1 // Copyright 2012-2014 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.
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.
11 use back::archive::{Archive, METADATA_FILENAME};
14 use driver::driver::{CrateTranslation, OutputFilenames};
15 use driver::config::NoDebugInfo;
16 use driver::session::Session;
19 use lib::llvm::ModuleRef;
21 use metadata::common::LinkMeta;
22 use metadata::{encoder, cstore, filesearch, csearch, loader};
23 use middle::trans::context::CrateContext;
24 use middle::trans::common::gensym_name;
26 use util::common::time;
28 use util::sha2::{Digest, Sha256};
30 use std::c_str::{ToCStr, CString};
32 use std::io::{fs, TempDir, Process};
36 use std::strbuf::StrBuf;
38 use serialize::hex::ToHex;
41 use syntax::ast_map::{PathElem, PathElems, PathName};
44 use syntax::attr::AttrMetaMethods;
45 use syntax::crateid::CrateId;
46 use syntax::parse::token;
48 #[deriving(Clone, Eq, Ord, TotalOrd, TotalEq)]
52 OutputTypeLlvmAssembly,
57 pub fn llvm_err(sess: &Session, msg: StrBuf) -> ! {
59 let cstr = llvm::LLVMRustGetLastError();
60 if cstr == ptr::null() {
61 sess.fatal(msg.as_slice());
63 let err = CString::new(cstr, true);
64 let err = str::from_utf8_lossy(err.as_bytes());
65 sess.fatal((msg.as_slice() + ": " + err.as_slice()));
70 pub fn WriteOutputFile(
72 target: lib::llvm::TargetMachineRef,
73 pm: lib::llvm::PassManagerRef,
76 file_type: lib::llvm::FileType) {
78 output.with_c_str(|output| {
79 let result = llvm::LLVMRustWriteOutputFile(
80 target, pm, m, output, file_type);
82 llvm_err(sess, "could not write output".to_strbuf());
91 use back::link::{WriteOutputFile, OutputType};
92 use back::link::{OutputTypeAssembly, OutputTypeBitcode};
93 use back::link::{OutputTypeExe, OutputTypeLlvmAssembly};
94 use back::link::{OutputTypeObject};
95 use driver::driver::{CrateTranslation, OutputFilenames};
96 use driver::config::NoDebugInfo;
97 use driver::session::Session;
100 use lib::llvm::{ModuleRef, TargetMachineRef, PassManagerRef};
102 use util::common::time;
105 use std::c_str::ToCStr;
106 use std::io::Process;
107 use libc::{c_uint, c_int};
110 // On android, we by default compile for armv7 processors. This enables
111 // things like double word CAS instructions (rather than emulating them)
112 // which are *far* more efficient. This is obviously undesirable in some
113 // cases, so if any sort of target feature is specified we don't append v7
114 // to the feature list.
115 fn target_feature<'a>(sess: &'a Session) -> &'a str {
116 match sess.targ_cfg.os {
118 if "" == sess.opts.cg.target_feature.as_slice() {
121 sess.opts.cg.target_feature.as_slice()
124 _ => sess.opts.cg.target_feature.as_slice()
128 pub fn run_passes(sess: &Session,
129 trans: &CrateTranslation,
130 output_types: &[OutputType],
131 output: &OutputFilenames) {
132 let llmod = trans.module;
133 let llcx = trans.context;
135 configure_llvm(sess);
137 if sess.opts.cg.save_temps {
138 output.with_extension("no-opt.bc").with_c_str(|buf| {
139 llvm::LLVMWriteBitcodeToFile(llmod, buf);
143 let opt_level = match sess.opts.optimize {
144 config::No => lib::llvm::CodeGenLevelNone,
145 config::Less => lib::llvm::CodeGenLevelLess,
146 config::Default => lib::llvm::CodeGenLevelDefault,
147 config::Aggressive => lib::llvm::CodeGenLevelAggressive,
149 let use_softfp = sess.opts.cg.soft_float;
151 // FIXME: #11906: Omitting frame pointers breaks retrieving the value of a parameter.
152 // FIXME: #11954: mac64 unwinding may not work with fp elim
153 let no_fp_elim = (sess.opts.debuginfo != NoDebugInfo) ||
154 (sess.targ_cfg.os == abi::OsMacos &&
155 sess.targ_cfg.arch == abi::X86_64);
157 // OSX has -dead_strip, which doesn't rely on ffunction_sections
158 // FIXME(#13846) this should be enabled for windows
159 let ffunction_sections = sess.targ_cfg.os != abi::OsMacos &&
160 sess.targ_cfg.os != abi::OsWin32;
161 let fdata_sections = ffunction_sections;
163 let reloc_model = match sess.opts.cg.relocation_model.as_slice() {
164 "pic" => lib::llvm::RelocPIC,
165 "static" => lib::llvm::RelocStatic,
166 "default" => lib::llvm::RelocDefault,
167 "dynamic-no-pic" => lib::llvm::RelocDynamicNoPic,
169 sess.err(format!("{} is not a valid relocation mode",
170 sess.opts.cg.relocation_model));
171 sess.abort_if_errors();
176 let tm = sess.targ_cfg
181 sess.opts.cg.target_cpu.as_slice().with_c_str(|cpu| {
182 target_feature(sess).with_c_str(|features| {
183 llvm::LLVMRustCreateTargetMachine(
185 lib::llvm::CodeModelDefault,
188 true /* EnableSegstk */,
198 // Create the two optimizing pass managers. These mirror what clang
199 // does, and are by populated by LLVM's default PassManagerBuilder.
200 // Each manager has a different set of passes, but they also share
201 // some common passes.
202 let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
203 let mpm = llvm::LLVMCreatePassManager();
205 // If we're verifying or linting, add them to the function pass
207 let addpass = |pass: &str| {
208 pass.as_slice().with_c_str(|s| llvm::LLVMRustAddPass(fpm, s))
210 if !sess.no_verify() { assert!(addpass("verify")); }
212 if !sess.opts.cg.no_prepopulate_passes {
213 llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod);
214 llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod);
215 populate_llvm_passes(fpm, mpm, llmod, opt_level);
218 for pass in sess.opts.cg.passes.iter() {
219 pass.as_slice().with_c_str(|s| {
220 if !llvm::LLVMRustAddPass(mpm, s) {
221 sess.warn(format!("unknown pass {}, ignoring", *pass));
226 // Finally, run the actual optimization passes
227 time(sess.time_passes(), "llvm function passes", (), |()|
228 llvm::LLVMRustRunFunctionPassManager(fpm, llmod));
229 time(sess.time_passes(), "llvm module passes", (), |()|
230 llvm::LLVMRunPassManager(mpm, llmod));
232 // Deallocate managers that we're now done with
233 llvm::LLVMDisposePassManager(fpm);
234 llvm::LLVMDisposePassManager(mpm);
236 // Emit the bytecode if we're either saving our temporaries or
237 // emitting an rlib. Whenever an rlib is created, the bytecode is
238 // inserted into the archive in order to allow LTO against it.
239 if sess.opts.cg.save_temps ||
240 (sess.crate_types.borrow().contains(&config::CrateTypeRlib) &&
241 sess.opts.output_types.contains(&OutputTypeExe)) {
242 output.temp_path(OutputTypeBitcode).with_c_str(|buf| {
243 llvm::LLVMWriteBitcodeToFile(llmod, buf);
248 time(sess.time_passes(), "all lto passes", (), |()|
249 lto::run(sess, llmod, tm, trans.reachable.as_slice()));
251 if sess.opts.cg.save_temps {
252 output.with_extension("lto.bc").with_c_str(|buf| {
253 llvm::LLVMWriteBitcodeToFile(llmod, buf);
258 // A codegen-specific pass manager is used to generate object
259 // files for an LLVM module.
261 // Apparently each of these pass managers is a one-shot kind of
262 // thing, so we create a new one for each type of output. The
263 // pass manager passed to the closure should be ensured to not
264 // escape the closure itself, and the manager should only be
266 fn with_codegen(tm: TargetMachineRef, llmod: ModuleRef,
267 f: |PassManagerRef|) {
269 let cpm = llvm::LLVMCreatePassManager();
270 llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod);
271 llvm::LLVMRustAddLibraryInfo(cpm, llmod);
273 llvm::LLVMDisposePassManager(cpm);
277 let mut object_file = None;
278 let mut needs_metadata = false;
279 for output_type in output_types.iter() {
280 let path = output.path(*output_type);
282 OutputTypeBitcode => {
283 path.with_c_str(|buf| {
284 llvm::LLVMWriteBitcodeToFile(llmod, buf);
287 OutputTypeLlvmAssembly => {
288 path.with_c_str(|output| {
289 with_codegen(tm, llmod, |cpm| {
290 llvm::LLVMRustPrintModule(cpm, llmod, output);
294 OutputTypeAssembly => {
295 // If we're not using the LLVM assembler, this function
296 // could be invoked specially with output_type_assembly,
297 // so in this case we still want the metadata object
299 let ty = OutputTypeAssembly;
300 let path = if sess.opts.output_types.contains(&ty) {
303 needs_metadata = true;
304 output.temp_path(OutputTypeAssembly)
306 with_codegen(tm, llmod, |cpm| {
307 WriteOutputFile(sess, tm, cpm, llmod, &path,
308 lib::llvm::AssemblyFile);
311 OutputTypeObject => {
312 object_file = Some(path);
315 object_file = Some(output.temp_path(OutputTypeObject));
316 needs_metadata = true;
321 time(sess.time_passes(), "codegen passes", (), |()| {
324 with_codegen(tm, llmod, |cpm| {
325 WriteOutputFile(sess, tm, cpm, llmod, path,
326 lib::llvm::ObjectFile);
332 with_codegen(tm, trans.metadata_module, |cpm| {
333 let out = output.temp_path(OutputTypeObject)
334 .with_extension("metadata.o");
335 WriteOutputFile(sess, tm, cpm,
336 trans.metadata_module, &out,
337 lib::llvm::ObjectFile);
342 llvm::LLVMRustDisposeTargetMachine(tm);
343 llvm::LLVMDisposeModule(trans.metadata_module);
344 llvm::LLVMDisposeModule(llmod);
345 llvm::LLVMContextDispose(llcx);
346 if sess.time_llvm_passes() { llvm::LLVMRustPrintPassTimings(); }
350 pub fn run_assembler(sess: &Session, outputs: &OutputFilenames) {
351 let cc = super::get_cc_prog(sess);
352 let assembly = outputs.temp_path(OutputTypeAssembly);
353 let object = outputs.path(OutputTypeObject);
355 // FIXME (#9639): This needs to handle non-utf8 paths
358 "-o".to_owned(), object.as_str().unwrap().to_owned(),
359 assembly.as_str().unwrap().to_owned()];
361 debug!("{} '{}'", cc, args.connect("' '"));
362 match Process::output(cc.as_slice(), args) {
364 if !prog.status.success() {
365 sess.err(format!("linking with `{}` failed: {}", cc, prog.status));
366 sess.note(format!("{} arguments: '{}'", cc, args.connect("' '")));
367 let mut note = prog.error.clone();
368 note.push_all(prog.output.as_slice());
369 sess.note(str::from_utf8(note.as_slice()).unwrap().to_owned());
370 sess.abort_if_errors();
374 sess.err(format!("could not exec the linker `{}`: {}", cc, e));
375 sess.abort_if_errors();
380 unsafe fn configure_llvm(sess: &Session) {
381 use sync::one::{Once, ONCE_INIT};
382 static mut INIT: Once = ONCE_INIT;
384 // Copy what clang does by turning on loop vectorization at O2 and
385 // slp vectorization at O3
386 let vectorize_loop = !sess.opts.cg.no_vectorize_loops &&
387 (sess.opts.optimize == config::Default ||
388 sess.opts.optimize == config::Aggressive);
389 let vectorize_slp = !sess.opts.cg.no_vectorize_slp &&
390 sess.opts.optimize == config::Aggressive;
392 let mut llvm_c_strs = Vec::new();
393 let mut llvm_args = Vec::new();
395 let add = |arg: &str| {
396 let s = arg.to_c_str();
397 llvm_args.push(s.with_ref(|p| p));
400 add("rustc"); // fake program name
401 if vectorize_loop { add("-vectorize-loops"); }
402 if vectorize_slp { add("-vectorize-slp"); }
403 if sess.time_llvm_passes() { add("-time-passes"); }
404 if sess.print_llvm_passes() { add("-debug-pass=Structure"); }
406 for arg in sess.opts.cg.llvm_args.iter() {
407 add((*arg).as_slice());
412 llvm::LLVMInitializePasses();
414 // Only initialize the platforms supported by Rust here, because
415 // using --llvm-root will have multiple platforms that rustllvm
416 // doesn't actually link to and it's pointless to put target info
417 // into the registry that Rust cannot generate machine code for.
418 llvm::LLVMInitializeX86TargetInfo();
419 llvm::LLVMInitializeX86Target();
420 llvm::LLVMInitializeX86TargetMC();
421 llvm::LLVMInitializeX86AsmPrinter();
422 llvm::LLVMInitializeX86AsmParser();
424 llvm::LLVMInitializeARMTargetInfo();
425 llvm::LLVMInitializeARMTarget();
426 llvm::LLVMInitializeARMTargetMC();
427 llvm::LLVMInitializeARMAsmPrinter();
428 llvm::LLVMInitializeARMAsmParser();
430 llvm::LLVMInitializeMipsTargetInfo();
431 llvm::LLVMInitializeMipsTarget();
432 llvm::LLVMInitializeMipsTargetMC();
433 llvm::LLVMInitializeMipsAsmPrinter();
434 llvm::LLVMInitializeMipsAsmParser();
436 llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int,
441 unsafe fn populate_llvm_passes(fpm: lib::llvm::PassManagerRef,
442 mpm: lib::llvm::PassManagerRef,
444 opt: lib::llvm::CodeGenOptLevel) {
445 // Create the PassManagerBuilder for LLVM. We configure it with
446 // reasonable defaults and prepare it to actually populate the pass
448 let builder = llvm::LLVMPassManagerBuilderCreate();
450 lib::llvm::CodeGenLevelNone => {
451 // Don't add lifetime intrinsics at O0
452 llvm::LLVMRustAddAlwaysInlinePass(builder, false);
454 lib::llvm::CodeGenLevelLess => {
455 llvm::LLVMRustAddAlwaysInlinePass(builder, true);
457 // numeric values copied from clang
458 lib::llvm::CodeGenLevelDefault => {
459 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder,
462 lib::llvm::CodeGenLevelAggressive => {
463 llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder,
467 llvm::LLVMPassManagerBuilderSetOptLevel(builder, opt as c_uint);
468 llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod);
470 // Use the builder to populate the function/module pass managers.
471 llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(builder, fpm);
472 llvm::LLVMPassManagerBuilderPopulateModulePassManager(builder, mpm);
473 llvm::LLVMPassManagerBuilderDispose(builder);
479 * Name mangling and its relationship to metadata. This is complex. Read
482 * The semantic model of Rust linkage is, broadly, that "there's no global
483 * namespace" between crates. Our aim is to preserve the illusion of this
484 * model despite the fact that it's not *quite* possible to implement on
485 * modern linkers. We initially didn't use system linkers at all, but have
486 * been convinced of their utility.
488 * There are a few issues to handle:
490 * - Linkers operate on a flat namespace, so we have to flatten names.
491 * We do this using the C++ namespace-mangling technique. Foo::bar
494 * - Symbols with the same name but different types need to get different
495 * linkage-names. We do this by hashing a string-encoding of the type into
496 * a fixed-size (currently 16-byte hex) cryptographic hash function (CHF:
497 * we use SHA256) to "prevent collisions". This is not airtight but 16 hex
498 * digits on uniform probability means you're going to need 2**32 same-name
499 * symbols in the same process before you're even hitting birthday-paradox
500 * collision probability.
502 * - Symbols in different crates but with same names "within" the crate need
503 * to get different linkage-names.
505 * - The hash shown in the filename needs to be predictable and stable for
506 * build tooling integration. It also needs to be using a hash function
507 * which is easy to use from Python, make, etc.
509 * So here is what we do:
511 * - Consider the package id; every crate has one (specified with crate_id
512 * attribute). If a package id isn't provided explicitly, we infer a
513 * versionless one from the output name. The version will end up being 0.0
514 * in this case. CNAME and CVERS are taken from this package id. For
515 * example, github.com/mozilla/CNAME#CVERS.
517 * - Define CMH as SHA256(crateid).
519 * - Define CMH8 as the first 8 characters of CMH.
521 * - Compile our crate to lib CNAME-CMH8-CVERS.so
523 * - Define STH(sym) as SHA256(CMH, type_str(sym))
525 * - Suffix a mangled sym with ::STH@CVERS, so that it is unique in the
526 * name, non-name metadata, and type sense, and versioned in the way
527 * system linkers understand.
530 pub fn find_crate_id(attrs: &[ast::Attribute], out_filestem: &str) -> CrateId {
531 match attr::find_crateid(attrs) {
532 None => from_str(out_filestem).unwrap_or_else(|| {
533 let mut s = out_filestem.chars().filter(|c| c.is_XID_continue());
534 from_str(s.collect::<StrBuf>()
535 .to_owned()).or(from_str("rust-out")).unwrap()
541 pub fn crate_id_hash(crate_id: &CrateId) -> StrBuf {
542 // This calculates CMH as defined above. Note that we don't use the path of
543 // the crate id in the hash because lookups are only done by (name/vers),
545 let mut s = Sha256::new();
546 s.input_str(crate_id.short_name_with_version().as_slice());
547 truncated_hash_result(&mut s).as_slice().slice_to(8).to_strbuf()
550 pub fn build_link_meta(krate: &ast::Crate, out_filestem: &str) -> LinkMeta {
552 crateid: find_crate_id(krate.attrs.as_slice(), out_filestem),
553 crate_hash: Svh::calculate(krate),
559 fn truncated_hash_result(symbol_hasher: &mut Sha256) -> StrBuf {
560 let output = symbol_hasher.result_bytes();
561 // 64 bits should be enough to avoid collisions.
562 output.slice_to(8).to_hex().to_strbuf()
566 // This calculates STH for a symbol, as defined above
567 fn symbol_hash(tcx: &ty::ctxt,
568 symbol_hasher: &mut Sha256,
570 link_meta: &LinkMeta)
572 // NB: do *not* use abbrevs here as we want the symbol names
573 // to be independent of one another in the crate.
575 symbol_hasher.reset();
576 symbol_hasher.input_str(link_meta.crateid.name.as_slice());
577 symbol_hasher.input_str("-");
578 symbol_hasher.input_str(link_meta.crate_hash.as_str());
579 symbol_hasher.input_str("-");
580 symbol_hasher.input_str(encoder::encoded_ty(tcx, t).as_slice());
581 // Prefix with 'h' so that it never blends into adjacent digits
582 let mut hash = StrBuf::from_str("h");
583 hash.push_str(truncated_hash_result(symbol_hasher).as_slice());
587 fn get_symbol_hash(ccx: &CrateContext, t: ty::t) -> StrBuf {
588 match ccx.type_hashcodes.borrow().find(&t) {
589 Some(h) => return h.to_strbuf(),
593 let mut symbol_hasher = ccx.symbol_hasher.borrow_mut();
594 let hash = symbol_hash(ccx.tcx(), &mut *symbol_hasher, t, &ccx.link_meta);
595 ccx.type_hashcodes.borrow_mut().insert(t, hash.clone());
600 // Name sanitation. LLVM will happily accept identifiers with weird names, but
602 // gas accepts the following characters in symbols: a-z, A-Z, 0-9, ., _, $
603 pub fn sanitize(s: &str) -> StrBuf {
604 let mut result = StrBuf::new();
607 // Escape these with $ sequences
608 '@' => result.push_str("$SP$"),
609 '~' => result.push_str("$UP$"),
610 '*' => result.push_str("$RP$"),
611 '&' => result.push_str("$BP$"),
612 '<' => result.push_str("$LT$"),
613 '>' => result.push_str("$GT$"),
614 '(' => result.push_str("$LP$"),
615 ')' => result.push_str("$RP$"),
616 ',' => result.push_str("$C$"),
618 // '.' doesn't occur in types and functions, so reuse it
620 '-' | ':' => result.push_char('.'),
622 // These are legal symbols
626 | '_' | '.' | '$' => result.push_char(c),
629 let mut tstr = StrBuf::new();
630 char::escape_unicode(c, |c| tstr.push_char(c));
631 result.push_char('$');
632 result.push_str(tstr.as_slice().slice_from(1));
637 // Underscore-qualify anything that didn't start as an ident.
638 if result.len() > 0u &&
639 result.as_slice()[0] != '_' as u8 &&
640 ! char::is_XID_start(result.as_slice()[0] as char) {
641 return ("_" + result.as_slice()).to_strbuf();
647 pub fn mangle<PI: Iterator<PathElem>>(mut path: PI,
649 vers: Option<&str>) -> StrBuf {
650 // Follow C++ namespace-mangling style, see
651 // http://en.wikipedia.org/wiki/Name_mangling for more info.
653 // It turns out that on OSX you can actually have arbitrary symbols in
654 // function names (at least when given to LLVM), but this is not possible
655 // when using unix's linker. Perhaps one day when we just use a linker from LLVM
656 // we won't need to do this name mangling. The problem with name mangling is
657 // that it seriously limits the available characters. For example we can't
658 // have things like &T or ~[T] in symbol names when one would theoretically
659 // want them for things like impls of traits on that type.
661 // To be able to work on all platforms and get *some* reasonable output, we
662 // use C++ name-mangling.
664 let mut n = StrBuf::from_str("_ZN"); // _Z == Begin name-sequence, N == nested
666 fn push(n: &mut StrBuf, s: &str) {
667 let sani = sanitize(s);
668 n.push_str(format!("{}{}", sani.len(), sani));
671 // First, connect each component with <len, name> pairs.
673 push(&mut n, token::get_name(e.name()).get().as_slice())
677 Some(s) => push(&mut n, s),
681 Some(s) => push(&mut n, s),
685 n.push_char('E'); // End name-sequence.
689 pub fn exported_name(path: PathElems, hash: &str, vers: &str) -> StrBuf {
690 // The version will get mangled to have a leading '_', but it makes more
691 // sense to lead with a 'v' b/c this is a version...
692 let vers = if vers.len() > 0 && !char::is_XID_start(vers.char_at(0)) {
698 mangle(path, Some(hash), Some(vers.as_slice()))
701 pub fn mangle_exported_name(ccx: &CrateContext, path: PathElems,
702 t: ty::t, id: ast::NodeId) -> StrBuf {
703 let mut hash = get_symbol_hash(ccx, t);
705 // Paths can be completely identical for different nodes,
706 // e.g. `fn foo() { { fn a() {} } { fn a() {} } }`, so we
707 // generate unique characters from the node id. For now
708 // hopefully 3 characters is enough to avoid collisions.
709 static EXTRA_CHARS: &'static str =
710 "abcdefghijklmnopqrstuvwxyz\
711 ABCDEFGHIJKLMNOPQRSTUVWXYZ\
714 let extra1 = id % EXTRA_CHARS.len();
715 let id = id / EXTRA_CHARS.len();
716 let extra2 = id % EXTRA_CHARS.len();
717 let id = id / EXTRA_CHARS.len();
718 let extra3 = id % EXTRA_CHARS.len();
719 hash.push_char(EXTRA_CHARS[extra1] as char);
720 hash.push_char(EXTRA_CHARS[extra2] as char);
721 hash.push_char(EXTRA_CHARS[extra3] as char);
725 ccx.link_meta.crateid.version_or_default())
728 pub fn mangle_internal_name_by_type_and_seq(ccx: &CrateContext,
730 name: &str) -> StrBuf {
731 let s = ppaux::ty_to_str(ccx.tcx(), t);
732 let path = [PathName(token::intern(s.as_slice())),
734 let hash = get_symbol_hash(ccx, t);
735 mangle(ast_map::Values(path.iter()), Some(hash.as_slice()), None)
738 pub fn mangle_internal_name_by_path_and_seq(path: PathElems, flav: &str) -> StrBuf {
739 mangle(path.chain(Some(gensym_name(flav)).move_iter()), None, None)
742 pub fn output_lib_filename(id: &CrateId) -> StrBuf {
743 format_strbuf!("{}-{}-{}",
746 id.version_or_default())
749 pub fn get_cc_prog(sess: &Session) -> StrBuf {
750 match sess.opts.cg.linker {
751 Some(ref linker) => return linker.to_strbuf(),
755 // In the future, FreeBSD will use clang as default compiler.
756 // It would be flexible to use cc (system's default C compiler)
757 // instead of hard-coded gcc.
758 // For win32, there is no cc command, so we add a condition to make it use gcc.
759 match sess.targ_cfg.os {
760 abi::OsWin32 => "gcc",
765 pub fn get_ar_prog(sess: &Session) -> StrBuf {
766 match sess.opts.cg.ar {
767 Some(ref ar) => (*ar).clone(),
768 None => "ar".to_strbuf()
772 fn remove(sess: &Session, path: &Path) {
773 match fs::unlink(path) {
776 sess.err(format!("failed to remove {}: {}", path.display(), e));
781 /// Perform the linkage portion of the compilation phase. This will generate all
782 /// of the requested outputs for this compilation session.
783 pub fn link_binary(sess: &Session,
784 trans: &CrateTranslation,
785 outputs: &OutputFilenames,
786 id: &CrateId) -> Vec<Path> {
787 let mut out_filenames = Vec::new();
788 for &crate_type in sess.crate_types.borrow().iter() {
789 let out_file = link_binary_output(sess, trans, crate_type, outputs, id);
790 out_filenames.push(out_file);
793 // Remove the temporary object file and metadata if we aren't saving temps
794 if !sess.opts.cg.save_temps {
795 let obj_filename = outputs.temp_path(OutputTypeObject);
796 if !sess.opts.output_types.contains(&OutputTypeObject) {
797 remove(sess, &obj_filename);
799 remove(sess, &obj_filename.with_extension("metadata.o"));
805 fn is_writeable(p: &Path) -> bool {
808 Ok(m) => m.perm & io::UserWrite == io::UserWrite
812 pub fn filename_for_input(sess: &Session, crate_type: config::CrateType,
813 id: &CrateId, out_filename: &Path) -> Path {
814 let libname = output_lib_filename(id);
816 config::CrateTypeRlib => {
817 out_filename.with_filename(format!("lib{}.rlib", libname))
819 config::CrateTypeDylib => {
820 let (prefix, suffix) = match sess.targ_cfg.os {
821 abi::OsWin32 => (loader::WIN32_DLL_PREFIX, loader::WIN32_DLL_SUFFIX),
822 abi::OsMacos => (loader::MACOS_DLL_PREFIX, loader::MACOS_DLL_SUFFIX),
823 abi::OsLinux => (loader::LINUX_DLL_PREFIX, loader::LINUX_DLL_SUFFIX),
824 abi::OsAndroid => (loader::ANDROID_DLL_PREFIX, loader::ANDROID_DLL_SUFFIX),
825 abi::OsFreebsd => (loader::FREEBSD_DLL_PREFIX, loader::FREEBSD_DLL_SUFFIX),
827 out_filename.with_filename(format!("{}{}{}", prefix, libname, suffix))
829 config::CrateTypeStaticlib => {
830 out_filename.with_filename(format!("lib{}.a", libname))
832 config::CrateTypeExecutable => out_filename.clone(),
836 fn link_binary_output(sess: &Session,
837 trans: &CrateTranslation,
838 crate_type: config::CrateType,
839 outputs: &OutputFilenames,
840 id: &CrateId) -> Path {
841 let obj_filename = outputs.temp_path(OutputTypeObject);
842 let out_filename = match outputs.single_output_file {
843 Some(ref file) => file.clone(),
845 let out_filename = outputs.path(OutputTypeExe);
846 filename_for_input(sess, crate_type, id, &out_filename)
850 // Make sure the output and obj_filename are both writeable.
851 // Mac, FreeBSD, and Windows system linkers check this already --
852 // however, the Linux linker will happily overwrite a read-only file.
853 // We should be consistent.
854 let obj_is_writeable = is_writeable(&obj_filename);
855 let out_is_writeable = is_writeable(&out_filename);
856 if !out_is_writeable {
857 sess.fatal(format!("output file {} is not writeable -- check its permissions.",
858 out_filename.display()));
860 else if !obj_is_writeable {
861 sess.fatal(format!("object file {} is not writeable -- check its permissions.",
862 obj_filename.display()));
866 config::CrateTypeRlib => {
867 link_rlib(sess, Some(trans), &obj_filename, &out_filename);
869 config::CrateTypeStaticlib => {
870 link_staticlib(sess, &obj_filename, &out_filename);
872 config::CrateTypeExecutable => {
873 link_natively(sess, trans, false, &obj_filename, &out_filename);
875 config::CrateTypeDylib => {
876 link_natively(sess, trans, true, &obj_filename, &out_filename);
885 // An rlib in its current incarnation is essentially a renamed .a file. The
886 // rlib primarily contains the object file of the crate, but it also contains
887 // all of the object files from native libraries. This is done by unzipping
888 // native libraries and inserting all of the contents into this archive.
889 fn link_rlib<'a>(sess: &'a Session,
890 trans: Option<&CrateTranslation>, // None == no metadata/bytecode
892 out_filename: &Path) -> Archive<'a> {
893 let mut a = Archive::create(sess, out_filename, obj_filename);
895 for &(ref l, kind) in sess.cstore.get_used_libraries().borrow().iter() {
897 cstore::NativeStatic => {
898 a.add_native_library(l.as_slice()).unwrap();
900 cstore::NativeFramework | cstore::NativeUnknown => {}
904 // Note that it is important that we add all of our non-object "magical
905 // files" *after* all of the object files in the archive. The reason for
906 // this is as follows:
908 // * When performing LTO, this archive will be modified to remove
909 // obj_filename from above. The reason for this is described below.
911 // * When the system linker looks at an archive, it will attempt to
912 // determine the architecture of the archive in order to see whether its
915 // The algorithm for this detection is: iterate over the files in the
916 // archive. Skip magical SYMDEF names. Interpret the first file as an
917 // object file. Read architecture from the object file.
919 // * As one can probably see, if "metadata" and "foo.bc" were placed
920 // before all of the objects, then the architecture of this archive would
921 // not be correctly inferred once 'foo.o' is removed.
923 // Basically, all this means is that this code should not move above the
927 // Instead of putting the metadata in an object file section, rlibs
928 // contain the metadata in a separate file. We use a temp directory
929 // here so concurrent builds in the same directory don't try to use
930 // the same filename for metadata (stomping over one another)
931 let tmpdir = TempDir::new("rustc").expect("needs a temp dir");
932 let metadata = tmpdir.path().join(METADATA_FILENAME);
933 match fs::File::create(&metadata).write(trans.metadata
937 sess.err(format!("failed to write {}: {}",
938 metadata.display(), e));
939 sess.abort_if_errors();
942 a.add_file(&metadata, false);
943 remove(sess, &metadata);
945 // For LTO purposes, the bytecode of this library is also inserted
947 let bc = obj_filename.with_extension("bc");
948 let bc_deflated = obj_filename.with_extension("bc.deflate");
949 match fs::File::open(&bc).read_to_end().and_then(|data| {
950 fs::File::create(&bc_deflated)
951 .write(match flate::deflate_bytes(data.as_slice()) {
952 Some(compressed) => compressed,
953 None => sess.fatal("failed to compress bytecode")
958 sess.err(format!("failed to write compressed bytecode: {}", e));
959 sess.abort_if_errors()
962 a.add_file(&bc_deflated, false);
963 remove(sess, &bc_deflated);
964 if !sess.opts.cg.save_temps &&
965 !sess.opts.output_types.contains(&OutputTypeBitcode) {
969 // After adding all files to the archive, we need to update the
970 // symbol table of the archive. This currently dies on OSX (see
971 // #11162), and isn't necessary there anyway
972 match sess.targ_cfg.os {
974 _ => { a.update_symbols(); }
983 // Create a static archive
985 // This is essentially the same thing as an rlib, but it also involves adding
986 // all of the upstream crates' objects into the archive. This will slurp in
987 // all of the native libraries of upstream dependencies as well.
989 // Additionally, there's no way for us to link dynamic libraries, so we warn
990 // about all dynamic library dependencies that they're not linked in.
992 // There's no need to include metadata in a static archive, so ensure to not
993 // link in the metadata object file (and also don't prepare the archive with a
995 fn link_staticlib(sess: &Session, obj_filename: &Path, out_filename: &Path) {
996 let mut a = link_rlib(sess, None, obj_filename, out_filename);
997 a.add_native_library("morestack").unwrap();
998 a.add_native_library("compiler-rt").unwrap();
1000 let crates = sess.cstore.get_used_crates(cstore::RequireStatic);
1001 for &(cnum, ref path) in crates.iter() {
1002 let name = sess.cstore.get_crate_data(cnum).name.clone();
1003 let p = match *path {
1004 Some(ref p) => p.clone(), None => {
1005 sess.err(format!("could not find rlib for: `{}`", name));
1009 a.add_rlib(&p, name.as_slice(), sess.lto()).unwrap();
1010 let native_libs = csearch::get_native_libraries(&sess.cstore, cnum);
1011 for &(kind, ref lib) in native_libs.iter() {
1012 let name = match kind {
1013 cstore::NativeStatic => "static library",
1014 cstore::NativeUnknown => "library",
1015 cstore::NativeFramework => "framework",
1017 sess.warn(format!("unlinked native {}: {}", name, *lib));
1022 // Create a dynamic library or executable
1024 // This will invoke the system linker/cc to create the resulting file. This
1025 // links to all upstream files as well.
1026 fn link_natively(sess: &Session, trans: &CrateTranslation, dylib: bool,
1027 obj_filename: &Path, out_filename: &Path) {
1028 let tmpdir = TempDir::new("rustc").expect("needs a temp dir");
1029 // The invocations of cc share some flags across platforms
1030 let cc_prog = get_cc_prog(sess);
1031 let mut cc_args = sess.targ_cfg.target_strs.cc_args.clone();
1032 cc_args.push_all_move(link_args(sess, dylib, tmpdir.path(), trans,
1033 obj_filename, out_filename));
1034 if (sess.opts.debugging_opts & config::PRINT_LINK_ARGS) != 0 {
1035 println!("{} link args: '{}'", cc_prog, cc_args.connect("' '"));
1038 // May have not found libraries in the right formats.
1039 sess.abort_if_errors();
1041 // Invoke the system linker
1042 debug!("{} {}", cc_prog, cc_args.connect(" "));
1043 let prog = time(sess.time_passes(), "running linker", (), |()|
1044 Process::output(cc_prog.as_slice(),
1046 .map(|x| (*x).to_owned())
1047 .collect::<Vec<_>>()
1051 if !prog.status.success() {
1052 sess.err(format!("linking with `{}` failed: {}", cc_prog, prog.status));
1053 sess.note(format!("{} arguments: '{}'", cc_prog, cc_args.connect("' '")));
1054 let mut output = prog.error.clone();
1055 output.push_all(prog.output.as_slice());
1056 sess.note(str::from_utf8(output.as_slice()).unwrap().to_owned());
1057 sess.abort_if_errors();
1061 sess.err(format!("could not exec the linker `{}`: {}", cc_prog, e));
1062 sess.abort_if_errors();
1067 // On OSX, debuggers need this utility to get run to do some munging of
1069 if sess.targ_cfg.os == abi::OsMacos && (sess.opts.debuginfo != NoDebugInfo) {
1070 // FIXME (#9639): This needs to handle non-utf8 paths
1071 match Process::status("dsymutil",
1072 [out_filename.as_str().unwrap().to_owned()]) {
1075 sess.err(format!("failed to run dsymutil: {}", e));
1076 sess.abort_if_errors();
1082 fn link_args(sess: &Session,
1085 trans: &CrateTranslation,
1086 obj_filename: &Path,
1087 out_filename: &Path) -> Vec<StrBuf> {
1089 // The default library location, we need this to find the runtime.
1090 // The location of crates will be determined as needed.
1091 // FIXME (#9639): This needs to handle non-utf8 paths
1092 let lib_path = sess.target_filesearch().get_lib_path();
1093 let stage = ("-L".to_owned() + lib_path.as_str().unwrap()).to_strbuf();
1095 let mut args = vec!(stage);
1097 // FIXME (#9639): This needs to handle non-utf8 paths
1099 "-o".to_strbuf(), out_filename.as_str().unwrap().to_strbuf(),
1100 obj_filename.as_str().unwrap().to_strbuf()]);
1102 // Stack growth requires statically linking a __morestack function. Note
1103 // that this is listed *before* all other libraries, even though it may be
1104 // used to resolve symbols in other libraries. The only case that this
1105 // wouldn't be pulled in by the object file is if the object file had no
1108 // If we're building an executable, there must be at least one function (the
1109 // main function), and if we're building a dylib then we don't need it for
1110 // later libraries because they're all dylibs (not rlibs).
1112 // I'm honestly not entirely sure why this needs to come first. Apparently
1113 // the --as-needed flag above sometimes strips out libstd from the command
1114 // line, but inserting this farther to the left makes the
1115 // "rust_stack_exhausted" symbol an outstanding undefined symbol, which
1116 // flags libstd as a required library (or whatever provides the symbol).
1117 args.push("-lmorestack".to_strbuf());
1119 // When linking a dynamic library, we put the metadata into a section of the
1120 // executable. This metadata is in a separate object file from the main
1121 // object file, so we link that in here.
1123 let metadata = obj_filename.with_extension("metadata.o");
1124 args.push(metadata.as_str().unwrap().to_strbuf());
1127 // We want to prevent the compiler from accidentally leaking in any system
1128 // libraries, so we explicitly ask gcc to not link to any libraries by
1129 // default. Note that this does not happen for windows because windows pulls
1130 // in some large number of libraries and I couldn't quite figure out which
1131 // subset we wanted.
1133 // FIXME(#11937) we should invoke the system linker directly
1134 if sess.targ_cfg.os != abi::OsWin32 {
1135 args.push("-nodefaultlibs".to_strbuf());
1138 // If we're building a dylib, we don't use --gc-sections because LLVM has
1139 // already done the best it can do, and we also don't want to eliminate the
1140 // metadata. If we're building an executable, however, --gc-sections drops
1141 // the size of hello world from 1.8MB to 597K, a 67% reduction.
1142 if !dylib && sess.targ_cfg.os != abi::OsMacos {
1143 args.push("-Wl,--gc-sections".to_strbuf());
1146 if sess.targ_cfg.os == abi::OsLinux {
1147 // GNU-style linkers will use this to omit linking to libraries which
1148 // don't actually fulfill any relocations, but only for libraries which
1149 // follow this flag. Thus, use it before specifying libraries to link to.
1150 args.push("-Wl,--as-needed".to_strbuf());
1152 // GNU-style linkers support optimization with -O. GNU ld doesn't need a
1153 // numeric argument, but other linkers do.
1154 if sess.opts.optimize == config::Default ||
1155 sess.opts.optimize == config::Aggressive {
1156 args.push("-Wl,-O1".to_strbuf());
1158 } else if sess.targ_cfg.os == abi::OsMacos {
1159 // The dead_strip option to the linker specifies that functions and data
1160 // unreachable by the entry point will be removed. This is quite useful
1161 // with Rust's compilation model of compiling libraries at a time into
1162 // one object file. For example, this brings hello world from 1.7MB to
1165 // Note that this is done for both executables and dynamic libraries. We
1166 // won't get much benefit from dylibs because LLVM will have already
1167 // stripped away as much as it could. This has not been seen to impact
1168 // link times negatively.
1169 args.push("-Wl,-dead_strip".to_strbuf());
1172 if sess.targ_cfg.os == abi::OsWin32 {
1173 // Make sure that we link to the dynamic libgcc, otherwise cross-module
1174 // DWARF stack unwinding will not work.
1175 // This behavior may be overridden by --link-args "-static-libgcc"
1176 args.push("-shared-libgcc".to_strbuf());
1178 // And here, we see obscure linker flags #45. On windows, it has been
1179 // found to be necessary to have this flag to compile liblibc.
1181 // First a bit of background. On Windows, the file format is not ELF,
1182 // but COFF (at least according to LLVM). COFF doesn't officially allow
1183 // for section names over 8 characters, apparently. Our metadata
1184 // section, ".note.rustc", you'll note is over 8 characters.
1186 // On more recent versions of gcc on mingw, apparently the section name
1187 // is *not* truncated, but rather stored elsewhere in a separate lookup
1188 // table. On older versions of gcc, they apparently always truncated the
1189 // section names (at least in some cases). Truncating the section name
1190 // actually creates "invalid" objects [1] [2], but only for some
1191 // introspection tools, not in terms of whether it can be loaded.
1193 // Long story short, passing this flag forces the linker to *not*
1194 // truncate section names (so we can find the metadata section after
1195 // it's compiled). The real kicker is that rust compiled just fine on
1196 // windows for quite a long time *without* this flag, so I have no idea
1197 // why it suddenly started failing for liblibc. Regardless, we
1198 // definitely don't want section name truncation, so we're keeping this
1199 // flag for windows.
1201 // [1] - https://sourceware.org/bugzilla/show_bug.cgi?id=13130
1202 // [2] - https://code.google.com/p/go/issues/detail?id=2139
1203 args.push("-Wl,--enable-long-section-names".to_strbuf());
1206 if sess.targ_cfg.os == abi::OsAndroid {
1207 // Many of the symbols defined in compiler-rt are also defined in libgcc.
1208 // Android linker doesn't like that by default.
1209 args.push("-Wl,--allow-multiple-definition".to_strbuf());
1212 // Take careful note of the ordering of the arguments we pass to the linker
1213 // here. Linkers will assume that things on the left depend on things to the
1214 // right. Things on the right cannot depend on things on the left. This is
1215 // all formally implemented in terms of resolving symbols (libs on the right
1216 // resolve unknown symbols of libs on the left, but not vice versa).
1218 // For this reason, we have organized the arguments we pass to the linker as
1221 // 1. The local object that LLVM just generated
1222 // 2. Upstream rust libraries
1223 // 3. Local native libraries
1224 // 4. Upstream native libraries
1226 // This is generally fairly natural, but some may expect 2 and 3 to be
1227 // swapped. The reason that all native libraries are put last is that it's
1228 // not recommended for a native library to depend on a symbol from a rust
1229 // crate. If this is the case then a staticlib crate is recommended, solving
1232 // Additionally, it is occasionally the case that upstream rust libraries
1233 // depend on a local native library. In the case of libraries such as
1234 // lua/glfw/etc the name of the library isn't the same across all platforms,
1235 // so only the consumer crate of a library knows the actual name. This means
1236 // that downstream crates will provide the #[link] attribute which upstream
1237 // crates will depend on. Hence local native libraries are after out
1238 // upstream rust crates.
1240 // In theory this means that a symbol in an upstream native library will be
1241 // shadowed by a local native library when it wouldn't have been before, but
1242 // this kind of behavior is pretty platform specific and generally not
1243 // recommended anyway, so I don't think we're shooting ourself in the foot
1245 add_upstream_rust_crates(&mut args, sess, dylib, tmpdir, trans);
1246 add_local_native_libraries(&mut args, sess);
1247 add_upstream_native_libraries(&mut args, sess);
1249 // # Telling the linker what we're doing
1252 // On mac we need to tell the linker to let this library be rpathed
1253 if sess.targ_cfg.os == abi::OsMacos {
1254 args.push("-dynamiclib".to_strbuf());
1255 args.push("-Wl,-dylib".to_strbuf());
1256 // FIXME (#9639): This needs to handle non-utf8 paths
1257 if !sess.opts.cg.no_rpath {
1258 args.push(format_strbuf!("-Wl,-install_name,@rpath/{}",
1259 out_filename.filename_str()
1263 args.push("-shared".to_strbuf())
1267 if sess.targ_cfg.os == abi::OsFreebsd {
1268 args.push_all(["-L/usr/local/lib".to_strbuf(),
1269 "-L/usr/local/lib/gcc46".to_strbuf(),
1270 "-L/usr/local/lib/gcc44".to_strbuf()]);
1273 // FIXME (#2397): At some point we want to rpath our guesses as to
1274 // where extern libraries might live, based on the
1275 // addl_lib_search_paths
1276 if !sess.opts.cg.no_rpath {
1277 args.push_all(rpath::get_rpath_flags(sess, out_filename).as_slice());
1280 // compiler-rt contains implementations of low-level LLVM helpers. This is
1281 // used to resolve symbols from the object file we just created, as well as
1282 // any system static libraries that may be expecting gcc instead. Most
1283 // symbols in libgcc also appear in compiler-rt.
1285 // This is the end of the command line, so this library is used to resolve
1286 // *all* undefined symbols in all other libraries, and this is intentional.
1287 args.push("-lcompiler-rt".to_strbuf());
1289 // Finally add all the linker arguments provided on the command line along
1290 // with any #[link_args] attributes found inside the crate
1291 args.push_all(sess.opts.cg.link_args.as_slice());
1292 for arg in sess.cstore.get_used_link_args().borrow().iter() {
1293 args.push(arg.clone());
1298 // # Native library linking
1300 // User-supplied library search paths (-L on the command line). These are
1301 // the same paths used to find Rust crates, so some of them may have been
1302 // added already by the previous crate linking code. This only allows them
1303 // to be found at compile time so it is still entirely up to outside
1304 // forces to make sure that library can be found at runtime.
1306 // Also note that the native libraries linked here are only the ones located
1307 // in the current crate. Upstream crates with native library dependencies
1308 // may have their native library pulled in above.
1309 fn add_local_native_libraries(args: &mut Vec<StrBuf>, sess: &Session) {
1310 for path in sess.opts.addl_lib_search_paths.borrow().iter() {
1311 // FIXME (#9639): This needs to handle non-utf8 paths
1312 args.push(("-L" + path.as_str().unwrap().to_owned()).to_strbuf());
1315 let rustpath = filesearch::rust_path();
1316 for path in rustpath.iter() {
1317 // FIXME (#9639): This needs to handle non-utf8 paths
1318 args.push(("-L" + path.as_str().unwrap().to_owned()).to_strbuf());
1321 // Some platforms take hints about whether a library is static or dynamic.
1322 // For those that support this, we ensure we pass the option if the library
1323 // was flagged "static" (most defaults are dynamic) to ensure that if
1324 // libfoo.a and libfoo.so both exist that the right one is chosen.
1325 let takes_hints = sess.targ_cfg.os != abi::OsMacos;
1327 for &(ref l, kind) in sess.cstore.get_used_libraries().borrow().iter() {
1329 cstore::NativeUnknown | cstore::NativeStatic => {
1331 if kind == cstore::NativeStatic {
1332 args.push("-Wl,-Bstatic".to_strbuf());
1334 args.push("-Wl,-Bdynamic".to_strbuf());
1337 args.push(format_strbuf!("-l{}", *l));
1339 cstore::NativeFramework => {
1340 args.push("-framework".to_strbuf());
1341 args.push(l.to_strbuf());
1346 args.push("-Wl,-Bdynamic".to_strbuf());
1350 // # Rust Crate linking
1352 // Rust crates are not considered at all when creating an rlib output. All
1353 // dependencies will be linked when producing the final output (instead of
1354 // the intermediate rlib version)
1355 fn add_upstream_rust_crates(args: &mut Vec<StrBuf>, sess: &Session,
1356 dylib: bool, tmpdir: &Path,
1357 trans: &CrateTranslation) {
1358 // All of the heavy lifting has previously been accomplished by the
1359 // dependency_format module of the compiler. This is just crawling the
1360 // output of that module, adding crates as necessary.
1362 // Linking to a rlib involves just passing it to the linker (the linker
1363 // will slurp up the object files inside), and linking to a dynamic library
1364 // involves just passing the right -l flag.
1366 let data = if dylib {
1367 trans.crate_formats.get(&config::CrateTypeDylib)
1369 trans.crate_formats.get(&config::CrateTypeExecutable)
1372 // Invoke get_used_crates to ensure that we get a topological sorting of
1374 let deps = sess.cstore.get_used_crates(cstore::RequireDynamic);
1376 for &(cnum, _) in deps.iter() {
1377 // We may not pass all crates through to the linker. Some crates may
1378 // appear statically in an existing dylib, meaning we'll pick up all the
1379 // symbols from the dylib.
1380 let kind = match *data.get(cnum as uint - 1) {
1384 let src = sess.cstore.get_used_crate_source(cnum).unwrap();
1386 cstore::RequireDynamic => {
1387 add_dynamic_crate(args, sess, src.dylib.unwrap())
1389 cstore::RequireStatic => {
1390 add_static_crate(args, sess, tmpdir, cnum, src.rlib.unwrap())
1396 // Converts a library file-stem into a cc -l argument
1397 fn unlib(config: &config::Config, stem: &str) -> StrBuf {
1398 if stem.starts_with("lib") && config.os != abi::OsWin32 {
1399 stem.slice(3, stem.len()).to_strbuf()
1405 // Adds the static "rlib" versions of all crates to the command line.
1406 fn add_static_crate(args: &mut Vec<StrBuf>, sess: &Session, tmpdir: &Path,
1407 cnum: ast::CrateNum, cratepath: Path) {
1408 // When performing LTO on an executable output, all of the
1409 // bytecode from the upstream libraries has already been
1410 // included in our object file output. We need to modify all of
1411 // the upstream archives to remove their corresponding object
1412 // file to make sure we don't pull the same code in twice.
1414 // We must continue to link to the upstream archives to be sure
1415 // to pull in native static dependencies. As the final caveat,
1416 // on linux it is apparently illegal to link to a blank archive,
1417 // so if an archive no longer has any object files in it after
1418 // we remove `lib.o`, then don't link against it at all.
1420 // If we're not doing LTO, then our job is simply to just link
1421 // against the archive.
1423 let name = sess.cstore.get_crate_data(cnum).name.clone();
1424 time(sess.time_passes(), format!("altering {}.rlib", name),
1426 let dst = tmpdir.join(cratepath.filename().unwrap());
1427 match fs::copy(&cratepath, &dst) {
1430 sess.err(format!("failed to copy {} to {}: {}",
1431 cratepath.display(),
1434 sess.abort_if_errors();
1437 let dst_str = dst.as_str().unwrap().to_strbuf();
1438 let mut archive = Archive::open(sess, dst);
1439 archive.remove_file(format!("{}.o", name));
1440 let files = archive.files();
1441 if files.iter().any(|s| s.as_slice().ends_with(".o")) {
1446 args.push(cratepath.as_str().unwrap().to_strbuf());
1450 // Same thing as above, but for dynamic crates instead of static crates.
1451 fn add_dynamic_crate(args: &mut Vec<StrBuf>, sess: &Session,
1453 // If we're performing LTO, then it should have been previously required
1454 // that all upstream rust dependencies were available in an rlib format.
1455 assert!(!sess.lto());
1457 // Just need to tell the linker about where the library lives and
1459 let dir = cratepath.dirname_str().unwrap();
1460 if !dir.is_empty() {
1461 args.push(format_strbuf!("-L{}", dir));
1463 let libarg = unlib(&sess.targ_cfg, cratepath.filestem_str().unwrap());
1464 args.push(format_strbuf!("-l{}", libarg));
1468 // Link in all of our upstream crates' native dependencies. Remember that
1469 // all of these upstream native dependencies are all non-static
1470 // dependencies. We've got two cases then:
1472 // 1. The upstream crate is an rlib. In this case we *must* link in the
1473 // native dependency because the rlib is just an archive.
1475 // 2. The upstream crate is a dylib. In order to use the dylib, we have to
1476 // have the dependency present on the system somewhere. Thus, we don't
1477 // gain a whole lot from not linking in the dynamic dependency to this
1480 // The use case for this is a little subtle. In theory the native
1481 // dependencies of a crate are purely an implementation detail of the crate
1482 // itself, but the problem arises with generic and inlined functions. If a
1483 // generic function calls a native function, then the generic function must
1484 // be instantiated in the target crate, meaning that the native symbol must
1485 // also be resolved in the target crate.
1486 fn add_upstream_native_libraries(args: &mut Vec<StrBuf>, sess: &Session) {
1487 // Be sure to use a topological sorting of crates because there may be
1488 // interdependencies between native libraries. When passing -nodefaultlibs,
1489 // for example, almost all native libraries depend on libc, so we have to
1490 // make sure that's all the way at the right (liblibc is near the base of
1491 // the dependency chain).
1493 // This passes RequireStatic, but the actual requirement doesn't matter,
1494 // we're just getting an ordering of crate numbers, we're not worried about
1496 let crates = sess.cstore.get_used_crates(cstore::RequireStatic);
1497 for (cnum, _) in crates.move_iter() {
1498 let libs = csearch::get_native_libraries(&sess.cstore, cnum);
1499 for &(kind, ref lib) in libs.iter() {
1501 cstore::NativeUnknown => {
1502 args.push(format_strbuf!("-l{}", *lib))
1504 cstore::NativeFramework => {
1505 args.push("-framework".to_strbuf());
1506 args.push(lib.to_strbuf());
1508 cstore::NativeStatic => {
1509 sess.bug("statics shouldn't be propagated");