 .collect::<Vec<_>>();
48663c56 961
abe05a73 962 for (imp_name, val) in globals {
dfeec247 963 let imp = llvm::LLVMAddGlobal(llmod, i8p_ty, imp_name.as_ptr().cast());
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964 llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty));
965 llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage);
966 }
967 }
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968
969 // Use this function to exclude certain symbols from `__imp` generation.
970 fn ignored(symbol_name: &[u8]) -> bool {
971 // These are symbols generated by LLVM's profiling instrumentation
972 symbol_name.starts_with(b"__llvm_profile_")
973 }
abe05a73 974}