| // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Finds crate binaries and loads their metadata |
| //! |
| //! Might I be the first to welcome you to a world of platform differences, |
| //! version requirements, dependency graphs, conflicting desires, and fun! This |
| //! is the major guts (along with metadata::creader) of the compiler for loading |
| //! crates and resolving dependencies. Let's take a tour! |
| //! |
| //! # The problem |
| //! |
| //! Each invocation of the compiler is immediately concerned with one primary |
| //! problem, to connect a set of crates to resolved crates on the filesystem. |
| //! Concretely speaking, the compiler follows roughly these steps to get here: |
| //! |
| //! 1. Discover a set of `extern crate` statements. |
| //! 2. Transform these directives into crate names. If the directive does not |
| //! have an explicit name, then the identifier is the name. |
| //! 3. For each of these crate names, find a corresponding crate on the |
| //! filesystem. |
| //! |
| //! Sounds easy, right? Let's walk into some of the nuances. |
| //! |
| //! ## Transitive Dependencies |
| //! |
| //! Let's say we've got three crates: A, B, and C. A depends on B, and B depends |
| //! on C. When we're compiling A, we primarily need to find and locate B, but we |
| //! also end up needing to find and locate C as well. |
| //! |
| //! The reason for this is that any of B's types could be composed of C's types, |
| //! any function in B could return a type from C, etc. To be able to guarantee |
| //! that we can always typecheck/translate any function, we have to have |
| //! complete knowledge of the whole ecosystem, not just our immediate |
| //! dependencies. |
| //! |
| //! So now as part of the "find a corresponding crate on the filesystem" step |
| //! above, this involves also finding all crates for *all upstream |
| //! dependencies*. This includes all dependencies transitively. |
| //! |
| //! ## Rlibs and Dylibs |
| //! |
| //! The compiler has two forms of intermediate dependencies. These are dubbed |
| //! rlibs and dylibs for the static and dynamic variants, respectively. An rlib |
| //! is a rustc-defined file format (currently just an ar archive) while a dylib |
| //! is a platform-defined dynamic library. Each library has a metadata somewhere |
| //! inside of it. |
| //! |
| //! When translating a crate name to a crate on the filesystem, we all of a |
| //! sudden need to take into account both rlibs and dylibs! Linkage later on may |
| //! use either one of these files, as each has their pros/cons. The job of crate |
| //! loading is to discover what's possible by finding all candidates. |
| //! |
| //! Most parts of this loading systems keep the dylib/rlib as just separate |
| //! variables. |
| //! |
| //! ## Where to look? |
| //! |
| //! We can't exactly scan your whole hard drive when looking for dependencies, |
| //! so we need to places to look. Currently the compiler will implicitly add the |
| //! target lib search path ($prefix/lib/rustlib/$target/lib) to any compilation, |
| //! and otherwise all -L flags are added to the search paths. |
| //! |
| //! ## What criterion to select on? |
| //! |
| //! This a pretty tricky area of loading crates. Given a file, how do we know |
| //! whether it's the right crate? Currently, the rules look along these lines: |
| //! |
| //! 1. Does the filename match an rlib/dylib pattern? That is to say, does the |
| //! filename have the right prefix/suffix? |
| //! 2. Does the filename have the right prefix for the crate name being queried? |
| //! This is filtering for files like `libfoo*.rlib` and such. |
| //! 3. Is the file an actual rust library? This is done by loading the metadata |
| //! from the library and making sure it's actually there. |
| //! 4. Does the name in the metadata agree with the name of the library? |
| //! 5. Does the target in the metadata agree with the current target? |
| //! 6. Does the SVH match? (more on this later) |
| //! |
| //! If the file answers `yes` to all these questions, then the file is |
| //! considered as being *candidate* for being accepted. It is illegal to have |
| //! more than two candidates as the compiler has no method by which to resolve |
| //! this conflict. Additionally, rlib/dylib candidates are considered |
| //! separately. |
| //! |
| //! After all this has happened, we have 1 or two files as candidates. These |
| //! represent the rlib/dylib file found for a library, and they're returned as |
| //! being found. |
| //! |
| //! ### What about versions? |
| //! |
| //! A lot of effort has been put forth to remove versioning from the compiler. |
| //! There have been forays in the past to have versioning baked in, but it was |
| //! largely always deemed insufficient to the point that it was recognized that |
| //! it's probably something the compiler shouldn't do anyway due to its |
| //! complicated nature and the state of the half-baked solutions. |
| //! |
| //! With a departure from versioning, the primary criterion for loading crates |
| //! is just the name of a crate. If we stopped here, it would imply that you |
| //! could never link two crates of the same name from different sources |
| //! together, which is clearly a bad state to be in. |
| //! |
| //! To resolve this problem, we come to the next section! |
| //! |
| //! # Expert Mode |
| //! |
| //! A number of flags have been added to the compiler to solve the "version |
| //! problem" in the previous section, as well as generally enabling more |
| //! powerful usage of the crate loading system of the compiler. The goal of |
| //! these flags and options are to enable third-party tools to drive the |
| //! compiler with prior knowledge about how the world should look. |
| //! |
| //! ## The `--extern` flag |
| //! |
| //! The compiler accepts a flag of this form a number of times: |
| //! |
| //! ```text |
| //! --extern crate-name=path/to/the/crate.rlib |
| //! ``` |
| //! |
| //! This flag is basically the following letter to the compiler: |
| //! |
| //! > Dear rustc, |
| //! > |
| //! > When you are attempting to load the immediate dependency `crate-name`, I |
| //! > would like you to assume that the library is located at |
| //! > `path/to/the/crate.rlib`, and look nowhere else. Also, please do not |
| //! > assume that the path I specified has the name `crate-name`. |
| //! |
| //! This flag basically overrides most matching logic except for validating that |
| //! the file is indeed a rust library. The same `crate-name` can be specified |
| //! twice to specify the rlib/dylib pair. |
| //! |
| //! ## Enabling "multiple versions" |
| //! |
| //! This basically boils down to the ability to specify arbitrary packages to |
| //! the compiler. For example, if crate A wanted to use Bv1 and Bv2, then it |
| //! would look something like: |
| //! |
| //! ```ignore |
| //! extern crate b1; |
| //! extern crate b2; |
| //! |
| //! fn main() {} |
| //! ``` |
| //! |
| //! and the compiler would be invoked as: |
| //! |
| //! ```text |
| //! rustc a.rs --extern b1=path/to/libb1.rlib --extern b2=path/to/libb2.rlib |
| //! ``` |
| //! |
| //! In this scenario there are two crates named `b` and the compiler must be |
| //! manually driven to be informed where each crate is. |
| //! |
| //! ## Frobbing symbols |
| //! |
| //! One of the immediate problems with linking the same library together twice |
| //! in the same problem is dealing with duplicate symbols. The primary way to |
| //! deal with this in rustc is to add hashes to the end of each symbol. |
| //! |
| //! In order to force hashes to change between versions of a library, if |
| //! desired, the compiler exposes an option `-C metadata=foo`, which is used to |
| //! initially seed each symbol hash. The string `foo` is prepended to each |
| //! string-to-hash to ensure that symbols change over time. |
| //! |
| //! ## Loading transitive dependencies |
| //! |
| //! Dealing with same-named-but-distinct crates is not just a local problem, but |
| //! one that also needs to be dealt with for transitive dependencies. Note that |
| //! in the letter above `--extern` flags only apply to the *local* set of |
| //! dependencies, not the upstream transitive dependencies. Consider this |
| //! dependency graph: |
| //! |
| //! ```text |
| //! A.1 A.2 |
| //! | | |
| //! | | |
| //! B C |
| //! \ / |
| //! \ / |
| //! D |
| //! ``` |
| //! |
| //! In this scenario, when we compile `D`, we need to be able to distinctly |
| //! resolve `A.1` and `A.2`, but an `--extern` flag cannot apply to these |
| //! transitive dependencies. |
| //! |
| //! Note that the key idea here is that `B` and `C` are both *already compiled*. |
| //! That is, they have already resolved their dependencies. Due to unrelated |
| //! technical reasons, when a library is compiled, it is only compatible with |
| //! the *exact same* version of the upstream libraries it was compiled against. |
| //! We use the "Strict Version Hash" to identify the exact copy of an upstream |
| //! library. |
| //! |
| //! With this knowledge, we know that `B` and `C` will depend on `A` with |
| //! different SVH values, so we crawl the normal `-L` paths looking for |
| //! `liba*.rlib` and filter based on the contained SVH. |
| //! |
| //! In the end, this ends up not needing `--extern` to specify upstream |
| //! transitive dependencies. |
| //! |
| //! # Wrapping up |
| //! |
| //! That's the general overview of loading crates in the compiler, but it's by |
| //! no means all of the necessary details. Take a look at the rest of |
| //! metadata::loader or metadata::creader for all the juicy details! |
| |
| use cstore::{MetadataBlob, MetadataVec, MetadataArchive}; |
| use common::{metadata_encoding_version, rustc_version}; |
| use decoder; |
| |
| use rustc::hir::svh::Svh; |
| use rustc::session::Session; |
| use rustc::session::filesearch::{FileSearch, FileMatches, FileDoesntMatch}; |
| use rustc::session::search_paths::PathKind; |
| use rustc::util::common; |
| |
| use rustc_llvm as llvm; |
| use rustc_llvm::{False, ObjectFile, mk_section_iter}; |
| use rustc_llvm::archive_ro::ArchiveRO; |
| use errors::DiagnosticBuilder; |
| use syntax_pos::Span; |
| use rustc_back::target::Target; |
| |
| use std::cmp; |
| use std::collections::HashMap; |
| use std::fmt; |
| use std::fs; |
| use std::io; |
| use std::path::{Path, PathBuf}; |
| use std::ptr; |
| use std::slice; |
| use std::time::Instant; |
| |
| use flate; |
| |
| pub struct CrateMismatch { |
| path: PathBuf, |
| got: String, |
| } |
| |
| pub struct Context<'a> { |
| pub sess: &'a Session, |
| pub span: Span, |
| pub ident: &'a str, |
| pub crate_name: &'a str, |
| pub hash: Option<&'a Svh>, |
| // points to either self.sess.target.target or self.sess.host, must match triple |
| pub target: &'a Target, |
| pub triple: &'a str, |
| pub filesearch: FileSearch<'a>, |
| pub root: &'a Option<CratePaths>, |
| pub rejected_via_hash: Vec<CrateMismatch>, |
| pub rejected_via_triple: Vec<CrateMismatch>, |
| pub rejected_via_kind: Vec<CrateMismatch>, |
| pub rejected_via_version: Vec<CrateMismatch>, |
| pub should_match_name: bool, |
| } |
| |
| pub struct Library { |
| pub dylib: Option<(PathBuf, PathKind)>, |
| pub rlib: Option<(PathBuf, PathKind)>, |
| pub metadata: MetadataBlob, |
| } |
| |
| pub struct ArchiveMetadata { |
| _archive: ArchiveRO, |
| // points into self._archive |
| data: *const [u8], |
| } |
| |
| pub struct CratePaths { |
| pub ident: String, |
| pub dylib: Option<PathBuf>, |
| pub rlib: Option<PathBuf> |
| } |
| |
| pub const METADATA_FILENAME: &'static str = "rust.metadata.bin"; |
| |
| #[derive(Copy, Clone, PartialEq)] |
| enum CrateFlavor { |
| Rlib, |
| Dylib |
| } |
| |
| impl fmt::Display for CrateFlavor { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.write_str(match *self { |
| CrateFlavor::Rlib => "rlib", |
| CrateFlavor::Dylib => "dylib" |
| }) |
| } |
| } |
| |
| impl CratePaths { |
| fn paths(&self) -> Vec<PathBuf> { |
| match (&self.dylib, &self.rlib) { |
| (&None, &None) => vec!(), |
| (&Some(ref p), &None) | |
| (&None, &Some(ref p)) => vec!(p.clone()), |
| (&Some(ref p1), &Some(ref p2)) => vec!(p1.clone(), p2.clone()), |
| } |
| } |
| } |
| |
| impl<'a> Context<'a> { |
| pub fn maybe_load_library_crate(&mut self) -> Option<Library> { |
| self.find_library_crate() |
| } |
| |
| pub fn load_library_crate(&mut self) -> Library { |
| self.find_library_crate().unwrap_or_else(|| self.report_load_errs()) |
| } |
| |
| pub fn report_load_errs(&mut self) -> ! { |
| let add = match self.root { |
| &None => String::new(), |
| &Some(ref r) => format!(" which `{}` depends on", |
| r.ident) |
| }; |
| let mut err = if !self.rejected_via_hash.is_empty() { |
| struct_span_err!(self.sess, self.span, E0460, |
| "found possibly newer version of crate `{}`{}", |
| self.ident, add) |
| } else if !self.rejected_via_triple.is_empty() { |
| struct_span_err!(self.sess, self.span, E0461, |
| "couldn't find crate `{}` with expected target triple {}{}", |
| self.ident, self.triple, add) |
| } else if !self.rejected_via_kind.is_empty() { |
| struct_span_err!(self.sess, self.span, E0462, |
| "found staticlib `{}` instead of rlib or dylib{}", |
| self.ident, add) |
| } else if !self.rejected_via_version.is_empty() { |
| struct_span_err!(self.sess, self.span, E0514, |
| "found crate `{}` compiled by an incompatible version of rustc{}", |
| self.ident, add) |
| } else { |
| struct_span_err!(self.sess, self.span, E0463, |
| "can't find crate for `{}`{}", |
| self.ident, add) |
| }; |
| |
| if !self.rejected_via_triple.is_empty() { |
| let mismatches = self.rejected_via_triple.iter(); |
| for (i, &CrateMismatch{ ref path, ref got }) in mismatches.enumerate() { |
| err.note(&format!("crate `{}`, path #{}, triple {}: {}", |
| self.ident, i+1, got, path.display())); |
| } |
| } |
| if !self.rejected_via_hash.is_empty() { |
| err.note("perhaps that crate needs to be recompiled?"); |
| let mismatches = self.rejected_via_hash.iter(); |
| for (i, &CrateMismatch{ ref path, .. }) in mismatches.enumerate() { |
| err.note(&format!("crate `{}` path #{}: {}", |
| self.ident, i+1, path.display())); |
| } |
| match self.root { |
| &None => {} |
| &Some(ref r) => { |
| for (i, path) in r.paths().iter().enumerate() { |
| err.note(&format!("crate `{}` path #{}: {}", |
| r.ident, i+1, path.display())); |
| } |
| } |
| } |
| } |
| if !self.rejected_via_kind.is_empty() { |
| err.help("please recompile that crate using --crate-type lib"); |
| let mismatches = self.rejected_via_kind.iter(); |
| for (i, &CrateMismatch { ref path, .. }) in mismatches.enumerate() { |
| err.note(&format!("crate `{}` path #{}: {}", |
| self.ident, i+1, path.display())); |
| } |
| } |
| if !self.rejected_via_version.is_empty() { |
| err.help(&format!("please recompile that crate using this compiler ({})", |
| rustc_version())); |
| let mismatches = self.rejected_via_version.iter(); |
| for (i, &CrateMismatch { ref path, ref got }) in mismatches.enumerate() { |
| err.note(&format!("crate `{}` path #{}: {} compiled by {:?}", |
| self.ident, i+1, path.display(), got)); |
| } |
| } |
| |
| err.emit(); |
| self.sess.abort_if_errors(); |
| unreachable!(); |
| } |
| |
| fn find_library_crate(&mut self) -> Option<Library> { |
| // If an SVH is specified, then this is a transitive dependency that |
| // must be loaded via -L plus some filtering. |
| if self.hash.is_none() { |
| self.should_match_name = false; |
| if let Some(s) = self.sess.opts.externs.get(self.crate_name) { |
| return self.find_commandline_library(s); |
| } |
| self.should_match_name = true; |
| } |
| |
| let dypair = self.dylibname(); |
| let staticpair = self.staticlibname(); |
| |
| // want: crate_name.dir_part() + prefix + crate_name.file_part + "-" |
| let dylib_prefix = format!("{}{}", dypair.0, self.crate_name); |
| let rlib_prefix = format!("lib{}", self.crate_name); |
| let staticlib_prefix = format!("{}{}", staticpair.0, self.crate_name); |
| |
| let mut candidates = HashMap::new(); |
| let mut staticlibs = vec!(); |
| |
| // First, find all possible candidate rlibs and dylibs purely based on |
| // the name of the files themselves. We're trying to match against an |
| // exact crate name and a possibly an exact hash. |
| // |
| // During this step, we can filter all found libraries based on the |
| // name and id found in the crate id (we ignore the path portion for |
| // filename matching), as well as the exact hash (if specified). If we |
| // end up having many candidates, we must look at the metadata to |
| // perform exact matches against hashes/crate ids. Note that opening up |
| // the metadata is where we do an exact match against the full contents |
| // of the crate id (path/name/id). |
| // |
| // The goal of this step is to look at as little metadata as possible. |
| self.filesearch.search(|path, kind| { |
| let file = match path.file_name().and_then(|s| s.to_str()) { |
| None => return FileDoesntMatch, |
| Some(file) => file, |
| }; |
| let (hash, rlib) = if file.starts_with(&rlib_prefix[..]) && |
| file.ends_with(".rlib") { |
| (&file[(rlib_prefix.len()) .. (file.len() - ".rlib".len())], |
| true) |
| } else if file.starts_with(&dylib_prefix) && |
| file.ends_with(&dypair.1) { |
| (&file[(dylib_prefix.len()) .. (file.len() - dypair.1.len())], |
| false) |
| } else { |
| if file.starts_with(&staticlib_prefix[..]) && |
| file.ends_with(&staticpair.1) { |
| staticlibs.push(CrateMismatch { |
| path: path.to_path_buf(), |
| got: "static".to_string() |
| }); |
| } |
| return FileDoesntMatch |
| }; |
| info!("lib candidate: {}", path.display()); |
| |
| let hash_str = hash.to_string(); |
| let slot = candidates.entry(hash_str) |
| .or_insert_with(|| (HashMap::new(), HashMap::new())); |
| let (ref mut rlibs, ref mut dylibs) = *slot; |
| fs::canonicalize(path).map(|p| { |
| if rlib { |
| rlibs.insert(p, kind); |
| } else { |
| dylibs.insert(p, kind); |
| } |
| FileMatches |
| }).unwrap_or(FileDoesntMatch) |
| }); |
| self.rejected_via_kind.extend(staticlibs); |
| |
| // We have now collected all known libraries into a set of candidates |
| // keyed of the filename hash listed. For each filename, we also have a |
| // list of rlibs/dylibs that apply. Here, we map each of these lists |
| // (per hash), to a Library candidate for returning. |
| // |
| // A Library candidate is created if the metadata for the set of |
| // libraries corresponds to the crate id and hash criteria that this |
| // search is being performed for. |
| let mut libraries = HashMap::new(); |
| for (_hash, (rlibs, dylibs)) in candidates { |
| let mut slot = None; |
| let rlib = self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot); |
| let dylib = self.extract_one(dylibs, CrateFlavor::Dylib, &mut slot); |
| if let Some((h, m)) = slot { |
| libraries.insert(h, Library { |
| dylib: dylib, |
| rlib: rlib, |
| metadata: m, |
| }); |
| } |
| } |
| |
| // Having now translated all relevant found hashes into libraries, see |
| // what we've got and figure out if we found multiple candidates for |
| // libraries or not. |
| match libraries.len() { |
| 0 => None, |
| 1 => Some(libraries.into_iter().next().unwrap().1), |
| _ => { |
| let mut err = struct_span_err!(self.sess, self.span, E0464, |
| "multiple matching crates for `{}`", |
| self.crate_name); |
| err.note("candidates:"); |
| for (_, lib) in libraries { |
| if let Some((ref p, _)) = lib.dylib { |
| err.note(&format!("path: {}", p.display())); |
| } |
| if let Some((ref p, _)) = lib.rlib { |
| err.note(&format!("path: {}", p.display())); |
| } |
| let data = lib.metadata.as_slice(); |
| let name = decoder::get_crate_name(data); |
| note_crate_name(&mut err, &name); |
| } |
| err.emit(); |
| None |
| } |
| } |
| } |
| |
| // Attempts to extract *one* library from the set `m`. If the set has no |
| // elements, `None` is returned. If the set has more than one element, then |
| // the errors and notes are emitted about the set of libraries. |
| // |
| // With only one library in the set, this function will extract it, and then |
| // read the metadata from it if `*slot` is `None`. If the metadata couldn't |
| // be read, it is assumed that the file isn't a valid rust library (no |
| // errors are emitted). |
| fn extract_one(&mut self, m: HashMap<PathBuf, PathKind>, flavor: CrateFlavor, |
| slot: &mut Option<(Svh, MetadataBlob)>) -> Option<(PathBuf, PathKind)> { |
| let mut ret: Option<(PathBuf, PathKind)> = None; |
| let mut error = 0; |
| |
| if slot.is_some() { |
| // FIXME(#10786): for an optimization, we only read one of the |
| // libraries' metadata sections. In theory we should |
| // read both, but reading dylib metadata is quite |
| // slow. |
| if m.is_empty() { |
| return None |
| } else if m.len() == 1 { |
| return Some(m.into_iter().next().unwrap()) |
| } |
| } |
| |
| let mut err: Option<DiagnosticBuilder> = None; |
| for (lib, kind) in m { |
| info!("{} reading metadata from: {}", flavor, lib.display()); |
| let (hash, metadata) = match get_metadata_section(self.target, flavor, &lib) { |
| Ok(blob) => { |
| if let Some(h) = self.crate_matches(blob.as_slice(), &lib) { |
| (h, blob) |
| } else { |
| info!("metadata mismatch"); |
| continue |
| } |
| } |
| Err(err) => { |
| info!("no metadata found: {}", err); |
| continue |
| } |
| }; |
| // If we see multiple hashes, emit an error about duplicate candidates. |
| if slot.as_ref().map_or(false, |s| s.0 != hash) { |
| let mut e = struct_span_err!(self.sess, self.span, E0465, |
| "multiple {} candidates for `{}` found", |
| flavor, self.crate_name); |
| e.span_note(self.span, |
| &format!(r"candidate #1: {}", |
| ret.as_ref().unwrap().0 |
| .display())); |
| if let Some(ref mut e) = err { |
| e.emit(); |
| } |
| err = Some(e); |
| error = 1; |
| *slot = None; |
| } |
| if error > 0 { |
| error += 1; |
| err.as_mut().unwrap().span_note(self.span, |
| &format!(r"candidate #{}: {}", error, |
| lib.display())); |
| continue |
| } |
| *slot = Some((hash, metadata)); |
| ret = Some((lib, kind)); |
| } |
| |
| if error > 0 { |
| err.unwrap().emit(); |
| None |
| } else { |
| ret |
| } |
| } |
| |
| fn crate_matches(&mut self, crate_data: &[u8], libpath: &Path) -> Option<Svh> { |
| let crate_rustc_version = decoder::crate_rustc_version(crate_data); |
| if crate_rustc_version != Some(rustc_version()) { |
| let message = crate_rustc_version.unwrap_or(format!("an unknown compiler")); |
| info!("Rejecting via version: expected {} got {}", rustc_version(), message); |
| self.rejected_via_version.push(CrateMismatch { |
| path: libpath.to_path_buf(), |
| got: message |
| }); |
| return None; |
| } |
| |
| if self.should_match_name { |
| match decoder::maybe_get_crate_name(crate_data) { |
| Some(ref name) if self.crate_name == *name => {} |
| _ => { info!("Rejecting via crate name"); return None } |
| } |
| } |
| let hash = match decoder::maybe_get_crate_hash(crate_data) { |
| None => { info!("Rejecting via lack of crate hash"); return None; } |
| Some(h) => h, |
| }; |
| |
| let triple = match decoder::get_crate_triple(crate_data) { |
| None => { debug!("triple not present"); return None } |
| Some(t) => t, |
| }; |
| if triple != self.triple { |
| info!("Rejecting via crate triple: expected {} got {}", self.triple, triple); |
| self.rejected_via_triple.push(CrateMismatch { |
| path: libpath.to_path_buf(), |
| got: triple.to_string() |
| }); |
| return None; |
| } |
| |
| if let Some(myhash) = self.hash { |
| if *myhash != hash { |
| info!("Rejecting via hash: expected {} got {}", *myhash, hash); |
| self.rejected_via_hash.push(CrateMismatch { |
| path: libpath.to_path_buf(), |
| got: myhash.to_string() |
| }); |
| return None; |
| } |
| } |
| |
| Some(hash) |
| } |
| |
| |
| // Returns the corresponding (prefix, suffix) that files need to have for |
| // dynamic libraries |
| fn dylibname(&self) -> (String, String) { |
| let t = &self.target; |
| (t.options.dll_prefix.clone(), t.options.dll_suffix.clone()) |
| } |
| |
| // Returns the corresponding (prefix, suffix) that files need to have for |
| // static libraries |
| fn staticlibname(&self) -> (String, String) { |
| let t = &self.target; |
| (t.options.staticlib_prefix.clone(), t.options.staticlib_suffix.clone()) |
| } |
| |
| fn find_commandline_library(&mut self, locs: &[String]) -> Option<Library> { |
| // First, filter out all libraries that look suspicious. We only accept |
| // files which actually exist that have the correct naming scheme for |
| // rlibs/dylibs. |
| let sess = self.sess; |
| let dylibname = self.dylibname(); |
| let mut rlibs = HashMap::new(); |
| let mut dylibs = HashMap::new(); |
| { |
| let locs = locs.iter().map(|l| PathBuf::from(l)).filter(|loc| { |
| if !loc.exists() { |
| sess.err(&format!("extern location for {} does not exist: {}", |
| self.crate_name, loc.display())); |
| return false; |
| } |
| let file = match loc.file_name().and_then(|s| s.to_str()) { |
| Some(file) => file, |
| None => { |
| sess.err(&format!("extern location for {} is not a file: {}", |
| self.crate_name, loc.display())); |
| return false; |
| } |
| }; |
| if file.starts_with("lib") && file.ends_with(".rlib") { |
| return true |
| } else { |
| let (ref prefix, ref suffix) = dylibname; |
| if file.starts_with(&prefix[..]) && |
| file.ends_with(&suffix[..]) { |
| return true |
| } |
| } |
| sess.struct_err(&format!("extern location for {} is of an unknown type: {}", |
| self.crate_name, loc.display())) |
| .help(&format!("file name should be lib*.rlib or {}*.{}", |
| dylibname.0, dylibname.1)) |
| .emit(); |
| false |
| }); |
| |
| // Now that we have an iterator of good candidates, make sure |
| // there's at most one rlib and at most one dylib. |
| for loc in locs { |
| if loc.file_name().unwrap().to_str().unwrap().ends_with(".rlib") { |
| rlibs.insert(fs::canonicalize(&loc).unwrap(), |
| PathKind::ExternFlag); |
| } else { |
| dylibs.insert(fs::canonicalize(&loc).unwrap(), |
| PathKind::ExternFlag); |
| } |
| } |
| }; |
| |
| // Extract the rlib/dylib pair. |
| let mut slot = None; |
| let rlib = self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot); |
| let dylib = self.extract_one(dylibs, CrateFlavor::Dylib, &mut slot); |
| |
| if rlib.is_none() && dylib.is_none() { return None } |
| match slot { |
| Some((_, metadata)) => Some(Library { |
| dylib: dylib, |
| rlib: rlib, |
| metadata: metadata, |
| }), |
| None => None, |
| } |
| } |
| } |
| |
| pub fn note_crate_name(err: &mut DiagnosticBuilder, name: &str) { |
| err.note(&format!("crate name: {}", name)); |
| } |
| |
| impl ArchiveMetadata { |
| fn new(ar: ArchiveRO) -> Option<ArchiveMetadata> { |
| let data = { |
| let section = ar.iter().filter_map(|s| s.ok()).find(|sect| { |
| sect.name() == Some(METADATA_FILENAME) |
| }); |
| match section { |
| Some(s) => s.data() as *const [u8], |
| None => { |
| debug!("didn't find '{}' in the archive", METADATA_FILENAME); |
| return None; |
| } |
| } |
| }; |
| |
| Some(ArchiveMetadata { |
| _archive: ar, |
| data: data, |
| }) |
| } |
| |
| pub fn as_slice<'a>(&'a self) -> &'a [u8] { unsafe { &*self.data } } |
| } |
| |
| fn verify_decompressed_encoding_version(blob: &MetadataBlob, filename: &Path) |
| -> Result<(), String> |
| { |
| let data = blob.as_slice_raw(); |
| if data.len() < 4+metadata_encoding_version.len() || |
| !<[u8]>::eq(&data[..4], &[0, 0, 0, 0]) || |
| &data[4..4+metadata_encoding_version.len()] != metadata_encoding_version |
| { |
| Err((format!("incompatible metadata version found: '{}'", |
| filename.display()))) |
| } else { |
| Ok(()) |
| } |
| } |
| |
| // Just a small wrapper to time how long reading metadata takes. |
| fn get_metadata_section(target: &Target, flavor: CrateFlavor, filename: &Path) |
| -> Result<MetadataBlob, String> { |
| let start = Instant::now(); |
| let ret = get_metadata_section_imp(target, flavor, filename); |
| info!("reading {:?} => {:?}", filename.file_name().unwrap(), |
| start.elapsed()); |
| return ret |
| } |
| |
| fn get_metadata_section_imp(target: &Target, flavor: CrateFlavor, filename: &Path) |
| -> Result<MetadataBlob, String> { |
| if !filename.exists() { |
| return Err(format!("no such file: '{}'", filename.display())); |
| } |
| if flavor == CrateFlavor::Rlib { |
| // Use ArchiveRO for speed here, it's backed by LLVM and uses mmap |
| // internally to read the file. We also avoid even using a memcpy by |
| // just keeping the archive along while the metadata is in use. |
| let archive = match ArchiveRO::open(filename) { |
| Some(ar) => ar, |
| None => { |
| debug!("llvm didn't like `{}`", filename.display()); |
| return Err(format!("failed to read rlib metadata: '{}'", |
| filename.display())); |
| } |
| }; |
| return match ArchiveMetadata::new(archive).map(|ar| MetadataArchive(ar)) { |
| None => Err(format!("failed to read rlib metadata: '{}'", |
| filename.display())), |
| Some(blob) => { |
| try!(verify_decompressed_encoding_version(&blob, filename)); |
| Ok(blob) |
| } |
| }; |
| } |
| unsafe { |
| let buf = common::path2cstr(filename); |
| let mb = llvm::LLVMRustCreateMemoryBufferWithContentsOfFile(buf.as_ptr()); |
| if mb as isize == 0 { |
| return Err(format!("error reading library: '{}'", |
| filename.display())) |
| } |
| let of = match ObjectFile::new(mb) { |
| Some(of) => of, |
| _ => { |
| return Err((format!("provided path not an object file: '{}'", |
| filename.display()))) |
| } |
| }; |
| let si = mk_section_iter(of.llof); |
| while llvm::LLVMIsSectionIteratorAtEnd(of.llof, si.llsi) == False { |
| let mut name_buf = ptr::null(); |
| let name_len = llvm::LLVMRustGetSectionName(si.llsi, &mut name_buf); |
| let name = slice::from_raw_parts(name_buf as *const u8, |
| name_len as usize).to_vec(); |
| let name = String::from_utf8(name).unwrap(); |
| debug!("get_metadata_section: name {}", name); |
| if read_meta_section_name(target) == name { |
| let cbuf = llvm::LLVMGetSectionContents(si.llsi); |
| let csz = llvm::LLVMGetSectionSize(si.llsi) as usize; |
| let cvbuf: *const u8 = cbuf as *const u8; |
| let vlen = metadata_encoding_version.len(); |
| debug!("checking {} bytes of metadata-version stamp", |
| vlen); |
| let minsz = cmp::min(vlen, csz); |
| let buf0 = slice::from_raw_parts(cvbuf, minsz); |
| let version_ok = buf0 == metadata_encoding_version; |
| if !version_ok { |
| return Err((format!("incompatible metadata version found: '{}'", |
| filename.display()))); |
| } |
| |
| let cvbuf1 = cvbuf.offset(vlen as isize); |
| debug!("inflating {} bytes of compressed metadata", |
| csz - vlen); |
| let bytes = slice::from_raw_parts(cvbuf1, csz - vlen); |
| match flate::inflate_bytes(bytes) { |
| Ok(inflated) => { |
| let blob = MetadataVec(inflated); |
| try!(verify_decompressed_encoding_version(&blob, filename)); |
| return Ok(blob); |
| } |
| Err(_) => {} |
| } |
| } |
| llvm::LLVMMoveToNextSection(si.llsi); |
| } |
| Err(format!("metadata not found: '{}'", filename.display())) |
| } |
| } |
| |
| pub fn meta_section_name(target: &Target) -> &'static str { |
| if target.options.is_like_osx { |
| "__DATA,__note.rustc" |
| } else if target.options.is_like_msvc { |
| // When using link.exe it was seen that the section name `.note.rustc` |
| // was getting shortened to `.note.ru`, and according to the PE and COFF |
| // specification: |
| // |
| // > Executable images do not use a string table and do not support |
| // > section names longer than 8 characters |
| // |
| // https://msdn.microsoft.com/en-us/library/windows/hardware/gg463119.aspx |
| // |
| // As a result, we choose a slightly shorter name! As to why |
| // `.note.rustc` works on MinGW, that's another good question... |
| ".rustc" |
| } else { |
| ".note.rustc" |
| } |
| } |
| |
| pub fn read_meta_section_name(target: &Target) -> &'static str { |
| if target.options.is_like_osx { |
| "__note.rustc" |
| } else if target.options.is_like_msvc { |
| ".rustc" |
| } else { |
| ".note.rustc" |
| } |
| } |
| |
| // A diagnostic function for dumping crate metadata to an output stream |
| pub fn list_file_metadata(target: &Target, path: &Path, |
| out: &mut io::Write) -> io::Result<()> { |
| let filename = path.file_name().unwrap().to_str().unwrap(); |
| let flavor = if filename.ends_with(".rlib") { CrateFlavor::Rlib } else { CrateFlavor::Dylib }; |
| match get_metadata_section(target, flavor, path) { |
| Ok(bytes) => decoder::list_crate_metadata(bytes.as_slice(), out), |
| Err(msg) => { |
| write!(out, "{}\n", msg) |
| } |
| } |
| } |
