1 // Copyright 2012-2015 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.
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 //! Finds crate binaries and loads their metadata
13 //! Might I be the first to welcome you to a world of platform differences,
14 //! version requirements, dependency graphs, conflicting desires, and fun! This
15 //! is the major guts (along with metadata::creader) of the compiler for loading
16 //! crates and resolving dependencies. Let's take a tour!
20 //! Each invocation of the compiler is immediately concerned with one primary
21 //! problem, to connect a set of crates to resolved crates on the filesystem.
22 //! Concretely speaking, the compiler follows roughly these steps to get here:
24 //! 1. Discover a set of `extern crate` statements.
25 //! 2. Transform these directives into crate names. If the directive does not
26 //! have an explicit name, then the identifier is the name.
27 //! 3. For each of these crate names, find a corresponding crate on the
30 //! Sounds easy, right? Let's walk into some of the nuances.
32 //! ## Transitive Dependencies
34 //! Let's say we've got three crates: A, B, and C. A depends on B, and B depends
35 //! on C. When we're compiling A, we primarily need to find and locate B, but we
36 //! also end up needing to find and locate C as well.
38 //! The reason for this is that any of B's types could be composed of C's types,
39 //! any function in B could return a type from C, etc. To be able to guarantee
40 //! that we can always typecheck/translate any function, we have to have
41 //! complete knowledge of the whole ecosystem, not just our immediate
44 //! So now as part of the "find a corresponding crate on the filesystem" step
45 //! above, this involves also finding all crates for *all upstream
46 //! dependencies*. This includes all dependencies transitively.
48 //! ## Rlibs and Dylibs
50 //! The compiler has two forms of intermediate dependencies. These are dubbed
51 //! rlibs and dylibs for the static and dynamic variants, respectively. An rlib
52 //! is a rustc-defined file format (currently just an ar archive) while a dylib
53 //! is a platform-defined dynamic library. Each library has a metadata somewhere
56 //! A third kind of dependency is an rmeta file. These are metadata files and do
57 //! not contain any code, etc. To a first approximation, these are treated in the
58 //! same way as rlibs. Where there is both an rlib and an rmeta file, the rlib
59 //! gets priority (even if the rmeta file is newer). An rmeta file is only
60 //! useful for checking a downstream crate, attempting to link one will cause an
63 //! When translating a crate name to a crate on the filesystem, we all of a
64 //! sudden need to take into account both rlibs and dylibs! Linkage later on may
65 //! use either one of these files, as each has their pros/cons. The job of crate
66 //! loading is to discover what's possible by finding all candidates.
68 //! Most parts of this loading systems keep the dylib/rlib as just separate
73 //! We can't exactly scan your whole hard drive when looking for dependencies,
74 //! so we need to places to look. Currently the compiler will implicitly add the
75 //! target lib search path ($prefix/lib/rustlib/$target/lib) to any compilation,
76 //! and otherwise all -L flags are added to the search paths.
78 //! ## What criterion to select on?
80 //! This a pretty tricky area of loading crates. Given a file, how do we know
81 //! whether it's the right crate? Currently, the rules look along these lines:
83 //! 1. Does the filename match an rlib/dylib pattern? That is to say, does the
84 //! filename have the right prefix/suffix?
85 //! 2. Does the filename have the right prefix for the crate name being queried?
86 //! This is filtering for files like `libfoo*.rlib` and such. If the crate
87 //! we're looking for was originally compiled with -C extra-filename, the
88 //! extra filename will be included in this prefix to reduce reading
89 //! metadata from crates that would otherwise share our prefix.
90 //! 3. Is the file an actual rust library? This is done by loading the metadata
91 //! from the library and making sure it's actually there.
92 //! 4. Does the name in the metadata agree with the name of the library?
93 //! 5. Does the target in the metadata agree with the current target?
94 //! 6. Does the SVH match? (more on this later)
96 //! If the file answers `yes` to all these questions, then the file is
97 //! considered as being *candidate* for being accepted. It is illegal to have
98 //! more than two candidates as the compiler has no method by which to resolve
99 //! this conflict. Additionally, rlib/dylib candidates are considered
102 //! After all this has happened, we have 1 or two files as candidates. These
103 //! represent the rlib/dylib file found for a library, and they're returned as
106 //! ### What about versions?
108 //! A lot of effort has been put forth to remove versioning from the compiler.
109 //! There have been forays in the past to have versioning baked in, but it was
110 //! largely always deemed insufficient to the point that it was recognized that
111 //! it's probably something the compiler shouldn't do anyway due to its
112 //! complicated nature and the state of the half-baked solutions.
114 //! With a departure from versioning, the primary criterion for loading crates
115 //! is just the name of a crate. If we stopped here, it would imply that you
116 //! could never link two crates of the same name from different sources
117 //! together, which is clearly a bad state to be in.
119 //! To resolve this problem, we come to the next section!
123 //! A number of flags have been added to the compiler to solve the "version
124 //! problem" in the previous section, as well as generally enabling more
125 //! powerful usage of the crate loading system of the compiler. The goal of
126 //! these flags and options are to enable third-party tools to drive the
127 //! compiler with prior knowledge about how the world should look.
129 //! ## The `--extern` flag
131 //! The compiler accepts a flag of this form a number of times:
134 //! --extern crate-name=path/to/the/crate.rlib
137 //! This flag is basically the following letter to the compiler:
141 //! > When you are attempting to load the immediate dependency `crate-name`, I
142 //! > would like you to assume that the library is located at
143 //! > `path/to/the/crate.rlib`, and look nowhere else. Also, please do not
144 //! > assume that the path I specified has the name `crate-name`.
146 //! This flag basically overrides most matching logic except for validating that
147 //! the file is indeed a rust library. The same `crate-name` can be specified
148 //! twice to specify the rlib/dylib pair.
150 //! ## Enabling "multiple versions"
152 //! This basically boils down to the ability to specify arbitrary packages to
153 //! the compiler. For example, if crate A wanted to use Bv1 and Bv2, then it
154 //! would look something like:
156 //! ```compile_fail,E0463
163 //! and the compiler would be invoked as:
166 //! rustc a.rs --extern b1=path/to/libb1.rlib --extern b2=path/to/libb2.rlib
169 //! In this scenario there are two crates named `b` and the compiler must be
170 //! manually driven to be informed where each crate is.
172 //! ## Frobbing symbols
174 //! One of the immediate problems with linking the same library together twice
175 //! in the same problem is dealing with duplicate symbols. The primary way to
176 //! deal with this in rustc is to add hashes to the end of each symbol.
178 //! In order to force hashes to change between versions of a library, if
179 //! desired, the compiler exposes an option `-C metadata=foo`, which is used to
180 //! initially seed each symbol hash. The string `foo` is prepended to each
181 //! string-to-hash to ensure that symbols change over time.
183 //! ## Loading transitive dependencies
185 //! Dealing with same-named-but-distinct crates is not just a local problem, but
186 //! one that also needs to be dealt with for transitive dependencies. Note that
187 //! in the letter above `--extern` flags only apply to the *local* set of
188 //! dependencies, not the upstream transitive dependencies. Consider this
189 //! dependency graph:
201 //! In this scenario, when we compile `D`, we need to be able to distinctly
202 //! resolve `A.1` and `A.2`, but an `--extern` flag cannot apply to these
203 //! transitive dependencies.
205 //! Note that the key idea here is that `B` and `C` are both *already compiled*.
206 //! That is, they have already resolved their dependencies. Due to unrelated
207 //! technical reasons, when a library is compiled, it is only compatible with
208 //! the *exact same* version of the upstream libraries it was compiled against.
209 //! We use the "Strict Version Hash" to identify the exact copy of an upstream
212 //! With this knowledge, we know that `B` and `C` will depend on `A` with
213 //! different SVH values, so we crawl the normal `-L` paths looking for
214 //! `liba*.rlib` and filter based on the contained SVH.
216 //! In the end, this ends up not needing `--extern` to specify upstream
217 //! transitive dependencies.
221 //! That's the general overview of loading crates in the compiler, but it's by
222 //! no means all of the necessary details. Take a look at the rest of
223 //! metadata::locator or metadata::creader for all the juicy details!
225 use cstore
::{MetadataRef, MetadataBlob}
;
226 use creader
::Library
;
227 use schema
::{METADATA_HEADER, rustc_version}
;
229 use rustc
::hir
::svh
::Svh
;
230 use rustc
::middle
::cstore
::MetadataLoader
;
231 use rustc
::session
::{config, Session}
;
232 use rustc
::session
::filesearch
::{FileSearch, FileMatches, FileDoesntMatch}
;
233 use rustc
::session
::search_paths
::PathKind
;
234 use rustc
::util
::nodemap
::FxHashMap
;
236 use errors
::DiagnosticBuilder
;
237 use syntax
::symbol
::Symbol
;
238 use syntax_pos
::Span
;
239 use rustc_target
::spec
::{Target, TargetTriple}
;
242 use std
::collections
::HashSet
;
245 use std
::io
::{self, Read}
;
246 use std
::path
::{Path, PathBuf}
;
247 use std
::time
::Instant
;
249 use flate2
::read
::DeflateDecoder
;
251 use rustc_data_structures
::owning_ref
::OwningRef
;
252 pub struct CrateMismatch
{
257 pub struct Context
<'a
> {
258 pub sess
: &'a Session
,
261 pub crate_name
: Symbol
,
262 pub hash
: Option
<&'a Svh
>,
263 pub extra_filename
: Option
<&'a
str>,
264 // points to either self.sess.target.target or self.sess.host, must match triple
265 pub target
: &'a Target
,
266 pub triple
: &'a TargetTriple
,
267 pub filesearch
: FileSearch
<'a
>,
268 pub root
: &'a Option
<CratePaths
>,
269 pub rejected_via_hash
: Vec
<CrateMismatch
>,
270 pub rejected_via_triple
: Vec
<CrateMismatch
>,
271 pub rejected_via_kind
: Vec
<CrateMismatch
>,
272 pub rejected_via_version
: Vec
<CrateMismatch
>,
273 pub rejected_via_filename
: Vec
<CrateMismatch
>,
274 pub should_match_name
: bool
,
275 pub is_proc_macro
: Option
<bool
>,
276 pub metadata_loader
: &'a
dyn MetadataLoader
,
279 pub struct CratePaths
{
281 pub dylib
: Option
<PathBuf
>,
282 pub rlib
: Option
<PathBuf
>,
283 pub rmeta
: Option
<PathBuf
>,
286 #[derive(Copy, Clone, PartialEq)]
293 impl fmt
::Display
for CrateFlavor
{
294 fn fmt(&self, f
: &mut fmt
::Formatter
) -> fmt
::Result
{
295 f
.write_str(match *self {
296 CrateFlavor
::Rlib
=> "rlib",
297 CrateFlavor
::Rmeta
=> "rmeta",
298 CrateFlavor
::Dylib
=> "dylib",
304 fn paths(&self) -> Vec
<PathBuf
> {
305 self.dylib
.iter().chain(self.rlib
.iter()).chain(self.rmeta
.iter()).cloned().collect()
309 impl<'a
> Context
<'a
> {
310 pub fn maybe_load_library_crate(&mut self) -> Option
<Library
> {
311 let mut seen_paths
= HashSet
::new();
312 match self.extra_filename
{
313 Some(s
) => self.find_library_crate(s
, &mut seen_paths
)
314 .or_else(|| self.find_library_crate("", &mut seen_paths
)),
315 None
=> self.find_library_crate("", &mut seen_paths
)
319 pub fn report_errs(&mut self) -> ! {
320 let add
= match self.root
{
321 &None
=> String
::new(),
322 &Some(ref r
) => format
!(" which `{}` depends on", r
.ident
),
324 let mut msg
= "the following crate versions were found:".to_string();
325 let mut err
= if !self.rejected_via_hash
.is_empty() {
326 let mut err
= struct_span_err
!(self.sess
,
329 "found possibly newer version of crate `{}`{}",
332 err
.note("perhaps that crate needs to be recompiled?");
333 let mismatches
= self.rejected_via_hash
.iter();
334 for &CrateMismatch { ref path, .. }
in mismatches
{
335 msg
.push_str(&format
!("\ncrate `{}`: {}", self.ident
, path
.display()));
340 for path
in r
.paths().iter() {
341 msg
.push_str(&format
!("\ncrate `{}`: {}", r
.ident
, path
.display()));
347 } else if !self.rejected_via_triple
.is_empty() {
348 let mut err
= struct_span_err
!(self.sess
,
351 "couldn't find crate `{}` \
352 with expected target triple {}{}",
356 let mismatches
= self.rejected_via_triple
.iter();
357 for &CrateMismatch { ref path, ref got }
in mismatches
{
358 msg
.push_str(&format
!("\ncrate `{}`, target triple {}: {}",
365 } else if !self.rejected_via_kind
.is_empty() {
366 let mut err
= struct_span_err
!(self.sess
,
369 "found staticlib `{}` instead of rlib or dylib{}",
372 err
.help("please recompile that crate using --crate-type lib");
373 let mismatches
= self.rejected_via_kind
.iter();
374 for &CrateMismatch { ref path, .. }
in mismatches
{
375 msg
.push_str(&format
!("\ncrate `{}`: {}", self.ident
, path
.display()));
379 } else if !self.rejected_via_version
.is_empty() {
380 let mut err
= struct_span_err
!(self.sess
,
383 "found crate `{}` compiled by an incompatible version \
387 err
.help(&format
!("please recompile that crate using this compiler ({})",
389 let mismatches
= self.rejected_via_version
.iter();
390 for &CrateMismatch { ref path, ref got }
in mismatches
{
391 msg
.push_str(&format
!("\ncrate `{}` compiled by {}: {}",
399 let mut err
= struct_span_err
!(self.sess
,
402 "can't find crate for `{}`{}",
406 if (self.ident
== "std" || self.ident
== "core")
407 && self.triple
!= &TargetTriple
::from_triple(config
::host_triple()) {
408 err
.note(&format
!("the `{}` target may not be installed", self.triple
));
410 err
.span_label(self.span
, "can't find crate");
414 if !self.rejected_via_filename
.is_empty() {
415 let dylibname
= self.dylibname();
416 let mismatches
= self.rejected_via_filename
.iter();
417 for &CrateMismatch { ref path, .. }
in mismatches
{
418 err
.note(&format
!("extern location for {} is of an unknown type: {}",
421 .help(&format
!("file name should be lib*.rlib or {}*.{}",
428 self.sess
.abort_if_errors();
432 fn find_library_crate(&mut self,
434 seen_paths
: &mut HashSet
<PathBuf
>)
436 // If an SVH is specified, then this is a transitive dependency that
437 // must be loaded via -L plus some filtering.
438 if self.hash
.is_none() {
439 self.should_match_name
= false;
440 if let Some(s
) = self.sess
.opts
.externs
.get(&self.crate_name
.as_str()) {
441 return self.find_commandline_library(s
.iter());
443 self.should_match_name
= true;
446 let dypair
= self.dylibname();
447 let staticpair
= self.staticlibname();
449 // want: crate_name.dir_part() + prefix + crate_name.file_part + "-"
450 let dylib_prefix
= format
!("{}{}{}", dypair
.0, self.crate_name
, extra_prefix
);
451 let rlib_prefix
= format
!("lib{}{}", self.crate_name
, extra_prefix
);
452 let staticlib_prefix
= format
!("{}{}{}", staticpair
.0, self.crate_name
, extra_prefix
);
454 let mut candidates
= FxHashMap();
455 let mut staticlibs
= vec
![];
457 // First, find all possible candidate rlibs and dylibs purely based on
458 // the name of the files themselves. We're trying to match against an
459 // exact crate name and a possibly an exact hash.
461 // During this step, we can filter all found libraries based on the
462 // name and id found in the crate id (we ignore the path portion for
463 // filename matching), as well as the exact hash (if specified). If we
464 // end up having many candidates, we must look at the metadata to
465 // perform exact matches against hashes/crate ids. Note that opening up
466 // the metadata is where we do an exact match against the full contents
467 // of the crate id (path/name/id).
469 // The goal of this step is to look at as little metadata as possible.
470 self.filesearch
.search(|path
, kind
| {
471 let file
= match path
.file_name().and_then(|s
| s
.to_str()) {
472 None
=> return FileDoesntMatch
,
475 let (hash
, found_kind
) =
476 if file
.starts_with(&rlib_prefix
) && file
.ends_with(".rlib") {
477 (&file
[(rlib_prefix
.len())..(file
.len() - ".rlib".len())], CrateFlavor
::Rlib
)
478 } else if file
.starts_with(&rlib_prefix
) && file
.ends_with(".rmeta") {
479 (&file
[(rlib_prefix
.len())..(file
.len() - ".rmeta".len())], CrateFlavor
::Rmeta
)
480 } else if file
.starts_with(&dylib_prefix
) &&
481 file
.ends_with(&dypair
.1) {
482 (&file
[(dylib_prefix
.len())..(file
.len() - dypair
.1.len())], CrateFlavor
::Dylib
)
484 if file
.starts_with(&staticlib_prefix
) && file
.ends_with(&staticpair
.1) {
485 staticlibs
.push(CrateMismatch
{
486 path
: path
.to_path_buf(),
487 got
: "static".to_string(),
490 return FileDoesntMatch
;
493 info
!("lib candidate: {}", path
.display());
495 let hash_str
= hash
.to_string();
496 let slot
= candidates
.entry(hash_str
)
497 .or_insert_with(|| (FxHashMap(), FxHashMap(), FxHashMap()));
498 let (ref mut rlibs
, ref mut rmetas
, ref mut dylibs
) = *slot
;
499 fs
::canonicalize(path
)
501 if seen_paths
.contains(&p
) {
502 return FileDoesntMatch
504 seen_paths
.insert(p
.clone());
506 CrateFlavor
::Rlib
=> { rlibs.insert(p, kind); }
507 CrateFlavor
::Rmeta
=> { rmetas.insert(p, kind); }
508 CrateFlavor
::Dylib
=> { dylibs.insert(p, kind); }
512 .unwrap_or(FileDoesntMatch
)
514 self.rejected_via_kind
.extend(staticlibs
);
516 // We have now collected all known libraries into a set of candidates
517 // keyed of the filename hash listed. For each filename, we also have a
518 // list of rlibs/dylibs that apply. Here, we map each of these lists
519 // (per hash), to a Library candidate for returning.
521 // A Library candidate is created if the metadata for the set of
522 // libraries corresponds to the crate id and hash criteria that this
523 // search is being performed for.
524 let mut libraries
= FxHashMap();
525 for (_hash
, (rlibs
, rmetas
, dylibs
)) in candidates
{
527 let rlib
= self.extract_one(rlibs
, CrateFlavor
::Rlib
, &mut slot
);
528 let rmeta
= self.extract_one(rmetas
, CrateFlavor
::Rmeta
, &mut slot
);
529 let dylib
= self.extract_one(dylibs
, CrateFlavor
::Dylib
, &mut slot
);
530 if let Some((h
, m
)) = slot
{
541 // Having now translated all relevant found hashes into libraries, see
542 // what we've got and figure out if we found multiple candidates for
544 match libraries
.len() {
546 1 => Some(libraries
.into_iter().next().unwrap().1),
548 let mut err
= struct_span_err
!(self.sess
,
551 "multiple matching crates for `{}`",
553 let candidates
= libraries
.iter().filter_map(|(_
, lib
)| {
554 let crate_name
= &lib
.metadata
.get_root().name
.as_str();
555 match &(&lib
.dylib
, &lib
.rlib
) {
556 &(&Some((ref pd
, _
)), &Some((ref pr
, _
))) => {
557 Some(format
!("\ncrate `{}`: {}\n{:>padding$}",
561 padding
=8 + crate_name
.len()))
563 &(&Some((ref p
, _
)), &None
) | &(&None
, &Some((ref p
, _
))) => {
564 Some(format
!("\ncrate `{}`: {}", crate_name
, p
.display()))
566 &(&None
, &None
) => None
,
568 }).collect
::<String
>();
569 err
.note(&format
!("candidates:{}", candidates
));
576 // Attempts to extract *one* library from the set `m`. If the set has no
577 // elements, `None` is returned. If the set has more than one element, then
578 // the errors and notes are emitted about the set of libraries.
580 // With only one library in the set, this function will extract it, and then
581 // read the metadata from it if `*slot` is `None`. If the metadata couldn't
582 // be read, it is assumed that the file isn't a valid rust library (no
583 // errors are emitted).
584 fn extract_one(&mut self,
585 m
: FxHashMap
<PathBuf
, PathKind
>,
587 slot
: &mut Option
<(Svh
, MetadataBlob
)>)
588 -> Option
<(PathBuf
, PathKind
)> {
589 let mut ret
: Option
<(PathBuf
, PathKind
)> = None
;
593 // FIXME(#10786): for an optimization, we only read one of the
594 // libraries' metadata sections. In theory we should
595 // read both, but reading dylib metadata is quite
599 } else if m
.len() == 1 {
600 return Some(m
.into_iter().next().unwrap());
604 let mut err
: Option
<DiagnosticBuilder
> = None
;
605 for (lib
, kind
) in m
{
606 info
!("{} reading metadata from: {}", flavor
, lib
.display());
607 let (hash
, metadata
) =
608 match get_metadata_section(self.target
, flavor
, &lib
, self.metadata_loader
) {
610 if let Some(h
) = self.crate_matches(&blob
, &lib
) {
613 info
!("metadata mismatch");
618 info
!("no metadata found: {}", err
);
622 // If we see multiple hashes, emit an error about duplicate candidates.
623 if slot
.as_ref().map_or(false, |s
| s
.0 != hash
) {
624 let mut e
= struct_span_err
!(self.sess
,
627 "multiple {} candidates for `{}` found",
630 e
.span_note(self.span
,
631 &format
!(r
"candidate #1: {}",
636 if let Some(ref mut e
) = err
{
645 err
.as_mut().unwrap().span_note(self.span
,
646 &format
!(r
"candidate #{}: {}",
652 // Ok so at this point we've determined that `(lib, kind)` above is
653 // a candidate crate to load, and that `slot` is either none (this
654 // is the first crate of its kind) or if some the previous path has
655 // the exact same hash (e.g. it's the exact same crate).
657 // In principle these two candidate crates are exactly the same so
658 // we can choose either of them to link. As a stupidly gross hack,
659 // however, we favor crate in the sysroot.
661 // You can find more info in rust-lang/rust#39518 and various linked
662 // issues, but the general gist is that during testing libstd the
663 // compilers has two candidates to choose from: one in the sysroot
664 // and one in the deps folder. These two crates are the exact same
665 // crate but if the compiler chooses the one in the deps folder
666 // it'll cause spurious errors on Windows.
668 // As a result, we favor the sysroot crate here. Note that the
669 // candidates are all canonicalized, so we canonicalize the sysroot
671 if let Some((ref prev
, _
)) = ret
{
672 let sysroot
= self.sess
.sysroot();
673 let sysroot
= sysroot
.canonicalize()
674 .unwrap_or(sysroot
.to_path_buf());
675 if prev
.starts_with(&sysroot
) {
679 *slot
= Some((hash
, metadata
));
680 ret
= Some((lib
, kind
));
691 fn crate_matches(&mut self, metadata
: &MetadataBlob
, libpath
: &Path
) -> Option
<Svh
> {
692 let rustc_version
= rustc_version();
693 let found_version
= metadata
.get_rustc_version();
694 if found_version
!= rustc_version
{
695 info
!("Rejecting via version: expected {} got {}",
698 self.rejected_via_version
.push(CrateMismatch
{
699 path
: libpath
.to_path_buf(),
705 let root
= metadata
.get_root();
706 if let Some(is_proc_macro
) = self.is_proc_macro
{
707 if root
.macro_derive_registrar
.is_some() != is_proc_macro
{
712 if self.should_match_name
{
713 if self.crate_name
!= root
.name
{
714 info
!("Rejecting via crate name");
719 if &root
.triple
!= self.triple
{
720 info
!("Rejecting via crate triple: expected {} got {}",
723 self.rejected_via_triple
.push(CrateMismatch
{
724 path
: libpath
.to_path_buf(),
725 got
: root
.triple
.to_string(),
730 if let Some(myhash
) = self.hash
{
731 if *myhash
!= root
.hash
{
732 info
!("Rejecting via hash: expected {} got {}", *myhash
, root
.hash
);
733 self.rejected_via_hash
.push(CrateMismatch
{
734 path
: libpath
.to_path_buf(),
735 got
: myhash
.to_string(),
745 // Returns the corresponding (prefix, suffix) that files need to have for
747 fn dylibname(&self) -> (String
, String
) {
748 let t
= &self.target
;
749 (t
.options
.dll_prefix
.clone(), t
.options
.dll_suffix
.clone())
752 // Returns the corresponding (prefix, suffix) that files need to have for
754 fn staticlibname(&self) -> (String
, String
) {
755 let t
= &self.target
;
756 (t
.options
.staticlib_prefix
.clone(), t
.options
.staticlib_suffix
.clone())
759 fn find_commandline_library
<'b
, LOCS
>(&mut self, locs
: LOCS
) -> Option
<Library
>
760 where LOCS
: Iterator
<Item
= &'b String
>
762 // First, filter out all libraries that look suspicious. We only accept
763 // files which actually exist that have the correct naming scheme for
765 let sess
= self.sess
;
766 let dylibname
= self.dylibname();
767 let mut rlibs
= FxHashMap();
768 let mut rmetas
= FxHashMap();
769 let mut dylibs
= FxHashMap();
771 let locs
= locs
.map(|l
| PathBuf
::from(l
)).filter(|loc
| {
773 sess
.err(&format
!("extern location for {} does not exist: {}",
778 let file
= match loc
.file_name().and_then(|s
| s
.to_str()) {
781 sess
.err(&format
!("extern location for {} is not a file: {}",
787 if file
.starts_with("lib") &&
788 (file
.ends_with(".rlib") || file
.ends_with(".rmeta")) {
791 let (ref prefix
, ref suffix
) = dylibname
;
792 if file
.starts_with(&prefix
[..]) && file
.ends_with(&suffix
[..]) {
797 self.rejected_via_filename
.push(CrateMismatch
{
805 // Now that we have an iterator of good candidates, make sure
806 // there's at most one rlib and at most one dylib.
808 if loc
.file_name().unwrap().to_str().unwrap().ends_with(".rlib") {
809 rlibs
.insert(fs
::canonicalize(&loc
).unwrap(), PathKind
::ExternFlag
);
810 } else if loc
.file_name().unwrap().to_str().unwrap().ends_with(".rmeta") {
811 rmetas
.insert(fs
::canonicalize(&loc
).unwrap(), PathKind
::ExternFlag
);
813 dylibs
.insert(fs
::canonicalize(&loc
).unwrap(), PathKind
::ExternFlag
);
818 // Extract the rlib/dylib pair.
820 let rlib
= self.extract_one(rlibs
, CrateFlavor
::Rlib
, &mut slot
);
821 let rmeta
= self.extract_one(rmetas
, CrateFlavor
::Rmeta
, &mut slot
);
822 let dylib
= self.extract_one(dylibs
, CrateFlavor
::Dylib
, &mut slot
);
824 if rlib
.is_none() && rmeta
.is_none() && dylib
.is_none() {
827 slot
.map(|(_
, metadata
)|
838 // Just a small wrapper to time how long reading metadata takes.
839 fn get_metadata_section(target
: &Target
,
842 loader
: &dyn MetadataLoader
)
843 -> Result
<MetadataBlob
, String
> {
844 let start
= Instant
::now();
845 let ret
= get_metadata_section_imp(target
, flavor
, filename
, loader
);
846 info
!("reading {:?} => {:?}",
847 filename
.file_name().unwrap(),
852 fn get_metadata_section_imp(target
: &Target
,
855 loader
: &dyn MetadataLoader
)
856 -> Result
<MetadataBlob
, String
> {
857 if !filename
.exists() {
858 return Err(format
!("no such file: '{}'", filename
.display()));
860 let raw_bytes
: MetadataRef
= match flavor
{
861 CrateFlavor
::Rlib
=> loader
.get_rlib_metadata(target
, filename
)?
,
862 CrateFlavor
::Dylib
=> {
863 let buf
= loader
.get_dylib_metadata(target
, filename
)?
;
864 // The header is uncompressed
865 let header_len
= METADATA_HEADER
.len();
866 debug
!("checking {} bytes of metadata-version stamp", header_len
);
867 let header
= &buf
[..cmp
::min(header_len
, buf
.len())];
868 if header
!= METADATA_HEADER
{
869 return Err(format
!("incompatible metadata version found: '{}'",
870 filename
.display()));
873 // Header is okay -> inflate the actual metadata
874 let compressed_bytes
= &buf
[header_len
..];
875 debug
!("inflating {} bytes of compressed metadata", compressed_bytes
.len());
876 let mut inflated
= Vec
::new();
877 match DeflateDecoder
::new(compressed_bytes
).read_to_end(&mut inflated
) {
879 let buf
= unsafe { OwningRef::new_assert_stable_address(inflated) }
;
880 rustc_erase_owner
!(buf
.map_owner_box())
883 return Err(format
!("failed to decompress metadata: {}", filename
.display()));
887 CrateFlavor
::Rmeta
=> {
888 let buf
= fs
::read(filename
).map_err(|_
|
889 format
!("failed to read rmeta metadata: '{}'", filename
.display()))?
;
890 rustc_erase_owner
!(OwningRef
::new(buf
).map_owner_box())
893 let blob
= MetadataBlob(raw_bytes
);
894 if blob
.is_compatible() {
897 Err(format
!("incompatible metadata version found: '{}'", filename
.display()))
901 // A diagnostic function for dumping crate metadata to an output stream
902 pub fn list_file_metadata(target
: &Target
,
904 loader
: &dyn MetadataLoader
,
905 out
: &mut dyn io
::Write
)
907 let filename
= path
.file_name().unwrap().to_str().unwrap();
908 let flavor
= if filename
.ends_with(".rlib") {
910 } else if filename
.ends_with(".rmeta") {
915 match get_metadata_section(target
, flavor
, path
, loader
) {
916 Ok(metadata
) => metadata
.list_crate_metadata(out
),
917 Err(msg
) => write
!(out
, "{}\n", msg
),