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Commit | Line | Data |
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dfeec247 XL |
1 | use crate::back::write::{ |
2 | self, save_temp_bitcode, to_llvm_opt_settings, with_llvm_pmb, DiagnosticHandlers, | |
3 | }; | |
9fa01778 | 4 | use crate::llvm::archive_ro::ArchiveRO; |
29967ef6 | 5 | use crate::llvm::{self, build_string, False, True}; |
a2a8927a | 6 | use crate::{llvm_util, LlvmCodegenBackend, ModuleLlvm}; |
dfeec247 | 7 | use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule, ThinShared}; |
a1dfa0c6 | 8 | use rustc_codegen_ssa::back::symbol_export; |
fc512014 XL |
9 | use rustc_codegen_ssa::back::write::{ |
10 | CodegenContext, FatLTOInput, ModuleConfig, TargetMachineFactoryConfig, | |
11 | }; | |
a1dfa0c6 | 12 | use rustc_codegen_ssa::traits::*; |
f9f354fc | 13 | use rustc_codegen_ssa::{looks_like_rust_object_file, ModuleCodegen, ModuleKind}; |
29967ef6 | 14 | use rustc_data_structures::fx::FxHashMap; |
60c5eb7d | 15 | use rustc_errors::{FatalError, Handler}; |
dfeec247 | 16 | use rustc_hir::def_id::LOCAL_CRATE; |
ba9703b0 XL |
17 | use rustc_middle::bug; |
18 | use rustc_middle::dep_graph::WorkProduct; | |
19 | use rustc_middle::middle::exported_symbols::SymbolExportLevel; | |
60c5eb7d | 20 | use rustc_session::cgu_reuse_tracker::CguReuse; |
f9f354fc | 21 | use rustc_session::config::{self, CrateType, Lto}; |
3dfed10e | 22 | use tracing::{debug, info}; |
1a4d82fc | 23 | |
b7449926 | 24 | use std::ffi::{CStr, CString}; |
dfeec247 XL |
25 | use std::fs::File; |
26 | use std::io; | |
cdc7bbd5 | 27 | use std::iter; |
dfeec247 | 28 | use std::path::Path; |
ff7c6d11 | 29 | use std::ptr; |
ea8adc8c XL |
30 | use std::slice; |
31 | use std::sync::Arc; | |
1a4d82fc | 32 | |
29967ef6 XL |
33 | /// We keep track of the computed LTO cache keys from the previous |
34 | /// session to determine which CGUs we can reuse. | |
35 | pub const THIN_LTO_KEYS_INCR_COMP_FILE_NAME: &str = "thin-lto-past-keys.bin"; | |
dfeec247 | 36 | |
f9f354fc | 37 | pub fn crate_type_allows_lto(crate_type: CrateType) -> bool { |
476ff2be | 38 | match crate_type { |
f9f354fc XL |
39 | CrateType::Executable | CrateType::Staticlib | CrateType::Cdylib => true, |
40 | CrateType::Dylib | CrateType::Rlib | CrateType::ProcMacro => false, | |
476ff2be SL |
41 | } |
42 | } | |
43 | ||
dfeec247 XL |
44 | fn prepare_lto( |
45 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
46 | diag_handler: &Handler, | |
47 | ) -> Result<(Vec<CString>, Vec<(SerializedModule<ModuleBuffer>, CString)>), FatalError> { | |
2c00a5a8 XL |
48 | let export_threshold = match cgcx.lto { |
49 | // We're just doing LTO for our one crate | |
50 | Lto::ThinLocal => SymbolExportLevel::Rust, | |
51 | ||
52 | // We're doing LTO for the entire crate graph | |
dfeec247 | 53 | Lto::Fat | Lto::Thin => symbol_export::crates_export_threshold(&cgcx.crate_types), |
2c00a5a8 XL |
54 | |
55 | Lto::No => panic!("didn't request LTO but we're doing LTO"), | |
ea8adc8c XL |
56 | }; |
57 | ||
0531ce1d | 58 | let symbol_filter = &|&(ref name, level): &(String, SymbolExportLevel)| { |
ea8adc8c | 59 | if level.is_below_threshold(export_threshold) { |
e74abb32 | 60 | Some(CString::new(name.as_str()).unwrap()) |
476ff2be SL |
61 | } else { |
62 | None | |
63 | } | |
64 | }; | |
dfeec247 | 65 | let exported_symbols = cgcx.exported_symbols.as_ref().expect("needs exported symbols for LTO"); |
f035d41b XL |
66 | let mut symbols_below_threshold = { |
67 | let _timer = cgcx.prof.generic_activity("LLVM_lto_generate_symbols_below_threshold"); | |
dfeec247 | 68 | exported_symbols[&LOCAL_CRATE].iter().filter_map(symbol_filter).collect::<Vec<CString>>() |
e74abb32 | 69 | }; |
f035d41b | 70 | info!("{} symbols to preserve in this crate", symbols_below_threshold.len()); |
ea8adc8c XL |
71 | |
72 | // If we're performing LTO for the entire crate graph, then for each of our | |
73 | // upstream dependencies, find the corresponding rlib and load the bitcode | |
74 | // from the archive. | |
75 | // | |
76 | // We save off all the bytecode and LLVM module ids for later processing | |
77 | // with either fat or thin LTO | |
78 | let mut upstream_modules = Vec::new(); | |
2c00a5a8 | 79 | if cgcx.lto != Lto::ThinLocal { |
ea8adc8c | 80 | if cgcx.opts.cg.prefer_dynamic { |
dfeec247 XL |
81 | diag_handler |
82 | .struct_err("cannot prefer dynamic linking when performing LTO") | |
83 | .note( | |
84 | "only 'staticlib', 'bin', and 'cdylib' outputs are \ | |
85 | supported with LTO", | |
86 | ) | |
87 | .emit(); | |
88 | return Err(FatalError); | |
ea8adc8c XL |
89 | } |
90 | ||
91 | // Make sure we actually can run LTO | |
92 | for crate_type in cgcx.crate_types.iter() { | |
93 | if !crate_type_allows_lto(*crate_type) { | |
dfeec247 XL |
94 | let e = diag_handler.fatal( |
95 | "lto can only be run for executables, cdylibs and \ | |
96 | static library outputs", | |
97 | ); | |
98 | return Err(e); | |
ea8adc8c XL |
99 | } |
100 | } | |
101 | ||
102 | for &(cnum, ref path) in cgcx.each_linked_rlib_for_lto.iter() { | |
dfeec247 XL |
103 | let exported_symbols = |
104 | cgcx.exported_symbols.as_ref().expect("needs exported symbols for LTO"); | |
e74abb32 | 105 | { |
f035d41b XL |
106 | let _timer = |
107 | cgcx.prof.generic_activity("LLVM_lto_generate_symbols_below_threshold"); | |
108 | symbols_below_threshold | |
109 | .extend(exported_symbols[&cnum].iter().filter_map(symbol_filter)); | |
e74abb32 | 110 | } |
ea8adc8c | 111 | |
c295e0f8 | 112 | let archive = ArchiveRO::open(path).expect("wanted an rlib"); |
f9f354fc | 113 | let obj_files = archive |
dfeec247 XL |
114 | .iter() |
115 | .filter_map(|child| child.ok().and_then(|c| c.name().map(|name| (name, c)))) | |
f9f354fc XL |
116 | .filter(|&(name, _)| looks_like_rust_object_file(name)); |
117 | for (name, child) in obj_files { | |
118 | info!("adding bitcode from {}", name); | |
119 | match get_bitcode_slice_from_object_data(child.data()) { | |
120 | Ok(data) => { | |
121 | let module = SerializedModule::FromRlib(data.to_vec()); | |
122 | upstream_modules.push((module, CString::new(name).unwrap())); | |
123 | } | |
124 | Err(msg) => return Err(diag_handler.fatal(&msg)), | |
125 | } | |
ea8adc8c | 126 | } |
ea8adc8c XL |
127 | } |
128 | } | |
1a4d82fc | 129 | |
f035d41b | 130 | Ok((symbols_below_threshold, upstream_modules)) |
0731742a XL |
131 | } |
132 | ||
f9f354fc XL |
133 | fn get_bitcode_slice_from_object_data(obj: &[u8]) -> Result<&[u8], String> { |
134 | let mut len = 0; | |
135 | let data = | |
136 | unsafe { llvm::LLVMRustGetBitcodeSliceFromObjectData(obj.as_ptr(), obj.len(), &mut len) }; | |
137 | if !data.is_null() { | |
138 | assert!(len != 0); | |
139 | let bc = unsafe { slice::from_raw_parts(data, len) }; | |
140 | ||
141 | // `bc` must be a sub-slice of `obj`. | |
142 | assert!(obj.as_ptr() <= bc.as_ptr()); | |
143 | assert!(bc[bc.len()..bc.len()].as_ptr() <= obj[obj.len()..obj.len()].as_ptr()); | |
144 | ||
145 | Ok(bc) | |
146 | } else { | |
147 | assert!(len == 0); | |
148 | let msg = llvm::last_error().unwrap_or_else(|| "unknown LLVM error".to_string()); | |
149 | Err(format!("failed to get bitcode from object file for LTO ({})", msg)) | |
150 | } | |
151 | } | |
152 | ||
0731742a XL |
153 | /// Performs fat LTO by merging all modules into a single one and returning it |
154 | /// for further optimization. | |
dfeec247 XL |
155 | pub(crate) fn run_fat( |
156 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
157 | modules: Vec<FatLTOInput<LlvmCodegenBackend>>, | |
158 | cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>, | |
159 | ) -> Result<LtoModuleCodegen<LlvmCodegenBackend>, FatalError> { | |
0731742a | 160 | let diag_handler = cgcx.create_diag_handler(); |
f035d41b XL |
161 | let (symbols_below_threshold, upstream_modules) = prepare_lto(cgcx, &diag_handler)?; |
162 | let symbols_below_threshold = | |
163 | symbols_below_threshold.iter().map(|c| c.as_ptr()).collect::<Vec<_>>(); | |
164 | fat_lto( | |
165 | cgcx, | |
166 | &diag_handler, | |
167 | modules, | |
168 | cached_modules, | |
169 | upstream_modules, | |
170 | &symbols_below_threshold, | |
171 | ) | |
0731742a XL |
172 | } |
173 | ||
174 | /// Performs thin LTO by performing necessary global analysis and returning two | |
175 | /// lists, one of the modules that need optimization and another for modules that | |
176 | /// can simply be copied over from the incr. comp. cache. | |
dfeec247 XL |
177 | pub(crate) fn run_thin( |
178 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
179 | modules: Vec<(String, ThinBuffer)>, | |
180 | cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>, | |
181 | ) -> Result<(Vec<LtoModuleCodegen<LlvmCodegenBackend>>, Vec<WorkProduct>), FatalError> { | |
0731742a | 182 | let diag_handler = cgcx.create_diag_handler(); |
f035d41b XL |
183 | let (symbols_below_threshold, upstream_modules) = prepare_lto(cgcx, &diag_handler)?; |
184 | let symbols_below_threshold = | |
185 | symbols_below_threshold.iter().map(|c| c.as_ptr()).collect::<Vec<_>>(); | |
9fa01778 | 186 | if cgcx.opts.cg.linker_plugin_lto.enabled() { |
dfeec247 XL |
187 | unreachable!( |
188 | "We should never reach this case if the LTO step \ | |
189 | is deferred to the linker" | |
190 | ); | |
0731742a | 191 | } |
f035d41b XL |
192 | thin_lto( |
193 | cgcx, | |
194 | &diag_handler, | |
195 | modules, | |
196 | upstream_modules, | |
197 | cached_modules, | |
198 | &symbols_below_threshold, | |
199 | ) | |
0731742a XL |
200 | } |
201 | ||
dfeec247 | 202 | pub(crate) fn prepare_thin(module: ModuleCodegen<ModuleLlvm>) -> (String, ThinBuffer) { |
0731742a XL |
203 | let name = module.name.clone(); |
204 | let buffer = ThinBuffer::new(module.module_llvm.llmod()); | |
0731742a | 205 | (name, buffer) |
ea8adc8c XL |
206 | } |
207 | ||
dfeec247 XL |
208 | fn fat_lto( |
209 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
210 | diag_handler: &Handler, | |
211 | modules: Vec<FatLTOInput<LlvmCodegenBackend>>, | |
212 | cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>, | |
213 | mut serialized_modules: Vec<(SerializedModule<ModuleBuffer>, CString)>, | |
f035d41b | 214 | symbols_below_threshold: &[*const libc::c_char], |
dfeec247 | 215 | ) -> Result<LtoModuleCodegen<LlvmCodegenBackend>, FatalError> { |
e74abb32 | 216 | let _timer = cgcx.prof.generic_activity("LLVM_fat_lto_build_monolithic_module"); |
ea8adc8c XL |
217 | info!("going for a fat lto"); |
218 | ||
e1599b0c XL |
219 | // Sort out all our lists of incoming modules into two lists. |
220 | // | |
221 | // * `serialized_modules` (also and argument to this function) contains all | |
222 | // modules that are serialized in-memory. | |
223 | // * `in_memory` contains modules which are already parsed and in-memory, | |
224 | // such as from multi-CGU builds. | |
225 | // | |
226 | // All of `cached_modules` (cached from previous incremental builds) can | |
227 | // immediately go onto the `serialized_modules` modules list and then we can | |
228 | // split the `modules` array into these two lists. | |
229 | let mut in_memory = Vec::new(); | |
230 | serialized_modules.extend(cached_modules.into_iter().map(|(buffer, wp)| { | |
231 | info!("pushing cached module {:?}", wp.cgu_name); | |
232 | (buffer, CString::new(wp.cgu_name).unwrap()) | |
233 | })); | |
234 | for module in modules { | |
235 | match module { | |
236 | FatLTOInput::InMemory(m) => in_memory.push(m), | |
237 | FatLTOInput::Serialized { name, buffer } => { | |
238 | info!("pushing serialized module {:?}", name); | |
239 | let buffer = SerializedModule::Local(buffer); | |
240 | serialized_modules.push((buffer, CString::new(name).unwrap())); | |
241 | } | |
242 | } | |
243 | } | |
244 | ||
ea8adc8c XL |
245 | // Find the "costliest" module and merge everything into that codegen unit. |
246 | // All the other modules will be serialized and reparsed into the new | |
247 | // context, so this hopefully avoids serializing and parsing the largest | |
248 | // codegen unit. | |
249 | // | |
250 | // Additionally use a regular module as the base here to ensure that various | |
251 | // file copy operations in the backend work correctly. The only other kind | |
252 | // of module here should be an allocator one, and if your crate is smaller | |
253 | // than the allocator module then the size doesn't really matter anyway. | |
dfeec247 XL |
254 | let costliest_module = in_memory |
255 | .iter() | |
ea8adc8c XL |
256 | .enumerate() |
257 | .filter(|&(_, module)| module.kind == ModuleKind::Regular) | |
258 | .map(|(i, module)| { | |
dfeec247 | 259 | let cost = unsafe { llvm::LLVMRustModuleCost(module.module_llvm.llmod()) }; |
ea8adc8c XL |
260 | (cost, i) |
261 | }) | |
9fa01778 XL |
262 | .max(); |
263 | ||
264 | // If we found a costliest module, we're good to go. Otherwise all our | |
265 | // inputs were serialized which could happen in the case, for example, that | |
266 | // all our inputs were incrementally reread from the cache and we're just | |
267 | // re-executing the LTO passes. If that's the case deserialize the first | |
268 | // module and create a linker with it. | |
269 | let module: ModuleCodegen<ModuleLlvm> = match costliest_module { | |
e1599b0c | 270 | Some((_cost, i)) => in_memory.remove(i), |
9fa01778 | 271 | None => { |
74b04a01 | 272 | assert!(!serialized_modules.is_empty(), "must have at least one serialized module"); |
e1599b0c XL |
273 | let (buffer, name) = serialized_modules.remove(0); |
274 | info!("no in-memory regular modules to choose from, parsing {:?}", name); | |
9fa01778 | 275 | ModuleCodegen { |
e1599b0c XL |
276 | module_llvm: ModuleLlvm::parse(cgcx, &name, buffer.data(), diag_handler)?, |
277 | name: name.into_string().unwrap(), | |
9fa01778 XL |
278 | kind: ModuleKind::Regular, |
279 | } | |
280 | } | |
281 | }; | |
ea8adc8c | 282 | let mut serialized_bitcode = Vec::new(); |
b7449926 XL |
283 | { |
284 | let (llcx, llmod) = { | |
285 | let llvm = &module.module_llvm; | |
286 | (&llvm.llcx, llvm.llmod()) | |
287 | }; | |
288 | info!("using {:?} as a base module", module.name); | |
289 | ||
290 | // The linking steps below may produce errors and diagnostics within LLVM | |
291 | // which we'd like to handle and print, so set up our diagnostic handlers | |
292 | // (which get unregistered when they go out of scope below). | |
293 | let _handler = DiagnosticHandlers::new(cgcx, diag_handler, llcx); | |
294 | ||
295 | // For all other modules we codegened we'll need to link them into our own | |
296 | // bitcode. All modules were codegened in their own LLVM context, however, | |
297 | // and we want to move everything to the same LLVM context. Currently the | |
298 | // way we know of to do that is to serialize them to a string and them parse | |
299 | // them later. Not great but hey, that's why it's "fat" LTO, right? | |
e1599b0c XL |
300 | for module in in_memory { |
301 | let buffer = ModuleBuffer::new(module.module_llvm.llmod()); | |
302 | let llmod_id = CString::new(&module.name[..]).unwrap(); | |
303 | serialized_modules.push((SerializedModule::Local(buffer), llmod_id)); | |
304 | } | |
416331ca | 305 | // Sort the modules to ensure we produce deterministic results. |
e1599b0c | 306 | serialized_modules.sort_by(|module1, module2| module1.1.cmp(&module2.1)); |
1a4d82fc | 307 | |
b7449926 XL |
308 | // For all serialized bitcode files we parse them and link them in as we did |
309 | // above, this is all mostly handled in C++. Like above, though, we don't | |
310 | // know much about the memory management here so we err on the side of being | |
311 | // save and persist everything with the original module. | |
312 | let mut linker = Linker::new(llmod); | |
313 | for (bc_decoded, name) in serialized_modules { | |
74b04a01 XL |
314 | let _timer = cgcx |
315 | .prof | |
316 | .generic_activity_with_arg("LLVM_fat_lto_link_module", format!("{:?}", name)); | |
b7449926 | 317 | info!("linking {:?}", name); |
74b04a01 | 318 | let data = bc_decoded.data(); |
c295e0f8 | 319 | linker.add(data).map_err(|()| { |
ee023bcb | 320 | let msg = format!("failed to load bitcode of module {:?}", name); |
c295e0f8 | 321 | write::llvm_err(diag_handler, &msg) |
b7449926 | 322 | })?; |
b7449926 XL |
323 | serialized_bitcode.push(bc_decoded); |
324 | } | |
325 | drop(linker); | |
c295e0f8 XL |
326 | save_temp_bitcode(cgcx, &module, "lto.input"); |
327 | ||
328 | // Fat LTO also suffers from the invalid DWARF issue similar to Thin LTO. | |
329 | // Here we rewrite all `DICompileUnit` pointers if there is only one `DICompileUnit`. | |
330 | // This only works around the problem when codegen-units = 1. | |
331 | // Refer to the comments in the `optimize_thin_module` function for more details. | |
332 | let mut cu1 = ptr::null_mut(); | |
333 | let mut cu2 = ptr::null_mut(); | |
334 | unsafe { llvm::LLVMRustLTOGetDICompileUnit(llmod, &mut cu1, &mut cu2) }; | |
335 | if !cu2.is_null() { | |
336 | let _timer = | |
337 | cgcx.prof.generic_activity_with_arg("LLVM_fat_lto_patch_debuginfo", &*module.name); | |
338 | unsafe { llvm::LLVMRustLTOPatchDICompileUnit(llmod, cu1) }; | |
339 | save_temp_bitcode(cgcx, &module, "fat-lto-after-patch"); | |
340 | } | |
1a4d82fc | 341 | |
f035d41b | 342 | // Internalize everything below threshold to help strip out more modules and such. |
1a4d82fc | 343 | unsafe { |
f035d41b | 344 | let ptr = symbols_below_threshold.as_ptr(); |
dfeec247 XL |
345 | llvm::LLVMRustRunRestrictionPass( |
346 | llmod, | |
347 | ptr as *const *const libc::c_char, | |
f035d41b | 348 | symbols_below_threshold.len() as libc::size_t, |
dfeec247 | 349 | ); |
c295e0f8 | 350 | save_temp_bitcode(cgcx, &module, "lto.after-restriction"); |
b7449926 | 351 | } |
1a4d82fc JJ |
352 | } |
353 | ||
dfeec247 | 354 | Ok(LtoModuleCodegen::Fat { module: Some(module), _serialized_bitcode: serialized_bitcode }) |
ea8adc8c XL |
355 | } |
356 | ||
1b1a35ee | 357 | crate struct Linker<'a>(&'a mut llvm::Linker<'a>); |
0531ce1d | 358 | |
a2a8927a | 359 | impl<'a> Linker<'a> { |
1b1a35ee | 360 | crate fn new(llmod: &'a llvm::Module) -> Self { |
0531ce1d XL |
361 | unsafe { Linker(llvm::LLVMRustLinkerNew(llmod)) } |
362 | } | |
363 | ||
1b1a35ee | 364 | crate fn add(&mut self, bytecode: &[u8]) -> Result<(), ()> { |
0531ce1d | 365 | unsafe { |
dfeec247 XL |
366 | if llvm::LLVMRustLinkerAdd( |
367 | self.0, | |
368 | bytecode.as_ptr() as *const libc::c_char, | |
369 | bytecode.len(), | |
370 | ) { | |
0531ce1d XL |
371 | Ok(()) |
372 | } else { | |
373 | Err(()) | |
374 | } | |
375 | } | |
376 | } | |
377 | } | |
378 | ||
a2a8927a | 379 | impl Drop for Linker<'_> { |
0531ce1d | 380 | fn drop(&mut self) { |
dfeec247 XL |
381 | unsafe { |
382 | llvm::LLVMRustLinkerFree(&mut *(self.0 as *mut _)); | |
383 | } | |
0531ce1d XL |
384 | } |
385 | } | |
386 | ||
ea8adc8c XL |
387 | /// Prepare "thin" LTO to get run on these modules. |
388 | /// | |
389 | /// The general structure of ThinLTO is quite different from the structure of | |
390 | /// "fat" LTO above. With "fat" LTO all LLVM modules in question are merged into | |
391 | /// one giant LLVM module, and then we run more optimization passes over this | |
392 | /// big module after internalizing most symbols. Thin LTO, on the other hand, | |
393 | /// avoid this large bottleneck through more targeted optimization. | |
394 | /// | |
395 | /// At a high level Thin LTO looks like: | |
396 | /// | |
397 | /// 1. Prepare a "summary" of each LLVM module in question which describes | |
398 | /// the values inside, cost of the values, etc. | |
399 | /// 2. Merge the summaries of all modules in question into one "index" | |
400 | /// 3. Perform some global analysis on this index | |
401 | /// 4. For each module, use the index and analysis calculated previously to | |
402 | /// perform local transformations on the module, for example inlining | |
403 | /// small functions from other modules. | |
404 | /// 5. Run thin-specific optimization passes over each module, and then code | |
405 | /// generate everything at the end. | |
406 | /// | |
407 | /// The summary for each module is intended to be quite cheap, and the global | |
408 | /// index is relatively quite cheap to create as well. As a result, the goal of | |
409 | /// ThinLTO is to reduce the bottleneck on LTO and enable LTO to be used in more | |
410 | /// situations. For example one cheap optimization is that we can parallelize | |
411 | /// all codegen modules, easily making use of all the cores on a machine. | |
412 | /// | |
413 | /// With all that in mind, the function here is designed at specifically just | |
414 | /// calculating the *index* for ThinLTO. This index will then be shared amongst | |
94b46f34 | 415 | /// all of the `LtoModuleCodegen` units returned below and destroyed once |
ea8adc8c | 416 | /// they all go out of scope. |
dfeec247 XL |
417 | fn thin_lto( |
418 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
419 | diag_handler: &Handler, | |
420 | modules: Vec<(String, ThinBuffer)>, | |
421 | serialized_modules: Vec<(SerializedModule<ModuleBuffer>, CString)>, | |
422 | cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>, | |
f035d41b | 423 | symbols_below_threshold: &[*const libc::c_char], |
dfeec247 | 424 | ) -> Result<(Vec<LtoModuleCodegen<LlvmCodegenBackend>>, Vec<WorkProduct>), FatalError> { |
e74abb32 | 425 | let _timer = cgcx.prof.generic_activity("LLVM_thin_lto_global_analysis"); |
ea8adc8c XL |
426 | unsafe { |
427 | info!("going for that thin, thin LTO"); | |
428 | ||
dfeec247 XL |
429 | let green_modules: FxHashMap<_, _> = |
430 | cached_modules.iter().map(|&(_, ref wp)| (wp.cgu_name.clone(), wp.clone())).collect(); | |
b7449926 | 431 | |
a1dfa0c6 XL |
432 | let full_scope_len = modules.len() + serialized_modules.len() + cached_modules.len(); |
433 | let mut thin_buffers = Vec::with_capacity(modules.len()); | |
434 | let mut module_names = Vec::with_capacity(full_scope_len); | |
435 | let mut thin_modules = Vec::with_capacity(full_scope_len); | |
ea8adc8c | 436 | |
0731742a XL |
437 | for (i, (name, buffer)) in modules.into_iter().enumerate() { |
438 | info!("local module: {} - {}", i, name); | |
439 | let cname = CString::new(name.clone()).unwrap(); | |
ea8adc8c | 440 | thin_modules.push(llvm::ThinLTOModule { |
0731742a | 441 | identifier: cname.as_ptr(), |
ea8adc8c XL |
442 | data: buffer.data().as_ptr(), |
443 | len: buffer.data().len(), | |
444 | }); | |
445 | thin_buffers.push(buffer); | |
0731742a | 446 | module_names.push(cname); |
b039eaaf | 447 | } |
ea8adc8c XL |
448 | |
449 | // FIXME: All upstream crates are deserialized internally in the | |
450 | // function below to extract their summary and modules. Note that | |
451 | // unlike the loop above we *must* decode and/or read something | |
452 | // here as these are all just serialized files on disk. An | |
453 | // improvement, however, to make here would be to store the | |
454 | // module summary separately from the actual module itself. Right | |
455 | // now this is store in one large bitcode file, and the entire | |
456 | // file is deflate-compressed. We could try to bypass some of the | |
457 | // decompression by storing the index uncompressed and only | |
458 | // lazily decompressing the bytecode if necessary. | |
459 | // | |
460 | // Note that truly taking advantage of this optimization will | |
461 | // likely be further down the road. We'd have to implement | |
462 | // incremental ThinLTO first where we could actually avoid | |
463 | // looking at upstream modules entirely sometimes (the contents, | |
464 | // we must always unconditionally look at the index). | |
a1dfa0c6 | 465 | let mut serialized = Vec::with_capacity(serialized_modules.len() + cached_modules.len()); |
b7449926 | 466 | |
dfeec247 XL |
467 | let cached_modules = |
468 | cached_modules.into_iter().map(|(sm, wp)| (sm, CString::new(wp.cgu_name).unwrap())); | |
b7449926 XL |
469 | |
470 | for (module, name) in serialized_modules.into_iter().chain(cached_modules) { | |
471 | info!("upstream or cached module {:?}", name); | |
ea8adc8c XL |
472 | thin_modules.push(llvm::ThinLTOModule { |
473 | identifier: name.as_ptr(), | |
474 | data: module.data().as_ptr(), | |
475 | len: module.data().len(), | |
476 | }); | |
477 | serialized.push(module); | |
478 | module_names.push(name); | |
479 | } | |
480 | ||
b7449926 XL |
481 | // Sanity check |
482 | assert_eq!(thin_modules.len(), module_names.len()); | |
483 | ||
ea8adc8c XL |
484 | // Delegate to the C++ bindings to create some data here. Once this is a |
485 | // tried-and-true interface we may wish to try to upstream some of this | |
486 | // to LLVM itself, right now we reimplement a lot of what they do | |
487 | // upstream... | |
488 | let data = llvm::LLVMRustCreateThinLTOData( | |
489 | thin_modules.as_ptr(), | |
490 | thin_modules.len() as u32, | |
f035d41b XL |
491 | symbols_below_threshold.as_ptr(), |
492 | symbols_below_threshold.len() as u32, | |
dfeec247 | 493 | ) |
c295e0f8 | 494 | .ok_or_else(|| write::llvm_err(diag_handler, "failed to prepare thin LTO context"))?; |
b7449926 | 495 | |
29967ef6 | 496 | let data = ThinData(data); |
ea8adc8c | 497 | |
29967ef6 | 498 | info!("thin LTO data created"); |
b7449926 | 499 | |
29967ef6 XL |
500 | let (key_map_path, prev_key_map, curr_key_map) = if let Some(ref incr_comp_session_dir) = |
501 | cgcx.incr_comp_session_dir | |
502 | { | |
503 | let path = incr_comp_session_dir.join(THIN_LTO_KEYS_INCR_COMP_FILE_NAME); | |
504 | // If the previous file was deleted, or we get an IO error | |
505 | // reading the file, then we'll just use `None` as the | |
506 | // prev_key_map, which will force the code to be recompiled. | |
507 | let prev = | |
508 | if path.exists() { ThinLTOKeysMap::load_from_file(&path).ok() } else { None }; | |
509 | let curr = ThinLTOKeysMap::from_thin_lto_modules(&data, &thin_modules, &module_names); | |
510 | (Some(path), prev, curr) | |
511 | } else { | |
512 | // If we don't compile incrementally, we don't need to load the | |
513 | // import data from LLVM. | |
514 | assert!(green_modules.is_empty()); | |
515 | let curr = ThinLTOKeysMap::default(); | |
516 | (None, None, curr) | |
517 | }; | |
518 | info!("thin LTO cache key map loaded"); | |
519 | info!("prev_key_map: {:#?}", prev_key_map); | |
520 | info!("curr_key_map: {:#?}", curr_key_map); | |
b7449926 | 521 | |
ea8adc8c XL |
522 | // Throw our data in an `Arc` as we'll be sharing it across threads. We |
523 | // also put all memory referenced by the C++ data (buffers, ids, etc) | |
524 | // into the arc as well. After this we'll create a thin module | |
94b46f34 | 525 | // codegen per module in this data. |
ea8adc8c XL |
526 | let shared = Arc::new(ThinShared { |
527 | data, | |
528 | thin_buffers, | |
529 | serialized_modules: serialized, | |
530 | module_names, | |
531 | }); | |
b7449926 XL |
532 | |
533 | let mut copy_jobs = vec![]; | |
534 | let mut opt_jobs = vec![]; | |
535 | ||
536 | info!("checking which modules can be-reused and which have to be re-optimized."); | |
537 | for (module_index, module_name) in shared.module_names.iter().enumerate() { | |
538 | let module_name = module_name_to_str(module_name); | |
29967ef6 XL |
539 | if let (Some(prev_key_map), true) = |
540 | (prev_key_map.as_ref(), green_modules.contains_key(module_name)) | |
dfeec247 XL |
541 | { |
542 | assert!(cgcx.incr_comp_session_dir.is_some()); | |
543 | ||
29967ef6 XL |
544 | // If a module exists in both the current and the previous session, |
545 | // and has the same LTO cache key in both sessions, then we can re-use it | |
546 | if prev_key_map.keys.get(module_name) == curr_key_map.keys.get(module_name) { | |
b7449926 XL |
547 | let work_product = green_modules[module_name].clone(); |
548 | copy_jobs.push(work_product); | |
549 | info!(" - {}: re-used", module_name); | |
dfeec247 XL |
550 | assert!(cgcx.incr_comp_session_dir.is_some()); |
551 | cgcx.cgu_reuse_tracker.set_actual_reuse(module_name, CguReuse::PostLto); | |
552 | continue; | |
b7449926 XL |
553 | } |
554 | } | |
555 | ||
556 | info!(" - {}: re-compiled", module_name); | |
557 | opt_jobs.push(LtoModuleCodegen::Thin(ThinModule { | |
ea8adc8c | 558 | shared: shared.clone(), |
b7449926 XL |
559 | idx: module_index, |
560 | })); | |
561 | } | |
562 | ||
74b04a01 | 563 | // Save the current ThinLTO import information for the next compilation |
29967ef6 XL |
564 | // session, overwriting the previous serialized data (if any). |
565 | if let Some(path) = key_map_path { | |
566 | if let Err(err) = curr_key_map.save_to_file(&path) { | |
567 | let msg = format!("Error while writing ThinLTO key data: {}", err); | |
c295e0f8 | 568 | return Err(write::llvm_err(diag_handler, &msg)); |
dfeec247 XL |
569 | } |
570 | } | |
571 | ||
b7449926 | 572 | Ok((opt_jobs, copy_jobs)) |
b039eaaf | 573 | } |
ea8adc8c | 574 | } |
b039eaaf | 575 | |
dfeec247 XL |
576 | pub(crate) fn run_pass_manager( |
577 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
17df50a5 | 578 | diag_handler: &Handler, |
dfeec247 XL |
579 | module: &ModuleCodegen<ModuleLlvm>, |
580 | config: &ModuleConfig, | |
581 | thin: bool, | |
17df50a5 | 582 | ) -> Result<(), FatalError> { |
a2a8927a | 583 | let _timer = cgcx.prof.extra_verbose_generic_activity("LLVM_lto_optimize", &*module.name); |
74b04a01 | 584 | |
1a4d82fc JJ |
585 | // Now we have one massive module inside of llmod. Time to run the |
586 | // LTO-specific optimization passes that LLVM provides. | |
587 | // | |
588 | // This code is based off the code found in llvm's LTO code generator: | |
589 | // tools/lto/LTOCodeGenerator.cpp | |
590 | debug!("running the pass manager"); | |
591 | unsafe { | |
a2a8927a XL |
592 | if llvm_util::should_use_new_llvm_pass_manager( |
593 | &config.new_llvm_pass_manager, | |
594 | &cgcx.target_arch, | |
595 | ) { | |
74b04a01 XL |
596 | let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO }; |
597 | let opt_level = config.opt_level.unwrap_or(config::OptLevel::No); | |
17df50a5 XL |
598 | write::optimize_with_new_llvm_pass_manager( |
599 | cgcx, | |
600 | diag_handler, | |
601 | module, | |
602 | config, | |
603 | opt_level, | |
604 | opt_stage, | |
605 | )?; | |
74b04a01 | 606 | debug!("lto done"); |
17df50a5 | 607 | return Ok(()); |
74b04a01 XL |
608 | } |
609 | ||
1a4d82fc | 610 | let pm = llvm::LLVMCreatePassManager(); |
60c5eb7d | 611 | llvm::LLVMAddAnalysisPasses(module.module_llvm.tm, pm); |
8faf50e0 XL |
612 | |
613 | if config.verify_llvm_ir { | |
e74abb32 | 614 | let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast()); |
b7449926 | 615 | llvm::LLVMRustAddPass(pm, pass.unwrap()); |
8faf50e0 | 616 | } |
1a4d82fc | 617 | |
dfeec247 XL |
618 | let opt_level = config |
619 | .opt_level | |
620 | .map(|x| to_llvm_opt_settings(x).0) | |
a1dfa0c6 | 621 | .unwrap_or(llvm::CodeGenOptLevel::None); |
a1dfa0c6 | 622 | with_llvm_pmb(module.module_llvm.llmod(), config, opt_level, false, &mut |b| { |
ea8adc8c | 623 | if thin { |
a1dfa0c6 | 624 | llvm::LLVMRustPassManagerBuilderPopulateThinLTOPassManager(b, pm); |
ea8adc8c | 625 | } else { |
dfeec247 XL |
626 | llvm::LLVMPassManagerBuilderPopulateLTOPassManager( |
627 | b, pm, /* Internalize = */ False, /* RunInliner = */ True, | |
628 | ); | |
ea8adc8c | 629 | } |
c1a9b12d | 630 | }); |
1a4d82fc | 631 | |
a1dfa0c6 XL |
632 | // We always generate bitcode through ThinLTOBuffers, |
633 | // which do not support anonymous globals | |
634 | if config.bitcode_needed() { | |
e74abb32 | 635 | let pass = llvm::LLVMRustFindAndCreatePass("name-anon-globals\0".as_ptr().cast()); |
a1dfa0c6 XL |
636 | llvm::LLVMRustAddPass(pm, pass.unwrap()); |
637 | } | |
638 | ||
8faf50e0 | 639 | if config.verify_llvm_ir { |
e74abb32 | 640 | let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast()); |
b7449926 | 641 | llvm::LLVMRustAddPass(pm, pass.unwrap()); |
8faf50e0 | 642 | } |
1a4d82fc | 643 | |
74b04a01 | 644 | llvm::LLVMRunPassManager(pm, module.module_llvm.llmod()); |
1a4d82fc JJ |
645 | |
646 | llvm::LLVMDisposePassManager(pm); | |
647 | } | |
648 | debug!("lto done"); | |
17df50a5 | 649 | Ok(()) |
1a4d82fc JJ |
650 | } |
651 | ||
b7449926 | 652 | pub struct ModuleBuffer(&'static mut llvm::ModuleBuffer); |
ea8adc8c XL |
653 | |
654 | unsafe impl Send for ModuleBuffer {} | |
655 | unsafe impl Sync for ModuleBuffer {} | |
656 | ||
657 | impl ModuleBuffer { | |
b7449926 | 658 | pub fn new(m: &llvm::Module) -> ModuleBuffer { |
dfeec247 | 659 | ModuleBuffer(unsafe { llvm::LLVMRustModuleBufferCreate(m) }) |
ea8adc8c | 660 | } |
a1dfa0c6 | 661 | } |
ea8adc8c | 662 | |
a1dfa0c6 XL |
663 | impl ModuleBufferMethods for ModuleBuffer { |
664 | fn data(&self) -> &[u8] { | |
ea8adc8c XL |
665 | unsafe { |
666 | let ptr = llvm::LLVMRustModuleBufferPtr(self.0); | |
667 | let len = llvm::LLVMRustModuleBufferLen(self.0); | |
668 | slice::from_raw_parts(ptr, len) | |
669 | } | |
670 | } | |
671 | } | |
672 | ||
673 | impl Drop for ModuleBuffer { | |
674 | fn drop(&mut self) { | |
dfeec247 XL |
675 | unsafe { |
676 | llvm::LLVMRustModuleBufferFree(&mut *(self.0 as *mut _)); | |
677 | } | |
ea8adc8c XL |
678 | } |
679 | } | |
680 | ||
a1dfa0c6 | 681 | pub struct ThinData(&'static mut llvm::ThinLTOData); |
ea8adc8c XL |
682 | |
683 | unsafe impl Send for ThinData {} | |
684 | unsafe impl Sync for ThinData {} | |
685 | ||
686 | impl Drop for ThinData { | |
687 | fn drop(&mut self) { | |
688 | unsafe { | |
b7449926 | 689 | llvm::LLVMRustFreeThinLTOData(&mut *(self.0 as *mut _)); |
ea8adc8c XL |
690 | } |
691 | } | |
692 | } | |
693 | ||
b7449926 | 694 | pub struct ThinBuffer(&'static mut llvm::ThinLTOBuffer); |
ea8adc8c XL |
695 | |
696 | unsafe impl Send for ThinBuffer {} | |
697 | unsafe impl Sync for ThinBuffer {} | |
698 | ||
699 | impl ThinBuffer { | |
b7449926 | 700 | pub fn new(m: &llvm::Module) -> ThinBuffer { |
abe05a73 XL |
701 | unsafe { |
702 | let buffer = llvm::LLVMRustThinLTOBufferCreate(m); | |
703 | ThinBuffer(buffer) | |
704 | } | |
705 | } | |
a1dfa0c6 | 706 | } |
abe05a73 | 707 | |
a1dfa0c6 XL |
708 | impl ThinBufferMethods for ThinBuffer { |
709 | fn data(&self) -> &[u8] { | |
ea8adc8c XL |
710 | unsafe { |
711 | let ptr = llvm::LLVMRustThinLTOBufferPtr(self.0) as *const _; | |
712 | let len = llvm::LLVMRustThinLTOBufferLen(self.0); | |
713 | slice::from_raw_parts(ptr, len) | |
714 | } | |
715 | } | |
1a4d82fc JJ |
716 | } |
717 | ||
ea8adc8c XL |
718 | impl Drop for ThinBuffer { |
719 | fn drop(&mut self) { | |
720 | unsafe { | |
b7449926 | 721 | llvm::LLVMRustThinLTOBufferFree(&mut *(self.0 as *mut _)); |
ea8adc8c XL |
722 | } |
723 | } | |
1a4d82fc JJ |
724 | } |
725 | ||
a1dfa0c6 XL |
726 | pub unsafe fn optimize_thin_module( |
727 | thin_module: &mut ThinModule<LlvmCodegenBackend>, | |
728 | cgcx: &CodegenContext<LlvmCodegenBackend>, | |
a1dfa0c6 XL |
729 | ) -> Result<ModuleCodegen<ModuleLlvm>, FatalError> { |
730 | let diag_handler = cgcx.create_diag_handler(); | |
fc512014 XL |
731 | |
732 | let module_name = &thin_module.shared.module_names[thin_module.idx]; | |
5869c6ff | 733 | let tm_factory_config = TargetMachineFactoryConfig::new(cgcx, module_name.to_str().unwrap()); |
fc512014 XL |
734 | let tm = |
735 | (cgcx.tm_factory)(tm_factory_config).map_err(|e| write::llvm_err(&diag_handler, &e))?; | |
a1dfa0c6 XL |
736 | |
737 | // Right now the implementation we've got only works over serialized | |
738 | // modules, so we create a fresh new LLVM context and parse the module | |
739 | // into that context. One day, however, we may do this for upstream | |
740 | // crates but for locally codegened modules we may be able to reuse | |
741 | // that LLVM Context and Module. | |
742 | let llcx = llvm::LLVMRustContextCreate(cgcx.fewer_names); | |
c295e0f8 | 743 | let llmod_raw = parse_module(llcx, module_name, thin_module.data(), &diag_handler)? as *const _; |
a1dfa0c6 | 744 | let module = ModuleCodegen { |
dfeec247 | 745 | module_llvm: ModuleLlvm { llmod_raw, llcx, tm }, |
a1dfa0c6 XL |
746 | name: thin_module.name().to_string(), |
747 | kind: ModuleKind::Regular, | |
748 | }; | |
749 | { | |
f035d41b | 750 | let target = &*module.module_llvm.tm; |
a1dfa0c6 | 751 | let llmod = module.module_llvm.llmod(); |
c295e0f8 | 752 | save_temp_bitcode(cgcx, &module, "thin-lto-input"); |
a1dfa0c6 XL |
753 | |
754 | // Before we do much else find the "main" `DICompileUnit` that we'll be | |
755 | // using below. If we find more than one though then rustc has changed | |
756 | // in a way we're not ready for, so generate an ICE by returning | |
757 | // an error. | |
758 | let mut cu1 = ptr::null_mut(); | |
759 | let mut cu2 = ptr::null_mut(); | |
c295e0f8 | 760 | llvm::LLVMRustLTOGetDICompileUnit(llmod, &mut cu1, &mut cu2); |
a1dfa0c6 XL |
761 | if !cu2.is_null() { |
762 | let msg = "multiple source DICompileUnits found"; | |
dfeec247 | 763 | return Err(write::llvm_err(&diag_handler, msg)); |
a1dfa0c6 | 764 | } |
ff7c6d11 | 765 | |
a1dfa0c6 XL |
766 | // Up next comes the per-module local analyses that we do for Thin LTO. |
767 | // Each of these functions is basically copied from the LLVM | |
768 | // implementation and then tailored to suit this implementation. Ideally | |
769 | // each of these would be supported by upstream LLVM but that's perhaps | |
770 | // a patch for another day! | |
771 | // | |
772 | // You can find some more comments about these functions in the LLVM | |
773 | // bindings we've got (currently `PassWrapper.cpp`) | |
e74abb32 | 774 | { |
74b04a01 XL |
775 | let _timer = |
776 | cgcx.prof.generic_activity_with_arg("LLVM_thin_lto_rename", thin_module.name()); | |
f035d41b | 777 | if !llvm::LLVMRustPrepareThinLTORename(thin_module.shared.data.0, llmod, target) { |
e74abb32 | 778 | let msg = "failed to prepare thin LTO module"; |
dfeec247 | 779 | return Err(write::llvm_err(&diag_handler, msg)); |
e74abb32 XL |
780 | } |
781 | save_temp_bitcode(cgcx, &module, "thin-lto-after-rename"); | |
a1dfa0c6 | 782 | } |
e74abb32 XL |
783 | |
784 | { | |
74b04a01 XL |
785 | let _timer = cgcx |
786 | .prof | |
787 | .generic_activity_with_arg("LLVM_thin_lto_resolve_weak", thin_module.name()); | |
e74abb32 XL |
788 | if !llvm::LLVMRustPrepareThinLTOResolveWeak(thin_module.shared.data.0, llmod) { |
789 | let msg = "failed to prepare thin LTO module"; | |
dfeec247 | 790 | return Err(write::llvm_err(&diag_handler, msg)); |
e74abb32 XL |
791 | } |
792 | save_temp_bitcode(cgcx, &module, "thin-lto-after-resolve"); | |
ea8adc8c | 793 | } |
e74abb32 XL |
794 | |
795 | { | |
74b04a01 XL |
796 | let _timer = cgcx |
797 | .prof | |
798 | .generic_activity_with_arg("LLVM_thin_lto_internalize", thin_module.name()); | |
e74abb32 XL |
799 | if !llvm::LLVMRustPrepareThinLTOInternalize(thin_module.shared.data.0, llmod) { |
800 | let msg = "failed to prepare thin LTO module"; | |
dfeec247 | 801 | return Err(write::llvm_err(&diag_handler, msg)); |
e74abb32 XL |
802 | } |
803 | save_temp_bitcode(cgcx, &module, "thin-lto-after-internalize"); | |
a1dfa0c6 | 804 | } |
e74abb32 XL |
805 | |
806 | { | |
74b04a01 XL |
807 | let _timer = |
808 | cgcx.prof.generic_activity_with_arg("LLVM_thin_lto_import", thin_module.name()); | |
f035d41b | 809 | if !llvm::LLVMRustPrepareThinLTOImport(thin_module.shared.data.0, llmod, target) { |
e74abb32 | 810 | let msg = "failed to prepare thin LTO module"; |
dfeec247 | 811 | return Err(write::llvm_err(&diag_handler, msg)); |
e74abb32 XL |
812 | } |
813 | save_temp_bitcode(cgcx, &module, "thin-lto-after-import"); | |
a1dfa0c6 | 814 | } |
b7449926 | 815 | |
a1dfa0c6 XL |
816 | // Ok now this is a bit unfortunate. This is also something you won't |
817 | // find upstream in LLVM's ThinLTO passes! This is a hack for now to | |
818 | // work around bugs in LLVM. | |
819 | // | |
820 | // First discovered in #45511 it was found that as part of ThinLTO | |
821 | // importing passes LLVM will import `DICompileUnit` metadata | |
822 | // information across modules. This means that we'll be working with one | |
823 | // LLVM module that has multiple `DICompileUnit` instances in it (a | |
824 | // bunch of `llvm.dbg.cu` members). Unfortunately there's a number of | |
825 | // bugs in LLVM's backend which generates invalid DWARF in a situation | |
826 | // like this: | |
827 | // | |
828 | // https://bugs.llvm.org/show_bug.cgi?id=35212 | |
829 | // https://bugs.llvm.org/show_bug.cgi?id=35562 | |
830 | // | |
831 | // While the first bug there is fixed the second ended up causing #46346 | |
832 | // which was basically a resurgence of #45511 after LLVM's bug 35212 was | |
833 | // fixed. | |
834 | // | |
835 | // This function below is a huge hack around this problem. The function | |
836 | // below is defined in `PassWrapper.cpp` and will basically "merge" | |
837 | // all `DICompileUnit` instances in a module. Basically it'll take all | |
838 | // the objects, rewrite all pointers of `DISubprogram` to point to the | |
839 | // first `DICompileUnit`, and then delete all the other units. | |
840 | // | |
841 | // This is probably mangling to the debug info slightly (but hopefully | |
842 | // not too much) but for now at least gets LLVM to emit valid DWARF (or | |
843 | // so it appears). Hopefully we can remove this once upstream bugs are | |
844 | // fixed in LLVM. | |
e74abb32 | 845 | { |
74b04a01 XL |
846 | let _timer = cgcx |
847 | .prof | |
848 | .generic_activity_with_arg("LLVM_thin_lto_patch_debuginfo", thin_module.name()); | |
c295e0f8 | 849 | llvm::LLVMRustLTOPatchDICompileUnit(llmod, cu1); |
e74abb32 XL |
850 | save_temp_bitcode(cgcx, &module, "thin-lto-after-patch"); |
851 | } | |
a1dfa0c6 XL |
852 | |
853 | // Alright now that we've done everything related to the ThinLTO | |
854 | // analysis it's time to run some optimizations! Here we use the same | |
855 | // `run_pass_manager` as the "fat" LTO above except that we tell it to | |
856 | // populate a thin-specific pass manager, which presumably LLVM treats a | |
857 | // little differently. | |
e74abb32 | 858 | { |
e74abb32 XL |
859 | info!("running thin lto passes over {}", module.name); |
860 | let config = cgcx.config(module.kind); | |
17df50a5 | 861 | run_pass_manager(cgcx, &diag_handler, &module, config, true)?; |
e74abb32 XL |
862 | save_temp_bitcode(cgcx, &module, "thin-lto-after-pm"); |
863 | } | |
b7449926 | 864 | } |
a1dfa0c6 | 865 | Ok(module) |
b7449926 XL |
866 | } |
867 | ||
29967ef6 | 868 | /// Maps LLVM module identifiers to their corresponding LLVM LTO cache keys |
0bf4aa26 | 869 | #[derive(Debug, Default)] |
29967ef6 XL |
870 | pub struct ThinLTOKeysMap { |
871 | // key = llvm name of importing module, value = LLVM cache key | |
872 | keys: FxHashMap<String, String>, | |
b7449926 XL |
873 | } |
874 | ||
29967ef6 | 875 | impl ThinLTOKeysMap { |
dfeec247 XL |
876 | fn save_to_file(&self, path: &Path) -> io::Result<()> { |
877 | use std::io::Write; | |
878 | let file = File::create(path)?; | |
879 | let mut writer = io::BufWriter::new(file); | |
29967ef6 XL |
880 | for (module, key) in &self.keys { |
881 | writeln!(writer, "{} {}", module, key)?; | |
dfeec247 XL |
882 | } |
883 | Ok(()) | |
884 | } | |
885 | ||
29967ef6 | 886 | fn load_from_file(path: &Path) -> io::Result<Self> { |
dfeec247 | 887 | use std::io::BufRead; |
29967ef6 | 888 | let mut keys = FxHashMap::default(); |
dfeec247 XL |
889 | let file = File::open(path)?; |
890 | for line in io::BufReader::new(file).lines() { | |
891 | let line = line?; | |
29967ef6 XL |
892 | let mut split = line.split(' '); |
893 | let module = split.next().unwrap(); | |
894 | let key = split.next().unwrap(); | |
895 | assert_eq!(split.next(), None, "Expected two space-separated values, found {:?}", line); | |
896 | keys.insert(module.to_string(), key.to_string()); | |
dfeec247 | 897 | } |
29967ef6 | 898 | Ok(Self { keys }) |
dfeec247 XL |
899 | } |
900 | ||
29967ef6 XL |
901 | fn from_thin_lto_modules( |
902 | data: &ThinData, | |
903 | modules: &[llvm::ThinLTOModule], | |
904 | names: &[CString], | |
905 | ) -> Self { | |
cdc7bbd5 | 906 | let keys = iter::zip(modules, names) |
29967ef6 XL |
907 | .map(|(module, name)| { |
908 | let key = build_string(|rust_str| unsafe { | |
909 | llvm::LLVMRustComputeLTOCacheKey(rust_str, module.identifier, data.0); | |
910 | }) | |
911 | .expect("Invalid ThinLTO module key"); | |
912 | (name.clone().into_string().unwrap(), key) | |
913 | }) | |
914 | .collect(); | |
915 | Self { keys } | |
b7449926 XL |
916 | } |
917 | } | |
918 | ||
919 | fn module_name_to_str(c_str: &CStr) -> &str { | |
dfeec247 XL |
920 | c_str.to_str().unwrap_or_else(|e| { |
921 | bug!("Encountered non-utf8 LLVM module name `{}`: {}", c_str.to_string_lossy(), e) | |
922 | }) | |
1a4d82fc | 923 | } |
9fa01778 | 924 | |
e1599b0c | 925 | pub fn parse_module<'a>( |
9fa01778 XL |
926 | cx: &'a llvm::Context, |
927 | name: &CStr, | |
928 | data: &[u8], | |
929 | diag_handler: &Handler, | |
930 | ) -> Result<&'a llvm::Module, FatalError> { | |
931 | unsafe { | |
dfeec247 XL |
932 | llvm::LLVMRustParseBitcodeForLTO(cx, data.as_ptr(), data.len(), name.as_ptr()).ok_or_else( |
933 | || { | |
934 | let msg = "failed to parse bitcode for LTO module"; | |
c295e0f8 | 935 | write::llvm_err(diag_handler, msg) |
dfeec247 XL |
936 | }, |
937 | ) | |
9fa01778 XL |
938 | } |
939 | } |