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62682a34 SL |
1 | // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
9e0c209e | 11 | use std::collections::HashMap; |
cc61c64b | 12 | use std::ffi::{OsStr, OsString}; |
e9174d1e | 13 | use std::fs::{self, File}; |
e9174d1e | 14 | use std::io::prelude::*; |
9e0c209e | 15 | use std::io::{self, BufWriter}; |
62682a34 | 16 | use std::path::{Path, PathBuf}; |
3157f602 | 17 | |
c1a9b12d | 18 | use back::archive; |
ea8adc8c XL |
19 | use back::command::Command; |
20 | use back::symbol_export; | |
476ff2be | 21 | use rustc::hir::def_id::{LOCAL_CRATE, CrateNum}; |
ea8adc8c | 22 | use rustc::middle::dependency_format::Linkage; |
7cac9316 XL |
23 | use rustc::session::Session; |
24 | use rustc::session::config::{self, CrateType, OptLevel, DebugInfoLevel}; | |
ea8adc8c | 25 | use rustc::ty::TyCtxt; |
0531ce1d | 26 | use rustc_back::{LinkerFlavor, LldFlavor}; |
8bb4bdeb | 27 | use serialize::{json, Encoder}; |
3157f602 XL |
28 | |
29 | /// For all the linkers we support, and information they might | |
30 | /// need out of the shared crate context before we get rid of it. | |
31 | pub struct LinkerInfo { | |
9e0c209e | 32 | exports: HashMap<CrateType, Vec<String>>, |
3157f602 XL |
33 | } |
34 | ||
ea8adc8c XL |
35 | impl LinkerInfo { |
36 | pub fn new(tcx: TyCtxt) -> LinkerInfo { | |
3157f602 | 37 | LinkerInfo { |
ea8adc8c XL |
38 | exports: tcx.sess.crate_types.borrow().iter().map(|&c| { |
39 | (c, exported_symbols(tcx, c)) | |
9e0c209e | 40 | }).collect(), |
3157f602 XL |
41 | } |
42 | } | |
43 | ||
ea8adc8c XL |
44 | pub fn to_linker<'a>(&'a self, |
45 | cmd: Command, | |
46 | sess: &'a Session) -> Box<Linker+'a> { | |
cc61c64b | 47 | match sess.linker_flavor() { |
0531ce1d | 48 | LinkerFlavor::Lld(LldFlavor::Link) | |
cc61c64b XL |
49 | LinkerFlavor::Msvc => { |
50 | Box::new(MsvcLinker { | |
3b2f2976 XL |
51 | cmd, |
52 | sess, | |
cc61c64b XL |
53 | info: self |
54 | }) as Box<Linker> | |
55 | } | |
56 | LinkerFlavor::Em => { | |
57 | Box::new(EmLinker { | |
3b2f2976 XL |
58 | cmd, |
59 | sess, | |
cc61c64b XL |
60 | info: self |
61 | }) as Box<Linker> | |
62 | } | |
63 | LinkerFlavor::Gcc => { | |
64 | Box::new(GccLinker { | |
3b2f2976 XL |
65 | cmd, |
66 | sess, | |
cc61c64b XL |
67 | info: self, |
68 | hinted_static: false, | |
69 | is_ld: false, | |
70 | }) as Box<Linker> | |
71 | } | |
0531ce1d XL |
72 | |
73 | LinkerFlavor::Lld(LldFlavor::Ld) | | |
74 | LinkerFlavor::Lld(LldFlavor::Ld64) | | |
cc61c64b XL |
75 | LinkerFlavor::Ld => { |
76 | Box::new(GccLinker { | |
3b2f2976 XL |
77 | cmd, |
78 | sess, | |
cc61c64b XL |
79 | info: self, |
80 | hinted_static: false, | |
81 | is_ld: true, | |
82 | }) as Box<Linker> | |
83 | } | |
0531ce1d XL |
84 | |
85 | LinkerFlavor::Lld(LldFlavor::Wasm) => { | |
86 | Box::new(WasmLd { | |
87 | cmd, | |
88 | }) as Box<Linker> | |
abe05a73 | 89 | } |
3157f602 XL |
90 | } |
91 | } | |
92 | } | |
62682a34 SL |
93 | |
94 | /// Linker abstraction used by back::link to build up the command to invoke a | |
95 | /// linker. | |
96 | /// | |
97 | /// This trait is the total list of requirements needed by `back::link` and | |
98 | /// represents the meaning of each option being passed down. This trait is then | |
99 | /// used to dispatch on whether a GNU-like linker (generally `ld.exe`) or an | |
100 | /// MSVC linker (e.g. `link.exe`) is being used. | |
101 | pub trait Linker { | |
102 | fn link_dylib(&mut self, lib: &str); | |
c1a9b12d | 103 | fn link_rust_dylib(&mut self, lib: &str, path: &Path); |
62682a34 SL |
104 | fn link_framework(&mut self, framework: &str); |
105 | fn link_staticlib(&mut self, lib: &str); | |
106 | fn link_rlib(&mut self, lib: &Path); | |
c1a9b12d | 107 | fn link_whole_rlib(&mut self, lib: &Path); |
62682a34 SL |
108 | fn link_whole_staticlib(&mut self, lib: &str, search_path: &[PathBuf]); |
109 | fn include_path(&mut self, path: &Path); | |
110 | fn framework_path(&mut self, path: &Path); | |
111 | fn output_filename(&mut self, path: &Path); | |
112 | fn add_object(&mut self, path: &Path); | |
a7813a04 | 113 | fn gc_sections(&mut self, keep_metadata: bool); |
62682a34 | 114 | fn position_independent_executable(&mut self); |
0531ce1d | 115 | fn no_position_independent_executable(&mut self); |
3b2f2976 | 116 | fn full_relro(&mut self); |
0531ce1d XL |
117 | fn partial_relro(&mut self); |
118 | fn no_relro(&mut self); | |
62682a34 | 119 | fn optimize(&mut self); |
0531ce1d | 120 | fn pgo_gen(&mut self); |
c1a9b12d | 121 | fn debuginfo(&mut self); |
62682a34 SL |
122 | fn no_default_libraries(&mut self); |
123 | fn build_dylib(&mut self, out_filename: &Path); | |
3b2f2976 | 124 | fn build_static_executable(&mut self); |
62682a34 | 125 | fn args(&mut self, args: &[String]); |
3157f602 | 126 | fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType); |
c30ab7b3 | 127 | fn subsystem(&mut self, subsystem: &str); |
0531ce1d XL |
128 | fn group_start(&mut self); |
129 | fn group_end(&mut self); | |
cc61c64b XL |
130 | // Should have been finalize(self), but we don't support self-by-value on trait objects (yet?). |
131 | fn finalize(&mut self) -> Command; | |
62682a34 SL |
132 | } |
133 | ||
cc61c64b XL |
134 | pub struct GccLinker<'a> { |
135 | cmd: Command, | |
3157f602 | 136 | sess: &'a Session, |
cc61c64b XL |
137 | info: &'a LinkerInfo, |
138 | hinted_static: bool, // Keeps track of the current hinting mode. | |
139 | // Link as ld | |
140 | is_ld: bool, | |
62682a34 SL |
141 | } |
142 | ||
cc61c64b XL |
143 | impl<'a> GccLinker<'a> { |
144 | /// Argument that must be passed *directly* to the linker | |
145 | /// | |
146 | /// These arguments need to be prepended with '-Wl,' when a gcc-style linker is used | |
147 | fn linker_arg<S>(&mut self, arg: S) -> &mut Self | |
148 | where S: AsRef<OsStr> | |
149 | { | |
150 | if !self.is_ld { | |
151 | let mut os = OsString::from("-Wl,"); | |
152 | os.push(arg.as_ref()); | |
153 | self.cmd.arg(os); | |
154 | } else { | |
155 | self.cmd.arg(arg); | |
156 | } | |
157 | self | |
158 | } | |
159 | ||
62682a34 SL |
160 | fn takes_hints(&self) -> bool { |
161 | !self.sess.target.target.options.is_like_osx | |
162 | } | |
cc61c64b XL |
163 | |
164 | // Some platforms take hints about whether a library is static or dynamic. | |
165 | // For those that support this, we ensure we pass the option if the library | |
166 | // was flagged "static" (most defaults are dynamic) to ensure that if | |
167 | // libfoo.a and libfoo.so both exist that the right one is chosen. | |
168 | fn hint_static(&mut self) { | |
169 | if !self.takes_hints() { return } | |
170 | if !self.hinted_static { | |
171 | self.linker_arg("-Bstatic"); | |
172 | self.hinted_static = true; | |
173 | } | |
174 | } | |
175 | ||
176 | fn hint_dynamic(&mut self) { | |
177 | if !self.takes_hints() { return } | |
178 | if self.hinted_static { | |
179 | self.linker_arg("-Bdynamic"); | |
180 | self.hinted_static = false; | |
181 | } | |
182 | } | |
62682a34 SL |
183 | } |
184 | ||
cc61c64b XL |
185 | impl<'a> Linker for GccLinker<'a> { |
186 | fn link_dylib(&mut self, lib: &str) { self.hint_dynamic(); self.cmd.arg("-l").arg(lib); } | |
187 | fn link_staticlib(&mut self, lib: &str) { self.hint_static(); self.cmd.arg("-l").arg(lib); } | |
188 | fn link_rlib(&mut self, lib: &Path) { self.hint_static(); self.cmd.arg(lib); } | |
62682a34 SL |
189 | fn include_path(&mut self, path: &Path) { self.cmd.arg("-L").arg(path); } |
190 | fn framework_path(&mut self, path: &Path) { self.cmd.arg("-F").arg(path); } | |
191 | fn output_filename(&mut self, path: &Path) { self.cmd.arg("-o").arg(path); } | |
192 | fn add_object(&mut self, path: &Path) { self.cmd.arg(path); } | |
193 | fn position_independent_executable(&mut self) { self.cmd.arg("-pie"); } | |
0531ce1d | 194 | fn no_position_independent_executable(&mut self) { self.cmd.arg("-no-pie"); } |
3b2f2976 | 195 | fn full_relro(&mut self) { self.linker_arg("-z,relro,-z,now"); } |
0531ce1d XL |
196 | fn partial_relro(&mut self) { self.linker_arg("-z,relro"); } |
197 | fn no_relro(&mut self) { self.linker_arg("-z,norelro"); } | |
3b2f2976 | 198 | fn build_static_executable(&mut self) { self.cmd.arg("-static"); } |
62682a34 SL |
199 | fn args(&mut self, args: &[String]) { self.cmd.args(args); } |
200 | ||
c1a9b12d | 201 | fn link_rust_dylib(&mut self, lib: &str, _path: &Path) { |
cc61c64b | 202 | self.hint_dynamic(); |
c1a9b12d SL |
203 | self.cmd.arg("-l").arg(lib); |
204 | } | |
205 | ||
62682a34 | 206 | fn link_framework(&mut self, framework: &str) { |
cc61c64b | 207 | self.hint_dynamic(); |
62682a34 SL |
208 | self.cmd.arg("-framework").arg(framework); |
209 | } | |
210 | ||
cc61c64b XL |
211 | // Here we explicitly ask that the entire archive is included into the |
212 | // result artifact. For more details see #15460, but the gist is that | |
213 | // the linker will strip away any unused objects in the archive if we | |
214 | // don't otherwise explicitly reference them. This can occur for | |
215 | // libraries which are just providing bindings, libraries with generic | |
216 | // functions, etc. | |
62682a34 | 217 | fn link_whole_staticlib(&mut self, lib: &str, search_path: &[PathBuf]) { |
cc61c64b | 218 | self.hint_static(); |
62682a34 SL |
219 | let target = &self.sess.target.target; |
220 | if !target.options.is_like_osx { | |
cc61c64b XL |
221 | self.linker_arg("--whole-archive").cmd.arg("-l").arg(lib); |
222 | self.linker_arg("--no-whole-archive"); | |
62682a34 | 223 | } else { |
cc61c64b | 224 | // -force_load is the macOS equivalent of --whole-archive, but it |
62682a34 | 225 | // involves passing the full path to the library to link. |
cc61c64b | 226 | let mut v = OsString::from("-force_load,"); |
c1a9b12d | 227 | v.push(&archive::find_library(lib, search_path, &self.sess)); |
cc61c64b | 228 | self.linker_arg(&v); |
c1a9b12d SL |
229 | } |
230 | } | |
231 | ||
232 | fn link_whole_rlib(&mut self, lib: &Path) { | |
cc61c64b | 233 | self.hint_static(); |
c1a9b12d | 234 | if self.sess.target.target.options.is_like_osx { |
cc61c64b | 235 | let mut v = OsString::from("-force_load,"); |
c1a9b12d | 236 | v.push(lib); |
cc61c64b | 237 | self.linker_arg(&v); |
c1a9b12d | 238 | } else { |
cc61c64b XL |
239 | self.linker_arg("--whole-archive").cmd.arg(lib); |
240 | self.linker_arg("--no-whole-archive"); | |
62682a34 SL |
241 | } |
242 | } | |
243 | ||
a7813a04 | 244 | fn gc_sections(&mut self, keep_metadata: bool) { |
62682a34 SL |
245 | // The dead_strip option to the linker specifies that functions and data |
246 | // unreachable by the entry point will be removed. This is quite useful | |
247 | // with Rust's compilation model of compiling libraries at a time into | |
248 | // one object file. For example, this brings hello world from 1.7MB to | |
249 | // 458K. | |
250 | // | |
251 | // Note that this is done for both executables and dynamic libraries. We | |
252 | // won't get much benefit from dylibs because LLVM will have already | |
253 | // stripped away as much as it could. This has not been seen to impact | |
254 | // link times negatively. | |
255 | // | |
256 | // -dead_strip can't be part of the pre_link_args because it's also used | |
257 | // for partial linking when using multiple codegen units (-r). So we | |
258 | // insert it here. | |
259 | if self.sess.target.target.options.is_like_osx { | |
cc61c64b | 260 | self.linker_arg("-dead_strip"); |
7453a54e | 261 | } else if self.sess.target.target.options.is_like_solaris { |
cc61c64b XL |
262 | self.linker_arg("-z"); |
263 | self.linker_arg("ignore"); | |
62682a34 SL |
264 | |
265 | // If we're building a dylib, we don't use --gc-sections because LLVM | |
266 | // has already done the best it can do, and we also don't want to | |
267 | // eliminate the metadata. If we're building an executable, however, | |
268 | // --gc-sections drops the size of hello world from 1.8MB to 597K, a 67% | |
269 | // reduction. | |
a7813a04 | 270 | } else if !keep_metadata { |
cc61c64b | 271 | self.linker_arg("--gc-sections"); |
62682a34 SL |
272 | } |
273 | } | |
274 | ||
275 | fn optimize(&mut self) { | |
276 | if !self.sess.target.target.options.linker_is_gnu { return } | |
277 | ||
278 | // GNU-style linkers support optimization with -O. GNU ld doesn't | |
279 | // need a numeric argument, but other linkers do. | |
9cc50fc6 SL |
280 | if self.sess.opts.optimize == config::OptLevel::Default || |
281 | self.sess.opts.optimize == config::OptLevel::Aggressive { | |
cc61c64b | 282 | self.linker_arg("-O1"); |
62682a34 SL |
283 | } |
284 | } | |
285 | ||
0531ce1d XL |
286 | fn pgo_gen(&mut self) { |
287 | if !self.sess.target.target.options.linker_is_gnu { return } | |
288 | ||
289 | // If we're doing PGO generation stuff and on a GNU-like linker, use the | |
290 | // "-u" flag to properly pull in the profiler runtime bits. | |
291 | // | |
292 | // This is because LLVM otherwise won't add the needed initialization | |
293 | // for us on Linux (though the extra flag should be harmless if it | |
294 | // does). | |
295 | // | |
296 | // See https://reviews.llvm.org/D14033 and https://reviews.llvm.org/D14030. | |
297 | // | |
298 | // Though it may be worth to try to revert those changes upstream, since | |
299 | // the overhead of the initialization should be minor. | |
300 | self.cmd.arg("-u"); | |
301 | self.cmd.arg("__llvm_profile_runtime"); | |
302 | } | |
303 | ||
c1a9b12d | 304 | fn debuginfo(&mut self) { |
0531ce1d XL |
305 | match self.sess.opts.debuginfo { |
306 | DebugInfoLevel::NoDebugInfo => { | |
307 | // If we are building without debuginfo enabled and we were called with | |
308 | // `-Zstrip-debuginfo-if-disabled=yes`, tell the linker to strip any debuginfo | |
309 | // found when linking to get rid of symbols from libstd. | |
310 | match self.sess.opts.debugging_opts.strip_debuginfo_if_disabled { | |
311 | Some(true) => { self.linker_arg("-S"); }, | |
312 | _ => {}, | |
313 | } | |
314 | }, | |
315 | _ => {}, | |
316 | }; | |
c1a9b12d SL |
317 | } |
318 | ||
62682a34 | 319 | fn no_default_libraries(&mut self) { |
cc61c64b XL |
320 | if !self.is_ld { |
321 | self.cmd.arg("-nodefaultlibs"); | |
322 | } | |
62682a34 SL |
323 | } |
324 | ||
325 | fn build_dylib(&mut self, out_filename: &Path) { | |
326 | // On mac we need to tell the linker to let this library be rpathed | |
327 | if self.sess.target.target.options.is_like_osx { | |
cc61c64b XL |
328 | self.cmd.arg("-dynamiclib"); |
329 | self.linker_arg("-dylib"); | |
62682a34 | 330 | |
476ff2be SL |
331 | // Note that the `osx_rpath_install_name` option here is a hack |
332 | // purely to support rustbuild right now, we should get a more | |
333 | // principled solution at some point to force the compiler to pass | |
334 | // the right `-Wl,-install_name` with an `@rpath` in it. | |
335 | if self.sess.opts.cg.rpath || | |
336 | self.sess.opts.debugging_opts.osx_rpath_install_name { | |
cc61c64b | 337 | let mut v = OsString::from("-install_name,@rpath/"); |
62682a34 | 338 | v.push(out_filename.file_name().unwrap()); |
cc61c64b | 339 | self.linker_arg(&v); |
62682a34 SL |
340 | } |
341 | } else { | |
342 | self.cmd.arg("-shared"); | |
343 | } | |
344 | } | |
345 | ||
3157f602 | 346 | fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType) { |
a7813a04 XL |
347 | // If we're compiling a dylib, then we let symbol visibility in object |
348 | // files to take care of whether they're exported or not. | |
349 | // | |
350 | // If we're compiling a cdylib, however, we manually create a list of | |
351 | // exported symbols to ensure we don't expose any more. The object files | |
352 | // have far more public symbols than we actually want to export, so we | |
353 | // hide them all here. | |
9e0c209e | 354 | if crate_type == CrateType::CrateTypeDylib || |
c30ab7b3 | 355 | crate_type == CrateType::CrateTypeProcMacro { |
a7813a04 XL |
356 | return |
357 | } | |
358 | ||
9e0c209e | 359 | let mut arg = OsString::new(); |
a7813a04 | 360 | let path = tmpdir.join("list"); |
9e0c209e | 361 | |
476ff2be SL |
362 | debug!("EXPORTED SYMBOLS:"); |
363 | ||
364 | if self.sess.target.target.options.is_like_osx { | |
365 | // Write a plain, newline-separated list of symbols | |
9e0c209e SL |
366 | let res = (|| -> io::Result<()> { |
367 | let mut f = BufWriter::new(File::create(&path)?); | |
9e0c209e | 368 | for sym in self.info.exports[&crate_type].iter() { |
476ff2be SL |
369 | debug!(" _{}", sym); |
370 | writeln!(f, "_{}", sym)?; | |
9e0c209e | 371 | } |
9e0c209e SL |
372 | Ok(()) |
373 | })(); | |
374 | if let Err(e) = res { | |
476ff2be | 375 | self.sess.fatal(&format!("failed to write lib.def file: {}", e)); |
a7813a04 | 376 | } |
a7813a04 | 377 | } else { |
476ff2be | 378 | // Write an LD version script |
9e0c209e SL |
379 | let res = (|| -> io::Result<()> { |
380 | let mut f = BufWriter::new(File::create(&path)?); | |
476ff2be | 381 | writeln!(f, "{{\n global:")?; |
9e0c209e | 382 | for sym in self.info.exports[&crate_type].iter() { |
476ff2be SL |
383 | debug!(" {};", sym); |
384 | writeln!(f, " {};", sym)?; | |
9e0c209e | 385 | } |
476ff2be | 386 | writeln!(f, "\n local:\n *;\n}};")?; |
9e0c209e SL |
387 | Ok(()) |
388 | })(); | |
389 | if let Err(e) = res { | |
476ff2be | 390 | self.sess.fatal(&format!("failed to write version script: {}", e)); |
9e0c209e | 391 | } |
a7813a04 | 392 | } |
9e0c209e | 393 | |
476ff2be | 394 | if self.sess.target.target.options.is_like_osx { |
cc61c64b XL |
395 | if !self.is_ld { |
396 | arg.push("-Wl,") | |
397 | } | |
398 | arg.push("-exported_symbols_list,"); | |
476ff2be | 399 | } else if self.sess.target.target.options.is_like_solaris { |
cc61c64b XL |
400 | if !self.is_ld { |
401 | arg.push("-Wl,") | |
402 | } | |
403 | arg.push("-M,"); | |
476ff2be | 404 | } else { |
cc61c64b XL |
405 | if !self.is_ld { |
406 | arg.push("-Wl,") | |
407 | } | |
408 | arg.push("--version-script="); | |
476ff2be SL |
409 | } |
410 | ||
411 | arg.push(&path); | |
a7813a04 | 412 | self.cmd.arg(arg); |
e9174d1e | 413 | } |
c30ab7b3 SL |
414 | |
415 | fn subsystem(&mut self, subsystem: &str) { | |
cc61c64b XL |
416 | self.linker_arg(&format!("--subsystem,{}", subsystem)); |
417 | } | |
418 | ||
419 | fn finalize(&mut self) -> Command { | |
420 | self.hint_dynamic(); // Reset to default before returning the composed command line. | |
421 | let mut cmd = Command::new(""); | |
422 | ::std::mem::swap(&mut cmd, &mut self.cmd); | |
423 | cmd | |
c30ab7b3 | 424 | } |
0531ce1d XL |
425 | |
426 | fn group_start(&mut self) { | |
427 | if !self.sess.target.target.options.is_like_osx { | |
428 | self.linker_arg("--start-group"); | |
429 | } | |
430 | } | |
431 | ||
432 | fn group_end(&mut self) { | |
433 | if !self.sess.target.target.options.is_like_osx { | |
434 | self.linker_arg("--end-group"); | |
435 | } | |
436 | } | |
62682a34 SL |
437 | } |
438 | ||
439 | pub struct MsvcLinker<'a> { | |
cc61c64b | 440 | cmd: Command, |
3157f602 XL |
441 | sess: &'a Session, |
442 | info: &'a LinkerInfo | |
62682a34 SL |
443 | } |
444 | ||
445 | impl<'a> Linker for MsvcLinker<'a> { | |
446 | fn link_rlib(&mut self, lib: &Path) { self.cmd.arg(lib); } | |
447 | fn add_object(&mut self, path: &Path) { self.cmd.arg(path); } | |
448 | fn args(&mut self, args: &[String]) { self.cmd.args(args); } | |
7453a54e SL |
449 | |
450 | fn build_dylib(&mut self, out_filename: &Path) { | |
451 | self.cmd.arg("/DLL"); | |
452 | let mut arg: OsString = "/IMPLIB:".into(); | |
453 | arg.push(out_filename.with_extension("dll.lib")); | |
454 | self.cmd.arg(arg); | |
455 | } | |
456 | ||
3b2f2976 XL |
457 | fn build_static_executable(&mut self) { |
458 | // noop | |
459 | } | |
460 | ||
a7813a04 | 461 | fn gc_sections(&mut self, _keep_metadata: bool) { |
476ff2be SL |
462 | // MSVC's ICF (Identical COMDAT Folding) link optimization is |
463 | // slow for Rust and thus we disable it by default when not in | |
464 | // optimization build. | |
465 | if self.sess.opts.optimize != config::OptLevel::No { | |
466 | self.cmd.arg("/OPT:REF,ICF"); | |
467 | } else { | |
468 | // It is necessary to specify NOICF here, because /OPT:REF | |
469 | // implies ICF by default. | |
470 | self.cmd.arg("/OPT:REF,NOICF"); | |
471 | } | |
a7813a04 | 472 | } |
62682a34 SL |
473 | |
474 | fn link_dylib(&mut self, lib: &str) { | |
475 | self.cmd.arg(&format!("{}.lib", lib)); | |
476 | } | |
c1a9b12d SL |
477 | |
478 | fn link_rust_dylib(&mut self, lib: &str, path: &Path) { | |
479 | // When producing a dll, the MSVC linker may not actually emit a | |
480 | // `foo.lib` file if the dll doesn't actually export any symbols, so we | |
481 | // check to see if the file is there and just omit linking to it if it's | |
482 | // not present. | |
7453a54e | 483 | let name = format!("{}.dll.lib", lib); |
c1a9b12d SL |
484 | if fs::metadata(&path.join(&name)).is_ok() { |
485 | self.cmd.arg(name); | |
486 | } | |
487 | } | |
488 | ||
62682a34 SL |
489 | fn link_staticlib(&mut self, lib: &str) { |
490 | self.cmd.arg(&format!("{}.lib", lib)); | |
491 | } | |
492 | ||
493 | fn position_independent_executable(&mut self) { | |
494 | // noop | |
495 | } | |
496 | ||
0531ce1d | 497 | fn no_position_independent_executable(&mut self) { |
3b2f2976 XL |
498 | // noop |
499 | } | |
500 | ||
501 | fn full_relro(&mut self) { | |
502 | // noop | |
503 | } | |
504 | ||
0531ce1d XL |
505 | fn partial_relro(&mut self) { |
506 | // noop | |
507 | } | |
508 | ||
509 | fn no_relro(&mut self) { | |
510 | // noop | |
511 | } | |
512 | ||
62682a34 SL |
513 | fn no_default_libraries(&mut self) { |
514 | // Currently we don't pass the /NODEFAULTLIB flag to the linker on MSVC | |
515 | // as there's been trouble in the past of linking the C++ standard | |
516 | // library required by LLVM. This likely needs to happen one day, but | |
517 | // in general Windows is also a more controlled environment than | |
518 | // Unix, so it's not necessarily as critical that this be implemented. | |
519 | // | |
520 | // Note that there are also some licensing worries about statically | |
521 | // linking some libraries which require a specific agreement, so it may | |
522 | // not ever be possible for us to pass this flag. | |
523 | } | |
524 | ||
525 | fn include_path(&mut self, path: &Path) { | |
526 | let mut arg = OsString::from("/LIBPATH:"); | |
527 | arg.push(path); | |
528 | self.cmd.arg(&arg); | |
529 | } | |
530 | ||
531 | fn output_filename(&mut self, path: &Path) { | |
532 | let mut arg = OsString::from("/OUT:"); | |
533 | arg.push(path); | |
534 | self.cmd.arg(&arg); | |
535 | } | |
536 | ||
537 | fn framework_path(&mut self, _path: &Path) { | |
54a0048b | 538 | bug!("frameworks are not supported on windows") |
62682a34 SL |
539 | } |
540 | fn link_framework(&mut self, _framework: &str) { | |
54a0048b | 541 | bug!("frameworks are not supported on windows") |
62682a34 SL |
542 | } |
543 | ||
544 | fn link_whole_staticlib(&mut self, lib: &str, _search_path: &[PathBuf]) { | |
545 | // not supported? | |
546 | self.link_staticlib(lib); | |
547 | } | |
c1a9b12d SL |
548 | fn link_whole_rlib(&mut self, path: &Path) { |
549 | // not supported? | |
550 | self.link_rlib(path); | |
551 | } | |
62682a34 SL |
552 | fn optimize(&mut self) { |
553 | // Needs more investigation of `/OPT` arguments | |
554 | } | |
c1a9b12d | 555 | |
0531ce1d XL |
556 | fn pgo_gen(&mut self) { |
557 | // Nothing needed here. | |
558 | } | |
559 | ||
c1a9b12d | 560 | fn debuginfo(&mut self) { |
b039eaaf SL |
561 | // This will cause the Microsoft linker to generate a PDB file |
562 | // from the CodeView line tables in the object files. | |
563 | self.cmd.arg("/DEBUG"); | |
3b2f2976 XL |
564 | |
565 | // This will cause the Microsoft linker to embed .natvis info into the the PDB file | |
566 | let sysroot = self.sess.sysroot(); | |
567 | let natvis_dir_path = sysroot.join("lib\\rustlib\\etc"); | |
568 | if let Ok(natvis_dir) = fs::read_dir(&natvis_dir_path) { | |
ea8adc8c XL |
569 | // LLVM 5.0.0's lld-link frontend doesn't yet recognize, and chokes |
570 | // on, the /NATVIS:... flags. LLVM 6 (or earlier) should at worst ignore | |
571 | // them, eventually mooting this workaround, per this landed patch: | |
572 | // https://github.com/llvm-mirror/lld/commit/27b9c4285364d8d76bb43839daa100 | |
573 | if let Some(ref linker_path) = self.sess.opts.cg.linker { | |
574 | if let Some(linker_name) = Path::new(&linker_path).file_stem() { | |
575 | if linker_name.to_str().unwrap().to_lowercase() == "lld-link" { | |
576 | self.sess.warn("not embedding natvis: lld-link may not support the flag"); | |
577 | return; | |
578 | } | |
579 | } | |
580 | } | |
3b2f2976 XL |
581 | for entry in natvis_dir { |
582 | match entry { | |
583 | Ok(entry) => { | |
584 | let path = entry.path(); | |
585 | if path.extension() == Some("natvis".as_ref()) { | |
586 | let mut arg = OsString::from("/NATVIS:"); | |
587 | arg.push(path); | |
588 | self.cmd.arg(arg); | |
589 | } | |
590 | }, | |
591 | Err(err) => { | |
592 | self.sess.warn(&format!("error enumerating natvis directory: {}", err)); | |
593 | }, | |
594 | } | |
595 | } | |
596 | } | |
c1a9b12d SL |
597 | } |
598 | ||
e9174d1e SL |
599 | // Currently the compiler doesn't use `dllexport` (an LLVM attribute) to |
600 | // export symbols from a dynamic library. When building a dynamic library, | |
601 | // however, we're going to want some symbols exported, so this function | |
602 | // generates a DEF file which lists all the symbols. | |
603 | // | |
604 | // The linker will read this `*.def` file and export all the symbols from | |
605 | // the dynamic library. Note that this is not as simple as just exporting | |
606 | // all the symbols in the current crate (as specified by `trans.reachable`) | |
607 | // but rather we also need to possibly export the symbols of upstream | |
608 | // crates. Upstream rlibs may be linked statically to this dynamic library, | |
609 | // in which case they may continue to transitively be used and hence need | |
610 | // their symbols exported. | |
a7813a04 | 611 | fn export_symbols(&mut self, |
a7813a04 XL |
612 | tmpdir: &Path, |
613 | crate_type: CrateType) { | |
e9174d1e SL |
614 | let path = tmpdir.join("lib.def"); |
615 | let res = (|| -> io::Result<()> { | |
54a0048b | 616 | let mut f = BufWriter::new(File::create(&path)?); |
e9174d1e SL |
617 | |
618 | // Start off with the standard module name header and then go | |
619 | // straight to exports. | |
54a0048b SL |
620 | writeln!(f, "LIBRARY")?; |
621 | writeln!(f, "EXPORTS")?; | |
9e0c209e | 622 | for symbol in self.info.exports[&crate_type].iter() { |
8bb4bdeb | 623 | debug!(" _{}", symbol); |
3157f602 | 624 | writeln!(f, " {}", symbol)?; |
e9174d1e | 625 | } |
e9174d1e SL |
626 | Ok(()) |
627 | })(); | |
628 | if let Err(e) = res { | |
3157f602 | 629 | self.sess.fatal(&format!("failed to write lib.def file: {}", e)); |
e9174d1e SL |
630 | } |
631 | let mut arg = OsString::from("/DEF:"); | |
632 | arg.push(path); | |
633 | self.cmd.arg(&arg); | |
634 | } | |
c30ab7b3 SL |
635 | |
636 | fn subsystem(&mut self, subsystem: &str) { | |
637 | // Note that previous passes of the compiler validated this subsystem, | |
638 | // so we just blindly pass it to the linker. | |
639 | self.cmd.arg(&format!("/SUBSYSTEM:{}", subsystem)); | |
640 | ||
641 | // Windows has two subsystems we're interested in right now, the console | |
642 | // and windows subsystems. These both implicitly have different entry | |
643 | // points (starting symbols). The console entry point starts with | |
644 | // `mainCRTStartup` and the windows entry point starts with | |
645 | // `WinMainCRTStartup`. These entry points, defined in system libraries, | |
646 | // will then later probe for either `main` or `WinMain`, respectively to | |
647 | // start the application. | |
648 | // | |
649 | // In Rust we just always generate a `main` function so we want control | |
650 | // to always start there, so we force the entry point on the windows | |
651 | // subsystem to be `mainCRTStartup` to get everything booted up | |
652 | // correctly. | |
653 | // | |
654 | // For more information see RFC #1665 | |
655 | if subsystem == "windows" { | |
656 | self.cmd.arg("/ENTRY:mainCRTStartup"); | |
657 | } | |
658 | } | |
cc61c64b XL |
659 | |
660 | fn finalize(&mut self) -> Command { | |
661 | let mut cmd = Command::new(""); | |
662 | ::std::mem::swap(&mut cmd, &mut self.cmd); | |
663 | cmd | |
664 | } | |
0531ce1d XL |
665 | |
666 | // MSVC doesn't need group indicators | |
667 | fn group_start(&mut self) {} | |
668 | fn group_end(&mut self) {} | |
62682a34 | 669 | } |
a7813a04 | 670 | |
8bb4bdeb | 671 | pub struct EmLinker<'a> { |
cc61c64b | 672 | cmd: Command, |
8bb4bdeb XL |
673 | sess: &'a Session, |
674 | info: &'a LinkerInfo | |
675 | } | |
676 | ||
677 | impl<'a> Linker for EmLinker<'a> { | |
678 | fn include_path(&mut self, path: &Path) { | |
679 | self.cmd.arg("-L").arg(path); | |
680 | } | |
681 | ||
682 | fn link_staticlib(&mut self, lib: &str) { | |
683 | self.cmd.arg("-l").arg(lib); | |
684 | } | |
685 | ||
686 | fn output_filename(&mut self, path: &Path) { | |
687 | self.cmd.arg("-o").arg(path); | |
688 | } | |
689 | ||
690 | fn add_object(&mut self, path: &Path) { | |
691 | self.cmd.arg(path); | |
692 | } | |
693 | ||
694 | fn link_dylib(&mut self, lib: &str) { | |
695 | // Emscripten always links statically | |
696 | self.link_staticlib(lib); | |
697 | } | |
698 | ||
699 | fn link_whole_staticlib(&mut self, lib: &str, _search_path: &[PathBuf]) { | |
700 | // not supported? | |
701 | self.link_staticlib(lib); | |
702 | } | |
703 | ||
704 | fn link_whole_rlib(&mut self, lib: &Path) { | |
705 | // not supported? | |
706 | self.link_rlib(lib); | |
707 | } | |
708 | ||
709 | fn link_rust_dylib(&mut self, lib: &str, _path: &Path) { | |
710 | self.link_dylib(lib); | |
711 | } | |
712 | ||
713 | fn link_rlib(&mut self, lib: &Path) { | |
714 | self.add_object(lib); | |
715 | } | |
716 | ||
717 | fn position_independent_executable(&mut self) { | |
718 | // noop | |
719 | } | |
720 | ||
0531ce1d | 721 | fn no_position_independent_executable(&mut self) { |
3b2f2976 XL |
722 | // noop |
723 | } | |
724 | ||
725 | fn full_relro(&mut self) { | |
726 | // noop | |
727 | } | |
728 | ||
0531ce1d XL |
729 | fn partial_relro(&mut self) { |
730 | // noop | |
731 | } | |
732 | ||
733 | fn no_relro(&mut self) { | |
734 | // noop | |
735 | } | |
736 | ||
8bb4bdeb XL |
737 | fn args(&mut self, args: &[String]) { |
738 | self.cmd.args(args); | |
739 | } | |
740 | ||
741 | fn framework_path(&mut self, _path: &Path) { | |
742 | bug!("frameworks are not supported on Emscripten") | |
743 | } | |
744 | ||
745 | fn link_framework(&mut self, _framework: &str) { | |
746 | bug!("frameworks are not supported on Emscripten") | |
747 | } | |
748 | ||
749 | fn gc_sections(&mut self, _keep_metadata: bool) { | |
750 | // noop | |
751 | } | |
752 | ||
753 | fn optimize(&mut self) { | |
754 | // Emscripten performs own optimizations | |
755 | self.cmd.arg(match self.sess.opts.optimize { | |
756 | OptLevel::No => "-O0", | |
757 | OptLevel::Less => "-O1", | |
758 | OptLevel::Default => "-O2", | |
759 | OptLevel::Aggressive => "-O3", | |
760 | OptLevel::Size => "-Os", | |
761 | OptLevel::SizeMin => "-Oz" | |
762 | }); | |
763 | // Unusable until https://github.com/rust-lang/rust/issues/38454 is resolved | |
764 | self.cmd.args(&["--memory-init-file", "0"]); | |
765 | } | |
766 | ||
0531ce1d XL |
767 | fn pgo_gen(&mut self) { |
768 | // noop, but maybe we need something like the gnu linker? | |
769 | } | |
770 | ||
8bb4bdeb XL |
771 | fn debuginfo(&mut self) { |
772 | // Preserve names or generate source maps depending on debug info | |
773 | self.cmd.arg(match self.sess.opts.debuginfo { | |
774 | DebugInfoLevel::NoDebugInfo => "-g0", | |
775 | DebugInfoLevel::LimitedDebugInfo => "-g3", | |
776 | DebugInfoLevel::FullDebugInfo => "-g4" | |
777 | }); | |
778 | } | |
779 | ||
780 | fn no_default_libraries(&mut self) { | |
781 | self.cmd.args(&["-s", "DEFAULT_LIBRARY_FUNCS_TO_INCLUDE=[]"]); | |
782 | } | |
783 | ||
784 | fn build_dylib(&mut self, _out_filename: &Path) { | |
785 | bug!("building dynamic library is unsupported on Emscripten") | |
786 | } | |
787 | ||
3b2f2976 XL |
788 | fn build_static_executable(&mut self) { |
789 | // noop | |
790 | } | |
791 | ||
8bb4bdeb XL |
792 | fn export_symbols(&mut self, _tmpdir: &Path, crate_type: CrateType) { |
793 | let symbols = &self.info.exports[&crate_type]; | |
794 | ||
795 | debug!("EXPORTED SYMBOLS:"); | |
796 | ||
797 | self.cmd.arg("-s"); | |
798 | ||
799 | let mut arg = OsString::from("EXPORTED_FUNCTIONS="); | |
800 | let mut encoded = String::new(); | |
801 | ||
802 | { | |
803 | let mut encoder = json::Encoder::new(&mut encoded); | |
804 | let res = encoder.emit_seq(symbols.len(), |encoder| { | |
805 | for (i, sym) in symbols.iter().enumerate() { | |
806 | encoder.emit_seq_elt(i, |encoder| { | |
807 | encoder.emit_str(&("_".to_string() + sym)) | |
808 | })?; | |
809 | } | |
810 | Ok(()) | |
811 | }); | |
812 | if let Err(e) = res { | |
813 | self.sess.fatal(&format!("failed to encode exported symbols: {}", e)); | |
814 | } | |
815 | } | |
816 | debug!("{}", encoded); | |
817 | arg.push(encoded); | |
818 | ||
819 | self.cmd.arg(arg); | |
820 | } | |
821 | ||
822 | fn subsystem(&mut self, _subsystem: &str) { | |
823 | // noop | |
824 | } | |
cc61c64b XL |
825 | |
826 | fn finalize(&mut self) -> Command { | |
827 | let mut cmd = Command::new(""); | |
828 | ::std::mem::swap(&mut cmd, &mut self.cmd); | |
829 | cmd | |
830 | } | |
0531ce1d XL |
831 | |
832 | // Appears not necessary on Emscripten | |
833 | fn group_start(&mut self) {} | |
834 | fn group_end(&mut self) {} | |
8bb4bdeb XL |
835 | } |
836 | ||
ea8adc8c | 837 | fn exported_symbols(tcx: TyCtxt, crate_type: CrateType) -> Vec<String> { |
476ff2be | 838 | let mut symbols = Vec::new(); |
a7813a04 | 839 | |
abe05a73 | 840 | let export_threshold = symbol_export::crates_export_threshold(&[crate_type]); |
0531ce1d | 841 | for &(symbol, level) in tcx.exported_symbols(LOCAL_CRATE).iter() { |
ea8adc8c | 842 | if level.is_below_threshold(export_threshold) { |
0531ce1d | 843 | symbols.push(symbol.symbol_name(tcx).to_string()); |
ea8adc8c XL |
844 | } |
845 | } | |
846 | ||
847 | let formats = tcx.sess.dependency_formats.borrow(); | |
3157f602 | 848 | let deps = formats[&crate_type].iter(); |
476ff2be SL |
849 | |
850 | for (index, dep_format) in deps.enumerate() { | |
851 | let cnum = CrateNum::new(index + 1); | |
852 | // For each dependency that we are linking to statically ... | |
853 | if *dep_format == Linkage::Static { | |
854 | // ... we add its symbol list to our export list. | |
0531ce1d | 855 | for &(symbol, level) in tcx.exported_symbols(cnum).iter() { |
ea8adc8c | 856 | if level.is_below_threshold(export_threshold) { |
0531ce1d | 857 | symbols.push(symbol.symbol_name(tcx).to_string()); |
ea8adc8c XL |
858 | } |
859 | } | |
a7813a04 | 860 | } |
476ff2be SL |
861 | } |
862 | ||
3157f602 | 863 | symbols |
a7813a04 | 864 | } |
0531ce1d XL |
865 | |
866 | pub struct WasmLd { | |
867 | cmd: Command, | |
868 | } | |
869 | ||
870 | impl Linker for WasmLd { | |
871 | fn link_dylib(&mut self, lib: &str) { | |
872 | self.cmd.arg("-l").arg(lib); | |
873 | } | |
874 | ||
875 | fn link_staticlib(&mut self, lib: &str) { | |
876 | self.cmd.arg("-l").arg(lib); | |
877 | } | |
878 | ||
879 | fn link_rlib(&mut self, lib: &Path) { | |
880 | self.cmd.arg(lib); | |
881 | } | |
882 | ||
883 | fn include_path(&mut self, path: &Path) { | |
884 | self.cmd.arg("-L").arg(path); | |
885 | } | |
886 | ||
887 | fn framework_path(&mut self, _path: &Path) { | |
888 | panic!("frameworks not supported") | |
889 | } | |
890 | ||
891 | fn output_filename(&mut self, path: &Path) { | |
892 | self.cmd.arg("-o").arg(path); | |
893 | } | |
894 | ||
895 | fn add_object(&mut self, path: &Path) { | |
896 | self.cmd.arg(path); | |
897 | } | |
898 | ||
899 | fn position_independent_executable(&mut self) { | |
900 | } | |
901 | ||
902 | fn full_relro(&mut self) { | |
903 | } | |
904 | ||
905 | fn partial_relro(&mut self) { | |
906 | } | |
907 | ||
908 | fn no_relro(&mut self) { | |
909 | } | |
910 | ||
911 | fn build_static_executable(&mut self) { | |
912 | } | |
913 | ||
914 | fn args(&mut self, args: &[String]) { | |
915 | self.cmd.args(args); | |
916 | } | |
917 | ||
918 | fn link_rust_dylib(&mut self, lib: &str, _path: &Path) { | |
919 | self.cmd.arg("-l").arg(lib); | |
920 | } | |
921 | ||
922 | fn link_framework(&mut self, _framework: &str) { | |
923 | panic!("frameworks not supported") | |
924 | } | |
925 | ||
926 | fn link_whole_staticlib(&mut self, lib: &str, _search_path: &[PathBuf]) { | |
927 | self.cmd.arg("-l").arg(lib); | |
928 | } | |
929 | ||
930 | fn link_whole_rlib(&mut self, lib: &Path) { | |
931 | self.cmd.arg(lib); | |
932 | } | |
933 | ||
934 | fn gc_sections(&mut self, _keep_metadata: bool) { | |
935 | } | |
936 | ||
937 | fn optimize(&mut self) { | |
938 | } | |
939 | ||
940 | fn pgo_gen(&mut self) { | |
941 | } | |
942 | ||
943 | fn debuginfo(&mut self) { | |
944 | } | |
945 | ||
946 | fn no_default_libraries(&mut self) { | |
947 | } | |
948 | ||
949 | fn build_dylib(&mut self, _out_filename: &Path) { | |
950 | } | |
951 | ||
952 | fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType) { | |
953 | } | |
954 | ||
955 | fn subsystem(&mut self, _subsystem: &str) { | |
956 | } | |
957 | ||
958 | fn no_position_independent_executable(&mut self) { | |
959 | } | |
960 | ||
961 | fn finalize(&mut self) -> Command { | |
962 | self.cmd.arg("--threads"); | |
963 | ||
964 | // FIXME we probably shouldn't pass this but instead pass an explicit | |
965 | // whitelist of symbols we'll allow to be undefined. Unfortunately | |
966 | // though we can't handle symbols like `log10` that LLVM injects at a | |
967 | // super late date without actually parsing object files. For now let's | |
968 | // stick to this and hopefully fix it before stabilization happens. | |
969 | self.cmd.arg("--allow-undefined"); | |
970 | ||
971 | // For now we just never have an entry symbol | |
972 | self.cmd.arg("--no-entry"); | |
973 | ||
974 | let mut cmd = Command::new(""); | |
975 | ::std::mem::swap(&mut cmd, &mut self.cmd); | |
976 | cmd | |
977 | } | |
978 | ||
979 | // Not needed for now with LLD | |
980 | fn group_start(&mut self) {} | |
981 | fn group_end(&mut self) {} | |
982 | } |